Power supply device

Abstract

The present invention makes it possible to radiate heat without providing a mechanism for performing air cooling in which cooling air is forcibly fed. A power supply device 100 comprises: a plurality of heat transfer plates 20 that are thermally conductive and are respectively arranged on one surface of each of a plurality of battery blocks 50, said one surface having cell end surfaces 2 of a plurality of secondary battery cells 1 arranged thereon in the same plane; and a power supply case 10 provided with a first main surface 14 that is thermally conductive and extends in a first direction, and a second main surface 15 that is thermally conductive and is separated from the first main surface 14 in a facing orientation, the power supply case 10 accommodating the plurality of battery blocks 50 in a state of being stacked in multiple stages along the first direction between the first main surface 14 and the second main surface 15. Each of the plurality of heat transfer plates 20 is provided with coupling pieces 22 at which end edges on both sides of the heat transfer plates are bent and which are thermally coupled along the first main surface 14 and the second main surface 15, respectively. Thermal coupling structures for thermally coupling the coupling pieces 22 to the first main surface 14 and the second main surface 15 are provided at joining interfaces therebetween.

Description

power supply

[0001] The present disclosure relates to a power supply device.

[0002] Battery modules, which are made up of multiple rechargeable secondary battery cells, such as lithium-ion secondary batteries, connected in series or parallel, are used in various fields as power supplies for driving target devices. For example, battery blocks, each made up of multiple secondary battery cells connected in series or parallel, are stacked in multiple stages and inserted into a power supply case to be used as backup power supplies for homes, businesses, and factories. Such power supplies use a large number of secondary battery cells, which generate heat during charging and discharging and therefore require efficient cooling. For this reason, air cooling is used, which involves forcibly blowing cooling air over heat-generating components, such as secondary battery cells, to exchange heat.

[0003] However, in order to perform air cooling, it is necessary to provide a cooling fan to draw cooling air into the power supply case and to exhaust it, and to form a cooling air path to allow the cooling air to flow, which creates the problem of making the power supply device configuration more complex.

[0004] International Publication No. 2018 / 159009

[0005] One object of the present disclosure is to provide a power supply device that can dissipate heat without providing a mechanism for forced air cooling. Another object is to provide a power supply device that can efficiently dissipate heat from a large number of secondary battery cells. Note that the description of these objects and objects of the present disclosure does not preclude the existence of other objects and objects. Furthermore, it is not necessary for one embodiment of the present disclosure to solve all of these objects. Furthermore, other objects can be extracted from the description of the specification, drawings, and claims of the present disclosure.

[0006] a power supply case that houses the battery blocks in a multi-tiered stack along the first direction between the first and second main surfaces; a power supply case that houses the battery blocks in a multi-tiered stack along the first direction between the first and second main surfaces; and a power supply case that houses the battery blocks in a multi-tiered stack along the first direction between the first and second main surfaces; and a power supply case that houses the battery blocks in a multi-tiered stack along the first direction between the first and second main surfaces. The power supply case has a first main surface that is thermally conductive and that extends in a first direction, and a second main surface that is thermally conductive and spaced apart from the first main surface. The power supply case has a first main surface that is thermally conductive and extends in a first direction, and a second main surface that is thermally conductive and spaced apart from the first main surface. The power supply case has a first main surface that is thermally conductive and extends in a first direction, and a second main surface that is thermally conductive and spaced apart from the first main surface. The power supply case has a first main surface that is thermally conductive and extends in a first direction, and a second main surface that is thermally conductive and spaced apart from the first main surface. The power supply case houses the battery blocks in a multi-tiered stack along the first direction between the first and second main surfaces. The power supply case has a first main surface that is thermally conductive and extends in a first direction, and a second main surface that is thermally conductive and spaced apart from the first main surface ...

[0007] According to one embodiment of the power supply device of the present disclosure, a heat transfer plate is provided in each battery block, and this heat transfer plate is thermally coupled to the first and second main surfaces of the power supply case, respectively. This makes it possible to efficiently cool the secondary battery cells with a simple configuration, without the need to provide a cooling fan or the like to forcibly blow cooling air.

