Power supply device, method for manufacturing same, and method for replacing secondary battery cell

Abstract

The present invention enables replacement of a secondary battery cell. The present invention also reduces the number of structures requiring destruction for decomposition to increase the number of reusable members. A power supply device 100 includes: a plurality of secondary battery cells 1 each having a cell end face 1a; and a battery block 10 for housing the plurality of secondary battery cells 1. The battery block 10 is provided with a plurality of sub-blocks 20. The sub-blocks 20 each comprise: a cell holder 21 having a plurality of housing cylinders 24 each housing the plurality of secondary battery cells 1; and a pair of collector plates 40 each electrically connected to the cell end face 1a exposed from an opening window 25 opened at an end edge of the housing cylinder 24. The plurality of sub-blocks 20 are connected to each other by a screwing structure.

Description

Power supply device, its manufacturing method, and secondary battery cell replacement method

[0001] The present disclosure relates to a power supply device, a manufacturing method thereof, and a method for replacing a secondary battery cell.

[0002] Power supply devices with many secondary battery cells connected in series and parallel are used for stationary power storage applications, such as backup power sources for servers, power supplies for homes, offices, and factories, as power sources for driving vehicles such as electric scooters, electric carts, hybrid cars, and electric cars, and as power sources for power-assisted bicycles and portable electric devices such as electric cleaners and power tools.

[0003] On the other hand, in light of recent social demands such as reducing environmental impact and realizing a sustainable society, there is a demand for products that consider recycling, reusing, and reducing resources. Power supplies also require mechanisms that allow for the reuse of usable parts and the replacement of deteriorated parts.

[0004] However, conventional power supply devices have a problem in that they are not easy to reuse. For example, in a power supply device in which multiple rechargeable battery cells are housed in a battery block and the cell ends of the rechargeable battery cells are welded to the lead plates with lead plates, removing some of the rechargeable battery cells from the battery block and replacing them for reuse requires breaking all of the lead plates and temporarily removing them from the cell ends of each rechargeable battery cell before removing the rechargeable battery cells from the battery block. This process is time-consuming, and the more rechargeable battery cells and lead plates there are, the more lead plates that must be removed from the cell ends, which increases the amount of work involved.

[0005] Special Publication No. 2022-549322

[0006] One object of the present disclosure is to provide a power supply device that allows replacement of secondary battery cells, a manufacturing method thereof, and a method for replacing secondary battery cells. Another object is to provide a power supply device that reduces the structure that requires destruction for disassembly and increases the number of reusable components, a manufacturing method thereof, and a method for replacing secondary battery cells. Note that the description of these objects and objects of the present disclosure does not preclude the existence of other objects and objects. Furthermore, it is not necessary for one embodiment of the present disclosure to solve all of these objects. Furthermore, other objects can be extracted from the description of the specification, drawings, and claims of the present disclosure.

[0007] A power supply device according to one embodiment of the present disclosure is a power supply device comprising a plurality of secondary battery cells having cell end faces, and a battery block that houses the plurality of secondary battery cells, wherein the battery block comprises a plurality of sub-blocks, each of which comprises a cell holder having a plurality of storage tubes that respectively house the plurality of secondary battery cells, and a pair of current collector plates that are each electrically connected to the cell end faces that are exposed through an opening window opened at the edge of the storage tube, and the plurality of sub-blocks are connected to each other by a screw structure.

[0008] A manufacturing method for a power supply device according to another embodiment of the present disclosure is a manufacturing method for a power supply device including a plurality of secondary battery cells having cell end faces and a battery block that houses the plurality of secondary battery cells, and includes the steps of preparing a plurality of sub-blocks that constitute the battery block, housing the plurality of secondary battery cells in storage tubes of cell holders that constitute each sub-block, welding lead plates to the cell end faces that are exposed through opening windows opened in the edge of the storage tubes, and fixing current collector plates in a stacked state to the lead plates, connecting a plurality of the sub-blocks to form the battery block, covering a first surface of the battery block with a first plate that extends along the connection direction of the battery block, covering a second surface opposite the first surface with a second plate that extends along the connection direction of the battery block, and screwing the battery block to the first plate and the second plate, respectively, to fix the sub-blocks in a connected state.

[0009] A method for replacing secondary battery cells according to another aspect of the present disclosure is a method for replacing some of the secondary battery cells of a power supply device including: a plurality of secondary battery cells having cell end faces; a battery block formed by connecting a plurality of sub-blocks that house the plurality of secondary battery cells; a first plate that is screwed to a first surface of the battery block and extends along the connecting direction of the battery block; and a second plate that is screwed to a second surface of the battery block opposite the first surface and extends along the connecting direction of the battery block, the method including the steps of: unscrewing the battery block from the first plate and the second plate, and removing the first plate and the second plate from the battery block; removing a sub-block that includes a secondary battery cell to be replaced from among the plurality of secondary battery cells, replacing it with a new sub-block that includes a replacement secondary battery cell, and screwing the first plate to the first surface and the second plate to the second surface of the battery block including the new sub-block, thereby fixing the sub-blocks in a connected state.

[0010] This means that by connecting multiple sub-blocks by screwing them together to form a battery block, the sub-blocks can be disassembled even after the power supply device has been constructed, making it possible to replace each sub-block individually and facilitating the replacement of secondary battery cells.

[0011] 16 is a perspective view showing a battery pack according to an embodiment. FIG. 17 is an exploded perspective view of the battery pack of FIG. 1. FIG. 18 is an exploded perspective view of the battery block of FIG. 2, seen from diagonally below the rear side. FIG. 19 is an exploded perspective view showing the battery block of FIG. 2 with a circuit board removed. FIG. 29 is an exploded perspective view showing the battery block of FIG. 4 with bus bars further removed. FIG. 20 is a plan view of the battery block of FIG. 5. FIG. 21 is an exploded perspective view showing the battery block of FIG. 5 disassembled into sub-blocks. FIG. 22 is an enlarged perspective view showing the first sub-block and the second sub-block connected together. FIG. 23 is an exploded perspective view showing the sub-block of FIG. 8 separated. FIG. 24 is an exploded perspective view of the first sub-block. FIG. 25 is an exploded perspective view of the first sub-block of FIG. 10, seen from diagonally below. FIG. 26 is an exploded perspective view of the second sub-block. FIG. 27 is an exploded perspective view of the second sub-block of FIG. 12, seen from diagonally below. FIG. 28 is a side view of the second sub-block. FIG. 29 is an exploded perspective view showing how current collecting plates are fixed to the lead plates of the second sub-block of FIG. 12. FIG. 29 is a plan view of a sub-block according to a comparative example. FIG. 29 is an exploded perspective view of the sub-block of FIG. 16.

