Assembly comprising a stack of cells for an electrochemical module

Abstract

The invention relates to an assembly for an electrochemical module, comprising a stack (1) of solid oxide electrolyser cells or solid oxide fuel cells, the stack being positioned between an upper end plate (2) and a lower end plate, each of the upper and lower end plates respectively comprising a part for connection to a current rod (5), which comprises an opening (4) formed in the upper and / or the lower end plate, accommodating the current rod (5), and also a notch (6) which is made in the thickness of the plate and extends as far as the opening (4), defining in the plate a first portion (61) and a second portion (62) which are able to be forced against the current rod (5).

Description

ASSEMBLY CONTAINING A STACK OF CELLS FOR AN ELECTROCHEMICAL MODULE

[0001] The present invention relates to an assembly for an electrochemical module, comprising a stack of solid oxide electrolyzer cells or solid oxide fuel cells, as well as means for connection to at least one current rod. State of the art

[0002] An electrochemical device can be implemented for high-temperature electrolysis and include a stack of solid oxide electrolyzer cells or SOECs (solid oxide electrolyzer cell in Anglo-Saxon terminology) or as a fuel cell and include a stack of solid oxide fuel cells or SOFCs (solid oxide fuel cell in Anglo-Saxon terminology).

[0003] Such a device comprises a module (or "stack" in Anglo-Saxon terminology) consisting of a stack of electrochemical cells clamped between two clamping plates. The cells are electrically connected in series.

[0004] Each electrochemical cell contains an electrolyte between two electrodes. Interconnecting plates are placed between the cells and provide the electrical connection. These interconnecting plates also supply the cells with gas and collect the gases produced by each cell.

[0005] One of the end plates forms a frame that defines a window on the intermediate plate and receives a cell, which is then in contact with the intermediate plate. The electric current passes from bottom to top or top to bottom through the cells and the interconnector areas, which are vertically aligned with the cells.

[0006] During operation, the anode and cathode are the site of electrochemical reactions, while the electrolyte allows the transport of ions from the cathode to the anode, or vice versa depending on whether the electrochemical device operates in electrolyzer mode or fuel cell mode.

[0007] To enable the supply of current to such a stack in order to ensure the chemical reactions, an upper terminal plate of the stack and a lower terminal plate of the stack are connected respectively to an upper current rod and a lower current rod.

[0008] The connection is usually made via a mounting interface: a connector (also called a "whistle"), fitted to one end of the connecting rod, is attached to the terminal plate, typically by screwing. In other words, a connector from the upper current rod is connected to the upper terminal plate, and a connector from the lower current rod is connected to the lower terminal plate of the stack.

[0009] However, it is observed that this type of connection causes heating at the terminal plate connectors, and that this heating can lead to the current rod melting.

[0010] There is therefore a need to replace these current rod connectors, or to find an alternative solution to supply current to the stacks without damaging the current rods or the stack.

[0011] The invention offers a solution to the problem mentioned above by proposing an assembly for an electrochemical module, comprising a stack of solid oxide electrolyzer cells or solid oxide fuel cells, said stack being positioned between an upper terminal plate and a lower terminal plate, each of the upper and lower terminal plates having respectively an upper and lower connection part to, respectively, an upper current rod and a lower current rod, said assembly being characterized in that at least one of the connection parts comprises an opening formed in said upper and / or lower terminal plate, to accommodate at least one of the two said current rods, as well as a notch made in the thickness of the upper and / or lower terminal plate from an edge of the upper and / or lower terminal plate to said opening,said upper and / or lower terminal plate comprising, a first portion of plate positioned on one side of the notch and a second portion of plate positioned on the other side of the notch, the first and second portions of plate being capable of being constrained against said current rod.

[0012] Thus implemented, the invention provides an opening that directly accommodates the end of a current rod, without a connector, ensuring direct current transmission from the rod to the plate (or from the plate to the rod). This improves the contact between the rod and the plate, resulting in better current flow with reduced contact resistance. Consequently, any overheating is minimized, thus preventing potential damage to any part of the current rod or the terminal plate. Furthermore, the notch between the edge of the plate and the rod opening creates two adjacent portions within the plate. These two portions allow for elastic deformation of the plate at the opening, thereby generating a clamping force by deforming the two portions.

[0013] Several technical solutions, proposed by the invention, make it possible to create tension around the opening, so as to firmly hold the end of the cane in the opening.

