Battery pack and method for manufacturing same

Abstract

A secondary battery cell can be fixed to a battery holder with high reliability. A battery pack (100) is provided with a battery holder (20) and a plurality of secondary battery cells (1), wherein the battery holder (20) is provided with a plurality of storage cartridges (22) that hold each of the plurality of secondary battery cells (1). The battery holder (20) is divided into at least a first divided holder (21A) and a second divided holder (21B) in the longitudinal direction of the secondary battery cell (1), and a first housing tube (22A) of the first divided holder (21A) and a second housing tube (22B) of the second divided holder (21B) are joined to form a cell housing space for housing the secondary battery cell (1). A recess (24) is formed in at least a portion of the inner surface of at least a portion of the second housing tube (22B), and an adhesive material (50) is sandwiched between the recess (24) of the housing tube (22) and the secondary battery cell (1).

Description

Technical Field

[0001] The present disclosure relates to a battery pack and a method of manufacturing the same. Background Art

[0002] In order to use a rechargeable secondary battery such as a lithium-ion secondary battery to drive an electrical device, a battery pack is used in which a secondary battery cell is held on a battery holder, connected with a lead plate, and housed in an outer casing (e.g., Patent Document 1). In such a battery pack, when the secondary battery cell moves in the battery holder, the connection with the lead plate sometimes becomes disconnected. In particular, when a cylindrical outer can is used for the secondary battery cell, the cylindrical secondary battery cell is inserted into the cylindrical storage cylinder, so it is difficult to restrict the movement of the secondary battery cell in the rotation direction. In addition, depending on the purpose of the electrical device using the battery pack, it is sometimes subjected to vibration or impact, and it is required that the connection with the lead plate does not become disconnected due to the movement of the secondary battery cell.

[0003] In order to fix the secondary battery unit to the battery holder, it is considered to fix it with an adhesive. Figure 7 As shown in the three-dimensional view of the battery pack 700, in the state where the upper and lower end surfaces of the cylindrical secondary battery unit are covered with the upper bracket 721 and the lower bracket 722, as shown in FIG. Figure 8 As shown in the enlarged view of , it is considered that the adhesive is applied in a state where the secondary battery cell 701 is exposed from the opening provided in the upper bracket 721.

[0004] However, in this method, it is difficult to adjust the amount of adhesive applied. In other words, depending on the secondary battery cell 701, sometimes too much or too little adhesive is applied, and each secondary battery cell cannot be stably fixed on the upper bracket 721. In addition, when assembling the battery assembly, since the adhesive is applied to the surface of the upper bracket 721, there is also a problem that the adhesive adheres to undesired parts and is easily contaminated.

[0005] Prior Art Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2013-008655 Summary of the invention

[0007] Problems to be solved by the invention

[0008] One of the objects of the present disclosure is to provide a battery pack capable of fixing a secondary battery cell on a battery holder with high reliability and a method of manufacturing the same.

[0009] Means for solving problems

[0010] A technical solution of the present invention relates to a battery pack, comprising a battery holder and a plurality of secondary battery cells, the battery holder comprising a plurality of storage tubes for respectively holding the plurality of secondary battery cells, the battery holder being divided into at least a first split holder and a second split holder in a length direction of the secondary battery cells, the first storage tube of the first split holder being joined with the second storage tube of the second split holder to form a unit storage space for storing the secondary battery cells, at least a portion of the second storage tube having a recess formed on at least a portion of its inner surface, and an adhesive material being sandwiched between the recess of the second storage tube and the secondary battery cells.

[0011] In addition, another technical scheme of the present invention relates to a method for manufacturing a battery pack, wherein the battery pack comprises: a plurality of secondary battery cells each having a cylindrical outer can; and a battery holder having a plurality of storage tubes capable of respectively holding the plurality of secondary battery cells, the method for manufacturing the battery pack comprising: a process of respectively inserting the plurality of secondary battery cells into a plurality of first storage tubes of a first battery holder that is shorter than the length of the outer can; a process of applying an uncured adhesive material to a gap surrounded by end faces of a plurality of adjacent outer cans while each outer can is partially exposed from the plurality of first storage tubes; a process of respectively inserting each outer can exposed from the plurality of first storage tubes into a plurality of second storage tubes of a second battery holder that is shorter than the length of the outer can, and guiding the uncured adhesive material to a recess formed on at least a portion of an inner surface of each second storage tube; and a process of curing the uncured adhesive material to fix the plurality of secondary battery cells to the battery holder.

