Battery pack, manufacturing method thereof, and disassembling method

Abstract

The present invention makes it possible to suppress rotation of a secondary battery cell. A battery pack includes: one or more secondary battery cells 1 that each have a cylindrical cell side surface 1b and a pair of cell end surfaces 1a, and are each provided with a cell electrode on at least one of the cell end surfaces 1a; a battery holder 10 having one or more storage cylinders 13 for respectively storing the secondary battery cells 1; a lead plate 3 for connecting the cell electrodes; and double-sided adhesive tape 20 for fixing the secondary battery cells 1 so as not to rotate inside the storage cylinders 13. The double-sided adhesive tape 20 fixes at least one of the cell end surfaces 1a of the secondary battery cell 1 and a holder end surface 10a of the battery holder 10. The double-sided adhesive tape 20 includes a first adhesive layer 22 having a first adhesive force for fixing to the cell end surface 1a, and a second adhesive layer 23 having a second adhesive force for fixing to the holder end surface 10a. The first adhesive force is higher than the second adhesive force.

Description

Battery Pack, Method for Manufacturing the Same, and Disassembly Method

[0001] The present disclosure relates to a battery pack, a method for manufacturing the same, and a disassembly method.

[0002] A battery pack in which a large number of secondary battery cells are connected in series and in parallel is used as a power source for an assist bicycle, a portable electric device such as an electric cleaner or an electric tool, or as a backup power source for a server in a stationary power storage application, a power supply for household, commercial, or industrial use, or further as a drive power source for vehicles such as an electric scooter, an electric cart, or a hybrid vehicle or an electric vehicle. Some of such battery packs adopt a structure in which a plurality of cylindrical secondary battery cells are housed and held in a battery holder. In this case, the secondary battery cells are connected in series or in parallel by fixing the electrodes on the cell end faces with lead plates.

[0003] The cylindrical secondary battery cells stored in the battery holder may rotate due to vibration, impact, etc. When the secondary battery cells rotate, a load is applied to the lead plates welded to the cell end faces, and there is concern about situations such as breakage of the lead plates or breakage of the welded portions with the secondary battery cells. Therefore, a structure for fixing with an adhesive or the like has been adopted so that the secondary battery cells do not rotate in the battery holder (for example, Patent Document 1).

[0004] However, fixing with an adhesive takes time. Also, if it is fixed with an adhesive, the secondary battery cells cannot be taken out of the battery holder. As a result, it is also impossible to extract and replace some of the secondary battery cells from the battery holder. In recent years, from the perspective of social demands such as reducing environmental impact and realizing a sustainable society, products that consider resource recycling, reuse, and reduction are required. In the case of a battery pack as well, there may be a demand for a mechanism that enables reuse of available secondary battery cells and replacement of deteriorated secondary battery cells.

[0005] Japanese Unexamined Patent Application Publication No. 2016 - 100255

[0006] One objective of this disclosure is to provide a battery pack capable of suppressing the rotation of secondary battery cells, a method for manufacturing the same, and a method for disassembling the same. Another objective is to provide a battery pack that allows for the replacement of secondary battery cells, a method for manufacturing the same, and a method for disassembling the same. The description of these objectives and objectives in this disclosure does not preclude the existence of other objectives and objectives. Furthermore, one aspect of this disclosure is not required to solve all of these objectives. In addition, it is possible to extract other objectives from the description, drawings, and claims of this disclosure.

[0007] A battery pack according to one embodiment of the present disclosure comprises one or more secondary battery cells having a cylindrical cell side surface and a pair of cell end surfaces that form the end surface of the cell side surface, with cell electrodes provided on at least one of the cell end surfaces; a battery holder having one or more storage cylinders for housing one or more secondary battery cells; lead plates for connecting the cell electrodes of the secondary battery cells housed in the battery holder; and double-sided adhesive tape for fixing the secondary battery cells housed in the storage cylinders so as not to rotate within the storage cylinders, wherein the double-sided adhesive tape fixes at least one cell end surface of the secondary battery cell and the holder end surface that defines the storage cylinder of the battery holder, and the double-sided adhesive tape comprises a first adhesive layer having a first adhesive force for fixing to the cell end surface and a second adhesive layer having a second adhesive force for fixing to the holder end surface, with the first adhesive force being higher than the second adhesive force.

[0008] A method for manufacturing a battery pack according to another embodiment of the present disclosure comprises one or more secondary battery cells having a cylindrical cell side surface and a pair of cell end surfaces that form the end surface of the cell side surface, with cell electrodes provided on at least one of the cell end surfaces; a battery holder having one or more storage cylinders for housing one or more secondary battery cells; lead plates for connecting the cell electrodes of the secondary battery cells housed in the battery holder; and double-sided adhesive tape for fixing the secondary battery cells housed in the storage cylinders so as not to rotate within the storage cylinders, the method comprising the steps of: attaching the first adhesive layer of the double-sided adhesive tape having a first adhesive layer having a first adhesive force for fixing to the cell end surface and a second adhesive layer having a second adhesive force weaker than the first adhesive force for fixing to the holder end surface; and attaching the second adhesive layer of the battery holder to the holder end surface that defines the storage cylinder.

[0009] A method for disassembling a battery pack according to another embodiment of the present disclosure involves removing a secondary battery cell from a battery pack comprising: one or more secondary battery cells having a cylindrical cell side surface and a pair of cell end surfaces that form the end surface of the cell side surface, with cell electrodes provided on at least one of the cell end surfaces; a battery holder having one or more storage cylinders for housing one or more secondary battery cells; lead plates for connecting the cell electrodes of the secondary battery cells housed in the battery holder; and double-sided adhesive tape for fixing the secondary battery cells housed in the storage cylinders so as not to rotate within the storage cylinders. A disassembly method for removing a battery, comprising the steps of: attaching the second adhesive layer of a double-sided adhesive tape, which has a first adhesive layer having a first adhesive strength for fixing to the cell end face and a second adhesive layer having a second adhesive strength weaker than the first adhesive strength for fixing to the holder end face, to the holder end face defining the storage cylinder of the battery holder; and with the first adhesive layer attached to the cell end face, removing the secondary battery cell stored in the storage cylinder by peeling the adhesion between the second adhesive layer of the double-sided adhesive tape and the holder end face, leaving the double-sided adhesive tape on the secondary battery cell side.

[0010] The battery pack, its manufacturing method, and disassembly method described above have the advantage of suppressing the rotation of the secondary battery cells. Furthermore, they have the advantage of making the secondary battery cells replaceable.

[0011] Figure 1 shows a schematic cross-sectional view and an enlarged cross-sectional view of the main part of a battery pack according to Embodiment 1. Figure 1 shows a schematic exploded perspective view of the battery pack. Figure 1 shows a schematic perspective view of a double-sided adhesive tape according to one embodiment. Figure 2 shows a schematic perspective view of a double-sided adhesive tape according to another embodiment. Figure 3 shows a schematic cross-sectional view of a double-sided adhesive tape according to another embodiment. Figure 4 shows a schematic cross-sectional view of a battery pack according to another embodiment. Figure 5 shows a schematic cross-sectional view of an embodiment of a method for manufacturing a battery pack. Figure 6 shows a schematic plan view of a double-sided adhesive sheet according to one embodiment. Figure 7 shows a schematic plan view of a double-sided adhesive sheet according to another embodiment. Figure 8 shows a schematic plan view of a double-sided adhesive sheet according to another embodiment.

[0012] The form of this disclosure may be limited by the following configurations and features.

[0013] A battery pack according to one embodiment of the present disclosure comprises one or more secondary battery cells having a cylindrical cell side surface and a pair of cell end surfaces that form the end surface of the cell side surface, with cell electrodes provided on at least one of the cell end surfaces; a battery holder having one or more storage cylinders for housing one or more secondary battery cells; lead plates for connecting the cell electrodes of the secondary battery cells housed in the battery holder; and double-sided adhesive tape for fixing the secondary battery cells housed in the storage cylinders so as not to rotate within the storage cylinders, wherein the double-sided adhesive tape fixes at least one cell end surface of the secondary battery cell and the holder end surface that defines the storage cylinder of the battery holder, and the double-sided adhesive tape comprises a first adhesive layer having a first adhesive force for fixing to the cell end surface and a second adhesive layer having a second adhesive force for fixing to the holder end surface, with the first adhesive force being higher than the second adhesive force. In this disclosure, "the first adhesive strength of the first adhesive layer is higher than the second adhesive strength of the second adhesive layer" means that the first adhesive strength of the first adhesive layer is higher overall or partially than the second adhesive strength in a portion of it.

