镍掺杂对碳气凝胶结构及电化学性能的影响

Effect of Ni-doped on the structure and electrochemical performance of carbon aerogel

以间苯二酚、间苯三酚和甲醛为反应物,在硝酸镍存在下,经过溶胶-凝胶、溶剂置换、常压干燥及高温炭化制得镍掺杂碳气凝胶材料。利用N2吸附法、XRD及FE-SEM-EDΛX对碳气凝胶的结构和形貌进行表征,利用循环伏安法、恒流充放电方法对制得的镍掺杂碳气凝胶材料在6 mol/L KOH中的电化学性能进行评价。XRD和FE-SEM-EDΛX测试表明,金属镍成功地掺入到碳气凝胶结构中,随着镍质量分数的增大,碳气凝胶结构中出现较大的孔道;N2吸附-脱附数据表明,镍质量分数为0.5%时,比表面积、总孔容、介孔率较大,表明少量硝酸镍的存在,起到造孔的作用。循环伏安及恒流充放电测试表明,在0~0.8 V电位范围内,电极材料具有典型的双电层电容和充放电可逆性,当镍质量分数为0.5%,在0.5 A/g的电流密度下测得的比电容为134.4 F/g。

Ni-doped carbon aerogels are prepared by sol-gel process,solvent exchange,ambient pressure drying and high temperature carbonization,using phloroglucinol,resorcinol,formaldehyde and nickel nitrate as row materials. The structure and morphology of carbon aerogels are characterized by N2 adsorption,XRD and FE-SEM-EDΛX. Cyclic voltammetry and constant current charging and discharging method are used to evaluate the electrochemical performance of carbon aerogel in 6 mol/LKOH. The results of XRD and FE-SEM-EDΛX demonstrate that metal nickel has been successfully incorporated into the carbon aerogels. With the increase of the mass fraction of nickel,the carbon aerogels has a large pore structure. Nitrogen adsorption data analysis indicates that when the mass fraction of nickel is 0. 5%,the specific surface area,the total pore volume and the mesopore ratio are large,suggesting that the presence of a small amount of nickel nitrate plays the role of making holes. Cyclic voltammetry and constant current charge and discharge tests show that the electrode material has a typical electric double layer capacitance and charge and discharge reversibility in the range of 0- 0. 8 V. When the nickel mass fraction is 0. 5%,the specific capacitance is 134. 4 F/g at0. 5 A/g of the current density.