LAUSR

Abstract In this paper, activated carbon was prepared from microalgae via chemical activation with a mass ratio of charcoal/KOH = 1:5 at an activation temperature of 700 °C for high surface area and porosity. The activated carbon/nickel oxide composites were produced by precipitation method in aqueous solution. The prepared activated carbon had a high surface area, many mesopore, and nitrogen atoms which improved good capacitance in the composite. In addition, the activated carbon/nickel oxide composites exhibited better electrochemical properties than those of nickel oxide in which activated carbon improved the dispersion of nickel oxide particles to prevent aggregation. When the nickel oxide was mixed to about a mass ratio of about 20 times compared to the activated carbon, the composite had the highest capacity in 624.20 F/g at 1 A/g. The specific capacitance represented an increase of 40% with respect to those composites with the nickel oxide electrode. Also, the specific capacitance increased by 530% compared to the activated carbon. In addition, the composite electrode materials exhibited good retention of the specific capacitance for 1000 cycle tests. Consequently, activated carbon/nickel oxide composites are suitable for use in supercapacitor electrodes.