Facile synthesis of integrated electrode-separator-electrolyte hydrogel for solid-state supercapacitor

A new integrated electrode-separator-electrolyte hydrogel is designed and prepared, which is composed of organic liquid crystal, polyvinyl alcohol (PVA), polyaniline (PANI), and reduced graphene oxide (rGO). The organic liquid crystal is introduced into PVA hydrogel, effectively improving compatibility between active materials and hydrogel matrix. The PANI active material is in situ polymerized in hydrogel to prepare PANI-double-network hydrogel. It simultaneously acts as electrode, separator, and electrolyte for assembling flexible solid-state supercapacitor. It obtains an area-specific capacitance of 160.2 mF/cm² and a power density of 101.5 μW/cm² with an energy density of 21.0 μWh/cm². This work provides a new method to reduce interfacial resistance of electrode, separator, and electrolyte of flexible solid-state supercapacitor, further improving its electrochemical performance.