Wide Temperature All-Solid-State Ti 3 C 2 T x Quantum Dots/L-Ti 3 C 2 T x Fiber Supercapacitor with High Capacitance and Excellent Flexibility.

Ti 3 C 2 T x Quantum dots (QDs)/L-Ti 3 C 2 T x fiber electrode (Q 3 M 7 ) with high capacitance and excellent flexibility is prepared by a wet spinning method. The assembled units Ti 3 C 2 T x nanosheets (NSs) with large size (denoted as L-Ti 3 C 2 T x ) is obtained by natural sedimentation screen raw Ti 3 AlC 2 , etching, and mechanical delamination. The pillar agent Ti 3 C 2 T x QDs is fabricated by an ultrasound method. Q 3 M 7 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) Q 3 M 7 fiber supercapacitor is assembled by using Q 3 M 7 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.