[0008] 1. A perspective view showing a power supply device according to a first embodiment. 2. An exploded perspective view of the power supply device of FIG. 1. 3. A further exploded perspective view of the power supply device of FIG. 2. 4. A cross-sectional view taken along line IV-IV of FIG. 1. 5. A perspective view with an enlarged view of the main parts of the cross section of FIG. 4. 6. A perspective view of the battery block of FIG. 3. 7. A plan view of the battery block of FIG. 6. 8. A plan view of the front of the battery block of FIG. 6, viewed obliquely from above. 9. A side view of the battery block of FIG. 6. 10. An image showing the results of a simulation of the temperature distribution of a heat transfer plate. 11. A perspective view with an enlarged view of the main parts of the battery holder of FIG. 8. 12. A schematic cross-sectional view of a battery holder. 13. A schematic cross-sectional view of a battery holder according to a comparative example, showing an insulating plate superimposed on the battery holder of another comparative example, with a thermal conductor interposed therebetween. 14. A schematic cross-sectional view of an insulating plate screwed into the battery holder of FIG. 15. 15. A schematic cross-sectional view of an insulating plate and a metal plate superimposed on the battery holder of FIG. 13, with a thermal conductor interposed therebetween. 16. A schematic cross-sectional view of a battery holder according to a modified example, showing a metal plate superimposed on the battery holder with a thermal conductor interposed therebetween. Fig. 20 is a cross-sectional view of a power supply device according to embodiment 2. Fig. 21 is a cross-sectional perspective view with an enlarged perspective view of a main part of the power supply device of Fig. 19. Fig. 22 is an exploded perspective view of the battery block of Fig. 20.

[0009] The embodiments of the present disclosure may be specified by the following configurations and features.

[0010] In a power supply device according to another aspect of the present disclosure, in the above-described aspect, the heat transfer plate is made of metal, and the first main surface and the second main surface are each made of metal. With this configuration, the heat transfer plate, which is made of metal and has excellent thermal conductivity, is thermally coupled to the first main surface and the second main surface, which are also made of metal, making it possible to achieve heat dissipation performance without adding a forced cooling mechanism.

[0011] In another aspect of the power supply device according to the present disclosure, in any of the above aspects, the thermal coupling structure has flexible thermal conductors interposed at the interface between the coupling piece and the first main surface and at the bonding interface between the coupling piece and the second main surface. This configuration makes it possible to accommodate dimensional tolerances of the metal heat transfer plate and the first and second main surfaces, while avoiding the formation of a heat insulating layer due to gaps at the bonding interfaces, thereby enabling heat dissipation performance to be exhibited.

[0012] In a power supply device according to another aspect of the present disclosure, in any of the above aspects, each secondary battery cell is a cylindrical secondary battery cell having a cylindrical outer can, and the battery block includes a battery holder that holds the multiple secondary battery cells in an orientation where the end faces of each cell are flush with each other. With this configuration, the cylindrical secondary battery cells are held in an orientation where the end faces are flush with each other by the battery holder, and a heat transfer plate is placed on one side of the cylindrical secondary battery cells, allowing each secondary battery cell to be directly thermally coupled to the heat transfer plate, thereby enabling efficient heat dissipation.

[0013] In addition, a power supply device according to another aspect of the present disclosure is any of the above-described aspects, further including lead plates electrically connected to the plurality of secondary battery cells, wherein each secondary battery cell has one of the cell end faces thermally coupled to the heat transfer plate and a positive electrode and a negative electrode provided on the other of the cell end faces, and the positive electrode and the negative electrode are each electrically connected to the lead plate. With this configuration, by making an electrical connection on one of the cell end faces, it is possible to use the other cell end face for thermal coupling.

[0014] In a power supply device according to still another aspect of the present disclosure, in any of the above aspects, the power supply device further includes a flexible second thermal conductor interposed between the other end of each secondary battery cell and the heat transfer plate, the battery holder has an electrode window exposing the other end of each secondary battery cell, and the other end of each secondary battery cell exposed from the battery holder through the electrode window is thermally coupled to the heat transfer plate via the second thermal conductor. With this configuration, the second thermal conductor prevents an air gap from being formed on the other end of each secondary battery cell due to the thickness of the battery holder, thereby forming an insulating layer. This allows each secondary battery cell to be thermally coupled to the heat transfer plate, thereby achieving heat dissipation performance.

[0015] Furthermore, in the power supply device according to any one of the above aspects, the thermal conductor is a TIM sheet.

