Vanadyl Ethylene Glycolate for Aqueous Zinc-Ion Batteries with High Rate Capability and Ultralong Cycling Stability

Abstract

Aqueous zinc-ion batteries (ZIBs) have shown great potential for large scale energy storage applications for its high energy density, low cost and good safety. Among the various ZIB cathode candidates, vanadium‐based oxides have attracted intensive attentions due its high theoretical capacity. However, their development is still hindered by the low electronic conductivity, sluggish Zn-ion diffusion, slow electrochemical kinetics and poor structural stability. Herein, we developed a high performance vanadyl ethylene glycolate (VEG) for Zn2+ ions storage by modifying the vanadium oxide with organic ligands. As a result, the obtained Zn/VEG batteries exhibit a high Zn ion storage capability, a long cycling stability as well as an impressive rate performance. In addition, the intercalation pseudocapacitance behavior, the ultrafast Zn-ion diffusion kinetics as well as the high electronic conductivity of VEG are confirmed via various electrochemical analyses.