Chemically building interpenetrating polymeric networks of Bi-crosslinked hydrogel macromolecules for membrane supercapacitors

•Prepares an interpenetrating polymeric networks of bi-crosslinked hydrogel membrane.•Shows high ion conductivity due to the interpenetrating network structure.•A "conductive polymer hydrogel" formed by in-situ polymerization of aniline.•It has a high specific capacitance of 580 m F·cm−2 (0.5 mA·cm-1).•Flexible membrane supercapacitor is assembled with reduced interface impedance.