Preparation and Supercapacitor Properties of Carbon-Coated SnO2 Hollow Fibers

A new carbon-coated SnO2 hollow fiber was successfully prepared by coaxial electrospinning, and its supercapacitor properties were well studied. The surface morphology and structure were examined using X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and the Brunauer-Emmett-Teller (BET) method. The results showed hollow fibers of average diameter 1 mu m and carbon-coated SnO2 particles of average size 3-15 nm uniformly distributed on the fiber shell. The surface area was 565 m(2).g(-1). In a three-electrode system, the electrode achieved a respectable specific capacitance of 397.5 F.g(-1) at 0.25 A.g(-1), and the capacitance retained ratio was still 88% of the initial value after 3000 cycles at 1.0 A.g(-1). In the case of a symmetrical two-electrode system, the electrode achieved a specific capacitance of 162.0 F.g(-1) at 0.25 A.g(-1) current density, and the capacitance retained ratio was 84% of the initial value after 3000 cycles at 1.0 A.g(-1).