Electrolyzer cell arrangement

Abstract

Some embodiments of the present invention provide electrolyzer cells in which distribution of water over the surface of an electrolyte layer (e.g. a MEA) is improved. Specifically, some embodiments provide an electrolyzer cell, including a flow field plate arranged in combination with at least two porous metal layers having smooth and flat surfaces, in which water is more uniformly distributed across an active surface of an electrolyte layer, which in turn may lead to a more uniform reaction rate over the active area of the electrolyte layer. Other related embodiments also include simplifications that may reduce costs related to manufacturing and assembly of electrochemical cells.

Description

PRIORITY CLAIM [0001] This application claims the benefit, under 35 USC 119(e), of U.S. Provisional Application Nos. 60 / 504,220 and 60 / 504,223 which were filed on Sep. 22, 2003; and, the entire contents of each of the U.S. Provisional Application Nos. 60 / 504,220 and 60 / 504,223 are hereby incorporated by reference. Moreover, this application is also a continuation-in-part of U.S. Application No. [Attorney Ref: 9351-444], entitled “Flow Field Plate Arrangement”, which was filed on Aug. 13, 2004, and the entire contents of which is also hereby incorporated by reference.FIELD OF THE INVENTION [0002] The present invention relates to electrochemical cells, and, in particular to various arrangements of electrolyzer cells. BACKGROUND OF THE INVENTION [0003] An electrolyzer cell is a type of electrochemical cell that uses electricity to electrolyze water (H2O) into hydrogen (H2) and oxygen (O2). Generally, an electrolyzer includes an anode electrode, a cathode electrode and an electrolyte la...

AI Technical Summary

Benefits of technology

The invention provides an electrolyzer cell with improved electrochemical performance. The cell includes an anode flow field plate, a cathode flow field plate, and an electrolyte layer arranged between the two plates. The plates have openings that allow for the flow of process gas and heat. The cell also includes first and second flat screens that have a plurality of openings. The screens are positioned between the anode and cathode flow field plates and the electrolyte layer. The screens have a shape that is at least partially hexagonal, circular, square, or triangular. The openings of the screens have the same area. The cell also includes a coolant flow field plate and a manifold aperture that supply and evacuate coolant. The openings of the screens have the same area. The invention also provides an electrochemical cell stack with improved performance.

Problems solved by technology

However, the lateral distribution of water is impeded by the entangled edges of the screens.

For similar reasons, the screens also impede the evacuation of product gases from the surface of the electrolyte layer where the electrolysis reactions occur.

Thus, due in part to the impediments to flow introduced by the layers of woven screens, a conventional electrolyzer cell inherently includes areas of restricted flow that limit water and product gas flow which, in turn results in a poor use of the available reaction area, occasional flooding and / or poisoning.

Understandably, efficiency and overall performance is typically reduced as a result.

However, for PEM electrolyzer cells, the contact resistance between a flow field plate and a MEA is typically high which is undesirable.

It is also difficult to control the flow, pressure and temperature of the process gases / fluids across most flow field plates, since conventional flow field structures provide numerous places for water and contaminants to accumulate, increasing the risk of flooding and / or poisoning an electrolyzer cell.

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