Highly Reversible Zinc Metal Anode in a Dilute Aqueous Electrolyte Enabled by a pH Buffer Additive. (7th December 2022)

• Record Type: Journal Article
• Authors: 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.
• Is Part Of: Angewandte Chemie. Volume 135:Number 5(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-12-07
• Subjects: Additive -- Aqueous Electrolyte -- Dendrite Growth -- Zinc Anode -- pH Buffer; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.202212695
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: 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 (H2 PO4 ) − 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. Abstract : A multifunctional additive, NH4 H2 PO4, is proposed to regulate uniform zinc deposition and to suppress side reactions in a dilute aqueous electrolyte. Due to the pH buffer chemistry of NH4 + and (H2 PO4 ) − and the "shielding effect" of NH4 +, promoted Coulombic efficiencies and lifespans of Zn based symmetric/asymmetric cells can be achieved.