[0014] The above configuration prevents secondary battery cells from rotating within the storage cylinder using double-sided adhesive tape, and allows for the replacement of secondary battery cells by peeling off the double-sided adhesive tape, thereby realizing a battery pack that enables maintenance and recycling. This configuration prevents secondary battery cells from rotating within the storage cylinder using double-sided adhesive tape without requiring them to be glued and fixed to the battery holder with adhesive, and allows for the removal of secondary battery cells from the battery holder as needed by peeling off the double-sided adhesive tape, making it possible to easily replace some of the secondary battery cells. In addition, by making the first adhesive strength of the first adhesive layer fixed to the cell end face higher than the second adhesive strength, the peeled double-sided adhesive tape remains on the secondary battery cell side when the secondary battery cell is removed, eliminating the need to peel the double-sided adhesive tape from the holder end face of the battery holder and improving work efficiency. In other words, by making the second adhesive strength of the second adhesive layer that fixes to the holder end face relatively lower than the first adhesive strength, the double-sided adhesive tape can be peeled off using the second adhesive layer, making it easier to peel off, and also making the manufacturing and disassembly of the battery pack more efficient and cost-effective.

[0015] In addition to the above embodiments, a battery pack according to another embodiment of the present disclosure includes a battery holder comprising a first holder having a first storage cylinder for housing a portion of a secondary battery cell, and a second holder having a second storage cylinder for housing the other portion of the secondary battery cell, wherein the first and second holders constitute a battery holder such that the first and second storage cylinders form a storage cylinder, and double-sided adhesive tape can be fixed to the second holder end face of the second storage cylinder of the second holder. With this configuration, by fixing the double-sided adhesive tape to the cell end face and the second holder end face of the second holder, it is possible to prevent the secondary battery cell from rotating within the storage cylinder, and the secondary battery cell can be replaced by peeling off the double-sided adhesive tape. With this configuration, the manufacturing and disassembly of the battery pack can be made easier and less expensive.

[0016] In addition to the above embodiments, battery packs according to other embodiments of the present disclosure may omit the provision of double-sided adhesive tape on the first holder end face of the first storage cylinder of the first holder. With this configuration, by not providing double-sided adhesive tape on the first holder end face, the first holder can be smoothly removed from the core block when replacing secondary battery cells, and the work of peeling off the double-sided adhesive tape from the cell end face of the secondary battery cell on the first holder side is eliminated, thereby improving work efficiency.

[0017] In addition to the above embodiments, battery packs according to other embodiments of the present disclosure may be configured such that, through a specific process, the second adhesive force of the second adhesive layer is weaker than the first adhesive force of the first adhesive layer, or the first adhesive force of the first adhesive layer is stronger than the second adhesive force of the second adhesive layer. With this configuration, by applying a specific process during assembly, the first adhesive force can be made relatively higher than the second adhesive force, and the second adhesive force relatively lower than the first adhesive force, thereby preventing the rotation of the secondary battery cell and enabling the replacement of the secondary battery cell by peeling off the double-sided adhesive tape, with the peeled double-sided adhesive tape remaining on the secondary battery cell side. Furthermore, while normally increasing the first adhesive force to prevent the rotation of the secondary battery cell, it is possible to subsequently weaken the second adhesive force at necessary timings, such as when replacing the secondary battery cell or removing the secondary battery cell, making it easier to peel off the double-sided adhesive tape from its fixation, and further enabling it to remain on the cell end face side of the secondary battery cell.

[0018] Other embodiments of the present disclosure of a battery pack may, in addition to the above embodiments, include, in addition to the above embodiments, a specific treatment to make the second adhesive force of the second adhesive layer weaker than the first adhesive force of the first adhesive layer, which may include at least one of heat treatment, ultraviolet irradiation, energization, or a change in moisture content. With the above configuration, the second adhesive force can be easily relatively weakened to prevent rotation of the secondary battery cell and improve the workability when removing the secondary battery cell from the battery holder. With the above configuration, a specific treatment can be easily applied to the first adhesive layer and / or the second adhesive layer, and the specific treatment can be applied before and / or after adhesion. The specific treatment can make the adhesive forces of the first and second adhesive forces within a predetermined range and can create a relative difference between the adhesive forces of the first and second adhesive forces.

[0019] In addition to the above embodiment, a battery pack according to another embodiment of the present disclosure may also have double-sided adhesive tape provided on the first holder end face of the first storage cylinder of the first holder. With this configuration, the secondary battery cells are fixed to the battery holder (first holder end face, second holder end face) at both cell end faces, respectively, thereby effectively preventing the rotation of the secondary battery cells within the storage cylinder.

[0020] In addition to the above embodiments, battery packs according to other embodiments of the present disclosure have a double-sided adhesive tape that includes a flexible member, and the thickness of the double-sided adhesive tape can be 0.1 mm or more. With this configuration, by using a flexible, thick double-sided adhesive tape, the manufacturing tolerances of the secondary battery cells can be absorbed by the double-sided adhesive tape, and the secondary battery cells can be stably held in the storage cylinder, which is an advantage.

[0021] In addition to the above embodiments, battery packs according to other embodiments of this disclosure can have a double-sided adhesive tape thickness of 0.4 mm or more. With this configuration, by using a more flexible and thicker double-sided adhesive tape, the manufacturing tolerances of the secondary battery cells can be absorbed by the double-sided adhesive tape, and the secondary battery cells can be stably held within the storage cylinder, which is an advantage.

[0022] In addition to the above embodiments, battery packs according to other embodiments of the present disclosure may include a double-sided adhesive tape comprising a base material, a first adhesive layer provided on a first surface of the base material, and a second adhesive layer provided on a second surface facing the first surface of the base material. With this configuration, the thickness of the double-sided adhesive tape can be adjusted and set by the thickness of the base material, and the advantage is obtained that manufacturing tolerances of the secondary battery cells can be absorbed and the secondary battery cells can be stably held in the storage cylinder.

[0023] In addition to the above embodiments, battery packs according to other embodiments of the present disclosure may have double-sided adhesive tape fixed to the cell end face on the bottom side of the secondary battery cell. With this configuration, the double-sided adhesive tape adheres tightly to the cell end face and the holder end face due to the weight of the secondary battery cell, thereby enabling greater adhesive strength.

[0024] In addition to the above embodiments, battery packs according to other embodiments of the present disclosure may have a double-sided adhesive tape having an opening in the center. This configuration makes it possible to weld the electrodes and lead plates through the opening in the center, other than the outer edge.

[0025] In addition to the above embodiments, battery packs according to other embodiments of this disclosure may have a ring-shaped double-sided adhesive tape. This configuration facilitates, streamlines, and reduces the cost of applying the double-sided adhesive tape and manufacturing the battery pack. A ring shape refers to a shape having a ring width between its outer diameter and inner diameter, and includes an annular ring and a divided ring.

[0026] In addition to the above embodiment, a battery pack according to another embodiment of this disclosure may have a through-hole for the battery holder in the covering portion of the double-sided adhesive tape. With this configuration, the secondary battery cells can be easily replaced.

[0027] A method for manufacturing a battery pack according to another embodiment of the present disclosure comprises one or more secondary battery cells having a cylindrical cell side surface and a pair of cell end surfaces that form the end surface of the cell side surface, with cell electrodes provided on at least one of the cell end surfaces; a battery holder having one or more storage cylinders for housing one or more secondary battery cells; lead plates for connecting the cell electrodes of the secondary battery cells housed in the battery holder; and double-sided adhesive tape for fixing the secondary battery cells housed in the storage cylinders so as not to rotate within the storage cylinders, the method comprising the steps of: attaching the first adhesive layer of the double-sided adhesive tape having a first adhesive force for fixing to the cell end surface and a second adhesive layer having a second adhesive force weaker than the first adhesive force for fixing to the holder end surface; and attaching the second adhesive layer of the battery holder to the holder end surface that defines the storage cylinder.

[0028] The battery pack manufactured using the above method prevents the secondary battery cells from rotating within the housing cylinder by using double-sided adhesive tape, and allows for the replacement of secondary battery cells by peeling off the double-sided adhesive tape, thereby realizing a battery pack that enables maintenance and recycling. Furthermore, when removing the secondary battery cells, the peeled-off double-sided adhesive tape remains on the secondary battery cell side, eliminating the need to peel the tape from the end face of the battery holder and improving work efficiency.

[0029] A method for manufacturing a battery pack according to another embodiment of the present disclosure may, in addition to the above embodiment, include a step of attaching the first adhesive layer of the multiple double-sided adhesive tapes to the end faces of multiple cells, wherein a plurality of double-sided adhesive tapes are detachably connected via connecting portions. In this method, the first adhesive layer of the plurality of double-sided adhesive tapes can be attached to the end faces of multiple cells, and in the step of attaching the second adhesive layer to the end face of the battery holder, the second adhesive layer of the plurality of double-sided adhesive tapes can be attached to the end faces of multiple holders. This eliminates and reduces the effort and time required to individually attach the double-sided adhesive tapes to each cell end face and holder end face, thereby improving the efficiency and cost of the manufacturing process.

