Mitigating Zn Dendrite Growth and Enhancing the Utilization of Zn Electrode in Aqueous Zn‐Ion Batteries
Yang Gao, Mingshan Wang, Yuanwei Chu, Xinpeng Li, Xinpeng Li, Jingcheng Li, Junchen Chen, Zhiyuan Ma, Bingshu Guo, Bo Yu, Yong Pan, Yun Huang, Guozhong Cao, Xing Li, Xing Li
Abstract
Abstract In spite of extensive research and appreciable progress, in aqueous zinc‐ion batteries, Zn metal anode is struggling with low Zn utility and poor cycling stability. In this study, a 3D “electrochemical welding” composite electrode is designed by introduction of ZnO/C nanofibers film to copper foils as an anode according to pre‐electrodeposition active Zn (Zn@ZnO/C‐Cu). The flow of Zn 2+ through carbon fiber layer is regulated by zincophilic ZnO, promoting homogeneous diffusion of Zn 2+ to Cu foil. In subsequent Zn deposition/stripping processes, the hydrophobicity of ZnO/C fiber layer reduces water at the interface of Zn@ZnO/C‐Cu and results in uniform electric field significant suppressing growth of Zn dendritic and side reactions. Thus, pre‐electrodeposition active Zn electrochemical welds ZnO/C nanofibers and Cu foil collectively provide stable charge/electron transfer and stripping/plating of Zn with low polarization and excellent cycling performance. The assembled symmetrical batteries exhibit stable cycling performance for over 470 h under 20% utilization of Zn at 5 mA cm −2 , and an average coulombic efficiency of 99.9% at low negative/positive capacity ratio (N/P = 1) after 1000 cycles in the Zn@ZnO/C‐Cu||Na 2 V 6 O 16 ·1.5H 2 O full cell.