Effect of different pretreatment methods on sesame husk-based activated carbon for supercapacitors with aqueous and organic electrolytes

Sesame husks have been explored as a novel precursor to prepare high-performance activated carbons through two pretreatment processes coupled with KOH activation. The optimal structure of as-prepared carbon, which consisted of numerous micropores, well-defined mesopores, high specific surface of 2772m(2)/g and large total pore volume of 1.206cm(3)/g, is obtained via pre-carbonization and KOH activation. When applied in supercapacitors, the as-prepared carbon-based electrode achieves high specific capacitance of 301F/g and 155F/g in 6M KOH aqueous electrolyte and 1M Et4NBF4/PC organic electrolyte, respectively. Moreover, it also shows superior cycling stability of 94.9% and 92.5% capacitance retention after 10,000 cycles in KOH and Et4NBF4/PC electrolyte. Hence, this work makes the sesame husks act as a novel carbonaceous precursor and makes the pre-carbonization combined with KOH activation as an effective method for electrode materials in supercapacitor applications.