For a wider application in batteries and electrochemical capacitors, an improvement of the electrochemical stability of imidazolium cation - based room - temperature molten salt is required. We found that a certain type of combination of anions can change the anodic stability and other properties of molten salt systems. The 1:1 mixture of 1-ethyl-3-methyl imidazolium (EMI) tetrafluoroborate and EMI bis(trifluoromethylsulphonyl)imide (TFSI) showed a similar anodic stability to that of EMITFSI, the most anodically stable single anion molten salt. This effect may originate from the difference of association of both cation and neighborhood anions. A molten salt which has BF^-_4 and TFSI^- anions has a high stability toward an anodic oxidation and provides the highest energy density double-layer capacitor in this study by enlarging the cell voltage.
|Translated title of the contribution||The Improvement of the Electrochemical Stability of Room-temperature Molten Salt by Dual Anion System|
|Number of pages||5|
|Journal||The Reports of Institute of Advanced Material Study,Kyushu University|
|Publication status||Published - 2000|