Design apparatus, design system, design method, and design program for electrochemical cell stacks

Abstract

To provide a design device for an electrochemical cell stack capable of reducing cost by reusing used cells.SOLUTION: A design device for an electrochemical cell stack according to an embodiment comprises a deterioration degree acquisition unit for acquiring the degree of cell deterioration of used cells together with identification information, a specification acquisition unit for acquiring a specification life, and a selection calculation unit for selecting used cells to be used for the electrochemical cell stack so that the life of the electrochemical cell stack satisfies the specification life and for calculating the life of the electrochemical cell stack on the basis of the number of specification cells and the degree of cell deterioration.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The embodiments relate to a design apparatus, design system, design method, and design program for electrochemical cell stacks. [Background technology]

[0002] Electrochemical cell stacks, which constitute fuel cells, water electrolyzers, and carbon dioxide electrolyzers, are constructed by stacking multiple cells. The membrane electrode assembly that makes up a cell includes an anode electrode, a cathode electrode, and an electrolyte membrane interposed between the anode and cathode electrodes. With continued use of the electrochemical cell stack, the catalyst material contained in the anode and cathode electrodes, or the electrolyte membrane, deteriorates. In this case, the performance of the electrochemical cell stack may decrease. When a certain degree of performance degradation is observed, the used electrochemical cell stack is discarded and replaced with a new one.

[0003] Used electrochemical cell stacks may contain cells with low levels of degradation. On the other hand, new electrochemical cell stacks composed solely of new cells have the problem of being costly. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2015-069948 [Patent Document 2] Japanese Patent Publication No. 2019-160701 [Patent Document 3] Japanese Patent Publication No. 2022-137607 [Patent Document 4] Japanese Patent Publication No. 2021-046575 [Patent Document 5] Japanese Patent Publication No. 2012-214904 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] The embodiment aims to provide a design apparatus, design system, design method, and design program for an electrochemical cell stack that can reduce costs by reusing used cells. [Means for solving the problem]

[0006] The electrochemical cell stack design apparatus according to this embodiment is an electrochemical cell stack design apparatus in which a plurality of cells, including used cells, are stacked. The electrochemical cell stack design apparatus includes a degradation degree acquisition unit that acquires the degree of cell degradation of used cells to which identification information has been assigned, along with the identification information; a specification acquisition unit that acquires the specified lifespan of the electrochemical cell stack; and a selection calculation unit that selects used cells to be used in the electrochemical cell stack based on the specified number of cells and the degree of cell degradation of the electrochemical cell stack so that the lifespan of the electrochemical cell stack satisfies the specified lifespan, and calculates the lifespan of the electrochemical cell stack based on the cell degradation degree of the selected used cells.

[0007] The electrochemical cell stack design system according to this embodiment includes a database that stores the degree of cell degradation of multiple used cells in association with identification information, and the electrochemical cell stack design apparatus described above.

[0008] The electrochemical cell stack design method according to this embodiment is a method for designing an electrochemical cell stack in which a plurality of cells, including used cells, are stacked. The electrochemical cell stack design method includes the steps of: obtaining the degree of cell degradation of used cells to which identification information has been assigned, along with the identification information; obtaining the specified lifespan of the electrochemical cell stack; selecting used cells to be used in the electrochemical cell stack based on the specified number of cells and the degree of cell degradation of the electrochemical cell stack, so that the lifespan of the electrochemical cell stack meets the specified lifespan, and calculating the lifespan of the electrochemical cell stack based on the degree of cell degradation of the selected used cells.

[0009] The design program for an electrochemical cell stack according to this embodiment is a design program for an electrochemical cell stack that causes a computer to execute a design method for an electrochemical cell stack in which a plurality of cells, including used cells, are stacked. The design method includes the steps of: obtaining the degree of cell degradation of used cells to which identification information has been assigned, along with the identification information; obtaining the specified lifespan of the electrochemical cell stack; selecting used cells to be used in the electrochemical cell stack based on the specified number of cells and the degree of cell degradation of the electrochemical cell stack so that the lifespan of the electrochemical cell stack meets the specified lifespan, and calculating the lifespan of the electrochemical cell stack based on the degree of cell degradation of the selected used cells. [Effects of the Invention]

[0010] According to this embodiment, costs can be reduced by reusing used cells. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is a cross-sectional view showing the schematic configuration of the electrochemical cell stack according to this embodiment. [Figure 2] Figure 2 is a plan view showing the cells shown in Figure 1. [Figure 3] Figure 3 shows the schematic system configuration of the electrochemical cell stack shown in Figure 1. [Figure 4] Figure 4 is a diagram illustrating the commercial transaction of the electrochemical cell stack shown in Figure 1. [Figure 5] Figure 5 shows the design system of the electrochemical cell stack according to this embodiment. [Figure 6] Figure 6 is a schematic diagram illustrating the information stored in the first database shown in Figure 5. [Figure 7] Figure 7 is a schematic diagram illustrating the information stored in the second database shown in Figure 5. [Figure 8]FIG. 8 is a diagram showing an example of rank assignment by the rank assignment unit shown in FIG. 5. [Figure 9] FIG. 9 is a schematic diagram showing an example of the processing of the design device shown in FIG. 5. [Figure 10] FIG. 10 is a table showing an example of the relationship between the cell degradation degree and the price reduction rate used by the price calculation unit shown in FIG. 5. [Figure 11] FIG. 11 is a diagram showing an example of the display content by the display unit shown in FIG. 5. [Figure 12] FIG. 12 is a diagram for explaining a measurement method for obtaining characteristic data showing the voltage-current characteristics of a cell. [Figure 13] FIG. 13 is a graph showing the voltage-current characteristics of a cell. [Figure 14] FIG. 14 is a graph showing the voltage-time characteristics of a cell. [Figure 15] FIG. 15 is a flowchart showing a design method of an electrochemical cell stack according to the present embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION

[0012] Next, a design device, a design system, a design method, and a design program of an electrochemical cell stack according to the present embodiment will be described. Here, first, an electrochemical cell stack that is a design target of the design device of the electrochemical cell stack according to the present embodiment will be described. The electrochemical cell stack is used for an electrolyzer such as carbon dioxide or water, or a fuel cell.

[0013] As shown in FIG. 1, the electrochemical cell stack 1 includes a pair of collector plates 2, a plurality of cells 10 stacked between the pair of collector plates 2, and a plurality of separators 30 stacked alternately with the cells 10. The cell 10 includes a membrane electrode assembly (MEA) 10M and a cell frame 20. The cell 10, the separator 30, and the collector plate 2 are clamped and pressed by a pair of clamping plates 3. The pair of clamping plates 3 are clamped using bolts and nuts (not shown). An insulating plate 4 is interposed between the clamping plate 3 and the collector plate 2.

[0014] The membrane electrode assembly 10M includes a cathode electrode 11, an anode electrode 12, and an electrolyte membrane 13 interposed between the cathode electrode 11 and the anode electrode 12. The membrane electrode assembly 10M is formed in the shape of a thin plate. The membrane electrode assembly 10M may also be formed in a rectangular shape when viewed in the stacking direction D of the electrochemical cell stack 1.

[0015] The cathode electrode 11 includes a cathode catalyst layer 11a and a cathode gas diffusion layer 11b. The cathode catalyst layer 11a is in contact with the electrolyte membrane 13. The cathode gas diffusion layer 11b is in contact with the separator 30 and diffuses the cathode fluid supplied from the cathode channel, which will be described later. When the electrochemical cell stack 1 is used in an electrolysis apparatus, the cathode gas diffusion layer 11b may be formed of, for example, carbon paper or titanium nonwoven fabric. The cathode gas diffusion layer 11b is bonded to the cathode catalyst layer 11a. If the cathode catalyst layer 11a can diffuse the cathode fluid, the cathode gas diffusion layer 11b may not be provided.

