Metal Oxide Aerogels: A New Horizon for Stabilizing Anodes in Rechargeable Zinc Metal Batteries

摘要

Dendritic deposition and side reactions have been long-standing interfacialchallenges of Zn anode, which have prevented the development of practicalaqueous zinc-based batteries. Herein, an oxygen vacancy-rich CeO_2aerogel (VAG-Ce) interface layer that simultaneously integrates Zn~(2+) selectivity,porosity, and is lightweight is reported as a new strategy to achievedendrite-free and corrosion-free Zn anodes. The well-defined and uniformnanochannels of VAG-Ce can act as ion sieves that redistribute Zn~(2+) at the Znanode surface by regulating Zn~(2+) flux, leading to uniform Zn deposition andsignificantly suppressing dendrite growth. Importantly, the abundant oxygenvacancies exposed on VAG-Ce surface can strongly capture SO_4~(2-), forming anegatively charged layer that can attract Zn~(2+) and accelerate the Zn~(2+) migrationkinetics, while the subsequent repulsion of additional anions can effectivelysuppress the generation of (Zn_4SO_4(OH)_6·xH_2O) byproducts, therebyrealizing very stable Zn anodes. Consequently, VAG-Ce modified Zn anode(VAG-Ce@Zn) enables a long-term lifespan over 4000 h at 4 mA cm~(-2) and arecord-high cycle life of 1200 h is achieved under an ultrahigh 85 Zn utilizationat 8 mA cm~(-2), which enables excellent capacity retention and cyclingperformance of VAG@Zn/MnO_2 cells. This work contributes an innovativedesign concept by introducing oxygen vacancy-rich aerogels and provides anew horizon for stabilizing Zn anode for large-scale energy storage.