Phosphoric Acid Activated Carbon Fabrics as Supercapacitor Materials

• Main Authors: Chung-kai Pan, 潘仲凱
• Other Authors: Tse-hao Ko
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/45371813364590711505

碩士 === 逢甲大學 === 材料科學所 === 94 === Activated carbon fiber fabrics were prepared with oxidized PAN fiber precursor in which phosphoric acid is used as a chemical-activation agent, and co-activated with steam or carbon dioxide gas in various temperature, 700 to 1000℃. Due to the high specific surface area, ACFFs were often used as an electrode of the electric double-layer capacitor. The study was focused on the influence of different chemical activation method and the physical properties to the microstructures of ACFFs, and also the performances of the capacitance of the electric double-layer. The porous structure of ACFFs was created in the activation and the porous texture was influenced by different activation method technique which is depended on the activated agents. The experimental data shows that the micropores structure were created very fast in the early stage of activation, and then the porous structure will connected with each other to from supermicro- or meso-pores in the further activation gradually. There is a maximum specific surface area, 1087 m2/g, contributed from the micropore structure for the major porous system of ACFFs. When raising the activation temperature to 1000℃, a large amount of mesopores was created on ACFFs, and with 660 m2/g specific surface area for mesopore which was activated with steam agent. From cyclic voltammetry, there was a the maximum specific capacitance, 173 F/g, which the ACFFs electrode was activated at 900℃ with 829 m2/g. The result suggests that specific capacitance was not only dependent on specific surface area, but the porous texture.