Zerui Deng, Xincheng Liang, Xingfa Chen, Yuquan Gou, Anning Wang, Peixin Xie, Qian Liu, Huan Wen, Shibin Yin*

Cite this article: Chin. J. Struct. Chem., 2025, 44(11), 100706. DOI: 10.1016/j.cjsc.2025.100706

Publication date: November 1, 2025

Keywords: Aqueous zinc ion batteries; Electrolyte additive; Zn(002) plane; Hydrogen bond network

ABSTRACT

Aqueous Zinc-Ion Batteries (AZIBs) are promising due to the advantages of metallic zinc, including the high specific capacity (820 mAh g−1), low redox potential (–0.76 V vs. SHE), inherent safety, low cost, and environmental sustainability. Despite these benefits, AZIBs face challenges such as uneven Zn deposition and excessive hydrogen evolution reaction (HER) at the Zn anode, which reduce the battery's coulombic efficiency and cycling life. This study introduces an ammonium formate (AF) additive into a 2.0 M ZnSO4 electrolyte to address these issues. The AF additive promotes a three-dimensional rapid diffusion of Zn2+ on the anode surface and induces the preferential Zn(002) plane deposition, thus inhibiting dendritic growth and enhancing cycling stability. It also disrupts the hydrogen bond network of electrolytes, reducing the number of active H2O molecules and suppressing H2O-induced side reactions. Consequently, the Zn||Zn symmetric cell with the AF additive shows stable cycling over 2100 hours at 5.0 mA cm−2 with an areal capacity of 1.0 mAh cm−2, and maintains stability over 9700 cycles at 30 mA cm−2. When Applied in a Zn||VO2 full cell, it achieves capacity retention of 68.9% after 2000 cycles, demonstrating significant performance improvements in AZIBs.