Conventional self-charging systems are generally complicated and highly reliant on the availability of energy sources. Herein, a chemically self-charging, flexible solid-state zinc ion battery (ssZIB) based on a vanadium dioxide (VO2) cathode and a polyacrylamide-chitin nanofiber (PAM-ChNF) hydrogel electrolyte is developed. With a power density of 139.0 W kg-1, the ssZIBs can deliver a high energy density of 231.9 Wh kg-1. The superior electrochemical performance of the ssZIBs is attributed to the robust tunnel structure of the VO2 cathode and the entangled network of PAM-ChNF electrolyte, which provide efficient pathways for ion diffusion. Impressively, the designed ssZIBs can be chemically self-charged by the redox reaction between the cathode and oxygen in ambient conditions. After oxidation for 6 h in air, the ssZIBs manifest a high discharging capacity of 263.9 mAh g-1 at 0.2 A g-1, showing excellent self-rechargeability. With the assistance of a small amount of acetic acid added to the hydrogel electrolyte, the galvanostatic discharging and chemical self-charging cycles can reach 20. More importantly, such ssZIBs are able to operate well at chemical or/and galvanostatic charging hybrid modes, demonstrating superior reusability. This work brings a new prospect for designing flexible chemically self-charging ssZIBs for portable self-powered systems.
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© 2021 Wiley-VCH GmbH
All Science Journal Classification (ASJC) codes
- Renewable Energy, Sustainability and the Environment
- General Materials Science