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 Zn 2+ striping/plating process. Herein, the novel electrolyte additive (histidine) was introduced into the conventional ZnSO 4 electrolyte. The strong strong cationic specific absorption between the additive molecule and zinc anode regulated the behavior of Zn 2+ deposition and inhibited hydrogen evolution reaction. Significantly, the unique buffer-like amphoteric functional groups on histidine can further alleviate by-product generation 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.