The present invention relates to a composition for lubricating a propulsion system of an electric or hybrid vehicle, comprising at least one base oil and 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 lubricating a propulsion system of an electric or hybrid vehicle, including at least one battery, to give it ignition-resistance properties.
Finally, the invention relates to a process for cooling and fire-protecting a battery of a propulsion system of an electric or hybrid vehicle, comprising at least one step of placing at least one battery, in particular a lithium-ion or nickel-cadmium battery, in contact with a composition according to the invention.