Battery pack

Abstract

This battery pack comprises: a battery block having a plurality of battery cells; a battery holder for positioning the battery cells in fixed positions; and a first bus bar for connecting electrodes in the respective battery cells and a first electrode terminal in the battery block. The first bus bar has: a first split bus bar connected to the electrodes in the battery cells; a second split bus bar spaced apart from the first split bus bar and connected to the first electrode terminal; and a fuse plate which is a separate member from the first split busbar and the second split busbar and connects the first split bus bar and second split bus bar. The fuse plate has: a first joint portion joined to the first split bus bar; a second joint portion joined to the second split bus bar; and a fuse portion which connects the first joint portion and the second joint portion and is blown out by an overload current.

Description

Battery pack

[0001] The present disclosure relates to a battery pack having a fusing portion that is blown out by an overload current.

[0002] Battery packs that charge and discharge multiple batteries connected in series and parallel require a protection mechanism against overload current, and battery packs equipped with such a protection mechanism have been developed. For example, the battery pack disclosed in Patent Document 1 electrically connects multiple battery cells and connects them to a voltage detection circuit via lead wires. This battery pack requires wiring space for the lead wires, resulting in a problem of increased battery pack size. Even when fuses are provided instead of protection circuits such as voltage detection circuits, the fuses and lead wires still require a large amount of space. As battery packs become increasingly smaller, it is important to improve the safety of the battery pack by implementing fuse functions appropriate for each battery block while saving space.

[0003] International Publication No. 2018 / 168982

[0004] One object of the present disclosure is to provide a battery pack that can achieve fuse functions according to the battery blocks while saving space.

[0005] A battery pack according to one aspect of the present disclosure includes a battery block having a plurality of battery cells, a battery holder that positions the battery cells in a fixed position, and a first bus bar that connects an electrode of the battery cell to a first electrode terminal of the battery block, the first bus bar having a first segment bus bar connected to the electrode of the battery cell, a second segment bus bar that is spaced apart from the first segment bus bar and connected to the first electrode terminal, and a fuse plate that is a separate member from the first and second segment bus bars and connects the first and second segment bus bars, the fuse plate having a first joint joined to the first segment bus bar, a second joint joined to the second segment bus bar, and a fusing portion that connects the first joint and the second joint and melts down due to an overload current.

[0006] The above battery pack has the advantage of being space-saving while being able to provide fuse functionality suited to the battery block.

[0007] 1 is a schematic perspective view of a battery pack according to one embodiment of the present invention; FIG. 2 is a circuit diagram of the battery pack of FIG. 1; FIG. 3 is a schematic exploded perspective view of a first bus bar and a lead plate of the battery pack shown in FIG. 3; FIG. 4 is a schematic exploded perspective view of the battery pack shown in FIG. 3, as viewed from below; FIG. 5 is a schematic exploded perspective view of the battery pack shown in FIG. 5, as viewed from the opposite side; FIG. 6 is a schematic perspective view of a second bus bar and a lead plate of the battery pack shown in FIG. 5; FIG. 7 is a schematic perspective view of a battery pack according to another embodiment of the present invention; FIG. 8 is a circuit diagram of the battery pack of FIG.

[0008] The present invention will be described in detail below with reference to the drawings. In the following description, terms indicating specific directions or positions (e.g., "upper," "lower," and other terms incorporating these terms) will be used as necessary. However, the use of these terms is intended to facilitate understanding of the invention with reference to the drawings, and the meaning of these terms does not limit the technical scope of the present invention. Furthermore, parts with the same reference numerals appearing in multiple drawings indicate the same or equivalent parts or components. Furthermore, the embodiments described below are illustrative examples of the technical concept of the present invention and do not limit the scope of the present invention. Furthermore, unless otherwise specified, the dimensions, materials, shapes, relative positions, etc. of the components described below are intended for illustrative purposes only and are not intended to limit the scope of the present invention. Furthermore, the content described in one embodiment or example may also be applicable to other embodiments or examples. Furthermore, the sizes and positional relationships of components shown in the drawings may be exaggerated for clarity.

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

[0010] A battery pack according to one embodiment of the present disclosure includes a battery block having a plurality of battery cells, a battery holder that positions the battery cells in a fixed position, a case that houses the battery block, and a first bus bar that connects electrodes of the battery cells to first electrode terminals of the battery block, the first bus bar including a first segment bus bar that is connected to the electrodes of the battery cells, a second segment bus bar that is spaced apart from the first segment bus bar and that is connected to the first electrode terminals, and a fuse plate that is a separate member from the first and second segment bus bars and connects the first and second segment bus bars, the fuse plate having a first joint that is joined to the first segment bus bar, a second joint that is joined to the second segment bus bar, and a fusing portion that connects the first joint and the second joint and that melts down due to an overload current.

[0011] The above battery pack has the advantage of being able to achieve fuse functionality tailored to the battery block while saving space. The above configuration has the advantage that by using a fuse plate made of a separate material from the first and second segment bus bars, the fusing characteristics (It characteristics) can be precisely set by adjusting the shape, thickness, width, and material of the fusing portion. The above configuration has the advantage that by using the shape, thickness, width, and material of the fusing portion, and by combining these, it is possible to determine and select fuse plates with a wide variety of fusing characteristics tailored to the allowable current and fusing time of each battery block, rather than being limited to the characteristics of commercially available current fuses. Furthermore, the separate fuse plate allows the fuse plate and fusing portion to be selected and determined without being restricted by the shape, thickness, and material of the first and second segment bus bars. Furthermore, separate fuse plates are easy to process and manufacture, resulting in low costs. The above configuration allows the first bus bar to improve heat dissipation.

[0012] In another embodiment of the battery pack of the present disclosure, the fuse plate is a plate thinner than the first and second segment bus bars, and the fusing portion can be a narrow portion with a cross-sectional area smaller than the first and second joints. This battery pack has the advantage of being able to achieve fuse function suited to the battery block while saving space. The plate-shaped fuse plate, which is thinner than the first and second segment bus bars, not only saves space in the placement surface but also achieves fuse function suited to the high-current bus bars and battery blocks. Furthermore, fusing portions of a predetermined shape and width can be easily manufactured inexpensively and with high precision by, for example, punching, thereby reducing costs.

[0013] In another embodiment of the battery pack of the present disclosure, the fusing portion has multiple narrow portions, at least some of which have different heights (h), and the narrow portions are spaced apart to connect the first and second segment bus bars. This battery pack has the advantage of being able to achieve fuse functionality tailored to the battery block while saving space. This is because, by having at least some of the multiple narrow portions have different heights (h), it is possible to reliably achieve fusing characteristics and more precisely set the fusing order, fusing timing, fusing time, etc., thereby improving the accuracy of the fusing characteristics and achieving fuse functionality tailored to the battery block. Furthermore, it is possible to prevent the fusing portion from being broken during use of the battery pack when the fuse plate is attached by welding or other means, for example, due to vibration or impact.

[0014] In a battery pack according to another embodiment of the present disclosure, the fusing portion can be disposed between the first segment bus bar and the second segment bus bar. This battery pack has the advantage of being able to achieve fuse function according to the battery block while saving space. This is because disposing the fusing portion between the first segment bus bar and the second segment bus bar, which are disposed apart, ensures that the fusing portion's fusing characteristics are fully exhibited.

[0015] In another embodiment of the battery pack of the present disclosure, the battery holder is a rectangular parallelepiped, and the fuse plate can be arranged on a surface of the battery holder other than the surface facing the battery cell electrodes and other than the surface on which the first and second electrode terminals of the battery block are arranged. This battery pack has the advantage of being able to achieve fuse functionality suited to the battery block while saving space. Space can be saved on the fuse plate arrangement surface. This configuration allows the fuse plate (fusing portion) to be arranged away from the battery cell electrodes and the first and second electrode terminals of the battery block. Furthermore, by being able to arrange the fuse plate on a surface other than the surface facing the battery cell electrodes and other than the surface on which the first and second electrode terminals of the battery block are arranged, it is possible to prevent the fuse plate (fusing portion) from affecting the battery cell electrodes and the first and second electrode terminals of the battery block.

