Evaluating device and evaluating method

Abstract

This evaluating device comprises: a first holder (41) which holds a first sample (61) of an electrode catalyst and in which a first supply hole (41g) for supplying a first gas to the first sample (61) is formed; a second holder (42) which holds an electrolyte membrane (55); a pressing unit (4) which presses the electrolyte membrane (55) against the first sample (61) with a force in a direction reducing a gap between the first holder (41) and the second holder (42); and a characteristic measuring unit (75) that measures an electrochemical characteristic of the first sample (61) or the electrolyte membrane (55) in a state in which the electrolyte membrane (55) is pressed against the first sample (61) and the first gas is supplied to the first sample (61).

Description

Evaluation device and evaluation method

[0001] This application claims priority to Japanese Patent Application No. 2024-046457, filed on March 22, 2024, the contents of which are incorporated herein by reference.

[0002] With growing interest in environmental protection, fuel cells that generate electricity using hydrogen are becoming more prevalent in society. While platinum and platinum alloys are commonly used as electrode catalysts for fuel cells, new electrode catalysts that can replace these materials are being explored to reduce their cost (see Patent Document 1). Candidate electrode catalyst materials are tested for their electrochemical properties by immersing an electrode, consisting of a uniformly thin layer of electrode catalyst on a corrosion-resistant material such as glassy carbon, in a solution. While this solution test is simple and widely used to evaluate basic properties, optimizing test parameters such as catalyst coating conditions can take days to weeks when using samples with different compositions. However, this electrochemical property evaluation does not necessarily reflect the catalyst properties under actual fuel cell operation, which is problematic. Therefore, single-cell testing, performed by assembling electrodes and an electrolyte membrane, is essential for the final selection of catalysts. However, single-cell testing requires an even longer period of time, making it difficult to identify materials that are effective in real-world environments, and technological progress is slow. In particular, electrochemical testing using solutions is subjective, with test results varying depending on the tester and laboratory, and test results rarely match, even for reference catalysts. This makes it difficult to build a database showing the characteristics of each electrode catalyst, and data-driven search to find the next candidate material based on the database is also not easy. Similar problems exist with electrolyte membranes that make up fuel cells and water splitting devices that generate hydrogen.

[0003] Japanese Patent Application Publication No. 2018-206700 (A)

[0004] In one aspect, the present invention aims to provide an evaluation device and an evaluation method that can perform evaluation automatically.

[0005] According to one aspect, the evaluation device includes a first holder that holds a first sample of an electrode catalyst and has a first supply hole formed therein for supplying a first gas to the first sample; a second holder that holds an electrolyte membrane; a pressure unit that presses the electrolyte membrane against the first sample with a force in a direction that reduces the gap between the first holder and the second holder; and a characteristic measurement unit that measures the electrochemical characteristics of the first sample or the electrolyte membrane while the electrolyte membrane is pressed against the first sample and the first gas is being supplied to the first sample.

[0006] The evaluation device may further include a pressure sensor that measures the pressure with which the electrolyte membrane is pressed against the first sample, and the characteristic measurement unit may measure the electrochemical characteristics while the pressure is maintained at a constant value.

[0007] The evaluation device may further include a pressure sensor that measures a pressure with which the electrolyte membrane is pressed against the first sample, and the characteristic measuring unit may measure the electrochemical characteristic while changing the pressure.

[0008] In the evaluation device, the characteristic measuring unit may measure the electrochemical characteristic while a constant distance is maintained between the first holder and the second holder.

[0009] The evaluation device may further include a humidifying unit that humidifies the first gas.

[0010] In the evaluation apparatus, the characteristic measuring unit may measure the electrochemical characteristic after a predetermined time has elapsed since the humidified first gas was supplied to the first sample.

[0011] The evaluation device may further include a humidity adjusting unit that adjusts the relative humidity of the first gas.

[0012] In the above evaluation device, the first holder may have a first main surface, a convex portion protruding from the first main surface toward the electrolyte membrane, and a recess formed on a top surface of the convex portion, into which the first sample is fitted and which has a depth shallower than a thickness of the first sample.

[0013] In the evaluation device, a groove connected to the first supply hole may be formed in a bottom surface of the recess.

[0014] In the evaluation device, the groove may be formed in a spiral or serpentine shape in a plan view, or a plurality of grooves may be formed in parallel.

[0015] In the above evaluation device, a through hole may be formed in the second holder, a first opening into which the protrusion fits may be formed, and the evaluation device may further include a first spacer that is fitted into the through hole and a second spacer that is fitted into the through hole, and the electrolyte membrane may be fitted into the through hole while being sandwiched between the first spacer and the second spacer.

[0016] The evaluation device may further include a first sealing member attached to an outer peripheral side surface of the first spacer and in close contact with an inner peripheral side surface of the through hole.

[0017] The evaluation device may further include a second sealing member attached to an inner peripheral side surface of the first opening and in close contact with an outer peripheral side surface of the protrusion.

[0018] In the evaluation device, the second holder may have a second main surface opposite to the first main surface, a hole formed in the second main surface into which the protrusion fits, and a recess formed around the hole into which the electrolyte membrane fits.

[0019] The evaluation device may further include a sealing member provided around the protrusion and in close contact with each of the first main surface and the second main surface to seal the first sample and the electrolyte membrane.

[0020] In the evaluation device, a first opening is formed that overlaps the hole in a planar view, and the evaluation device may further include a first spacer that is fitted into the recess and a second spacer that is fitted into the recess, and the electrolyte membrane may be fitted into the recess while being sandwiched between the first spacer and the second spacer.

[0021] The evaluation device may further include a third spacer that is provided on the second spacer and is fitted into the recess.

[0022] In the above evaluation device, the first holder may further have a pin erected on the first main surface, and a hole into which the pin fits may be formed in the second main surface of the second holder.

[0023] In the evaluation device, the electrochemical characteristics may be oxidation-reduction reaction characteristics of the first sample or impedance characteristics of the electrolyte membrane.

[0024] In the evaluation device, the first holder and the second holder may be detachable from the pressure unit.

[0025] The evaluation device may further include a third holder that holds a second sample of the electrode catalyst and has a second supply hole formed therein for supplying a second gas to the second sample, wherein the pressurizing unit presses the electrolyte membrane against the second sample with a force in a direction that reduces the gap between the second holder and the third holder, and the characteristic measuring unit measures the electrochemical characteristics of any of the first sample, the electrolyte membrane, and the second sample while the electrolyte membrane is pressed against the second sample and the second gas is being supplied to the second sample.

[0026] According to another aspect, the evaluation method includes a control unit that presses an electrolyte membrane against a first sample of an electrode catalyst with a force in a direction that reduces the gap between a first holder that holds the first sample and a second holder that holds an electrolyte membrane, and measures the electrochemical characteristics of the first sample or the electrolyte membrane while the electrolyte membrane is pressed against the first sample and the first gas is supplied to the first sample.

[0027] In the above evaluation method, a humidified gas may be supplied as the first gas.

[0028] According to the present invention, it is possible to provide an evaluation device and an evaluation method that can perform evaluation automatically.

[0029] FIG. 1 is a schematic diagram showing an example of an evaluation device according to the first embodiment. FIG. 2 is a functional configuration diagram of a control device according to the first embodiment. FIG. 3A is a top view of a first holder. FIG. 3B is a cross-sectional view taken along line II of FIG. 3A. FIG. 4A is an enlarged top view of a first protrusion. FIG. 4B is a cross-sectional view taken along line II-II of FIG. 4A. FIG. 5A is a top view of a second holder. FIG. 5B is a cross-sectional view taken along line III-III of FIG. 5A. FIG. 6A is a cross-sectional view of an O-ring being mounted on the second holder (before mounting). FIG. 6B is a cross-sectional view of an O-ring being mounted on the second holder (after mounting). FIG. 7A is a cross-sectional view of an electrolyte membrane being fitted into the second holder (before fitting). FIG. 7B is a cross-sectional view of an electrolyte membrane being fitted into the second holder (after fitting). FIG. 8A is a top view of a third holder. FIG. 8B is a cross-sectional view taken along line IV-IV in FIG. 8A. FIG. 9A is an enlarged top view of a second convex portion. FIG. 9B is a cross-sectional view taken along line V-V in FIG. 9A. FIG. 10 is a cross-sectional view illustrating a method for stacking the first to third holders. FIG. 11 is a cross-sectional view of the stacked holders. FIG. 12A is a schematic view of the stacked holders when pressurizing them (before pressurizing). FIG. 12B is a schematic view of the stacked holders when pressurizing them (after pressurizing). FIG. 13 is an enlarged cross-sectional view of the holders when measuring electrochemical characteristics. FIG. 14 is a flowchart illustrating an example of processing performed by the evaluation device. FIG. 15 is a timing chart illustrating an example of processing performed by the evaluation device. FIG. 16 is an example of a hardware configuration diagram of a control device according to the first embodiment. FIG. 17A is a plan view of a flow channel according to a modified example. FIG. 17B is a plan view of a flow channel according to a modified example. FIG. 17C is a plan view of a flow channel according to a modified example. Fig. 18A is a top view of a second holder according to the second embodiment. Fig. 18B is a cross-sectional view taken along line VI-VI in Fig. 18A. Fig. 19A is a top view of a first spacer fitted into a through-hole in the second embodiment. Fig. 19B is a cross-sectional view taken along line VII-VII in Fig. 19A. Fig. 20A is a top view of a second spacer fitted into a through-hole together with the first spacer in the second embodiment. Fig. 20B is a cross-sectional view taken along line VIII-VIII in Fig. 20A.FIG. 21A is a cross-sectional view (part 1) of the second embodiment when each spacer is fitted into the through-hole of the second holder (before fitting). FIG. 21B is a cross-sectional view (part 1) of the second embodiment when each spacer is fitted into the through-hole of the second holder (after fitting). FIG. 22A is a cross-sectional view (part 2) of the second embodiment when each spacer is fitted into the through-hole of the second holder (before fitting). FIG. 22B is a cross-sectional view (part 2) of the second embodiment when each spacer is fitted into the through-hole of the second holder (after fitting). FIG. 23 is a cross-sectional view for explaining a method of stacking the first to third holders in the second embodiment. FIG. 24 is a cross-sectional view of the stacked holders in the second embodiment. FIG. 25 is an enlarged cross-sectional view of the stacked holders in the second embodiment.