[0016] In yet another aspect of the power supply device according to the present disclosure, in any of the above aspects, the power supply case has thermally conductive frames on the inner surfaces of the first and second main surfaces, the heat transfer plate has a heat transfer main surface that is thermally coupled to each cell end face of the plurality of secondary battery cells, and connecting pieces provided on both edge edges of the heat transfer main surface, the connecting pieces being thermally coupled to the frame via the thermal coupling structure and thermally coupled to the first and second main surfaces via the frame. With the above configuration, by providing a frame inside the power supply case, it is possible to thermally couple each battery block to the first and second main surfaces via the frame via the connecting pieces.

[0017] In addition, in the power supply device according to any one of the above aspects, the connecting piece is bent in a direction away from the plurality of secondary battery cells.

[0018] In addition, in the power supply device according to another aspect of the present disclosure, in any of the above aspects, the connecting piece has both sides cut out from the main heat transfer surface. With this configuration, by cutting out the corners where cooling performance is relatively high, it is possible to intentionally suppress cooling performance and achieve uniform cooling performance overall.

[0019] In a power supply device according to still another aspect of the present disclosure, in any of the above aspects, the heat transfer plate has a main heat transfer surface that connects to each cell end face of the plurality of secondary battery cells, and the joining pieces are provided on both edge edges of the main heat transfer surface, and the joining pieces are bent in two stages and thermally coupled to the first main surface and the second main surface via the thermal coupling structure. This configuration increases the flexibility of the joining pieces, making it easier to absorb manufacturing tolerances, and enables each battery block to be thermally coupled directly to the first main surface and the second main surface of the power supply case via the joining pieces.

[0020] In addition, in the power supply device according to any one of the above embodiments, the connecting piece is bent in two stages in a direction approaching the plurality of secondary battery cells. This configuration can contribute to reducing the height of the battery block.

[0021] Embodiments of the present disclosure will be described below with reference to the drawings. However, the embodiments described below are merely examples for embodying the technical concepts of the present disclosure, and the present disclosure is not limited to the following. Furthermore, this specification does not in any way specify the components set forth in the claims to be those of the embodiments. The dimensions, materials, shapes, relative positions, etc. of components described in the embodiments are not intended to limit the scope of the present disclosure, and are merely illustrative examples, unless otherwise specified. The size and positional relationships of components shown in the drawings may be exaggerated for clarity. Furthermore, in the following description, the same names and symbols indicate components that are identical or of the same quality, and detailed descriptions will be omitted as appropriate. Furthermore, the elements constituting the present disclosure may be configured with the same components, such that multiple elements are served by a single component, or conversely, the functions of a single component may be shared by multiple components.

[0022] The power supply device of the present disclosure can be used as a stationary power supply device, for example, a backup power supply for a data center, a power storage device for storing power obtained from solar power generation or the like for home, business, or factory use, or a power supply for daytime peak cutting, etc. Hereinafter, as one embodiment of the present disclosure, a power supply device used as a power supply capable of storing power in a home will be described. [Embodiment 1]

[0023] 1 to 12 show a power supply device 100 according to a first embodiment of the present disclosure. In these figures, Fig. 1 is a perspective view showing the power supply device 100 according to the first embodiment, Fig. 2 is an exploded perspective view of the power supply device 100 of Fig. 1, Fig. 3 is a further exploded perspective view of the power supply device 100 of Fig. 2, Fig. 4 is a cross-sectional view taken along line IV-IV of Fig. 1, Fig. 5 is a perspective view with an enlarged view of a main portion of the cross-section of Fig. 4, Fig. 6 is a perspective view of the battery block 50 of Fig. 3, Fig. 7 is a plan view of the battery block 50 of Fig. 6, Fig. 8 is an exploded perspective view of the battery block 50 of Fig. 6, Fig. 9 is a plan view of the front of the battery block 50 of Fig. 6 seen obliquely from above, Fig. 10 is a side view of the battery block 50 of Fig. 6, Fig. 11 is an image diagram showing the results of a simulation of the temperature distribution of the heat transfer plate 20, and Fig. 12 is a perspective view with an enlarged view of a main portion of the battery holder 54 of Fig. 8. The power supply device 100 shown in these figures includes a power supply case 10, a plurality of battery blocks 50 housed within the power supply case 10, and a heat transfer plate 20. (Power supply case 10)

[0024] The power supply case 10 is a member for housing multiple battery blocks 50 and constitutes the outer shape of the power supply device 100 as shown in Figure 1. The power supply case 10 has a first main surface 14 and a second main surface 15. The first main surface 14 and the second main surface 15 each extend in a first direction (the vertical direction in the figure). The first main surface 14 and the second main surface 15 are made of a thermally conductive material, preferably a metal.

