An irreversible electrolyte anion-doping strategy toward a superior aqueous Zn-organic battery

Redox-active organic compounds with accessible redox states and structural diversity are essentially important as promising electrode materials for rechargeable batteries. Herein, we propose a new bipolar redox chemistry that involves anion delocalization and cation localization in a ladder-like polymer ((C₆S₂O₂)_n)-based aqueous Zn-battery. Notably, a unique irreversible electrolyte anion-doping followed by a reversible cation insertion is revealed in (C₆S₂O₂)_n during the operation of the battery, which works excellent regardless of either charge or discharge is applied first. Due to the in-situ formation of the S⋅⋅⋅S intermolecular interaction, the stabilized battery delivers a fast-charge ability (in 30.6 s) and an ultra-stable cycle-life (>6000 cycles). The combination results of CV, ex-situ FTIR, EDS elemental mapping and DFT calculations are discussed to confirm the proposed mechanism. This novel redox chemistry provides an effective strategy to design highly stable and long-cycle-life aqueous batteries.