In situ growth of Co 3 O 4 coating layer derived from MOFs on LiNi 0.8 Co 0.15 Al 0.05 O 2 cathode materials

LiNi0.8Co0.15Al0.05O2 (NCA) has become one of the research focuses due to its advantages including low cost and high reversible capacity. However, many drawbacks such as the dissolution of the cation into the electrolyte caused by hydrofluoric acid severely limited its electrochemical performance. In this study, Co3O4 derived from metal-organic frameworks (MOFs) is coated on the surface of commercial NCA utilizing in situ growth followed by annealing. The structure and morphology of the samples are characterized by X-ray diffraction, scanning electron microscope, and transmission electron microscope. NCA@Co3O4 delivers a remarkable capacity retention of 73.7% and 84.4% at 1 C and 2 C after 100 cycles at each rate, respectively. Meanwhile, the rate performance of NCA@Co3O4 is significantly improved. The inhibition of the side reaction between cathode materials and electrolyte, and the reduced charge-transfer resistance that brought by Co3O4 coating layer are the main reasons for the excellent electrochemical performance.