Non-thermal cutting of sintered solid oxide cells

Abstract

A method for cutting sintered solid oxide cells (05) suitable for solid oxide electrolysis using abrasive waterjet cutting, which minimizes micro-cracks and produces a burr-free edge, eliminating the need for mechanical post-processing; the sintered solid oxide cells produced by this method are suitable for use in solid oxide electrolyzer cell stacks with improved structural integrity and reliability.

Description

[0001]

[0002] The invention relates to a method and apparatus for nonthermal cutting of sintered solid oxide cells suitable for solid oxide electrolysis, specifically using abrasive waterj et cutting to minimize edge defects such as burrs and micro-cracks, and to the sintered solid oxide cells produced by this method.

[0003] BACKGROUND OF THE INVENTION

[0004] This invention can generally be used in the production of sintered solid oxide cells (SOCs) used in solid oxide electrolysis cell stacks . Traditionally, laser cutting, has been used in pilot production to shape sintered solid oxide cells to their final geometry. However, the laser cutting process leads to the formation of a heat affected zone in the cut area, resulting in melted and re-solidified material on the cell edges that often must be mechanically deburred. The high local temperatures during laser cutting (>2200°C) cause micro-cracks in the cell edges, which increase the risk of cell cracking and failure during production or operation.

[0005] The need for mechanical post-processing, such as deburring, adds complexity and cost to the production process . Also, no viable automated solution for mechanical deburring in large-scale production has been found in the industry.SUMMARY OF THE INVENTION

[0006] The present invention provides a solution to these problems by utilizing abrasive waterj et cutting as a cold cutting method for shaping sintered solid oxide cells . This method results in a burr-free cell that does not require mechanical post-processing, except for rinsing and cleaning. Furthermore, it significantly minimizes micro-cracks on the cell edges, which enhances the manufacturability and reliability of the cells in large-scale production.

[0007] Furthermore, the present invention provides a solution for a problem to cutting sintered solid oxide cells using waterj et cutting; a support to the edge of the solid oxide cell which is cut away by the water j et during the cutting process .

[0008] The known art relevant to this invention includes the following patent applications :

[0009] US2004258970 AA discloses an integrated heat sink fuel cell assembly made of a heat sink assembly with a base and at least one cooling fin extending from the base, at least one connector extending from the heat sink assembly to a heat source, and at least one fuel cell comprising a cathode and an anode integrally disposed within the cooling fin and between the cathode and the anode is an electrolyte .

[0010] W007003628 Al concerns a flow magnetoresistor for fuel cell comprising several plates . The flow magnetoresistor for hydrogen or for air / oxygen comprises at least two partial plates . The partial plates are substantially identical and arranged without mutually coinciding. Protrusions serve tocontrol and provide arrangement / succession of the various plates which constitute a fuel stack.

[0011] US2003152821 AA describes a composite separator plate for use in a fuel cell stack and method of manufacture is provided. The composite separator plate includes a plurality of elongated support members oriented generally parallel to each other and a polymeric body portion formed around the support members . The body portion includes a first surface with a plurality of flow channels and a second surface opposite the first surface . A plurality of electrically conductive fibres are disposed within the polymeric body portion, each fibre extending continuously from the first surface of the polymeric body portion to the second surface of the polymeric body portion in a through plane configuration .

[0012] US2013280634 AA discloses a unit cell of a metal-supported solid oxide fuel cell in which a manifold is formed integrally with electrodes, and includes a metal support; a first electrode formed on a surface of the metal support; an electrolyte formed on a surface of the first electrode; and a second electrode formed on a surface of

[0013] the electrolyte and having a polarity opposed to that of the first electrode, wherein the metal support, the first electrode, the electrolyte, and the second electrode are formed with a manifold, a fluid passage . The present invention also relates to a method of manufacturing a unit cell of a metal-supported solid oxide fuel cell, and a stack using the solid oxide fuel cell .

[0014] US2023002920 AA describes an electrolyzer stack configuredfor high-speed manufacturing and assembly of a plurality of scalable electrolysis cells . Each cell comprises a plurality of water windows configured to maintain a pressure loss, temperature rise and / or oxygen outlet volume fraction below predetermined thresholds . Repeating components of the cells are configured based on a desired roll web width for production and a stack compression system is configured to enable a variable quantity and variable area of said repeating cells in a single stack. A high-speed manufacturing system is configured to produce scalable cells and assemble scalable stacks at rates in excess of 1, 000 MW-class stacks per year .

[0015] US2014234745 AA discloses methods, systems, and articles relating to enhanced bonding of layers in a planar fuel cell . A planar fuel cell having a composite layer is bonded to an outer layer (e . g. , a fuel or fluid manifold) using intrusions that extend through an electrolyte layer and into an underlying layer (e . g. , a substrate component or a current-collector component) .

[0016] These patents disclose various methods and apparatus for cutting and processing solid oxide cells but do not address the specific advantages and methods of using abrasive waterj et and supporting when cutting to minimize edge defects in sintered solid oxide cells .

[0017] DETAILED DESCRIPTION

[0018] The present invention provides a method for cutting sintered solid oxide cells, which are typically used in solidoxide electrolyzer cells (SOECs) . The method involves several key steps and offers multiple advantages over traditional cutting methods such as laser cutting.

[0019] Initially, the sintered solid oxide cell is placed in an apparatus that includes an abrasive waterj et cutting system and a specially designed support mechanism. This setup ensures that the cell is securely held in place during the cutting process, which is crucial for achieving precise and clean cuts .