[0012] Effects of the Invention

[0013] According to a technical solution of the present invention, a battery pack and a manufacturing method thereof can extrude and supply adhesive material into a recess formed on the inner surface of a second storage tube, thereby achieving the advantage of being able to evenly control the amount of adhesive material in each secondary battery cell and fix it to a battery holder with high reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a perspective view of the battery pack according to the first embodiment.

[0015] Figure 2 yes Figure 1 An exploded perspective view of a battery pack.

[0016] Figure 3 yes Figure 2 An exploded perspective view of a battery module.

[0017] Figure 4 Observed from the back side Figure 3Exploded perspective view of the battery bracket.

[0018] Figure 5 yes Figure 4 Enlarged back view of the first split bracket.

[0019] Figure 6 It means from Figure 2 A three-dimensional view of the battery module after the lead plate is removed and the battery holder is rotated 90°.

[0020] Figure 7 It is a perspective view showing a battery pack according to a comparative example.

[0021] Figure 8 yes Figure 7 An enlarged perspective view of the main parts of the battery pack.

[0022] Fig. 9 It means in Figure 6 A perspective view showing a state in which a secondary battery unit is inserted into a second split bracket during assembly of a battery module.

[0023] Fig.10 It means in Fig. 9 A top view of the location where adhesive material is applied on a battery module.

[0024] Fig.11 It means in Fig.10 A three-dimensional view of a battery module covered with a first split bracket.

[0025] Fig.12 yes Figure 3 An enlarged top view of the main part of the first split bracket. DETAILED DESCRIPTION

[0026] The technical solution of the present invention can be determined by the following structures or features.

[0027] Another technical solution of the present invention relates to a battery pack, based on the above technical solution, wherein the battery holder stacks a plurality of tube continuums formed by linearly connecting a plurality of the storage tubes, and the recess is formed on the inner surface of each storage tube facing the middle tube continuum of the middle tube continuum located in the stacking direction of the multiple stacked tube continuums, and the adjacent tube continuums adjacent to the middle tube continuum. According to the above structure, the adhesive material is not applied on the entire surface of all the secondary battery cells, but is applied around the secondary battery cell located in the middle and the secondary battery cells located around it on the surface adjacent to the middle, so that the secondary battery cells can be efficiently fixed to the battery holder.

[0028] In addition, another technical solution of the present invention relates to a battery pack, based on any of the above technical solutions, wherein the battery holder is stacked with the plurality of storage tubes, and no recess is provided on the inner side of the surface of the second storage tube located around the battery holder in the stacked storage tubes, which is exposed because there is no adjacent second storage tube around. According to the above structure, by not providing a recess on the outer peripheral surface of the battery holder, it is possible to avoid applying the adhesive material around the stack of secondary battery cells, avoid exposing uncured adhesive material during assembly, and avoid the adhesive material adhering to undesirable parts and getting dirty.

[0029] In addition, another technical solution of the present invention relates to a battery pack, based on any of the above technical solutions, wherein the battery holder is formed with an opening window on at least one end surface to expose the gap between the inner surface of the second storage cylinder and the surface of the secondary battery cell. According to the above structure, it is possible to visually confirm from the outside of the battery holder whether the gap between the second storage cylinder exposed by the opening window and the secondary battery cell is filled with adhesive material, and the coating state of the adhesive material can be visually confirmed, so that the bonding state of the secondary battery cell can be grasped, thereby improving reliability.

[0030] In addition, another technical solution of the present invention relates to a battery pack, based on any of the technical solutions above, wherein the inner surface of the first storage tube is a smooth surface.

[0031] In addition, a battery pack according to another aspect of the present invention is characterized in that, in addition to any of the above aspects, the recessed portion is formed in a gently curved shape.

[0032] In addition, a battery pack according to another aspect of the present invention is one of the above aspects, wherein each secondary battery cell has a cylindrical outer shape.

[0033] In addition, another technical solution of the present invention relates to a battery pack, which, based on any of the above technical solutions, further comprises a lead plate for connecting the plurality of secondary battery cells. According to the above structure, by firmly fixing the cylindrical secondary battery cell in the battery holder, the possibility of the secondary battery cell rotating and breaking the welded part with the lead plate, resulting in poor connection, can be reduced.

