NOVELTY - A bipolar plate cooler module for fuel cell stacks has complementary grooves for sealing material on both sides of each pole plate, an integral, injection moulded sealing element to fix and seal the plates together, and a compressible, conductive element between the cooling surfaces to compensate for shrinkage of sealing material on cooling.    USE - As a plate cooler module for a fuel cell stack.    ADVANTAGE - Plate cooler modules which can be combined with membrane electrode units to form a complete sub-assembly for a fuel cell stack with a reliable seal for the coolant distribution structure between the pole plates and for the interfaces between pole plates and electrodes.    DETAILED DESCRIPTION - A bipolar plate cooler module for a fuel cell stack comprises:    (a) a cathode-side pole plate (7a) and an anode-side pole plate (7b) each with grooves (26a, 26b) for sealing material in the surfaces facing the cathode (3) or anode (2) (to seal the interfaces with the electrodes) and with complementary grooves (22a, 22b) on the other sides (facing each other and acting as cooling surfaces) to hold sealing material for sealing the gap (27) between the cooling surfaces, at least one of which has a coolant distribution structure comprising open channels (19a or 19b) and enclosed within the sealing groove (22a, 22b);    (b) an integral sealing element (25) made of injection mouldable material which encompasses and/or penetrates both pole plates, fixes them in position as a composite, fills the complementary grooves (22a, 22b), seals the gap (27), fills the grooves (26a, 26b) on the plate surfaces facing the electrodes (2, 3) and seals the interfaces between plate (7a) and the cathode (3) and between plate (7b) and the anode (2'); and    (c) a compressible, conductive, flat element (28) between the cooling surfaces of the plates (7a, 7b), with a reserve compression which is greater than the cooling-induced thickness shrinkage of the sealing material in grooves (22a, 22b) , which extends only over the area enclosed by grooves (22a, 22b) and containing the coolant distribution structure.    An INDEPENDENT CLAIM is also included for a method for the production of a module as above by:    (a) preforming the pole plates (7a, 7b);    (b) inserting a compressible sealing element (28) between the plates over the area enclosed by the sealant grooves (22a, 22b);    (c) injecting the sealing material, filling the grooves (22a, 22b, 26a, 26b) and forming the sealing element (25);    (d) cooling the sealing material; and    (e) demoulding the assembly.    DESCRIPTION OF DRAWING(S) - The diagram shows a plate cooler module with a sealing element encompassing the pole plates. (Drawing includes non-English language text).    Pole plates (7a, 7b)    Through hole (8)    Coolant channels (19a,19b)    Sealing grooves (22,26)    Coolant feed (23)    Sealant element (25)    Compressible element (28)    Recess for compressible element (30)