[0020] One of the critical aspects of this method is the support mechanism, which plays a dual role . Firstly, it supports the edge of the cell that is being cut away by the water j et . Secondly, it can be further configured to support the rest of the cell during the cutting process . This comprehensive support minimizes any risk of the cell cracking or breaking, a common issue with traditional cutting methods where the cells are more prone to mechanical stress . The support mechanism can be adjusted to accommodate different sizes and shapes of the cells, ensuring versatility and adaptability in various production scenarios .

[0021] Once the cell is securely positioned and supported, the cutting process begins . The abrasive waterj et cutting system uses a high-pressure stream of water mixed with abrasive materials such as garnet, aluminum oxide, or silicon carbide . This high-pressure stream, typically ranging from 700 to 6200 bar, is directed precisely along the desired cutting path. The use of a computer numerical control (CNC) system ensures precision and repeatability in the cutting process, allowing for the production of cells with con-sistent quality and dimensions .

[0022] One of the primary advantages of using abrasive waterj et cutting is that it is a cold cutting method. Unlike laser cutting, which generates significant heat and creates a heat-affected zone, abrasive waterj et cutting avoids these thermal issues . As a result, there are no melted or resolidified materials on the edges of the cells, and the risk of forming micro-cracks is significantly minimized. The edges of the cells remain intact and free from the defects typically associated with hot cutting methods .

[0023] The method produces burr-free cells, eliminating the need for mechanical post-processing. In traditional laser cutting, deburring is necessary to remove the melted material and smooth out the edges . This additional step not only increases production time and cost but also introduces further risks of damaging the cells . By using abrasive waterj et cutting, the cells come out of the cutting process ready for immediate use, requiring only rinsing and cleaning to remove any residual abrasive particles .

[0024] Furthermore, the absence of heat-affected zones and minimal micro-cracks on the cell edges enhance the structural integrity of the cells . This improvement is particularly beneficial during the subsequent stages of cell production and operation within SOEC stacks . The cells are less likely to crack or fail, thereby increasing their reliability and lifespan. This method also supports large-scale production, as the abrasive waterj et cutting system can be configured for automated operation, ensuring high throughput and efficiency .In summary, the method for cutting sintered solid oxide cells using an abrasive waterj et cutting system and a support mechanism offers numerous advantages :

[0025] - Secure and adaptable support mechanism minimizes the risk of cell cracking.

[0026] - Precise and repeatable cutting process ensured by CNC control .

[0027] - Cold cutting method avoids heat-affected zones and minimizes micro-cracks .

[0028] - Produces burr-free cells, eliminating the need for mechanical post-processing.

[0029] - Enhanced structural integrity and reliability of the cells .

[0030] - Suitable for large-scale automated production.

[0031] This innovative method addresses the limitations of traditional cutting techniques and provides a robust, efficient, and cost-effective solution for shaping sintered solid oxide cells .

[0032] The present invention according to claim 1 introduces a novel method for cutting sintered solid oxide cells, which are typically used in applications such as solid oxide electrolyzer cells (SOECs) . This method involves a series of carefully controlled steps that ensure the production of high-quality cells with minimal defects .

[0033] The first step in the method involves placing the sintered solid oxide cell in a specially designed apparatus . In some embodiments of the invention, it may be parts of a solid oxide cell which is placed in the apparatus, e . g. a part of a cell comprising the fuel electrode support, fuel elec-trode, electrolyte and barrier layer . The cell is missing the oxy electrode and contact layers during cutting. Those are added at a later step . Also the cutting may be done on "fuel electrode supports" or "fuel electrode supports + fuel electrode" or "fuel electrode supports + fuel electrode + electrolyte" or "fuel electrode supports + fuel electrode + electrolyte + barrier layer"... or for electrolyte supported cells it can be the thick electrolyte only.

[0034] In any case, the apparatus is equipped with an abrasive waterj et cutting system and a support mechanism. The placement of the cell in this apparatus is crucial for achieving precise and clean cuts . The apparatus is engineered to securely hold the cell in place, preventing any movement that could lead to inaccuracies during the cutting process .

[0035] A critical feature of this method is the support mechanism, which plays a vital role in maintaining the integrity of the cell during cutting. Specifically, the support mechanism is designed to support the edge of the cell that is being cut away by the water j et . By providing this support, the mechanism ensures that the cell remains stable throughout the cutting process . This stability is essential to minimize the risk of the cell cracking or breaking, which is particularly important given the brittle nature of sintered solid oxide cells . The support mechanism can be adjusted to accommodate different sizes and shapes of cells, making the method versatile and adaptable to various production requirements .

[0036] Once the cell is securely positioned and supported, the cutting process is initiated using the abrasive waterj etcutting system. This system utilizes a high-pressure stream of water mixed with abrasive materials . The high-pressure stream is directed precisely along the desired cutting path, allowing for the creation of accurate and clean cuts . The abrasive materials, such as garnet, aluminum oxide, or silicon carbide, enhance the cutting efficiency and quality.

[0037] One of the primary advantages of using abrasive waterj et cutting is that it is a cold cutting method. Unlike traditional laser cutting, which generates significant heat and creates a heat-affected zone, abrasive waterj et cutting avoids these thermal issues . The high temperatures associated with laser cutting can cause the ceramic material of the cells to melt, leading to the formation of resolidified zones and melted material on the edges . These effects necessitate additional post-processing steps, such as deburring, to remove the unwanted material .

