Power supply device and method for manufacturing same

Abstract

This power supply device is provided with: a plurality of secondary battery cells each having a cell end surface; one or more battery blocks accommodating the plurality of secondary battery cells; a battery cooling section thermally coupled to the battery blocks; and an exterior case accommodating the battery blocks and the battery cooling section. The battery cooling section internally defines a cooling air path through which cooling air flows, provides communication between the cooling air path and the outside through the exterior case, and is provided with a battery waterproof section for waterproofing the gap between the battery blocks and the exterior case. Thus, the battery blocks can be waterproofed while securing the cooling air path from the outside of the exterior case using the battery cooling section, and simplification of waterproof structure can be achieved while air-cooling 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 cell end face; one or more battery blocks housing the plurality of secondary battery cells; a battery cooling section thermally coupled to the battery block; and an outer case housing the battery block and the battery cooling section, wherein the battery cooling section defines a cooling air path through which cooling air flows, the cooling air path is connected to the outside through the outer case, and the battery cooling section comprises a battery waterproofing section that waterproofs the gap between the battery block and the outer case.

[0007] According to a power supply device according to one embodiment of the present disclosure, the battery block can be waterproofed while a cooling air path is secured from the outside of the outer case using a battery cooling section, making it possible to simplify the waterproof structure while still air-cooling the secondary battery cells.

[0008] 1 is a perspective view showing a power supply device according to a first embodiment. 1 is a perspective view of the power supply device of FIG. 1, seen obliquely from below on the rear side. 1 is an exploded perspective view of the power supply device of FIG. 1, with the upper case disassembled. 2 is a further exploded perspective view of the power supply device of FIG. 3. 3 is an exploded perspective view of the power supply device of FIG. 2. 4 is a cross-sectional view of the power supply device of FIG. 1, taken along line VI-VI. 5 is an exploded perspective view of the battery module of FIG. 4. 6 is a perspective view of one battery block of FIG. 4. 7 is a plan view of one battery block of FIG. 4. 8 is an exploded perspective view of the lead plates disassembled from the battery block of FIG. 8. 9 is an exploded perspective view showing the battery block of FIG. 10 removed from the holder case. 10 is an exploded perspective view of the battery holder of FIG. 11. 11 is a cross-sectional view of the power supply device of FIG. 1, taken along line XIII-XIII.

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

[0010] In a power supply device according to another aspect of the present disclosure, in the above-described aspect, the plurality of secondary battery cells are held in the battery block with the cell end faces of the same pole aligned in the same plane, and the surface of the battery block where the cell end faces are aligned in the same plane is coupled to the battery cooling unit. This configuration enables efficient cooling by the battery cooling unit from the cell end face side of the secondary battery cells.

[0011] In addition, in a power supply device according to another aspect of the present disclosure, in any of the above aspects, the one or more battery blocks include two battery blocks, and the battery cooling unit is disposed between the two battery blocks. With this configuration, it is possible to efficiently cool each battery block on both sides of one battery cooling unit.

[0012] In a power supply device according to another aspect of the present disclosure, in any of the above aspects, the plurality of secondary battery cells are held in the battery block in a position where a cell end face on the negative electrode side of each secondary battery cell faces the battery cooling unit. With the above configuration, if a cell end face on the positive electrode side of a secondary battery cell is provided with a gas release valve that opens when internal pressure becomes high, in the unlikely event that high-temperature, high-pressure gas is released from one secondary battery cell, safety can be improved by ensuring that other secondary battery cells are not placed on the side opposite the cell end face, in other words, by placing the cell end faces without gas release valves facing each other.

[0013] In a power supply device according to still another aspect of the present disclosure, in any of the above aspects, the battery cooling section has the cooling air passage opened in the form of a plurality of slits, each slit being opened along the direction in which the plurality of secondary battery cells face each other. With this configuration, since each slit is opened to face a secondary battery cell, cooling air can be circulated through each slit to efficiently cool the secondary battery cells.