[0034] In addition, another technical solution of the present invention relates to a method for manufacturing a battery pack, based on any of the above technical solutions, in the step of applying the uncured adhesive material, the adhesive material is not applied to the outer cans located at the outer periphery of the plurality of outer cans partially exposed from the plurality of first storage cylinders. As a result, in all the secondary battery cells, the adhesive is not applied to the entire surface around them, but only to the area surrounded by adjacent secondary battery cells, thereby achieving the advantage of being able to efficiently apply the adhesive material.

[0035] In addition, another technical solution of the present invention relates to a method for manufacturing a battery pack, which, based on any of the above technical solutions, further includes a step of confirming whether the adhesive material is filled into the recess through an opening window provided on the surface of the battery holder coated with the uncured adhesive material to expose the gap between the inner surface of the second storage cylinder and the surface of the secondary battery cell. Thus, it is possible to visually confirm from the outside of the battery holder whether the gap between the second storage cylinder exposed by the opening window and the secondary battery cell is filled with the adhesive material, and the coating state of the adhesive material can be visually confirmed, so that the bonding state of the secondary battery cell can be grasped, thereby improving reliability.

[0036] Hereinafter, the embodiments of the present invention will be described based on the accompanying drawings. However, the embodiments shown below are examples for concretizing the technical ideas of the present invention, and the present invention is not limited to the following embodiments. In addition, the components shown in the claims are not limited to the components of the embodiments in this specification. In particular, the size, material, shape, relative configuration, etc. of the components described in the embodiments are only simple illustrative examples as long as there is no particularly specific description, and the scope of the present invention is not limited thereto. In addition, in order to make the description clearer, the size and positional relationship of the components shown in the drawings are sometimes exaggerated. In addition, in the following description, the same name and symbol represent the same or homogeneous components, and detailed description is appropriately omitted. In addition, the various elements constituting the present invention can be a method in which the same component constitutes multiple elements and one component serves as multiple elements, or conversely, multiple components share the function of one component to achieve the same effect.

[0037] The battery pack of the present invention can be used as a driving power source for power-assisted bicycles, electric carts for home delivery or golf courses, electric scooters and other mobile devices. In addition, it can also be used as a driving power source for vehicles such as construction machinery, hybrid vehicles or electric vehicles. Furthermore, it can also be used as a power source for portable electrical equipment such as electric cleaners, cleaning robots, power tools, and wireless devices. Alternatively, it can also be used as a backup power source for servers or a power supply device for home use, office use, and factory use in fixed power storage applications. Below, as an embodiment of the present invention, a battery pack used as a driving power source for a power-assisted bicycle is used as an example for description.

[0038] [Implementation Method 1]

[0039] The battery pack 100 according to the first embodiment of the present invention is shown in FIG. Figure 1 to Figure 6 In these figures, Figure 1 is a perspective view of a battery pack 100 according to Embodiment 1. Figure 2 yes Figure 1 An exploded perspective view of the battery pack 100, Figure 3yes Figure 2 An exploded perspective view of the battery module 2, Figure 4 Observed from the back side Figure 3 An exploded perspective view of the battery holder 20, Figure 5 yes Figure 4 An enlarged back view of the first split bracket 21A, Figure 6 It means from Figure 2 The battery module 2 is a three-dimensional view of a battery holder 20 rotated 90 degrees after the lead plate is removed. The battery pack 100 shown in these figures includes an outer casing 10, a battery module 2, and a circuit board 3. The battery module 2 includes one or more secondary battery cells 1 and a battery holder 20 that holds the secondary battery cells 1. In addition, each secondary battery cell 1 is connected to the circuit board 3 via a lead plate 30.

[0040] (External housing 10)

[0041] The outer casing 10 accommodates one or more secondary battery cells 1 and a battery holder 20. Figure 1 , Figure 2 As shown in the figures, the outer shell 10 has a box-like appearance. The outer shell 10 is formed into a cylindrical shape with the ends in the longitudinal direction opened. The open ends are closed by covers 11 and 12, respectively. In addition, the outer shell is not limited to this structure, and can be divided into an upper shell and a lower shell, for example. The outer shell 10 can be made of a metal with excellent rigidity and heat dissipation, or a lightweight resin with excellent insulation, such as polycarbonate, PC-ABS alloy, etc. In addition, as Figure 2 As shown, a module housing space 14 for housing the battery module 2 is provided inside the outer casing 10 .

