Dual-functional PEGDA hydrogel electrolyte: Suppressing water activity and regulating Zn2+ flux for long-life aqueous zinc-ion batteries and Ah-level scalability

An in-situ polymerized PEGDA hydrogel electrolyte is developed for AZIBs. • Ether groups disrupt water's hydrogen-bond network to suppress side reactions. • Carbonyl groups regulate Zn 2+ flux and enable dendrite-free deposition. • An Ah-level pouch cell validates the practical applicability of this work. Aqueous zinc-ion batteries (AZIBs) are promising for low-cost, safe, and eco-friendly energy storage. Vanadium-based cathode materials have garnered intense research interest due to their inherently high specific capacity. However, their practical applications are severely hindered by stability issues, including cathode dissolution, hydrogen evolution reactions, and zinc dendrite formation. Here, we report a novel in-situ polymerized hydrogel electrolyte based on polyethylene glycol diacrylate (PEGDA-HGE) to tackle these challenges. The abundant ether oxygen groups preferentially coordinate with water, disrupting its intrinsic hydrogen-bond networks and thus suppress water-induced parasitic hydrogen evolution and Vanadium-based cathode dissolution. Simultaneously, the carbonyl groups served as zincophilic sites not only facilitate ordered Zn 2+ transport but also homogenize interfacial Zn 2+ flux, thereby effectively preventing dendritic zinc growth. Meanwhile, the PEGDA chain can partially anchor OTf − , thereby suppressing its migration. As a result, the PEGDA-HGE delivers a high ionic conductivity (9.95 mS cm −1 ) and a large Zn 2+ transference number of 0.69. The Zn||Zn cells demonstrate exceptional cycling stability for 4380 h at 1 mA cm −2 /1 mAh cm −2 . Zn||V 2 O 3 full cells exhibit a high specific capacity of 454 mAh g −1 at 0.1 A g −1 and maintain a reversible capacity of 279 mAh g −1 across 500 cycles at 0.5 A g −1 . Notably, an Ah-level pouch cell achieves a high reversible capacity of 2642 mAh with stable operation for 50 cycles at 0.1 A g −1 . This work introduces a novel class of polymerizable monomer and achieves a significant advance in the fabrication of dual-functional hydrogel electrolytes for long-life aqueous AZIBs and Ah-level scalability. A novel dual functional in-situ polymerized PEGDA-based hydrogel electrolyte is designed for aqueous zinc-ion batteries with stable cyclability and Ah-level scalability. Abundant ether moieties immobilize free water, reduce water activity, and break H-bond networks to impede H + ion migration, thus suppressing cathode dissolution and HER/corrosion at Zn anode. Carbonyl groups served as zincophilic sites optimize Zn 2+ ion flux and effectively inhibit dendrite formation. Download: Download high-res image (206KB) Download: Download full-size image