Tubular TiC fibre nanostructures as supercapacitor electrode materials with stable cycling life and wide-temperature performance

摘要

Highly active electrode materials with judicious design of nanostructure are important for the construction of high-performance electrochemical energy storage devices. In this work, we have fabricated a tubular TiC fibre cloth as an interesting type of stable supercapacitive material. Hollow microfibres of TiC are synthesized by carbothermal treatment of commercial T-shirt cotton fibres. To demonstrate the rationale of nanostructuring in energy storage, the hollow fibres are further covered by interwoven TiC nanotube branches, forming 3D tubular all-TiC hierarchical fibres with high electrical conductivity, high surface area, and high porosity. For energy storage functions, organic symmetric supercapacitors based on the hollow fibre-nanotube (HFNT) TiC cloth electrodes are assembled and thoroughly characterized. The TiC-based electrodes show very stable capacitance in long charge-discharge cycles and at different temperatures. In particular, the integrated TiC HFNT cloth electrodes show a reasonably high capacitance (185 F g(-1) at 2 A g(-1)), better cycling stability at high-rates (e.g., 97% retention at room temperature after 150000 cycles, and 67% at -15 degrees C after 50000 cycles) than other control electrodes (e.g., pure carbon fibre cloths). It is envisaged that this 3D tubular TiC fibre cloth is also useful for solar cells and electrocatalysis.