Vanadium phosphate as a promising high-voltage magnesium ion (de)-intercalation cathode host†
Abstract
Magnesium batteries (MBs) have been considered as one of the most promising safe and low cost energy storage systems. Herein, vanadium phosphates, prepared by the electrochemical de-lithiation of Li3V2(PO4)3, are investigated as a high-voltage cathode host for Mg2+ (de)-intercalation. The reversible (de)-intercalation of Mg2+ into (from) the host structure of V2(PO4)3 are verified by the comprehensive analysis of the results from the electrochemical tests, synchrotron X-ray diffraction and absorption, and inductively coupled plasma measurements. Its exceptional high average working voltage (∼3.0 V vs. Mg/Mg2+) surpasses other reported values of cathode hosts for MBs.