the present invention relates to polymers used as rolling lubricating agents , to compositions comprising said polymers , and to alkali metal films including the polymers or compositions on the surface thereof . the use of said polymers and compositions is also described for strip - rolling alkali metals or alloys thereof in order to obtain thin films . methods for producing said thin films , which are suitable for use in electrochemical cells , are also described . the present invention proposes an improved lubricant according to formula i , which , for example , achieves enhanced conductivity , and / or enables the production of electrochemical cells having an improved life span in cycles .