Electrochemical cell, battery operating system, and battery operating method

Abstract

Provided are an electrochemical cell, a cell operation system, and a cell operation method. An anode supply body (62) of an electrochemical cell (24) has an inner side portion (74) and an outer side portion (76), wherein the inner side portion (74) is formed with first holes (80) having cross-sectional areas that increase as they approach a supply flow path (70); and the outer side portion (76) is located outside the inner side portion (74) and is formed with second holes (82) having cross-sectional areas that increase as they approach an electrolyte membrane (60). Accordingly, the decrease in hydrogen transport performance and energy efficiency due to stagnant water can be suppressed.

Description

TECHNICAL FIELD

[0001] The present application relates to an electrochemical cell including a structure in which a catalyst layer and a power supply are arranged on both sides of an electrolyte membrane having hydrogen ion conductivity. BACKGROUND

[0002] An electrochemical cell is used for a fuel cell, a water electrolysis device, or an electrochemical hydrogen pressure-rising device, etc. The electrochemical hydrogen pressure-rising device has an advantage that high-pressure hydrogen required for a fuel cell electric vehicle, etc. can be generated even if the number of electrochemical cells is one. In addition, the electrochemical hydrogen pressure-rising device has an advantage that it is small and has low operating noise compared to a mechanical hydrogen compressor.

[0003] In the electrochemical hydrogen pressure-rising device, a pressure difference of hydrogen acts on the electrolyte membrane. Therefore, a support member that supports the electrolyte membrane in a manner adjacent to the electrolyte membrane is sometimes provided in the electrochemical hydrogen pressure-rising device. For example, an electrochemical hydrogen pressure-rising device is disclosed in Japanese Patent Application Publication No. 2018-109221, which is configured by laminating a plurality of metal sheets having a vent hole to form an anode diffusion layer (support member). SUMMARY

[0004] In the electrolyte membrane having hydrogen ion conductivity, the resistance increases when the amount of moisture decreases. Therefore, water vapor is sometimes contained in hydrogen supplied to the electrochemical cell.

[0005] However, depending on the operating conditions of the electrochemical cell, the amount of moisture supplied to the electrolyte membrane by hydrogen is sometimes more than the amount of moisture consumed in the electrolyte membrane. In this case, there is a tendency that the moisture that returns from the cathode electrode side of the electrolyte membrane to the anode electrode side due to the pressure difference is retained as water condensed on the surface of the anode and the like.

[0006] When the moisture is retained on the surface of the anode and the like, the reaction area of the treatment target such as hydrogen and the catalyst layer decreases, and thus there is a problem that the transport performance of hydrogen and the energy efficiency decrease.

[0007] An object of the present application is to solve the above-described technical problem.

[0008] One aspect of the present application is an electrochemical cell having an electrolyte membrane, an anode power supply, a cathode power supply, and a supply flow path, wherein the anode power supply is laminated to one surface side of the electrolyte membrane; the cathode power supply is laminated to the other surface side of the electrolyte membrane; the supply flow path is provided on the surface side of the anode power supply opposite to the electrolyte membrane side, and a fluid for supplying the anode power supply flows therein; the anode power supply has an inner side portion and an outer side portion, wherein the inner side portion is formed with a first void having a cross-sectional area that increases toward the supply flow path; and the outer side portion is located outside the inner side portion and is formed with a second void having a cross-sectional area that increases toward the electrolyte membrane.

[0009] Another aspect of the present application is a battery operation system having the above-described electrochemical cell, a fluid supply device, a power supply device, a sensor, and a control device, wherein the fluid supply device supplies the fluid to the electrochemical cell; the power supply device applies a voltage between the anode power supply and the cathode power supply; the sensor detects an electrical state between the anode power supply and the cathode power supply; and the control device controls the power supply device to stop applying the voltage and controls the fluid supply device to increase the flow rate of the fluid flowing in the supply flow path when a value indicating the electrical state is greater than a predetermined threshold value.

[0010] Another aspect of the present application is a battery operation method for operating the above-described electrochemical cell, applying a voltage between the anode power supply and the cathode power supply, stopping applying the voltage when a value indicating an electrical state between the anode power supply and the cathode power supply is greater than a predetermined threshold value, and increasing the flow rate of a fluid flowing in the supply flow path.

[0011] In the above-described electrochemical cell, battery operation system, and battery operation method, the stagnant water stagnating on the anode side of the electrochemical cell is sucked out to the supply flow path by the negative pressure generated in the first void. As a result, the above-described electrochemical cell, battery operation system, and battery operation method can suppress the decrease in the hydrogen transport performance and the energy efficiency due to the stagnant water.

[0012] In addition, in the above-described electrochemical cell, battery operation system, and battery operation method, the stagnant water flows from the outer side portion of the electrochemical cell into the inner side portion by the negative pressure generated in the second void, and the moisture is made uniform in the surface of the interlayer or the like. As a result, the above-described electrochemical cell, battery operation system, and battery operation method can suppress the decrease in the hydrogen transport performance and the energy efficiency due to the drying of the electrolyte membrane.