[0012] The embodiments of the present disclosure may be specified by the following configurations and features.

[0013] In another aspect of the present disclosure, in the above-described power supply device, a first plate extending in the connecting direction of the battery blocks and covering the first surface of the battery blocks, and a second plate extending in the connecting direction of the battery blocks and covering a second surface of the battery blocks opposite the first surface, the screwing structure is a structure in which the battery blocks are screwed to the first plate and the second plate, respectively. With the above configuration, by screwing to the first plate and the second plate extending in the connecting direction of the sub-blocks, the connection between the sub-blocks is reinforced, and a decrease in strength in the connecting direction due to disassembling the battery block into multiple sub-blocks can be reduced.

[0014] In addition, in a power supply device according to another aspect of the present disclosure, in any of the above aspects, each sub-block further includes a bus bar connected to the current collecting plate, each cell holder is divided into a first holder and a second holder in the extension direction of the secondary battery cell, and the bus bar is fixed to the sub-block by a second screw structure so as to intersect with the joint surface between the first holder and the second holder. With the above configuration, by fixing the bus bar to the sub-block so as to intersect with the joint surface between the first holder and the second holder, the bus bar connecting the current collecting plate can also be used to reinforce the joint between the first holder and the second holder.

[0015] In addition, the power supply device according to another aspect of the present disclosure is any of the above-described aspects, further including a circuit board electrically connected to each current collecting plate via the bus bar, the circuit board being disposed on a third surface connecting the first surface and the second surface of the battery block, and the bus bar being disposed on the third surface but not on a fourth surface of the battery block opposing the third surface. With this configuration, connecting the bus bar on only one side of the battery block reduces assembly work and simplifies the configuration by eliminating the need to run wiring to electrically connect each secondary battery cell to the circuit board.

[0016] According to yet another aspect of the power supply device of the present disclosure, in any of the above aspects, the bus bar is formed linearly, one end of the current collector plate has a bent piece bent from the cell end face toward the side surface of the secondary battery cell, the joint surfaces of the first holder and the second holder are offset, and the bent piece is disposed on the offset side surface of the first holder and the offset side surface of the second holder, respectively, and connected to the bus bar. With the above configuration, by arranging the bent piece in the offset portion, it is possible to protrude from the sub-block, and to connect the bent piece protruding from the adjacent sub-block by the bus bar in a linear manner.

[0017] According to still another aspect of the power supply device of the present disclosure, in any of the above aspects, the bus bar has a U-shaped cross section formed by bending the linear end edge, and the U-shaped end edge is fixed to the circuit board. With this configuration, by making the bus bar U-shaped in cross section, the rigidity of the bus bar is increased, thereby increasing the connection strength between the first holder and the second holder and enabling both ends of the bus bar to be fixed to the circuit board for electrical connection.

[0018] According to yet another aspect of the present disclosure, in any of the above-described power supply devices, the power supply device further includes a plurality of screws that secure the circuit board to the third surface of the battery block at a plurality of locations, and the second screw structure includes a structure in which each of the plurality of screws penetrates the circuit board and is screwed to and fixed by the battery block via the bus bar. With the above configuration, by passing the screws for screwing the circuit board to the side surface of the battery block through the bus bar, the battery blocks can be firmly connected while preventing the screws from loosening.

[0019] According to a power supply device according to another aspect of the present disclosure, in any of the above aspects, each sub-block further includes a lead plate physically connected to the cell end face exposed through the opening window of the storage cylinder, the lead plate being thinner than the current collector plate and overlapping the current collector plate for electrical connection. With this configuration, by fixing thin, flexible lead plates to the cell end faces, the work of fixing the lead plates to the cell end faces is made easier, and by overlapping thicker current collector plates on the lead plates, a power supply device can be configured that reduces electrical resistance and suppresses the generation of Joule heat due to current flow.

[0020] According to yet another aspect of the power supply device of the present disclosure, in any of the above aspects, the plurality of secondary battery cells are cylindrical cells each having a cylindrical outer can, the battery block has the plurality of secondary battery cells arranged in a plurality of rows with the cell end faces of the cylindrical cells offset between the rows, and each sub-block includes a first sub-block on the first surface of the battery block such that the cell end faces of the arranged plurality of rows are aligned one on one side and two on the other side, and a second sub-block on the first surface of the battery block such that two on one side and one on the other side. This configuration limits the number of secondary battery cells included in a sub-block, reducing the number of secondary battery cells to be replaced when replacing a sub-block and increasing the effectiveness of cell replacement, and also makes it possible to standardize the shape of the offset-aligned sub-blocks and reduce costs.

[0021] According to a power supply device manufacturing method according to still another aspect of the present disclosure, in any of the above aspects, the step of fixing the current collector plate to the lead plate is performed by welding a position different from the position where the lead plate is welded to the cell end face. This makes it possible to ensure reliability of welding by differentiating the welding position between the secondary battery cell and the lead plate from the welding position between the lead plate and the current collector plate.

[0022] Embodiments of the present disclosure will be described below with reference to the drawings. However, the embodiments described below are merely examples for embodying the technical concepts of the present disclosure, and the present disclosure is not limited to the following. Furthermore, this specification does not in any way specify the components set forth in the claims to be those of the embodiments. The dimensions, materials, shapes, relative positions, etc. of components described in the embodiments are not intended to limit the scope of the present disclosure, and are merely illustrative examples, unless otherwise specified. The size and positional relationships of components shown in the drawings may be exaggerated for clarity. Furthermore, in the following description, the same names and symbols indicate components that are identical or of the same quality, and detailed descriptions will be omitted as appropriate. Furthermore, the elements constituting the present disclosure may be configured with the same components, such that multiple elements are served by a single component, or conversely, the functions of a single component may be shared by multiple components.

[0023] The power supply device of the present disclosure can be used as a stationary power supply device, for example, a backup power supply for servers or data centers, a power storage device for storing power generated by solar power generation or the like for home, business, or factory use, or a power supply for daytime peak cutting. It can also be used as a driving power source for mobile objects such as a power-assisted bicycle, an electric scooter for home delivery, an electric cart for golf courses, factories, airports, etc., a power source for a self-propelled robot for home delivery, a power source for construction machinery, and a power source for vehicles such as hybrid cars and electric cars. It can also be used as a power source for portable electrical devices such as radios, electric cleaners, and power tools. Hereinafter, a power supply device used as a backup power supply for an indoor server will be described as one embodiment of the present disclosure. [Embodiment 1]

