Lattice modulation improving surface passivation of LiMnPO4 for stable cycling at high temperatures

The undesirable capacity degradation of LiMnPO₄ upon cycling at high temperatures is a challenge to its practical application. Herein, a lattice doping strategy is adopted to improve the high-temperature cycling stability of LiMnPO₄, and the comparative study reveals that Al³⁺ doping into LiMnPO₄ in a form of Li_0.98Al_0.02MnPO₄ is highly beneficial to the cycling performance of LiMnPO₄ and the capacity retention can be significantly improved from 67.4 % to 93.4 % after 100 cycles at 1C at 60 °C, because Al³⁺ doping can effectively reduce passivation products deposition on the cathode and manganese dissolution in the electrolyte, which thus improve the cathode/electrolyte interface and stabilize the structure of LiMnPO₄ at high temperatures.