Ilnicka et al. proposed a strategy to use nitrogen-doped carbon materials derived from green algae (A), and gelatin (G) through chemical treatment for supercapacitor electrodes . The carbon materials were activated using KOH, and carbonized at 800 ˚C, and 900 ˚C under N2 atmosphere, and the samples were labelled as 1NCA-800, 2NCA-800, and 1NGA-800, 2NGA-800. XPS studies showed the presence of oxygen content with 6.5 at% in 1NCA-800, and 9.2 at% in 2NGA-800, and the maximum amount of nitrogen (0.72 wt%) was obtained in 1NCA-800. The porous structure of the carbon materials was changed depending on the carbon precursor, and the maximum SBET was evaluated as 2270 m 2 g -1 . XPS analysis showed the presence of oxygen content with 6.5 at% in 1NCA-800, and 9.2 at% in 2NGA-800. And for the KOH activated samples, the highest amount of nitrogen was observed for 1NCA-800 with 0.72 wt%. The electrochemical experiments were performed in neutral electrolyte (0.2 M K2SO4). The highest specific capacitance of 327 F g -1 at 5 A g -1 , was determined for 1NGA- The tea-waste based activated carbon was labelled as TAC, TAC2, TAC3, and TAC4, where TAC was sample without KOH activation. The SBET was increased with increasing KOH agent from TAC2 (2143 m 2 g -1 ) to TAC3 (2235 m 2 g -1 ), and decreased for TAC4 (2206 m 2 g -1 ), and the mesoporosity increased from 20.7 to 63.2 % with increasing level of KOH amount. The XPS analysis showed the higher content of nitrogen, and oxygen heteroatoms in TAC3 sample.