Sulu ve Sulu Olmayan Elektrolitlerde Tavlanmış Yüksek Karbonlu Çeliğin Elektrokimyasal Kapasitansı

Abstract

High-carbon steel was heat treated in a furnace at 400 ᵒC, 600 ᵒC and 800 ᵒC for 30 minutes. Annealed and non-annealed high carbon steels were immersed in aqueous (KOH and Na2SO4) and non-aqueous (choline chloride and urea based ionic liquid called Reline) electrolyte in order to understand their electrochemical behavior depending on different annealing temperatures. Areal capacitance of heat treated and non-heat treated high carbon steel was calculated based on applied elevated temperatures. Roughness of high-carbon steel increased after thermal oxidation. The current density and specific capacitance increased upon increasing annealing temperature of high carbon steel charged/discharged in KOH electrolyte. The capacitance of steel heat-treated at 800 ᵒC was 50 times greater than that of non-annealed steel in KOH. The areal capacitance of high-carbon steel scanned in Na2SO4 increased as annealing temperature increased. The specific capacitance of steel annealed at high temperature in Na2SO4 was greater than that in KOH and in Reline electrolyte. Although non-annealed and 400 ᵒC annealed high carbon steel was electrochemically inactive in Reline ionic liquid, the specific capacitance of steel treated at 600 ᵒC and 800 ᵒC increased significantly in Reline. Reline, Na2SO4 and KOH could be used conveniently as supercapacitor electrolyte with annealed high-carbon steels.