Power supply device

Abstract

A power supply device 100 comprises: a plurality of battery cells 1 that each have a cell side surface and a pair of cell end surfaces serving as end surfaces of the cell side surface, and are each provided with one cell electrode 4 at one cell end surface and another cell electrode 4 at the other cell end surface; a battery holder 5 that holds the battery cells 1; and a lead plate 10 that is connected to the battery cells 1. The plurality of battery cells 1 are arranged with the orientations of the cell electrodes 4 being in the same direction. The lead plate 10 has a parallel lead plate 11 that connects the plurality of battery cells 1 in parallel. The parallel lead plate 11 has at least one lead plate 11A that is connected to the one cell electrodes 4, and at least one second parallel lead plate 11B that is connected to the other cell electrodes 4. The first parallel lead plate 11A has a series lead piece 12 that is electrically connected to a second cell electrode 4B of another battery cell 1.

Description

power supply

[0001] This disclosure relates to a power supply device comprising multiple battery cells.

[0002] Power supply devices, which house rechargeable battery cells such as lithium-ion secondary batteries in a battery holder and connect the end faces of each battery cell with lead plates, are used in a wide range of applications, including as power sources for electric mobile devices such as vehicles and construction machinery. When a large number of battery cells are used in such a power supply device, if lead plates are welded to the upper and lower end faces of each battery cell and connected in series with busbars, the positive and negative cell electrodes can be aligned in the same direction. However, this requires the busbars to be installed on the sides of the battery blocks (battery cells), increasing the number of parts and necessitating a welding process between the busbars and lead plates. Furthermore, the power supply device 900 in Figure 8 eliminates the need for busbars by arranging the positive and negative electrodes alternately in parallel block units and connecting them with lead plates. However, this does not unify the orientation of the positive and negative cell electrodes on the end faces of the cells, and the assembly process requires equipment and processes to insert the battery cells in either an upward or downward direction. Furthermore, there is a one-sided current collection method in which the orientation of the cell electrodes on the cell end faces is unified, and the lead plates are concentrated on one cell end face side (see Patent Document 1). However, this configuration tends to result in thinner lead plates concentrated and arranged on one cell end face, leading to problems with heat dissipation, which is thermally disadvantageous under high currents. In addition, stacking multiple lead plates and using lead plates of different thicknesses results in lead plates and connections with complex shapes, thicknesses, and structures, making manufacturing difficult.

[0003] U.S. Patent No. 10707471B2

[0004] One of the objectives of one embodiment of the present disclosure is to provide a power supply device that can unify the directions of cell electrodes without providing a bus bar. Another objective is to provide a power supply device in which the lead plate is not thermally disadvantaged and the heat dissipation can be improved. Another objective is to provide a power supply device in which the lead plate can have a simple structure. Note that the description of these objectives and problems of the present disclosure does not prevent the existence of other objectives and problems. Also, one aspect of the present disclosure does not need to solve all of these problems. Furthermore, other problems can be extracted from the description of the specification, drawings, and claims of the present disclosure.

[0005] The power supply device according to one embodiment of the present disclosure includes a cell side surface, a pair of cell end surfaces that are end surfaces of the cell side surface, a plurality of battery cells each provided with one cell electrode on one cell end surface and the other cell electrode on the other cell end surface, a battery holder that holds the battery cells, and a lead plate that connects the battery cells. The plurality of battery cells are arranged with the directions of the one and the other cell electrodes aligned in the same direction. The lead plate has a parallel lead plate that connects the plurality of battery cells in parallel. The parallel lead plate has one or more first parallel lead plates connected to one cell electrode and one or more second parallel lead plates connected to the other cell electrode. The first parallel lead plate has a series lead piece electrically connected to the other cell electrode of another battery cell.

[0006] The above configuration has the feature that the directions of the cell electrodes can be unified without providing a bus bar. Also, the above configuration has the feature that the lead plate is not thermally disadvantaged and the heat dissipation can be improved. Also, the above configuration has the feature that the lead plate can have a simple structure.

[0007] It is a schematic connection diagram showing a power supply device according to one embodiment. It is a schematic cross-sectional view of the power supply device. It is a schematic perspective view showing the battery cells and the lead plate of the power supply device. It is an exploded perspective view of the power supply device in FIG. 3. It is a partial exploded perspective view of the power supply device in FIG. 3. It is a schematic plan view seen from above and below showing the connection state of one cell end surface. It is a schematic connection diagram showing a power supply device according to another embodiment. It is a schematic connection diagram showing a power supply device according to a conventional example.

[0008] The form of this disclosure may be specified by the following configurations and features.

