Replacement cell manufacturing method, cell replacement method, and fuel cell stack manufacturing method

Abstract

To provide a method for manufacturing a replacement cell that suppresses performance degradation of a fuel cell stack caused by differences between the characteristics of a new replaced cell and the characteristics of an old cell that has not been replaced, when replacing some cells of a used fuel cell stack.SOLUTION: A method for manufacturing a replacement cell is a method for manufacturing a replacement cell to replace a target cell of a fuel cell stack that has deteriorated due to use, and includes a first acquisition step of acquiring the amount of water produced when a non-target cell, which is a cell other than the target cell among a plurality of cells, is caused to generate electricity under specified conditions, a coating amount determination step of determining the amount of catalyst coating to be applied to the replacement cell based on the amount of water produced in the non-target cell, and a manufacturing step of manufacturing a replacement cell coated with an amount of catalyst corresponding to the catalyst coating amount determined in the coating amount determination step.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a method for manufacturing a replacement cell, a method for replacing a cell, and a method for manufacturing a fuel cell stack. [Background technology]

[0002] A fuel cell has been disclosed in which, if a defective cell is found in a stack of cells, the defective cell can be removed and replaced. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-363093 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, efforts to significantly reduce waste generation through waste prevention, reduction, recycling, and reuse have become more active. To achieve this, research and development into the reuse of fuel cell stacks is being conducted.

[0005] However, in technology related to the reuse of fuel cell stacks, when some of the cells in a used fuel cell stack are replaced, a problem arises in that the performance of the fuel cell stack deteriorates due to differences in the characteristics of the new replaced cells and the characteristics of the old cells that have not been replaced.

[0006] The present disclosure aims to solve the above problems, and ultimately contributes to a significant reduction in waste generation. [Means for solving the problem]

[0007] A first aspect of the present disclosure is a method for manufacturing a replacement cell to replace a target cell selected from a plurality of cells assembled in a fuel cell stack that has deteriorated due to use, the method comprising: a first acquisition step for acquiring a first physical quantity, which is a physical quantity related to the amount of water produced when a non-target cell, which is a cell other than the target cell among the plurality of cells, is caused to generate electricity under specified conditions; a coating amount determination step for determining a catalyst coating amount, which is the amount of catalyst to be coated on the replacement cell, based on the first physical quantity; and a manufacturing step for manufacturing the replacement cell coated with an amount of catalyst corresponding to the catalyst coating amount determined in the coating amount determination step.

[0008] A second aspect of the present disclosure is a cell replacement method for replacing a target cell selected from a plurality of cells assembled in a fuel cell stack that has deteriorated due to use with a replacement cell, the cell replacement method comprising: a first acquisition step for acquiring a first physical quantity, which is a physical quantity related to the amount of water produced when a non-target cell, which is a cell other than the target cell among the plurality of cells, is caused to generate electricity under specified conditions; a coating amount determination step for determining a catalyst coating amount, which is the amount of catalyst to be coated on the replacement cell, based on the first physical quantity; and a replacement step for replacing the target cell with the cell coated with the catalyst in an amount corresponding to the catalyst coating amount determined in the coating amount determination step, as the replacement cell.

[0009] A third aspect of the present disclosure is a method for manufacturing a fuel cell stack, in which a target cell selected from a plurality of cells assembled in a fuel cell stack that has deteriorated due to use is replaced with a replacement cell to manufacture the fuel cell stack, the method comprising: a first acquisition step for acquiring a first physical quantity, which is a physical quantity related to the amount of water produced when a non-target cell, which is a cell other than the target cell among the plurality of cells, is caused to generate electricity under specified conditions; a coating amount determination step for determining a catalyst coating amount, which is the amount of catalyst to be coated on the replacement cell, based on the first physical quantity; and a replacement step for replacing the target cell with the cell coated with the catalyst in an amount corresponding to the catalyst coating amount determined in the coating amount determination step. [Effects of the Invention]

[0010] The present invention provides a better method for manufacturing a replacement cell, a cell replacement method, and a method for manufacturing a fuel cell stack. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of a fuel cell stack according to the first embodiment. [Figure 2] FIG. 2 is a schematic diagram showing the flow of recycling of the fuel cell stack in the first embodiment. [Figure 3] FIG. 3 is a flowchart showing the fuel cell stack regeneration process carried out in the recycling plant in the first embodiment. [Figure 4] FIG. 4 is a map for determining the amount of water produced in the cell from the proton resistance of the cell in the first embodiment. [Figure 5] FIG. 5 is a map for determining the catalyst coating amount in the electrode catalyst layer of the cathode electrode of a replacement cell from the amount of water generated in the non-target cell during manufacturing and the amount of water generated in the non-target cell during regeneration in the first embodiment. [Figure 6] FIG. 6 is an image diagram of a cell in a power generating state in the first embodiment. [Figure 7]FIG. 7 is a conceptual diagram of a cell in a non-power generating state in the first embodiment. [Figure 8] FIG. 8 is a flowchart showing the proton resistance acquisition process for the non-target cell in the first embodiment. [Figure 9] FIG. 9 is a flowchart showing the aging process for a replacement cell in the first embodiment. [Figure 10] FIG. 10 is a flowchart showing the proton resistance acquisition process for the non-target cell in the second embodiment. [Figure 11] FIG. 11 is a flowchart showing the aging process for a replacement cell in the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] There is a demand for regenerating and reusing fuel cell stacks that have deteriorated through use and can no longer maintain sufficient performance. Because a fuel cell stack is composed of multiple cells connected in series, if even one of the multiple cells is significantly deteriorated compared to the other cells, the performance of the fuel cell stack will decrease. By replacing the significantly deteriorated cell among the multiple cells assembled in the fuel cell stack with a new cell, the performance of the fuel cell stack can be restored.

[0013] In a regenerated fuel cell stack, all the cells assembled in the fuel cell stack except for the target cell are reused, so the regenerated fuel cell stack contains a mixture of new and old cells.

[0014] A polymer electrolyte fuel cell stack generates electricity through an electrochemical reaction between an anode gas and a cathode gas. The anode gas is, for example, hydrogen gas. The cathode gas is, for example, air. In the fuel cell stack, hydrogen and oxygen combine to produce water during power generation.

[0015] The catalyst in an old cell is less active than the catalyst in a new cell. Therefore, when a new cell and an old cell are operated under the same conditions to generate power, the amount of water generated in the new cell is greater than that in the old cell. Fuel cell stacks are required to prevent clogging of the gas supply path by generated water (flooding). However, in a regenerated fuel cell stack, the amount of water generated in the new cell is relatively greater than that in the old cell, which can cause flooding in the regenerated fuel cell stack.

[0016] In the present disclosure, flooding in the regenerated fuel cell stack can be suppressed by making the amount of water produced in the new replaced cells equal to the amount of water produced in the old cells.

[0017] [First embodiment] 1 is a schematic diagram showing the configuration of a fuel cell stack 10 according to this embodiment. The fuel cell stack 10 is mounted on a vehicle such as a fuel cell automobile 12 (FIG. 2). The fuel cell stack 10 may also be mounted on equipment other than a vehicle.

