Building electrode/electrolyte interphases in aqueous zinc batteries via self-polymerization of electrolyte additives
Yaheng Geng, Wenli Xin, Lei Zhang, Han Yu, Huiling Peng, Min Yang, Hui Zhang, Xilin Xiao, Junwei Li, Zichao Yan, Zhiqiang Zhu, Fangyi Cheng
Abstract
ABSTRACT Aqueous zinc batteries offer promising prospects for large-scale energy storage, yet their application is limited by undesired side reactions at the electrode/electrolyte interface. Here, we report a universal approach for the in situ building of an electrode/electrolyte interphase (EEI) layer on both the cathode and the anode through the self-polymerization of electrolyte additives. In an exemplified Zn||V2O5·nH2O cell, we reveal that the glutamate additive undergoes radical-initiated electro-polymerization on the cathode and polycondensation on the anode, yielding polyglutamic acid-dominated EEI layers on both electrodes. These EEI layers effectively mitigate undesired interfacial side reactions while enhancing reaction kinetics, enabling Zn||V2O5·nH2O cells to achieve a high capacity of 387 mAh g−1 at 0.2 A g−1 and maintain >96.3% capacity retention after 1500 cycles at 1 A g−1. Moreover, this interphase-forming additive exhibits broad applicability to varied cathode materials, encompassing VS2, VS4, VO2, α-MnO2, β-MnO2 and δ-MnO2. The methodology of utilizing self-polymerizable electrolyte additives to construct robust EEI layers opens a novel pathway in interphase engineering for electrode stabilization in aqueous batteries.