双电层电容器用煤基活性炭的制备与电化学性能表征

以河南永城无烟煤为原料、KOH为活化剂制备了高比表面积的煤基活性炭,采用低温N_2吸附法对活性炭的比表面积、孔容及孔径分布进行了表征,并对其用作双电层电容器电极材料的电化学性能进行了系统测试.在KOH与煤的质量比为4:1、活化温度为800℃、活化时间为1h的条件下制备出的活性炭其比表面积高达3224m~2/g,总孔容达1.76cm~3/g,中孔率为57.95%.该活性炭电极在3mol/L KOH电解液中的比电容高达324F/g,且具有良好的循环性能,当电流密度为40mA/g时,经1000次循环后,比电容保持率超过92%,且其漏电流很小.

Preparation and Electrochemical Performance of Coal-based Activated Carbons for Electric Double Layer Capacitor

High specific surface area coal-based activated carbons are prepared from Yongcheng anthracite using KOH as activator. The specific surface area, pore volume and pore size distribution of activated carbons are characterized by low temperature nitrogen adsorption. The electrochemical performance of activated carbons electrode material for electric double layer capacitor is tested by constant current charge-discharge, alternating current impedance and cyclic voltammetry. The result indicates that high specific surface area coal-based activated carbons can be prepared under the condition of the ratio of KOH to anthracite being 4 : 1, activation temperature being 800℃ and activation time being 1h, and the specific surface area is 3224m~2/g, total pore volume is 1.76cm~3/g and mesoporosity is 57.95%. In the 3mol/L KOH electrolyte, the specific capacitance of activated carbons electrode material is 324F/g, and it has excellent cyclic performance and low leakage current. The residual specific capacitance is more than 92% after 1000 cycles under the current density of 40mA/g.