[0014] Furthermore, in another form of the power supply device of the present disclosure, in any of the above forms, the outer case has a partition section that holds the battery block inside, the partition section defines a partition opening that exposes the battery cooling section, and the battery waterproof section is provided between the periphery of the partition opening and the periphery of the battery cooling section.

[0015] In yet another aspect of the power supply device of the present disclosure, in any of the above aspects, the exterior case has a first external opening in a portion of its surface that connects the cooling air path defined by the battery cooling section to the outside, and the battery waterproof section has an opening waterproof structure that waterproofs the battery block between the periphery of the first external opening and the periphery of the battery cooling section. With this configuration, the first external opening is opened in a portion of the exterior case to allow cooling air to enter the exterior case for cooling, while waterproofing the first external opening and the battery block makes it possible to prevent unintended short-circuiting of the secondary battery cells in the battery block.

[0016] 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.

[0017] 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.

[0018] [Embodiment 1] A power supply device 100 according to embodiment 1 of the present disclosure is shown in Figures 1 to 13. 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 seen from diagonally below the rear side, Figure 3 is an exploded perspective view with the upper case 11 of the power supply device 100 of Figure 1 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, and Figure 7 is an exploded perspective view of the battery module 2 of Figure 4. Fig. 13 is a cross-sectional view of the power supply device 100 taken along line XIII-XIII in Fig. 1. The power supply device 100 shown in these figures includes an outer case 10, battery modules 2, and a circuit board 3.

[0019] (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.

[0020] 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.

[0021] (Partition 20) A partition 20 is also disposed on the top surface of the battery module 2. The partition 20 is installed at the edge of the upper opening 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 defined by the partition 20. The partition 20 has a partition opening 21, and as shown in Figure 3, the upper part of the battery cooling section 50 is exposed through the partition opening 21. This allows the battery cooling section 50 to communicate with the outside, allowing cooling air to be taken in or discharged into the battery cooling section 50.

[0022] 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 the cooling air passage of the battery cooling unit 50. 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).

[0023] (Battery waterproof section 60) The power supply device 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 contaminants 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. As a specific configuration of the battery waterproof section 60, a first seal section 61 is disposed between the partition section 20 and the battery module 2, as shown in Figure 4 etc. This achieves a waterproof structure that waterproofs the battery module 2 except for the portion exposed through the partition opening 21.

[0024] The first seal portion 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 portion 61 provided along the partition opening 21 is formed in a rectangular shape.

[0025] The area between the periphery of the partition 20 and the lower case 12 of the outer case 10 is also waterproofed by the second seal 62. 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 battery cooling section 50.

[0026] Furthermore, a battery waterproof section 60 is provided on the bottom surface of the power supply device 100, between the lower part of the battery cooling section 50 and the first external opening 13 of the lower case 12. Specifically, as shown in the exploded perspective view of FIG. 5 , a third seal section 63 is disposed around the first external opening 13. The third seal section 63 constitutes an opening waterproof structure that waterproofs the battery block 30, provided between the periphery of the first external opening 13 and the periphery of the battery cooling section 50. Therefore, the internal space in which the battery block 30 and circuit board 3 of the outer case 10 are disposed is partitioned by the partition section 20 of the lower case 12 of the outer case 10, and the periphery of the partition opening 21 of the partition section 20 is waterproofed by the first seal section 61, the space between the periphery of the partition section 20 and the lower case 12 of the outer case 10 is waterproofed by the second seal section 62, and the periphery of the first external opening 13 is waterproofed by the third seal section 63. As a result, the waterproof structure is achieved except for the portion exposed by the partition opening 21 and the portion exposed by the first external opening 13. With this configuration, an external first opening 13 is opened in a part of the outer case 10 to allow cooling air to enter the interior of the outer case 10 for cooling, while the external first opening and the battery block 30 are waterproofed, making it possible to prevent unintentional short-circuiting of the secondary battery cells 1 in the battery block 30.

[0027] 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.

[0028] (Battery Module 2) The battery module 2, also called a core pack, houses multiple secondary battery cells 1. The battery module 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.

