Power supply device and method for manufacturing same

Abstract

This power supply device comprises: a plurality of secondary battery cells each having a cell end surfaces with an electrode provided thereon; one or more battery blocks for accommodating the plurality of secondary battery cells; and an exterior case for accommodating the one or more battery blocks. Each battery block forms a cooling air path, through which cooling air flows, between the inner surface of the battery block and the surface of a cell intermediate region which is between end regions continuous with the cell end surfaces of each secondary battery cell. The exterior case forms an external opening that communicates with the cooling air path, and comprises an electrode waterproof part that is interposed between each battery block and the cell end surface of each secondary battery cell, and that waterproofs the electrodes with respect to the cooling air path.

Description

Power supply device and method for manufacturing the same

[0001] The present disclosure relates to a power supply device and a method for manufacturing the same.

[0002] Power supply devices are used for applications in which multiple rechargeable secondary battery cells, such as lithium-ion secondary batteries, are connected in series or parallel and housed in an exterior case to drive electrical equipment such as power tools, or electrically powered mobile objects such as vehicles and construction machinery (see, for example, Patent Document 1). The secondary battery cells used in such power supply devices generate heat during charging and discharging and therefore need to be cooled. For this reason, in order to cool the secondary battery cells by air, cooling air channels are formed between the secondary battery cells, and openings are provided in the exterior case to communicate with the cooling channels.

[0003] On the other hand, power supplies and other devices used outdoors must be waterproof, so the exterior case must have an opening to allow cooling air in from the outside, while also preventing unintended internal short circuits caused by water seeping in from the outside.

[0004] Republished Patent No. WO2017 / 175487

[0005] One object of one embodiment of the present disclosure is to provide a power supply device and a manufacturing method thereof that can cool a secondary battery cell while waterproofing it. Another object of another embodiment is to provide a novel power supply device and a manufacturing method thereof. Note that the description of these objects and problems of the present disclosure does not preclude the existence of other objects and problems. Furthermore, it is not necessary for one embodiment of the present disclosure to solve all of these problems. Furthermore, problems other than these can be extracted from the description of the specification, drawings, and claims of the present disclosure.

[0006] A power supply device according to one embodiment of the present disclosure is a power supply device comprising a plurality of secondary battery cells, each having a cell end face with an electrode, one or more battery blocks housing the plurality of secondary battery cells, and an outer case housing the one or more battery blocks, wherein each battery block forms a cooling air passage for flowing cooling air between the inner surface of the battery block and the surface of a cell intermediate region between end regions of each secondary battery cell that are continuous with the cell end face, and the outer case forms an external opening that communicates with the cooling air passage, and is provided with an electrode waterproofing portion interposed between each battery block and the cell end face of each secondary battery cell to waterproof the electrodes from the cooling air passage.

[0007] Another embodiment of a method for manufacturing a power supply device is a method for manufacturing a power supply device including a plurality of secondary battery cells, each having a cell end face with an electrode, one or more battery blocks that house the plurality of secondary battery cells, and an exterior case that houses the one or more battery blocks, and includes the steps of: preparing each battery block with an electrode window formed therein to expose each electrode of the plurality of secondary battery cells; fixing an electrode waterproof part between the cell end face of each secondary battery cell and the electrode window of each battery block to expose the electrode through the electrode window; connecting lead plates to the electrodes through the electrode window; and housing the one or more battery blocks in the exterior case and communicating a cooling air passage for flowing cooling air, the cooling air passage being formed between the inner surface of each battery block and the surface of a cell intermediate region between end regions of each secondary battery cell that are continuous with the cell end face, with an external opening formed in the exterior case.

[0008] According to a power supply device and a manufacturing method thereof according to one embodiment of the present disclosure, cooling air is circulated through the cell intermediate region of the secondary battery cell to cool it, while an electrode waterproofing section provided between the cell end face of the secondary battery cell and the battery block makes it possible to waterproof the electrodes, and the necessary waterproof structure can be maintained while an external opening is opened in the exterior case for cooling.

[0009] 1. A perspective view showing a power supply device according to a first embodiment. 1. A perspective view of the power supply device of FIG. 1, seen from diagonally below the rear side. 2. An exploded perspective view of the power supply device of FIG. 1, with the upper case disassembled. 3. A further exploded perspective view of the power supply device of FIG. 3. 4. An exploded perspective view of the power supply device of FIG. 2. 5. A cross-sectional view of the power supply device of FIG. 1, taken along line VI-VI. 6. An exploded perspective view of the battery module of FIG. 4. 7. An exploded perspective view of the lead plates disassembled from one battery block of FIG. 7. 8. An exploded perspective view of one holder case of FIG. 8. 9. A further exploded perspective view of the holder case of FIG. 9. 10. An exploded perspective view showing the electrode waterproof part set in the holder side case of FIG. 9. 11. A cross-sectional view of the battery block of FIG. 1, taken along line XII-XII. 12. A cross-sectional view of the battery block of FIG. 7, taken along line XIII-XIII. 13. An enlarged cross-sectional view of a main portion of the battery block of FIG. 13. 14. A cross-sectional perspective view of the power supply device of FIG. 1, taken along line XV-XV. 15. A cross-sectional perspective view of the power supply device of FIG. 1, taken along line XVI-XVI.

