Li Wanting, Li Liansheng, Fu Xiangxiang, Hu Yangming, Deng Yuanfu
Guangdong Provincial Key Laboratory of Fuel Cell Technology, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, Guangdong, 510640, P. R. China.
Key Laboratory of Rare Earths, Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou, Jiangxi, 341000, P. R. China.
Small. 2025 Mar;21(11):e2411915. doi: 10.1002/smll.202411915. Epub 2025 Feb 14.
The rampant "top-growth" dendrites, hydrogen evolution reaction (HER), and zinc (Zn) self-corrosion severely impede the further development of rechargeable aqueous zinc ion batteries. To address these challenges, a novel double-layer gradient coating consisting of a zincophilic Sn inner layer and an organic polymer outer layer (OSA/PAM@Sn) is constructed on the surface of the Zn anode. The organic outer layer, composed of cross-linked oxidized sodium alginate and polyacrylamide (OSA/PAM), not only serves as a physical barrier to isolate active water but also accelerates Zn diffusion by facilitating the desolvation process of [Zn(HO)] due to its plentiful polar functional groups, thereby effectively suppressing the detrimental HER and Zn self-corrosion. Simultaneously, the loose Sn inner layer can offer abundant nucleation sites to induce uniform "bottom-to-top" Zn deposition with low overpotential. Benefiting from the synergistic effect of the designed double-layer gradient coating, the OSA/PAM@Sn-Zn anode exhibits remarkable reversibility, with lifespans of over 5000 and 1200 h at 1 mA cm-1 mAh cm and 5 mA cm-5 mAh cm in symmetric cells, respectively. Additionally, the MnO||OSA/PAM@Sn-Zn full battery also displays an improved rate performance and cycle stability. This work emphasizes the importance of synergistic effects in interface design to achieve side reaction-free and dendrite-free Zn anodes.
猖獗的“顶端生长”枝晶、析氢反应（HER）和锌（Zn）自腐蚀严重阻碍了可充电水系锌离子电池的进一步发展。为应对这些挑战，在锌阳极表面构建了一种由亲锌Sn内层和有机聚合物外层组成的新型双层梯度涂层（OSA/PAM@Sn）。由交联氧化海藻酸钠和聚丙烯酰胺（OSA/PAM）组成的有机外层不仅作为物理屏障隔离活性水，还因其丰富的极性官能团促进[Zn(HO)]的去溶剂化过程而加速锌扩散，从而有效抑制有害的析氢反应和锌自腐蚀。同时，疏松的Sn内层可提供丰富的成核位点，以低过电位诱导均匀的“自下而上”锌沉积。受益于设计的双层梯度涂层的协同效应，OSA/PAM@Sn-Zn阳极表现出显著的可逆性，在对称电池中，在1 mA cm-1 mAh cm和5 mA cm-5 mAh cm下的寿命分别超过5000小时和1200小时。此外，MnO||OSA/PAM@Sn-Zn全电池也显示出改善的倍率性能和循环稳定性。这项工作强调了协同效应在界面设计中实现无副反应和无枝晶锌阳极的重要性。
