Fuel cell terminal plate

Abstract

To provide a terminal plate that can suppress heat generation. [Solution] The fuel cell terminal plates 120 and 130 have a rectangular planar shape and include a plate body portion 121 used for current collection, and a terminal 150 provided on one side S1 of the plate body portion, having a joint portion 160 joined to the plate body portion and an output portion 170 joined to the plate body portion via the joint portion. The joint portion has a first projection 161 that protrudes in a first direction D1 parallel to the direction in which one side extends, and the center M2 of the output portion in the first direction is separated from the center M1 on one side in a second direction D2 opposite to the first direction.

Description

Technical Field

[0001] The present disclosure relates to a terminal plate for a fuel cell.

Background Art

[0002] Various techniques related to terminal plates for fuel cells have been proposed. For example, Patent Document 1 discloses a technique of joining a terminal for outputting power generated by a fuel cell to the outside to the outer peripheral portion of a plate portion.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The terminal may be arranged at a position separated from the center in the longitudinal direction of the plate portion. In such a case, since the current flowing in the plate toward the terminal tries to flow along the shortest path, the current concentrates on the end portion in the direction opposite to the separating direction at the terminal. As a result, the amount of heat generation at the end portion may increase.

Means for Solving the Problems

[0005] The present disclosure can be realized in the following forms.

[0006] (1) According to one embodiment of the present disclosure, a terminal plate for a fuel cell is provided. The terminal plate has a rectangular planar shape and comprises a plate body portion used for current collection, and a terminal provided on one side of the plate body portion, the terminal having a joint portion joined to the plate body portion, and an output portion joined to the plate body portion via the joint portion, wherein the joint portion has a first projection portion that protrudes in a first direction parallel to the direction in which the one side extends, and the center of the output portion in the first direction is separated from the center of the one side in a second direction opposite to the first direction. In this form of terminal plate, the joint has a first projection extending in a first direction, so compared to a configuration in which the joint does not have a first projection, current concentration at the joint can be suppressed and heat generation can be suppressed. Furthermore, since the center of the output section in the first direction is separated from the center of one side in the second direction, compared to a configuration where the center of the output section and the center of one side coincide, interference between the fuel cell and the surrounding members where the fuel cell is placed, at least a portion of which is located near the center of one side (hereinafter also referred to as "surrounding members"), can be suppressed. (2) In the terminal plate of the above form, the joint portion further has a second projection that protrudes in the second direction, and the length of the first projection may be longer than the length of the second projection in the first and second directions. With this configuration of terminal plate, since the joint has a second protrusion, current concentration at the end of the joint on the second direction side can be suppressed compared to a configuration without a second protrusion. Furthermore, in both the first and second directions, the length of the first protrusion is longer than the length of the second protrusion. Therefore, the relatively long first protrusion can suppress current concentration on the first direction side of the junction, thereby suppressing heat generation. (3) In the terminal plate of the above form, the entire output section may be separated in the second direction from the center of one side of the plate body. With this type of terminal plate, the entire output section is spaced away from the center of one side of the main plate body in a second direction, allowing the output section to be positioned further away from the center of the main plate body. This further reduces interference between the surrounding components and the output section. (4) In the terminal plate of the above form, the output section may have a shape in which the width gradually narrows from the side closer to the main body of the plate to the side further away at the connection portion with the joint. With this type of terminal plate, the output section has a shape in which the width gradually narrows from the side closer to the main body of the plate to the side further away from the connection part with the joint. Compared to a configuration in which the width of the output section is uniform, this suppresses abrupt changes in the width of the output section. As a result, the concentration of current flowing from the joint to the output section can be suppressed, and heat generation in the output section can be suppressed. [Brief explanation of the drawing]

[0007] [Figure 1] This is a perspective view showing the schematic configuration of a fuel cell using a terminal plate in one embodiment of the present disclosure. [Figure 2] This is a plan view of the terminal plate. [Figure 3] This graph shows the relationship between the length of the first protrusion and the maximum temperature in the main body of the plate. [Figure 4] This diagram schematically shows the current flow in the configuration of a comparative example that does not have the first protrusion. [Figure 5] This is a plan view of a terminal plate in another embodiment. [Modes for carrying out the invention]

[0008] A. Embodiments: A1. Equipment configuration: <Outline configuration of fuel cell 100> Figure 1 is a perspective view showing a schematic configuration of a fuel cell 100 in which terminal plates 120 and 130 in one embodiment of the present disclosure are used. The fuel cell 100 is mounted in a fuel cell electric vehicle (FCEV) and supplies power to a traction motor. The fuel cell 100 comprises a laminate 110 and a pair of terminal plates 120 and 130.

