超级电容器碳纳米管与二氧化锰复合电极材料的研究

以碳纳米管(carbon nanotubes，CNTs)为基体材料，采用浓硝酸和浓硫酸的混合液对其进行回流，将CNTs的端帽打开并进行表面改性，通过液相反应在经过回流处理的CNTs上沉积MnO2，制备CNTs／MnO2复合电极材料。利用透射电镜、红外光谱、循环伏安和恒流充放电测试对复合电极材料进行分析，研究MnO2沉积和回流处理对CNTs超级电容器性能的影响。结果表明：基于CNTs／MnO2复合电极材料的超级电容器具有比容高、能量密度高、可逆性好和寿命长等特点。MnO2的质量分数(下同)为65％时，其比容可达134 F／g；MnO2不超过50％时，电容器保持良好的功率特性。通过回流处理不仅产生了大量的电活性官能团，而且CNTs的内表面也被充分利用而形成双电层。

STUDY ON CARBON NANOTUBES/MANGANESE DIOXIDE COMPOSITE ELECTRODE MATERIALS FOR SUPERCAPACITORS

A composite electrode material comprised of carbon nanotubes(CNTs) and MnO_(2) was prepared by the method of refluxing the CNTs firstly, and then depositing MnO_(2) on the refluxed CNTs. The prepared material was analyzed by transmission electron microscopy(TEM),infra-red spectra(IR), cyclic voltammetry and galvanostatic charge/discharge. The effects of refluxing treatment and MnO_(2 ) depositing on the performance of CNTs supercapacitors were also studied. The results show that supercapacitors based on the composite electrode material are characterized by high specific capacitance, high energy density, excellent reversibility and long lifetime. The specific capacitance reaches to 134 F/g when MnO_(2 ) mass fraction(the same below) is 65% . The surpercapacitors keep in good power performance when MnO_(2) is less than 50%. Through refluxing treatment, large quantities of electroactive functional groups are produced, and the inner surface of the CNTs can also be used to form electric double-layer.