Battery pack

Abstract

To provide a battery pack easy to dismantle.SOLUTION: A case 20 of a battery pack 1 or 2 has a lower case 30 and an upper case 40. The lower case 30 has a bottom part 31 and an opening part 33 in the upper side. The upper case 40 blocks the opening part 33 of the lower case 30. The lower case 30 and the upper case 40 are attached together by an adhesive 60. The upper case 40 has a through-hole 45 penetrating the upper case and a connector component 50 closing the penetration hole 45. The connector component 50 can be removed from the outside of the case 20. The adhesive 60 has a nature of becoming less adhesive when being exposed to specific light. The adhesive 60 has an exposure part 61 exposed to the inner space 21 of the case 20.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The disclosed technology relates to a battery pack in which a battery stack including a plurality of battery cells is housed in a case.

Background Art

[0002] A battery pack is generally configured by housing a battery stack composed of a plurality of battery cells inside a case. For example, Patent Document 1 discloses a case for housing a battery stack, which is composed of a box-shaped lower case having an opening and an upper case that closes the opening of the lower case. Also, a state in which the upper case and the lower case are fixed to each other using screw components such as bolts is shown in the figure.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, it is conceivable to fix a plurality of case components constituting the case of the battery pack to each other using an adhesive. However, when the case components are adhered to each other using an adhesive, it may become difficult to separate the adhered case components from each other. And in a battery pack that is difficult to disassemble, for example, there is a possibility that repair and recycling of the battery pack cannot be easily performed.

[0005] The disclosed technology aims to provide a battery pack that is easy to disassemble.

Means for Solving the Problems

[0006] One aspect of the disclosed technology includes a battery stack including a plurality of battery cells and a case that houses the battery stack in an internal space. The case has a first case component having a bottom and an opening on the upper side, and a second case component that closes the opening of the first case component. The first case component and the second case component are adhered by an adhesive. Either the first case component or the second case component has a through hole penetrating the inside and outside and has a lid portion that closes the through hole. The lid portion can be removed from the outside of the case. The adhesive has a property that the adhesive force decreases when either specific light or specific liquid hits it. It is a battery pack having an exposed portion exposed to the internal space of the case.

[0007] In the battery pack according to the above aspect, it is possible to remove the lid portion from the outside of the case and apply either specific light or specific liquid from the location of the through hole blocked by the lid portion to the exposed portion of the adhesive in the internal space of the case. Thereby, the adhesive force of the adhesive can be decreased. After decreasing the adhesive force of the adhesive, the first case component and the second case component can be easily separated. Therefore, the battery pack according to the above aspect can be easily disassembled.

Effect of the Invention

[0008] According to the disclosed technology, a battery pack that is easy to disassemble is provided.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Mode for Carrying Out the Invention

[0010] Hereinafter, embodiments embodying the disclosed technology will be described in detail with reference to the accompanying drawings.

[0011] [First Embodiment] FIG. 1 is a cross-sectional view of a battery pack 1 according to the first embodiment. The battery pack 1 includes a battery stack 10 and a case 20.

[0012] The battery stack 10 is configured to include a plurality of battery cells 11. FIG. 1 shows an example in which flat battery cells 11 having a rectangular outer shape are used. The battery cell 11 has a positive electrode terminal 12 and a negative electrode terminal 13. In the battery stack 10 of this embodiment, the plurality of battery cells 11 are arranged so as to be stacked in the depth direction of the paper surface of FIG. 1. A spacer 15 is provided between adjacent battery cells 11 in the battery stack 10.

[0013] The case 20 has an internal space 21 inside. The battery stack 10 is housed in the internal space 21 of the case 20. The case 20 has a lower case 30 and an upper case 40.

[0014] The lower case 30 has a bottom portion 31 that constitutes the bottom surface and side walls 32 that constitute the side surfaces. The lower case 30 has an opening 33 on the upper side and is a case component having a box shape as a whole. A lower flange portion 34 protruding laterally is provided at the upper portion of the side wall 32. The lower flange portion 34 is provided in an annular shape along the upper portion of the side wall 32 for one round.