[0042] (Secondary battery cell 1)

[0043] The one or more secondary battery cells 1 may use a secondary battery cell having a cylindrical or rectangular outer can. Figure 3 , Figure 4 In the example, a cylindrical secondary battery cell is used. Each secondary battery cell 1 has a positive electrode and a negative electrode. The positive and negative electrodes are preferably provided on each end surface of the secondary battery cell 1. Such a secondary battery cell 1 can appropriately utilize a known secondary battery such as a lithium ion secondary battery, a nickel-hydrogen battery, or a nickel-cadmium battery.

[0044] (Battery holder 20)

[0045] The plurality of secondary battery cells 1 are housed in the battery holder 20. Such a battery holder 20 can be made of a resin such as polycarbonate having excellent insulation properties. The battery holder 20 has a plurality of housing tubes 22 for housing the secondary battery cells 1 on the end panel 28. Figure 3 to Figure 6In the example shown in the figures, the battery holder 20 is divided into two parts, the first divided holder 21A and the second divided holder 21B, in the horizontal direction. In the example shown in these figures, the cylindrical secondary battery unit 1 in a horizontal position is stored in the first storage tube 22A of the first divided holder 21A and the second storage tube 22B of the second divided holder 21B from both sides. In this way, the first storage tube 22A of the first divided holder 21A and the second storage tube 22B of the second divided holder 21B are connected to form a unit storage space 27 for storing the secondary battery unit 1.

[0046] The first storage tube 22A and the second storage tube 22B are respectively shorter than the length of the outer can of the secondary battery unit 1. It is preferred to set the first storage tube 22A and the second storage tube 22B to about 1 / 2 of the outer can. These first storage tube 22A and the second storage tube 22B are joined to cover the outer can of the secondary battery unit 1. In addition, in addition to setting the first storage tube 22A and the second storage tube 22B to the same length, their lengths can also be different. However, the first storage tube 22A and the second storage tube 22B are designed to be the length of the outer can together.

[0047] (Lead plate 30)

[0048] A lead plate 30 is disposed on the side of the battery holder 20. The lead plate 30 connects the electrodes at the end surfaces of the secondary battery cells 1 to each other, and connects the plurality of secondary battery cells 1 in series or in parallel. Figure 3 , Figure 4 In the example of , 40 secondary battery cells 1 are connected in groups of 4 in parallel and 10 in series. The number and arrangement of the secondary battery cells, the number of series and parallel connections, etc. are not limited to this example, and any number and arrangement may be appropriately adopted.

[0049] The lead plate 30 is made of a metal plate having excellent electrical conductivity, such as nickel or aluminum. Insulating plates 40 are disposed on the end surfaces of the lead plate 30. The insulating plates 40 are made of a material having excellent insulating properties, such as paper or polycarbonate.

[0050] In addition, if Figure 3 As shown in the exploded perspective view of FIG. 1 , a circuit substrate 3 is placed on the upper surface of the battery holder 20. The battery holder 20 holds the secondary battery unit 1 and the circuit substrate 3. The battery module 2 is connected to the circuit substrate 3 via a lead plate 30. A placement surface on which the circuit substrate 3 is placed is formed on the upper surface of the battery holder 20 constituting the battery module 2.

[0051] (Circuit board 3)

[0052] The circuit board 3 is mounted with a charge and discharge circuit for charging and discharging the secondary battery cell 1, a protection circuit for monitoring the voltage and / or temperature of the secondary battery cell 1 and interrupting the current in the event of an abnormality, etc. The circuit board 3 is made of a glass epoxy resin substrate or the like.

