VO₂ Nanoflakes as the Cathode Material of Hybrid Magnesium–Lithium-Ion Batteries with High Energy Density

The hybrid magnesium–lithium-ion batteries (MLIBs) combining the dendrite-free deposition of the Mg anode and the fast Li intercalation cathode are better alternatives to Li-ion batteries (LIBs) in large-scale power storage systems. In this article, we reported hybrid MLIBs assembled with the VO 2 cathode, dendrite-free Mg anode, and the Mg–Li dual-salt electrolyte. Satisfactorily, the VO 2 cathode delivered a stable plateau at about 1.75 V, and a high specific discharge capacity of 244.4 mA h g –1 . To the best of our knowledge, the VO 2 cathode displays the highest energy density of 427 Wh kg –1 among reported MLIBs in coin-type batteries. In addition, an excellent rate performance and a wide operating temperature window from 0 to 55 °C have been obtained. The combination of VO 2 cathode, dual-salt electrolyte, and Mg anode would pave the way for the development of high energy density, safe, and low-cost batteries.