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2022, Vol. 75, No. 12　Online: 25 December 2022

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Tailoring the interactions of heterostructured Ni4N/Ni3ZnC0.7 for efficient CO2 electroreduction Junjie Wang, Zhao Li, Zhaozhao Zhu, Jinxia Jiang, Yulan Li, Jinju Chen, Xiaobin Niu, Jun Song Chen, Rui Wu 2022, 75(12): 1-7.  DOI: 10.1016/j.jechem.2022.07.037 Abstract ( 14 )   PDF (5477KB) ( 9 )   Electrocatalytic CO2 reduction into CO has been regarded as one of the most promising strategies for sus-tainable carbon cycles at ambient conditions, but still faces challenges to achieve both high product selec-tivity and large current density. Here, we report a Ni4N/Ni3ZnC0.7 heterostructured electrocatalyst embedded in accordion-like N-doped carbon through a simple molten salt annealing strategy. The opti-mal Ni4N/Ni3ZnC0.7 electrocatalyst achieves a high CO Faraday efficiency of 92.3% and a large total current density of 15.8 mA cm-2 at 0.8 V versus reversible hydrogen electrode, together with a long-term sta-bility about 30 h. Density functional theory results reveal that the energy barrier for *COOH intermediate formation largely decreased on Ni4N/Ni3ZnC0.7 heterostructure compared with Ni4N and Ni3ZnC0.7, thus giving rise to enhanced activity and selectivity. A rechargeable Zn-CO2 battery is further assembled with Ni4N/Ni3ZnC0.7 catalyst as the cathode, which shows a maximum power density of 0.85 mW cm-2 and excellent stability.

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Enhancing carrier transport in flexible CZTSSe solar cells via doping Li strategy Qiong Yan, Quanzhen Sun, Hui Deng, Weihao Xie, Caixia Zhang, Jionghua Wu, Qiao Zheng, Shuying Cheng 2022, 75(12): 8-15.  DOI: 10.1016/j.jechem.2022.07.031 Abstract ( 5 )   PDF (4827KB) ( 4 )   The passivation of non-radiative states and inhibition of band tailings are desirable for improving the open-circuit voltage (Voc) of CZTSSe thin-film solar cells. Recently, alkali metal doping has been investi-gated to passivate defects in CZTSSe films. Herein, we investigate Li doping effects by applying LiOH into CZTSSe precursor solutions, and verify that carrier transport is enhanced in the CZTSSe solar cells. Systematic characterizations demonstrate that Li doping can effectively passivate non-radiative recombi-nation centers and reduce band tailings of the CZTSSe films, leading to the decrease in total defect density and the increase in separation distance between donor and acceptor. Fewer free carriers are trapped in the band tail states, which speeds up carrier transport and reduces the probability of deep-level defects capturing carriers. The charge recombination lifetime is about twice as long as that of the undoped CZTSSe device, implying the heterojunction interface recombination is also inhibited. Besides, Li doping can increase carrier concentration and enhance build-in voltage, leading to a better carrier collection. By adjusting the Li/(Li + Cu) ratio to 18%, the solar cell efficiency is increased significantly to 9.68% with the fill factor (FF) of 65.94%, which is the highest FF reported so far for the flexible CZTSSe solar cells. The increased efficiency is mainly attributed to the reduction of Voc deficit and the improved CZTSSe/CdS junction quality. These results open up a simple route to passivate non-radiative states and reduce the band tailings of the CZTSSe films and improve the efficiency of the flexible CZTSSe solar cells.

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Interface-engineered MoS2/CoS/NF bifunctional catalysts for highly-efficient water electrolysis Wenxia Chen, Xingwang Zhu, Rui Wang, Wei Wei, Meng Liu, Shuai Dong, Kostya Ken Ostrikov, Shuang-Quan Zang 2022, 75(12): 16-25.  DOI: 10.1016/j.jechem.2022.08.012 Abstract ( 5 )   PDF (8846KB) ( 2 )   The utilization of non-noble metal catalysts with robust and highly efficient electrocatalytic activity for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) are extremely important for the large-scale implementation of renewable energy devices. Integration of bifunctional electrocatalysts on both anode and cathode electrodes remains a significant challenge. Herein, we report on a novel and facile strategy to construct the ordered and aligned MoS2 nanosheet-encapsulated metal-organic frame-works (MOFs) derived hollow CoS polyhedron, in-situ grown on a nickel foam (NF). The starfish-like MoS2/CoS/NF heterojunctions were formed due to the ordered growth of the material caused by NF sub-strate. The optimized 2-MoS2/CoS/NF heterojunction exhibits robust bifunctional electrocatalytic activity with a low overpotential of 67 and 207 mV toward the HER and OER at 10 mA cm-2, and the long-term stability, which exceeds most of the reported bifunctional electrocatalysts. Such high electrocatalytic per-formance arises due to the synergistic effect between the MoS2 and CoS phases across the interface, the abundant active sites, as well as the hierarchical pore framework, which collectively enhance the mass and electron transfer during the reactions. The work provides a promising approach to fabricating bifunc-tional catalysts with custom-designed heterojunctions and remarkable performance for applications in electrochemical energy devices and related areas.

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Coupling boron-modulated bimetallic oxyhydroxide with photosensitive polymer enable highly-active and ultra-stable seawater splitting Weiju Hao, Chengyu Fu, Yingming Wang, Kui Yin, Hongyuan Yang, Ruotao Yang, Ziliang Chen 2022, 75(12): 26-37.  DOI: 10.1016/j.jechem.2022.07.042 Abstract ( 10 )   PDF (13995KB) ( 4 )   Seawater photoelectrolysis is showing huge potential in green energy conversion field, yet it is still a formidable challenge to develop one catalyst that can drive the electrolysis reaction stably, economically and efficiently. Motivated by this point, the inorganic-organic hybridization strategy is proposed to in-situ construct one hierarchical electrode via concurrent electroless plating and polymerization, which assures the growth of boron-modulated nickel-cobalt oxyhydroxide nanoballs and photosensitive polyaniline nanochains on the self-supporting Ti-based foil (B-CoNiOOH/PANI@TiO2/Ti). Upon inducing photoelectric effect (PEE), the designed target electrode delivers overpotentials as low as 196 and 398 mV at 100 mA cm-2 for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), respectively, corresponding to an activity enhancement by about 15% as compared to those without PEE. Inspiringly, when served as bifunctional electrocatalysts for overall seawater electrolysis, it can sta-bly maintain at 200 mA cm-2 with negligible decay over 72 h. Further analysis reveals that the excep-tional catalytic performance can be credit to the B-CoNiOOH, polyaniline (PANI) and TiO2 subunit coupling-induced physically and chemically synergistic catalysis effect such as admirable composition stability, photoelectric function and adhesion capability. The finding in this contribution may trigger much more broad interest to the novel hybrid catalysts consisting of photosensitive polymer and transi-tion metal-based electrocatalysts.

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Oxygen vacancies with localized electrons direct a functionalized separator toward dendrite-free and high loading LiFePO4 for lithium metal batteries Qi An, Qing Liu, Shimin Wang, Lixiang Liu, Han Wang, Yongjiang Sun, Lingyan Duan, Genfu Zhao, Hong Guo 2022, 75(12): 38-45.  DOI: 10.1016/j.jechem.2022.08.006 Abstract ( 4 )   PDF (7489KB) ( 2 )   The pursuit of high energy density has promoted the development of high-performance lithium metal batteries (LMBs). However, the underestimated but non-negligible dendrites of Li anode have been observed to shorten battery lifespan. Herein, a composite separator (TiO2-x@PP), in which TiO2 with electron-localized oxygen vacancies (TiO2-x) is coated on a commercial PP separator, is fabricated to homogenize lithium ion transport and stabilize the lithium anode interface. With the utilization of TiO2-x@PP separators, the symmetric lithium metal battery displays enhanced cycle stability over 800 h under a high current density of 8 mA cm-2. Moreover, the LMBs assembled with high-loading LiFePO4 (9.24 mg cm-2) deliver a stable cycling performance over 900 cycles at a rate of 0.5 C. Comprehensive theoretical studies based on density functional theory (DFT) further unveil the mecha-nism. The favorable TiO2-x is beneficial for facilitating fast Li+ migration and impeding anions transfer. In addressing the Li dendrite issues, the use of TiO2-x@PP separator potentially provides a facile and attractive strategy for designing well-performing LMBs, which are expected to meet the application requirements of rechargeable batteries.

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Electron-enriched Pt induced by CoSe2 promoted bifunctional catalytic ability for low carbon alcohol fuel electro-reforming of hydrogen evolution Yang Zhou, Qiaowei Wang, Xinlong Tian, Jinfa Chang, Ligang Feng 2022, 75(12): 46-54.  DOI: 10.1016/j.jechem.2022.08.009 Abstract ( 9 )   PDF (3073KB) ( 4 )   Alcohol fuel electro-reforming is promising for green hydrogen generation while developing efficient bifunctional catalysts for alcohol fuel electrolysis is still very tricky. Herein, we for the first time proposed the electron-enriched Pt induced by CoSe2 has an efficient bi-functional catalytic ability for alcohol fuels electro-reforming of hydrogen in acid electrolytes. The theoretical calculation revealed the advantages of electron-enriched Pt surface for the adsorption of intermediate, which is well supported by spectroscopic analysis and CO-stripping techniques. Largely improved catalytic performances of activity, durability, and kinetics are demonstrated compared to the conventional alloy system and commercial Pt/C catalyst, due to the efficient synergism of Pt and CoSe2; the peak current density of Pt/CoSe2 for methanol (ethanol) oxidation is 87.61 (48.27) mA cm-2, which is about 3.3 (2.0) times higher than that of Pt/C catalyst and 2.0 (1.5) times that of the traditional PtCo alloy catalysts. Impressively, about 80% of the initial cur-rent was found after 1000 cycles of stability test for alcohol fuel oxidation of Pt/CoSe2 catalyst, higher than that of Pt/C (ca. 50%) and PtCo catalyst (65%). When Pt/CoSe2 catalyst serviced as bi-functional cat-alysts for electrolyzer, a low cell potential of 0.65 (0.78) V for methanol (ethanol) electrolysis was required to reach 10 mA cm-2, which was about 1030 (900) mV less than that of conventional water elec-trolysis using Pt/C as the catalyst. The current result is instructive for the design of novel bifunctional cat-alyst and the understanding of hydrogen generation via alcohol fuel electro-reforming.

