An environmentally adaptive quasi-solid-state zinc-ion battery based on magnesium vanadate hydrate with commercial-level mass loading and anti-freezing gel electrolyte

摘要

Aqueous zinc-ion batteries (AZIBs) are promising due to their intrinsic safety and low cost. However, the unsatisfactory cathode materials with low mass loading (<3 mg cm(-2)) and high freezing point of aqueous electrolytes severely limit the application prospects of AZIBs. Herein, Mg0.19V2O5 center dot 0.99H(2)O (delta-MgVO) with a large interlayer spacing of 13.4 angstrom is synthesized through a facile pre-intercalation strategy, and is used to construct a cathode with a commercial-level mass loading of 10 mg cm(-2). At such a high mass loading, the delta-MgVO shows reversible charge storage behavior, high Zn2+ ion diffusion coefficients, and fast electrochemical kinetics. Moreover, a quasi-solid-state battery is assembled by combining the delta-MgVO cathode with polyvinyl alcohol/glycerol gel electrolyte, which shows high ionic conductivity in a wide temperature range (e.g., 10.7 mS cm(-1) at -30 degrees C) and excellent compatibility with a Zn foil anode. Thanks to that, the quasi-solid-state battery exhibits great performances from -30 to 60 degrees C. Remarkably, at a rather low temperature of -30 degrees C, an admirable energy density of 48.14 mW h cm(-3) (1940 mu W h cm(-2)) can be achieved at 17.83 mW cm(-3) (0.72 mW cm(-2)). Overall, this work opens new opportunities for developing environmentally adaptive aqueous energy storage devices towards practical applications.