Gao Yang, Wang Mingshan, Chu Yuanwei, Li Xinpeng, Li Jingcheng, Chen Junchen, Ma Zhiyuan, Guo Bingshu, Yu Bo, Pan Yong, Huang Yun, Cao Guozhong, Li Xing
School of New Energy and Materials, Southwest Petroleum University, Chengdu, 610500, China.
Energy Storage Research Institute, Southwest Petroleum University, Chengdu, 610500, China.
Small. 2024 Dec;20(52):e2405139. doi: 10.1002/smll.202405139. Epub 2024 Aug 12.
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 through carbon fiber layer is regulated by zincophilic ZnO, promoting homogeneous diffusion of Zn 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, 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||NaVO·1.5HO full cell.
尽管进行了广泛的研究并取得了显著进展，但在水系锌离子电池中，锌金属负极仍存在锌利用率低和循环稳定性差的问题。在本研究中，通过将ZnO/C纳米纤维膜引入铜箔作为阳极，根据预电沉积活性锌（Zn@ZnO/C-Cu）设计了一种三维“电化学焊接”复合电极。亲锌的ZnO调节锌通过碳纤维层的流动，促进锌向铜箔的均匀扩散。在随后的锌沉积/剥离过程中，ZnO/C纤维层的疏水性减少了Zn@ZnO/C-Cu界面处的水，并导致均匀电场显著抑制锌枝晶的生长和副反应。因此，预电沉积活性锌将ZnO/C纳米纤维和铜箔进行电化学焊接，共同提供稳定的电荷/电子转移以及低极化和优异循环性能的锌剥离/电镀。组装的对称电池在5 mA cm下锌利用率为20%时，可稳定循环超过470小时，在Zn@ZnO/C-Cu||NaVO·1.5HO全电池中1000次循环后，在低负/正容量比（N/P = 1）下平均库仑效率为99.9%。