[0018] The fuel cell stack 10 is a polymer electrolyte fuel cell. The fuel cell stack 10 generates power through an electrochemical reaction between an anode gas and a cathode gas. The anode gas is, for example, hydrogen gas. The anode gas is not particularly limited as long as it is a gas containing hydrogen. The cathode gas is, for example, an oxygen-containing gas such as air. The cathode gas is not particularly limited as long as it is a gas containing oxygen.

[0019] The fuel cell stack 10 is formed by stacking a plurality of cells 14. Each cell 14 has a membrane electrode assembly (MEA) 30 and a pair of separators 32a and 32b that sandwich the membrane electrode assembly 30.

[0020] The membrane electrode assembly 30 includes an electrolyte membrane 34, an anode electrode 36, and a cathode electrode 38. The electrolyte membrane 34 is sandwiched between the cathode electrode 38 and the anode electrode 36. The electrolyte membrane 34 is, for example, a solid polymer electrolyte membrane. The solid polymer electrolyte membrane is, for example, a thin film formed from a material containing a proton-conducting component that contains water. An example of the proton-conducting component is perfluorosulfonic acid.

[0021] The anode electrode 36 includes an electrode catalyst layer 39 joined to the electrolyte membrane 34, and a gas diffusion layer 41 laminated on the electrode catalyst layer 39. The electrode catalyst layer 39 is formed by kneading platinum-supported carbon with a material having a proton-conducting component to form a paste catalyst, and applying the paste catalyst to the electrolyte membrane 34 or the gas diffusion layer 41. The gas diffusion layer 41 is formed from a material containing carbon fiber.

[0022] The cathode electrode 38 includes an electrode catalyst layer 40 joined to the electrolyte membrane 34 and a gas diffusion layer 42 laminated on the electrode catalyst layer 40. The electrode catalyst layer 40 is formed by kneading platinum-supported carbon with a material having a proton-conducting component to form a paste catalyst, and applying the paste catalyst to the electrolyte membrane 34 or the gas diffusion layer 42. The gas diffusion layer 42 is formed from a material containing carbon fiber.

[0023] An anode gas flow channel (not shown) is formed on the surface of the anode-side separator 32a facing the membrane electrode assembly 30. A cathode gas flow channel (not shown) is formed on the surface of the cathode-side separator 32b facing the membrane electrode assembly 30.

[0024] 2 is a schematic diagram showing the process for reusing a fuel cell stack 10 in this embodiment. A new fuel cell stack 10 is manufactured in a manufacturing factory. The manufactured fuel cell stack 10 is then mounted on a fuel cell vehicle 12 or the like for use.

[0025] A fuel cell stack 10 that can no longer maintain sufficient performance due to use is sent to a recycling plant. At the recycling plant, of the cells 14 assembled in the fuel cell stack 10, a cell 14 whose generated voltage falls below a predetermined voltage is considered to be a severely deteriorated cell 14. The cell 14 whose generated voltage falls below the predetermined voltage is selected as a target cell 16. The target cell 16 is replaced with a new replacement cell 18. The target cell 16 may be one cell or multiple cells. The same number of replacement cells 18 as the target cells 16 are prepared.

[0026] The fuel cell stack 10 that has been replaced with a new replacement cell 18 and regenerated is then re-installed in a fuel cell vehicle 12 or the like and reused.

[0027] [Reproduction processing] At the recycling plant, replacement cells 18 are manufactured so that the amount of water produced when the replacement cells 18 are used to generate electricity under specified conditions is approximately the same as the amount of water produced when the non-target cells 20 (Figure 2) are used to generate electricity under specified conditions.

[0028] Generally, the amount of platinum contained in the electrode catalyst layer 40 of the cathode electrode 38 is greater than the amount of platinum contained in the electrode catalyst layer 39 of the anode electrode 36. In addition, in the cell 14, water is mainly produced in the electrode catalyst layer 40 of the cathode electrode 38. Therefore, the amount of water produced in the replacement cell 18 can be adjusted by the catalyst coating amount in the electrode catalyst layer 40 of the cathode electrode 38.

[0029] Of the multiple cells 14 assembled in the fuel cell stack 10, cells 14 other than the target cell 16 and adjacent to the target cell 16 are selected as non-target cells 20. The non-target cells 20 may be cells 14 that are not adjacent to the target cell 16. Even when there are multiple target cells 16, only one non-target cell 20 may be selected.

[0030] At the recycling plant, the manufactured replacement cells 18 are aged. Aging activates the electrode catalyst layer 40 of the cathode 38 of the replacement cells 18. When the activated replacement cells 18 are operated to generate electricity under specified conditions, the amount of water produced becomes approximately the same as the amount of water produced when the non-target cells 20 are operated to generate electricity under the specified conditions.

[0031] Hereinafter, the term "amount of water produced by a cell 14 (replacement cell 18, non-target cell 20)" refers to the amount of water produced when the cell 14 (replacement cell 18, non-target cell 20) is used to generate electricity under predetermined conditions. The predetermined conditions include the current output by the cell 14, the amount of anode gas supplied to the cell 14, the pressure of the anode gas supplied to the cell 14, the humidity of the anode gas supplied to the cell 14, the amount of cathode gas supplied to the cell 14, the pressure of the cathode gas supplied to the cell 14, the humidity of the cathode gas supplied to the cell 14, the temperature around the cell 14, etc.

[0032] At the manufacturing factory, before each cell 14 is assembled into the fuel cell stack 10, the amount of water produced when each cell 14 is caused to generate electricity under predetermined conditions is obtained in advance for all cells 14. The cells 14 before being assembled into the fuel cell stack 10 at the manufacturing factory can be said to be cells 14 before deterioration occurs. Hereinafter, the amount of water produced in the cells 14 obtained in advance at the manufacturing factory may be referred to as the amount of water produced in the cells 14 during manufacturing. The amount of water produced in the cells 14 during manufacturing corresponds to the second physical quantity of the present invention.

[0033] FIG. 3 is a flowchart showing the regeneration process of the fuel cell stack 10 carried out in the recycling plant in this embodiment.

[0034] In step S1, a process for acquiring the proton resistance of the non-target cell 20 is executed. Then, the process proceeds to step S2. In the process for acquiring the proton resistance of the non-target cell 20, the proton resistance of the non-target cell 20 is acquired. The process for acquiring the proton resistance of the non-target cell 20 in step S1 will be described in detail later.

[0035] In step S2, the amount of water produced in the non-target cell 20 is acquired. Then, the process proceeds to step S3. The amount of water produced in the non-target cell 20 can be obtained from the proton resistance of the non-target cell 20. The amount of water produced in the non-target cell 20 corresponds to the first physical quantity of the present invention.

[0036] FIG. 4 is a map for determining the amount of water produced in the cell 14 from the proton resistance of the cell 14 in this embodiment.

