Fluoro-Compounds in Electrolytes for Energy Storage Devices

1 Results Electrochemical energy storage devices such as lithium-ion batteries1-2] and double-layer capacitors3-4] have attracted a great deal of attention because of their potential application to electric hybrid vehicles. They utilize nonaqueous electrolyte solutions comprising from organic solvents and lithium or quaternary ammonium salts with fluorine-containing anions. This is because the relatively large anions with electron-withdrawing atoms enable ionic dissociation in dipolar aprotic solvents and afford enough oxidation potentials for high voltage devices.The author reviews their fundamental electrochemical properties such as electrolytic conductivity and electrochemical window based on our experimental results,and explains why fluoro-compounds are important for the electrochemical energy storage devices. Discussion is extended to ionic liquids5],which recently receive much attention as a non-flammable and non-volatile electrolyte.