Power supply device and manufacturing method therefor

Abstract

This power supply device comprises at least one battery block for accommodating a plurality of secondary battery cells, and an exterior case for accommodating the battery block. The battery block comprises: an intermediate holder that exposes, on each side thereof, an end region spanning a fixed distance from each cell end face of each secondary battery cell and holds a cell intermediate region that is between the end regions; and a pair of cover holders that are disposed on respective sides of the intermediate holder and cover the end regions of the secondary battery cells. A cooling air passage through which cooling air flows to the cell intermediate region of each secondary battery cell is formed in the interior of the intermediate holder. The exterior case has formed therein an external opening communicating with the cooling air passage, and comprises an end waterproofing structure which waterproofs the interface between the cell intermediate region and the end regions of each of the secondary battery cells.

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 cylindrical outer can with each end face of the cylinder serving as a cell end face having an electrode; one or more battery blocks housing the plurality of secondary battery cells; and an outer case housing the battery blocks, wherein the battery blocks comprise: an intermediate holder that exposes end regions at a certain distance from each cell end face of each secondary battery cell on both sides and holds a cell intermediate region between the end regions; and a pair of lid holders arranged on either side of the intermediate holder and covering the end regions of each secondary battery cell, wherein the intermediate holder forms a cooling air passage on its inner surface that flows cooling air to the cell intermediate region of the secondary battery cell; and the outer case forms an external opening that communicates with the cooling air passage and comprises an end waterproofing structure that waterproofs the interface between the cell intermediate region and the end region of the secondary battery cell.

[0007] Also, a method for manufacturing a power supply device according to another aspect includes the steps of preparing one or more battery blocks each having a plurality of secondary battery cells each having a cylindrical exterior can with each end face of the cylinder as a cell end face having an electrode, an intermediate holder that exposes an end region of each secondary battery cell at a certain distance from each cell end face on both sides and holds a cell intermediate region between the end regions, and a pair of lid holders that are respectively disposed on both sides of the intermediate holder and cover the end region of each secondary battery cell, and an exterior case that houses the battery block; The method includes the steps of: fixing the intermediate holder and the lid holder together in a state in which the end regions of each secondary battery cell exposed from the intermediate holder are closed with a first surface of the lid holder while holding the plurality of secondary battery cells, and waterproofing at least the interface between the end region and the middle portion with an end waterproof structure; storing the battery block in the outer case; forming a cooling air path on the inner surface of the intermediate holder for flowing cooling air to the cell middle regions of the secondary battery cells; and communicating the cooling air path with an external opening opened in the outer case.

[0008] According to one embodiment of the power supply device and its manufacturing method of the present disclosure, cooling air is circulated within the intermediate holder to air-cool the cell intermediate region of the secondary battery cell, while the end region of the secondary battery cell is waterproofed to protect the electrodes and prevent unintended short circuits, etc.

[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. An exploded perspective view of the power supply device of FIG. 2. A cross-sectional view of the power supply device of FIG. 1, taken along line VI-VI. 4. An exploded perspective view of the battery module of FIG. 4. An exploded perspective view of the lead plates disassembled from one battery block of FIG. 7. An exploded perspective view of one holder case of FIG. 8. A further exploded perspective view of the holder case of FIG. 9. A perspective view showing the application of adhesive to the intermediate holder of FIG. 9. A cross-sectional view of the battery block of FIG. 1, taken along line XII-XII. 7. 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. A cross-sectional perspective view of the power supply device of FIG. 1, taken along line XV-XV. 14. A cross-sectional perspective view of the power supply device of FIG. 1, taken along line XII-XII.

[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, each lid holder has an insertion recess formed on the surface facing the intermediate holder into which the end region of each secondary battery cell is inserted, and an electrode window formed on the bottom surface of the insertion recess that exposes a portion of the cell end face from the lid holder. This configuration enables connection of electrodes while holding the end region of each secondary battery cell with the lid holder.

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

[0013] According to a further aspect of the present disclosure, in addition to any of the above-described power supply devices, the power supply device further includes a circuit board electrically connected to the plurality of secondary battery cells via the lead plates, and the circuit board is waterproof.

[0014] In a power supply device according to still another aspect of the present disclosure, in any of the above aspects, the intermediate holder includes a pair of wall portions constituting main surfaces and a pair of side walls connecting both sides of the pair of wall portions, the pair of wall portions having intermediate windows through which the plurality of secondary battery cells are inserted, and the pair of wall portions are open at the top and bottom, directly exposing intermediate cell regions of the secondary battery cells in the cooling air passage. With the above configuration, the intermediate holder has a hollow structure, exposing the intermediate cell regions of the secondary battery cells, enabling efficient cooling.