[0009] A power supply device according to one embodiment of the present disclosure comprises a plurality of battery cells, each having a cell side surface and a pair of cell end surfaces that form the end surfaces of the cell side surface, with one cell electrode provided on one cell end surface and the other cell electrode on the other cell end surface; a battery holder for holding the battery cells; and a lead plate for connecting the battery cells. The plurality of battery cells are arranged so that the orientation of the one and the other cell electrodes is aligned in the same direction. The lead plate has a parallel lead plate for connecting the plurality of battery cells in parallel, and the parallel lead plate has one or more first parallel lead plates connected to one cell electrode and one or more second parallel lead plates connected to the other cell electrode, with the first parallel lead plate having a series lead piece that is electrically connected to the other cell electrode of another battery cell. For example, one cell electrode (first cell electrode) can be the positive terminal and the other cell electrode (second cell electrode) can be the negative terminal.

[0010] The above configuration has the advantage of unifying the direction of the cell electrodes without providing busbars. This is because the lead plate has parallel lead plates for connecting multiple battery cells in parallel, and the parallel lead plate has one or more first parallel lead plates connected to one cell electrode and one or more second parallel lead plates connected to the other cell electrode, and the first parallel lead plate has a series lead piece that is electrically connected to the other cell electrode of another battery cell. In the above configuration, the first parallel lead plate has a series lead piece, and the series lead piece can be electrically connected to the other cell electrode of another battery cell other than the battery cell to which the first and second parallel lead plates are connected in parallel. In the above configuration, the series lead piece can be extended from the first parallel lead plate and positioned on the side of one cell electrode. Furthermore, the above configuration has a simple structure in which the series lead piece is extended from the first parallel lead plate, and the parallel lead plate connects one cell electrode of the battery cell connected in parallel to the other battery cell electrode of the other battery cell not connected in parallel, eliminating the need for a busbar and reducing material costs, welding processes, and manufacturing costs, thereby lowering costs. In addition, it eliminates the need for a busbar, which is thicker and heavier than the lead plate, thus reducing weight. Moreover, by arranging the first parallel lead plate and the second parallel lead plate on each of the pair of cell end faces, the above configuration does not require concentrating the lead plates on one cell end face, and does not require thinning the lead plates, thus avoiding thermal disadvantages compared to single-sided current collection and improving heat dissipation. The above configuration has the advantage that the shape of the series lead piece is extended from the first parallel lead plate, allowing the lead plate to have a structure close to a flat plate, and the first and second parallel lead plates and series lead piece can be made into a simple structure and shape that is easy to manufacture. Furthermore, this configuration has the advantage that the series lead pieces are positioned on the end face side of one cell, allowing one cell electrode of one battery cell to be connected in close proximity to the other cell electrode of another battery cell, thereby preventing and suppressing voltage drops that may occur in the busbar.

[0011] In addition to the above embodiments, power supply devices according to other embodiments of the present disclosure can have series lead pieces integrally configured with the first parallel lead plate. This configuration allows the connected series lead pieces and the first parallel lead plate to be integrated, can be easily manufactured from a single metal plate, and has the advantage of reducing material and manufacturing costs and weight, as the single metal plate does not require welding, fixing processes, or structures for the series lead pieces and the first parallel lead plate.

[0012] In addition to the above embodiments, a power supply device according to another embodiment of the present disclosure has the following features: the first parallel lead plate is connected to one cell electrode located in the center of one cell end face, and the series lead piece is insulated from one cell electrode and connected to the other cell electrode at a position spaced apart from the other cell end face. The above configuration has the advantages of allowing the length of the series lead piece to be shortened, the lead plate to have a structure close to a flat plate, a simple shape and structure, easy manufacturing, and cost reduction and weight reduction of materials and manufacturing.

[0013] In addition to the above embodiments, power supply devices according to other embodiments of the present disclosure can have series lead pieces connected to the other cell electrode at the periphery of one cell end face. The above configuration has the advantage that the series lead pieces are arranged on one cell end face side and can be electrically connected to the same cell electrode as on the other cell end face side. The above configuration has the advantage that the length of the series lead pieces can be shortened, the lead plates can be made into a structure close to a flat plate, the shape and structure can be simple, manufacturing is easy, and materials and manufacturing costs can be reduced and weight can be reduced. Furthermore, the above configuration has the advantage that the connection and welding area of ​​the series lead pieces can be defined within the range of the periphery of one cell end face, making connection and welding easier.

[0014] In addition to the above embodiments, power supply devices according to other embodiments of the present disclosure have a series lead piece arranged on the end face side of one cell and electrically connected to the electrode of the other cell. The above configuration has the advantage that, on the end face side of one cell, the series lead piece can be extended from the first parallel lead plate and electrically connected to the electrode of the other battery cell with a simple structure without requiring a busbar, the lead plate can be made into a structure close to a flat plate, and the first and second parallel lead plates and the series lead piece can be made into a simple structure that is easy to manufacture.

