Unveiling enhanced electrochemical performance of LiMn1-xCoxPO4/C cathode materials through co-doping strategy

LiMnPO4(LMP), an olivine-type material, is considered as a cathode for lithium-ion battery material, but faces challenges such as the Jahn-Teller effect, poor conductivity, and low ionic conductivity. To overcome these limitations, we explored Co doping as a potential solution. By utilizing a solvothermal method, we successfully synthesized LiMn1-xCoxPO4/C (x is the mass fraction of Co doping in LiMnPO4 sample) materials with a high (200) exposed surface. Our first-principles calculations indicated that Co doping significantly impacts the material's structure and electrochemical performance. Notably, the LiMn0.95Co0.05PO4/C sample demonstrated the highest performance, delivering capacities of 164.7 mAh g−1 at 0.1 C and 97.5 mAh g−1 at 1 C, while maintaining a remarkable 95.4 % capacity retention after 100 cycles at 0.5 C. Furthermore, the preferential growth on the b-c plane results in an enhanced (200) orientation, which exposes more reactive sites and facilitates Li+ migration. This study not only offers a straightforward approach for obtaining high-performance electrode materials but also bridges the gap between theory and experiment, providing a new avenue for understanding cation doping in polyanionic cathode materials.