[0029] (Holder Case 31) Each battery block 30 includes a holder case 31, a battery holder 40, rechargeable battery cells 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 the battery holder 40 is stored within the holder storage space. The holder case 31 shown in FIGS. 8 to 11 is divided into two sections, with a front first holder case 31A and a rear second holder case 31B joined together. However, the holder case is not limited to a two-section structure and may be divided into three or more sections. 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.

[0030] (Battery Holder 40) The battery holder 40 stores and holds multiple rechargeable battery cells 1. To this end, the battery holder 40 has multiple cell storage cylinders 42 that individually store the rechargeable battery cells 1. In the example shown in FIGS. 10 to 12, the outer shape of each cell storage cylinder 42 is hexagonal. As a result, the outer shape of the battery holder 40 is formed in a honeycomb shape. However, the shape of the battery holder is not limited to this configuration; for example, the outer shape of each storage cylinder may be polygonal, such as an octagon, or cylindrical.

[0031] On the other hand, the interior of the cell storage cylinder 42 is formed to be large enough to accommodate the rechargeable battery cells 1. Preferably, as shown in Figure 12 etc., the interior of the cell storage cylinder 42 is formed to be cylindrical enough to fit the cylindrical outer can of the rechargeable battery cell 1 so that the cylindrical outer can of the rechargeable battery cell 1 can be inserted, so that the cylindrical rechargeable battery cell 1 can be accommodated. In addition, it is preferable that there is a small gap between the outer can of the rechargeable battery cell 1 inserted into the cell storage cylinder 42 and the inner surface of the cell storage cylinder 42. By bringing the outer can and the cell storage cylinder 42 into surface contact, the rechargeable battery cells 1 are thermally coupled to the battery holder 40, and heat generated by the rechargeable battery cells 1 is efficiently conducted to the battery holder 40, thereby improving the cooling effect of the rechargeable battery cells 1.

[0032] The battery holder 40 is preferably made of a material with higher thermal conductivity than the resin that makes up the holder case 31. The battery holder 40 is made of metal such as aluminum or copper, or a resin with higher thermal conductivity than the resin that makes up the holder case 31, or a resin containing a metal filler. This makes it easier for the secondary battery cells 1 housed in the battery holder 40 to dissipate heat to the outside through the battery holder 40.

[0033] It is preferable that the length of the cell storage cylinders 42 of the battery holder 40 be shorter than that of the rechargeable battery cells 1. For example, in the example shown in Figures 11 and 12, when a rechargeable battery cell 1 is stored in each cell storage cylinder 42, the ends of the rechargeable battery cells 1 protrude from the cell storage cylinders 42. This configuration reduces the risk of unintended conduction caused by the end faces of the battery holder 40 coming into contact with the lead plates 5 or the like when connecting the cell end faces of the rechargeable battery cells 1 with the lead plates 5 or the like, even when a conductive battery holder 40 is used.

[0034] The battery holder 40 may also be divided into multiple pieces. Multiple battery holders 40 can also be stacked and housed in the holder case 31. In the example shown in Figures 11 and 12, seven battery holders 40 are stacked horizontally and housed in the holder case 31. In this case, it is preferable to form the joint surfaces connecting adjacent battery holders 40 into a periodic shape to facilitate stacking. For example, the side surfaces of the polygonal cell storage cylinder 42 can be formed with concave and convex shapes on each side of the battery holder 40, allowing the concave and convex shapes to interlock. In the example shown in Figure 12, the side surfaces of each battery holder 40 have an isosceles trapezoidal shape with a flat top and V-shaped concaves. This allows the convex and concave parts to interlock.

[0035] (Case tubular portion 32) The holder case 31 also has case tubular portions 32 formed on its inner surface that cover the ends of the rechargeable battery cells 1 housed in the battery holder 40. In the example shown in Fig. 11, 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 of the rechargeable battery cells 1.

[0036] (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.