[0016] The anode electrode 12 includes an anode catalyst layer 12a and an anode gas diffusion layer 12b. The anode catalyst layer 12a is in contact with the electrolyte membrane 13. The anode gas diffusion layer 12b is in contact with the separator 30 and diffuses the anode fluid supplied from the anode channel 32, which will be described later. When the electrochemical cell stack 1 is used in an electrolysis apparatus, the anode gas diffusion layer 12b may be formed of, for example, carbon paper or titanium nonwoven fabric. The anode gas diffusion layer 12b is bonded to the anode catalyst layer 12a. If the anode catalyst layer 12a can diffuse the anode fluid, the anode gas diffusion layer 12b may not be provided.

[0017] The electrolyte membrane 13 is formed of an electrolyte material. When the electrochemical cell stack 1 is used in an electrolysis apparatus, examples of the electrolyte membrane 13 include ion exchange membranes or porous membranes, but are optional.

[0018] The anode electrode 12 is formed on one side of the electrolyte membrane 13, and the cathode electrode 11 is formed on the other side of the electrolyte membrane 13. The anode electrode 12 and the cathode electrode 11 are bonded to the electrolyte membrane 13.

[0019] When the electrochemical cell stack 1 is used as a fuel cell, a power generation reaction is carried out to produce electrical energy. In this case, a cathode fluid (see symbol F1 in Figure 1) is supplied to the cathode electrode 11 from the cathode channel 31, which will be described later. The cathode fluid is an oxygen-containing gas, and may be air, for example. An anode fluid (see symbol F2 in Figure 1) is supplied to the anode electrode 12 from the anode channel 32, which will be described later. The anode fluid may be a hydrogen-containing gas, for example. When the cathode fluid and anode fluid are supplied, an electrochemical reaction occurs in the membrane electrode assembly 10M. As a result, electrical energy can be extracted.

[0020] When the electrochemical cell stack 1 is used as an electrolysis apparatus, the electrolysis reaction is carried out using electrical energy. In this case, the cathode fluid may be water vapor or carbon dioxide gas, and the water vapor or carbon dioxide gas may be electrolyzed at the cathode electrode. An electrolytic solution may be supplied to the anode electrode 12. The electrolytic solution may be an aqueous solution containing an electrolyte such as calcium bicarbonate (KHCO3).

[0021] As shown in Figure 2, the cell 10 is marked with an identification symbol 14 indicating identification information. The identification information may be an ID code. The identification symbol 14 may be affixed to the surface of the cathode electrode 11 facing the cathode channel 31, or to the surface of the anode electrode 12 facing the anode channel 32. The identification symbol 14 may also be affixed to the margin portion. The margin portion is located outside the seal portion (not shown) of the cell frame 20, which will be described later. The identification symbol 14 may be affixed to the cell frame 20, cathode electrode, or anode electrode by, for example, printing, laser, or handwriting. The identification symbol 14 may be affixed to the cell frame 20 using alphanumeric characters, or it may be affixed to the cell frame 20 using a one-dimensional barcode or a two-dimensional barcode.

[0022] As shown in Figure 2, when viewed in the stacking direction D of the electrochemical cell stack 1, the membrane electrode assembly 10M is surrounded by the cell frame 20. The cell frame 20 may be made of a plastic film. Examples of materials that can be used for the plastic film include polyethylene, polypropylene, polyethylene terephthalate, polystyrene, polycarbonate, polyurethane, phenolic resin, polyimide, polyamide, melamine resin, polyethylene naphthalate, polyacetal, ABS resin, polyether ethyl ketone, polyphenylene ether, polyvinyl acetate, and fluororesin. The cell frame 20 is impermeable to the anode fluid and cathode fluid.

[0023] The cell frame 20 includes an opening 20a. A membrane electrode assembly 10M is inserted into this opening 20a and bonded with an adhesive. The adhesive can be acrylic, epoxy, polyethylene, polypropylene, polyester, polyolefin, urethane, polyvinyl acetate, or the like.

[0024] The cell frame 20 is provided with a cathode fluid supply port 21, an anode fluid supply port 22, a cathode fluid outlet port 23, and an anode fluid outlet port 24. In other words, the electrochemical cell stack 1 according to this embodiment has an internal manifold structure. Each fluid supply port 21, 22 and each fluid outlet port 23, 24 penetrates the cell frame 20. Each fluid supply port 21, 22 is located on one side of the membrane electrode assembly 10M, and each fluid outlet port 23, 24 is located on the other side of the membrane electrode assembly 10M.

[0025] The separator 30 is both conductive and gas-impermeable. The separator 30 separates the atmosphere of the anode fluid from the atmosphere of the cathode fluid.

[0026] As shown in Figure 1, the separator 30 includes a plurality of cathode channels 31 and a plurality of anode channels 32. The cathode channels 31 are formed on the side of the separator 30 facing the cathode electrode 11, and the cathode fluid flowing through the cathode channels 31 is supplied to the cathode electrode 11. The cathode channels 31 may have a straight channel structure, a serpentine channel structure, or a crank channel structure, and are optional. The anode channels 32 are formed on the side of the separator 30 facing the anode electrode 12, and the anode fluid flowing through the anode channels 32 is supplied to the anode electrode 12. The anode channels 32 may have a straight channel structure, a serpentine channel structure, or a crank channel structure, and are optional.

[0027] Similar to the cell frame 20 described above, the separator 30 has a cathode fluid supply port 33 (see Figure 12), an anode fluid supply port 34, a cathode fluid outlet 35, and an anode fluid outlet 36. The cathode fluid flows from the cathode fluid supply port 33 through the cathode flow path 31 to the cathode fluid outlet 35. The anode fluid flows from the anode fluid supply port 34 through the anode flow path 32 to the anode fluid outlet 36. The separator 30 may be formed by pressing a thin metal film or by injection molding of a carbon material, and this is optional.

[0028] The separator 30 is not joined to the cell 10, but is pressed against the cell 10 by the pressing force of the clamping plate 3 as described above, as shown in Figure 1.

[0029] The electrochemical cell stack 1 configured in this way can be disassembled after operation. More specifically, first, the bolts and nuts that fastened the clamping plate 3 are removed. Then, the clamping plate 3, insulating plate 4, and current collector plate 2 located at the top of the electrochemical cell stack 1 are removed. Next, the separator 30 and the cells 10 are removed sequentially, and each cell 10 is separated. In this way, the cell 10 equipped with the membrane electrode assembly 10M cathode electrode anode electrode can be removed.

[0030] Figure 3 shows an example of an electrochemical cell stack system 100 equipped with the electrochemical cell stack 1 described above. The electrochemical cell stack system 100 shown in Figure 3 may include the electrochemical cell stack 1, an auxiliary device 101, a power converter 102, and a control device 103.

[0031] The electrochemical cell stack 1 can be started and operated by the auxiliary equipment 101. When the electrochemical cell stack 1 is used as a fuel cell, the auxiliary equipment 101 supplies hydrogen gas and air to the fuel cell. The auxiliary equipment 101 consists of, for example, a blower. While the fuel cell is operating, the auxiliary equipment 101 is supplied with operating power from the commercial grid. The power generated by the fuel cell is converted from DC current to AC current by the power converter 102 and supplied to the external load. When the electrochemical cell stack 1 is used as an electrolysis apparatus, the auxiliary equipment 101 supplies steam or carbon dioxide gas and an electrolytic solution to the electrolysis apparatus. The power used for electrolysis is supplied from the commercial grid through the power converter 102. The power converter 102 converts the power from the commercial grid from AC current to DC current and supplies it to the electrolysis apparatus. The auxiliary equipment 101 and the power converter 102 are controlled by the control device 103.

