Strong conductive hybrid hydrogel electrode based on inorganic hybrid crosslinking.

Polyaniline/poly(vinyl alcohol)/TiO₂ (PANI/PVA/TiO₂) hybrid hydrogels with improved mechanical and electrochemical properties were fabricated via in situ oxidative polymerization of aniline (ANI) and in situ synthesized TiO₂ with sol–gel method. Due to the combination of hydrogen bonds and electrostatic interactions among PANI, PVA, and TiO₂, this inorganic hybrid crosslinking structures enabled the PANI/PVA/TiO₂ hybrid hydrogel to possess reinforced tensile/compressive strength (26.5 kPa/8.2 MPa) and unprecedented self-healing performance. Moreover, with the optimized conductive pathways in the hybrid hydrogel, its conductivity was up to 1.38 S/m, which meets the requirement of being utilized as high-performance flexible solid-state supercapacitors. At current density of 0.5 A/g, the hydrogel-based supercapacitor provided a large capacitance of 41.0–127.5 F/g and a high energy density of 0.9–2.8 Wh/kg, which were superior to other flexible supercapacitors. The easily fabricated PANI/PVA/TiO₂ conducting hydrogels provides a novel strategy to prepare hydrogel electrodes for flexible energy storage devices. [ABSTRACT FROM AUTHOR]