[0037] Each lead plate 5 connects electrodes on the cell end faces of the secondary battery cells 1 to connect multiple secondary battery cells 1 together. The lead plate 5 is made of a highly conductive metal plate such as aluminum, nickel, or copper. The multiple secondary battery cells 1 are connected in series or 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. 10 , each lead plate 5 connects the end faces of approximately 10 secondary battery cells, and a total of 70 secondary battery cells 1 are connected in one battery block 30, forming a 7 series x 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 x 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.

[0038] (Bus bars 6) The lead plates 5 are also connected to each other with bus bars 6 as needed. By connecting parts of the lead plates 5 with the bus bars 6, a series or parallel pattern of the rechargeable battery cells 1 is formed and connected to the circuit board 3 or output terminals. In the example of the battery block 30 in Figures 9 and 10 , the upper ends of the lead plates 5 are bent and connected to the bus bars 6, achieving a 7 series x 10 parallel configuration. Here, all of the rechargeable battery cells 1 are held in the battery block 30 in an orientation where the same poles on the end faces of each cell are aligned on the same plane. In Figure 9 , the lower surface of the battery block 30 is the positive pole and the upper surface is the negative pole.

[0039] (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.

[0040] (Secondary Battery Cells 1) As shown in Figures 10 and 11, each battery block 30 houses secondary battery cells 1 in a holder case 31. The secondary battery cells 1 are housed and held in the cell housing cylinders 42 of the battery holder 40. Each secondary battery cell 1 can be cylindrical or rectangular. In the examples shown in Figures 6, 10 to 12, 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 may 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.

[0041] 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 of the secondary battery cell 1. In the examples shown in Figures 10 to 12, etc., a positive electrode terminal is provided on one cell end surface of the secondary battery cell 1, and the other surface of the outer casing serves as the negative electrode. In the example shown in Figure 10, each secondary battery cell 1 is held by a battery holder 40 in an orientation where the positive electrodes of all secondary battery cells 1 are on the same side (the front side in the figure).

[0042] A gas release valve 1a is provided in the exterior can of each secondary battery cell 1. The gas release valve 1a opens in response to an increase in the internal pressure of the exterior can, releasing gas from inside the exterior can to the outside. Such a gas release valve 1a is provided, for example, on the positive electrode side of the secondary battery cell 1.

[0043] The exterior 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 exterior 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 exterior case 10, the first external opening 13 and the second external opening 14 are preferably provided on different sides of the exterior case 10. In the example shown in FIG. 2 , the first external opening 13 is provided on the bottom surface of the exterior case 10, and the second external opening 14 is provided on the upper side of the rear surface of the exterior case 10. Note that this disclosure describes an example in which cooling air is drawn in through the first external opening 13 and discharged through the second external opening 14, as shown in FIG. 13 (to be described later), but is not limited to this configuration. It goes without saying that cooling air may also be drawn in through the second external opening and discharged through the first external opening.

[0044] 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 example of Fig. 5, the first external opening 13 is rectangular, while the second external opening 14 is slit-like.

[0045] The first external opening 13 is opened at a position corresponding to the battery cooling unit 50 housed inside the exterior case 10. This allows the cooling air path of the battery cooling unit 50 to be exposed from the exterior case 10 through the first external opening 13, and fresh cooling air taken into the exterior case 10 through the first external opening 13 can efficiently cool the rechargeable battery cells 1 housed in the battery holders 40. As the cooling air flows through the cooling air path, it exchanges heat with the rechargeable battery cells 1 inside the battery block 30 and flows to the top of the battery block 30. It is then guided through the partition opening 21 of the divider 20 to the top of the exterior case 10, into the interior of the upper case 11 in FIG. 13 , and then discharged through the second external opening 14 opened above the back surface of the exterior case 10. In this way, cooling air can flow inside the exterior case 10 to directly cool the middle portions of the rechargeable battery cells 1 housed in the battery block 30.