[0015] In addition to the above embodiments, power supply devices according to other embodiments of the present disclosure may have two or more series lead pieces in the first parallel lead plate. This configuration has the advantage of being able to disperse the heat generated by the series lead pieces, suppress uneven heat generation on the lead plate, and be more thermally advantageous.

[0016] In addition to the above embodiments, power supply devices according to other embodiments of this disclosure can have the first parallel lead plate and the second parallel lead plate made of metal plates having a width greater than or equal to the diameter of the battery cell. This configuration is thermally advantageous compared to single-sided current collection without having to make the lead plates thinner, and improves heat dissipation. Furthermore, it has the advantage of being easy to manufacture the lead plates, resulting in lower costs and lighter weight.

[0017] In addition to the above embodiments, power supply devices according to other embodiments of this disclosure can use cylindrical batteries. The above configuration has the advantage that, in a power supply device having multiple cylindrical batteries, the orientation of the cell electrodes can be unified without providing busbars, and the lead plates do not suffer thermal disadvantages, thereby improving heat dissipation.

[0018] In addition to the above embodiments, a power supply device according to another embodiment of the present disclosure has a battery cell comprising a bottomed cylindrical outer casing with one end open and a sealing plate that closes the opening of the outer casing, with one cell electrode positioned on the sealing plate and the other cell electrode on the bottom surface of the outer casing, and a series lead piece connected to the periphery of the opening of the outer casing and electrically connected to the other cell electrode. The above configuration has the advantages of being able to shorten the length of the series lead piece, make the lead plate a structure close to a flat plate, have a simple shape and structure, be easy to manufacture, and reduce the cost and weight of materials and manufacturing.

[0019] In addition to the above embodiments, power supply devices according to other embodiments of this disclosure may have series lead pieces welded to the outer casing. The above configuration has the advantage of improving the reliability and stability of fixing and connection.

[0020] The embodiments of this disclosure will be described below with reference to the drawings. However, the embodiments shown below are illustrative examples for embodying the technical concept of this disclosure, and this disclosure is not limited to the following. Furthermore, this specification does not limit the components shown in the claims to the components of the embodiments. In particular, the dimensions, materials, shapes, relative arrangements, etc. of the components described in the embodiments are merely illustrative examples and are not intended to limit the scope of this disclosure to those components unless specifically stated otherwise. In the following description, terms indicating specific directions or positions (e.g., "up," "down," and other terms including these terms) will be used as needed, but the use of these terms is for the purpose of facilitating the understanding of the invention with reference to the drawings, and the technical scope of the present invention is not limited by the meaning of these terms. The size and positional relationships of the components shown in each drawing may be exaggerated for the sake of clarity in the explanation. Furthermore, in the following description, the same name and reference numerals indicate the same or identical components, and detailed explanations will be omitted as appropriate. Furthermore, each element constituting this disclosure may be configured such that multiple elements are made from the same material, with one material serving multiple purposes, or conversely, the function of one material may be shared among multiple materials.

[0021] The power supply unit disclosed herein is not specific to the load to which it is connected. For example, it can be used as a power source for movement, transportation, and predetermined actions of vehicles such as electric carts, hybrid cars and electric vehicles, electric scooters, electric assist bicycles, construction machinery, forklifts, and ships; as a power source for electric equipment used indoors and outdoors; or for stationary energy storage applications, as a backup power source for servers, or as a power source for homes, offices, and factories. [Embodiment 1]

[0022] Figures 1 to 5 show a power supply device 100 according to Embodiment 1 of this disclosure. In these figures, Figure 1 is a schematic connection diagram of the power supply device 100 according to Embodiment 1, Figure 2 is a schematic cross-sectional view of the power supply device 100, Figure 3 is a schematic perspective view of the power supply device 100, and Figures 4 and 5 are exploded perspective views of the power supply device 100. The power supply device 100 in these figures comprises a plurality of battery cells 1, a battery holder 5 that holds the battery cells 1, and a lead plate 10 that connects the plurality of battery cells 1. (Battery cell 1)

[0023] The battery cell 1 has a cell side and a pair of cell end faces that form the end faces of the cell side. The battery cell 1 is a rechargeable secondary battery, and cylindrical or rectangular battery cells 1 can be used. In the example shown in Figure 3, the battery cell 1 is a cylindrical battery, and multiple battery cells 1 are held in a vertical position with their cell end faces arranged substantially on the same plane by a battery holder 5. In the example in Figures 3 and 4, eight battery cells 1 are connected in 4 parallel × 2 series configurations using each lead plate 10. Note that the number and arrangement of battery cells 1 are not limited to this example, and any number and arrangement can be appropriately adopted with a similar configuration. Multiple battery cells 1 can be stacked vertically in a horizontal position. The battery cells 1 may also be arranged in a position where the cell end faces are in a matrix. Any arrangement can be used for the matrix-shaped battery cells 1, such as arranging the cell end faces in a grid pattern or in a staggered pattern with adjacent cell end faces offset. Lithium-ion secondary batteries can be used for the battery cell 1. Lithium-ion batteries have a large charge / discharge capacity relative to their capacity and weight, allowing for a smaller and lighter power supply unit 100 while maintaining high charge / discharge capacity. Battery cell 1 can use any rechargeable secondary battery, including other non-aqueous electrolyte secondary batteries, nickel-metal hydride batteries, nickel-cadmium batteries, all-solid-state batteries, and other known and future-developed secondary batteries.

