Hollow carbon spheres/hollow carbon nanorods composites as electrode materials for supercapacitor

Abstract

Carbon-based materials with different morphologies have special properties suitable for application in adsorption, catalysis, energy storage and so on. Carbon composites consisting of different morphologies are proved to improve the performance due to combination of favorable structural features. In this work, hollow carbon spheres/hollow carbon nanorods (HCS/HCR) composites are prepared by “dissolution–reassembly” combined with hard template method. Taking advantage of compositional inhomogeneity of 3-aminophenol/formaldehyde (3-AF) resin sphere, 3-AF oligomers are obtained by dissolution of resin sphere with acetone and then used to reassemble with silica oligomer on MnO2 nanorods template under the function of CTAB to form HCS/HCR composites after carbonization and removing template. The obtained HCS/HCR composites with combined characteristics of hollow sphere and hollow nanorod exhibit high surface area (1590 m2 g−1), large pore volumes (2.4 cm3 g−1), and uniform pore size distribution (9.3 nm). When used as electrode material, the obtained HCS/HCR composites show good specific capacitance of 250 F g−1 at a current density of 1 A g−1 in 6 M KOH aqueous electrolyte solution, as well as good cycling stability (91.3% capacity retention after 5000 cycles), suggesting that the HCS/HCR composites electrode materials have potential applications in high-performance supercapacitor.