[0037] The proton resistance of the cell 14 indicates the ionic conductivity in the electrode catalyst layer 39 and the electrode catalyst layer 40. The proton resistance can be determined, for example, by electrochemical impedance spectroscopy (hereinafter referred to as EIS). When the amount of water produced in the cell 14 is small, the movement of protons is inhibited in the electrode catalyst layer 39 and the electrode catalyst layer 40 of the cell 14, and the proton resistance increases. Therefore, the proton resistance of the cell 14 has a high correlation with the amount of water produced in the cell 14, and the amount of water produced in the cell 14 can be determined from the proton resistance of the cell 14. The map of FIG. 4 is determined in advance by experiment or the like.

[0038] The amount of water produced in the non-target cell 20 is determined based on the map of Figure 4 and the proton resistance of the non-target cell 20. For example, if the proton resistance of the non-target cell 20 is Ra [Ω], the amount of water produced in the non-target cell 20 can be determined as Aa [L] from the map of Figure 4. Hereinafter, the amount of water produced in the non-target cell 20 obtained in step S2 may be referred to as the amount of water produced in the non-target cell 20 during regeneration.

[0039] In step S3, the catalyst coating weight in the electrode catalyst layer 40 of the cathode electrode 38 of the replacement cell 18 is determined. Then, the process proceeds to step S4. As described above, the electrode catalyst layer 40 is formed by kneading platinum-supported carbon with a material having a proton-conducting component to form a catalyst paste, and coating the catalyst paste on the electrolyte membrane 34 or the gas diffusion layer 42.

[0040] FIG. 5 is a map for determining the catalyst coating amount in the electrode catalyst layer 40 of the cathode electrode 48 of the replacement cell 18 from the amount of water generated in the non-target cell 20 during manufacturing and the amount of water generated in the non-target cell 20 during regeneration in this embodiment.

[0041] The catalyst coating amount in the electrode catalyst layer 40 of the cathode electrode 38 of the replacement cell 18 can be calculated from the amount of water produced in the non-target cell 20 during regeneration and the amount of water produced in the non-target cell 20 during manufacture, based on the map in Figure 5.

[0042] In order to make the amount of water produced in the replacement cell 18 approximately the same as the amount of water produced in the non-target cell 20, it is necessary to coat an amount of catalyst corresponding to the degree of deterioration of the non-target cell 20 during regeneration as the electrode catalyst layer 40 of the cathode electrode 38 of the replacement cell 18. The degree of deterioration of the non-target cell 20 during regeneration can be determined from the amount of water produced in the non-target cell 20 during regeneration and the amount of water produced in the non-target cell 20 during manufacturing.

[0043] For example, even if the amount of water produced in the non-target cell 20 during regeneration is the same (P[L]), if the amount of water produced in the non-target cell 20 during manufacturing is relatively high (R[L]) compared to when the amount of water produced in the non-target cell 20 during manufacturing is relatively low (Q[L]), it can be determined that the degree of deterioration of the non-target cell 20 during regeneration is high.

[0044] By using the map of FIG. 5, the catalyst coating amount in the electrode catalyst layer 40 of the cathode electrode 38 of the replacement cell 18 can be determined based on the degree of deterioration of the non-target cell 20 during regeneration.

[0045] For example, if the amount of water generated in the non-target cell 20 during regeneration is Aa [L] and the amount of water generated in the non-target cell 20 during manufacture is Ab [L], then from the map of FIG. 5, the catalyst coating amount of the replacement cell 18 is 0.3 [mg / cm 2 ] can be obtained.

[0046] The catalyst coating weight in the electrode catalyst layer 40 of the cathode electrode 38 of the replacement cell 18 may be determined based on the proton resistance of the non-target cell 20 during manufacture and the proton resistance of the non-target cell 20 during regeneration.

[0047] The catalyst coating mass of the electrode catalyst layer 39 of the anode electrode 36 of the replacement cell 18 may be constant regardless of the amount of water produced in the non-target cell 20. Alternatively, the catalyst coating mass of the electrode catalyst layer 39 of the anode electrode 36 of the replacement cell 18 may be determined based on a map (not shown) different from that in FIG.

[0048] In step S4, a replacement cell 18 is manufactured. Then, the process proceeds to step S5. When manufacturing the replacement cell 18, an amount of catalyst corresponding to the catalyst coating amount determined in step S3 is applied to the electrolyte membrane 34 or gas diffusion layer 42 of the replacement cell 18, thereby forming the electrode catalyst layer 40.

[0049] In step S5, an aging process is performed on the replacement cell 18. Then, the process proceeds to step S6. This aging process will be described in detail later.

[0050] In step S6, the replacement cell 18 and the non-target cell 20 are assembled into the fuel cell stack 10. Thereafter, the regeneration process is terminated.

[0051] In addition, replacement cells 18 with different catalyst coating amounts may be manufactured in advance, and in step S4, a replacement cell 18 coated with an amount of catalyst corresponding to the catalyst coating amount determined in step S3 may be selected.

[0052] [How to calculate the cell's proton resistance] Typically, in EIS, the impedance of the cell 14 is measured after the cell 14 is brought into a state where it is generating electricity (power generation state). Fig. 6 is an image diagram of the cell 14 in a power generation state in this embodiment.

[0053] In this disclosure, the power generation state refers to a state in which hydrogen gas is supplied as the anode gas and an oxygen-containing gas is supplied as the cathode gas to the cell 14. In the power generation state of the cell 14, protons move from the anode to the cathode. The protons move accompanied by water. Hereinafter, the water that moves accompanied by the protons may be referred to as "produced water." In the cathode electrode catalyst layer 40 of the power generation state of the cell 14, protons, oxygen, and electrons combine to produce water.

[0054] The greater the amount of water contained in cell 14, the lower the proton resistance of cell 14. When cell 14 is placed in a power generation state, the amount of water contained in cell 14 increases due to produced water and produced water. Therefore, the proton resistance of cell 14 after being placed in a power generation state is lower than the proton resistance of cell 14 before being placed in a power generation state. However, the decrease in proton resistance of cell 14 after being placed in a power generation state includes the influence of the decrease in proton resistance due to the increase in the amount of water caused by produced water and the influence of the decrease in proton resistance due to the increase in the amount of water caused by produced water. Therefore, when the amount of produced water is calculated from the proton resistance of cell 14 after being placed in a power generation state, the accuracy of the calculated amount of produced water is low.

[0055] FIG. 7 is an image diagram of the cell 14 in a non-power-generating state in this embodiment. In this disclosure, the non-power-generating state refers to a state in which hydrogen gas is supplied as the anode gas and an inert gas such as nitrogen gas is supplied as the cathode gas to the cell 14, as shown in FIG. 7. Note that even when the cell 14 is not generating power, the electromotive force of the cell 14 is not necessarily zero. However, the electromotive force of the cell 14 in a non-power-generating state is sufficiently smaller than the electromotive force of the cell 14 in a power-generating state.

