Effect of Protic and Aprotic Formamide-Based Organic Electrolytes for Rechargeable Zinc/MnO<inf>2</inf> Battery

Abstract

Zinc ion batteries (ZIBs) are emerging as a promising and cost-effective alternative energy storage system compared to other metal-ion batteries. Aqueous electrolytes have been extensively studied in Zn-ion batteries which has shown issues related to cathode dissolution. In comparison, little has been looked into the use of organic electrolytes in ZIBs. Here, we have studied both protic and aprotic forms of formamide-based organic electrolytes containing Zn trifluoromethanesulfonate and their influence on the Zn solvation chemistry, electrochemistry, and performance of Zn-MnO2 battery. It was observed that protic-based electrolytes gave a much better capacity and stability for the Zn-MnO2 battery. A capacity close to 150 mAh g−1 was obtained with formamide electrolyte at a current density of 0.25 A g−1. For all the other formamide-based electrolytes tested, the capacity was lower. After 100 cycles, an average capacity retention of 72 % was obtained for formamide-based electrolyte. This study shows that protic-based electrolytes might be a suitable option for non-aqueous-based Zn-ion batteries.