2007 Volume 75 Issue 8 Pages 565-572
A capacitor is an electrical device that can store energy in an electric field between a pair of closely spaced conductors. Its application as an energy storage device —an alternative to rechargeable batteries— has been receiving considerable attention. There are chemical capacitors using liquid electrolytes such as aluminum electrolytic capacitors and double-layer capacitors, and they utilize quaternary ammonium salts in their nonaqueous electrolytes. After a brief explanation of the working principles of these chemical capacitors and their requirements for electrolytes, the practical applications of quaternary ammonium salts for aluminum electrolytic capacitors and double-layer capacitors are reviewed from the historical and technological viewpoints based on research conducted in our laboratory.