[0030] In addition to the above embodiments, a method for manufacturing a battery pack according to another embodiment of the present disclosure allows the connecting portion to be connected by a release liner which is detachably laminated to the base material and / or second adhesive layer side of the double-sided adhesive tape. The above method facilitates, streamlines, and ensures the application of multiple double-sided adhesive tapes and the removal of unnecessary parts other than the double-sided adhesive tapes, thereby achieving increased efficiency and cost reduction in the manufacturing process.

[0031] A method for manufacturing a battery pack according to another embodiment of the present disclosure may, in addition to the above embodiment, include a step of attaching the second adhesive layer of the multiple double-sided adhesive tapes to the end faces of multiple holders, wherein a plurality of double-sided adhesive tapes are detachably connected via connecting portions. In this method, the first adhesive layer of the plurality of double-sided adhesive tapes can be attached to the end faces of multiple cells, and in the step of attaching the second adhesive layer to the end face of the battery holder, the second adhesive layer of the plurality of double-sided adhesive tapes can be attached to the end faces of multiple holders. This eliminates and reduces the effort and time required to individually attach the double-sided adhesive tapes to each cell end face and holder end face, thereby improving the efficiency and cost of the manufacturing process.

[0032] A method for disassembling a battery pack according to another embodiment of the present disclosure comprises one or more secondary battery cells having a cylindrical cell side surface and a pair of cell end surfaces that form the end surface of the cell side surface, with cell electrodes provided on at least one of the cell end surfaces; a battery holder having one or more storage cylinders for housing one or more secondary battery cells; lead plates for connecting the cell electrodes of the secondary battery cells housed in the battery holder; and double-sided adhesive tape for fixing the secondary battery cells housed in the storage cylinders so as not to rotate within the storage cylinders; and from a battery pack comprising these, the secondary battery cells A disassembly method for removing a battery holder may include the step of attaching the second adhesive layer of a double-sided adhesive tape, which has a first adhesive layer having a first adhesive strength for fixing to the cell end face and a second adhesive layer having a second adhesive strength weaker than the first adhesive strength for fixing to the holder end face, to the holder end face defining the storage cylinder of the battery holder, and with the cell end face attached to the first adhesive layer, removing the secondary battery cell from the storage cylinder by peeling off the adhesion between the second adhesive layer of the double-sided adhesive tape and the holder end face, leaving the double-sided adhesive tape on the secondary battery cell side. The above method improves work efficiency by leaving the peeled double-sided adhesive tape on the secondary battery cell side, eliminating the need to peel the double-sided adhesive tape from the holder end face of the battery holder. It also improves the efficiency and reduces the cost of the disassembly process.

[0033] 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 not intended to limit the scope of this disclosure to those components alone, unless otherwise specifically stated, but are merely illustrative examples. Note that the size and positional relationships of the components shown in each drawing may be exaggerated for clarity of explanation. For example, the secondary battery cell in the schematic diagram is for illustrative purposes only, and the thickness of the double-sided adhesive tape and base material are exaggerated for illustrative purposes, and neither is an accurate dimension. Furthermore, in the following description, the same name and reference numeral indicate the same or similar components, and detailed explanations are omitted as appropriate. Furthermore, each element constituting this disclosure may be configured such that multiple elements are made of the same component, with one component serving multiple elements, or conversely, the function of one component may be shared among multiple components.

[0034] This disclosure does not specify the intended use of the battery pack. The battery pack is particularly useful for all power sources where forces may be applied in a direction that causes the internal secondary battery cells to rotate due to vibration, shock, etc. For example, it can be used as a power source for vehicles, both for driving and non-driving purposes, such as electric assist bicycles, electric carts, electric scooters, hybrid cars, electric vehicles, and construction machinery. It can also be used as a power source for portable and mobile electrical equipment such as wireless devices, electric cleaners, power tools, and other devices, or as a stationary power storage device for server backups, or as a power supply for homes, offices, and factories. [Embodiment 1]

[0035] Figures 1 to 5 show a battery pack 100 according to Embodiment 1 of the present disclosure. In these figures, Figure 1 is a schematic cross-sectional view showing the battery pack 100 according to Embodiment 1, Figure 2 is a schematic exploded perspective view of Figure 1, Figure 3 is an example of double-sided adhesive tape 20, and Figures 4 and 5 show other examples of double-sided adhesive tape 20. The battery pack 100 shown in these figures comprises one or more secondary battery cells 1, a battery holder 10 having one or more storage cylinders 13 for housing each of the secondary battery cells 1, lead plates 3 connected to the cell electrodes of the secondary battery cells 1 housed in the storage cylinders 13 of the battery holder 10, and double-sided adhesive tape 20 for fixing the secondary battery cells 1 housed in the storage cylinders 13 so as not to rotate within the storage cylinders 13. One or more secondary battery cells 1 include a plurality of secondary battery cells 1, and one or more storage cylinders 13 include a plurality of storage cylinders 13. Furthermore, the battery pack 100 disclosed herein only needs to house the secondary battery cell 1 in the storage cylinder 13 of the battery holder 10, and is not limited to those that are charged and replaced as a unit of battery pack 100, but also includes battery packs 100 in which the secondary battery cell 1 is built into the casing of the electrical device itself, and is applicable to electrical devices that have a battery pack 100 (secondary battery cell 1) built into them. (Secondary battery cell 1)

[0036] Each secondary battery cell 1 has a cylindrical shape and each has a pair of cell end faces 1a and a cylindrical cell side 1b located between the pair of cell end faces 1a. Each secondary battery cell 1 has a pair of cell electrodes, i.e., a positive electrode and a negative electrode. Multiple secondary battery cells 1 are arranged by a battery holder 10 in a position where the cell end faces 1a of each secondary battery cell 1 are substantially on the same plane. In the example shown in Figures 1 and 2, cylindrical secondary battery cells 1 are arranged in a vertical upright position, offset from each other in a staggered pattern. This allows the battery holder 10 to efficiently arrange and hold the cylindrical secondary battery cells 1. The number, arrangement, and connection of the secondary battery cells 1 are not specified, and any number, arrangement, and connection can be appropriately adopted according to the required specifications. For example, cylindrical secondary battery cells 1 may be arranged in a grid pattern.

[0037] Each secondary battery cell 1 has a pair of cell electrodes, i.e., positive and negative electrodes. The secondary battery cell 1 has cell electrodes on one or both of its cell end faces 1a. Preferably, one cell electrode is provided on one cell end face 1a of the secondary battery cell 1, and the other is provided on the other cell end face 1a. The same electrode can be placed on the same side of the cell end face 1a, and different electrodes can be mixed and placed on the same side of the cell end face 1a. Figure 1 shows a secondary battery cell 1 with a positive electrode on one cell end face 1a and the outer casing as the negative electrode. Such a secondary battery cell 1 can appropriately use known secondary batteries such as lithium-ion secondary batteries, nickel-metal hydride batteries, and nickel-cadmium batteries. Note that this disclosure does not specify the shape and structure of the secondary battery cell 1, cell electrodes, and cell end faces 1a, and all shapes and structures that can be fixed to the battery holder 10 with double-sided adhesive tape 20 can be used.

[0038] The lead plates 3 electrically connect the cell electrodes 1a of multiple secondary battery cells 1 housed in the battery holder 10 in series or parallel. The lead plates 3 are fixed to the cell end faces 1a by welding or other means. At least a portion of the lead plates 3 is also connected to a circuit board. In Figure 1, the lead plates 3 connect the cell electrodes provided on the cell end faces 1a on both sides of the secondary battery cells 1 housed in the battery holder 10. (Battery holder 10, storage cylinder 13)

[0039] The battery pack 100 arranges multiple secondary battery cells 1 in fixed positions using a battery holder 10. The battery holder 10 has multiple storage cylinders 13 that house and hold the multiple secondary battery cells 1. The battery holder 10 can be composed of multiple divided holders, and the multiple holders can be connected, joined, and positioned in predetermined locations to arrange the secondary battery cells 1 in fixed positions. The battery holder 10 illustrated in the schematic cross-sectional views of Figures 1 and 2 has a first holder 11 and a second holder 12 that are divided in the center of the cell side surface 1b of the secondary battery cell 1. The first holder 11 has a first storage cylinder 14 that houses a part of the secondary battery cell 1, and the second holder 12 has a second storage cylinder 15 that houses the other part of the secondary battery cell 1. The first holder 11 and the second holder 12 are joined together so that the first storage cylinder 14 and the second storage cylinder 15 are aligned to form a storage cylinder 13, thereby constituting the battery holder 10. The battery holder 10 in Figures 1 and 2 is divided into two parts, upper and lower, and consists of an upper first holder 11 and a lower second holder 12. With the lower part of the secondary battery cell 1 inserted into the lower second holder 12, the upper part of the secondary battery cell 1 protruding from the open end of the second holder 12 is inserted into and covered by the first holder 11, thereby the battery holder 10 houses and holds the secondary battery cell 1. This disclosure does not specify the configuration, shape, arrangement, division positions, coverage area of ​​the secondary battery cell 1, number of divisions, length of the storage cylinder 13, etc., and any holder structure having a storage cylinder 13 capable of housing and holding the secondary battery cell 1 can be used. For example, the battery holder 10 can consist of a holder body that houses most of the secondary battery cell 1 and a holder lid that covers only the part of the secondary battery cell 1 that is exposed and protruding when housed in the holder body, and it may also be divided into three or more parts. The first holder 11 and the second holder 12 can be connected to form a holder, and unconnected portions, openings, notches, etc., can be provided.

