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

The serious dendrite growth and H 2 O-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 Zn 2+ ion flux. Secondly, the AT coating as a solid barrier can effectively inhibit H 2 O-induced side reactions by lowering the activity of H 2 O 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//MnO 2 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.