The present invention relates to a composition for cooling a propulsion system of an electric or hybrid vehicle, comprising (i) at least one hydrocarbon-based fluid with a boiling point of greater than or equal to 50° C., and (ii) at least one fire retardant corresponding to formula (I) RF-L-RH  (I) in which RF is a perfluorinated or partially fluorinated group, RH is a hydrocarbon-based group, and L is a linker. The invention also relates to the use of at least one fire retardant of formula (I), in a composition for cooling a propulsion system of an electric or hybrid vehicle, and more particularly its power electronics and its batteries, to give it ignition-resistance properties, said cooling composition comprising at least one hydrocarbon-based fluid with a boiling point of greater than or equal to 50° C.
Finally, the invention relates to a process for cooling and fire-protecting at least one battery of a propulsion system of an electric or hybrid vehicle, comprising at least one step of placing at least one battery in contact with a composition according to the invention.