Ti3C2Tx/RGO//PANI/RGO all-solid-state asymmetrical fiber supercapacitor with high energy density and superior flexibility

Abstract Ti3C2Tx nanosheets/reduced graphene oxide (Ti3C2Tx/RGO-0.9) fiber with superior flexibility and high volumetric capacitance is prepared by spinning the suspension of Ti3C2Tx nanosheets and graphene oxide (GO) nanosheets and followed by treating in HI solution at 80 oC. The oxidation of Ti3C2Tx nanosheets can be effectively protected in N2 atmosphere at 5 oC, and the as-prepared Ti3C2Tx/RGO-0.9 fiber electrode shows a specific volume capacitance of 415 F cm-3 at a current density of 1 A cm-3 in 1 M H2SO4 electrolyte and superior flexibility. Ti3C2Tx/RGO//PANI (polyaniline)/RGO all-solid-state asymmetrical fiber supercapacitor (AFSC) is assembled by using Ti3C2Tx/RGO-0.9 fiber as negative electrode and PANI/RGO-0.4 fiber as positive electrode in PVA-H2SO4 gel electrolyte, it exhibits not only excellent volumetric capacitance of 25 F cm-3 at a current density of 20 mA cm-3, but also high energy density of up to 3.4 mWh cm-3 at a power density of 10.2 mW cm-3. Moreover, the assembled AFSC shows outstanding flexibility and mechanical property, its volumetric capacitance has no obvious change after bending 500 times. The high energy density and superior mechanical flexibility make it can be used as a promising flexible power source in the fields of portable wearable electronic devices.