Acid-Assisted Strategy Combined with KOH Activation to Efficiently Optimize Carbon Architectures from Green Copolymer Adhesive for Solid-State Supercapacitors

A portable carbon-based solid-state supercapacitor (SC), together with ideal performance and cost-effectiveness, is currently drawing extensive attention, of which the carbon electrode with tuned structure and properties is the key component. The present work opens up an innovated avenue to full utilization of novel acrylonitrile copolymer waterborne adhesive with dual functions as both carbon and nitrogen sources for fabricating a honeycomb-like nitrogen/oxygen (N/O) co-doped porous carbon with a texture remarkably enhanced by a simple acid-assisted strategy combined with KOH activation. The final carbon (A-LAC2) achieves quite high capacitance of 317.5 F g–1 at 0.5 A g–1 and superb rate capability in a three-electrode cell. Specially, a promising solid-state symmetric SC is demonstrated by relatively high energy/power densities of 6.7 Wh kg–1/3486 W kg–1 as well as a long lifespan of over 10 000 cycles, as a result of synergistic coupling of large surface area, hierarchical porous texture, rich surface species, and multidimensional ionic/electronic transfer channels presented by this material. This research provides a new yet efficient strategy to build high-performance carbon materials from clean copolymer adhesive and holds great potential for energy storage applications.