Method of manufacturing an electrical contact in Lanthanum Strontium Manganite on a substrate

Abstract

"Method for manufacturing an electrical contact made of Lanthanum Strontium Manganite on a substrate" The invention relates to a method for manufacturing an electrical contact made of Lanthanum Strontium Manganite, known as LSM, on a substrate. The method comprises a step of contactless deposition, on said substrate, of one or more LSM patterns by flowing or spraying a liquid or pasty LSM slip. Figure for abstract: Figure 1

Description

Title of the invention: Method for manufacturing an electrical contact in Lanthanum Strontium Manganite on a substrate Technical field

[0001] The present invention relates to a method of manufacturing an electrical contact made of Lanthanum Strontium Manganite on a substrate.

[0002] The invention also relates to an interconnection part, in particular for an electrochemical device, obtained by such a method.

[0003] The invention relates to the field of high-temperature electrochemical devices, such as, for example, electrolyzers and fuel cells.

[0004] The invention belongs, in particular, to the field of interconnections for electrolysers and fuel cells. State of the art

[0005] Interconnections, or electrical interconnections, are structures providing the electrical connection between two adjacent elements or modules.

[0006] With regard to high-temperature electrochemical devices, typically designed to operate at temperatures above 400°C, the interconnections are provided by elements commonly referred to as “interconnectors”. In this case, the interconnections can be made by a metal layer or a ceramic layer.

[0007] With regard to high-temperature electrochemical devices, such as, for example, electrolyzers and fuel cells. It is known to those skilled in the art that these devices comprise a stack of unitary electrochemical modules each composed of an anode and a cathode.

[0008] Each unit module of the stack, except the end modules, are therefore connected and separated from the two modules of the stack which are adjacent to it by two interconnectors. The electrically conductive LSM layer ensures a good electrical connection, or interconnection, between the interconnector, with which it is in contact, and the unit module, with which it is also in contact. The interconnectors are also porous to gases so as to allow their circulation from one unit module to the adjacent unit module(s).

[0009] Metallic interconnections are known from the state of the art.

[0010] Metal interconnects for high-temperature electrochemical devices have the advantage of being inexpensive. However, they degrade over time and do not allow for maintaining an optimal electrical connection over time.

[0011] Ceramic interconnections for high-temperature electrochemical devices are known from the state of the art.

[0012] However, the manufacturing processes for ceramic interconnections, in particular of the Lanthanum Strontium Manganite type, known as LSM, are based on a top-down approach requiring the implementation of a succession of steps to obtain an interconnector comprising LSM patterns on a substrate. Typically, current processes require the implementation of a continuous layer of LSM, then the cutting of the continuous layer, for example into a set of squares, the heat-pressing of the squares onto the substrate and then the machining of the squares to obtain LSM patterns on a substrate.

[0013] The methods of the state of the art generate a loss of more than 50% of the initial quantity of LSM. LSM is a scarce material. In addition, LSM is an expensive material. Also, there is a need to limit the quantity of ceramic, in particular LSM, necessary for the implementation of the interconnectors. There is also a need to limit the losses of LSM generated by the implementation of the manufacturing method of the interconnectors.

[0014] Furthermore, the state-of-the-art methods are time-consuming in that they require the implementation of several successive steps. In addition to the actual manufacturing steps, there are control and verification steps between some of the steps in the manufacturing process. The time required to manufacture the interconnectors is also further increased.

[0015] In addition, the use of several successive manufacturing and control stages requires the use of several manufacturing and control stations and tools. Also, the cost of the tools, added to the cost of maintaining these tools, is not negligible.

[0016] An aim of the present invention is to remedy at least one of the drawbacks of the state of the art.

[0017] Another aim of the invention is to propose a method for manufacturing an electrical contact in Lanthanum Strontium Manganite on a substrate allowing: • to limit the quantity of LSM required for the manufacture of LSM patterns, and / or • to limit the losses of LSM generated by the manufacturing process, and / or • to simplify the manufacturing process of LSM patterns, and / or • reduce manufacturing costs, and / or • reduce the maintenance costs of manufacturing tools, and / or • to reduce the operations required for manufacturing, and / or • reduce manufacturing time. Statement of the invention

[0018] For this purpose, the invention proposes a method for manufacturing an electrical contact made of Lanthanum Strontium Manganite, known as LSM, on a substrate. The method comprises a step of contactless deposition, on the substrate, of one or more LSM patterns by flowing or spraying a liquid or pasty slip of LSM.

