Enhanced high-rate cycling performance of LiMn${}_2$O${}_4$ cathode materials by coating nano-TiO${}_2$

LiMn${}_2$O${}_4$ has the advantages of low cost and no pollution, and is widely regarded as a large-scale lithium battery cathode material. However, the capacity decays rapidly, which seriously affects the application of LiMn${}_2$O${}_4$ cathode materials. Therefore, improving the cycling performance of LiMn${}_2$O${}_4$ is the focus of current research. LiMn${}_2$O${}_4$ precursors were prepared by chemical precipitation and the precursors were coated to prepare LiMn${}_2$O${}_4$/TiO${}_2$ composites. X-ray diffraction and scanning electron microscopy showed that LiMn${}_2$O${}_4$ had been successfully combined with TiO${}_2$. Electrode charge–discharge and electrochemical impedance tests showed that LiMn${}_2$O${}_4$/TiO${}_2$ had the best cycle performance at high rates. The initial discharge capacities of LiMn${}_2$O${}_4$/TiO${}_2$ reached 106.4 mAh·g${}^{-1}$ at 0.2 C. After 100 cycles, the 2 C capacity retention rates was 76.3 %, compared to only 66.5 % for pristine LiMn${}_2$O${}_4$. The improved electrochemical performance was attributed to the nanoscale oxides hindering the reaction between the electrolyte and the electrode, which effectively improved the stability of the material during high current charge and discharge.