Method for controlling the temperature of a battery comprising a lithium salt
A method for controlling the temperature of a battery in an electric or hybrid motor vehicle by means of a system including a vapor compression circuit in which a first heat transfer composition flows, and a secondary circuit in which a second heat transfer composition flows, the method involving: —heat exchange between the battery and the second heat transfer composition; —heat exchange between the second heat transfer composition and the first heat transfer composition; wherein the battery includes at least one electrochemical cell having a negative electrode, a positive electrode and an electrolyte including a lithium salt composition, the lithium salt composition including: —at least 99.75% by weight of a lithium salt of bis(fluorosulfonyl)imide; —chlorides Cl— at a mass content strictly less than 20 ppm. Also a system for carrying out the method.
1 . A method for regulation of the temperature of a battery of an electric or hybrid motor vehicle by means of a system comprising a vapor compression circuit in which a first heat-transfer composition circulates and a secondary circuit in which a second heat-transfer composition circulates, the method comprising:
an exchange of heat between the battery and the second heat-transfer composition;
an exchange of heat between the second heat-transfer composition and the first heat-transfer composition;
the battery comprising at least one electrochemical cell comprising a negative electrode, a positive electrode and an electrolyte comprising a lithium salt composition, said lithium salt composition comprising:
at least 99.75% by weight of a bis(fluorosulfonyl)imide lithium salt;
chlorides Cl − in a content by weight strictly of less than 20 ppm.
2 . The method as claimed in claim 1 , in which the first heat-transfer composition comprises 2,3,3,3-tetrafluoropropene.
3 . The method as claimed in claim 1 , in which the first heat-transfer composition comprises one or more heat-transfer compounds other than 2,3,3,3-tetrafluoropropene.
4 . The method as claimed in claim 3 , in which 2,3,3,3-tetrafluoropropene is present at a content of approximately 78.5% by weight in the first heat-transfer composition and difluoromethane is present at a content of approximately 21.5% by weight in the first heat-transfer composition.
5 . The method as claimed in claim 1 , in which the second heat-transfer composition comprises one or more heat-transfer compounds having a boiling point of 0 to 40° C.
6 . The method as claimed in claim 1 , in which the second heat-transfer composition is at a uniform pressure in the secondary circuit.
7 . The method as claimed in claim 1 , in which the battery is maintained at a temperature of between a minimum temperature t 1 and a maximum temperature t 2 .
8 . The method as claimed in claim 7 , in which the minimum temperature t 1 is greater than or equal to 0° C. and the maximum temperature t 2 is less than or equal to 60° C.
9 . The method as claimed in claim 1 , implemented during a charging of the battery of the vehicle.
10 . The method as claimed in claim 1 , in which the second heat-transfer composition is in direct contact with the battery of the vehicle.
11 . An installation for regulation of the temperature of a battery of an electric or hybrid motor vehicle, comprising:
a vapor compression circuit in which a first heat-transfer composition circulates; and
a secondary circuit in which a second heat-transfer composition circulates;
the vapor compression circuit being coupled with the secondary circuit by an intermediate heat exchanger, so as to make possible an exchange of heat between the first heat-transfer composition and the second heat-transfer composition; and the installation comprising an additional heat exchanger configured to exchange heat between the battery and the second heat-transfer composition;
the battery comprising at least one electrochemical cell comprising a negative electrode, a positive electrode and an electrolyte comprising a lithium salt composition, said lithium salt composition comprising:
at least 99.75% by weight of a bis(fluorosulfonyl)imide lithium salt;
chlorides Cl − in a content by weight strictly of less than 20 ppm.
12 . The installation as claimed in claim 11 , in which the secondary circuit does not comprise a compressor.
13 . The installation as claimed in claim 11 , in which the circulation of the second heat-transfer composition in the secondary circuit is carried out by means of a pump, or by gravity, or by capillary action.
14 . The installation as claimed in claim 11 , adapted for air conditioning of a passenger compartment of the vehicle, and/or heating of the passenger compartment of the vehicle, and/or cooling of electronic compounds of the vehicle, and/or heating of electronic compounds of the vehicle.
15 . The installation as claimed in claim 11 , in which the first heat-transfer composition comprises one or more heat-transfer compounds other than 2,3,3,3-tetrafluoropropene.
16 . The installation as claimed in claim 15 , in which 2,3,3,3-tetrafluoropropene is present at a content of approximately 78.5% by weight in the first composition and difluoromethane is present at a content of approximately 21.5% by weight in the first composition.