Effects of oxidation and heat treatment of acetylene blacks on their electrochemical double layer capacitances

• Published in: Carbon (New York) Vol. 47; no. 1; pp. 226 - 233
• Main Authors: Kim, Taegon, Ham, Chulho, Rhee, Choong Kyun, Yoon, Seong-Ho, Tsuji, Masaharu, Mochida, Isao
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 2009; Elsevier
• Subjects: Acetylene; Chemistry; Colloidal state and disperse state; Correlation; Cross-disciplinary physics: materials science; rheology; Double layer; Exact sciences and technology; Fullerenes and related materials; diamonds, graphite; General and physical chemistry; Graphene; Graphite; Heat treatment; Materials science; Morphology; Oxidation; Physical and chemical studies. Granulometry. Electrokinetic phenomena; Physics; Specific materials; Plane surface; Correlations; Electrochemical double layer; Morphology; Graphite; Capacitance; Oxidation; Air; Spherical particle; Heat treatments; Diameter; Acetylene
• ISSN: 0008-6223; 1873-3891
• DOI: 10.1016/j.carbon.2008.10.010

Correlations between the electrochemical double layer capacitances of various acetylene blacks modified by surface oxidation and heat treatment, and their morphologies are presented. The acetylene blacks were different from each other in primary structural unit size (equivalent to mean particle diameter). They were oxidized in air at 300 °C for 1 h to produce graphene sheets protruding from the surfaces of the spherical particles. In addition, the surfaces of the acetylene blacks were modified by heat treatments from 1000 °C to 2800 °C, which resulted in a morphological change from surfaces covered with protruding graphene sheets to ones wrapped with basal planes of graphite. Correlations between the capacitances of the acetylene blacks and the observed morphologies showed that the surface covered with protruding graphene sheets was roughly 10 times more effective in capacitive charging than the surface of graphite basal planes. Specifically, the surface specific capacitance of the edged-graphene-sheet-covering surface was 146 mF/m 2, while that of the basal-planes-wrapping surface was 16 mF/m 2. It was concluded that the capacitances of the acetylene blacks were mainly defined by surface morphology, which were in turn influenced by structural unit size and degree of oxidation.