Battery pack

Abstract

To provide a battery pack that can more efficiently dissipate the heat accumulated inside the battery pack to the outside. [Solution] A battery pack according to one embodiment of this technology comprises a plurality of batteries, a holder, and a plurality of spacers. Each battery has a pair of end faces on which terminals are provided, and a circumferential surface perpendicular to the pair of end faces. The holder is capable of housing a plurality of batteries, one battery at a time. A plurality of spacers are provided for each housing section. Each spacer is provided in the gap between the circumferential surface of the battery and the inner surface of the housing section. The housing section is provided with a through hole into which a battery can be housed. The through hole is provided with a tapered inner surface in the direction of extension of the through hole. The spacer is made of an elastic member having a tapered circumferential surface that can fill the gap between the circumferential surface of the battery and the inner surface of the through hole.

Description

Technical Field

[0001] This technology relates to a battery pack.

Background Art

[0002] Since electronic devices have become widespread, the development of batteries as power sources applied to such electronic devices has been underway. In this case, in order to handle a plurality of batteries easily and safely, a battery pack including the plurality of batteries has been proposed.

[0003] Regarding technologies related to the configuration of a battery pack, various studies have been made. For example, Patent Document 1 discloses a technology for preventing a short circuit between two adjacent batteries in a battery pack and releasing heat accumulated in the battery pack to the outside.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, it is required to release more efficiently the heat accumulated in the battery pack to the outside. It is desirable to provide a battery pack capable of releasing more efficiently the heat accumulated in the battery pack to the outside.

Means for Solving the Problems

[0006] The battery pack relating to the first aspect of this technology comprises a plurality of batteries, a holder, and a plurality of spacers. Each battery has a pair of end faces on which terminals are provided, and a circumferential surface perpendicular to the pair of end faces. The holder is capable of housing a plurality of batteries, one battery at a time. The plurality of spacers are provided for each housing section. Each spacer is provided in the gap between the circumferential surface of the battery and the inner surface of the housing section. The housing section is provided with a through hole capable of housing a battery. The through hole is provided with a tapered inner surface in the direction of extension of the through hole. The spacer is made of an elastic member having a tapered circumferential surface capable of filling the gap between the circumferential surface of the battery and the inner surface of the through hole.

[0007] A battery pack relating to the second aspect of this technology comprises a plurality of batteries, a holder, a plurality of first spacers, and a plurality of second spacers. Each battery has a pair of end faces on which terminals are provided, and a circumferential surface perpendicular to the pair of end faces. The holder has a plurality of first housings and a plurality of second housings. The first housings and the second housings are arranged with a predetermined gap between them. A plurality of first spacers are provided for each first housing. Each first spacer is provided in the gap between the circumferential surface of the battery and the inner surface of the first housing. A plurality of second spacers are provided for each second housing. Each second spacer is provided in the gap between the circumferential surface of the battery and the inner surface of the second housing. The first housing is provided with a first through hole capable of housing a portion of one end face side of the plurality of batteries. The second housing is provided with a second through hole capable of housing a portion of the other end face side of the plurality of batteries. The first through-hole is provided with a tapered inner surface in the direction of extension of the first through-hole. The second through-hole is provided with a tapered inner surface in the direction of extension of the second through-hole. The first spacer is made of an elastic member having a tapered circumferential surface that can fill the gap between the circumferential surface of the battery and the inner surface of the first through-hole. The second spacer is made of an elastic member having a tapered circumferential surface that can fill the gap between the circumferential surface of the battery and the inner surface of the second through-hole. [Effects of the Invention]

[0008] In the battery pack relating to the first aspect of this technology, the housing section is provided with a through-hole capable of housing a battery, and the through-hole has a tapered inner surface in the direction of extension of the through-hole, and the spacer is made of an elastic member having a tapered circumferential surface that can fill the gap between the circumferential surface of the battery and the inner surface of the through-hole. As a result, heat generated by the battery is efficiently transferred to the holder via the spacer compared to the case where there is an air gap between the circumferential surface of the battery and the inner surface of the housing section. Consequently, the heat accumulated in the battery pack can be released to the outside more efficiently.

[0009] In the battery pack relating to the second aspect of this technology, the first housing is provided with a first through-hole capable of housing a portion of one end face of the battery, and the first through-hole has a tapered inner surface in the direction of extension of the first through-hole, and the first spacer is made of an elastic member having a tapered circumferential surface that can fill the gap between the circumferential surface of the battery and the inner surface of the first through-hole. Furthermore, the second housing is provided with a second through-hole capable of housing a portion of the other end face of the battery, and the second through-hole has a tapered inner surface in the direction of extension of the second through-hole, and the second spacer is made of an elastic member having a tapered circumferential surface that can fill the gap between the circumferential surface of the battery and the inner surface of the second through-hole. As a result, compared to the case where there is a gap between the circumferential surface of the battery and the inner surfaces of the first and second housings, the heat generated by the battery is efficiently transferred to the holder via the first and second spacers. As a result, the heat accumulated inside the battery pack can be released to the outside more efficiently. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a diagram showing an example of a perspective view configuration of a battery pack according to one embodiment of this technology. [Figure 2] Figure 2 shows an example of a perspective view of a battery module, which is one of the components contained in the battery pack shown in Figure 1. [Figure 3]Figure 3 shows an example of the unfolded, oblique view configuration of the battery pack contents shown in Figure 1. [Figure 4] Figure 4(A) shows an example of a cross-sectional configuration of the housing, battery, and spacer in the housing, which is part of the battery holder in Figure 2, with the battery and spacer housed inside. Figure 4(B) shows an example of an unfolded configuration of the housing, battery, and spacer in Figure 4(A). [Figure 5] Figure 5(A) shows a modified example of the cross-sectional configuration of the housing, battery, and spacer in a state where the battery and spacer are housed in the housing, which is part of the battery holder in Figure 2. Figure 5(B) shows an example of the unfolded configuration of the housing, battery, and spacer in Figure 5(A). [Figure 6] Figure 6(A) shows a modified example of the cross-sectional configuration of the housing, battery, and spacer in a state where the battery and spacer are housed in the housing, which is part of the battery holder in Figure 2. Figure 6(B) shows an example of the unfolded configuration of the housing, battery, and spacer in Figure 6(A). [Figure 7] Figure 7(A) shows a modified example of the cross-sectional configuration of the housing, battery, and spacer in a state where the battery and spacer are housed in the housing, which is part of the battery holder in Figure 2. Figure 7(B) shows an example of the unfolded configuration of the housing, battery, and spacer in Figure 7(A). [Figure 8] Figure 8(A) shows a modified example of the cross-sectional configuration of the housing, battery, and spacer when the battery and spacer are housed in the housing, which is part of the battery holder in Figure 2. Figure 8(B) shows an example of the unfolded configuration of the housing, battery, and spacer in Figure 8(A). [Figure 9] Figure 9(A) shows a modified example of the cross-sectional configuration of the housing, battery, and spacer in a state where the battery and spacer are housed in the housing, which is part of the battery holder in Figure 2. Figure 9(B) shows an example of the unfolded configuration of the housing, battery, and spacer in Figure 9(A). [Figure 10]Figure 10(A) shows a modified example of the cross-sectional configuration of the housing, battery, and spacer in a state where the battery and spacer are housed in the housing, which is part of the battery holder in Figure 2. Figure 10(B) shows an example of the unfolded configuration of the housing, battery, and spacer in Figure 10(A). [Figure 11] Figure 11(A) shows a modified example of the cross-sectional configuration of the housing, battery, and spacer in a state where the battery and spacer are housed in the housing, which is part of the battery holder in Figure 2. Figure 11(B) shows an example of the unfolded configuration of the housing, battery, and spacer in Figure 11(A). [Figure 12] Figure 12 shows a modified example of the cross-sectional configuration of a battery module, which is one of the components contained in the battery pack shown in Figure 1. [Figure 13] Figure 13 shows a modified example of the cross-sectional configuration of a battery module, which is one of the components contained in the battery pack shown in Figure 1. [Figure 14] Figure 14 shows a modified example of a perspective view of the battery module, which is one of the components of the battery pack shown in Figure 1. [Figure 15] Figure 15(A) shows an example of a cross-sectional configuration of the housing, battery, and spacer in the housing, which is part of the battery holder shown in Figure 14, with the battery and spacer housed within it. Figure 15(B) shows an example of an unfolded configuration of the housing, battery, and spacer shown in Figure 15(A). [Figure 16] Figure 16(A) shows an example of a cross-sectional configuration of the housing, battery, and spacer in the housing, which is part of the battery holder shown in Figure 14, with the battery and spacer housed within it. Figure 16(B) shows an example of an unfolded configuration of the housing, battery, and spacer shown in Figure 16(A). [Figure 17] Figure 17(A) shows an example of a cross-sectional configuration of the housing, battery, and spacer in the housing, which is part of the battery holder shown in Figure 14, with the battery and spacer housed within it. Figure 17(B) shows an example of an unfolded configuration of the housing, battery, and spacer shown in Figure 17(A). [Figure 18]FIG. 18(A) is a diagram showing a cross-sectional configuration example of the housing portion, the battery, and the spacer in a state where the battery and the spacer are housed in the housing portion that is a part of the battery holder of FIG. 14. FIG. 18(B) is a diagram showing an exploded configuration example of the housing portion, the battery, and the spacer of FIG. 18(A). [Embodiments for Carrying Out the Invention]

