Chemically Self-Charging Aqueous Zinc-Organic Battery.

Zn-organic batteries are attracting extensive attention, but their energy density is limited by the low capacity (<400 mAh g-1) and potential (<1 V vs Zn/Zn2+) of organic cathodes. Herein, we propose a long-life and high-rate Zn-organic battery that includes a poly(1,5-naphthalenediamine) cathode and a Zn anode in an alkaline electrolyte, where the cathode reaction is based on the coordination reaction between K+ and the C═N group (i.e., C═N/C-N-K conversion). Interestingly, we find that the discharged Zn-organic battery can recover to its initial state quickly with the presence of O2, and the theoretical calculation demonstrates that the K-N bond in the discharged cathode can be easily broken by O2 via redox reaction. Accordingly, we design a chemically self-charging aqueous Zn-organic battery. Benefiting from the excellent self-rechargeability, the organic cathode exhibits an accumulated capacity of 16264 mAh g-1, which enables the Zn-organic battery to show a record high energy density of 625.5 Wh kg-1.