[0013] The above-described objects, features, and advantages will be easily understood from the following description of the embodiments with reference to the attached drawings. Attached Figure Description

[0014] Figure 1 This is a schematic diagram illustrating the battery operating system of an implementation method.

[0015] Figure 2 It is a cross-sectional view showing the structure of the battery device.

[0016] Figure 3 It is a cross-sectional view showing the structure of an electrochemical cell.

[0017] Figure 4 This is a view of the electrochemical cell from the stacking direction.

[0018] Figure 5 It is a diagram showing the state of a fluid in an electrochemical cell.

[0019] Figure 6 It is a flowchart that shows the sequence of control processing.

[0020] Figure 7 It is a diagram showing the state of a fluid in an electrochemical cell after the stagnant water has been removed.

[0021] Figure 8 This is a diagram showing the increase in pressure of the generated fluid in an electrochemical cell after the removal of stagnant water. Detailed Implementation

[0022] Figure 1 This is a schematic diagram illustrating a battery operating system 10 according to an embodiment. The battery operating system 10 includes a fluid supply device 12, a battery device 14, a power supply device 16, and a control device 18.

[0023] The fluid supply device 12 is a device for supplying fluid to the battery device 14. In this embodiment, the fluid is hydrogen (hydrogen gas). Hydrogen gas contains water vapor. The fluid supply device 12 has a fluid supply source 20 and an inlet path 22. The inlet path 22 introduces the fluid output from the fluid supply source 20 into the battery device 14.

[0024] In this embodiment, the battery device 14 is an electrochemical hydrogen booster device that uses electricity to compress hydrogen through a hydrogen redox reaction. The battery device 14 includes an electrochemical cell 24, an inlet 26, a first outlet 28, and a second outlet 30. The electrochemical cell 24 is configured to perform an electrochemical reaction. The structure of the electrochemical cell 24 will be described later. The inlet path 22 of the fluid supply device 12 is connected to the inlet 26. Fluid flowing in the inlet path 22 flows into the battery device 14 from the inlet 26.

[0025] The fluid that has not been consumed by the electrochemical cell 24 among the fluid flowing in from the inlet port 26 is discharged to the first discharge port 28. The fluid supply device 12 can be connected to the first discharge port 28 via a return path 32. Thus, the fluid supply device 12 can supply the fluid flowing in from the first discharge port 28 via the return path 32 to the cell device 14 again.

[0026] The discharge flow path 34 is connected to the second discharge port 30. In the discharge flow path 34, a generated fluid generated by the electrochemical reaction of the electrochemical cell 24 flows. In addition, in the case of the present embodiment, the generated fluid is high-pressure hydrogen gas having a higher pressure than the hydrogen gas supplied to the cell device 14.

[0027] In the discharge flow path 34, a pressure regulating valve 36 that regulates the pressure of the generated fluid in the discharge flow path 34 is provided. The opening degree of the pressure regulating valve 36 is regulated by the control of the control device 18. In addition, the pressure regulating valve 36 can also be a back pressure valve that regulates the pressure of the generated fluid in such a manner that the pressure of the primary side (valve input side) is constant.

[0028] The power supply device 16 applies a voltage to the electrochemical cell 24 of the cell device 14. In the case where the cell device 14 has a plurality of electrochemical cells 24, the power supply device 16 applies a voltage to each of the electrochemical cells 24.

[0029] The control device 18 appropriately controls the fluid supply device 12, the power supply device 16, and the pressure regulating valve 36 in such a manner that the electrochemical reaction is performed in the electrochemical cell 24 or the plurality of electrochemical cells 24 of the cell device 14.

[0030] Figure 2 is a cross-sectional view that shows the structure of the cell device 14. In addition, Figure 2 is an example in the case where the cell device 14 has a plurality of electrochemical cells 24. The cell device 14 has a cell stack 38. The cell stack 38 has a plurality of electrochemical cells 24. These plurality of electrochemical cells 24 are stacked together.

[0031] A first end plate 40 is arranged at one end in the stacking direction of the cell stack 38, and a second end plate 42 is arranged at the other end in the stacking direction of the cell stack 38. The cell stack 38 is sandwiched by the first end plate 40 and the second end plate 42, and a prescribed fastening load is applied to the cell stack 38.

[0032] The first end plate 40 and the second end plate 42 are formed in a planar shape larger than the battery stack 38. A side wall 44 is provided so as to connect the outer peripheral portion of the first end plate 40 and the outer peripheral portion of the second end plate 42. The side wall 44 surrounds the outer peripheral portion of the battery stack 38. The internal space 44a in which the battery stack 38 is disposed is hermetically partitioned by the first end plate 40, the second end plate 42, and the side wall 44. The inlet port 26 is provided on the side wall 44. The first discharge port 28 is provided on the side wall 44 on the side opposite to the portion of the side wall 44 on which the inlet port 26 is provided.

[0033] The distribution flow path 46 is provided in the internal space 44a so as to communicate with the inlet port 26. As indicated by the arrow, the distribution flow path 46 guides the hydrogen gas introduced from the inlet port 26 toward the anode side of each of the electrochemical cells 24.