[0011] Hereinafter, embodiments for carrying out the present technology will be described in detail with reference to the drawings. The order of description is as follows. 1. Embodiment 1-1. Configuration 1-2. Effects 2. Variation

[0012] [1. Embodiment] First, the battery pack 1 of one embodiment of the present technology will be described.

[0013] The battery pack 1 described here is a power source including a plurality of batteries and is applied to various uses such as electronic devices. Details of the use of the battery pack 1 will be described later. Since the type of the battery is not particularly limited, it may be a primary battery or a secondary battery. The type of the secondary battery is not particularly limited, but specifically, it is a lithium-ion secondary battery that obtains battery capacity by utilizing the absorption and release of lithium ions. The number of batteries is not particularly limited and can be arbitrarily set. Hereinafter, the case where the battery is a secondary battery (lithium-ion secondary battery) will be described. That is, the battery pack 1 described below is a power source including a plurality of secondary batteries.

[0014] [1-1. Configuration] FIG. 1 shows a perspective configuration example of the battery pack 1 according to one embodiment of the present technology. FIG. 2 shows a perspective configuration example of a part of the contents of the battery pack 1. FIG. 3 shows an exploded perspective configuration example of the contents of the battery pack 1.

[0015] The battery pack 1 comprises, for example, an outer case 10 and a battery module 20 housed in the outer case 10, as shown in Figures 1 and 2. The battery pack 1 further comprises, for example, tabs 60a and 60b and a control board 70, as shown in Figure 3.

[0016] The outer casing 10 is composed of a lower case 10a and an upper case 10b, as shown in Figure 1, for example. By overlapping the lower case 10a and the upper case 10b, a housing space is formed for housing the battery module 20, tabs 60a, 60b and the control board 70. The outer casing 10 is capable of housing the battery module 20, tabs 60a, 60b and the control board 70. The outer casing 10 (for example, the lower case 10a) is provided with an external terminal 11 connected to the control board 70. Multiple batteries 30, described later, are connected to the external terminal 11 via the control board 70.

[0017] The outer casing 10 is made of a resin material such as polyethylene (PE), polypropylene (PP), polycarbonate (PC), modified polyphenylene ether (mPPE), polyamide (PA), polybutylene terephthalate (PBT), acrylonitrile-butadiene-styrene copolymer resin (ABS), or polyacetal (POM). The outer casing 10 may also be made of a resin material in which a conductive material such as a metal or conductive filler is dispersed. In this case, the resin material may be one of the resin materials described above.

[0018] The battery pack 1 has a discharge mode in which it supplies power output from the battery module 20 to a load via the external terminal 11. The battery pack 1 may also have a charge mode in which it stores power supplied via the external terminal 11 from a power source connected to the external terminal 11 in the battery module 20. If the battery 30 is a secondary battery, the control board 70 switches between the discharge mode and the charge mode depending on the type of connected object connected to the external terminal 11. If the battery 30 is a primary battery, the control board 70 performs only the discharge mode. The control board 70 is in contact with the upper surface of the battery holder 40, for example. The control board 70 is fixed to the upper surface of the battery holder 40 by, for example, pressure fixing, screw fixing, adhesive fixing, or ultrasonic welding.

[0019] The battery module 20 includes a plurality of batteries 30 and a battery holder 40 capable of supporting the plurality of batteries 30. The batteries 30 correspond to a specific example of the "battery" according to one embodiment of the present disclosure. The battery holder 40 corresponds to a specific example of the "holder" according to one embodiment of the present disclosure. The plurality of batteries 30 are electrically connected to each other via tabs 60a and 60b. The plurality of batteries 30 are connected to each other in series by tabs 60a and 60b, for example. The configuration of connection of the plurality of batteries 30 is not limited to the above. For example, if a plurality of batteries 30 that are part of the plurality of batteries 30 are connected to each other in series by tabs 60a and 60b, and further, the plurality of batteries 30 connected to each other in series are referred to as a series unit, the plurality of series units may be connected to each other in parallel by tabs 60a and 60b.

[0020] Tabs 60a and 60b are made of, for example, metal lead plates. Each battery 30 is either a primary or secondary battery. If each battery 30 is a secondary battery, the type of secondary battery is not particularly limited, but specifically, it could be a lithium-ion secondary battery, which obtains battery capacity by utilizing the intercalation and deintercalation of lithium ions. The following description will focus on the case where each battery 30 is a secondary battery (lithium-ion secondary battery). That is, the battery pack 1 described below is a power source equipped with multiple secondary batteries.

[0021] The battery 30 has a pair of end faces that face each other and a circumferential surface perpendicular to the pair of end faces. The battery 30 extends in a first direction in which the pair of end faces face each other. Tabs 60a and 60b are positioned opposite each other in the first direction with a plurality of batteries 30 in between.

[0022] The battery 30 has a positive electrode 31 and a negative electrode 32. The positive electrode 31 and the negative electrode 32 correspond to a specific example of a "terminal" according to one embodiment of the present disclosure. The positive electrode 31 is provided on one of a pair of end faces of the battery 30. The negative electrode 32 is provided on the other of a pair of end faces of the battery 30. The battery 30 has a cylindrical shape, for example, with a pair of end faces extending in a first direction opposite to each other, and each end face is, for example, circular. The shape of the battery 30 is not limited to a cylindrical shape. The shape of each end face is not limited to a circular shape. The positive electrode 31 is made of a metal material. The positive electrode 31 has a shape that protrudes from the end face of the battery 30. The negative electrode 32 is made of a metal material. The negative electrode 32 forms a flat surface on the end face of the battery 30.

