Electrochemical cell, electrolyte suitable for the filling thereof, production method thereof, and method for the operation thereof

Patent metadata

Field	Value
Publication number	US-12506176-B2
Application number	US-201715468299-A
Country	US
Kind code	B2
Filing date	Mar 24, 2017
Priority date	Sep 25, 2014
Publication date	Dec 23, 2025
Grant date	Dec 23, 2025

Abstract

An electrochemical cell includes a negative electrode, a positive electrode, an aluminum current collector that is connected to the positive electrode in an electrically conductive manner, and an electrolyte. The electrolyte includes non-ionic organic compounds present in an amount of less than 1.0 wt % of the total electrolyte, and an ionic liquid as a solvent. The ionic liquid is present in the electrolyte in an amount of at least 80 wt % of all electrolytes. In addition, the ionic liquid includes a cation of the formula: and an anion of the formula: Furthermore, the ionic liquid includes a conducting salt containing: The electrolyte has less than 0.5 wt % of PF6−. The aluminum current collector is provided with a protective layer comprising AlF3.

First claim

What is claimed is:

1 . An electrochemical cell, comprising:
(i) a positive electrode; (ii) a negative electrode; (iii) an aluminum current collector, having an electrically conducting connection to the positive electrode; and (iv) an electrolyte, the electrolyte comprising: nonionic organic compounds present in an amount of less than 1.0 percent by weight of the total electrolyte, wherein the nonionic organic compounds contain no cations or anions; and an ionic liquid as a solvent, wherein the ionic liquid is present in the electrolyte in an amount of at least 80 percent by weight of the total electrolyte, the ionic liquid consisting of: a cation of the formula:

wherein the radicals R 1 to R 4 independently of one another may be substituents comprising 1 to 15 carbon atoms, wherein the radicals can be linear or branched, wherein the radicals R 3 and R 4 also, together with the central N atom of the cation, can form a saturated ring, wherein the ring can have five to seven members, wherein only one of the R 1 and R 2 is (CH 2 CH 2 O) m —CH 3 , where m=1 or 2, and wherein the peripheral H atoms thereof can be substituted;
an anion of the formula:

wherein X and Y are selected from the following combinations: X is CF 3 and Y is F, or X is C 2 F 5 and Y is F; and
a conducting salt consisting of:

wherein the electrolyte contains no PF 6 − , and
wherein the aluminum current collector has a protective layer comprising AlF 3 .

2 . The electrochemical cell according to claim 1 , wherein the amount of nonionic organic compounds present in the electrolyte is less than 0.5 percent by weight.

3 . The electrochemical cell according to claim 1 , wherein the amount of nonionic compounds present in the electrolyte is less than 0.1 percent by weight.

4 . The electrochemical cell according to claim 1 , wherein the negative electrode has a protective layer comprising a polymer obtainable by a reaction of the negative electrode with

5 . The electrochemical cell according to claim 1 , wherein the cation comprises cations of the formulae

6 . The electrochemical cell according to claim 1 , wherein the cation is asymmetric.

7 . An electrochemical cell, comprising:
(i) a positive electrode; (ii) a negative electrode; (iii) an aluminum current collector, having an electrically conducting connection to the positive electrode; and (iv) an electrolyte, the electrolyte comprising: nonionic organic compounds present in an amount of less than 1.0 percent by weight of the total electrolyte, wherein the nonionic organic compounds contain no cations or anions; and an ionic liquid as a solvent, wherein the ionic liquid is present in the electrolyte in an amount of at least 80 percent by weight of the total electrolyte, the ionic liquid consisting of: a first cation of the formula:

wherein the radicals R 1 to R 4 independently of one another may be substituents comprising 1 to 15 carbon atoms, wherein the radicals can be linear or branched, wherein the radicals R 3 and R 4 also, together with the central N atom of the cation, can form a saturated ring, wherein the ring can have five to seven members, wherein only one of the R 1 and R 2 is (CH 2 CH 2 O) m —CH 3 , where m=1 or 2, and wherein the peripheral H atoms thereof can be substituted;
a second cation of the formula:

wherein the radicals R A to R D independently of one another may be substituents comprising 1 to 15 carbon atoms, wherein the radicals can be linear or branched, and wherein the radicals R C and R D additionally, together with the central N atom of the cation, can form a saturated ring, where the ring can have five to seven members, and wherein the peripheral H atoms thereof can be substituted, wherein the second cation is different from the first cation in the ionic liquid;
an anion of the formula:

wherein X and Y are selected from the following combinations: X is CF 3 and Y is F, or X is C 2 F 5 and Y is F; and
a conducting salt consisting of:

wherein the electrolyte contains no PF 6 − , and
wherein the aluminum current collector has a protective layer comprising AlF 3 .

8 . The electrochemical cell according to claim 1 , wherein the electrochemical cell is a lithium-ion battery.

Assignees

• Bayerische Motoren Werke Ag

Inventors

• Reiter Jakub
• Oberhumer Philipp

Classifications

• H01M10/052

  Li-accumulators · CPC title

• H01M2300/0045

  Room temperature molten salts comprising at least one organic ion · CPC title

• H01M10/446

  Initial charging measures · CPC title

• H01M10/0568

  characterised by the solutes · CPC title

• H01M10/0567 Primary

  characterised by the additives · CPC title