[0034] In addition, the collection flow path 48 is provided in the internal space 44a so as to communicate with the first discharge port 28. As indicated by the arrow, the collection flow path 48 guides the excess hydrogen gas that is not consumed by each of the electrochemical cells 24 toward the first discharge port 28.

[0035] The communication hole 50 is formed in the central portion of the battery stack 38 so as to penetrate in the stacking direction of the plurality of electrochemical cells 24. The communication hole 50 penetrates the plurality of electrochemical cells 24. The communication hole 50 communicates with the cathode side of each of the electrochemical cells 24. The communication hole 50 is connected to the second discharge port 30, so that the cathode side of each of the electrochemical cells 24 communicates with the second discharge port 30.

[0036] Figure 3 is a sectional view showing the structure of the electrochemical cell 24. The electrochemical cell 24 is sandwiched by a first separator 52 disposed on one end side (anode side) in the thickness direction (stacking direction) of the electrochemical cell 24 and a second separator 54 disposed on the other end side (cathode side). The first separator 52 and the second separator 54 are, for example, composed of a steel plate, a stainless steel plate, an aluminum plate, or a plated steel plate.

[0037] The electrochemical cell 24 has an electrolyte membrane 60, an anode power supply body 62, an anode catalyst layer 64, a cathode power supply body 66, and a cathode catalyst layer 68.

[0038] The electrolyte membrane 60 is, for example, a solid polymer electrolyte membrane (cation exchange membrane). The electrolyte membrane 60 can use an HC (hydrocarbon) type electrolyte in addition to a fluorine type electrolyte. As a specific example, the electrolyte membrane 60 can be a thin film containing water and perfluorosulfonic acid. The electrolyte membrane 60 can have a protective sheet (not shown) including a fibrous skeleton on the anode side.

[0039] The anode power supply body 62 is laminated on one surface side of the electrolyte membrane 60. Specifically, the anode power supply body 62 is laminated on a surface of the anode catalyst layer 64 on the opposite side from the electrolyte membrane 60. The anode power supply body 62 can be formed by overlapping a plurality of sheet-like members having a mesh shape and having electrical conductivity. Alternatively, the anode power supply body 62 can be formed by a plate-like member having electrical conductivity.

[0040] In the case of the present embodiment, the anode power supply body 62 has a two-layer structure including a power supply layer 62A and a support layer 62B. The power supply layer 62A is disposed on the electrolyte membrane 60 side. The power supply layer 62A is formed by overlapping a plurality of sheet-like members having a mesh shape and having electrical conductivity. The support layer 62B is disposed on a surface of the power supply layer 62A on the opposite side from the surface of the power supply layer 62A on the electrolyte membrane 60 side. The support layer 62B is formed by a plate-like member having electrical conductivity.

[0041] The anode catalyst layer 64 is disposed between the electrolyte membrane 60 and the anode power supply body 62. The anode catalyst layer 64 is joined to one surface of the electrolyte membrane 60. The anode catalyst layer 64 is composed of, for example, a carbon porous body on which catalyst particles of platinum or the like are supported.

[0042] The cathode power supply body 66 is laminated on the other surface side of the electrolyte membrane 60. Specifically, the cathode power supply body 66 is laminated on a surface of the cathode catalyst layer 68 on the opposite side from the electrolyte membrane 60. The cathode power supply body 66 can be formed by overlapping a plurality of sheet-like members having a mesh shape and having electrical conductivity. Alternatively, the cathode power supply body 66 can be formed by a plate-like member having electrical conductivity. Figure 3 In the case of the present embodiment, the cathode power supply body 66 is formed by overlapping a plurality of sheet-like members having a mesh shape and having electrical conductivity.

[0043] The cathode catalyst layer 68 is disposed between the electrolyte membrane 60 and the cathode power supply body 66. The cathode catalyst layer 68 is joined to the other surface of the electrolyte membrane 60. The cathode catalyst layer 68 is composed of, for example, a carbon porous body on which catalyst particles of platinum or the like are supported.

[0044] In the electrochemical cell 24, a supply flow path 70 is provided between the support layer 62B of the anode power supply body 62 and the first separator 52. The supply flow path 70 is in communication with the distribution flow path 46( Figure 2 ) and the collection flow path 48( Figure 2 ). The supply flow path 70 can also be a groove formed in a surface of the support layer 62B facing the first separator 52 or a surface of the first separator 52 facing the support layer 62B. Further, the support layer 62B has a contact portion in contact with the first separator 52. The electrochemical cell 24 is supported to the first separator 52 via the contact portion.

[0045] In the electrochemical cell 24, there is a discharge flow path portion 72 between the cathode current collector 66 and the second separator 54. The discharge flow path portion 72 communicates with the communication hole 50. The discharge flow path portion 72 can also be a groove formed in a surface of the cathode current collector 66 facing the second separator 54 or a surface of the second separator 54 facing the cathode current collector 66. Further, there is a contact site on the cathode current collector 66 that contacts the second separator 54.

[0046] Figure 4 is a stacking direction view of the electrochemical cell 24 as viewed from the stacking direction. The electrochemical cell 24 has an inner side portion 74 and an outer side portion 76. The outer side portion 76 is located on the outer side of the inner side portion 74.