[0025] The first main surface 14 and the second main surface 15 are spaced apart and facing each other. The power supply case 10 houses multiple battery blocks 50 stacked in multiple stages along a first direction between the first main surface 14 and the second main surface 15, which form a pair of opposing surfaces. In the example shown in FIG. 2 , the power supply case 10 is composed of a case body 13 having a box-like outer shape. The case body 13 is formed like a shelf that houses the battery blocks 50 therein. The case body 13 has the first main surface 14 on the front side and the second main surface 15 on the back side. These components are fixed by screwing or the like. Furthermore, as shown in FIG. 3 , the left side of the case body 13 is closed by a first side surface 11, and the right side is closed by a second side surface 12. Such a power supply case 10 is preferably made of a metal such as sheet metal that has excellent heat dissipation properties and strength. In the example shown in Figure 3, the first main surface 14 and the second main surface 15, and the first side surface 11 and the second side surface 12 of the case body 13 are separate members, but they may also be integrated with the case body (battery block 50).

[0026] A plurality of battery blocks 50 are stacked in multiple stages inside the power supply case 10. In the example of Fig. 3, the plurality of battery blocks 50 are stacked vertically in alternating opposite orientations. Furthermore, when the plurality of battery blocks 50 are stacked vertically, a space is formed between adjacent battery blocks 50 in the vertical stacked state, as shown in the cross-sectional view of Fig. 4.

[0027] Each battery block 50 includes a plurality of secondary battery cells 1. Each battery block 50 is held by a battery holder 54 so that one of the cell end faces 2 of the plurality of secondary battery cells 1 is flush with one another. (Heat transfer plate 20)

[0028] A heat transfer plate 20 is provided on one side of each battery block 50. As shown in the cross-sectional views of Figures 4 and 5 and the perspective view of Figure 6, each heat transfer plate 20 is thermally coupled to one of the cell end faces 2 of the multiple secondary battery cells 1 arranged in the same plane. Furthermore, each heat transfer plate 20 is thermally coupled to the first and second main surfaces 14 and 15 of the power supply case 10, and heat generated by the secondary battery cells 1 is transferred to the power supply case 10 for heat dissipation, as indicated by the arrows in the plan view of Figure 7. The heat transfer plate 20 is made of a metal with excellent heat transfer performance. This allows the metal heat transfer plate 20, which has excellent thermal conductivity, to be thermally coupled to the first and second main surfaces 14 and 15, which are also made of metal, to transfer heat from heat-generating components such as the secondary battery cells 1 to the first and second main surfaces 14 and 15 of the power supply case 10. This effectively allows the power supply case 10 itself to function as a heat dissipation component, thereby achieving heat dissipation to the outside. (Connecting pieces 22)

[0029] As shown in the exploded perspective view of FIG. 8 , the heat transfer plate 20 includes a flat heat transfer main surface 21 and connecting pieces 22 attached to both edges of the heat transfer main surface 21. The heat transfer main surface 21 and connecting pieces 22 are integrally formed, and both edges of the heat transfer main surface 21 are bent to erect the connecting pieces 22. The heat transfer main surface 21 is thermally coupled to each cell end surface 2 of the multiple secondary battery cells 1. The connecting pieces 22 are also thermally coupled along the first main surface 14 and the second main surface 15. Here, as shown in FIGS. 9 and 10 , each connecting piece 22 is bent upward in the figure, away from the multiple secondary battery cells 1. This allows thermal coupling to the power supply case 10 at a position spaced apart from the side of the battery holder 54, improving workability. (Thermal Coupling Structure)

[0030] A thermal bonding structure is provided at the bonding interface between the joining piece 22 and the first main surface 14, and between the joining piece 22 and the second main surface 15. This allows for efficient cooling of the secondary battery cells 1 with a simple configuration, without the need to add an air-cooling structure such as a cooling fan.

