長寿命化が進むナトリウムイオン電池(Longer Lasting Sodium-Ion Batteries on the Horizon)

技術的課題を克服した先進のナトリウムイオン電池設計 An advanced sodium-ion battery design overcomes technical hurdles

2022-07-13 アメリカ・パシフィック・ノースウェスト国立研究所(PNNL)

＜関連情報＞

• https://www.pnnl.gov/news-media/longer-lasting-sodium-ion-batteries-horizon
• https://www.nature.com/articles/s41560-022-01055-0

高電圧ナトリウムイオン電池のための低溶媒和電解質 Low-solvation electrolytes for high-voltage sodium-ion batteries

Yan Jin,Phung M. L. Le,Peiyuan Gao,Yaobin Xu,Biwei Xiao,Mark H. Engelhard,Xia Cao,Thanh D. Vo,Jiangtao Hu,Lirong Zhong,Bethany E. Matthews,Ran Yi,Chongmin Wang,Xiaolin Li,Jun Liu & Ji-Guang Zhang
Nature Energy  Published:16 June 2022
DOI:https://doi.org/10.1038/s41560-022-01055-0

Abstract

Sodium-ion batteries (NIBs) have attracted worldwide attention for next-generation energy storage systems. However, the severe instability of the solid–electrolyte interphase (SEI) formed during repeated cycling hinders the development of NIBs. In particular, the SEI dissolution in NIBs with a high-voltage cathode is more severe than in the case of Li-ion batteries (LIBs) and leads to continuous side reactions, electrolyte depletion and irreversible capacity loss, making NIBs less stable than LIBs. Here we report a rational electrolyte design to suppress the SEI dissolution and enhance NIB performance. Our electrolyte lowers the solvation ability for SEI components and facilitates the formation of insoluble SEI components, which minimizes the SEI dissolution. In addition to the stable SEI on a hard carbon (HC) anode, we also show a stable interphase formation on a NaNi_0.68Mn_0.22Co_0.1O₂ (NaNMC) cathode. Our HC||NaNMC full cell with this electrolyte demonstrates >90% capacity retention after 300 cycles when charged to 4.2 V. This study enables high-voltage NIBs with long cycling performance and provides a guiding principle in electrolyte design for sodium-ion batteries.