High energy density electrode materials for rechargeable magnesium batteries

Rechargeable magnesium batteries are drawing increasing interest as a future alternative to lithium-based batteries due to their high energy density, low environmental impact and low cost. However, the sluggish diffusion of Mg²⁺ and incompatibility between magnesium anode and traditional electrolytes are hindering the realization of practical magnesium batteries. In this report, we present the preparation, characterization and magnesium electrochemistry of a cathode material, MgxV2O5, and a novel bismuth based composite anode material, Bi-CNT. The MgxV2O5 cathode material was developed via sol-gel route, and it is shown here that the material is of high capacity and favorable for Mg²⁺ diffusion. The Bi-CNT composite electrode was prepared by electrodeposition, and it shows quasi-reversible electrochemistry and compatibility with non-corrosive electrolyte. The deposition of Bi via a cyclic voltammetry technique was systematically studied, establishing a paradigm for future development of electrodeposited-Bi electrodes.