Battery pack

Abstract

To provide a battery pack easy to dismantle.SOLUTION: A case 20 of a battery pack 1 includes 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 closes 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 case 20 is provided with an outside gas space 50 between the lower case 30 and the upper case 40 in an outer side than the adhesive 60. The outside gap space 50 is continuous from an outside gap end 51 opening in the outside to the adhesive 60. The outside gap end 51 of the outside gap space 50 opens downward with respect to a horizontal direction. The adhesive 60 has a nature of becoming less adhesive when is exposed to specific light. The adhesive 60 has an exposure part 61 exposing to the outside gap space 50.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 for closing the opening of the lower case. Also, the state of fixing the upper case and the lower case to each other using screw parts 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 parts constituting the case of the battery pack to each other using an adhesive. However, when the case parts are adhered to each other using an adhesive, it may become difficult to separate the adhered case parts from each other. And in a battery pack that is difficult to disassemble, for example, it may become impossible to easily repair or recycle the battery pack.

[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. A gap is provided between the first case component and the second case component on the outer side of the adhesive, and the space of the gap is continuous from the outer gap end opening to the outside to the adhesive. The outer gap end of the gap opens downward rather than in the horizontal direction. The adhesive has a property that its adhesive force decreases when one of specific light and specific liquid hits it. The battery pack has an exposed portion that is exposed in the space of the gap.

[0007] In the battery pack according to the above aspect, it is possible to apply one of specific light or specific liquid from the opening on the outer side of the gap between the first case component and the second case component to the exposed portion of the adhesive exposed in the space of the gap. 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.

Effects 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

Figure 5

Mode for Carrying Out the Invention

[0010] Hereinafter, embodiments embodying the disclosed technology will be described in detail with reference to the accompanying drawings. FIG. 1 is a cross-sectional view of a battery pack 1 according to this embodiment. The battery pack 1 includes a battery stack 10 and a case 20.

[0011] The battery stack 10 is configured to include a plurality of battery cells 11. FIG. 1 shows an example in which a flat battery cell 11 having a rectangular outer shape is 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.

[0012] 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.

[0013] 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 part having a box shape as a whole. An outwardly protruding lower flange portion 34 is provided at the upper part of the side wall 32. The lower flange portion 34 is provided in a circular shape along the upper part of the side wall 32 for one round. The lower case 30 can be manufactured, for example, by casting aluminum.

[0014] 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, an upper flange portion 42, and a cover portion 44. The upper flange portion 42 is provided at the outer edge of the top plate portion 41. The upper flange portion 42 is provided in a circular shape along the outer edge of the top plate portion 41 for one full turn. The lower surface 43 of the upper flange portion 42 of the upper case 40 is provided to face the upper surface 35 of the side wall 32 of the lower case 30.

[0015] The cover portion 44 is provided at the outer edge of the upper flange portion 42. The cover portion 44 is provided in a circular shape along the outer edge of the upper flange portion 42 for one full turn. The cover portion 44 extends downward from the outer edge of the upper flange portion 42 in a direction more downward than the horizontal direction. The upper case 40 can be manufactured, for example, by sheet metal working of an iron plate.

[0016] A gap is provided between the cover portion 44 of the upper case 40 and the side wall 32 of the lower case 30. The outer gap space 50, which is the space of the gap between the lower case 30 and the upper case 40, is continuous from the outer gap end 51 that opens to the outside of the case 20 to the adhesive 60.

[0017] The lower case 30 has a lower gap surface 52 which is a surface exposed to the outer gap space 50. Also, the upper case 40 has an upper gap surface 55 which is a surface exposed to the outer gap space 50. The lower gap surface 52 and the upper gap surface 55 face each other.

[0018] 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 upper surface 35 of the side wall 32 of the lower case 30 and the lower surface 43 of the upper flange portion 42.

[0019] Figure 2 is a plan view of the lower case 30. As shown in Figure 2, the opening 33 of the lower case 30 of this embodiment is quadrilateral. That is, the opening 33 of the lower case 30 of this embodiment has a shape with four corner portions 38.

[0020] 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, entry of water or the like from the outside of the case 20 into the internal space 21 through the opening 33 of the lower case 30 is prevented. 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.