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Boosting lifespan of conversion-reaction anodes for full/half potassium-ion batteries via multi-dimensional carbon nano-architectures confinement effect Weifang Zhao, Xinyue Xu, Lin Wang, Ying Liu, Tengfei Zhou, Shilin Zhang, Juncheng Hu, Qingqing Jiang 2022, 75(12): 55-65.  DOI: 10.1016/j.jechem.2022.08.002 Abstract ( 6 )   PDF (19799KB) ( 3 )   Transition metal selenides are regarded as prospective conversion-reaction anodes for potassium-ion bat-teries (PIBs) because of their relatively high electrical conductivity, large theoretical specific capacity, abundant resources and low cost. The challenge of the metal selenides originates from a serious volume change during cycling, which induces serious structural collapse and fast capacity degradation. In the pre-sent work, the multi-dimensional carbon nano-architectures confined bimetallic selenides (ZnSe/ CoSe2@N-CNTs/rGO) were constructed by a facile MOF-assisted strategy. In such special nano-architectures, N-doped CNTs protect the metal selenides centers from serious volume expansion/electrode pulverization, as well as improve the sluggish kinetics. ZnSe/CoSe2@N-CNTs/rGO electrode boosts the lifespan of half PIBs with a large discharge specific capacity of 200 mAh g-1 at 2 A g-1 after 3800 cycles. The full PIBs battery with ZnSe/CoSe2@N-CNTs/rGO electrode as anode and Prussian blue as cathode exhi-bits well electrochemical performance (151 mAh g-1 at 100 mA g-1 after 100 cycles). DFT calculation sug-gests that the CNTs could change the K+ adsorption energy and decrease K+ diffusion energy barrier, which dramatically enhances K+ storage kinetics. This work offers an effective material engineering approach for designing hierarchical ‘‘all-in-one” electrodes with high excellent cycling stability for PIBs.

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Synergistically enhanced activity and stability of bifunctional nickel phosphide/sulfide heterointerface electrodes for direct alkaline seawater electrolysis Hao-Yu Wang, Jin-Tao Ren, Lei Wang, Ming-Lei Sun, Hui-Min Yang, Xian-Wei Lv, Zhong-Yong Yuan 2022, 75(12): 66-73.  DOI: 10.1016/j.jechem.2022.08.019 Abstract ( 10 )   PDF (4652KB) ( 11 )   Direct electrolysis of seawater to generate hydrogen is an attractive but challenging renewable energy storage technology. Reasonable design of seawater electrolysis catalysts should integrate high activity for hydrogen evolution reaction (HER)/ oxygen evolution reaction (OER) and enhanced physical/electro-chemical stability in seawater. Herein, we demonstrate the development of a Ni foam (NF) supported interfacial heterogeneous nickel phosphide/sulfide (Ni2P/NiS2) microsphere electrocatalyst (NiPS/NF) through a facile electrodeposition and subsequent phosphorization/sulfuration process. After NiS2 mod-ification, a charge redistribution on the heterointerface is demonstrated and a more advantageous cova-lent nature of the Ni-P bond is obtained for more easily adsorption of H* and H2O. The NiPS/NF thus yields an impressive electrocatalytic performance in 1.0 M KOH, requiring small overpotentials of 169 and 320 mV for HER and OER to obtain a high current density of 100 mA cm-2, respectively. The NiPS/NF can also work efficiently in alkaline seawater with negligible activity degradation, requiring overpoten-tials of only 188 and 344 mV for a current density of 100 mA cm-2 for HER and OER, respectively. A syn-ergistically enhanced physical/electrochemical long-term stability NiPS/NF in saline water is also demonstrated.

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In situ induced cation-vacancies in metal sulfides as dynamic electrocatalyst accelerating polysulfides conversion for Li-S battery Rongrong Li, Hao Sun, Caiyun Chang, Yuan Yao, Xiong Pu, Wenjie Mai 2022, 75(12): 74-82.  DOI: 10.1016/j.jechem.2022.08.015 Abstract ( 5 )   PDF (7336KB) ( 3 )   Cation vacancy engineering is considered to be one of the effective methods to solve the issues of shut-tling and sluggish redox kinetics of LiPSs owing to the intrinsic tunability of electronic structure. However, cation vacancies are few studied in the Li-S realm due to their complex and rigid preparation methods. In this work, one-step pyrolysis is reported to in situ introduce Fe-vacancies into iron sulfide (Fe0.96S) as a sulfur host. For this host structure, Fe0.96S is first employed as an adsorbent and catalyst in Li-S system. During the carbonization process, a tight contact structure of Fe0.96S crystal and carbon network (Fe0.96S@C) is in situ constructed, and the carbon layer as a conductor provides smooth electrons transfer pathways for redox reactions. Meanwhile, due to the introduction of Fe-vacancies in FeS crystal, the adsorption capability and catalytic effect for LiPSs have been substantially enhanced. Moreover, the presence of Fe0.96S crystal favors the mobility of electron and diffusion of Li+, which is revealed by the experiments and theoretical calculations. Through synergy respective advantages effect of Fe0.96S and carbon, the Fe0.96S@C-S cathode delivers high-rate capability at 5.0 C and stable long-life performance. Even under a high sulfur loading of 3.5 mg/cm2, the durable cyclic stability is still exhibited with the capacity retention of 93% over 400 cycles at 1.0 C, and the coulombic efficiency is 98%. Noting that this strategy greatly simplifies the synthetic process of currently known cation-vacancy materials and fur-nishes a universal mentality for designing both divinable and astonishing new cation-vacancy materials.

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An ion-released MgI2-doped separator inducing a LiI-containing solid electrolyte interphase for dendrite-free Li metal anodes Shan Yi, Zhe Su, Wanyu Zhang, Hongli Chen, Yayun Zhang, Bo Niu, Donghui Long 2022, 75(12): 83-94.  DOI: 10.1016/j.jechem.2022.08.021 Abstract ( 8 )   PDF (12997KB) ( 2 )   Lithium metal batteries are among the strong contenders to satisfy the ever-increasing needs of energy storage systems, which however suffer from poor composition of the solid electrolyte interphase (SEI) layer and uncontrolled Li dendrites formation. In this regard, we report on the design of an ion-released MgI2-doped polyacrylonitrile (PAN) based nanofiber (MPANF) separator, which can lead to con-ducive SEI layer and dendrite-free Li anode. The combination of the lithophilic MgI2 nanoparticles with polarized PAN matrix comprehensively functions as a high-compatible interpenetrating network to homogenize ionic transportation and confront dendrite growth. The released I ions introduce the high-ion-conductivity LiI into SEI layer, which could induce the formation of favorable and protective interface layer in the early stage, as embodied in the enrichment of advantageous components such as LiNxOy, Li2O, LiF, and Li3N. Profited from the high-affinity MPANF separator, the Li||Li symmetric cell achieves an ultra-low voltage hysteresis of 46 mV with an extended lifespan of 580 h. And a prolonged lifetime of 590 cycles with an enhanced specific capacity of 140.1 mAh g-1 and the Coulombic efficiency of 96.2% at 1 C can be obtained in full cells. This work may offer a facile and high-affinity alternative to traditional polymeric separators for high-performance and dendrite-free Li metal batteries.

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Base-free oxidative esterification of 5-hydroxymethylfurfural to furan-2,5-dimethylcarboxylate over n-doped carbon-supported Co/Fe bimetallic catalyst under batch-operation or continuous-flow conditions Weizhen Xie, Binglin Chen, Wenlong Jia, Huai Liu, Zheng Li, Shuliang Yang, Xing Tang, Xianhai Zeng, Yong Sun, Xixian Ke, Tianyuan Li, Huayu Fang, Lu Lin 2022, 75(12): 95-108.  DOI: 10.1016/j.jechem.2022.07.018 Abstract ( 10 )   PDF (9259KB) ( 5 )   Developing an efficient and easily available catalyst for the selective conversion of biomass-derived 5-hydroxymethylfurfural (HMF) into furan-2,5-dimethylcarboxylate (FDMC), a valuable biomass-based monomer, remains a high demand but formidable challenge. Herein, a facile strategy for the synthesis of N-doped carbon-supported Co/Fe bimetallic catalyst (CoFe-NC) was developed, which provided an out-standing FDMC yield of 93% in a batch reactor (base-free, 80 LC, 2 bar O2, 4 h). Interestingly, CoFe-NC also gave a high FDMC yield of 91% under continuous-flow conditions for 80 h (5 bar O2, 80 LC, GHSV 1320 h-1, LHSV 0.6 h-1, base-free). Notably, it is the first time that a non-noble catalyst gave such a high FDMC yield under continuous-flow conditions. The introduction of Fe could greatly improve both the electron inten-sity of Co-Nx species and basicity of the catalyst, which endowed CoFe-NC with improved O2 activation capacity and enhanced dehydrogenation activity for the oxidation-esterification of HMF. This work delin-eates the efficient strategy on the construction of N-doped carbon-supported non-noble catalyst, which might open a new avenue for developing highly efficient catalyst for FDMC production.

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Structural and electronic effects boosting Ni-doped Mo2C catalyst toward high-efficiency CAO/CAC bonds cleavage Xiangze Du, Jinjia Liu, Dan Li, Hui Xin, Xiaomei Lei, Rui Zhang, Linyuan Zhou, Huiru Yang, Yan Zeng, Hualong Zhang, Wentao Zheng, Xiaodong Wen, Changwei Hu 2022, 75(12): 109-116.  DOI: 10.1016/j.jechem.2022.08.024 Abstract ( 4 )   PDF (5028KB) ( 3 )   The selective cleavage of CAO and CAC is facing a challenge in the field of catalysis. In the present work, we studied the influence of doped Ni on the structure and electronic properties, as well as the selective C-O/C-C bond cleavages in the hydrodeoxygenation of palmitic acid over Ni-Mo2C catalyst. The catalytic activity on Ni doped Mo2C with TOF of 6.9 103 h-1 is much superior to intrinsic Mo2C catalyst, which is also higher than most noble metal catalysts. Structurally, the doped Ni raises the active particle disper-sion and the coordination numbers of Mo species (Mo-C and Mo-O), improves the graphitization degree to promote the electron transfer, and increases the amount of Lewis and Brønsted acid, which are respon-sible for the excellent hydrodeoxygenation performance. The Ni promotes simultaneously C-O and C-C bonds cleavage to produce pentadecane and hexadecane owing to the increase of electron-rich Mo sites after Ni doping. These findings contribute to the understanding of the nature of Ni-doped Mo2C on the roles as catalytic active sites for C-O and C-C bonds cleavage.

