The invention provides an apparatus and method for producing multilayer laminates of polymeric electrolyte material incorporating one of more electrode layers. The apparatus (40) comprises an extrusion apparatus (42) for extruding a polymeric material (76) and a pair of heated rollers (46, 48) between which the material (76) and electrodes (60, 68, 72) are pressed in order to produce a continuous extrudate (80). The method may also include producing a gellable mixture comprising a crystallisable polymer and an aprotic organic liquid, forming the mixture as an elongate tape and contacting the tape with an electrode material. A compression and heating step may be present.