[0030] First Embodiment Hereinafter, a first embodiment will be described with reference to the drawings. Note that like elements are given like reference numerals and their description will be omitted.

[0031] 1 is a schematic diagram showing an example of an evaluation device according to this embodiment. The evaluation device 1 is a device for evaluating the electrochemical properties of an electrode catalyst or an electrolyte membrane of a polymer electrolyte fuel cell (PEFC). The evaluation target is not limited to a polymer electrolyte fuel cell, and the evaluation device 1 may also be used to evaluate an electrode catalyst or an electrolyte membrane of a water splitting device.

[0032] As an example, the evaluation device 1 includes a base 2 , a frame 3 , a pressurizing unit 4 , a gas supply unit 5 , a control device 7 , a pressure sensor 8 , a first bubbler 31 , and a second bubbler 32 .

[0033] The base 2 is a plate-shaped metal member extending horizontally for fixing the frame 3. A first gas supply jig 40 made of metal for supplying oxygen gas to the evaluation object is fixed to the base 2.

[0034] In this example, a tester or a robot places first to third holders 41 to 43 in a stacked order on the first gas supply jig 40. Of the holders 41 to 43, the first holder 41 and the third holder 43 are holders for holding the electrode catalyst to be tested, and the second holder 42 is a holder for holding the electrolyte membrane to be tested.

[0035] The frame 3 is a metal member that supports the pressure unit 4, and has a side portion 3a that extends vertically upward from the frame 3, and an upper portion 3b that extends horizontally from the upper end of the side portion 3a.

[0036] The pressure unit 4 is a part that applies pressure to the first to third holders 41 to 43. In this example, the pressure unit 4 includes a load cell 4a and a servo motor 4b. The servo motor 4b is a motor that moves the load cell 4a up and down in the vertical direction, and is fixed to the upper part 3b of the frame 3.

[0037] The load cell 4a is a cylindrical part that applies pressure to the first to third holders 41 to 43 by clamping the first to third holders 41 to 43 between itself and the base 2 when it is lowered by the servo motor 4b. When the load cell 4a is raised by the servo motor 4b, the clamping of the holders 41 to 43 is released. This allows the holders 41 to 43 to be attached to and detached from the pressure unit 4 in accordance with the elevation of the load cell 4a.

[0038] The load cell 4a also incorporates a pressure sensor 8 that measures the pressure applied to each of the holders 41 to 43 when pressure is applied. The configuration of the pressure sensor 8 is not particularly limited. For example, the pressure sensor 8 may be provided with a resistor that expands due to pressure and a measurement circuit that measures the pressure from the change in resistance of the resistor that accompanies a change in pressure.

[0039] A narrow-diameter portion 4c is provided on the upper portion of the load cell 4a. The narrow-diameter portion 4c is inserted into an opening 3c in the upper portion 3a and is fixed to a servo motor 4b. A second metal gas supply jig 44 is fixed to the lower portion of the load cell 4a to supply hydrogen to the object to be evaluated.

[0040] The gas supply unit 5 is a section that supplies hydrogen gas and oxygen gas to the evaluation object. As an example, the gas supply unit 5 includes a nitrogen gas supply source 11, a hydrogen gas supply source 12, and an oxygen gas supply source 13. The supply sources 11 to 13 may be tanks that store liquefied nitrogen, liquefied hydrogen, and liquefied oxygen, respectively, or may be supply ports for nitrogen gas, hydrogen gas, and oxygen gas provided in facilities such as a factory or laboratory. Furthermore, the nitrogen gas, hydrogen gas, and oxygen gas are all dry gases that do not contain moisture.

[0041] Furthermore, the gas supply unit 5 includes MFCs (Mass Flow Controllers) 15 to 19 and pipes 21 to 28 .

[0042] Each of the MFCs 15 to 19 is hardware that controls the flow rate of a gas. Note that controlling the flow rate also includes controlling the cutoff of the gas flow. For example, the MFC 15 controls the flow rate of nitrogen gas supplied from the nitrogen gas supply source 11 and sends it to a downstream stage, or cuts off the flow of nitrogen gas.

[0043] Furthermore, the MFCs 16 and 17 each control the flow rate of the hydrogen gas supplied from the hydrogen gas supply source 12 and send it to a subsequent stage, or cut off the flow of hydrogen gas.

[0044] The MFCs 18 and 19 each control the flow rate of the oxygen gas supplied from the oxygen gas supply source 13 to send it to a subsequent stage or cut off the flow of oxygen gas.

[0045] On the other hand, pipes 21 and 22 are pipes through which nitrogen gas for purging flows. For example, pipe 22 is connected to MFC 15 on its upstream side, and nitrogen gas delivered from MFC 15 is guided to pipe 23. Furthermore, pipe 21 is connected to the middle of pipe 22 on its upstream side, and nitrogen gas flowing through pipe 22 is guided to pipe 25.

[0046] The pipe 23 has its ends connected to the MFC 16 and the second gas supply jig 44 , and guides hydrogen delivered from the MFC 16 to the second gas supply jig 44 .

[0047] The pipe 24 has each end connected to the MFC 17 and the first bubbler 31, and guides the hydrogen gas delivered from the MFC 17 to the first bubbler 31. The first bubbler 31 is an example of a humidifier that humidifies hydrogen gas, and water is stored inside. One end of the pipe 24 is immersed in the water, and hydrogen gas bubbles are generated from this end, thereby humidifying the hydrogen gas. Hereinafter, the humidified hydrogen gas will also be referred to as wet hydrogen gas. The wet hydrogen gas passes through the pipe 27 that connects the space above the water surface to the second gas supply jig 44, and is supplied to the second gas supply jig 44.

[0048] The pipe 25 has its ends connected to the MFC 18 and the first gas supply jig 40 , and guides the oxygen gas delivered from the MFC 18 to the first gas supply jig 40 .

[0049] The pipe 26 has each end connected to the MFC 19 and the second bubbler 32, and guides the oxygen gas delivered from the MFC 19 to the second bubbler 32. The second bubbler 32 is an example of a humidifier that humidifies the oxygen gas, and water is stored inside. One end of the pipe 26 is immersed in the water, and oxygen gas bubbles are generated from this end, thereby humidifying the oxygen gas. Hereinafter, the humidified oxygen gas will also be referred to as wet oxygen gas. The wet oxygen gas passes through the pipe 28 that connects the space above the water surface to the first gas supply jig 40, and is supplied to the first gas supply jig 40.

[0050] The pressure sensor 8 is a sensor that measures the pressure when the load cell 4a is lowered to pressurize each of the holders 41 to 43, and is built into the load cell 4a. The configuration of the pressure sensor 8 is not particularly limited. For example, the pressure sensor 8 may be provided with a resistor that expands due to pressure and a measurement circuit that measures the pressure from the change in resistance of the resistor that accompanies a change in pressure. The pressure sensor 8 also outputs a pressure measurement signal that indicates the measured pressure to the control device 7.

[0051] The control device 7 is a computer such as a PC (Personal Computer) that controls each part of the evaluation device 1. For example, the control device 7 outputs a drive signal indicating a lifting distance to the servo motor 4b, thereby lifting and lowering the load cell 4a by the lifting distance.

[0052] The control device 7 also outputs a characteristic measurement signal for measuring the electrochemical characteristic of the evaluation object to the load cell 4a, and receives a response signal output by the evaluation object in response to the characteristic measurement signal.