[0046] (Battery Cooling Section 50) The battery module 2 also includes a battery cooling section 50 thermally coupled to the battery block 30. The battery cooling section 50 defines a cooling air path therein through which cooling air flows. The battery cooling section 50 is open at its top and bottom, and the cooling air path is internally connected. The cooling air path is also connected to the outside of the power supply unit 100 through the exterior case 10. Specifically, as shown in FIG. 13 , the bottom end of the battery cooling section 50 is exposed through a first external opening 13 on the bottom surface of the exterior case 10. The top end of the battery cooling section 50 is also exposed through a partition opening 21 in the partition section 20. The partition opening 21 is also connected to a second external opening 14 of the exterior case 10. As a result, the cooling air path of the battery cooling section 50 is connected to the outside of the power supply unit 100, allowing cooling air taken in from the outside to flow into the interior of the exterior case 10 and cool the battery block 30 through heat exchange. An upper space within the exterior case 10 is formed above the partition opening 21. A portion of the surface facing the upper end of the battery cooling section 50 on the inner wall of the exterior case 10 is an inclined surface 16, which bends the flow of cooling air flowing out from the upper end of the battery cooling section 50 toward the second external opening 14. The inclined surface 16 on the surface facing the upper end of the battery cooling section 50 on the inner wall of the exterior case 10 is formed with a recess 18 provided by the formation of a handle 17 on the upper case 11 of the exterior case 10 that is used when transporting the power supply device 100. The inclined surface 16 is also formed with a plurality of ribs 19 extending in the inclined direction, which improve the strength of the plate surface of the inclined surface portion of the exterior case 10 and also rectify the flow of cooling air.

[0047] The cooling air path also includes a battery waterproof section 60 that waterproofs the gap between the battery block 30 and the exterior case 10. With this configuration, the battery cooling section 50 is used to ensure a cooling air path from the outside of the exterior case 10 while waterproofing the battery block 30, thereby air-cooling the rechargeable battery cells 1 and simplifying the waterproof structure.

[0048] In a structure that uses air cooling by flowing cooling air into the exterior case, an opening is necessarily provided in the exterior case to ensure an air flow path. On the other hand, a waterproof structure is required to protect the battery blocks housing the rechargeable battery cells from external water and other elements to prevent unintended short circuits of the rechargeable battery cells housed inside the exterior case. This required a complex structure because the exterior case had to be waterproof while still providing openings for the rechargeable battery cells housed inside. In contrast, the power supply device 100 according to this embodiment makes the battery block 30 waterproof as described above and thermally couples the battery cooling unit 50 to the battery block 30, thereby satisfying the contradictory requirements of allowing the exterior case 10 to be open for air cooling while still providing waterproof protection for the parts that require waterproofing.

[0049] 13 and other examples, a battery module 2 is constructed by stacking two battery blocks 30 with a battery cooling unit 50 sandwiched between them. By disposing the battery cooling unit 50 between the battery blocks 30 in this way, it becomes possible to efficiently cool each battery block 30 on both sides of one battery cooling unit 50.

[0050] (Thermal Conduction Sheet 55) As shown in FIG. 7 , a thermal conduction sheet 55 is interposed between the holder case 31 and the battery cooling unit 50 that constitute the battery block 30, improving the thermal bonding at the interface between the battery block 30 and the battery cooling unit 50. The thermal conduction sheet 55 is made of a sheet material with excellent thermal conductivity and insulation, preferably with a certain degree of elasticity. Examples of such materials include acrylic, urethane, epoxy, and silicone resins. Plastic sheets or mica filled with a filler with excellent thermal conductivity may also be used. Ceramic fillers or metal fillers can be blended into the resin as fillers with excellent thermal conductivity. Furthermore, a thermally conductive paste such as silicone oil can be applied between the thermal conduction sheet 55 and the battery cooling unit 50, etc., to achieve a structure that allows for more efficient heat conduction.

[0051] Furthermore, for example, a 1 mm to 3 mm thick, elastically deformable cushion sheet with excellent thermal conductivity can be used for the thermally conductive sheet 55. The thermally conductive sheet 55 is sandwiched between the holder case 31 and the battery cooling unit 50 in a crushed state, and is in close contact with the holder case 31 and the battery cooling unit 50. This reduces the formation of a heat insulating layer due to the occurrence of gaps, and brings the holder case 31 and the battery cooling unit 50 into close thermal contact, allowing for efficient heat dissipation from the secondary battery cells 1.

