Journal of Energy Chemistry ›› 2022, Vol. 74 ›› Issue (11): 18-25.DOI: 10.1016/j.jechem.2022.07.010

Previous Articles     Next Articles

An asymmetric bilayer polymer-ceramic solid electrolyte for high-performance sodium metal batteries

Han Wang, Yongjiang Sun*, Qing Liu, Zhiyuan Mei, Li Yang, Lingyan Duan, Hong Guo*   

  1. School of Materials and Energy, Yunnan University, Kunming 650091, Yunnan, China
  • Received:2022-04-25 Revised:2022-07-05 Accepted:2022-07-08 Online:2022-11-15 Published:2022-11-07
  • Contact: * E-mail addresses: yongjiangsun1985@ynu.edu.cn (Y. Sun), guohong@ynu.edu.cn (H. Guo).

Abstract: Manufacturing an excellent solid electrolyte compatible with a high-voltage cathode is viewed as a crit-ical tactic for improving the energy density of solid-state sodium-ion batteries (SSIBs). A novel asymmet-ric bilayer solid electrolyte of the PEO-SN-NaClO4|NZSP-NSO with an anti-reduction PEO-SN-NaClO4 layer close to the Na side is constructed by solution casting. The ionic conductivity is enhanced by using suc-cinonitrile (SN) in polyethylene oxide (PEO) polymer electrolyte. The anti-oxidation layer of Na3Zr2Si2PO12 with Na2SiO3 (NZSP-NSO) is served as the support of the membrane on the cathode, which could improve the interface compatibility and electrochemical performance of SSIBs. The asymmetric bilayer solid electrolyte simultaneously features a wide electrochemical stability window (4.65 V vs. Na+/Na) and a high conductivity (2.68 × 10-4 S cm-1). Furthermore, the solid electrolyte demonstrates stable Na plating/stripping over 700 h and remarkably improves cycling stability in Na/Na3V2(PO4)3 bat-teries with an ultra-high capacity retention of 99.6% after 100 cycles at 50 °C and 0.5 C. This study pro-vides an effective strategy for designing asymmetric high sodium ion conductivity solid-state electrolytes for high-performance SSIBs.

Key words: Solid sodium batteries, Bilayer electrolytes, NASICON, Polyethylene oxide