Battery

Abstract

To provide a battery capable of cooling a cell even if an opening / closing plate provided at an inlet of a branch passage cannot be moved due to deterioration or the like.SOLUTION: The battery of the present disclosure includes a cell stack in which a plurality of cells 21 are stacked, an intake passage (refrigerant passage) 3 through which a refrigerant for cooling the cell stack flows in a stacking direction of the cell stack, and a plurality of flow paths branched from the intake passage 3 toward each of the plurality of cells 21. A plurality of branch passages 5 for cooling the cell 21 in contact with the outside of the cell 21, and an opening / closing plate 30 provided at an inlet from an intake passage 3 to the branch passages 5 are provided, the opening / closing plate 30 is provided so as to cover a part of the inlet, is constituted of a deforming member deformed according to the temperature of the cell 21, and the opening of the inlet becomes larger as the temperature of the cell 21 becomes higher.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to batteries, and more particularly to cooling a cell stack in which multiple cells are stacked. [Background technology]

[0002] Hybrid vehicles, electric vehicles, and other vehicles are equipped with batteries that supply power to the motors that serve as the power source. The batteries have a cell stack made up of multiple stacked cells, and if the temperature of the cell stack rises, it must be cooled to maintain an appropriate temperature.

[0003] Patent Document 1 discloses a battery having a refrigerant passage provided in a lower region of a cell stack and branch passages branching from the refrigerant passage toward the side of each cell. In the battery disclosed in Patent Document 1, in order to equalize the temperature in each cell, an opening and closing plate is provided at the boundary between the refrigerant flow path and the branch passage, i.e., at the entrance of the branch passage, which can open the branch passage when the temperature of the refrigerant remaining in the branch passage rises. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-142390 Summary of the Invention [Problem to be solved by the invention]

[0005] In Patent Document 1, if the opening and closing plate that blocks the branch passage becomes stuck due to deterioration, or if the opening and closing plate becomes fixed and immovable due to cell expansion, it becomes impossible to cool the multiple cells. The present disclosure is intended to solve such problems and provides a battery that can cool cells even if the opening and closing plate provided at the entrance of the branch passage becomes immovable due to deterioration or the like. [Means for solving the problem]

[0006] The battery of the present disclosure comprises a cell stack in which a plurality of cells are stacked; a refrigerant passage through which a refrigerant for cooling the cell stack flows in the stacking direction of the cell stack; a plurality of branch passages branching from the refrigerant passage toward each of the plurality of cells and contacting the outside of the cells to cool the cells; and an opening / closing plate provided at the entrance from the refrigerant passage to the branch passage, the opening / closing plate being provided so as to cover part of the entrance and being made of a deformable member that deforms according to the temperature of the cells, and the opening degree of the entrance increasing as the temperature of the cells increases. With this configuration, the cells can be cooled even if the opening and closing plate provided at the entrance of the branch passage becomes immovable due to deterioration or the like.

[0007] A plurality of the opening and closing plates may be provided in each cell, aligned in a direction substantially perpendicular to the stacking direction of the cell stack. With this configuration, it is possible to cool a portion of the cell where the temperature is relatively high in a concentrated manner.

[0008] The branch passage may be provided with a plurality of ribs that divide the refrigerant flow path into a plurality of sections, and the opening and closing plate may be disposed between the plurality of ribs as viewed from the refrigerant passage. With this configuration, it is possible to intensively cool the portion of the cell where the temperature is relatively high. [Effects of the Invention]

[0009] The present disclosure makes it possible to provide a battery that can cool cells even if the opening and closing plate provided at the entrance of the branch passage becomes inoperable due to deterioration or the like. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 2 is a schematic side view of the battery and the blower according to the first embodiment. [Figure 2] This is an enlarged view of the dashed line portion in FIG. 1, showing the case where the cell temperature is relatively low. [Figure 3] The enlarged view of the dashed line portion in FIG. 1 shows the case where the cell temperature is relatively high. [Figure 4]3 is a schematic cross-sectional view taken along the line III-III in FIG. 2. [Figure 5] 3 is a schematic view of the battery shown in FIG. 2 as seen from the intake passage side. DETAILED DESCRIPTION OF THE INVENTION

[0011] Embodiment 1 Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. FIG. 1 is a schematic side view of the battery and blower of the first embodiment. FIG. 2 is an enlarged view of the dashed line portion shown in FIG. 1, showing a case where the cell temperature is relatively low. FIG. 3 is an enlarged view of the dashed line portion shown in FIG. 1, showing a case where the cell temperature is relatively high. FIG. 4 is a schematic cross-sectional view taken along line III-III of FIG. 2. FIG. 5 is a schematic view of the battery shown in FIG. 2, seen from the intake passage side.

