Fuel cell plate

Abstract

The invention relates to a fuel cell plate (1) comprising a cooling face (10) provided with a cooling circuit (3) comprising a plurality of cavities (28) and teeth (2), the plurality of cavities (28) comprising a first cavity (8) forming the periphery of the cooling circuit (6) and comprising a first axial portion (31) extending along a first axis (22) and a second axial portion (32) extending along a second axis (23) orthogonal to the first axis, the cooling circuit (3) being configured such that there is at least one of the teeth (2) whose width is variable between a first axial segment and a second axial segment, the first and second segments extending along the first axis (22) and that there is at least one other of the teeth (2) whose width is constant at least when it extends axially along the first axis (22). Abstract figure: Fig. 1

Description

Title of the invention: Fuel cell plate

[0001] The present invention relates to a fuel cell plate, a fuel cell cell and a fuel cell.

[0002] The invention finds a particularly advantageous application with fuel cells whose plates are machined. The invention finds a particularly advantageous application with graphite plates.

[0003] In a manner known per se, a fuel cell is an electrochemical device which makes it possible to convert chemical energy into electrical energy from a fuel, generally dihydrogen, and an oxidant, generally dioxygen or a gas containing it such as air, the product of the reaction being water accompanied by a release of heat and a production of electricity.

[0004] According to a known configuration, the plates comprise on each face, reliefs and hollows, the hollows being obtained by machining the plate. These reliefs and hollows are used in particular for the production of circuits for the circulation of fluids.

[0005] When designing the geometry of the plate, it is necessary to find a good compromise to accommodate the fluid circulation circuits, forming in particular the active surface, but also the zones which are not dedicated to the electrochemical reaction, namely: collectors, joint grooves, connection orifices between collector and active surface.

[0006] It is also appropriate to provide space for the passage of a joint or a bead of glue for assembling two plates together, to form a bipolar plate.

[0007] A known solution is to move the connecting orifices away from the periphery of the fluid circulation circuits. One problem is that such an arrangement unnecessarily increases the overall surface area of the plate, which significantly increases the size of the fuel cell.

[0008] Conversely, by bringing the connecting orifices closer to the periphery of the fluid circulation circuits, the overall surface area of the cooling circuit is reduced compared to that of the reagent circuit and thermal management is affected.

[0009] The present invention aims to effectively overcome these drawbacks by proposing a fuel cell plate of the proton exchange membrane type, the plate comprising a first edge, a second edge opposite the first edge, a third edge, a fourth edge opposite the third edge, the plate comprising a reactive face and a cooling face opposite each other, the reactive face being intended to face a Membrane Electrode Assembly and being provided with reliefs and hollows forming a reagent circuit for the circulation of a reactive fluid, the reagent circuit comprising an inlet opening into a discharging orifice tribution, the plate comprising a reagent inlet collector orifice separate from the distribution orifice, the reagent inlet collector orifice being arranged to supply reagent to the inlet of the reagent circuit via an inlet passage placing the reagent inlet collector orifice and the distribution orifice in fluid communication, the reagent circuit comprising an outlet opening into a reagent discharge orifice, the plate comprising a reagent outlet collector orifice separate from the discharge orifice, the outlet collector orifice being arranged to recover the reagent at the outlet of the reagent circuit via an outlet passage placing the outlet collector orifice and the discharge orifice in fluid communication, the reagent circuit comprising a plurality of reagent cavities arranged on the reagent face,the cooling face being in particular intended to face the cooling face of another fuel cell plate, the cooling face being provided with reliefs and hollows forming a cooling circuit for the circulation of a cooling fluid, the cooling circuit comprising a plurality of cooling cavities and a plurality of teeth, two adjacent cooling cavities being separated from each other by one of the teeth, the plurality of cooling cavities comprising a first cooling cavity and a last cooling cavity each forming at least in part the periphery of the cooling circuit, the first cooling cavity comprising a first axial portion extending along a first axis and a second axial portion extending along a second axis orthogonal to the first axis,the last cooling cavity comprising a third axial portion extending along the first axis and a fourth axial portion extending along the second axis, the plurality of reagent cavities comprising a first reagent cavity and a last reagent cavity each forming at least in part the periphery of the reagent circuit, the first reagent cavity comprising a fifth axial portion extending along the second axis and a sixth axial portion extending along the first axis, the last reagent cavity comprising a seventh axial portion extending along the first axis and an eighth axial portion extending along the second axis, the plate being configured so that there is a first plane orthogonal to the plane in which the plate extends, the plate being configured so that: , - the first plane intersecting the first axial portion in the direction of the first axis, said first plane being located between the sixth axial portion and a portion of the reagent cavity adjacent to the sixth axial portion; - the first plane intersecting the second axial portion in the direction of the second axis, said first plane being located between the eighth axial portion and a portion of the reagent cavity adjacent to the eighth axial portion; - the first plane cutting the third axial portion in the direction of the first axis, said first plane being located between the seventh axial portion and a portion of the reagent cavity adjacent to the seventh axial portion; - the first plane intersecting the fourth axial portion in the direction of the second axis, said first plane being located between the fifth axial portion and a portion of the reagent cavity adjacent to the fifth axial portion; - the first plane intersecting, in the direction of the first axis, an axial portion of the first cooling cavity located opposite the distribution orifice, said first plane being separated from the first reagent cavity by at least two reagent cavities.