[0015] Furthermore, in the power supply device according to another aspect of the present disclosure, in any of the above aspects, the structure that fixes the lid holder to the intermediate holder also serves as the end waterproof structure.

[0016] In addition, in the power supply device according to any one of the above aspects, the end waterproof structure is a waterproof double-sided tape interposed at the interface between the intermediate holder and the lid holder.

[0017] In addition, in the power supply device according to any one of the above aspects, the end waterproof structure is an adhesive layer that bonds the intermediate holder and the lid holder.

[0018] 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.

[0019] Furthermore, in another form of the method for manufacturing a power supply device according to the present disclosure, in any of the above forms, the step of fixing the intermediate holder and the lid holder includes a step of filling the interface between the intermediate holder and the lid holder with uncured adhesive and curing it.

[0020] Furthermore, in another embodiment of the method for manufacturing a power supply device according to the present disclosure, in any of the above embodiments, the step of fixing the intermediate holder and the lid holder includes the step of attaching waterproof double-sided tape to the interface between the intermediate holder and the lid holder.

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

[0022] 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.

[0023] [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 of Figure 8. Fig. 10 is an exploded perspective view of the holder case 31 of Fig. 9, Fig. 11 is a perspective view showing the application of adhesive to the intermediate holder 31C 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 portion 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 XII-XII. The power supply device 100 shown in these figures includes an outer case 10, battery modules 2, and a circuit board 3.

[0024] (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.

[0025] 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 housing space where the battery block 30 of the battery module 2 and the circuit board 3 are placed is waterproofed by a battery waterproof section 60.

[0026] (Partition 20) A partition 20 is disposed on the top surface of the battery module 2. The partition 20 has a partition opening 21. In the example of Fig. 3, two partition openings 21 are formed in the partition 20. A portion of the battery module 2 is exposed through each partition opening 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.

[0027] 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).

[0028] 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).

[0029] (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.

[0030] (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 in the holder storage space. The holder case 31 shown in FIG. 9 and other figures is divided into three sections, consisting of a pair of lid holders 31A and 31B and an intermediate holder 31C sandwiched between them. However, the holder case is not limited to a three-section structure and may be divided into four or more sections. The sections of the holder case are waterproofed by an end waterproof structure 50 (details will be described later). 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.

[0031] (Intermediate Holder 31C) The intermediate holder 31C exposes the end regions 1b of each secondary battery cell 1 at a certain distance from each cell end face 1a on both sides, holding the cell intermediate regions 1c between the end regions 1b. The intermediate holder 31C includes a pair of wall portions 31C1 that form the main surface, and a pair of side walls 31C3 that connect the two sides of the pair of wall portions 31C1. The pair of wall portions 31C1 have intermediate window portions 31C2 through which multiple secondary battery cells 1 are inserted. The pair of wall portions 31C1 are also open at the top and bottom, directly exposing the cell intermediate regions 1c of the secondary battery cells 1 held by the intermediate holder 31C in the cooling air path. In this way, the intermediate holder 31C has a hollow structure, exposing the cell intermediate regions 1c of the secondary battery cells 1, enabling efficient cooling (described in detail below).

[0032] (Lid holders 31A, 31B) A pair of lid holders 31A, 31B are arranged on both sides of the intermediate holder 31C, respectively closing each side of the intermediate holder 31C, thereby covering the end regions 1b of each secondary battery cell 1 exposed on both sides of the intermediate holder 31C with the lid holders 31A, 31B.

[0033] (Insertion recess 32) Furthermore, the lid holders 31A, 31B have insertion recesses 32 formed on their first surfaces facing the intermediate holder 31C that cover the end regions 1b of the secondary battery cells 1. In the example shown in Figures 9 and 10, etc., cylindrical insertion recesses 32 are formed integrally with the lid holders 31A, 31B on their first surfaces at positions corresponding to the end regions 1b of the secondary battery cells 1.

[0034] Additionally, an electrode window 33 is formed on the bottom surface of the insertion recess 32, which exposes a portion of the cell end surface 1a from the lid holders 31A, 31B when the end region 1b of each secondary battery cell 1 is inserted. This configuration allows electrodes to be connected while the end region 1b of each secondary battery cell 1 is held by the lid holders 31A, 31B.

[0035] (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 lead plates 5 are electrically connected to the terminals of the rechargeable battery cells 1 that are exposed through electrode windows 33 that communicate with insertion recesses 32 opened in the lid holders 31A and 31B.

[0036] 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.

[0037] (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 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 the two battery blocks 30 are connected together by screwing. By adding bus bars 6 in addition to the 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.