[0015] The upper surface 35 of the side wall 32 has an outer upper surface 36 and an inner upper surface 37 located closer to the internal space 21 side than the outer upper surface 36. The inner upper surface 37 is recessed more than the outer upper surface 36. As a result, a step is formed on the upper surface 35 of the side wall 32 where the side closer to the internal space 21 is lower. The lower case 30 can be manufactured, for example, by casting aluminum.

[0016] The upper case 40 is a case component that closes the opening 33 of the lower case 30. The upper case 40 has a top plate portion 41 and an upper flange portion 42 provided at the outer edge of the top plate portion 41. The upper flange portion 42 is provided in an annular shape along the outer edge of the top plate portion 41 for one round. The lower surface 43 of the upper flange portion 42 is provided so as to contact the outer upper surface 36 of the side wall 32. On the other hand, a gap is provided between the inner upper surface 37 of the side wall 32 and the lower surface 43 of the upper flange portion 42. The upper case 40 can be manufactured, for example, by sheet metal working of an iron plate.

[0017] A connector component 50 is provided on the top plate portion 41 of the upper case 40. At the mounting location of the connector component 50 on the top plate portion 41, a holding portion 44 for holding the connector component 50 is provided. The vicinity of the outer edge of the holding portion 44 is joined to the top plate portion 41. A through hole 45 penetrating the inside and outside of the case 20 is formed inside the outer edge of the holding portion 44. The holding portion 44 has a shape that is recessed toward the internal space 21 side, the closer to the through hole 45. The holding portion 44 is manufactured, for example, by sheet metal working of an iron plate and then joined to the top plate portion 41.

[0018] The connector component 50 has a main body portion 51 and a snap fit portion 52 extending from the main body portion 51. The main body portion 51 is located outside the upper case 40 and has a shape that spreads wider than the diameter of the through hole 45. The snap fit portion 52 passes through the inside of the through hole 45 from the main body portion 51 and has a shape that spreads wider than the through hole 45 on the internal space 21 side. Thereby, the connector component 50 is held at the location of the through hole 45 formed in the holding portion 44 of the upper case 40.

[0019] The connector component 50 held by the holding portion 44 closes the through hole 45. Therefore, in this embodiment, the connector component 50 is a lid portion that closes the through hole 45 of the upper case 40. The connector component 50 held at the location of the through hole 45 of the upper case 40 by the snap fit portion 52 can be easily removed from the outside of the case 20. That is, the connector component 50 can be removed from the battery pack 1 without disassembling the case 20. In this embodiment, the connector component 50 is made of an opaque resin material.

[0020] The lower case 30 and the upper case 40 are adhered by an adhesive 60. The adhesive 60 is filled in the gap between the inner upper surface 37 of the side wall 32 and the lower surface 43 of the upper flange portion 42.

[0021] FIG. 2 is a plan view of the lower case 30. As shown in FIG. 2, the opening 33 of the lower case 30 of this embodiment is square. That is, the opening 33 of the lower case 30 of this embodiment has a shape with four corner portions 38.

[0022] The adhesive 60 is provided in a circular shape along the opening 33 for one round. That is, in this embodiment, the lower case 30 and the upper case 40 are adhesively bonded continuously without a gap along the opening 33. Thereby, the case 20 is sealed at the position of the opening 33 of the lower case 30. Therefore, for example, it is prevented that water or the like enters the internal space 21 through the opening 33 of the lower case 30 from the outside of the case 20. In the battery pack 1 of this embodiment, no sealing member for sealing the opening 33 is provided other than the adhesive 60, and the opening 33 is sealed by the adhesive 60.

[0023] The adhesive 60 is a so-called disintegrable adhesive. That is, the adhesive 60 adheres the lower case 30 and the upper case 40 by being applied and exerting its adhesive force. The adhesive 60 of the present embodiment has the property that its adhesive force decreases when irradiated with specific light. More specifically, the adhesive 60 of the present embodiment causes a decrease in adhesive force when irradiated with ultraviolet light having a wavelength within a predetermined range. Hereinafter, the light that reduces the adhesive force of the adhesive 60 may be referred to as specific light.

[0024] As shown in FIG. 1, the inner space 21 side of the adhesive 60 is not covered by other members or the like. For this reason, the adhesive 60 has an exposed portion 61 that is exposed to the inner space 21. In the battery pack 1 of the present embodiment, the exposed portion 61 of the adhesive 60 to the inner space 21 is provided in a ring shape along the opening 33 for one round.

