Fabricating architected zinc electrodes with unprecedented volumetric capacity in rechargeable alkaline cells

Abstract Recasting zinc electrodes into sponge form factors enables dendrite-free, rechargeable zinc batteries. Prior versions of these electrodes suffer from poor volumetric capacity and insufficient mechanical strength to scale beyond a few square centimeters. Most approaches to fortify zinc electrodes involve adding supportive inactive materials that decrease capacity. In contrast, we boost electrode strength through zinc/zinc-oxide fabrication advances that increase capacity. The resulting electrodes reach a tensile strength of 1 MPa, which now affords large-format scaling of zinc sponges. The tuned architecture achieves a 102% increase in rechargeable volumetric capacity over previously reported electrodes, yielding 928 mAh cmZn–3 in a nickel–zinc battery cycled 115 times with a coulombic efficiency near 100%. These advances in strength, scalability, manufacturability, and rechargeable capacity expand Zn-battery capabilities for a variety of applications including grid storage, personal electronics, and electric vehicles.