[0038] 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.

[0039] (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.

[0040] (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.

[0041] (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.

[0042] 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 1 are held in an orientation in which the positive and negative electrodes appear alternately on the cell end surfaces 1a. However, each secondary battery cell may be held in a battery block in an orientation in which the positive or negative electrodes of all secondary battery cells are on the same side.

[0043] 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.

[0044] (Holder upper opening 34) Each holder case 31 has a holder upper opening 34 and a holder lower opening 35 formed on the upper and lower surfaces of the intermediate holder 31C, 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 intermediate holder 31C, 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 intermediate holder 31C, the cooling air can be made to flow smoothly in a straight line.

[0045] Each of the holder upper openings 34 and the holder lower opening 35 preferably extends in a direction intersecting the longitudinal direction of the rechargeable battery cells 1. This allows the holder upper openings 34 and the holder lower openings 35 to be open in the direction in which the rechargeable battery cells 1 are stacked, allowing many of the rechargeable battery cells 1 to be exposed from the holder case 31, improving heat dissipation performance.

[0046] 8, the holder case 31 is divided into three sections, and the middle section, the intermediate holder 31C, is provided with an upper holder opening 34 and a lower holder opening 35. The intermediate holder 31C is open at the top and bottom and closed at the periphery, facilitating the flow of cooling air in the vertical direction. Note that a plurality of upper holder openings and a plurality of lower holder openings may be formed on the top and bottom surfaces of the intermediate holder.

[0047] 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.

[0048] (Cooling Air Path) Each battery block 30 has a cooling air path that allows cooling air to flow between the inner surface of the battery block 30 and the surface of the cell intermediate region 1c between the end regions 1b that are continuous with the cell end faces 1a of each rechargeable battery cell 1. The cooling air path is formed inside the holder case 31 in the gap between the inner surface of the holder case 31 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 directed over the surfaces of the rechargeable battery cells 1, enabling efficient heat exchange and cooling.

[0049] 13 to 15, etc., an end region 1b including the terminals of each rechargeable battery cell 1 and a partitioned cell intermediate region 1c are exposed inside the holder case 31. The intermediate holder 31C of the holder case 31 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 opening 15. The holder lower opening 35 communicates with the external second opening 14. This configuration allows cooling air to flow over the surfaces of the cell intermediate regions 1c of the rechargeable battery cells 1, enabling the rechargeable battery cells 1 to be cooled efficiently.

[0050] 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.

[0051] 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.

[0052] The first external openings 13 are opened at positions corresponding to the holder bottom openings 35 of the battery blocks 30 housed in the outer case 10. This exposes the cooling air passages from the outer case 10 through the first external openings 13 and the holder bottom openings 35 opened on the bottom surface of the intermediate holder 31C. As a result, fresh cooling air taken into the outer case 10 through the first external openings 13 and the holder bottom openings 35 can efficiently cool the cell middle regions 1c of the rechargeable battery cells 1 housed in the intermediate holder 31C. In the example shown in FIG. 2 , the first external openings 13 opened on the bottom surface of the outer case 10 take in cooling air from the bottom surface to the cell middle regions 1c of the rechargeable battery cells 1 on the bottom surface of the intermediate holder 31C. This cooling air travels through the cooling air passages and then flows down the cooling air passages within 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 intermediate holder 31C and the partition opening 21 in the partition 20 to the top of the outer 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 outer case 10. In this way, cooling air can flow into the interior of the outer case 10 through the cooling air path, directly cooling the middle portions of the secondary battery cells 1 housed in the battery block 30.

[0053] (Edge waterproof structure 50) The power supply device 100 is equipped with an edge waterproof structure 50 that waterproofs the interface between the cell middle region 1c and the edge region 1b of each rechargeable battery cell 1, preventing water from entering the electrodes through the cooling air path. With this configuration, cooling air taken in from outside is circulated into the intermediate holder 31C to air-cool the cell middle region 1c of the rechargeable battery cell 1, while waterproofing the edge region 1b of the rechargeable battery cell 1 to protect the electrodes and prevent unintended short circuits.

[0054] 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 rechargeable battery cells housed inside must be waterproofed while still providing an opening in the exterior case. 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 end waterproof structure 50 as described above, while exposing the cell middle region 1c of the rechargeable battery cell 1 to the cooling air path for direct heat exchange, thereby achieving efficient cooling.

