Providing high stability to suppress metal dissolution in LiMn0.5Fe0.5PO4 cathode materials by Zn doping

LiMn x Fe 1-x PO 4 (LMFP) is a promising cathode material for Li-ion batteries owing to its higher energy density than that of LiFePO 4 . However, the Jahn-Teller distortion caused by Mn 3+ and oxidation of Fe 2+ leading electrolyte decomposition lowers its cycling performance and structure stability. To address these problems, this study proposes an optimized Zn-doping content to enhance the electrochemical performance of LMFP. Results indicate that doping with 1.0 % Zn (LMFP-Zn 1.0 %) achieves the optimal cycling performance. Especially, LMFP-Zn 1.0 % exhibits 92.6 % capacity retention after 100 cycles at 2C. The HR-TEM and XPS analyses confirm that this level of doping suppresses metal dissolution and structure destruction effectively after cycling at high C-rates, resulted in improving the electrochemical performance and stability of LMFP cathode materials. • LiZn x Mn 0.5 Fe 0.5-x PO 4 cathode materials are synthesized by solvothermal method. • The effect of varying Zn doping content on electrochemical properties is investigated. • 1.0 % Zn doping shows 92.6 % capacity retention after 100 cycles at 2C. • Post-mortem analysis proves that Zn doping successfully suppressed metal dissolution.