Modification of LiCo1/3Ni1/3Mn1/3O2 cathode material by CeO2-coating

LiCo1/3Ni1/3Mn1/3O2 was coated by a layer of 1.0 wt% CeO2 via sol-gel method. The bared and coated LiMn1/3Co1/3Ni1/3O2 was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), cyclic voltammogram (CV) and galvanotactic charge-discharge test. The results show that the coating layer has no effect on the crystal structure, only coating on the surface; the 1.0 wt% CeO2-coated LiCo1/3Ni1/3Mn1/3O2 exhibits better discharge capacity and cycling performance than the bared LiCo1/3Ni1/3Mn1/3O2. The discharge capacity of 1.0 wt% CeO2-coated cathode is 182.5 mAh·g−1 at a current density of 20 mA·g−1, in contrast to 165.8 mAh·g−1of the bared sample. The discharge capacity retention of 1.0 wt% CeO2-coated sample after 12 cycles reaches 93.2%, in comparison with 86.6% of the bared sample. CV results show that the CeO2 coating could suppress phase transitions and prevent the surface of cathode material from direct contact with the electrolyte, thus enhance the electrochemical performance of the coated material.