TiCT Nanosheets/TiCT Quantum Dots/RGO (Reduced Graphene Oxide) Fibers for an All-Solid-State Asymmetric Supercapacitor with High Volume Energy Density and Good Flexibility.

By using TiCT quantum dots as interlayer spacers, TiCT nanosheets/TiCT quantum dots/RGO (reduced graphene oxide) fiber (MMRG) is prepared by a wet-spinning method; it shows good capacitance and excellent flexibility. The MMRG fiber electrode possesses a novel network structure and a maximum volumetric capacitance of 542 F cm, and its capacitance and flexibility are affected by the amount of TiCT quantum dots. Also, the TiCT/PEDOT:PSS [poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)] fiber (MP) is prepared by injecting a homogeneous suspension of TiCT nanosheets and PEDOT:PSS into a bath of 98 wt % HSO. The MMRG fiber is used as the positive electrode, and the MP fiber is used as the negative electrode; a MMRG//MP asymmetric, flexible, solid-state supercapacitor is assembled in a PVA-HSO gel electrolyte. The assembled device exhibits a volumetric capacitance of 53.1 F cm and a good cycle stability of 96.6% after 5000 cycles. It also shows outstanding flexibility and mechanical properties; for example, the volumetric capacitance has no obvious change after the device is bent at 90° for 500 times. Moreover, its voltage window can be expanded to 1.5 V, and a maximum volumetric energy density of 16.6 mWh cm can be achieved. This work will open up a new application area for new wearable energy storage devices based on the TiCT fibers.