[0053] (recess 24)

[0054] In the first split bracket 21A and the second split bracket 21B constituting the battery bracket 20, the first split bracket 21A is as follows: Figure 3 As shown, the inner surface of the first storage tube 22A is set as a smooth surface. Figure 4 , Figure 5 As shown in FIG. 1 , a recess 24 is provided on the inner surface of the second storage tube 22B of the second split bracket 21. Fig.12 As shown, by placing the adhesive material 50 in the recess 24, the secondary battery cell 1 can be fixed to the storage tube 22. By adopting such a structure, the adhesive material 50 can be extruded and supplied to the recess 24 formed on the inner surface of the storage tube 22. In addition, the amount of the adhesive material 50 can be controlled to be uniform in each secondary battery cell 1.

[0055] As described above, the electrodes of the end faces of the secondary battery cell 1 are fixed by welding the lead plate or the like. When the secondary battery cell 1 rotates on the inner surface of the storage tube 22, a twisting force is applied to the lead plate, and the connection part may be damaged. In particular, in a battery pack for a mobile body such as an assist bicycle, the secondary battery cell 1 is in an environment where it is easy to rotate due to vibration or the like. Therefore, in order to limit the relative movement of the secondary battery cell 1 and the battery holder 20, it is considered to fix them with an adhesive.

[0056] As a coating method of the adhesive, Figure 7 As in the battery pack 700 of the comparative example shown in the perspective view of FIG. 1 , in the structure where the cylindrical secondary battery cell 701 is covered by the upper bracket 721 and the lower bracket 722 from above and below, as shown in FIG. Figure 8 As shown in the enlarged view of , it is considered that the adhesive is applied in a state where the secondary battery cell 701 is exposed from the opening provided in the upper bracket 721. That is, the adhesive is applied from the surface of the upper bracket 721 to bond to the secondary battery cell 701.

[0057] However, in this method, since the adhesive is applied to the surface of the upper bracket 721 when assembling the battery pack 700, there is a problem that the uncured adhesive is easily attached to an unintended portion during the operation and causes contamination.

[0058] In addition, although it is desired that the adhesive be evenly applied along the entire length of the secondary battery cell, it is not easy to evenly apply the adhesive on the outer surface of the secondary battery cell and the inner surface of the storage cylinder like this. That is, even if the adhesive is applied to the inner surface of the cylindrical storage cylinder 22 or the outer surface of the secondary battery cell and the secondary battery cell is inserted into the cylinder, the adhesive may not spread evenly. According to the experiments conducted by the inventors of the present application, it was found that the adhesive does not expand as expected, but is partially bonded into blocks. Moreover, it is impossible to confirm from the outside whether the adhesive is applied as intended, and there is no other confirmation method except decomposition or destruction, and the reliability is poor.

[0059] In contrast, in the battery pack 100 according to the first embodiment, as described above, the recess 24 is partially provided on the inner surface of the storage tube 22 of the battery holder 20, and the adhesive material 50 is interposed in the recess 24. Thus, the adhesive material 50 is prevented from being exposed on the surface of the battery holder 20, and the uncured adhesive material 50 is prevented from being attached to unnecessary parts, and the amount of adhesive material 50 applied can be controlled at the desired position where the recess 24 is provided.

[0060] (Battery Pack Manufacturing Method)

[0061] An example of a specific method for manufacturing a battery assembly is described. Fig. 9 As shown in FIG. 1 , the plurality of secondary battery cells 1 are respectively inserted into the plurality of first storage tubes 22A of the first battery holder 20. Next, with the outer cans of the secondary battery cells 1 partially exposed from the plurality of first storage tubes 22A, as shown in FIG. Fig.10 As shown in the cross-hatched circle, an uncured adhesive material 50 is applied in the gap GP surrounded by the end faces of the adjacent multiple outer cans. In this example, the secondary battery cells 1 are stacked alternately in a direction orthogonal to the longitudinal direction of the secondary battery cells 1, with 13 first and second layers and 14 third layers, for a total of 40. Then, the adhesive material 50 is supplied to the areas surrounded by three secondary battery cells of the staggered secondary battery cells by scanning in a dotted manner using a dispenser or the like. The adhesive material 50 supplied to the area surrounded by the three secondary battery cells descends along the longitudinal direction of the secondary battery cells due to its own weight and stops at the end face of the first split bracket 21A. The viscosity of the adhesive material 50 is adjusted to be higher so that it remains in the outer can of the secondary battery cell to a certain extent in an uncured state. Such an adhesive material 50 can be made of a flame retardant material such as silicone that can bond metals and resins.