[0024] 1 to 15 show a power supply device 100 according to a first embodiment of the present disclosure. In these figures, Fig. 1 is a perspective view showing a battery pack according to the embodiment, Fig. 2 is an exploded perspective view of the battery pack of Fig. 1, Fig. 3 is an exploded perspective view of the battery block 10 of Fig. 2 seen from diagonally below the rear side, Fig. 4 is an exploded perspective view showing the battery block 10 of Fig. 2 with the circuit board 60 removed, Fig. 5 is an exploded perspective view showing the battery block 10 of Fig. 4 with the bus bar 50 further removed, Fig. 6 is a plan view of the battery block 10 of Fig. 5, Fig. 7 is an exploded perspective view showing the battery block 10 of Fig. 5 disassembled into sub-blocks 20, Fig. 8 is a plan view of the battery block 10 of Fig. 5 with the battery block 10 of Fig. 5 disassembled into sub-blocks 20, and Fig. 9 is a plan view of the battery block 10 of Fig. 5 with the bus bar 50 removed. FIG. 1 is an enlarged perspective view showing the state in which the sub-blocks 20A and 20B are connected, FIG. 9 is an exploded perspective view showing the state in which the sub-blocks 20 of FIG. 8 are separated, FIG. 10 is an exploded perspective view of the first sub-block 20A, FIG. 11 is an exploded perspective view of the first sub-block 20A of FIG. 10 viewed from diagonally below, FIG. 12 is an exploded perspective view of the second sub-block 20B, FIG. 13 is an exploded perspective view of the second sub-block 20B of FIG. 12 viewed from diagonally below, FIG. 14 is a side view of the second sub-block 20B, and FIG. 15 is an exploded perspective view showing how the current collecting plate 40 is fixed to the lead plate 30 of the second sub-block 20B of FIG. 12. As shown in FIG. 1, the power supply device 100 is formed in a rod shape extending in one direction. However, the external shape of the power supply device is not limited to this and can be any shape, such as a flat plate or a cube, depending on the shape of the battery blocks. The power supply device 100 shown in these figures includes multiple secondary battery cells 1, a battery block 10, a circuit board 60, a first plate 71, and a second plate 72. As shown in Figures 2 and 3, the first plate 71 is disposed on the top surface (first surface 11) of the battery block 10, and the second plate 72 is disposed on the bottom surface (second surface 12) of the battery block 10. The first plate 71 and the second plate 72 screw together the battery block 10, which connects multiple sub-blocks 20. In other words, the screw-connected structure maintains the connected state of the sub-blocks 20. In addition, a circuit board 60 is fixed to the side surface (third surface 13) of the battery block 10, as shown in Figures 4 and 5. (Battery Block 10)

[0025] The battery block 10 houses multiple secondary battery cells 1. As shown in Figures 6 to 9, the battery block 10 is constructed by connecting multiple sub-blocks 20. The battery block 10 has a first surface 11 (top surface in Figure 2) and a second surface 12 (bottom surface in Figure 2) that face each other in the extension direction. The battery block 10 also has a third surface 13 (right surface on the front side in Figure 2) and a fourth surface 14 (left surface on the back side in Figure 2) that face each other between the first surface 11 and the second surface 12 in the extension direction. Each of the sub-blocks 20 that make up the battery block 10 houses multiple secondary battery cells 1. The secondary battery cells 1 have a cylindrical outer can, and the end surfaces of the cylinder are cell end surfaces 1a, on which electrodes are provided. (Secondary Battery Cell 1)

[0026] The multiple secondary battery cells 1 are arranged in a battery block 10 so that the cell end faces 1a of each secondary battery cell 1 are flush with one another. Each secondary battery cell 1 can be a cylindrical secondary battery cell. In the example shown in Figures 2 to 7, the cylindrical secondary battery cells 1 are arranged horizontally in a grid pattern. Note that the number and arrangement of the secondary battery cells are not limited to this example, and any number and arrangement can be used as appropriate. For example, the cylindrical secondary battery cells may be arranged in a grid pattern instead of a staggered pattern.

[0027] Each secondary battery cell 1 has a positive and negative electrode. Preferably, one of the positive and negative electrodes is provided on one cell end surface 1a of the secondary battery cell 1, and the other is provided on the other cell end surface 1b. In the examples shown in Figures 10 to 13, the negative electrode is provided on the bottom side of the exterior can of the secondary battery cell 1, and the exterior can serves as the negative electrode. Known secondary batteries, such as lithium-ion secondary batteries, nickel-metal hydride batteries, and nickel-cadmium batteries, can be used as appropriate for such secondary battery cells 1. (Sub-block 20)

[0028] The battery block 10 is divided into multiple sub-blocks 20. As shown in FIG. 14 , each sub-block 20 includes a cell holder 21, a current collector plate 40, and a bus bar 50. The multiple sub-blocks 20 are connected to one another using a screw structure. An example of a screw structure is a structure in which the multiple sub-blocks 20 are connected together and screwed to a first plate 71 or a second plate 72. By connecting multiple sub-blocks 20 using screwing in this way to form the battery block 10, the sub-blocks 20 can be disassembled even after the power supply device 100 has been constructed, allowing for replacement of each sub-block 20, facilitating the replacement of secondary battery cells 1. (Cell holder 21)

[0029] As shown in Figures 7, 10 to 13, etc., each sub-block 20 has a cell holder 21 that holds the rechargeable battery cells 1 in a vertical position. As shown in Figure 6, etc., the cell holder 21 has a plurality of cylindrical rechargeable battery cells 1 arranged in a staggered pattern, offset from one another. For this reason, the cell holder 21 has a storage cylinder 24 that stores the rechargeable battery cells 1. The storage cylinders 24 are arranged in a staggered pattern to efficiently hold the cylindrical rechargeable battery cells 1 stacked in multiple levels. Here, each cell holder 21 holds a total of six rechargeable battery cells 1 stacked in four levels: 1, 2, 1, 2, or 2, 1, 2, 1.

[0030] The cell holder 21 has flat surfaces 27 formed on part of its side surfaces. Specifically, as shown in Figures 7 to 9, a pair of connecting surfaces (the left and right side surfaces in Figure 9) connecting the sub-blocks 20 to each other are each formed in a wave shape that follows the unevenness of the staggered storage tubes 24, while the holder side surfaces (the front and back surfaces in Figure 9) that intersect with the connecting surfaces are each formed as flat surfaces 27. By forming them in this manner, the sub-blocks 20 are connected to each other by meshing the unevenness of the connecting surfaces, achieving positioning and stable connection, while the holder side surfaces that form the third surface 13 and fourth surface 14 of the battery block 10 are formed as flat surfaces 27, making it easier to position the bus bars 50 and circuit boards 60 and improving workability during connection work such as screwing.

