Structural characterization and electrochemical properties of Co3O4 anode materials synthesized by a hydrothermal method

Cobalt oxide [Co3O4] anode materials were synthesized by a simple hydrothermal process, and the reaction conditions were optimized to provide good electrochemical properties. The effect of various synthetic reaction and heat treatment conditions on the structure and electrochemical properties of Co3O4 powder was also studied. Physical characterizations of Co3O4 are investigated by X-ray diffraction, scanning electron microscopy, and Brunauer-Emmett-Teller [BET] method. The BET surface area decreased with values at 131.8 m2/g, 76.1 m2/g, and 55.2 m2/g with the increasing calcination temperature at 200°C, 300°C, and 400°C, respectively. The Co3O4 particle calcinated at 200°C for 3 h has a higher surface area and uniform particle size distribution which may result in better sites to accommodate Li+ and electrical contact and to give a good electrochemical property. The cell composed of Super P as a carbon conductor shows better electrochemical properties than that composed of acetylene black. Among the samples prepared under different reaction conditions, Co3O4 prepared at 200°C for 10 h showed a better cycling performance than the other samples. It gave an initial discharge capacity of 1,330 mAh/g, decreased to 779 mAh/g after 10 cycles, and then showed a steady discharge capacity of 606 mAh/g after 60 cycles.