Constructing Robust Hydrogen Bond Networks in Electrolytes for Long‐Life Zinc‐Ion Batteries
Zuqiao Ou, Minjing Zhao, Kaiyue Zhu, Zheyi Liu, Shirui Yang, Hongyan Zhang, Fangjun Wang, Weishen Yang
Abstract
Abstract Hydrogen bonding in the aqueous electrolyte of zinc‐ion batteries is a key factor dominating cycling stability due to the corrosive effects of water on both anode and cathode. Herein, we designed a robust, continuous hydrogen‐bond network using ethylene glycol as a cosolvent and sulfate ion (SO 4 2− ) as structure‐making anion. Both hydrogen (H) and oxygen (O) atoms of water and ethylene glycol in the electrolyte are inter‐anchored to mitigate the attack of O on a vanadium‐based cathode and the attack of H on the zinc (Zn) anode. Furthermore, the entry of ethylene glycol into the Zn 2+ solvation structure facilitates Zn 2+ intercalation and improves the reversibility of byproducts arising from H + ‐insertion. As a result, excellent cycling performances was achieved in coin cells, with capacity retentions of 87% after 500 cycles at 0.5 A g −1 and 95% after 150 cycles at 0.2 A g −1 , ranking among the highest cycling stabilities reported to date. Moreover, a pouch cell with an area of 90 cm 2 delivered a substantial capacity of 2 Ah and maintained 80% capacity retention after 70 cycles, highlighting the strong potential for practical scalability.