[0019] The manufacturing method according to the invention can be defined as a method for manufacturing an LSM electrical contact for an electrochemical device.

[0020] Preferably, the LSM pattern(s) is intended to form an electrical contact between the substrate and an electrochemical device.

[0021] The electrical contact in LSM can consist of any set of patterns, for example composed of a set of geometric structures, which can be spatially distinct, identical or different.

[0022] Preferably, the pattern(s) do not cover the entire substrate.

[0023] The substrate may be gas porous or may allow gas diffusion.

[0024] Preferably, the substrate is conductive, at least for temperatures above 400°C.

[0025] Preferably, the LSM pattern or patterns are one or more LSM cords.

[0026] By cords it can be understood: a pattern, preferably continuous, such that, for example, a line, preferably continuous, or a serpentine, preferably continuous.

[0027] Preferably, in the present description, the entire description referring to the LSM cords is directly transposable to any type of pattern whatsoever.

[0028] The contactless deposition step may comprise the deposition of several cords or patterns on the same substrate.

[0029] In the present description, reference will be made indistinctly to "cord" or "pattern", a cord being a type of pattern envisaged according to the invention.

[0030] Preferably, the LSM cord and the substrate are intended to form or constitute, preferably form or constitute, preferably at least in part, an interconnection part for a high-temperature electrochemical device.

[0031] Preferably, according to the invention, the method is dedicated to or intended for or is specially adapted to, or designed for or specially designed for, the manufacture of an interconnection part for a high-temperature electrochemical device.

[0032] According to the invention, “high temperatures” may be understood to mean temperatures between 400°C and 1000°C.

[0033] The interconnection part may consist of one, preferably a single, LSM bead on the substrate.

[0034] The interconnection part may comprise two or more LSM cords on a substrate.

[0035] Preferably, the high temperature electrochemical device is an electrolyzer or a fuel cell.

[0036] Preferably, the substrate is an interconnector for an electrolyzer or fuel cell or for a solid oxide electrochemical device, preferably for a solid oxide electrolyzer or solid oxide fuel cell.

[0037] The method may be dedicated to or intended for or specially adapted to, or designed for or specially designed for, the manufacture of an interconnector for an electrolyzer or fuel cell.

[0038] The LSM and the substrate, or the interconnection part for a high-temperature electrochemical device, may form or constitute, or be intended to form or constitute, the interconnector. In other words, in this case, the interconnection part for a high-temperature electrochemical device may be or constitute or form an interconnector.

[0039] The LSM and the substrate, or the interconnection part for a high temperature electrochemical device, may be mounted on or associated with or assembled with, or may be intended to be mounted on or associated with or assembled with, an interconnector.

[0040] Preferably, the substrate is made of stainless steel.

[0041] Preferably, the contactless deposition step is implemented by a flow or projection deposition system.

[0042] Preferably, the deposition system comprises a deposition member. Preferably, the deposition member comprises: • a container intended to receive the LSM slip, • a means of ejecting or flowing the LSM slip out of the containing, and / or • a nozzle arranged for the flow or projection of the LSM slip out of the container, through the nozzle, onto the substrate.

[0043] Preferably, the deposition system is capable of or is suitable for or is adapted for implementing the method according to the invention.

[0044] Preferably, the method comprises a step of continuously flowing the LSM slip out of the container to form a bead of LSM on the substrate.

[0045] Preferably, the step of flowing the LSM slip out of the container is carried out so that at least a portion or fraction of a desired, desired or final thickness of a bead of LSM is deposited during a pass, deposit or pass, preferably continuous or without interruption. Preferably, each pass, deposit or pass, preferably continuous or without interruption, carried out during the flow step allows the deposition, on the substrate, of at least a portion or fraction of a desired, desired or final thickness of a bead of LSM.

[0046] Preferably, the flow step may comprise several passages, deposits or passes to deposit the same LSM bead and / or to deposit several LSM beads. Preferably, the successive passages, deposits or passes are carried out so that the addition of the successive thicknesses deposited of the same LSM bead corresponds to a desired, desired or final thickness of the LSM bead.