[0053] The electrochemical characteristics include the oxidation-reduction reaction (ORR) characteristics of the electrode catalyst of the polymer electrolyte fuel cell, and the control device 7 measures the oxidation-reduction reaction characteristics using linear sweep voltammetry (LSV) or cyclic voltammetry (CV). In the case of LSV or CV, the sweep voltage applied to the electrode catalyst serves as a characteristic measurement signal, and the reaction current flowing through the polymer electrolyte fuel cell, which is composed of the electrode catalyst and the electrolyte membrane when the sweep voltage is applied, serves as a response signal.

[0054] The electrochemical characteristics are not limited to the redox reaction characteristics of the electrode catalyst, but may also be the impedance characteristics of the electrolyte membrane. In this case, the AC voltage applied to the electrode catalyst serves as the characteristic measurement signal, and the AC current flowing through the cell serves as the response signal.

[0055] Furthermore, the control device 7 outputs flow rate control signals for controlling the flow rate of each gas to the gas supply unit 5. As an example, the flow rate control signals control each of the MFCs 15 to 19, thereby controlling the flow rate of the gas flowing through each of the MFCs 15 to 19.

[0056] Next, the functional configuration of the control device 7 will be described.

[0057] 2 is a functional configuration diagram of the control device 7 according to this embodiment. As shown in FIG. 2, the control device 7 includes a control unit 71, a storage unit 72, and a communication unit 73.

[0058] The control unit 71 is a processing unit that controls each unit of the evaluation device 1 , and includes a pressure control unit 74 , a characteristic measurement unit 75 , a humidity adjustment unit 76 , and a flow rate control unit 77 .

[0059] The pressure control unit 74 is a processing unit that controls the pressure that the load cell 4a applies to each of the holders 41 to 43. For example, the pressure control unit 74 controls the elevation distance of the load cell 4a using a drive signal while monitoring the pressure measurement signal output by the pressure sensor 8, thereby maintaining the pressure applied to each of the holders 41 to 43 at a constant value. Alternatively, the pressure control unit 74 may control the pressure applied to each of the holders 41 to 43 to change.

[0060] The pressure control unit 74 may use a drive signal to control the lifting distance of the load cell 4a, thereby maintaining constant the intervals between the holders 41 to 43. In this case, the pressure control unit 7 does not use the pressure measurement signal to control the lifting distance of the load cell 4a.

[0061] The characteristic measurement unit 75 is a processing unit that generates a characteristic measurement signal and measures the electrochemical characteristics of the electrode catalyst and electrolyte membrane based on a response signal to the characteristic measurement signal. For example, if the electrochemical characteristic is the redox reaction characteristic of the electrode catalyst, the characteristic measurement unit 75 generates an LSV or CV sweep voltage as the characteristic measurement signal and obtains the reaction current as a response signal to the characteristic measurement signal. The characteristic measurement unit 75 then measures the relationship between the characteristic measurement signal and the response signal as the redox reaction characteristic of the electrode catalyst.

[0062] When the electrochemical characteristic is the impedance characteristic of the electrolyte membrane, the characteristic measurement unit 75 generates an AC voltage as a characteristic signal and acquires an AC current as a response signal. The characteristic measurement unit 75 then measures the ratio of the AC voltage to the AC current as the impedance characteristic of the electrolyte membrane. The characteristic measurement unit 75 may measure the impedance characteristic for each frequency by changing the frequency of the AC voltage.

[0063] The humidity adjusting unit 76 is a processing unit that adjusts the relative humidity of the hydrogen gas and oxygen gas. For example, the humidity adjusting unit 76 adjusts the flow rate ratio of the dry hydrogen gas flowing through the pipe 23 to the wet hydrogen gas flowing through the pipe 27 by controlling the flow rate of the hydrogen gas flowing through each of the MFCs 16 and 17, thereby adjusting the relative humidity of the hydrogen gas supplied to the second gas supply jig 44.

[0064] In addition, the humidity adjustment unit 76 adjusts the flow rate ratio of the dry oxygen gas flowing through the pipe 25 to the wet oxygen gas flowing through the pipe 28 by controlling the flow rate of the oxygen gas flowing through each of the MFCs 18 and 19, and adjusts the relative humidity of the oxygen gas supplied to the first gas supply jig 40.

[0065] The flow rate control unit 77 is a processing unit that controls the total flow rate of each of the nitrogen gas, hydrogen gas, and oxygen gas supplied to the first gas supply jig 40 and the second gas supply jig 44 by controlling the flow rate of each MFC 15 to 19.

[0066] In this example, the humidity adjustment unit 76 and the flow control unit 77 are separate processing units, but the humidity adjustment unit 76 may be omitted by having the flow control unit 77 also perform the function of the humidity adjustment unit 76.

[0067] The storage unit 72 also stores evaluation result information 78 indicating the electrochemical characteristics measured by the characteristic measurement unit 75. For example, if the electrochemical characteristics are oxidation-reduction reaction characteristics of an electrode catalyst, the relationship between the sweep voltage and the reaction current is stored in the evaluation result information 78. If the electrochemical characteristics are impedance characteristics of an electrolyte membrane, the ratio of AC voltage to AC current is stored in the evaluation result information 78 as the impedance characteristics.

[0068] The communication unit 73 is an interface that connects the control device 7 to a network such as the Internet or a LAN (Local Area Network).

[0069] Next, the structures of the first to third holders 41 to 43 will be described in detail.

[0070] FIG. 3A is a top view of the first holder 41 according to this embodiment, and FIG. 3B is a cross-sectional view taken along line II in FIG. 3A.

[0071] 3A, the first holder 41 has a circular shape in top view. A circular first protrusion 41a is provided in the center of the first holder 41, and a plurality of first pins 41x are provided on the periphery.

[0072] 3B, the first holder 41 has a flat first main surface 41b on which the first protrusion 41a and the pins 41x are provided. Furthermore, a first outer circumferential groove 41c into which a robot hand (not shown) fits is formed on the outer periphery of the first holder 41.

[0073] The first holder 41 can be made by processing a metal material such as titanium or stainless steel.

[0074] The dimensions of each part of the first holder 41 are not particularly limited. In this example, the overall diameter φ1 of the first holder 41 is 20 mm or more and 200 mm or less, for example, 46 mm. The diameter φ2 of the first protrusion 41a is 5 mm or more and 180 mm or less, for example, 6 mm. The height h1 of the first protrusion 41a is 1 mm or more and 5 mm or less, for example, 2.5 mm.

[0075] FIG. 4A is an enlarged top view of the first protrusion 41a, and FIG. 4B is a cross-sectional view taken along line II-II in FIG. 4A.

[0076] As shown in FIG. 4A , a first recess 41d having a circular shape in a top view is formed in the top surface of the first protrusion 41a. The diameter φ3 of the first recess 41d is not particularly limited, but in this example, it is set to 3 mm or more and 179 mm or less, e.g., 5 mm. A first flow channel 41e having a spiral shape is formed in the bottom surface of the first recess 41d. One end of the first flow channel 41e is located at the center of the first recess 41d, and the other end is located on the periphery of the first recess 41d.

[0077] 4B , a first sample 61, which is a candidate material for the anode electrode catalyst, is fitted into the first recess 41 d. The material of the first sample 61 is not particularly limited. For example, the material of the first sample 61 may be any of Pt, a Pt alloy, a noble metal other than Pt, and a non-noble metal.

[0078] The first sample 61 is disk-shaped, and the depth of the first recess 41d is shallower than the thickness of the first sample 61. As a result, the surface of the first sample 61 protrudes from the first protrusion 41a by a difference Δz1 between the thickness of the first sample 61 and the depth of the first recess 41d. In this example, the depth of the first recess 41d is 0.01 mm or more and 0.4 mm or less, for example, 0.1 mm, and the thickness of the first sample 61 is 0.19 mm or more and 0.2 mm or less.

[0079] The first holder 41 is also formed with a first supply hole 41g connected to one end of the spiral-shaped first flow channel 41e and a first discharge hole 41h connected to the other end of the first flow channel 41e. The dimensions of the first flow channel 41e are not particularly limited. For example, the depth of the first flow channel 41e is 0.01 mm to 1.0 mm, e.g., 0.5 mm, and the width of the first flow channel 41e is 0.01 mm to 2.0 mm, e.g., 0.4 mm. The distance between two adjacent first flow channel 41e in a cross-sectional view is 0.01 mm to 2.0 mm, e.g., 0.2 mm.

[0080] The space defined by the first sample 61 and the first flow channel 41e functions as an oxygen flow channel through which oxygen flows, and oxygen gas can be supplied to the oxygen flow channel from the first supply hole 41g along the arrow A1. The oxygen gas is supplied to the first sample 61 while swirling along the first flow channel 41e, and excess oxygen gas is discharged from the first discharge hole 41h along the arrow B1.

[0081] In this manner, by forming the first flow channel 41e in a spiral shape, oxygen gas can be supplied uniformly to the first sample 61 in this embodiment.

[0082] 5A is a top view of the second holder 42, and FIG. 5B is a cross-sectional view taken along line III-III in FIG. 5A.

[0083] 5A, the second holder 42 is circular in top view, and has a circular recess 42a and a ring-shaped ring groove 42e formed concentrically in its center. The recess 42a is a recess into which an electrolyte membrane to be evaluated is fitted, as described below. The ring groove 42e is a groove into which an O-ring (not shown) is fitted.