[0040] The battery holder 10 has a storage cylinder 13 for housing the secondary battery cells 1. In Figure 2, the battery holder 10 (first holder 11 and second holder 12) has multiple storage cylinders 13 arranged adjacent to each other, with adjacent storage cylinders 13 arranged in a staggered pattern. The battery holder 10 holds multiple secondary battery cells 1 in a position where the end faces 1a of each cell are substantially on the same plane, and adjacent secondary battery cells 1 are arranged in a staggered pattern. This arrangement allows for efficient arrangement and holding of cylindrical secondary battery cells 1, but they may be arranged in a pattern other than staggered, for example, in a grid pattern. The inside of the storage cylinder 13 is slightly larger than the outer shape of the secondary battery cell 1, and is formed in a cylindrical shape that allows the cylindrical outer casing of the secondary battery cell 1 to be inserted, so that the cylindrical secondary battery cell 1 can be housed inside. The battery holder 10 combines the first storage cylinder 14 of the first holder 11 and the second storage cylinder 15 of the second holder 12 to accommodate one secondary battery cell 1. The lengths of the first storage cylinder 14 and the second storage section are approximately half the length of the secondary battery cell 1 (including being approximately the same length), but they can be of different lengths. In Figures 1 and 2, the multiple storage cylinders 13 are arranged horizontally with multiple secondary battery cells 1 in a vertical position. This allows the battery holder 10 to stack and hold multiple secondary battery cells 1 in a vertical, parallel position. The number of stacked storage cylinders 13 and their layout are not limited to this configuration. Furthermore, the vertical and horizontal positions described above are merely for convenience in explaining the state shown in the drawings, and it goes without saying that a different explanation would be required if, for example, the battery were placed in a position rotated 90°.

[0041] Each storage cylinder 13 has an open end that is on the same plane. The first holder 11 and the second holder 12, which provide multiple storage cylinders 13, are each molded as a single unit. Such a battery holder 10 is made of a thermoplastic resin, such as polycarbonate, polypropylene, polybutylene terephthalate, modified polyphenylene ether, ABS, PPS, etc.

[0042] The battery holder 10 may be provided with one or more holes 27 for inserting a protruding rod. The protruding rod is inserted into the hole 27 to push out the secondary battery cell 1, to which the double-sided adhesive tape 20 is attached, in a direction that separates and peels it from the battery holder 10, thereby peeling off the double-sided adhesive tape 20. In Figure 2, the battery holder 10 has a through-hole for the protruding rod 27 on the holder end face 10a on the side to which the double-sided adhesive tape 20 is attached. By pushing out the double-sided adhesive tape 20 and the secondary battery cell 1 from the hole 27 with the protruding rod, the second adhesive layer 23 is peeled off, and the secondary battery cell 1 can be removed from the storage cylinder 13 while leaving the double-sided adhesive tape 20 on the secondary battery cell 1 side. (Double-sided adhesive tape 20)

[0043] The double-sided adhesive tape 20 has adhesive layers on both sides and is interposed between the secondary battery cell 1 and the battery holder 10 to fix the secondary battery cell 1 to the battery holder 10. The double-sided adhesive tape 20 also fixes the secondary battery cell 1 housed in the storage cylinder 13 so that it does not rotate within the storage cylinder 13. The double-sided adhesive tape 20 is interposed between at least one cell end face 1a of the secondary battery cell 1 and the holder end face 10a, adhering to each and fixing the secondary battery cell 1 to the battery holder 10. The double-sided adhesive tape 20 in Figure 1 has a base material 21, a first adhesive layer 22 having a first adhesive strength for fixing to the cell end face 1a provided on the first surface 21a of the base material 21, and a second adhesive layer 23 having a second adhesive strength for fixing to the holder end face 10a provided on the second surface 21b of the base material 21 facing the first surface 21a. Furthermore, the double-sided adhesive tape 20 can also be composed of a first adhesive layer 22 and a second adhesive layer 23 without providing a base material 21.

[0044] The double-sided adhesive tape 20 requires no drying time, can be easily applied in a short time, and can suppress cell rotation with the ease of interposing it between the adhesive components. The double-sided adhesive tape 20 can be easily applied to the flat surface of the cell end face 1a and can exhibit a predetermined adhesive strength. It can also be applied according to the unevenness of the cell end face 1a. The adhesive strength of the double-sided adhesive tape 20 can be set and adjusted by the base material 21, each adhesive layer, thickness, material, and adhesive area. This disclosure prevents the rotation of the secondary battery cell 1 inside the storage cylinder 13 with a unique configuration in which the double-sided adhesive tape 20 is placed on the cell end face 1a. The rotation of the cell can be prevented by the surface resistance of the double-sided adhesive tape 20 that is adhered to and sandwiched between the cell end face 1a and the holder end face 10a. Furthermore, the double-sided adhesive tape 20 placed on the cell end face 1a is sized and shaped within the outer diameter of the cell end face 1a, so as not to increase the outer diameter of the cell side surface 1b, and does not make it difficult to insert the secondary battery cell 1 into the storage cylinder 13. Furthermore, the adhesive tape can be easily attached to the cell end face 1a, simplifying and facilitating the assembly and manufacturing process of the battery pack 100. Multiple double-sided adhesive tapes 20 can be easily and quickly attached to multiple cell end faces 1a arranged on the same plane, improving the efficiency, speed, and cost of the manufacturing process. In addition, the predetermined adhesive strength and accuracy of the attachment position can be easily and uniformly maintained. Moreover, the secondary battery cell 1 can be made removable and easy to remove. On the other hand, for example, the double-sided adhesive tape can also be attached to the side of the secondary battery cell, rather than the cell end face, to prevent cell rotation. However, while the adhesive strength can be improved by increasing the thickness of the double-sided adhesive tape, this configuration presents a problem where the outer diameter of the cell side increases with the thickness of the double-sided adhesive tape, making it difficult to insert the secondary battery cell, resulting in a trade-off between ease of insertion and adhesive strength. Furthermore, the process of applying double-sided adhesive tape to the side of the cell is time-consuming and difficult to streamline. Moreover, manufacturing technology and experience can affect the application accuracy and strength, for example, by creating steps or gaps between the ends of the double-sided adhesive tape. In addition, it is difficult to touch the double-sided adhesive tape after it has been applied to the side of the cell, making it difficult to apply force in the direction of removing the secondary battery cell. In particular, secondary battery cells that have been press-fitted into a housing cylinder after the double-sided adhesive tape has been applied to the side of the cell are difficult to remove and disassemble.The same problem can also occur when an elastic body made of resin, such as unevenness, protrusions, and stopper portions, is provided on the cell side surface of the battery holder by pressing against the secondary battery cell to increase the frictional resistance. Different from these, the double-sided adhesive tape 20 does not make it difficult to insert the secondary battery cell 1 into the storage cylinder 13, and can realize easy insertion of the cell while preventing rotation of the cell. Also, the assembly and manufacture of the battery pack 100 can be facilitated.

[0045] The double-sided adhesive tape 20 in FIG. 1 includes a base material 21, a first adhesive layer 22 provided on the first surface 21a of the base material 21, and a second adhesive layer 23 provided on the second surface 21b facing the first surface 21a of the base material 21. The base material 21 is a support body that forms and supports the double-sided adhesive tape 20 with adhesive layers provided on both sides, and can be formed of a flexible member. For example, it can be made of plastics such as acrylic, PET, PE, and PU, foam, non-woven fabric, paper, etc., or can contain any of them. The thickness of the double-sided adhesive tape 20 or the base material 21 can be, for example, 0.1 mm or more, 0.2 mm or more, 0.3 mm or more, 0.4 mm or more, 0.5 mm or more. By using a thick flexible member and having the base material 21, the double-sided adhesive tape 20 can absorb manufacturing tolerances, dimensional errors, and variations in the length of the secondary battery cell 1 and the depth of the battery holder 10 (storage cylinder 13). It can adhere according to not only the flat portion of the cell end face 1a but also the unevenness, and can stably hold and fix the secondary battery cell 1 in the storage cylinder 13, realizing suppression of cell rotation. The thickness of the base material 21 can be thicker than that of the first adhesive layer 22 and / or the second adhesive layer 23, and the thickness of the double-sided adhesive tape 20 can be adjusted by the thickness of the base material 21. By relatively reducing the thicknesses of the first adhesive layer 22 and the second adhesive layer 23, rotation and displacement of the cell can be reduced. The double-sided adhesive tape 20 can be easily attached to the flat portion of the cell end face 1a due to its thickness and flexibility, and can exhibit a predetermined adhesive force. It can also be attached according to the unevenness of the cell end face 1a.