[0009] <Structure of the laminated body 110> The laminate 110 is composed of multiple cells 10 stacked on top of each other. Figure 1 shows a simplified representation of the multiple stacked cells 10 for illustrative purposes. Each cell 10 is composed of a fuel electrode (not shown), an electrolyte membrane, an air electrode, and a separator, all stacked on top of each other. The cell 10 generates electricity when supplied with a fuel gas containing hydrogen and an oxidizing gas containing oxygen.

[0010] <Configuration of terminal plates 120 and 130> A pair of terminal plates 120 and 130 are arranged to sandwich the laminate 110. Power generated by the cell 10 is collected by the terminal plates 120 and 130. The terminal plates 120 and 130 have symmetrical shapes. The terminal plate 120 will be described below.

[0011] Figure 2 is a plan view of the terminal plate 120. The terminal plate 120 has a plate body 121 and terminals 150. The plate body 121 has a rectangular plan view shape. In this disclosure, "rectangular" includes shapes where the corners are rounded by R processing or the like. In this embodiment, the plate body 121 has a rectangular plan view shape. The plate body 121 is used to collect power generated by the laminate 110. The plate body 121 is made of a metal such as titanium or stainless steel. The plate body 121 has a plurality of holes 11a, 11b, 12a, 12b, 13a, and 13b. Each of the plurality of holes 11a, 11b, 12a, 12b, 13a, and 13b is in communication with a manifold (not shown) provided in the laminate 110 and extending in the lamination direction. Cooling water, oxidizing gas, and fuel gas are supplied to each of the multiple holes 11a, 11b, 12a, 12b, 13a, and 13b, respectively. For example, hole 11a is used to supply cooling water, and hole 11b is used to discharge cooling water. Hole 12a is used to supply oxidizing gas, and hole 12b is used to discharge oxidizing gas. Hole 13a is used to supply fuel gas, and hole 13b is used to discharge fuel gas.

[0012] The terminal 150 is provided on one side (long side) S1 of the plate body 121. The terminal 150 is located on the side of the plate body 121 opposite to the laminate 110 side. The terminal 150 is made of a metal such as aluminum or copper. The electrical resistance of the terminal 150 is smaller than the electrical resistance of the plate body 121. That is, electricity flows more easily through the terminal 150 than through the plate body 121. Therefore, the electricity collected in the plate body 121 flows toward the terminal 150. In this embodiment, the terminal 150 has a T-shaped plan view. The terminal 150 has a joint portion 160 and an output portion 170.

[0013] The joint portion 160 is a portion that is joined to the plate main body portion 121 of the terminal 150. The joining method is performed by welding using any technique. The joining is performed, for example, by laser welding, arc welding, resistance welding, friction stir joining, etc. The joint portion 160 has a first protruding portion 161 and a second protruding portion 162.

[0014] The first protruding portion 161 protrudes in the first direction D1. The entire first protruding portion 161 is joined to the plate main body portion 121. The first direction D1 is a direction parallel to the direction in which one side S1 of the plate main body portion 121 extends. In the present embodiment, the tip of the first protruding portion 161 is located on the first direction side rather than at the center M1 on one side S1 of the plate main body portion 121.

[0015] The second protruding portion 162 protrudes in the second direction D2. The entire second protruding portion 162 is joined to the plate main body portion 121. The second direction D2 is a direction opposite to the first direction D1. In the first direction D1 and the second direction D2, the length of the first protruding portion 161 is longer than the length of the second protruding portion 162.

