Fuel cell plate

Abstract

The invention relates to a fuel cell plate (1) comprising an opposing reactive face (2) and a cooling face, the reactive face (2) being provided with reliefs and hollows forming a reactive circuit (4), the cooling face being provided with reliefs and hollows forming a cooling circuit comprising a plurality of cooling channels, at least one of the cooling channels comprising a first section having a first width and a first height and a second longitudinal section having a second section having a second width and a second height, the first maximum width being greater than the second maximum width, the second height being strictly greater than the first height. 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 comprising such a plate and a fuel cell comprising such a cell. The invention finds a particularly advantageous application with fuel cells whose plates are machined.

[0002] 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.

[0003] According to a known configuration, the plates comprise on each face, reliefs and hollows, the hollows being obtained by machining the plate.

[0004] When the geometry of the plate requires the presence of a hollow on one face and a complementary hollow on the other face, it locally has a reduced thickness which can weaken the plate.

[0005] A known solution is to use a plate whose nominal thickness before machining is sufficient to avoid the presence of a reduced thickness at certain locations on the plate after machining.

[0006] One problem is that the stack resulting from stacking a large number of such plates has dimensions that can become critical.

[0007] The present invention aims to effectively overcome these drawbacks by proposing a fuel cell plate of the proton exchange membrane type, the plate extending in a plate plane and 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 reactive circuit comprising a plurality of reactive channels for the circulation of a reactive fluid, the cooling face being provided with reliefs and hollows forming a cooling circuit comprising a plurality of cooling channels for the circulation of a cooling fluid, the plate comprising a cooling fluid inlet collector orifice formed through the plate, the cooling channels opening through a first end into the cooling fluid inlet collector orifice,the reactive face comprising a first seal groove surrounding the coolant inlet collector orifice and intended to receive a first collector seal forming, together with the Membrane Electrode Assembly, a barrier to prevent the coolant from circulating in the reactive circuit, at least one of the cooling channels,

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[0014] development including: - a first longitudinal section having a first section having a first maximum width and a first maximum height, the first section being in a first plane orthogonal to the plate plane and orthogonal to the longitudinal direction of the first section, the first plane intersecting the plate in the joint groove; - a second longitudinal section having a second section having a second maximum width and a second maximum height, the second section being in a second plane orthogonal to the plate plane and orthogonal to the longitudinal direction of the second section, the second plane intersecting the plate in one of the reagent channels, characterized in that the first maximum width is strictly greater than the second maximum width and in that the second maximum height is strictly greater than the first maximum height. Such a configuration makes it possible to reduce the nominal thickness of the plate while ensuring good mechanical strength. This makes it possible to reduce the weight and volume of a fuel cell equipped with a plurality of plates, each plate ensuring an optimal flow rate for the cooling fluid, particularly at the point where the channels on one face are less deep, i.e. at the point where they cross a complementary groove on the other face on their path. According to one embodiment, the hydraulic diameter of the first section is between 0.6 and 1.2 times the hydraulic diameter of the second section, for example between 0.8 and 1 times the hydraulic diameter of the second section. The hydraulic diameter of a section can be defined as being equal to four times the surface area of ​​the section of said section, divided by the perimeter of the same section. According to one embodiment, the cooling circuit comprises a plurality of ribs, each rib being arranged between two adjacent cooling channels, the maximum width of a rib, measured in the first plane, being strictly less than the maximum width of the same rib, measured in the second plane. According to one embodiment, the at least one of the cooling channels comprises a third section between the first section and the second section, the third section comprising a first end section and a second end section, the first end section being distinct from the second end section. According to one embodiment, the third section has an internal wall. According to one embodiment, the internal wall of the third section has a slope configured to allow the transition from the first maximum height to the second maximum height.

[0015] According to one embodiment, the internal wall of the third section comprises a conical portion.

[0016] According to one embodiment, the first section and the second section extend in the same longitudinal direction.

[0017] According to one embodiment, the at least one of the cooling channels comprises a fourth section forming an elbow, the second section being located between the first section and the fourth section.

[0018] According to one embodiment, the elbow is configured so that the fourth section extends in the plate plane, forming a bend of between 40° and 140°, for example between 60° and 120°.

[0019] According to one embodiment, the plate is made of metal, graphite or expanded graphite.

[0020] The invention also relates to a fuel cell, in particular a fuel cell with a proton exchange membrane, the cell comprising two plates as described above and a Membrane Electrode Assembly sandwiched between the plates.

[0021] According to one embodiment, one of the two plates is an anodic plate and the other of the plates is a cathodic plate.