[0047] Preferably, the method comprises a step of setting the deposition member and the substrate in relative motion relative to each other by a system for setting the deposition member and / or the substrate in motion.

[0048] Preferably, the deposition system comprises the relative movement system.

[0049] Preferably, the method comprises a step of controlling, by a control unit, the movement system according to a predefined trajectory.

[0050] Preferably, the deposition system comprises a control unit arranged to control and / or command, in addition, the means for ejecting the LSM slip and / or the movement system.

[0051] Preferably, the deposition member is a volumetric head.

[0052] The manufacturing method according to the invention makes it possible to obtain an LSM electrical contact and / or an interconnection part in one step, preferably in a single step.

[0053] The manufacturing method according to the invention makes it possible to avoid lithography steps.

[0054] The manufacturing method according to the invention makes it possible, at a minimum, to reduce, preferably to eliminate, LSM losses during manufacturing.

[0055] Preferably, the flow or projection deposition system according to the invention is suitable, more preferably is particularly suitable, more preferably is designed and particularly advantageously is specially designed, for implementing the levitation method according to the invention.

[0056] Any characteristic of the flow or projection deposition system according to the invention can be directly transposed to the levitation method according to the invention and vice versa.

[0057] According to the invention, a computer program is provided comprising executable instructions which, when executed by computer, control the implementation of the steps of the manufacturing method.

[0058] Preferably, the computer program comprises executable instructions which, when executed by computer, command the deposition system to command and / or control the implementation of the method according to the invention.

[0059] Preferably, according to the invention, there is also provided a computer medium, for example a recording medium, readable by computer comprising instructions which, when executed by a computer, lead the latter to implement the method according to the invention.

[0060] According to the invention, a computer-readable data carrier is also provided, on which the computer program according to the invention is recorded.

[0061] The computer program can be in any computer language, such as for example machine language, C, C++, JAVA, Python, etc.

[0062] According to the invention, the term “computer” may be understood to mean: any type of device such as a server, a tablet, a calculator, a processor, a computer chip, programmed to implement the method according to the invention, for example by executing the computer program according to the invention.

[0063] Preferably, according to the invention, there is also provided an electrical contact made of Lanthanum Strontium Manganite, called LSM, on a substrate comprising, being formed or constituted or consisting of, preferably at least in part, a bead of LSM on the substrate capable of being obtained or obtained or directly obtained by the implementation of the method according to the invention.

[0064] Preferably, the electrical contact in Lanthanum Strontium Manganite, called LSM, on substrate comprises the substrate and the LSM bead(s) deposited on said substrate.

[0065] Preferably, there is also provided an interconnection part for a high-temperature electrochemical device, comprising, or being formed or made of or consisting of, preferably at least in part, a Lanthanum Strontium Manganite cord, called LSM, on a substrate, capable of being obtained or obtained or directly obtained by implementing the method according to the invention.

[0066] Preferably, the interconnection part for high temperature electrochemical device comprises the substrate and the LSM bead(s) deposited on said substrate.

[0067] Preferably, according to the invention, there is also provided an interconnector for an electrolyser or fuel cell, comprising, or being formed or made of or consisting of, preferably at least in part, a Lanthanum Strontium Manganite cord, called LSM, on a substrate, capable of being obtained or obtained or directly obtained by implementing the method according to the invention.

[0068] Preferably, the interconnector for electrolyzer or fuel cell comprises the substrate and the LSM cord(s) deposited on said substrate. Brief description of the FIGURES

[0069] The invention will be better understood on reading the following description, given solely as a non-limiting example and with reference to the appended drawings in which: - [Fig.l] is a schematic representation of a non-limiting example of an LSM bead being deposited on a substrate.

[0070] It is understood that the embodiments which will be described below are in no way limiting. In particular, it will be possible to imagine variants of the invention comprising only a selection of characteristics described below isolated from the other characteristics described, if this selection of characteristics is sufficient to confer a technical advantage or to differentiate the invention compared to the state of the prior art. This selection comprises at least one preferably functional characteristic without structural details, or with only a part of the structural details if it is this part which is only sufficient to confer a technical advantage or to differentiate the invention compared to the state of the prior art.

