Separator materials play an important part in lithium nonaqueous rechargeable battery operation. Their wettability limits the performances of batteries. To avoid wetting agents or undesirable substances to the electrode system, grafted separators are used. Acrylic acid (AA) and diethyleneglycol-dimethacrylate (DEGDM) are grafted onto 50 mu m polypropylene films. The physicochemical properties of the polymer films obtained are studied versus the characteristics of grafting. The influence of temperature and monomer content on grafting kinetics is pointed out. Cycling performances of secondary lithium batteries including these grafted films as separators are also presented.∧