[0012] Naturally, the right-handed XYZ Cartesian coordinate system shown in Fig. 1 is a convenient way to explain the positional relationships of the components. In Fig. 1 and other figures, for example, the positive direction of the Z axis is vertically upward, and the XY plane is a horizontal plane, which is common to all figures.

[0013] Battery 10 is disposed, for example, below the seats of the vehicle. However, the location of battery 10 is not limited to this, and it may be disposed, for example, below the trunk. A motor (not shown) is driven by the power supplied from battery 10 to run the vehicle. The vehicle is not limited to an electric vehicle, and may be a hybrid vehicle, a fuel cell vehicle, or the like, as long as it can be driven by electric power.

[0014] As shown in FIG. 1, the battery 10 has a case 1. The case 1 has a rectangular parallelepiped shape extending in the X-axis direction and is made of a metal such as aluminum. The case 1 is disposed on the vehicle so that its longitudinal direction extends in the width direction of the vehicle. Inside the case 1, an intake passage 3, a cell stack 20, and an exhaust passage 4 are provided in this order from the thickness direction (Z-axis direction). A blower 2 is connected to one end of the intake passage 3.

[0015] As shown in FIG. 1, the cell stack 20 has a plurality of cells 21. The cells 21 are rectangular cells having a rectangular parallelepiped shape, and are configured by secondary batteries such as lithium-ion batteries or nickel-metal hydride batteries, or by capacitors. The plurality of cells 21 are stacked in the thickness direction (X-axis direction) to configure the cell stack 20. The plurality of cells 21 are electrically connected in series by connecting the positive terminal of a cell 21 to the negative terminal of an adjacent cell 21 via a bus bar (not shown). Note that all or some of the plurality of cells 21 may be electrically connected in parallel.

[0016] As shown in Fig. 2, a resin frame 22 is disposed between the cells 21. The resin frame 22 is made of resin, which is an insulating material, and can insulate two adjacent cells 21. A cell stack 20 is formed by stacking multiple cells 21 and resin frames 22 alternately in the thickness direction (X-axis direction). End plates (not shown) are disposed on both ends of the cell stack 20 in the stacking direction (X-axis direction), and by fixing bands (not shown) to both end plates, a restraining force can be applied to the multiple cells 21 and multiple resin frames 22 that constitute the cell stack 20.

[0017] As shown in FIG. 4, the resin frame 22 has a rectangular base portion 23 that is generally flat and has long and short sides in a plan view. As shown in FIG. 5, the resin frame 22 has frame portions 24 that are provided at both longitudinal ends of the base portion 23 in a plan view and that protrude in the thickness direction (X-axis direction). As shown in FIG. 2, the resin frame 22 has a fixing portion 25 that is provided at one end of the base portion 23 in a short side direction in a plan view and that protrudes in the thickness direction (X-axis direction), and a rectifying portion 26 that is provided at the other end of the base portion 23 in a short side direction in a plan view and that protrudes in the thickness direction (X-axis direction) on the side opposite the fixing portion 25. Furthermore, as shown in FIG. 2, the resin frame 22 has a plurality of ribs 27 that protrude from one surface of the base portion 23 in the same direction (X-axis direction) as the rectifying portion 26.

[0018] As shown in FIGS. 2 and 5, the base portion 23 constitutes a part of the branch passage 5, which will be described later. A heat receiving portion 31 of an opening / closing plate 30, which will be described later, is fixed to the base portion 23. As shown in FIG. 5, the frame portion 24 is formed linearly in the short-side direction (Z-axis direction) in a plan view, and restricts movement of the cells 21 by contacting with the cells 21. As shown in FIG. 2, a part of an opening / closing portion 32 of the opening / closing plate 30, which will be described later, is fixed to the fixing portion 25. The rectifying portion 26 rectifies the cooling air discharged from the branch passage 5, which will be described later, toward the exhaust outlet. As shown in FIG. 4, a plurality of ribs 27 are formed linearly in the short-side direction in a plan view, and divide the flow path of the cooling air in the branch passage 5, which will be described later, into a plurality of sections.