[0071] In particular, all the variants and all the embodiments described can be combined with each other if nothing prevents this combination from a technical point of view. Detailed description of the FIGURES

[0072] In [Fig.l] is illustrated an embodiment of the method of manufacturing an electrical contact in Lanthanum Strontium Manganite (LSM) on a substrate 102 according to the invention.

[0073] A type of widespread method for obtaining LSM electrical contacts on a substrate is known in the state of the art. These methods typically consist of a succession of steps, each carried out on a different station, consisting of: • deposit a strip of LSM on a first substrate, • cut the strip into a set of patterns spaced apart from each other on the first substrate, • check the thickness of the patterns obtained, • heat press the patterns onto a second substrate, then • machine the heat pressed patterns.

[0074] This type of manufacturing of electrical contacts in LSM is time-consuming. In addition, this type of manufacturing mobilizes a significant set of resources and tools, contributing to increasing the manufacturing cost. Finally, this type of manufacturing generates significant losses of raw material.

[0075] To overcome the defects of the methods of the state of the art, the method according to the invention comprises a step of depositing one or more LSM patterns 101 on the substrate 102.

[0076] After implementing the method according to the invention, a part is obtained comprising one or more LSM patterns 101 on the substrate 102. The part obtained 1 forms, or is intended to be used as, an interconnection part 1 in a high-temperature electrochemical device, typically at temperatures above 400°C. According to a preferred application, the LSM bead 101 on the substrate 102 forms an interconnector 1 for an electrolyzer or fuel cell.

[0077] The substrate 102 is stainless steel according to the non-limiting embodiment.

[0078] The deposition of the LSM pattern(s) 101 on the substrate 102 is carried out by flow or projection of an LSM slip. The LSM slip is liquid or pasty.

[0079] According to the invention, flow or projection is understood to mean a "distribution" or projection of material, or "dispensing" in English, of a liquid solution, sometimes referred to as ink. Those skilled in the art know the techniques relating to this method of deposition. These techniques are based on the controlled expulsion (or distribution) of material from a container.

[0080] Advantageously, as shown in [Fig. 1], the LSM pattern(s) 101 according to the embodiment are a continuous bead 101 of LSM. This embodiment has the advantage of continuously depositing, in particular without moving the deposition system 2 vertically or in height, a single bead. The bead can thus advantageously pave the substrate 102 without any loss of time being caused by successive withdrawals and approaches of the deposition member 201, 202, 203 of the substrate 102.

[0081] Other shapes or patterns, not necessarily in a cord, can be obtained. The typical dimensions of an obtained LSM 101 pattern, a cord 101 according to the embodiment presented, is a thickness and a width of about 400 μm (typically 420 μm). The spacing between two LSM 101 patterns, two parallel lines of the LSM 101 cord according to the embodiment, is about 1 mm (typically 1.3 mm).

[0082] The inventors obtained, by the method according to the invention, LSM 101 patterns having characteristics, in terms of profile (sizes, regularity, edges, etc.), identical to those obtained by the methods of the state of the art described above.

[0083] Still with reference to [Fig.l], there is illustrated, by way of non-limiting example, the deposition system 2 used to implement the manufacturing method according to the invention.

[0084] The deposition system 2 is arranged to flow or project the LSM slip.

[0085] The deposition system comprises a deposition member 201, 202, 203. The deposition member 201, 202, 203 comprises a container 201 intended to receive the slip of LSM. The deposition member 201, 202, 203 further comprises a means 202 for ejecting or flowing the LSM slip out of the container 201. The deposition member 201, 202, 203 further comprises a nozzle 203 arranged to allow, and preferably direct and / or orient and / or locate, the flow or projection of the LSM slip out of the container 201.

[0086] Any “dispenser” type deposition system, a term in the English language designating a “distributor”, is suitable for implementing the method according to the invention as long as it is suitable for a flow or projection of a liquid or a paste. By way of non-limiting examples, the deposition system 2 according to the invention may be any system for ejecting or continuously flowing material, such as inkjet or printing systems, for example certain so-called “3D” or “additive” printing methods.

[0087] The deposition system 2 comprises a means for setting into relative movement the deposition member 201, 202, 203 and / or the substrate 102 relative to each other.

[0088] In practice, a three-axis motorized platform, or a motorized arm, can be used as a means of moving the deposition member 201, 202, 203 relative to the substrate 102. In combination or as an alternative, a three-axis motorized platform, or a motorized arm, can be used as a means of moving the substrate 102 relative to the deposition member 201, 202, 203.

