P-doping boosting electronic properties and ionic kinetics of MnV2O6 for high-performance lithium-ion batteries.

Abstract

Vanadate electrodes are potential candidates for lithium-ion batteries (LIBs) due to their large theoretical specific capacity. However, their practical application suffers from limitations of poor conductivity, inferior ion kinetics, and severe volume changes upon cycling. Herein, a doping strategy is realized to prepare phosphorus (P)-doped MnV2O6 (PMVO) nanosheets to enhance the electrochemical activity and structural stability. On combining experimental and computation results, it is found that the PMVO structure enhances the electrical conductivity, reduces the adsorption energy of lithium ions, increases the structural stability, and facilitates rapid surface diffusion kinetics. As expected, the desirable electrode of PMVO delivers a reversible capacity of 812.7 mA h g-1 at 200 mA g-1 and shows excellent coulombic efficiency, as well as an extraordinary energy density of 472.1 W h kg-1. Meanwhile, an excellent rate performance (from 0.1 to 5.0 and return to 0.1 A g-1; 779.6 to 319.6 and return to 811.9 mA h g-1) could be achieved. The strategy proposed here may aid in further development of doped vanadate electrodes for high-performance LIBs.