[0084] Furthermore, a plurality of first holes 42y and a plurality of second holes 42z are formed outside the ring groove 42e when viewed from above.

[0085] 5B, the second holder 42 has a flat second main surface 42b and a flat third main surface 42c facing each other. The recess 42a, the ring groove 42e, and the second hole 42z are all formed on the third main surface 42c.

[0086] On the other hand, a ring groove 42f and a first hole 42y are formed in the second main surface 42b. The ring groove 42f is ring-shaped like the aforementioned ring groove 42e and is a groove into which an O-ring (not shown) is attached. The first hole 42y has a shape that allows the aforementioned first pin 41x (see FIGS. 3A and 3B) to fit.

[0087] Furthermore, a hole 42g into which the aforementioned protrusion 41a (see FIGS. 3A and 3B) is fitted is formed in the second main surface 42b, and the aforementioned recess 42a is formed in the third main surface 42c around the hole 42g.

[0088] The second holder 42 is made of insulating resin such as fluororesin or high density polyethylene, and is produced by, for example, injection molding.

[0089] Although the dimensions of each part of the second holder 42 are not particularly limited, in this example, the overall diameter φ4 of the second holder 42 is 20 mm or more and 200 mm or less, for example, 46 mm. The diameter φ5 of the recess 42a is 8 mm or more and 180 mm or less, for example, 12 mm. The diameter φ6 of the hole 42g is 5 mm or more and 180 mm or less, for example, 6 mm.

[0090] The depth d1 of the recess 42a is 2.5 mm to 4.0 mm, for example, 4 mm, and the depth d2 of the hole 42g is 1 mm to 2.5 mm, for example, 1 mm.

[0091] Furthermore, the width W of the ring grooves 42e, 42f is 1 mm or more and 2.5 mm or less, for example, 1.5 mm, and the depth is 0.5 mm or more and 2.0 mm or less, for example, 1.3 mm.

[0092] 6A and 6B are cross-sectional views showing the O-ring being attached to the second holder 42. FIG.

[0093] 6A, a tester first aligns the ring groove 42e with the O-ring 47, and then aligns the ring groove 42f with the O-ring 48. Each of the O-rings 47 and 48 is an example of a sealing member, and is a rubber ring large enough to fit into each of the grooves 42e and 42f by elastic deformation.

[0094] 6B, the tester fits the O-ring 47 into the ring groove 42e, and then fits the O-ring 48 into the ring groove 42f. This completes the attachment of the O-rings 47 and 48 to the second holder 42.

[0095] 7A and 7B are cross-sectional views showing the electrolyte membrane being fitted into the second holder 42. FIG.

[0096] First, as shown in FIG. 7A , first to third spacers 51 to 53 and an electrolyte membrane 55 to be evaluated are prepared. The material of the electrolyte membrane 55 is not particularly limited, and a proton exchange membrane (PEM) or an anion exchange membrane (AEM) may be used as the electrolyte membrane 55. Examples of such electrolyte membranes include fluorine-based electrolyte membranes and hydrocarbon-based electrolyte membranes. Alternatively, a Nafion membrane or a support membrane may be provided on the electrolyte membrane 55. Polymer membranes such as proton exchange membranes and anion exchange membranes have side chains that conduct ions, and humidification allows them to conduct hydrated protons and hydrated OH ions. Alternatively, a polymer membrane that conducts ions without hydration or humidification may be used as the electrolyte membrane 55.

[0097] The first to third spacers 51 to 53 and the electrolyte membrane 55 are all circular in top view, and have a diameter that is approximately the same as or slightly smaller than the diameter φ5 of the recess 42a (see FIG. 5B).

[0098] Furthermore, openings 51 a, 52 a, and 53 a are formed in the first to third spacers 51 to 53, respectively. The openings 51 a, 52 a, and 53 a are all circular in top view, and are sized to overlap with the aforementioned hole 42 g when the first to third spacers 51 to 53 are fitted into the recess 42 a with their respective circumferences aligned. Here, the diameters of the openings 51 a, 52 a, and 53 a are set to be approximately the same as or slightly larger than the diameter φ6 of the hole 42 g (see FIG. 5B ).

[0099] Each of the spacers 51 to 53 is made by injection molding an insulating resin such as fluororesin or high density polyethylene.

[0100] 7B , the first spacer 51, the electrolyte membrane 55, the second spacer 52, and the third spacer 53 are fitted into the recess 42a in this order. As a result, the electrolyte membrane 55 is held in the second holder 52 while being sandwiched between the first spacer 51 and the second spacer 52. In this state, no step is formed between the third main surface 42c of the second holder 42 and the surface 53x of the third spacer 53, and the third main surface 42c and the surface 53x form a continuous, flat surface. This completes the fitting of the electrolyte membrane into the second holder 42.

[0101] Next, a description will be given of the third holder 43. As will be described below, the third holder 43 has a structure in which the first holder 41 (FIGS. 3A and 3B) is turned upside down.

[0102] 8A is a top view of the third holder 43, and FIG. 8B is a cross-sectional view taken along line IV-IV in FIG. 8A.

[0103] 8A, the third holder 43 has a circular shape in top view. A circular second protrusion 43a is provided in the center of the first holder 43, and a plurality of second pins 43x are provided on the periphery.

[0104] 8B, the third holder 43 has a flat fourth main surface 43b, on which the second protrusion 43a and the pins 43x are provided. Furthermore, a third outer circumferential groove 43c into which a robot hand (not shown) fits is formed on the outer periphery of the third holder 43.

[0105] Similar to the first holder 41, the third holder 43 can also be fabricated by processing a metal material such as titanium or stainless steel.

[0106] The dimensions of each part of the third holder 43 are not particularly limited. In this example, the overall diameter φ7 of the third holder 43 is 20 mm or more and 200 mm or less, for example, 46 mm. The diameter φ8 of the second protrusion 43a is 5 mm or more and 180 mm or less, for example, 6 mm. The height h2 of the second protrusion 43a is 1 mm or more and 5 mm or less, for example, 2.5 mm.

[0107] 9A is an enlarged top view of the second protrusion 43a, and FIG. 9B is a cross-sectional view taken along line VV in FIG. 9A.

[0108] As shown in FIG. 9A , a second recess 43d having a circular shape in a top view is formed in the top surface of the second protrusion 43a. The diameter φ9 of the second recess 43d is not particularly limited, but in this example, it is set to 3 mm or more and 179 mm or less, for example, 5 mm. A second flow path groove 43e having a spiral shape is formed in the bottom surface of the second recess 43d. One end of the second flow path groove 43e is located at the center of the second recess 43d, and the other end is located on the periphery of the second recess 43d.

[0109] As shown in FIG. 9B , a second sample 62, which is a candidate material for the cathode electrode catalyst, is fitted into the second recess 43d. The structure of the second sample 62 is not particularly limited. For example, the second sample 62 may be a gas diffusion layer (GDL) with a microporous layer (MPL) (not shown), with an electrode catalyst deposited thereon. The electrode catalyst may be deposited on the gas diffusion layer by a dry method such as sputtering or arc plasma. Alternatively, the electrode catalyst may be deposited by applying a catalyst dispersion liquid on the gas diffusion layer and drying it. An example of a candidate material for the cathode electrode catalyst is PtCo nanoparticles.

[0110] Like the first sample 61 (see FIG. 4B ), the second sample 62 is also disk-shaped. The depth of the second recess 43d is shallower than the thickness of the second sample 62. Therefore, the surface of the second sample 62 protrudes from the second convex portion 43a by a difference Δz2 between the thickness of the second sample 62 and the depth of the second recess 43d. In this example, the depth of the second recess 43d is 0.01 mm or more and 0.4 mm or less, for example, 0.1 mm, and the thickness of the second sample 62 is 0.19 mm or more and 0.2 mm or less.

[0111] The second holder 43 is also formed with a second supply hole 43g connected to one end of a spiral-shaped second flow channel 43e and a second discharge hole 43h connected to the other end of the second flow channel 43e. The dimensions of the second flow channel 43e are similar to those of the first flow channel 41e (see FIG. 4B ). For example, the depth of the second flow channel 43e is 0.01 mm to 1.0 mm, e.g., 0.5 mm, and the width of the second flow channel 43e is 0.01 mm to 2.0 mm, e.g., 0.4 mm. The distance between two adjacent second flow channel 43e in a cross-sectional view is 0.01 mm to 2.0 mm, e.g., 0.2 mm.

[0112] The space defined by the second sample 62 and the second flow channel 43e functions as a hydrogen flow channel through which hydrogen flows, and hydrogen gas can be supplied to the hydrogen flow channel from the second supply hole 43g along the arrow A2. The hydrogen gas is supplied to the second sample 62 while swirling along the second flow channel 43e, and excess hydrogen gas is discharged from the second discharge hole 43h along the arrow B2.

[0113] In this manner, by forming the second flow channel 42e in a spiral shape, hydrogen gas can be supplied uniformly to the second sample 62 in this embodiment.