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Modulation of lattice oxygen boosts the electrochemical activity and stability of Co-free Li-rich cathodes Gui-Jing Xu, Wang Ke, Fu-Da Yu, , Jie Feng, Yun-Shan Jiang, Lan-Fang Que, Lei Zhao, Zhen-Bo Wang 2022, 75(12): 117-126.  DOI: 10.1016/j.jechem.2022.08.018 Abstract ( 6 )   PDF (13024KB) ( 2 )   Co-free Li-rich layered oxide cathodes have drawn much attention owing to their low cost and high energy density. Nevertheless, anion oxidation of oxygen leads to oxygen peroxidation during the first charging process, which leads to co-migration of transition metal ions and oxygen vacancies, causing structural instability. In this work, we propose a pre-activation strategy driven by chemical impregnation to modulate the chemical state of surface lattice oxygen, thus regulating the structural and electrochem-ical properties of the cathodes. In-situ X-ray diffraction confirms that materials based on activated oxy-gen configuration have higher structural stability. More importantly, this novel efficient strategy endows the cathodes having a lower surface charge transfer barrier and higher Li+ transfer kinetics characteristic and ameliorates its inherent issues. The optimized cathode exhibits excellent electrochemical perfor-mance: after 300 cycles, high capacity (from 238 mAh g-1 to 193 mAh g-1 at 1 C) and low voltage atten-uation (168 mV) are obtained. Overall, this modulated surface lattice oxygen strategy improves the electrochemical activity and structural stability, providing an innovative idea to obtain high-capacity Co-free Li-rich cathodes for next-generation Li-ion batteries.

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Ternary layered double hydroxide oxygen evolution reaction electrocatalyst for anion exchange membrane alkaline seawater electrolysis Yoo Sei Park, Jae-Yeop Jeong, Myeong Je Jang, Chae-Yeon Kwon, Geul Han Kim, Jaehoon Jeong, Ji-hoon Lee, Jooyoung Lee, Sung Mook Choi 2022, 75(12): 127-134.  DOI: 10.1016/j.jechem.2022.08.011 Abstract ( 39 )   PDF (5652KB) ( 27 )   Anion exchange membrane (AEM) water electrolyzers are promising energy devices for the production of clean hydrogen from seawater. However, the lack of active and robust electrocatalysts for the oxygen evolution reaction (OER) severely impedes the development of this technology. In this study, a ternary layered double hydroxide (LDH) OER electrocatalyst (NiFeCo-LDH) is developed for high-performance AEM alkaline seawater electrolyzers. The AEM alkaline seawater electrolyzer catalyzed by the NiFeCo-LDH shows high seawater electrolysis performance (0.84 A/cm2 at 1.7 Vcell) and high hydrogen produc-tion efficiency (77.6% at 0.5 A/cm2), thus outperforming an electrolyzer catalyzed by a benchmark IrO2 electrocatalyst. The NiFeCo-LDH electrocatalyst greatly improves the kinetics of the AEM alkaline seawa-ter electrolyzer, consequently reducing its activation loss and leading to high performance. Based on the results, this NiFeCo-LDH-catalyzed AEM alkaline seawater electrolyzer can likely surpass the energy con-version targets of the US Department of Energy.

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Functional carbon materials for high-performance Zn metal anodes Caiwang Mao, Yuxin Chang, Xuanting Zhao, Xiaoyu Dong, Yifei Geng, Ning Zhang, Lei Dai, Xianwen Wu, Ling Wang, Zhangxing He 2022, 75(12): 135-153.  DOI: 10.1016/j.jechem.2022.07.034 Abstract ( 6 )   PDF (25125KB) ( 1 )   The realization of ‘‘carbon peak” and ‘‘carbon neutralization” highly depends on the efficient utilization of renewable energy sources. Exploring reliable and low-cost electrochemical energy storage systems is an ever-growing demand for renewable energy integration. Among available candidates, aqueous zinc-ion batteries (AZIBs) receive extensive researchers’ attention because of their material abundance, high capacity, high safety, and environmental friendliness. However, the irreversible issues of Zn anode in terms of notorious dendric Zn growth, Zn corrosion/hydrogen evolution, and passivation significantly impede the commercialization of high-performance AZIBs. Carbon materials have advantages of large specific surface area, low cost, high electrical conductivity, controllable structure, and good stability. Their application provides remedies for improving the comprehensive performance of Zn anodes. In this review, the fundamentals and issues of Zn anodes, and the research progress with functional carbon materials for Zn anodes in recent years are presented. Three major strategies are described in detail, including the use of carbon materials (carbon nanotubes, graphene, carbon fiber, metal-organic frame-work (MOF) derived host, etc.) as Zn plating/stripping substrates, as protective coating layers on Zn, and as electrolyte additives. Finally, the remaining challenges and perspectives of carbon materials in high-performance AZIBs are outlined.

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Dealloying-induced dual-scale nanoporous indium-antimony anode for sodium/potassium ion batteries Hui Gao, Yan Wang, Zhiyuan Guo, Bin Yu, Guanhua Cheng, Wanfeng Yang, Zhonghua Zhang 2022, 75(12): 154-163.  DOI: 10.1016/j.jechem.2022.08.016 Abstract ( 9 )   PDF (9949KB) ( 4 )   InSb alloy is a promising candidate for sodium/potassium ion batteries (SIBs/PIBs) but challenged with achieving high performance by dramatic volumetric changes. Herein, nanoporous (np)-InSb with dual-scale phases (cubic/hexagonal (C/H)-InSb) was fabricated by chemical dealloying of ternary Mg-In-Sb precursor. Operando X-ray diffraction (XRD) and ex-situ characterizations well rationalize the dealloy-ing/alloying mechanisms and the formation of dual-scale microstructures/phases. As an anode for SIB/ PIBs, the np-InSb electrode exhibits superior reversible capacities and lifespan compared with the monometallic porous (p)-In electrode, stemming from the dealloying-induced dual-scale nanoporous architecture and alloying strategy with proper composition. The operando XRD results demonstrate that the (de)sodiated mechanism of the np-InSb electrode involves a two-step (de)alloying process, while the (de)potassiated mechanism is associated with a full electrochemically-driven amorphization upon cycling. Additionally, the gas evolution during the (dis)charge process was monitored by on-line mass spectrometry.

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Pyrrole derivatives as interlayer modifier of Li-S batteries: Modulation of electrochemical performance by molecular perturbation Jiajv Lin, Yuan Zhou, Jingbo Wen, Weijie Si, Hongcheng Gao, Gongming Wang, Xiongwu Kang 2022, 75(12): 164-172.  DOI: 10.1016/j.jechem.2022.08.014 Abstract ( 7 )   PDF (4818KB) ( 3 )   The electrochemical performance of lithium-sulfur (Li-S) batteries is strongly hampered by the shuttle effect and slow redox kinetics of lithium polysulfides (LiPSs). Surface modified interlayer of a separator of Li-S batteries is demonstrated to be an effective strategy to overcome this problem. Herein, cobalt nanoparticles confined in nitrogen co-doped porous carbon framework (Co-CN) were developed from pyrolysis of ZIF-67 and used as interlayer of PP separator for Li-S batteries, and were functionalized by four pyrrole derivatives, 1-phenylpyrrole, 1-methyl pyrrole, 1-(p-toluenesulfonyl) pyrrole, and 1-pyrrole, respectively, which were screened in terms of the electron-withdrawing/donating ability of the substituent groups on the pyrrolic nitrogen. The impact of the molecular structure of pyrrole deriva-tives on the interaction with LiPSs and the electrochemical performance of Li-S batteries were explored by nuclear magnetic resonance and theoretical calculation. It is uncovered that 1-phenylpyrrole shows the highest enhancement of redox kinetics of LiPSs, attributing to the optimal interaction with Co nanoparticles and LiPSs. Therefore, 1-phenylpyrrole modified Co-CN interlayer enables the best electro-chemical performance for the Li-S batteries, delivering a specific capacity of 562 mAh g-1 at 5 C and a capacity of 538, 526, and 449 mAh g-1 after 500 cycles at 1, 2, and 3 C, respectively. At a high sulfur load-ing of 5.5 mg cm-2, it achieves a capacity of 440 mAh g-1 after 500 cycles at 1 C. This work reveals the interaction mechanism among LiPSs, Co nanoparticles and the molecular modifiers in improving the elec-trochemical performance of Li-S batteries.

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Progress and key challenges in catalytic combustion of lean methane Xiangbo Feng, Lei Jiang, Danyang Li, Shaopeng Tian, Xing Zhu, Hua Wang, Chi He, Kongzhai Li 2022, 75(12): 173-215.  DOI: 10.1016/j.jechem.2022.08.001 Abstract ( 32 )   PDF (14501KB) ( 42 )   As a primary type of clean energy, methane is also the second most important greenhouse gas after CO2 due to the high global warming potential. Large quantities of lean methane (0.1-1.0 vol%) are emitted into the atmosphere without any treatment during coal mine, oil, and natural gas production, thus lead-ing to energy loss and greenhouse effect. In general, it is challenging to utilize lean methane due to its low concentration and flow instability, while catalytic combustion is a vital pathway to realize an efficient utilization of lean methane owing to the reduced emissions of polluting gases (e.g., NOx and CO) during the reaction. In particular, to efficiently convert lean methane, it necessitates both the designs of highly active and stable heterogeneous catalysts that accelerate lean methane combustion at low temperatures and smart reactors that enable autothermal operation by optimizing heat management. In this review, we discuss the in-depth development, challenges, and prospects of catalytic lean methane combustion technology in various configurations, with particular emphasis on heat management from the point of view of material design combined with reactor configuration. The target is to describe a framework that can correlate the guiding principles among catalyst design, device innovation and system optimization, inspiring the development of groundbreaking combustion technology for the efficient utilization of lean methane.

