模板法中孔炭及其双电层电容性能(英文)

Templated mesoporous carbons and their performance for electric double layer capacitors

以乙酸镁和柠檬酸镁热解得到的MgO为模板,热塑性沥青为碳前驱体,采用程序升温一步炭化法(950℃,N2)制备了高比表面积中孔炭材料。尽管未进行活化,两种模板前驱体与沥青混合所制中孔炭材料均可获得非常高的比表面积。以这两种中孔炭作为双电层电容器的电极材料,在质量分数为30%的KOH电解液中测试其电化学性能。结果表明:这两种中孔炭电极均可得到较高的比电容量和理想的功率特性,尤其是柠檬酸镁作前驱体时,MgO与沥青质量比为4时得到的炭材料(MCP8/2)在20mA.g-1的电流密度下得到284F.g-1的比电容量,且在1000mA.g-1时仍能得到236F.g-1的比电容。交流阻抗测试表明:组装的双电层电容器的内部阻抗均小于3.5Ω。

Templated mesoporous carbons with high surface area were successfully prepared by the carbonization of a mixture of thermoplastic precursor pitch with MgO precursors（magnesium acetate and citrate）at 950℃ in a N2 atmosphere.The BET surface area of the carbons obtained reached a very high value without any activation process.The carbons were rich in mesopores.The electrochemical performance of mesoporous carbons prepared as electrode materials for electric double layer capacitors were also investigated.Measurement of capacitance was carried out in a mass fraction 30% KOH electrolyte.Results showed that the mesoporous carbons had a high specific capacitance and perfect rate performance.In particular,the sample prepared with a mass ratio of MgO to pitch of 4 for the magnesium citrate template showed a fairly high capacitance,about 284F·g^-1 at a current density of 20mA·g^-1 and 236F·g^-1 at 1000mA·g^-1.The impedance of all the capacitors was smaller than 3.5Ω.