[0031] Rechargeable battery cells generate heat during charging and discharging, and charging and discharging must be limited or stopped at high temperatures. Therefore, efficient cooling is essential. Particularly in large power supplies using many rechargeable battery cells, the temperature variation among the rechargeable battery cells within a battery block can affect their lifespan. For this reason, air cooling, which involves forcibly blowing cooling air into heat-generating components such as rechargeable battery cells for heat exchange, has traditionally been used. Water cooling has also been adopted to further enhance cooling performance. However, air cooling and air cooling structures, such as a cooling fan for drawing in and expelling cooling air into the power supply case and a cooling air passage for circulating the cooling air, are required. Water cooling requires the addition of a water cooling unit, etc., which results in a complex power supply configuration.

[0032] In contrast, in the power supply unit 100 according to this embodiment, a heat transfer plate 20 is provided for each battery block 50, and these heat transfer plates 20 are thermally coupled to the first main surface 14 and the second main surface 15 of the power supply case 10, respectively. This makes it possible to improve heat dissipation performance and dissipate heat efficiently without the need for a forced cooling mechanism such as a cooling fan that forcibly blows cooling air or a water-cooling unit (thermal conductor 30).

[0033] The thermally coupled structure thermally couples the heat transfer plate 20 fixed to the battery block 50 to the power supply case 10. For example, the heat transfer plate 20 may be directly bonded to the power supply case 10, or a separate member may be used. An example of such a thermally coupled structure using a separate member is a structure in which flexible thermal conductors 30 are interposed at the interface between the connecting piece 22 and the first main surface 14 and at the interface between the connecting piece 22 and the second main surface 15. This structure accommodates the dimensional tolerances of the metal heat transfer plate 20 and the first and second main surfaces 14 and 15, avoiding the formation of a heat insulating layer at the interface between them, and thereby achieving excellent heat dissipation performance. Examples of such thermal conductors 30 include TIM (Thermal Interface Material) sheets and thermally conductive fillers. TIM sheets are typically made of materials such as silicone, acrylic, and carbon fiber. Silicon bond or other thermally conductive fillers can be used. (Frame 16)

[0034] Furthermore, a thermally conductive frame 16 may be provided on each of the inner surfaces of the first and second main surfaces 14, 15 of the power supply case 10. The frame 16 is made of a material with excellent thermal conductivity, preferably metal. As shown in the cross-sectional perspective view of Figure 5, the connecting pieces 22 are thermally coupled to the frame 16 via a thermal coupling structure. Each connecting piece 22 is thermally coupled to the first and second main surfaces 14, 15 via the frame 16.

[0035] In the example of Figure 5, a thermal conductor 30 is interposed between each of the left and right frames 16 and the connecting piece 22. However, this configuration is not limited thereto. For example, a thermal conductor 30 may be interposed between either the left or right frame 16 and the connecting piece 22, while either the left or right frame 16 and the connecting piece 22 may be directly joined. For joining, screwing, welding, or the like may be used. In this way, by using a flexible thermal conductor 30 to accommodate tolerances on only one side, the thermal coupling structure can be simplified.

[0036] Furthermore, it is preferable that the heat transfer plate 20 does not have the connecting pieces 22 along the entire length of the side surface of the main heat transfer surface 21, but rather does not have the connecting pieces 22 at the edges of the main heat transfer surface 21. In other words, it is preferable that both sides of the connecting pieces 22 are notched from the main heat transfer surface 21, i.e., that the four corners of the main heat transfer surface 21 are notched. This reduces the variation in the heat distribution along the surface of the main heat transfer surface 21. Figure 11 shows the results of a simulation in which current was applied to the battery block 50 and the temperature distribution of the heat transfer plate 20, which thermally connected multiple secondary battery cells 1. As shown in this figure, the temperature distribution of the battery block is higher in the secondary battery cells located in the center, while the secondary battery cells located on the periphery are relatively lower because they are more likely to be cooled from the side surfaces. In particular, the secondary battery cells located in the corners are cooled from both side surfaces and therefore have the lowest temperature. Since variations in cooling performance cause uneven deterioration of the secondary battery cells, and the lifespan of the battery block is determined by the secondary battery cell with the most advanced deterioration, it is desirable to prevent variations in cooling performance. Therefore, in order to reduce the cooling capacity of the secondary battery cells at the corners, connecting pieces are intentionally not provided at the corners of the main heat transfer surface, thereby reducing the cooling capacity at the corners and achieving a uniform cooling capacity. (Details of the battery block 50)

