Cooling and flame-retardant composition for a propulsion system of an electric or hybrid vehicle

1. A composition for cooling a propulsion system of an electric or hybrid vehicle, comprising:

(i) at least 80% by weight of at least one hydrocarbon-based fluid with a boiling point of greater than or equal to 50° C., based on a total weight of the composition; and

(ii) at least one fire retardant corresponding to formula (I):

R F -L-R H   (I),

wherein,

R F is a perfluorinated or partially fluorinated group,

R H is a hydrocarbon-based group comprising from 3 to 22 carbon atoms, and

L is a linker,

wherein the hydrocarbon-based fluid comprises biocarbon in an amount of greater than or equal to 90% by weight, relative to the total weight of the hydrocarbon-based fluid.

2. The composition as claimed in claim 1 , wherein the hydrocarbon-based fluid has a boiling point of between 50° C. and 350° C.

3. The composition as claimed in claim 1 , wherein the hydrocarbon-based fluid has a kinematic viscosity at 40° C. of less than or equal to 5 cSt.

4. The composition as claimed in claim 1 , wherein the hydrocarbon-based fluid is totally saturated.

5. The composition as claimed in claim 1 , wherein the hydrocarbon-based fluid comprises isoparaffins in an amount of greater than or equal to 90% by weight, relative to the total weight of hydrocarbon-based fluid.

6. The composition as claimed in claim 1 , wherein the hydrocarbon-based fluid is obtained via catalytic hydrogenation of a deoxygenated and/or isomerized feedstock of biological origin, at a temperature ranging from 80° C. to 180° C. and at a pressure ranging from 50 bar to 160 bar.

7. The composition as claimed in claim 1 , wherein the hydrocarbon-based fluid comprises isoparaffins in an amount ranging from 98% to 100% by weight, relative to the total weight of the hydrocarbon-based fluid, and has a kinematic viscosity at 40° C. of less than or equal to 5 cSt.

8. The composition as claimed in claim 1 , wherein:

R F is a perfluorinated or partially fluorinated (C 1 -C 16 )alkyl group optionally interrupted with one or two heteroatoms chosen from a nitrogen atom and an oxygen atom; and

R H is a (C 3 -C 12 )alkyl or (C 6 -C 12 )alkenyl group, the group being optionally substituted with a (C 3 -C 6 )cycloalkyl, phenyl or benzyl group.

9. The composition as claimed in claim 1 , wherein the linker L is a divalent group chosen from —CH 2 —, —CH═CH—, —O—, —S— or —PO 4 —.

10. The composition as claimed in claim 1 , wherein the fire retardant of formula (I) is present in an amount between 0.5% and 40% by weight, relative to the total weight of the composition.

11. The composition as claimed in claim 1 , wherein the hydrocarbon-based fluid comprises isoparaffins in an amount of greater than or equal to 90% by weight, of relative to the total weight of hydrocarbon-based fluid, at least one fire retardant of formula (I) and optionally at least one phosphorus-based free-radical inhibitor.

12. The composition as claimed in claim 1 , wherein:

the hydrocarbon-based fluid comprises isoparaffins in an amount ranging from 98% to 100% by weight, relative to the total weight of the hydrocarbon-based fluid; and a kinematic viscosity at 40° C. of less than or equal to 5 cSt; and

the composition optionally comprises at least one phosphorus-based free-radical inhibitor.

13. A method for giving ignition-resistance properties to a composition for cooling a propulsion system of an electric or hybrid vehicle, comprising adding to the composition a fire retardant corresponding to formula (I):

R F -L-R H   (I),

wherein,

R F is a perfluorinated or partially fluorinated group,

R H is a hydrocarbon-based group comprising between 3 and 22 carbon atoms, and

L is a linker,

wherein the composition comprises at least 80% by weight of a hydrocarbon-based fluid having a boiling point of greater than or equal to 50° C., based on a total weight of the composition, the hydrocarbon-based fluid comprising biocarbon in an amount of greater than or equal to 90% by weight, relative to the total weight of the hydrocarbon-based fluid.

14. A process for cooling and fire-protecting a battery of a propulsion system of an electric or hybrid vehicle, comprising placing the battery in contact with a composition comprising:

(i) at least 80% by weight of at least one hydrocarbon-based fluid with a boiling point of greater than or equal to 50° C., based on a total weight of the composition; and

(ii) at least one fire retardant corresponding to formula (I):

R F -L-R H   (I),

wherein,

R F is a perfluorinated or partially fluorinated group,

R H is a hydrocarbon-based group comprising from 3 to 22 carbon atoms, and

L is a linker.

15. The process as claimed in claim 14 , wherein the battery is in immersed or semi-immersed in a static or in circulating amount of the composition, or the composition is placed in direct contact with the batteries by injection, by jetting, by spraying, or by misting the composition, under pressure or by gravity, on the battery.

16. The composition as claimed in claim 1 , wherein R F is a perfluorinated or partially fluorinated group including from 1 to 16 carbon atoms.

17. The composition as claimed in claim 1 , wherein the hydrocarbon-based fluid has a boiling point of between 80° C. and 200° C.

18. The composition as claimed in claim 1 , wherein the hydrocarbon-based fluid comprises isoparaffins in an amount of greater than or equal to 98% by weight, relative to the total weight of hydrocarbon-based fluid.

19. The composition as claimed in claim 1 , wherein the fire retardant of formula (I) is present in an amount of between 3% and 10% by weight, relative to the total weight of the composition.

20. The method as claimed in claim 13 , wherein R F is a perfluorinated or partially fluorinated group including from 1 to 16 carbon atoms.

21. The composition as claimed in claim 1 , wherein the hydrocarbon-based fluid is a hydrocarbon comprising between 8 and 22 carbon atoms.