[0016] In another embodiment of the battery pack of the present disclosure, the battery holder is a rectangular parallelepiped, the first bus bar is arranged extending longitudinally on the side surface of the battery holder, and portions of the first segment bus bar and / or the second segment bus bar are arranged along the corners of the battery holder. This battery pack has the advantage of being able to achieve fuse functionality tailored to the battery block while saving space. By arranging the first bus bar extending longitudinally on the side surface of the battery holder, the side surface of the battery holder can be effectively utilized, ensuring the placement and area of ​​the fuse plate, achieving fusing characteristics tailored to the battery block, and improving heat dissipation. Furthermore, by arranging portions of the first segment bus bar and / or the second segment bus bar along the corners of the battery holder, positioning and placement are facilitated. The side surface of the battery holder is defined based on the electrode surface of the battery cell, and refers to the surface (side surface 6c in FIG. 1 ) other than the opposing surface of the battery holder where the battery cell electrodes face (top surface 6a and bottom surface 6b in FIG. 1 ). The side surface of the battery holder refers to the side surface 6c of the battery holder 5 when multiple battery cells 1 are arranged in a vertical position as shown in Figure 1. Note that the battery pack can be placed and used upside down, left to right, or rotated 90 degrees, and the side surface of the battery holder may not match the side surface in the actual placement and use state.

[0017] In another embodiment of the battery pack of the present disclosure, the battery holder can hold battery cells arranged in the same or different orientations, parallel to each other, with the end faces of the battery cells aligned on the same plane. The above battery pack has the advantage of being able to achieve fuse functionality appropriate for the battery block while saving space. Furthermore, arranging the battery cells in the same or different orientations can reduce costs by simplifying the structure and reducing the number of parts, while also expanding design flexibility and enabling improved and more efficient heat dissipation by providing a heat dissipation or cooling plate.

[0018] A battery pack according to another embodiment of the present disclosure further includes a second bus bar connected to the second electrode terminal of the battery block, and the first and second electrode terminals can be arranged on the same surface of the battery holder. The battery pack described above has the advantage of being able to achieve fuse functionality suited to the battery block while saving space. The first and second bus bars improve heat dissipation and efficiency. The first and second bus bars save space on their respective placement surfaces, and by arranging the first and second electrode terminals on the same surface of the battery holder, the increase in size of the battery pack and battery holder due to the placement of the first and second electrode terminals can be suppressed and minimized.

[0019] A battery pack according to another embodiment of the present disclosure may further include a second bus bar connected to a second electrode terminal of the battery block, with the first bus bar and the second bus bar disposed on opposing surfaces of the battery holder, extending longitudinally along both opposing surfaces. The battery pack described above has the advantage of being able to achieve fuse functionality suited to the battery block while saving space. The first bus bar and the second bus bar disposed on opposing surfaces of the battery holder, extending longitudinally, saves space while ensuring the placement and area of ​​the fuse plate, and also improves heat dissipation and efficiency.

[0020] In another embodiment of the battery pack of the present disclosure, the battery holder can have a support portion that supports the first bus bar. This battery pack has the advantage of being able to achieve fuse functionality tailored to the battery block while saving space. The support portion positions and supports at least the first segment bus bar, the second segment bus bar, or the fuse plate in a predetermined position, ensuring that fusing characteristics tailored to the battery block are achieved. In addition, the simplified structure, reduced number of parts, and easier assembly allow for lower costs.

[0021] A battery pack according to another embodiment of the present disclosure further includes a series bus bar that connects the battery cells in series, and the series bus bar and the first bus bar can be arranged in a twisted position while being insulated from each other. The above-described battery pack has the advantage of being able to achieve fuse functionality suited to the battery block while saving space. By arranging the series bus bar in a twisted position while being insulated from the first bus bar, it is possible to reliably achieve fusing characteristics suited to the battery block.

[0022] In another embodiment of the battery pack of the present disclosure, the fuse plate can be positioned closer to a corner of the battery holder. On the surface on which the fuse plate is positioned, the distance from both edges (corners) of the battery holder to the end of the fuse plate is not the same, and the fuse plate can be positioned closer to one of the corners of the battery holder. For example, in FIG. 1 , the fuse plate 13 is positioned closer to the corner 5b on the first electrode terminal 2A side of the battery block 2. The above battery pack has the advantage of being able to achieve fuse functionality tailored to the battery block while saving space. Increasing the length (L1, L2) of either the first or second segment bus bar increases design flexibility and improves heat dissipation and efficiency.

[0023] In a battery pack according to another embodiment of the present disclosure, the length (L1) of the first segment bus bar and the length (L2) of the second segment bus bar can be different. The above-described battery pack has the advantage of being able to achieve fuse functionality suited to the battery block while saving space. Increasing the length (L1, L2) of either the first segment bus bar or the second segment bus bar increases design flexibility and improves heat dissipation and efficiency.

[0024] The battery pack is used in power supply devices, battery modules, energy storage modules, etc., which have multiple battery cells that require a fusing part that melts down due to an overload current. It is particularly suited to large current applications, and can be used, for example, as a power source for motor-driven electric devices such as construction machinery, electric cars, electric carts, electric motorcycles, electric wheelchairs, electric tricycles, electric bicycles, and power tools. However, this disclosure does not specify the use of the battery pack, and it can be used for power sources and energy storage power sources for electric devices and products other than those mentioned above.

[0025] 1 to 7 show a battery pack 100 according to Embodiment 1. Fig. 1 shows a schematic perspective view of the battery pack 100. Fig. 2 shows a circuit diagram of the battery pack 100, Fig. 3 shows an exploded perspective view of the battery pack 100, Fig. 4 shows an exploded perspective view of a first bus bar 10A, Fig. 5 shows an exploded perspective view of the battery pack 100 seen from a diagonal downward direction, Fig. 6 shows an exploded perspective view of the battery pack 100 seen from the opposite side to Fig. 3 (diagonal right direction), and Fig. 7 shows a perspective view of a second bus bar 15.

[0026] The battery pack 100 shown in FIG. 1 includes a battery block 2 having a plurality of battery cells 1, a battery holder 5 that positions the plurality of battery cells 1 in fixed positions, a first bus bar 10A that connects the electrode 1a of the battery cell 1 to a first electrode terminal 2A of the battery block 2, and a second bus bar 15 that connects the electrode 1a of the battery cell 1 to a second electrode terminal 2B of the battery block 2.

[0027] (Battery Block 2) The battery block 2 includes multiple battery cells 1. This disclosure does not specify the type, shape, number, arrangement, alignment, connection, electrode shape, or electrode arrangement of the battery cells 1. However, for example, the battery block 2 shown in FIGS. 1 and 3 has multiple rechargeable battery cells 1 arranged in a parallel position in a battery holder 5. The battery cells 1 in FIG. 3 are cylindrical batteries 1A, and the battery block 2 has multiple cylindrical batteries 1A arranged vertically in multiple rows and columns (15 rows and 14 columns in FIG. 3 ), stacked like a straw bag. The battery cells 1 are rechargeable secondary batteries, and lithium-ion secondary batteries can be used. However, this disclosure does not limit the battery cells 1 to lithium-ion batteries; all other rechargeable secondary batteries can be used, including currently used batteries such as lithium polymer secondary batteries and all-solid-state batteries to be developed. Furthermore, although the battery pack 100 in FIG. 3 uses cylindrical batteries 1A, the battery cells 1 can also be batteries other than cylindrical batteries, such as prismatic batteries.

[0028] The battery cell 1 has an electrode 1a on one or both end faces. The battery cells 1 in Figures 3 and 5 have positive and negative electrodes 1a on both end faces, respectively. This battery cell 1 is a cylindrical battery 1A, and has a discharge valve opening on one end face. The end face of the battery cell 1 facing the discharge valve is the discharge end face for ejected material, and the end face opposite the discharge end face is a non-discharge end face without a discharge valve opening and from which ejected material is not discharged. In a cylindrical battery, the opening of the outer can, which is made, for example, by pressing a metal plate, is airtightly sealed with a sealing plate. The sealing plate has a discharge valve opening, and the end face facing the discharge valve is, for example, the positive electrode side. Note that the battery cell may also have a discharge valve opening on the bottom plate of the outer can.

[0029] In the battery block 2 of FIGS. 1 and 3 , multiple battery cells 1 are arranged parallel to each other in a vertical position in the Z direction using battery holders 5, and the multiple battery cells 1 are electrically connected. As shown in the figures, the battery block 2 can divide the multiple battery cells 1 into parallel units 4 by connecting them in parallel. This battery block 2 can increase output voltage by connecting multiple parallel units 4 in series. In the battery block 2, the multiple battery cells 1 are connected in series and / or in parallel using connecting members such as lead plates 7 and bus bars 10. In the battery pack 100, the output voltage can be increased by connecting multiple battery cells 1 in series, and the maximum output current can be increased by connecting multiple battery cells 1 in parallel. Therefore, the battery pack 100 connects the battery cells 1 in series and / or in parallel to achieve the optimal output voltage and maximum output current for the application. The battery block 2 of FIG. 1 has multiple parallel units 4 connected in series, each connecting multiple battery cells 1 in parallel. In the parallel unit 4 of FIG. 1, the multiple battery cells 1 are arranged in the X direction and connected in parallel using lead plates 7. In the battery block 2 of FIG. 1, adjacent parallel units 4 in the Y direction are connected in series using lead plates 7. 1 and 3, the battery block 2 has 15 rows of battery cells 1 connected in parallel in the X direction as parallel units 4, and 14 rows of parallel units 4 connected in series in the Y direction. The parallel units 4 can connect multiple rows of battery cells 1 in parallel, in addition to the single row shown in FIG. 1.