[0114] Next, a method for stacking the first to third holders 41 to 43 will be described.

[0115] FIG. 10 is a cross-sectional view for explaining a method for stacking the first to third holders 41 to 43.

[0116] First, a robot (not shown) grasps the first holder 41 by fitting the robot hand 59 into the first outer groove 41c, and places the first holder 41 on the first supply jig 40 with the first main surface 41b facing up.

[0117] Next, the robot grips the second holder 42 by fitting the robot hand 59 into the second outer peripheral groove 42c, and faces the second main surface 42b of the second holder 42 toward the first main surface 41b. As a result, the first protrusion 41a of the first holder 41 protrudes from the first main surface 41b toward the electrolyte membrane 55. Then, the robot lowers the second holder 42 so that the first protrusion 41a enters the hole 42g and the opening 51a, and places the second holder 42 on the first holder 41.

[0118] Next, the robot grips the third holder 43 by fitting the robot hand 59 into the third outer peripheral groove 43c. Then, the robot positions the fourth main surface 43b of the third holder 43 facing the third main surface 42c of the second holder 42. As a result, the second protrusion 43a of the third holder 43 protrudes from the fourth main surface 43b toward the electrolyte membrane 55. Thereafter, the robot lowers the third holder 43 so that the second protrusion 43a enters each of the openings 52a, 53a, and places the third holder 43 on the second holder 42.

[0119] In this way, the robot can automatically stack the first to third holders 41 to 43. Note that instead of using the robot, a tester may manually stack the holders 41 to 43.

[0120] Figure 11 is a cross-sectional view of each of the holders 41 to 43 stacked in this manner. As shown in Figure 11, in this example, the first holder 41 and the second holder 42 can be aligned by fitting the first pin 41x into the first hole 42y. Although not shown in the cross section of Figure 11, the second holder 42 and the third holder 43 can be aligned in a similar manner by fitting the second pin 43x into the second hole 42z.

[0121] Furthermore, because the O-rings 48 are in close contact with the first main surface 41 b and the second main surface 42 b, it is possible to prevent outside air from reaching the first sample 61 (see FIG. 4B ) and the electrolyte membrane 55 through the gaps between the main surfaces 41 b and 42 b, thereby sealing the first sample 61 and the electrolyte membrane 55. Similarly, because the O-rings 47 are in close contact with the third main surface 42 c and the fourth main surface 43 b, it is possible to prevent outside air from reaching the second sample 62 (see FIG. 9B ) and the electrolyte membrane 55 through the gaps between the main surfaces 42 c and 43 b, thereby sealing the second sample 62 and the electrolyte membrane 55.

[0122] 12A and 12B are schematic diagrams showing how the holders 41 to 43 stacked in this manner are pressed together.

[0123] First, as shown in FIG. 12A, the pressure control unit 74 (see FIG. 2) lowers the load cell 4a toward each of the holders 41 to 43 stacked as described above.

[0124] 12B , the pressure control unit 74 continues to lower the load cell 4a, and the second gas supply jig 44 abuts against the third holder 43. The pressure control unit 74 then further lowers the load cell 4a, thereby applying a force F to each of the sample holders 41 to 43 in a direction that reduces the spacing between them. In this embodiment, the electrochemical characteristics of the electrolyte membrane 55 and each of the samples 61 and 62 are measured in this state.

[0125] FIG. 13 is an enlarged cross-sectional view of each of the holders 41 to 43 when measuring the electrochemical characteristics.

[0126] As shown in FIG. 13 , when the holders 41 to 43 are pressed with the force F, the lower and upper surfaces of the electrolyte membrane 55 come into contact with the surfaces of the samples 61 and 62. The first to third spacers 51 to 53 function to reliably bring the electrolyte membrane 55 into contact with the samples 61 and 62 by adjusting their respective thicknesses. For example, if the lower surface of the electrolyte membrane 55 is spaced apart from the first sample 61, the first spacer 51 can be made thinner to bring the lower surface of the electrolyte membrane 55 into contact with the first sample 61. Similarly, if the upper surface of the electrolyte membrane 55 is spaced apart from the second sample 62, the second spacer 52 can be made thinner to bring the upper surface of the electrolyte membrane 55 into contact with the first sample 62.

[0127] It is preferable to use the first spacer 51 and the second spacer 52 as the same part having the same dimensions and material in order to reduce the manufacturing cost of the evaluation device 1. In this case, the thickness of the third spacer 53 can be adjusted so that the upper surface of the electrolyte membrane 55 comes into contact with the first sample 62.

[0128] 4B , the surface of the first sample 61 protrudes from the first protrusion 41 a by Δz1, which allows the first sample 61 to elastically deform by Δz1. Therefore, when the first sample 61 is pressed against the electrolyte membrane 55, the first sample 61 elastically deforms, and the elastic force causes the surface of the first sample 61 to be pressed uniformly against the electrolyte membrane 55, thereby preventing pressure unevenness from occurring on the surface.

[0129] 9B , the surface of the second sample 62 protrudes from the second convex portion 43 a by Δz2, which provides a margin for elastic deformation of the second sample 62. As a result, the surface of the second sample 62 is pressed uniformly against the electrolyte membrane 55, thereby preventing uneven pressure from occurring on the surface.

[0130] The pressure measured by the pressure sensor 8 (see FIG. 1) is equal to the pressure with which the samples 61, 62 are pressed against the electrolyte membrane 55. When measuring the electrochemical characteristics, the pressure is used to reliably bring the samples 61, 62 into contact with the electrolyte membrane 55, thereby allowing the samples 61, 62 and the electrolyte membrane 55 to function as a test solid polymer fuel cell FC.

[0131] Oxygen gas and hydrogen gas are supplied to the fuel cell FC from gas supply jigs 40 and 44, respectively.

[0132] For example, first gas supply jig 40 is formed with holes 40a and 40b that are connected to first supply hole 41g and first exhaust hole 41h of first holder 41. Hole 40a is connected to pipes 25 and 28 (see FIG. 1), and oxygen gas supplied from pipes 25 and 28 is guided from opening 40a to first supply hole 41g. Excess oxygen gas is guided from first exhaust hole 41h to hole 40b and then exhausted to the outside.

[0133] On the other hand, the second gas supply jig 44 is formed with holes 44a and 44b that are connected to the first supply hole 43g and the second exhaust hole 43h of the second holder 43, respectively. The hole 44a is connected to the pipes 23 and 27 (see FIG. 1), and hydrogen gas supplied from the pipes 23 and 27 is guided from the opening 44a to the second supply hole 43g. Excess hydrogen gas is guided from the second exhaust hole 43h to the hole 44b and then exhausted to the outside.

[0134] The electrochemical characteristics are measured based on a response signal output from the fuel cell FC in response to a characteristic measurement signal applied to the fuel cell FC. The characteristic measurement signal is applied from the load cell 4a to the second sample 62 via the metallic second gas supply jig 44 and the third holder 43. Alternatively, the characteristic measurement signal may be applied to the second holder 41 via the metallic first gas supply jig 40 and the first holder 41.

[0135] As described above, the second holder 42 and the first to third spacers 51 to 53 are all made of insulating resin, which prevents an electrical short circuit between the metallic first holder 41 and third holder 43, making it possible to apply a characteristic measurement signal to the fuel cell FC.

[0136] Next, an evaluation method according to this embodiment will be described. In the following example, a candidate material for the cathode electrode catalyst is searched for by material search using machine learning, and the candidate material is used for a second sample 62 to evaluate its electrochemical characteristics. In this case, platinum, whose various physical properties are known, is used as the material for the first anode sample 61. This makes it possible to extract and evaluate only the electrochemical characteristics of the second sample 62.

[0137] Fig. 14 is a flowchart showing an example of processing performed by the evaluation device 1. In the following, the description will be made with reference to Fig. 15 in addition to this flowchart.

[0138] FIG. 15 is a timing chart showing an example of processing performed by the evaluation device 1. In FIG. 15, "pressure" is the pressure value measured by the pressure sensor 8. Furthermore, "nitrogen gas," "hydrogen gas," and "oxygen gas" are the flow rates of the respective gases controlled by the flow rate control unit 77 (see FIG. 2). Furthermore, "characteristic measurement signal" is the characteristic measurement signal generated by the characteristic measurement unit 75. Here, when a characteristic measurement signal is generated, the "characteristic measurement signal" is shown at a high level, and when a characteristic measurement signal is not generated, the "characteristic measurement signal" is shown at a low level. Therefore, the height of the "characteristic measurement signal" in FIG. 15 does not necessarily indicate the value of the characteristic measurement signal.

[0139] 14, the robot places the holders 41 to 43 on the first gas supply jig 40, thereby setting the holders 41 to 43 in the evaluation device 1 (step S1). Note that instead of using the robot, the tester may manually set the holders 41 to 43.

[0140] Next, the pressure control unit 74 (see FIG. 2) applies pressure to the holders 41 to 43 by lowering the load cell 4a using a drive signal (step S2). １ Pressurization begins at and then increases.

