The composite cathode materials consisting of spinel-structure Li1.05Ni0.1Mn1.9O3.98F0.02 and nano-sized solid electrolyte Li–La–Ti–O (LLTO) coating were synthesized by the molten salt method and sol–gel coating process. Our results showed that Ni–F co-doping, recrystallization and LLTO coating can significantly improve the electrochemical performance of spinel LiMn2O4 cathode materials at elevated temperature and large rates. The doping and recrystallization can improve the stability of spinel grain structure and solid electrolyte LLTO coating can effectively suppresses HF-induced Mn2+ dissolution and maintains the structural integrity during cycling. At room temperature and low rates, the doping and recrystallization play dominant roles, at elevated temperature and large rates, the protective role of solid electrolyte coating is prominent.