[0062] Then, in this state, if Fig.11As shown, the outer cans of each secondary battery cell 1 exposed from the plurality of first storage tubes 22A are respectively inserted into the plurality of second storage tubes 22B of the second split bracket 21B. At this time, the uncured adhesive material 50 is guided to the recess 24 formed in a part of the inner surface of each second storage tube 22B. Here, the adhesive material 50 is not directly applied to the recess 24, but on the basis of supplying the adhesive material 50 to the gap GP surrounded by the outer cans of the secondary battery cell 1, the second storage tube 22B covers the secondary battery cell 1, thereby squeezing the adhesive material 50 at the lower end of the second storage tube 22B, and the adhesive material 50 invades each recess 24 opened on the end surface, and is guided as the second split bracket 21B descends. Then, in the state where the first split bracket 21A is blocked by the second split bracket 21B, the uncured adhesive material 50 is cured. The temperature and the placement time are set according to the type of the adhesive material 50 and the curing time. Heating or ultraviolet irradiation can also be performed as needed. For example, when a single-liquid humidity-curing adhesive is used, the curing time is 7 to 15 minutes for surface curing at 23 degrees and 50% RH, and more than 24 hours for complete curing. In this way, the adhesive is cured to fix the secondary battery cell 1 on the battery holder 20. Figure 6 As shown, a battery module 2 is obtained.

[0063] Thus, the uncured adhesive material 50 can be extruded and supplied to the recessed portion 24 formed on the inner surface of the storage tube 22, and the amount of the adhesive material 50 can be uniformly controlled in each secondary battery cell 1, thereby being fixed to the battery holder 20 with high reliability. In addition, the adhesive material 50 is not applied to the outer surface of the battery holder 20, but is applied to the inner surface side of the battery holder 20, between the outer can and the second split holder 21B, so that the uncured adhesive material 50 will not be exposed, and it can be avoided that it adheres to other parts and becomes dirty.

[0064] The recessed portion 24 is preferably formed into a gently curved surface. Thus, the adhesive material 50 can be smoothly introduced into the recessed portion 24, and the remaining portion can be discharged from the recessed portion 24 along the curved surface to the inner surface of the second storage tube 22B.

[0065] The recessed portions 24 may be evenly provided on the inner surface of all the second storage tubes 22B, but are preferably provided only at the locations where the adhesive material 50 is applied. Fig. 9 , Fig.10 As shown in FIG. 1 , it is preferred that the uncured adhesive material 50 is not exposed to the outside as much as possible. Thus, it is easy to avoid the undesired adhesion of the adhesive material 50. Specifically, Fig. 9 The side surface of the assembly of the secondary battery cells 1 shown in FIG. 1 is not coated with the adhesive material 50. In contrast, the second split bracket 21B is as shown in FIG. Figure 5As shown in the top view, the storage tube 22 located around the battery holder 20 in the storage tube 22 of the second storage tube 22B, that is, the outer surface area of ​​the storage tube 22 exposed by the absence of adjacent storage tubes 22 around it and the corresponding inner surface side, are not provided with a recess 24. In other words, in the part of the second storage tube 22B constituting the outer edge of the second split bracket 21B, the recess 24 is not provided and a flat surface is formed. On the other hand, in the second storage tube 22B located on the inner side surrounded by other second storage tubes 22B, a recess 24 is provided on its inner surface. In this way, the number and / or setting position of the recess 24 are different depending on the position of the second storage tube 22B. As a result, the number, i.e., amount, and coating position of the adhesive material 50 that fixes the secondary battery cell 1 to the battery holder 20 are also different depending on the position of the secondary battery cell 1. In this embodiment, it is sufficient as long as the secondary battery cell 1 can be prevented from rotating inside the battery holder 20, so it is sufficient as long as a fixing force that can prevent rotation can be exerted. That is, the secondary battery cells 1 located on the outer peripheral side have weaker fixing force to the battery holder 20 than the secondary battery cells 1 located on the inner side. However, as long as the adhesive force can be exerted to prevent the secondary battery cells 1 from rotating, there is no problem even with such a structure.

