Research on LiNixMn2-xO4 surface modification of LiCoO2 as cathode materials for Li-ion batteries

LiCoO2 was coated with a thin layer of LiNixMn2-xO4 on its surface to improve its structural stability as cathode materials of lithium ion batteries during cycling. XRD, SEM and electrochemical tests were performed to investigate the surface morphology, structure and electrochemical properties of the LiNixMn2-xO4-coated LiCoO2. It is found that the surface modification has improved the cycle stability of the material significantly. The results show that LiCoO2 coated with a small amount (35%) of LiNixMn2-xO4 exhibits good charge-discharge properties, and retains its initial reversible capacity after 69 cycles. The layer of LiNixMn2-xO4 prevents the LiCoO2 from getting in touch with electrolyte directly, thus reducing capacity loss, and greatly increasing its plateau efficiency.