[0023] Multiple batteries 30 are arranged in a two-dimensional direction (a second direction and a third direction perpendicular to both the first and second directions) that is perpendicular to the longitudinal direction (first direction) of the batteries 30. At this time, one end face of each battery 30 provided in the battery pack 1 is located in the first plane, and the end face of each battery 30 provided in the battery pack 1 that is opposite to the end face located in the first plane is located in the second plane. Tab 60a is in contact with multiple electrodes located in the first plane either directly or via a conductive material such as solder. Tab 60b is in contact with multiple electrodes located in the second plane either directly or via a conductive material such as solder.

[0024] In this specification, "extension direction of the battery 30" means the direction parallel to the direction in which the pair of end faces face each other, when the battery 30 has a columnar shape in which the pair of end faces face each other. In this specification, "arrangement direction of the battery 30" means the direction perpendicular to the direction in which the pair of end faces face each other, when the battery 30 has a columnar shape in which the pair of end faces face each other.

[0025] The battery holder 40 is composed of a pair of holders 40a and 40b, as shown in Figures 2 and 3, for example. Both holders 40a and 40b have a common structure. Holders 40a and 40b are resin parts formed by injection molding.

[0026] Holders 40a and 40b each have end faces 41 and 42 facing each other in the extending direction of the battery 30, for example, as shown in Figure 3. An opening 41A is provided in the end face 41 of holders 40a and 40b at a location facing the positive electrode 31 or negative electrode 32 of each battery 30. Therefore, the positive electrode 31 or negative electrode 32 is exposed in the opening 41A. Tab 60a is positioned close to the end face 41 of holder 40a. Tab 60a contacts the positive electrode 31 or negative electrode 32 of each battery 30 directly or via a conductive material such as solder through the opening 41A of holder 40a. Tab 60b is positioned close to the end face 41 of holder 40b. Tab 60b contacts the positive electrode 31 or negative electrode 32 of each battery 30 directly or via a conductive material such as solder through the opening 41A of holder 40b. An opening 42A is provided on the end faces 42 of holders 40a and 40b at a location facing the positive electrode 31 or negative electrode 32 of each battery 30. Therefore, the positive electrode 31 or negative electrode 32 is exposed in the opening 42A. The end face 42 of holder 40a is positioned close to the end face 42 of holder 40b.

[0027] Each holder 40a and 40b further has a support portion 43 capable of supporting multiple batteries 30 in a tiered manner with predetermined gaps between them, for example, as shown in Figure 3. Figure 3 illustrates how the support portion 43 is provided to support multiple batteries 30 in three layers: the bottom layer, the middle layer, and the top layer. The bottom layer is the lowest layer when the battery pack 1 (battery module 20) is viewed from the direction shown in Figure 3. The bottom layer is the layer closest to the bottom surface of the lower case 10a. The top layer is the uppermost layer when the battery pack 1 (battery module 20) is viewed from the direction shown in Figure 3. The top layer is the layer closest to the top surface of the upper case 10b. The middle layer is the layer between the bottom layer and the top layer. The support portion 43 is capable of supporting multiple batteries 30 such that, for example, six batteries 30 surround each battery 30 in the intermediate layer, excluding the two batteries 30 at both ends in the arrangement direction of the batteries 30. The support portion 43 may also be capable of supporting multiple batteries 30 such that the multiple batteries 30 are arranged in the second direction described above and in the third direction described above.

[0028] One end face of the support portion 43 is end face 41, and the other end face of the support portion 43 is end face 42. Multiple openings 41A are provided on one end face (end face 41) of the support portion 43. Multiple openings 42A are provided on the other end face (end face 42) of the support portion 43. The support portion 43 is provided with a through hole H1 connected to the openings 41A and 42A. A portion of the battery 30 is housed in the through hole H1. A portion of the battery 30, including the end face on the tab 60a side, is housed in the through hole H1 of the holder 40a. A portion of the battery 30, including the end face on the tab 60b side, is housed in the through hole H1 of the holder 40b, excluding the portion housed in the through hole H1 of the holder 40a. In other words, the entire circumferential surface of each battery 30 is covered by the through holes H1 of the holders 40a and 40b.

[0029] Holders 40a and 40b are made of resin materials such as polyethylene (PE), polypropylene (PP), polycarbonate (PC), modified polyphenylene ether (mPPE), polyamide (PA), polybutylene terephthalate (PBT), copolymer synthetic resin of acrylonitrile-butadiene-styrene (ABS), and polyacetal (POM). The wall thickness of holders 40a and 40b is preferably within a range that allows for easy molding, for example, 0.5 mm to 5 mm.

[0030] The battery module 20 has a plurality of spacers 50 provided for each battery 30, as shown in Figure 3, for example. The spacers 50 correspond to a specific example of the "spacer" according to one embodiment of the present disclosure. The spacers 50 are provided in the gap between the circumferential surface of the battery 30 and the inner surface of the support portion 43 (or through hole H1).

[0031] Figure 4(A) shows an example of the cross-sectional configuration of the housing 40i, battery 30, and spacer 50 when the battery 30 and spacer 50 are housed in the housing 40i, which is part of the battery holder 40. Figure 4(B) shows an example of the unfolded configuration of the housing 40i, battery 30, and spacer 50 shown in Figure 4(A). Figures 4(A) and 4(B) show an example in which the battery 30 has an end face S1 on which the positive electrode 31 is provided, an end face S2 on which the negative electrode 32 is provided, and a circumferential surface S3 perpendicular to the end faces S1 and S2.

[0032] The battery holder 40 has a plurality of housing sections 40i (1≦i≦n) capable of housing n batteries 30, one battery 30 per section. A housing section 40i corresponds to a specific example of a "housing section" according to one embodiment of the present disclosure. A housing section 40i corresponds to a section when the battery holder 40 is conceptually partitioned, and is composed of, for example, a housing section 40ai (1≦i≦n) and a housing section 40bi (1≦i≦n), as shown in Figures 4(A) and 4(B). A housing section 40ai corresponds to a portion of the holder 40a in which one through hole H1 is formed, and corresponds to a part of the holder 40a, which is a resin part formed by injection molding. A housing section 40ai corresponds to a specific example of a "first housing section" according to one embodiment of the present disclosure. A housing section 40bi corresponds to a portion of the holder 40b in which one through hole H1 is formed, and corresponds to a part of the holder 40b, which is a resin part formed by injection molding. The storage section 40bi corresponds to a specific example of the "second storage section" according to one embodiment of the present disclosure.

[0033] The housing sections 40ai and 40bi both have a common structure. Each housing section 40ai and 40bi has end faces 41 and 42 that face each other in the extending direction of the battery 30, for example, as shown in Figure 4(B). An opening 41A is provided on the end face 41 of the housing sections 40ai and 40bi at a location facing the positive electrode 31 or negative electrode 32 of the battery 30. Therefore, the positive electrode 31 or negative electrode 32 is exposed at the opening 41A. Figure 4(A) shows an example in which the positive electrode 31 is exposed at the opening 41A. An opening 42A is provided on the end face 42 of the housing sections 40ai and 40bi at a location facing the positive electrode 31 or negative electrode 32 of the battery 30. Therefore, the positive electrode 31 or negative electrode 32 is exposed at the opening 42A. Figure 4(A) shows an example in which the negative electrode 32 is exposed at the opening 42A.

[0034] The housing sections 40ai and 40bi are provided with through holes H1 connected to openings 41A and 42A, respectively. A portion of the battery 30 is housed in the through holes H1. The through hole H1 of housing section 40ai houses a portion of the battery 30, including the end face on the tab 60a side. The through hole H1 of housing section 40bi houses the portion of the battery 30, including the end face on the tab 60b side, excluding the portion housed by the through hole H1 of holder 40a. In other words, the entire circumferential surface of the battery 30 is covered by the housing sections 40ai and 40bi.

