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

Abstract

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.