Power supply device

Abstract

This power supply device is provided with: a plurality of secondary battery cells each having a cylindrical outer can, each end surface of the cylinder serving as a cell end surface; a battery holder housing the plurality of secondary battery cells; an exterior case housing the battery holder; and a cooling part thermally coupled to a side surface of the battery holder. The side surface of the battery holder is curved along the outer shape of the outer can, and the cooling part is curved along the shape of the side surface of the battery holder. By thus placing the cooling part so as to follow the outer shape of the secondary battery cells positioned on the side surface of the battery holder, cooling can be efficiently performed due to an increase in contact area.

Description

power supply

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

[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. In particular, in recent years, there has been a demand for power supply devices with higher output and capacity. As a result of the progress in increasing the capacity of the secondary battery cells used, the amount of heat generated also tends to increase. In addition to the secondary battery cells, the amount of heat generated by power system components mounted on a circuit board must also be taken into consideration.

[0003] As a countermeasure against such heat, it is conceivable to arrange cooling pipes 840 for flowing a medium such as cooling air on the side of a battery block 830 composed of multiple secondary battery cells 801 as shown in Figure 4, and to perform heat exchange by bringing the cooling pipes 840 into contact with the secondary battery cells 801 arranged at the end.

[0004] However, in a configuration in which multiple cylindrical secondary battery cells 801 are stacked, they are often arranged in a staggered pattern with each row offset, as shown in Figure 4, for space efficiency reasons. As a result, the secondary battery cells 801 located at the end of the battery block 830 alternate between being in contact with the cooling pipes 840 installed on the side of the battery block 830 and not being in contact with them. Furthermore, for the secondary battery cells 801 that are in contact with the cooling pipes 840, because the secondary battery cells 801 are cylindrical, the contact points are line contact, and the contact area is small. This makes it difficult to achieve efficient heat exchange.

[0005] Republished Patent No. WO2017 / 175487

[0006] One object of one embodiment of the present disclosure is to provide a power supply device that can efficiently cool secondary battery cells. Another object of another embodiment is to provide a power supply device that facilitates heat exchange between cylindrical secondary battery cells. 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.

[0007] A power supply device according to one embodiment of the present disclosure comprises 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, a battery holder for housing the plurality of secondary battery cells, an outer case for housing the battery holder, and a cooling section thermally coupled to a side face of the battery holder, wherein the side face of the battery holder is curved to conform to the outer shape of the outer can, and the cooling section is curved to conform to the shape of the side face of the battery holder.

[0008] According to one embodiment of the power supply device of the present disclosure, by arranging the cooling section so as to follow the outer shape of the secondary battery cell located on the side of the battery holder, the contact area is increased, enabling efficient cooling.

[0009] FIG. 5 is an exploded perspective view showing a power supply device according to embodiment 1. FIG. 5 is an exploded perspective view of the battery module of FIG. 1. FIG. 5 is a schematic cross-sectional view of the power supply device of FIG. 1. FIG. 5 is a schematic cross-sectional view of a power supply device according to comparative example 1. FIG. 5A is a cross-sectional view of a cooling section according to embodiment 1. FIG. 5B is a cross-sectional view of a cooling section according to embodiment 2. FIG. 5C is a cross-sectional view of a cooling section according to embodiment 3. FIG. 5D is a cross-sectional view of a cooling section according to embodiment 4. FIG. 5B is a cross-sectional view of a cooling section according to embodiment 4. FIG. 5C is a cross-sectional view of a cooling section according to embodiment 5. FIG. 5D is a cross-sectional view of a power supply device according to embodiment 6. FIG. 5D is a schematic cross-sectional view of a power supply device according to comparative example 2.