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Molecular and atomic manipulation of metal-organic frameworkderived LiCoMnO4: An oxygen-deficient strategy for advanced lithium storage Jian-En Zhou, Jiahao Chen, Xiaoke Zhang, Akif Zeb, Xiaoming Lin 2022, 75(12): 216-228.  DOI: 10.1016/j.jechem.2022.08.028 Abstract ( 18 )   PDF (10204KB) ( 3 )   As a novel class of high-voltage cathode materials, spinel lithium transition metal oxides have been faced with demerits including pronounced structural instability caused by Jahn-Teller distortion (especially at the lower voltage region) and severe capacity degradation despite their intriguing electrochemical prop-erties. To extend their functionalities as broad-voltage cathodes, the sacrificial template method has been regarded as a promising way to realize structural and compositional control for desirable electrochemical behaviors. Herein, we report a synthetic protocol to directionally prepare LiCoMnO4 (LCMO) using carboxyl-based metal-organic frameworks (MOFs) as self-sacrificing templates. Impressively, LCMO derived from CoMn-BDC (H2BDC = 1,4-benzenedicarboxylate) displays superior electrochemical perfor-mances with a specific capacity of 151.6 mAh g-1 at 1 C (150 mA g-1) after 120 cycles and excellent rate capacity of 91.9 mAh g-1 at 10 C due to the morphology control, microstructural modulation, and atomic manipulation of the MOF precursor. Bestowed by the optimized atomic and electronic structure, abun-dant oxygen vacancies, and the nanostructure retained from MOF precursors, LCMO materials display extraordinary electrochemical properties, which have been extensively verified by both experimental and theoretical studies. This work not only provides guidelines for the directional design of spinel mate-rials at molecular and atomic levels but also sheds light on the practical use of LIBs with broad range voltage.

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Mechanically strong, flexible, and multi-responsive phase change films with a nacre-mimetic structure for wearable thermal management Jiankang Zhang, Jiahui Mu, Sheng Chen, Feng Xu 2022, 75(12): 229-239.  DOI: 10.1016/j.jechem.2022.08.003 Abstract ( 7 )   PDF (13572KB) ( 3 )   Phase change materials (PCMs) are a highly promising candidate for thermal energy storage owing to their large latent heat and chemical stability. However, their intrinsic brittle induces poor flexibility and low mechanical strength, which limits them use for wearable thermal management. And, the elec-trical insulation and weak solar absorption make them lack multi-responsive capability. Herein, we report a facile strategy to synthesize mechanically strong and flexible multi-responsive phase change films by stirring an aqueous dispersion of cellulose nanofibrils (CNFs), MXene (Ti2C3) nanosheets, and polyethylene glycol (PEG), followed by air-drying self-assembly and coating with hydrophobic fluorocar-bon. The hydrogen bonds and nacre-mimetic synergistic toughening networks formed by ternary CNFs, Ti2C3 nanosheets, and PEG endow films with high mechanical strength (16.7 MPa) and strain (10.4%), which are 18.6 and 8.7 times higher than those of pure PEG film, respectively. The films exhibit outstand-ing flexibility and do not crack or fracture even when bent, twisted, and folded into a complex small boat. Meanwhile, the laminar structure formed by the self-assembly Ti3C2 nanosheets enhances electrical con-ductivity (3.95 S/m) and solar absorption, affording excellent electro-thermal (68.3%-81.0%) and solar-thermal (85.6%-90.6%) conversion efficiency, thus achieving multi-response to external stimuli (elec-tron/solar radiation). In addition, the as-prepared films also deliver large latent heat (136.1 J/g), outstand-ing cyclic and shape stability, leak-free encapsulation even under compressed at above 5000 times its weight, excellent hydrophobicity (131.4L), and self-cleaning function. This work paves the way for devel-oping flexible, mechanically strong, and self-cleaning phase change film with multi-responsive function for wearable thermal management devices under high humidity condition.

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Embedding amorphous MoSx within hierarchical porous carbon by facile one-pot synthesis for superior sodium ion storage Jalal Rahmatinejad, Xudong Liu, Ximeng Zhang, Bahareh Raisi, Zhibin Ye 2022, 75(12): 240-249.  DOI: 10.1016/j.jechem.2022.08.008 Abstract ( 6 )   PDF (12153KB) ( 2 )   The design of anode materials with a high specific capacity, high cyclic stability, and superior rate performance is required for the practical applications of sodium-ion batteries (SIBs). In this regard, we introduce in this work a facile, low-cost and scalable method for the synthesis of nanocomposites of amorphous molybdenum sulfide (a-MoSx) and hierarchical porous carbon and have systematically inves-tigated their performance for sodium ion storage. In the synthesis, ammonium molybdate tetrahydrate and thioacetamide are used as molybdenum and sulfur sources, respectively, with abundant corn starch as the carbon source and KOH as an activation agent. A simple pyrolysis of their mixtures leads to the formation of nanocomposites with a-MoSx embedded within a hierarchical porous carbon (MoSx@HPC), which are featured with a high surface area of up to 518.4 m2 g-1 and hierarchical pores ranging from micropores to macropores. It has also been shown that the annealing of MoSx@HPC results in the formation of crystalline MoS2 nanosheets anchored in the hierarchical porous carbon matrix (MoS2@HPC). The as-prepared nanocomposite MoSx@HPC1 at an optimum carbon content of 32 wt% delivers a high specific sodium storage capacity of 599 mAh g-1 at 0.2 A g-1 and a high-rate performance with a retained capacity of 289 mAh g-1 at 5 A g-1. A comparison of the electrochemical performances of MoSx@HPC and MoS2@HPC demonstrates the superior specific capacity, rate performance, and charge transfer kinetics of the former, highlighting the unique advantageous role of amorphous MoSx relative to crystalline MoS2.

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Highly active CoP-Co2N confined in nanocarbon enabling efficient electrocatalytic immobilizing-conversion of polysulfide targeting high-rate lithium-sulfur batteries Xiaojun Zhao, Tianqi Gao, Wenhao Ren, Chuan Zhao, Zhi-Hong Liu, Linbo Li 2022, 75(12): 250-259.  DOI: 10.1016/j.jechem.2022.08.033 Abstract ( 7 )   PDF (10488KB) ( 1 )   Lithium-sulfur batteries suffer from poor cycling stability because of the intrinsic shuttling effect of inter-mediate polysulfides and sluggish reaction kinetics, especially at high rates and high sulfur loading. Herein, we report the construction of a CoP-Co2N@N-doped carbon polyhedron uniformly anchored on three-dimensional carbon nanotubes/graphene (CoP-Co2N@NC/CG) scaffold as a sulfur reservoir to achieve the trapping-diffusion-conversion of polysulfides. Highly active CoP-Co2N shows marvelous cat-alytic effects by effectively accelerating the reduction of sulfur and the oxidation of Li2S during the dis-charging and charging process, respectively, while the conductive NC/CG network with massive mesoporous channels ensures fast and continuous long-distance electron/ion transportation. DFT calcu-lations demonstrate that the CoP-Co2N with excellent intrinsic conductivity serves as job-synergistic immobilizing-conversion sites for polysulfides through the formation of P Li/N Li and Co S bonds. As a result, the S@CoP-Co2N@NC/CG cathode (sulfur content 1.7 mg cm-2) exhibits a high capacity of 988 mAh g-1 at 2 C after 500 cycles, which is superior to most of the electrochemical performance reported. Even under high sulfur content (4.3 mg cm-2), it also shows excellent cyclability with high capacity at 1 C.

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Activation of iridium site by anchoring ruthenium atoms on defects for efficient anodic catalyst in polymer electrolyte membrane water electrolyzers Shiqian Du, Ru Chen, Wei Chen, Hongmei Gao, Jianfeng Jia, Zhaohui Xiao, Chao Xie, Hao Li, Li Tao, Jia Huo, Yanyong Wang, Shuangyin Wang 2022, 75(12): 260-266.  DOI: 10.1016/j.jechem.2022.08.020 Abstract ( 27 )   PDF (5163KB) ( 27 )

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Unveiling the mechanism of charge compensation in Li2RuxMn1-xO3 by tracking atomic structural evolution Ji Li, Hongzhou Liu, Shun Zheng, Yande Li, Daming Zhu, Fanfei Sun, Jingyuan Ma, Songqi Gu, Panzhe Qiao, Shuai Yang, Xianlong Du, Xiaosong Liu, Zhi Liu, Bingbao Mei, Zheng Jiang 2022, 75(12): 267-275.  DOI: 10.1016/j.jechem.2022.08.025 Abstract ( 6 )   PDF (8006KB) ( 3 )   The relationship between the structural evolution and redox of Li-rich transition-metal layered oxides (LLOs) cathodes remains ambiguous, obstructing the development of high-performance lithium-ion (Li+) battery. Herein, the coherent effects of local atomic and electronic structure in Li2RuxMn1 xO3 (LRMO) with a wide voltage window (1.3-4.8 V) is identified by in situ X-ray absorption fine spec-troscopy (XAFS) and chemometrics. We not only skillfully separated the redox active structures to track the electrochemical path, but also visualized the coupling mechanism between the evolution of Ru-Ru dimer and the (de) excitation of cations and anions. Furthermore, introducing manganese triggers the ‘‘heterogeneity” of coordination environment and electronic structure between Ru and Mn after dis-charge to 3 V. The change of thermodynamic and kinetic paths affects the relithiation, and further leads to the hysteresis of the anion activation structure relaxation of Li2Ru0.4Mn0.6O3 relative to Li2RuO3 (LRO). Additionally, it is demonstrated that the high charge cut-off voltage restrains the relaxation of anionic active structure in LRO from a new perspective through comparative experiments. Our work associates the evolution of atomic structure with charge compensation and negative electrochemical reactions such as voltage hysteresis (VH) and capacity attenuation, deepening the understanding electrochemical reac-tion mechanism of LLOs during the first cycle and providing a theoretical support for the further design and synthesis of high-efficiency cathodes.

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Surface modulation of MoS2/O-ZnIn2S4 to boost photocatalytic H2 evolution Yanhua Peng, Xinlei Guo, Shufei Xu, Ya’nan Guo, Dongsheng Zhang, Meijiao Wang, Guosong Wei, Xiaolong Yang, Zhuo Li, Yan Zhang, Fenghui Tian 2022, 75(12): 276-284.  DOI: 10.1016/j.jechem.2022.06.027 Abstract ( 12 )   PDF (3703KB) ( 8 )   To realize the continuous production of hydrogen energy, the efficient photocatalysts are required in the heterogeneous reaction for water splitting. Herein, we reported a surface modulation strategy, via doping oxygen atoms to tune the surface state of ZnIn2S4 nanosheets with cocatalyst MoS2 modification, to enhance water adsorption and surface catalytic reaction for boosting the photocatalytic activity. Consequently, MoS2/O-ZnIn2S4 photocatalysts showed a remarkably superior photocatalytic H2 produc-tion performance of 4.002 mmol g-1 h-1 and an apparent quantum yield (AQY) of 2.53%, 5.4 folds higher than ZnIn2S4. Using operando infrared spectroscopy and DFT calculation, we revealed the dynamic struc-tural evolution, as well as the active sites for water adsorption and the catalytic reaction at the MoS2/O-ZnIn2S4 interface. This work reveals the effect of surface modulation on the photocatalytic activity for MoS2/O-ZnIn2S4 and offers a feasible method to devise excellent nanomaterial photocatalysts for H2 production.