[0019] As shown in Fig. 2, a plurality of branch passages 5 are provided between the cells 21 and the resin frame 22. The branch passages 5 branch off from the intake passage 3 toward the plurality of cells 21 and are in contact with the outside of the cells 21 to cool the cells 21. As shown in Fig. 5, the branch passages 5 are formed by a space surrounded by the cells 21, the base portion 23 of the resin frame 22, and the frame portion 24.

[0020] As shown in FIG. 2, an opening / closing plate 30 is provided at each entrance from the intake passage 3 to the plurality of branch passages 5. The opening / closing plate 30 is made of a plate member that is L-shaped in side view, and is composed of a heat receiving portion 31 that is one side of the L shape and receives heat from the cells 21, and an opening / closing portion 32 that is the other side of the L shape and adjusts the flow rate of cooling air flowing from the intake passage 3 to the branch passages 5. The opening / closing plate 30 is arranged so that the heat receiving portion 31 is adjacent to the flat portion of the cells 21 and the opening / closing portion 32 covers part of the entrance of the branch passage 5. Note that, although a gap is provided between the heat receiving portion 31 and the cells 21 as shown in FIG. 2, the two may be in close contact with each other.

[0021] The opening / closing plate 30 is composed of a deformable member that deforms in response to the temperature of the cells 21. The deformable member is, for example, a so-called bimetal in which two metal plate members with different thermal expansion coefficients are bonded together. Specifically, in the bimetal, the thermal expansion coefficient of the metal plate member on the side facing the cells 21 is greater than the thermal expansion coefficient of the metal plate member on the side not facing the cells 21. In addition, the opening / closing plate 30 is fixed, by fixing means not shown, with the heat receiving portion 31 to the base portion 23 of the resin frame 22 and with the heat receiving portion 31 side of the opening / closing portion 32 to the fixing portion 25 of the resin frame 22.

[0022] The opening / closing plate 30 does not have to be a bimetal, but may be made of a deformable member that deforms in response to the temperature of the cells 21, such as a shape memory alloy. Also, instead of making the entire opening / closing plate 30 out of a deformable member, for example, only the opening / closing part 32 may be made out of a deformable member.

[0023] As shown in Fig. 2, when the temperature of the cells 21 is relatively low, the amount of heat received by the heat receiving portion 31 from the cells 21 is small, and therefore the opening / closing portion 32 does not deform. On the other hand, as shown in Fig. 3, when the temperature of the cells 21 is relatively high, the amount of heat received by the heat receiving portion 31 from the cells 21 increases, and therefore the tip end of the opening / closing portion 32 deforms toward the intake passage 3.

[0024] As shown in Figure 5, multiple such opening and closing plates 30 are arranged in each cell 21 in a direction approximately perpendicular to the stacking direction of the cell stack 20 (Y-axis direction), and are also arranged between multiple ribs 27 when viewed from the intake passage 3 side. It should be noted that instead of providing a plurality of separate opening / closing plates 30 for one cell 21, a single opening / closing plate 30 may be provided.

[0025] As shown in FIGS. 1 to 3 , when the temperature of the cell stack 20 rises, the blower 2 is activated, and cooling air is circulated through the intake passage 3 in the stacking direction (X-axis direction) of the cell stack 20. Here, the cooling air is a refrigerant that cools the cell stack 20, and the intake passage 3 is a refrigerant flow path through which the refrigerant flows. The cells 21 are cooled by the cooling air introduced from the intake passage 3 into the branch passage 5. The branch passage 5 is connected to the exhaust passage 4, and the cooling air warmed by heat exchange with the cells 21 in the branch passage 5 is discharged into the exhaust passage 4. The cooling air circulates through the exhaust passage 4 in the same direction (X-axis direction) as the cooling air in the intake passage 3, and is discharged from an exhaust outlet 4a provided at one end of the exhaust passage 4 in the stacking direction of the cell stack 20. The arrows in FIGS. 1 to 3 indicate the direction in which the cooling air flows within the case 1. The thickness of the arrow indicates the volume of the cooling air; the thicker the arrow, the greater the volume of the cooling air.

[0026] The exhaust outlet 4a may be provided at the other end in the stacking direction of the cell stack 20, or may be provided at both one end and the other end in the stacking direction of the cell stack 20. The refrigerant may be cooling water instead of cooling air.