[0032] Next, the design system 40 for the electrochemical cell stack 1 according to this embodiment will be described. The design system 40 is a system for designing an electrochemical cell stack 1 in which a plurality of cells 10, including used cells 10, are stacked.

[0033] Here, we will explain the commercial transaction of the electrochemical cell stack 1 using used cells 10, using Figure 4. In Figure 4, the manufacturer and distributor of the electrochemical cell stack 1 is Company A. The users of Company A's electrochemical cell stack 1 are Company a, Company b, and Company c.

[0034] As shown in Figure 4, Company A has acquired an electrochemical cell stack 1 from Company A, which uses only new cells 10. Company A conducts its business activities by operating the electrochemical cell stack 1. For example, if the electrochemical cell stack 1 is a carbon dioxide electrolyzer, carbon dioxide is electrolyzed in the electrochemical cell stack 1 to produce carbon monoxide. The produced carbon monoxide is filled into cylinders or the like and delivered to a company that handles carbon monoxide (not shown).

[0035] Company A decides to replace electrochemical cell stack 1 because its performance has deteriorated and malfunctions have occurred due to continued operation. Therefore, Company A consults with Company A by providing specifications. Based on these specifications, Company A presents a lineup of electrochemical cell stacks 1 that can be introduced to Company A. Because these specifications include the number of cells and their lifespan, this lineup includes not only electrochemical cell stacks 1 using only new cells 10, but also electrochemical cell stacks 1 including used cells 10. Electrochemical cell stacks 1 including used cells 10 are priced lower than the same configuration of electrochemical cell stacks 1 using only new cells 10. Company A decides to purchase the electrochemical cell stack 1 including used cells 10 and places an order with Company A. Company A manufactures the electrochemical cell stack 1 that Company A has decided to purchase and delivers it to Company A.

[0036] The electrochemical cell stack 1 previously owned by company a will be taken over by company A. Company A takes back electrochemical cell stack 1 from users when it becomes unnecessary due to replacement or other reasons. Therefore, company A has also taken back electrochemical cell stack 1 from companies b and c, etc., when they deliver replacement parts.

[0037] The retrieved electrochemical cell stack 1 undergoes measurement tests to determine the degree of cell degradation in each cell 10. Then, as described above, the electrochemical cell stack 1 is disassembled and each cell 10 is removed. Each removed cell 10 may be repaired for reuse in the electrochemical cell stack 1. Each cell 10 is then stored as a used cell 10. The degree of cell degradation of the stored used cells 10 is stored in the first database 41 (described later), associated with the identification information of the cell 10. If the repair process described above is performed, the details of that process may be stored in association with the degree of cell degradation.

[0038] When considering its product lineup, Company A designs an electrochemical cell stack 1, including used cells 10, based on Company A's specifications, and presents a price. At this time, Company A selects used cells 10 that satisfy the user's specifications from the used cells 10 in storage, thereby reusing the used cells 10. Based on this design, Company A's assembly workers take the selected used cells 10 from storage and assemble the electrochemical cell stack 1. The assembled electrochemical cell stack 1 is delivered to Company A. The electrochemical cell stack 1 design system 40 according to this embodiment is a device that can be used in Company A's design work in this manner.

[0039] As shown in Figure 5, the design system 40 of the electrochemical cell stack 1 according to this embodiment may include a plurality of databases 41, 42 and a design device 50. Each database 41, 42 and the design device 50 are connected by a network N such as a LAN (Local Area Network). In this embodiment, the first database 41 and the second database 42 are connected to the design device 50.

[0040] The first database 41 stores the cell degradation levels of multiple used cells 10. The first database 41 stores the cell degradation levels of used cells 10 from various used electrochemical cell stacks 1. Each used cell 10 is assigned identification information, and the cell degradation level of each cell 10 is associated with this identification information. Figure 6 shows an example in which the cell degradation levels of five used cells 10 from a used first electrochemical cell stack 1a and five used cells 10 from a used second electrochemical cell stack 1b are stored in the first database 41. Details of the cell degradation levels will be described later. The cell degradation level of each used cell 10 is associated with the identification information of that used cell 10. If the identification information is an ID code, consecutive ID codes may be assigned to each used cell 10, as shown in Figure 6. However, the numbering of the ID codes assigned to each used cell 10 is arbitrary as long as it has an identification function. The first database 41 may be recorded on a cloud server. The degree of cell degradation may be recorded on a cloud server when measured and stored in the first database 41.

[0041] The second database 42 stores user specification information. As shown in Figure 7, the specification information includes information on the specified lifespan of the electrochemical cell stack 1. Details of the cell degradation degree and specification information will be described later. The second database 42 may also be recorded on a cloud server. The user specification information may also be information entered on a terminal device 43 different from the design device 50 and stored in the second database 42.

[0042] As shown in Figure 5, the design apparatus 50 is a device for designing an electrochemical cell stack 1 using used cells 10. The design apparatus 50 is primarily configured to select used cells 10 from a plurality of used cells 10 that can be used to manufacture an electrochemical cell stack 1 that satisfies the user's specifications.

[0043] The design device 50 may include an input unit 51, a display unit 52, a storage unit 53, a communication unit 54, and a calculation unit 60. The input unit 51 is configured to input information and may consist of, for example, a keyboard, mouse, or touch panel. The display unit 52 is configured to display information and may consist of, for example, a display. The display unit 52 may display display information created by a display information creation unit 68, which will be described later. The storage unit 53 is configured to store information and may consist of, for example, a memory or storage device. The communication unit 54 may be configured to communicate with an external device that stores databases 41 and 42 via a network N. For example, the communication unit 54 may consist of a communication interface.

[0044] As shown in Figure 5, the calculation unit 60 may include functional blocks such as a degradation degree acquisition unit 61, a rank assignment unit 62, a specification acquisition unit 63, a specification calculation unit 64, a selection calculation unit 65, a location determination unit 66, and a price calculation unit 67. These functional blocks may be implemented, for example, by the calculation unit 60 executing a computer program stored in the storage unit 53. This program is an example of a design program for the electrochemical cell stack 1 and may be installed on the design device 50 from a recording medium. Alternatively, the design program may be downloaded to the design device 50 from a server on the network N or the like.

[0045] The degradation level acquisition unit 61 acquires the cell degradation level of the used cell 10, along with associated identification information, from the first database 41 described above. The degradation level acquisition unit 61 is configured to acquire the cell degradation level from the first database 41 via the communication unit 54 and the network N.

[0046] The degree of cell degradation of used cells 10 can be determined by various methods. For example, the degree of cell degradation can be calculated using the voltage characteristics of each cell 10 obtained when carbon dioxide electrolysis is performed using the electrochemical cell stack 1. Alternatively, for example, the degree of cell degradation can be calculated using the voltage characteristics of each cell 10 obtained when water electrolysis is performed using the electrochemical cell stack 1. The method for calculating the degree of cell degradation will be described later.

[0047] The numerical value calculated in this way may be used as the cell degradation degree for various processes described later, but in this embodiment, a degradation degree rank set based on this value is used. As an example, the cell degradation degree is explained in five stages from A to E. A cell degradation degree of 0 (zero) corresponds to the cell degradation degree of a new cell 10 before use. The higher the cell degradation degree value, the more advanced the degradation of cell 10.

[0048] The rank assignment unit 62 assigns a degradation rank to the used cell 10 based on the cell degradation level calculated as described above. The degradation rank has a predetermined range of cell degradation levels. More specifically, as shown in Figure 8, multiple degradation ranks are set based on the cell degradation level. Here, we will describe an example in which five degradation ranks, A to E, are assigned.