[0022] According to one embodiment, a first collector seal is arranged in the seal groove.

[0023] According to one embodiment, the first manifold seal is configured to surround the coolant inlet manifold port.

[0024] According to one embodiment, the first manifold seal is configured to form, together with the Membrane Electrode Assembly, a barrier to prevent coolant from flowing from the coolant inlet manifold port to the reactant circuit.

[0025] The invention also relates to a fuel cell, in particular with a proton exchange membrane, comprising a stack of cells as described above.

[0026] According to one embodiment, the anode plate of one of the cells of the battery is fixed, in particular glued or welded, to the cathode plate of another of the cells of the battery, thus forming a bipolar plate.

[0027] Alternatively, the anode plate of one of the cells of the battery is mounted tightly against the cathode plate of another of the cells of the battery, with the interposition of a bipolar plate seal to form the cooling circuit.

[0028] 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.

[0029] [Fig.l] [Fig.l] is a schematic representation of a plate according to the invention;

[0030] [Fig.2] [Fig.2] is a schematic representation of a detail along A, of the plate of [Fig.l];

[0031] [Fig.3] [Fig.3] represents an elevation and sectional view along BB, of the detail of [Fig.2]; and

[0032] [Fig.4] [Fig.3] represents an elevation and sectional view along CC, of ​​the detail of [Fig.3],

[0033] Identical, similar, or analogous elements retain the same reference from one figure to another.

[0034] [Fig.l] represents a fuel cell plate 1 of the proton exchange membrane type. The plate 1 extends generally in a plane called the plate plane.

[0035] The plate 1 comprises a reactive face 2 and a cooling face 3 opposite each other.

[0036] The reactive face 2 is intended to face a Membrane Electrode Assembly. The reactive face 2 is provided with reliefs and hollows, forming a reactive circuit 4. In [Fig.l], the visible face is the reactive face 2 and the opposite face, not visible, is the cooling face 3.

[0037] The plate 1 comprising a cooling fluid inlet collector orifice 7 formed through the plate 1.

[0038] The reactive face 2 comprises a first seal groove 8 surrounding the coolant inlet collector orifice 7. This first seal groove 8 is intended to receive a first collector seal forming, together with the Membrane Electrode Assembly and when the plate 1 is integrated into a fuel cell, a barrier to prevent the coolant from circulating from the coolant inlet collector 7 into the reactant circuit 4.

[0039] [Fig.2] represents a detail of plate [Fig.l], the detail being represented in [Fig.l] by rectangle A.

[0040] The cooling face 3 is provided with reliefs and hollows forming a cooling circuit 5 comprising a plurality of cooling channels 6 for the circulation of a cooling fluid. The cooling channels 6 open through a first end into the cooling fluid inlet collector orifice 7.

[0041] In [Fig.2], the plurality of cooling channels 6 is shown schematically by transparency, in dotted lines.

[0042] [Fig.3] represents a detail in elevation and in section along the BB axis, of the detail of [Fig.2] and [Fig.4] represents another detail in elevation and in section along the CC axis, of the detail of [Fig.3].

[0043] As shown in Figures 3 and / or 4, the reagent circuit 4 comprises a plurality of reagent channels 9 for circulating a reagent fluid.

[0044] At least one of the cooling channels 6 comprises: - a first longitudinal section 11 having a first section having a first maximum width L1 and a first maximum height Hl, the first section being in a first plane orthogonal to the plate plane and orthogonal to the longitudinal direction of the first section 11, the first plane intersecting the plate 1 in the joint groove 8; and - a second longitudinal section 12 having a second section having a second maximum width L2 and a second maximum height H2, the second section being in a second plane orthogonal to the plate plane and orthogonal to the longitudinal direction of the second section 12, the second plane intersecting the plate 1 in one of the reagent channels 9, characterized in that the first maximum width L1 is strictly greater than the second maximum width L2 and in that the second maximum height H2 is strictly greater than the first maximum height H1.

[0045] The first section 11 of at least one of the cooling channels 6 comprises the first end of said at least one of the cooling channels 6.

[0046] The cooling circuit 5 comprises a plurality of ribs 15, each rib being arranged between two adjacent cooling channels 6.

[0047] The maximum width of a rib 15, measured in the first plane, is strictly less than the maximum width of the same rib 15, measured in the second plane.

[0048] The at least one of the cooling channels 6 comprises a third section 13, located between the first section 11 and the second section 12.