[0035] The through-hole H1 is provided with a tapered inner surface in the direction of extension of the through-hole H1. The diameter of the opening 41A is smaller than the diameter of the opening 42A. The through-hole H1 is provided with an inner surface in which the diameter of the through-hole H1 continuously widens as it moves from the opening 41A to the opening 42A. The through-hole H1 is provided with an inner surface in which the diameter of the through-hole H1 widens linearly as it moves from the opening 41A to the opening 42A.

[0036] Spacer 50 is provided one at a time for each housing section 40i. Spacer 50 is composed of spacer 50a provided in housing section 40ai and spacer 50b provided in housing section 40bi. Spacer 50a corresponds to a specific example of the "first spacer" according to one embodiment of the present disclosure. Spacer 50b corresponds to a specific example of the "second spacer" according to one embodiment of the present disclosure.

[0037] Spacer 50a is made of an elastic member having a tapered circumferential surface that can fill the gap between the circumferential surface S3 of the battery 30 and the inner surface of the through-hole H1 of the housing 40ai. Spacer 50a is made of a hollow frustoconical elastic member that can fill the gap between the circumferential surface S3 of the battery 30 and the inner surface of the through-hole H1 of the housing 40ai. Spacer 50a makes surface contact with the circumferential surface S3 of the battery 30 and also makes surface contact with the inner surface of the through-hole H1 of the housing 40ai. Spacer 50b is made of an elastic member having a tapered circumferential surface that can fill the gap between the circumferential surface S3 of the battery 30 and the inner surface of the through-hole H1 of the housing 40bi. Spacer 50b is made of a hollow frustoconical elastic member that can fill the gap between the circumferential surface S3 of the battery 30 and the inner surface of the through-hole H1 of the housing 40bi. The spacer 50b makes surface contact with the circumferential surface S3 of the battery 30, and also makes surface contact with the inner surface of the through hole H1 of the housing portion 40bi.

[0038] Examples of elastic materials used in the spacer 50 include a resin material with a thermal conductivity of approximately 0.1 to 3.0 W / m·K, which is a rubber material with a Shore A hardness of approximately 20° to 70° containing a heat dissipation filler. However, the elastic materials used in the spacer 50 are not limited to the above examples.

[0039] Spacers 50a and 50b both have a common structure. Spacers 50a and 50b each have end faces 51 and 52 that face each other in the extending direction of the battery 30, for example, as shown in Figure 4(B). An opening 51A is provided on the end face 51 of spacers 50a and 50b at a location facing the positive electrode 31 or negative electrode 32 of the battery 30. Therefore, the positive electrode 31 or negative electrode 32 is exposed at the opening 51A. An opening 52A is provided on the end face 52 of spacers 50a and 50b at a location facing the positive electrode 31 or negative electrode 32 of the battery 30. Therefore, the positive electrode 31 or negative electrode 32 is exposed at the opening 52A. The end face 52 of spacer 50a is positioned close to the end face 52 of spacer 50b.

[0040] Spacers 50a and 50b are provided with through holes H2 connected to openings 51A and 52A, respectively. A portion of the battery 30 is housed in the through holes H2. The through hole H2 of spacer 50a houses a portion of the battery 30, including the end face on the tab 60a side. The through hole H2 of spacer 50b houses the portion of the battery 30, including the end face on the tab 60b side, excluding the portion housed in the through hole H2 of spacer 50a. In other words, the entire circumferential surface of the battery 30 is covered by spacers 50a and 50b.

[0041] Spacers 50a and 50b are provided with tapered circumferential surfaces with respect to the extending direction of the through hole H2. The diameter of the end face 51 of spacers 50a and 50b is smaller than the diameter of the end face 52 of spacers 50a and 50b. Spacers 50a and 50b are provided with circumferential surfaces in which the diameter of spacers 50a and 50b continuously widens from end face 51 to end face 52. Spacers 50a and 50b are provided with circumferential surfaces in which the diameter of spacers 50a and 50b widens linearly from end face 51 to end face 52.

[0042] [1-2. Effects] Next, I will explain the effects of battery pack 1.

[0043] Due to the widespread use of electronic devices, the development of batteries as power sources for these devices is progressing. In this case, battery packs containing multiple batteries have been proposed to facilitate easy and safe handling of these batteries. In battery holders that support multiple batteries in a battery pack, a tolerance of approximately +0.1 mm is set relative to the maximum outer diameter of each battery, due to the relationship between each battery being incorporated into the battery holder. Furthermore, when the battery holder is formed by injection molding, a mold release taper (approximately 0.5°) is set relative to the mold. As a result, a clearance of approximately 0.39 to 0.7 mm is created between the inner wall of the battery holder and the circumferential surface of the battery.

[0044] This clearance acts as an insulating layer of air, hindering the dissipation of heat emitted from the battery to the outside. As a result, the temperature rise of the battery during charging and discharging cannot be suppressed, and it quickly reaches a temperature that can affect the battery's charge and discharge characteristics. Consequently, the battery's performance cannot be utilized to its fullest potential.

[0045] On the other hand, in this embodiment, the housing section 40i is provided with a through hole H1 capable of housing the battery 30, and the through hole H1 has a tapered inner surface in the direction of extension of the through hole H1. The spacer 50 is made of an elastic member having a tapered circumferential surface that can fill the gap between the circumferential surface S3 of the battery 30 and the inner surface of the through hole H1. As a result, compared to the case where there is an air gap between the circumferential surface S3 of the battery 30 and the inner surface of the housing section 40i, the heat generated in the battery 30 can be efficiently transferred to the battery holder 40 via the spacer 50. As a result, the heat accumulated in the battery pack 1 can be efficiently released to the outside. Therefore, it is possible to make maximum use of the performance of the battery 30.

[0046] In this embodiment, the housing section 40i is composed of housing sections 40ai and 40bi. The housing section 40ai is provided with a frustoconical through-hole H1 capable of housing a portion of the battery 30. The housing section 40bi is provided with a frustoconical through-hole H1 capable of housing the portion of the battery 30 excluding the portion housed in the through-hole H1 of the housing section 40ai. The spacer 50 is composed of a hollow frustoconical spacer 50a capable of filling the gap between the circumferential surface S3 of the battery 30 and the inner surface of the through-hole H1 of the housing section 40ai, and a hollow frustoconical spacer 50b capable of filling the gap between the circumferential surface S3 of the battery 30 and the inner surface of the through-hole H1 of the housing section 40bi. As a result, compared to the case where there is an air gap between the circumferential surface S3 of the battery 30 and the inner surface of the housing section 40i, the heat generated in the battery 30 can be efficiently transferred to the battery holder 40 via the spacers 50a and 50b. As a result, the heat accumulated inside the battery pack 1 can be efficiently released to the outside. Therefore, it becomes possible to make maximum use of the performance of the battery 30.

[0047] In this embodiment, the through holes H1 of the housing sections 40ai and 40bi are provided with an inner surface in which the diameter of the through hole H1 increases linearly from the opening 41A toward the opening 42A. This allows the housing sections 40ai and 40bi to be resin parts formed by injection molding. Furthermore, in this embodiment, the spacers 50a and 50b are provided with a circumferential surface in which the diameter of the spacers 50a and 50b increases linearly from the end face 51 toward the end face 52. This allows the inner surfaces of the housing sections 40ai and 40bi to be in surface contact with the circumferential surfaces of the spacers 50a and 50b. As a result, the heat accumulated inside the battery pack 1 can be efficiently released to the outside. Therefore, it becomes possible to maximize the performance of the battery 30.