[0010] The embodiments of the present disclosure may be specified by the following configurations and features.

[0011] In a power supply device according to another aspect of the present disclosure, in any of the above aspects, the battery blocks each have an electrode window that exposes the electrode at a position facing the cell end face, and the electrode waterproof part is formed in an annular shape, with one surface of the electrode waterproof part fixed to the periphery of the electrode window of the battery block and the other surface fixed to the cell end face, the electrodes are arranged inside the annular shape, and the electrodes are exposed from the battery block through the electrode window. With this configuration, it is possible to expose the electrodes and establish electrical connection between the cell end face of the secondary battery cell and the battery block while the electrode waterproof part is fixed between the cell end face of the secondary battery cell and the battery block.

[0012] In addition, the power supply device according to another aspect of the present disclosure is any of the above-described aspects, further including a lead plate connected to the electrode through the electrode window. With this configuration, it is possible to ensure an area for connecting the lead plate and the electrode while waterproofing the electrode with the annular electrode waterproof portion.

[0013] In accordance with another aspect of the present disclosure, there is provided a power supply device according to any one of the above aspects, further comprising a circuit board electrically connected to the plurality of secondary battery cells via the lead plates, wherein a waterproof space configured to have a waterproof structure is provided inside the exterior case between the inner surface of the exterior case and the outer surface of the battery block, and the circuit board is disposed in the waterproof space to provide waterproofing.

[0014] Furthermore, in the power supply device according to any one of the above aspects, the electrode waterproofing portion is configured with a waterproof double-sided tape.

[0015] In a power supply device according to still another aspect of the present disclosure, in any of the above aspects, the battery block has a holder-top opening that is in communication with the cooling air passage, and the holder-top opening is in communication with the external opening.

[0016] In yet another aspect of the power supply device of the present disclosure, in any of the above aspects, the exterior case includes a partition that holds the battery block therein. The partition defines a partition opening that exposes an end of the cooling air path and communicates with the external opening. A first seal is provided between the periphery of the partition opening and the periphery of the cooling air path.

[0017] Furthermore, in the power supply device according to another aspect of the present disclosure, in addition to any of the above aspects, a second seal is provided between the periphery of the partition and the inner surface of the exterior case.

[0018] Furthermore, in a power supply device according to another aspect of the present disclosure, in any of the above-mentioned aspects, the outer case has a first external opening and a second external opening, which connect the cooling air path to the outside, opened on a portion of its surface as the external openings.

[0019] A third seal portion that waterproofs the battery block is provided between the periphery of the first external opening and the periphery of the cooling air passage.

[0020] The second external opening is in communication with the partition opening.

[0021] In addition, in the power supply device according to any one of the above aspects, each secondary battery cell includes an outer can formed in a cylindrical shape.

[0022] The electrode waterproof parts are fixed to the cell end faces at both ends of the cylindrical outer can.

[0023] In addition, the power supply device according to another aspect of the present disclosure is any one of the above aspects, wherein the battery blocks are divided so as to cover the end regions of the respective secondary battery cells.

[0024] In yet another aspect of the power supply device of the present disclosure, in any of the above aspects, the cell intermediate area is exposed from the battery block. The cell intermediate area is exposed to the cooling air path. With this configuration, by exposing the cell intermediate area of ​​each secondary battery cell to the cooling air path, cooling air can come into direct contact with the cell intermediate area, allowing for efficient heat exchange.

[0025] In addition, the power supply device according to another aspect of the present disclosure is any of the above-described aspects, wherein the one or more battery blocks are a set of battery blocks arranged adjacent to each other.

[0026] 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 shared by one component, or conversely, the functions of one component may be shared by multiple components.

[0027] The power supply device of the present disclosure can be used as a power source for portable electrical devices such as power tools and electric cleaners, as a driving power source for mobile objects such as electric carts, electric scooters and assisted bicycles, as a backup power source for servers in stationary power storage applications, as a power supply device for home, office or factory use, and as a driving power source for vehicles such as hybrid cars and electric automobiles, etc. Below, a power supply device used as a driving power source for power tools will be described as one embodiment of the present invention.

[0028] [Embodiment 1] A power supply device 100 according to embodiment 1 of the present disclosure is shown in Figures 1 to 16. In these figures, Figure 1 is a perspective view showing the power supply device 100 according to embodiment 1, Figure 2 is a perspective view of the power supply device 100 of Figure 1 as seen from diagonally below the rear side, Figure 3 is an exploded perspective view of the power supply device 100 of Figure 1 with the upper case 11 disassembled, Figure 4 is a further exploded perspective view of the power supply device 100 of Figure 3, Figure 5 is an exploded perspective view of the power supply device 100 of Figure 2, Figure 6 is a cross-sectional view of the power supply device 100 of Figure 1 taken along line VI-VI, Figure 7 is an exploded perspective view of the battery module 2 of Figure 4, Figure 8 is an exploded perspective view of the lead plates 5 disassembled from one battery block 30 of Figure 7, and Figure 9 is an exploded perspective view of one holder case 31 of Figure 8. Fig. 10 is a further exploded perspective view of the holder case 31 of Fig. 9, Fig. 11 is an exploded perspective view showing the electrode waterproof part 50 set in the holder side case 31B of Fig. 9, Fig. 12 is a cross-sectional view of the battery block 30 of Fig. 1 taken along line XII-XII, Fig. 13 is a cross-sectional view of the battery block 30 of Fig. 7 taken along line XIII-XIII, Fig. 14 is an enlarged cross-sectional view of a main part of the battery block 30 of Fig. 13, Fig. 15 is a cross-sectional perspective view of the power supply device 100 of Fig. 1 taken along line XV-XV, and Fig. 16 is a cross-sectional perspective view of the power supply device 100 of Fig. 1 taken along line XVI-XVI. The power supply device 100 shown in these figures includes an outer case 10, a battery module 2, and a circuit board 3.