[0141] Next, the pressure control unit 74 (see FIG. 2) determines whether the pressure measured by the pressure sensor 8 has reached a predetermined pressure (step S3). The predetermined pressure is a pressure that serves as a reference for determining whether evaluation of the fuel cell FC can begin, and is set in advance by the tester in the evaluation device 1. In the following, evaluation of the fuel cell FC is performed while maintaining a constant pressure, and the predetermined pressure in this case is selected by the tester from a range of, for example, 0.1 MPa or more and 0.4 MPa or less.

[0142] If it is determined that the predetermined pressure has not been reached (NO), the process returns to step S2, whereas if it is determined that the predetermined pressure has been reached (YES), the process proceeds to step S4.

[0143] In step S4, the flow rate control unit 77 (see FIG. 2) performs purging with nitrogen gas. For example, the flow rate control unit 77 opens the MFC 15 to supply nitrogen gas to the pipes 23 and 25 while blocking the flow of hydrogen gas and oxygen gas in the MFCs 16 to 19. This purges the pipes 23 and 25 and the inside of each holder 41 to 43 with nitrogen gas, and the air contained in each sample 61 and 62 is replaced with nitrogen. This prevents inaccurate measurement results of the electrochemical properties due to air contained in each sample 61.

[0144] In the example of FIG. 15, time t ２ After the pressure reaches a predetermined pressure at time t ２ From time t ３ Purging with nitrogen gas is performed during the period up to 100° C. The length of the purging period is not particularly limited, and may be, for example, about 1 to 5 minutes.

[0145] Next, the flow rate control unit 77 (see FIG. 2 ) starts supplying hydrogen gas and oxygen gas (step S5). For example, the flow rate control unit 77 controls the MFCs 16 and 17 to control the total flow rate of hydrogen gas supplied to the second gas supply jig 44 through the pipes 23 and 27. The flow rate control unit 77 controls the MFCs 18 and 19 to control the total flow rate of oxygen gas supplied to the first gas supply jig 40 through the pipes 25 and 28. The total flow rates of the respective gases are not particularly limited. For example, the total flow rate of hydrogen gas is 1 cc / min or more and 1000 cc / min or less, for example, 100 cc / min. The total flow rate of oxygen gas is 1 cc / min or more and 1000 cc / min or less, for example, 100 cc / min.

[0146] At the same time, the humidity adjusting unit 76 (see FIG. 2 ) adjusts the mixture ratio of dry hydrogen gas and wet hydrogen gas by controlling the flow rate of hydrogen gas flowing through each of the MFCs 16 and 17, thereby humidifying the hydrogen gas supplied to the second sample 62. Similarly, the humidity adjusting unit 76 adjusts the mixture ratio of dry oxygen gas and wet oxygen gas by controlling the flow rate of oxygen gas flowing through each of the MFCs 18 and 19, thereby humidifying the oxygen gas supplied to the first sample 61.

[0147] By supplying humidified hydrogen gas and oxygen gas in this manner, gases containing moisture are supplied to the electrolyte membrane 55 via the samples 61 and 62. As a result, the moisture causes the electrolyte membrane 55, such as a proton exchange membrane or an anion exchange membrane, to exhibit ionic conductivity, enabling the fuel cell FC (see FIG. 13 ) to generate electricity. As an example, the humidity adjustment unit 76 adjusts the relative humidity of the hydrogen gas to greater than 0% and less than 100%, for example, 50%, and the relative humidity of the oxygen gas to greater than 0% and less than 100%, for example, 50%. By adopting such relative humidities, the electrolyte membrane 55 can be moistened to a degree that enables ionic conduction. Note that if a polymer membrane that conducts ions without humidification is used as the electrolyte membrane 55, the humidity adjustment unit 76 (see FIG. 2 ) does not need to humidify the oxygen gas and hydrogen gas.

[0148] In the example of FIG. 15, time t ３The supply of hydrogen gas and the supply of oxygen gas are started at step 100. Note that the supply of hydrogen gas and the supply of oxygen gas may not be started simultaneously, but may be started at different times.

[0149] Next, the characteristic measurement unit 75 (see FIG. 2) waits for a predetermined time after starting the supply of hydrogen gas and oxygen gas (step S6). The predetermined waiting time is set to a time during which the electrolyte membrane 55 is sufficiently moistened by the humidified hydrogen gas and oxygen gas to exhibit ion conductivity, thereby enabling the fuel cell FC to generate sufficient power. As an example, the predetermined time is set to 0 to 60 minutes, for example, 10 minutes. In the example of FIG. 15, at time t ３ From time t ４ When a polymer membrane that conducts ions without humidification is used as the electrolyte membrane 55, and the oxygen gas and the hydrogen gas are not humidified, step S6 may be skipped.

[0150] Subsequently, after the predetermined time has elapsed, the characteristic measurement unit 75 (see FIG. 2) measures the electrochemical characteristics of the second sample 62 and stores evaluation result information 78 indicating the measurement results in the memory unit 72 (step S7). For example, the characteristic measurement unit 75 outputs the sweep voltage of the LSV or CV to the load cell 4a as a characteristic measurement signal, and acquires the reaction current of the fuel cell FC in response to the characteristic measurement signal as a response signal. The characteristic measurement unit 75 then stores the relationship between the characteristic measurement signal and the response signal in the memory unit 72 as evaluation result information 78 indicating the oxidation-reduction reaction characteristics of the second sample 62.

[0151] In the example of FIG. 15, time t ４ Measurement of the redox reaction characteristics is started at time t ５ This shows the case where the measurement is terminated at

[0152] In this embodiment, the pressure measured by the pressure sensor 8 (see FIG. 1) is maintained at a constant value, so that the electrochemical characteristics can be measured at that pressure.

[0153] However, this embodiment is not limited to this, and the characteristic measuring unit 75 may measure the electrochemical characteristics while the pressure control unit 74 changes the pressure, thereby making it possible to measure the electrochemical characteristics for each different pressure.

[0154] Furthermore, instead of controlling the pressure in this manner, the electrochemical characteristics may be measured while controlling the spacing between the holders 41 to 43. For example, the pressure control unit 74 may use a drive signal to control the lifting distance of the load cell 4a, thereby maintaining a constant spacing between the first holder 41 and the second holder 42, or between the second holder 42 and the third holder 43, and the characteristic measurement unit 75 may measure the electrochemical characteristics in this state. Even when a polymer electrolyte fuel cell is used with the spacing between its components maintained constant, the stress acting on the electrode catalyst and electrolyte membrane relaxes over time. Therefore, by maintaining the spacing constant as described above and measuring the electrochemical characteristics, it is possible to perform an evaluation that simulates pressure relaxation under actual use.

[0155] Next, the flow rate control unit 77 (see FIG. 2) stops the supply of hydrogen gas and oxygen gas (step S8), and performs purging with nitrogen gas in the same manner as in step S4 (step S9). ６ At time t ６ From time t ７ Nitrogen gas purging is performed during the period up to .

[0156] Next, the pressure control unit 74 raises the load cell 4a by a drive signal (step S10), and the robot removes each of the holders 41 to 43 from the evaluation device 1 (step S11). Note that instead of using the robot, the tester may manually remove each of the holders 41 to 43. In the example of FIG. 15, at time t ７ From time t ８ During the period from time t ８ After that, each of the holders 41 to 43 is removed from the evaluation device 1 .

[0157] This completes the basic processing performed by the evaluation device 1. In the above example, the electrochemical characteristics of a candidate material for the cathode electrode catalyst were evaluated using the second sample 62, but the electrochemical characteristics of a candidate material for the anode electrode catalyst may also be evaluated using the first sample 61. Furthermore, instead of the electrochemical characteristics of each of the samples 61 and 62, the electrochemical characteristics of the electrolyte membrane 55 may also be evaluated.

[0158] 13 , the pressurizing unit 4 presses each of the samples 61, 62 against the electrolyte membrane 55 with a force F in a direction that reduces the gap between each of the holders 41 to 43. This eliminates the need for a tester to tighten the fuel cell FC with a torque wrench in order to press each of the samples 61, 62 against the electrolyte membrane 55, and the evaluation device 1 can automatically measure the electrochemical characteristics of the electrolyte membrane 55 and each of the samples 61, 62.

[0159] Furthermore, since it is possible to eliminate the personal dependency of the pressure acting on the fuel cell FC, which may differ depending on the tester, it is possible to obtain the same measurement results for the same samples 61, 62 and the same electrolyte membrane 55. As a result, it becomes easy to build a database showing the electrochemical characteristics of each electrode catalyst and electrolyte membrane, and data-driven search using the database becomes possible.

[0160] Moreover, in this embodiment, hydrogen gas or oxygen gas is supplied during measurement, rather than supplying a solution to the electrolyte membrane 55 or the samples 61 and 62. Therefore, there is no need to optimize test parameters such as the conditions for applying an electrode catalyst, as in electrochemical tests that use a solution, and the electrochemical characteristics can be evaluated in a short time.

