Biomass derived activated carbon has been emerged as alternatives to the depletable resources due to its sustainability and 

low cost. Large surface area and the optimal pore distribution of micropores, mesopores, and macropores are crucial for 

achieving high performance activated carbon. Thereby, we synthesized KOH activated carbon derived from protein-rich 

dried pollack which exhibits mesoporous structure with high surface area. We improved the electrolyte wettability and 

charge transfer capability by performing a doping process to introduce electrochemically active nitrogen species (graphitic 

N and pyrrolic N) and functional groups forming surface functionalities (C-N, C-S). 2SN-DP electrode shows the largest 

specific surface area (2764.8 m2

 g-1), favorable pore distribution, nearly capacitive charge storage behavior (b≈0.774), and 

superior specific capacitance (189.5 F g-1 at a current density of 0.2 A g-1 and 128.52 F g-1 at 20 A g-1). The outstanding 

performance of 2SN-DP electrode was attributed to the interactive effects of improved ion transportation and conductivity 

provided by KOH activation and N/S co-doping.