[0046] The first adhesive layer 22 has a first adhesive force for fixing to the cell end face 1a, and the second adhesive layer 23 has a second adhesive force for fixing to the holder end face 10a. The double-sided adhesive tape 20 of the battery pack 100 has a unique configuration in which the first adhesive layer 22 and the second adhesive layer 23 have different adhesive forces, and the first adhesive force of the first adhesive layer 22 is higher than the second adhesive force of the second adhesive layer 23. This configuration prevents the secondary battery cell 1 from rotating inside the storage cylinder 13, makes the secondary battery cell 1 removable from the battery holder 10, and improves work efficiency by ensuring that the peeled double-sided adhesive tape 20 remains on the secondary battery cell 1 side when removing the secondary battery cell 1, thus eliminating the need to peel the double-sided adhesive tape 20 from the holder end face 10a of the battery holder 10. The first adhesive force or the second adhesive force can each have the same adhesive force within a certain range, or they can have partially different adhesive forces. For example, by making the second adhesive force on the outer edge stronger than that on the inner edge, the rotation of the secondary battery cell 1 can be effectively prevented. Alternatively, by making the second adhesive force on the outer edge weaker than that on the inner edge, an incentive for peeling off the second adhesive layer 23 can be provided, making it easier to peel off the second adhesive layer 23 when removing the secondary battery cell 1. The adhesive force of the double-sided adhesive tape 20 can be set and adjusted by the material, thickness, shape, and unevenness of the first adhesive layer 22 and the second adhesive layer 23, and the respective materials and thicknesses can be sandwiched from both sides to achieve a predetermined adhesive strength. Furthermore, the double-sided adhesive tape 20 can have an adhesive layer whose adhesive force can be set and adjusted within a predetermined range by a specific treatment, and the second adhesive force of the second adhesive layer 23 or the first adhesive force of the first adhesive layer 22 can be reduced or strengthened compared to before the specific treatment. The double-sided adhesive tape 20 can have the second adhesive strength of the second adhesive layer 23 made weaker than the first adhesive strength of the first adhesive layer 22 by certain treatments, such as heat treatment, ultraviolet irradiation, electric current application, and changes in moisture content, one or more of these treatments. The certain treatments can be performed before manufacturing, during manufacturing, after manufacturing, or before disassembly, and can be performed on the double-sided adhesive tape 20 (double-sided adhesive sheet 30) alone, or during manufacturing while it is attached to, for example, one of the cell end faces 1a. The certain treatments can be performed on the entire surface or partially on the first adhesive layer 22 or the second adhesive layer 23.

[0047] The first adhesive layer 22 can use an adhesive that can be cured by a curing means. For example, when the double-sided adhesive tape 20 is attached to the secondary battery cell 1, the first adhesive layer 22 can be hardened by a curing means (specific treatment) such as UV irradiation, and the first adhesive layer 22 can be fixed to the cell side (cell end face 1a). By having a non-curable adhesive that does not cure, the second adhesive layer 23 can ensure that the double-sided adhesive tape 20 remains on the cell side when the secondary battery cell 1 is removed.

[0048] The double-sided adhesive tape 20 has a covering portion that covers a certain range of the surface of the cell end face 1a. The double-sided adhesive tape 20 (covering portion) has an outer shape within the outer edge of the cell end face 1a, and while ensuring an adhesive area that prevents cell rotation, it does not protrude from the cell end face 1a and does not hinder the insertion of the secondary battery cell 1 into the storage cylinder 13. Further, the double-sided adhesive tape 20 can have a non-covered portion that does not cover the surface of the cell end face 1a. The double-sided adhesive tape 20A in FIGS. 2 and 3 has an opening 24 that opens at the central portion other than the outer peripheral edge portion as the non-covered portion. The lead plate 3 can be fixed to the cell end face 1a, such as by welding, through the opening 24. Also, the secondary battery cell 1 can be pushed out through the opening 24.

[0049] The double-sided adhesive tapes 20A, 20B, and 20C in Figures 2 to 5 have a ring shape 25, either entirely or partially. The ring shape 25 has a ring width (w) between its outer peripheral edge (outer diameter) and inner peripheral edge (inner diameter), and includes an annular ring 25A (Figure 3) and a segmented ring 25B (Figure 4) in which the annular shape is divided or separated. The ring shape 25 has an adhesive area that can be peeled off while suppressing cell rotation. The ring shape 25 can have its outer peripheral edge shaped to follow the outer edge of the cell end face 1a, allowing it to cover and adhere without gaps right up to the outer edge. The ring shape 25 has a particularly strong effect in suppressing cell rotation on the outer peripheral edge side of the cell end face 1a, and has a ring width (w) from the outer peripheral edge side toward the center of the cell end face 1a, and the double-sided adhesive tape 20 of the ring width (w) extends in an annular shape, that is, it extends in any direction of rotation, so that it adheres to the secondary battery cell 1 that is trying to rotate, creating a large surface resistance and effectively preventing and suppressing cell rotation, and effectively preventing displacement of the secondary battery cell 1. In the ring shape 25 of Figures 3 and 4, the outer peripheral edge and the inner peripheral edge are arranged substantially parallel to each other and the ring width (w) is a constant width, but the outer peripheral edge and the inner peripheral edge can be arranged non-parallel and have different ring widths (w), and one or more recesses, protrusions 29, unevenness, or wave shapes can be provided on the outer peripheral edge or the inner peripheral edge. The ring shape 25 illustrated in Figure 5 has a pair of protrusions 29 that project inward from opposing positions on the inner peripheral edge. The protrusion 29 can increase the adhesive area and can also be bent and hooked onto the battery holder 10, allowing the double-sided adhesive tape 20 to remain on the battery holder 10 side. By reducing the distance (t) between the outer edge of the double-sided adhesive tape 20 and the outer edge of the cell end face 1a, the anti-rotation effect of the cell can be improved. By drastically reducing the distance (t), the pressed double-sided adhesive tape 20 adheres not only to the holder end face 10a but also to the side of the holder, further improving the anti-rotation effect of the cell.

[0050] In Figure 4, the pair of dividing rings 25B are positioned with their ends separated from each other, and the separated portion 26 serves as a connecting portion 32 that connects the unnecessary parts 31 other than the double-sided adhesive tape 20, as described later, thereby facilitating the application of the double-sided adhesive tape 20 and the removal of the unnecessary parts 31. In Figures 4 and 9, the separated portion 26 has its upper and lower sides parallel, and is a roughly rectangular shape with a constant length (w) between the upper and lower sides and a constant width (s) between the upper and lower sides. In Figure 4, the pair of separated portions 26 (connecting portions 32) on both sides of the opening 24 divide the ring evenly into two, and are positioned so that the pair of separated portions 26 become an annular ring 25A when the double-sided adhesive tape 20 is connected to them. Both of the pair of separated portions 26 (connecting portions 32) extend in a straight line, and the pair of separated portions 26 (connecting portions 32) are positioned parallel to each other and on the same straight line. Furthermore, the connecting portions 32 are arranged symmetrically (point symmetry, line symmetry) with respect to the ring shape 25, point symmetrically with respect to the center point of the ring shape 25, and line symmetrically with respect to the perpendicular bisector of the line connecting the pair of connecting portions 32 that passes through the center point.In the double-sided adhesive sheet 30 described later, by arranging the double-sided adhesive tapes 20 of the ring shape 25 adjacent to each other, multiple double-sided adhesive tapes 20 can be attached to multiple adhesive surfaces (for example, cell end faces 1a) simultaneously.The pair of connecting portions 32, and further adjacent pairs of connecting portions 32, are continuous, connected and extended, making it easy and smooth to peel off the unnecessary portion 31 from the double-sided adhesive sheet 30.

