Achieving high performance in aqueous iron-ion batteries using tunnel-like VO2 as a cathode material

The research on aqueous iron-ion batteries (AIIBs) is still in its early stages and highly limited by the lack of suitable cathode materials. In this study, we propose using tunnel-like VO2 as a cathode material, which delivers a high capacity of 198 mA h g(-1) at 0.2 A g(-1). Besides, the AIIB exhibits appreciable cycling performance, retaining 78.9% of its initial capacity after 200 cycles. The unique structure of VO2 and the multiple valence states of vanadium in VO2 enable the reversible storage of Fe2+ during cycling. This work presents a new choice for the cathode and considerable development prospects in AIIBs.

Automated summary

The research on aqueous iron-ion batteries (AIIBs) is limited by the lack of suitable cathode materials. In this study, tunnel-like VO2 is proposed as a cathode material, delivering a high capacity of 198 mA h g(-1) at 0.2 A g(-1). The AIIB shows good cycling performance, retaining 78.9% of its initial capacity after 200 cycles. The unique structure of VO2 and the multiple valence states of vanadium enable the reversible storage of Fe2+ during cycling. This work presents a new choice for the cathode and has considerable development prospects in AIIBs.