Interpenetrating Framework with Three-Dimensionally Ordered Macroporous Carbon Substrates and Well-Dispersed Co3O4 Nanocrystals for Supercapacitor

In this work, we present the synthesis and electrochemical performance of a novel Co3O4/carbon nanocomposite composed of a homogeneous dispersion of Co3O4 nanocrystals and carbon in a three dimensionally ordered macroporous framework with a pore-hierarchical structure (3DOM Co3O4-C). Structural and morphological properties of the 3DOM Co3O4-C are characterized by various techniques. Cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy tests are employed to assess the properties of the nanocomposite for use in supercapacitor. The results demonstrate that Co3O4 can be effectively utilized with assistance of the carbon in the 3DOM framework. The specific capacitance of the 3DOM Co3O4-C can reach as high as 687.5 F g(-1) and 555.2 F g(-1) at 20 mV s(-1) and 1 A g(-1), respectively, much higher than those of the carbon and Co3O4-free 3DOM counterparts. Moreover, the nanocomposite exhibits excellent rate-capability and durable cyclability, keeping over 96% of its initial charge after 5000 cycles at a current density of 10 A g(-1). Such superior electrochemical behavior can be attributed to the positive synergetic contributions of Co3O4 and carbon including a short diffusion length for both electrons and OH- ions, large accessible surface area, homogeneously dispersed Co3O4, and the enhanced electrolyte flux. (C) 2015 The Electrochemical Society. All rights reserved.