# US 9,520,600 B2 · Conductive and hydrophilic bipolar plate coatings and method of making the same

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 9,520,600 B2
- Document ID: US9520600B2
- Status: Granted
- Kind: B2
- Application number: 12/564,344
- Filed: 2009-09-22
- Published: 2011-03-24
- Granted: 2016-12-13
- Earliest claimed: 2009-09-22
- Assignees: GM Global Technology Operations LLC
- Applicants: Gayatri Vyas Dadheech; Michael J. Lukitsch
- Inventors: Gayatri Vyas Dadheech; Michael J. Lukitsch
- Web page: https://patentgrep.com/patent/US9520600B2

## CPC

- H01M 8/0228: in the form of layered or coated products
- H01M 2008/1095: {Fuel cells with polymeric electrolytes}
- Y02E 60/50: Fuel cells
- Y02P 70/50: Manufacturing or production processes characterised by the final manufactured product
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS

## Abstract

A flow field plate for fuel cell applications includes a metal with a carbon layer disposed over at least a portion of the metal plate. The carbon layer is overcoated with a titanium oxide layer to form a titanium oxide/carbon bilayer. The titanium oxide/carbon bilayer may be activated to increase hydrophilicity. The flow field plate is included in a fuel cell with a minimal increase in contact resistance. Methods for forming the flow field plates are also provided.

## Claims

### Claim 1

A flow field plate for fuel cell applications comprising:
a metal plate having a first surface and a second surface, the first surface defining a plurality of channels for directing flow of a first gaseous composition;
a carbon layer disposed over and directly connected to at least a portion of the metal plate; and
a titanium oxide layer disposed over and directly connected to at least a portion of the carbon layer to form a titanium oxide/carbon bilayer wherein the titanium oxide/carbon bilayer is activated by a UV or plasma source to render the titanium oxide/carbon bilayer surface clean and maintain hydrophilicity.

### Claim 2 (depends on 1)

The flow field plate of claim 1 wherein the titanium oxide/carbon bilayer has a surface with a contact angle less than 40 degrees.

### Claim 3 (depends on 1)

The flow field plate of claim 1 wherein the contact resistance is less than 40 mohm-cm2 when the flow field plate is sandwiched between carbon papers at 200 psi.

### Claim 4 (depends on 1)

The flow field plate of claim 1 wherein the titanium oxide layer is selectively deposited on a plurality of walls of the channels.

### Claim 5 (depends on 1)

The flow field plate of claim 1 further comprising one or more additional titanium oxide/carbon bilayers disposed over at least a portion of the titanium oxide/carbon bilayer.

### Claim 6 (depends on 1)

The flow field plate of claim 1 wherein the titanium oxide layer includes hydrocarbons in an amount that is less than 40 weight percent of the total weight of the titanium oxide layer.

### Claim 7 (depends on 1)

The flow field plate of claim 1 wherein the titanium oxide layer includes hydrocarbons in an amount that is less than 20 weight percent of the total weight of the titanium oxide layer.

### Claim 8 (depends on 1)

The flow field plate of claim 1 wherein the carbon layer comprises amorphous carbon.

### Claim 9 (depends on 8)

The flow field plate of claim 8 wherein the carbon layer has a surface including on average at least 5 pores per cm2.

### Claim 10 (depends on 1)

The flow field plate of claim 1 wherein the titanium oxide layer comprises a component selected from the group consisting of TiO2 , titanium suboxides, titanium oxide hydrate and mixtures thereof.

### Claim 11 (depends on 1)

The flow field plate of claim 1 wherein the titanium oxide layer comprises an amphorous titanium oxide or a polycrystalline titanium oxide.

### Claim 12 (depends on 1)

The flow field plate of claim 1 wherein the metal plate has a second surface defining a second plurality of channels for directing flow of a second gaseous composition.

### Claim 13 (depends on 12)

The flow field plate of claim 12 wherein the second surface is a second non-crystalline carbon layer.

### Claim 14

A flow field plate for fuel cell applications comprising:
a metal plate having a first surface and a second surface, the first surface defining a plurality of channels for directing flow of a first gaseous composition;
a carbon layer disposed over and directly connected to at least a portion of the metal plate; and
a titanium oxide layer disposed over and directly connected to at least a portion of the carbon layer to form a titanium oxide/carbon bilayer wherein the titanium oxide/carbon bilayer is activated by visible light after treatment with a nitrogen-containing gas.