High-capacity zinc-ion storage in an open-tunnel oxide for aqueous and nonaqueous Zn-ion batteries

Abstract

Zinc-based rechargeable batteries with two-electron transfer are promising for large-scale energy storage systems. However, the use of zinc metal in practical cells has been challenging due to the formation of Zn dendrites, which could lead to unreliable electrochemical performance and safety issues. To overcome this problem, we present a high-capacity zinc-insertion-compound anode Zn_xMo_2.5+yVO_9+z by inserting Zn²⁺ into an open-tunnel oxide host with a novel chemical Zn-insertion technique. The ultrafast chemical Zn-insertion is performed in ambient atmosphere with diethylene glycol (DEG) and zinc acetate (Zn(CH₃COO)₂) within 30 min. To the best of our knowledge, this is the first Zn-containing insertion anode ever reported. Zn_xMo_2.5+yVO_9+z can be used as an anode in both aqueous and non-aqueous electrolytes for Zn-based batteries, with a capacity as high as 220 mA h g⁻¹.