[0030] A battery cell 1 has an electrode 1a on one or both end faces. The battery cell 1 in FIG. 3 has an electrode 1a on each of both end faces (top and bottom end faces in FIG. 3). In a battery block 2, multiple battery cells 1 can be arranged with the same or different electrode 1a orientations. For example, in the battery blocks 2 in FIGS. 1 and 3, the positive and negative electrodes 1a of the battery cells 1 are not uniformly oriented, but are arranged with different electrode 1a orientations. In the battery block 2 shown in the figure, the electrodes 1a of the battery cells 1 are arranged in the same orientation for each parallel unit 4, multiple battery cells 1 in the same parallel unit 4 are arranged with the same electrode 1a orientation, and battery cells 1 in adjacent parallel units 4 are arranged with the top and bottom electrodes 1a reversed and aligned. The battery block 2 in FIGS. 1 and 3 has parallel units 4 arranged in 14 rows in the Y direction. Starting from the front (corner 5b where the first electrode terminals 2A are arranged), the odd-numbered rows, namely the first row, third row, ..., and thirteenth row, have positive electrodes 1a on their upper end faces and negative electrodes 1a on their lower end faces. Similarly, the even-numbered rows, namely the second row, fourth row, ..., and fourteenth row, starting from the front, have negative electrodes 1a on their upper end faces and positive electrodes 1a on their lower end faces.

[0031] The battery block 2 has multiple battery cells 1 arranged in parallel in a vertical position, multiple parallel units 4 arranged in parallel, and both ends (top and bottom surfaces in FIG. 1 ) of the electrodes 1 a of the battery cells 1 arranged on the same plane to form a rectangular parallelepiped (including a substantially rectangular parallelepiped). The rectangular parallelepiped battery block 2 has an upper surface (top surface), side surfaces, and a lower surface (bottom surface). The battery block 2 has first electrode terminals 2A and second electrode terminals 2B, which are arranged on the same surface (third side surface 6 f) of the battery holder 5.

[0032] (Battery Holder 5) The battery holder 5 holds and arranges multiple battery cells 1 in a predetermined orientation and position. The battery holder 5 can be manufactured by molding a material with excellent insulating properties, preferably thermoplastic plastic. The battery holder 5 in FIGS. 1 and 3 holds each battery cell 1 in a fixed position with each end face of the battery cell 1 aligned in a parallel orientation. The battery holder 5 has multiple cell holding openings 5a into which battery cells 1 are inserted and held in a fixed position. Each cell holding opening 5a has an interior shape that follows almost the entire periphery of the surface of the battery cell 1. The battery holder 5 holds and arranges each battery cell 1 in a predetermined position by inserting a battery cell 1 into each cell holding opening 5a. The battery holder 5 in FIGS. 1 and 3 arranges multiple battery cells 1 in a parallel orientation (Z direction).

[0033] The battery holder 5 in Figures 1 and 3 has a pair of split holders 5A, 5B that are split in half at the middle of the battery cell 1. The pair of split holders 5A, 5B split the cell holding opening 5a in half at the center of each battery cell 1. Alternatively, the battery holder 5 can be split into three or more sections, split into different positions, and closed with a lid or bottom plate. It can also be an integrated structure without being split.

[0034] The battery holder 5 in FIG. 1 is a rectangular parallelepiped (including a substantially rectangular parallelepiped) with an uneven surface. The rectangular parallelepiped battery holder 5 shown in FIG. 1 has a top surface 6a (top surface), side surfaces 6c connected to the top surface 6a, and a bottom surface 6b (bottom surface) connected to the side surfaces 6c. The side surfaces 6c have a pair of opposing first and second side surfaces 6d and 6e, and a pair of opposing third and fourth side surfaces 6f and 6g. In the battery holder 5 shown in the figure, both ends of each parallel unit 4 (the upper and lower end surfaces of the battery cells 1) are arranged on the same plane. The opposing side surfaces 6c (first side surface 6d, second side surface 6e) are used as placement surfaces for the first bus bar 10A and the second bus bar 15, respectively. The side surface 6c adjacent to the both side surfaces 6c (third side surface 6f) is used as placement surface for the first electrode terminals 2A and second electrode terminals 2B of the battery block 2. The battery holder 5 in Fig. 1 has a rectangular top surface 6a with a first side surface 6d and a second side surface 6e arranged along the long sides and a third side surface 6f and a fourth side surface 6g arranged along the short sides. The battery holder 5 in Fig. 1 has a first bus bar 10A arranged on the first side surface 6d on one of the long sides and a second bus bar 15 arranged on the second side surface 6e on the other long side, in parallel positions extending in the longitudinal direction (X direction), and the first electrode terminals 2A and second electrode terminals 2B of the battery block 2 arranged on the third side surface 6f (end surface) of the short sides.

[0035] The battery pack 100 has a first bus bar 10A connected to the first electrode terminal 2A and a second bus bar 15 connected to the second electrode terminal 2B arranged on a pair of opposing surfaces (first side surface 6d, second side surface 6e) of the battery holder 5, and the first electrode terminal 2A and the second electrode terminal 2B of the battery block 2 arranged on the same surface (third side surface 6f) of the battery holder 5, thereby achieving a compact battery pack 100. Arranging the metal plate-shaped first bus bar 10A and second bus bar 15 on both side surfaces 6c (first side surface 6d, second side surface 6e) of the battery holder 5 saves space, reducing the width (width in the Y direction) of the battery pack 100 and making it more compact. Furthermore, arranging the first electrode terminal 2A and the second electrode terminal 2B of the battery block 2 on the same surface (third side surface 6f) of the battery holder 5 prevents the width (width in the Y direction) of the battery pack 100 from increasing, thereby achieving a compact battery pack 100. Furthermore, by arranging the metal plate-shaped first bus bar 10A and second bus bar 15 on both side surfaces 6c (first side surface 6d and second side surface 6e) of the battery holder 5, heat dissipation can be further improved.

[0036] The connecting portion 8 connects the divided holder segments 5A and 5B. The two divided holder segments 5A and 5B are connected by the connecting portion 8 without any relative misalignment when both ends of the battery cells 1 are inserted into the cell holding openings 5a. While the present disclosure does not specify the connecting portion 8, for example, the connecting portion 8 connects the divided battery holders 5 and the battery holder 5 made up of multiple components by locking, a fitting structure, screw fastening, or a combination thereof. For example, the connecting portion 8 shown in FIGS. 1 and 3 connects and secures the divided holders 5A and 5B by locking the locking portion 8a and the locked portion 8b, and by threading a screw 8e into the threaded portions 8c and 8d that open into the screw holes. The connecting portion can also be connected by a fitting structure in which the fitting protrusion fits into the fitting recess. The battery holder 5 can be connected to the divided holders 5A, 5B by arranging connecting portions 8 on the side surface 6c and / or a surface other than the side surface 6c, for example, on the opposing surfaces of the pair of divided holders 5A, 5B.