[0016] The output portion 170 outputs the power generated by the fuel cell 100 to the outside. The output portion 170 protrudes in a direction parallel to the short side S2 and away from the plate main body portion 121. It can be said that the output portion 170 is not directly joined to the plate main body portion 121 but is joined to the plate main body portion 121 via the joint portion 160. The output portion 170 has a shape in which the width gradually narrows from the side close to the plate main body portion 121 toward the side far from it at the connection portion with the joint portion 160. In the present disclosure, the "width" refers to the length in the direction parallel to the first direction D1 and the second direction D2. In the present disclosure, the center M2 of the output portion 170 in the first direction D1 is separated from the center M1 on one side S1 of the plate main body portion 121 in the second direction D2. In other words, in the first direction D1, the center M1 of the plate main body portion 121 and the center M2 of the output portion 170 are at positions shifted from each other. Also, in the present embodiment, the entire output portion 170 is separated from the center M1 on one side S1 of the plate main body portion 121 in the second direction D2.

[0017] A2. Suppression of heat generation by the first protrusion 161: FIG. 3 is a graph showing the relationship between the length L of the first protrusion 161 and the maximum temperature T in the terminal plate 120. As shown in FIG. 2, in the first direction D1, the length from the end of the output portion 170 on the D1 side of the first direction to the tip of the first protrusion 161 was defined as L, and the correlation between the length L and the maximum temperature of the terminal plate 120 was analyzed. In the terminal plate 120 used for the analysis, similar to the terminal plate 120 shown in FIG. 2, the position of the output portion 170 was deviated from the center M1 of one side S1 of the plate main body portion 121. The analysis was performed using CAE. The maximum temperature means the highest temperature among the temperatures at each point of the terminal plate 120 when power is supplied by the fuel cell 100.

[0018] As shown in FIG. 3, when the first protrusion 161 was not provided, that is, when the length L was 0, the maximum temperature of the terminal plate 120 was T1. The maximum temperature was observed at the end closer to the center M1 of one side S1 in the plate main body portion 121 among the two ends along the first direction D1 of the joint portion 160.

[0019] FIG. 4 is a diagram schematically showing the flow of current in the configuration of a comparative example having no first protrusion 161. As shown in FIG. 4, in the configuration of the comparative example, the current in the plate main body portion 121 tries to flow to the terminal TL1 along the shortest path. At this time, if the position of the terminal TL1 is deviated from the center M1 of one side S1 in the plate main body portion 121, current concentrates at the end E1 in the opposite direction to the deviation direction of the terminal TL1 in the joint portion 160. As a result, a large amount of Joule heat is generated at this location, and it is considered that the maximum temperature in the terminal plate 120 was observed.

[0020] As shown in FIG. 3, when the first protrusion 161 with a length L1 was provided, the maximum temperature of the terminal plate 120 was T2, which was lower than the above-described temperature T1. The maximum temperature was observed near the tip of the first protrusion 161.

[0021] When a first protrusion 161 with a length L2 that is longer than length L1 was provided, the maximum temperature of the terminal plate 120 was T3, which is slightly lower than the temperature T2 mentioned above. The maximum temperature was observed near the tip of the first protrusion 161.

[0022] The results of the above analysis suggest that by providing the first protrusion 161, heat generation in the terminal plate 120 can be suppressed compared to a configuration without the first protrusion 161. Furthermore, it was suggested that the effect of suppressing heat generation decreases when the length L of the first protrusion 161 is extended.

[0023] According to the terminal plate 120 of the embodiment described above, the joint portion 160 has a first projection 161 extending in the first direction D1. Compared to a configuration in which the joint portion 160 does not have a first projection 161, current concentration at the joint portion 160 can be suppressed, and heat generation can be suppressed.

[0024] Furthermore, since the center M1 of the output unit 170 in the first direction D1 is separated in the second direction D2 from the center M1 of one side S1, interference between the output unit 170 and the surrounding members on which the fuel cell 100 is arranged, at least a portion of which is located near the center of one side S1 (hereinafter also referred to as "surrounding members"), can be suppressed.

[0025] Furthermore, since the joint portion 160 has a second protrusion 162, current concentration at the end of the joint portion 160 on the second direction D2 side can be suppressed compared to a configuration without a second protrusion 162.

[0026] Furthermore, according to the terminal plate 120 of this embodiment, the length of the first protrusion 161 in the first direction D1 and the second direction D2 is longer than the length of the second protrusion 162. Therefore, the relatively long first protrusion 161 can suppress the concentration of current on the first direction D1 side of the joint 160, thereby suppressing heat generation.