[0056] In the cell 14 when not generating electricity, the difference in proton concentration between the anode and the cathode causes protons to migrate from the anode to the cathode. Alternatively, applying a voltage to the cell 14 when not generating electricity can cause protons to migrate from the anode to the cathode. As described above, protons migrate accompanied by water, which allows water to penetrate into the electrolyte membrane 34 and improve the wetness of the electrolyte membrane 34. In the electrode catalyst layer 40 of the cell 14 when not generating electricity, protons and electrons combine to produce hydrogen, but water is not produced. Therefore, the decrease in proton resistance of the cell 14 when not generating electricity includes the effect of the decrease in proton resistance due to the increase in water content caused by produced water, but does not include the effect of the decrease in proton resistance due to the increase in water content caused by produced water.

[0057] In this embodiment, the amount of water produced in the non-target cell 20 is calculated from the value obtained by subtracting the proton resistance of the non-target cell 20 after it has been placed in a power generating state from the proton resistance of the non-target cell 20 in a non-power generating state. Also, in this embodiment, the amount of water produced in the replacement cell 18 is calculated from the value obtained by subtracting the proton resistance of the replacement cell 18 after it has been placed in a power generating state from the proton resistance of the replacement cell 18 in a non-power generating state.

[0058] [Proton resistance acquisition process for non-target cells] A detailed description will be given of the proton resistance acquisition process for the non-target cell 20 performed in step S1 of Fig. 3. Fig. 8 is a flowchart showing the proton resistance acquisition process for the non-target cell 20 in this embodiment.

[0059] In step S11, non-power generation aging is performed on the non-target cells 20. After non-power generation aging is performed on the non-target cells 20 for a predetermined time, the process proceeds to step S12.

[0060] Examples of non-power generation aging include CV (Cyclic Voltammetry) aging and HP (Hydrogen Pump) aging. In CV aging and HP aging, aging is performed with the non-target cells 20 in a non-power generation state. That is, in CV aging and HP aging, hydrogen gas is supplied as the anode gas to the non-target cells 20, and an inert gas is supplied as the cathode gas.

[0061] In CV aging, a voltage is applied to the non-target cell 20, with the anode electrode 36 serving as the negative electrode and the cathode electrode 38 serving as the positive electrode. In CV aging, the voltage applied to the non-target cell 20 is varied, for example, within a range of 0.05 V to 0.9 V. Due to deterioration of the electrode catalyst layer 39 of the anode electrode 36 and the electrode catalyst layer 40 of the cathode electrode 38 of the non-target cell 20, oxides adhere to the surfaces of the platinum contained in the electrode catalyst layer 39 and the electrode catalyst layer 40. As described above, by varying the voltage applied to the non-target cell 20, oxides covering the surfaces of the platinum contained in the electrode catalyst layer 39 and the electrode catalyst layer 40 are removed. This increases the active surface area of ​​the platinum, allowing the non-target cell 20 to be reactivated.

[0062] In HP aging, a voltage is applied to the non-target cell 20, with the anode electrode 36 acting as the negative electrode and the cathode electrode 38 acting as the positive electrode. In HP aging, the voltage applied to the non-target cell 20 is maintained at, for example, 0.05 V. When HP aging is performed on the non-target cell 20, the natural potential of the anode electrode 36 becomes approximately 0.1 V. This generates a potential difference between the anode electrode 36 and the cathode electrode 38 of the non-target cell 20, causing protons to migrate from the anode electrode 36 to the cathode electrode 38. The protons migrate with water. This allows moisture to penetrate into the electrolyte membrane 34, improving the wetness of the electrolyte membrane 34.

[0063] In step S11, one of CV aging and HP aging is performed on the non-target cells 20. In step S11, both CV aging and HP aging may be performed on the non-target cells 20. Also, in step S11, non-power generation aging other than CV aging and HP aging may be performed.

[0064] In step S12, the proton resistance of the non-target cell 20 in a non-power-generating state is acquired. Then, the process proceeds to step S13. Hereinafter, the proton resistance of the non-target cell 20 in a non-power-generating state may be referred to as the first proton resistance. In the non-target cell 20 in a non-power-generating state, protons accompanying water move, but water is not produced. Therefore, it can be considered that the first proton resistance includes the effect of a decrease in proton resistance due to an increase in the amount of water caused by produced water, but does not include the effect of a decrease in proton resistance due to an increase in the amount of water caused by produced water.

[0065] In step S13, performance evaluation is performed on the non-target cell 20. Then, the process proceeds to step S14.

[0066] In the performance evaluation, the non-target cell 20 is put into a power generating state, and, for example, the voltage, current, etc., of the non-target cell 20 during power generation are evaluated. That is, in the performance evaluation, hydrogen gas is supplied as the anode gas, and an oxygen-containing gas is supplied as the cathode gas to the non-target cell 20. In the performance evaluation, it is confirmed that the voltage of the non-target cell 20 is equal to or higher than a predetermined voltage when the current output from the non-target cell 20 in the power generating state is approximately 470 [A].

[0067] In step S14, the proton resistance of the non-target cell 20 is acquired. Then, the process proceeds to step S15. When the proton resistance of the non-target cell 20 is acquired in step S14, hydrogen gas is supplied as the anode gas to the non-target cell 20, and an inert gas is supplied as the cathode gas to the non-target cell 20. In this way, the proton resistance of the non-target cell 20 is acquired while power generation of the non-target cell 20 is stopped.

[0068] Hereinafter, the proton resistance of the non-target cell 20 after it has been placed in a power generating state may be referred to as a second proton resistance. In the non-target cell 20 in a power generating state, protons accompanying water move and water is produced. Therefore, the second proton resistance can be considered to include the influence of the decrease in proton resistance due to the increase in the amount of water caused by produced water and the influence of the decrease in proton resistance due to the increase in the amount of water caused by produced water.

[0069] In step S15, the non-target cells 20 are purged with an inert gas. Then, the process proceeds to step S16. By purging, hydrogen, generated water, and the like remaining in the non-target cells 20 are discharged.

[0070] In step S16, a third proton resistance is obtained by subtracting the second proton resistance of the non-target cell 20 from the first proton resistance of the non-target cell 20. Thereafter, the process of obtaining the proton resistance of the non-target cell 20 ends.

[0071] In step S2 of FIG. 3, the third proton resistance of the non-target cell 20 is used as the proton resistance of the non-target cell 20 to determine the amount of water produced in the non-target cell 20.

[0072] [Aging process for replacement cells] A detailed description will be given of the aging process of the replacement cell 18 carried out in step S5 of Fig. 3. Fig. 9 is a flowchart showing the aging process of the replacement cell 18 in this embodiment.

[0073] In step S21, non-power generation aging is performed on the replacement cell 18. After non-power generation aging has been performed on the replacement cell 18 for a predetermined period of time, the process proceeds to step S22.

[0074] Examples of non-power generation aging include CV aging and HP aging. In CV aging and HP aging, aging is performed with the replacement cell 18 in a non-power generation state. That is, in CV aging and HP aging, hydrogen gas is supplied as the anode gas and an inert gas is supplied as the cathode gas to the replacement cell 18.