[0024] Each battery cell 1 has a positive electrode and a negative electrode 4. The terminals of the positive or negative electrode 4 are provided on the respective cell end faces of the battery cell 1. That is, each battery cell 1 has one cell electrode 4 exposed on one cell end face, and the other cell electrode 4 exposed on the opposite cell end face at a position opposite to it. In the examples shown in Figures 1 and 2, the first cell electrode 4A, which is the positive terminal, is provided on the upper cell end face of the battery cell 1, and the second cell electrode 4B, which is the negative terminal, is provided on the lower cell end face. Alternatively, the positive terminal can be provided on the lower cell end face of the battery cell 1, and the negative terminal on the upper cell end face. Multiple battery cells 1 are arranged so that the orientation of the positive and negative cell electrodes 4, which are located on the respective cell end faces, is aligned in the same direction.

[0025] Each of the one or more battery cells 1 further has a cell electrode 4 exposed and positioned at a location separated from the cell electrode 4 on one of the cell end faces, the same cell electrode 4 as on the cell end face. In the battery cell 1A shown in Figures 2 to 6, the same second cell electrode 4B (negative electrode terminal) is exposed on the peripheral edge 2c of the upper cell end face, separated from the second cell electrode 4B (negative electrode terminal) on the lower cell end face (bottom surface 2b). In the battery cell 1A shown in Figures 3 and 4, the first cell electrode 4A (positive electrode terminal) is exposed in the circular center of one cell end face (upper end face, sealing plate 3), and the second cell electrode 4B (negative electrode terminal) is exposed in the circular center of the other cell end face (lower end face, bottom surface 2 of the outer casing 2) and on the peripheral edge 2c of the outer casing 2 on the circumferential side of the upper end face. At the upper end face, the first cell electrode 4A (positive terminal) in the central part and the second cell electrode 4B (negative terminal) at the peripheral part 2c are arranged in an insulated manner. Although not shown in the figure, the same second cell electrode 4B (negative terminal) as on the lower end face (bottom surface 2b) can also be exposed on the side of the cell.

[0026] The battery cell 1 has a cell side and a pair of cell end faces that form the end faces of the cell side. One cell end face (upper end face) has a first cell electrode 4A in the center, and the other cell end face (lower end face) has a second cell electrode 4B in the center. The battery cell 1 has positive and negative electrodes (not shown) arranged inside a metal outer casing 2, and the opening 2a of the outer casing 2 is closed with a sealing plate 3. The battery cell 1 in Figure 2 has a bottomed cylindrical outer casing 2 with one end open, and a sealing plate 3 that seals and closes the opening 2a of the outer casing 2. The battery cell 1 insulates and seals the opening 2a of the metal cylindrical outer casing 2 with the sealing plate 3, with the outer casing 2 being the negative electrode (second cell electrode 4B) and the center of the sealing plate 3 being the positive electrode (first cell electrode 4A). This battery cell 1 is formed by crimping the peripheral edge 2c of the upper end face of the outer casing 2, and sealing the opening 2a of the outer casing 2 with a sealing plate 3. An insulating material is placed between the outer casing 2 and the sealing plate 3 to insulate them. Figure 2 shows a first cell electrode 4A (positive terminal) arranged on the sealing plate 3 and a second cell electrode 4B (negative terminal) arranged on the outer casing 2. The first cell electrode 4A (positive terminal) is arranged in the center of the sealing plate 3, insulated from the peripheral edge 2c, or is provided on the sealing plate 3 which is arranged at the opening 2a of the outer casing 2 via an insulating gasket.