[0048] In this embodiment, the through holes H1 of the housing sections 40ai and 40bi are provided with an inner surface in which the diameter of the through hole H1 increases linearly from the opening 41A towards the opening 42A, and the spacers 50a and 50b are provided with a circumferential surface in which the diameter of the spacers 50a and 50b increases linearly from the end face 51 towards the end face 52. This makes it easy to remove the spacers 50a and 50b from the housing sections 40ai and 40bi. Furthermore, in the event of an external impact, the stress from the housing sections 40ai and 40bi to the spacers 50a and 50b can be evenly distributed. In addition, since both the inner surfaces of the housing sections 40ai and 40bi and the circumferential surfaces of the spacers 50a and 50b are linear in shape, there is also the advantage that it is easy to process and control the dimensions of the housing sections 40ai and 40bi and the spacers 50a and 50b.

[0049] In this embodiment, the thickness of the spacers 50a and 50b (the distance between the inner surface and the circumferential surface of the spacers 50a and 50b) is greater in the portion of the battery 30 closer to the center than in the portion of the battery 30 closer to the terminals. In this case, if the thermal conductivity of the spacers 50a and 50b is higher than that of the housing portion 40i, and the temperature of the battery 30 is particularly higher in the central portion of the battery 30 than at the edges, the heat in the central portion of the battery 30 can be efficiently dissipated by the spacers 50a and 50b.

[0050] In this embodiment, if the volume occupied by the housing section 40i is greater than the volume occupied by the spacers 50a and 50b, the overall durability of the battery pack 1 can be improved.

[0051] <2. Variant> Next, we will describe a modified version of battery pack 1.

[0052] [Differentiation A] Figure 5(A) shows one modified example of the cross-sectional configuration of the housing 40i, battery 30, and spacer 50 when the battery 30 and spacer 50 are housed in the housing 40i. Figure 5(B) shows one modified example of the unfolded configuration of the housing 40i, battery 30, and spacer 50 shown in Figure 5(A).

[0053] In the above embodiment, for example, as shown in Figures 5(A) and 5(B), the through-hole H1 may be provided with a convex inner surface in which the diameter of the through-hole H1 widens in a second-order nonlinear manner from the opening 41A toward the opening 42A. In this case, the spacers 50a and 50b are provided with concave circumferential surfaces in which the diameter of the spacers 50a and 50b widens in a second-order nonlinear manner from the end face 51 toward the end face 52. The spacers 50a and 50b are in surface contact with the circumferential surface S3 of the battery 30 and also in surface contact with the inner surface of the through-hole H1. As a result, compared to the case where there is an air gap between the circumferential surface S3 of the battery 30 and the inner surface of the housing 40i, the heat generated in the battery 30 is efficiently transferred to the battery holder 40 via the spacers 50a and 50b. As a result, the heat accumulated in the battery pack 1 can be efficiently released to the outside. Therefore, it is possible to make maximum use of the performance of the battery 30.

[0054] In this modified example, the thickness of the spacers 50a and 50b (the distance between the inner surface and the circumferential surface of the spacers 50a and 50b) is greater in the central part of the battery 30 than in the terminal part of the battery 30. In this case, if the thermal conductivity of the spacers 50a and 50b is higher than that of the housing part 40i, and the temperature of the battery 30 is particularly high in the central part of the battery 30 than at the ends of the battery 30, the heat in the central part of the battery 30 can be efficiently dissipated by the spacers 50a and 50b.

[0055] In this modified example, if the volume occupied by the housing section 40i is greater than the volume occupied by the spacers 50a and 50b, the overall durability of the battery pack 1 can be improved.

[0056] [Variation B] Figure 6(A) shows one modified example of the cross-sectional configuration of the housing 40i, battery 30, and spacer 50 when the battery 30 and spacer 50 are housed in the housing 40i. Figure 6(B) shows one modified example of the unfolded configuration of the housing 40i, battery 30, and spacer 50 shown in Figure 6(A).

[0057] In the above embodiment, for example, as shown in Figures 6(A) and 6(B), the through-hole H1 may be provided with a concave inner surface in which the diameter of the through-hole H1 widens in a second-order nonlinear manner from the opening 41A toward the opening 42A. In this case, the spacers 50a and 50b are provided with convex circumferential surfaces in which the diameter of the spacers 50a and 50b widens in a second-order nonlinear manner from the end face 51 toward the end face 52. The spacers 50a and 50b are in surface contact with the circumferential surface S3 of the battery 30 and also in surface contact with the inner surface of the through-hole H1. As a result, compared to the case where there is an air gap between the circumferential surface S3 of the battery 30 and the inner surface of the housing 40i, the heat generated in the battery 30 is efficiently transferred to the battery holder 40 via the spacers 50a and 50b. As a result, the heat accumulated in the battery pack 1 can be released to the outside more efficiently. Therefore, it becomes possible to make maximum use of the performance of the battery 30.

[0058] In this modified example, the thickness of the spacers 50a and 50b (the distance between the inner surface and the circumferential surface of the spacers 50a and 50b) is greater in the central part of the battery 30 than in the terminal part of the battery 30. In this case, if the thermal conductivity of the spacers 50a and 50b is higher than that of the housing part 40i, and the temperature of the battery 30 is particularly high in the central part of the battery 30 than at the ends of the battery 30, the heat in the central part of the battery 30 can be efficiently dissipated by the spacers 50a and 50b.

[0059] In this modified example, if the volume occupied by the housing 40i is smaller than the volume occupied by the spacers 50a and 50b, the vibration absorption performance of the spacers 50a and 50b can be improved.

[0060] [Differentiation C] Figure 7(A) shows one modified example of the cross-sectional configuration of the housing 40i, battery 30, and spacer 50 when the battery 30 and spacer 50 are housed in the housing 40i. Figure 7(B) shows one modified example of the unfolded configuration of the housing 40i, battery 30, and spacer 50 shown in Figure 7(A).

[0061] In the above embodiment, for example, as shown in Figures 7(A) and 7(B), the through-hole H1 may be provided with an inner surface in which the diameter of the through-hole H1 widens in a stepped manner from the opening 41A toward the opening 42A. In this case, the spacers 50a and 50b are provided with circumferential surfaces in which the diameter of the spacers 50a and 50b widens in a stepped manner from the end face 51 toward the end face 52. The spacers 50a and 50b are in surface contact with the circumferential surface S3 of the battery 30 and also in surface contact with the inner surface of the through-hole H1. As a result, compared to the case where there is an air gap between the circumferential surface S3 of the battery 30 and the inner surface of the housing 40i, the heat generated in the battery 30 is efficiently transferred to the battery holder 40 via the spacers 50a and 50b. As a result, the heat accumulated in the battery pack 1 can be released to the outside more efficiently.

[0062] In this modified example, a step is provided on the inner surface of the housing section 40i, and further steps are provided on the circumferential surfaces of the spacers 50a and 50b. This allows the spacers 50a and 50b to be easily fixed inside the housing section 40i, and improves the positional stability of the spacers 50a and 50b within the housing section 40i.

[0063] In this modified example, the thickness of the spacers 50a and 50b (the distance between the inner surface and the circumferential surface of the spacers 50a and 50b) is greater in the central part of the battery 30 than in the terminal part of the battery 30. In this case, if the thermal conductivity of the spacers 50a and 50b is higher than that of the housing part 40i, and the temperature of the battery 30 is particularly high in the central part of the battery 30 than at the ends of the battery 30, the heat in the central part of the battery 30 can be efficiently dissipated by the spacers 50a and 50b.

