Calcium alginate/polyaniline double network aerogel electrode for compressible and high electrochemical performance integrated supercapacitors

As a new type of energy storage device, supercapacitors have attracted more and more attention due to their excellent performance. However, the current electrode materials have limited specific surface area and cannot meet the needs of high energy storage. The aerogel material is a 3D network structure containing interconnected micro-nano structures, and also has hierarchical pores on the micro, meso and macro scales. The microporous and mesoporous structures can provide high specific surface area, while the macropores provide channels for the entry of active substances. In this study, calcium alginate (CA)/polyaniline (PANI)/reduced graphene oxide (RGO) aerogels based on double network structure with high mechanical property and excellent electrochemical performance are successfully constructed by sol-gel method. Due to the double network structure, the CA/PANI/RGO aerogel exhibits self-supported 3D porous network structures with high surface areas (330.3 m²/g). CA/PANI/RGO composite aerogel electrode shows high specific capacitance (908 F/g at 1 A/g) and excellent rate performance. The initial capacitance of more than 80 % can be maintained after 10,000 times of charge/discharge cycle test. Most importantly, the assembled flexible solid-state supercapacitor has high specific capacitance (885 F/g at 1 A/g) and mechanical flexibility (92.6 % of the capacitance retention after 1000 bending cycles).