Optimizing the sulfonic groups of a polymer to coat the zinc anode for dendrite suppression
Yan Wang, Yuetao Wang, Chuanxi Chen, Xin Chen, Qinghe Zhao, Luyi Yang, Lu Yao, Runzhi Qin, Hong Wu, Zhongyi Jiang, Feng Pan
Abstract
The zinc metal anodes in aqueous zinc-ion batteries suffer from low cycling performance caused by uncontrolled dendrite. We have designed sulfonated poly-ether-ether-ketone (SPEEK) polymers as a surface coating layer on the zinc anode for dendrite suppression, in which the sulfonic groups in polymers act as effective active sites for zinc-ion diffusion. In SPEEK, the un-sulfonated domain serves as the framework and the sulfonated domain serves as the functional part to re-distribute the zinc ions. By optimizing the degree of SPEEK sulfonation, the best zinc anode coating has been achieved to present a high reversibility of over 1600 hours in symmetric cells and improved performance in full cells.