[0010] This allows the plate to have a reduced footprint while having sufficient space to position a glue joint, an adhesive or solder in order to fix two plates together, while avoiding having distribution and / or evacuation orifices set back from the active surface. This is achieved without significantly reducing the cooling efficiency of the cell.

[0011] The invention thus makes it possible to enable optimal thermal management while reducing the size of the fuel cell.

[0012] According to one embodiment, the plate is machined.

[0013] According to one embodiment, the plate is made of machined graphite or machined expanded graphite or machined metal.

[0014] Alternatively, the plate is made of a molded material, for example being molded composite graphite.

[0015] According to one embodiment, the periphery of the cooling circuit is configured to delimit a surface strictly smaller than that delimited by the periphery of the reagent circuit.

[0016] According to one embodiment, the periphery of the reagent circuit is configured to delimit a surface area substantially equal to the surface area of a diffusion layer of the Membrane Electrode Assembly.

[0017] According to one embodiment, the periphery of the reagent circuit is configured to delimit a surface area less than 99.9% of the surface area of a diffusion layer of the Membrane Electrode Assembly.

[0018] According to one embodiment, the first axis extends along the axis in which the plate extends.

[0019] According to one embodiment, the first plane intersecting, in the direction of the first axis, an axial portion of the last cooling cavity located opposite the discharge orifice, said first plane is separated from the last reagent cavity by at least two reagent cavities.

[0020] According to one embodiment, the dispensing orifice is arranged relative to the periphery of the reagent circuit which is opposite the latter, at a distance less than the width of two reagent cavities.

[0021] According to one embodiment, the dispensing orifice is arranged relative to the periphery of the reagent circuit which is opposite the latter, at a distance: - less than the width of two reagent cavities, and - greater than 1 mm.

[0022] According to one embodiment, the discharge orifice is arranged relative to the periphery of the reagent circuit which is opposite the latter, at a distance less than the width of two reagent cavities.

[0023] According to one embodiment, the discharge orifice is arranged relative to the periphery of the reagent circuit which is opposite the latter, at a distance: - less than the width of two reagent cavities, and - greater than 1 mm.

[0024] According to one embodiment, the first edge and the second edge are each a longitudinal edge of the plate.

[0025] According to one embodiment, the third edge and the fourth edge are each a transverse edge of the plate.

[0026] According to one embodiment, the width of each cavity of the plurality of cooling cavities is constant, at least on the portions extending axially along the first axis and on the portions extending axially along the second axis.

[0027] According to one embodiment, the width of each tooth is constant, over all the portions extending axially along the second axis.