[0029] (External Case 10) The external case 10 houses the battery module 2 and the circuit board 3. The external shape of the external case 10 can be any shape that has an internal storage space. In the example shown in FIGS. 1 to 6, the external case 10 has a box-like shape that extends in one direction (the horizontal direction in the figures). As shown in FIGS. 3 to 5, the box-shaped external case 10 is composed of an upper case 11 and a lower case 12 that are divided into two parts, upper and lower. However, the present disclosure is not limited to this configuration, and the external case may be divided into three or more parts. The external case may also be divided into left and right parts.

[0030] The exterior case 10 is preferably made of a material with excellent insulating properties, such as a resin such as polycarbonate or PC-ABS alloy. However, the exterior case may also be made of a metal material such as aluminum or its alloy. An internal space is provided inside the exterior case 10 to house the battery module 2 and circuit board 3. In the example shown in Figures 5 and 6, an internal space is formed in the lower case 12, and the battery module 2 and circuit board 3 are housed therein. The portion of the internal storage space where the battery block 30 of the battery module 2 and the circuit board 3 are disposed is waterproofed by a battery waterproof section 60, and a waterproof space 16 is provided inside the exterior case 10 between the inner surface of the exterior case 10 and the outer surface of the battery block 30, providing a waterproof structure.

[0031] (Partition 20) A partition 20 is also disposed on the top surface of the battery module 2. The partition 20 is installed at the upper opening edge of the lower case 12, and the battery module 2 and the circuit board 3 are housed in the internal space of the lower case 12 of the exterior case 10, which is partitioned by the partition 20. The partition 20 has partition openings 21. In the example of FIG. 3 , the partition 20 has two partition openings 21 formed in it. A portion of the battery module 2 is exposed from each of the partition openings 21. This allows the battery module 2 to be partially connected to the outside, allowing cooling air to be taken in or discharged into the battery module 2.

[0032] Furthermore, the exterior case 10 has a first external opening 13 and a second external opening 14 in a portion thereof. These first external opening 13 and second external opening 14 are connected to a cooling air passage. In the example shown in Figures 2 and 5, the first external opening 13 is opened on the bottom surface of the exterior case 10, and the second external opening 14 is opened on the upper side of the back surface of the exterior case 10 (details will be described later).

[0033] 4 to 5, 7 to 10, etc., in order to cool the multiple secondary battery cells 1 housed in each battery block 30 that constitutes the battery module 2, a holder upper opening 34 is provided on the top surface of the holder case 31 that constitutes each battery block 30, and a holder lower opening 35 is provided on the bottom surface. The holder upper opening 34 is in communication with the first external opening 13 of the exterior case 10, and the holder lower opening 35 is in communication with the second external opening 14 (details will be described later).

[0034] (Battery Module 2) The battery module 2, also called a core pack, houses multiple secondary battery cells 1. The battery module 2 may also be composed of multiple battery blocks 30, with each battery block 30 housing multiple secondary battery cells 1. In the examples shown in Figures 4, 6 to 7, etc., the battery module 2 is constructed by stacking two battery blocks 30.

[0035] (Holder Case 31) Each battery block 30 includes a holder case 31, a rechargeable battery cell 1, and lead plates 5. The holder case 31 has a box-shaped exterior as shown in FIG. 8. A holder storage space is formed inside the holder case 31, and multiple rechargeable battery cells 1 are stored within the holder storage space. The holder case 31 shown in FIG. 9 and other figures is divided into three sections, with left and right holder side cases 31A and 31B joined to a middle holder intermediate case 31C. However, the holder case is not limited to a three-section structure and may be divided into four or more sections, or into two sections. The spaces between the divided holder cases are waterproofed by a waterproof structure. The holder case 31 is made of a material with excellent insulating properties. Preferably, it is made of a resin such as polycarbonate or PC-ABS alloy.

[0036] (Case tubular portion 32) Furthermore, the holder case 31 forms case tubular portions 32 on the inner surface of the holder side cases 31A, 31B that cover the end regions of the rechargeable battery cells 1. In the example shown in Figures 9 to 11, etc., cylindrical case tubular portions 32 are formed integrally with the holder case 31 on the inner surface of the holder case 31 at positions corresponding to each end region of the rechargeable battery cells 1.

[0037] (Lead Plates 5) The battery block 30 also includes lead plates 5 for electrically connecting the rechargeable battery cells 1 to each other. The lead plates 5 are preferably arranged on the outer surface of the holder case 31. The holder case 31 also has electrode windows 33 on its side that communicate with the case cylindrical portion 32 to connect the lead plates 5 arranged on the outer surface to the terminals of the rechargeable battery cells 1.

