Journal of Energy Chemistry ›› 2022, Vol. 69 ›› Issue (6): 450-455.DOI: 10.1016/j.jechem.2022.01.021

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Confining ultrahigh oxygen vacancy SnO2 nanocrystals into nitrogen-doped carbon for enhanced Li-ion storage kinetics and reversibility

Ying Liua, Chen Hua, Ling Chenb, Yanjie Hua, Hao Jianga,*, Chunzhong Lia,b,*   

  1. aKey Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China;
    bShanghai Engineering Research Center of Hierarchical Nanomaterials, Frontiers Science Center for Materiobiology and Dynamic Chemistry, School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China
  • Received:2021-11-22 Revised:2022-01-13 Accepted:2022-01-15 Online:2022-06-15 Published:2022-10-25
  • Contact: * E-mail addresses: jianghao@ecust.edu.cn (H. Jiang), czli@ecust.edu.cn (C. Li).

Abstract: Oxygen vacancies (VO) engineering has been deemed to an effective tactic for enhancing Li-ion storage kinetics and reversibility of SnO2-based anode materials. Herein, we demonstrated the confinement of ultrahigh VO SnO2 nanocrystals into N-doped carbon frameworks to boost their high-rate and cycle life. Density functional theory (DFT) calculations reveal that abundant VO in SnO2 facilitates the adsorption to Li-ion with remarkably increased carrier concentration. The 6.0 nm-sized SnO2 particles and the embed-ded design effectively stabilize the structural integrity during de-/lithiation. Meantime, the as-formed large hetero-interface also expedites the electron transfer. These merits guarantee its high-rate perfor-mance and superior cycling stability. Consequently, this sample exhibits a high capacity of 1368.9 mAh g-1 at 0.1 A g-1, and can still maintain 488.5 mAh g-1 at 10 A g-1 and a long life over 400 cycles at 5 A g-1 with 96.6% capacity retention, which is among the best report for Sn-contained anode mate-rials. This work sheds light on ultrahigh Vo and structural design in conversion-type oxides for high-performance lithium-ion batteries (LIBs).

Key words: Li-ion batteries SnO2, Oxygen vacancy, Confined synthesis, Rate capability