[0037] The battery holder 5 may have support portions 9 that support, hold, temporarily fasten, and position the busbar 10 and lead plates 7. This disclosure does not specify the shape, number, configuration, or structure of the support portions 9. However, for example, the support portions 9 that support and position the busbar 10 may be made of plastic and have a fitting structure between the battery holder 5 and the busbar 10, thereby positioning the busbar 10 in a fixed position. The same applies to the lead plates 7. The support portions 9 in FIGS. 1 and 4 are protrusions 9a that protrude from the side surface 6c of the battery holder 5 and support and position the first busbar 10A in a fixed position. This support portion 9 positions and positions the first busbar 10A in a predetermined position and restricts movement and vibration, ensuring the fuse characteristics of the first busbar 10A. The support portions 9 and protrusions 9a also function as insulating members, ensuring insulation between components that require insulation, such as the insulation of the first busbar 10A. The protrusions 9a are arranged at the portions where the outer periphery of the first busbar 10A abuts, allowing the first busbar 10A to be positioned at a predetermined location. The protrusions 9 are arranged, for example, below and / or above the first busbar 10A extending in the horizontal direction (X direction), to define the vertical position of the first busbar 10A, allowing the first busbar 10A to be positioned at a predetermined location. The protrusions 9 can be shaped to match the portions where the first busbar 10A abuts, and can be, for example, plate-shaped, wall-shaped, rod-shaped, U-shaped, L-shaped, rail-shaped, rib-shaped, or block-shaped. The support portions 9 abut against the busbar 10 and lead plate 7 to position them and place them at a predetermined location. The support portions 9 abut against predetermined portions of the first busbar 10A, such as the end, edge, or bent portions 11d and 12e, allowing the first busbar 10A to be positioned and placed at a predetermined location. The support parts 9 that abut against the corners 5b of the battery holder 5 can be easily positioned by abutting the bent parts of the first bus bar 10A, such as the bent parts 11d and 12e and the connecting part 12b. The connecting parts 8 that connect the divided holders 5A and 5B can also be used as the support parts 9 that temporarily fasten and support the first bus bar 10A and the second bus bar 15 that are respectively placed in predetermined positions.1 and 3, the connecting portion 8 connects and secures the split holders 5A and 5B by engaging the locking portion 8a with the locked portion 8b, and by threading the screws 8e into the threaded portions 8c and 8d that open into the screw holes, thereby fastening the split holders 5A and 5B together. The locking portion 8a (and / or the locked portion 8b) and the threaded portion 8c protrude to support the support portion 9 (protruding portion 9a), which positions the first bus bar 10A, which is disposed on the longitudinal side surface 6c of the battery holder 5, in a predetermined position and defines its vertical position. The support portion 9 also has a through hole and an opening in the first bus bar 10A, and the protruding portion 9a, which has a shape that matches the through hole and opening, can be inserted and fitted into the through hole and opening.

[0038] The battery pack 100 can have a case that houses the battery blocks 2. The first bus bar 10A can save space on the placement surface. The first bus bar 10A is placed between the battery holder 5 and the case, saving space on the placement surface and allowing the battery pack 100 to be made smaller. The case has an inner wall that covers the battery blocks 2 and is made, for example, by molding a thermoplastic plastic. The plastic for the case can be a thermoplastic plastic with high heat resistance and strength, such as high-density polyethylene, polypropylene, polyimide, or polycarbonate. The case can be, for example, a pair of separate cases connected at the opening edges to accommodate and place the battery blocks 2 inside. The separate cases can be, for example, box-shaped plastic molded with two sets of screw connection portions on each of the box-shaped opening edges, and the separate cases can be connected by screws, ensuring reliable connection of the pair of separate cases without misalignment. However, this disclosure does not specify the structure, configuration, connection method, etc. of the case, and the case can have any structure that can arrange and store the battery block 2 inside, including an inner case, an outer case, an interior case, an exterior case, etc.

[0039] (Lead Plates 7) The lead plates 7 electrically connect the multiple battery cells 1. In the battery block 2 shown in FIGS. 1 to 3 and 5, the electrodes 1a of the multiple battery cells 1 are each connected to the first electrode terminal 2A and the second electrode terminal 2B via the lead plates 7 and bus bars 10. The lead plates 7 are shaped and arranged according to the arrangement and layout of the electrodes 1a of the battery cells 1, and electrically connect the multiple battery cells 1. The lead plates 7 can connect the multiple battery cells 1 in series or parallel, or both series and parallel. The lead plate 7 in FIG. 1 connects multiple battery cells 1 arranged in parallel in each row in the X direction to form a parallel unit 4. Furthermore, the lead plate 7 can be wide enough to span multiple rows, allowing adjacent parallel units 4 to be connected in series. The lead plate 7 in FIG. 1 connects adjacent parallel units 4 in series across the width in the Y direction. For example, adjacent parallel units 4 in the second and third rows are connected in series by a lead plate 7 with a width equivalent to two rows. In the battery blocks 2 shown in Figures 1 to 3 and 5, the electrodes 1a of the battery cells 1 are arranged alternately on the top and bottom surfaces of each parallel unit 4, and the lead plates 7 for series connection are arranged alternately on the top and bottom surfaces 6a and 6b of the battery holders 5 that face the electrodes 1a of the battery cells 1, connecting adjacent parallel units 4 in series. These lead plates 7 connect multiple battery cells 1 in parallel and in series, eliminating the need for separate connecting members (such as a series bus bar 17) for connecting parallel units 4 in series, thereby reducing the number of parts and lowering costs. The lead plates 7 in Figures 1 and 5 extend in the longitudinal direction (X direction) of the top and bottom surfaces 6a and 6b, and are arranged to extend in the same X direction as the first bus bar 10A and second bus bar 15. However, depending on the arrangement of the multiple battery cells 1 and parallel units 4, the lead plates 7 can be shaped and arranged to extend in a different direction (e.g., Y direction).

[0040] The lead plates 7 are conductive metal members that electrically connect multiple battery cells 1. The lead plates 7 in FIGS. 1 and 4 are fixed to and connected to the electrodes 1a of each battery cell 1 via fixed terminals that are fixed to the electrodes 1a of the battery cell 1. The fixed terminals of the lead plates 7 are electrically connected and fixed to the electrodes 1a of the battery cell 1 by spot welding, laser welding, resistance welding, ultrasonic welding, or the like. The lead plates 7 in FIGS. 1 and 4 connect multiple battery cells 1 in parallel and series. The lead plates 7 can also function as fuses. The lead plates 7 in FIGS. 1 and 4 have fuse links 7c. In the figures, the thin fuse links 7c attached to the lead plates 7 located on the sealing plate side of the battery cell 1 function as current fuses and / or temperature fuses that generate heat and melt when a set overload current flows. These fuse links have different melting characteristics from the fuse plate 13, thereby improving the safety of the battery pack 100.

[0041] The lead plates 7 in FIGS. 1 and 4 are made of conductive metal and include multiple fixed terminals connected to the electrodes 1a of the battery cells 1, a base that connects the multiple battery cells 1 via the fixed terminals, and fuse links 7c that connect the fixed terminals to the base. The fixed terminals are fixed pieces that electrically connect and secure the lead plates 7 to the electrodes 1a of the battery cells 1. The fixed terminals are located inside electrode windows on the end plates (top surface 6a) of the battery holder 5 and are connected to the electrodes 1a of the battery cells 1 by welding. The fuse links 7c are connected to the base at their base ends and to the fixed terminals at their tip ends (fixed terminal side). The lead plates 7 are manufactured by cutting and bending a single metal plate using a die. The lead plates 7 in FIG. 3 include eight first lead plates 7A located on the top surface 6a of the battery holder 5 and seven second lead plates 7B located on the bottom surface 6b. The present disclosure does not specify the shape, length, width, thickness, size, number, configuration, connection method, etc. of the lead plates 7.

[0042] (First Bus Bar 10A) The bus bar 10 is a connecting member that electrically connects the battery pack 100. The bus bar 10 connects, for example, the electrode 1a of a battery cell 1 to the electrode terminal of a battery block 2, thereby connecting multiple battery cells 1 together. The bus bar 10 can be manufactured, for example, by cutting and bending a single metal plate using a die. The bus bar 10 in FIG. 1 includes a first bus bar 10A and a second bus bar 15. The first bus bar 10A connects the electrode 1a of a battery cell 1 to the first electrode terminal 2A of the battery block 2. The first bus bar 10A is divided into a first divided bus bar 11 and a second divided bus bar 12, which are connected by a fuse plate 13. The first bus bar 10A in FIGS. 1 and 2 carries the total current of the parallel units 4, so a metal plate with a larger current capacity than the lead plate 7 is used. The busbars 10 can be made of the same metal material as the lead plates 7, but the first busbars 10A can be made thicker and / or wider than the lead plates 7 to reduce electrical resistance. The second busbars 15 connect the electrodes 1a of the battery cells 1 to the second electrode terminals 2B of the battery block 2. The series busbars 17, which will be described later, connect the parallel units 4 in series. The busbars 10 are connecting members used to electrically connect the battery pack 100 and may include connecting members other than the first busbars 10A, second busbars 15, and series busbars 17, and the lead plates 7 may also be included in the busbars 10. The busbars 10 can be made of a conductive metal plate, such as aluminum, nickel, copper, or an alloy containing any of aluminum alloys, nickel alloys, copper alloys, etc.

[0043] The first bus bar 10A in FIG. 1 includes a first segment bus bar 11 connected to the electrode 1a of the battery cell 1, a second segment bus bar 12 connected to the first electrode terminal 2A, and a fuse plate 13 connecting the first segment bus bar 11 and the second segment bus bar 12. The first bus bar 10A is a metal plate, making it ideal for high-current applications while saving space in its placement position, enabling a smaller, more compact battery pack 100. Lead wires offer great flexibility in wiring, but they require wiring space equal to the external width (diameter). The larger the current, the thicker the lead wires become. Furthermore, the lead wires cannot be bent at right angles at corners 5b, causing bulges and further increasing the size of the battery pack 100. Using a metal plate-shaped bus bar 10 instead of lead wires saves space, can be placed along the battery holder 5, and can be bent at right angles at corners 5b, contributing to a more compact battery pack 100. Furthermore, the first bus bar 10A is a thick metal plate that is rigid, and therefore the installation work and process can be simplified compared to flexible lead wires, and is suitable for automated assembly.