[0038] Each lead plate 5 connects the electrodes of the cell end surfaces 1a of the secondary battery cells 1 to each other, thereby connecting multiple secondary battery cells 1 together. The lead plate 5 is made of a highly conductive metal plate such as an aluminum plate, a nickel plate, or a copper plate. The multiple secondary battery cells 1 are connected in series or in parallel via the lead plates 5. The number of series connections and the number of parallel connections can be set as desired depending on the required specifications. In the example shown in FIG. 8 , each lead plate 5 connects the end surfaces of approximately 10 secondary battery cells 1, and a total of 70 secondary battery cells 1 are connected in one battery block 30, forming a 7 series × 10 parallel configuration. In the example shown in FIG. 4 , two battery blocks 30 are stacked in the longitudinal direction of the secondary battery cells 1 and connected in series, forming a 14 series × 10 parallel configuration for a total of 140 secondary battery cells 1. However, the number of secondary battery cells and the connection configuration, i.e., the number of series and parallel connections, are not limited to this configuration.

[0039] (Bus Bars 6) Bus bars 6 are used to connect the lead plates 5 together as needed. In the example of the battery block 30 shown in the exploded perspective view of Figure 8, the bus bars 6 are arranged and connected on top of the surfaces of the lead plates 5, achieving a 7 series x 10 parallel configuration. The bus bars 6B located at the ends have their total output connection pieces 6C exposed on the top surface of the holder case 31. In the examples of Figures 4 and 7, the connection pieces 6C of two battery blocks 30 are connected together by a second bus bar 6D. By adding bus bars 6 in addition to lead plates 5 in this way, heat generation can be suppressed even when the current value is large. Note that in this embodiment, the lead plates 5 and bus bars 6 are configured as separate parts. However, depending on the current value, the bus bars can be omitted by having the lead plates function as bus bars.

[0040] In this example, the stacked secondary battery cells 1 are held in a position where the positive and negative electrodes alternate on the cell end faces 1 a. It is also preferable to arrange the adjacent battery blocks 30 so that the positive electrodes do not face each other. By arranging the secondary battery cells 1 in this manner, even if a gas release valve that opens when internal pressure becomes high is provided on the cell end face 1 a on the positive electrode side of the secondary battery cell 1, and another secondary battery cell 1 is not arranged opposite the cell end face 1 a, even if high-temperature, high-pressure gas is released from one secondary battery cell 1, safety can be improved by arranging the cell end faces 1 a without gas release valves facing each other.

[0041] (Insulating Sheet 40) Furthermore, an insulating sheet 40 may be added to each end surface of the holder case 31 to insulate the areas where the lead plate 5 and the bus bar 6 are exposed. The insulating sheet 40 may be formed as a single sheet or as multiple sheets. In the example of FIG. 8 , a first insulating sheet 41 and a second insulating sheet 42 are superimposed on the surface of the bus bar 6 as the insulating sheet 40. The first insulating sheet 41 superimposed on the bus bar 6 has an opening window 43 that opens at a position corresponding to the cell end face 1 a. Meanwhile, the second insulating sheet 42 superimposed on the first insulating sheet 41 closes the opening window 43.

[0042] (Circuit Board 3) The battery block 30 is connected to the circuit board 3 via lead plates 5 and bus bars 6. The circuit board 3 is equipped with a charge / discharge circuit that charges and discharges the rechargeable battery cells 1, and a protection circuit that monitors the voltage and temperature of the rechargeable battery cells 1 and cuts off the current in the event of an abnormality. The circuit board 3 is made of a glass epoxy board or the like. A board holder 4 may also be provided as a member to hold the circuit board 3.

[0043] (Secondary battery cells 1) As shown in Figures 6, 8, 12 to 14, etc., each battery block 30 houses secondary battery cells 1 in a holder case 31. Each secondary battery cell 1 can be a cylindrical or rectangular secondary battery cell. In the example shown in Figure 6, etc., cylindrical secondary battery cells 1 are used in a staggered arrangement in a horizontal position. Note that the number and arrangement of the secondary battery cells 1 are not limited to this example, and any number and arrangement can be used as appropriate. For example, cylindrical secondary battery cells can be arranged in a matrix. Known secondary batteries, such as lithium-ion secondary batteries, nickel-metal hydride batteries, and nickel-cadmium batteries, can be used as the secondary battery cells 1.

[0044] Each secondary battery cell 1 has a positive electrode and a negative electrode. The positive or negative electrode terminal is preferably provided on one cell end surface 1a of the secondary battery cell 1. In the examples of Figures 6 and 8, a positive electrode terminal is provided on one cell end surface 1a of the secondary battery cell 1, and the other surface of the outer can serves as the negative electrode. This example also shows an example in which the stacked secondary battery cells are held in an orientation in which the positive and negative electrodes appear alternately on the cell end surfaces. However, the secondary battery cells 1 may also be held in a battery block 30 in an orientation in which the positive or negative electrodes of all the secondary battery cells 1 are on the same side.

[0045] A gas release valve is provided on one cell end surface 1a of the exterior can of each secondary battery cell 1. The gas release valve opens in response to an increase in internal pressure of the exterior can, releasing gas inside the exterior can to the outside. Such a gas release valve is provided, for example, on the positive electrode side of the secondary battery cell 1.

