Bipolar plate for a fuel cell, and fuel cell

Patent metadata

Field	Value
Publication number	US-2022006106-A1
Application number	US-201917265156-A
Country	US
Kind code	A1
Filing date	Jul 8, 2019
Priority date	Aug 2, 2018
Publication date	Jan 6, 2022
Grant date	—

Abstract

A bipolar plate for a fuel cell has flow channels for the reactants formed between webs in a plate body, and lines for a coolant, and has hydrophilic structures associated with the plate body formed in a gradient. The gradient of hydrophilic structures is associated with the web with hydrophilicity increasing towards the bottom of the flow channels, wherein microchannels to the flow channels, opening into the flow channels and generating capillary force, are formed in the boundary surface of the webs.

First claim

1 . A bipolar plate for a fuel cell, comprising:
flow channels for reactants formed between webs in a plate body; lines for a coolant; and hydrophilic structures arranged in a gradient associated with the plate body, wherein the gradient of hydrophilic structures is associated with the webs with hydrophilicity increasing towards bottoms of the flow channels, and wherein microchannels to the flow channels, opening into the flow channels and generating capillary force are formed in boundary surfaces of the webs.

2 . A bipolar plate according to claim 1 , wherein the bipolar plate is formed of a hydrophilic material.

3 . A bipolar plate according to claim 1 , wherein the hydrophilic structures are formed as a coating of the webs.

4 . A bipolar plate according to claim 1 , wherein areal density of the mouths of the microchannels increase from edges to the bottoms of the flow channels.

5 . A bipolar plate according to claim 1 , wherein the microchannels are oriented perpendicular to the boundary surfaces.

6 . A bipolar plate according to claim 1 , wherein the bottoms of the flow channels are more hydrophilic than the webs in adjacent areas.

7 . A fuel cell, comprising:
a membrane electrode arrangement; a first bipolar plate on a first side of the membrane electrode arrangement, the first bipolar plate including:
first flow channels for a first reactant formed between first webs in a first plate body;
first lines for a coolant; and
first hydrophilic structures arranged in a gradient associated with the first plate body,
wherein the gradient of first hydrophilic structures is associated with the first webs with hydrophilicity increasing towards bottoms of the first flow channels, and
wherein microchannels to the first flow channels, opening into the first flow channels and generating capillary force are formed in boundary surfaces of the first webs;
a second bipolar plate on a second side of the membrane electrode arrangement, the second bipolar plate including:
second flow channels for a second reactant formed between second webs in a second plate body;
second lines for the coolant; and
second hydrophilic structures arranged in a gradient associated with the second plate body,
wherein the gradient of second hydrophilic structures is associated with the second webs with hydrophilicity increasing towards bottoms of the second flow channels, and
wherein microchannels to the second flow channels, opening into the second flow channels and generating capillary force are formed in boundary surfaces of the second webs;
a first gas diffusion layer arranged between the membrane electrode arrangement and the first bipolar plate; and a second gas diffusion layer arranged between the membrane electrode arrangement and the second bipolar plate.

8 . The fuel cell according to claim 7 wherein the first and second bipolar plates exhibit greater hydrophilicity in areas of the webs facing the gas diffusion layer than in the gas diffusion layer.

Assignees

• Audi Ag
• Volkswagen Ag

Inventors

• Kirsch Sebastian

Classifications

• H01M8/0258

  characterised by the configuration of channels, e.g. by the flow field of the reactant or coolant · CPC title

• H01M8/0267 Primary

  having heating or cooling means, e.g. heaters or coolant flow channels · CPC title

• H01M8/026 Primary

  characterised by grooves, e.g. their pitch or depth · CPC title

• Y02E60/50

  Fuel cells · CPC title

• H01M8/0228

  in the form of layered or coated products · CPC title