[0075] In CV aging, a voltage is applied to the replacement cell 18, with the anode 36 serving as the negative electrode and the cathode 38 serving as the positive electrode. In CV aging, the voltage applied to the replacement cell 18 is varied, for example, within a range of 0.05 V to 0.9 V. Even in an unused replacement cell 18, oxides adhere to the surfaces of the platinum contained in the electrode catalyst layer 39 of the anode 36 and the electrode catalyst layer 40 of the cathode 38. As described above, varying the voltage applied to the replacement cell 18 removes oxides that cover the surfaces of the platinum contained in the electrode catalyst layer 39 and the electrode catalyst layer 40. This increases the active surface area of ​​the platinum, thereby activating the replacement cell 18.

[0076] In HP aging, a voltage is applied to the replacement cell 18, with the anode electrode 36 acting as the negative electrode and the cathode electrode 38 acting as the positive electrode. In HP aging, the voltage applied to the replacement cell 18 is maintained at, for example, 0.05 V. When HP aging is performed on the replacement cell 18, the natural potential of the anode electrode 36 becomes approximately 0.1 V. This creates a potential difference between the anode electrode 36 and the cathode electrode 38 of the replacement cell 18, causing protons to migrate from the anode electrode 36 to the cathode electrode 38. The migrating protons are accompanied by moisture. This allows moisture to penetrate into the electrolyte membrane 34, keeping the electrolyte membrane 34 in a wet state.

[0077] In step S21, one of CV aging and HP aging is performed on the replacement cell 18. In step S21, both CV aging and HP aging may be performed on the replacement cell 18. Also, in step S21, non-power generation aging other than CV aging and HP aging may be performed.

[0078] In step S22, the proton resistance of the exchange cell 18 in a non-power-generating state is acquired. Then, the process proceeds to step S23. Hereinafter, the proton resistance of the exchange cell 18 in a non-power-generating state may be referred to as a fourth proton resistance. In the exchange cell 18 in a non-power-generating state, protons accompanying water move, but water is not produced. Therefore, it can be considered that the fourth proton resistance includes the effect of a decrease in proton resistance due to an increase in the amount of water caused by produced water, but does not include the effect of a decrease in proton resistance due to an increase in the amount of water caused by produced water.

[0079] In step S23, a performance evaluation is performed on the replacement cell 18. Then, the process proceeds to step S24.

[0080] In the performance evaluation, the replacement cell 18 is put into a power generating state, and the voltage, current, etc., of the replacement cell 18 during power generation are evaluated. That is, in the performance evaluation, hydrogen gas is supplied as the anode gas, and an oxygen-containing gas is supplied as the cathode gas to the replacement cell 18. In the performance evaluation, it is confirmed that the voltage of the non-target cell 20 is equal to or higher than a predetermined voltage when the current output from the replacement cell 18 in a power generating state is approximately 470 [A].

[0081] In step S24, the proton resistance of the replacement cell 18 is acquired. Then, the process proceeds to step S25. When acquiring the proton resistance of the replacement cell 18 in step S24, hydrogen gas is supplied as the anode gas to the replacement cell 18, and an inert gas is supplied as the cathode gas. In this way, the proton resistance of the replacement cell 18 is acquired while power generation by the replacement cell 18 is stopped.

[0082] Hereinafter, the proton resistance of the replacement cell 18 after power generation may be referred to as the fifth proton resistance. In the replacement cell 18 in the power generation state, the movement of protons accompanied by water occurs, and water is produced. Therefore, the fifth proton resistance can be considered to include the influence of the decrease in proton resistance due to the increase in the amount of water caused by produced water and the influence of the decrease in proton resistance due to the increase in the amount of water caused by produced water.

[0083] In step S25, the replacement cell 18 is purged with an inert gas. Then, the process proceeds to step S26. By purging, hydrogen, generated water, and the like remaining in the replacement cell 18 are discharged.

[0084] In step S26, a sixth proton resistance is obtained, which is a value obtained by subtracting the fifth proton resistance of the replacement cell 18 from the fourth proton resistance of the replacement cell 18. Then, the process proceeds to step S27.

[0085] In step S27, the amount of water produced in the replacement cell 18 is acquired. Then, the process proceeds to step S28. The amount of water produced in the replacement cell 18 is found from the map of FIG. 4 using the sixth proton resistance of the replacement cell 18 as the proton resistance of the replacement cell 18. The amount of water produced in the replacement cell 18 acquired in step S27 corresponds to the third physical quantity of the present invention.

[0086] In step S28, it is determined whether the difference between the amount of water produced in the non-target cell 20 obtained in step S2 (FIG. 3) of the regeneration process and the amount of water produced in the replacement cell 18 obtained in step S27 is equal to or less than a predetermined amount.

[0087] If the difference between the amount of water produced in the non-target cells 20 and the amount of water produced in the replacement cells 18 is equal to or less than the predetermined amount (step S28: YES), the aging process for the replacement cells 18 ends. If the difference between the amount of water produced in the non-target cells 20 and the amount of water produced in the replacement cells 18 is greater than the predetermined amount (step S28: NO), the process returns to step S21, and aging is further performed on the replacement cells 18. As a result, aging is performed on the replacement cells 18 until the difference between the amount of water produced in the non-target cells 20 and the amount of water produced in the replacement cells 18 becomes equal to or less than the predetermined amount.

[0088] The replacement cell 18 may be aged until the difference between the third proton resistance of the non-target cell 20 and the sixth proton resistance of the replacement cell 18 becomes equal to or less than a predetermined value.

[0089] Second Embodiment In this embodiment, the proton resistance acquisition process for the non-target cell 20 performed in step S1 of Fig. 3 is different from the proton resistance acquisition process for the non-target cell 20 in the first embodiment. Also, in this embodiment, the aging process for the replacement cell 18 performed in step S5 of Fig. 3 is different from the aging process for the replacement cell 18 in the first embodiment.

[0090] [Proton resistance acquisition process for non-target cells] FIG. 10 is a flowchart showing the proton resistance acquisition process for the non-target cell 20 in this embodiment.

[0091] In step S31, performance evaluation is performed on the non-target cell 20. Then, the process proceeds to step S32.

[0092] In the performance evaluation, the non-target cell 20 is put into a power generating state, and, for example, the voltage, current, etc., of the non-target cell 20 during power generation are evaluated. That is, in the performance evaluation, hydrogen gas is supplied as the anode gas, and an oxygen-containing gas is supplied as the cathode gas to the non-target cell 20. In the performance evaluation, it is confirmed that the voltage of the non-target cell 20 is equal to or higher than a predetermined voltage when the current output from the non-target cell 20 in the power generating state is approximately 470 [A].

[0093] In step S32, the proton resistance (second proton resistance) of the non-target cell 20 is acquired. Then, the process proceeds to step S33. When the proton resistance of the non-target cell 20 is acquired in step S32, hydrogen gas is supplied to the non-target cell 20 as the anode gas, and an inert gas is supplied to the non-target cell 20 as the cathode gas. In this way, the proton resistance of the non-target cell 20 is acquired while power generation of the non-target cell 20 is stopped.

