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

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. © 2023 Wiley-VCH GmbH.