Enabling high-performance 4.6 V LiCoO2 in a wide temperature range via a synergetic strategy

Abstract

Nowadays, LiCoO₂ has dominated the cathode technology of lithium-ion batteries (LIBs) for 3C digital devices, but the sluggish electrochemical kinetics and severe structure destruction limit its further application under extreme temperatures. Herein, we design a synergetic strategy including La, Mg co-doping and LiAlO₂@Al₂O₃ surface coating. Typically, the La³⁺ increases the interlayer distance and significantly enhances the ionic conductivity, the Mg²⁺ improves electronic conductivity, and the LiAlO₂@Al₂O₃ coating layer improves the interfacial charge transfer and suppresses the polarization. The co-modified LiCoO₂ (CM-LCO) shows excellent temperature adaptability with remarkable electrochemical performance in a wide temperature range (−40–70°C). Remarkably, the CM-LCO also exhibits excellent cycle stability and high-rate performance at extreme temperatures. The synergistic effects of this co-modification strategy are demonstrated by investigating the electrochemical reaction kinetics and structure evolution of CM-LCO. This work proposes a promising strategy for the application of the high-voltage LCO in a wide temperature range.