Wide Temperature All-Solid-State Ti3C2Tx Quantum Dots/L-Ti3C2Tx Fiber Supercapacitor with High Capacitance and Excellent Flexibility

Abstract

Ti3C2Tx Quantum dots (QDs)/L-Ti3C2Tx fiber electrode (Q3M7) with high capacitance and excellent flexibility is prepared by a wet spinning method. The assembled units Ti3C2Tx nanosheets (NSs) with large size (denoted as L-Ti3C2Tx) is obtained by natural sedimentation screen raw Ti3AlC2, etching, and mechanical delamination. The pillar agent Ti3C2Tx QDs is fabricated by an ultrasound method. Q3M7 fiber electrode gave a specific capacitance of 1560 F cm−3, with a capacity retention rate of 79% at 20 A cm−3, and excellent mechanical strength of 130 Mpa. A wide temperature all-solid-state the delaminated montmorillonite (F-MMT)/Polyvinyl alcohol (PVA) dimethyl sulfoxide (DMSO) flexible hydrogel (DHGE) (F-MMT/PVA DHGE) Q3M7 fiber supercapacitor is assembled by using Q3M7 fiber as electrodes and F-MMT/PVA DHGE as electrolyte and separator. It showed a volume specific capacitance of 413 F cm−3 at 0.5 A cm−3, a capacity retention of 97% after 10 000 cycles, an energy density of 36.7 mWh cm−3 at a power density of 311 mW cm−3, and impressive capacitance and flexibility over a wide temperature range of −40 to 60 °C. This work provides an effective strategy for designing and assembling wide temperature all-solid-state fiber supercapacitors with optimal balance of capacitive performance and flexibility.