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Facile and scalable fabrication of lithiophilic CuxO enables stable lithium metal anode Yanmei Nie, Xiangyu Dai, Jiexi Wang, Zhengfang Qian, Zhixing Wang, Huajun Guo, Guochun Yan, Dongting Jiang, Renheng Wang 2022, 75(12): 285-292.  DOI: 10.1016/j.jechem.2022.08.013 Abstract ( 7 )   PDF (11617KB) ( 2 )   Equipped with highest-energy density anode, lithium metal batteries are of great interests for the next-generation energy storage systems. However, the existing problems like uneven Li deposition, large vol-ume expansion and short cycling lifespan severely retard the implementation of Li metal anodes. Herein, we report an in-situ formed CuxO nanofiber network synthesized by facile and scalable calcination pro-cess and employ as stable lithium metal anode. The CuO/Cu2O ratio in the lithiophilic CuxO network can be adjusted through an optimal annealing time, thus guiding the homogeneous distribution of Li atoms and regulating the repeated plating/stripping processes. As a result, Li@CuxO 3D scaffold displays an ultralow overpotential of 7.7 mV, long cycling life for more than 1000 h in symmetric cell, and excep-tional stability for LiFePO4//Li full cells. This work provides guidelines for the design and fabrication of lithiophilic 3D matrixes and advances the practical use of lithium metal batteries.

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Boosting nitrogen electrocatalytic fixation by three-dimensional TiO2 dNd nanowire arrays Jianjia Mu, Xuan-Wen Gao, Zhaomeng Liu, Wen-Bin Luo, Zhenhua Sun, Qinfen Gu, Feng Li 2022, 75(12): 293-300.  DOI: 10.1016/j.jechem.2022.08.007 Abstract ( 5 )   PDF (9088KB) ( 1 )   Owing to the environmental and inherent advantages, nitrogen reduction reaction (NRR) by electrocata-lysts attracts global attention. The surface engineering is widely employed to enhance the electrocatalytic activity by atomic defects and heterostructure effects. A three-dimensional (3D) free-standing integrated electrode was fabricated by numerous nearly-single-crystal TiO2 dNd nanowire arrays. Based on the high electronic conductivity network, it exposes numerous active sites as well to facilitate the selective nitro-gen adsorption and *H adsorption suppression. The synergistic effects between Ti3+ and oxygen vacancy (Ov) boost the intrinsic catalytic activity, in which Ti3+ acquired electrons via Ov can effectively activate the N≡N bond and make it easy to bind with protons. The energy barrier of primary protonation process (*N2+H++e →*NNH) can be dramatically decreased. The highest ammonia yield rate (14.33 lg h-1 mgcat1) emerges at 0.2 V, while the optimal ammonia Faradaic efficiency (9.17%) is acquired at 0.1 V. Density functional theory (DFT) calculation reveals that the Ti3+ can be served as the active sites for nitrogen adsorption and activation, while ammonia synthesis is accomplished by the distal pathway. The high electronic conductivity integrated network and synergistic effects can significantly facilitate nitrogen absorption and accelerate electrocatalytic reaction kinetic, which are responsible for the excellent NRR performance at room temperature.

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Enhancing structure and cycling stability of Ni-rich layered oxide cathodes at elevated temperatures via dual-function surface modification Ying-De Huang, Han-Xin Wei, Pei-Yao Li, Yu-Hong Luo, Qing Wen, Ding-Hao Le, Zhen-Jiang He, Hai-Yan Wang, You-Gen Tang, Cheng Yan, Jing Mao, Ke-Hua Dai, Xia-Hui Zhang, Jun-Chao Zheng 2022, 75(12): 301-309.  DOI: 10.1016/j.jechem.2022.08.010 Abstract ( 11 )   PDF (11612KB) ( 2 )   High-nickel single-crystal layered oxide material has become the most promising cathode material for electric vehicle power battery due to its high energy density. However, this material still suffers from structural degradation during cycling and especially the severe interfacial reactions at elevated temper-atures that exacerbate irreversible capacity loss. Here, a simple strategy was used to construct a dual-function Li1.5Al0.5Ge1.5P3O12 (LAGP) protective layer on the surface of the high-nickel single-crystal (SC) cathode material, leading to SC@LAGP material. The strong Al-O bonding effectively inhibits the release of lattice oxygen (O) at elevated temperatures, which is supported by the positive formation energy of O vacancy from first-principal calculations. Besides, theoretical calculations demonstrate that the appropri-ate amount of Al doping accelerates the electron and Li+ transport, and thus reduces the kinetic barriers. In addition, the LAGP protective layer alleviates the stress accumulation during cycling and effectively reduces the erosion of materials from the electrolyte decomposition at elevated temperatures. The obtained SC@LAGP cathode material demonstrates much enhanced cycling stability even at high voltage (4.6 V) and elevated temperature (55 LC), with a high capacity retention of 91.3% after 100 cycles. This work reports a simple dual-function coating strategy that simultaneously stabilizes the structure and interface of the single-crystal cathode material, which can be applied to design other cathode materials.

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Flexible PEDOT:PSS nanopapers as ‘‘anion-cation regulation” synergistic interlayers enabling ultra-stable aqueous zinc-iodine batteries Ying Zhang, Tianyu Zhao, Shanchen Yang, Yaxin Zhang, Yue Ma, Zhaohui Wang 2022, 75(12): 310-320.  DOI: 10.1016/j.jechem.2022.08.026 Abstract ( 12 )   PDF (12805KB) ( 5 )   Aqueous zinc-iodine (Zn-I2) batteries are promising candidates for low-cost grid-scale energy storage systems. However, the long-term stability and energy density of the Zn-I2 batteries are largely hindered by the lack of feasible and scalable methods that coherently suppress polyiodide shuttling and Zn den-drites growth, especially at high current densities. Herein, a flexible, thin and lightweight poly(3,4-ethy lenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) nanopaper is designed as an ‘‘anion-cation reg-ulation” synergistic interlayer to tackle the above issues. The PEDOT:PSS interlayer exhibits a 3D nanofi-brous network with uniformly distributed mesopores, abundant polar groups and intrinsic conductivity, which renders an even Zn2+ flux at Zn anode and facilitates homogeneous current distributions at I2 cath-ode. Meanwhile, such interlayer can act as physiochemical shield to enhance the utilization of I2 cathode via the coulombic repulsion and chemical adsorption effect against polyiodide shuttling. Thus, long-term dendrite-free Zn plating/stripping is achieved at simultaneous high current density and high areal capac-ity (550 h at 10 mA cm-2/5 mAh cm-2). Zn-I2 batteries harvest a high capacity (230 mAh g-1 at 0.1 A g-1) and an ultralong lifespan (>20000 cycles) even at 10 A g-1. This work demonstrates the potential use of the multifunctional interlayers for Zn-I2 battery configuration innovation by synergistic regulation of cations and anions at the electrodes/electrolyte interface.

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Over 12% efficient kesterite solar cell via back interface engineering Yunhai Zhao, Zixuan Yu, Juguang Hu, Zhuanghao Zheng, Hongli Ma, Kaiwen Sun, Xiaojing Hao, Guangxing Liang, Ping Fan, Xianghua Zhang, Zhenghua Su 2022, 75(12): 321-329.  DOI: 10.1016/j.jechem.2022.08.031 Abstract ( 9 )   PDF (6950KB) ( 2 )   Kesterite Cu2ZnSn(S,Se)4 (CZTSSe) has attracted considerable attention as a non-toxic and earth-abundant solar cell material. During selenization of CZTSSe film at high temperature, the reaction between CZTSSe and Mo is one of the main reasons that result in unfavorable absorber and interface qual-ity, which leads to large open circuit voltage deficit (VOC-def) and low fill factor (FF). Herein, a WO3 inter-mediate layer introduced at the back interface can effectually inhibit the unfavorable interface reaction between absorber and back electrode in the preliminary selenization progress; thus high-quality crystals are obtained. Through this back interface engineering, the traditional problems of phase segregation, voids in the absorber and over thick Mo(S,Se)2 at the back interface can be well solved, which greatly les-sens the recombination in the bulk and at the interface. The increased minority carrier diffusion length, decreased barrier height at back interface contact and reduced deep acceptor defects give rise to system-atic improvement in VOC and FF, finally a 12.66% conversion efficiency for CZTSSe solar cell has been achieved. This work provides a simple way to fabricate highly efficient solar cells and promotes a deeper understanding of the function of intermediate layer at back interface in kesterite-based solar cells.

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Structure and surface modification of MXene for efficient Li/K-ion storage Keke Guan, Long Dong, Yingying Xing, Xuke Li, Jin Luo, Quanli Jia, Haijun Zhang, Shaowei Zhang, Wen Lei 2022, 75(12): 330-339.  DOI: 10.1016/j.jechem.2022.08.023 Abstract ( 7 )   PDF (11286KB) ( 2 )   In this paper, three-dimensional (3D) hollow Ti3C2Tx MXene tubes (HTCTs) with more -O terminal groups and fewer -F groups are successfully prepared via the template-oriented electrostatic self-assembly and the subsequent annealing treatment. The obtained 3D hollow structure with large specific surface area, unique porous structure, and enlarged interlayer spacing could prevent the re-stacking of two-dimensional (2D) sheets and shorten the diffusion pathway of ions. Furthermore, density functional the-ory (DFT) calculations and electrochemical tests reveal that Ti3C2O2 MXene possesses higher adsorption ability and lower diffusion barrier for K+ and Li+ compared to Ti3C2 MXene dominated by -F terminal groups. Benefiting from the synergistic effect of the structural design and surface modification, the as-prepared 3D HTCTs exhibit excellent electrochemical performance as anodes for K+ and Li+ storage com-pared with 2D Ti3C2Tx sheets (TCSs).