[0046] (Holder upper opening 34) Each holder case 31 has a holder upper opening 34 and a holder lower opening 35 formed on its upper and lower surfaces, respectively. As shown in the cross-sectional views of Figures 12, 15, and 16, cooling air can be taken into the holder case 31 through the holder upper opening 34 and holder lower opening 35 opened at the top and bottom of the holder case 31, and can be discharged after heat exchange. Furthermore, by opening the holder upper opening 34 and the holder lower opening 35 on opposing surfaces of the holder case 31, the cooling air can be made to flow smoothly in a straight line.

[0047] Each holder upper opening 34 and holder lower opening 35 preferably extends in a direction intersecting the longitudinal direction of the secondary battery cells 1. This allows the holder upper openings 34 and holder lower openings 35 to be open in the direction in which the secondary battery cells 1 are stacked, allowing many secondary battery cells 1 to be exposed from the holder case 31, improving heat dissipation performance.

[0048] 10, the holder case 31 is divided into three sections, and the middle section, the holder intermediate case 31C, is provided with the holder upper opening 34 and the holder lower opening 35. The holder intermediate case 31C is formed in a frame shape, with the long side surfaces open and the short side surfaces closed. Note that multiple holder upper openings and multiple holder lower openings may be formed on the top and bottom surfaces of the holder case.

[0049] Furthermore, a holder upper opening 34 opened on the top surface of the holder case 31 communicates with the partition opening 21 of the partition section 20. A holder lower opening 35 opened on the bottom surface of the holder case 31 communicates with the second external opening 14 of the exterior case 10.

[0050] (Cooling Air Path) Each battery block 30 has a cooling air path for flowing cooling air between the inner surface of the battery block 30 and the surface of the cell intermediate region 1c between the end regions of each rechargeable battery cell 1 that are connected to the cell end faces 1a. The cooling air path is formed inside the holder case 31, in the gap between the inner surface of the holder case 31, i.e., the path between the holder lower opening 35 and the holder upper opening 34 of the holder intermediate case 31C, and the surface of the rechargeable battery cell 1, and between adjacent rechargeable battery cells 1. The exterior case 10 also has a first external opening 13 and a second external opening 14 that communicate with the cooling air path. With this configuration, cooling air is taken in from the outside through the cooling air path and flows through the path between the holder lower opening 35 and the holder upper opening 34 of the holder intermediate case 31C. This ensures gaps between the cells in the holder case 31, allowing the cooling air to flow directly to the sides of each of the rechargeable battery cells 1 stacked in a bale-like pattern, enabling efficient heat exchange and cooling.

[0051] 13 to 15 , etc., the cell intermediate region 1c of each secondary battery cell 1 is exposed inside the holder case 31, except for the terminals. The holder case 31 also has a holder upper opening 34 and a holder lower opening 35 that communicate with the cooling air path. The holder upper opening 34 communicates with the external second opening 14. The holder lower opening 35 communicates with the external first opening 13. This configuration allows cooling air to flow over the surfaces of the cell intermediate region 1c of the secondary battery cell 1, making it possible to efficiently cool the secondary battery cell 1.

[0052] The outer case 10 has a first external opening 13 and a second external opening 14. Cooling air is drawn in through the first external opening 13 and introduced into the outer case 10, where it undergoes heat exchange and is then discharged through the second external opening 14. For example, a fan or the like is provided to forcibly circulate the cooling air. To ensure smooth intake and discharge of cooling air into and from the outer case 10, the first external opening 13 and the second external opening 14 are preferably provided on different sides of the outer case 10. In the example shown in FIG. 2 , the first external opening 13 is provided on the bottom surface of the outer case 10, and the second external opening 14 is provided on the upper side of the back surface of the outer case 10. Note that, in the present disclosure, examples are described in which cooling air is drawn in through the first external opening 13 and discharged through the second external opening 14, as shown in FIGS. 12 , 15 , 16 , etc., but this configuration is not limited thereto, and it goes without saying that cooling air may be drawn in through the second external opening and discharged through the first external opening.

[0053] The first external opening 13 and the second external opening 14 may be rectangular or may have multiple slit-like openings. This narrows the opening of each slit to prevent foreign matter from entering, while providing multiple slits makes it possible to increase the total opening area. In the examples shown in Figures 2 and 5, the first external opening 13 is formed in a mesh pattern, while the second external opening 14 is formed in a slit-like shape.

[0054] The first external opening 13 is opened at a position corresponding to the holder lower opening 35 of the battery block 30 housed in the outer case 10. As a result, a cooling air path is exposed from the outer case 10 through the first external opening 13 and the holder lower opening 35 opened in the bottom surface of the holder case 31. As a result, fresh cooling air taken into the outer case 10 through the first external opening 13 and the holder lower opening 35 can efficiently cool the cell intermediate region 1c of the rechargeable battery cells 1 housed in the holder case 31. In the example shown in FIG. 2 , the first external opening 13 opened in the bottom surface of the outer case 10 takes in cooling air from the bottom surface to the cell intermediate region 1c of the rechargeable battery cells 1 on the bottom surface of the holder case 31. This cooling air travels through the cooling air path and then flows down the cooling air path inside the battery block 30 to the top surface of the battery block 30, exchanging heat with the rechargeable battery cells 1, as shown in FIGS. 12 , 15 , and 16 . The air is then guided through the holder upper opening 34 on the top surface of the holder case 31 and the partition opening 21 in the partition 20 to the top of the exterior case 10, or into the interior of the upper case 11 in Figures 12, 15 and 16, and then discharged through the second external opening 14 opened above the back surface of the exterior case 10. In this way, cooling air flows into the interior of the exterior case 10 through the cooling air path, directly cooling the middle portions of the secondary battery cells 1 housed in the battery block 30.