[0094] In step S33, the non-target cell 20 is purged with an inert gas. Then, the proton resistance acquisition process for the non-target cell 20 is terminated. By purging, hydrogen, generated water, and the like remaining in the non-target cell 20 are discharged.

[0095] In step S2 of FIG. 3 , the amount of water produced in the non-target cell 20 is calculated using the second proton resistance of the non-target cell 20 as the proton resistance of the non-target cell 20. The second proton resistance of the non-target cell 20 includes the influence of a decrease in proton resistance due to an increase in the amount of water caused by produced water and the influence of a decrease in proton resistance due to an increase in the amount of water caused by produced water. Therefore, the accuracy of the amount of water produced in the non-target cell 20 calculated in this embodiment may be lower than the accuracy of the amount of water produced in the non-target cell 20 calculated in the first embodiment. However, in this embodiment, there is no need to calculate the proton resistance (first proton resistance) of the non-target cell 20 in a non-power-generating state. This makes it possible to ensure a certain degree of accuracy in the amount of water produced in the non-target cell 20 while shortening the time required for the proton resistance acquisition process for the non-target cell 20.

[0096] [Aging process for replacement cells] In this embodiment, in the aging process of the replacement cell 18, the replacement cell 18 is subjected to power generation aging.

[0097] Power generation aging is a technique for aging the anode electrode 36 and cathode electrode 38 of a replacement cell 18 that has not yet been aged. In power generation aging, the flow rate and pressure of the anode gas and cathode gas supplied to the replacement cell 18 are gradually increased, and the replacement cell 18 is run-in until it reaches a state where performance can be evaluated.

[0098] During power generation aging, hydrogen gas is supplied as the anode gas and an oxygen-containing gas is supplied as the cathode gas. During power generation aging, the replacement cell 18 is aged by generating power and supplying it to a load.

[0099] FIG. 11 is a flowchart showing the aging process for the replacement cell 18 in this embodiment.

[0100] In step S41, power generation aging is performed on the replacement cell 18. After power generation aging has been performed on the replacement cell 18 for a predetermined time, the process proceeds to step S42.

[0101] In step S42, a performance evaluation is performed on the replacement cell 18. Then, the process proceeds to step S43.

[0102] In the performance evaluation, the replacement cell 18 is put into a power generating state, and the voltage, current, etc., of the replacement cell 18 during power generation are evaluated. That is, in the performance evaluation, hydrogen gas is supplied as the anode gas, and an oxygen-containing gas is supplied as the cathode gas to the replacement cell 18. In the performance evaluation, it is confirmed that the voltage of the replacement cell 18 is equal to or higher than a predetermined voltage when the current output from the replacement cell 18 in a power generating state is approximately 470 A.

[0103] In step S43, the proton resistance (fifth proton resistance) of the replacement cell 18 is acquired. Then, the process proceeds to step S44. When acquiring the fifth proton resistance of the replacement cell 18 in step S43, hydrogen gas is supplied to the replacement cell 18 as the anode gas, and an inert gas is supplied as the cathode gas. In this way, the fifth proton resistance of the replacement cell 18 is acquired with power generation by the replacement cell 18 stopped.

[0104] In step S44, the replacement cell 18 is purged with an inert gas. Then, the process proceeds to step S45. By purging, hydrogen, generated water, and the like remaining in the replacement cell 18 are discharged.

[0105] In step S45, the amount of water produced in the replacement cell 18 is obtained. Then, the process proceeds to step S46. The amount of water produced in the replacement cell 18 is obtained from the map of FIG. 4 using the fifth proton resistance of the replacement cell 18 as the proton resistance of the replacement cell 18.

[0106] The fifth proton resistance of the exchange cell 18 includes the influence of a decrease in proton resistance due to an increase in the amount of water caused by produced water and the influence of a decrease in proton resistance due to an increase in the amount of water caused by produced water. Therefore, the accuracy of the amount of water produced in the exchange cell 18 calculated in this embodiment is lower than the accuracy of the amount of water produced in the exchange cell 18 calculated in the first embodiment. However, in this embodiment, there is no need to calculate the proton resistance (fourth proton resistance) of the exchange cell 18 in a non-power-generating state, and it is possible to ensure a certain degree of accuracy in the calculated amount of water produced in the exchange cell 18 while shortening the time required for the aging process of the exchange cell 18.

[0107] In step S46, it is determined whether the difference between the amount of water produced in the non-target cell 20 obtained in step S2 (FIG. 3) of the regeneration process and the amount of water produced in the replacement cell 18 obtained in step S45 is equal to or less than a predetermined amount.

[0108] If the difference between the amount of water produced in the non-target cells 20 and the amount of water produced in the replacement cells 18 is equal to or less than the predetermined amount (step S46: YES), the aging process for the replacement cells 18 ends. If the difference between the amount of water produced in the non-target cells 20 and the amount of water produced in the replacement cells 18 is greater than the predetermined amount (step S46: NO), the process returns to step S41, and aging is further performed on the replacement cells 18. As a result, aging is performed on the replacement cells 18 until the difference between the amount of water produced in the non-target cells 20 and the amount of water produced in the replacement cells 18 becomes equal to or less than the predetermined amount.

[0109] The replacement cell 18 may be aged until the difference between the second proton resistance of the non-target cell 20 and the fifth proton resistance of the replacement cell 18 becomes equal to or less than a predetermined value.

[0110] The following additional notes are further disclosed regarding the above embodiment.

[0111] (Appendix 1) A method for manufacturing a replacement cell (18) according to the present disclosure is a method for manufacturing a replacement cell to replace a target cell (16) selected from a plurality of cells (14) assembled in a fuel cell stack (10) that has deteriorated due to use. The method includes a first acquisition step of acquiring a first physical quantity, which is a physical quantity relating to the amount of water produced when a non-target cell (20) of the plurality of cells other than the target cell is operated to generate electricity under predetermined conditions; a coating weight determination step of determining a catalyst coating weight, which is the amount of catalyst to be applied to the replacement cell, based on the first physical quantity; and a manufacturing step of manufacturing the replacement cell coated with the catalyst in an amount corresponding to the catalyst coating weight determined in the coating weight determination step. This allows the amount of water produced when the replacement cell is operated to generate electricity under the predetermined conditions to be approximately the same as the amount of water produced when the non-target cell is operated to generate electricity under the predetermined conditions. This reduces flooding in the regenerated fuel cell stack.

[0112] (Appendix 2) In the method for manufacturing a replacement cell described in Appendix 1, a second physical quantity, which is the physical quantity related to the amount of water produced when power is generated under the predetermined conditions, may be acquired in advance for each of the plurality of cells before the deterioration occurs, and the catalyst coating amount determination step may determine the catalyst coating amount for the replacement cell based on the first physical quantity of the non-target cell and the second physical quantity of the non-target cell. This allows the amount of water produced when the replacement cell is operated to generate power under the predetermined conditions to be approximately the same as the amount of water produced when the non-target cell is operated to generate power under the predetermined conditions. This makes it possible to suppress flooding in the regenerated fuel cell stack.

