Prelithiation of Alpha Phase Nanosheet-Type VOPO4·2H2O Anode for Lithium-Ion Batteries

Abstract

Owing to the rising concern of global warming, lithium-ion batteries have gained immense attention over the past few years for the development of highly efficient electrochemical energy conversion and storage systems. In this study, alpha-phase VOPO4·2H2O with nanosheet morphology was prepared via a facile hydrothermal method for application in high-performance lithium-ion batteries. The X-ray diffraction and scanning electron microscopy (SEM) analyses indicated that the obtained sample had an alpha-2 (αII) phase, and the nanosheet morphology of the sample was confirmed using SEM. The lithium-ion battery with VOPO4·2H2O as the anode exhibited excellent long-term cycle life and a high capacity of 256.7 mAh g−1 at room temperature. Prelithiation effectively improved the specific capacity of pristine VOPO4·2H2O. The underlying electrochemical mechanisms were investigated by carrying out AC impedance, rate capability, and other instrumental analyses.