Production of moulded products, especially film includes the following stage (I): compounding and melt-extrusion of a mixture (I) containing 1-100 wt% of a mixture (II) comprising (a) 1-95 wt% pigment(s) (III) with a primary particle size of 5 nm to 20 microns, selected from an electrochemically inert solid (IIIa), a compound (IIIb) which is able to release lithium ions on charging, a compound (IIIc) which is able to take up Li ions on charging, and a mixture of (IIIa) with (IIIb) or (IIIc), (b) 5-99 wt% copolymer(s) (IV) of vinylidene fluoride (VDF) and hexafluoropropylene (HFP) with an HFP content of 8-25 wt% and (c) 1-200 wt% (based on a + b) of a plasticiser (V) selected from dibutyl, dimethyl or diethyl phthalate, tris-(butoxyethyl) phosphate, propylene or ethylene carbonate, trimethyl trimellitate, or a mixture of two or more of these. Also claimed are: (i) a process for the production of composite products comprising (I) forming first layer(s) by compounding and melt-extruding mixture (I) as above, (II) forming second layer(s) by compounding a mixture (I) containing a mixture (II) which contains a solid (IIIa) but not (IIIb) or (IIIc), and then (III) combining these layers by a conventional coating process; (ii) moulded products, especially film, obtained by process stage I; (iii) composite products obtained by the complete process as in (i); (iv) separators, solid electrolytes, electrodes, sensors, electrochromic windows, displays, condensers or ion-conducting film containing moulded products or composites as above; and (v) electrochemical cells containing a separator, solid electrolyte or electrode as in (iv), or a combination of two or more of these.    USE -   For the production of components (see above) of lithium ion batteries, especially car batteries, batteries for instruments or flat batteries.    ADVANTAGE -   An improved process enabling the production of film and composite film with a special micro-structure and better mechanical properties. Separators, solid electrolytes and electrodes made by this process have better short circuit resistance, higher compressive strength and greater porosity than prior-art materials, and also suppress the formation of lithium dendrites. The use pigment (III) results in cells with an improved cycle stability and a higher power rating, in which acids can be neutralised by using a basic component (IIIa). The process requires no solvent, no drying or extraction of film, and no further treatment before using the film in a battery; it ensures a homogeneous dispersion of pigment and gives films with better mechanical stability than cast film.