[0021] The adhesive 60 is a so-called disassembly adhesive. That is, the adhesive 60 is applied to exhibit its adhesive force, thereby bonding the lower case 30 and the upper case 40. The adhesive 60 of this embodiment has the property that its adhesive force decreases when irradiated with specific light. More specifically, the adhesive 60 of this embodiment causes a decrease in adhesive force when irradiated with ultraviolet light having a wavelength within a predetermined range. Hereinafter, the light that decreases the adhesive force of the adhesive 60 may be referred to as specific light.

[0022] As shown in FIG. 1, the outer gap space 50 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 exposed to the outer gap space 50. In the battery pack 1 of this embodiment, the exposed portion 61 of the adhesive 60 to the outer gap space 50 is provided in a circular shape along the opening 33 for one round.

[0023] 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 bonded portion by the adhesive 60 of the battery pack 1.

[0024] When disassembling the battery pack 1, specific light L is irradiated to the exposed portion 61 of the adhesive 60 to the outer gap space 50. The specific light L to be irradiated is ultraviolet light having a wavelength capable of decreasing the adhesive force of the adhesive 60 as described above.

[0025] As shown in FIG. 3, the specific light L projected from the irradiation unit 70 provided outside the case 20 passes through the outer gap space 50 while being reflected by the lower case 30 and the upper case 40, and is irradiated onto the exposed portion 61 of the adhesive 60. For this reason, both the lower case 30 and the upper case 40 shown in FIG. 3 are bounce-back case parts that can bounce back the specific light L on the surface exposed to the outer gap space 50.

[0026] The reflection location of the specific light L on the lower case 30 is the passage region 53 of the lower gap surface 52. The reflection location of the specific light L on the upper case 40 is the passage region 56 of the upper gap surface 55. That is, the battery pack 1 can pass the specific light L through the outer gap space 50 from the outer gap end 51 to the exposed portion 61 of the adhesive 60 via the passage region 53 of the lower gap surface 52 and the passage region 56 of the upper gap surface 55. Then, the adhesive 60 irradiated with the specific light L has its adhesive force reduced.

[0027] 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 sufficient if the adhesive force of at least a part of the section in the circumferential direction among the adhesives 60 provided in a circular shape for one round can be reduced by the specific light L. The adhesive 60 can peel off the whole starting from the location where its adhesive force has been reduced due to the reduction of a part of the adhesive force by the irradiation of the specific light L. When reducing the adhesive force of only a part of the section in the circumferential direction among the adhesives 60 provided along the opening 33 for one round, it is only necessary to provide the exposed portion 61 for at least that section.

[0028] Of the lower gap surface 52, the passage region 53, and of the upper gap surface 55, the passage region 56 preferably have a small surface roughness in order to appropriately reflect the specific light L. Note that, for example, when reducing the surface roughness of all of the lower gap surface 52 of the lower case 30, the lower case 30 tends to become expensive. Therefore, it is preferable that the lower case 30 is made such that the surface roughness is small not for all of the lower gap surface 52 but at least for the passage region 53. In other words, it is preferable that the lower case 30 has, on the lower gap surface 52, a passage region 53 and a region having a larger surface roughness than the passage region 53. The same applies to the upper case 40.

[0029] FIG. 4 is a view seen from the direction indicated by the arrow A shown in FIG. 3. That is, FIG. 4 is a view of the outer gap space 50 seen from the outer gap end 51 side. In the lower case 30 of the present embodiment, the passage region 53 is provided in a streak shape only in a part of the lower gap surface 52 in the horizontal direction. That is, non-passage regions 54 having a larger surface roughness than the passage region 53 are provided on both sides in the horizontal direction of the passage region 53 of the lower gap surface 52. The streak-shaped passage region 53 is provided on the lower gap surface 52 from the outer gap end 51 side toward the inner side of the outer gap space 50, that is, toward the exposed portion 61 of the adhesive 60.