[0049] Rank A is assigned to used cells 10 with a cell degradation degree greater than 0% and less than or equal to 5%. Rank B is assigned to used cells 10 with a cell degradation degree greater than 5% and less than or equal to 10%. Rank C is assigned to used cells 10 with a cell degradation degree greater than 10% and less than or equal to 15%. Rank D is assigned to used cells 10 with a cell degradation degree greater than 15% and less than or equal to 20%. Rank E is assigned to used cells 10 with a cell degradation degree greater than 20%. Because Rank E cells have a high degree of degradation, they do not need to be used in the design of electrochemical cell stack 1.

[0050] The degradation ranks A through D each have a deemed cell degradation level, which is the maximum value within the range of cell degradation levels corresponding to the degradation rank. More specifically, the deemed cell degradation level for rank A is 5%, and for rank B it is 10%. For rank C it is 15%, and for rank D it is 20%. The selection calculation unit 65, the position determination unit 66, and the price calculation unit 67, described later, process the deemed cell degradation level as the cell degradation level.

[0051] The specification acquisition unit 63 acquires the number of specified cells and the specified lifespan of the electrochemical cell stack 1 as user specification information. The specification acquisition unit 63 is configured to acquire the number of specified cells and the specified lifespan from the second database 42 via the communication unit 54 and the network N.

[0052] The specification calculation unit 64 calculates the specification stack degradation degree of the electrochemical cell stack 1 based on the specification life. The stack degradation degree may be the sum of the cell degradation degrees of the cells 10 used in the electrochemical cell stack 1.

[0053] The selection calculation unit 65 selects used cells 10 to be used in the electrochemical cell stack 1 based on the specified number of cells and the specified stack degradation level. In this embodiment, the rank assignment unit 62 described above assigns a degradation level rank to the used cells 10. Therefore, the selection calculation unit 65 considers the above-described deemed cell degradation level for each degradation level rank as the cell degradation level of each used cell 10 and performs the following processing.

[0054] The selection calculation unit 65 selects used cells 10 to be used in the electrochemical cell stack 1 so as to satisfy the specified stack degradation level calculated as described above. For example, it determines a combination of used cells 10 such that the sum of the cell degradation levels of the used cells 10 is less than or equal to the specified stack degradation level. For example, the cell degradation level (deemed cell degradation level) is α k , the degree of cell degradation is α k The number of used cells 10 is β k In this case, a combination of used cells 10 that satisfies the following equation is selected, where n is the number of cells 10 and γ is the specification stack degradation degree.

number

[0055] In this case, in order to reduce the cost of the electrochemical cell stack 1, a combination of used cells 10 that satisfies the specified stack degradation level may be determined. The selection calculation unit 65 in this embodiment assigns used cells 10 to all cells 10 that make up the electrochemical cell stack 1.

[0056] The selection calculation unit 65 calculates the lifespan of the electrochemical cell stack 1 based on the cell degradation degree of the selected used cells 10. More specifically, the selection calculation unit 65 calculates the stack degradation degree, which is the sum of the cell degradation degrees of the selected used cells 10. For example, the stack degradation degree is calculated by the left side of equation (1) described above. Then, the lifespan is calculated from the stack degradation degree. In the example shown in Figure 9, for convenience, used cells 10 are selected such that the lifespan is 5 years, relative to the specification lifespan of 5 years. However, as shown in equation (1) described above, used cells 10 may be selected so that the lifespan is not shorter than the specification lifespan of 5 years.

[0057] The selection calculation unit 65 may exclude used cells 10 whose cell degradation level is higher than a predetermined value from the selection target. For example, used cells 10 with a rank degradation level of rank D are excluded from the selection target. The degradation rank of used cells 10 to be excluded from the selection target is not limited to rank D. Depending on the user's specifications, the degradation rank to be excluded from the selection target may be set.

[0058] The specific processing of the selection calculation unit 65 will be explained using Figure 9. In the example shown in Figure 9, the degradation degree acquisition unit 61 acquires the cell degradation degrees of 10 used cells 10 stored in the first database 41 shown in Figure 6. The rank assignment unit 62 assigns a degradation degree rank to each used cell 10 based on the cell degradation degrees shown in Figure 8. The specification acquisition unit 63 acquires the number of specified cells and the specified lifespan of the electrochemical cell stack 1 as user specification information stored in the second database 42 shown in Figure 7. The specification calculation unit 64 calculates the specification stack degradation degree calculated from the user's specified lifespan as "10%". In this case, the selection calculation unit 65 selects a combination of used cells 10 such that the total value of the cell degradation degrees is "10%". An example of this is shown in Figure 9.

[0059] The method for selecting one used cell 10 from multiple used cells 10 with the same degree of cell degradation is arbitrary. For example, the used cell 10 with the smallest ID code may be selected. Alternatively, if manufacturing date information can be obtained from the identification information of the used cells 10, the used cell 10 with the earliest manufacturing date may be selected. As shown in Figure 9, the selection calculation unit 65 calculates the sum of the cell degradation degrees of the five selected used cells 10 (stack degradation degree). In this case, the stack degradation degree is "10%". Then, the selection calculation unit 65 calculates the lifespan of the electrochemical cell stack 1 from the stack degradation degree.

[0060] The position determination unit 66 determines the stacking position of the used cells 10 when multiple used cells 10 are selected. Similar to the selection calculation unit 65, the position determination unit 66 may determine the stacking position by considering the above-mentioned deemed cell degradation degree for each degradation degree rank as the cell degradation degree of each used cell 10.

[0061] The position determination unit 66 may determine the stacking position of the used cells 10 by any method. For example, the position determination unit 66 may place used cells 10 with a high degree of cell degradation towards the center in the stacking direction D of the electrochemical cell stack 1.

[0062] More specifically, the multiple used cells 10 selected by the selection calculation unit 65 may include a first used cell 10a (see Figure 9) and a second used cell 10b. The second used cell 10b has a higher degree of cell degradation than the first used cell 10a. In this case, the position determination unit 66 places the second used cell 10b closer to the center in the stacking direction D of the electrochemical cell stack 1 than the first used cell 10a. In the example shown in Figure 9, ID004 (rank B) as the second used cell 10b is placed closer to the center in the stacking direction D than ID003 (rank A) as the first used cell 10a. Also, ID001 (rank C) as the second used cell 10b is placed closer to the center in the stacking direction D than ID004 (rank B) as the first used cell 10a.

[0063] The price calculation unit 67 calculates the price of the electrochemical cell stack 1 based on the cell degradation degree of the used cells 10 selected by the selection calculation unit 65. The price calculation unit 67 may, similar to the selection calculation unit 65, consider the above-mentioned deemed cell degradation degree for each degradation degree rank as the cell degradation degree of each used cell 10 and calculate the price. For example, as shown in Figure 10, the price reduction rate of the used cells 10 may be set according to the cell degradation degree. The price reduction rate indicates the reduction rate relative to the price of a new cell 10. The price of the electrochemical cell stack 1 may be calculated by multiplying the price reduction rate by the number of used cells 10 and then multiplying that value by the price of a new electrochemical cell stack 1. For example, if the cell degradation degree is α k The price decrease rate of used cell 10 is δ k , the degree of cell degradation is α k The number of used cells 10 is β k In this case, the price ε1 of electrochemical cell stack 1 may be calculated using the following formula. ε0 is the price of electrochemical cell stack 1 using only new cells 10.

number

[0064] The selection calculation unit 65, position determination unit 66, and price calculation unit 67 described above may be configured to use artificial intelligence (AI) for processing.

[0065] The display information creation unit 68 creates display information including the identification information and lifespan of the selected used cell 10. For example, as shown in Figure 11, display information including the identification information and lifespan of the used cell 10 may be created. As shown in Figure 11, the degree of cell degradation of the used cell 10 may be created as display information, and the price ε1 of the electrochemical cell stack 1 may be created as display information. The used cells 10 may be displayed in the order of their stacking positions. The display information created by the display information creation unit 68 may be displayed by the display unit 52 described above.

