ScholarWorks@숙명여자대학교

초록

Carbon materials synthesized from biomass are promising candidates for supercapacitor electrodes. Various activation processes for developing carbon materials with high surface areas have been investigated. Here, a manganese monoxide (MnO)-porous-activated carbon (AC) composite was fabricated via the chemical activation of coconut shell by the co-activation agents KOH and KMnO4. Besides influencing the physical properties, such as the specific surface area, pore size, and MnO particle size, co-activation significantly influenced the chemical properties, such as the surface functional groups. These alterations in physical and chemical properties affected the electrochemical performance of a supercapacitor using the composite as an electrode. The fabricated MnO-AC samples exhibited unstable long-term cycling properties due to MnO's structural instability during redox reactions. The samples fabricated by activation and in situ MnO formation using a co-activation-agent solution showed a better initial capacity and long-term stability than those activated and metal oxide-loaded exclusively with a KMnO4 aqueous solution. This enhanced performance is attributable to the formation of MnO nanoparticles on AC with a large specific surface area owing to a microporous carbon structure and carbon vacancy creation within the carbon framework owing to sufficient K+-ion availability.

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