[0031] Note that multiple types of sub-blocks 20 may be prepared and connected. In the example shown in Figures 8 and 9 , two types of sub-blocks 20 are used. Specifically, first sub-blocks 20A, each with one cell on the holder side exposed on the third surface 13 of the battery block 10, and second sub-blocks 20B, each with two cells, are connected alternately. The first sub-block 20A at the back in the figure has the rechargeable battery cells 1 stacked in four layers, one, two, one, and two, from the front. Meanwhile, the second sub-block 20B at the front in the figure has the rechargeable battery cells 1 stacked in four layers, two, one, two, and one, from the front. The sub-blocks are not limited to two types; three or more types of sub-blocks may be connected, or a single type of sub-block may be connected. For example, a single type of cell holder may be used and connected alternately by rotating them 180° in the horizontal plane. (First holder 22, second holder 23)

[0032] The cell holder 21 can be configured by dividing it into multiple holders. The dividing direction of the cell holder 21 is preferably the extension direction of the secondary battery cells 1. In the example shown in Figures 10 to 13, it is configured by a first holder 22 and a second holder 23 that are divided into two parts, upper and lower. The first sub-block 20A is composed of a first holder 22A and a second holder 23A, and the second sub-block 20B is composed of a first holder 22B and a second holder 23B. The number and dividing direction of the cell holder 21 can be changed as appropriate depending on the shape and number of secondary battery cells 1.

[0033] The first holder 22 and the second holder 23 each have a storage cylinder 24 that stores the rechargeable battery cells 1. Here, the first holder 22 and the second holder 23 are combined to have a length that is approximately 1 / 8 of the length of the outer can of the cylindrical rechargeable battery cell 1 so that at least the edges of the outer can of the cylindrical rechargeable battery cell 1 can be covered. This configuration allows the outer can of the rechargeable battery cell 1 to be exposed from the cell holder 21, making it easy to dissipate heat. The length of the storage cylinder that covers the rechargeable battery cell can be set as desired; for example, the storage cylinder may be made longer to completely cover the sides of the rechargeable battery cell.

[0034] The end faces of the cylindrical storage tube 24 form opening windows 25, and the cell end faces 1 a of the secondary battery cells 1 stored in the cylindrical storage tube 24 are exposed through the opening windows 25. That is, the cell end faces 1 a are exposed on the first surface 11 and the second surface 12 of the battery block 10, respectively.

[0035] A connecting structure for connecting the first holder 22 and the second holder 23 is provided on the holder side of the cell holder 21. In the example shown in Figures 8 to 13, the connecting structure is a claw engagement. Here, a slit-shaped locking groove 16 is formed on the first flat surface 27a of the first holder 22, protruding toward the second flat surface 27b of the second holder 23. A locking claw 17 that engages with the locking groove 16 is also formed on the second flat surface 27b of the second holder 23. The connecting structure for connecting the first holder 22 and the second holder 23 is not limited to this structure, and any known structure capable of engaging two components can be used as appropriate. The first holder 22 and the second holder 23 that constitute such a cell holder 21 are preferably formed from a resin with excellent insulating properties. For example, a thermoplastic resin, specifically at least one of polycarbonate, polypropylene, polyamide, polybutylene terephthalate, modified polyphenylene ether, ABS, and PPS, can be used.

[0036] 14, the first flat surface 27a of the first holder 22 and the second flat surface 27b of the second holder 23 have offset joint surfaces. This allows the joint surface on the third surface 13 of the battery block 10 to have a stepped shape, stabilizing positioning and connection. When the bent pieces 42 from the current collector plates 40 provided on the upper and lower first and second surfaces 11 and 12 of the battery block 10 are pulled out toward the third surface 13, the bent pieces 42 pulled out from each sub-block 20 can be aligned in a straight line between adjacent sub-blocks 20 and connected by bus bars 50 (details will be described later). (Lead plates 30)

[0037] Each sub-block 20 has lead plates 30 that connect to the electrodes on the cell end surfaces 1a of the rechargeable battery cells 1 stored in the storage cylinder 24. The lead plates 30 are physically connected to the cell end surfaces 1a that are exposed through the opening windows 25 of the storage cylinder 24, connecting the rechargeable battery cells 1 in series or parallel. The cell holder 21 has multiple positioning pins 26 so that the lead plates 30 can be positioned on the first surface 11 and second surface 12 of the battery block 10, i.e., the top and bottom surfaces of the cell holder 21. Each lead plate 30 also has lead holes 36 at positions corresponding to the positioning pins 26.

[0038] Furthermore, each lead plate 30 has a lead connection piece 32 at a position facing the cell end face 1a. Each lead connection piece 32 is formed so as to protrude into a lead window 31, which is opened at a position facing the cell end face 1a of the lead plate 30. Each lead connection piece 32 is bent in a stepped pattern toward the cell end face 1a of the secondary battery cell 1. The lead connection pieces 32 are branched into two rows, and each welding position is formed in a concave shape. As shown in Figures 8 to 13 and 15, each sub-block 20 is fixed by welding the lead connection pieces 32 of the lead plate 30, which is fixed to the end face of each cell holder 21, to the cell end face 1a of the secondary battery cell 1. Here, each lead connection piece 32 is welded at four locations, but the number and locations of welds are not limited to this example. The lead plate 30 is formed by bending a metal plate. Each lead plate 30 can be made of a metal plate with excellent conductivity, such as nickel, aluminum, or copper. The surface may also be plated. The lead plates 30 are welded by spot welding, laser welding, or other methods to the electrodes on the cell end faces 1a of the secondary battery cells 1 and electrically connected to them. The thickness of the lead plates 30 is set to 0.10 mm to 0.30 mm.

[0039] In the examples of Figures 10 to 13, each sub-block 20 has six secondary battery cells 1 connected in parallel. As shown in Figure 7, 14 of these sub-blocks 20 are connected in series, resulting in a 14-in-series x 6-in-parallel configuration. However, the number of series and parallel connections of secondary battery cells 1 can be designed appropriately depending on the required output and capacity. For example, in the examples of Figures 10 to 13, each secondary battery cell 1 is held in an orientation where the upper cell end surface 1a is the positive electrode and the lower cell end surface 1b is the negative electrode. However, the number of series and parallel connections within a sub-block can be changed by switching the positions or using multiple lead plates. (Current collector plate 40)

[0040] Furthermore, each sub-block 20 has a current collecting plate 40 disposed on top of the lead plate 30. The current collecting plate 40 is electrically connected via the lead plate 30 to the cell end face 1a exposed through the opening window 25 of the housing cylinder 24. Each current collecting plate 40 is formed to be thicker than the lead plate 30. As shown in FIG. 15 , the current collecting plate 40 is placed on top of the lead plate 30 and electrically connected to it. In this way, by fixing the thin, flexible lead plate 30 to the cell end face 1a, the work of fixing the lead plate 30 to the cell end face 1a is simplified, and by overlapping the thicker current collecting plate 40 on the lead plate 30, electrical resistance is reduced, thereby forming a power supply device 100 that suppresses the generation of Joule heat due to current flow.

