炭气凝胶微球的物理活化与化学活化比较

Activation of Carbon Aerogel Spheres:Physical Activation and Chemical Activation

以炭气凝胶微球为原料,分别采用CO2和KOH作为活化剂,研究物理活化和化学活化对炭气凝胶微球孔结构和电化学性能的影响差异,探讨CO2和KOH的活化机理。结果表明,CO2和KOH活化均能有效改善炭气凝胶微球的孔结构,比表面积最高可达1 320 m2/g;同时显著提高材料的电化学性能,活化后的比电容最高可为活化前的3倍。结果还表明两种方法的活化机理不同,CO2活化,有利于保持炭气凝胶微球的中孔,为电子进出提供大量的快速通道,提高传质速率;KOH活化,对炭气凝胶微球的微孔形成非常有利,可增大电化学活化表面,提高电化学性能。

Carbon aerogel spheres were activated by carbon dioxide （CO2 ） and potassium hydroxide （ KOH）, respectively. The electrodes of supercapacitor were made from the products before and after activation. To understand the activation mechanism, the pore structure and electrochemical performance of these products were investigated. The results showed that both CO2 and KOH activation could improved the pore structure and electrochemical performance, the highest BET surface area of active products could reach 1 320 m2/g and the capacitance were increased by three times, respectively. Furthermore the re- suits also showed that the activation mechanisms of CO2 and KOH were different. The mesopores of car- bon aerogel spheres were kept after CO2activation. Such mesopores acted as the fast channel of electrons to enhance mass transfer rate. The micropores of carbon aerogel spheres were increased significantly after KOH activation, which enhanced the active surface area to improve the electrochemical performance.