Carbon Supported MoO 2 Spheres Boosting Ultra-Stable Lithium Storage with High Volumetric Density

[摘要] As important ingredients in lithium-ion battery, the Coulombic efficiency and power density greatly impact the electrochemical performances. Although recent literatures have reported nano-porous materials to enhance the specific capacities, intrinsic drawbacks such as poor initial Coulombic efficiency and low volumetric capacity could not be avoided. Herein, we propose a strategy to prepare carbon supported MoO 2 spheres used for lithium-ion battery with high volumetric capacity density. A high initial Coulombic efficiency of 76.5% is obtained due to limited solid electrolyte interface film formed on the exposed surface. Meantime, the sample with an optimal carbon content and a proper structural strength reveals a higher reversible capacity of 956 mA h g −1 than the theoretical capacity of crystalline MoO 2 (838 mA h g −1 ) and a high capacity retention ratio of 96.4% after 100 cycles at 0.5 A g −1 . And an effective compaction capacity density (under 5 MPa) of 670 mA h cm −3 of the spheres proves its potential value in practical applications.

[关键词] high volumetric density;lithium-ion battery;MoO2 spheres;optimal carbon content