[0038] In contrast, the abrasive waterj et cutting method minimizes the generation of heat, thereby preventing the formation of heat-affected zones . As a result, the edges of the cells remain intact and free from the defects typically associated with hot cutting methods . This method ensures that the cut edges are burr-free, which means that the cells do not require any mechanical post-processing. The elimination of post-processing steps not only reduces production time and cost but also minimizes the risk of further damaging the cells .

[0039] Another significant advantage of this method is the minimization of micro-cracks on the edges of the cells . Micro-cracks are a common issue with traditional hot cutting methods and can lead to cell failure either during production or operation within a SOEC stack. By using a cold cutting method, the invention significantly reduces the occurrence of these micro-cracks, thereby enhancing the overall structural integrity and reliability of the cells .

[0040] In summary, the method for cutting sintered solid oxide cells using an abrasive waterj et cutting system and a support mechanism offers several key features and advantages : - Secure Support : The support mechanism ensures that the edge of the cell being cut away is stably supported, minimizing the risk of cracks .

[0041] - Precise Cutting: The abrasive waterj et cutting system uses a high-pressure stream of water mixed with abrasive materials to achieve precise and clean cuts .

[0042] - Cold Cutting: The method avoids the formation of heat-affected zones, preventing defects such as melted material and re-solidified zones on the edges of the cells .

[0043] - Burr-Free Edges : The method produces burr-free cells, eliminating the need for mechanical post-processing.

[0044] - Minimized Micro-Cracks : The minimization of micro-cracks enhances the structural integrity and reliability of the cells .

[0045] This innovative method addresses the limitations of traditional cutting techniques and provides a robust, efficient, and cost-effective solution for shaping sintered solid oxide cells .

[0046] In a further embodiment of the invention according to claim 2 an additional step is introduced that further enhancesthe quality and readiness of the cut sintered solid oxide cells . Claim 2 specifies that, after the cutting process, the method includes rinsing and cleaning the cut cell to remove any residual abrasive particles . This step is crucial for ensuring that the cells are free from contaminants and are ready for further use or assembly.

[0047] Once the abrasive waterj et cutting system has precisely cut the sintered solid oxide cell, the next step involves rinsing and cleaning the cell . The cutting process, which utilizes a high-pressure stream of water mixed with abrasive materials such as garnet, aluminum oxide, or silicon carbide, inevitably leaves behind some abrasive particles on the surface of the cell . Furthermore, parts of the cell material itself may leave particles . These residual particles, if not removed, could potentially interfere with the cell ' s performance or cause damage during subsequent handling and processing.

[0048] The rinsing and cleaning step effectively removes these residual abrasive particles from the surface of the cut cell . This is typically done using a high-purity water rinse or a similar cleaning solution that can thoroughly clean the cell without causing any damage . The cleaning process ensures that all abrasive particles are washed away, leaving the cell surface clean and free of contaminants .

[0049] The benefits of this additional rinsing and cleaning step are significant :

[0050] Enhanced Cell Quality: By removing residual abrasive particles, the rinsing and cleaning step ensures that the cutcells are of high quality and free from contaminants that could affect their performance . This is particularly important for sintered solid oxide cells used in SOEC stacks, where even small contaminants can lead to performance issues or failures .

[0051] Improved Reliability: The thorough cleaning of the cells enhances their reliability during subsequent production steps and final assembly. Clean cells are less likely to suffer from defects or failures caused by residual abrasive particles, leading to more consistent and reliable performance in their final applications .

[0052] Ready for Further Processing: The cleaned cells are immediately ready for further processing or assembly without the need for additional cleaning steps . This streamlines the production process, reducing the overall time and cost involved in preparing the cells for use .

[0053] Prevention of Damage : Residual abrasive particles can cause scratches or other damage to the cell surfaces during handling and subsequent processing. By removing these particles, the rinsing and cleaning step helps to prevent such damage, preserving the integrity of the cells .

[0054] Compliance with Quality Standards : The rinsing and cleaning step ensures that the cut cells meet stringent quality standards required for their use in high-performance applications . This is particularly important in industries where the cleanliness and quality of components are critical to the overall performance and safety of the final product .In summary, claim 2 enhances the method described in Claim 1 by adding a rinsing and cleaning step to remove any residual abrasive particles from the cut cells .

[0055] This additional step further refines the innovative method for cutting sintered solid oxide cells, providing a comprehensive solution that delivers clean, high-quality cells ready for use in various applications .

[0056] In an embodiment according to claim 3, the present invention further enhances the method described in claim 1 by refining the design and functionality of the support mechanism used during the cutting process . Claim 3 specifies that the support mechanism is not only designed to support the edge of the cell being cut away but is also configured to support the rest of the cell during the cutting process . This comprehensive support system is crucial for maintaining the structural integrity of the sintered solid oxide cells throughout the cutting operation.

[0057] When cutting sintered solid oxide cells, one of the primary concerns is the potential for cracking or breaking due to the brittle nature of the material . Traditional cutting methods, which often involve significant mechanical stress, can exacerbate this issue, leading to high rates of cell failure . The support mechanism described in claim 3 addresses this problem by providing robust and stable support for the entire cell, not just the edge being cut away.

[0058] By supporting the rest of the cell during the cutting process, the support mechanism ensures that any forces exerted by the abrasive waterj et cutting system are evenly distrib-uted across the cell . This even distribution of forces minimizes the risk of localized stress concentrations that could lead to cracking or breaking. The support mechanism can be adjusted to accommodate cells of various sizes and shapes, ensuring that each cell is securely held in place regardless of its specific dimensions .