[0064] In this modified example, if the volume occupied by the housing 40i is smaller than the volume occupied by the spacers 50a and 50b, the vibration absorption performance of the spacers 50a and 50b can be improved.

[0065] [Differentiation D] Figure 8(A) shows one modified example of the cross-sectional configuration of the housing 40i, battery 30, and spacer 50 when the battery 30 and spacer 50 are housed in the housing 40i. Figure 8(B) shows one modified example of the unfolded configuration of the housing 40i, battery 30, and spacer 50 shown in Figure 8(A).

[0066] In the above embodiment, for example, as shown in Figures 8(A) and 8(B), the through-hole H1 may be provided with an inner surface in which the diameter of the through-hole H1 narrows linearly from the opening 41A toward the opening 42A. In this case, the spacers 50a and 50b are provided with circumferential surfaces in which the diameter of the spacers 50a and 50b narrows linearly from the end face 51 toward the end face 52. The spacers 50a and 50b are in surface contact with the circumferential surface S3 of the battery 30 and also in surface contact with the inner surface of the through-hole H1. As a result, compared to the case where there is an air gap between the circumferential surface S3 of the battery 30 and the inner surface of the housing 40i, the heat generated in the battery 30 is efficiently transferred to the battery holder 40 via the spacers 50a and 50b. As a result, the heat accumulated in the battery pack 1 can be released to the outside more efficiently.

[0067] In this modified example, the through-holes H1 of the housing sections 40ai and 40bi are provided with an inner surface in which the diameter of the through-hole H1 narrows linearly from the opening 41A towards the opening 42A, and the spacers 50a and 50b are provided with a circumferential surface in which the diameter of the spacers 50a and 50b narrows linearly from the end face 51 towards the end face 52. This allows the heat generated by the battery 30 to be efficiently dissipated towards the end face 41 of the housing sections 40ai and 40bi. Furthermore, the spacers 50a and 50b can be easily removed from the housing sections 40ai and 40bi. In addition, in the event of an external impact, the stress from the housing sections 40ai and 40bi to the spacers 50a and 50b can be evenly distributed. Moreover, since both the inner surfaces of the housing sections 40ai and 40bi and the circumferential surfaces of the spacers 50a and 50b are linear in shape, there is also the advantage that processing and dimensional control of the housing sections 40ai and 40bi and the spacers 50a and 50b are easier.

[0068] In this modified example, if the volume occupied by the housing section 40i is greater than the volume occupied by the spacers 50a and 50b, the overall durability of the battery pack 1 can be improved.

[0069] [Differentiation Example E] Figure 9(A) shows one modified example of the cross-sectional configuration of the housing 40i, battery 30, and spacer 50 when the battery 30 and spacer 50 are housed in the housing 40i. Figure 9(B) shows one modified example of the unfolded configuration of the housing 40i, battery 30, and spacer 50 shown in Figure 9(A).

[0070] In the above embodiment, for example, as shown in Figures 9(A) and 9(B), the through-hole H1 may be provided with an inner surface where the diameter of the through-hole H1 is constant from the opening 41A to a predetermined point before the opening 42A, and a convex inner surface where the diameter of the through-hole H1 expands linearly and quadratically from the predetermined point toward the opening 42A. In this case, the spacers 50a and 50b are provided with concave circumferential surfaces where the diameter of the spacers 50a and 50b expands quadratically and nonlinearly from the end face 51 toward the end face 52. The spacers 50a and 50b are in surface contact with the circumferential surface S3 of the battery 30 and also in surface contact with a part of the inner surface (convex inner surface) of the through-hole H1. As a result, compared to the case where there is an air gap between the circumferential surface S3 of the battery 30 and the inner surface of the housing 40i, the heat generated in the battery 30 is efficiently transferred to the battery holder 40 via the spacers 50a and 50b. As a result, the heat accumulated in the battery pack 1 can be released to the outside more efficiently.

[0071] In this modified example, the thickness of the spacers 50a and 50b (the distance between the inner surface and the circumferential surface of the spacers 50a and 50b) is greater in the central part of the battery 30 than in the terminal part of the battery 30. In this case, if the thermal conductivity of the spacers 50a and 50b is higher than that of the housing part 40i, and the temperature of the battery 30 is particularly high in the central part of the battery 30 than at the ends of the battery 30, the heat in the central part of the battery 30 can be efficiently dissipated by the spacers 50a and 50b.

[0072] In this modified example, if the volume occupied by the housing section 40i is greater than the volume occupied by the spacers 50a and 50b, the overall durability of the battery pack 1 can be improved.

[0073] [Modification F] Figure 10(A) shows one modified example of the cross-sectional configuration of the housing 40i, battery 30, and spacer 50 when the battery 30 and spacer 50 are housed in the housing 40i. Figure 10(B) shows one modified example of the unfolded configuration of the housing 40i, battery 30, and spacer 50 shown in Figure 10(A).

[0074] In the above embodiment, the battery holder 40 and the housing portion 40i may be made of a single resin block. In this case, the spacer 50 may be made of a single elastic resin block.

[0075] The housing portion 40i has end faces 41 and 42 that face each other in the extending direction of the battery 30, as shown in Figures 10(A) and 10(B), for example. An opening 41A is provided on end face 41 of the housing portion 40i at a location facing the positive electrode 31 or negative electrode 32 of the battery 30. Therefore, the positive electrode 31 or negative electrode 32 is exposed at the opening 41A. Figure 10(A) shows an example in which the positive electrode 31 is exposed at the opening 41A. An opening 42A is provided on end face 42 of the housing portion 40i at a location facing the positive electrode 31 or negative electrode 32 of the battery 30. Therefore, the positive electrode 31 or negative electrode 32 is exposed at the opening 42A. Figure 10(A) shows an example in which the negative electrode 32 is exposed at the opening 42A.

[0076] Each housing section 40i is provided with a through-hole H1 connected to the openings 41A and 42A. The entire battery 30 is housed in the through-hole H1. In other words, the entire circumferential surface of the battery 30 is covered by the housing section 40i. The through-hole H1 has a tapered inner surface in the direction of extension of the through-hole H1. The diameter of the opening 41A is smaller than the diameter of the opening 42A. The through-hole H1 has an inner surface in which the diameter of the through-hole H1 continuously widens from the opening 41A towards the opening 42A.

[0077] The spacer 50 is made of an elastic member having a tapered circumferential surface that can fill the gap between the circumferential surface S3 of the battery 30 and the inner surface of the through hole H1 of the housing 40i. The spacer 50 is made of a hollow frustoconical elastic member that can fill the gap between the circumferential surface S3 of the battery 30 and the inner surface of the through hole H1 of the housing 40i. The spacer 50 makes surface contact with the circumferential surface S3 of the battery 30 and also makes surface contact with the inner surface of the through hole H1 of the housing 40i.

[0078] The spacer 50 has end faces 51 and 52 that face each other in the extending direction of the battery 30, as shown in Figure 10(B), for example. An opening 51A is provided on the end face 51 of the spacer 50 at a location facing the positive electrode 31 or negative electrode 32 of the battery 30. Therefore, the positive electrode 31 or negative electrode 32 is exposed at the opening 51A. An opening 52A is provided on the end face 52 of the spacer 50 at a location facing the positive electrode 31 or negative electrode 32 of the battery 30. Therefore, the positive electrode 31 or negative electrode 32 is exposed at the opening 52A.

