Molding process for making fuel cell components

Patent metadata

Field	Value
Publication number	US-2017012298-A1
Application number	US-201415121204-A
Country	US
Kind code	A1
Filing date	Feb 27, 2014
Priority date	Feb 27, 2014
Publication date	Jan 12, 2017
Grant date	—

Abstract

An illustrative method of making a fuel cell component includes obtaining at least one blank plate including graphite and a polymer; establishing a temperature of the blank that is sufficient to maintain the polymer in an at least partially molten state; and applying a compression molding force to the blank until the polymer is essentially solidified to form a plate including a plurality of channels on at least one side of the plate. The blank plate has a central area having a first thickness. The blank plate also has two generally parallel edges on opposite sides of the central area. The edges have a second thickness that is greater than the first thickness.

First claim

1 - 17 . (canceled)

18 . A method of making a fuel cell component, comprising the steps of:
obtaining at least one blank plate comprising graphite and a polymer; establishing a temperature of the blank plate that is sufficient to maintain the polymer in an at least partially molten state; and applying a compression molding force to the blank plate at least until the polymer essentially solidifies to form a plate including a plurality of channels on at least one side of the plate; wherein the blank plate has a central area having a first thickness; wherein the blank plate has two generally parallel edges on opposite sides of the central area; and wherein the edges have a second thickness that is greater than the first thickness.

19 . The method of claim 18 , wherein obtaining the blank plate comprises extrusion molding a mixture of the graphite and the polymer to form the blank plate.

20 . The method of claim 19 , comprising
extrusion molding the blank plate; subsequently transferring the blank plate into a compression mold while the temperature is the established temperature; and applying the compression molding force in the compression mold.

21 . The method of claim 19 , wherein
establishing the temperature of the blank plate occurs during the extrusion molding; and applying the compression molding force occurs subsequent to the extrusion molding and before the temperature of the extruded blank plate cools below the temperature at which the polymer is solidified.

22 . The method of claim 18 , wherein obtaining the blank plate comprises compression molding a mixture of the graphite and the polymer to form the blank plate.

23 . The method of claim 22 , wherein establishing a temperature of the blank plate comprises
heating the blank plate subsequent to the compression molding and prior to applying the compression molding force.

24 . The method of claim 18 , wherein the established temperature is at least 300° C.

25 . The method of claim 24 , wherein the established temperature is between 300° C. and 380° C.

26 . The method of claim 18 , comprising applying the compression molding force until the temperature of the plate is about 200° C.

27 . The method of claim 18 , wherein the compression molding force is at least 7,000 kPa (1000 psi).

28 . The method of claim 27 , wherein the compression molding force is between 7,000 kPa and 14,000 kPa (1000 psi and 2000 psi).

29 . The method of claim 18 , wherein
the formed plate has a first areal density along the central area; and the formed plate has a second, greater areal density along the two edges.

30 . The method of claim 18 , comprising
obtaining a first blank plate that has two generally parallel first edges that are thicker than a central portion of the first blank plate; obtaining a second blank plate that has two generally parallel second edges that are thicker than a central portion of the second blank plate; situating the first blank plate adjacent the second blank plate with the first edges generally perpendicular to the second edges; and applying the compression molding force to the situated first and second blank plates.

31 . The method of claim 18 , wherein the polymer comprises fluorinated ethylene propylene (FEP).

32 . The method of claim 18 , wherein the graphite comprises flake graphite.

33 . The method of claim 18 , wherein the formed plate comprises a bipolar separator plate.

Assignees

• Doosan Fuel Cell America Inc

Inventors

• Breault Richard D
• Tenneti Kishore Kumar

Classifications

• B29C43/02

  of articles of definite length, i.e. discrete articles {(B29C35/0227 takes precedence)} · CPC title

• H01M8/0258 Primary

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

• B29L2031/3468

  Batteries, accumulators or fuel cells (battery cases B29L2031/7146) · CPC title

• H01M8/0226

  in the form of mixtures · CPC title

• B29C43/021

  characterised by the shape of the surface · CPC title