[0047] The communication hole 50 is formed in the inner side portion 74. As shown in Figure 3 , the first void 80 is formed in the anode current collector 62 of the inner side portion 74. The cross-sectional area of the first void 80 increases as it approaches the supply flow path 70. On the other hand, as shown in Figure 3 , the second void 82 is formed in the anode current collector 62 of the outer side portion 76. The cross-sectional area of the second void 82 increases as it approaches the electrolyte membrane 60. The first void 80 and the second void 82 can also be formed in such a way as to penetrate one component. Alternatively, the first void 80 and the second void 82 can be formed by a plurality of sheets of different sizes that overlap.

[0048] As shown in Figure 3 , the first communication hole 84 that communicates with the first void 80 is formed in the anode catalyst layer 64 of the inner side portion 74. The first communication hole 84 can be formed in the anode catalyst layer 64 in such a way as to be continuous with the first void 80. Alternatively, the first communication hole 84 can be formed in the anode catalyst layer 64 in such a way as to be discontinuous with the first void 80. In the case where the first communication hole 84 is formed in the anode catalyst layer 64 in such a way as to be continuous with the first void 80, the cross-sectional area of the first communication hole 84 increases as it approaches the supply flow path 70. In this case, it is preferable that the inner wall of the first void 80 be continuous with the inner wall of the first communication hole 84. In Figure 3 , a case is shown in which the inner wall of the first void 80 is continuous with the inner wall of the first communication hole 84.

[0049] On the other hand, as shown in Figure 3As shown, the second communication hole 86 that communicates with the second void hole 82 is formed in the anode catalyst layer 64 of the outer portion 76. The second communication hole 86 can be formed in the anode catalyst layer 64 in a continuous manner with the second void hole 82. Alternatively, the second communication hole 86 can be formed in the anode catalyst layer 64 in a discontinuous manner with the second void hole 82. In the case where the second communication hole 86 is formed in the anode catalyst layer 64 in a continuous manner with the second void hole 82, the cross-sectional area of the second communication hole 86 increases as it approaches the electrolyte membrane 60. In this case, it is preferable that the inner wall of the second void hole 82 and the inner wall of the second communication hole 86 be continuous. In Figure 3 In the figure, a case where the inner wall of the second void hole 82 and the inner wall of the second communication hole 86 are continuous is shown.

[0050] Next, a cell operation method of operating the electrochemical cell 24 will be described. The cell operation method is executed by the control device 18. The control device 18 operates the electrochemical cell 24 to generate high-pressure hydrogen gas. That is, the control device 18 controls the power supply device 16 to apply a voltage between the anode current collector 62 and the cathode current collector 66 of the cell device 14. In addition, the control device 18 controls the fluid supply device 12 to supply hydrogen gas to the cell device 14. Furthermore, the control device 18 adjusts the opening degree of the pressure regulating valve 36 with respect to the discharge flow path 34.

[0051] The hydrogen gas supplied from the fluid supply device 12 to the cell device 14 flows into the distribution flow path 46 Figure 2 ) inside the cell device 14 from the introduction port 26 Figure 2 ). The hydrogen gas flowing into the distribution flow path 46 flows in the supply flow path 70 Figure 3 ) of the electrochemical cell 24.

[0052] Figure 5 is a figure showing the state of the fluid in the electrochemical cell 24. As shown by the arrows, a part of the hydrogen gas flowing in the supply flow path 70 reaches the anode catalyst layer 64 through the second void hole 82 and the second communication hole 86. In addition, as shown by the arrows, another part of the hydrogen gas flowing in the supply flow path 70 reaches the anode catalyst layer 64 through the first void hole 80 and the first communication hole 84. The hydrogen gas reaching the anode catalyst layer 64 is converted into protons (H + ions) by the catalytic action of the anode catalyst layer 64.

[0053] The protons are transported to the cathode catalyst layer 68 through the electrolyte membrane 60 in accordance with the voltage applied between the anode current collector 62 and the cathode current collector 66. The protons transported to the cathode catalyst layer 68 are converted into high-pressure hydrogen gas by the catalytic action of the cathode catalyst layer 68 through an electrochemical reaction. The converted high-pressure hydrogen gas is discharged to the discharge flow path portion 72 through the cathode current collector 66. The high-pressure hydrogen gas discharged to the discharge flow path portion 72 is discharged to the outside of the cell device 14 through the communication hole 50Figure 2 ) from the second discharge port 30 to the discharge flow path 34 Figure 1 ) flows out.

[0054] A part of the water vapor contained in the hydrogen is used for humidification of the electrolyte membrane 60. The remaining moisture of the electrolyte membrane 60 returns to the anode side due to a pressure gradient. The moisture that returns to the anode side has a tendency to be trapped in the interface between the electrolyte membrane 60 and the anode catalyst layer 64 or the interface between the anode catalyst layer 64 and the anode current collector 62, or the like. When trapped water is generated in the interface or the like, the hydrogen transport performance and the energy efficiency are degraded.

[0055] Therefore, in the control device 18 of the present embodiment, there is a control process for removing the trapped water. The control process is executed at the time of operation of the electrochemical cell 24 for generating high-pressure hydrogen gas. Figure 6 is a flowchart showing the sequence of the control process.