[0066] Next, we will explain in more detail the cell degradation levels stored in the first database 41. Here, we will explain using the example of the electrochemical cell stack 1 shown in Figure 1, which constitutes a carbon dioxide electrolysis device.

[0067] First, as an example, we will explain a method for calculating the degree of cell degradation using the voltage-current characteristics of cell 10 of the electrochemical cell stack 1, using Figures 12 and 13.

[0068] In this case, a first target voltage value is calculated based on first characteristic data showing the voltage-current characteristics of cell 10, and a second target voltage value is calculated based on second characteristic data showing the voltage-current characteristics of cell 10 when new. The degree of cell degradation is calculated based on the first and second target voltage values. The first characteristic data is data showing the voltage-current characteristics obtained when water electrolysis is performed in a carbon dioxide electrolyzer equipped with electrochemical cell stack 1. The second characteristic data is data showing the voltage-current characteristics obtained when water electrolysis is performed using electrochemical cell stack 1 when new. The method for calculating the degree of cell degradation based on the first and second characteristic data is described below.

[0069] As shown in Figure 12, the electrochemical cell stack 1 is equipped with multiple measuring pins 70 to measure the voltage applied to the cell 10 and the current flowing through the cell 10. The measuring pins 70 for the cathode electrode 11 may be inserted into cathode-side recesses 37 formed on the surface of the separator 30 facing the cathode electrode 11. The cathode-side recesses 37 are formed in a different location from the cathode channel 31 formed on the surface in Figure 12. For convenience, the cathode channel 31 is simplified in Figure 12. The measuring pins 70 inserted into the cathode-side recesses 37 can electrically contact the cathode electrode 11. The measuring pins 70 for the anode electrode 12 may be inserted into anode-side recesses 38 formed on the surface of the separator 30 facing the anode electrode 12. The anode-side recesses 38 are formed in a different location from the anode channel 32 formed on the back surface in Figure 12. The measuring pins 70 inserted into the anode-side recesses 38 can electrically contact the anode electrode 12. Figure 12 shows a typical measurement state for one cell 10. However, to measure the voltage and current values ​​for each cell 10 constituting the electrochemical cell stack 1, measurement pins 70 are inserted into the cathode-side recess 37 and anode-side recess 38 of each separator 30. In other words, measurements may be performed using two measurement pins 70 for a single cell 10.

[0070] Each measuring pin 70 for the cathode electrode 11 and each measuring pin 70 for the anode electrode 12 are connected to the measuring device 72 via an electrical wire 71. The electrical wire 71 electrically connects the measuring pins 70 to the measuring device 72. If the electrochemical cell stack 1 has an internal manifold structure, the measuring pins 70 are hermetically attached to the separator 30 using a sealing material (not shown). This prevents leakage of fluids such as cathode fluid and anode fluid. The electrical wire 71 passes through a housing (not shown) and is connected to the measuring device 72 located externally.

[0071] The measuring device 72 measures the voltage and current values ​​of each cell 10. The measuring device 72 is connected to a database (not shown) via a network N. The voltage and current values ​​measured by the measuring device 72 are associated with the identification information of the corresponding cell 10 and stored in the database. The database stores multiple first characteristic data for each cell 10. Each first characteristic data is associated with the identification information of the corresponding cell 10.

[0072] The first characteristic data may also represent the voltage-current characteristics obtained when water electrolysis is performed instead of carbon dioxide electrolysis in a carbon dioxide electrolytic apparatus equipped with an electrochemical cell stack 1. During water electrolysis, water as the cathode fluid F1 shown in Figure 1 is supplied to the cathode electrode 11, and an electrolytic solution (such as calcium bicarbonate) as the anode fluid F2 is supplied to the anode electrode 12. Water electrolysis is performed in the membrane electrode assembly 10M, hydrogen gas is generated at the cathode electrode 11 and discharged from the cathode electrode 11, and oxygen gas is generated at the anode electrode 12 and discharged from the anode electrode 12.

[0073] Measurements for creating the first characteristic data are performed while water electrolysis is in progress. After the water electrolysis reaction reaches a steady state, the voltage and current values ​​are measured while either the voltage or current value is varied. The voltage and current values ​​measured for each cell 10 are stored in a database as multiple first characteristic data. In this way, first characteristic data showing the voltage-current characteristics, as shown by the solid line in Figure 13, is obtained. That is, the first characteristic data can be obtained without disassembling the electrochemical cell stack 1. Each first characteristic data stored in the database is assigned identification information, and each first characteristic data is associated with this identification information.

[0074] The first characteristic data may be obtained by measuring the voltage and current values ​​of cell 10 of the electrochemical cell stack 1 after operation. For example, the measurements to obtain the first characteristic data may be performed by company A after the equipment has been taken over from company a as shown in Figure 4.

[0075] The second characteristic data may be data indicating the voltage-current characteristics obtained when performing water electrolysis using the new electro-chemical cell stack 1. That is, before operation such as at the time of shipment or delivery of the electro-chemical cell stack 1, voltage values and current values are measured in the same manner as the first characteristic data described above. The voltage values and current values are stored in a database not shown as the second characteristic data. In this way, the second characteristic data indicating the voltage-current characteristics as shown by the broken line in FIG. 13 is obtained.

[0076] Based on the above-described first characteristic data, a first target voltage value V1 (see FIG. 13) is calculated. The first target voltage value V1 is the voltage value corresponding to the reference current value in the first characteristic data. A first characteristic curve as shown in FIG. 13 may be calculated from the current values and voltage values constituting the first characteristic data, and the voltage value corresponding to the reference current value on this first characteristic curve may be used as the first target voltage value. An example of the first characteristic curve is shown by the solid line in FIG. 13.

[0077] Based on the above-described second characteristic data, a second target voltage value V2 (see FIG. 13) is calculated. The second target voltage value V2 is the voltage value corresponding to the reference current value in the second characteristic data. A second characteristic curve as shown in FIG. 13 may be calculated from the current values and voltage values constituting the second characteristic data, and the voltage value corresponding to the reference current value on this second characteristic curve may be used as the second target voltage value. An example of the second characteristic curve is shown by the broken line in FIG. 13.

[0078] The reference current value may be set as a current value I greater than the current value (zero-point current value I0) when the voltage value is zero from the first characteristic data, or the minimum current value at which the change rate (ΔV / ΔI) of the voltage value with respect to the current value of the first characteristic data becomes less than or equal to the change rate threshold value may be set as the reference current value I S and the minimum current value at which the change rate (ΔV / ΔI) of the voltage value with respect to the current value of the first characteristic data becomes less than or equal to the change rate threshold value may be set as the reference current value I SIt may also be set to this value. In this case, the reference current value can be set to a current value at which the change in voltage value accompanying an increase in current value becomes small. When the rate of change of the voltage value with respect to the current value described above becomes small, fluctuations in this rate of change are suppressed, and the accuracy of the first target voltage value and the second target voltage value can be improved. For this reason, the rate of change threshold may be set to a value that allows for accurate calculation of the degree of cell degradation.

[0079] The degree of cell degradation is calculated based on the first target voltage value and the second target voltage value. For example, the degree of cell degradation may be calculated by dividing the difference obtained by subtracting the first target voltage value from the second target voltage value by the second target voltage value. That is, if the first target voltage value is V1 and the second target voltage value is V2, the degree of cell degradation α1 may be calculated according to the following equation (1).

number

[0080] As another example, Figure 14 illustrates a method for calculating the degree of cell degradation using the voltage-time characteristics of cell 10 in the electrochemical cell stack 1.

