Densification of Cathode/Electrolyte Interphase to Enhance Reversibility of LiCoO2 at 4.65 V

• DOI: 10.1002/adma.202408875
• Publication Date: 2024-08-29T07:10:18Z
• Authors: Hengyu Ren; Jiaxuan Hu; Haocheng Ji; Yuxiang Huang; Wenguang Zhao; Weiyuan Huang; Xiaohu Wang; Haocong Yi; Yongli Song; Jiajie Liu; Tongchao Liu; Ming Liu; Qinghe Zhao; Feng Pan
• Keywords: Interphase

Abstract For LiCoO 2 (LCO) operated beyond 4.55 V (vs Li/Li + ), it usually suffers from severe surface degradation. Constructing a robust cathode/electrolyte interphase (CEI) is effective to alleviate the above issues, however, correlated mechanisms still remain vague. Herein, progressively reinforced CEI realized via constructing Zr─O deposits (ZrO and Li ZrO 3 ) on LCO (i.e., Z‐LCO). Upon cycle, these can promote decomposition of LiPF 6 , convert highly dispersed Zr─O─F species. In particular, chemical reaction between LiF species further leads densification CEI, which greatly reinforces its toughness conductivity. Combining thin rock‐salt layer Z‐LCO, several benefits are achieved, including stabilizing lattice oxygen, facilitating interface transport kinetics, enhancing reversibility O3/H1‐3 phase transition, etc. As result, Z‐LCO||Li cells exhibit high capacity retention 84.2% after 1000 cycles in 3–4.65 V, 80.9% 1500 3–4.6 rate 160 mAh g −1 at 16 C (1 = 200 mA ). This work provides new insight for developing advanced cathodes.