[0056] In step S1, the control device 18 measures the electrical state between the anode current collector 62 and the cathode current collector 66 in time series using the sensor 88 Figure 1 ) measures the electrical state between the anode current collector 62 and the cathode current collector 66. The sensor 88 detects the electrical state between the anode current collector 62 and the cathode current collector 66.

[0057] Further, in the case where the cell device 14 has a plurality of electrochemical cells 24, one sensor 88 is provided with respect to each of the plurality of electrochemical cells 24. In this case, the control device 18 measures the electrical state between the anode current collector 62 and the cathode current collector 66 of each electrochemical cell 24 using each sensor 88.

[0058] The sensor 88 is a sensor that detects the electrical state between the anode current collector 62 and the cathode current collector 66. Specifically, a voltage sensor or a current sensor can be cited. The electrical state measured by the control device 18 can be the voltage value V applied between the anode current collector 62 and the cathode current collector 66. In addition, the electrical state measured by the control device 18 can also be the current value I flowing between the anode current collector 62 and the cathode current collector 66. In the case of the present embodiment, the control device 18 measures the voltage value V applied between the anode current collector 62 and the cathode current collector 66. Further, even if the sensor 88 is a current sensor, the control device 18 can measure the voltage value V applied between the anode current collector 62 and the cathode current collector 66 from the signal output from the current sensor.

[0059] In step S2, the control device 18 compares the measured voltage value V with a prescribed threshold value. Here, in the case where the voltage value V is equal to or lower than the threshold value, the control device 18 returns to step S1. On the other hand, in the case where the voltage value V is greater than the prescribed threshold value, the control device 18 proceeds to step S3.

[0060] Further, in a case where the electrochemical cells 24 possessed by the battery device 14 are a plurality of electrochemical cells 24, when the electrochemical cells 24 whose voltage values V are greater than the threshold value exceed a prescribed number, the control device 18 proceeds to step S3.

[0061] In step S3, the control device 18 controls the pressure regulating valve 36 in such a manner that the opening degree of the pressure regulating valve 36 is reduced (the opening degree of the pressure regulating valve 36 is made smaller), and proceeds to step S4. By reducing the opening degree of the pressure regulating valve 36, the pressure of the high-pressure hydrogen gas generated at the cathode catalyst layer 68 (the force for pressing the electrochemical cell 24 toward the anode side) is increased.

[0062] In step S4, the control device 18 controls the power supply device 16 in such a manner that the voltage applied between the anode current collector 62 and the cathode current collector 66 is stopped, and proceeds to step S5.

[0063] In step S5, the control device 18 controls the fluid supply device 12 in such a manner that the flow rate of the hydrogen gas flowing in the supply flow path 70 is increased. For example, the control device 18 can increase the flow rate of the hydrogen gas flowing in the supply flow path 70 by increasing the opening degree of the introduction valve (not shown) of the fluid supply device 12 provided on the introduction path 22. When the control device 18 increases the flow rate of the hydrogen gas flowing in the supply flow path 70, the process proceeds to step S6.

[0064] In step S6, the control device 18 sets the count value T of the timer for counting the voltage stop time to "0", and proceeds to step S7.

[0065] In step S7, the control device 18 compares the count value T of the timer with a prescribed count threshold value. Here, in a case where the count value T of the timer is equal to or less than the count threshold value, the control device 18 proceeds to step S8, and returns to step S7 after incrementing the count value T of the timer by "1". On the other hand, in a case where the count value T of the timer is greater than the count threshold value, the control device 18 proceeds to step S9.

[0066] In step S9, the control device 18 controls the fluid supply device 12 in such a manner that the flow rate of the hydrogen gas flowing in the supply flow path 70 is reduced. For example, the control device 18 returns the opening degree of the introduction valve (not shown) of the fluid supply device 12 to the original opening degree (the opening degree before the opening degree of the introduction valve was increased in step S5). Accordingly, the flow rate of the hydrogen gas flowing in the supply flow path 70 is reduced. When the control device 18 reduces the flow rate of the hydrogen gas flowing in the supply flow path 70, the process proceeds to step S10.

[0067] In step S10, the control device 18 returns the opening degree of the pressure regulating valve 36 to the original opening degree (the opening degree before the opening degree of the pressure regulating valve 36 is decreased in step S3) and proceeds to step Sll.

[0068] In step Sll, the control device 18 controls the power supply device 16 in such a manner that a voltage is applied between the anode power supply body 62 and the cathode power supply body 66, after which the control process ends.

[0069] Further, in step Sll, the control device 18 can control the power supply device 16 in such a manner that a voltage is applied between the anode power supply body 62 and the cathode power supply body 66, after which the control process returns to step S 1. In addition, the order of the above-described control process can be changed. For example, the order of step S3 and step S4 can be changed, or the order of step S4 and step S5 can be changed. Alternatively, the order of step S9 and step S10 can be changed, or the order of step S10 and step Sll can be changed.

