Compressible solid‐state supercapacitors are emerging as promising power sources for next‐generation flexible electronics with enhanced safety and mechanical integrity. Highly elastic and compressible solid electrolytes are in great demand to achieve reversible compressibility and excellent capacitive stability of these supercapacitor devices. Here, a lithium ion‐conducting hydrogel electrolyte by integrating natural protein nanoparticles into polyacrylamide network is reported. Due to the synergistic effect of natural protein nanoparticles and polyacrylamide chains, the obtained hydrogel shows remarkable elasticity, high compressibility, and fatigue resistance properties. More significantly, the supercapacitor device based on this hydrogel electrolyte exhibits reversible compressibility under multiple cyclic compressions, working well under 80% strain for 1000 compression cycles without sacrificing its capacitive performance. This work offers a promising approach for compressible supercapacitors.

Graphene oxide/polyurethane/epoxy resin nanocomposites containing various contents of graphene oxide were prepared by a sequential physical and polymeric technique. For the nanocomposites with a 0.3 mass% loading of graphene oxide, great improvement in tensile properties such as the elongation at break and toughness have been achieved by 45% and 87%, respectively. Meanwhile, the damping property of the nanocomposites is superior to that of the polyurethane/epoxy composite, with a 1 C loss for the glass transition temperature. Combined with the morphology analysis, it has been proved that the polyurethane prepolymer terminated with hydroxyl groups and graphene oxide exhibit synergistic effect on improving mechanical properties of neat epoxy resin.