[0041] To secure the lead plates to the cell end faces of rechargeable battery cells, welding is primarily used for reliability reasons. Therefore, lead plates must be thin enough to allow spot welding or laser welding. However, thinner lead plates have higher resistance values. When large currents are passed through them during charging and discharging, Joule heat is generated, proportional to the square of the current. Therefore, thicker lead plates are required to lower resistance, reduce losses, and suppress heat generation. However, thicker lead plates make welding to rechargeable battery cells more difficult. Because lead plates have low electrical resistance, they also have high thermal conductivity, making them difficult to heat and melt, and the thicker they are, the more difficult it becomes. However, heating the cell end faces with a high-power laser could damage the rechargeable battery cells. Thus, securing the lead plates to the rechargeable battery cell and suppressing heat generation are conflicting technical challenges, and solving these problems has not been easy.

[0042] In contrast, the power supply device 100 according to this embodiment is configured such that the current collector plate 40 is layered on the lead plate 30, and the current collector plate 40 is thicker than the lead plate 30. This configuration allows the lead plate 30 to be made thin, facilitating welding between the lead plate 30 and the cell end surface 1a of the secondary battery cell 1. Furthermore, by layering a thicker current collector plate 40 on the lead plate 30, the two are integrally formed, increasing the thickness and reducing resistance. In other words, the same effect as essentially increasing the thickness of the lead plate 30 is achieved. In this way, the conflicting technical challenges of securing the lead plate 30 to the secondary battery cell 1 and suppressing heat generation are resolved.

[0043] The current collector plate 40 is fixed to the lead plate 30 by welding. As shown in FIG. 15 , the welding position where the current collector plate 40 and the lead plate 30 are welded is set to a different position from the lead plate 30 and the secondary battery cell 1. This allows welding to be performed at a new location rather than at a location that has already been welded and altered, thereby improving the reliability of the welding. Preferably, the welding position is set to a region where no secondary battery cell 1 is present, such as a position around the cell end face 1a. This prevents heat from being directly conducted to the secondary battery cell 1 when welding the current collector plate 40 to the lead plate 30. Preferably, the current collector plate 40 has a current collection window 41 that is larger than the lead window 31 of the lead plate 30 and that is located at a position corresponding to the lead window 31. This allows the welding position between the lead plate 30 and the secondary battery cell 1 to be visually confirmed from the outside, allowing the welding status to be confirmed. Furthermore, avoiding the welding position between the lead plate 30 and the secondary battery cell 1 makes it easier to weld the current collector plate 40 and the lead plate 30. Furthermore, like the lead plates 30, the current collector plates 40 also have current collection holes 46 that allow them to be positioned on the first surface 11 or second surface 12 of the battery block 10. The current collection holes 46 are opened at positions that correspond to the positioning pins 26 of the cell holders 21, allowing the lead plates 30 and current collector plates 40 to share a common positioning mechanism (bent pieces 42).

[0044] The current collector plate 40 also has a bent piece 42 bent at one end from the cell end face 1a toward the side of the secondary battery cell 1. In the example shown in FIGS. 10 to 13, the bent piece 42 is bent at a substantially right angle at the edge of the current collector plate 40 on the third surface 13 of the battery block 10, i.e., the edge on the holder side. In the first sub-block 20A, as shown in FIGS. 10 to 11, first bent pieces 42aA and 42bA are provided on the edges of the upper and lower first current collector plates 40aA and 40bA where there is only one secondary battery cell 1. In the second sub-block 20B, as shown in FIGS. 12 to 13, second bent pieces 42aB and 42bB are provided on the edges of the upper and lower second current collector plates 40aB and 40bB where there are two secondary battery cells 1. Each bent piece 42 has a fixing hole 43 at its tip.

[0045] Meanwhile, the cell holder 21 has a holder groove 28 formed on the flat surface 27 of its side surface at a position corresponding to the bent piece 42. Furthermore, a nut hole 29 is formed at the end of the holder groove 28, allowing a nut 81 to be placed therein, as shown in FIGS. 10 and 11 . The nut 81 may be insert-molded into the cell holder 21 in advance. When the bent piece 42 is guided into the holder groove 28, the fixing hole 43 of the bent piece 42 and the hole of the nut 81 set in the nut hole 29 of the holder groove 28 are aligned. This allows each bent piece 42 to be screwed and fixed to the cell holder 21. Furthermore, as shown in FIG. 5 , this screwing can also be used to secure the bus bar 50 and the circuit board 60 (details will be described later). This screwing is referred to as a second screwing structure to distinguish it from the screwing structure of the first plate 71 and the second plate 72.

[0046] Such current collector plate 40 is made of a material with excellent conductivity, such as a metal plate such as an aluminum plate, a nickel plate, or a copper plate. Preferably, it is made of the same material as the lead plate 30. This makes welding easier and reduces the electrical resistance at the interface. The thickness of the current collector plate 40 is about 3 to 10 times that of the lead plate 30. Preferably, it is 0.3 mm to 3.0 mm.

[0047] In the above example, the problem of high electrical resistance in the thin portions is solved by stacking the thick current collector plate 40 on the thin lead plate 30. However, the present disclosure is not limited to this configuration, and for example, three or more current collector plates or lead plates may be stacked on top of each other to further increase the thickness and reduce the electrical resistance. Alternatively, a single current collector plate may be used, welded to the cell end face, and fastened by screwing to the side of the cell holder. In this case, the lead plate can be omitted. (Bus bar 50)

[0048] Furthermore, each sub-block 20 includes a bus bar 50 connected to each current collector plate 40. In the example of Figures 10 to 13 (bus bar 50 not shown), the bent piece 42a of the current collector plate 40 on the upper surface of each sub-block 20 is connected to the bent piece 42b of the current collector plate 40 on the lower surface by the bus bar 50. In this case, as shown in Figure 8, the first bent piece 42aA of the first current collector plate 40aA of the first sub-block 20A and the second bent piece 42bB of the second current collector plate 40bB of the second sub-block 20B are configured to be aligned in a straight line. Therefore, in each sub-holder, the joining position between the first flat surface 27a of the first holder 22 and the second flat surface 27b of the second holder 23 is offset, so that the first holder groove 28a of the first holder 22 extends to the left of the second flat surface 27b of the second holder 23, and the second holder groove 28b of the second holder 23 extends to the right of the first flat surface 27a of the first holder 22. As a result, the first bent piece 42aA and the second bent piece 42bB are aligned in a straight line, allowing them to be connected by a linear bus bar 50. Similarly, the first bent piece 42bA of the first current collector plate 40bA of the first sub-block 20A is aligned in a straight line with the second bent piece 42aB of the second current collector plate 40aB of the second sub-block 20B (not shown in FIG. 8 ) located to the right of the first sub-block 20A, allowing them to be similarly connected by a linear bus bar 50. In this way, the bent pieces 42 from the current collector plates 40 provided on the first surface 11 and the second surface 12 at the top and bottom of the battery block 10 are pulled out toward the third surface 13, and the bent pieces 42 pulled out from each sub-block 20 are linearly arranged between adjacent sub-blocks 20, making it possible to connect them using a linear bus bar 50. Furthermore, by offsetting the divided first holder 22 and second holder 23 and arranging the bent pieces 42 in the offset portions, the bent pieces 42 protrude from the sub-block 20, and the bent pieces 42 protruding from each other between adjacent sub-blocks 20 can be linearly connected using the bus bar 50.