[0014] The invention may also have the following characteristics, taken separately or in combination:

[0015] – the opening, which accommodates the current rod, is a through opening,

[0016] – according to a first embodiment, said current rod has a diameter equal to or substantially equal to the diameter of said opening and is forced into said opening, the first and second portions of plate being constrained against said current rod by a force exerted by said current rod against the internal wall of said opening into which it is forced,

[0017] – according to an alternative embodiment, the first and second plate portions are constrained against said current rod by a device for fixing one plate portion to the other plate portion,

[0018] – the fastening device is a screw that passes through any one of the first or second plate sections and a nut that screws around said screw, against the other of the first and second plate sections,

[0019] – according to yet another embodiment, said fixing device is a screw which passes through any one of the first or second portions of the plate and which is fixed in a tapped hole provided in the other of the first and second portions of the plate,

[0020] – furthermore, following an advantageous example, the notch extends in a straight line from said edge of the upper and / or lower terminal plate to said opening, said direction being parallel to a second plate edge, adjacent to said plate edge, so that the notch is made in a plane perpendicular to a terminal plate surface,

[0021] – according to yet another variant, the notch extends in a straight line from said edge of the upper and / or lower terminal plate to said opening, said straight line being parallel or substantially parallel to a surface of terminal plate so that the notch is made in the thickness of said terminal plate. Brief description of the figures

[0022] The invention will be better understood upon reading the following description, given solely by way of non-limiting example and made with reference to the accompanying drawings in which:

[0023] This is a schematic representation of a cell stack for a SOEC or SOFC module.

[0024] This is a perspective and enlarged view of a terminal stacking plate of an assembly conforming to a first embodiment of the invention.

[0025] This is a perspective and enlarged view of a terminal stacking plate of an assembly conforming to a second embodiment of the invention.

[0026] This is a perspective and enlarged view of a terminal stacking plate of an assembly conforming to a third embodiment of the invention.

[0027] This is a perspective and enlarged view of a stacking terminal plate of an assembly conforming to a fourth embodiment of the invention, and

[0028] : laest a perspective and enlarged view of a terminal stacking plate of an assembly conforming to a fifth embodiment of the invention.

[0029] It is understood that the embodiments described below are by no means exhaustive. In particular, variants of the invention may be conceived comprising only a selection of the features described below, isolated from the other features described, if this selection of features is sufficient to confer a technical advantage or to differentiate the invention from the prior art. This selection includes at least one preferably functional feature without structural details, or with only a portion of the structural details if this portion alone is sufficient to confer a technical advantage or to differentiate the invention from the prior art.

[0030] In particular, all the variants and embodiments described can be combined with each other if there are no technical obstacles to this combination.

[0031] In the figures and in the rest of the description, elements common to several figures retain the same reference. Detailed description

[0032] Lamontre presents a stack of 1 electrolyzer cells, schematically represented. The cells can independently be solid oxide cells or solid oxide fuel cells, depending on whether the invention is to be applied in a SOEC or a SOFC.

[0033] The stack is, in a classic way, positioned between an upper end plate 2 and a lower end plate 3.

[0034] In the following figures, only the upper terminal plate 2 has been represented and the cell stacking does not appear: it should be understood that the embodiments which will be described are applicable to both the upper terminal plate and the lower terminal plate.

[0035] Typically, each of the upper terminal plates 2 and lower terminal plates 3 includes a connection part (either upper and lower, respectively) to a current rod which is either upper or lower.

[0036] On the figure, a first example of a connecting part according to the invention is illustrated: this connecting part has the function of fixing the rod onto the plate.

[0037] In, we observe that a through opening 4 has been provided, through the said upper terminal plate 2, to accommodate a current rod 5.

[0038] In this example of an embodiment, the current rod is oriented so that it is vertically positioned relative to the terminal plate 2.

[0039] A notch 6 is made in the thickness of the upper end plate 2, from an edge 60 of the end plate 2 to the opening 4.

[0040] On either side of notch 6, we therefore observe two portions of plate 61 or 62, called first and second portions of plate 2.

[0041] The through opening 4 has the function of accommodating the current rod 5: it therefore has a diameter which is slightly greater than the diameter of the current rod 5 with a circular section.

[0042] To keep the rod 5 in place in the through opening 4, because the diameter of the opening is greater than that of the rod 5, it is necessary (in this context of this example) to provide means of fixing (or fixing device 7).

[0043] The first and second portions 60 and 61 of plate 2 can be constrained and exert a force which allows the rod 5 to be tightened in the opening 4.

[0044] To achieve this, in this example, the fixing device 7 allows the two plate portions 61 and 62 to be brought closer together, to create a pressure force of the inner wall of the through opening 4 against the wall of the current rod 5.

[0045] Several fastening devices 7 are shown in the figures: the reference 7 has been retained for each of the examples in order to facilitate the reading of the figures.

[0046] In the example illustrated, said fastening device 7 includes a screw 71 which passes through the first and second portions of plate 61 and 62, by means of a through hole which has been made in the thickness of the edge 60 of plate 2. The screw 71 is held in place by the nut 72 which screws onto the screw.

[0047] To allow the nut to be aimed, a notch 63 has been made on the edge of the plate 2 which is contiguous with the edge 60.

[0048] The two plate portions 61 and 62 are brought together by screwing the nut onto the screw shank, which creates a clamping force around the rod 5 in the opening 4.

[0049] A first variant embodiment is shown in: the fixing device is only a screw 73 which passes through the first and second portions 61 and 62 of the plate 2, the portions 61 and 62 both being crossed by a tapped hole 74.

[0050] Note that hole 74 crosses portion 62 and is a blind tapped hole in portion 61. The hole crossing portion 62 may not be a tapped hole (simple hole).