[0070] Figure 7 is a view showing the state of the fluid in the electrochemical cell 24 in the case where the stagnant water is removed. As shown by the hollow arrow, when the flow rate of the hydrogen gas flowing in the supply flow path 70 is increased by the above-described control process, negative pressure is generated in the first void 80 and the second void 82 formed in the anode power supply body 62.

[0071] The cross-sectional area of the first void 80 formed in the anode power supply body 62 increases as it approaches the supply flow path 70. Therefore, as shown by the dotted arrow, when negative pressure is generated in the first void 80, the stagnant water that has stagnated in the interlayer or the like is sucked out to the supply flow path 70 through the first void 80. As a result, it is possible to suppress the decrease in the transport performance of the hydrogen and the energy efficiency due to the stagnant water.

[0072] Further, in the case where the cross-sectional area of the first communication hole 84 increases as it approaches the supply flow path 70 and the inner wall of the first communication hole 84 is continuous with the inner wall of the first void 80, negative pressure is easily generated in the first communication hole 84 as the flow rate of the hydrogen gas flowing in the supply flow path 70 increases. Therefore, by the first void 80 and the first communication hole 84, it is possible to increase the force with which the stagnant water that has stagnated in the interlayer or the like is sucked out to the supply flow path 70. Therefore, it is possible to increase the removal efficiency of the stagnant water.

[0073] On the other hand, the cross-sectional area of the second void 82 formed in the anode current supplier 62 increases as it approaches the electrolyte membrane 60. Therefore, even if negative pressure is generated in the second void 82, the amount of the stagnant water sucked out to the supply flow path 70 through the second void 82 can be limited. Therefore, as indicated by the double-dot chain line arrows, the stagnant water stagnating in the interlayer or the like flows from the outer side portion 76 of the electrochemical cell 24 to the inner side portion 74, and the moisture is homogenized on the surface of the interlayer or the like. As a result, the decrease in the hydrogen transport performance and the energy efficiency due to drying can be suppressed.

[0074] Further, in the case where the cross-sectional area of the second communication hole 86 increases as it approaches the electrolyte membrane 60, and the inner wall of the second communication hole 86 is continuous with the inner wall of the second void 82, the stagnant water stagnating in the interlayer or the like easily flows from the outer side portion 76 of the electrochemical cell 24 to the inner side portion 74. Therefore, the homogenization of the moisture on the surface of the interlayer or the like can be improved.

[0075] Figure 8 is a view indicating a state where the pressure of the generated fluid increases in the electrochemical cell 24 in the case where the stagnant water is removed. In the above-described control process, in a state where the flow rate of the hydrogen gas flowing in the supply flow path 70 increases, the opening degree of the pressure regulating valve 36 is reduced. Therefore, the pressure of the high-pressure hydrogen gas discharged to the discharge flow path 34 by the electrochemical reaction increases, and the electrochemical cell 24 is pressed to the anode side as indicated by the black solid arrows. Therefore, the stagnant water stagnating in the interlayer or the like is pushed out to the first void 80 or the first communication hole 84. As a result, the amount of the water sucked out to the supply flow path 70 increases, and the removal efficiency of the stagnant water can be improved.

[0076] The above-described embodiment can be modified as follows.

[0077] For example, the cell device 14 can also be a water splitting device that generates hydrogen (hydrogen gas) as the generated fluid by electrically splitting water. In the case where the cell device 14 is the water splitting device, the fluid supply device 12 supplies water to the cell device 14. In this case, the support layer 62B of the anode current supplier 62 in the electrochemical cell 24 possessed by the cell device 14 can also be omitted.

[0078] Even if the cell device 14 is the water splitting device, depending on the operating conditions of the electrochemical cell 24, the stagnant water sometimes stagnates on the anode side of the electrochemical cell 24. Therefore, even if the cell device 14 is the water splitting device, the decrease in the hydrogen transport performance and the energy efficiency can be suppressed as in the case where the cell device 14 is the electrochemical hydrogen pressure increasing device.

[0079] As the present application that can be obtained according to the above-described embodiment, the first application, the second application, and the third application can be cited.

[0080] The first invention is an electrochemical cell (24) having an electrolyte membrane (60), an anode power supply body (62), a cathode power supply body (66), and a supply flow path (70), wherein the anode power supply body (62) is laminated to one surface side of the electrolyte membrane (60); the cathode power supply body (66) is laminated to the other surface side of the electrolyte membrane (60); and the supply flow path (70) is provided on the surface side of the anode power supply body (62) opposite to the electrolyte membrane (60) side, and a fluid for supplying to the anode power supply body (62) flows therethrough.

[0081] The anode power supply body (62) of the electrochemical cell (24) has an inner side portion (74) and an outer side portion (76), wherein the inner side portion (74) is formed with first holes (80) having cross-sectional areas that increase toward the supply flow path (70); and the outer side portion (76) is located outside the inner side portion (74) and is formed with second holes (82) having cross-sectional areas that increase toward the electrolyte membrane (60).

[0082] In the electrochemical cell (24), when the flow rate of the fluid flowing in the supply flow path (70) increases, negative pressure is generated in the first holes (80) and the second holes (82), and the stagnant water stagnating on the anode side of the electrochemical cell (24) is sucked out to the supply flow path (70) through the first holes (80). As a result, the electrochemical cell (24) can suppress the decrease in the hydrogen transport performance and the energy efficiency due to the stagnant water.