[0044] Furthermore, the metal plate-shaped first bus bar 10A has a large surface area and can effectively dissipate heat. The battery block 2 generates heat when charged and discharged with a large current, and ensuring heat dissipation is important to maintain the battery's life and characteristics. The metal plate-shaped first bus bar 10A has a large surface area due to its wide width and / or extended length, which improves and ensures the heat dissipation of the battery pack 100. Increasing the length (L) of the first bus bar 10A improves heat dissipation while maintaining space savings and compactness, enabling a design that is advantageous for the heat dissipation of the bus bar 10 and the battery block 2. Increasing the length (L) of the first bus bar 10A also allows the placement position of the fuse plate 13 to be determined depending on other components and designs, thereby increasing design freedom.

[0045] The first bus bar 10A realizes a fuse function appropriate for the battery block 2, improving the safety of the battery pack 100. The fuse plate 13 is a separate member from the first segment bus bar 11 and the second segment bus bar 12. The shape, thickness, and material of the separate fuse plate 13 can be appropriately determined without being restricted by the first segment bus bar 11 and the second segment bus bar 12, allowing an optimal fuse plate 13 to be selected according to the various required fusing characteristics. The thickness of the fuse plate 13 can be thinner than the first segment bus bar 11 and / or the second segment bus bar 12. The fuse plate 13 is a plate-like member thinner than the first segment bus bar 11 and the second segment bus bar 12, thereby reducing the space required for the battery pack 100, enabling the first bus bar 10A to function as a bus bar for large currents, and exhibiting a highly accurate, predetermined fusing characteristic to reliably fuse and interrupt overload currents, thereby improving the safety of the battery pack 100. Furthermore, the fuse plate 13, which is a separate member, can be easily manufactured to a predetermined shape with high precision by, for example, press punching, thereby reducing costs.

[0046] In the first bus bar 10A, first and second segment bus bars 11 and 12, each of which is a metal plate, are connected and joined to a fuse plate 13. When the fuse plate 13 is joined to the first and second segment bus bars 11 and 12, the first and second segment bus bars 11 and 12 are joined to the fuse plate 13 with their flat surfaces facing each other, which makes it possible to make the current density of the overload current flowing uniform and to achieve stable fusing characteristics of the fusing portion 13c.

[0047] The first busbar 10A prevents degradation of fuse function due to dimensional tolerances. The first busbar 10A is divided into first and second segment busbars 11 and 12, which are arranged at a distance and connected by fuse plates 13. The arrangement of the first and second segment busbars 11 and 12 and their connection to the fuse plates 13 easily and reliably accommodates dimensional tolerances arising from the first busbar 10A and battery holders 5. If the first busbar 10A were an integrated structure, in which the position of the first busbar 10A could not be adjusted, it would be difficult to accommodate dimensional tolerances arising from the first busbar 10A and battery holders 5, and dimensional tolerances could result in degradation of fuse function.

[0048] The first bus bar 10A can improve the safety, lifespan, battery characteristics, and design freedom of the battery pack 100 while saving space on the placement surface. The first bus bar 10A in FIG. 1 can effectively utilize the side surface 6c of the battery holder 5 that faces the side surface of the battery cell 1 while saving space. The first bus bar 10A can be placed on a surface of the battery holder 5 other than the surface facing the electrode 1a of the battery cell 1. In the battery holder 5 in FIGS. 1 and 3, the surfaces facing the electrode 1a of the battery cell 1 are the upper surface 6a and the lower surface 6b, and the first bus bar 10A is placed on a side surface 6c of the battery holder 5 that is different from the upper surface 6a and the lower surface 6b and is perpendicular to the upper surface 6a and the lower surface 6b. The above configuration allows the fuse plate 13 (fusing portion 13c) to be positioned away from the electrode 1a of the battery cell 1, and further allows the fuse plate 13 (fusing portion 13c) to be positioned on a surface different from the surface facing the electrode 1a of the battery cell 1, thereby avoiding or preventing effects on the electrode 1a, such as arcing when the fusing portion 13c melts, and improving the safety of the battery pack 100. Furthermore, the above configuration ensures the position and range for arranging the first bus bar 10A without being restricted by the shape, arrangement, or configuration of the electrode 1a of the battery cell 1. The first bus bar 10A can have a large surface area, improving the heat dissipation of the battery pack 100 and improving the life, battery characteristics, and safety of the battery pack 100. Furthermore, by arranging the first bus bar 10A so that it extends in a plane perpendicular to the electrode 1a surface of the battery cell 1 (first side surface 6d), a wide connection area can be ensured between the bent connection portion 7a of the lead plate 7 that is bent from the lead plate 7 on the top surface 6a of the battery holder 5 to the side surface 6c (first side surface 6d) and the connection portion 11b of the first segment bus bar 11. The above battery pack 100 can achieve connection and insulation between the first bus bar 10A and the lead plate 7 with a simple structure, thereby reducing costs and improving the safety of the battery pack 100.

[0049] The first bus bar 10A can be positioned on a surface other than the surface on which the first electrode terminal 2A of the battery block 2 is positioned. In the battery holder 5 shown in FIG. 1 , the first electrode terminal 2A of the battery block 2 is positioned on an end face (third side face 6f) of the side face 6c, and the first bus bar 10A is positioned on a side face 6c (first side face 6d) of the battery holder 5 that is different from the end face (third side face 6f) of the side face 6c and perpendicular to the end face of the side face 6c. This configuration, similar to positioning the first bus bar 10A on a surface other than the one facing the electrode 1a, allows the fuse plate 13 (fusing portion 13c) to be positioned away from the first electrode terminal 2A and can be positioned on a surface other than the surface on which the first electrode terminal 2A is positioned. This avoids or prevents effects on the first electrode terminal 2A, such as arcs that may occur when the fusing portion 13c melts, and improves the safety of the battery pack 100, improves heat dissipation, and reduces costs. In FIG. 1, the second electrode terminal 2B is disposed on the same plane as the first electrode terminal 2A, and the influence of the fusion portion 13c on the second electrode terminal 2B can be avoided or prevented.

[0050] The first bus bar 10A is preferably arranged on the arrangement surface of the battery holder 5 where a predetermined length and area can be ensured. For example, by arranging the first bus bar 10A on the side surface 6c of the battery holder 5, the wide width and / or extension length of the first bus bar 10A can be ensured, and the features of the first bus bar 10A can be further utilized. The first bus bar 10A shown in FIG. 1 is arranged on the long side surface 6c (first side surface 6d) and extends in the longitudinal direction (X direction), which saves space in the arrangement position and improves heat dissipation while maintaining the compactness of the battery pack 100, and enables fuse function corresponding to the battery block 2.

[0051] The first bus bar 10A can be arranged along one or more surfaces of the battery holder 5. By extending the first bus bar 10A longitudinally on one or more surfaces of the battery holder 5, the length of the first bus bar 10A can be ensured, and both ends of the first bus bar 10A can be arranged on different surfaces and connected to the first electrode terminal 2A. The first bus bar 10A in FIG. 1 is arranged extending in the longitudinal direction (X direction) on a first side surface 6d of the side surface 6c of the battery holder 5 and connected to a first electrode terminal 2A arranged on a third side surface 6f, an end surface of the side surface 6c. The first split bus bar 11 in FIG. 1 is arranged extending in the longitudinal direction (X direction) on the first side surface 6d of the side surface 6c of the battery holder 5. The second segment busbar 12 has a main body portion 12a and a joint portion 12c arranged on the first side surface 6d of the side surface 6c of the battery holder 5. The upper half of the second segment busbar 12 is bent inward (in the Y direction) at a right angle to form a connection portion 12b arranged on the third side surface 6f, spanning the first and third side surfaces 6d and 6f. The bent connection portion 12b can be positioned by abutting its inner edge against the battery holder 5, ensuring proper positioning without misalignment, connecting to the first electrode terminal 2A, and reinforcing the corners 5b of the battery holder 5. The first busbar 10A is not limited to the first busbar 10A shown in FIG. 1 . For example, the first segment busbar 11 can have a main body portion 11a, a joint portion 12c, and a connection portion 12b. For example, the main body portion 12a and the joint portion 12c can be arranged on the first side surface 6d of the battery holder 5, and the connection portion 12b can be arranged on the fourth side surface 6g. This first split bus bar 11 maximizes the length of the main body 11a extending in the longitudinal direction (X direction) of the first side surface 6d of the battery holder 5, and the connection portion 11b can be connected to the lead plate 7 on the fourth side surface 6g or the top surface 6a. The connection portion 11b can be secured to extend in the longitudinal direction of the fourth side surface 6g. The first split bus bar 11 can be easily positioned by abutting the bent connection portion 11b. The corners 5b of the battery holder 5 can also be reinforced.

