International Fuel Cells, LLC

Utc Fuel Cells, LLC

Michael J Rajpolt

Richard D Breault

John C Trocciola

Myron Krasij

Albert P Grasso

A sub-stack assembly of a number of cells bonded together with thermoplastic film is disclosed. Each of the individual cell components are bonded to one another with thermoplastic film . A number of sub-stack assemblies are stacked and sealed relative to one another by a soft compliant gasket seal , such as a foam rubber or other suitable materials. As a result, only one soft foam rubber seal would be required for each sub-stack assembly rather than for every cell.

Bonded fuel cell stack assemblies

An improved membrane electrode assembly for PEM fuel cells is provided. Catalyst layers (40, 44) are disposed, respectively, on both sides of the proton exchange membrane (48). Gas diffusion layers (38, 50) are disposed, respectively, on sides of the catalyst layers (40, 44) not in contact with the proton exchange membrane (48). Porous substrates (32, 34) are disposed, respectively, on sides of the gas diffusion layers (38, 50) not in contact with the catalyst layers (40, 44). The porous substrates (32, 34) are impregnated at their periphery with a thermoplastic material. Thermoplastic film layers (42, 46, 68) are employed at the periphery of the assembly (10) between component parts to bond and seal water transport plates (12' and 16) to each other, as well as substrates (32, 32', 34) to the membrane electrode assembly (20). A foam tape 60, 62, 62' are employed to seal water transport plates (12, 12', 16) to respective substrates (32, 32', 34).

Use of thermoplastic films to create seals and bond PEM cell components

A seal structure 60 for a porous plate of an electrochemical cell, such as plates 18, 20, includes a sealing material disposed in a seal region 66 of the plate to form a hydrophilic barrier to gas with an electrolyte and a hydrophobic layer 62 to block the loss of electrolyte from the hydrophilic layer is disclosed. Various construction details including a method for making the plate are disclosed which increase the cross pressure the sealing region of the plate can withstand. In one embodiment, the seal region 66 is impregnated with powder having a low structure and predetermined particle size using a pressurized liquid carrier. A FEP Teflon film bonds adjacent electrolyte reservoir plates together.

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Marlborough, CT, United States of America

Michael J Rajpolt