[0059] The comprehensive support provided by this mechanism offers several key benefits :

[0060] Enhanced Structural Integrity: By supporting the entire cell, the mechanism helps maintain its structural integrity throughout the cutting process . This reduces the likelihood of cracks forming, which is particularly important for maintaining the cell ' s functionality and reliability in subsequent applications .

[0061] Minimized Risk of Cracks : The even distribution of forces across the cell minimizes stress concentrations that can lead to cracks . This is crucial for ensuring that the cells remain intact and free from defects that could compromise their performance .

[0062] Versatility and Adaptability: The adjustable nature of the support mechanism allows it to be used with cells of different sizes and shapes . This versatility makes the method adaptable to a wide range of production scenarios, enhancing its overall utility.

[0063] Improved Production Efficiency: By reducing the risk of cell failure during cutting, the support mechanism contributes to higher production yields and efficiency. Fewer de-fective cells mean less waste and lower production costs, making the method more cost-effective .

[0064] Consistency in Quality: The robust support provided by the mechanism ensures that each cell is cut with consistent quality. This consistency is vital for applications where uniformity and precision are critical, such as in the assembly of SOEC stacks .

[0065] In a further embodiment according to claim 4 an additional step that enhances the versatility and adaptability of the support mechanism is introduced. Specifically, claim 4 involves adjusting the support mechanism to accommodate the size and shape of the sintered solid oxide cell before the cutting process begins ( for cutting a completely different geometry of the cell, it is also an option to exchange part of the fixture . This process can be simplified so that it is easy to swap the support fixture without disassembly of the whole fixture geometry.

[0066] This adjustment capability is crucial for ensuring that the support mechanism can securely hold cells of various dimensions and geometries . Sintered solid oxide cells can come in different sizes and shapes depending on their specific applications and design requirements . The ability to adjust the support mechanism ensures that each cell, regardless of its unique dimensions, is properly supported during the cutting process .

[0067] By adjusting the support mechanism to fit the cell precisely, the method ensures that the cell is held firmly inplace, preventing any movement that could lead to inaccuracies or defects during cutting. This precise fit minimizes the risk of uneven stress distribution, which can cause cracks or breaks in the brittle cell material . The adjustment process is typically straightforward and can be performed quickly, making it an efficient addition to the overall cutting method.

[0068] The primary advantage of this feature is the increased flexibility it provides in the production process . Manufacturers can use the same cutting apparatus to handle a wide range of cell sizes and shapes without needing to invest in multiple specialized support mechanisms . This adaptability reduces equipment costs and streamlines the production process, allowing for greater efficiency and scalability.

[0069] Additionally, the ability to adjust the support mechanism enhances the overall quality of the cut cells . By ensuring that each cell is securely and accurately positioned, the method produces cells with precise dimensions and clean edges, free from defects such as burrs and micro-cracks . This precision is essential for applications where the cells must meet stringent performance and reliability standards, such as in SOEC stacks .

[0070] In the embodiment according to claim 5, the method described in Claim 1 is specified using the optimal pressure range for the abrasive waterj et cutting process . The method involves performing the abrasive waterj et cutting at a pressure ranging from 700 to 6200 bar .

[0071] Operating within this pressure range is crucial for achiev-ing precise and efficient cutting of sintered solid oxide cells . The high-pressure stream of water, combined with abrasive materials, provides the necessary force to cut through the dense and brittle ceramic material of the cells . The specified range ensures that the pressure is sufficient to achieve clean cuts without causing excessive stress or damage to the cells .

[0072] Using a pressure as low as 700 bar allows for controlled cutting of thinner or less dense sections of the cell, reducing the risk of over-stressing the material . On the other hand, a pressure of up to 6200 bar provides the necessary power to cut through thicker or more challenging sections efficiently. This wide pressure range offers flexibility in handling various cell geometries and materials, making the method adaptable to different production requirements .

[0073] The high-pressure stream ensures that the cutting process is swift and precise, which is essential for maintaining the integrity of the cell edges . By avoiding lower pressures that might lead to incomplete cuts or higher pressures that could cause excessive damage, the method produces cells with clean, burr-free edges and minimal microcracks . This balance is vital for ensuring the structural integrity and performance of the cells in their final applications .

[0074] Moreover, the specified pressure range contributes to the efficiency of the cutting process . Using the appropriate pressure for different cutting tasks optimizes the use of energy and abrasive materials, reducing waste and operational costs . It also minimizes the wear and tear on thecutting equipment, extending its lifespan and reducing maintenance needs .

[0075] Overall, performing the abrasive waterj et cutting within the pressure range of 700 to 6200 bar ensures that the method is both efficient and effective, producing high-quality sintered solid oxide cells with precise cuts and minimal defects .

[0076] In an embodiment according to claim 6, the abrasive material used in the waterj et cutting process can be selected from a group consisting of garnet, specifically almandine garnet, aluminum oxide, and silicon carbide . These materials are chosen for their exceptional hardness and cutting efficiency. Almandine garnet is particularly noted for its durability and effectiveness, providing high-quality cuts with minimal wear on the cutting equipment . Aluminum oxide and silicon carbide are also highly effective abrasives, known for their sharpness and ability to cut through tough materials . By selecting high-quality abrasives, the method ensures the efficient removal of material, resulting in clean, smooth edges on the sintered solid oxide cells . The use of these abrasives minimizes the risk of introducing defects such as micro-cracks and burrs, which can compromise the performance and reliability of the cells . Additionally, these abrasives can extend the operational life of the cutting equipment, reducing maintenance costs and downtime . The choice of abrasive material is important for achieving optimal cutting performance and maintaining the quality of the cut cells .