[0052] The first bus bar 10A can have a stepped portion 14 that provides a step or height difference. For example, the stepped portion 14 can be located near the base of the portion where the fuse plate 13 is joined. Making the stepped portion 14 greater than or equal to the thickness of the fuse plate 13 prevents the case from contacting or rubbing against the edge, joint, or welded portion of the fuse plate 13. This reduces the contact area, protecting and ensuring a reliable joint state of the fuse plate 13. In FIG. 4 , a stepped portion 14 that extends outward from the base where the fuse plate 13 is joined is located at the base where the joint portion 12c is connected to the main body 12a of the second divided bus bar 12 near the corner 5b of the battery holder 5. Note that the stepped portion 14 is not necessarily required for the first bus bar 10A. This is because the fuse plate 13 is a thin plate, and the first bus bar 10A including the fuse plate 13 can be sandwiched between the battery holder 5 and the case.

[0053] The first split busbar 11 has a main body 11a, a connection portion 11b connected to the main body 11a and directly or indirectly connected to the electrode 1a of the battery cell 1, and a joint portion 11c connected to the main body 11a and joined to the first joint portion 13a of the fuse plate 13. The connection portion 11b in FIG. 4 is connected to one end (left side) of the rectangular main body 11a, extends from the one end (left side) to the other end (right side), and is connected to the bent connection portion 7a of the lead plate 7 of the end parallel unit 4 (the parallel unit 4a in the first row), and is then connected to the electrode 1a of the battery cell 1. The joint portion 11c is connected to the other end (right side) of the main body 11a and has the same vertical width as the first joint portion 13a of the fuse plate 13. Increasing the length (L1) of the first split busbar 11 improves the heat dissipation of the first split busbar 11 and ensures a large contact area between the bent connection portion 7a and the connection portion 11b.

[0054] The second split bus bar 12 has a main body portion 12a, a connection portion 12b connected to the main body portion 12a and connected to the first electrode terminal 2A of the battery block 2, and a joint portion 12c connected to the main body portion 12a and joined to the second joint portion 13b of the fuse plate 13. For example, the connection portion 12b in FIG. 4 has a shape in which the upper side of the main body portion 12a is bent inward (in the Y direction) at a right angle, and has a through hole 12d into which a screw is threaded to connect and fix to the first electrode terminal 2A. A screw is threaded into the through hole 12d of the connection portion 12b to fasten the connection portion 12b to the first electrode terminal 2A of the battery block 2. However, the connection and fixation to the first electrode terminal 2A is not limited to screw fastening, and other methods of connection and fixation are possible. Furthermore, since the second split busbar 12 has a bent shape, it is advantageous for the length of the main body 12a to be short, so it is preferable to make the length (L1) of the first split busbar 11 longer than the length of the main body 12a of the second split busbar 12 to ensure the length (L) of the first busbar 10A.

[0055] (Fuse Plate 13) The fuse plate 13 connects the first segment bus bar 11 and the second segment bus bar 12. The fuse plate 13 has a first joint 13a joined to the first segment bus bar 11, a second joint 13b joined to the second segment bus bar 12, and a fusing portion 13c that connects the first joint 13a and the second joint 13b and melts down when an overload current flows. In the battery pack 100 shown in FIG. 1 , the connecting member that connects the electrode 1a of the battery cell 1 to the first electrode terminal 2A of the battery block 2 is a metal plate-shaped first bus bar 10A rather than a lead wire. The first segment bus bar 11 and the second segment bus bar 12, which are formed by dividing the first bus bar 10A, are connected by a fuse plate 13. The fusing portion 13c of the fuse plate 13 melts down when an overload current flows, interrupting the current. This disclosure does not specify the shape, thickness, material, etc. of the fuse plate 13 or the fusing portion 13c. For example, the fuse plate 13 may have an opening or cutout portion with a general shape such as a square, rectangle, or polygon. The first joint portion 13a, second joint portion 13b, and one or more fusing portions 13c of the fuse plate 13 may have an H-shape, a U-shape, an inverted U-shape, a V-shape, an L-shape, or the like. The fuse plate 13 is a plate made of metal such as aluminum, copper, nickel, or an alloy containing any of these, and may be made of the same or a different material from the first segment bus bar 11 or the second segment bus bar 12.

[0056] The first joint portion 13a of the fuse plate 13 is joined to the joint portion 11c of the first split bus bar 11, and the second joint portion 13b is joined to the joint portion 12c of the second split bus bar 12. The joining method is not limited, but the joining and fixing can be performed by, for example, spot welding, laser welding, resistance welding, ultrasonic welding, or the like. The joining and fixing can also be performed by screws, adhesive, or the like. For example, when the fuse plate 13 is fixed by screws, the fuse plate 13 can be made replaceable or removable as needed, and the fuse plate 13 is not limited to weldable materials, which expands the range of materials that can be selected.

[0057] The fuse plate 13 can be easily manufactured with high precision by forming notches and openings using, for example, a punching tool, to form the fusing portion 13c with a predetermined height, width, and length. Furthermore, the fuse plate 13 can be easily manufactured with an integrated structure of the first and second joints 13a, 13b, and fusing portion 13c. The integrated fuse plate 13 can easily make the thickness of the narrow portion 13d, i.e., the fusing portion 13c, the first and second joints 13a, 13b the same. The shape of the fusing portion 13c reliably achieves the desired fusing characteristics, thereby stabilizing the fusing characteristics. The fuse plate 13 can also be manufactured by stacking or connecting the same or different materials, and the thickness of the narrow portion can be different from the thickness of the first and second joints 13a, 13b, for example, thinner or thicker than the first and second joints 13a, 13b. The fuse plate 13 can also have elastic portions, bent portions, etc.

[0058] The fusing portion 13c connects the first joint portion 13a and the second joint portion 13b and is blown by an overload current. The fuse plate 13 in FIG. 4 has a pair of first and second joint portions 13a and 13b at both ends in the width direction (X direction), with the fusing portion 13c located in the center between the first and second joint portions 13a and 13b. The length (L3) of the fuse plate 13 is longer than the distance (d) between the tip of the first segment bus bar 11 (joint portion 11c) and the tip of the second segment bus bar 12 (joint portion 12c). This ensures a sufficient width for joining the first and second joint portions 13a and 13b of the fuse plate 13, allowing the fuse plate 13 to be reliably joined to the first and second segment bus bars 11 and 12, respectively. The fusing portion 13c is disposed between the first segment busbar 11 and the second segment busbar 12 (distance d), ensuring a predetermined cross-sectional area of ​​the fusing portion 13c and ensuring the fusing characteristics of the fusing portion 13c. The fuse plate 13 can be provided with one or more fusing portions 13c, and the multiple fusing portions 13c contribute to uniform current density. The fusing portion 13c can be shaped to extend in the same direction as or in a different direction from the extension direction of the first segment busbar 11 or the second segment busbar 12. For example, the fusing portion 13c in FIG. 4 is shaped to extend in the width direction (X direction) parallel to the extension direction of the first segment busbar 11 and the second segment busbar 12, which also contributes to uniform current density.

[0059] The fusing portion 13c is a narrow portion 13d having a smaller cross-sectional area than the first joint portion 13a and the second joint portion 13b. The fusing portion 13c can have one or more narrow portions 13d. The multiple narrow portions 13d (fusing portion 13c) are arranged spaced apart from each other. Preferably, at least one of the multiple narrow portions 13d has a different height (h), allowing the fusing current, order of fusing, fusing timing, fusing time, and the like to be specified, identified, and adjusted. For example, by making the height (h) of one narrow portion 13d narrower than the other narrow portions 13d, the narrow portion 13d that will fusing first can be identified, the fusing timing can be more precisely specified, and after fusing one narrow portion 13d, the overload current flowing through the other narrow portions 13d can fuse the other narrow portions 13d in a chain reaction, allowing the fusing time to be specified and adjusted. Furthermore, arranging the multiple narrow portions 13d evenly and spaced apart contributes to uniform current density. Furthermore, the multiple narrow portions 13d prevent the fusing portion 13c from being accidentally cut off due to vibration, external impact, or during welding to connect the fuse plate 13 to the first and second segmented bus bars 11 and 12, or during use of the battery pack 100. The fusing portion 13c in FIG. 4 has three narrow portions 13d, each spaced apart at the top, middle, and bottom in the vertical direction (Z direction) from the center of the fuse plate 13 in the width direction (X direction). The central narrow portion 13d has a height (h2) that is narrower than the heights (h1, h3) of the other central narrow portions 13d. In this case, the central narrow portion 13d with a narrower height (h2) than the others is blown first. The number of narrow portions 13d may be more than three. The narrow portions 13d may be straight, curved, flat, curved, or any combination thereof, and may have the same or different heights (h).

