Abstract: The invention concerns a composite plate for Pb/PbO2 batteries with bipolar electrodes, characterized by unidirectional electronic conduction provided by metal wires made at least at the surface of lead or lead alloy, arranged in a regular array and coated with a polymer, stable in an acid medium and capable of generating a strong bonding with the lead or lead alloy constituting the wire surface—the wire volume representing only at most 4% of the plate total volume at most. Hence the mass per unit area thereof remains of the order of 15 g/km2.

Abstract: The invention concerns a bipolar collector for a solid polymer electrolyte fuel cell whereof the electronic conduction is provided by uniformly distributed metal cylinders, and whereof the tips penetrate into the electrodes. The minimal distance between two cylinders ranges between 2 and 4 mm and the tightness between the two surfaces is provided by a polymer plate wherein the cylinders are inserted. Said design is applicable to plates incorporating ducts for transporting fluids or plates whereon are arranged, on either side, microporous structures serving as fluid distributor. Said type of collector is characterised in that the ohmic drop is very low, even for current density levels of the order of 1 A/cm2.