[0027] 1, if the amount of cooling air flowing through the intake passage 3 is not uniform in the stacking direction of the cell stack 20, uneven temperatures will occur among the multiple cells 21. As shown in Fig. 2, for cells 21 with relatively low temperatures, the heat receiving portion 31 receives less heat from the cells 21, and the opening / closing plate 30 does not deform. Therefore, cooling air flows into the branch passage 5 from the inlet portion of the branch passage 5 that is not covered by the opening / closing portion 32.

[0028] On the other hand, as shown in Fig. 3, in cells 21 with a relatively high temperature, the heat receiving portion 31 receives a large amount of heat from the cells 21, and therefore the tip side of the opening / closing portion 32 of the opening / closing plate 30 deforms toward the intake passage 3. As a result, the opening of the inlet of the branch passage 5 increases, and the flow rate of cooling air flowing from the intake passage 3 into the branch passage 5 increases. Then, the high-temperature cells 21 are cooled, and the temperature can be made uniform among the multiple cells 21.

[0029] 2, the opening / closing portion 32 of the opening / closing plate 30 is disposed so as to cover a part of the inlet of the branch passage 5. Therefore, even if the opening / closing portion 32 becomes inoperable due to deterioration or the like, cooling air is circulated into the branch passage 5 from the inlet portion of the branch passage 5 that is not covered by the opening / closing portion 32, so that the cells 21 can be cooled.

[0030] Furthermore, a plurality of opening / closing plates 30 are arranged in each cell 21 in a direction (Y-axis direction) approximately perpendicular to the stacking direction of the cell stack 20. Therefore, if there is temperature non-uniformity in the longitudinal direction (Y-axis direction) of the cell 21 in a plan view, the opening / closing parts 32 of the opening / closing plates 30 close to the position of the cell 21 where the temperature is relatively high will deform, and the relatively high-temperature part of the cell 21 can be cooled intensively.

[0031] Moreover, the multiple opening / closing plates 30 are arranged between the multiple ribs 27 when viewed from the intake passage 3 side. Therefore, if there is temperature unevenness in the longitudinal direction (Y-axis direction) of the cell 21 in a plan view, the opening / closing portion 32 of the opening / closing plate 30 close to the position of the cell 21 where the temperature is relatively high will deform, and further, the cooling air flowing into the branch passage 5 will circulate linearly in the lateral direction (Z-axis direction) of the cell 21 in a plan view, so that the portion of the cell 21 where the temperature is relatively high can be cooled intensively.

[0032] The present disclosure is not limited to the above-described embodiment, and can be modified as appropriate within the scope of the present disclosure.

[0033] For example, if the amount of cooling air flowing into the branch passage 5 decreases as the cell 21 is positioned downstream of the intake passage 3, the amount of cooling air flowing into the branch passage 5 can be increased by reducing the area of ​​the cell 21 located downstream of the intake passage 3 that covers part of the entrance to the branch passage 5 with the opening / closing portion 32.

[0034] Furthermore, when the temperature of the cell 21 becomes relatively high in the middle region in the longitudinal direction (Y-axis direction) when viewed in a plane, the flow rate of the cooling air flowing into the same region of the branch passage 5 can be increased by reducing the area of ​​the opening / closing plate 30 located in the same region that covers part of the entrance of the branch passage 5 with the opening / closing portion 32. [Explanation of symbols]

[0035] 3. Intake passage 4 Exhaust passage 5 Branching passage 10. Battery 20 Cell stack 21...cell 22 Resin frame 27 Ribs 30···Opening and closing plate

Claims

1. a cell stack in which a plurality of cells are stacked; a coolant passage through which a coolant for cooling the cell stack flows in a stacking direction of the cell stack; a plurality of branch passages branching from the refrigerant passage toward each of the plurality of cells and contacting the outside of the cells to cool the cells; an opening / closing plate provided at an entrance from the refrigerant passage to the branch passage, The opening and closing plate is a deformable member that is provided to cover a portion of the inlet and that deforms in response to the temperature of the cell, and the opening degree of the inlet increases as the temperature of the cell increases; Battery.

2. The opening and closing plates are arranged in a direction substantially perpendicular to the stacking direction of the cell stack in each cell.

10. The battery of claim 1.

3. The branch passage is provided with a plurality of ribs that divide the refrigerant flow path into a plurality of sections, and the opening and closing plate is disposed between the plurality of ribs as viewed from the refrigerant passage.

3. The battery of claim 2.

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