[0030] Also, in the upper case 40 of the present embodiment, the passage region 56 is provided in a streak shape only in a part of the upper gap surface 55 in the horizontal direction. That is, non-passage regions 57 having a larger surface roughness than the passage region 56 are provided on both sides in the horizontal direction of the passage region 56 of the upper gap surface 55. Further, the streak-shaped passage region 56 is provided on the upper gap surface 55 from the outer gap end 51 side toward the inner side of the outer gap space 50, that is, toward the exposed portion 61 of the adhesive 60.

[0031] The passage regions 53 of the lower gap surface 52 and 56 of the upper gap surface 55 can be formed, for example, by polishing. That is, by polishing the passage region 53 of the lower gap surface 52 of the lower case 30, the surface roughness of the passage region 53 can be made smaller than that of the non-passage region 54. Also, by polishing the passage region 56 of the upper gap surface 55 of the upper case 40, the surface roughness of the passage region 56 can be made smaller than that of the non-passage region 57.

[0032] Also, for example, the passage regions 53 of the lower gap surface 52 and 56 of the upper gap surface 55 can be provided by using a reflective material with a small surface roughness. That is, the lower case 30 can be provided with a reflective material having a smaller surface roughness than the non-passage region 54 at least in the passage region 53 of the lower gap surface 52. Also, the upper case 40 can be provided with a reflective material having a smaller surface roughness than the non-passage region 57 at least in the passage region 56 of the upper gap surface 55.

[0033] Note that the battery pack 1 may be configured to be able to irradiate the adhesive 60 with the specific light L via at least one of the lower gap surface 52 of the lower case 30 and the upper gap surface 55 of the upper case 40. FIG. 4 shows an example in which the adhesive 60 is irradiated with the specific light L via only the upper gap surface 55 of the upper case 40. In the example of FIG. 4, it is not always necessary to provide a region with a small surface roughness on the lower gap surface 52 of the lower case 30. Also, when providing a passage region with a small surface roughness and a non-passage region with a larger surface roughness than that, the passage region may be provided in a range corresponding to at least the exposed portion 61 where the specific light is to be irradiated.

[0034] The lower case 30 and the upper case 40, which are adhesively bonded by an adhesive 60 in a circular shape 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 is reduced. 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 is reduced, not much force is required.

[0035] For example, different from this embodiment, when the lower case and the upper case are adhesively bonded in a circular shape along the opening of the lower case by an adhesive that is not a disassembly adhesive, they must be separated while the adhesive force of the adhesive remains strong. In such a case, a large force has to be 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 of electricity from the battery cell.

[0036] In contrast, in the battery pack 1 of this 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 perform disassembly during repair or recycling safely and easily. 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.

[0037] Further, 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. And the outer gap end 51 of the outer gap space 50 opens downward rather than horizontally. For this reason, for example, even if ultraviolet rays caused by sunlight hit the battery pack 1 from the outside in the environment where the battery pack 1 is used, a decrease in the adhesive strength of the adhesive 60 is suppressed. This is because sunlight usually hits the battery pack 1 from above the battery pack 1. Therefore, separation of the lower case 30 and the upper case 40 is suppressed in a normal usage environment. Also, since the outer gap end 51 of the outer gap space 50 opens downward rather than horizontally, accumulation of water, dust, etc. in the outer gap space 50 is also suppressed.

[0038] Also, it is preferable that the battery pack 1 of the present embodiment is such that specific light cannot directly pass through the outer gap space 50 from the outer gap end 51 to the exposed portion 61 of the adhesive 60. Depending on the usage environment of the battery pack 1, for example, sunlight reflected below the outer gap end 51 outside the battery pack 1 may enter the outer gap space 50. In such a case, it is not preferable for the sunlight to be directly irradiated to the exposed portion 61 of the adhesive 60 as it is. This is because the adhesive strength of the adhesive 60 may be reduced by ultraviolet rays caused by sunlight.

[0039] On the other hand, if the structure is such that specific light cannot directly pass through the outer gap space 50 to the exposed portion 61 of the adhesive 60, the sunlight that has entered the outer gap space 50 will hit the adhesive 60 after being reflected at least once within the outer gap space 50. That is, the sunlight will be irradiated to the adhesive 60 after being attenuated by absorption or diffusion associated with reflection within the outer gap space 50. That is, by having a structure in which specific light cannot directly pass through the outer gap space 50 to the exposed portion 61 of the adhesive 60, a decrease in the adhesive strength of the adhesive 60 in the usage environment of the battery pack 1 can be suppressed.

