Secondary zinc batteries represent a low-cost,environmentally friendly,and highly safe energy storage technology.However,the insufficient compatibility of zinc-metal anodes with traditional aqueous electrolytes and the growth of zinc dendrites have long posed challenges to their energy density and operational lifespan.Developing solid-state secondary zinc batteries presents a practical pathway to address this bottleneck.However,the high-charge density of divalent zinc ions renders solid-state zinc-ion conduction in conventional ceramic and polymer electrolytes at room temperature exceedingly challenging.In this study,we leveraged zinc trifluoromethyl sulfonate[Zn(TFO)2]with an intrinsic layered crystal structure as the primary ionic salt framework.We reshaped the coordination environment of zinc ions by incorporating succinonitrile(SN),a bidentate,weakly coordinating ligand recognized for its soft base properties.We designed a new class of crystalline coordination compounds for zinc-ion solid electrolytes[Zn(TFO)2(SN)n].The co-coordination structure of the cyano group(—CN)and the trifluoromethyl anion(TFO-)significantly reduce the electrostatic constraint of the anion framework to zinc ions,leading to three orders of magnitude improvement in the room-temperature ion conductivity(from 1.1×10-9 S/cm for Zn(TFO)2 to approximately 1.8×10-6 S/cm).This solid electrolyte can support long-term zinc-plating/stripping cycles with low polarization voltages(0.08 V,0.05 mA/cm2)and the reversible charging and discharging of a solid zinc-air battery at room temperature.
维普
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