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A cation-dipole-reinforced elastic polymer electrolyte enabling long-cycling quasi-solid-state lithium metal batteries Zhuyi Wang, Yiming Wang, Pan Zhai, Preeyaporn Poldorn, Siriporn Jungsuttiwong, Shuai Yuan 2022, 75(12): 340-348.  DOI: 10.1016/j.jechem.2022.08.042 Abstract ( 4 )   PDF (8658KB) ( 4 )   The application of ionic liquids (IL) in polymer electrolytes represents a safer alternative to the currently used organic solvents in lithium batteries due to their nonflammability and thermal stability. However, as a plasticizer, it is generally agreed that the introduction of ionic liquid usually leads to a trade-off between ion transport and mechanical properties of polymer electrolyte. Here we report the synthesis of an IL-embedded polymer electrolyte with both high ionic conductivity (2.77 10-4 S cm-1 at room temperature) and excellent mechanical properties (high tensile strength up to 11.4 MPa and excellent stretchability of 387% elongation at break) achieved by strong ion-dipole interactions between polymer electrolyte components, which was unveiled by the DFT calculation. Moreover, this polymer electrolyte also exhibits nonflammability, good thermal stability and the ability to recover reversibly from applied stress, i.e., excellent elasticity. This highly viscoelastic polymer electrolyte enables tight interfacial con-tact and good adaptability with electrodes for stable lithium stripping/plating for 2000 h under a current density of 0.1 mA cm-2. By coupling with this polymer electrolyte, the LiFePO4/Li cells exhibit outstand-ing cycling stability at room temperature as well as the reliability under extreme environmental temper-ature or being abused.

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Fast Li+ migration in LiPON electrolytes doped by multi-valent Fe ions Shuyu Zhou, Ruixue Tian, Aimin Wu, Li Lin, Hao Huang 2022, 75(12): 349-359.  DOI: 10.1016/j.jechem.2022.08.044 Abstract ( 10 )   PDF (9279KB) ( 6 )   Achieving superior ionic conductivity of LiPON solid electrolyte films is critical for the solid-state thin-film batteries with high energy density. Here we describe a method of preparing LiPON with promising ionic migration capability and high work function by systematically tailoring the concentration of Fe ions doping. Fe-doped LiPON exhibits excellent ionic conductivity (1.08 10 5 S cm 1, nearly 10 times higher than the pristine LiPON), low ionic activation energy, and moderate equilibrium potential difference (ver-sus LiCoO2, 0.78 V) at room temperature. The favorable ionic mobility and electrochemical stability of Fe-doped LiPON are fully confirmed. All-solid-state ‘‘Li/LiPON/LiCoO2” TFB has been successfully constructed with a large specific capacity ( 36.3 lAh cm-2 lm 1 at 10 lA cm-2) and good cycle performance (87.8 % capacity retention after 40 cycles). Fe with the unique d-orbital electronic structure changes the local electron density of LiPON system with the weakened electrostatic constraint of PO3N4 tetrahedrons to Li+. A low Li+ migration barrier center is established around the Fe-N bridge bonds.

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Flexible ion-conducting membranes with 3D continuous nanohybrid networks for high-performance solid-state metallic lithium batteries Lehao Liu, Dongmei Zhang, Tianrong Yang, Weihao Hu, Xianglong Meng, Jinshan Mo, Wenyan Hou, Qianxiao Fan, Kai Liu, Bing Jiang, Lihua Chu, Meicheng Li 2022, 75(12): 360-368.  DOI: 10.1016/j.jechem.2022.08.036 Abstract ( 3 )   PDF (13045KB) ( 1 )   Polyethylene oxide (PEO)-based electrolytes are considered as one of the most promising solid-state elec-trolytes for next-generation lithium batteries with high safety and energy density; however, the draw-backs such as insufficient ion conductance, mechanical strength and electrochemical stability hinder their applications in metallic lithium batteries. To enhance their overall properties, flexible and thin com-posite polymer electrolyte (CPE) membranes with 3D continuous aramid nanofiber (ANF)- Li1.4Al0.4Ti1.6(PO4)3 (LATP) nanoparticle hybrid frameworks are facilely prepared by filling PEO-LiTFSI in the 3D nanohybrid scaffolds via a solution infusion way. The construction of the 3D continuous nanohybrid networks can effectively inhibit the PEO crystallization, facilitate the lithium salt dissociation and meanwhile increase the fast-ion transport in the continuous LATP electrolyte phase, and thus greatly improving the ionic conductivity ( 3 times that of the pristine one). With the integration of the 3D con-tinuity and flexibility of the 3D ANF networks and the thermostability of the LATP phase, the CPE mem-branes also show a wider electrochemical window ( 5.0 V vs. 4.3 V), higher tensile strength ( 4-10 times that of the pristine one) and thermostability, and better lithium dendrite resistance capability. Furthermore, the CPE-based LiFePO4/Li cells exhibit superior cycling stability (133 mAh/g after 100 cycles at 0.3 C) and rate performance (100 mAh/g at 1 C) than the pristine electrolyte-based cell (79 and 29 mAh/g, respectively). This work offers an important CPE design criteria to achieve comprehensively-upgraded solid-state electrolytes for safe and high-energy metal battery applications.

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Pomegranate-inspired porous SnSe/ZnSe@C anode: A stress-buffer nanostructure for fast and ultrastable sodium-ion storage Zhixin Liang, Qinghua Li, Wang Zhang, Dandan Yu, Wei Zhang, Jiawei Wu, Gaoyu Wang, Wenbo Fan, Junling Wang, Shaoming Huang 2022, 75(12): 369-377.  DOI: 10.1016/j.jechem.2022.08.022 Abstract ( 13 )   PDF (12479KB) ( 7 )   Tin selenide (SnSe) is considered as a potential anode for sodium-ion batteries (SIBs) owing to its high theoretical specific capacity. Unfortunately, it suffers from drastic volume expansion/contraction during sodium ions insertion/extraction, resulting in poor cycling stability. Herein, a pomegranate-inspired por-ous carbon shell wrapped heterogeneous SnSe/ZnSe composite (SnSe/ZnSe@C) is exquisitely designed and fabricated through electrostatic spraying followed by high-temperature selenization. The polyacrylonitrile-derived carbon shell acts as an adhesive to link the porous cubic SnSe/ZnSe and form highly interconnected microcircuits to improve the electron/ion transfer efficiency and inhibit the bulk volume change of internal metallic selenide nanoparticles and polyselenides dissolution during repeated cycling. Moreover, the abundant heterostructure interface of SnSe/ZnSe further significantly accelerates the electrons/ions transport. As a result, the as-prepared SnSe/ZnSe@C electrode exhibits a high specific capacity (508.3 mAh g-1 at 0.05 A g-1), excellent rate performance (177.8 mAh g-1 at 10.0 A g-1), and remarkable cycling stability (195.9 mAh g-1 after 10,000 cycles at 5.0 A g-1). Furthermore, in-situ X-ray diffraction (XRD)/Raman, ex-situ transmission electron microscopy, and kinetic analysis clearly reveal a four-step electrochemical reaction process and battery-capacitor dual-mode sodium storage mecha-nism. This work provides a new perspective for developing commercial SIBs anode materials with high capacity and long lifespan.

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Hierarchical intercalation of tetrafluoroborate anion into graphite electrode from sulfolane Yunju Wang, Hongyu Wang 2022, 75(12): 378-382.  DOI: 10.1016/j.jechem.2022.08.047 Abstract ( 4 )   PDF (6271KB) ( 2 )   The anion storage behavior of graphite positive electrode in a dual-ion battery is closely related to the solvation of anion in the corresponding electrolyte solution. The classical electrolyte solutions of LiBF4-sulfolane (SL) have long been recognized in the community of lithium batteries and still appear promising in dual-ion batteries. Nevertheless, the solvation of BF4 by SL has seldom been addressed before. In this study, the solvation states of SL-BF4- are adjusted by varying LiBF4 concentration or introducing auxiliary salts of LiPF6 or SBPBF4 (SBP: spiro-(1,1’)-bipyrrolidinium) in the electrolyte solutions of Li/graphite dual-ion cells. The electrochemical storage processes of SL-BF4- anions in graphite electrodes are investigated through in situ X-ray diffraction measurements. Two kinds of graphite intercalation compounds (GICs) with contrastive intercalation gallery heights (IGHs) have been discovered, which are ascribed to the stor-age of different kinds of SL-BF4 anions in graphite electrode. The interactions between ions and SL in the electrolyte solutions are characterized by Fourier transform infrared spectroscopy and then correlated with the performance of Li/graphite cells.

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Perforated nitrogen-rich graphene-like carbon nanolayers supported Cu-In catalyst for boosting CO2electroreduction to CO Xinxin Zhang, Yuxiao Zhu, Ziyong Liu, Fuli Li, Wei Zhou, Zichao Dong, Jingxin Fan, Licheng Liu, Chunhua Du 2022, 75(12): 383-390.  DOI: 10.1016/j.jechem.2022.09.003 Abstract ( 6 )   PDF (6340KB) ( 6 )   The combination of a powerful CO2-enriching carrier and robust active component provides a new idea for the construction of efficient catalysts for electrocatalytic CO2 reduction. Herein, novel perforated nitrogen-rich graphene-like carbon nanolayers (PNGC) are prepared from biomass derivatives, which promotes the oriented deposition of In-doped Cu2(OH)3(NO3) nanosheet patches. A robust Cu-In/PNGC composite catalyst is then obtained via simple in-situ electrochemical reduction. Unsurprisingly, Cu-In/PNGC exhibits a CO Faradaic efficiency (FECO) of 91.3% and a remarkable CO partial current density (jCO) of 136.4 mA cm-2 at a moderate overpotential of 0.59 V for electrocatalytic CO2 reduction reaction (CO2RR). DFT calculations and experimental studies indicate that the strong carrier effect of PNGC makes PNGC carried Cu-In nanosheets improved the adsorption capacity of CO2 gas, reconfigured electronic structure, and reduced free energy of key intermediate formation, thereby the CO2 activation and conver-sion are promoted.