[0113] (Appendix 3) The method for manufacturing a replacement cell described in Appendix 1 may further include an aging step of aging the replacement cell manufactured in the manufacturing step, and a second acquisition step of acquiring a third physical quantity, which is the physical quantity related to the amount of water produced when the aged replacement cell is operated to generate electricity under the predetermined conditions. The aging step may perform the aging on the replacement cell until the difference between the first physical quantity of the non-target cell and the third physical quantity of the replacement cell becomes equal to or less than a predetermined amount. This allows the amount of water produced when the replacement cell is operated to generate electricity under the predetermined conditions to be closer to the amount of water produced when the non-target cell is operated to generate electricity under the predetermined conditions. This can suppress flooding in the regenerated fuel cell stack.

[0114] (Appendix 4) In the method for manufacturing a replacement cell described in Appendix 1, the first acquisition step may include a first proton resistance acquisition step of supplying hydrogen gas as the anode gas and an inert gas as the cathode gas to place the non-target cell in a non-power-generating state and acquiring a first proton resistance of the non-target cell, a second proton resistance acquisition step of supplying the hydrogen gas as the anode gas and an oxygen-containing gas as the cathode gas to place the non-target cell in a power-generating state in which it generates electricity, and then supplying an inert gas as the cathode gas to acquire a second proton resistance of the non-target cell, and a third proton resistance acquisition step of subtracting the second proton resistance of the non-target cell from the first proton resistance of the non-target cell to acquire a third proton resistance of the non-target cell, and the amount of water produced in the non-target cell may be calculated as the first physical quantity from the third proton resistance. This allows the amount of water produced when the non-target cell is operated to generate electricity under predetermined conditions to be calculated with high accuracy.

[0115] (Appendix 5) In the method for manufacturing a replacement cell described in Supplementary Note 1, the first obtaining step may include a second proton resistance obtaining step of supplying hydrogen gas as the anode gas and an oxygen-containing gas as the cathode gas to bring the non-target cell into a power generation state in which it generates electricity, and then supplying an inert gas as the cathode gas to obtain a second proton resistance of the non-target cell, which is the first physical quantity, and calculating the amount of water produced in the non-target cell from the second proton resistance. This makes it possible to obtain the amount of water produced when the non-target cell is caused to generate electricity under predetermined conditions.

[0116] (Appendix 6) In the method for manufacturing a replacement cell described in Supplementary Note 3, the second acquisition step may include a fourth proton resistance acquisition step of supplying hydrogen gas as the anode gas and an inert gas as the cathode gas to place the replacement cell in a non-power-generating state and acquiring a fourth proton resistance of the replacement cell, a fifth proton resistance acquisition step of supplying the hydrogen gas as the anode gas and an oxygen-containing gas as the cathode gas to place the replacement cell in a power-generating state and then supplying an inert gas as the cathode gas to acquire a fifth proton resistance of the replacement cell, and a sixth proton resistance acquisition step of subtracting the fifth proton resistance of the replacement cell from the fourth proton resistance of the replacement cell to acquire a sixth proton resistance of the replacement cell, wherein the amount of water produced in the replacement cell is calculated as the third physical quantity from the sixth proton resistance. This allows the amount of water produced when the replacement cell is operated to generate electricity under predetermined conditions to be calculated with high accuracy.

[0117] (Appendix 7) In the method for manufacturing a replacement cell described in Supplementary Note 3, the second obtaining step may include a fifth proton resistance obtaining step of supplying hydrogen gas as the anode gas and an oxygen-containing gas as the cathode gas to bring the replacement cell into a power generating state for generating electricity, and then supplying an inert gas as the cathode gas and obtaining a fifth proton resistance of the replacement cell, which is the third physical quantity, and calculating the amount of water produced in the replacement cell from the fifth proton resistance. This makes it possible to determine the amount of water produced when the replacement cell is caused to generate electricity under predetermined conditions.

[0118] (Appendix 8) In the method for manufacturing a replacement cell described in Supplementary Note 6, the aging step may include performing non-power generation aging, in which the replacement cell is placed in the non-power generation state, and the aging step and the fourth proton resistance acquisition step may be performed consecutively. This reduces the time required for the aging step.

[0119] (Appendix 9) In the method for manufacturing a replacement cell according to Supplementary Note 6 or 7, the aging step may include performing at least one of power generation aging, in which the replacement cell is placed in the power generation state and the aging is performed, and performance evaluation, in which the replacement cell is placed in the power generation state and the voltage and current of the replacement cell during power generation may be obtained, and the aging step and the fifth proton resistance obtaining step may be performed consecutively. This reduces the time required for the aging step.

[0120] (Appendix 10) The cell replacement method disclosed herein replaces a target cell selected from a plurality of cells assembled in a fuel cell stack that has deteriorated due to use with a replacement cell. The cell replacement method includes a first acquisition step of acquiring a first physical quantity related to the amount of water generated when a non-target cell, i.e., a cell other than the target cell, is operated to generate electricity under predetermined conditions; a coating weight determination step of determining a catalyst coating weight, which is the amount of catalyst to be applied to the replacement cell, based on the first physical quantity; and a replacement step of replacing the target cell with the replacement cell coated with the amount of catalyst determined in the coating weight determination step. This allows the amount of water generated when the replacement cell is operated to generate electricity under predetermined conditions to be approximately the same as the amount of water generated when the non-target cell is operated to generate electricity under predetermined conditions. This reduces flooding in the regenerated fuel cell stack.

[0121] (Appendix 11) A method for manufacturing a fuel cell stack according to the present disclosure includes a first acquisition step of acquiring a first physical quantity related to the amount of water generated when a non-target cell, i.e., a cell other than the target cell, is operated under predetermined conditions to generate electricity. The method includes a coating amount determination step of determining a catalyst coating amount, which is the amount of catalyst to be applied to the replacement cell, based on the first physical quantity. The method further includes a replacement step of replacing the target cell with the cell coated with the catalyst in an amount corresponding to the catalyst coating amount determined in the coating amount determination step. This allows the amount of water generated when the replacement cell is operated under predetermined conditions to be approximately the same as the amount of water generated when the non-target cell is operated under predetermined conditions. This reduces flooding in the regenerated fuel cell stack.

[0122] Although the present disclosure has been described in detail, the present disclosure is not limited to the individual embodiments described above. Various additions, substitutions, modifications, partial deletions, etc. are possible in these embodiments without departing from the gist of the present disclosure or the spirit of the present disclosure derived from the content of the claims and their equivalents. These embodiments can also be implemented in combination. For example, in the above-described embodiments, the order of each operation and the order of each process are shown as examples and are not limited to these. The same applies when numerical values ​​or mathematical expressions are used in the description of the above-described embodiments.