[0077] In the embodiment according to claim 7, the method of claim1 is further enhanced with regard to precision and repeatability by controlling the cutting path of the abrasive waterj et using a computer numerical control (CNC) system. The CNC system provides precise control over the movement and positioning of the waterj et, ensuring that each cut follows the exact desired path with high accuracy. This level of control is crucial for achieving consistent, high-quality cuts with minimal deviation. The CNC system allows for the execution of complex cutting patterns and shapes, making the method suitable for producing sintered solid oxide cells with intricate geometries and tight tolerances . The precision offered by the CNC system ensures that each cell is cut to the exact specifications required, reducing the likelihood of defects and enhancing the overall quality of the final product . Furthermore, the repeatability of the CNC system ensures that each cell produced is consistent in quality, which is essential for applications where uniformity and precision are critical . The use of CNC technology also facilitates faster setup times and reduces the need for manual adjustments, increasing overall production efficiency.

[0078] According to the embodiment of the invention according to claim 8 the risk of cracking during the cutting process is further minimized as the support mechanism is configured to support the cells on both sides of the cut line . Providing support on both sides of the cut line ensures that the cell remains stable and evenly supported throughout the cutting operation. This dual support reduces the likelihood of stress concentrations and mechanical failures, maintaining the structural integrity of the cell . By evenly distributing the forces exerted during cutting, the support mecha-nism minimizes the risk of cracks and breaks, which is particularly important for the brittle material of sintered solid oxide cells . This comprehensive support system is especially advantageous for cutting larger or more fragile cells, where maintaining stability is critical to prevent damage . The enhanced stability provided by the dual support mechanism contributes to higher production yields and reduces the need for rework, improving overall production efficiency. Additionally, the dual support mechanism ensures that the cut edges are clean and precise, further enhancing the quality of the final product .

[0079] According to another embodiment of the invention as disclosed in claim 9, the method of claim 1 further comprises an additional step of inspecting the cut cells inline to ensure they are free from burrs and micro-cracks . Inline inspection involves real-time monitoring and quality control during the production process . This step ensures that any defects are identified and addressed immediately, preventing defective cells from progressing further in the production line . By ensuring that each cell meets stringent quality standards, this step enhances the overall reliability and performance of the final product . Inline inspection also allows for the early detection of potential issues, enabling prompt corrective actions and reducing the risk of producing a large batch of defective cells . This proactive approach to quality control helps maintain high standards of production and ensures that the final cells are of the highest quality, ready for use in demanding applications such as SOEC stacks . The use of advanced inspection technologies, such as optical or laser scanning, can further enhance the accuracy and efficiency of the inspection pro-cess .

[0080] In yet another embodiment of the invention, according to claim 10, the abrasive waterj et cutting system is configured for automated operation to enable large-scale production of sintered solid oxide cells . Automation increases production efficiency and consistency by reducing the need for manual intervention. Automated systems can operate continuously, producing a high volume of cells with consistent quality. This scalability is essential for meeting the demands of large-scale manufacturing while maintaining high standards of precision and reliability. Automation also reduces the likelihood of human error, further enhancing the quality and consistency of the produced cells . The automated operation allows for faster production cycles and increased throughput, making it possible to meet high demand while keeping production costs low. The integration of automation into the cutting process streamlines the workflow and ensures that each cell is produced efficiently and accurately. Additionally, automated systems can be programmed to handle various cell sizes and shapes, further increasing the versatility and adaptability of the production process .

[0081] In a further embodiment of the invention, the edge of the cell which is cut away by the water j et during the cutting process is cut away in sections . This lowers the forces, such as bending moment, tear and vibrations in the area of the cell which is still connected to the edge which is being cut away, hence the risk of cracks and faults in the cell during cutting is further reduced. In an embodiment where the edge support is in the form of individual areas,the sections may start at a support area and finish just before the next support area .

[0082] In a further embodiment of the invention, a plurality of areas within the cell are also supported and cut away by the water j et during the cutting process . Not only the edge, but also a plurality of areas within the cell may need to be cut away, to provide the cell with apertures for instance for gas flow during operation of the cell . These areas may also be supported along the cutting edge according to the invention.

[0083] In another aspect of the invention, according to claim 13, a sintered solid oxide cell produced by the method described in claim 1 is characterized by being burr-free and not requiring mechanical post-processing except for rinsing and cleaning. The absence of burrs eliminates the need for additional finishing steps, reducing production time and costs . Burrs can cause issues such as poor fit and sealing in subsequent assembly steps, leading to potential failures in the final product . By producing burr-free cells, the method ensures that the cells are ready for immediate use or further processing without the need for additional deburring or finishing. This streamlines the production workflow and increases efficiency. The elimination of postprocessing steps also reduces the risk of introducing additional defects or damage to the cells, ensuring that the final product is of the highest quality. The high-quality edges produced by the method contribute to improved performance and reliability in the final application, such as in SOEC stacks .According to claim 12, another embodiment of the invention, a sintered solid oxide cell according to claim 13 has edges that are free of micro-cracks in the amount known from laser cutting at comparable cutting speeds . Micro-cracks can compromise the structural integrity and performance of the cells, leading to potential failures during operation. By minimizing these defects, the method ensures that the cells are more durable and reliable . This is particularly important for applications where the cells are subj ected to mechanical stress and thermal cycling, such as in SOEC stacks . The absence of micro-cracks enhances the overall strength and longevity of the cells, ensuring consistent performance and reducing the likelihood of premature failures . This improvement in quality directly translates to better reliability and efficiency in the final application. The method' s ability to produce micro-crack-free edges is a significant advantage over traditional cutting methods, which often introduce such defects .

