Non-aqueous electrolytes for electrical storage devices
View Patent ↗A non-aqueous electrolyte for electric storage devices consisting of a nitrile solvent and a complex salt formed by the reaction of a tetraalkyl ammonium salt and hydrogen fluoride. The electrolyte may include a component which a cation of an imidazolium or quaternary tetraalkylammonium salt.
1. A non-aqueous electrolyte for electric storage devices which comprises a nitrile solvent and a conductive salt comprising a cation selected from the group consisting of
(a) an imidazolium compound of the formula:
wherein R 1 , R 2 , R 3 , R 4 , and R 5 are the same or different and are selected from the group consisting of hydrogen, an alkyl of 1-4 carbon atoms, and fluoroalkyl, with the proviso that at least one of R 1 , R 2 , R 3 , R 4 and R 5 is hydrogen,
(b) an ammonium compound of the formula:
wherein R 5 , R 6 , R 7 , and R 8 , are the same or different and consists of alkyl of 1-4 carbon atoms, or fluoroalkyl, and
(c) a tetraalkylammonium compound of the formula:
R 6 R 7 R 8 R 9 N+
wherein R 6 , R 7 , R 8 , and R 9 are the same or different and consists of alkyl of 1-4 carbon atoms and an anion which is fluoro hydrogen fluoride (F(HF)x wherein x is 1-4), said salt being present in a molar concentration of 0.4 to 3.0.
2. The non-aqueous electrolyte of claim 1 wherein said salt is tetraalkylammonium F(HF) 1.5 .
3. The non-aqueous electrolyte of claim 1 wherein said nitrile solvent is selected from the group consisting of a mononitrile and a dinitrile.
4. The non-aqueous electrolyte of claim 3 wherein said nitrile is selected from the group consisting of acetonitrile, proprionitrile, glutaronitrile, isobutyronitrile, succinonitrile, and methylglutaronitrile.
5. The non-aqueous electrolyte of claim 4 wherein said mononitrile is acetonitrile.
6. The non-aqueous electrolyte of claim 1 including a salt of a cation selected from the group consisting of an:
(a) imidazolium compound of the formula:
wherein R 1 , R 2 , R 3 , R 4 , and R 5 are the same or different and are selected from the group consisting of hydrogen, an alkyl of 1-4 carbon atoms, and fluoroalkyl,
(b) an ammonium compound of the formula:
wherein R 5 , R 6 , R 7 , and R 8 , are the same or different and consists of alkyl of 1-4 carbon atoms, and
(c) a tetraalkylammonium compound of the formula:
R 6 R 7 R 8 R 9 N+
wherein R 6 , R 7 , R 8 , and R 9 are the same or different and consists of an alkyl group of 1-4 carbon atoms, and
an anion of the formula F(HF) x wherein x is 1-4.
7. The non-aqueous electrolyte of claim 6 wherein said imidazolium cation is selected from the group consisting of 1,3-dialkylimidazolium, and 1,2-dialkylimidazolium.
8. The non-aqueous electrolyte of claim 6 wherein said cation is 1-ethyl-3-methylimidazolium.
9. The non-aqueous electrolyte of claim 1 including a salt comprising of a cation which is 1,3-dialkyl imidazolium and the anion is selected from the group consisting of tetrafluoroborate, hexafluoroarsenate, and hexafluorophosphate.
10. The non-aqueous electrolyte of claim 9 wherein said 1,3-dialkyl imidazolium cation is 1-ethyl-3-methylimidazolium.
11. A non-aqueous electrolyte for electric storage devices comprising a mixture of tetraethylammonium tetrafluoroborate, 1-methyl-3-imidazolium tetrafluoroborate and tetraethylammonium (F(HF) 2.33 in acetonitrile in a molar concentration of 0.4 to 3.0.