[0055] (Electrode waterproofing part 50) The power supply device 100 is equipped with an electrode waterproofing part 50 interposed between each battery block 30 and the cell end face 1 a of each secondary battery cell 1 to waterproof the electrodes from the cooling air path. By joining the holder side cases 31A, 31B to the holder intermediate case 31C using the electrode waterproofing part 50 on the cell end face 1 a of each secondary battery cell 1, the outer surfaces of the holder side cases 31A, 31B are waterproofed through the openings in the electrode waterproofing part 50 that expose the electrodes on the cell end face 1 a of the secondary battery cell 1 and the electrode windows 33 in the holder side cases 31A, 31B. With this configuration, cooling air is circulated through the cell intermediate region 1 c of the secondary battery cell 1 for cooling, while the electrode waterproofing part 50 provided between the cell end face 1 a of the secondary battery cell 1 and the battery block 30 waterproofs the electrodes. This allows the necessary waterproofing to be maintained even while leaving the external opening 15 open in the exterior case 10 for cooling.

[0056] In a structure that uses air cooling by flowing cooling air through the exterior case, an opening is necessarily provided in the exterior case to ensure an air flow path. However, to prevent unintended short circuits of the rechargeable battery cells housed inside the exterior case, a waterproof structure is required to protect the battery block housing each rechargeable battery cell from external water, etc. This requires a complex structure because the exterior case must be waterproofed while still providing an opening. In contrast, the power supply device 100 according to this embodiment ensures waterproofing of the electrical connections of the rechargeable battery cells 1 using the electrode waterproofing part 50 as described above, while exposing the cell middle region 1c of each rechargeable battery cell 1 to the cooling air path for direct heat exchange, thereby achieving efficient cooling.

[0057] As shown in FIGS. 9 and 11 , the electrode waterproof part 50 is preferably formed in an annular shape. By arranging the electrodes inside the annular shape, the electrodes can be exposed from the battery block 30 through the electrode windows 33 as shown in FIG. 8 . As described above, the battery blocks 30 each have an electrode window 33 that exposes the electrodes at a position facing the cell end face 1 a. For this battery block 30, as shown in the cross-sectional view of FIG. 14 , one surface of the electrode waterproof part 50 is fixed around the electrode window 33 within the tubular case portion 32 of the battery block 30. The other surface of the electrode waterproof part 50 is fixed to the cell end face 1 a. The electrode on the cell end face 1 a is positioned so that it is exposed through the opening of the annular electrode waterproof part 50. This allows the electrode waterproof part 50 to be fixed between the cell end face 1 a of the secondary battery cell 1 and the battery block 30, while still exposing the electrodes as shown in FIG. 8 and other figures, enabling electrical connection to the lead plate 5 and bus bar 6. Such an electrode waterproof part 50 can be made of a waterproof double-sided tape.

[0058] [Manufacturing Method of Power Supply Device] Here, we will explain one example of a manufacturing method of the power supply device 100 that includes the electrode waterproofing part 50. First, each battery block 30 is prepared, in which electrode windows 33 are formed to expose each electrode of the multiple secondary battery cells 1.

[0059] Next, an electrode waterproof part 50 is fixed between the cell end surface 1 a of each secondary battery cell 1 and the electrode window 33 of each battery block 30, exposing the electrodes through the electrode window 33. As shown in Fig. 11 , the electrode waterproof part 50 is previously set in the case tube portion 32 of the holder side case 31B that constitutes the holder case 31, and in this state, the end of the secondary battery cell 1 is pressed into the case tube portion 32 to attach the electrode waterproof part 50 around the electrodes on the cell end surface 1 a. Alternatively, as shown in Fig. 9 , the electrode waterproof part 50 may be attached to the cell end surface 1 a of the secondary battery cell 1 inserted into the holder intermediate case 31C first, and then the holder side cases 31A and 31B may be joined to the holder intermediate case 31C and attached to the inner surface of the cell tube portion.

[0060] Next, the lead plates 5 are connected to the electrodes through the electrode windows 33. Furthermore, one or more battery blocks 30 are housed in an exterior case 10, and cooling air paths for flowing cooling air, which are formed between the inner surface of each battery block 30 and the surface of the cell intermediate region 1c between the end regions of each rechargeable battery cell 1 that are continuous with the cell end face 1a, are connected to the external openings 15 formed in the exterior case 10. In this way, cooling air is circulated through the cell intermediate region 1c of the rechargeable battery cell 1 for cooling, and the electrodes can be waterproofed by the electrode waterproofing parts 50 provided between the cell end face 1a of the rechargeable battery cell 1 and the battery block 30, so the necessary waterproof structure can be maintained even while the external openings 15 are open in the exterior case 10 for cooling.

[0061] (Battery waterproof section 60) Furthermore, the power supply unit 100 has an opening for allowing cooling air to flow inside the exterior case 10, and also has a battery waterproof section 60 for waterproofing the battery block 30 housed inside the exterior case 10. The battery waterproof section 60 prevents water and other substances from entering the exterior case 10 through the opening in the partition section 20 provided in the exterior case 10 or through gaps around it.