[0052] The multiple secondary battery cells 1 are held in the battery block 30 with the cell end faces aligned with the same poles on the same plane. The surface of the battery block 30 where the cell end faces are aligned on the same plane is coupled to the battery cooling unit 50. This configuration allows the battery cooling unit 50 to efficiently cool the secondary battery cells 1 from their cell end faces. In particular, as shown in the cross-sectional view of Figure 6 , by arranging each of the secondary battery cells 1 housed in the battery block 30 so that their cell end faces face the battery cooling unit 50, all of the secondary battery cells 1 are thermally coupled to the battery cooling unit 50, allowing each secondary battery cell 1 to be efficiently air-cooled.

[0053] (Case Holder 57) In the example shown in Figure 7 and elsewhere, the battery cooling unit 50 is formed to be slightly smaller than the battery block 30. By interposing a thermally conductive sheet 55, heat can be dissipated through the thermally conductive sheet 55 even in areas where the battery cooling unit 50 does not overlap the battery block 30. In the example shown in Figures 4 and 5, the battery module 2, with the battery cooling unit 50 sandwiched between the battery blocks 30, is held in the lower case 12 by a case holder 57. The case holder 57 positions and holds the battery module 2 within the exterior case 10, and also functions as a cushioning material to protect the battery block 30 when external forces such as vibrations or impacts are applied to the power supply device 100. Such a case holder 57 can be made of resin or cushioning material.

[0054] Furthermore, it is preferable to arrange the secondary battery cells 1 so that the cell end face on the negative electrode side faces the battery cooling unit 50. By arranging them in this way, if the cell end face on the positive electrode side of the secondary battery cell 1 is provided with a gas release valve that opens when internal pressure becomes high, in the unlikely event that high-temperature, high-pressure gas is released from one secondary battery cell 1, other secondary battery cells 1 will not be arranged on the side opposite that cell end face.In other words, by arranging the cell end faces without gas release valves facing each other, safety can be improved.

[0055] As shown in Figures 4, 7, etc., the battery cooling unit 50 has cooling air passages formed in the form of multiple slits. Each slit is opened along the direction in which the multiple secondary battery cells 1 face each other. With this configuration, each slit is opened so as to face the secondary battery cell 1, allowing cooling air to flow through each slit, thereby efficiently cooling the secondary battery cells 1.

[0056] An air-cooled pipe can be used for the battery cooling unit 50. The battery cooling unit 50 is made of a material with excellent thermal conductivity. The battery cooling unit 50 is formed by extruding aluminum, for example.

[0057] Furthermore, a waterproof structure that separates the battery block 30 and the battery cooling unit 50 also makes the circuit board 3 waterproof. That is, by locating the circuit board 3 in isolation from the cooling air path that is provided between the first external opening 13 and the second external opening 14 and that allows cooling air to flow, the waterproof structure also makes the circuit board 3 waterproof. In the examples shown in Figures 6 and 13, the circuit board 3 is located on the side of the battery block 30 opposite the side where the battery cooling unit 50 is provided. This effectively prevents unintended conduction of the circuit board 3 in addition to short-circuiting the terminals of the secondary battery cells 1.

[0058] 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.

[0059] The power supply device 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 used as a cooling mechanism for electrical devices with built-in heating elements, and can 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.

