Stabilization of Zn anodes via a butanediol additive

Aqueous zinc ion batteries have shown great prospects in large-scale energy storage. However, severe dendritic growth and unrestrained side reactions have limited the high speed development of aqueous zinc ion batteries due to the instability of zinc anodes in aqueous electrolytes. Here, butanediol additive is introduced into ZnSO 4 electrolyte to improve the stability of zinc anode by adjusting the solvation structure of zinc hydration layer. This leads to a long cycle life (1000 h), which is more than 8 times greater than that of ZnSO 4 basic electrolyte, for Zn||Zn symmetric batteries utilizing 2 M ZnSO 4 and 15% butanediol additions. The butanediol additive can also achieve high Coulombic efficiency with an average value of 99.58% in Zn||Cu batteries. The Zn||V 2 O 5 full battery exhibits a maximum capacity of 205 mAh g −1 , and even after 1000 cycles at 1.0 A g −1 , it still has a high reversible specific capacity of 177 mAh g −1 .