[0062] As a specific configuration of the battery waterproof part 60, a first seal part 61 is arranged around each partition opening 21 between the partition part 20 and the battery module 2, as shown in Fig. 4 etc. This realizes a waterproof structure that waterproofs the battery module 2 except for the part exposed by the partition opening 21.

[0063] Each of the first seal portions 61 is formed in an annular shape that is slightly larger than the partition opening 21. In the example of Fig. 4, the first seal portions 61 provided along each of the partition openings 21 are each formed in a rectangular shape. This achieves a waterproof structure that waterproofs the battery module 2 except for the portions exposed by the partition openings 21.

[0064] The second seal 62 also provides waterproofing between the periphery of the divider 20 and the lower case 12 of the exterior case 10. This makes it possible to waterproof the area indicated by the dashed line in Figure 3, making it possible to waterproof the area other than the cell middle region 1c of the rechargeable battery cell 1. The holder upper openings 34 of each battery block 30 are exposed through the partition openings 21, and the second seal 62 prevents water and other substances from entering the lower case 12 through gaps between the periphery of the partition openings 21 and the battery blocks 30.

[0065] Furthermore, a battery waterproof part 60 is provided on the bottom surface of the power supply device 100, between the bottom surface of the battery block 30 and the first external opening 13 of the lower case 12. Specifically, as shown in the exploded perspective view of Figure 5, a third seal part 63 is arranged around the first external opening 13 on the inner surface of the lower case 12. The third seal part 63 is provided between the periphery of the first external opening 13 and the periphery of the holder lower opening 35 of the battery block 30, and constitutes an opening waterproof structure that waterproofs the battery block 30. With this configuration, the first external opening 13 is opened in part of the outer case 10 to allow cooling air to enter the interior of the outer case 10 for cooling, while waterproofing the first external opening 13 and the battery block 30, making it possible to prevent unintended short-circuiting of the rechargeable battery cells 1 in the battery block 30.

[0066] As described above, a waterproof structure is achieved between the outer case 10 and the holder case 31 by waterproofing the battery module 2 by the first seal portions 61 other than the portion exposed by the partition opening 21, waterproofing by the second seal portion 62 between the periphery of the partition portion 20 and the lower case 12 of the outer case 10, and waterproofing by the third seal portion 63 between the bottom surface of the battery block 30 and the external first opening 13 of the lower case 12.

[0067] As mentioned above, the outer surfaces of the holder side cases 31A and 31B are waterproofed through the openings in the electrode waterproofing section 50 that expose the electrodes of the cell end surfaces 1a of the secondary battery cells 1 and the electrode windows 33 in the holder side cases 31A and 31B.

[0068] Therefore, the space inside the outer case 10 between the inner surface of the outer case 10 and the outer surface of the battery block 30 forms a waterproof space 16, and the electrodes on the cell end faces 1a of each secondary battery cell 1 between each battery block 30 form a waterproof space 17.

[0069] The first seal portion 61, the second seal portion 62, and the third seal portion 63 can be made of any known material that can exhibit waterproof properties, such as waterproof double-sided tape, packing, O-rings, etc. The first seal portion 61, the second seal portion 62, and the third seal portion 63 may be made of the same material and structure, or may be made of different materials and structures.

[0070] This waterproof structure also makes the circuit board 3 waterproof. That is, by locating the circuit board 3 so that it is isolated from the cooling air path for cooling air provided between the first external opening 13 and the second external opening 14, the waterproof structure can also make the circuit board 3 waterproof. In the examples shown in Figures 6 and 15, the circuit board 3 is located between the battery block 30 and the inner surface of the exterior case 10. This effectively prevents short-circuiting of the terminals of the secondary battery cells 1 as well as unintended electrical conduction of the circuit board 3.

[0071] In the above configuration, an example has been described in which lead plates 5 are connected to both cell end faces of the secondary battery cell 1 to electrically connect to the positive and negative electrodes. However, the present disclosure is not limited to this configuration, and the positive and negative electrodes may be connected to one of the cell end faces. For example, in a configuration in which a positive electrode is provided in the center of one cell end face and a negative electrode is provided around it, electrical connection to the positive and negative electrodes is possible only at that cell end face. In this case, it is sufficient to waterproof only one cell end face with an electrode waterproofing part. In other words, there is no need to waterproof the other cell end face.

[0072] In the above examples, the power supply device is attached to the electrical equipment to be driven and supplies power to the electrical equipment. When the remaining capacity of the power supply device becomes low or when the power supply device deteriorates over time, the power supply device can be replaced to continue using the electrical equipment. However, the present invention is not limited to replaceable power supply devices that mainly house secondary battery cells, but can also be applied to configurations in which secondary battery cells are housed within the housing of the electrical equipment. In this disclosure, a power supply device is sufficient as long as it houses secondary battery cells in a case, and also includes power supply devices that incorporate secondary battery cells for driving the electrical equipment within the housing of the electrical equipment itself. In other words, the present invention is not limited to replaceable power supply devices, but can also be applied to electrical equipment that incorporates secondary battery cells.