[0027] In this structure, the entire outer casing 2 of the battery cell 1 serves as the negative electrode (second cell electrode 4B). Therefore, the lead plate 10 connected to the negative electrode (second cell electrode 4B) does not necessarily need to be connected to the lower end face, i.e., the bottom surface 2b of the outer casing 2. Figure 2 shows that the bottom surface 2b of the outer casing 2 at the lower end face of the battery cell 1 (1A) is used as the negative electrode (second cell electrode 4B), and the second parallel lead plate 11B is connected to it. Also, the peripheral edge 2c of the outer casing 2 at the upper end face of the battery cell 1 (1A) is used as the negative electrode (second cell electrode 4B), and a series lead piece 12 is connected to it. The series lead piece 12 and the second parallel lead plate 11B are connected to the respective cell end faces of the battery cell 1 (1A) and both are connected to the negative electrode (second cell electrode 4B), thus electrically connecting them. This configuration electrically connects the series lead piece 12 and the second parallel lead plate 11B via the outer casing 2 without directly connecting the series lead piece 12 to the second parallel lead plate 11B, and without providing a separate connecting member from the outer casing 2. The first cell electrode 4A can also be the negative electrode and the second cell electrode 4B the positive electrode. Figure 2 shows the first cell electrode 4A on the upper end face as a convex portion, but it can also be a concave portion or substantially a flat portion.

[0028] There are two types of battery cells 1: a surface-insulated type in which the surface of the outer casing 2 is covered with an insulating film (not shown), such as a heat-shrinkable film, and a surface-exposed type in which the surface of the outer casing 2 is exposed without being covered with an insulating film. The surface-exposed type battery cell 1 can be electrically connected by directly contacting the metal parallel lead plates 11 and series lead pieces 12 with the surface (bottom surface 2b, peripheral edge 2c) of the outer casing 2. The surface-insulated type battery cell 1 can have the surface of the outer casing 2 exposed, allowing for electrical connection of the parallel lead plates 11 and series lead pieces 12 to the exposed portion. (Battery holder 5)

[0029] The battery holder 5 holds multiple battery cells 1. The battery holder 5 has multiple cylindrical storage tubes into which each battery cell 1 is inserted. Each storage tube has an opening at least at one end, and the battery cells 1 are inserted into each storage tube and held in a predetermined position and orientation. The battery holder 5 can house all the battery cells 1 as a single unit, or it may be divided into multiple sub-holders, with some of the battery cells 1 housed in the sub-holders. Alternatively, the battery holder 5 may be divided into two or more sections along the length of the battery cells 1. The battery holder 5 is made of a material with excellent insulating properties to prevent unintended electrical conductivity. The battery holder 5 is preferably made of a thermoplastic plastic with excellent strength and heat resistance. For example, resins such as polycarbonate, polypropylene, polybutylene terephthalate, modified polyphenylene ether, ABS, PPS, and PC-ABS alloy can be used.

[0030] The battery holder 5 arranges multiple battery cells 1 in a parallel position, aligning the orientation of the cell electrodes 4 in the same direction, and arranging the cell electrodes 4 (cell end faces) substantially on the same plane. In the battery holder 5 shown in Figure 2, all of the multiple battery cells 1 are arranged with the positive electrode of the cell end face facing upwards and the negative electrode of the cell end face facing downwards. The battery holder 5 has a support portion integrally molded to support the cell end faces of the battery cells 1 and prevent the battery cells 1 from falling out, and has an opening in the support portion to expose the cell electrodes 4 provided on the cell end faces of the battery cells 1. The cell electrodes 4 on the cell end faces exposed through the opening are electrically connected to the lead plate 10. The battery holder 5 fits, locks, and holds the lead plate 10, positions it in place, and connects and fixes it to the cell electrodes 4 by welding or the like. (Lead plate 10)

[0031] Multiple battery cells 1 are connected in series or in parallel via multiple lead plates 10. The lead plates 10 have one or more pairs of parallel lead plates 11 that connect the multiple battery cells 1 in parallel. Each parallel lead plate 11 has one or more first parallel lead plates 11A connected to one cell electrode 4 and one or more second parallel lead plates 11B connected to the other cell electrode 4. The lead plates 10 in Figures 3 to 5 have two pairs of parallel lead plates 11 that connect the four battery cells 1 in parallel, forming a parallel block 7 (7A, 7B). In one pair of parallel lead plates 11, the first parallel lead plate 11A is connected to the first cell electrode 4A (positive terminal) in the center of the upper end face of the four battery cells 1 (parallel block 7), and the second parallel lead plate 11B is connected to the second cell electrode 4B (negative terminal) in the center of the lower end face of the same four battery cells 1 (parallel block 7). The first and second parallel lead plates 11A and 11B are arranged on both sides of a pair of cell end faces to connect multiple battery cells 1 in parallel. The lead plates 10 are made of metal plates with excellent conductivity, such as aluminum plates, nickel plates, or copper plates. The lead plates 10 can be securely connected to the cell electrodes 4 by methods such as laser welding, spot welding, ultrasonic welding, resistance welding, or soldering, ensuring a reliable connection. Conductive adhesives can also be used, and mechanical connections and fixation can also be achieved by crimping, crimping, or clamping.