[0040] As a structure in which specific light cannot directly pass through to the exposed portion 61 of the adhesive 60, for example, it is conceivable to provide at least one bent portion between the outer gap end 51 in the outer gap space 50 and the exposed portion 61 of the adhesive 60. Specifically, it is sufficient if at least one of the lower gap surface 52 and the upper gap surface 55 has a protruding portion protruding into the outer gap space 50. In the battery pack 1 of this embodiment, as shown in FIGS. 3 and 5, the convex portion 52A exists on the lower gap surface 52. Thereby, it is suppressed that the ultraviolet rays caused by sunlight or the like entering the outer gap space 50 directly hit the exposed portion 61 of the adhesive 60.

[0041] Further, the opening 33 of the lower case 30 of the battery pack 1 of this embodiment has a rectangular shape having a corner portion 38. In the battery pack 1 having such a shape, when separating the lower case 30 and the upper case 40, it preferably starts from the corner portion 38. The side wall 32 of the lower case 30 extends 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 tends to have higher rigidity near the corner portion 38 than, for example, the middle of the side wall 32 far from the corner portion 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 where specific light can be irradiated is preferably in a range including at least the corner portion 38.

[0042] As described in detail above, the battery pack 1 according to the above embodiment includes 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 is a first case component having a bottom 31 and 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, an outer gap space 50 is provided between the lower case 30 and the upper case 40 on the outer side of the adhesive 60. The outer gap space 50 is continuous from an outer gap end 51 that opens to the outside to the adhesive 60. The outer gap end 51 of the outer gap space 50 opens downward rather than in the horizontal direction. And the adhesive 60 has a property that its adhesive force decreases when specific light hits it. The specific light is ultraviolet light having a wavelength within a predetermined range. Also, the adhesive 60 has an exposed portion 61 that is exposed to the outer gap space 50. For this reason, when disassembling the battery pack 1 for repair or recycling, for example, by irradiating specific light from the outer gap end 51 to the exposed portion 61 of the adhesive 60 in the outer gap space 50, 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.

[0043] Each of the above embodiments is merely an example and does not limit the present disclosed technology in any way. Therefore, the present disclosed technology can naturally be improved and modified in various ways without departing from its gist.

[0044] Also, for example, what is 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 portion where the adhesive 60 of the lower case 30 and the upper case 40 is adhered only needs to be 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.

[0045] Also, for example, in the above-described embodiment, an example was described in which an outer gap space 50 that is continuous from the outer gap end 51 to the adhesive 60 is provided continuously for one round on the outside of the adhesive 60. However, such an outer gap space 50 does not necessarily have to be provided continuously for one round on the outside of the adhesive 60.

[0046] Also, for example, in the above-described embodiment, an example was described in which the adhesive 60 is provided in a circular shape for one round 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 for one round along the opening 33 of the lower case 30.

[0047] Also, for example, in the above-described embodiment, a configuration in which the adhesive 60 is continuously provided in a circular shape for one round along the opening 33 of the lower case 30 was described. However, the adhesive portion between the lower case 30 and the upper case 40 by the adhesive 60 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 intermittently provided adhesive 60.

[0048] Also, for example, in the above-described embodiment, it was described that the adhesive 60 has a property that its adhesive force decreases when irradiated with ultraviolet rays having a predetermined wavelength range. However, as the adhesive 60, any so-called disassembly adhesive that exhibits the property of reducing 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 rays may be adopted.

[0049] For example, some so-called detachable adhesives have the property that their adhesive strength decreases when they come into contact with a specific liquid. Such adhesives that have their adhesive strength decreased by a specific liquid can also be used as the adhesive 60. For example, an adhesive having the property that an oxidation reaction occurs upon contact with sodium hypochlorite and its adhesive strength decreases can be used as the adhesive 60. Regarding the specific liquid, it is sufficient that the outer gap space 50 can be passed through directly from the outer gap end 51 to the exposed portion 61 of the adhesive 60, or via the passing region of the rebounding case component.

