Siemens Aktiengesellschaft

Herbert Hartnack

Arno Mattejat

Josef Lersch

Igor Mehltretter

Joachim Hoffmann

Albert Hammerschmidt

Karl Strasser

Florian Eder

Armin Datz

Torsten Brandt

Frank Baernreuther

Anett Eder

Frank Barnreuther

Frank BÄRNREUTHER

An electrochemical cell has at least one plate element which can be cooled by a liquid coolant, such as water. The plate element has a surface that can be wetted for the purpose of cooling with the coolant. The surface of the plate element in the electrochemical cell is configured such that a contact angle between the surface and the liquid coolant is less than 90&#xb0;. In the method for producing the electrochemical cell an additional method step is carried out which influences the wettable surfaces of plate elements for cooling with coolant and by which a contact angle between the surface and the coolant is decreased.

Electrochemical cell

The invention relates to a contact device which is arranged in a terminal compartment of a fuel cell stack and is used to electrically contact the fuel cell stack. According to the invention, the surface of said contact device is at least partially provided with a hydrophobic surface layer, facilitating the removal of water, e.g., condensation water, from the terminal compartment and thus from the fuel cell stack.

Contact device and fuel cell stack or fuel cell block comprising one such contact device

The invention relates to an electrochemical battery, in particular a fuel cell battery or electrolytic cell battery comprising several electrolytic electrode units, a number of cooling cards for respectively cooling at least one of the electrolytic electrode units and at least one pressure chamber, which can be impinged by a pressure independently of the media supply of the electrolytic electrode units, for creating a contact pressure between components of the electrochemical battery that adjoin the pressure chamber. The pressure chamber adjoins at least one of the cooling cards and is at least partly delimited by said cooling cards.

Electrolytic cell or fuel cell with pressure pads and improved transfer resistance

When an insulator is used in a humid atmosphere, the cooling thereof causes a humidity condensation, which is deposited on the insulator surface. Drops of water formed by the humidity condensation are connected to each other that a water film substantially reducing the insulation resistance of the insulator is formed. In order to solve said problem, the inventive insulator is provided, at least partially, with a hydrophobe surface. In such a way, the water layers formed by condensation are drained off the surface or detached there from without connection and the drops of water produced by condensation are unable to be bound to each other, thereby making it possible to maintain a desired high insulation resistance.

Insulator with enhanced insulating capacity

During the humidification of operating gases for a fuel cell, the operating gases cool to such an extent as a result of the loss of evaporation heat that they cannot absorb humidity to prevent damage to the membrane of the fuel cell. To solve this problem, a fuel cell assembly includes a humidification cell, which contains a planar heating element. The humidification cell is configured in terms of shape, location and materials in the same way as a fuel cell of the fuel-cell stack.

Fuel-cell stack

The fuel cell block has stacked elements. At least two adjacent elements define an intermediate space between them. Radial channels are formed between the two elements or in one of the elements. The radial channels connect the space to an axial channel through the stack. At least one of the radial channels is a blind channel which, in contrast with the other radial channels, does not allow fluid communication between the space and the axial channel. The number of radial channels that are configured as blind channels influences the quantity of operating medium flowing through the intermediate space.

Fuel cell block

The composite conductor plate of a low-temperature fuel cell poses the following problem: it must be extremely corrosion-resistant to pure oxygen that is humidified by water and to pure hydrogen and must at the same time be able to be processed mechanically. To solve the problem, a composite conductor plate contains 50 to 60 wt. % Ni, 12 to 22 wt. % Cr, 10 to 18 wt. % Mo, 4 to 10 wt. % Fe and 0.5 to 5 wt. % W.

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Erlangen, Germany

Herbert Hartnack