A Novel Ultrathin Multiple‐Kinetics‐Enhanced Polymer Electrolyte Editing Enabled Wide‐Temperature Fast‐Charging Solid‐State Zinc Metal Batteries

Abstract The sluggish ion transport kinetics and poor interface compatibility are the major challenges for developing high‐performance solid‐state zinc metal batteries. Here, using the densified polyacrylonitrile/silicon dioxide (PAN‐SiO₂) nanofiber membrane as a unique multifunctional mediator, a novel mediator‐bridged type of ultrathin (28.6 µm) polymer electrolyte that is rationally designed. The PAN/SiO₂ /polyethylene oxide/Zn(OTf)₂(PSPZ) polymer electrolyte is demonstrated to significantly enhance multiple kinetics. In addition to superior mechanical properties, the efficient thermal conductive effect endows it with good high‐temperature structural stability. Interestingly, a unique PAN skeleton‐locking‐anion‐enabled fast ion transport mechanism is uncovered to achieve a high Zn²⁺ migration number (0.71). Moreover, an efficient dendrite‐free Zn deposition guided by a flat dense SEI is demonstrated. In this case, highly reversible Zn metal anodes can be realized in the temperature range extending to −25–80 °C, as well as an impressive 4800 h‐cycle lifespan at the condition of 0.1 mA cm⁻². Beyond that, wide‐temperature, high‐rate, durable PSPZ‐based solid‐state Zn/VO₂ batteries are also successfully verified. This brand‐new concept of multiple‐kinetics‐enhanced polymer electrolyte design can provide a new perspective for developing all‐climate fast‐charging solid‐state batteries, including but not limited to zinc metal batteries.