采用单壁碳纳米管作为合成电容器电极材料的基础原料,以氧化石墨烯提高单壁碳纳米管的分散性,以二氧化锰来增强其比电容,分别采用微波处理与传统水热法合成复合材料,重点探讨不同合成方式对电极材料结构及性能的影响。与传统水热法相比,微波法除了具有操作简便、加热时间短等优点外,合成的复合材料具有更均一的微观结构,且更加均匀的覆盖在碳质材料的表面,因而作为超级电容器电极材料时能表现出更优良的电学性能:在0.2 A/g的电流密度下,其比电容达173 F/g,比传统水热法合成的材料高出24.5%;具有更低的电荷转移电阻,仅为1.425Ω;更高的充放电稳定性,在20 m V/s的扫描速率下循环1000次,电容损失率仅为3.74%。
HNO3-oxidized single-wall carbon nanotubes ( SWCNTs) and graphene oxide ( GO) were ultrasonically dispersed in water to which potassium permanganate was added, and the resulting mixtures were treated under microwave radiation at 100℃ for 1 h or hydrothermal conditions at 100℃ for 1, 5 and 10 h to prepare SWCNT-GO/MnO2 composites as electrode materials of electro-chemical capacitors. Results indicate that the composite prepared using the microwave method has a higher specific capacitance (173F/g at 0.2A/g), lower pseudo-charge transfer resistance (1.425Ω) and longer cyclic stability (3.74% capacitance loss after 1 000 cycles at the scan rate of 20 mV/s) than the ones prepared using the hydrothermal method. Moreover, the microwave method has the advantages of simplicity of operation and shorter heating time.