Stable electrolyte for high voltage electrochemical double-layer capacitors [electronic resource]

• Ngôn ngữ: eng
• Ký hiệu phân loại: 621.312 Generation, modification, storage
• 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, 2016
• Mô tả vật lý: Size: p. A277-A283 : , digital, PDF file.
• Bộ sưu tập: Metadata
• ID: 255747
• Chủ đề: 1. 30 direct energy conversion; 2. Double layer capacitor; 3. Electrochemical window; 4. Electrolyte; 5. Ether; 6. Glyme; 7. High voltage; 8. Supercapacitor; 9. Voltage window

Tóm tắt

 A simple electrolyte consisting of NaPF<
 sub>
 6<
 /sub>
  salt in 1,2-dimethoxyethane (DME) can extend the voltage window of electric double-layer capacitors (EDLCs) to >
 3.5 V. DME does not passivate carbon electrodes at very negative potentials (near Na/Na<
 sup>
 +<
 /sup>
 ), extending the practical voltage window by about 1.0 V compared to standard, non-aqueous electrolytes based on acetonitrile. The voltage window is demonstrated in two- and three-electrode cells using a combination of electrochemical impedance spectroscopy (EIS), charge-discharge cycling, and measurements of leakage current. DME-based electrolytes cannot match the high conductivity of acetonitrile solutions, but they can satisfy applications that demand high energy density at moderate power. The conductivity of NaPF<
 sub>
 6<
 /sub>
  in DME is comparable to commercial lithium-ion battery electrolytes and superior to most ionic liquids. Lastly, factors that limit the voltage window and EDLC energy density are discussed, and strategies to further boost energy density are proposed.