I made the activated carbons with KOH activation, and then did the measurement of electrochemical performances. Is there any relationship between surface area and specific capacitance? For my results, the activated carbons prepared from the same precursor, but different activation conditions. For the pore size distributions, with the surface area increased, it increased in all the pore size range. So it is hard the explain why the C increaded first and then decreased a lot with surface area increasing. Most of the literrature said that the C shoule increased with surface area. Thanks a lot.
pore size is very important, and the surface chemistry of your carbon with the typr of electrolyte you are using. The porosity properties are very important, macro and meso pores are needed for fast ion diffusion (rate capability) and micropores are usefull to increase capacitance values. From published work, the scientific community was asking the same question as you. Why does the capacitance value do not increase with increasing surface area? and then they started to look for carbons with controlled porosity and they found the porosity properties that I previously mentioned. Also, when increasing surface area you loose electric conductivity because you have more defects on the carbon.
Dear Ana Karina Cuentas Gallegos and Joseph Gbertyo, thanks a lot for both of you. It is ture that the pore sieze play very importnat role. But the sample with highest surface area also having both the highest micropore and mesopore volume. So the reason should be because that the sample with highest surface area having the lower O content and also more defects on the carbon. But i did not expect that the C will drop so much, the sample with highest surface area only have 1/3 of C, compared with others.
Thanks. BR.
Thank a lot ,Ana Karina Cuentas Gallegos, I am planing to do the analysis of electric conductivity,
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