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Preparation and Supercapacitor Properties of Carbon-Coated SnO 2 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 μm and carbon-coated SnO2 particles of average size 3–15 nm uniformly distributed on the fiber shell. The surface area was 565 m2 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.