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

[0011] In another aspect of the power supply device of the present disclosure, in the above aspect, the plurality of secondary battery cells are stacked in multiple vertical stages with the end faces of each cell coplanar, the end faces of adjacent secondary battery cells in the multiple stages are offset with the centers of the circles shifted, the side surfaces of the battery holder are corrugated in cross section, and the cooling part is corrugated to follow the corrugation of the side surfaces of the battery holder. With this configuration, the cooling part can be similarly corrugated to the battery holder whose side surfaces are corrugated due to the staggered arrangement, thereby improving thermal coupling and improving heat dissipation by contacting the cooling part over a wide area.

[0012] In addition, in a power supply device according to another aspect of the present disclosure, in any of the above aspects, the cooling units are disposed on both side surfaces of the battery holder. With this configuration, the cooling units cool the battery holder from both the left and right sides, thereby cooling the internal secondary battery cells from both the left and right sides, thereby promoting heat dissipation.

[0013] In a power supply device according to another aspect of the present disclosure, in any of the above aspects, the battery holder includes a plurality of battery holders, and the cooling unit includes a plurality of cooling units, each of which is interposed between adjacent battery holders. With this configuration, cooling units are arranged not only on the sides of the battery holders but also between the plurality of secondary battery cells, and the secondary battery cells that are located in the middle and prone to heat buildup can be directly cooled by the additional cooling units, thereby achieving more efficient cooling.

[0014] In a power supply device according to yet another aspect of the present disclosure, in any of the above aspects, the cooling section is formed in a tubular shape for circulating cooling gas therein. With this configuration, an air-cooled cooling pipe is brought into contact with the curved surface of the battery holder so as to conform to the curved surface, enabling efficient heat exchange.

[0015] In addition, the power supply device according to another aspect of the present disclosure may further include a flexible heat-conducting sheet interposed between the battery holder and the cooling unit. By interposing the flexible heat-conducting sheet between the side surface of the battery holder and the cooling unit, a gap can be eliminated, thereby preventing the formation of a heat-insulating layer at the bonding interface.

[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 3. In these figures, Figure 1 shows an exploded perspective view of the power supply device 100 according to embodiment 1, Figure 2 shows an exploded perspective view of the battery module 2 of Figure 1, and Figure 3 shows a schematic cross-sectional view of the power supply device 100 of Figure 1. The power supply device 100 shown in these figures includes an outer case 10, a battery module 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 FIG. 1 , the external case 10 has a box-like shape that extends in one direction. 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. The divided external cases are waterproofed by a waterproof structure.

[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 FIG. 1 , an internal space is formed in the lower case 12, and the battery module 2 and circuit board 3 are housed therein.

[0021] Furthermore, the outer case 10 has an external opening 15 formed in a part thereof. The external opening 15 is connected to a cooling air path. In the example shown in Fig. 1, the external openings 15 include a first external opening 13 formed in the bottom surface of the outer case 10 and a second external opening 14 formed in the upper side of the outer case 10.

[0022] (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 example of FIG. 2 , two battery blocks 30 are stacked horizontally to form the battery module 2. A circuit board 3 is placed around each battery block 30. Furthermore, a cooling unit 40 is arranged on each side of the battery block 30.

[0023] (Battery Holder 31) Each battery block 30 includes a battery holder 31, a rechargeable battery cell 1, and lead plates 5. As shown in Figure 2, the battery holder 31 has multiple cylindrical holder sections 34, into which a rechargeable battery cell 1 is inserted and held. The battery holder 31 may be configured to house all of the rechargeable battery cells 1 as a whole, or may be divided into multiple sub-holders, with some of the multiple rechargeable battery cells housed in each sub-holder. The battery holder may also be divided in the length direction of the rechargeable battery cells.

[0024] The battery holder 31 is made of a material with excellent insulating properties, preferably a resin such as polycarbonate or PC-ABS alloy.

[0025] (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 located on the outer surface of the battery holder 31. The lead plates 5 are electrically connected to the terminals of the rechargeable battery cells 1 that are exposed through electrode windows opened in the battery holder 31.

