Improving the electrochemical performance of LiMn2O4 cathode materials via coating NiO

Abstract Abstrct LiMn2O4 cathode material is considered a highly promising cathode material for lithium-ion batteries due to its low cost and excellent safety performance. However, it suffers from rapid capacity decay, significantly impacting the practical application of LiMn2O4 cathode material. Therefore, enhancing the cycling performance of LiMn2O4 is a focal point in current research. In this study, LiMn2O4 was coated with various amounts of NiO using the chemical precipitation method. Analysis through X-ray diffraction and scanning electron microscopy confirmed LiMn2O4 was coating modification with NiO. Electrode charge-discharge and electrochemical impedance tests revealed that LiMn2O4 coated with the amount of NiO was 1.5% exhibited the optimal cycling performance. Specifically, the initial discharge capacity of LiMn2O4 coated with 1.5% NiO reached 116.8 mAh·g-1 at 0.2C, with a capacity retention of 91.8% after 100 cycles at 2C, in comparison to only 74.9% for pristine LiMn2O4. The enhanced electrochemical performance can be attributed to the oxides impeding the reaction between the electrolyte and the electrodes, thereby enhancing the stability of LiMn2O4 during high-current charging and discharging. Keywords LiMn2O4; NiO; Coating; Electrochemical performance.