[0081] In this case, the third target voltage value is calculated based on the third characteristic data showing the voltage-time characteristics of cell 10 after carbon dioxide electrolysis has stopped, and the fourth target voltage value is calculated based on the fourth characteristic data showing the voltage-time characteristics of cell 10 after water electrolysis has stopped. The degree of cell degradation is calculated based on the third target voltage value and the fourth target voltage value. The method for calculating the degree of cell degradation based on the third characteristic data and the fourth characteristic data is described below.

[0082] To measure the voltage applied to each cell 10, the aforementioned measuring pins 70 (see Figure 12) and measuring device 72 may be used.

[0083] The third characteristic data may be data showing the voltage-time characteristics of cell 10 after carbon dioxide electrolysis has stopped in a carbon dioxide electrolysis apparatus equipped with an electrochemical cell stack 1. During carbon dioxide electrolysis, carbon dioxide gas as cathode fluid F1 as shown in Figure 1 is supplied to the cathode electrode 11, and an electrolytic solution (such as calcium bicarbonate) as anode fluid F2 is supplied to the anode electrode 12. Carbon dioxide electrolysis is performed in the membrane electrode assembly 10M, carbon monoxide is generated at the cathode electrode 11 and discharged from the cathode electrode 11. Oxygen gas is generated at the anode electrode 12 and discharged from the anode electrode 12.

[0084] The measurements for creating the third characteristic data are performed after carbon dioxide electrolysis has been stopped. After stopping, the voltage value is measured along with the measurement time. This yields third characteristic data showing the voltage-time characteristics after stopping carbon dioxide electrolysis, as shown by the solid line in Figure 14. In other words, the third characteristic data can be obtained without disassembling the electrochemical cell stack 1. Each third characteristic data stored in a database (not shown) is assigned identification information, and each third characteristic data is associated with this identification information. The measurements for obtaining the third characteristic data may also be performed by company A after the product is taken over from company a as shown in Figure 4.

[0085] The fourth characteristic data may be data showing the voltage-time characteristics of cell 10 after water electrolysis has stopped in a carbon dioxide electrolysis apparatus equipped with an electrochemical cell stack 1. During water electrolysis, water as the cathode fluid F1 shown in Figure 1 is supplied to the cathode electrode 11, and an electrolytic solution (such as calcium bicarbonate) as the anode fluid F2 is supplied to the anode electrode 12. Water electrolysis is performed in the membrane electrode assembly 10M, hydrogen gas is generated at the cathode electrode 11 and discharged from the cathode electrode 11. Oxygen gas is generated at the anode electrode 12 and discharged from the anode electrode 12.

[0086] The measurements for creating the fourth characteristic data are performed after water electrolysis has been performed and then stopped. Water electrolysis may be performed after the creation of the third characteristic data, or it may be performed before the creation of the third characteristic data. After stopping, the voltage value is measured along with the measurement time. This yields the third characteristic data showing the voltage-time characteristics after stopping water electrolysis, as shown by the dashed line in Figure 14. In other words, the third characteristic data can be obtained without disassembling the electrochemical cell stack 1. Each fourth characteristic data stored in a database (not shown) is assigned identification information, and each fourth characteristic data is associated with this identification information. The measurements for obtaining the fourth characteristic data may be performed by company A after the data has been taken over from company a as shown in Figure 4.

[0087] Based on the third characteristic data described above, the third target voltage value V3 (see Figure 14) is calculated.

[0088] As shown by the solid line in Figure 14, the third characteristic data may be data showing the voltage-time characteristics obtained after carbon dioxide electrolysis has been performed and stopped in a carbon dioxide electrolysis apparatus equipped with an electrochemical cell stack 1. In Figure 14, carbon dioxide electrolysis is performed until time t0, at which time t0 the carbon dioxide electrolysis is stopped. From time 4t0 onward, the cessation of carbon dioxide electrolysis continues, and the voltage value of cell 10 is shown to be decreasing.

[0089] The voltage-time characteristics after carbon dioxide electrolysis cessation, as shown by the solid line in Figure 14, have a first time period T1 in which the rate of decrease in voltage increases, and a second time period T2 in which the rate of decrease in voltage decreases after the first time period. The third target voltage value V3 is the voltage value when the rate of decrease in voltage reaches a first threshold after the second time period T2 of the third characteristic data has elapsed. In the second time period, the rate of decrease in voltage gradually decreases, and thereafter the voltage value becomes almost constant. The first threshold may be set as the rate of decrease in voltage at which the voltage value can be considered constant. A third characteristic curve as shown in Figure 14 may be calculated using the time and voltage values ​​that constitute the third characteristic data, and the voltage value at which the rate of decrease in voltage reaches the first threshold on this third characteristic curve may be set as the third target voltage value. An example of a third characteristic curve is shown by the solid line in Figure 14.

[0090] Based on the fourth characteristic data described above, the fourth target voltage value V4 (see Figure 14) is calculated.

[0091] As shown by the dashed line in Figure 14, the fourth characteristic data may be data showing the voltage-time characteristics obtained after water electrolysis has been performed and stopped in a carbon dioxide electrolysis apparatus equipped with an electrochemical cell stack 1. In Figure 14, water electrolysis is performed until time t0, at which point water electrolysis is stopped. After time t0, the cessation of water electrolysis continues, and the voltage value of cell 10 is shown to be decreasing.

[0092] The voltage-time characteristics after water electrolysis is stopped have a third time period T3 in which the rate of decrease in voltage increases, and a fourth time period T4 in which the rate of decrease in voltage decreases after the third time period, as shown by the dashed line in Figure 14. The fourth target voltage value is the voltage value when the rate of decrease in voltage reaches the second threshold after the fourth time period T4 of the fourth characteristic data has elapsed. In the fourth time period, the rate of decrease in voltage gradually decreases, and thereafter the voltage value becomes almost constant. The second threshold may be set as the rate of decrease in voltage at which the voltage value can be considered constant. A fourth characteristic curve as shown in Figure 14 may be calculated using the time and voltage values ​​that constitute the fourth characteristic data, and the voltage value at which the rate of decrease in voltage reaches the second threshold on this fourth characteristic curve may be set as the fourth target voltage value. An example of a fourth characteristic curve is shown by the dashed line in Figure 14.

[0093] The degree of cell degradation is calculated based on the third target voltage value and the fourth target voltage value. For example, the degree of cell degradation may be calculated by dividing the difference obtained by subtracting the fourth target voltage value from the third target voltage value by the third target voltage value. That is, if the third target voltage value is V3 and the fourth target voltage value is V4, the degree of cell degradation α2 may be calculated according to the following formula (1).

number

[0094] In this way, the cell degradation degree α2 can be calculated for multiple cells 10 using the voltage-time characteristics of the cells 10 in the electrochemical cell stack 1.

[0095] The cell degradation degrees α1 and α2 calculated in this way are stored in the first database 41.

[0096] For example, the cell degradation degree α1 for each cell 10 described above may be stored in the first database 41 in association with identification information, in which case the cell degradation degree α2 described above may not be stored. Alternatively, the cell degradation degree α2 for each cell 10 described above may be stored in the first database 41 in association with identification information, in which case the cell degradation degree α1 described above may not be stored.

[0097] Alternatively, the cell degradation degree calculated based on the above-mentioned cell degradation degrees α1 and α2 for each cell 10 does not have to be stored in the first database 41. For example, the numerical value calculated as shown in the following formula may be stored in the first database 41 as the cell degradation degree. Cell degradation degree α1 × film degradation contribution rate + cell degradation degree α2 × catalyst degradation contribution rate Cell degradation degree α1 primarily indicates the degree of cell degradation caused by film degradation, while cell degradation degree α2 primarily indicates the degree of cell degradation caused by catalyst degradation. Therefore, by adjusting the film degradation contribution rate and the catalyst degradation contribution rate according to user specifications, the cell degradation degree that meets the user's requirements can be calculated. For example, both the film degradation contribution rate and the catalyst degradation contribution rate may be set to 0.5. However, the film degradation contribution rate may be made larger or smaller than the catalyst degradation contribution rate.

