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

Abstract

Dendritic deposition and side reactions have been long-standing interfacial challenges of Zn anode, which have prevented the development of practical aqueous zinc-based batteries. Herein, an oxygen vacancy-rich CeO2 aerogel (VAG-Ce) interface layer that simultaneously integrates Zn2+ selectivity, porosity, and is lightweight is reported as a new strategy to achieve dendrite-free and corrosion-free Zn anodes. The well-defined and uniform nanochannels of VAG-Ce can act as ion sieves that redistribute Zn2+ at the Zn anode surface by regulating Zn2+ flux, leading to uniform Zn deposition and significantly suppressing dendrite growth. Importantly, the abundant oxygen vacancies exposed on VAG-Ce surface can strongly capture SO42−, forming a negatively charged layer that can attract Zn2+ and accelerate the Zn2+ migration kinetics, while the subsequent repulsion of additional anions can effectively suppress the generation of (Zn4SO4(OH)6·xH2O) byproducts, thereby realizing 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 a record-high cycle life of 1200 h is achieved under an ultrahigh 85% Zn utilization at 8 mA cm−2, which enables excellent capacity retention and cycling performance of VAG@Zn/MnO2 cells. This work contributes an innovative design concept by introducing oxygen vacancy-rich aerogels and provides a new horizon for stabilizing Zn anode for large-scale energy storage.