Carboxymethyl cellulose assisted polyaniline in conductive hydrogels for high-performance self-powered strain sensors

Engineering high mass electroactive materials into hydrogel scaffolds remains an enormous challenge in achieving flexible energy storage devices. Herein, carboxymethyl cellulose (CMC) assisted high mass polyaniline (PANI) into an interpenetrating double-network polyethyleneimine/polyacrylamide (PEI/PAAM) hydrogel was developed. With the optimum mass loading of PANI at 9.04 mg/cm², the all-in-gel CMC-PANI_0.8M/PEI/PAAM supercapacitor can deliver a high specific capacitance of 679 mF/cm², a maximum energy density of 58.82 μWh/cm² at a power density of 14.69 mW/cm², and an enhanced capacitance retention of 98 % after 5000 cycles. Such device can withstand severely bending/compressing deformations and operate properly at extreme temperatures (-30-70 °C). The CMC-PANI_0.8M/PEI/PAAM hydrogel exhibits high sensitivity and stable electrical performance for wearable strain sensors. By connecting the supercapacitor with the strain sensor, the fabricated self-powered sensing system is capable of monitoring human activities accurately. Therefore, the multifunctional performance of the CMC-PANI_0.8M/PEI/PAAM hydrogel is competent in the field of flexible electronics.