Research progress on surface modification of spinel LiMn2O4 cathode materials for lithium-ion batteries

Lithium-ion batteries have become increasingly prevalent in modern society due to the rapid development of electronic devices and renewable energy technologies. Spinel LiMn₂O₄ (lithium manganese oxide) cathodes are considered among the most promising materials for lithium-ion batteries due to their low cost, environmental sustainability, and abundant availability. However, structural collapse and manganese dissolution lead to rapid deterioration of its electrochemical performance, limiting further application of spinel LiMn₂O₄. Nonetheless, surface coating modification can enhance the electrochemical performance of LiMn₂O₄. In this paper, we briefly discuss the structural characteristics and the capacity decay mechanisms of LiMn₂O₄ cathode materials. Furthermore, the applications and research progress of various surface coating materials, including oxides, phosphates, fluorides, carbon-based materials, and other coating materials (lithium-containing composite oxides, conductive polymers, and multifunctional materials), have been reviewed. The related mechanisms in improving cycling stability, suppressing manganese dissolution, and enhancing material conductivity were also analyzed. Importantly, the current challenges related to surface coating technologies and future research trends have been discussed. Therefore, this paper provides a theoretical foundation and practical reference for the development of high-performance lithium-ion batteries.