Dual crosslinked interpenetrating polymer network-based porous hydrogel membrane for solid-state supercapacitor applications.

Hydrogel membranes have emerged as promising candidates for solid-state supercapacitors (SSCs), overcoming limitations associated with traditional liquid electrolytes like leakage, thermal hazards, and flammability. However, single-network hydrogels often suffer from poor mechanical properties, making them inadequate for wearable applications. Herein, solution casting technique is used to develop a novel dual-crosslinked semi-interpenetrating polymer network (semi-IPN) hydrogel membrane through in-situ polymerisation of acrylic acid (AA) in a polyvinyl alcohol (PVA) matrix, followed by doping with KOH solution. By adjusting the composition between PVA and AA, the phase separation pathway is controlled, resulting in a homogeneously distributed porous architecture that enhances ion-conductive pathways. The hydrogel exhibited excellent properties, including high ionic conductivity (174 mS cm−1), considerable tensile strength (5 MPa), and significant elongation at break (460 %). Dielectric studies confirmed its significantly improved capacitive behaviour and low conductivity relaxation characteristics. Additionally, the resulting pseudocapacitor assembled with graphite-silvernanowire-polyaniline based composite electrode demonstrated a high specific capacitance (302 F g−1 at 0.2 A g−1) with outstanding capacity retention (75 % up to 500 cycles). Overall, the incorporation of this novel material provides great potential for high-performance SSC applications. [Display omitted] • Quasi-sold state semi-IPN membranes prepared via dual crosslinking method. • The homogeneously distributed porous novel architecture enhances ion transmission. • High ionic conductivity of 174 mS cm−1 achieved with >500 % KOH uptake. • The assembled pseudocapacitor gives a capacitance of 302 F g−1 at 0.2 A g−1. [ABSTRACT FROM AUTHOR]