LiMn2O4 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 LiMn2O4 cathode materials. Therefore, improving the cycling performance of LiMn2O4 is the focus of current research. LiMn2O4 precursors were prepared by chemical precipitation and the precursors were coated to prepare LiMn2O4/TiO2 composites. X-ray diffraction and scanning electron microscopy showed that LiMn2O4 had been successfully combined with TiO2. Electrode charge–discharge and electrochemical impedance tests showed that LiMn2O4/TiO2 had the best cycle performance at high rates. The initial discharge capacities of LiMn2O4/TiO2 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 LiMn2O4. 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.

The application of lithium iron phosphate (LiFePO4) was still hindered by its poor high rate performance. Surface coating had proven to be an effective strategy to solve these problems. However, the previous surface coating method made the synthesis process more complicated. In this work, a simple organic salt decomposition method was developed to prepare LiFePO4@Ni cathode material (LFP@Ni). Scanning electron microscope (SEM), X-ray diffractometer (XRD) energy disperse spectroscopy (EDS) confirmed that a uniform nickel-coated composite structure had been successfully constructed without changing the crystal structure. The charge and discharge test showed that after 200 cycles at 5C, LFP@Ni maintained a discharge specific capacity of 65.02% and the exchange current density was 1.3 times that of LFP. Compared with LFP and LFP-Ni, the composite cathode LFP@Ni had better cycle capacity. This improvement was attributed to the good conductivity of nickel, which can quickly conduct electrons in the LFP cathode material, thereby improving the dynamic performance of the LFP cathode material.