Physical and electrochemical properties of quaternary ammonium bis(oxalato)borates and their application to electric double-layer capacitors

• Published in: Electrochimica acta Vol. 52; no. 4; pp. 1763 - 1770
• Main Authors: Nanbu, Noritoshi, Ebina, Takahito, Uno, Hiroyuki, Ishizawa, Saki, Sasaki, Yukio
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Oxford Elsevier Ltd 01.12.2006; Elsevier
• Subjects: Applied sciences; Capacitors. Resistors. Filters; Conductivity; Electric double-layer capacitor; Electrical engineering. Electrical power engineering; Exact sciences and technology; Gravimetric capacitance; Quaternary ammonium bis(oxalato)borate; Various equipment and components; Wettability; Conductivity; Wettability; Gravimetric capacitance; Electric double-layer capacitor; Quaternary ammonium bis(oxalato)borate; Electrical conductivity; Organic carbonate; Electrolyte solution; Electrochemical double layer; Electrolytic capacitor; Discharge; Quaternary ammonium compound; Organic borate; Electrochemical properties; Concentration effect; Surface properties; Surface tension; Thermal analysis; Specific capacity; Electrical characteristic
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2006.03.105

The use of nonhalogenated electrolyte salts for electrochemical devices is very important from the point of view of safety and cost. We have investigated the physical and electrochemical properties of a series of quaternary ammonium bis(oxalato)borates (QABOBs) and the performance of electric double-layer capacitors (EDLCs). The mass and van der Waals volume of BOB − are higher and larger than those of BF 4 −. The mass densities, viscosities, and surface tensions of propylene carbonate (PC) solutions containing the QABOBs are higher than those obtained for tetraethylammonium tetrafluoroborate (TEABF 4), and the electric conductivities become lower. However, the electrochemical voltage windows measured with an activated carbon electrode and the gravimetric capacitances of 2025-type coin cells are comparable to those obtained for the PC solutions containing the TEABF 4.