[0084] In an embodiment of the invention according to claim 15, the sintered solid oxide cell described in claim 11 is suitable for use in a solid oxide electrolyzer cell stack without further mechanical treatment . The high-quality cuts produced by the method eliminate the need for additional finishing processes, making the cells immediately compatible with SOEC stacks . This compatibility reduces production steps and costs, facilitating faster assembly and deployment of SOEC systems . By providing cells that are ready for immediate integration into SOEC stacks, the method streamlines the manufacturing process and ensures that the cells meet the stringent requirements for performance and reliability. This readiness for use enhances the overall effi-ciency of the production workflow and reduces the time to market for SOEC systems . The method' s ability to produce high-quality, ready-to-use cells is a significant advantage for manufacturers looking to optimize their production processes .

[0085] In a further embodiment of the invention according to claim 16, the sintered solid oxide cell of Claim 13 has been cut to its final geometry with precision and repeatability suitable for a solid oxide electrolyzer cell stack. Precision and repeatability are critical for ensuring that each cell fits perfectly within the stack, maintaining consistent performance and efficiency. The method guarantees that each cell meets stringent dimensional tolerances, which is essential for the reliable operation of SOEC stacks . Consistent geometry ensures that the cells are properly aligned and sealed within the stack, preventing issues such as leaks and electrical inefficiencies . The precise and repeatable cutting process ensures that each cell contributes to the overall performance and reliability of the SOEC stack, enhancing its efficiency and lifespan. The method' s ability to produce cells with consistent geometry and high precision is crucial for maintaining the performance and reliability of SOEC systems .

[0086] In a further embodiment of the invention according to claim 17, the sintered solid oxide cell of Claim 13 exhibits improved structural integrity during subsequent production steps, such as during leak testing after cutting, as compared to laser-cut solid oxide cells . This improvement is due to the absence of heat-affected zones, minimal microcracks, and no need for further mechanical treatment . Theenhanced structural integrity reduces the likelihood of failures during testing and operation, ensuring that the cells perform reliably in their intended applications . The method produces cells that are more robust and capable of withstanding the rigors of production and operation. By minimizing defects and enhancing structural integrity, the method ensures that the final cells are of the highest quality, ready for use in demanding applications such as SOEC stacks . The method' s ability to produce cells with improved structural integrity is a significant advantage for manufacturers looking to ensure the reliability and performance of their products .

[0087] In embodiments of the invention, a support mechanism is provided adapted to support the sintered solid oxide cells as the are being cut by an abrasive waterj et according to the method described in the above . ( It is to be understood that the sintered solid oxide cells may be cut one at a time according to the described method) . The support mechanism comprises at least a first support part which is adapted to support the inner area of the solid oxide cell which is being cut, i . e . the first support part supports the area of the cell which is the final cell product, the part which is going to be used for the production of a solid oxide cell stack. The outer part of the cells, the edges which need to be cut away is supported by at least a second support part of the support mechanism. This second support part serves the purpose of supporting the edge which is cut away, which has the effect that micro-cracks in the solid oxide cell is minimized. If the edge is not supported during the waterj et cutting, there is a risk that edge parts will break away uncontrolled from the inner area of thesolid oxide cell, leaving micro-cracks or damaged areas in the outer edge of the final solid oxide cells . Hence, it was discovered during testing of the waterj et cutting that this second support part is very important for the final quality of the solid oxide cells .

[0088] To further improve the quality of the solid oxide cells, the second support part may comprise an upper surface which has an angle relative to the plane of the solid oxide cell being cut . A slight angle ensures that the outer edge of the solid oxide cell is supported during cutting, but at the same time the cut-away material is led away from the cutting zone during the cutting, leading to an even better quality of the outer edge of the solid oxide cells after the waterj et cut . The angle of the upper surface of the second support part relative to the plane of the solid oxide cell may be between zero and thirty degrees, between one and fifteen degrees or between one and eight degrees .

[0089] In an embodiment of the invention, the second support part may comprise a plurality of secondary support areas arranged along the zone to be cut . In a further embodiment of the invention (not shown in the drawings) the second support part may comprise a rim running along the outer part of the zone to be cut .

[0090] In an embodiment of the invention, the uppermost part of the second support part is slightly lowered relative to the first support part, to ensure that the sintered solid oxide cells rest on the first support part while they are being cut . As the cells may not be entirely plane, it can be beneficial to positively ensure that they are primarily supported on the first support part - the part that support the final cell product - while they are being cut . This again to minimize the rist of crack-formations . Depending of the tolerances of the cell, the second support part may be slightly lowered relative to the first support part .

[0091] FEATURES OF THE INVENTION

[0092] 1. A method for cutting sintered solid oxide cells, the method comprising:

[0093] - placing the sintered solid oxide cell in an apparatus having an abrasive waterj et cutting system and a support mechanism;

[0094] - supporting the edge of the cell or a part of the edge which is cut away by the water j et during the cutting process using the support mechanism;

[0095] - cutting the sintered solid oxide cell with the abrasive waterj et cutting system;

[0096] - wherein the abrasive waterj et cutting minimizes microcracks on the edges of the cells and produces a burr-free cell that does not require mechanical post-processing.

