The hollow Co9S8 nanospheres with ca. 50 nm were elaborately fabricated by a facile solvothermal method and characterized by powder X-ray diffraction (XRD), Scanning electron microscopy (SEM) and BET measurement to result in a specific surface area of 226 m(2) g(-1). The prepared hollow Co9S8 nanosphere electrode delivers a initial specific capacitance of 234.7 F g(-1) at a current density of 0.5 A g(-1), which can be retained up to the 60th cycle, indicating the good cycleability and excellent rate capability. As a consequence, the energy density of the prepared Co9S8 pseudocapacitor could re...