[0089] According to the preferred embodiment presented, the deposition member 201, 202, 203 is a volumetric head 201, 202, 203. The volumetric deposition head may comprise any suitable means 202 for ejecting or flowing the LSM slip. By way of non-limiting example, the ejection means may be a piston (exerting pressure on the slip), a pressurized gas (exerting pressure on the slip) or any other means making it possible to exert controlled pressure on the LSM slip contained in the container 201. The tip 203 of the volumetric deposition head is conical in shape; it may be described as a needle. By way of example, the tip 203 is, for example, made of polyethylene.

[0090] Advantageously, the deposition system 2 comprises a control unit 3. Preferably, the control unit 3 is arranged and / or programmed and / or configured to control and / or monitor the ejection or flow means 202 so as to ensure and / or modulate a flow and / or flow rate or projection of the slip out of the container 201.

[0091] Advantageously, the control unit 3 is, in addition, arranged and / or programmed and / or configured to command and / or control the movement system(s).

[0092] In particular, the control unit 3 is, in addition, arranged and / or programmed and / or configured to move the deposition member 201, 202, 203 and / or the substrate 102 in depending on a given and / or predefined trajectory, preferably also depending, in addition, on characteristics of the LSM slip (for example in terms of viscosity and / or composition).

[0093] Furthermore, in order to modulate / control the thickness and / or width of a deposited pattern 101 and / or the deposition speed of the LSM slip: • the control unit 3 is advantageously arranged and / or programmed and / or configured to: • control and / or modulate the lateral movement speed of the substrate 102 relative to the deposition system 2, and / or • control and / or modulate the position, or the height, between the tip 203 and the substrate 102, and / or • control and / or modulate the ejection or flow means 202 so as to adapt and / or define the flow rate of LSM slip ejected from or flowing through the nozzle 203, and / or • adapt and / or define and / or modulate a diameter of the size of the orifice of the tip 203 through which the LSM slip flows.

[0094] According to the invention, there is also proposed and described a method for preparing an LSM slip.

[0095] In a first step, solid LSM powder is ground and dispersed. Depending on the embodiment, a planetary ball mill is used during this step. This step is carried out in Zirconium (ZrO2) jars. It is specified that any type of suitable mill can be used. The grinding time for dispersion is from 30 min to 4 h, typically 2 h depending on the embodiment.

[0096] This first step aims to disperse the LSM powder in a solvent, or a mixture of solvents. A dispersant is advantageously added to the composition. According to the non-limiting embodiment, a mixture of butanone solvent, or methyl ethyl ketone (MEK in English), and ethanol is used. An ester is used as a dispersant according to the embodiment. The phosphoric ester CP213 Beycostat ® is used, as a non-limiting example according to the embodiment.

[0097] The particular composition, in grams, according to the non-limiting embodiment, is 1 to 4 gr of dispersant (2.4 gr according to the embodiment), between 45 and 51 gr of MEK, between 45 and 51 gr of ethanol and between 230 and 250 gr of LSM powder. In terms of solvents, between 55 and 65 ml of MEK and between 55 and 65 ml of ethanol are used.

[0098] The first grinding and dispersion step can be carried out at a grinding speed of between 150 and 190 rpm (a speed of 170 rpm depending on the embodiment).

[0099] In a second step of the process for preparing an LSM slip, a binder and a plasticizer are added to the LMS composition. According to the embodiment a binder, PVB B90®, and two plasticizers, DBS and PEG 400, are used. For example, the binder and the plasticizer may comprise, in grams, between 12 and 16 g of binder (PVB B90 depending on the embodiment), and between 12 and 18 g of plasticizer, for example between 1 and 4 g of DBS and between 11 and 14 g of PEG 400).

[0100] After the addition of the plasticizer and the binder, an additional grinding and dispersion step, preferably, but not necessarily, carried out in the same manner as that described in the first step, is carried out.

[0101] The second step can be carried out in two separate stages. An initial step, aimed primarily at providing fine grinding, can be carried out for 30 to 90 minutes. This initial step can be carried out at a speed of between 180 and 240 rpm. A final step, aimed primarily at homogenizing and mixing the slip, can be carried out for a period of between 15 and 25 hours. This final step can be carried out at a speed of between 50 and 110 rpm.

