Affiliation:
1. School of New Energy and Materials Southwest Petroleum University Chengdu 610500 China
2. Energy Storage Research Institute Southwest Petroleum University Chengdu 610500 China
3. Department of Materials Science and Engineering University of Washington Seattle WA 98195 USA
Abstract
AbstractIn 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 Zn2+ through carbon fiber layer is regulated by zincophilic ZnO, promoting homogeneous diffusion of Zn2+ 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||Na2V6O16·1.5H2O full cell.
Funder
National Natural Science Foundation of China
Science and Technology Department of Sichuan Province