[0028] According to one embodiment, the cooling circuit is configured so that there is at least one of the teeth whose width is variable between a first axial segment and a second axial segment, the first and second segments extending along the first axis and so that there is at least one other of the teeth whose width is constant at least when it extends axially along the first axis.

[0029] According to one embodiment, the first segment is adjacent to the first cavity.

[0030] According to one embodiment, the discharge orifice, the outlet collector orifice, the reagent inlet collector orifice and the reagent distribution orifice are each formed by a hole passing through the plate.

[0031] The invention further relates to a bipolar fuel cell plate comprising two plates as described above, the plates being assembled to each other via their cooling face, in particular by welding or gluing.

[0032] The invention further relates to a fuel cell, in particular a proton exchange membrane fuel cell, the cell comprising two plates as described above and a Membrane Electrode Assembly sandwiched between the plates.

[0033] The invention further relates to a fuel cell, in particular a membrane fuel cell. proton exchanger, comprising a stack of cells as described above.

[0034] The invention will be better understood upon reading the following description and examining the accompanying figures. These figures are given only for illustrative purposes but in no way limit the invention.

[0035] [Fig-1] is a schematic representation of the reactive face of a plate according to the invention; and

[0036] [Fig.2] is a schematic representation of the cooling face of the plate of [Fig. 1].

[0037] With reference to [Fig.l] and [Fig.2], a fuel cell plate 1 is shown. The plate 1 comprises a reactive face 16 and a cooling face 10 opposite each other.

[0038] [Fig.l] represents the reactive face 16 of the plate 1 while [Fig.2] represents the cooling face 10 of the plate 1.

[0039] The fuel cell plate 1 is of the proton exchange membrane type.

[0040] The plate 1 has a first edge 21, a second edge 20 opposite the first edge 21, a third edge 19, a fourth edge 18 opposite the third edge 19.

[0041] The reactive face 16 is intended to face a Membrane Electrode Assembly (MEA).

[0042] The reactive face 16 is provided with reliefs and hollows forming a reactive circuit 11 for the circulation of a reactive fluid. The reactive circuit 11 comprises an inlet opening into a distribution orifice 17.

[0043] The plate 1 comprises a reagent inlet collector orifice 14 separate from the distribution orifice 17. The reagent inlet collector orifice 14 is arranged to supply reagent to the inlet of the reagent circuit 11 via an inlet passage 13 placing the reagent inlet collector orifice 14 and the distribution orifice 17 in fluid communication.

[0044] The reagent circuit 11 comprises an outlet opening into a reagent discharge orifice 7.

[0045] The plate 1 comprises a reagent outlet collector orifice 4 separate from the discharge orifice 7. The outlet collector orifice 4 is arranged to recover the reagent at the outlet of the reagent circuit 11 via an outlet passage 5 placing the outlet collector orifice 4 and the discharge orifice 7 in fluid communication.

[0046] The reagent circuit 11 comprises a plurality of reagent cavities 27 arranged on the reactive face 16.

[0047] The cooling face 10 is intended to face the cooling face 10 of another fuel cell plate 1.

[0048] The cooling face 10 is provided with reliefs and hollows forming a circuit of cooling 3 for the circulation of a cooling fluid.

[0049] The cooling circuit 3 comprises a plurality of cooling cavities 28 and a plurality of teeth 2. Two adjacent cooling cavities 28 are separated from each other by one of the teeth 2.

[0050] The plurality of cooling cavities 28 comprises a first cooling cavity 8 and a last cooling cavity 9 each forming at least in part the periphery of the cooling circuit 6.

[0051] The first cooling cavity 8 comprises a first axial portion 31 extending along a first axis 22 and a second axial portion 32 extending along a second axis 23 orthogonal to the first axis 22. As shown in [Fig.l] and in [Fig.2], the first axis 22 extends along the axis in which the plate 1 extends. The second axis 23 extends perpendicular to the first axis 22.

[0052] The last cooling cavity 9 comprises a third axial portion 33 extending along the first axis 22 and a fourth axial portion 34 extending along the second axis 23.