[0026] Each lead plate 5 connects electrodes on the cell end faces of the rechargeable battery cells 1 to each other, thereby connecting multiple rechargeable battery cells 1 together. The lead plates 5 are made of highly conductive metal plates such as aluminum, nickel, or copper. The multiple rechargeable 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. 2 , each lead plate 5 connects the end faces of mainly 10 rechargeable battery cells 1, and a total of 21 rechargeable battery cells 1 are used in one battery block 30, forming a 1 series × 21 parallel connection. Two battery blocks 30 are stacked in the longitudinal direction of the rechargeable battery cells 1, and these battery blocks 30 are connected in series, forming a 2 series × 21 parallel connection for a total of 42 rechargeable battery cells 1. However, the number of rechargeable battery cells and the connection configuration, i.e., the number of series and parallel connections, are not limited to this configuration.

[0027] (Circuit Board 3) The battery block 30 is connected to the circuit board 3 via lead plates 5. 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 may also be provided as a member to hold the circuit board 3.

[0028] In the example of Figure 2 etc., an example is shown in which a circuit board 3 is placed on the upper surface of each battery block 30, but the present disclosure is not limited to this configuration, and one circuit board may be connected to each battery block.

[0029] (Rechargeable Battery Cells 1) As shown in FIG. 2 , each battery block 30 houses rechargeable battery cells 1 in a battery holder 31. Each rechargeable battery cell 1 can be cylindrical or rectangular. In the example shown in FIG. 2 and other figures, cylindrical rechargeable battery cells 1 are arranged horizontally in a staggered pattern. The number and arrangement of the rechargeable battery cells 1 are not limited to this example, and any number and arrangement can be used as appropriate. For example, cylindrical rechargeable battery cells can be arranged in a matrix (details will be described later). Known rechargeable batteries, such as lithium-ion rechargeable batteries, nickel-metal hydride batteries, and nickel-cadmium batteries, can be used as appropriate for the rechargeable battery cells 1.

[0030] 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 example of Fig. 2, a positive electrode terminal is provided on one cell end surface of the secondary battery cell 1, and the other surface of the outer can serves as the negative electrode.

[0031] The battery holder 31 stacks multiple rechargeable battery cells 1 in multiple vertical tiers with the end faces of each cell flush. The end faces of adjacent rechargeable battery cells 1 in the vertical tiers are offset with the centers of their circles shifted. As a result, the assembly of multiple rechargeable battery cells 1 housed in the battery block 30 is aligned flatly on the top and bottom, but has an uneven shape on the side with the centers of the cell end faces shifted. For this reason, the side faces of the battery holder 31 are curved to match the outer shape of the exterior can of the rechargeable battery cells 1, as shown in Figure 3 .

[0032] (Cooling section 40) A cooling section 40 is disposed on the side of the battery holder 31. The cooling section 40 is thermally coupled to the cooling section 40 via a thermally conductive sheet 50. The cooling section 40 is curved to fit the shape of the side of the battery holder 31. By arranging the cooling section 40 in this way to fit the outline of the secondary battery cells 1 located on the side of the battery holder 31, the contact area is increased, enabling efficient cooling.

[0033] In a power supply device using multiple secondary battery cells, the secondary battery cells housed inside generate heat during charging and discharging, and therefore need to be cooled. One possible cooling structure is a power supply device 800 according to a comparative example shown in Figure 4, in which cooling pipes 840 for flowing a refrigerant such as cooling air are arranged on the side of a battery block 30 made up of multiple secondary battery cells 801, and heat exchange is performed by bringing the cooling pipes 840 into contact with the secondary battery cells 801 arranged at the end.

[0034] In a battery block 830 in which multiple cylindrical secondary battery cells 1 are stacked, the secondary battery cells 801 are often stacked vertically in a staggered arrangement with rows offset, as shown in Figure 4, for space efficiency reasons. As a result, the secondary battery cells 801 located at the ends of the battery block 830 alternate between being in contact with the cooling pipes 840 installed on the side of the battery block 830 and not being in contact with them. Furthermore, because the secondary battery cells 801 are cylindrical, the contact points with the cooling pipes 840 are line contact, resulting in a small contact area. This makes it difficult to achieve efficient heat exchange.

