Constructing Dynamic Cross‐Linking Networks as Durable Bifunctional Coating for Highly Stable Zinc Anodes

• Published in: Chemistry : a European journal 2024-08, Vol.30 (43), p.e202401693-n/a
• Main Authors: Qiao, Liteng, Zhang, Pengfei, Yu, Yuanze, Jia, Xu, Song, Hongjiang, Zhong, Shengkui, Liu, Jie
• Format: Article
• Language: English
• Subjects: Alginic acid; Anodes; aqueous Zn-ion battery; Battery cycles; bifunctional coating; Coatings; Cycles; Durability; dynamic cross-linking network; Electrodes; Functional groups; Ion flux; Manganese dioxide; self-healing capacity; Side reactions; Sodium alginate; Specific capacity; Trehalose; Zinc; Zinc coatings; Zn anode
• ISSN: 0947-6539; 1521-3765; 1521-3765
• DOI: 10.1002/chem.202401693

The serious dendrite growth and H2O‐induced side reactions on the Zn electrode lead to a significant fading in the cycling performance, hindering the development of commercial applications of aqueous Zn‐ion batteries (AZIBs). Herein, a novel bifunctional network coating of dynamically cross‐linking sodium alginate with trehalose has been rationally constructed on the Zn anode (Zn@AT). Firstly, the AT coating possesses abundant zinophilic oxygen‐containing functional groups, which are able to induce uniform Zn2+ ion flux. Secondly, the AT coating as a solid barrier can effectively inhibit H2O‐induced side reactions by lowering the activity of H2O molecules. More specially, based on the dynamic cross‐linking, AT network coating is endowed with self‐healing capacity during cycling for durable battery operation. Consequentially, Zn@AT anodes in symmetric cells can cycle stably for 2787 h at 2 mA cm−2/2 mAh cm−2, and even achieve a significantly long cycle performance of 1087 h at large charge/discharge depths of 10 mA cm−2/10 mAh cm−2. Moreover, the Zn@AT//MnO2 full cell shows excellent specific capacity of 175 mAh g−1 after 400 cycles. This study lights an effective strategy to enhance the durability of Zn electrodes in AZIBs. The bifunctional AT network coating on Zn anode has been constructed via the reversible dynamic cross‐linking interactions, which not only acts as a solid isolation layer to hinder H2O‐induced side reactions but also induces Zn2+ ion flux and lastingly suppresses the Zn dendrites. As a result, the symmetric cell can maintain a significantly prolonged cycle life of 1087 h at 10 mA cm−2/10 mAh cm−2.