Backside Coating for Stable Zn Anode with High Utilization Rate.

Stable Zn anodes with high utilization rate are urgently required to promote the specific and volumetric energy densities of Zn-ion batteries for practical applications. Herein, contrary to the widely utilized surface coating on Zn anodes, we show that a zinc foil with a backside coated layer delivers much enhanced cycling stability even under high depth of discharge. The backside coating significantly reduces stress concentration, accelerates heat diffusion and facilitates electron transfer, thus effectively prevents dendrite growth and structural damage at high Zn utilization. As a result, the developed anode can be stably cycled for 334 h at 85.5% Zn utilization, which outperforms bare Zn and previously reported results on surface-coated Zn foils. An NVO-based full cell also shows stable performance with high Zn utilization (69.4%), low negative-positive electrodes ratio (1.44) and high specific/volumetric energy densities (155.8 Wh kg -1 /178 Wh L -1 ), which accelerates the progress toward practical zinc-ion batteries. This article is protected by copyright. All rights reserved.