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Electrolyte Chemistry Enables Simultaneous Stabilization of Potassium Metal and Alloying Anode for Potassium‐Ion Batteries
Author(s) -
Wang Hua,
Yu Dandan,
Wang Xiao,
Niu Zhiqiang,
Chen Mengxue,
Cheng Liwei,
Zhou Wei,
Guo Lin
Publication year - 2019
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201908607
Subject(s) - electrolyte , anode , materials science , potassium , metal , electrode , salt (chemistry) , inorganic chemistry , chemical engineering , solvent , amorphous solid , chemistry , metallurgy , organic chemistry , engineering
Alloying anodes are promising high‐capacity electrode materials for K‐ion batteries (KIBs). However, KIBs based on alloying anodes suffer from rapid capacity decay due to the instability of K metal and large volume expansion of alloying anodes. Herein, the effects of salts and solvents on the cycling stability of KIBs based on a typical alloying anode such as amorphous red phosphorus (RP) are investigated, and the potassium bis(fluorosulfonyl)imide (KFSI) salt‐based carbonate electrolyte is versatile to achieve simultaneous stabilization of K metal and RP electrodes for highly stable KIBs. This salt‐solvent complex with a moderate solvation energy can alleviate side reactions between K metal and the electrolyte and facilitate K + ion diffusion/desolvation. Moreover, robust SEI layers that form on K metal and RP electrodes can suppress K dendrite growth and resist RP volume change. This strategy of electrolyte regulation can be applicable to other alloying anodes for high‐performance KIBs.