Preparation of Mesoporous Nanocrystalline Co[sub 3]O[sub 4] and Its Applicability of Porosity to the Formation of Electrochemical Capacitance

In this paper we describe a new synthesis strategy for preparing loose-packed porous materials with the particle diameter down scaled to nanometer size. Mesoporous nanocrystalline was prepared using this method, and an attempt was made to apply it as an active electrode material for electrochemical capacitors. The composition and microstructure of the resulting nanocrystalline material were investigated by X-ray diffraction spectroscopy and high-resolution transit electron microscopy (HRTEM). Based on the value of from HRTEM, the molecular formula of was obtained by comparing it with those of CoO and . Static adsorption and desorption isotherm (SADI) analysis show that porous nanocrystalline prepared by this method has a high Brunauer-Emmett-Teller surface area with mesopore distributions. The formation mechanism of mesoporous nanocrystalline was proposed based on Fourier transform infrared spectroscopy and SADI analysis. Electrochemical studies revealed that the electrode prepared with this kind of material exhibits a high specific capacitance of . The charge-storage mechanism of the measured capacitance was investigated. In addition, the electrochemical processes, such as ion transfer and electrical conduction, were investigated with electrochemical impedance spectroscopy. The correlation between the microstructure and the energy density as well as the power density is discussed.