Novel fuel cell fluid flow field plate

Claim 2

A fluid flow field plate for use in a solid polymer electrolyte fuel cell, said plate being made of a suitable electrically conducting material and formed in a major surface thereof a single continuous open-faced fluid flow channel, said channel having a fluid inlet at one end and a fluid outlet at the other end, wherein said channel traverses a major central area of said surface in a plurality of passes, and wherein said plate further includes a fluid supply opening and a fluid exhaust opening defined in said surface and directly connected to said fluid inlet and to said fluid outlet, respectively.

Claim 3

A fluid flow plate according to claim 1, wherein the channel follows a serpentine traversing path.

Claim 4

A fluid flow plate according to claim 1, wherein the channel traverses the major surface of the plate in a plurality of alternating closely spaced longer and shorter passes.

Claim 5

A fluid flow plate according to claim 1, wherein in said major surface, adjacent channel passes are separated by lands.

Claim 6

A fluid flow plate according to claim 1, wherein a channel is formed in both major surfaces of the plate.

Claim 7

A fluid flow plate according to claim 1, wherein the plate is a rigid non-porous graphite plate.

Claim 8

A fluid flow plate according to claim 1, wherein the channel comprises a base and opposing side walls diverging outwardly from said base toward said open-face.

Claim 9

A fluid flow plate according to claim 7, wherein the base of the channel is flat.

Claim 10

A fluid flow plate according to claim 1, wherein the channel is of uniform depth throughout the length of the channel.

Claim 11

A fluid flow plate according to claim 1 wherein the channel includes a hydrophobic coating thereon.

Claim 12

A fluid flow plate according to claim 10, wherein the hydrophobic coating is selected from the group consisting of polytetrafluoroethylene and silicone.

Claim 13

A fluid flow plate according to claim 1, wherein the major central area of the plate is recessed to accommodate an electrode of said fuel cell.

Claim 14

A fluid flow plate according to claim 12, wherein opposing plates in said fuel cell include matching recesses.

Claim 15

A fluid flow plate according to claim 4, wherein the lands are of a width less than the width of the open-face of the channel.

Claim 16

A fluid flow plate according to claim 14, wherein the width of the open-face of the channel is in the range of 0.030 to 0.240 inches.

Claim 17

A fluid flow plate according to claim 15, wherein the land width is in the range of 0.010 to 0.200 inches.

Claim 18

A fluid flow plate according to claim 16, wherein the width of the open-face of the channel is in the range of 0.40 to 0.100 inches.

Claim 19

A fluid flow plate according to claim 17, wherein the width of the open-face of the channel is in the range of 0.045 to 0.055 inches.

Claim 20

A fluid flow plate according to claim 18, wherein the width of the open-face of the channel is about 0.050 inches.

Claim 21

A fluid flow plate according to claim 16, wherein the land width is in the range of 0.020 to 0.100 inches.

Claim 22

A fluid flow plate according to claim 20, wherein the land width is in the range of 0.035 to 0.055 inches.

Claim 23

A fluid flow plate according to claim 20, wherein the land width is about 0.040 inches.

Claim 24

A fluid flow plate according to claim 1, wherein the suitable electrically conducting material is selected from the group consisting of graphite; a corrosion-resistant material; a base metal plated with a corrosion resistant metal; and a composite material composed of a corrosion-resistant metal powder, a base metal powder plated with a corrosion resistant metal or other chemically inert electrically conducting powders, bonded together with a suitable binder.

Claim 25

A fluid flow plate according to claim 23, wherein the suitable electronically conducting material is graphite.

Claim 26

A fluid flow plate according to claim 23, wherein the suitable electronically conducting material is niobium.

Claim 27

A fluid flow plate according to claim 23, wherein the suitable binder is polyvinylidene fluoride.

Claim 28

A fluid flow plate according to claim 23, wherein the composite material composes 10-30%/w of polyvinylidene fluoride and 90-70%/w of graphite powder.

Claim 29

A fluid flow plate according to claim 16, wherein the channel depth is in the range of 0.010 to 0.250 inches.

Claim 30

A fluid flow plate according to claim 28, wherein the channel depth is in the range of 0.030 to 0.150 inches.

Claim 31

A fluid flow plate according to claim 29, wherein the channel depth is in the range of 0.040 to 0.080 inches.

Claim 32

A fluid flow plate according to claim 30, wherein the channel depth is about 0.050 inches.

Claim 33

A fluid flow plate according to claim 1, wherein the width of the open-face of the channel is in the range of 0.030 to 0.240 inches.

Claim 34

A solid polymer electrolyte fuel cell comprising: an anode; a cathode; a solid polymer electrolyte sandwiched between said anode and cathode; and a pair of opposing fluid flow field plates in respective operative association with said anode and cathode, one of said field plates having a first fluid flow field adjacent said anode for supplying fuel thereto and exhausting reaction products therefrom, and the other of said field plates having a second fluid flow field adjacent said cathode for supplying an oxidant thereto and exhausting reaction products therefrom, wherein said fluid flow field plates are each made of a suitable electrically conducting material and define in a major surface thereof a single continuous open-faced fluid flow channel corresponding respectively to said first and second fluid flow fields; each said channel having a fluid inlet at one end and a fluid outlet at the other end, said channel traversing a major central area of said surface in a plurality of passes, and wherein each said fluid flow field plate further includes a fluid supply opening and a fluid exhaust opening defined in said surface and respectively directly connected to said fluid inlet and to said fluid outlet of each said channel.

Claim 35

A solid polymer electrolyte fuel cell comprising: an anode; a cathode; a solid polymer electrolyte sandwiched between said anode and cathode; and a pair of opposing fluid flow field plates in respective operative association with said anode and cathode, one of said field plates having a first fluid flow field adjacent said anode for supplying fuel thereto and exhausting reaction products therefrom, and the other of said field plates having a second fluid flow field adjacent said cathode for supplying an oxidant thereto and exhausting reaction products therefrom, wherein said fluid flow field plates are each made of a suitable electrically conducting material and define in a major surface thereof a single continuous open-faced fluid flow channel corresponding respectively to said first and second fluid flow fields; each said channel having a fluid inlet at one end and a fluid outlet at the other end, said channel traversing a major central area of said surface in a plurality of passes, and wherein each said fluid flow field plate further includes a fluid supply opening and a fluid exhaust opening defined in said surface and respectively directly connected to said fluid inlet and to said fluid outlet of each said channel.

Claim 36

A fuel cell as in claim 33, wherein each said channel follows a serpentine traversing path.

Claim 37

A fuel cell as in claim 33, wherein each said fluid flow plate is a rigid non-porous graphite plate.

Claim 38

A fuel cell as in claim 33, wherein at least one of said fluid flow plates has a major central area that is recessed to accommodate at least one of said anode and cathode.