Enhancing the wide-temperature range performance of LiCoO₂ through high-entropy doping

The high energy density single-crystal cathode material LiCoO₂ has garnered significant interest for its application in current portable electronic products and the electric vehicle market. However, the sluggish electrochemical kinetics of LiCoO₂ at low temperatures and the severe structural degradation under high temperature and high voltage conditions impose limitations on its further utilization in extreme temperature environments. In this study, we propose a high-entropy doping strategy to enhance the performance of LiCoO₂ across a wide temperature range (−30–50 °C). The as-prepared high-entropy LiCoO₂ (HE-LCO) exhibits remarkable electrochemical performance within the wide temperature range, which can be attributed to following factors. Firstly, high-entropy doping effectively eliminates the order–disorder phase transition and alleviates the lattice changes. Secondly, enhanced Li-ion diffusion kinetics is revealed for HE-LCO, effectively suppressing electrochemical polarization and exhibiting a uniform contract/expansion behavior with less incompatibility inside the particle at high current density. Furthermore, side reactions on the surface are largely mitigated by high-entropy doping, leading to enhanced interfacial stability. The results obtained from this study offer valuable insights for developing cathode materials that are suitable for the reliable performance of lithium-ion batteries in various weather conditions. © 2024 Elsevier B.V.