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Scalable spray coated high performance sulfurized electron transporter for efficient and stable perovskite solar modules Siqing Nie, Qifan Feng, Ziheng Tang, Yaolin Hou, Xiaofeng Huang, Ruihao Chen, Fang Cao, Binghui Wu, Jun Yin, Jing Li, Nanfeng Zheng 2022, 75(12): 391-398.  DOI: 10.1016/j.jechem.2022.08.045 Abstract ( 3 )   PDF (5364KB) ( 4 )   The stability issue has been acknowledged as the bottleneck in the practical application of perovskite photovoltaics, while the stabilized interface between the perovskites and charge transport layers domi-nates their stability performance under different stresses. Here, we developed a high-performance sulfu-rized zinc-titanium mixed oxide (ZTO-S) electron transport layer (ETL) to fabricate large-area efficient and long-term 85 LC/85% RH stable perovskite solar modules. The scalably prepared ZTO-S using the facile spray coating method demonstrates excellent electron mobility close to that of ZnO, in addition to promoting the uniform crystallization of perovskite film across the entire module via the interaction between surface S and Pb2+. Furthermore, this novel coordination stabilized the interface and reduced the interfacial non-radiative recombination defects within the devices, yielding an efficient and stable perfor-mance for the modules. High efficiency of 21.73% and 17.50% was achieved for blade-coated 36 cm2 and 100 cm2 perovskite solar modules, respectively. In addition, the encapsulated module (36 cm2) shows an attractive humidity and heat stability (85 LC/85% RH) performance with a maintained 93.5% of the initial PCE over 1000 h.

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Graphene/carbon structured catalyst layer to enhance the performance and durability of the high-temperature proton exchange membrane fuel cells Zhaoqi Ji, Jianuo Chen, Zunmin Guo, Ziyu Zhao, Rongsheng Cai, Maxwell T.P. Rigby, Sarah J. Haigh, Maria Perez-Page, Yitao Shen, Stuart M. Holmes 2022, 75(12): 399-407.  DOI: 10.1016/j.jechem.2022.08.004 Abstract ( 8 )   PDF (8204KB) ( 4 )   In this study, nitrogen doped electrochemically exfoliated reduced graphene oxide and carbon black sup-ported platinum (Pt/NrEGO2-CB3) has been prepared to enhance the performance and durability of high-temperature PEMFCs with lower Pt loading. On the one hand, Pt/NrEGO2-CB3 with the strong interaction between the Pt and nitrogen (N) prevent agglomeration of Pt particles and Pt particles is 5.46 ± 1.46 nm, which is smaller than that of 6.78 ± 1.34 nm in Pt/C. Meanwhile, ECSA of Pt/NrEGO2-CB3 decrease 13.65% after AST, which is much lower than that of 97.99% in Pt/C. On the other hand, the NrEGO flakes in MEAac act as a barrier to mitigate phosphoric acid redistribution, which improves the formation of triple-phase boundaries (TPBs) and gives stable operation of the MEAac with a lower decay rate of 0.02 mV h-1 within 100 h. After steady-state operation, the maximum power density of Pt/NrEGO2-CB3 (0.411 W cm-2) is three times higher than that of conventional Pt/C (0.134 W cm-2) in high-temperature PEMFCs. After AST, the mass transfer resistance of Pt/NrEGO2-CB3 electrode (0.560 X cm2) is lower than that in Pt/C (0.728 X cm2).

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Enabling dendrite-free charging for lithium batteries based on transport-reaction competition mechanism in CHAIN framework Lisheng Zhang, Siyan Chen, Wentao Wang, Hanqing Yu, Haicheng Xie, Huizhi Wang, Shichun Yang, Cheng Zhang, Xinhua Liu 2022, 75(12): 408-421.  DOI: 10.1016/j.jechem.2022.09.007 Abstract ( 5 )   PDF (24669KB) ( 2 )   Worldwide trends in mobile electrification will skyrocket demands for lithium-based battery production, driven by the popularity of electric vehicles. However, both lithium metal batteries and lithium ion bat-teries face severe safety issues due to dendrite nucleation and growth process. Li deposition is signifi-cantly influenced by interfacial factors and charging conditions. In this paper, an electrochemical model considering the internal and external factors is proposed based on Monte Carlo method. The influ-ence of internal solid electrolyte interphase (SEI) porosity, thickness and the external conditions on den-drite growth process is systematically described. The simulation results support that the three factors investigated in this model could synergistically regulate the dendrite growth process. Three competition mechanisms are proposed to tailor lithium deposition for Li-based batteries and numerical solutions for variation pattern of dendrite growth with time are fitted. A three-step process describing kinetic process of lithium deposition is proposed. To achieve dendrite-free charging process, charging strategies and emerging materials design should be considered, including physicochemical materials engineering, arti-ficial SEI, and design for dynamic safety boundary. This work could contribute to the foundation for insights of Li deposition mechanism, which is promising to provide guidelines for next-generation high-energy-density and safe batteries in CHAIN framework.

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Design of experiments unravels insights into selective ethylene or methane production on evaporated Cu catalysts Jian Cheng, Yuqing Bai, Zhihe Wei, Qiaoqiao Mu, Hao Sun, Ling Lin, Long Xiao, Xulan Xie, Zhao Deng, Yang Peng 2022, 75(12): 422-429.  DOI: 10.1016/j.jechem.2022.06.036 Abstract ( 6 )   PDF (5918KB) ( 2 )   As a highly tempting technology to close the carbon cycle, electrochemical CO2 reduction calls for the development of highly efficient and durable electrocatalysts. In the current study, Design of Experiments utilizing the response surface method is exploited to predict the optimal process variables for preparing high-performance Cu catalysts, unraveling that the selectivity towards methane or ethylene can be simply modulated by varying the evaporation parameters, among which the Cu film thickness is the most pivotal factor to determine the product selectivity. The predicted optimal catalyst with a low Cu thickness affords a high methane Faradaic efficiency of 70.6% at the partial current density of 211.8 mA cm-2, whereas that of a high Cu thickness achieves a high ethylene selectivity of 66.8% at 267.2 mA cm-2 in the flow cell. Further structure-performance correlation and in-situ electro-spectroscopic measurements attribute the high methane selectivity to isolated Cu clusters with low pack-ing density and monotonous lattice structure, and the high ethylene efficiency to coalesced Cu nanopar-ticles with rich grain boundaries and lattice defects. The high Cu packing density and crystallographic diversity is of essence to promoting C-C coupling by stabilizing *CO and suppressing *H coverage on the catalyst surface. This work highlights the implementation of scientific and mathematic methods to uncover optimal catalysts and mechanistic understandings toward selective electrochemical CO2 reduction.

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ZnS-assisted evolution of N,S-doped hierarchical porous carbon nanofiber membrane with highly exposed Fe-N4/Cx sites for rechargeable Zn-air battery Leping Yang, Lingxiao Yu, Zheng-Hong Huang, Feiyu Kang, Ruitao Lv 2022, 75(12): 430-440.  DOI: 10.1016/j.jechem.2022.08.017 Abstract ( 8 )   PDF (6676KB) ( 3 )   Binder-free bifunctional electrocatalysts are attractive for rechargeable Zn-air batteries (ZABs) in grid-scale energy storage and flexible electronics, but suffering from the sluggish mass transport and inade-quate catalytic capability. Herein, we propose a scalable approach of in-situ engineering highly exposed Fe-N4/Cx sites on the N,S-doped porous carbon nanofiber membrane as a binder-free air electrode catalyst for ZABs. ZnS nanospheres are firstly used as integrated structure-directing agents to facilitate the elec-tronic modulation of Fe-N4/Cx sites by S doping and construct the hierarchical macro/meso/micropores at high temperature. Neither additional step for removal of ZnS nanospheres nor doping process is required, significantly simplifying the pore formation process and improving the S doping efficiency. Benefiting from the enhanced intrinsic activity of high-density Fe-N4/Cx sites (23.53 lmol g-1) and the optimized mass transport of carbon nanofibers, as-synthesized electrocatalyst shows a positive half-wave potential of 0.89 V for oxygen reduction reaction and a small overpotential of 0.47 V at 10 mA cm-2 for oxygen evolution reaction. When used as the air cathode catalyst for ZABs, it delivers a high specific capacity of 699 mAh g-1 at 5 mA cm-2, a large peak power density of 228 mW cm-2 and a prolonged cycling over 1000 h. At 10 mA cm-2, a robust structure with atomically dispersed Fe is also remained after cycling for 420 h. Due to the flexible properties of the electrocatalyst, as-assembled quasi-solid-state ZAB shows stable cycling over 90 h at alternately flat/bent states, demonstrating great prospects in flexible electronic device applications.

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Ionic covalent organic frameworks with tailored anionic redox chemistry and selective ion transport for high-performance Na-ion cathodes Zhongqiu Tong, Hui Wang, Tianxing Kang, Yan Wu, Zhiqiang Guan, Fan Zhang, Yongbing Tang, Chun-Sing Lee 2022, 75(12): 441-447.  DOI: 10.1016/j.jechem.2022.05.044 Abstract ( 6 )   PDF (6634KB) ( 6 )   Employing cathode materials with multiple redox couples and electrolytes with efficient cation transport kinetics are two effective approaches to improving the electrochemical performance of batteries. In this work, for the first time, we present a design strategy of simultaneously realizing reversible cationic and anionic redox chemistries as well as selective anion/cation transport in the viologen-based COFs (BAV-COF:X, coordinated anions of X = Cl , Br , I , and ClO4 ) for high-performance Na-ion cathodes. Besides the cationic redox of viologen segments, the different redox activities of anions effectively tune the total capacities of the COFs. Meanwhile, electrochemical analysis and ab-initial molecular dynamics (AIMD) calculation illustrate that the anion/cation transport kinetics of electrolytes caged in the COFs’ channels can be selectively tuned by the coordinated anions. As a result, combining high-potential Br /Br2 redox couple, cationic redox of viologen segments, and enhanced Na+ transport kinetics, the BAV-COF:Br demonstrates stable performance with energy densities of 358.7 and 145.2 Wh kg-1 at power densities of 116.5 and 2124.1 W kg-1, respectively. This study offers new insight into the fabrication of organic cathodes with anionic redox and the advantages of COFs electrode materials in anion/cation transport selectivity for energy storage applications.