[0035] In contrast, in the power supply device 100 according to the first embodiment, as shown in FIG. 3 , the cooling section 40 is not linear but curved to conform to the side shape of the battery holder 31, thereby increasing the contact area and promoting heat exchange, enabling efficient cooling. In the example shown in FIG. 3 , the side surfaces of the battery holder 31 are corrugated in cross section. The side surfaces of the battery holders 31 constituting each of the two battery blocks 30 face each other so that the corrugated recesses and protrusions of adjacent battery holders 31 fit together. Accordingly, the cooling sections 40 are arranged on the outer and adjacent side surfaces of each of the two battery blocks 30 and are corrugated to conform to the corrugations of the side surfaces of the battery holders 31. The cooling section 40 arranged between two adjacent battery blocks 30 is shared by both battery blocks 30. This ensures the density of the multiple rechargeable battery cells 1, while improving thermal coupling and heat dissipation by forming the cooling section 40 in a similar corrugated shape and contacting the battery holders 31 over a wide area, even though the side surfaces are corrugated due to the staggered arrangement. In particular, compared to Figure 4, by having the cooling section 40 in direct contact with all of the secondary battery cells 1 arranged on the side of the battery holder 31, the contact area is wider, allowing for more efficient air cooling.

[0036] In addition, the cooling unit 40 can not only cool the heat generated by the secondary battery cells 1 stored in the battery holder 31, but also the heat-generating components mounted on the circuit board 3 placed on the battery holder 31, such as power semiconductors.

[0037] The cooling unit 40 is connected to an external opening 15 formed in the outer case 10. Specifically, as shown in FIG. 3 , the first external opening 13, which is an external opening 15 on the bottom surface of the outer case 10, is connected to the lower end of the cooling unit 40, and the second external opening 14, which is an external opening 15 on the upper side of the outer case 10, is connected to the upper end of the cooling unit 40. As a result, air taken into the outer case 10 through the external opening 15 is used as a cooling medium and cooled by heat exchange in the cooling unit 40. If necessary, a fan or the like may be provided to forcibly circulate the cooling air. Note that in this disclosure, an example is described in which cooling air is taken in through the first external opening 13 and discharged through the second external opening 14 as shown in FIG. 3 . However, this configuration is not limited to this, and it goes without saying that cooling air may be taken in through the second external opening and discharged through the first external opening.

[0038] The cooling unit 40 may be placed on only one side of the battery holder 31, but preferably, as shown in Figure 3, multiple cooling units 40 are used and placed on both sides of the battery holder 31. This allows the cooling units 40 to cool the battery holder 31 from both the left and right sides, and cooling the internal secondary battery cells 1 from both the left and right promotes heat dissipation.

[0039] 2 and other examples, the battery module 2 includes multiple battery holders 31. In such a configuration using multiple battery holders 31, it is preferable to interpose cooling units 40 between adjacent battery holders 31. This allows cooling units 40 to be arranged not only on the side surfaces of the battery module 2 but also between the multiple secondary battery cells 1, thereby enabling more efficient cooling by directly cooling the secondary battery cells 1 that are located in the middle and prone to trapping heat with the additional cooling units 40.

[0040] The cooling unit 40 is made of a material such as a metal with excellent electrical conductivity. The cooling unit 40 is formed into a hollow tube. By flowing a refrigerant such as a cooling gas inside this tube, heat exchange can be achieved using air-cooled cooling pipes. In the example shown in Figure 2, multiple cooling pipes are spaced apart from one another on the side of each battery holder 31. Each cooling pipe is deformed into a corrugated shape to fit the curved surface of the battery holder 31. This type of configuration is relatively easy to achieve.