[0073] The power supply device and method for manufacturing the same according to the present disclosure can be suitably used as a driving power source for assisted bicycles, self-propelled delivery robots, electric carts for delivery and golf courses, electric scooters, construction machinery, hybrid vehicles, electric vehicles, and other vehicles. It can also be used as a power source for portable electrical devices such as radios, electric cleaners, and power tools. It can also be applied to cooling mechanisms for electrical devices with built-in heating elements, not limited to power sources. It can also be used as a stationary power storage device, for example, a power supply device for home, business, or factory use, or as a backup power source for servers.

[0074] DESCRIPTION OF SYMBOLS 100...power supply device 1...secondary battery cell 1a...cell end surface 1c...cell intermediate region 2...battery module 3...circuit board 4...board holder 5...lead plate 6...bus bar 6B...bus bar located at end 6C...connecting piece 6D...second bus bar 10...exterior case 11...upper case 12...lower case 13...external first opening 14...external second opening 15...external opening 16, 17...waterproof space 20...partition section 21...partition opening 30...battery block 31...holder case 31A...holder side case 31B...holder side case 31C...holder intermediate case 32...case cylindrical section 33...electrode window 34...holder upper opening 35...holder lower opening 40...insulating sheet 41...first insulating sheet 42...second insulating sheet 43...opening window 50...electrode waterproof section 60...battery waterproof section 61...First seal portion 62...Second seal portion 63...Third seal portion

Claims

1. A power supply device comprising: a plurality of secondary battery cells, each having a cell end face with an electrode; one or more battery blocks housing the plurality of secondary battery cells; and an exterior case housing the one or more battery blocks, wherein a cooling air passage for flowing cooling air is formed between an inner surface of one of the one or more battery blocks and a surface of a cell intermediate region between end regions of each of the plurality of secondary battery cells that are connected to the cell end face, the exterior case forms an external opening that communicates with the cooling air passage, and the power supply device further comprises an electrode waterproofing portion interposed between each of the one or more battery blocks and the cell end face of each secondary battery cell to waterproof the electrodes from the cooling air passage.

2. A power supply device as described in claim 1, wherein the one or more battery blocks each have an electrode window that exposes the electrode at a position opposite the cell end face, the electrode waterproof part is formed in a ring shape, one face of the electrode waterproof part is fixed to the periphery of the electrode window of the one or more battery blocks and the other face is fixed to the cell end face, the electrodes are arranged inside the ring shape, and the electrodes are exposed from the one or more battery blocks through the electrode window.

3. A power supply device according to claim 2, further comprising a lead plate connected to said electrode through said electrode window.

4. A power supply device as claimed in claim 3, further comprising a circuit board electrically connected to said plurality of secondary battery cells via said lead plates, a waterproof space configured to have a waterproof structure is provided inside said exterior case between the inner surface of said exterior case and the outer surface of said one or more battery blocks, and said circuit board is disposed in said waterproof space to make it waterproof.

5. A power supply device according to any one of claims 1 to 4, wherein the electrode waterproof part is made of a waterproof double-sided tape.

6. A power supply device as claimed in any one of claims 1 to 4, wherein the one or more battery blocks have an upper holder opening communicating with the cooling air passage, and the upper holder opening is in communication with the external opening.

7. A power supply device as claimed in any one of claims 1 to 4, wherein the exterior case has a partition section therein for holding the one or more battery blocks, the partition section defines a partition opening for exposing an end of the cooling air path and communicating with the external opening, a first seal section is provided between the periphery of the partition opening and the periphery of the cooling air path, and a second seal section is provided between the periphery of the partition section and the inner surface of the exterior case, the exterior case has, on parts of its surface as the external openings, a first external opening and a second external opening which communicate the cooling air path with the outside, and a third seal section which waterproofs the one or more battery blocks is provided between the periphery of the first external opening and the periphery of the cooling air path, and the second external opening is in communication with the partition opening.

8. A power supply device as claimed in any one of claims 1 to 4, wherein each of a plurality of secondary battery cells is provided with a cylindrical exterior can, and the electrode waterproof part is fixed to each of the cell end faces at both ends of the cylindrical exterior can.

9. A power supply device according to claim 7, wherein the one or more battery blocks are divided so as to cover the end regions of each of a plurality of secondary battery cells.

10. A power supply device according to claim 7, wherein the cell intermediate area is exposed from the one or more battery blocks, and the cell intermediate area is exposed to the cooling air passage.

11. A power supply device according to any one of claims 1 to 4, wherein the one or more battery blocks are a set of battery blocks arranged adjacent to each other.

12. A method for manufacturing a power supply device comprising a plurality of secondary battery cells, each having a cell end face with an electrode, one or more battery blocks housing the plurality of secondary battery cells, and an exterior case housing the one or more battery blocks, the method comprising the steps of: preparing each of the one or more battery blocks with an electrode window formed therein for exposing each electrode of the plurality of secondary battery cells; fixing an electrode waterproof part between the cell end face of each secondary battery cell and the electrode window of each of the one or more battery blocks, thereby exposing the electrode from the electrode window; connecting a lead plate to the electrode through the electrode window; housing the one or more battery blocks in the exterior case, and communicating a cooling air passage for flowing cooling air, which is formed between the inner surface of each of the one or more battery blocks and the surface of a cell intermediate region between end regions of each secondary battery cell that are continuous with the cell end face, with an external opening formed in the exterior case.

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