[0053] The plurality of reagent cavities 27 comprises a first reagent cavity 41 and a last reagent cavity 42 each forming at least in part the periphery of the reagent circuit 12.

[0054] The first reagent cavity 41 comprises a fifth axial portion 35 extending along the second axis 23 and a sixth axial portion 36 extending along the first axis 22.

[0055] The last reagent cavity 42 comprises a seventh axial portion 37 extending along the first axis 22 and an eighth axial portion 38 extending along the second axis 23.

[0056] The plate 1 is configured such that there is a first plane orthogonal to the plane in which the plate 1 extends, the plate 1 being configured such that: - the first plane intersecting the first axial portion 31 in the direction of the first axis 22, said first plane being located between the sixth axial portion 36 and a portion of the reagent cavity adjacent to the sixth axial portion 36; - the first plane intersecting the second axial portion 32 in the direction of the second axis 23, said first plane being located between the eighth axial portion 38 and a portion of the reagent cavity adjacent to the eighth axial portion 38; - the first plane intersecting the third axial portion 33 in the direction of the first axis 22, said first plane being located between the seventh axial portion 37 and a portion of the reagent cavity adjacent to the seventh axial portion 37; - the first plane intersecting the fourth axial portion 34 in the direction of the second axis 23, said first plane being located between the fifth portion axial 35 and a portion of the reagent cavity adjacent to the fifth axial portion 35; - the first plane intersecting, in the direction of the first axis 22, an axial portion of the first cooling cavity 8 located opposite the distribution orifice 17, said first plane being separated from the first reagent cavity 41 by at least two reagent cavities 27.

[0057] The first plane intersecting, in the direction of the first axis 22, an axial portion of the last cooling cavity 9 located opposite the discharge orifice 7, said first plane is separated from the last reagent cavity 42 by at least two reagent cavities 27.

[0058] The dispensing orifice 17 is arranged relative to the periphery of the reagent circuit 12 which is opposite the latter, at a distance less than the width of two reagent cavities 27.

[0059] The discharge orifice 7 is arranged relative to the periphery of the reagent circuit 12 which is opposite the latter, at a distance less than the width of two reagent cavities 27.

[0060] The width of each cavity of the plurality of cooling cavities 28 is constant, at least on the portions extending axially along the first axis 22 and on the portions extending axially along the second axis 23.

[0061] The width of each tooth 2 is constant, over all the portions extending axially along the second axis 23.

[0062] The cooling circuit 3 is configured such that there is at least one of the teeth 2 having a variable width between a first axial segment and a second axial segment, the first axial segment and the second axial segment extending along the first axis 22 and such that there is at least one other of the teeth 2 having a constant width at least when it extends axially along the first axis 22.