[0025] Next, a method for disassembling the battery pack 1 will be described with reference to FIG. 3. FIG. 3 is an enlarged cross-sectional view of the vicinity of the adhered portion by the adhesive 60 of the battery pack 1. In FIG. 3, the connector component 50 has been removed. The connector component 50 has been removed from the outside of the case 20 without disassembling the case 20. When the connector component 50 is removed, the through hole 45 is opened in the case 20.

[0026] When disassembling the battery pack 1, after removing the connector component 50, specific light L is irradiated onto the exposed portion 61 of the adhesive 60 to the inner space 21. The specific light L to be irradiated is ultraviolet light having a wavelength that can reduce the adhesive force of the adhesive 60 as described above.

[0027] As shown in FIG. 3, the specific light L projected from the irradiation unit 70 provided outside the case 20 passes through the through hole 45 and the internal space 21 and is directly irradiated onto the exposed portion 61 of the adhesive 60. That is, in a state where the connector component 50 is removed, the battery pack 1 can directly pass the specific light L through the internal space 21 of the case 20 from the through hole 45 to the exposed portion 61 of the adhesive 60. Then, the adhesive 60 irradiated with the specific light L has a reduced adhesive force.

[0028] The specific light L only needs to be able to irradiate at least a part of the adhesive 60 provided along the opening 33 for one round. Specifically, it is only necessary to be able to reduce the adhesive force of at least a part of the circumferential section of the adhesive 60 provided in a ring for one round by the specific light L. When a part of the adhesive force of the adhesive 60 decreases due to the irradiation of the specific light L, the entire adhesive 60 can be peeled off starting from the portion where the adhesive force has decreased. When reducing the adhesive force of only a part of the circumferential section of the adhesive 60 provided along the opening 33 for one round, it is only necessary to provide an exposed portion 61 for at least that section.

[0029] Then, the lower case 30 and the upper case 40 adhered by the adhesive 60 in a ring along the opening 33 can be separated by applying a force to move them away from each other in a state where the adhesive force of a part of the adhesive 60 has decreased. To separate the lower case 30 and the upper case 40 in a state where the adhesive force of a part of the adhesive 60 has decreased, not much force is required.

[0030] For example, unlike the present embodiment, when the lower case and the upper case are adhesively bonded in a circular shape along the opening of the lower case using an adhesive that is not a disassembling adhesive, they must be separated while the adhesive force of the adhesive remains strong. In such a case, a large force is applied to the lower case and the upper case. And if the lower case is damaged by that large force, for example, there is a possibility of damaging the battery cell inside the case. Also, for example, there is a possibility of leakage or the like from the battery cell.

[0031] On the other hand, in the battery pack 1 of the present embodiment, the lower case 30 and the upper case 40 can be separated in a state where the adhesive force of the adhesive 60 is reduced. Thereby, the lower case 30 and the upper case 40 can be easily separated without damaging any of the components of the battery pack 1. That is, the battery pack 1 can be disassembled safely and easily during repair or recycling. Also, the battery cell 11 etc. can be recovered from the disassembled battery pack 1 without being damaged. For this reason, for example, the battery cell 11 taken out and recovered from the disassembled battery pack 1 can be reused for other purposes. Also, for example, the deteriorated battery cell 11 in the battery stack 10 can be easily replaced.

[0032] Also, in the battery pack 1 of the present embodiment, the lower case 30 and the upper case 40 are made of a material that can block ultraviolet rays. The connector component 50 also has a thickness that can block ultraviolet rays. For this reason, for example, even if ultraviolet rays caused by sunlight from the outside hit the battery pack 1 in the environment where the battery pack 1 is used, a decrease in the adhesive force of the adhesive 60 is suppressed. Therefore, in a normal use environment, separation of the lower case 30 and the upper case 40 is suppressed.

