Strong Lewis-acid coordinated PEO electrolyte achieves 4.8 V-class all-solid-state batteries over 580 Wh kg<sup>-1</sup>.

An, Hanwen; Li, Menglu; Liu, Qingsong; Song, Yajie; Liu, Jiaxuan; Yu, Zhihang; Liu, Xingjiang; Deng, Biao et al. · Nat Commun · 2024

basic_science · Level V

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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 Mg<sup>2+</sup> and Al<sup>3+</sup> 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<sup>‒1</sup> with good cyclic stability, suggests the potential of our strategy in practical applications of all-solid-state batteries.