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

Abstract

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.

Keywords

• 4.6 V LiCoO2
• electrochemical kinetics
• Li‐ion batteries
• structure stability
• wide temperature range