[0049] The third section 13 comprises a first end section and a second end section, the first end section being distinct from the second end section. The third section 13 thus comprises a variable section by moving from one end to the other. This makes it possible to form a transition between the first section 11 and the second section 12.

[0050] The third section 13 comprises an internal wall.

[0051] The internal wall of the third section 13 comprises a slope configured to allow the passage from the first maximum height H1 to the second maximum height H2. In the example shown, the slope comprises a curvature in section.

[0052] The internal wall of the third section 13 comprises a curved portion, the curve being considered in the plate plane. The curved portion is configured to allow the transition from the first maximum width L1 to the second maximum width L2.

[0053] The internal wall of the third section 13 comprises a conical portion. Such a conical portion allows both the passage from the first maximum height H1 to the second maximum height H2 and the passage from the first maximum width L1 to the second maximum width L2. Alternatively, the conical portion is configured to allow a change in the section of the third section 13.

[0054] The first section 11 and the second section 12 extend in the same longitudinal direction.

[0055] As visible in [Fig.3], at least one of the cooling channels 6 comprises a fourth section 14 forming an elbow. The second section 12 is located between the first section 11 and the fourth section 14.

[0056] The elbow is configured so that the fourth section 14 extends in the plate plane, forming a bend of between 40° and 140°, for example between 60° and 120°. In the example shown in [Fig. 3], the bend is substantially 90°.

[0057] The third section 13 is located between the first section 11 and the fourth section 14.

Claims

1. Claims Fuel cell plate (1) of the proton exchange membrane type, the plate (1) extending in a plate plane and comprising a reactive face (2) and a cooling face (3) opposite one another, the reactive face (2) being intended to face a Membrane Electrode Assembly and being provided with reliefs and hollows forming a reactant circuit (4) comprising a plurality of reactant channels (9) for the circulation of a reactant fluid, the cooling face (3) being provided with reliefs and hollows forming a cooling circuit (5) comprising a plurality of cooling channels (6) for the circulation of a cooling fluid, the plate (1) comprising a coolant inlet collector orifice (7) formed through the plate (1), the cooling channels (6) opening at a first end into the coolant inlet collector orifice (7),the reactive face (2) comprising a first seal groove (8) surrounding the coolant inlet collector orifice (7) and intended to receive a first collector seal forming, together with the Membrane Electrode Assembly, a barrier to prevent the coolant from circulating in the reactive circuit (4), at least one of the cooling channels (6) comprising:, - a first longitudinal section (11) having a first section having a first maximum width (Ll) and a first maximum height (Hl), the first section being in a first plane orthogonal to the plate plane and orthogonal to the longitudinal direction of the first section (11), the first plane intersecting the plate (1) in the joint groove (8); - a second longitudinal section (12) having a second section having a second maximum width (L2) and a second maximum height (H2), the second section being in a second plane orthogonal to the plate plane and orthogonal to the longitudinal direction of the second section (12), the second plane intersecting the plate (1) in one of the reagent channels (9), characterized in that the first maximum width (L1) is strictly greater than the second maximum width (L2) and in that the second maximum height (H2) is strictly greater than the first maximum height (Hl).

2. Plate (1) according to the preceding claim, the hydraulic diameter of the first section (11) being between 0.6 and 1.2 times the hydraulic diameter of the second section (12), for example between 0.8 and 1 times the hydraulic diameter of the second section (12).

3. Plate (1) according to one of the preceding claims, the cooling circuit (5) comprising a plurality of ribs (15), each rib being arranged between two adjacent cooling channels (6), the maximum width of a rib (15), measured in the first plane being strictly less than the maximum width of the same rib (15), measured in the second plane.

4. Plate (1) according to one of the preceding claims, the at least one of the cooling channels (6) comprising a third section (13) between the first section (11) and the second section (12), the third section (13) comprising a first end section and a second end section, the first end section being distinct from the second end section.

5. Plate (1) according to the preceding claim, the third section (13) comprising an internal wall, the internal wall of the third section (13) comprising a slope configured to allow the passage from the first maximum height (H1) to the second maximum height (H2).

6. Plate (1) according to one of the preceding claims, the first section (11) and the second section (12) extending in the same longitudinal direction.

7. Plate (1) according to one of the preceding claims, the at least one of the cooling channels (6) comprising a fourth section (14) forming an elbow, the second section (12) being located between the first section (11) and the fourth section (14).

8. Plate (1) according to the preceding claim, the elbow being configured so that the fourth section (14) extends in the plate plane forming a bend of between 40° and 140°, for example between 60° and 120°.

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

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

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