Enhanced high-temperature performances of LiMn2O4 cathode by LiMnPO4 coating

LiMnPO4/LiMn2O4 (LMP/LMO) composite cathodes with LMP coating on the surface of LMO were synthesized by hydrothermal method at 180 °C for 10 h. The crystal structures and microstructures were characterized via power X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), and high-resolution transmission electron microscope (HRTEM). The electrochemical properties were characterized by cyclic voltammetry (CV) measurement and charge–discharge test. LMP/LMO composite cathodes exhibited higher discharge capacity and better cycle stability than the bare LiMn2O4 cathode. Taking both capacity and cycle ability into concern, 15 wt% LiMnPO4 that coated LiMn2O4 possessed the best performances. At 55 °C, it delivered an initial discharge capacity of 120.1 mAh g−1 and retained 97.1 % of the initial capacity after 100 cycles at 1 C rate.