[0041] The cross-sectional shape of the cooling pipe can be circular as shown in FIG. 5A , but can also be other shapes. For example, the cooling section 40B of the power supply device according to embodiment 2 shown in FIG. 5B is a flattened pipe with an elliptical cross-section. This allows for a larger contact area with the battery holder 31 compared to a circular shape. In the power supply device according to embodiment 3 shown in FIG. 5C , the cooling section 40C has a track-shaped cross-section. This further increases the contact area with the battery holder 31. Alternatively, the cooling section 40D may have a rectangular cross-section, as in the power supply device according to embodiment 4 shown in FIG. 5D . This further increases the contact area with the battery holder 31. A rectangular cooling section is preferably rectangular, with the long side of the contact surface with the cooling pipe. It is also preferable to chamfer the corners. Furthermore, the cross-sectional shape is not limited to a square, but can also be a polygonal shape such as a triangle.

[0042] (Thermal Conduction Sheet 50) A thermal conduction sheet 50 with excellent thermal conductivity can be interposed between the battery holder 31 and the cooling unit 40. The thermal conduction sheet 50 is flexible. By interposing this flexible thermal conduction sheet 50 between the side surface of the battery holder 31 and the cooling unit 40, the gap at the bonding interface between them is reduced, preventing the formation of an insulating air layer and improving thermal bonding.

[0043] Furthermore, the thermally conductive sheet 50 preferably has insulating properties that electrically insulate the metal cooling unit 40 from the battery holder 31. This prevents unintended electrical conduction between the secondary battery cells 1 in the battery holder 31 through the cooling unit 40. The thermally conductive sheet 50 can be made of a material that has excellent thermal conductivity and insulation properties, as well as 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 filler or metal filler can be blended into the resin as a filler with excellent thermal conductivity. Furthermore, applying a thermally conductive paste such as silicone oil between the thermally conductive sheet 50 and the cooling unit 40 can provide a structure that conducts heat more efficiently.

[0044] The thermally conductive sheet 50 can be, for example, a 1-3 mm thick, elastically deformable cushion sheet with excellent thermal conductivity. The thermally conductive sheet 50 is sandwiched between the battery holder 31 and the cooling unit 40 in a crushed state, and is in close contact with the battery holder 31 and the cooling unit 40. This reduces the formation of a heat insulating layer due to gaps, and brings the battery holder 31 and the cooling unit 40 into close thermal contact, allowing for efficient heat dissipation from the rechargeable battery cells 1.

[0045] 1 and other examples show the thermally conductive sheet 50 as a sheet that covers the entire side surface of the battery holder 31, but this configuration is not limited thereto and it may cover only the area where the cooling unit contacts the battery holder. For example, the thermally conductive sheet may be formed into multiple strips.

[0046] (Waterproof Structure) As described above, the power supply unit 100 is configured to cool each battery block 30 from both sides using cooling air circulating through the cooling unit 40 inside the exterior case 10. The inlets and outlets for the cooling air circulating through the cooling unit 40 are joined to the first external opening 13 on the bottom surface of the exterior case 10 and the second external opening 14 on the top surface of the exterior case 10. The gaps between the first external opening 13 and the inlet and outlet of the cooling unit 40 and the gaps between the second external opening 14 and the inlet and outlet of the cooling unit 40 are each liquid-tight sealed with a sealant. In addition, the joint surfaces of the upper case 11 and the lower case 12 that constitute the exterior case 10 are also liquid-tight sealed with a sealant, thereby providing a waterproof structure for the exterior case 10. This prevents water and other contaminants from entering each battery block 30 in the exterior case 10 through the first external opening 13 and the second external opening 14 in the exterior case 10 or the gaps at the joint surfaces of the upper case 11 and the lower case 12.