[0055] The edge waterproof structure 50 can be formed using a sealant, filler, adhesive, or waterproof double-sided tape that waterproofs the interface between the cell middle region 1c and the edge region 1b of each secondary battery cell 1. In the example shown in FIG. 10, the edge waterproof structure 50 is achieved by interposing waterproof double-sided tape between the intermediate holder 31C and the lid holders 31A and 31B. The waterproof double-sided tape has tape holes 52 through which the secondary battery cells 1 can be inserted. The tape holes 52 are approximately the same size as the outer diameter of the cylindrical outer can of the secondary battery cell 1. With this method, the waterproof double-sided tape is attached to a wide area of ​​the wall portion 31C1 of the intermediate holder 31C, ensuring reliable waterproofing. Furthermore, the opening diameter of the insertion recesses 32 of the lid holders 31A, 31B is slightly larger than the outer diameter of the exterior can of the secondary battery cell 1 because the secondary battery cell 1 is inserted therein, and the tape holes 52 are preferably made slightly smaller than the opening diameter of the insertion recesses 32, with the waterproof double-sided tape extending slightly inside the periphery of the opening of the insertion recess 32. In this way, when the lid holders 31A, 31B are joined to the intermediate holder 31C, the waterproof double-sided tape is adhered all the way to the interface with the outer periphery of the exterior can of the secondary battery cell 1, achieving a waterproof structure.

[0056] The waterproof end structure 50 may also be constructed using an adhesive. For example, as shown in Figure 11, with a secondary battery cell 1 inserted into an intermediate window 31C2 formed in the wall 31C1 of the intermediate holder 31C, uncured adhesive 54 is applied to the wall 31C1 of the intermediate holder 31C. Then, with the adhesive 54 still uncured, the lid holder 31A is placed on top and bonded.

[0057] The waterproof edge structure 50 can also be used to bond the intermediate holder 31C to the lid holders 31A, 31B. This not only waterproofs the interface between the cell intermediate region 1c and the end region 1b and protects the electrodes of the secondary battery cells 1, but also simultaneously fastens the intermediate holder 31C to the lid holders 31A, 31B. As a result, it is possible to reduce the number of steps required to add a fastening structure, such as screwing the intermediate holder 31C to the lid holders 31A, 31B, and to fasten them together. In this way, the waterproof edge structure 50 can be used to both waterproof the secondary battery cells 1 and fasten the holder case 31, which can also contribute to simplifying the power supply device 100.

[0058] [Manufacturing Method of Power Supply Device] Here, an example of a manufacturing method for a power supply device 100 equipped with an end waterproof structure 50 will be described. First, a battery block 30 and an exterior case 10 for housing the battery block 30 are prepared. As described above, the battery block 30 is a member for housing multiple rechargeable battery cells 1, and is composed of an intermediate holder 31C and a pair of lid holders 31A, 31B. The intermediate holder 31C exposes end regions 1b at a certain distance from each cell end face 1a of each rechargeable battery cell 1 on both sides, and holds the cell intermediate region 1c between the end regions 1b. The pair of lid holders 31A, 31B are also positioned on both sides of the intermediate holder 31C to cover the end regions 1b of each rechargeable battery cell 1.

[0059] Next, with the intermediate holder 31C holding the multiple secondary battery cells 1, the end region 1b of each secondary battery cell 1 exposed from the intermediate holder 31C is closed with the first surface of the lid holders 31A, 31B, and the intermediate holder 31C and the lid holders 31A, 31B are fixed together so that at least the interface between the end region 1b and the middle portion is waterproofed with the end waterproof structure 50. The intermediate holder 31C and the lid holders 31A, 31B can be fixed together by filling the interface between the intermediate holder 31C and the lid holders 31A, 31B with uncured adhesive and curing it. Alternatively, waterproof double-sided tape can be applied to the interface between the intermediate holder 31C and the lid holders 31A, 31B.

[0060] The battery block 30 is then housed in the exterior case 10, and a cooling air path is formed on the inner surface of this intermediate holder 31C to allow cooling air to flow through the cell intermediate regions 1c of the secondary battery cells 1, and the cooling air path is connected to an external opening in the exterior case 10. This allows cooling air to flow inside the intermediate holder 31C to air-cool the cell intermediate regions 1c of the secondary battery cells 1, while waterproofing the end regions 1b of the secondary battery cells 1 to protect the terminals and prevent unintended short circuits.

[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 partition opening 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] 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.

[0067] 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.

[0068] 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 provide an end waterproofing structure only on one cell end face to ensure waterproofing. In other words, there is no need to waterproof the other cell end face.

[0069] 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.

[0070] 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.