[0051] The double-sided adhesive tape 20 is provided on one or both cell end faces 1a of the secondary battery cell 1, and adheres the cell end face 1a to the holder end face 10a to fix the secondary battery cell 1 to the battery holder 10 and prevent the cell from rotating. In Figures 1 and 2, the secondary battery cell 1 is in a vertical position and has a first cell end face 1a1 at the upper end and a second cell end face 1a2 at the lower end. The double-sided adhesive tape 20 can adhere to and fix the second cell end face 1a2 at the lower end of the secondary battery cell 1, or the first cell end face 1a1 at the upper end. In Figure 1, it is provided only on the second cell end face 1a2 (second holder 12 end face 12a) on the bottom side of the secondary battery cell 1, and not on the first cell end face 1a1 (first holder 11 end face 11a) on the top side. The double-sided adhesive tape 20 provided on the bottom side of the secondary battery cell 1 is supported by the weight of the secondary battery cell 1 and is sandwiched between the end face 1a2 of the second cell and the end face 12a of the second holder 12, allowing them to be tightly attached and fixed together. [Embodiment 2]

[0052] The battery pack 200 illustrated in Figure 6 has double-sided adhesive tape 20 placed on both cell end faces 1a of the secondary battery cell 1. The double-sided adhesive tape 20 is provided on the upper end of the secondary battery cell 1, the first cell end face 1a1 (end face 11a of the first holder 11), and on the lower end of the secondary battery cell 1, the second cell end face 1a2 (end face 12a of the second holder 12). The cell end faces 1a are held in place by the battery holder 10 at both ends of the secondary battery cell 1, and the double-sided adhesive tape 20 fixes the first cell end faces 1a1 and the second cell end faces 1a2 at both ends of the secondary battery cell 1 to the first holder 11 and the second holder 12, thereby achieving more secure cell fixing and preventing cell rotation. The double-sided adhesive tape 20 provided on the first cell end face 1a1 side and the second cell end face 1a2 side can have the same or different adhesive strengths. For example, by making the adhesive force on either the end face 11a side of the first holder 11 or the end face 12a side of the second holder 12 weaker than the other, the removal and replacement of the secondary battery cell 1 can be made easier when replacing the secondary battery cell 1. [Manufacturing method of battery pack 100]

[0053] The manufacturing method for the battery pack 100 includes the steps of attaching the first adhesive layer 22 of the double-sided adhesive tape 20 to the cell end face 1a of the secondary battery cell 1, and attaching the second adhesive layer 23 of the double-sided adhesive tape 20 to the holder end face 10a of the battery holder 10. The double-sided adhesive tape 20 can be attached to either the secondary battery cell 1 or the battery holder 10 first and the other later, or both at the same time. In the manufacturing method for the battery pack 100, the first adhesive layer 22 of the double-sided adhesive tape 20 can be attached to the cell end face 1a first, the secondary battery cell 1 with the double-sided adhesive tape 20 attached can be inserted into the storage cylinder 13 of the battery holder 10, and the second adhesive layer 23 can be attached to the holder end face 10a of the battery holder 10. In this method, it is easy to attach the double-sided adhesive tape 20 to the secondary battery cell 1 before inserting it into the storage tube, and it can be easily and accurately attached to the predetermined position on the cell end face 1a. By inserting the secondary battery cell 1 into the storage tube 13 of the battery holder 10 and pressing it, the double-sided adhesive tape can be tightly adhered to the cell end face 1a and the holder end face 10a. Alternatively, after placing the double-sided adhesive tape 20 inside the storage tube 13, inserting the secondary battery cell 1 into the storage tube 13 of the battery holder 10 and pressing it will tightly adhere the double-sided adhesive tape 20 to the cell end face 1a and the holder end face 10a, allowing both sides to be adhesively fixed. Note that the first adhesive layer 22 and the second adhesive layer 23 of the double-sided adhesive tape 20 can also be attached in the same process.

[0054] The manufacturing method for the battery pack 100 allows for the attachment of double-sided adhesive tape 20 to the secondary battery cell 1 and / or battery holder 10 using a jig 40 that positions and holds the secondary battery cell 1 in a predetermined position and orientation. The jig 40 allows for the attachment of multiple double-sided adhesive tapes 20 at once, simplifies the attachment and removal processes of the double-sided adhesive tape 20, reduces the effort, time, and cost required for the attachment process, and further improves the accuracy of the attachment position. The jig 40 has a structure that positions and holds the secondary battery cell 1 in a predetermined position and orientation according to the position of the storage cylinder 13 into which each cell is inserted. The jig 40 illustrated in Figures 7B and 7C has a cylindrical jig storage section 41. The position of the jig storage section 41 is set and positioned according to the positional relationship of the storage cylinder 13 of the battery holder 10. By attaching the double-sided adhesive tape 20 (first adhesive layer 22) to the cell end faces 1a of each of the multiple secondary battery cells 1 inserted into the jig storage section 41, the secondary battery cells 1 with the double-sided adhesive tape 20 attached are inserted into and pressed into each storage cylinder 13 of the battery holder 10, and the second adhesive layer 23 is attached to the holder end face 10a. After that, the jig 40 is removed and the exposed portion of the secondary battery cells is stored in the first holder 11 or the like. Alternatively, the second adhesive layer 23 of the double-sided adhesive tape 20 can be attached to the holder end face 10a of the battery holder 10 first, and the secondary battery cells 1 set in the jig 40 can be inserted into the storage cylinder 13 with the double-sided adhesive tape 20 attached, and the cell end faces 1a can be attached to the first adhesive layer 22.

[0055] The manufacturing method for the battery pack 100 uses a double-sided adhesive sheet 30 having multiple double-sided adhesive tapes 20, allowing multiple double-sided adhesive tapes 20 to be attached together, and any connected unnecessary portions 31 to be peeled off. Compared to the case where each double-sided adhesive tape 20 is attached to its respective attachment position (cell end face 1a or holder end face 10a), the double-sided adhesive sheet 30 makes it easier to attach the double-sided adhesive tapes 20, reduces the effort, time, and cost required for attachment, and further improves the accuracy of the attachment position. This is because the double-sided adhesive sheet 30 has multiple double-sided adhesive tapes 20 spaced apart and arranged in predetermined positions according to their respective attachment positions, allowing multiple double-sided adhesive tapes 20 to be attached together to the attachment positions on the cell end face 1a or holder end face 10a which are positioned in predetermined positions and orientations, and also allows any connected unnecessary portions 31 to be peeled off from the double-sided adhesive tapes 20 after attachment. The double-sided adhesive sheet 30 has a release liner 33 that is peelably laminated on the adhesive layers on both sides of the double-sided adhesive tape 20, and the release liner 33 can be peeled off to expose the first adhesive layer 22 and the second adhesive layer 23, making it possible to apply it.

[0056] The double-sided adhesive sheet 30 in Figures 8 to 10 has multiple double-sided adhesive tapes 20 and connecting portions 32 that connect the multiple double-sided adhesive tapes 20 via unnecessary portions 31 other than the double-sided adhesive tapes 20. The double-sided adhesive sheet 30 connects multiple double-sided adhesive tapes 20 into a single sheet shape at the connecting portions 32, making it easy to apply the multiple double-sided adhesive tapes 20 and remove the unnecessary portions 31 in one go, thus shortening the process time and improving efficiency. The connecting portions 32 are the parts that connect the unnecessary portions 31 that are not needed for the application and adhesion of the double-sided adhesive tapes 20. The connecting portions 32 connect one or more of the unnecessary portions 31, including the connecting portions 32c around the multiple double-sided adhesive tapes 20, the connecting portions 32b inside the opening 24 of the ring shape 25, the connecting portions 32a of the separating portions 26 if there is a dividing ring 25B, and other connecting portions 32d. The connecting portion 32 can connect the unwanted portion 31 using, for example, one or more of the release liner 33, base material 21, first adhesive layer 22, and second adhesive layer 23. For example, a double-sided adhesive sheet 30 can be composed of multiple double-sided adhesive tapes 20 and a connecting portion 32 of a release liner 33, and the release liner 33 can be easily peeled off from the double-sided adhesive tapes 20. Furthermore, a double-sided adhesive sheet 30 using a thick base material 21 as the connecting portion 32 allows the unwanted portion 31 to be easily and smoothly peeled off from the double-sided adhesive tapes 20 without tearing, while the unwanted portion 31 remains connected. The double-sided adhesive sheet 30 in Figure 10 has multiple pairs of dividing rings 25B arranged alternately in a staggered pattern. These are arranged in three vertical rows, with 3, 4, and 3 rings from left to right, for a total of 10 pairs of dividing rings 25B (20 dividing rings 20B). The ends of each pair of dividing rings 25B are spaced apart, and the spaced portion 26 between them forms a connecting portion 32a. In the connecting portion 32 in Figures 9 and 10, the ends of each dividing ring 25B are arranged parallel to each other, and a release line 34 is positioned in the center that bisects the width of the connecting portion 32a. This allows the unwanted portion 31 to be smoothly peeled off the double-sided adhesive tape 20 while remaining connected, without tearing along the release line 34. In Figures 9 and 10, the connecting portion 32 connects the connecting portion 32b inside the opening 24 with the connecting portions 32a of the pair of separation portions 26 on both sides, and also connects the connecting portion 32c around the adjacent double-sided adhesive tape 20, allowing the peeling off of the unnecessary portion 31 to proceed from either the left or the right.

