Robust 3D Zn Sponges Enable High-Power, Energy-Dense Alkaline Batteries

Abstract

We previously demonstrated that a redesign of the form factor for zinc (Zn) anodes to a monolithic, porous 3D-wired sponge sets a new benchmark for rechargeable alkaline Zn batteries. By engineering the solid volume fraction from the benchmarked 20% (Zn20) to 30% (Zn30), we increase the degree of metallic connectivity, boost mechanical integrity, and out-power the first-generation counterpart. Visualizing the internal structure using X-ray computed microtomography (XCMT) confirms increased interconnectivity within the denser Zn30. To highlight the energy and power improvements, we pair the zinc sponges with a silver oxide cathode in prototype Ag–Zn cells and demonstrate superior performance with Zn30 anodes: 50% improvement in zinc-normalized volumetric capacity (up to 1.6 Ah LZn–1) and supercapacitor-like specific power (up to ∼6 kW kgZn–1), all while maintaining rechargeability.