(US4649091-A)      Internally cooled, bipolar, reactant flow-defining assemblies are used to separate the ion exchange membranes of adjacent cells. Coolant flow through the interior of the separator is controlled to cool one side more than the other. The cooler side of one separator contacts the fuel side of a membrane, and the warmer side of the adjacent separator contacts the oxidant side.    Membrane (11), anode (19) and one side of separator (12) form an anode chamber. A cathode is bonded to the other side of the membrane (11) and to separator (13) to form a cathode chamber.    ADVANTAGE -   Achieves effective temp. control to minimise membrane drying on fuel gas side.    (10pp)    (US4678724-A)      A fuel cell battery comprising at least two adjoining fuel cells of the type including a membrane with anodes and cathodes in intimate electrical contact, has fuel and oxygen gases supplied to the anode and cathode electrode of each cell.    The anode side of the membrane is maintained cooler than the cathode side, and cooler than it would normally by to minimise anode side drying of the membrane.    The cooling is preformed by electrically conductive bipolar separators positioned between electrodes of adjacent cells opposite sides of the separators having projections contacting the electrodes.    The bipolar separators are differentially cooled on opposite sides, the cooler side contacting the anode in contact with the membrane of one cell and the other side contacting cathode of the adjacent cell whereby an increased temperature differential is established across each membrane.    (11pp)    (DE3321984-C)      The fuel cell battery has at least two adjacent fuel cells, each consisting of the following component parts: a hydrogenated ion exchanging diaphragm (11), an anode (19) and a cathode electrode (40) in intimate contact with the opposite lying surfaces of the diaphragm (11).    A unit is provided respectively for the supply of fuel gas to the anode and an oxidising gas to the cathode of each cell, also a unit is set up, in order to give a temp. difference across the diaphragm (11), hence the anode electrode side is maintained colder than the cathode side.    ADVANTAGE -   Allows continuous operation with greater current density and higher power output. Effective temp. control is attained so that drying out of diaphragm on side of fuel gas is kept as small as possible.