Double Cross‐Linking Strategy and Polar Additives Reconfigured Hydrogen Bond Networks in Potassium Polyacrylate‐Gelatin Hydrogels for Flexible Zn‐Air Batteries with Wide‐Temperature Range
Mengwen Fan, Tong Liu, Lin Lv, Zebin Zheng, Chunli Li, Guokun Ma, Hanbin Wang, Hanbin Wang, Houzhao Wan, Hao Wang, Hao Wang
Abstract
Abstract Flexible zinc‐air batteries (FZABs) have seized wide attention in wearable electronics due to their high energy density, inherent safety, and environmental sustainability. Whereas, gel polymer electrolytes (GPEs) confront with persistent challenges to achieve high‐performance FZABs with superior liquid retention, zinc anode compatibility and wide‐temperature operation. Here, it is demonstrated that incorporating gelatin (Gel) networks and sodium citrate (SC) buffers into potassium polyacrylate (PAAK) effectively modulates the hydrogen‐bonding network of the hybrid hydrogel. This co‐modulation strategy results in a dual‐crosslinked hydrogel with significantly enhanced electrolyte retention (70.4% after 96 h exposure to air). Meanwhile, the ternary gel delivers robust intermolecular interactions to impart its exceptional flexibility and ultrahigh ionic conductivity (285.7 mS cm −1 ) and zinc‐affinitive properties to suppress dendrite growth via the reconfiguring of hydrogen bond networks. Experimental and computational results elucidate the origin of the ternary hybrid hydrogel's superior performance, highlighting the essential roles of both the double cross‐linking network and SC co‐mediating hydrogen‐bond network. These features endow the FZABs with a high power density of 122.2 mW cm −2 , a specific capacity of 771.2 mA h g Zn −1 , and a long cycle life of 100 h at −40 °C, which are superior to those of batteries with commonly used polymer‐based electrolytes.