Flexible supercapacitor constructed by talc reinforced polyaniline/polyvinyl alcohol composite hydrogel

Polyaniline hydrogels exhibit good conductivity and biocompatibility, however, their electrical conductivity is susceptible to environmental influences, their stability is limited, and their mechanical properties require improvement. To address the limitations of low strength and short cycle life in polyaniline hydrogels, this study prepared a talc/conductive polyaniline composite hydrogel flexible supercapacitor exhibiting excellent electrochemical performance and high cycling stability. In a mixed system of polyvinyl alcohol (PVA) and polyaniline (PANI), a talc/polyaniline/polyvinyl alcohol (Talc/PANI/PVA) composite material was prepared via the in-situ polymerization of aniline. The Talc/PANI/PVA composite hydrogel electrode exhibited a remarkable specific capacitance of 767 mF cm −2 at a current density of 0.5 mA cm −2 , while maintaining an impressive capacitance retention rate of 93.2 % after 5000 charge-discharge cycles. This indicates both high specific capacitance and exceptional cycling stability. In mechanical evaluations, the composite demonstrated a stress of 7.5 MPa and a strain of 230 %, with an elastic modulus reaching 2.4 MPa, signifying significantly improved mechanical properties. Furthermore, symmetric flexible supercapacitors constructed with the Talc/PANI/PVA composite hydrogel achieved an energy density of 31 μWh cm −2 at a power density of 250 μW cm −2 , retaining 81.1 % of their initial capacitance after 5000 cycles. Three serially connected supercapacitors can power a blue LED for 3 min after charging 20 s. This research has substantial implications for the advancement of high-performance composite hydrogels intended for wearable and flexible energy storage devices.