[0033] Further, in the battery pack 1 of this embodiment, a through hole 45 serving as an entrance for specific light into the internal space 21 is formed in the upper case 40 when the battery pack is disassembled. The battery pack 1 of this embodiment is heavy because the battery stack 10 is housed therein. Also, in a general battery pack, there is a tendency that it is not assumed to be placed with the bottom of the lower case facing down. Since the through hole 45 is provided in the upper case 40 in the battery pack 1 of this embodiment, in a normal placement state where the bottom 31 of the lower case 30 is facing down, specific light can be easily irradiated onto the exposed portion 61 of the adhesive 60 into the internal space 21. Therefore, in the battery pack 1, the work at the time of disassembly can be easily performed.

[0034] Also, the opening 33 of the lower case 30 of the battery pack 1 of this embodiment has a rectangular shape with corner portions 38. In a battery pack 1 having such a shape, when separating the lower case 30 and the upper case 40, it is preferably started from the corner portions 38. The side walls 32 of the lower case 30 extend in two different directions from near each corner portion 38 toward the two adjacent corner portions 38. The lower case 30 having such a shape has a tendency that the rigidity near the corner portions 38 is higher than, for example, the middle of the side walls 32 far from the corner portions 38. For this reason, in the battery pack 1, when reducing the adhesive force of a part of the adhesive 60 and separating the lower case 30 and the upper case 40 starting from there, it is preferable that the starting point is the corner portion 38. This is because the applied force is more likely to be appropriately transmitted to a portion with higher rigidity. That is, the exposed portion 61 of the adhesive 60 capable of irradiating specific light preferably includes at least the range including the corner portions 38.

[0035] Further, in the battery pack 1 of this embodiment, a step is formed on the upper surface 35 of the side wall 32 of the lower case 30 such that the inner space 21 side is lower, and the gap between the lower case 30 and the upper case 40 formed by the step is filled with an adhesive 60. As a result, the adhesive 60 is covered by the step portion of the upper surface 35 of the side wall 32 of the lower case 30 on the side opposite to the inner space 21 side. That is, the case 20 has a portion that covers the side of the adhesive 60 opposite to the inner space 21. That is, in the battery pack 1, the adhesive 60 is not exposed to the outside. Therefore, even if ultraviolet rays hit the battery pack 1 from the outside, it is possible to prevent the adhesive force of the adhesive 60 from decreasing. Therefore, in a normal use environment, it is possible to prevent the lower case 30 and the upper case 40 from separating.

[0036] [Second Embodiment] Next, a second embodiment different from the above embodiment will be described. Regarding the configurations similar to those of the above embodiment, the same reference numerals will be used for description.

[0037] FIG. 4 is an enlarged cross-sectional view of the vicinity of the bonding portion of the adhesive 60 of the battery pack 2 according to this embodiment. FIG. 4 shows a state in which the through-hole 45 is open. However, also in the battery pack 2, normally, the through-hole 45 is blocked by the connector component 50. That is, FIG. 4 shows the battery pack 2 in a state where the connector component 50 is removed.

[0038] The battery pack 2 of this embodiment has a reflecting component 80 in the inner space 21 of the case 20. The reflecting component 80 is a rebounding component that can bounce back specific light L by reflection. The reflecting component 80 has a fixing portion 81 and a reflecting portion 82. The fixing portion 81 of the reflecting component 80 is fixed to the spacer 15. The reflecting portion 82 has a passing region 83 on the surface on the side of the through-hole 45. The reflecting component 80 only needs to be able to reflect the specific light L at least in the passing region 83.

[0039] Also in FIG. 4, the specific light L projected from the irradiation unit 70 provided outside the case 20 passes through the through hole 45 and the internal space 21 and is irradiated onto the exposed portion 61 of the adhesive 60. However, in the battery pack 2 of this embodiment, the specific light L can pass through the internal space 21 of the case 20 from the through hole 45 to the exposed portion 61 of the adhesive 60 via the passage region 83 of the reflecting component 80. Also in this embodiment, the specific light L only needs to irradiate at least a part of the adhesive 60 provided along the opening 33 for one round. Note that the passage region 83 of the reflecting component 80 does not necessarily have to be a flat surface and may be a curved surface.

[0040] Therefore, also in the battery pack 2 of this embodiment, by irradiating the specific light L from the through hole 45, the adhesive strength of the adhesive 60 can be reduced. That is, the lower case 30 and the upper case 40 can be easily separated in a state where the adhesive strength of the adhesive 60 is reduced. That is, also in the battery pack 2, disassembly during repair or recycling can be performed safely and easily.