[0037] As shown in the exploded perspective view of Figure 8, each battery block 50 includes a heat transfer plate 20, an insulating sheet 51, a second thermal conductor 52, a battery holder 54, a secondary battery cell 1, lead plates 55, and a circuit board 56. (Secondary Battery Cell 1)

[0038] Each secondary battery cell 1 can be a cylindrical or rectangular secondary battery cell. In the example shown in Fig. 8, cylindrical secondary battery cells 1 are arranged vertically. By arranging the secondary battery cells 1 vertically, one of the cell end faces 2 of each secondary battery cell 1 can be easily thermally coupled to the heat transfer plate 20 or a heat transfer surface, allowing the multiple secondary battery cells 1 to exert their cooling capacity uniformly.

[0039] Each secondary battery cell 1 has positive and negative electrodes. The positive and negative electrodes are preferably provided on one cell end surface 2 of the secondary battery cell 1. In the example shown in FIG. 8 , the lower cell end surface 2 is connected to a lead plate 55. As a result, a lead plate is not required on the upper cell end surface 2, which is used for heat dissipation. That is, each secondary battery cell 1 has one cell end surface 2 (the upper surface in the figure) thermally coupled to a heat transfer plate 20, and the other cell end surface 2 (the lower surface in the figure) has a positive electrode and a negative electrode, which are each electrically connected to a lead plate 55. In this way, by concentrating electrical connections on one cell end surface 2, the other cell end surface 2 can be used for thermal coupling.

[0040] The secondary battery cells 1 are lithium-ion secondary batteries. A battery block 50 using lithium-ion secondary batteries as the secondary battery cells 1 can achieve a high output relative to its volume and weight. However, instead of lithium-ion batteries, known secondary batteries such as lithium polymer batteries, nickel-metal hydride batteries, and nickel-cadmium batteries can also be used for the secondary battery cells (battery holder 54).

[0041] The battery holder 54 is a component for holding multiple rechargeable battery cells 1. This battery holder 54 is divided into multiple sub-holders 54a and 54b, which sandwich the rechargeable battery cells 1. In the example shown in FIG. 8 , the battery holder 54 holds multiple cylindrical rechargeable battery cells 1 in a vertical orientation. The multiple rechargeable battery cells 1 are connected in series or parallel via lead plates 55 or the like. The number of series or parallel connections can be set as desired depending on the required specifications. In other words, the number and arrangement of the rechargeable battery cells 1 are not limited to this example and can be any number or arrangement as appropriate. The battery block 50 may also be composed of multiple sub-blocks, with each sub-block housing multiple rechargeable battery cells. The battery holder 54 may also include a mechanism for holding or positioning the lead plates 55. Such a battery holder 54 is made of a material with excellent insulating and heat-resistant properties, such as a resin such as polycarbonate or ABS. (Circuit Board 56)

[0042] As shown in Figure 8 and other figures, the battery block 50 is connected to a circuit board 56 via lead plates 55. The circuit board 56 is equipped with a charge / discharge circuit that charges and discharges the secondary battery cells 1, and a protection circuit that monitors the voltage and temperature of the secondary battery cells 1 and cuts off the current in the event of an abnormality. The circuit board 56 is made of a glass epoxy board or the like. A board holder for holding such a circuit board 56 may also be provided. (Second thermal conductor 52)

[0043] A second thermal conductor 52 is interposed between the upper cell end surface 2 of each secondary battery cell 1 and the heat transfer plate 20. Like the thermal conductor 30 described above, the second thermal conductor 52 is also made of a flexible material with excellent thermal conductivity. Preferably, the same TIM sheet or thermally conductive filler as the thermal conductor 30 is used. The upper cell end surface 2 of each secondary battery cell 1 exposed from the battery holder 54 through the electrode window 54c is thermally coupled to the heat transfer plate 20 via the second thermal conductor 52. This prevents the thickness of the battery holder 54 from forming an air layer on the other side of the cell end surface 2 of each secondary battery cell 1, creating an insulating layer. The second thermal conductor 52 thermally couples each secondary battery cell 1 to the heat transfer plate 20, enabling heat dissipation performance to be achieved. (Insulating Sheet 51)

