淀粉基活性炭的制备及在超级电容器中的应用

Preparation of activated carbon from starch and its application in supercapacitors

以淀粉为原料,分别采用H3PO4活化法和物理-化学复合活化法制备活性炭,并将制备的活性炭组装成超级电容器。研究了制备工艺对活性炭孔结构及电容特性的影响;通过氮气吸附和SEM方法表征了淀粉基活性炭的孔结构和表面形貌,通过循环伏安曲线、恒流充放电、交流阻抗实验考察了其电化学性能。结果表明,比表面积与比电容并没有线性关系;物理-化学复合活化法在温度为850℃、活化时间为2 h条件下,制备的淀粉基活性炭比表面积为1438 m2/g,比电容为150 F/g。

Activated carbon has been prepared from starch using phosphoric acid（H3PO4） activation and combined physical-chemical activation methods.The resulting activated carbon materials were assembled into supercapacitors.The effects of varying the preparation process of the activated carbon samples on their pore structure and capacity characteristics have been studied.The pore structure and surface morphology of the activated carbon samples were characterized by N2 adsorption measurements and scanning electron microscopy（SEM）,respectively.The electrochemical performance of the activated carbon materials was characterized by cyclic voltammetry,galvanostatic charge-discharge measurements,and alternating current impedance spectroscopy.The results showed that the capacitance did not have a linear relationship with the surface area,and that the optimum conditions for the preparation of activated carbon from starch involve combined physical and chemical methods at an activation temperature of 850 ℃ with an activation time of 2 h.The surface area of the activated carbon can reach 1438 m2/g with a capacitance as high as 150 F/g.