[0041] Further, in order to appropriately reflect the specific light L, the passage region 83 preferably has a small surface roughness. When reducing the surface roughness of all surfaces of the reflecting component 80, the reflecting component 80 tends to become expensive. Therefore, it is preferable that the reflecting component 80 has a small surface roughness at least for the passage region 83, rather than all surfaces. In other words, it is preferable that the reflecting component 80 has a passage region 83 and a non-passage region 84 on the surface with a larger surface roughness than the passage region 83. In the reflecting component 80 of this embodiment, all surfaces other than the surface on the through hole 45 side in the reflecting portion 82 are non-passage regions 84 with a larger surface roughness than the passage region 83.

[0042] The passage region 83 can be formed, for example, by polishing. That is, by polishing the passage region 83 of the reflecting component 80, the surface roughness of the passage region 83 can be made smaller than that of the non-passage region 84.

[0043] For example, the passage area 83 can also be provided by using a reflector with a small surface roughness. That is, the reflector component 80 can be provided with a reflector having a smaller surface roughness than the non-passage area 84 at least in the passage area 83.

[0044] As described in detail above, the battery packs 1 and 2 according to the above embodiments include a battery stack 10 including a plurality of battery cells 11 and a case 20 that houses the battery stack 10 in an internal space 21. The case 20 has a lower case 30 and an upper case 40. The lower case 30 has a bottom 31 and is a first case component having an opening 33 on the upper side. The upper case 40 is a second case component that closes the opening 33 of the lower case 30. Further, in the case 20, the lower case 30 and the upper case 40 are adhered by an adhesive 60. Furthermore, the upper case 40 has a through hole 45 penetrating the inside and outside, and has a connector component 50. The connector component 50 is a lid that closes the through hole 45. The connector component 50 can be removed from the outside of the case 20. And the adhesive 60 has a property that its adhesive force decreases when exposed to specific light. The specific light is ultraviolet light having a wavelength within a predetermined range. Also, the adhesive 60 has an exposed portion 61 exposed to the internal space 21 of the case 20. For this reason, when disassembling the battery packs 1 and 2 for repair or recycling, for example, the connector component 50 is removed, and specific light is irradiated from the through hole 45 to the exposed portion 61 of the adhesive 60 to the internal space 21, whereby the adhesive force of the adhesive 60 can be decreased. Thereby, the lower case 30 and the upper case 40 can be separated without applying a strong load. Therefore, a battery pack that is easy to disassemble is realized.

[0045] All of the above embodiments are merely examples and do not limit the disclosed technology in any way. Therefore, the disclosed technology can naturally be variously improved and modified without departing from the gist thereof.

[0046] For example, in the above-described embodiment, the lid portion that closes the through hole 45 of the upper case 40 has been described as the connector component 50. However, the lid portion that closes the through hole 45 of the upper case 40 does not necessarily have to be the connector component 50. Specifically, for example, it may be a valve component having a valve body that can adjust the internal pressure of the case 20 to a pressure within an appropriate range. Also, for example, the lid portion that closes the through hole 45 of the upper case 40 may not be the connector component 50 or the valve component, but may have only the function of a lid that closes the through hole 45. However, since the lid portion that closes the through hole 45 of the upper case 40 is a component that also has the functions required for the battery pack, the structure of the battery pack can be made simple.

[0047] Also, for example, in the above-described embodiment, the through hole 45 of the upper case 40 has been described as being provided in the holding portion 44 provided in the top plate portion 41. However, the through hole 45 of the upper case 40 may be provided directly in the top plate portion 41, for example.

[0048] Also, for example, what has been described as the material of the lower case 30, the upper case 40, the lid portion, etc. is merely an example, and other materials can also be used. That is, the lower case 30, the portion where the adhesive 60 of the upper case 40 is adhered, and the lid portion may be of a material and thickness that block the specific light irradiated on one side to such an extent that the adhesive force of the adhesive 60 provided on the opposite side is maintained.

[0049] Also, for example, in the above-described embodiment, an example in which the through hole 45 that allows the specific light to pass from the outside of the case 20 to the internal space 21 is provided in the upper case 40 has been described. However, the through hole that allows the specific light to pass into the internal space 21 may be provided in the lower case 30. Also, for example, a plurality of through holes that allow the specific light to pass into the internal space 21 may be provided.