[0057] The double-sided adhesive sheet 30 allows for the complete or partial peeling and separation of unwanted portions 31 from the double-sided adhesive tape 20 after application. The double-sided adhesive sheet 30 may have one or more peel lines 34 to facilitate the peeling and separation of unwanted portions 31. The peel lines 34 can be provided, for example, as partial cutting lines, fragmentary or dashed-line cutting lines on the unwanted portions 31, which can trigger the peeling of the unwanted portions 31, making it easier to start peeling and facilitating peeling along the peel lines 34. By providing the peel lines 34 at the connecting portions 32, the unwanted portions 31 connected at the connecting portions 32 can be smoothly peeled off along the peel lines 34 without tearing. The peel lines 34 can be provided, for example, at the connecting portion 32b of the opening 24 and the portion connected by the pair of connecting portions 32a on both sides, or at the portion extending to multiple connecting portions 32a (Figures 9 and 10). If the double-sided adhesive sheet 30 has a shape having a longitudinal direction and a transverse direction, for example, a roughly rectangular shape having the length (L) and transverse (W) of Figure 10, the release line 34 can be provided to extend in the transverse (W) direction of the transverse side. Furthermore, by providing the release line 34 on multiple connecting portions 32, the unwanted portions 31 connected by the connecting portions 32 can be peeled off more smoothly along the release line 34 without tearing. Note that this disclosure does not specify the shape, size of the double-sided adhesive sheet 30, the number, shape, and arrangement of the double-sided adhesive tapes 20, or the arrangement of the connecting portions 32 and the release line 34, and arrangements other than those shown are possible.

[0058] The manufacturing method of the battery pack 100 described above allows the secondary battery cell 1 and the battery holder 10 to be fixed by interposing the double-sided adhesive tape 20 between the cell end face 1a and the holder end face 10a in the following illustrated steps, and the secondary battery cell 1 to be housed in the battery holder 10. (1) Peel off the release liner 33 from the side to be attached (first adhesive layer 22 side) of the double-sided adhesive sheet 30 shown in Figure 7A. (2) Set the secondary battery cell 1 in the jig 40. Insert the secondary battery cell 1 into the jig storage section 41 of the jig 40 to set the secondary battery cell 1 in a predetermined position and orientation. (3) Set the double-sided adhesive sheet 30. Using the jig positioning mechanism (positioning section 42) of the jig 40, position the double-sided adhesive sheet 30 in a predetermined position through the positioning hole 28 of the double-sided adhesive sheet 30 and set it. (4) Attach the double-sided adhesive tape 20 to the secondary battery cell 1. The first adhesive layer 22 and the cell end face 1a are brought into close contact, and the double-sided adhesive tape 20 is attached to the secondary battery cell 1.

[0059] (5) Peel off the unwanted portion 31 from the double-sided adhesive sheet 30. For example, grasp the double-sided adhesive sheet 30, such as the base material 21 or the release liner 33, and peel off the unwanted portion 31 while it is still attached to the double-sided adhesive sheet 30 on the side from which it is to be peeled off. Alternatively, as shown in Figures 7B and 7C, the unwanted portion 31 can be peeled off while the double-sided adhesive tape 20 remains attached to the secondary battery cell 1 by pushing out the unwanted portion 31 with the pressing portion 43. Furthermore, in the case of a double-sided adhesive sheet 30 having a connecting portion 32, the unwanted portion 31 connected by the connecting portion 32 can be easily and smoothly peeled off without leaving the unwanted portion 31 on the double-sided adhesive tape 20 side, and the unwanted portion 31 can be peeled off with or without using the pressing portion 34. Along with the peeling off of the unwanted portion 31, the release liner 33 on the second adhesive layer 23 side is peeled off from the double-sided adhesive sheet 30. (6) Insert the secondary battery cell 1 protruding from the jig 40 into one of the battery holders 10 (second holder 12 in Figure 7D), and attach the double-sided adhesive tape 20 to the battery holder 10. Insert all the secondary battery cells 1, each with the double-sided adhesive tape 20 attached to its end face 1a, into the storage cylinder 13 of each battery holder 10 (second storage cylinder 15 in Figure 7), press and apply pressure to the secondary battery cells 1 to ensure close contact between the second adhesive layer 23 and the holder end face 10a, thereby fixing the double-sided adhesive tape 20 to the battery holder 10. (7) With each secondary battery cell 1 fixed to the storage cylinder 13 of the battery holder 10 (second storage cylinder 15 in Figure 7) by the double-sided adhesive tape 20, remove the jig 40. (8) Insert the secondary battery cell 1 into the other battery holder 10 (first holder 11 in Figure 7), and join the first holder 11 and the second holder 12 to form the battery holder 10 (Figure 7D). Note that double-sided adhesive tape 20 can also be attached to the other battery holder 10 (first holder 11). [Method for disassembling the battery pack 100]

[0060] Furthermore, a method for disassembling the battery pack 100, which involves removing at least some of the multiple secondary battery cells 1 contained in the battery pack 100, will be described. The method for disassembling the battery pack 100 includes the step of removing the secondary battery cells 1, which are adhesively fixed to the battery holder 10 with double-sided adhesive tape 20, from the storage cylinder 13 while leaving the double-sided adhesive tape 20 on the secondary battery cell 1 side. The battery pack 100 described above prevents the secondary battery cells 1 from rotating inside the storage cylinder 13 using the double-sided adhesive tape 20, and allows for the replacement of the secondary battery cells 1 by peeling off the double-sided adhesive tape 20, thereby enabling maintenance and recycling. In addition, the double-sided adhesive tape 20 has a second adhesive strength of the second adhesive layer 23 that is weaker than the first adhesive strength of the first adhesive layer 22, making it easy to peel off at the second adhesive layer 23 and remove the secondary battery cells 1. Furthermore, when the secondary battery cells 1 are removed, the double-sided adhesive tape 20 remains on the secondary battery cell 1 side, saving the effort of peeling and improving work efficiency.

[0061] As shown in Figure 1, when the double-sided adhesive tape 20 is applied to only one cell end face 1a of the secondary battery cell 1 (the cell end face 1a1 on the bottom side of the secondary battery cell 1 in Figure 1), the first holder 11 can be removed by removing all the welded parts of the lead plate 3 on the first holder 11 side to the cell end face 1a, and the specific secondary battery cell 1 protruding from the storage cylinder 13 can be pulled or pushed from the opposite side to peel off and remove the double-sided adhesive tape 20. The double-sided adhesive tape 20 has a second adhesive layer 23 having a second adhesive strength weaker than the first adhesive strength, so the second adhesive layer 23 can be peeled off, and the first adhesive layer 22, which has a relatively stronger adhesive strength, remains on the cell end face 1a side of the secondary battery cell 1. Furthermore, by inserting a protruding rod through the hole 27 for the protruding rod provided in the holder end face 10a of the battery holder 10, the secondary battery cell 1 together with the double-sided adhesive tape 20 can be pushed out in the peeling direction, and the double-sided adhesive tape 20 can be separated and peeled off from the holder end face 10a. The protruding rod allows the double-sided adhesive tape 20 to be separated, leaving it on the cell end face 1a side of the secondary battery cell 1.

[0062] As shown in Figure 6, when double-sided adhesive tape 20 is provided on both ends of the first cell end face 1a1 on the top side and the second cell end face 1a2 on the bottom side of the secondary battery cell 1, one of the battery holders 10 can be removed by removing one of the lead plates 3 and then peeling off the double-sided adhesive tape 20. After that, the secondary battery cell 1 can be removed from the storage cylinder 13 in the same way as when double-sided adhesive tape 20 is provided on one side. First, all the welds on the cell end face 1a of the lead plate 3 on either the first holder 11 side or the second holder 12 side are removed, and then the battery holder 10, which is adhesively fixed with double-sided adhesive tape 20 on the side from which the welds were removed, is removed from the secondary battery cell 1, making it possible to remove a specific secondary battery cell 1 from the storage cylinder 13.

[0063] When removing the secondary battery cell 1, the cell end face 1a can be pushed out through the opening in the center of the battery holder 10 and the opening 24 in the double-sided adhesive tape 20, allowing the double-sided adhesive tape 20 to be peeled off. Furthermore, the battery holder 10 can be provided with one or more holes 27 for inserting a protruding rod. The protruding rod is inserted into the hole 27 and pushed out in a direction that separates and peels the second adhesive layer 23 from the holder end face 10a. In Figure 2, the battery holder 10 has a through-hole for the protruding rod 27 on the holder end face 10a on the side to which the double-sided adhesive tape 20 is attached. With this battery holder 10, a protruding rod can be inserted through the hole 27 to push out the double-sided adhesive tape 20 attached to the cell end face 1a of the secondary battery cell 1, reducing the adhesion between the second adhesive layer 23 of the adhered double-sided adhesive tape 20 and the holder end face 10a, allowing the double-sided adhesive tape 20 to be separated and peeled off from the holder end face 10a. By using the protruding rod to push out the double-sided adhesive tape 20 and the secondary battery cell 1 through the hole 27 for the protruding rod, the second adhesive layer 23 can be peeled off, leaving the double-sided adhesive tape 20 attached to the secondary battery cell 1, and allowing it to be removed from the storage cylinder 13.