[0047] [Embodiment 5] In the above examples, an example was described in which a tubular cooling pipe was used as the cooling unit 40. However, the present disclosure does not limit the cooling unit 40 to a tubular shape, and it may be plate-shaped. For example, it may be configured so that cooling air flows inside a hollow plate. Such an example is shown in the perspective view of a battery module 2' as a power supply device according to embodiment 5 of the present invention in FIG. 6. In this figure, components similar to those in embodiment 1 and the like are designated by the same reference numerals, and detailed descriptions thereof will be omitted where appropriate.

[0048] The cooling unit 40E located on the side of the battery module 2' shown in Figure 6 is a corrugated, hollow plate. The plate is made of a highly conductive material such as metal and is open at the top and bottom. This type of cooling unit 40E allows a single component to cool the entire side of the battery holder 31 over a wide area.

[0049] Sixth Embodiment In the above example, an example was described in which the secondary battery cells 1 are arranged in an offset configuration, but the present disclosure is not limited to this and may also be applied to an example in which the secondary battery cells are arranged in a matrix. Such an example is shown in the schematic cross-sectional view of Figure 7 as a power supply device 700 according to a seventh embodiment. In this figure, components similar to those in the first embodiment and the like are designated by the same reference numerals, and detailed descriptions thereof will be omitted where appropriate.

[0050] Even when cylindrical secondary battery cells 901 are arranged in a matrix, as in the power supply device 900 shown in Comparative Example 2 in Fig. 8 , if linear cooling pipes 940 are arranged on the side surfaces of the secondary battery cells 901, the cylindrical side surfaces of the secondary battery cells 901 come into linear contact, resulting in a small contact area between each secondary battery cell 901 and the cooling pipes 940. In contrast, by curving the cooling section 40 in a wave shape so as to fit the side surfaces of each secondary battery cell 1, as in the power supply device 700 according to the seventh embodiment shown in Fig. 7 , the contact area with each secondary battery cell 1 can be increased, improving thermal coupling and further enhancing cooling performance.

[0051] 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.

[0052] 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.

[0053] DESCRIPTION OF SYMBOLS 100, 700...power supply device 1...secondary battery cell 2, 2'...battery module 3...circuit board 5...lead plate 10...exterior case 11...upper case 12...lower case 13...first external opening 14...second external opening 15...exterior opening 30...battery block 31...battery holder 34...holder cylinder portion 40, 40B, 40C, 40D, 40E...cooling portion 50...thermal conduction sheet 800...power supply device 801...secondary battery cell 830...battery block 840...cooling pipe 900...power supply device 901...secondary battery cell 940...cooling pipe

Claims

1. A power supply device comprising: a plurality of secondary battery cells, each having a cylindrical outer can with each end face of the cylinder as a cell end face; a battery holder that houses the plurality of secondary battery cells; an outer case that houses the battery holder; and a cooling section that is thermally coupled to a side face of the battery holder, wherein the side face of the battery holder is curved to conform to the outer shape of the outer can, and the cooling section is curved to conform to the shape of the side face of the battery holder.

2. A power supply device as described in claim 1, wherein the multiple secondary battery cells are stacked in multiple stages in the vertical direction with each cell end face being on the same plane, the cell end faces of adjacent secondary battery cells among the multiple secondary battery cells in the vertical direction of the multiple stages are offset with the center of the circle shifted, the side surface of the battery holder is formed in a corrugated shape when viewed in cross section, and the cooling section is formed in a corrugated shape to follow the corrugated shape of the side surface of the battery holder.

3. A power supply device according to claim 1, wherein the cooling section is disposed on each of the opposite side surfaces of the battery holder.

4. A power supply device as claimed in claim 3, wherein the battery holder comprises a plurality of battery holders, the cooling section comprises a plurality of cooling sections, and each of the cooling sections is interposed between adjacent battery holders among the plurality of battery holders.

5. A power supply device according to any one of claims 1 to 4, wherein the cooling section is formed in a tubular shape for allowing cooling gas to flow therethrough.

6. A power supply device according to any one of claims 1 to 4, further comprising a flexible heat-conducting sheet interposed between said battery holder and said cooling section.

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