High-entropy doping for high-performance zero-cobalt high-nickel layered cathode materials

Abstract

Considering the high price and scarcity of cobalt resources, zero-cobalt, high-nickel layered cathode materials (LNMs) have been considered as the most promising material for next-generation high-energy-density lithium-ion batteries (LIBs). However, current LNMs face severe structural instability and poor electrochemical performance. Here, a high-entropy doping strategy has been developed to prepare high-performance LNMs by a typical co-precipitation method. Supported by transmission electron microscopy, in situ X-ray diffraction and X-ray absorption near edge structure analysis, the material exhibits small crystal size variations and no changes of (Ni, Mn)–O and (Ni, Mn)–Ni coordination distances, resulting in greatly reduced irreversible phase transformation and cracks. Formation energy and diffusion energy barrier analysis indicates that the material has a fast lithium-ion diffusion kinetics. Benefiting from these advantages, it exhibits excellent rate and cycling performance. This study provides a feasible high-entropy doping strategy to effectively achieve stable material circulation under a high capacity and gives more insights for developing new high-energy-density cathode materials.