[0032] The lead plates 10 can utilize both sides of the pair of cell end faces of multiple battery cells 1 (parallel blocks 7) for arranging the first and second parallel lead plates 11A and 11B. This allows for twice the area of ​​single-sided current collection, which uses only one end face. This reduces the constraints on arrangement, number, and area compared to single-sided current collection, making it easier to arrange the lead plates 10 without having to make them thinner. The vertical and / or horizontal lengths of the first and second parallel lead plates 11A and 11B can be made greater than or equal to the diameter of the battery cell 1. As the number of battery cells 1 increases, the area of ​​the end faces of the parallel blocks 7 increases, allowing for wider widths for the first and second parallel lead plates 11A and 11B by utilizing the cell end faces on both sides of the multiple battery cells 1 (the end faces on both sides of the parallel blocks 7). Furthermore, the series lead pieces 12 are only provided at the end of the first parallel lead plate 11A, resulting in virtually no constraints on the arrangement of the lead plates 10. Furthermore, the parallel lead plates 11 shown in Figures 2 and 4 have a simple shape and structure with current-collecting tabs 13b on a flat base, making them easy to manufacture.

[0033] The power supply unit 100 has multiple pairs of parallel lead plates 11 that connect multiple battery cells 1 in parallel to form multiple (2 in Figures 1 to 6) parallel blocks 7, and series lead pieces 12 that connect multiple parallel blocks 7 in series. In the power supply unit 100 of Figure 3, one series lead piece 12 connects two parallel blocks 7, each composed of four battery cells 1, in series. The number of series and parallel connections can be arbitrarily set according to the required specifications, and a parallel block 7 can be composed of five or more battery cells 1, and three or more parallel blocks 7 can be connected in series by two or more series lead pieces 12. A pair of parallel lead plates 11 can be grouped as a parallel block 7 by connecting the first and second parallel lead plates 11A and 11B to the positive and negative terminals of multiple battery cells 1. Furthermore, by connecting the peripheral portion 2c (negative electrode shoulder) of some of the battery cells 1A in the parallel block 7A and the cell electrode 4 (positive electrode, first cell electrode 4A) of the battery cells 1B of the parallel block 7B that is in series with the parallel block 7A using the series lead piece 12 and the first parallel lead plate 11A, the cell electrodes 4 (positive electrode, negative electrode) can be unified in the same direction, simplifying the battery cell insertion process and enabling a busbarless structure. In addition, this structure allows the lead plate 10 to be a structure close to a flat plate, making manufacturing easier. Since there are lead plates 10 not only on the top surface but also on the bottom surface of the parallel block 7, it is thermally advantageous and heat dissipation can be improved.

[0034] Each parallel lead plate 11 is fixed to the end face of the battery holder 5. Each parallel lead plate 11 also has an opening window 13a facing the cell end face of the battery cell 1, partially exposing the cell end face. Furthermore, each parallel lead plate 11 has a current collecting tab 13b protruding from the opening window 13a toward the cell end face. The current collecting tab 13b is a component for connecting to the cell electrode 4 on the cell end face of the battery cell 1. Each current collecting tab 13b is bent in the middle and protrudes diagonally downward, which allows for adjustment of the fixing position and height with respect to the cell electrode 4 by absorbing slight positional misalignment.

[0035] In Figures 3 to 5, the first parallel lead plate 11A has a notch 14 on the side where the series lead piece 12 is arranged and connected, ensuring that an area for arranging and connecting the series lead piece 12 is secured without interference from the first parallel lead plate 11A. In Figures 3 to 5, a connecting section is provided between the notch 14 and the opening window 13a, allowing the width of the connecting section to be set within an appropriate range by the arrangement of the opening window 13a. Alternatively, the connecting section can be omitted. Furthermore, in the first parallel lead plate 11A, the current collection tab 13b protruding from the opening window 13a can be made to protrude diagonally downward from the opposite side of the notch 14 toward the notch 14, allowing the position of the opening window 13a to be adjusted, enabling the current collection tab 13b to be provided without narrowing the width of the connecting section, and thus allowing the width of the connecting section to be adjusted and set.

[0036] The first parallel lead plate 11A has a series lead piece 12 that connects adjacent parallel blocks 7 in series. The series lead piece 12 of the parallel lead plate 11A is connected to the battery cell 1 (1A) of another adjacent parallel block 7 (7A), and electrically connected to the second cell electrode 4B of the battery cell 1 (1A), thereby connecting parallel block 7B in series with the adjacent parallel block 7A. The series lead piece 12 connects the first parallel lead plate 11A of parallel block 7B and the second parallel lead plate 11A of parallel block 7A via the battery cell 1 (1A) to which the series lead piece 12 is connected.

