Design High‐Entropy Core‐Shell Nickel‐Rich Cobalt‐Free Cathode Material Toward High Performance Lithium Batteries

Abstract The structural instability of lithium‐based transition metal layered oxides during electrochemical cycling‐exacerbated by phenomena such as metal dissolution and phase transitions‐induces rapid capacity degradation, thus constraining their applicability in high‐energy‐density lithium batteries. While coating these materials can bolster stability, the employment of electrochemically inactive coatings may inadvertently undermine energy storage performance, presenting a significant trade‐off. In response to this challenge, an innovative core‐shell cathode architecture is presented, wherein high entropy doped LiNi_1/6Mn_1/6Al_1/6Ti_1/6Mo_1/6Ta_1/6O₂ serves as the shell and nickel‐rich cobalt‐free LiNi_0.89Mn_0.11O₂ constitutes the core, synthesized through a simple two‐step co‐precipitation methodology (designated as LHECNM). This high‐entropy shell preserves the core's electrochemical performance while effectively mitigating phase transformations and transition metal ion dissolution, thereby enhancing structural robustness. Moreover, the core‐shell configuration significantly diminishes the energy barrier for Li⁺ diffusion, facilitating superior ion transport dynamics. Consequently, LHECNM demonstrates remarkable electrochemical performance, achieving a discharge capacity of 201.57 mAh g⁻¹, a commendable rate capability up to 5C, and an impressive 92% capacity retention over prolonged cycling. This investigation elucidates a promising paradigm for the design of high‐entropy cathode materials, offering profound insights for the advancement of future energy storage technologies.