[0102] Advantageously, but not necessarily, at the end of the second step, the process for preparing the slip may comprise a step of degassing the LSM slip. This step may comprise a step of stirring the composition obtained. This stirring step is carried out, according to the non-limiting embodiment, on a roller bench. According to the embodiment, the stirring is carried out for a period of at least 12 hours, preferably at least 15 hours.

[0103] The LSM composition obtained constitutes the slip used according to the embodiment.

[0104] As a non-limiting example, the LSM slip obtained has a viscosity (measured at 30 rpm) of 1 to 3 Pa.s, typically 2 Pa.s. The dry extract is between 70 and 78%, typically 74%. The pH of the LSM slip is 6.7 to 7, typically 6.85. The density of the slip is of the order of 2. The particle size of the LSM slip d90 (fine yellow) is less than 15 μm.

[0105] Of course, the invention is not limited to the examples which have just been described and numerous adjustments can be made to these examples without departing from the scope of the invention.

[0106] Thus, in variants which can be combined with each other of the embodiments previously described: • a computer program is proposed comprising executable instructions which, when executed by computer, control the implementation of the steps of the method for manufacturing an electrical contact in LSM on a substrate 102 according to the invention, and / or • a computer-readable computer medium, for example a recording medium, comprising instructions which, when executed by a computer, cause the latter to implement the steps of the method is provided of manufacturing an electrical contact in LSM 101 on a substrate 102 according to the invention, and / or an electrical contact on a substrate is proposed, comprising one or more LSM patterns 101 on a substrate 102, capable of being obtained, obtained or directly obtained by implementing the method for manufacturing an electrical contact in LSM on a substrate 102 according to the invention, and / or an interconnection part 1 for a high-temperature electrochemical device is proposed, comprising one or more LSM patterns 101 on a substrate 102, capable of being obtained, obtained or directly obtained by implementing the method for manufacturing an electrical contact in LSM on a substrate 102 according to the invention.

Claims

Claims

1. Method for manufacturing an electrical contact made of Lanthanum Strontium Manganite, known as LSM, on a substrate (102), said method comprising a step of contactless deposition, on said substrate, of one or more LSM patterns (101) by flowing or spraying a liquid or pasty slip of LSM.

2. The method of claim 1, wherein the LSM pattern(s) (101) and the substrate (102) form, at least in part, an interconnection part (1) for a high-temperature electrochemical device.

3. The method of claim 2, wherein the substrate (102) is an interconnector for an electrolyzer or fuel cell.

4. A method according to any one of claims 1 to 3, wherein the substrate (102) is stainless steel.

5. A method according to any preceding claim, wherein the LSM pattern or patterns (101) are one or more LSM cords.

6. Method according to any one of claims 1 to 5, in which the contactless deposition step is implemented by a deposition system (2) by flow or projection; said deposition system comprises a deposition member (201, 202, 203), said deposition member comprising a container (201) intended to receive the LSM slip, a means for ejecting or flowing (202) the LSM slip from the container and a nozzle (203) arranged for the flow or projection of the LSM slip from the container, through the nozzle, onto the substrate (102).

7. Method according to the preceding claim, comprising a step of continuously flowing the LSM slip out of the container (201) to form the LSM pattern(s) (101) on the substrate (102).

8. Method according to claim 6 or 7, comprising a step of setting in relative movement the deposition member (201, 202, 203) and the substrate (102) relative to each other by a system for setting in movement the deposition member and / or the substrate.

9. Method according to the preceding claim, comprising a step of controlling, by a control unit (3) the movement system according to a predefined trajectory.

10. A method according to any one of claims 6 to 9, wherein the deposition member (201, 202, 203) is a volumetric head.

11. A computer program comprising executable instructions which, when executed by a computer, control the implementation of the steps of the manufacturing method according to any one of claims 1 to 10.

12. Electrical contact made of Lanthanum Strontium Manganite, known as LSM, on a substrate (102), comprising one or more LSM patterns (101) on said substrate, obtained by implementing the method according to any one of claims 1 to 10.

13. Interconnection part (1) for high-temperature electrochemical device, comprising one or more Lanthanum Strontium Manganite patterns (101), called LSM, on a substrate (102), obtained by implementing the method according to any one of claims 1 to 10.

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