Highly Reversible Zinc Metal Anode in a Dilute Aqueous Electrolyte Enabled by a pH Buffer Additive

作者：Zhang, Wei; Dai, Yuhang; Chen, Ruwei; Xu, Zhenming; Li, Jianwei; Zong, Wei; Li, Huangxu; Li, Zheng; Zhang, Zhenyu; Zhu, Jiexin; Guo, Fei; Gao, Xuan; Du, Zijuan; Chen, Jintao; Wang, Tianlei; He, Guanjie^*; Parkin, Ivan P.^*

来源：Angewandte Chemie - International Edition, 2023, 62(5).

DOI：10.1002/anie.202212695

• Additive
• Aqueous Electrolyte
• Dendrite Growth
• Zinc Anode
• pH Buffer

Aqueous zinc-ion batteries have drawn increasing attention due to the intrinsic safety, cost-effectiveness and high energy density. However, parasitic reactions and non-uniform dendrite growth on the Zn anode side impede their application. Herein, a multifunctional additive, ammonium dihydrogen phosphate (NHP), is introduced to regulate uniform zinc deposition and to suppress side reactions. The results show that the NH4+ tends to be preferably absorbed on the Zn surface to form a "shielding effect" and blocks the direct contact of water with Zn. Moreover, NH4+ and (H2PO4)(-) jointly maintain pH values of the electrode-electrolyte interface. Consequently, the NHP additive enables highly reversible Zn plating/stripping behaviors in Zn//Zn and Zn//Cu cells. Furthermore, the electrochemical performances of Zn//MnO2 full cells and Zn//active carbon (AC) capacitors are improved. This work provides an efficient and general strategy for modifying Zn plating/stripping behaviors and suppressing side reactions in mild aqueous electrolyte.

• 单位
  1; 南京航空航天大学