[0123] This disclosure has described a method for manufacturing a replacement cell to replace a deteriorated target cell in a fuel cell stack. This method for manufacturing a replacement cell can also be applied to a method for manufacturing a replacement cell to replace a deteriorated target cell in a water electrolysis device. This disclosure has also described a cell replacement method for replacing a deteriorated target cell in a fuel cell stack with a replacement cell. This cell replacement method can also be applied to a replacement method for replacing a deteriorated target cell in a water electrolysis device with a replacement cell. This disclosure has also described a method for manufacturing a fuel cell stack by replacing a deteriorated target cell in a fuel cell stack with a replacement cell. This method for manufacturing a fuel cell stack can also be applied to a method for manufacturing a water electrolysis device by replacing a deteriorated target cell in a water electrolysis device with a replacement cell. [Explanation of symbols]

[0124] 10...Fuel cell stack 14...Cell 16...Target cell 18...Replacement cell 20...Non-target cell

Claims

1. A method for manufacturing a replacement cell to replace a target cell selected from a plurality of cells assembled in a fuel cell stack that has deteriorated due to use, the method comprising: a first acquisition step of acquiring a first physical quantity that is a physical quantity related to the amount of water generated when a non-target cell, which is a cell other than the target cell among the plurality of cells, is caused to generate electricity under predetermined conditions; a coating amount determination step of determining a catalyst coating amount, which is the amount of catalyst to be coated on the replacement cell, based on the first physical quantity; a manufacturing step of manufacturing the replacement cell coated with the catalyst in an amount corresponding to the catalyst coating amount determined in the coating amount determination step; A method for manufacturing a replacement cell comprising:

2. 2. The method of claim 1 for manufacturing a replacement cell, a second physical quantity relating to the amount of water produced when power is generated under the predetermined conditions is acquired in advance for each of the plurality of cells before the deterioration occurs; A method for manufacturing a replacement cell, wherein the coating amount determination step determines the catalyst coating amount of the replacement cell based on the first physical quantity of the non-target cell and the second physical quantity of the non-target cell.

3. 2. The method of claim 1 for manufacturing a replacement cell, an aging step of aging the replacement cell manufactured in the manufacturing step; a second acquisition step of acquiring a third physical quantity, which is the physical quantity related to the amount of water produced when the replacement cell that has been aged is caused to generate electricity under the predetermined conditions; and A method for manufacturing a replacement cell, wherein the aging step performs the aging on the replacement cell until a difference between the first physical quantity of the non-target cell and the third physical quantity of the replacement cell becomes a predetermined amount or less.

4. 2. The method of claim 1 for manufacturing a replacement cell, The first obtaining step a first proton resistance acquisition step of bringing the non-target cell into a non-power generating state by supplying hydrogen gas as an anode gas and an inert gas as a cathode gas, and acquiring a first proton resistance of the non-target cell; a second proton resistance acquisition step of supplying the hydrogen gas as the anode gas and the oxygen-containing gas as the cathode gas to bring the non-target cell into a power generation state in which the non-target cell generates power, and then supplying an inert gas as the cathode gas to acquire a second proton resistance of the non-target cell; a third proton resistance acquisition step of subtracting the second proton resistance of the non-target cell from the first proton resistance of the non-target cell to acquire a third proton resistance of the non-target cell; and A method for manufacturing a replacement cell, the method comprising: determining the amount of water produced in the non-target cell as the first physical quantity from the third proton resistance.

5. 2. The method of claim 1 for manufacturing a replacement cell, the first acquisition step includes a second proton resistance acquisition step of supplying hydrogen gas as an anode gas and an oxygen-containing gas as a cathode gas to bring the non-target cell into a power generation state in which the non-target cell generates power, and then supplying an inert gas as the cathode gas to acquire a second proton resistance of the non-target cell, which is the first physical quantity; The method for manufacturing a replacement cell includes determining the amount of water produced in the non-target cell from the second proton resistance.

6. 4. The method of claim 3 for producing a replacement cell, The second acquisition step a fourth proton resistance acquisition step of bringing the replacement cell into a non-power generating state by supplying hydrogen gas as an anode gas and an inert gas as a cathode gas, and acquiring a fourth proton resistance of the replacement cell; a fifth proton resistance acquisition step of supplying the hydrogen gas as the anode gas and the oxygen-containing gas as the cathode gas to bring the replacement cell into a power generation state in which the replacement cell generates electricity, and then supplying an inert gas as the cathode gas to acquire a fifth proton resistance of the replacement cell; a sixth proton resistance acquisition step of subtracting the fifth proton resistance of the replacement cell from the fourth proton resistance of the replacement cell to acquire a sixth proton resistance of the replacement cell; and A method for manufacturing a replacement cell, wherein the amount of water produced in the replacement cell is determined as the third physical quantity from the sixth proton resistance.

7. 4. The method of claim 3 for producing a replacement cell, the second obtaining step includes a fifth proton resistance obtaining step of supplying hydrogen gas as an anode gas and an oxygen-containing gas as a cathode gas to bring the replacement cell into a power generating state in which it generates electricity, and then supplying an inert gas as the cathode gas to obtain a fifth proton resistance of the replacement cell, which is the third physical quantity; A method for manufacturing a replacement cell, comprising determining the amount of water produced in the replacement cell from the fifth proton resistance.

8. 7. The method of claim 6, further comprising the steps of: In the aging step, non-power generation aging is performed by placing the replacement cell in the non-power generation state, and performing the aging. A method for manufacturing a replacement cell, wherein the aging step and the fourth proton resistance obtaining step are carried out consecutively.

9. 8. The method for manufacturing a replacement cell according to claim 6 or 7, In the aging step, at least one of power generation aging, in which the replacement cell is placed in the power generation state and the aging is performed, and performance evaluation, in which the replacement cell is placed in the power generation state and a voltage and a current during power generation of the replacement cell are obtained, is performed; A method for manufacturing a replacement cell, wherein the aging step and the fifth proton resistance obtaining step are carried out consecutively.

10. A cell replacement method for replacing a target cell selected from a plurality of cells assembled in a fuel cell stack that has deteriorated due to use with a replacement cell, comprising: a first acquisition step of acquiring a first physical quantity that is a physical quantity related to the amount of water generated when a non-target cell, which is a cell other than the target cell among the plurality of cells, is caused to generate electricity under predetermined conditions; a coating amount determination step of determining a catalyst coating amount, which is the amount of catalyst to be coated on the replacement cell, based on the first physical quantity; a replacement step of replacing the target cell with the cell coated with the catalyst in an amount corresponding to the catalyst coating amount determined in the coating amount determination step, as the replacement cell; A cell replacement method comprising:

11. 1. A method for manufacturing a fuel cell stack, comprising the steps of: replacing a target cell selected from a plurality of cells assembled in a fuel cell stack that has deteriorated due to use with a replacement cell; a first acquisition step of acquiring a first physical quantity that is a physical quantity related to the amount of water generated when a non-target cell, which is a cell other than the target cell among the plurality of cells, is caused to generate electricity under predetermined conditions; a coating amount determination step of determining a catalyst coating amount, which is the amount of catalyst to be coated on the replacement cell, based on the first physical quantity; a replacement step of replacing the target cell with the cell coated with the catalyst in an amount corresponding to the catalyst coating amount determined in the coating amount determination step, as the replacement cell; A method for manufacturing a fuel cell stack comprising:

Images