[0060] The size, shape, thickness, etc. of the fuse plate 13 and the fusing portions 13c, as well as the combination thereof, are determined by the required fusing characteristics. For example, if the fuse plate 13 is 30 mm long and 50 mm wide and has three fusing portions 13c, the thickness of the fuse plate 13 can be, for example, 0.1 mm to 1 mm. The thickness of the fuse plate 13 can be 5% to 80% of the thickness of the first bus bar 10A. The width (w) of the fusing portions 13c can be 2 mm to 15 mm, the height (h) of each fusing portion 13c can be 2 mm to 8 mm, and the total height (h) of the multiple narrow portions 13d can be 20% to 80% of the height of the fuse plate 13. The difference between the heights (h) of the multiple narrow portions 13d is 10% to 200% of the height (h) of the smallest narrow portion 13d. The predetermined fusing characteristics can be achieved within these ranges.

[0061] The fuse plate 13 can be positioned near the corner 5b of the battery holder 5. In the rectangular battery holder 5 shown in FIG. 1 , the fuse plate 13 is positioned near the corner 5b of the side 6c (first side 6d) of the battery holder 5. This fuse plate 13 ensures the length of the first segment bus bar 11, improving heat dissipation. It also allows the second segment bus bar 12 to be shaped to suit the connection shape of the first electrode terminal 2A, the corner 5b, and assembly requirements. This improves the safety of the battery pack 100, simplifies assembly, reduces costs, and expands design flexibility. The fuse plate 13 can be positioned on a surface other than the surface facing the electrode 1a of the battery cell 1. In the battery holder 5 shown in FIG. 1 , the surfaces facing the electrode 1a of the battery cell 1 are positioned on the top and bottom surfaces 6a and 6b, respectively, and the fuse plate 13 is positioned on a different side 6c (first side 6d) of the battery holder 5 that is perpendicular to the top and bottom surfaces 6a and 6b. This configuration allows the fuse plate 13 (fusing portion 13c) to be located away from the electrode 1a of the battery cell 1 and can be located on a different surface from the surface facing the electrode 1a of the battery cell 1, thereby avoiding or preventing effects on the electrode 1a, such as arcing when the fusing portion melts, and improving the safety of the battery pack 100. It also ensures the placement position and range of the first bus bar 10A, and the wide width and / or extension length of the first bus bar 10A improves heat dissipation. Furthermore, insulation between the fuse plate 13 and the lead plate 7 can be achieved with a simple structure, reducing costs and improving the safety of the battery pack 100.

[0062] The fuse plate 13 can be positioned on a surface other than the surface on which the first and second electrode terminals 2A and 2B of the battery block 2 are located. In the battery holder 5 shown in FIG. 1 , the first and second electrode terminals 2A and 2B of the battery block 2 are located on an end surface (third side surface 6f) of the side surface 6c, and the fuse plate 13 is positioned on a side surface 6c (first side surface 6d) of the battery holder 5 that is different from and perpendicular to the end surface (third side surface 6f) of the side surface 6c. This configuration, similar to positioning the fuse plate 13 on a surface other than the one facing the electrode 1a, allows the fuse plate 13 (fusing portion 13c) to be positioned away from the first and second electrode terminals 2A and 2B and can be positioned on a surface other than the surface on which the first and second electrode terminals 2A and 2B are located. This avoids or prevents the effects of arcing when the fusing portion melts on the first and second electrode terminals 2A and 2B, thereby improving the safety of the battery pack 100, improving heat dissipation, and reducing costs.

[0063] (Second Bus Bar 15) The second bus bar 15 connects the electrodes 1a of the battery cells 1 to the second electrode terminals 2B of the battery block 2. Similar to the first bus bar 10A, the metal plate-shaped second bus bar 15 has a large surface area and can effectively dissipate heat. The second bus bar 15 shown in FIG. 6 is arranged on the long side surface 6c (second side surface 6e) of the battery holder 5 and extends in the longitudinal direction (X direction), thereby improving heat dissipation while maintaining space savings. By arranging the second bus bar 15 shown in FIG. 6 so that it extends in the longitudinal direction (X direction) on the side surface 6c (second side surface 6e), a wide width and / or extension length can be ensured, improving heat dissipation. Furthermore, by arranging the metal plate-shaped first bus bar 10A and second bus bar 15 on the opposing side surfaces 6c (first side surface 6d and second side surface 6e) of the battery holder 5, heat dissipation can be further improved. The first bus bar 10A and the second bus bar 15 carry the total current of the parallel units 4 and generate a large amount of heat, so they improve heat dissipation, thereby achieving a longer life, maintaining performance, and improving safety of the battery pack 100. The second bus bar 15 can be the same length as or different from the first bus bar 10A. Note that the above description of the first bus bar 10A applies to the parts and contents of the second bus bar 15 that are similar to those of the first bus bar 10A.

[0064] The second bus bar 15 has a main body 15a, a first connection portion 15b connected to the main body 15a and connected to the electrode 1a of the battery cell 1, and a second connection portion 15c connected to the main body 15a and connected to the second electrode terminal 2B of the battery block 2. The first connection portion 15b in Figures 6 and 7 is connected to the bent connection portion 7b of the lead plate 7 of the end parallel unit 4 (parallel unit 4b in the 14th row) and is then connected to the electrode 1a of the battery cell 1. By arranging the second bus bar 15 in Figures 6 and 7 to extend to the second side surface 6e, which is perpendicular to the surface of the electrode 1a of the battery cell 1, a wide connection area can be ensured between the bent connection portion 7b of the lead plate 7 bent from the lead plate 7 on the top surface 6a of the battery holder 5 to the second side surface 6e of the side surface 6c, and the first connection portion 15b of the second bus bar 15. 6 and 7, the upper part of the second connection part 15c is bent inward (in the negative Y direction) at a right angle, and a through-hole 15d is provided into which a screw can be threaded to connect and secure the second electrode terminal 2B. The bent second connection part 15c can be positioned by abutting the inner edge against the battery holder 5, ensuring accurate placement in a predetermined position, and can be connected and secured to the second electrode terminal 2B by threading a screw into the through-hole 15d. This also reinforces the corner 5b of the battery holder 5.

[0065] [Embodiment 2] Fig. 8 is a schematic perspective view of a battery pack 200 according to embodiment 2, and Fig. 9 is a circuit diagram of the battery pack 200. In the present disclosure, the arrangement and connection method of the battery cells 1 are not limited to those of embodiment 1; they can be determined depending on the shape, number, electrodes, case, etc. of the battery cells 1; embodiment 2 is merely an example. In the battery block 2 shown in Figs. 8 and 9, a battery holder 5 arranges multiple battery cells 1 in parallel in multiple rows and columns, with the battery cells 1 positioned vertically in the Z direction. In the battery block 2, 15 rows of battery cells 1 are connected in parallel in the Y direction to form one parallel unit 4, and the parallel units 4 are arranged in 14 columns in the X direction. In the battery pack 200, the electrodes 1a of the battery cells 1 can be arranged in the same direction. For example, in the battery block 2, the upper end surface of each battery cell 1 can be the positive electrode 1a and the lower end surface can be the negative electrode 1a. This configuration places both ends of the electrodes 1a of the battery cells 1 on the same plane, and provides a cooling mechanism such as a cooling plate on the non-discharge end surface where no discharge valve opening is located and no ejected material is discharged, thereby improving the cooling performance and efficiency of the multiple battery cells 1 and battery block 2.

