Surface modification of LiNi0.5Mn1.5O4 by LiCoO2/Co3O4 composite for lithium-ion batteries

A novel and simple liquid-phase process has been first put forward to surface modify spinel LiNi0.5Mn1.5O4 with LiCoO2/Co3O4 composite. The results show that the LiCoO2/Co3O4 composite has been successfully coated on the surface of LiNi0.5Mn1.5O4 particles, and the electrochemical performance is improved remarkably. Compared with the pure LiNi0.5Mn1.5O4, the initial discharge capacities of the modified LiNi0.5Mn1.5O4 improve 9.1, 9.6, 11.6 mA h g−1 at rates of 1 C, 3 C and 5 C, respectively. It also exhibits excellent cycle performance, retaining 97.8% of the maximal attainable discharge capacity (110.1 mA h g−1) after 200 cycles at the rate of 5 C. These results demonstrate that the surface modification with LiCoO2/Co3O4 composite could be a feasible way to improve the electrochemical performance of spinel LiNi0.5Mn1.5O4 for lithium-ion batteries.

► The spinel LiNi0.5Mn1.5O4 has been surface-modified with LiCoO2/Co3O4 composite for the first time.
► LiCoO2/Co3O4-modified LiNi0.5Mn1.5O4 is synthesized via a novel and simple liquid-phase process.
► The LiCoO2/Co3O4-modified LiNi0.5Mn1.5O4 exhibits satisfactory rate capability.
► The LiCoO2/Co3O4-modified LiNi0.5Mn1.5O4 shows excellent cycle stability, retaining 97.8% of the maximal attainable discharge capacity after 200 cycles at 5 C.