Silver ion in combination intercalation/deintercalation reaction of aqueous zinc-ion batteries

Rechargeable aqueous zinc-ion batteries (ZIBs) have been gradually attracting attention, because they are inexpensive and abundant; thus, they are favorable choice for energy storage system. Layered vanadium oxides have excellent zinc-ion storage capacity; however, significant challenges, such as poor conductivity and slow zinc-ion intercalation/deintercalation reaction, remain. Herein, we fabricated a material comprising V 2 O 5 and Ag (Ag 0.3 V 2 O 5 , AVO) with a high conductivity and stable structure. Using this strategy, the ZIBs based on the AVO electrode achieved a high capacity of 340 mAh g −1 at 0.10 A g −1 , long-term cyclic stability with over 93.75% retention after 1600 cycles and a nice rate performance (135 mAh g −1 at 2.0 A g −1 ). The nanowire structure was hardly corroded after the reaction. These results indicate that Ag + can become “pillars” for V 2 O 5 , thereby improving the stability of the material. Moreover, Ag + is involved in the reaction of aqueous zinc-ion batteries; thus, the cyclic performance and battery capacity are improved.