[0050] For example, in the above embodiment, an example was described in which the adhesive 60 is provided in a circular shape along the opening 33 of the lower case 30, and specific light that reduces the adhesive force is irradiated only on a part of the adhesive 60. However, of course, it is also possible to irradiate specific light on all of the exposed portions 61 of the adhesive 60 provided along the opening 33 of the lower case 30 for one round.

[0051] For example, in the above embodiment, a configuration was described in which the adhesive 60 is continuously provided in a circular shape along the opening 33 of the lower case 30. However, the adhesive portion between the lower case 30 and the upper case 40 may be provided intermittently, for example, along the opening 33 of the lower case 30. Also in such a case, it is possible to separate the lower case 30 and the upper case 40 by reducing the adhesive force of a part of the adhesives 60 provided intermittently.

[0052] For example, in the above embodiment, the reflecting component 80 was described as a component fixed to the spacer 15. However, the reflecting component 80 only needs to be provided in the internal space 21 of the case 20 and may be fixed to a component other than the spacer 15. For example, the reflecting component 80 may have a function other than the function of reflecting specific light when the battery pack is disassembled. Specifically, for example, the passage area through which the specific light irradiated when the battery pack is disassembled passes may be provided in the spacer 15. Also for example, a plurality of passage areas through which the specific light irradiated when the battery pack is disassembled passes may be provided. That is, the battery pack may be configured to allow the specific light irradiated at the time of disassembly to pass through a plurality of passage areas from the through hole 45 in the internal space 21 of the case 20 to the exposed portion 61 of the adhesive 60.

[0053] Also, for example, in the above-described embodiment, the adhesive 60 was described as one whose adhesive force decreases when irradiated with ultraviolet light having a predetermined wavelength range. However, as the adhesive 60, any so-called disassembly adhesive that exhibits the property of decreasing the adhesive force when specific conditions are satisfied may be used. For this reason, for example, as the adhesive 60, one whose adhesive force decreases by light other than ultraviolet light may be adopted.

[0054] Also, for example, among so-called disassembly adhesives, there are some whose adhesive force decreases when they come into contact with a specific liquid. Such adhesives whose adhesive force decreases due to a specific liquid can also be used as the adhesive 60. For example, it is possible to use, as the adhesive 60, one that undergoes an oxidation reaction and has its adhesive force decreased when it comes into contact with sodium hypochlorite. Regarding the specific liquid, it is sufficient that the internal space 21 of the case 20 can pass through, directly or via a passage region of a predetermined rebounding component, from the through hole 45 of the upper case 40 to the exposed portion 61 of the adhesive 60.

[0055] When adopting, as the adhesive 60, one whose adhesive force decreases due to a specific liquid, it is preferable that the specific liquid has a low electrical conductivity. This is because if a liquid with a high electrical conductivity is applied to the battery cell 11, there is a possibility of leakage, short circuit, etc. Therefore, as the adhesive 60, it is preferable to adopt one whose adhesive force decreases by contact with a liquid other than the electrolytic solution.

[0056] Also, for example, the case 20 described in the above embodiment was described as one in which the lower case 30 and the upper case 40 are fixed to each other only by the adhesive 60. However, for example, the lower case 30 and the upper case 40 may be fixed by screw components or the like in addition to the adhesive 60.

[0057] For example, the shape and the like of the battery cell 11 constituting the battery stack 10 described in the above embodiment are merely examples. Specifically, the battery stack 10 may be constituted by cylindrical battery cells. Further, the application target of the above embodiment is not particularly limited with respect to the type of battery (type such as nickel-hydrogen battery, lithium-ion battery, etc.).

[0058] Further, the above disclosed technology includes the following means 1 to means 10. [Means 1] A battery pack according to claim 1, wherein, in a state where the lid portion is removed, the internal space of the case can directly pass the one from the through hole to the exposed portion of the adhesive.

[0059] [Means 2] A battery pack according to claim 1, wherein a rebounding component capable of rebounding the one is provided in the internal space of the case, and in a state where the lid portion is removed, the internal space of the case can pass the one through a passing region on the surface of the rebounding component from the through hole to the exposed portion of the adhesive.