[0098] Next, the design method for the electrochemical cell stack 1 according to this embodiment will be explained with reference to Figure 15.

[0099] First, in step S1, the degradation level acquisition unit 61 acquires the cell degradation level of the used cells 10, along with their identification information, from the first database 41. For example, as shown in Figure 9, the cell degradation levels of 10 used cells 10 are acquired. The ID codes indicating the identification information of the 10 used cells 10 are ID001 to ID010.

[0100] After step S1, in step S2, the rank assignment unit 62 assigns a degradation rank to the used cells 10 obtained from the first database 41. For example, the degradation rank shown in Figure 8 is assigned to the used cells 10 as shown in Figure 9.

[0101] In step S3, the specification acquisition unit 63 acquires the specified number of cells and specified lifespan of the electrochemical cell stack 1 from the second database 42. For example, in the example shown in Figure 9, the specification acquisition unit 63 acquires specification information that the number of cells is 5 and the specified lifespan is 5 years. Step S3 may be performed after steps S1 and S2. However, step S3 may be performed before step S1 or step S2, or simultaneously with step S1 or step S2.

[0102] After step S3, in step S4, the specification calculation unit 64 calculates the specification stack degradation degree of the electrochemical cell stack 1. In the example shown in Figure 9, when the specification life is 5 years, the specification stack degradation degree is calculated to be 10%.

[0103] After steps S2 and S4, in step S5, the selection calculation unit 65 selects used cells 10 to be used in the electrochemical cell stack 1 and calculates the lifespan of the electrochemical cell stack 1. The selection calculation unit 65 processes the above-mentioned assumed cell degradation degree as the cell degradation degree of the used cells 10. In the example shown in Figure 9, ID001, ID003, ID004, ID007, and ID009 are selected as five used electrochemical cell stacks 1 that satisfy the specified stack degradation degree. In this case, the stack degradation degree, which is the sum of the cell degradation degrees of each used electrochemical cell stack 1, becomes "10%", and a lifespan of 5 years is calculated.

[0104] After step S5, in step S6, the position determination unit 66 determines the stacking position of the used cells 10. The position determination unit 66 processes the assumed cell degradation level described above as the cell degradation level of the used cells 10. The stacking position of each used cell 10 is determined so that used cells 10 with a high cell degradation level are placed towards the center in the stacking direction D of the electrochemical cell stack 1. In the example shown in Figure 9, used cells 10 of rank C are placed in the center in the stacking direction D. Used cells 10 of rank A are placed at the top and bottom positions.

[0105] In step S7, the price calculation unit 67 calculates the price of the electrochemical cell stack 1. The price of the electrochemical cell stack 1 is calculated, for example, based on the price reduction rate of the used cells 10 shown in Figure 10. The price calculation unit 67 processes the deemed cell degradation level described above as the cell degradation level of the used cells 10. Step S7 may be performed after step S6. However, step S7 may be performed after step S5 and before step S6, or simultaneously with step S6.

[0106] Following step S7, in step S8, the display information creation unit 68 creates display information including identification information of the used cell 10, and the lifespan and price of the electrochemical cell stack 1. The display information created by the display information creation unit 68 may be, for example, information like that shown in Figure 11. The created display information is displayed on the display unit 52.

[0107] In this way, the design method for the electrochemical cell stack 1 according to this embodiment is completed.

[0108] Based on the display on the display unit 52, the assembly worker of the electrochemical cell stack 1 may take out the used cell 10 with the identification symbol 14 (see Figure 2) indicating the corresponding identification information from the storage location. The assembly worker may then assemble the electrochemical cell stack 1 according to the stacking position of the used cell 10 displayed on the display unit 52.

[0109] As described above, according to this embodiment, the degree of degradation of used cells 10 is obtained from the first database 41 along with identification information, and the specified lifespan of the electrochemical cell stack 1 is obtained. Based on the specified number of cells and the degree of degradation of the electrochemical cell stack 1, used cells 10 to be used in the electrochemical cell stack 1 are selected so that the lifespan of the electrochemical cell stack 1 satisfies the specified lifespan, and the lifespan of the electrochemical cell stack 1 is calculated based on the degree of degradation of the selected used cells 10. In this way, used cells 10 to be used in the electrochemical cell stack can be selected based on the degree of degradation of the used cells 10 so as to satisfy the user's specified lifespan. For this reason, costs can be reduced by reusing used cells 10.

[0110] Furthermore, according to this embodiment, when multiple used cells 10 are selected by the selection calculation unit 65, the stacking position of the used cells 10 is determined. This allows the used cells 10 to be placed in appropriate positions according to their degree of degradation. As a result, the lifespan of the electrochemical cell stack 1 using used cells 10 can be improved, and reliability can be enhanced. In addition, the used cells 10 can be effectively utilized.

[0111] Furthermore, according to this embodiment, when a first used cell 10a and a second used cell 10b having a higher degree of cell degradation than the first used cell 10a are selected, the second used cell 10b is positioned closer to the center in the stacking direction D of the electrochemical cell stack 1 than the first used cell 10a. This allows used cells 10 with a higher degree of cell degradation to be positioned closer to the center in the stacking direction D. Therefore, the lifespan of the electrochemical cell stack 1 using used cells 10 can be improved, and reliability can be enhanced.

[0112] Furthermore, according to this embodiment, the price of the electrochemical cell stack 1 is calculated based on the degree of cell degradation of the used cells 10 selected by the selection calculation unit 65. This makes it possible to know the price of the electrochemical cell stack 1 in a timely manner while designing the electrochemical cell stack 1 using used cells 10. Therefore, the convenience of designing the electrochemical cell stack 1 can be improved.

[0113] Furthermore, according to this embodiment, a degradation rank is assigned to the used cell 10 based on the degree of cell degradation, and the selection calculation unit 65 considers the maximum value within the range of cell degradation degrees that the degradation rank has as the degree of cell degradation. This simplifies the selection process of used cells 10 by the selection calculation unit 65.

[0114] Furthermore, according to this embodiment, used cells 10 with a cell degradation level higher than a predetermined value are excluded from selection. This improves the lifespan of the electrochemical cell stack 1 using used cells 10 and enhances reliability.

[0115] In the embodiment described above, the selection calculation unit 65 was described in an example where used cells 10 were assigned to all cells 10 constituting the electrochemical cell stack 1. However, the embodiment is not limited to this. For example, the selection calculation unit 65 may assign new cells 10 to some of the cells 10 constituting the electrochemical cell stack 1. In this case, the lifespan of the electrochemical cell stack 1 using used cells 10 can be improved, and reliability can be improved.

[0116] Furthermore, in the above-described embodiment, an example was explained in which the selection calculation unit 65 processes the deemed cell degradation level, which is the maximum value of the range of cell degradation levels corresponding to the degradation level rank, as the cell degradation level of the used cell 10. However, the embodiment is not limited to this. For example, the selection calculation unit 65 may use the cell degradation level of each used cell 10 obtained from the first database 41 to select the used cell 10 and calculate the lifespan of the electrochemical cell stack.

[0117] Furthermore, in the above-described embodiment, an example was explained in which the position determination unit 66 processes the deemed cell degradation level, which is the maximum value of the range of cell degradation levels corresponding to the degradation level rank, as the cell degradation level of the used cell 10. However, the embodiment is not limited to this. For example, the position determination unit 66 may determine the stacking position of the used cell 10 using the cell degradation level of each used cell 10 obtained from the first database 41.

