All-solid-state TiCT neutral symmetric fiber supercapacitors with high energy density and wide temperature range.

All-solid-state TiCT neutral symmetric fiber supercapacitors (PVA EGHG TiCT FSCs) with high energy density and wide temperature range are constructed by using polyvinyl alcohol (PVA)-ethylene glycol hydrogel (EGHG)-sodium perchlorate (NaClO) as electrolyte and separator, and TiCT fiber as electrodes. TiCT fiber is prepared using 130 mg mL TiCT nanosheet ink as an assembly unit in a coagulation bath of isopropyl alcohol (IPA) and distilled water with 5 wt% CaCl by a wet spinning method. The prepared TiCT fiber exhibits a specific capacity of 385 F cm and a capacitance retention of 94 % after 10,000 cycles in 1 M NaClO electrolyte. The assembled PVA EGHG TiCT FSCs deliver a specific capacitance of 41 F cm, a volumetric energy density of 5 mWh cm, and a capacitance retention of 92 % after 500 times continuous bending. Furthermore, it shows good flexibility and excellent capacitance over a wide temperature range of -40 to 40 °C and maintains its electrochemical performance under varying degrees of bending. This study provides a viable strategy for designing and assembling all-solid-state neutral symmetric fiber supercapacitors with high energy density and wide temperature range.