[0027] Furthermore, according to the terminal plate 120 of this embodiment, the entire output unit 170 is spaced away from the center M1 on one side S1 of the plate body 121 in the second direction D2, so the output unit 170 can be positioned at a location further away from the center M1 of the plate body 121. This further suppresses interference between the surrounding members and the output unit 170.

[0028] Furthermore, according to the terminal plate 120 of this embodiment, the output section 170 has a shape in which the width gradually narrows from the side closer to the plate body 121 to the side further away from the joint 160 at the connection portion. Compared to a configuration in which the width of the output section 170 is uniform, this suppresses abrupt changes in the width of the output section 170. As a result, the concentration of current flowing from the joint 160 to the output section 170 can be suppressed, and heat generation in the output section 170 can be suppressed.

[0029] B. Other Embodiments 1: (B1) In the above embodiment, the joint portion 160 had a second protrusion 162, but the disclosure is not limited thereto. Figure 5 is a plan view of the terminal plate 120b in another embodiment. As shown in Figure 5, the joint portion 160b may have only the first protrusion 161 and no second protrusion 162. Even with such a configuration, the first protrusion 161 can suppress current concentration and reduce heat generation.

[0030] (B2) In the above embodiment, the entire output unit 170 was separated in a second direction D2 from the center M1 on one side S1 of the plate body 121, but the disclosure is not limited thereto. A part of the output unit 170 may be separated in a second direction D2 from the center M1.

[0031] (B3) In the above embodiment, the output unit 170 had a shape in which the width gradually narrowed from the side closer to the plate body 121 to the side further away from the plate body 121 at the connection portion with the joint 160, but the present disclosure is not limited thereto. The shape of the output unit 170 may be any shape. For example, the output unit 170 may have a shape in which the width on the side closer to the plate body 121 and the width on the side further away from the plate body 121 are uniform.

[0032] C. Other Embodiments 2: (C1) In the above embodiment, the terminal 150 was provided on the long side S1 of the plate body 121, but the disclosure is not limited thereto. The terminal 150 may be provided at any position on the outer periphery of the plate body 121. For example, the terminal 150 may be provided on the short side S2.

[0033] (C2) In the above embodiment, the plate body portion 121 has a long side S1 and a short side S2 and is rectangular in plan view, but the disclosure is not limited thereto. The plate body portion 121 may have any shape. For example, the plate body portion 121 may be square in plan view.

[0034] This disclosure is not limited to the embodiments described above, and can be implemented in various configurations without departing from its spirit. For example, the technical features in the embodiments corresponding to the technical features in each form described in the summary of the invention can be replaced or combined as appropriate in order to solve some or all of the above-described problems, or to achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be deleted as appropriate. [Explanation of Symbols]

[0035] 10...Cell, 11a,11b,12b,13a,13b...Hole, 100...Fuel cell, 110...Laminate, 120,120b,130...Terminal plate, 121...Plate body, 150,TL1...Terminal, 160,160b...Joint, 161...First protrusion, 162...Second protrusion, 170...Output section, D1...First direction, D2...Second direction, E1...End, L...Length, M1,M2...Center, S1...One side, S2...Short side

Claims

1. A terminal plate for fuel cells, It has a rectangular planar shape and consists of a plate body used for current collection, A terminal provided on one side of the plate body, having a connecting portion joined to the plate body and an output portion joined to the plate body via the connecting portion, Equipped with, The joint portion has a first projection that protrudes in a first direction parallel to the direction in which the side extends, The center of the output section in the first direction is separated from the center of one side in a second direction opposite to the first direction. Terminal plate.

2. A terminal plate according to claim 1, The joint portion further has a second projection that protrudes in the second direction, In the first and second directions, the length of the first projection is longer than the length of the second projection. Terminal plate.

3. A terminal plate according to claim 1 or 2, The entire output section is spaced apart in the second direction from the center of one side of the plate body. Terminal plate.

4. A terminal plate according to claim 1 or 2, The output section has a shape in which the width gradually narrows from the side closer to the plate body to the side further away from the joint at the connection point with the joint. Terminal plate.

Images