[0066] (tube continuum 23)

[0067] In the battery holder 20, a plurality of tube continuous bodies 23 in which a plurality of storage tubes 22 are connected in a straight line are stacked in multiple stages in the short-side direction on the dividing surface between the first divided holder 21A and the second divided holder 21B. Figure 3 to Figure 5 In the examples of the above, the tube continuous body 23 stacked in multiple stages is arranged in a staggered pattern in the upper and lower parts, but it may also be arranged in a checkerboard pattern or a matrix pattern.

[0068] In addition, a recess 24 is formed on the inner surface of each storage tube 22 facing the middle tube continuous body 23A of the middle tube continuous body 23A in the stacking direction and the adjacent tube continuous body 23B adjacent to the middle tube continuous body 23A. Fig.10 In the example of the above, the second section of the three-section continuous tube body 23 becomes the intermediate continuous tube body 23A, and the first and third sections become the adjacent continuous tube bodies 23B. In other words, the recessed portion 24 is formed between the first section continuous tube body 23 and the second section continuous tube body 23, and between the second section continuous tube body 23 and the third section continuous tube body 23.

[0069] (Opening window 26)

[0070] In addition, the battery pack 100 may also be provided with an observation opening window 26 for confirming the coating state after the adhesive material is applied. The opening window 26 is provided on an end panel 28 of one side of the battery holder 20. Through the opening window 26, the gap between the inner surface of the storage cylinder 22 and the surface of the secondary battery cell 1 is exposed, thereby being able to visually confirm from the outside of the battery holder 20 whether the gap between the storage cylinder 22 and the secondary battery cell 1 exposed by the opening window 26 is filled with the adhesive material 50. By being able to visually confirm the coating state of the adhesive material 50, the bonding state of the secondary battery cell 1 can be grasped, thereby improving reliability.

[0071] exist Fig.12 In the example shown, an opening window 26 is formed on the second storage tube 22B of the second split bracket 21B. The opening window 26 is opened in a circular shape at the end surface of the second split bracket 21B, exposing a portion of the unit wall 25 that divides the second storage tube 22B and a portion of the unit storage space 27 of the second storage tube 22B. The gap between the unit storage space 27 and the unit wall 25 becomes the cross section of the recess 24. Here, by providing the opening window 26 in the area surrounded by the three unit storage tubes 22, the three unit storage spaces 27 are arranged at 120° intervals along the circumference. As shown Fig.11 As shown, the lower half of the outer can of the secondary battery unit 1 is inserted into the first split bracket 21A, and the adhesive material 50 is made to flow into the area surrounded by the outer cans while the upper half of the outer can is exposed, and the adhesive material 50 is covered with the second split bracket 21B, thereby the adhesive material 50 squeezed out at the lower end of the second storage tube 22B rises along the recess 24 on the inner surface of the second storage tube 22B. And, when the adhesive material 50 reaches the upper end of the second storage tube 22B, the recess 24 is filled with the adhesive material 50. By opening the opening window 26 on the upper surface of the second split bracket 21B, it can be visually confirmed through the opening window 26 that the adhesive material 50 has reached the upper end of the recess 24. Moreover, if it can be confirmed that the adhesive material 50 reaches the upper end or near the upper end of the recess 24, it can be determined that the adhesive material 50 is continuously applied from the lower end to the upper end of the recess 24, that is, the adhesive material 50 is applied throughout the length direction of the secondary battery cell 1. Therefore, it is possible to determine whether there are any adverse conditions such as insufficient adhesive material, thereby improving the reliability of the battery pack 100.

[0072] In the above example, the battery pack is installed on the electrical equipment to be driven to supply power to the electrical equipment. In addition, when the remaining capacity of the battery pack decreases or the battery pack deteriorates over the years, the battery pack can be replaced and the electrical equipment can continue to be used. However, the present invention is not limited to replaceable battery packs that mainly accommodate secondary battery cells, but can also be applied to a form in which secondary battery cells are accommodated in the housing of the electrical equipment. In the present disclosure, the so-called battery pack only needs to accommodate secondary battery cells in the housing, and the case in which a secondary battery cell for driving is built into the housing of the electrical equipment itself is also referred to as a battery pack. That is, the present invention is not limited to replaceable battery packs, but can also be applied to electrical equipment with built-in secondary battery cells.

[0073] Industrial Availability

[0074] The battery pack and its manufacturing method of the present invention are suitable for use as a power supply device for mobile bodies such as power-assisted bicycles or electric carts. In addition, they can also be appropriately used for power supplies for wireless devices, power cleaners, power tools and other portable electrical equipment.

