Self-Assembled LiNi_1/3Co_1/3Mn_1/3O₂ Nanosheet Cathode with High Electrochemical Performance

We have fabricated self-assembled LiNi_1/3Co_1/3Mn_1/3O₂ nanosheets via a facile synthesis method combining coprecipitation with the hydrothermal method. Scanning electron microscopic images show that the self-assembly processes for the LiNi_1/3Co_1/3Mn_1/3O₂ nanosheets depend on the reaction time and temperature. The nanosheet structure is uniform, and the width and thickness of the nanosheets are in the ranges of 0.7-1.5 μm and 10-100 nm, respectively. As a cathode material, the as-synthesized LiNi_1/3Co_1/3Mn_1/3O₂ nanosheets have demonstrated outstanding electrochemical performance. The initial specific capacity was 193 mAh g^-1, and the capacity was maintained at 189 mAh g^-1 after 100 cycles at 0.2 C, and 155 mAh g^-1 at 1 C (after 1000 cycles). The LiNi_1/3Co_1/3Mn_1/3O₂ nanosheets have efficient contact with the electrolyte and short Li⁺ diffusion paths, as well as sufficient void spaces to accommodate large volume variation. The nanosheets are thus beneficial to the diffusion of Li⁺ in the electrode. The enhanced electrical conductance and excellent capacity demonstrate the great potential of LiNi_1/3Co_1/3Mn_1/3O₂ nanosheets for energy storage applications. © 2017 American Chemical Society.