[0037] One end of the series lead piece 12 is connected to the first parallel lead plate 11A, and the other end is connected to the outer casing 2 of the battery cell 1A, excluding the bottom surface 2b. The series lead piece 12 is connected to the outer casing 2 of the battery cell 1A at a position spaced apart from the second cell electrode 4B on the bottom surface 2b of the outer casing 2 of the battery cell 1A. The outer casing 2 acts as a connecting member, electrically connecting the series lead piece 12 to the bottom surface 2b (second cell electrode 4B). In Figures 2 to 6, the other end of the series lead piece 12 is connected to the peripheral edge 2c (second cell electrode 4B) of the opening 2a of the outer casing 2 on the upper end face of the battery cell 1A. The series lead piece 12 is connected to the peripheral edge 2c of the outer casing 2 on the upper end face of the battery cell 1A, insulated from the central first cell electrode 4A (positive terminal). The series lead piece 12 is positioned on the upper end face side (the side with the first parallel lead plate 11) and is connected to the peripheral edge 2c of the casing 2 of the adjacent battery cell 1A. The connection to the peripheral edge 2c of the casing 2 on the upper end face is connected to the second cell electrode 4B (negative terminal) on the bottom surface 2b of the casing 2 on the opposite lower end face side, via the metal casing 2. In this configuration, the series lead piece 12 and the second parallel lead plate 11B are electrically connected via the casing 2, without direct connection. As described above, the first and second parallel lead plates 11A and 11B connect the cell electrodes 4 at both end faces of the cells to form a parallel block 7, a series lead piece 12 extends from the first parallel lead plate 11A on the parallel block 7B side, and the series lead piece 12 is connected to the peripheral edge 2c of the outer casing 2 of the battery cell 1A in the adjacent parallel block 7A, and the outer casing 2 is electrically connected to the bottom surface 2b of the outer casing 2 as a connecting member, thereby electrically connecting the second parallel lead plate 11B and the series lead piece 12, and thus simplifying the electrical connection.

[0038] The series lead piece 12 has a series tab 12a that connects to the peripheral edge 2c of another battery cell 1A. Similar to the current collection tab 13b, the series tab 12a protrudes diagonally downward toward the peripheral edge 2c of the outer casing 2 of the battery cell 1A to be connected, and can be bent in the middle to make the connection part conform to a flat or non-flat surface to be connected. The series lead piece 12 is provided at the end of the first parallel lead plate 11A that connects the battery cell 1B, on the connection destination side (battery cell 1A side). This series lead piece 12 can be extended in the same direction as the parallel lead plate 11 to create a structure close to a flat plate. Furthermore, the series lead piece 12 and the first parallel lead plate 11A are provided on the same cell end face or its periphery, connecting the battery cells 1B and 1A (parallel blocks 7B and 7A) and allowing them to connect to the peripheral edge 2c of the outer casing 2 of the battery cell 1A that are close by with a short length. Furthermore, the series lead pieces 12 connected to the peripheral edge 2c do not need to extend below the position of the peripheral edge 2c. Moreover, the series lead pieces 12 are connected to the first parallel lead plate 11A and are integrally formed with the first parallel lead plate 11A, and can be easily manufactured from a single metal plate at low cost. The first parallel lead plate 11A, including the series lead pieces 12 described above, can be made into a simple structure that is easy to manufacture.

[0039] The first parallel lead plate 11A can have two or more series lead pieces 12, and each series lead piece 12 can be connected to the peripheral edge 2c of the outer casing 2 of the battery cell 1. The series lead pieces 12 are provided on opposing battery cells 1 (1A and 1B) and parallel blocks 7 (7A and 7B), and the more opposing battery cells 1 there are, and the longer the side of the parallel block 7, the more series lead pieces can be provided. Multiple series lead pieces 12 can distribute the heat generated by the series lead pieces 12, and the uneven distribution of heat on the lead plate 10 can be suppressed. The series lead pieces 12 can be connected at regular intervals (equal intervals) or symmetrically by defining the connection position, such as the peripheral edge 2c of the outer casing 2. The first parallel lead plate 11A having series lead pieces 12 has a simple structure and provides a high cost-effectiveness.

[0040] The peripheral edge 2c (periphery of the cell end face) of the opening 2a of the outer can 2 to which the series lead pieces 12 are connected and fixed is the shoulder of the cell end face, the shoulder portion, the part where the outer can 2 is crimped and fixed to the sealing plate 3, and the vicinity thereof. The peripheral edge 2c extends and widens in an arc shape along the periphery of the cell end face. The central angle of the peripheral edge 2c of the circular cell end face is, for example, 20 degrees or more and 270 degrees or less, preferably 30 degrees or more and 180 degrees or less. Laser welding is preferred for fixing the series lead pieces 12 to the peripheral edge 2c, but other fixing methods are also possible. The series lead pieces 12 have a range along the peripheral edge 2c to which they can be connected and fixed.