[0083] On the other hand, even when negative pressure is generated in the second holes (82), the stagnant water can be limited from being sucked out to the supply flow path (70) through the second holes (82) and the second communication holes (86). Therefore, the stagnant water flows from the outer side portion (76) of the electrochemical cell (24) into the inner side portion (74). Thus, the moisture can be made uniform in the surface of the interlayer or the like, and thus the drying of the electrolyte membrane (60) can be suppressed. As a result, the electrochemical cell (24) can suppress the decrease in the hydrogen transport performance and the energy efficiency due to the drying.

[0084] The electrochemical cell (24) can have an anode catalyst layer (64) interposed between the electrolyte membrane (60) and the anode power supply body (62), and formed with first communication holes (84) communicating with the first holes (80) and second communication holes (86) communicating with the second holes (82), the cross-sectional areas of the first communication holes (84) continuously increasing toward the supply flow path (70), and the cross-sectional areas of the second communication holes (86) continuously increasing toward the electrolyte membrane (60).

[0085] Accordingly, in the electrochemical cell (24), as the flow rate of the fluid flowing in the supply flow path (70) increases, negative pressure is easily generated in the first communication hole (84). Therefore, the force of drawing out the stagnant water, which stagnates on the anode side of the electrochemical cell (24), to the supply flow path (70) through the first void hole (80) and the first communication hole (84) can be increased. Therefore, the removal efficiency of the stagnant water can be increased.

[0086] In addition, in the electrochemical cell (24), the stagnant water easily flows from the outer side portion (76) of the electrochemical cell (24) to the inner side portion (74). Therefore, the uniformity of the moisture in the surface of the layer and the like can be increased.

[0087] The inner wall of the first void hole (80) can be continuous with the inner wall of the first communication hole (84), and the inner wall of the second void hole (82) can be continuous with the inner wall of the second communication hole (86).

[0088] Accordingly, in the electrochemical cell (24), as the flow rate of the fluid flowing in the supply flow path (70) increases, negative pressure is easily generated in the first communication hole (84). Therefore, the force of drawing out the stagnant water, which stagnates on the anode side of the electrochemical cell (24), to the supply flow path (70) through the first void hole (80) and the first communication hole (84) can be increased. Therefore, the removal efficiency of the stagnant water can be increased.

[0089] In addition, in the electrochemical cell (24), the stagnant water easily flows from the outer side portion (76) of the electrochemical cell (24) to the inner side portion (74). Therefore, the uniformity of the moisture in the surface of the layer and the like can be increased.

[0090] The second application is a battery operation system (10). The battery operation system (10) has the above-described electrochemical cell (24), a fluid supply device (12) that supplies the fluid to the electrochemical cell (24), a power supply device (16) that applies a voltage between the anode power supply body (62) and the cathode power supply body (66), a sensor (88) that detects an electrical state between the anode power supply body (62) and the cathode power supply body (66), and a control device (18) that controls the power supply device (16) so as to stop the application of the voltage and controls the fluid supply device (12) so as to increase the flow rate of the fluid flowing in the supply flow path (70) when the value indicating the electrical state is greater than a prescribed threshold value.

[0091] In the battery operation system (10), negative pressure is generated in the first void hole (80), and the stagnant water, which stagnates on the anode side of the electrochemical cell (24), can be drawn out to the supply flow path (70) through the first void hole (80). As a result, the battery operation system (10) can suppress the decrease in the hydrogen transport performance and the energy efficiency due to the stagnant water.

[0092] Further, in the battery operating system (10), negative pressure is generated in the second air hole (82) to cause the stagnant water to flow from the outer portion (76) of the electrochemical cell (24) to the inner portion (74), and thus the water can be uniformly distributed on the surface of the layers and the like. As a result, the battery operating system (10) can suppress the decrease in the hydrogen transport performance and the energy efficiency due to the drying of the electrolyte membrane (60).

[0093] The battery operating system (10) can include a pressure regulating valve (36) provided in the discharge flow path (34) through which the generated fluid generated by the electrochemical reaction flows, for regulating the pressure of the generated fluid, and the control device (18) can control the pressure regulating valve (36) to decrease the opening degree of the pressure regulating valve (36) when the value is greater than the threshold value, and then control the power supply device (16) and the fluid supply device (12).

[0094] Accordingly, the pressure of the generated fluid in the discharge flow path (34) increases, and the electrochemical cell (24) is pressed toward the anode side. Thus, the battery operating system (10) can push the stagnant water stagnating in the anode side of the electrochemical cell (24) to the supply flow path (70), and thus the removal efficiency of the stagnant water can be improved.

[0095] The fluid can be hydrogen. In the case where the fluid is hydrogen, the battery operating system (10) can generate high-pressure hydrogen as the generated fluid.

[0096] The third invention is a battery operating method for operating the electrochemical cell (24) described above. In the battery operating method, a voltage is applied between the anode current collector (62) and the cathode current collector (66), and when a value indicating the electrical state between the anode current collector (62) and the cathode current collector (66) is greater than a predetermined threshold value, the voltage application is stopped, and the flow rate of the fluid flowing in the supply flow path (70) is increased.

