Authors: Xiao Zhang, Jiayi Li, Fengjin Xie, Xinming Xu, Xunzhen Sun, Long Su, Fei Lu, Liqiang Zheng, Xinpei Gao
Published: 2025-04-21
Source: Full article
AbstractAqueous Zn‐I2 batteries (AZIBs) have garnered attention for their high energy density and safety. However, challenges such as polyiodide shuttling, side reactions, and uncontrolled dendrite growth have hindered their practical application. Herein, a polyzwitterionic gel (PZG) electrolyte is designed to address these issues by enhancing both the Zn anode and iodine cathode performance. The anionic groups in PZG regulate the Zn2+ solvation structure, promoting uniform Zn deposition and mitigating dendrite formation. Simultaneously, the cationic groups interact electrostatically with anionic polyiodides (I3−, I5−), effectively inhibiting their shuttling between electrodes. As a result, these synergistic effects enable the electrolyte to achieve a high average coulombic efficiency (CE) of 99.5% in the Zn plating/stripping process. Moreover, the full Zn‐I2 batteries with PZG electrolyte demonstrate an impressive capacity retention rate of 96.4% after 10000 cycles. This work provides valuable insights into the advanced hydrogel electrolyte design and beyond for achieving highly reversible AZIBs.