[0041] The series lead piece 12 is insulated from the first cell electrode 4A in the central part of the sealing plate 3 on the upper end face of the battery cell 1A and connected to the peripheral edge 2c of the outer casing 2 of the battery cell 1A. An insulating gasket is interposed in the crimped portion of the outer casing 2 to ensure insulation, but in addition to the insulating gasket, an insulating material can be provided that allows the series lead piece 12 to be welded and joined to the peripheral edge 2c while maintaining insulation from the first cell electrode 4A. The insulating material can, for example, define the welding and connection range at the opening, be detachable to define the welding range during welding, and be made of a material and shape that can maintain and ensure insulation. [Embodiment 2]

[0042] In the first embodiment, the power supply device 100 arranges multiple battery cells 1 in a single stage, but the battery cells 1 can be stacked in two or more stages. The second embodiment, the power supply device 200 illustrated in Figure 7, arranges multiple battery cells 1 in two stages. In the power supply device 200 in Figure 7, the first battery unit 8A is arranged in the first stage, and the second battery unit 8B is arranged on top of the first battery unit 8A in the second stage. Similar to the power supply device 100, the first battery unit 8A consists of multiple parallel blocks 7 connected in parallel by parallel lead plates 11 and connected in series by series lead pieces 12. The cell end faces at both ends are arranged on the same plane in an upright, vertical parallel position, with the upper end face being the positive electrode and the lower end face being the negative electrode. The second battery unit 8B is configured with the cell electrodes 4 and parallel lead plates 11 positioned upside down compared to the first battery unit 8A, with the lower end face being the positive electrode and the upper end face being the negative electrode. The first parallel lead plate 11A is positioned on the lower end face side and the second parallel lead plate 11B is positioned on the upper end face side, with a series lead piece 12 connecting the first battery unit 8A and the second battery unit 8B. The first battery unit 8A and the second battery unit 8B are connected in series by the series lead piece 212 on the first parallel lead plate 11A on the lower end face side of the second stage of the second battery unit 8B. The second battery unit 8B can have the same or different number, connections, and arrangement of battery cells 1 as the first battery unit 8A.

[0043] The power supply unit 100 described above can be suitably used as a power supply unit 100 that can unify the direction of the cell electrodes 4 without providing busbars.

[0044] 100, 200…Power supply unit 1, 1A, 1B…Battery cell 2…Outer casing; 2a…Opening, 2b…Bottom, 2c…Peripheral part 3…Sealing plate 4…Cell electrode; 4A…First cell electrode, 4B…Second cell electrode 5…Battery holder 7, 7A, 7B…Parallel block 8A, 8B…First and second battery units 10…Lead plate 11…Parallel lead plate; 11A…First parallel lead plate, 11B…Second parallel lead plate 12, 212…Series lead piece; 12a…Series tab 13a…Opening window, 13b…Current collection tab 14…Notch

Claims

1. A power supply device comprising: a plurality of battery cells having a cell side surface and a pair of cell end surfaces that form the end surface of the cell side surface, with one cell electrode provided on one cell end surface and the other cell electrode on the other cell end surface; a battery holder for holding the battery cells; and a lead plate for connecting the battery cells, wherein the plurality of battery cells are arranged with the orientation of the one and other cell electrodes aligned in the same direction; the lead plate has a parallel lead plate for connecting the plurality of battery cells in parallel; the parallel lead plate has one or more first parallel lead plates connected to the one cell electrode and one or more second parallel lead plates connected to the other cell electrode; and the first parallel lead plate has a series lead piece that is electrically connected to the other cell electrode of another battery cell.

2. A power supply device according to claim 1, wherein the series lead piece is integrally formed with the first parallel lead plate.

3. A power supply device according to claim 1, wherein the first parallel lead plate is connected to the one cell electrode provided in the center of the one cell end face, and the series lead piece is insulated from the one cell electrode and connected to the other cell electrode at a position spaced apart from the other cell end face.

4. A power supply device according to claim 3, wherein the series lead piece is connected to the other cell electrode at the peripheral edge of the end face of one cell.

5. A power supply device according to claim 1, wherein the series lead piece is arranged on the end face side of one cell and electrically connected to the other cell electrode.

6. A power supply device according to claim 1, wherein the first parallel lead plate has two or more series lead pieces.

7. A power supply device according to claim 1, wherein the first parallel lead plate and the second parallel lead plate are metal plates having a width equal to or greater than the diameter of the battery cell.

8. A power supply device according to claim 1, wherein the battery cell is a cylindrical battery.

9. A power supply device according to any one of claims 1 to 8, wherein the battery cell comprises a bottomed cylindrical outer casing with one end open and a sealing plate that closes the opening of the outer casing, the one cell electrode is placed on the sealing plate and the other cell electrode is placed on the bottom surface of the outer casing, and the series lead piece is connected to the periphery of the opening of the outer casing and electrically connected to the other cell electrode.

10. A power supply device according to claim 9, wherein the series lead pieces are welded to the outer casing.

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