High area energy density of all-solid-state supercapacitor based on double-network hydrogel with high content of graphene/PANI fiber.

• A double-network hydrogel with high load of electrode materials is developed. • The electrode hydrogel can be processed by 3D printing, scraping method and so on. • All-solid-state supercapacitor with ultra-high area energy density is obtained. In order to improve the energy and power density of all-solid-state supercapacitor, more attention is currently focused on the development of electrodes and electrolyte materials with various chemical structure and compositions. However, current studies rarely report hydrogel electrodes with high content of active materials (i.e. > 20.0 wt%), and study their influence on the performance of supercapacitors. Here, a double-network hydrogel electrode was developed and prepared by blade-coating and 3D printing for application in all-solid-state supercapacitor. Moreover, the hydrogel electrode has an unusually high content (25.0 wt%) of active material, leading to high area specific capacitance (871.4mF/cm2) and area energy density (0.14 mWh/cm2 at 0.27 mW/cm2.). This study opens a new pathway to develop high-performance all-solid-state supercapacitors on large-scale. [ABSTRACT FROM AUTHOR]