[0075] Description of Reference Numerals

[0076] 100…Battery pack

[0077] 1…Secondary battery cell

[0078] 2…Battery Module

[0079] 3…Circuit board

[0080] 10…External housing

[0081] 11, 12... cover part

[0082] 14…Module storage space

[0083] 20…Battery holder

[0084] 21A…first split bracket; 21B…second split bracket

[0085] 22…storage tube; 22A…first storage tube; 22B…second storage tube

[0086] 23... tube continuum; 23A... middle tube continuum; 23B... adjacent tube continuum

[0087] 24…concave

[0088] 25…Cell wall

[0089] 26…Opening window

[0090] 27…Unit storage space

[0091] 28…End panel

[0092] 30...Lead plate

[0093] 40…Insulation board

[0094] 50… Adhesive material

[0095] 700…Battery Pack

[0096] 701…Secondary battery cell

[0097] 721…Upper bracket

[0098] 722…Lower bracket

[0099] GP…Gap

Claims

1. A battery pack comprising a battery holder and a plurality of secondary battery cells, The battery holder includes a plurality of storage tubes for respectively holding the plurality of secondary battery cells. The battery holder is divided into at least a first divided holder and a second divided holder in the length direction of the secondary battery unit. The first storage tube of the first split bracket is engaged with the second storage tube of the second split bracket to form a unit storage space for storing the secondary battery unit. At least a portion of the second storage tubes has a recess formed on at least a portion of the inner surface thereof. An adhesive material is interposed between the recessed portion of the second storage tube and the secondary battery cell.

2. The battery pack according to claim 1, The battery holder is composed of a plurality of storage tubes connected in a straight line, and a tube continuous body is stacked in multiple stages. The recessed portion is formed on the inner surface of each storage tube facing the intermediate tube continuous body, of an intermediate tube continuous body located in the middle in the stacking direction among the plurality of stacked tube continuous bodies, and of an adjacent tube continuous body adjacent to the intermediate tube continuous body.

3. The battery pack according to claim 1, The battery holder is stacked with the plurality of storage tubes, No recess is provided on the inner side of the exposed surface of the second storage tubes located around the battery holder among the stacked storage tubes where no adjacent second storage tubes are present.

4. The battery pack according to claim 1, The battery holder has an opening window formed on at least one end surface thereof to expose a gap between an inner surface of the second storage tube and a surface of the secondary battery cell.

5. The battery pack according to claim 1, The inner surface of the first storage tube is a smooth surface.

6. The battery pack according to any one of claims 1 to 5, The concave portion is formed in a gently curved shape.

7. The battery pack according to any one of claims 1 to 5, Each secondary battery cell has a cylindrical outer shape.

8. The battery pack according to claim 7, A lead plate for connecting the plurality of secondary battery cells is further provided.

9. A method for manufacturing a battery pack, the battery pack comprising: A plurality of secondary battery cells each having a cylindrical outer can; and a battery holder including a plurality of storage tubes capable of holding the plurality of secondary battery cells respectively; The manufacturing method of the battery pack comprises: The step of inserting the plurality of secondary battery cells into a plurality of first storage tubes of a first battery holder which is shorter than the outer can; A step of applying an uncured adhesive material to gaps surrounded by end surfaces of adjacent plurality of outer cans while each outer can is partially exposed from the plurality of first storage tubes; A step of inserting the outer cans exposed from the plurality of first storage tubes into the plurality of second storage tubes of the second battery holder which are shorter than the outer cans, and guiding the uncured adhesive material to a recess formed on at least a portion of the inner surface of each second storage tube; and The step of curing the uncured adhesive material to fix the plurality of secondary battery cells to the battery holder.

10. The method for manufacturing a battery pack according to claim 9, In the step of applying the uncured adhesive material, the adhesive material is not applied to the outer cans located at the outer periphery among the plurality of outer cans partially exposed from the plurality of first storage tubes.

11. The method for manufacturing a battery pack according to claim 9 or 10, The method further includes a step of confirming whether the recess is filled with the adhesive material through an opening window provided on the surface of the battery holder coated with the uncured adhesive material to expose a gap between the inner surface of the second storage tube and the surface of the secondary battery cell.

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