Claims

Claims

1. Fuel cell plate (1) of the proton exchange membrane type, the plate (1) comprising a first edge (21), a second edge (20) opposite the first edge (21), a third edge (19), a fourth edge (18) opposite the third edge (19), the plate (1) comprising a reactive face (16) and a cooling face (10) opposite each other, the reactive face (16) being intended to face a Membrane Electrode Assembly and being provided with reliefs and hollows forming a reagent circuit (11) for the circulation of a reactive fluid, the reagent circuit (11) comprising an inlet opening into a distribution orifice (17), the plate (1) comprising a reagent inlet collector orifice (14) separate from the distribution orifice (17),the reagent inlet collector orifice (14) being arranged to supply reagent to the inlet of the reagent circuit (11) via an inlet passage (13) placing the reagent inlet collector orifice (14) in fluid communication with the distribution orifice (17), the reagent circuit (11) comprising an outlet opening into a reagent discharge orifice (7), the plate (1) comprising a reagent outlet collector orifice (4) separate from the discharge orifice (7), the outlet collector orifice (4) being arranged to recover the reagent at the outlet of the reagent circuit (11) via an outlet passage (5) placing the outlet collector orifice (4) and the discharge orifice (7) in fluid communication, the reagent circuit (11) comprising a plurality of reagent cavities (27) arranged on the reagent face (16), the cooling face (10) being in particular intended to face the cooling face (10) of another fuel cell plate (1),the cooling face (10) being provided with reliefs and hollows forming a cooling circuit (3) for the circulation of a cooling fluid, the cooling circuit (3) comprising a plurality of cooling cavities (28) and a plurality of teeth (2), two adjacent cooling cavities (28) being separated from each other by one of the teeth (2), the plurality of cooling cavities (28) comprising a first cooling cavity (8) and a last cooling cavity (9) each forming at least in part the periphery of the cooling circuit (6), the first cooling cavity (8) comprising a first axial portion (31) extending along a first axis (22) and a second axial portion (32) extending along a, second axis (23) orthogonal to the first axis (22), the last cooling cavity (9) comprising a third axial portion (33) extending along the first axis (22) and a fourth axial portion (34) extending along the second axis (23), the plurality of reagent cavities (27) comprising a first reagent cavity (41) and a last reagent cavity (42) each forming at least in part the periphery of the reagent circuit (12), the first reagent cavity (41) comprising a fifth axial portion (35) extending along the second axis (23) and a sixth axial portion (36) extending along the first axis (22), the last reagent cavity (42) comprising a seventh axial portion (37) extending along the first axis (22) and an eighth axial portion (38) extending along the second axis (23), the plate (1) being configured so that there exists a first plane orthogonal to the plane in which the plate (1) extends,the plate (1) being configured so that:, - the first plane intersecting the first axial portion (31) in the direction of the first axis (22), said first plane being located between the sixth axial portion (36) and a portion of the reagent cavity adjacent to the sixth axial portion (36); - the first plane intersecting the second axial portion (32) in the direction of the second axis (23), said first plane being located between the eighth axial portion (38) and a portion of the reagent cavity adjacent to the eighth axial portion (38); - the first plane intersecting the third axial portion (33) in the direction of the first axis (22), said first plane being located between the seventh axial portion (37) and a portion of the reagent cavity adjacent to the seventh axial portion (37); - the first plane intersecting the fourth axial portion (34) in the direction of the second axis (23), said first plane being located between the fifth axial portion (35) and a portion of the reagent cavity adjacent to the fifth axial portion (35); - the first plane intersecting, in the direction of the first axis (22), an axial portion of the first cooling cavity (8) located opposite the distribution orifice (17), said first plane being separated from the first reagent cavity (41) by at least two reagent cavities (27).

2. Plate according to the preceding claim, the first cutting plane, in the direction of the first axis (22), an axial portion of the last cooling cavity (9) located opposite the discharge orifice (7), said first plane being separated from the last reagent cavity (42) by at least two reagent cavities (27).

3. Plate (1) according to one of the preceding claims, the dispensing orifice (17) being arranged relative to the periphery of the reagent circuit (12) which is opposite the latter, at a distance less than the width of two reagent cavities (27).

4. Plate (1) according to one of the preceding claims, the discharge orifice (7) being arranged relative to the periphery of the reagent circuit (12) which is opposite the latter, at a distance less than the width of two reagent cavities (27).

5. Plate (1) according to one of the preceding claims, the width of each cavity of the plurality of cooling cavities (28) being constant, at least on the portions extending axially along the first axis (22) and on the portions extending axially along the second axis (23).

6. Plate (1) according to one of the preceding claims, the width of each tooth (2) being constant, over all the portions extending axially along the second axis (23).

7. Plate (1) according to one of the preceding claims, the cooling circuit (3) being configured so that there is at least one of the teeth (2) whose width is variable between a first axial segment and a second axial segment, the first and second segments extending along the first axis (22) and so that there is at least one other of the teeth (2) whose width is constant at least when it extends axially along the first axis (22).

8. Fuel cell, in particular a proton exchange membrane fuel cell, the cell comprising two plates (1) according to one of the preceding claims and a Membrane Electrode Assembly sandwiched between the plates (1).

9. Fuel cell, in particular with a proton exchange membrane, comprising a stack of cells according to the preceding claim.

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