[0049] Additionally, by electrically connecting adjacent sub-blocks 20 not on the first surface 11 or second surface 12 where the lead plates 30 and current collector plates 40 are provided, but on the second surface 12, which is the side surface intersecting these surfaces, the size of the battery block 10 can be prevented from increasing. Dividing the battery block 10 into multiple sub-blocks 20 requires space for electrical connection between the sub-blocks 20. Consider a configuration in which a connection piece 932 is provided on a lead plate 930 and connected to the connection piece 932 of the lead plate 930 of an adjacent sub-block 920, as shown in FIG. 16 , as in the battery block 910 of the comparative power supply device. In this case, as shown in FIG. 17 , a connection piece 932 must be provided that protrudes from the lead plate 930 toward the adjacent lead plate 930. Although not shown, a similar configuration is also required on the second surface 12 on the bottom side. As a result, space must be provided for the electrical connection between the lead plates 930 by the amount of protrusion DT of the connection piece 932, which increases the length of the battery block 10 in the connecting direction. In particular, the more the number of divisions into the sub-blocks 20 increases, the more such spaces will be required, resulting in an even longer and larger block.

[0050] In contrast, in the power supply device 100 according to the present embodiment, as described above, the structure for electrical connection between the sub-blocks 20 is not provided on the first surface 11 or the second surface 12 on which the lead plates 30 and the current collecting plates 40 are provided, but is provided on the third surface 13 that intersects these surfaces. Furthermore, by consolidating the electrical connections between the first surface 11 and the second surface 12 on the third surface 13, the structure for electrical connection can be consolidated. In particular, by disposing the circuit board 60 on the third surface 13 as described below, the electrical connection with the circuit board 60 can also be made on the third surface 13, further simplifying the configuration. Additionally, by not providing such a structure for electrical connection between the sub-blocks 20 on the fourth surface 14 on the opposite side opposite the third surface 13, there is no need to route wiring from the third surface 13 to the circuit board 60, simplifying the wiring work. Furthermore, by concentrating the electrical connections of the sub-block 20 on the third surface 13, the wiring work performed when assembling the sub-block 20 can also be performed mainly on the third surface 13, which is advantageous in terms of work efficiency as it can be done all at once without having to rotate or change the position of the sub-block 20 for work on other surfaces.

[0051] 14 shows an example in which bus bars 50 are connected to first sub-blocks 20A and second sub-blocks 20B arranged alternately. The bus bars 50 are fixed by the second screw structure as shown in FIG. 5. By fixing the bus bars 50 to the sub-blocks 20 so that they intersect with the joint surfaces of the first holder 22 and the second holder 23 in this way, the bus bars 50 connecting the current collecting plates 40 can also be used to reinforce the joint between the first holder 22 and the second holder 23.

[0052] 5, each bus bar 50 is formed with a bent edge in the extension direction so as to have a U-shape in cross section. The U-shaped edge is fixed to the circuit board 60. With this configuration, the bus bar 50 has a U-shape in cross section, which increases its rigidity, thereby increasing the connection strength between the first holder 22 and the second holder 23 and enabling both ends of the bus bar 50 to be fixed to the circuit board 60 for electrical connection. (Circuit board 60)

[0053] A circuit board 60 is disposed on the third surface 13 of the battery block 10. As shown in Figure 5 , the circuit board 60 is fixed to the third surface 13, and no circuit board 60 is provided on the fourth surface 14 opposite the third surface 13. Connecting the bus bar 50 only on one side of the battery block 10 in this way reduces the assembly effort and simplifies the configuration by eliminating the need to run wires to electrically connect each secondary battery cell 1 to the circuit board 60.

[0054] The battery block 10 is connected to a circuit board 60 via lead plates 30, current collector plates 40, and bus bars 50. The circuit board 60 is equipped with a charge / discharge circuit that charges and discharges the secondary battery cells 1, and a protection circuit that monitors the voltage and temperature of the secondary battery cells 1 and cuts off the current in the event of an abnormality. The circuit board 60 is made of a glass epoxy board or the like. A board holder for holding such a circuit board 60 may also be provided. The board holder can be connected to the battery holder (screws 80).

[0055] The circuit board 60 is fixed to the third surface 13 of the battery block 10 using a second screw structure in which screws 80 are screwed into each of multiple locations. Each of the multiple screws 80 penetrates the circuit board 60 and is screwed into the battery block 10 via the bus bar 50. That is, by screwing each screw 80 into a nut 81 on each sub-block 20, the circuit board 60, the bus bar 50, and the bent piece 42 of the current collector plate 40 are fastened together and fixed, as shown in FIG. 5 . In this way, by passing the screws 80 for screwing the circuit board 60 into the side surface of the battery block 10 through the bus bar 50, the battery block 10 can be firmly connected while preventing the screws 80 from loosening. Furthermore, the circuit board 60 reinforces the mechanical connection of the sub-blocks 20 that make up the battery block 10 on the third surface 13. (First plate 71, second plate 72)

[0056] A first plate 71 is disposed on the first surface 11 of the battery block 10, and a second plate 72 is disposed on the second surface 12. As shown in Figures 2 and 3, the first plate 71 and the second plate 72 are sized and shaped to cover the first surface 11 and the second surface 12, respectively. These first plate 71 and second plate 72 are fixed to the battery block 10 using a detachable fixing structure such as a screw connection. In this way, by fixing the first plate 71 and the second plate 72, which extend in the connection direction of the sub-blocks 20 constituting the battery block 10, to opposing surfaces of the battery block 10, the connection between the sub-blocks 20 is reinforced and a decrease in strength in the connection direction due to disassembling the battery block 10 into multiple sub-blocks 20 can be reduced. The first plate 71 and the second plate 72 may also be composed of multiple plates. In the example shown in Figures 2 and 3, both the first plate 71 and the second plate 72 are constructed by stacking two plates and fixed using a common screw connection structure. The first plate 71 and the second plate 72 can be made of a metal plate having excellent rigidity, such as iron, an iron alloy, SUS, aluminum, or an aluminum alloy.