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Reconstructing proton channels via Zr-MOFs realizes highly ion-selective and proton-conductive SPEEK-based hybrid membrane for vanadium flow battery Denghua Zhang, Wenjie Yu, Yue Zhang, Sihan Cheng, Mingyu Zhu, Shuai Zeng, Xihao Zhang, Yifan Zhang, Chao Luan, Zishen Yu, Lansong Liu, Kaiyue Zhang, Jianguo Liu, Chuanwei Yan 2022, 75(12): 448-456.  DOI: 10.1016/j.jechem.2022.08.043 Abstract ( 4 )   PDF (7941KB) ( 4 )   There is an urgent need to break through the trade-off between proton conductivity and ion selectivity of proton exchange membrane (PEM) in vanadium flow battery (VFB). Proton channels in PEM are the key to controlling the ion sieving and proton conductivity in VFB. Herein, two types of proton channels are reconstructed in the hybrid membrane via introducing modified Zr-MOFs (IM-UIO-66-AS) into SPEEK matrix. Internal proton channels in IM-UIO-66-AS and interfacial proton channels between grafted imi-dazole groups on Zr-MOFs and SPEEK greatly improve the conductivity of the IM-UIO-66-AS/SPEEK hybrid membrane. More importantly, both reconstructed proton channels block the vanadium-ion per-meation to realize enhanced ion selectivity according to the size sieving and Donnan exclusion effects, respectively. Moreover, the hybrid membrane exhibits good mechanical property and dimensional stabil-ity. Benefiting from such rational design, a VFB loading with the optimized membrane exhibits enhanced voltage efficiency of 79.9% and outstanding energy efficiency of 79.6% at 200 mA cm-2, and keeps a nota-ble cycle stability for 300 cycles in the long-term cycling test. Therefore, this study provides inspiration for preparing next-generation PEMs with high ion selectivity and proton conductivity for VFB application.

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Assembly and electrochemical testing of renewable carbon-based anodes in SIBs: A practical guide Darío Alvira, Daniel Antorán, Joan J. Manyà 2022, 75(12): 457-477.  DOI: 10.1016/j.jechem.2022.09.002 Abstract ( 62 )   PDF (5206KB) ( 20 )   Sodium-ion batteries (SIBs) are considered as a promising candidate to replace lithium-ion batteries (LIBs) in large-scale energy storage applications. Abundant sodium resources and similar working prin-ciples make this technology attractive to be implemented in the near future. However, the development of high-performance carbon anodes is a focal point to the upcoming success of SIBs in terms of power density, cycling stability, and lifespan. Fundamental knowledge in electrochemical and physicochemical techniques is required to properly evaluate the anode performance and move it in the right direction. This review aims at providing a comprehensive guideline to help researchers from different backgrounds (e.g., nanomaterials and thermochemistry) to delve into this topic. The main components, lab configurations, procedures, and working principles of SIBs are summarized. Moreover, a detailed description of the most used electrochemical and physicochemical techniques to characterize electrochemically active materials is provided.

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Cu-substitution P2-Na0.66Mn1-xCuxO2 sodium-ion cathode with enhanced interlayer stability Huanqing Liu, Xu Gao, Jun Chen, Jinqiang Gao, Haoji Wang, Yu Mei, Huan Liu, Wentao Deng, Guoqiang Zou, Hongshuai Hou, Xiaobo Ji 2022, 75(12): 478-485.  DOI: 10.1016/j.jechem.2022.09.010 Abstract ( 13 )   PDF (7177KB) ( 5 )   P2-type Mn-based layered oxides are viewed as promising cathode materials for sodium ion battery by virtue of their high theoretical capacity. Considering that pure Na2/3MnO2 suffers from poor cycling per-formances, Cu-substitution strategy is proposed to effectively alleviate this issue. However, the structural evolution mechanism of the Cu-containing samples still remains unclear. Herein, we propose that Cu-Substitution P2-type Na0.66Mn1-xCuxO2 with enlarged lattice parameters are conducive to improving the interlayer structure stability through mitigating TMO2 slabs distortion. Proved by synchrotron XAS spectra and ex/in situ XRD, the expansion/contraction of MnO6 octahedron is dramatically reduced with the increased Cu content, showing the facilitated Na ion diffusion. Furthermore, when the ratio of Cu to Mn reaches 1:4, the phase transition from P2 to P’2 type at the end of discharge can be suppressed, result-ing in the improved interlayer skeleton stability. The Cu-containing samples with stable interlayer struc-ture exhibit high capacity retention and outstanding rate performances (a capacity of 79.9 mAh g-1 at 5 C). This Cu-substitution strategy provides a promising approach to designing highly stable cathodes.

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Tandem Co-O dual sites on halloysite with promoted reaction kinetics for sulfur reduction Qiang Zhang, Yinyin Qian, Ji-Jun Zou, Ruijie Gao, Huaming Yang 2022, 75(12): 486-493.  DOI: 10.1016/j.jechem.2022.09.011 Abstract ( 4 )   PDF (7681KB) ( 2 )   Facilitating sulfur reduction reaction (SRR) is a promising pathway to tackle the polysulfide shuttle effect and enhance the electrochemical performance of lithium-sulfur (Li-S) batteries. Catalysts with a solo active site can reduce a reaction barrier of a certain transition-intermediate, but the linear scaling rela-tionship between multi-intermediates still obstructs overall SRR. Herein, we construct tandem Co-O dual sites with accelerating SRR kinetics by loading highly dispersed cobalt sulfide clusters on halloysite. This catalyst features Co with upshifted d-orbital and O with downshifted p-orbital, which cooperatively adsorb long-chain polysulfide and dissociate an S-S bond, thus achieving both optimal adsorption-des-orption strength and reduced conversion energy barrier of multi-intermediates in SRR. The Li-S coin bat-teries using the electrocatalyst endows a high specific capacity of 1224.3 mAh g-1 at 0.2 C after 200 cycles, and enhances cycling stability with a low-capacity decay rate of 0.03% per cycle at 1 C after 1000 cycles. Moreover, the strategy of the tandem Co-O dual sites is further verified in a practical Li-S pouch battery that realizes 1014.1 mAh g-1 for 100 cycles, which opens up a novel avenue for designing electrocatalysts to accelerate multi-step reactions.

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Low-cost preferential different amine grafted silica spheres adsorbents for DAC CO2 removal Salman Qadir, Hongjiu Su, Defu Li, Yiming Gu, Shengsheng Zhao, Sheng Wang, Shudong Wang 2022, 75(12): 494-503.  DOI: 10.1016/j.jechem.2022.09.005 Abstract ( 3 )   PDF (2683KB) ( 2 )   DAC CO2 capture is gaining wide attention as one of the most difficult carbon approaches to tackle cli-mate change. In this work, different pore-size silica spheres were grafted using different amine groups such as APTES, APTMS, and Diamine. Herein, all samples based on the wet and dry grafting method were used for CO2 adsorption isotherm at room temperature and pressure (298 K and 1 bar). The sample based on the wet grafting (Silica-APTES-W) sample shows the highest CO2 uptake 1.67 mmol/g. Also, the adsorption isotherm of the Silica-APTES-W sample was showed a high capacity of CO2 1.2 mmol/g at 25 LC, which describes the strong physical interaction between CO2 and amine. The isosteric adsorption of Silica-APTES-W also confirmed that the physical adsorption was dominant because of low adsorption heat ranging from 23 to 37 kJ/mol. Also, the fixed bed experiment was conducted with 2000 ppm CO2 that obtains the optimal working capacity 4.5 mL/g with the lowest regeneration temperature 90 LC. It was shown that Silica-APTES-W sample was superior performance for DAC CO2 capture in practical applications.

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The interphasial degradation of 4.2 V-class poly(ethylene oxide)-based solid batteries beyond electrochemical voltage limit Renzhi Huang, Yang Ding, Fenglin Zhang, Wei Jiang, Canfu Zhang, Pengfei Yan, Min Ling, Huilin Pan 2022, 75(12): 504-511.  DOI: 10.1016/j.jechem.2022.06.014 Abstract ( 7 )   PDF (4422KB) ( 5 )   Solid-state polymer electrolytes (SPEs) have attracted increasing attention due to good interfacial con-tact, light weight, and easy manufacturing. However, the practical application of SPEs such as the most widely studied poly(ethylene oxide) (PEO) in high-energy solid polymer batteries is still challenging, and the reasons are yet elusive. Here, it is found that the mismatch between PEO and 4.2 V-class cathodes is beyond the limited electrochemical window of PEO in the solid LiNi1/3Mn1/3Co1/3O2 (NMC)-PEO batter-ies. The initial oxidation of PEO initiates remarkable surface reconstruction of NMC grains in solid batter-ies that are different from the situation in liquid electrolytes. Well-aligned nanovoids are observed in NMC grains during the diffusion of surface reconstruction layers towards the bulk in solid batteries. The substantial interphasial degradation, therefore, blocks smooth Li+ transport across the NMC-PEO interface and causes performance degradation. A thin yet effective LiF-containing protection layer on NMC can effectively stabilize the NMC-PEO interface with a greatly improved lifespan of NMC|PEO|Li bat-teries. This work deepens the understanding of degradations in high-voltage solid-state polymer batteries.

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Modulating of MoSe2 functional plane via doping-defect engineering strategy for the development of conductive and electrocatalytic mediators in Li-S batteries Mohammed A. Al-Tahan, Yutao Dong, Aml E. Shrshr, Xiyang Kang, Hui Guan, Yumiao Han, Zihao Cheng, Weihua Chen, Jianmin Zhang 2022, 75(12): 512-523.  DOI: 10.1016/j.jechem.2022.09.001 Abstract ( 4 )   PDF (22030KB) ( 1 )   The lithium polysulfide shuttle and sluggish sulfur reaction kinetics still pose significant challenges to lithium-sulfur (Li-S) batteries. The functional plane of Fe-MoSe2@rGO nanohybrid with abundant defects has been designed and applied in Li-S batteries to develop the functional separator and multi-layer sulfur cathode. The cell with a functional separator exhibits a retention capacity of 462 mAh g-1 after the 1000th at 0.5 C and 516 mAh g-1 after the 600th at 0.3 C. Even at low electrolyte conditions (7.0 lL mgsulfur1 and 15 lL mgsulfur1) under high sulfur loadings (3.46 mg cm-2 and 3.73 mg cm-2), the cell still presents high reversible discharge capacities 679 and 762 mAh g-1 after 70 cycles, respectively. Further, at sulfur loadings up to 8.26 and 5.2 mg cm-2, the cells assembled with the bi-layers sulfur cath-ode and the tri-layers sulfur cathode give reversible capacities of 3.3 mAh cm-2 after the 100th cycle and 3.0 mAh cm-2 after the 120th cycle, respectively. This research not only demonstrates that the Fe-MoSe2@rGO functional plane is successfully designed and applied in Li-S batteries with superior electro-chemical performances but also paves the novel way for developing a unique multi-layer cathode tech-nique to enhance and advance the electrochemical behavior of Li-S cells at a high-sulfur-loading cathode under lean electrolyte/sulfur (E/S) ratio.