Strong Lewis-acid coordinated PEO electrolyte achieves 4.8 V-class all-solid-state batteries over 580 Wh kg−1
Hanwen An, Menglu Li, Qingsong Liu, Yajie Song, Jiaxuan Liu, Zhihang Yu, Xingjiang Liu, Biao Deng, Jiajun Wang
Abstract
Polyethylene oxide (PEO) based electrolytes critically govern the security and energy density of solid-state batteries, but typically suffer from poor oxidation resistance at high voltages, which limits the energy density of batteries. Here, we report a Lewis-acid coordinated strategy to significantly improve the cyclic stability of 4.8 V-class PEO-based battery. The introduced Mg2+ and Al3+ with strong electron-withdrawing capability weaken the electron density of ether oxygen (EO) chains via chelation in the coordination structure, resulting in a locally limited interaction between the EO chains and the surface of cathodes at high state of charge. The batteries using Lewis-acid coordinated electrolytes and Ni-rich cathodes achieve high voltage stability of 4.8 V over 300 cycles. Further, the realization of industrial-scale electrolyte membranes, and Ah-level pouch cells over 586 Wh kg‒1 with good cyclic stability, suggests the potential of our strategy in practical applications of all-solid-state batteries. This work reports a Lewis-acid coordinated strategy to improve stability of a 4.8 V-class PEO-based battery. The batteries using Lewis-acid coordinated electrolytes and Ni-rich cathodes achieve high voltage stability of 4.8 V over 300 cycles.