[0079] Each spacer 50 is provided with a through hole H2 connected to openings 51A and 52A. A portion of the battery 30 is housed in the through hole H2. The entire battery 30 is housed in the through hole H2 of the spacer 50. The spacer 50 is provided with a tapered circumferential surface in the direction extending of the through hole H2. The diameter of the end face 51 of the spacer 50 is smaller than the diameter of the end face 52 of the spacer 50. The spacer 50 is provided with a circumferential surface in which the diameter of the spacer 50 continuously widens from the end face 51 to the end face 52.

[0080] In this modified example, the housing section 40i is provided with a through-hole H1 capable of housing the battery 30, and the through-hole H1 has a tapered inner surface in the direction of extension of the through-hole H1. The spacer 50 is made of an elastic member having a tapered circumferential surface that can fill the gap between the circumferential surface S3 of the battery 30 and the inner surface of the through-hole H1. As a result, heat generated in the battery 30 can be efficiently transferred to the battery holder 40 via the spacer 50, compared to the case where there is an air gap between the circumferential surface S3 of the battery 30 and the inner surface of the housing section 40i. Consequently, the heat accumulated in the battery pack 1 can be efficiently released to the outside. Therefore, it is possible to make maximum use of the performance of the battery 30.

[0081] In this modified example, the housing section 40i is provided with a frustoconical through-hole H1 capable of housing the entire battery 30. The spacer 50 has a hollow frustoconical shape capable of filling the gap between the circumferential surface S3 of the battery 30 and the inner surface of the through-hole H1 in the housing section 40i, and is made of an elastic member with a tapered circumferential surface that can fill the gap between the circumferential surface S3 of the battery 30 and the inner surface of the through-hole H1. As a result, heat generated in the battery 30 can be efficiently transferred to the battery holder 40 via the spacer 50, compared to the case where there is an air gap between the circumferential surface S3 of the battery 30 and the inner surface of the housing section 40i. Consequently, the heat accumulated in the battery pack 1 can be efficiently released to the outside. Therefore, it becomes possible to make maximum use of the performance of the battery 30.

[0082] In this modified example, the through-hole H1 of the housing section 40i is provided with an inner surface in which the diameter of the through-hole H1 increases linearly from the opening 41A toward the opening 42A. This allows the housing sections 40ai and 40bi to be resin parts formed by injection molding. Furthermore, in this modified example, the spacers 50a and 50b are provided with circumferential surfaces in which the diameter of the spacers 50a and 50b increases linearly from the end face 51 toward the end face 52. This allows the inner surface of the housing section 40i and the circumferential surface of the spacer 50 to be in surface contact. As a result, the heat accumulated inside the battery pack 1 can be efficiently released to the outside. Therefore, it becomes possible to make maximum use of the performance of the battery 30.

[0083] In this modified example, the through-hole H1 of the housing section 40i is provided with an inner surface in which the diameter of the through-hole H1 increases linearly from the opening 41A to the opening 42A, and the spacer 50 is provided with a circumferential surface in which the diameter of the spacer 50 increases linearly from the end face 51 to the end face 52. This makes it easy to remove the spacer 50 from the housing section 40i. In addition, in the event of an external impact, the stress from the housing section 40i to the spacer 50 can be evenly distributed. Furthermore, since both the inner surface of the housing section 40i and the circumferential surface of the spacer 50 are linear in shape, there is also the advantage that it is easier to process and control the dimensions of the housing section 40i and the spacer 50.

[0084] In this modified example, the through-hole H1 of the housing section 40i is provided with an inner surface in which the diameter of the through-hole H1 narrows linearly from the opening 41A to the opening 42A, and the spacer 50 is provided with a circumferential surface in which the diameter of the spacer 50 narrows linearly from the end face 51 to the end face 52. This allows heat generated by the battery 30 to be efficiently dissipated towards the end face 41 of the housing section 40i. Furthermore, the spacer 50 can be easily removed from the housing section 40i. In addition, in the event of an external impact, the stress from the housing section 40i to the spacer 50 can be evenly distributed. Moreover, since both the inner surface of the housing section 40i and the circumferential surface of the spacer 50 are linear in shape, there is also the advantage that processing and dimensional control of the housing section 40i and the spacer 50 are easier.

[0085] In this modified example, if the volume occupied by the housing section 40i is greater than the volume occupied by the spacer 50, the overall durability of the battery pack 1 can be improved.

[0086] [Differentiation G] Figure 11(A) shows one modified example of the cross-sectional configuration of the housing 40i, battery 30, and spacers 50a, 50b when the battery 30 and spacers 50a, 50b are housed in the housing 40i. Figure 11(B) shows one modified example of the unfolded configuration of the housing 40i, battery 30, and spacers 50a, 50b shown in Figure 11(A).

[0087] In the above embodiment, the battery holder 40 and the housing portion 40i may be made of a single resin block. The housing portion 40i has end faces 41 and 42 that face each other in the extending direction of the battery 30, for example, as shown in Figures 11(A) and 11(B). An opening 41A is provided on the end face 41 of the housing portion 40i at a location facing the positive electrode 31 or negative electrode 32 of the battery 30. Therefore, the positive electrode 31 or negative electrode 32 is exposed at the opening 41A. Figure 11(A) shows an example in which the positive electrode 31 is exposed at the opening 41A. An opening 42A is provided on the end face 42 of the housing portion 40i at a location facing the positive electrode 31 or negative electrode 32 of the battery 30. Therefore, the positive electrode 31 or negative electrode 32 is exposed at the opening 42A. Figure 11(A) shows an example in which the negative electrode 32 is exposed at the opening 42A.

[0088] Each housing section 40i is provided with a through-hole H1 connected to openings 41A and 42A. The entire battery 30 is housed in the through-hole H1. In other words, the entire circumferential surface of the battery 30 is covered by the housing section 40i. The through-hole H1 has a tapered inner surface in the direction of extension of the through-hole H1. The diameter of opening 41A is equal to the diameter of opening 42A. The through-hole H1 has an inner surface in which the inner diameter of the central part in the direction in which openings 41A and 42A face each other is narrower than the diameters of openings 41A and 42A. The through-hole H1 has a shape in which two frustums are connected at the ends with the smaller diameters.

[0089] Spacers 50a and 50b are provided with circumferential surfaces that narrow linearly in diameter from end face 51 towards end face 52. Spacers 50a and 50b are made of elastic members with tapered circumferential surfaces that can fill the gap between the circumferential surface S3 of the battery 30 and the inner surface of the through hole H1 of the housing 40i. Spacer 50 makes surface contact with the circumferential surface S3 of the battery 30 and also makes surface contact with the inner surface of the through hole H1 of the housing 40i.

[0090] As described above, in this modified example, the through-hole H1 of the housing section 40i has a shape in which two frustums are connected at the ends with the smaller diameters. The spacers 50a and 50b are made of elastic members with tapered circumferential surfaces that can fill the gap between the circumferential surface S3 of the battery 30 and the inner surface of the through-hole H1 of the housing section 40i. As a result, the spacers 50 can make surface contact with the circumferential surface S3 of the battery 30 and the inner surface of the through-hole H1 of the housing section 40i. Consequently, compared to the case where a gap is provided between the circumferential surface S3 of the battery 30 and the inner surface of the housing section 40i, the heat generated in the battery 30 is efficiently transferred to the battery holder 40 via the spacers 50a and 50b. As a result, the heat accumulated in the battery pack 1 can be released to the outside more efficiently.

[0091] In this modified example, the through-hole H1 of the housing section 40i is provided with an inner surface in which the inner diameter of the central portion in the direction in which the openings 41A and 42A face each other is narrower than the diameters of the openings 41A and 42A. The spacers 50a and 50b are provided with circumferential surfaces in which the diameter of the spacers 50a and 50b narrows linearly from the end face 51 to the end face 52. This allows the heat generated by the battery 30 to be efficiently dissipated towards the end faces 41 and 42 of the housing section 40i. In addition, the spacers 50a and 50b can be easily removed from the housing section 40i.

