Inhibited voltage decay and enhanced electrochemical performance of the Li-rich layered Li1.2Mn0.54Ni0.13Co0.13O2 cathode material by CeAlOδ surface coating modification

Li-rich layered oxides are attracting attention in lithium-ion batteries due to its extremely high specific capacity, but it still faces fatal voltage decay caused by structure decay. In this paper, we report a newly surface coating of Li-rich layered oxides cathode material by nanoparticles-CeAlO delta through a facile chemical deposition way. The SEM and TEM images indicated the homogeneous and thin CeAlO delta layer on the surface of the Li1.2Mn0.54Ni0.13Co0.13O2. Due to the successful surface coating modification, the as-prepared CeAlO delta-coated Li1.2Mn0.54Ni0.13Co0.13O2 cathode materials exhibited improved specific discharge capacity, rate performance and cycling stability to some extent. Especially, it was noted that the voltage decay of the batteries after electrochemical cycles was greatly inhibited. In detail, the 3 wt% CeAlOd-coated Li1.2Mn0.54Ni0.13Co0.13O2 electrode delivered lower average discharge voltage decay of 368 mV with higher specific discharge capacity of 180.2 mAh g(-1) and capacity retention of 80.59% in comparison with the uncoated sample after 200 cycles at 1 C. The superior electrochemical performance of the CeAlO delta-coated Li1.2Mn0.54Ni0.13Co0.13O2 electrode was attributed to the presence of the stable and thin CeAlO delta layer, which could provide oxygen vacancies for active materials and inhibit the side reaction between electrode and electrolyte at the same time.