Dendrite-free zinc anode enabled by Buffer-like additive via strong cationic specific absorption

Metallic zinc-based anodes suffer low reversibility from dendrite growth, hydrogen evolution reaction, and by-product generation during the Zn2+ striping/plating process. Herein, the novel electrolyte additive (histidine) was introduced into the conventional ZnSO4 electrolyte. The strong cationic specific absorption between the additive molecule and zinc anode regulated the behavior of Zn2+ deposition and inhibited hydrogen evolution reaction. Significantly, histidine's unique buffer-like functional groups can further alleviate by-product gener-ation by stabilizing electrolyte interphase pH value. With such an electrolyte additive, Zn||Zn symmetric cell can run for more than 3000 h under the current density of 2 mA cm-2. When zinc anodes were coupled with an activated carbon cathode with a mass loading of 8 mg cm-2, the powering device showed high reversibility. This strategy can give insight into developing zinc anode with high stability.