Mitigating zinc dendrites and side reactions through the incorporation of ethylenediamine additive for zinc metal anode

Abstract

Aqueous zinc-ion battery (ZIBs) has garnered considerable attention for its economic, safe, and high-energy-density characteristics. However, impediments, such as undesirable side reactions and uneven dendrites, have restrained its progress. To overcome these challenges, diverse strategies have been proposed, with electrolyte modification emerging as a preferred approach due to its simplicity and practicality. Here, we introduced ethylenediamine (EDA) as an additive into ZnSO4 solution. Through a combination of theoretical calculations and experimental validation, we have demonstrated that EDA plays a pivotal role in reducing the free active H2O by modifying the solvation structure of Zn2+, thereby enhancing the stability of the zinc anode. Upon the incorporation of EDA into the ZnSO4 electrolyte, the symmetrical battery assembled showcased remarkable cycling stability, surpassing 1500 h at 1 mA cm−2 and 1 mAh cm−2. Notably, the coulombic efficiency and durability of Zn/Ti asymmetric batteries under identical conditions were significantly improved. Furthermore, the positive impact of EDA extended to Zn/NH4V4O10 full batteries assembled using the modified electrolyte, providing robust evidence of the practical efficacy of EDA additive. This study not only highlights the transformative potential of EDA in enhancing the stability and performance of ZIBs but also reinforces its practicality for advanced energy storage applications.