Synergistically Modified CNF/PAM Hydrogel with LiCl and Carboxylated Graphene for Zinc-Air Batteries

Flexible zinc-air batteries (ZABs) with high theoretical energy density, intrinsic safety, and low cost have gained significant attention for flexible energy storage devices. However, conventional single-component electrolytes struggle to simultaneously meet comprehensive performance requirements, including mechanical strength, conductivity, practical specific capacity, and cycling stability. Herein, carboxylated graphene (CG) and lithium chloride (LiCl) were incorporated into a cellulose nanofibril/polyacrylamide (CNF/PAM) hydrogel matrix to fabricate a series of multi-component, dual-crosslinked high-performance composite hydrogel electrolytes toward flexible and rechargeable zinc-air batteries. The results reveal that the LiCl-CG@CNF/PAM composite hydrogel achieves an ionic conductivity of up to 4.473 mS·cm^-1 and exhibits excellent mechanical properties, with a tensile elongation of 457% at a stress of 151.5 kPa. The assembled flexible ZABs deliver a peak power density of 60.7 mW·cm^-2, a steady discharge duration of 38 h, and a long cycling lifetime of 47 h. This hydrogel electrolyte affords a novel strategy for the design and fabrication of high-performance, long-lifetime flexible wearable zinc-air batteries.