Effect of glycine electrolyte additive on the electrochemical performance of aqueous zinc-ion batteries

Aqueous zinc-ion batteries (AZIBs) using the Zn metal anode have been considered one of the next generation commercial batteries with high security, robust capacity, and low price. However, side reactions, Zn dendrites, and limited lifespan still constrain their practical applications. Herein, the electrolyte additive (glyeine, Gly) was introduced into the conventional ZnSO4, electrolyte (denoted as ZnSO4-Gly). The abundant polar groups (-COOH and -NH2) on the Gly can regulate the solvation structure of Zn2+ and thus redistribute Zn2+ deposition to avoid dendrites and side reactions. As a result, the excellent cycle life (3 000 h, at 1 mA center dot cm(-2) and 1 mA center dot cm(-2)) of the Zn vertical bar vertical bar Zn symmetric cell was realized in typical ZnSO4 electrolytes with only 50 mmol center dot L-1 of Cly additive, overwhelmingly larger than bare ZnSO4 (300 h). The Zn vertical bar vertical bar MnO2, battery with ZnSO4-Gly electrolyte displayed much better than the additive-free device in terms of specific capacity and capacity relent ion.