[0118] Furthermore, in the above-described embodiment, an example was explained in which the price calculation unit 67 processes the deemed cell degradation level, which is the maximum value of the range of cell degradation levels corresponding to the degradation level rank, as the cell degradation level of the used cell 10. However, the embodiment is not limited to this. For example, the price calculation unit 67 may calculate the price of the electrochemical cell stack 1 using the cell degradation level of each used cell 10 obtained from the first database 41.

[0119] Furthermore, in the above-described embodiment, an example was given in which the calculation unit 60 includes a rank assignment unit 62. However, the embodiment is not limited to this. For example, the calculation unit 60 does not have to include a rank assignment unit 62. In this case, the used cells 10 may be designed without being assigned a degradation rank. Also, if the calculation unit 60 does not include a rank assignment unit 62, the used cells 10 stored in the first database 41 may already have a degradation rank assigned to them. In this case, in the various processes performed by the design device 50, the deemed cell degradation is treated as the cell degradation and processed accordingly.

[0120] Furthermore, in the above-described embodiment, an example was given in which the electrochemical cell stack 1 has an internal manifold structure. However, the embodiment is not limited to this. For example, the electrochemical cell stack 1 may have an external manifold structure. In this case, the cell frame 20 is not used, and a manifold forming the flow path for each gas is provided on the outer surface of the laminate in which the membrane electrode assembly 10M and the separator 30 are stacked.

[0121] Furthermore, in the embodiment described above, an example was described in which a single separator 30 including a cathode channel 31 and an anode channel 32 is interposed between the two cells 10. However, the embodiment is not limited to this. For example, a cathode-side separator including a cathode channel and an anode-side separator including an anode channel may be interposed between the two cells 10. A cooling water channel (not shown) may be formed between the cathode-side separator and the anode-side separator.

[0122] Furthermore, in the embodiment described above, an example was described in which the specification calculation unit 64 calculates the specification stack degradation degree of the electrochemical cell stack 1 based on the specification lifespan, and the selection calculation unit 65 selects used cells 10 based on the specification stack degradation degree. However, the embodiment is not limited to this. For example, the selection calculation unit 65 may select used cells 10 such that the lifespan of the electrochemical cell stack 1 satisfies the specification lifespan without using the specification stack degradation degree.

[0123] Furthermore, in the embodiment described above, an example was described in which the specification acquisition unit 63 acquires the number of specified cells along with the specified lifespan of the electrochemical cell stack 1. However, the embodiment is not limited to this. For example, if the number of specified cells is a fixed value regardless of user specifications, the specification acquisition unit 63 may acquire the number of specified cells without acquiring the specified lifespan. The selection calculation unit 65 may select used cells 10 based on the fixed value of the number of specified cells.

[0124] According to the embodiments described above, it is possible to reduce costs by reusing the used cells 10.

[0125] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be implemented in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. Naturally, these embodiments can also be combined in part as appropriate within the scope of the spirit of the invention. [Explanation of Symbols]

[0126] 1: Electrochemical cell stack, 10: Cell, 14: Identification symbol, 40: Design system, 41: First database, 42: Second database, 50: Design device, 61: Degradation degree acquisition unit, 62: Rank assignment unit, 63: Specification acquisition unit, 64: Specification calculation unit, 65: Selection calculation unit, 66: Position determination unit, 67: Price calculation unit, 68: Display information creation unit

Claims

1. An electrochemical cell stack comprising multiple cells including spent cells, and a design apparatus for an electrochemical cell stack used in a carbon dioxide electrolyzer, a water electrolyzer, or a fuel cell. A degradation degree acquisition unit that acquires the degree of cell degradation of used cells to which identification information has been assigned, along with the identification information, A specification acquisition unit for acquiring the specified lifespan of the electrochemical cell stack, A selection calculation unit selects used cells to be used in the electrochemical cell stack based on the specified number of cells and the degree of cell degradation of the electrochemical cell stack, such that the lifespan of the electrochemical cell stack satisfies the specified lifespan, and calculates the lifespan of the electrochemical cell stack based on the degree of cell degradation of the selected used cells. A design apparatus for electrochemical cell stacks, equipped with the following features.

2. The electrochemical cell stack design apparatus according to claim 1, further comprising a position determination unit that determines the stacking position of the used cells when a plurality of used cells are selected in the selection calculation unit.

3. The plurality of used cells selected by the selection calculation unit include a first used cell and a second used cell having a higher degree of cell degradation than the first used cell. The position determination unit positions the second used cell closer to the center of the stacking direction of the electrochemical cell stack than the first used cell. The design apparatus for an electrochemical cell stack according to claim 2.

4. The system further includes a price calculation unit that calculates the price of the electrochemical cell stack based on the degree of cell degradation of the used cells selected by the selection calculation unit. An electrochemical cell stack design apparatus according to any one of claims 1 to 3.

5. A degradation rank is assigned to the used cells based on the degree of cell degradation. The selection calculation unit considers the maximum value within the range of cell degradation degrees that the degradation degree rank has as the cell degradation degree. An electrochemical cell stack design apparatus according to any one of claims 1 to 3.

6. The selection calculation unit excludes used cells whose cell degradation level is higher than a predetermined value from the selection target. An electrochemical cell stack design apparatus according to any one of claims 1 to 3.

7. The selection calculation unit can select not only used cells but also new cells. An electrochemical cell stack design apparatus according to any one of claims 1 to 3.

8. The specification acquisition unit acquires the number of specified cells in the electrochemical cell stack. The selection calculation unit selects the used cells based on the number of specified cells obtained by the specification acquisition unit. An electrochemical cell stack design apparatus according to any one of claims 1 to 3.

9. The system further includes a specification calculation unit that calculates the degree of degradation of the electrochemical cell stack based on the specified lifespan, The selection calculation unit selects the used cells based on the specification stack degradation degree calculated by the specification calculation unit. An electrochemical cell stack design apparatus according to any one of claims 1 to 3.

10. The system further includes a display information creation unit that creates display information including the identification information of the used cell selected by the selection calculation unit and the lifespan of the used cell, The design apparatus for an electrochemical cell stack according to claim 9.

11. A database that stores the degree of cell degradation of multiple used cells in association with the aforementioned identification information, A design apparatus for an electrochemical cell stack according to any one of claims 1 to 3, comprising: Design system for electrochemical cell stacks.

12. An electrochemical cell stack comprising multiple cells including spent cells, and a method for designing an electrochemical cell stack used in a carbon dioxide electrolyzer, a water electrolyzer, or a fuel cell, A step of obtaining the degree of cell degradation of a used cell to which identification information has been assigned, along with the identification information, The steps include obtaining the specified lifespan of the electrochemical cell stack, A step of selecting used cells to be used in the electrochemical cell stack based on the specified number of cells and the degree of cell degradation of the electrochemical cell stack, such that the lifespan of the electrochemical cell stack meets the specified lifespan, and calculating the lifespan of the electrochemical cell stack based on the degree of cell degradation of the selected used cells. A method for designing an electrochemical cell stack equipped with the following features.

13. An electrochemical cell stack comprising multiple cells including used cells, and an electrochemical cell stack design program that causes a computer to execute a design method for an electrochemical cell stack used in a carbon dioxide electrolyzer, a water electrolyzer, or a fuel cell, The aforementioned design method is A step of obtaining the degree of cell degradation of a used cell to which identification information has been assigned, along with the identification information, The steps include obtaining the specified lifespan of the electrochemical cell stack, A step of selecting used cells to be used in the electrochemical cell stack based on the specified number of cells and the degree of cell degradation of the electrochemical cell stack, such that the lifespan of the electrochemical cell stack meets the specified lifespan, and calculating the lifespan of the electrochemical cell stack based on the degree of cell degradation of the selected used cells. A design program for electrochemical cell stacks, equipped with the following features.

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