(Invited) (More) Uniform Control of Oxidative Dissolution, Complexation, and Electrodeposition Using 3D Wiring of Aperiodic Zinc Sponge Anodes in Rechargeable Alkaline Batteries

Abstract

Our team at the U.S. Naval Research Laboratory has solved the chronic impediment of cell-shorting dendritic growth that has thwarted development of rechargeable zinc alkaline batteries—particularly to depths of zinc utilization that can challenge lithium-ion energy density. We do so using architectural design in which zinc particles are fused into a porous, highly conductive, and 3D-wired “sponge” monolith, as verified by X-ray tomography. This architectural configuration controls the behavior of the zinc anode during cycling such that an inner core of metallic zinc persists—even when discharging >90% of the zinc present—thus permitting recovery of >95% of that deeply discharged metal upon electroplating recharge. An additional key to our ability to oxidize and then re-plate the zinc lies in retaining at the inner and outer surfaces of the sponge the secondary discharge product, namely the zinc oxide that precipitates out of solution when zincate ions (the primary discharge product) dehydrate upon reaching supersaturation concentrations. The more uniform reactivity of zinc sponge anodes will be demonstrated for rechargeable Ni–Zn, Ag–Zn, and Zn–air cells.