[0161] <Hardware Configuration> Next, the hardware configuration of the control device 7 will be described.

[0162] Fig. 16 is an example of a hardware configuration diagram of the control device 7 according to this embodiment. As shown in Fig. 16, the control device 7 has a storage device 101, a memory 102, a processor 103, a communication interface 104, and a medium reader 105. These components are connected to each other by a bus 106.

[0163] Of these, the storage device 101 is a non-volatile storage such as a hard disk drive (HDD) or a solid state drive (SSD), and stores a control program 110 according to this embodiment.

[0164] The control program 110 may be recorded on a computer-readable recording medium 111 and the processor 103 may read the control program 110 via the medium reading device 105 .

[0165] Such recording medium 111 may be, for example, a physically portable recording medium such as a CD-ROM (Compact Disc-Read Only Memory), a DVD (Digital Versatile Disc), or a USB (Universal Serial Bus) memory. Also, a semiconductor memory such as a flash memory or a hard disk drive may be used as recording medium 111. These recording media 111 are not temporary media such as carrier waves that do not have a physical form.

[0166] Furthermore, the control program 110 may be stored in a device connected to a public line, the Internet, a LAN, etc. In this case, the processor 103 may read and execute the control program 110.

[0167] On the other hand, the memory 102 is hardware that temporarily stores data, such as a dynamic random access memory (DRAM). The processor 103 is hardware such as a central processing unit (CPU) or a graphical processing unit (GPU) that controls each part of the control device 7. The processor 103 also executes the control program 110 in cooperation with the memory 102.

[0168] In this way, the memory 102 and the processor 103 cooperate to execute the control program 110, thereby realizing the control unit 71 (see FIG. 2).

[0169] The storage unit 72 (see FIG. 2) is realized by the storage device 101 and the memory 102 .

[0170] Furthermore, the communication interface 104 is hardware such as a network interface card (NIC) for connecting the control device 7 to a network. The communication interface 104 realizes the communication unit 73 (see FIG. 2).

[0171] The medium reading device 105 is hardware such as a CD drive, a DVD drive, or a USB interface for reading the recording medium 111 .

[0172] Although the present embodiment has been described in detail above, the present embodiment is not limited to the above. For example, although an electrode catalyst for a fuel cell was used in each of the samples 61 and 62 in the above, an electrode catalyst for a water splitting device may be used in each of the samples 61 and 62. Similarly, an electrolyte membrane from a water splitting device may be used as the electrolyte membrane 55.

[0173] Furthermore, while the first flow channel 41e is spirally shaped in the example of FIG. 4A, it may also be shaped as shown in FIGS. 17A to 17C. FIGS. 17A to 17C are plan views of flow channel variations. FIGS. 17A and 17B show an example in which the first flow channel 41e extending from the first supply hole 41g to the first discharge hole 41h is formed in a serpentine shape. FIG. 17C also shows an example in which multiple parallel first flow channel 41e are provided between the first supply hole 41g and the first discharge hole 41h. In all of the examples shown in FIGS. 17A to 17C, oxygen gas can be uniformly supplied to the first sample 61, similar to the spiral shape. Similarly, by forming the second flow channel 43e in the shape shown in FIGS. 17A to 17C, hydrogen gas can be uniformly supplied to the second sample 62.

[0174] (Second embodiment) In this embodiment, an evaluation device is described that can bring the lower surface of the electrolyte membrane 55 into uniform contact with the surface of the first sample 61 across its surface, and can bring the upper surface of the electrolyte membrane 55 into uniform contact with the surface of the second sample 62 across its surface.

[0175] Figure 18A is a top view of the second holder 42 according to this embodiment, and Figure 18B is a cross-sectional view taken along line VI-VI in Figure 18A. In these figures, the same elements as those described in the first embodiment are denoted by the same reference numerals as those described in the first embodiment, and their description will be omitted below. This also applies to Figures 19A to 25 described below.

[0176] As shown in FIG. 18A, the second holder 42 according to this embodiment is circular in top view, similar to the first embodiment, and has a circular through-hole 42j formed in the center thereof.

[0177] 18B , the through-hole 42j is formed to extend from the second main surface 42b to the third main surface 42c of the second holder 42. The diameter φ10 of the through-hole 42j is not particularly limited, but in this example, φ10 is set to 12 mm or more and 24 mm or less, for example, 18 mm.

[0178] Furthermore, the material of the second holder 42 according to this embodiment is not particularly limited, but it is preferable to form the second holder 42 from PEEK (polyetheretherketoneketone) or PPS (polyphenylene sulfide), which have excellent wear resistance and mechanical strength.

[0179] 19A is a top view of the first spacer 81 fitted into the through-hole 42j, and FIG. 19B is a cross-sectional view taken along line VII-VII in FIG. 19A.

[0180] 19A, the first spacer 81 is circular in top view, and a first outer peripheral step 81b is formed on its periphery. Furthermore, a circular first opening 81a is formed in the center of the first spacer 81. The first opening 81a is formed to a size that allows the first protrusion 41a (see FIG. 3B) of the first holder 41 to fit therein, and a first inner peripheral step 81c is formed on its periphery.

[0181] 19B, the first spacer 81 has a fifth main surface 81x and a sixth main surface 81y that face each other. The steps 81b and 81c described above are formed on the sixth main surface 81y.

[0182] The diameter φ11 of the first spacer 81 is not particularly limited as long as the first spacer 81 can fit into the through-hole 42j. As an example, the diameter φ11 may be set to a value that is 100 μm or more and 500 μm or less smaller than the diameter φ10 of the through-hole 42j (see FIG. 18B ).

[0183] Furthermore, the diameter φ12 of the first opening 81a is not particularly limited as long as it is a diameter that fits the first protrusion 41a (see FIG. 3B) of the first holder 41. As an example, the diameter φ12 may be set to a value that is 50 μm or more and 200 μm or less larger than the diameter φ2 (see FIG. 3B) of the first protrusion 41a.

[0184] 20A is a top view of a second spacer 82 that is fitted into the through-hole 42j together with the first spacer 81, and FIG. 20B is a cross-sectional view taken along line VIII-VIII in FIG. 20A.

[0185] 20A, the second spacer 82 is circular in top view, and a second outer peripheral step 82b is formed on its periphery. Furthermore, a circular second opening 82a is formed in the center of the second spacer 82. The second opening 82a is formed to a size that allows the second protrusion 43a (see FIG. 8B) of the third holder 43 to fit therein, and a second inner peripheral step 82c is formed on its periphery.

[0186] 20B, the second spacer 82 has seventh and eighth main surfaces 82x and 82y that face each other. The steps 82b and 82c are formed on the eighth main surface 82y.

[0187] As with the first spacer 82, the diameter φ13 of the second spacer 82 is not particularly limited as long as the second spacer 82 can fit into the through-hole 42j (see FIG. 18A). As an example, the diameter φ13 can be the same value as the diameter φ11 of the first spacer 81 (see FIG. 19B).

[0188] Furthermore, the diameter φ14 of the second opening 82a is not particularly limited as long as it is a diameter that fits the second protrusion 43a (see FIG. 8B) of the third holder 43. As an example, the diameter φ14 may be the same value as the diameter φ12 of the first opening 81a (see FIG. 19B).

[0189] Next, a method for fitting the spacers 81 and 82 into the through holes 42j of the second holder 42 will be described.

[0190] 21A and 21B, and 22A and 22B are cross-sectional views showing how the spacers 81 and 82 are fitted into the through-holes 42j of the second holder 42. Each of the following steps is performed manually by an operator.

[0191] 21A , an O-ring 85 is fitted into the first outer peripheral step 81b of the first spacer 81, thereby attaching the O-ring 85 to the outer peripheral side surface 81p of the first spacer 81. Furthermore, an O-ring 86 is fitted into the first inner peripheral step 81c of the first spacer 81, thereby attaching the O-ring 86 to the inner peripheral side surface 81q of the first opening 81a. The O-ring 85 is an example of a first sealing member, and the O-ring 86 is an example of a second sealing member.

[0192] Similarly, an O-ring 87 is fitted into the second outer peripheral step 82b of the second spacer 82, thereby attaching the O-ring 87 to the outer peripheral side surface 82p of the second spacer 82. Furthermore, an O-ring 88 is fitted into the second inner peripheral step 82c of the second spacer 82, thereby attaching the O-ring 88 to the inner peripheral side surface 82q of the second opening 82a.

[0193] Thereafter, the spacers 81 and 82 are arranged above and below the electrolyte membrane 55. In this example, the sixth main surface 81x of the first spacer 81 faces the electrolyte membrane 55, and the eighth main surface 82x of the second spacer 82 faces the electrolyte membrane 55.

[0194] Next, as shown in FIG. 21B, the electrolyte membrane 55 is sandwiched between the spacers 81 and 82.

[0195] Subsequently, as shown in FIG. 22A, the spacers 81 and 82 and the electrolyte membrane 55 are disposed above the through-hole 42j of the second holder 42.