[0066] The first bus bar 10A in FIG. 8 is arranged along multiple sides of the battery holder 5, ensuring the length of the first bus bar 10A and improving heat dissipation. The first bus bar 10A in FIG. 8 is arranged along the first side surface 6d, third side surface 6f, and fourth side surface 6g of the battery holder 5. The first bus bar 10A extends along the first side surface 6d in the longitudinal direction (X direction), connects to the first electrode terminal 2A at the third side surface 6f, and connects to the electrode 1a of the battery cell 1 via the lead plate 7 at the fourth side surface 6g. The first bus bar 10A can have one or more bent portions 11d, 12e. The first split bus bar 11 in FIG. 8 has a main body portion 11a, a connecting portion 11b, and a joint portion 11c. The main body portion 11a extends longitudinally (in the X direction) to the first side surface 6d of the battery holder 5 and then extends longitudinally (in the Y direction) to the fourth side surface 6g via the bent portion 11d. The connecting portion 11b is connected to the main body portion 11a and is connected to the lead plate 7 on the fourth side surface 6g or the top surface 6a. The second segment bus bar 12 shown in FIG. 8 has a main body portion 12a, a connecting portion 12b, and a joint portion 12c. The main body portion 11a is disposed on the first side surface 6d and the third side surface 6f via the bent portion 12e. The bent portions 11d and 12e are shaped to match the shape of the battery holder 5 they abut. For example, they abut against the corners 5b of the battery holder 5, facilitating the positioning and placement of the first and second segment bus bars 11 and 12 and reinforcing the corners 5b of the battery holder 5. The second bus bar 15 is connected to the series bus bar 17 on the lower surface 6b or the first side surface 6d of the battery holder 5, and is connected to the second electrode terminal 2B on the third side surface 6f.

[0067] The battery pack 200 in Fig. 8 has a series bus bar 17 that connects multiple battery cells 1 in series. In the battery pack 200 in Fig. 8, the series bus bar 17 is connected to one end of the lead plate 7, connecting the adjacent parallel unit 4 in series. As shown in the circuit diagram in Fig. 9, the series bus bar 17 is connected to both ends of the lead plate 7, connecting the adjacent parallel unit 4 in series. In the battery pack 200 in Fig. 8, the series bus bars 17 arranged on both side surfaces 6c of the first side surface 6d and the second side surface 6e are connected to the first lead plate 7A and the second lead plate 7B, connecting the adjacent parallel units 4 in series via the series bus bar 17. The series bus bar 17 has its upper end connected to a first connection portion provided at one end of the first lead plate 7A and its lower end connected to a second connection portion provided at the other end of the second lead plate 7B, connecting the adjacent parallel units 4 in series.

[0068] The series bus bar 17 can be arranged on the same arrangement surface of the battery holder 5 as the arrangement surface of the first bus bar 10A and / or second bus bar 15. In FIG. 8 , the series bus bar 17 and the first bus bar 10A are arranged on the same side 6c (first side 6d) of the battery holder 5, and the series bus bar 17 is arranged insulated from the first bus bar 10A. An insulating member is interposed between the series bus bar 17 and the first bus bar 10A to ensure insulation between them. The support portion 9 of the insulating member allows each component to be arranged in a predetermined position while insulating necessary components such as the bus bar 10 and lead plate 7. In the battery holder 5 of FIG. 8 , the support portion 9 that arranges each series bus bar 17 in a predetermined position ensures insulation from adjacent series bus bars 17. The support portion 9, which positions the first bus bar 10A at a predetermined position, supports the first bus bar 10A so that the first bus bar 10A is positioned overlapping the series bus bar 17 while ensuring an insulating distance, thereby ensuring insulation between the first bus bar 10A and the series bus bar 17. As shown in FIG. 8 , the support portion 9, which is an insulating member, is interposed between the series bus bar 17 and the first bus bar 10A to ensure insulation between them. This configuration ensures insulation between the series bus bar 17 and the first bus bar 10A by positioning the series bus bar 17 in a twisted position relative to the first bus bar 10A. This allows for space savings in the arrangement of the first bus bar 10A while improving the safety of the battery pack 200. 8 has a support surface 9b that is arranged parallel to the plane of main body portions 11a, 12a of first bus bar 10A, and side edge projections 9c, 9d that are connected to support surface 9b and project from both side edges of support surface 9b toward first bus bar 10A, with support surface 9b and side edge projections 9c, 9d extending in the extension direction (X direction) of first bus bar 10A. By having support surface 9b of support portion 9 and extending between first bus bar 10A and series bus bar 17, and side edge projections 9c, 9d projecting from both side edges of support surface 9b to cover both side edges of first bus bar 10A and making support portion 9 concave or U-shaped, the insulation properties of support portion 9 of the insulating member can be more reliably achieved.

[0069] The present invention can be effectively used in a battery pack that can achieve fuse functions according to the battery block while saving space, and in products equipped with this battery pack.

[0070] DESCRIPTION OF SYMBOLS 100, 200...Battery pack 1...Battery cell 1A...Cylindrical battery 1a...Electrode 2...Battery block 2A...First electrode terminal 2B...Second electrode terminal 4...Parallel unit 4a...1st row of parallel units 4b...14th row of parallel units 5...Battery holder 5A, 5B...Divided holder 5a...Cell holding opening 5b...Corner 6a...Top surface 6b...Bottom surface 6c...Side surface 6d...First side surface 6e...Second side surface 6f...Third side surface 6g...Fourth side surface 7...Lead plate 7A...First lead plate 7B...Second lead plate 7a...Bent connection portion 7b...Bent connection portion 7c...Fuse link 8...Connecting portion 8a...Latching portion 8b...Latched portion 8c, 8d...Threaded portion 8e...Screw 9...Support portion 9a...Protrusion 9b...Support surface DESCRIPTION OF SYMBOLS 9c, 9d...Side edge protrusions 10...Busbar 10A...First busbar 11...First divided busbar 11a...Main body 11b...Connection portion 11c...Joint portion 11d...Bent portion 12...Second divided busbar 12a...Main body 12b...Connection portion 12c...Joint portion 12d...Through hole 12e...Bent portion 13...Fuse plate 13a...First joint portion 13b...Second joint portion 13c...Fusing portion 13d...Narrowed portion 14...Step portion 15...Second busbar 15a...Main body 15b...First connection portion 15c...Second connection portion 15d...Through hole 17...Series busbar

Claims

1. A battery pack having a plurality of battery cells and a first electrode terminal, a battery holder for arranging the plurality of battery cells in a fixed position, and a first bus bar for connecting a plurality of electrodes of the plurality of battery cells and the first electrode terminal of the battery block, wherein the first bus bar includes a first divided bus bar connected to the plurality of electrodes of the plurality of battery cells, a second divided bus bar arranged at a distance from the first divided bus bar and connected to the first electrode terminal, and a fuse plate which is a separate member from the first divided bus bar and the second divided bus bar and connects the first divided bus bar and the second divided bus bar, and the fuse plate has a first joint portion joined to the first divided bus bar, a second joint portion joined to the second divided bus bar, and a fusing portion connecting the first joint portion and the second joint portion and fusing due to an overload current.

2. The battery pack according to claim 1, wherein the fuse plate is in a plate shape thinner than the first divided bus bar and the second divided bus bar, and the fusing portion has a narrow portion with a smaller cross-sectional area than the first joint portion and the second joint portion.

3. The battery pack according to claim 2, wherein the fusing portion has a plurality of the narrow portions, at least some of the plurality of narrow portions have different height-widths (h), and each of the plurality of narrow portions is arranged spaced apart from each other to connect the first divided bus bar and the second divided bus bar.

4. The battery pack according to claim 1, wherein the fusing portion is arranged between the first divided bus bar and the second divided bus bar.

5. The battery pack according to claim 1, wherein the battery holder is a rectangular parallelepiped, the battery block further has a second electrode terminal, and the arrangement surface on which the fuse plate is arranged is other than the surface of the battery holder facing the electrodes of the battery cells and other than the surfaces on which the first electrode terminal and the second electrode terminal of the battery block are arranged.

6. The battery pack according to claim 1, wherein the battery holder is a rectangular parallelepiped, the first bus bar is arranged to extend in the longitudinal direction on the side surface of the battery holder, and at least a part of the first divided bus bar or the second divided bus bar is arranged along the corner of the battery holder.

7. The battery pack according to claim 1, wherein the battery holder arranges the plurality of battery cells in the same or different orientations, and arranges and holds the end faces of the battery cells on the same plane in parallel with each other.

8. The battery pack according to claim 1, further comprising a second electrode terminal of the battery block and a second bus bar connected to the second electrode terminal, wherein the first electrode terminal and the second electrode terminal are arranged on the same plane of the battery holder.

9. The battery pack according to claim 1, further comprising a second electrode terminal of the battery block and a second bus bar connected to the second electrode terminal, wherein the first bus bar and the second bus bar are arranged on opposite surfaces of the battery holder and extend in the longitudinal direction along the opposite surfaces on both sides.

10. The battery pack according to claim 1, wherein the battery holder has a support portion for supporting the first bus bar.

11. The battery pack according to claim 1, further comprising a series bus bar for connecting the plurality of battery cells in series, wherein the series bus bar and the first bus bar are arranged in a twisted position in an insulated state.

12. The battery pack according to claim 1, wherein the fuse plate is arranged near the corner of the battery holder.

13. The battery pack according to any one of claims 1 to 12, wherein the length of the first divided bus bar is different from the length of the second divided bus bar.

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