[0071] DESCRIPTION OF SYMBOLS 100...power supply device 1...secondary battery cell 1a...cell end surface 1b...end region 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...connection piece 10...exterior case 11...upper case 12...lower case 13...external first opening 14...external second opening 15...external opening 20...partition section 21...partition opening 30...battery block 31...holder case 31A, 31B...lid holder 31C...intermediate holder 31C1...wall section 31C2...intermediate window section 31C3...side wall 32...insertion recess 33...electrode window 34...upper holder opening 35...lower holder opening 40...insulating sheet 41...first insulating sheet 42...second insulating sheet 43...opening window 50...end waterproof structure 52: Tape hole 54: Adhesive 60: Battery waterproof section 61: First seal section 62: Second seal section 63: Third seal section

Claims

1. A power supply device comprising: a plurality of secondary battery cells, each of which has a cylindrical outer can with each end face of the cylinder as a cell end face having an electrode; one or more battery blocks housing the plurality of secondary battery cells; and an outer case housing the battery block, wherein the battery block comprises: an intermediate holder that exposes an end region a certain distance from each cell end face of the plurality of secondary battery cells from both sides and holds a cell intermediate region between the end regions; and a pair of lid holders arranged on either side of the intermediate holder and covering the end regions of the plurality of secondary battery cells, wherein the intermediate holder forms a cooling air passage on its inner surface for flowing cooling air to the cell intermediate region of each of the plurality of secondary battery cells, and the outer case forms an external opening that communicates with the cooling air passage, and the power supply device comprises an end waterproofing structure that waterproofs the interface between the cell intermediate region and the end region of the secondary battery cell.

2. A power supply device as described in claim 1, wherein each of the pair of lid holders has an insertion recess formed on the surface facing the intermediate holder into which the end region of each of the multiple secondary battery cells is inserted, and an electrode window is formed on the bottom surface of the insertion recess to expose a portion of the cell end face from each of the pair of lid holders.

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 according to claim 3, further comprising a circuit board electrically connected to said plurality of secondary battery cells via said lead plates, said circuit board being waterproofed.

5. A power supply device as claimed in any one of claims 1 to 4, wherein the intermediate holder comprises a pair of wall sections constituting a main surface, and a pair of side walls respectively connecting both sides of the pair of wall sections, the pair of wall sections having intermediate window sections into which the multiple secondary battery cells are respectively inserted, the pair of wall sections being open at the top and bottom, and directly exposing intermediate cell regions of the secondary battery cells in the cooling air passage.

6. A power supply device according to any one of claims 1 to 4, wherein the structure for fixing the lid holder to the intermediate holder also serves as the end waterproof structure.

7. A power supply device according to any one of claims 1 to 4, wherein the end waterproof structure is a waterproof double-sided tape interposed at the interface between the intermediate holder and the lid holder.

8. A power supply device according to any one of claims 1 to 4, wherein the end waterproof structure is an adhesive layer that bonds the intermediate holder and the lid holder.

9. 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.

10. A method for manufacturing a power supply device, comprising: preparing a plurality of secondary battery cells, each having a cylindrical exterior can with each end face of the cylinder as a cell end face having an electrode; an intermediate holder that exposes an end area a certain distance from each cell end face of each of the plurality of secondary battery cells from both sides and holds a cell intermediate area between the end areas; and a pair of lid holders that are disposed on both sides of the intermediate holder and cover the end areas of the plurality of secondary battery cells; and an exterior case that houses the battery block; and, with the plurality of secondary battery cells held by the intermediate holder, fixing the intermediate holder and the lid holder in a state in which the end areas of each secondary battery cell exposed from the intermediate holder are closed with a first surface of the lid holder, and at least the interface between the end area and an intermediate portion is waterproofed with an end waterproof structure; A method for manufacturing a power supply device, comprising: storing the battery block in the outer case; forming a cooling air passage on the inner surface of the intermediate holder for flowing cooling air to the cell intermediate region of the secondary battery cell; and connecting the cooling air passage to an external opening formed in the outer case.

11. A method for manufacturing a power supply device as described in claim 10, comprising filling an interface between said intermediate holder and said lid holder with uncured adhesive and curing the adhesive while said intermediate holder and said lid holder are fixed to each other.

12. A method for manufacturing a power supply device according to claim 10, comprising the step of attaching a waterproof double-sided tape to the interface between said intermediate holder and said lid holder while said intermediate holder and said lid holder are fixed together.

13. A power supply device as claimed in any one of claims 1 to 4, wherein the intermediate holder comprises a pair of wall portions constituting a main surface, and a pair of side walls respectively connecting both sides of the pair of wall portions, the pair of wall portions having intermediate window portions opening therein for inserting the respective multiple secondary battery cells, a pair of surfaces surrounded by edges of the pair of wall portions and edges of the pair of side walls being open, and an intermediate cell region of the secondary battery cell being directly exposed in the cooling air passage.

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