Polyaniline hydrogel anchored in carbon cloth network to support Co(OH)2 as flexible electrode for high-energy density supercapacitor

Abstract Carbon cloth (CC) is widely used as flexible substrate for supercapacitors, but its space utilization is low. In order to overcome this shortcoming, a new strategy was proposed to fill the gaps and voids in CC by anchoring polyaniline/phytic acid hydrogel (PAH) on CC. Then Co(OH)2 was electrodeposited on PAH/CC to obtain flexible electrode for supercapacitor. Due to the high mass loading of Co(OH)2/PAH (9.83 mg cm−2), Co(OH)2/PAH/CC provided excellent areal capacitance of 8142.5 mF cm−2 at current density of 5 mA cm−2. The symmetrical device demonstrated excellent energy density of 201.5 μWh cm−2 at power density of 3000 μW cm−2, which is larger than those of most devices reported previously. This strategy of anchoring conductive hydrogel network in macroporous frame opens up a new way to fabricate flexible supercapacitor electrode with high areal capacitance and energy density.