[0044] Furthermore, an insulating sheet 51 is interposed between the second thermal conductor 52 and the heat transfer plate 20. The insulating sheet 51 insulates the metal heat transfer plate 20 from electrical conduction with the cell end surface 2 of the secondary battery cell 1. Such insulating sheet 51 can be made of acrylic, urethane, epoxy, or silicone resin plate, insulating paper, mica sheet, or the like. (Electrode window 54c)

[0045] As shown in the enlarged perspective view of Fig. 12, the battery holder 54 has an electrode window 54c that exposes the upper cell end surface 2 of each secondary battery cell 1 that is thermally coupled to the heat transfer plate 20. To prevent the secondary battery cells 1 from slipping out of the battery holder 54, as shown in the cross-sectional view of Fig. 13, a portion of the battery holder 54 protrudes in a convex shape to engage with the cell end surface 2 of the secondary battery cell 1, and the electrode window 54c is formed around the periphery of the convex shape.

[0046] On the other hand, forming the electrode window 54c requires a convex shape on the battery holder 54. As a result, if an insulating plate 51X or a heat transfer plate is placed on the top surface of the battery holder 54 as shown in the cross-sectional view of Figure 14, the cell end face 2 is separated from the insulating sheet by the thickness d1 of the convex shape, forming a space, i.e., an air layer, which acts as a heat insulating layer and reduces thermal conductivity.

[0047] Therefore, it is necessary to fill the gap to prevent the formation of an insulating layer on the cell end surface 2. For example, as shown in the cross-sectional view of Figure 15, if a thermal conductor 53 is placed between the cell end surface 2 of the battery holder 54 and the insulating plate 51X, the thermal conductor 53 will float, the gap will not be filled, and an air gap will remain. Furthermore, if the corners of the insulating plate 51X are screwed into the battery holder 54, for example, and pressure is applied to the thermal conductor 53, the insulating plate 51X will deform, preventing sufficient pressure from being transmitted to the center of the thermal conductor 53, and the gap will still not be filled, leaving an air gap, as shown in the cross-sectional view of Figure 16.

[0048] In contrast, in this embodiment, as shown in the cross-sectional view of Figure 17, the heat transfer plate 20 is made rigid as a metal plate, and is screwed into the battery holder 54 while being pressed from the top surfaces of the second thermal conductor 52 and the insulating sheet 51, thereby reliably pressing the second thermal conductor 52 and bringing it into close contact with the cell end face 2, eliminating the air layer and allowing the thermally coupled state to exhibit heat transfer performance.

[0049] 18, if the insulation can be ensured by the second thermal conductor 52 alone, the insulating sheet may be omitted. This reduces the number of intervening members, further enhancing thermal coupling and improving heat dissipation. [Embodiment 2]

[0050] In the above-described first embodiment, an example has been described in which the heat transfer plate 20 is thermally coupled to the first main surface 14 and the second main surface 15 via the frame 16. However, the present disclosure is not limited to this configuration, and the heat transfer plate 20 may be thermally coupled directly to the first main surface 14 and the second main surface 15 without a frame or the like. Such an example is shown in FIGS. 19 to 21 as a power supply device 200 according to a second embodiment. In these figures, the same components as those in the first embodiment described above are designated by the same reference numerals (except for branch numbers, etc.), and detailed descriptions thereof will be omitted as appropriate.

[0051] In the power supply device 200 shown in Figures 19 and 20, the connecting piece 22' of the heat transfer plate 20' is bent in two stages. Specifically, unlike the first embodiment, the connecting piece 22' is bent in a direction that brings it closer to the multiple secondary battery cells 1 (downward in the figures). This contributes to a lower profile of the battery block 50, as shown in Figure 21. Furthermore, a stepped region is provided in the middle of the connecting piece 22'. As a result, the connecting piece 22' has three bent portions. This shape allows the connecting piece 22' to protrude from the side of the heat transfer plate 20' and make contact with the first main surface 14 and the second main surface 15 without the need for a frame.

[0052] The step region is preferably an inclined region that is inclined obliquely, which increases the flexibility of the connecting piece 22', making it easier to deform and to absorb manufacturing tolerances.