[0057] As described above, the sub-block 20 includes a first sub-block 20A and a second sub-block 20B. In the first sub-block 20A, the cell end faces 1a of the secondary battery cells 1 stacked in an offset manner in multiple stages in a direction intersecting the extension direction of the battery block 10 on the first surface 11 of the battery block 10 are arranged so that one cell end face 1a is located on the third surface 13 side and two cell end faces 1a are located on the fourth surface 14 side. On the other hand, in the second sub-block 20B, the cell end faces 1a of the secondary battery cells 1 stacked in an offset manner on the first surface 11 of the battery block 10 are arranged so that two cell end faces 1a are located on the third surface 13 side and one cell end face 1a is located on the fourth surface 14 side. In this way, limiting the number of secondary battery cells included in a sub-block reduces the number of secondary battery cells to be replaced when replacing a sub-block, increasing the effectiveness of cell replacement, and standardizing the shape of the offset-arranged sub-blocks enables cost reduction.

[0058] Power supply devices typically increase capacity and output by connecting multiple secondary battery cells in series or parallel. However, as a result of use, some secondary battery cells may deteriorate, rendering the power supply unusable even if other secondary battery cells and components remain usable. Power supply devices generally lack a structure that allows for partial replacement of secondary battery cells. Therefore, even if only some secondary battery cells deteriorate, the entire power supply device must be replaced, and usable components must also be discarded. Meanwhile, in light of recent societal demands for reducing environmental impact and realizing a sustainable society, products that consider resource recycling, reuse, and reduction are in demand. Power supply devices also require mechanisms that allow for the reuse of usable parts and the replacement of deteriorated parts. In light of these demands, the present disclosure proposes a structure in which a battery block 10 is divided into multiple sub-blocks 20, allowing for easy replacement of each sub-block 20. By primarily using threaded connections rather than welding to connect the sub-blocks 20, disassembly and reassembly can be performed without causing damage. In addition, as a result of dividing the battery block 10 into multiple sub-blocks 20, the mechanical connection between the sub-blocks 20 becomes weak, so reinforcement is provided by sandwiching both sides between a first plate 71 and a second plate 72 which have rigidity.

[0059] Note that a structure for connecting the sub-blocks to each other may be added at the interface between adjacent sub-blocks, for example, by screwing or claw engagement.

[0060] Furthermore, when screwing is used as a connecting structure between such sub-blocks, the screws may be fastened together with the current collector plates. This allows the sub-blocks to be fastened together and the current collector plates to be fixed using a common screw, thereby realizing a power supply device that is easy to disassemble and replace. (Manufacturing method of power supply device)

[0061] Here, an example of a manufacturing method for the power supply unit 100 is described. First, multiple sub-blocks 20 that make up the battery block 10 are prepared. Next, multiple secondary battery cells 1 are housed in the cylindrical storage 24 of the cell holder 21 that makes up each sub-block 20. Meanwhile, current collector plates 40 are welded and fixed in place to the lead plates 30. Then, the lead plates 30 are welded to the cell end faces 1a that are exposed through opening windows 25 opened at the edge of the cylindrical storage 24.

[0062] The sub-blocks 20 thus obtained are connected together by screwing them together. Here, the first surface 11 of the battery block 10 formed by connecting multiple sub-blocks 20 is covered with a first plate 71 that extends in the connecting direction of the battery blocks 10, while the second surface 12 opposite the first surface 11 is covered with a second plate 72 that also extends in the connecting direction of the battery blocks 10. The battery block 10 is then screwed together with the first plate 71 and the second plate 72, respectively, to fix the sub-blocks 20 in a connected state.

[0063] When fixing the current collector plate 40 to the lead plate 30, it is preferable to weld the lead plate 30 to a position different from the position where the lead plate 30 is welded to the cell end face 1a. By differentiating the welding position between the secondary battery cell 1 and the lead plate 30 from the welding position between the lead plate 30 and the current collector plate 40 in this way, reliability of the welding can be ensured. (Method of Replacing a Secondary Battery Cell)

[0064] Next, a method for replacing some of the secondary battery cells 1 in a power supply device 100 will be described. The power supply device 100 includes a battery block 10 formed by connecting a plurality of secondary battery cells 1 having cell end surfaces 1a, a plurality of sub-blocks 20 each housing the secondary battery cells 1, a first plate 71 threadedly engaged with a first surface 11 of the battery block 10 and extending in the connecting direction of the battery block 10, and a second plate 72 threadedly engaged with a second surface 12 of the battery block 10 opposite the first surface 11 and extending in the connecting direction of the battery block 10. First, the battery block 10 is unscrewed from the first plate 71 and the second plate 72, and the first plate 71 and the second plate 72 are removed from the battery block 10. Next, the sub-block 20 containing the secondary battery cell 1 to be replaced is removed from the plurality of secondary battery cells 1, and replaced with a new sub-block 20 containing the replacement secondary battery cell 1. Then, the first plate 71 is screwed onto the first surface 11 of the battery block 10 including the new sub-block 20, and the second plate 72 is screwed onto the second surface 12, thereby fixing the sub-blocks 20 in a connected state. By screwing together multiple sub-blocks 20 to form the battery block 10, the sub-blocks 20 can be disassembled even after the power supply device 100 has been constructed, allowing replacement of each sub-block 20 and facilitating the replacement of the secondary battery cells 1.

[0065] The power supply device and its manufacturing method and secondary battery cell replacement method according to the present disclosure can be suitably used, for example, as a backup power source for servers and data centers, a power storage device for home, business, and factory use, a power source for peak cutting, etc. They can also be used as a driving power source for mobile objects such as electric carts and electric scooters, a power source for wireless devices, and a power source for portable electrical devices such as electric cleaners and power tools.

[0066] Furthermore, by realizing partial replacement of the many secondary battery cells contained in the power supply unit, waste will be reduced, and pollution of soil and oceans caused by waste dumping will be suppressed. Furthermore, by promoting the reuse of usable parts, resources will be conserved, and in particular, the environmental impact will be reduced by making effective use of rare metals such as those used in the electrodes of secondary battery cells. As a result, of the 17 goals and 169 targets set out in the Sustainable Development Goals (SDGs) adopted at the UN Summit in September 2015, the following have been achieved: - "8. Decent work and economic growth", "8.4 By 2030, improve progressively global resource efficiency in consumption and production and endeavour to decouple economic growth from environmental degradation, in accordance with the 10-year framework of programmes on sustainable consumption and production, with developed countries taking the lead", "9. Industry, innovation and infrastructure", "9.4 By 2030, enhance sustainability through infrastructure improvement and industrial reform through increased resource-use efficiency and greater adoption of clean and environmentally friendly technologies and industrial processes. All countries will take action in accordance with their respective capabilities", - "11. Sustainable cities and communities", "11.6 By 2030, reduce the adverse per capita environmental impact of cities, including by paying special attention to air quality and municipal and other waste management", "12. Responsible consumption and production", "12.4 By 2020, achieve the environmentally sound management of chemicals and all wastes throughout their life cycle, in accordance with agreed international frameworks, and significantly reduce their release to air, water and soil in order to minimize their adverse impacts on human health and the environment", "12.5 By 2030, substantially reduce waste generation through prevention, reduction, recycling and reuse".