[0097] In the battery operating method, negative pressure is generated in the first air hole (80) to suck the stagnant water stagnating in the anode side of the electrochemical cell (24) to the supply flow path (70) through the first air hole (80). As a result, the battery operating method can suppress the decrease in the hydrogen transport performance and the energy efficiency due to the stagnant water.

[0098] Further, in the battery operating method, negative pressure is generated in the second air hole (82) to cause the stagnant water to flow from the outer portion (76) of the electrochemical cell (24) to the inner portion (74), and thus the water can be uniformly distributed on the surface of the layers and the like. As a result, the battery operating method can suppress the decrease in the hydrogen transport performance and the energy efficiency due to the drying of the electrolyte membrane (60).

[0099] The battery operation method can reduce the opening degree of a pressure regulating valve (36) provided on an exhaust flow path (34) in which a generated fluid generated by an electrochemical reaction is flowing, in a case where the value is greater than the threshold value, and then stop the application of the voltage and increase the flow rate of the fluid flowing in a supply flow path (70).

[0100] Accordingly, the pressure of the generated fluid in the exhaust flow path (34) rises, and the electrochemical cell (24) is pressed toward the anode side. Therefore, the battery operation method can push out the stagnant water stagnating on the anode side of the electrochemical cell (24) to the supply flow path (70), and as a result, can improve the removal efficiency of the stagnant water.

[0101] The fluid can be hydrogen gas. In a case where the fluid is hydrogen gas, the battery operation method can generate high-pressure hydrogen gas as the generated fluid.

[0102] Furthermore, the present application is not limited to the above-described embodiments, and various structures can be employed within the scope of the gist of the present application.

Claims

1. An electrochemical cell (24) comprising an electrolyte membrane (60), an anode power supply (62), a cathode power supply (66), and a supply flow path (70), wherein, The anode power supply (62) is stacked on one surface side of the electrolyte membrane; The cathode power supply (66) is stacked on the other surface of the electrolyte membrane; The supply flow path (70) is disposed on the surface side of the anode power supply opposite to the electrolyte membrane side, and a fluid for supplying to the anode power supply flows through it. The electrochemical cell (24) is characterized in that... The anode power supply has an inner portion (74) and an outer portion (76), wherein the inner portion (74) has a first hole (80) whose cross-sectional area increases as it moves toward the supply flow path; the outer portion (76) is located outside the inner portion and has a second hole (82) whose cross-sectional area increases as it moves toward the electrolyte membrane. The second hole is not formed on the inner side, and the first hole is not formed on the outer side.

2. The electrochemical battery according to claim 1, characterized in that, It has an anode catalyst layer (64) between the electrolyte membrane and the anode power supply, and forms a first connecting hole (84) communicating with the first pore and a second connecting hole (86) communicating with the second pore. The cross-sectional area of ​​the first connecting hole increases continuously as it moves closer to the supply flow path. The cross-sectional area of ​​the second connecting hole increases continuously as it moves closer to the electrolyte membrane.

3. The electrochemical battery according to claim 2, characterized in that, The inner wall of the first hollow hole is continuous with the inner wall of the first connecting hole, and the inner wall of the second hollow hole is continuous with the inner wall of the second connecting hole.

4. A battery operating system (10), characterized in that, The device comprises the electrochemical cell, fluid supply device (12), power supply device (16), sensor (88), and control device (18) as described in claim 1, wherein, The fluid supply device (12) supplies the fluid to the electrochemical cell; The power supply device (16) applies a voltage between the anode power supply body and the cathode power supply body; The sensor (88) detects the electrical state between the anode power supply and the cathode power supply; The control device (18) controls the power supply device to stop applying the voltage when the value representing the electrical state is greater than a predetermined threshold, and controls the fluid supply device to increase the flow rate of the fluid flowing in the supply path.

5. The battery operating system according to claim 4, characterized in that, It has a pressure regulating valve (36) disposed on a discharge flow path (34) through which a generating fluid produced by an electrochemical reaction flows, for regulating the pressure of the generating fluid. When the value is greater than the threshold, the control device controls the pressure regulating valve by reducing the opening of the pressure regulating valve, and then controls the power supply device and the fluid supply device.

6. The battery operating system according to claim 4, characterized in that, The fluid is hydrogen gas.

7. A battery operation method for operating the electrochemical battery of claim 1, characterized in that, A voltage is applied between the anode power supply and the cathode power supply. If the value representing the electrical state between the anode power supply and the cathode power supply is greater than a predetermined threshold, the application of the voltage is stopped, and the flow rate of the fluid flowing in the supply path is increased.

8. The battery operation method according to claim 7, characterized in that, If the value is greater than the threshold, the opening of the pressure regulating valve provided in the discharge flow path is reduced, then the applied voltage is stopped and the flow rate of the fluid flowing in the supply flow path is increased, wherein the discharge flow path contains the generating fluid produced by the electrochemical reaction.

9. The battery operation method according to claim 7, characterized in that, The fluid is hydrogen gas.

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