关键词: 稻壳;活化温度;活性炭电极;超级电容器;比电容

Abstract: Activated carbon was prepared from rice husk, using sodium hydroxide as activator.Then activated carbon was selected as electrode to assemble supercapacitor with electrolyte of potassium hydroxide solution.X-ray diffraction (XRD),nitrogen adsorption-desorption (BET) and scanning electron microscopy (SEM) were used to study surface area and pore structure of carbon prepared at different temperatures.Meanwhile,the electrochemical performance of supercapacitor was investigated by constant current charge/discharge and cyclic voltammetry (CV).The results show that the specific surface area of carbon reaches the maximum value of 2760 m2/g at activation temperature of 800 ℃ with developed pore structure.Under the optimal activation condition, the specific capacitance of activated carbon recorded as the maximum value of 267.2 F/g in 6 mol/L of KOH solution,and the equivalent resistance was only 2.2 Ω with the good rate performance.The capacitance retention ratio was still keeping a high level of 83.7% after 5000 cycles.It indicates that the rice husk-based activated carbon exhibits good charge-discharge reversibility and cycle stability.

Key words: rice husk;activation temperature;activated carbon electrode;supercapacitor;specific capacitance