[0060] DESCRIPTION OF SYMBOLS 100...power supply device 1...secondary battery cell 2...battery module 3...circuit board 4...board holder 5...lead plate 6...bus bar 10...exterior case 11...upper case 12...lower case 13...first external opening 14...second external opening 16...inclined surface 17...handle portion 18...recess 19...rib 20...partition portion 21...partition opening 30...battery block 31...holder case 31A...first holder case 31B...second holder case 32...case cylindrical portion 33...electrode window 40...battery holder 42...cell storage cylindrical portion 50...battery cooling portion 55...thermal conduction sheet 57...case holder 60...battery waterproof portion 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; one or more battery blocks housing the plurality of secondary battery cells; a battery cooling section thermally coupled to the one or more battery blocks; and an exterior case housing the one or more battery blocks and the battery cooling section, wherein the battery cooling section defines a cooling air path through which cooling air flows and communicates with the outside through the exterior case, and the power supply device further comprises a battery waterproofing section which waterproofs the gap between the battery block and the exterior case.

2. A power supply device as claimed in claim 1, wherein the multiple secondary battery cells are held in the battery block with the same poles arranged on the same plane at the cell end faces, and the surface of the one or more battery blocks on which the cell end faces are arranged on the same plane is coupled to the battery cooling section.

3. A power supply device according to claim 2, wherein the one or more battery blocks include two battery blocks, and the battery cooling section is disposed between the two battery blocks.

4. A power supply device according to claim 3, wherein the plurality of secondary battery cells are held in the one or more battery blocks with the cell end face of the negative electrode of each secondary battery cell facing the battery cooling section.

5. A power supply device as claimed in claim 3, wherein the battery cooling section has the cooling air passage opened in the form of a plurality of slits, each of the plurality of slits being opened along the direction in which the plurality of secondary battery cells face each other.

6. A power supply device as claimed in any one of claims 1 to 5, wherein the exterior case has a partition section for holding the battery block therein, the partition section defines a partition opening for exposing the battery cooling section, and the battery waterproof section is provided between the periphery of the partition opening and the periphery of the battery cooling section.

7. A power supply device as described in claim 6, wherein the exterior case has a first external opening on a portion of its surface that connects the cooling air path defined by the battery cooling section with the outside, and the battery waterproof section has an opening waterproof structure between the periphery of the first external opening and the periphery of the battery cooling section that waterproofs the battery block.

8. A power supply device comprising: a plurality of secondary battery cells, each of which has a cell end face at both positive and negative ends; one or more battery blocks that house the plurality of secondary battery cells; a battery cooling section that is thermally coupled to the one or more battery blocks; and an outer case that houses the one or more battery blocks and the battery cooling section, wherein the battery cooling section has a cooling air path that flows cooling air therein, and the cooling air path is connected to the outside through the outer case, and the power supply device comprises a battery waterproofing section that waterproofs the gap between the battery block and the outer case.

9. A power supply device as described in claim 8, wherein the battery block is provided with a holder case, the holder case holds the cell end faces of each of the plurality of secondary battery cells aligned in the same plane, and the holder case of the one or more battery blocks is thermally coupled to the battery cooling section.

10. A power supply device according to claim 9, wherein the one or more battery blocks include two battery blocks, and the battery cooling section is disposed between the two battery blocks.

11. A power supply device according to claim 10, wherein the cell end face of the negative electrode of each of the plurality of secondary battery cells faces the battery cooling section and is supported by the one or more battery blocks.

12. A power supply device as described in claim 10, wherein the battery cooling section has a plurality of slit-shaped openings communicating with the cooling air path and the outside, and each of the plurality of slits opens along a direction in which the one or more battery blocks sandwiching the battery cooling section face each other.

13. A power supply device as claimed in any one of claims 8 to 12, wherein the outer case has a partition section for holding the battery block therein, the partition section defines a partition opening for exposing the battery cooling section inside the outer case, and the battery waterproof section is provided between the periphery of the partition opening and the periphery of the battery cooling section.

14. A power supply device as described in claim 13, wherein the exterior case has a first external opening on a portion of its surface that connects the cooling air path defined by the battery cooling section with the outside, and the battery waterproof section has a waterproof seal section provided between the periphery of the first external opening and the periphery of the battery cooling section.

15. A power supply device as claimed in claim 14, wherein the exterior case has a second external opening on a surface different from the surface having the first external opening, and the partition opening is connected to the second external opening to form the cooling air path.

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