[0060] [Means 3] A battery pack according to means 2, wherein the one is the light, and the rebounding component has a non-passing region on the surface with a surface roughness larger than that of the passing region.

[0061] [Means 4] A battery pack according to means 3, wherein the rebounding component is subjected to polishing on the passing region.

[0062] [Means 5] A battery pack according to means 3, The battery pack in which a reflecting material having a smaller surface roughness than the non-passage region is provided in the passage region in the rebounding component.

[0063] [Means 6] The battery pack according to claim 1 or any one of Means 1 to Means 6, wherein one of them is the light, The battery pack in which the portions where the adhesive is adhered in the first case component, the portions where the adhesive is adhered in the second case component, and the lid portion are all made of a material and thickness that block the light irradiated on one side to such an extent that the adhesive force of the adhesive provided on the side opposite to the one side is maintained.

[0064] [Means 7] The battery pack according to claim 1, or any one of Means 1 and Means 2, wherein one of them is the liquid, and the battery pack in which the liquid is other than the electrolytic solution.

[0065] [Means 8] The battery pack according to claim 1 or any one of Means 1 to Means 7, wherein the through hole is formed in the second case component.

[0066] [Means 9] The battery pack according to claim 1 or any one of Means 1 to Means 8, wherein the lid portion is a connector component or a valve component having a valve body.

[0067] [Means 10] The battery pack according to claim 1 or any one of Means 1 to Means 8, wherein the opening of the first case component has a polygonal shape having corners, and the exposed portion is a range including at least the corners.

Explanation of Signs

[0068] 1, 2: Battery pack 10: Battery stack 11: Battery cell 20: Case 21: Internal space 30: Lower case (first case component) 31: Bottom 33: Opening 38: Corner 40: Upper case (second case component) 45: Through hole 50: Connector component (cover part) 60: Adhesive 61: Exposed part 80: Reflective component (rebound component) 83: Passage area 84: Non-passage area L: Specific light

Claims

1. A battery pack including a plurality of battery cells, and a case for housing the battery pack in an internal space, The case includes: A first case component having a bottom and an opening on the upper side, and a second case component closing the opening of the first case component, The first case component and the second case component are adhered by an adhesive, Either the first case component or the second case component has a through hole penetrating inside and outside, and has a lid portion closing the through hole, The lid portion is removable from the outside of the case, The adhesive is: One having a property that the adhesive force decreases when either specific light or specific liquid hits it, A battery pack having an exposed portion exposed in the internal space of the case.

2. The battery pack according to claim 1, wherein In a state where the lid portion is removed, the internal space of the case can directly pass the one from the through hole to the exposed portion of the adhesive.

3. The battery pack according to claim 1, wherein In the internal space of the case, a rebounding component capable of rebounding the one is provided, In a state where the lid portion is removed, the internal space of the case can pass the one from the through hole to the exposed portion of the adhesive through a passing region on the surface of the rebounding component.

4. The battery pack according to claim 3, wherein The one is the light, The rebounding component has a non-passing region on the surface with a surface roughness larger than that of the passing region.

5. The battery pack according to claim 4, wherein The battery pack in which the rebounding component is subjected to polishing in the passing area.

6. The battery pack according to claim 4, wherein the rebounding component is provided with a reflective material having a smaller surface roughness than the non-passing area in the passing area.

7. The battery pack according to any one of claims 1 to 3, wherein the one is the light, the portion where the adhesive is adhered in the first case component, the portion where the adhesive is adhered in the second case component, and the lid portion are all made of a material and thickness that block the light irradiated on one side to such an extent that the adhesive force of the adhesive provided on the side opposite to the one side is maintained.

8. The battery pack according to any one of claims 1 to 3, wherein the one is the liquid, and the liquid is a battery pack other than an electrolytic solution.

9. The battery pack according to any one of claims 1 to 6, wherein the through hole is formed in the second case component.

10. The battery pack according to any one of claims 1 to 6, wherein the lid portion is a connector component or a valve component having a valve body.

11. The battery pack according to any one of claims 1 to 6, wherein the opening of the first case component has a polygonal shape having corners, and the exposed portion is a range including at least the corners.

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