[0097] 2. The method of feature 1, further comprising the step of : - rinsing and cleaning the cut cell to remove any residual abrasive particles .

[0098] 3. The method of feature 1, wherein the support mechanism is further configured to support the rest of the cell during the cutting process to avoid cracks .4. The method of feature 1, further comprising adjusting the support mechanism to accommodate the size and shape of the cell before cutting.

[0099] 5. The method of feature 1, wherein the abrasive waterj et cutting is performed at a pressure ranging from 700 - 6200 bar .

[0100] 6. The method of feature 1, wherein the abrasive material used in the waterj et cutting is selected from a group consisting of garnet, specifically almandine garnet, aluminum oxide, and silicon carbide .

[0101] 7. The method of feature 1, wherein the cutting path of the abrasive waterj et is controlled by a computer numerical control (CNC) system for precision and repeatability.

[0102] 8. The method of feature 1, wherein the support mechanism is configured to support the cells on both sides of the cut line to further minimize the risk of cracking.

[0103] 9. The method of feature 1, further comprising the step of : inspecting the cut cells inline to ensure that they are free from burrs and micro-cracks .

[0104] 10. The method of feature 1, wherein the abrasive waterj et cutting system is configured for automated operation to enable large-scale production of the sintered solid oxide cells .

[0105] 11. A sintered solid oxide cell produced by the method of feature 1, wherein the cell is burr-free and does not re-quire mechanical post-processing except for rinsing and cleaning .

[0106] 12. The sintered solid oxide cell of feature 11, wherein the edges of the cell are free of micro-cracks in the amount known from laser cutting at comparable cutting speeds .

[0107] 13. The sintered solid oxide cell of feature 11, wherein the cell is suitable for use in a solid oxide electrolyzer cell stack without further mechanical treatment .

[0108] 14. The sintered solid oxide cell of feature 11, wherein the cell has been cut to its final geometry with precision and repeatability suitable for a solid oxide electrolyzer cell stack.

[0109] 15. The sintered solid oxide cell of feature 11, wherein the cell exhibits improved structural integrity during subsequent production steps, such as during leak testing after cutting, as compared to laser cut solid oxide cells, due to the absence of heat-affected zones, minimal micro-cracks, and no need for further mechanical treatment .BRIEF DESCRIPTION OF THE DRAWINGS

[0110] The invention is further illustrated by the accompanying drawings showing examples of embodiments of the invention. It is to be understood that the invention according to the claims covers many other embodiments than the ones shown in the drawings which serve the purpose of explaining the invention with specific examples .

[0111] Fig. 1 shows a top view of the support mechanism.

[0112] Fig. 2 shows a side cut view of the support mechanism and a solid oxide cell before a cut is performed.

[0113] Fig. 3 shows a side view of the support mechanism and a solid oxide cell before a cut is performed.

[0114] Fig. 4 shows an enlarged detail of the side cut view of the support mechanism and a solid oxide cell before a cut is performed .

[0115] POSITION NUMBERS .

[0116] 01. Support mechanism

[0117] 02 . First support part

[0118] 03. Second support part

[0119] 04. Secondary support areas

[0120] 05. Solid oxide cellDETAILED DESCRIPTION OF THE DRAWINGS

[0121] In Fig. 1, an embodiment of the invention is shown as a top view of the support mechanism 01 (shown through a solid oxide cell) with a solid oxide cell 05 supported on top of the support mechanism. The support mechanism comprises a first support part 02 which is supporting the whole area of the solid oxide cell which is the final part after the waterj et cutting is performed. Hence, the first support part is supporting the solid oxide cell bottom surface all the way to the periphery where the cutting zone is . The outer part of the solid oxide cell, the edge part which is to be cut away by the waterj et cutting, is supported by a second support part 03, which in this embodiment comprises six separate secondary support areas 04. As previously discussed, the second support part (which in this embodiment is separate secondary support areas, hence both position number 03 and 04 ) minimizes the forming of micro-cracks or other defects in the finalized product, the waterj et cut solid oxide cell . Therefore, the second support part is an important part of the present invention.

[0122] In Fig. 2 the same embodiment as in Fig. 1 is shown in a side cut view, through the cut line A-A shown in Fig. 1. Here the cut view shows in more clarity the first support part drawn with hatching; and the second support part, which in this embodiment is separate secondary support areas which are not cut through by the cut line A-A and therefore they are not drawn with hatching. Hence, the shift between the first support part and the second support part is more clear; this is also where the cut zone is located,this is where the solid oxide cell supported on top of the support mechanism is cut by the waterj et .

[0123] In Fig. 3 almost the same is shown as in Fig. 2, only now in a side view, not a cut view. Hence, the first support part is not drawn with hatching and a further secondary support area is visible .

