LiMnxFe1-xPO4 (LMFP) is a promising olivine cathode material successor to LiFePO4, offering a higher operating voltage platform for enhanced energy density. However, its commercial application is hindered by inherent poor kinetics. Herein, a dual-site doping strategy involving Na+ and Co2+ is proposed to synergistically enhance the ionic and electronic conductivity of LMFP. The codoped LMFP-Na-Co cathode delivers a specific capacity of 135.8 mAh/g at 1 C and exhibits outstanding cycling stability with 92.5% capacity retention after 200 cycles. Remarkably, it also maintains 90.2% capacity retention after 300 cycles even at 0 °C. Theoretical calculations reveal that Na+ doping expands the one-dimensional lithium-ion diffusion channels, while Co2+ doping elevates the intrinsic electronic conductivity and suppresses the Jahn-Teller distortion associated with Mn3+, collectively lowering the Li+ diffusion barrier and improving structural stability. This work demonstrates that Na+-Co2+ dual-site doping is a highly promising strategy for developing high-performance LiMnxFe1-xPO4 cathodes.
Han et al. (Sat,) studied this question.