Method for Operating a Lithium Ion Battery, Lithium Ion Battery, and Motor Vehicle

Abstract

The invention relates to a method for operating a lithium ion battery (1) comprising at least one lithium ion cell and a heating device (2), wherein: the heating device (2) is designed to operate the lithium ion battery (1) in a temperature range between 5 and 90° C.; the lithium ion cell comprises an anode (4), a cathode (5), a separator (6), a current collector (7) and an electrolyte (3); the method comprises a step of operating the lithium ion battery (1) in a temperature range between 5 and 90° C.; and the electrolyte (3) contains: LiBOB as conducting salt and at least one selected from: PC and EC as solvent or LiFSI and/or LiDFOB as conducting salt and at least one glycol ether and/or DMC as solvent or LiFSI and/or LiTFSI and/or LiDFOB and/or LiTDI as conducting salt and at least one compound selected from: imidazolium compounds, pyrrolidinium compounds and piperidinium compounds as solvent.

Claims

1.-10. (canceled)

11. A method for operating a lithium ion battery, the method comprising a step of operating the lithium ion battery in a temperature range between 5 and 90° C., wherein the lithium ion battery comprises at least one lithium ion cell and one heating device, wherein the heating device is equipped to operate the lithium ion battery in a temperature range between 5 and 90° C., wherein the lithium ion cell comprises an anode, a cathode, a separator, a power outlet lead and an electrolyte, and wherein the electrolyte comprises: a) lithium bisoxalatoborate as a conductive salt and at least one solvent selected from the group consisting of propylene carbonate and ethylene carbonate, or b) a conductive salt selected from lithium bis(fluorosulfonyl)imidate and/or lithium difluorooxalatoborate and at least one solvent selected from glycol ether and/or dimethyl carbonate, or c) a conductive salt selected from lithium bis(fluorosulfonyl)imidate and/or lithium bis(trifluoromethane)sulfoneimidate and/or lithium (difluorooxalatoborate) and/or lithium (4,5-dicyano-2-trifluoromethyl)imidazole and at least one solvent selected from the group consisting of imidazolium compounds, pyrrolidinium compounds and piperidinium compounds.

12. The method according to claim 11, wherein when the electrolyte comprises a conductive salt of lithium bis(fluorosulfonyl)imidate and/or lithium (difluorooxalatoborate) and at least one solvent selected from glycol ether and/or dimethyl carbonate, the total concentration of the conductive salt is more than 3 M to 10 M.

13. The method according to claim 11, wherein when the electrolyte comprises a conductive salt of lithium bis(fluorosulfonyl)imidate and/or lithium (difluorooxalatoborate) and at least one solvent selected from glycol ether and/or dimethyl carbonate, the total concentration of the conductive salt is more than 4 M to 7 M.

14. The method according to claim 11, wherein the glycol ether is selected from the group consisting of: 1,1-dimethoxyethane, 1,2 dimethoxyethane, bis(2-methoxyethyl) ether and mixtures thereof.

15. The method according to claim 12, wherein the glycol ether is selected from the group consisting of: 1,1-dimethoxyethane, 1,2 dimethoxyethane, bis(2-methoxyethyl) ether and mixtures thereof.

16. The method according to claim 11, wherein the imidazolium compounds, the pyrrolidinium compounds and the piperidinium compounds have a fluorinated anion.

17. The method according to claim 11, wherein the pyrrolidinium compound is 1-propyl-1-methylpyrrolidinium bis(fluorosulfonyl) imide.

18. The method according to claim 16, where the pyrrolidinium compound is 1-propyl-1-methylpyrrolidinium bis(fluorosulfonyl) imide.

19. The method according to claim 11, wherein the electrolyte is free from fluorinated conductive salts.

20. The method according to claim 12, wherein the electrolyte is free from fluorinated conductive salts.

21. The method according to claim 11, wherein, before the lithium ion battery enters operation, the electrolyte further comprises at least one fluorine-containing corrosion-protection additive.

22. The method according to claim 12, wherein, before the lithium ion battery enters operation, the electrolyte further comprises at least one fluorine-containing corrosion-protection additive.

23. The method according to claim 11, wherein the heating device is a heating device situated within the cell.

24. The method according to claim 12, wherein the heating device is a heating device situated within the cell.

25. A lithium ion battery comprising at least one lithium ion cell and one heating device, wherein the heating device is equipped to operate the lithium ion battery in a temperature range between 5 and 90° C., wherein the lithium ion cell comprises an anode, a cathode, a separator, a power outlet lead and an electrolyte, wherein the electrolyte comprises: a) lithium bisoxalatoborate as a conductive salt and at least one solvent selected from the group consisting of propylene carbonate and ethylene carbonate, or b) a conductive salt selected from lithium bis(fluorosulfonyl)imidate and/or lithium difluorooxalatoborate and at least one solvent selected from glycol ether and/or dimethyl carbonate, or c) a conductive salt selected from lithium bis(fluorosulfonyl)imidate and/or lithium bis(trifluoromethane)sulfoneimidate and/or lithium (difluorooxalatoborate) and/or lithium (4,5-dicyano-2-trifluoromethyl)imidazole and at least one solvent selected from the group consisting of imidazolium compounds, pyrrolidinium compounds and piperidinium compounds.

26. A motor vehicle comprising the lithium ion battery according to claim 25.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The figure shows a diagrammatic sectional view of a lithium ion battery of one embodiment of the invention.

[0022] The figure show only the essential features of the present invention. All other features are omitted in the interest of simplicity.

DETAILED DESCRIPTION OF THE DRAWINGS

[0023] In detail, the figure shows a lithium ion battery 1 which in particular is configured as lithium ion accumulator, and which includes a lithium ion cell and a heating device 2. The heating device 2 is configured in the form of a heating device situated within the cell. It is self-evident here that a lithium ion battery can include a plurality of, in particular stacked, lithium ion cells.

[0024] The lithium ion cell includes an anode 4, a cathode 5, a separator 6, power outlet lead 7, and an electrolyte 3. The anode 4 and the cathode 5 are configured in conventional manner and usually include a carbon support material. The electrolyte 3 can be present in the anode 4, in the cathode 5 and in the separator 6 and optionally also in the separators 7, and includes LiBOB as the conductive salt and at least one solvent selected from PC and EC; mixtures of PC and EC can also be used here. Alternatively, the electrolyte 3 can include LiFSI and/or LiDFOB as the conductive salt and at least one glycol ether and/or DMC as the solvent or LiFSI and/or LiTFSI and/or LiDFOB and/or LiTDI as the conductive salt and at least one compound selected from: imidazolium compounds, pyrrolidinium compounds and piperidinium compounds as the solvent. The lithium ion battery 1 of the invention is usually arranged in a casing and is in particular operated via use of the heating device 2 in a temperature range of 5 to 90° C., in particular in the range of 10 to 80° C.

[0025] By virtue of the correct use of the lithium ion battery 1 and of the specifically designed electrolyte 3, it is possible to achieve high user safety level, long lifetime and a high degree of freedom in respect of design and materials, together with high power density. By virtue of compact structure, very good thermal stability, high user safety level and high durability together with very good power density, the lithium ion battery 1 is in particular suitable for use in a motor vehicle.

LIST OF REFERENCE SIGNS

[0026] 1 Lithium ion battery [0027] 2 Heating device

[0028] 3 Electrolyte [0029] 4 Anode [0030] 5 Cathode [0031] 6 Separator [0032] 7 Power outlet lead