[0124] In Fig. 4 an important detail of one embodiment of the invention is shown in an enlarged side cut view. Clearer the cut zone is visible as a double line down through the solid oxide cell as well as down through the support mechanism. To the left of the cut zone a part of the first support part is visible, drawn with hatching; and to the right one of the secondary support areas is shown. The secondary support areas are supporting the edge of the solid oxide cell, the part of the solid oxide cell which is cut away by the waterj et . It is clear in fig. 4 how the upper surface of the secondary support area has an angle relative to the plane of the solid oxide cell . This improves the removal of the cut off edge of the solid oxide cell during the cutting, while still supporting the edge to minimize the forming of micro-cracks in the solid oxide cell .EXAMPLE

[0125] A sintered solid oxide is placed on a fixture to make sure it is held in position during cutting. Abrasive waterj et cutting is used for cutting the cell with high quality edges .

[0126] First, a lower pressure abrasive waterj et cutting is used to make small holes (piercing) in the cell . Those holes will subsequently be used as starting points for the real cutting of the cell .

[0127] Lower pressure means between 200 - 2000 bars, preferably between 400 and 1600, more preferably between 800 - 1200 bar .

[0128] A multitude of parameters then determines the quality of the cut : mesh size of the abrasive garnet, type of garnet material, cutting pressure, cutting speed, abrasive feed flow, size of focusing tube, size and type of j ewel orifice etc .

[0129] Some selected cutting parameters to achieve good cutting quality is as follows : j ewel orifice and focusing tube dimension ( 0.18 / 0.54 mm) , abrasive garnet mesh size (230) , abrasive garnet type (Barton HPX230) , abrasive feed flow ( 150 - 250 g / min) , cutting speed ( 1000 -2500 mm / min) .

Claims

1. 34CLAIMS1. A method for cutting sintered solid oxide cells ( 05) , the method comprising:- placing the sintered solid oxide cell in an apparatus having an abrasive waterj et cutting system and a support mechanism ( 01 ) ;- supporting the edge of the cell which is cut away by the water j et during the cutting process using the support mechanism;- cutting the sintered solid oxide cell with the abrasive waterj et cutting system;- wherein the abrasive waterj et cutting minimizes microcracks on the edges of the cells and produces a burr-free cell that does not require mechanical post-processing.

2. The method of claim 1, further comprising the step of : - rinsing and cleaning the cut cell to remove any residual abrasive particles .

3. The method of claim 1, wherein the support mechanism is further configured to support the rest of the cell during the cutting process to avoid cracks .

4. The method of claim 1, further comprising adjusting the support mechanism to accommodate the size and shape of the cell before cutting.

5. The method of claim 1, wherein the abrasive waterj et cutting is performed at a pressure ranging from 700 - 6200 bar .

356. The method of claim 1, wherein the abrasive material used in the waterj et cutting is selected from a group consisting of garnet, specifically almandine garnet, aluminum oxide, and silicon carbide .

7. The method of claim 1, wherein the cutting path of the abrasive waterj et is controlled by a computer numerical control (CNC) system for precision and repeatability.

8. The method of claim 1, wherein the support mechanism is configured to support the cells on both sides of the cut line to further minimize the risk of cracking.

9. The method of claim 1, further comprising the step of : inspecting the cut cells inline to ensure that they are free from burrs and micro-cracks .

10. The method of claim 1, wherein the abrasive waterj et cutting system is configured for automated operation to enable large-scale production of the sintered solid oxide cells .

11. The method of claim 1, wherein the edge of the cell which is cut away by the water j et during the cutting process is cut away in sections .

12. The method of claim 1, wherein a plurality of areas within the cell are also supported and cut away by the water j et during the cutting process .

13. A sintered solid oxide cell produced by the method of claim 1, wherein the cell is burr-free and does not requiremechanical post-processing except for rinsing and cleaning.

14. The sintered solid oxide cell of claim 13, wherein the edges of the cell are free of micro-cracks in the amount known from laser cutting at comparable cutting speeds .

15. The sintered solid oxide cell of claim 13, wherein the cell is suitable for use in a solid oxide electrolyzer cell stack without further mechanical treatment .

16. The sintered solid oxide cell of claim 13, wherein the cell has been cut to its final geometry with precision and repeatability suitable for a solid oxide electrolyzer cell stack .

17. The sintered solid oxide cell of claim 13, wherein the cell exhibits improved structural integrity during subsequent production steps, such as during leak testing after cutting, as compared to laser cut solid oxide cells, due to the absence of heat-affected zones, minimal micro-cracks, and no need for further mechanical treatment .

18. A support mechanism ( 01 ) adapted to support sintered solid oxide cells ( 05) while they are being cut according to the method according to any of the claims 1 - 12, wherein the support mechanism comprises at least a first support part ( 02 ) adapted to support an inner area of the sintered solid oxide cells and at least a second support part ( 03) adapted to support the outer area of the sintered solid oxide cells which is cut away by the waterj et cutting system, thereby minimizing micro-cracks on the edges of the cells .

19. A support mechanism according to claim 18, wherein the second support part comprises an upper support surface which has an angle between 0 to 30 degrees relative to the plane of the sintered solid oxide cells .

20. A support mechanism according to claim 18, wherein the second support part comprises an upper support surface which has an angle between 1 to 15 degrees relative to the plane of the sintered solid oxide cells .

21. A support mechanism according to claim 18, wherein the second support part comprises an upper support surface which has an angle between 1 to 8 degrees relative to the plane of the sintered solid oxide cells .

22. A support mechanism according to any of the claims 18 -21, wherein the second support part comprises a plurality of secondary support areas ( 04 ) disposed along the zone to be cut .

23. A support mechanism according to any of the claims 18 -22, wherein the uppermost part of the second support part is slightly lowered relative to the first support part, to ensure that the sintered solid oxide cells rest on the first support part while they are being cut .

Images