Localized high salt concentration electrolyte
A battery includes an electrolyte comprised of a solvating solvent, diluent, and a lithium salt. The electrolyte is a solution having a saturation point, the lithium salt being at least 5 times more soluble in the solvating solvent than in the diluent. The diluent and the solvating solvent are immiscible at a molar ratio of diluent/solvating solvent of 2 or more, and the solvating solvent and diluent are present in the electrolyte at a diluent/solvating solvent molar ratio of 0.1 to less than 2.
1 . A battery comprising an electrolyte comprised of a solvating solvent, diluent and a lithium salt, the electrolyte being a solution having a saturation point, the lithium salt being at least 5 times more soluble in the solvating solvent than the diluent, the diluent and the solvating solvent are immiscible at a molar ratio of diluent/solvating solvent of 2 or more and the solvating solvent and diluent are present in the electrolyte at a diluent/solvating solvent molar ratio of 0.1 to less than 2.
2 . The battery of claim 1 , wherein the lithium salt is less than 10 times more soluble in the solvating solvent.
3 . The battery of claim 1 , wherein the diluent has a miscibility point in the solvating solvent and the salt has a saturation point in the solvating solvent such that the saturation point is at least 5 times greater than the miscibility point.
4 . The battery of claim 3 , wherein the saturation point/the miscibility point is from 5 to 10.
5 . The battery of claim 3 , wherein the diluent and the solvating solvent are present in a molar ratio of diluent/solvating solvent of 0.5 to 1.8.
6 . The battery of claim 5 , wherein the diluent and the solvating solvent are present in a molar ratio of diluent/solvating solvent of 0.8 to 1.5.
7 . The battery of claim 1 , wherein the lithium salt is present in a molar concentration of about 0.5 M to about 3 M.
8 . The battery of claim 1 , wherein the lithium salt is present in an amount from 20 percent below to the saturation point of the solution.
9 . The battery of claim 8 , wherein the amount of lithium salt in the solution is in excess of the saturation point of the solvating solvent present in the solution.
10 . The battery of claim 1 , wherein the diluent comprises a fluorinated ether.
11 . The battery of claim 10 , wherein the fluorinated ether comprises an n-butyl group or an isobutyl group.
12 . The battery of claim 11 , wherein the solvating solvent comprises one or more dialkoxy alkanes, dialkyl glycol ethers, disubstituted esters, trisubstituted phosphates, disubstituted sulfones, and tetrasubstituted silanes.
13 . The battery of claim 10 , wherein the fluorinated ether comprises one or more of 1,1,2,2-tetrafluoroethyl 2,2,3,3-tetrafluoropropyl ether; bis(2,2,2-trifluoroethyl) ether, hexafluoroisopropyl methyl ether; 1,1,2,2-tetrafluoroethyl ethyl ether; 1H, 1H,5H-octafluoropentyl 1,1,2,2,-tetrafluoroethyl ether; 1,1,2,2-tetrafluoroethyl ether, 1,2-(1,1,2,2,-tetrafluoroethoxy) ethane; 1,3-(1,1,2,2-Tetrafluoroethoxy) propane, 1,1,2,3,3,3-hexafluoro propyl 2,2,2-trifluoroethyl ether; n-butyl 1,1,2,2-tetrafluoroethyl ether; 1H, 1H,2′H,3H-decafluoro dipropyl ether; 1,1,2,3,3,3-hexafluoropropyl ethyl ether; 1,1,1-trifluoro-2-[1-(2,2,2-trifluoroethoxy) ethoxy] ethane; 1H, 1H,2′H-perfluorodipropyl ether, 1,1,2,2-tetrafluoroethyl isobutyl ether; 1,1,1,2,2,3,4,5,5,5-decafluro-2-methoxy-4-(trifluoromethyl) pentane; 1-(ethoxy) nonafluorobutane having a mixture of n- and iso-butyl isomers; 2-(trifluormethyl)-3-ethoxydodecafluorohexane; 3-methoxyperfluoro(2-methylpentane); heptafluoropropyl 1,2,2,2-tetrafluoroethyl ether; 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether; methoxynonafluorobutane; ethoxynonafluorobutane; tris(2,2,2-trifluroethyl) orthoformate; and di(2,2,2-trifluroethyl) carbonate.
14 . A battery comprising an electrolyte comprised of a solvating solvent, diluent and a lithium salt, the electrolyte being a solution having a saturation point, the lithium salt being at least 5 times more soluble to less than 10 times more soluble in the solvating solvent than the diluent, and the solvating solvent and diluent are present in the electrolyte at a diluent/solvating solvent molar ratio of 0.1 to less than 5.
15 . A method of forming an electrolyte comprising,
a. dissolving a lithium salt in a solvating solvent to form a solvating solvent-lithium salt solution,
b. dissolving a diluent in the solvating solvent-lithium salt solution, wherein the salt has a saturation point in the diluent that is at least 5 times less than in the solvating solvent, and
c. further dissolving more lithium salt to a concentration that exceeds the amount of the lithium salt soluble in the solvating solvent present to form the electrolyte.
16 . The method of claim 15 , wherein the lithium salt present in the electrolyte is below the saturation point of the salt in the electrolyte.