US 2019/0058204 A1Published application

Protective interlayer coating on gdl against mea shorting

AssigneeGM Global Technology Operations LLC

InventorsYEH-HUNG LAI, ROLAND J. KOESTNER, SRIKANTH ARISETTY, MEHUL M. VORA

Life of this patent

Estimating the term…

Loading patent…

Abstract

A membrane-electrode assembly (MEA) for use in electrical applications, for example in polymer electrolyte fuel cells (PEFCs), includes a protective high-stiffness interlayer coating interposed between a gas diffusion layer and an ion conducting membrane layer, and includes also a catalyst layer. The interlayer mitigates electrical shorting across the ion conducting membrane layer, for example by providing mechanical support against fiber protrusions from the gas diffusion layers into the ion conducting membrane layer or by smoothing the roughness of the gas diffusion layer. The interlayer is typically a mixture of carbon black and one or more ionomers, and its properties are controlled by modulating its thickness, mechanical modulus, ionomer loading, and electrical conductivity.

Claims19

Dependent claims

A membrane-electrode assembly comprising:

a polymeric ion conducting membrane layer having a cathode side and an anode side;
a cathode catalyst layer disposed over the cathode side;
an anode catalyst layer disposed over the anode side;
a first gas diffusion layer disposed over the cathode catalyst layer;
a second gas diffusion layer disposed over the anode catalyst layer;
a first high-stiffness interlayer interposed between the cathode catalyst layer and either the first gas diffusion layer or the polymeric ion conducting membrane layer;
and
a second high-stiffness interlayer interposed between the anode catalyst layer and either the second gas diffusion layer or the polymeric ion conducting membrane layer;
wherein the first high-stiffness interlayer and the second high-stiffness interlayer each independently has a stiffness from about 5 N/mm to about 30 N/mm;
wherein the first high-stiffness interlayer and the second high-stiffness interlayer each independently has a porosity from about 0% to about 80% v/v;
and
wherein the first and second high-stiffness interlayer reduce the soft short density of the membrane-electrode assembly by about at least a factor of 2 relative to an otherwise identical assembly having no high-stiffness interlayer by providing mechanical support against fiber protrusions from the first and second gas diffusion layers into the polymeric ion conducting membrane layer or by smoothing the roughness of the first and second gas diffusion layers.

9 more elements

A polymer electrolyte fuel cell comprising:

a first electrically conductive flow field plate, further comprising a first gas channel;
a second electrically conductive flow field plate, further comprising a second gas channel;
and
a membrane-electrode assembly comprising:
a polymeric ion conducting membrane layer having a cathode side and an anode side;
a cathode catalyst layer disposed over the cathode side;
an anode catalyst layer disposed over the anode side;
a first gas diffusion layer disposed over the cathode catalyst layer;
a second gas diffusion layer disposed over the anode catalyst layer;
a first high-stiffness interlayer interposed between the cathode catalyst layer and either the first gas diffusion layer or the polymeric ion conducting membrane layer;
and
a second high-stiffness interlayer interposed between the anode catalyst layer and either the second gas diffusion layer or the polymeric ion conducting membrane layer;
wherein the first high-stiffness interlayer and the second high-stiffness interlayer each independently has a stiffness of at least about 5 N/mm;
and
wherein the first and second high-stiffness interlayer reduce the soft short density of the membrane-electrode assembly by about at least a factor of 2 relative to an otherwise identical assembly having no high-stiffness interlayer by providing mechanical support against fiber protrusions from the first and second gas diffusion layers into the polymeric ion conducting membrane layer or by smoothing the roughness of the first and second gas diffusion layers and the membrane-electrode assembly is interposed between the first and second electrically conductive flow field plates;

12 more elements

Dependencies are inferred from the claim text.