[0050] When an adhesive whose adhesive strength decreases due to a specific liquid is adopted as the adhesive 60, 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 an adhesive whose adhesive strength decreases upon contact with a liquid other than the electrolyte.

[0051] For example, the case 20 described in the above embodiment was described as being such that 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.

[0052] 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. Also, the application target of the above embodiment is not particularly limited with respect to the battery type (types such as nickel-hydrogen batteries and lithium-ion batteries).

[0053] The above disclosed technology includes the following means 1 to means 8. [Means 1] The battery pack according to claim 1, Either the first case part or the second case part, or both, are rebounding case parts that can rebound the one on the gap surface exposed in the space of the gap. A battery pack that can pass the one through the space of the gap from the outer gap end to the exposed portion of the adhesive via a passing area on the gap surface of the rebounding case part.

[0054] [Means 2] A battery pack according to Means 1, A battery pack that cannot directly pass the one from the outer gap end to the exposed portion of the adhesive through the space of the gap.

[0055] [Means 3] A battery pack according to Means 1 or Means 2, The one is the light, The rebounding case part has a non-passing area on the gap surface with a surface roughness greater than that of the passing area.

[0056] [Means 4] A battery pack according to Means 3, The rebounding case part is subjected to polishing on the passing area.

[0057] [Means 5] A battery pack according to Means 3, The rebounding case part is provided with a reflective material on the passing area with a surface roughness smaller than that of the non-passing area.

[0058] [Means 6] A battery pack according to Claim 1 or any one of Means 1 to Means 5, The one is the light, In the battery pack, both the portion where the adhesive is adhered in the first case part and the portion where the adhesive is adhered in the second case part are 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.

[0059] [Means 7] A battery pack according to any one of Claim 1, Means 1, and Means 2, wherein one of them is the liquid, and the liquid is a battery pack other than an electrolytic solution.

[0060] [Means 8] A battery pack according to Claim 1 or any one of Means 1 to Means 7, wherein the opening of the first case part has a polygonal shape having corners, and the exposed portion is a range including at least the corners.

Explanation of Reference Signs

[0061] 1: Battery pack 10: Battery stack 11: Battery cell 20: Case 21: Internal space 30: Lower case (first case part) 31: Bottom 33: Opening 38: Corner 40: Upper case (second case part) 50: Outer gap space 51: Outer gap end 52: Lower gap surface 53, 56: Passage region 54, 57: Non-passage region 55: Upper gap surface 60: Adhesive 61: Exposed portion L: Specific light

Claims

1. A battery pack including a plurality of battery cells and a case for housing the battery stack in an internal space, The case is 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, A gap is provided between the first case component and the second case component on the outer side of the adhesive, and the space of the gap is continuous from the outer gap end opening to the outside to the adhesive, The outer gap end of the gap opens downward rather than in the horizontal direction, The adhesive is One having a property that the adhesive force decreases when one of specific light and specific liquid hits it, A battery pack having an exposed portion exposed in the space of the gap.

2. The battery pack according to claim 1, Either one or both of the first case component and the second case component are rebounding case components that can rebound the one on the gap surface exposed in the space of the gap, A battery pack capable of passing the one from the outer gap end of the space of the gap to the exposed portion of the adhesive through a passage region among the gap surfaces of the rebounding case component.

3. The battery pack according to claim 2, A battery pack that cannot directly pass the one from the outer gap end of the space of the gap to the exposed portion of the adhesive.

4. The battery pack according to claim 2 or claim 3, The one is the light, The rebounding case component has a non-passage region on the gap surface with a surface roughness larger than that of the passage region.

5. The battery pack according to claim 4, wherein the rebounding case part is a battery pack in which the via region is subjected to polishing.

6. The battery pack according to claim 4, wherein the rebounding case part is a battery pack in which a reflective material having a smaller surface roughness than the non-via region is provided in the via region.

7. The battery pack according to any one of claims 1 to 3, wherein one of them is the light, and both the part where the adhesive is adhered in the first case part and the part where the adhesive is adhered in the second case part are 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. Battery pack.

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

9. The battery pack according to any one of claims 1 to 3, wherein the opening of the first case part has a polygonal shape having corners, and the exposed portion is a battery pack in a range including at least the corners.

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