[0196] Next, as shown in FIG. 22B, the spacers 81 and 82 and the electrolyte membrane 55 are fitted into the through-holes 42j.

[0197] As a result of the above, the structure in which the spacers 81 and 82 are fitted into the through holes 42j of the second holder 42 is completed.

[0198] Next, a method for stacking the first to third holders 41 to 43 in this embodiment will be described.

[0199] FIG. 23 is a cross-sectional view for explaining a method of stacking the first to third holders 41 to 43 in this embodiment.

[0200] As shown in FIG. 23, in this embodiment, similarly to the first embodiment (FIG. 10), a robot (not shown) automatically stacks the holders 41 to 43 using a robot hand 59.

[0201] Fig. 24 is a cross-sectional view of the holders 41 to 43 stacked in this manner. As shown in Fig. 24, the first convex portion 41a fits into the first opening 81a of the first spacer 81, and the second convex portion 43a fits into the second opening 82a of the second spacer 82.

[0202] FIG. 25 is an enlarged cross-sectional view of each of the stacked holders 41 to 43.

[0203] As shown in Figure 25, the first sample 61 fitted to the top surface of the first convex portion 41a is in close contact with the lower surface of the electrolyte membrane 55, and the second sample 62 fitted to the top surface of the second convex portion 43a is in close contact with the upper surface of the electrolyte membrane 55, and each sample 61, 62 and the electrolyte membrane 55 form a fuel cell FC.

[0204] Furthermore, in this state, the O-rings 85 and 87 are in close contact with the inner peripheral side surface of the through-hole 42j. The O-ring 86 is in close contact with the outer peripheral side surface 41m of the first protrusion 41a, and the O-ring 88 is in close contact with the outer peripheral side surface 42m of the second protrusion 42a. Furthermore, the O-rings 85 and 86 are in close contact with the first main surface 41b of the first holder 41, and the O-rings 87 and 88 are in close contact with the fourth main surface of the third holder 43. By having the O-rings 85 to 88 in close contact with their respective surfaces in this manner, the fuel cell FC can be isolated from the outside air, and the electrolyte membrane 55 of the fuel cell FC can be prevented from being exposed to the outside air.

[0205] Furthermore, in this embodiment, there is a margin for slight movement of the spacers 81, 82 within the through-hole 42j, and therefore the electrolyte membrane 55 sandwiched between the spacers 81, 82 moves slightly in accordance with the movement of the spacers 81, 82. This allows the lower surface of the electrolyte membrane 55 to be brought into uniform contact with the surface of the first sample 61 across its surface, and the upper surface of the electrolyte membrane 55 to be brought into uniform contact with the surface of the second sample 62 across its surface.

[0206] It is possible to provide an evaluation device and an evaluation method that can perform evaluation automatically.

[0207] REFERENCE SIGNS LIST 1 Evaluation device 2 Base 3 Frame 4 Pressurizing unit 4a Load cell 4b Servo motor 8 Pressure sensor 11 Nitrogen gas supply source 12 Hydrogen gas supply source 13 Oxygen gas supply source 15-19 MFC 21-28 Piping 31 First bubbler 32 Second bubbler 40 First gas supply jig 41 First holder 41a First convex portion 41b First main surface 41c First peripheral groove 41d First recess 41e First flow path groove 41g First supply hole 41h First discharge hole 41x First pin 42 Second holder 42a Recess 42b Second main surface 42c Third main surface 42d Second peripheral groove 42e, 42f Ring groove 42g Hole 42y First hole 42z Second hole 43 Third holder 43a Second convex portion 43b Fourth main surface 43c Third outer peripheral groove 43d Second recess 43e Second flow path groove 43g Second supply hole 43h Second discharge hole 43x Second pin 44 Second gas supply jig 47, 48 O-ring 51 First spacer 51a First opening 52 Second spacer 52a Second opening 53 Third spacer 53a Third opening 55 Electrolyte membrane 61 First sample 62 Second sample 71 Control unit 72 Storage unit 73 Communication unit 74 Pressure control unit 75 Characteristics measurement unit 76 Humidity adjustment unit 77 Flow rate control unit 78 Evaluation result information 101 Storage device 102 Memory 103 Processor 104 Communication interface 105 Media reader 106 Bus 110 Control program 111 Recording medium

Claims

1. A first holder having a first supply hole for holding a first sample of the electrode catalyst and supplying a first gas to the first sample, A second holder that holds the electrolyte membrane, A pressurizing section that presses the electrolyte membrane against the first sample with a force in a direction that reduces the distance between the first holder and the second holder, A characteristic measuring unit for measuring the electrochemical properties of the first sample or the electrolyte membrane while the electrolyte membrane is pressed against the first sample and the first gas is supplied to the first sample, An evaluation device having the following features.

2. The system further includes a pressure sensor for measuring the pressure applied to the electrolyte membrane against the first sample. The characteristic measurement unit measures the electrochemical characteristics while the pressure is maintained at a constant value. The evaluation apparatus according to claim 1.

3. The system further includes a pressure sensor for measuring the pressure applied to the electrolyte membrane against the first sample. The characteristic measurement unit measures the electrochemical characteristics while changing the pressure. The evaluation apparatus according to claim 1.

4. The characteristic measurement unit measures the electrochemical characteristics while the distance between the first holder and the second holder is kept constant. The evaluation apparatus according to claim 1.

5. The evaluation apparatus according to claim 1, further comprising a humidifying unit for humidifying the first gas.

6. The characteristic measurement unit measures the electrochemical characteristics after a predetermined time has elapsed since supplying the humidified first gas to the first sample. The evaluation apparatus according to claim 5.

7. The system further includes a humidity control unit for adjusting the relative humidity of the first gas. The evaluation apparatus according to claim 5.

8. The first holder is, The first main surface and A protrusion extending from the first main surface toward the electrolyte membrane, The top surface of the protrusion has a recess into which the first sample is fitted, and which is shallower in depth than the thickness of the first sample. The evaluation apparatus according to claim 1.

9. The evaluation apparatus according to claim 8, wherein a groove connected to the first supply hole is formed on the bottom surface of the recess.

10. In a plan view, the grooves are formed in a spiral or meandering shape, or multiple grooves are formed in parallel. The evaluation apparatus according to claim 9.

11. A through hole is formed in the second holder. A first opening is formed into which the protrusion fits, and a first spacer is fitted into the through hole, It further comprises a second spacer that is fitted into the through hole, The electrolyte membrane is fitted into the through hole while being sandwiched between the first spacer and the second spacer. The evaluation apparatus according to claim 8.

12. The first spacer further comprises a first sealing member that is attached to the outer peripheral surface and is in close contact with the inner peripheral surface of the through hole. The evaluation apparatus according to claim 11.

13. The device further comprises a second sealing member that is attached to the inner circumferential surface of the first opening and is in close contact with the outer circumferential surface of the protrusion. The evaluation apparatus according to claim 11.

14. The second holder is, A second main surface opposite to the first main surface, A hole formed on the second main surface into which the protrusion fits, A recess formed around the hole into which the electrolyte membrane fits, The evaluation apparatus according to claim 8.

15. The present invention further comprises a sealing member provided around the protrusion, which adheres closely to the first main surface and the second main surface, thereby sealing the first sample and the electrolyte membrane. The evaluation apparatus according to claim 14.

16. A first opening is formed that overlaps the hole in a plan view, and a first spacer is fitted into the recess, It further comprises a second spacer that fits into the recess, The evaluation apparatus according to claim 14, wherein the electrolyte membrane is fitted into the recess while being sandwiched between the first spacer and the second spacer.

17. The evaluation apparatus according to claim 16, further comprising a third spacer provided on the second spacer and fitted into the recess.

18. The first holder further has a pin erected on the first main surface, A hole into which the pin fits is formed on the second main surface of the second holder. The evaluation apparatus according to claim 11.

19. The electrochemical characteristics are the oxidation-reduction reaction characteristics of the first sample, or the impedance characteristics of the electrolyte membrane. The evaluation apparatus according to claim 1.

20. The first holder and the second holder are detachably attached to the pressurized portion. The evaluation apparatus according to claim 1.

21. The device further comprises a third holder having a second supply hole for holding a second sample of the electrode catalyst and supplying a second gas to the second sample, The pressurizing section presses the electrolyte membrane against the second sample with a force in a direction that reduces the distance between the second holder and the third holder. The characteristic measurement unit measures the electrochemical properties of the first sample, the electrolyte membrane, and the second sample while the electrolyte membrane is pressed against the second sample and the second gas is supplied to the second sample. The evaluation apparatus according to any one of claims 1 to 20.

22. The electrolyte membrane is pressed against the first sample by applying a force in a direction that reduces the distance between the first holder, which holds the first sample of the electrode catalyst, and the second holder, which holds the electrolyte membrane. With the electrolyte membrane pressed against the first sample and the first gas supplied to the first sample, the electrochemical properties of the first sample or the electrolyte membrane are measured. An evaluation method performed by the control unit.

23. The evaluation method according to claim 22, wherein a humidified gas is supplied as the first gas.