Yttrium Oxide-Catalyzed Formation of Electrically Conductive Carbon for Supercapacitors

Abstract

The development of electrically conductive and high surface area carbon is important for the improvement of supercapacitor energy densities. Yttrium hydroxide microspindles were prepared and shown to catalyze carbon growth. The carbon exhibited a high surface area of 932 m2/g and high conductivity of 2.2 × 105 S/m. The carbon/yttrium oxide interface was probed using XPS, Raman spectroscopy, infrared spectroscopy, and solid-state fluorescence. Supercapacitor cells were assembled using the yttrium-catalyzed carbon and EMI-TFSI ionic liquid as the electrolyte. The symmetric supercapacitor cell had a specific capacitance of 137.2 F/g, energy density of 57.4 Wh/kg, and power density of 1724.3 W/kg, at 1 A/g.

Two-Dimensional Hexagonal-Shaped Mesoporous Carbon Sheets for Supercapacitors

“…According to the x -intercept, the solution resistance ( R s ) was only 3 Ω, which is also smaller than those for LaNRTC with 3.4 Ω and YTC with 7.9 Ω. 12 , 14 …”

“…Based on previous studies, 12 − 14 a mechanism for this reaction is proposed below Equation 4 shows that the oxygen in MgO reacts with acetylene to form CO, leaving the magnesium to form a carbide. When the steam was supplied, magnesium acetylide was hydrolyzed to Mg(OH) 2 and acetylene anions C 2– .…”

“… 29 , 30 The templated carbon derived from lanthanum hydroxide nanorod and yttrium hydroxide templates also showed a broad D band for disordered defects. 12 , 14 …”

“… 32 , 33 The conductivity of MHCS measured by a four-point probe method was 5.237 × 10 3 S·m –1 , which is comparable to that of calcium hydroxide and yttrium hydroxide-templated carbons. 12 , 14 …”

“… 10 , 11 Recently, we established a templating process that involves metal carbide (LaC 2 , CaC 2 , YC 2 ) intermediates to form graphitic carbon. 12 − 14 At temperatures above 500 °C, carbon is formed by passing steam and acetylene gas over the metal carbide. Hydrolyzable carbides have been known since 1837.…”