Research On The Preparation Of Carbon Nanotube/Activated Carbon Supercapacitor And Its Electrochemical Performance

As a new type of energy storage device,supercapacitor has the characteristics of high energy density,long cycle life,safety and reliability and excellent environmental protection performance.Supercapacitor has already been applied in railway transportation and mass transportation.Nowadays the present supercapacitor energy density is not high enough to reach the market demand,thus it is necessary to enhance supercapacitor's energy density.These paper focus on the application of different carbon nanotubes materials,different methods used during the preparation process and their effects on the performance of supercapacitor.By using three carbon nanotubes materials,two preparation methods,supercapacitors showed different performance.Through the comparative analysis of the supercapacitor sample's specific capacity,IR-Drop,circulation capacity maintenance,the result showed in the condition of dry preparation process,the FT7000 carbon nanotubes/activated carbon supercapacitors present the most execllent performance.Its capacity is 35.06F/g;its IR-Drop(50m A/g)is 0.01V;its circulation capacity maintenance is 95.6%.The performance of carbon nanotubes / activated carbon supercapacitors c ould be affected by the weight ratio of carbon nanotubes in the composite electrodes.Based on the selected carbon nanotube materials and process methods,2wt%,5wt%,7wt%,10wt% carbon nanotube were selected to prodece supercapacitors,then we compared and analyzed their performances.It is concluded that the 5wt% carbon nanotubes is more suitable for supercapacitor.Its capacity is 35.56F/g;its IR-Drop(50m A/g)is 0.009V;its circulation capacity maintenance is 97.6%.On the basis of previous studies,we fabricated prismatic and cylindrical carbon nanotubes / activated carbon supercapacitors respectively.The prismatic supercapacitor's specific capacity is 7.09F/g;its IR-Drop(50m A/g)is 0.007V;its circulation capacity maintenance is 97.9%.The cylindrical supercapacitor's specific capacity is 6.18F/g;its IR-Drop(50m A/g)is 0.008V;its circulation capacity maintenance is 97.8%.The supercapacitor cells were assembed into modules and systems,which were applied on the trams and trolley buses.These applications demonstrated carbon nanotubes/activated carbon supercapacitors can be applied in engineering field.