In situ construction of a continuous ionic conductive coating for a high-performance Li3VO4 anode

Abstract

Li₃VO₄ (LVO) has been widely considered as a promising new insertion-type anode material for lithium-ion batteries. However, the surface instability of LVO nanoparticles leads to a sharp decline in the first coulombic efficiency and cycle capacity. In this work, an ionic interface nanolayer of 5–10 nm is effectively coated on the LVO nanoparticle surface by an in situ liquid chemical reaction. The tightly wrapped nanolayer prevents the repeated growth of the SEI, and direct contact between LVO particles and the electrolyte, thus stabilizing the interface layer. The nanolayer with high conductivity for ionic transportation facilitates the delivery of higher capacity from LVO. Compared with the uncoated counterpart, the coated LVO exhibits an increased first coulombic efficiency from 75.7% to 82.3% and a higher reversible capacity from 159 mA h g⁻¹ to 283 mA h g⁻¹. The reversible capacity can be maintained at 238 mA h g⁻¹ after 500 cycles at 0.25 C (98.75 mA g⁻¹), indicating that the coating nanolayer can effectively improve the electronic performance of LVO.