Lithium salt-derived artificial near-surface reconfiguration to stabilize high-voltage LiCoO2†

Abstract

Pushing the limit of the charging cut-off voltage inevitably leads to the instability of bulk and interfacial structures. Herein, one-step dual-modified LiCoO₂ (LCO) is achieved by thermodynamic decomposition of lithiuim salts on the surface, featuring F-doped bulk and LiF & Li_xB_yO_z coating layers. Notably, such artificial near-surface reconfiguration effectively suppresses Co dissolution, structural deconstruction and electrolyte side reactions during repeated lithiation/delithiation processes. As a result, the modified LCO delivers a high capacity retention of 81.4% after 150 cycles at 0.5C and 81.7% after 300 cycles at 2C in the voltage region of 3.0–4.6 V (vs. Li/Li⁺).