[0053] The power supply device according to the present disclosure can be suitably used as a stationary power storage device, for example, a power supply device for home use, business use, or factory use, or as a backup power supply for a data center.

[0054] DESCRIPTION OF SYMBOLS 100, 200... Power supply device 1... Secondary battery cell 2... Cell end surface 10... Power supply case 11... First side surface 12... Second side surface 13... Case body 14... First main surface 15... Second main surface 16... Frame 20, 20'... Heat transfer plate 21... Heat transfer main surface 22, 22'... Joint piece 30... Thermal conductor 50... Battery block 51... Insulating sheet 51X... Insulating plate 52... Second thermal conductor 53... Thermal conductor 54... Battery holder; 54a, 54b... Sub-holder; 54c... Electrode window 55... Lead plate 56... Circuit board d1... Thickness of convex shape

Claims

1. A power supply device comprising: a plurality of battery blocks each including a plurality of secondary battery cells each having a cell end face; a plurality of thermally conductive heat transfer plates arranged on one surface of each of the plurality of battery blocks where the cell end faces of the plurality of secondary battery cells are arranged in the same plane; and a power supply case having a first main surface with thermal conductivity extending in a first direction and a second main surface with thermal conductivity spaced apart from and facing the first main surface, the power supply case housing the plurality of battery blocks stacked in multiple stages along the first direction between the first main surface and the second main surface, wherein each of the plurality of heat transfer plates has both side edges folded and is provided with connecting pieces that are aligned along the first main surface and the second main surface for thermal bonding, and wherein the power supply device is provided with thermal bonding structures at the bonding interfaces between the connecting pieces and the first main surface and the second main surface for thermal bonding.

2. A power supply device according to claim 1, wherein the heat transfer plate is made of metal, and the first main surface and the second main surface are each made of metal.

3. A power supply device according to claim 2, wherein the thermal coupling structure comprises a flexible thermal conductor interposed at the interface between the coupling piece and the first main surface, and at the bonding interface between the coupling piece and the second main surface.

4. A power supply device according to claim 1, wherein each secondary battery cell is a cylindrical secondary battery cell with a cylindrical outer casing, and the battery block is provided with a battery holder that holds the multiple secondary battery cells in a position where the end faces of each cell are flush with one another.

5. A power supply device according to claim 4, further comprising lead plates electrically connected to the plurality of secondary battery cells, wherein each secondary battery cell has one of the cell end faces thermally coupled to the heat transfer plate, and the other of the cell end faces is provided with a positive electrode and a negative electrode, each of which is electrically connected to the lead plate.

6. A power supply device as claimed in claim 5, further comprising a flexible second thermal conductor interposed between the other of the cell end faces of each secondary battery cell and the heat transfer plate, wherein the battery holder has an electrode window that exposes the other of the cell end faces of each secondary battery cell, and the other of the cell end faces of each secondary battery cell exposed from the battery holder through the electrode window is thermally coupled to the heat transfer plate via the second thermal conductor.

7. A power supply device according to claim 3, wherein the thermal conductor is a TIM sheet.

8. A power supply device according to any one of claims 1 to 7, wherein the power supply case has thermally conductive frames on the inner surfaces of the first main surface and the second main surface, and the heat transfer plate has a heat transfer main surface that is thermally coupled to each cell end face of the plurality of secondary battery cells, and connecting pieces that are provided on both side edges of the heat transfer main surface, and the connecting pieces are thermally coupled to the frame via the thermal coupling structure, and are thermally coupled to the first main surface and the second main surface via the frame.

9. A power supply device according to claim 8, wherein the connecting piece is bent in a direction away from the plurality of secondary battery cells.

10. A power supply device according to claim 8, wherein the connecting piece is formed by cutting out both sides of the main heat transfer surface.

11. A power supply device according to any one of claims 1 to 7, wherein the heat transfer plate comprises a heat transfer main surface that connects to each cell end face of the plurality of secondary battery cells, and a connecting piece provided on each of the edge portions on both sides of the heat transfer main surface, and the connecting piece is bent in two stages and thermally connected to the first main surface and the second main surface via the thermal coupling structure.

12. A power supply device according to claim 11, wherein the connecting piece is bent in two stages in a direction approaching the plurality of secondary battery cells.

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