High capacitance of coarse-grained carbide derived carbon electrodes [electronic resource]

• Ngôn ngữ: eng
• Ký hiệu phân loại: 666.3 Pottery
• Thông tin xuất bản: Washington, D.C. : Oak Ridge, Tenn. : United States. Dept. of Energy. Office of Science ; Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy, 2015
• Mô tả vật lý: Size: 32-41 : , digital, PDF file.
• Bộ sưu tập: Metadata
• ID: 255810
• Chủ đề: 1. 30 direct energy conversion; 2. 36 materials science

Tóm tắt

 Here, we report exceptional electrochemical properties of supercapacitor electrodes composed of large, granular carbide-derived carbon (CDC) particles. We synthesized 70?250 ?m sized particles with high surface area and a narrow pore size distribution, using a titanium carbide (TiC) precursor. Electrochemical cycling of these coarse-grained powders defied conventional wisdom that a small particle size is strictly required for supercapacitor electrodes and allowed high charge storage densities, rapid transport, and good rate handling ability. Moreover, the material showcased capacitance above 100 F g<
 sup>
 -1<
 /sup>
  at sweep rates as high as 250 mV s<
 sup>
 -1<
 /sup>
  in organic electrolyte. 250?1000 micron thick dense CDC films with up to 80 mg cm<
 sup>
 -2<
 /sup>
  loading showed superior areal capacitances. The material significantly outperformed its activated carbon counterpart in organic electrolytes and ionic liquids. Furthermore, large internal/external surface ratio of coarse-grained carbons allowed the resulting electrodes to maintain high electrochemical stability up to 3.1 V in ionic liquid electrolyte. In addition to presenting novel insights into the electrosorption process, these coarse-grained carbons offer a pathway to low-cost, high-performance implementation of supercapacitors in automotive and grid-storage applications.