It is not correct to measure energy density and power density in three electrode system. Because these two parameters are used to compare data with actual energy storage device such as battery and supercapacitor in full cell configuration. Three electrode system is not full cell, it is  called half cell and only used for measuring capacitance of one electrode. two electrode system is full cell. Therefore, if you want to measure energy density and power density then try to use two electrode system.

Hi Arulmani,

Follow this discussion in RG.

https://www.researchgate.net/post/What_is_the_best_and_the_most_reliable_way_to_calculate_energy_density_and_power_density_of_a_supercapacitor