Ternary DES Electrolyte Integrates High‐Value Utilization of Spent Zn‐Mn Batteries for Opening up ZnO‐Based Wide Temperature Zn‐Ion Batteries

ABSTRACT Unlocking the recycling and application of spent zinc‐manganese dry batteries (SZMBs) can effectively unleash the potential of urban resources. A zinc‑ion electrolyte strategy is proposed herein, which directly employs recycled ZnO from SZMBs within a ternary deep eutectic solvent (DES) of choline chloride (ChCl), urea, and ethylene glycol (EG). Regulating EG amount renders the ZnO‐based electrolyte suitable for a wide temperature range. Spectroscopic and dynamics simulations reveal that EG weakens the energy barrier for Zn 2+ reduction, achieving reversible Zn 2+ /Zn 0 redox. Simultaneously, the DES adsorbed on the Zn anode induces a solid electrolyte interphase film for guiding preferential zinc deposition along the Zn(100) plane. The ZnO‐based electrolyte enables the Zn||Zn symmetric cell to operate steadily for over 4100 h at 25°C, over 200 h at 60°C, and over 1400 h at –10°C. The Zn||PANI full cell delivers a specific capacity of 220 mA h g −1 at 0.1 A g −1 and maintains a capacity retention of 93.98% after 175 cycles at 0.5 A g −1 . This integrated design concept not only provides a practical value‐added approach for the utilization of zinc from SZMBs, but also offers a feasible strategy for the development of new high‐performance, wide‐temperature zinc‐ion battery electrolytes.