Let`s say your current collector size is 5mm*5mm*3.6mm and the size of anode electrode which was prepared with aligned CNT is 3mm or 7 mm. Do you think that sizes of current collector and CNT sample should matched? When I do charge/discharge measurement, I think charge/discharge data comes from current collector not from the CNT. What can be the reason for this? I still can not figure out why.
I'm having a hard time envisioning the experimental setup and electrode. Assuming the CNTs are coated on to the current collector, you can run the experiment with a bare current collector and compare the capacitance to one coated with CNTs. Are you measuring one supercapacitor electrode in a 3-electrode cell or are you measuring a 2 electrode supercapacitor device?
Mine is 2 electrode supercapacitor device. Actually I coated vertically aligned CNT surface with gold firstly to create a good contact between CNT and current collector which was copper. But I get the data from copper not from CNT. So I was thinking maybe I should change the size of current collector or CNT (which is 1cm*1cm).
Actually some capacitance from copper some from CNT but it is not totaly from CNT. I did galvanostatic charge/discharge test several times and that potential-time graph does not look like supercapacitor response.
You can use current collector that has less thickness ( < 0.2 mm). In addition before coating the current collector should be pretreated to remove surface oxide layers.