[0067] DESCRIPTION OF SYMBOLS 100...power supply device 1...secondary battery cell; 1a, 1b...cell end surface 10...battery block 11...first surface 12...second surface 13...third surface 14...fourth surface 16...locking groove 17...locking claw 20...sub-block; 20A...first sub-block; 20B...second sub-block 21...cell holder 22, 22A, 22B...first holder 23, 23A, 23B...second holder 24...storage tube 25...opening window 26...positioning pin 27...flat surface; 27a...first flat surface; 27b...second flat surface 28...holder groove portion; 28a...first holder groove portion; 28b...second holder groove portion 29...nut hole 30...lead plate 31...lead window 32...lead connection piece 36...lead hole 40... Current collecting plate; 40aA, 40bA... First current collecting plate; 40aB, 40bBA... Second current collecting plate 41... Current collecting window 42... Folding piece; 42aA, 42bA... First folding piece; 42aB, 42bBA... Second folding piece 43... Fixing hole 46... Current collecting hole 50... Bus bar 60... Circuit board 71... First plate 72... Second plate 80... Screw 81... Nut 910... Battery block 920... Sub-block 930... Lead plate 932... Connection piece DT... Protrusion amount of connection piece

Claims

1. A power supply device comprising: a plurality of secondary battery cells having cell end faces; and a battery block that houses the plurality of secondary battery cells, wherein the battery block comprises a plurality of sub-blocks, each of which comprises: a cell holder having a plurality of storage cylinders that respectively house the plurality of secondary battery cells; and a pair of current collector plates that are each electrically connected to the cell end faces that are exposed through opening windows opened at the end edges of the storage cylinders, and wherein the plurality of sub-blocks are connected to each other by a screw structure.

2. A power supply device as claimed in claim 1, further comprising: a first plate extending in the connecting direction of the battery block and covering a first surface of the battery block; and a second plate extending in the connecting direction of the battery block and covering a second surface of the battery block opposite the first surface, wherein the screwing structure is a structure for screwing the battery block to the first plate and the second plate, respectively.

3. A power supply device as claimed in claim 2, wherein each sub-block further comprises a bus bar connected to each of the current collector plates, each cell holder is divided into a first holder and a second holder in the extension direction of the secondary battery cell, and the bus bar is fixed to the sub-block by a second screw structure so as to intersect with the joint surface of the first holder and the second holder.

4. A power supply device as claimed in claim 3, further comprising a circuit board electrically connected to each current collecting plate via the bus bar, the circuit board being arranged on a third surface connecting the first surface and the second surface of the battery block, and the bus bar being arranged on the third surface, and not on a fourth surface of the battery block opposite the third surface.

5. A power supply device according to claim 4, wherein the bus bar is formed in a straight line, one end of the current collector plate is provided with a bent piece that is bent from the cell end face toward the side face of the secondary battery cell, the joint surfaces of the first holder and the second holder are offset, and the bent piece is disposed on the offset side face of the first holder and the offset side face of the second holder, respectively, and connected to the bus bar.

6. A power supply device according to claim 5, wherein the bus bar is formed with the straight edge bent to have a U-shape in cross section, and the U-shaped edge is fixed to the circuit board.

7. A power supply device as claimed in claim 6, further comprising a plurality of screws for fixing the circuit board to the third surface of the battery block at a plurality of locations, and the second screwing structure includes a structure for each of the plurality of screws to penetrate the circuit board and screw into and fix the battery block via the bus bar.

8. A power supply device according to any one of claims 1 to 7, wherein each sub-block further comprises a lead plate physically connected to the cell end face exposed through the opening window of the storage cylinder, the lead plate being thinner than the current collector plate, and the current collector plate being overlapped on the lead plate and electrically connected.

9. A power supply device according to any one of claims 1 to 7, wherein the plurality of secondary battery cells are cylindrical cells each having a cylindrical outer casing, the battery block has the plurality of secondary battery cells arranged in a plurality of rows with the cell end faces of the cylindrical cells offset between the rows, and each sub-block comprises a first sub-block arranged on the first surface of the battery block so that the cell end faces arranged in the plurality of rows are one on one side and two on the other side, and a second sub-block arranged so that two on one side and one on the other side.

10. A method for manufacturing a power supply device comprising a plurality of secondary battery cells having cell end faces, and a battery block that houses the plurality of secondary battery cells, the method comprising the steps of: preparing a plurality of sub-blocks that constitute the battery block; housing the plurality of secondary battery cells in cylindrical cell holder storage tubes that constitute each sub-block; welding lead plates to the cell end faces that are exposed through opening windows opened in the edge of the cylindrical storage tubes; and fixing current collector plates in a state in which they are overlapped on the lead plates.

10. A method for manufacturing a power supply device comprising: preparing a plurality of sub-blocks that constitute the battery block; housing the plurality of secondary battery cells in cylindrical cell holder storage tubes that constitute each sub-block; welding lead plates to the cell end faces that are exposed through opening windows opened in the edge of the cylindrical storage tubes; and fixing current collector plates in a state in which they are overlapped on the lead plates.

11. A method for manufacturing a power supply device as claimed in claim 10, wherein the step of fixing the current collector plate to the lead plate is carried out by welding the lead plate to a position different from the position where the lead plate is welded to the cell end face.

12. A method for replacing some of the secondary battery cells of a power supply device comprising: a plurality of secondary battery cells having cell end faces; a battery block formed by connecting a plurality of sub-blocks that house the plurality of secondary battery cells; a first plate that is screwed to a first surface of the battery block and extends along the connecting direction of the battery block; and a second plate that is screwed to a second surface of the battery block opposite the first surface and extends along the connecting direction of the battery block, the method comprising: releasing the screw connections between the battery block and the first plate and the second plate, and removing the first plate and the second plate from the battery block; removing a sub-block that includes the secondary battery cell to be replaced from among the plurality of secondary battery cells, replacing it with a new sub-block that includes the replacement secondary battery cell, and screwing the first plate to the first surface and the second plate to the second surface of the battery block including the new sub-block, thereby fixing the sub-blocks in a connected state.

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