[0051] By screwing the screw 73 into the tapped hole 74, the two portions 61 and 62 of plate 2, which adjoin the notch 6, are brought closer together and the current rod 5 is thus held by clamping in the opening 4.

[0052] The fixing of the cane in the opening 4 could also not include a fixing device 7: laen illustrates the example.

[0053] In, the through opening 4 was made with a diameter approximately equal to the diameter of the cane 5.

[0054] The rod 5 is thus forced into the opening 4, the first and second portions 61 and 62 of the plate being constrained against said current rod by a force exerted by said current rod 5 against the internal wall of the opening 4.

[0055] Another version could also be imagined, with a non-through opening 4.

[0056] The figure shows yet another embodiment with a fastening device 7.

[0057] In this example, notch 6 is made differently from notch 6 shown in figures 2 and 3, and opening 4 eis made in the thickness of the wall of plate 2: the current rod 5 is presented laterally with respect to plate 2.

[0058] The notch 6 of the embodiment shown extends along a direction D which is straight from said edge 60 of the terminal plate 2 to the opening 4. The direction D is parallel to a second edge 64 of plate 2, adjacent to the edge 60 of plate 2, so that the notch 6 is made along a plane P perpendicular to the surface 20 of terminal plate 2.

[0059] In this embodiment, portions 61 and 62 (on either side of notch 6) are brought together (to fix the rod 5 in the opening 4) by means of a screw 71 / nut 72 system similar to that illustrated in, the screw 71 being positioned in an opening which is made through portions 61 and 62, perpendicular to the surface 20 of the upper terminal plate 2.

[0060] This illustrates yet another variant of the realization: the notch 6 and the opening 4 are made as in the example shown in: the notch 6 made along a straight line D from said edge 60 of the terminal plate 2 to said opening, 4.

[0061] It should be noted that the straight direction D is parallel or substantially parallel to a surface 20 of terminal plate 2, so that the notch 6 is made in the thickness of said terminal plate 2.

[0062] In this embodiment example, the screw / nut system is replaced by a screw 73 / tapped hole 74 system, the tapped hole being made through portion 62 and partially through portion 63, the tapped hole being blind in portion 61.

[0063] It is understood from the above how the invention makes it possible to fix a current rod directly in the plate, whether in the upper plate or in the lower plate, by putting the current rod directly in contact with the plate, without an intermediate element between them, with a fixing device possibly being provided separately, without direct contact with the rod.

[0064] Of course the invention is not limited to the examples just described and extends to the implementation of any equivalent means which allows a cane to be fixed in an opening made in a plate wall.

Claims

Assembly for an electrochemical module, comprising a stack (1) of solid oxide electrolyzer cells or solid oxide fuel cells, said stack being positioned between an upper terminal plate (2) and a lower terminal plate (3), each of the upper and lower terminal plates (2, 3) having respectively an upper and lower connection portion to, respectively, an upper current rod (5) and a lower current rod (5), said assembly being characterized in that at least one of the connection portions comprises an opening (4) formed in said upper terminal plate (2) and / or lower terminal plate (3), to accommodate at least one of the two said current rods (5), as well as a notch (6) made in the thickness of the upper terminal plate (2) and / or lower terminal plate (3) from an edge (60, 63) of the upper terminal plate (2) and / or lower terminal plate (3) to said opening (4),said upper (2) and / or lower (3) terminal plate comprising, a first portion of plate (61) positioned on one side of the notch and a second portion of plate (62) positioned on the other side of the notch, the first (61) and second (62) portions of plate being able to be constrained against said current rod (5). Assembly according to claim 1, characterized in that said opening (4) is through. Assembly according to claim 1 or 2, characterized in that said at least one current rod (5) has a diameter equal to the diameter of said opening (4) and is forced into said opening (4), the first and second plate portions (61, 62) being constrained against said current rod (5) by a force exerted by said current rod (5) against the internal wall of said opening (4) into which it is forced. Assembly according to claim 1 or 2, characterized in that the first and second plate portions (61, 62) are constrained against said current rod (5) by a fixing device (7) of one of the plate portions on the other plate portion. Assembly according to claim 4, characterized in that said fastening device (7) is a screw (71) which passes through the first and second portions of plate and a nut (72) which is screwed onto said screw, against the other among the first and second portions of plate. Assembly according to claim 4, characterized in that said fastening device is a screw which passes through any one of the first or second portions of plate and which is fixed in a tapped hole provided in the other of the first and second portions of plate. Assembly according to any one of the preceding claims, characterized in that the notch extends in a straight line from said edge of the upper and / or lower terminal plate to said opening, said direction being parallel to a second plate edge, adjacent to said plate edge, so that the notch is made in a plane perpendicular to a terminal plate surface. Assembly according to any one of claims 1 to 6, characterized in that the notch extends in a straight line from said edge of the upper and / or lower terminal plate to said opening, said straight line being parallel to a surface of the terminal plate, so that the notch is made in the thickness of said terminal plate.

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