Microsphere LiMn_0.6Fe_0.4PO₄/C cathode with unique rod-like secondary architecture for high energy lithium ion batteries

LiMn_xFe_1-xPO₄/C is considered a promising next-generation cathode material with significant commercial potential, inheriting the safety of LiFePO₄ while offering higher energy densities. However, the extremely low conductivity and the Jahn-Teller effect induced by Mn³⁺ limit its practical capacity and rate performance. Effective modifications can be achieved through particle nanonization and uniform carbon coating. Here, we synthesized microspherical LiMn_0.6Fe_0.4PO₄/C cathode materials using a hydrothermal method combined with spray drying carbon coating. The cathode material exhibits a microsphere structure composed of aggregated nanorods with a uniform 3 nm carbon coating, showing good dispersibility, small specific surface area and high tap density. In-situ diffraction analysis showed that expanding the single-phase solid solution region during (de)lithiation can reduce the energy barrier for electron transport, improve the kinetics of the (dis)charge process, and enhance both cycling and rate performance. The initial capacity at 0.1C can reach 155 mAh/g, and the capacity remains at 133.5 mAh/g with a retention rate of 97.1 % after 300 cycles. The synergistic effect of particle nanonization and uniform carbon coating endows the LiMn_xFe_1-xPO₄/C material with excellent electrochemical performance.