[0064] The following describes how to disassemble the battery pack 100 to remove the secondary battery cell 1. (1) First, prepare the battery pack 100 from which to remove the secondary battery cell 1. The battery pack 100 is housed in a storage cylinder 13, and the inserted secondary battery cell 1 is fixed with double-sided adhesive tape 20 so as not to rotate within the storage cylinder 13. The second adhesive layer 23 is attached to the holder end face 10a of the battery holder 10, and the first adhesive layer 22 is attached to the cell end face 1a. (2) Next, remove all the welds on the lead plate 3 to the cell end face 1a. By doing so, one of the battery holders 10 can be made removable. If the secondary battery cell 1 is fixed to the battery holder 10 with double-sided adhesive tape 20, one of the battery holders 10 can be made removable by peeling off the double-sided adhesive tape 20. (3) Remove one of the battery holders 10. (4) Remove the specific secondary battery cell 1. The adhesive fixing of the secondary battery cell 1 with double-sided adhesive tape 20 is peeled off, and the secondary battery cell 1 is removed from the storage cylinder 13. The second adhesive layer 23 of the adhesively fixed double-sided adhesive tape 20 is separated and peeled off from the holder end face 10a, and the battery cell 1 is removed from the storage cylinder 13 with the double-sided adhesive tape 20 remaining on the secondary battery cell 1 side. In a battery holder 10 provided with a hole 27 for a protruding rod on the holder end face 10a, a protruding rod can be inserted through the hole 27, and the secondary battery cell 1 is pushed out together with the double-sided adhesive tape 20 in the direction that separates and peels the double-sided adhesive tape 20 (second adhesive layer 23) from the holder end face 10a, thereby separating and peeling the double-sided adhesive tape 20 from the holder end face 10a. The protrusion of the protruding rod from the hole 27 allows the double-sided adhesive tape 20 to be separated while remaining on the cell end face 1a side of the secondary battery cell 1.

[0065] The above-described battery pack 100, manufacturing method, and disassembly method allow for the removal and replacement of one or more specific secondary battery cells 1 when they deteriorate or malfunction over time, thereby extending the usable period of the battery pack 100 and enabling its recycling.

[0066] This disclosure can be suitably used as a battery pack that can suppress the rotation of secondary battery cells and allows for the replacement of secondary battery cells, as well as a method for manufacturing and disassembling the same.

[0067] 100, 200…Battery pack 1…Secondary battery cell; 1a…Cell end face; 1b…Cell side 1a1…First cell end face 1a2…Second cell end face 3…Lead plate 10…Battery holder; 10a…Holder end face 11…First holder; 11a…First holder end face 12…Second holder; 12a…Second holder end face 13…Storage cylinder 14…First storage cylinder 15…Second storage cylinder 20, 20A, 20B…Double-sided adhesive tape 21…Base material; 21a…First surface; 21b…Second surface 22…First adhesive layer 23…Second adhesive layer 24…Opening 25…Ring shape 25A…Annular ring 25B…Divided ring 26…Separation portion 27…Hole for protruding rod 28…Positioning hole 29…Protrusion 30…Double-sided adhesive sheet 31... Unnecessary part 32, 32a, 32b, 32c, 32d... Connecting part 33... Peeling liner 34... Peeling line 40... Jig 41... Jig storage part 42... Positioning part 43... Pressing part

Claims

1. A battery pack comprising: one or more secondary battery cells having a cylindrical cell side surface and a pair of cell end surfaces that form the end surface of the cell side surface, with cell electrodes provided on at least one of the cell end surfaces; a battery holder having one or more storage cylinders for housing the one or more secondary battery cells; lead plates for connecting the cell electrodes of the secondary battery cells housed in the battery holder; and double-sided adhesive tape for fixing the secondary battery cells housed in the storage cylinders so as not to rotate within the storage cylinders, wherein the double-sided adhesive tape fixes at least one of the cell end surfaces of the secondary battery cells and the holder end surface of the battery holder that defines the storage cylinders, and the double-sided adhesive tape comprises a first adhesive layer having a first adhesive strength for fixing to the cell end surfaces, and a second adhesive layer having a second adhesive strength for fixing to the holder end surfaces, wherein the first adhesive strength is higher than the second adhesive strength.

2. A battery pack according to claim 1, wherein the battery holder includes a first holder having a first storage cylinder for storing a part of the secondary battery cell, and a second holder having a second storage cylinder for storing another part of the secondary battery cell, wherein the first holder and the second holder constitute the battery holder such that the first storage cylinder and the second storage cylinder form the storage cylinder, and the double-sided adhesive tape is fixed to the second holder end face of the second storage cylinder of the second holder.

3. A battery pack according to claim 2, wherein the double-sided adhesive tape is not provided on the first holder end face of the first storage cylinder of the first holder.

4. A battery pack according to claim 1, wherein the double-sided adhesive tape is configured such that, by a specific process, the second adhesive force of the second adhesive layer is weaker than the first adhesive force of the first adhesive layer, or the first adhesive force of the first adhesive layer is stronger than the second adhesive force of the second adhesive layer.

5. A battery pack according to claim 4, wherein the specific treatment comprises at least one of heat treatment, ultraviolet irradiation, electric current application, and a change in moisture content.

6. A battery pack according to claim 2, wherein the double-sided adhesive tape is also provided on the first holder end face of the first storage cylinder of the first holder.

7. A battery pack according to any one of claims 1 to 6, wherein the double-sided adhesive tape has a flexible member and the thickness of the double-sided adhesive tape is 0.1 mm or more.

8. A battery pack according to claim 7, wherein the thickness of the double-sided adhesive tape is 0.4 mm or more.

9. A battery pack according to claim 7, wherein the double-sided adhesive tape comprises a base material, a first adhesive layer provided on a first surface of the base material, and a second adhesive layer provided on a second surface of the base material facing the first surface.

10. A battery pack according to claim 1, wherein the double-sided adhesive tape is fixed to the cell end face on the bottom side of the secondary battery cell.

11. A battery pack according to claim 1, wherein the double-sided adhesive tape has an opening in the center.

12. A battery pack according to claim 1, wherein the double-sided adhesive tape has a ring shape.

13. A battery pack according to claim 1, wherein the battery holder has a through hole in the covering portion of the double-sided adhesive tape.

14. A method for manufacturing a battery pack comprising: one or more secondary battery cells having a cylindrical cell side surface and a pair of cell end surfaces that form the end surface of the cell side surface, with cell electrodes provided on at least one of the cell end surfaces; a battery holder having one or more storage cylinders for housing the one or more secondary battery cells; lead plates connected to the cell electrodes of the secondary battery cells housed in the battery holder; and double-sided adhesive tape for fixing the secondary battery cells housed in the storage cylinders so as not to rotate within the storage cylinders, the method comprising: attaching the first adhesive layer of the double-sided adhesive tape having a first adhesive strength for fixing to the cell end surfaces and a second adhesive layer having a second adhesive strength weaker than the first adhesive strength for fixing to the holder end surface; and attaching the second adhesive layer of the battery holder to the holder end surface that defines the storage cylinder.

15. A method for manufacturing a battery pack according to claim 14, wherein a plurality of the double-sided adhesive tapes are detachably connected via connecting portions of a double-sided adhesive sheet, and the method for manufacturing a battery pack includes the step of attaching the first adhesive layers of the plurality of the double-sided adhesive tapes to the end faces of the plurality of cells.

16. A method for manufacturing a battery pack according to claim 15, wherein the connecting portion is connected by a release liner which is detachably laminated to the base material of the double-sided adhesive sheet and / or the second adhesive layer side.

17. A method for manufacturing a battery pack according to claim 14, wherein a plurality of the double-sided adhesive tapes are detachably connected via connecting portions of a double-sided adhesive sheet, and the method for manufacturing a battery pack includes the step of attaching the second adhesive layers of the plurality of the double-sided adhesive tapes to the end faces of the plurality of the holders.

18. A method for disassembling a battery pack comprising: one or more secondary battery cells having a cylindrical cell side surface and a pair of cell end surfaces that form the end surface of the cell side surface, with cell electrodes provided on at least one of the cell end surfaces; a battery holder having one or more storage cylinders for housing the one or more secondary battery cells; lead plates connected to the cell electrodes of the secondary battery cells housed in the battery holder; and double-sided adhesive tape for fixing the secondary battery cells housed in the storage cylinders so as not to rotate within the storage cylinders; the method for disassembling a battery pack comprising: a first adhesive layer having a first adhesive strength for fixing to the cell end surface; and a second adhesive layer having a second adhesive strength weaker than the first adhesive strength for fixing to the holder end surface. A method for disassembling a battery pack, comprising the steps of: attaching the second adhesive layer of the double-sided adhesive tape to the holder end face defining the storage cylinder of the battery holder, and with the first adhesive layer attached to the cell end face, removing the secondary battery cell stored in the storage cylinder by peeling off the adhesion between the second adhesive layer of the double-sided adhesive tape and the holder end face, leaving the double-sided adhesive tape on the secondary battery cell side.

Images