[0092] In this modified example, if the volume occupied by the housing section 40i is greater than the volume occupied by the spacers 50a and 50b, the overall durability of the battery pack 1 can be improved.

[0093] [Modified form H] Figure 12 shows a modified example of the cross-sectional configuration of a battery module 20, which is one of the components of the battery pack 1. In this modified example, the thermal conductivity λ of the spacers 50a and 50b located on the central side in the arrangement direction of the batteries 30 may be higher than the thermal conductivity λ of the spacers 50a and 50b located at both ends in the arrangement direction of the batteries 30.

[0094] For example, as shown in Figure 12, in a plurality of spacers 50a, 50b provided in the intermediate layer of holders 40a, 40b, let λa be the thermal conductivity of the spacer 50a, 50b provided in the center, let λc be the thermal conductivity of the spacers 50a, 50b provided at both ends, and let λb be the thermal conductivity of the spacer 50a, 50b provided between the center and both ends. In this case, λa, λb, λc satisfy, for example, the following equation (1). λa, λb, λc may also satisfy, for example, the following equation (2). λa > λb > λc ... (1) λa > λb = λc ... (2)

[0095] Generally, when multiple batteries 30 are housed in a battery holder 40, the batteries 30 located towards the center of the battery arrangement direction tend to accumulate more heat than the batteries 30 located at both ends of the battery arrangement direction. The battery arrangement direction is either parallel to each layer of the battery holder 40 or perpendicular to each layer of the battery holder 40. Here, the battery 30 located in the center of the battery arrangement direction is referred to as 30a. The batteries 30 located at both ends of the battery arrangement direction are referred to as 30b. In this case, by making the thermal conductivity of the spacers 50a and 50b in contact with battery 30a greater than that of the spacers 50a and 50b in contact with battery 30b, the heat emitted from battery 30a can be dissipated to the outside more efficiently than the heat emitted from battery 30b. As a result, it is possible to make the temperature distribution of the multiple batteries 30 housed in the battery holder 40 more uniform.

[0096] In this modified example, the shape and size of each through-hole H1 in the battery holder 40 may be equal to each other, and furthermore, the shape, size, and thickness of each spacer 50a, 50b may be equal to each other. In addition, in this modified example, one or more slits may be provided on the circumferential surface of the spacers 50a, 50b that are in contact with the battery 30b. In this case, the contact area between the spacers 50a, 50b and the battery 30b is reduced by the amount of the one or more slits provided. Therefore, by adjusting the size of one or more slits, the heat dissipation of the spacers 50a, 50b that are in contact with the battery 30b can be adjusted, and the temperature distribution of the multiple batteries 30 housed in the battery holder 40 can be made more uniform.

[0097] [Modification I] Figure 13 shows a modified cross-sectional configuration of a battery module 20, which is one of the components of the battery pack 1. In this modified configuration, the average thickness T of the spacers 50a and 50b located on the central side in the arrangement direction of the batteries 30 may be thicker than the average thickness T of the spacers 50a and 50b located at both ends in the arrangement direction of the batteries 30. The average thickness T is the average of the thickness at the end face 51 of the spacers 50a and 50b, the thickness at the end face 52 of the spacers 50a and 50b, and the thickness at the central portion of the spacers 50a and 50b in the direction in which the end faces 51 and 52 face each other.

[0098] For example, as shown in Figure 13, in a plurality of spacers 50a, 50b provided in the intermediate layer of holders 40a, 40b, let Ta be the average thickness of the spacers 50a, 50b provided in the center, Tc be the average thickness of the spacers 50a, 50b provided at both ends, and Tb be the average thickness of the spacers 50a, 50b provided between the center and both ends. In this case, Ta, Tb, and Tc satisfy, for example, the following equation (3). Ta, Tb, and Tc may also satisfy, for example, the following equation (4). Ta>Tb>Tc…(3) Ta > Tb = Tc ... (4)

[0099] Generally, when multiple batteries 30 are housed in a battery holder 40, the batteries 30 located towards the center of the battery arrangement direction tend to accumulate more heat than the batteries 30 located at both ends of the battery arrangement direction. The battery arrangement direction is either parallel to each layer of the battery holder 40 or perpendicular to each layer of the battery holder 40. Here, the batteries 30 located towards the center of the battery arrangement direction are referred to as 30a. The batteries 30 located at both ends of the battery arrangement direction are referred to as 30b. In this case, the thermal conductivity of the spacers 50a and 50b is made higher than that of the battery holder 40, and the average inner diameter of the through-hole H1 corresponding to battery 30a in the battery holder 40 is made larger than the average inner diameter of the through-hole H1 corresponding to battery 30b in the battery holder 40. The average inner diameter is the average of the inner diameter at end face 51 of the through hole H1, the inner diameter at end face 52 of the through hole H1, and the inner diameter in the central portion of the through hole H1 in the direction in which end faces 51 and end face 52 face each other. Furthermore, the average thickness of the spacers 50a and 50b in contact with the battery 30a is made thicker than the average thickness of the spacers 50a and 50b in contact with the battery 30b. This allows heat emitted from battery 30a to be dissipated to the outside more efficiently than heat emitted from battery 30b. As a result, it is possible to make the temperature distribution of the multiple batteries 30 housed in the battery holder 40 more uniform.

[0100] [Modification J] Figure 14 shows a modified example of a perspective view of a battery module 20, one of the components of the battery pack 1. In this modified example, the battery holder 40 has a pair of holders 40a and 40b arranged with a predetermined gap between them, for example, as shown in Figure 14. An air-cooling channel 44 through which gas can pass is provided between holder 40a and holder 40b. The circumferential surfaces of the multiple batteries 30 supported by the battery holder 40 are exposed to the air-cooling channel 44. By flowing gas through the air-cooling channel 44, the heat generated by the batteries 30 is discharged from the circumferential surfaces of the batteries 30 into the air-cooling channel 44.

[0101] Holders 40a and 40b both have a common structure. Holders 40a and 40b are resin parts formed by injection molding. In this modified example, holder 40a is composed of multiple housing sections 40ai capable of housing a portion of one end face side of a plurality of batteries 30, one battery 30 at a time. In this modified example, holder 40b is composed of multiple housing sections 40bi capable of housing a portion of the other end face side of a plurality of batteries 30, one battery 30 at a time.

[0102] The housing sections 40ai and 40bi each have end faces 41 and 42 that face each other in the extending direction of the battery 30, as shown in Figure 15(B), for example. An opening 41A is provided on the end face 41 of the housing sections 40ai and 40bi at a location facing the positive electrode 31 or negative electrode 32 of the battery 30. Therefore, the positive electrode 31 or negative electrode 32 is exposed at the opening 41A. Figure 15(A) shows an example in which the positive electrode 31 is exposed at the opening 41A. An opening 42A is provided on the end face 42 of the housing sections 40ai and 40bi at a location facing the positive electrode 31 or negative electrode 32 of the battery 30. Therefore, the positive electrode 31 or negative electrode 32 is exposed at the opening 42A. Figure 15(A) shows an example in which the negative electrode 32 is exposed at the opening 42A.

[0103] The housing sections 40ai and 40bi are provided with through holes H1 connected to openings 41A and 42A, respectively. The tip portion of the battery 30 is housed in the through holes H1. The through hole H1 of housing section 40ai houses a portion of the battery 30, including the end face on the tab 60a side. The through hole H1 of housing section 40bi houses a portion of the battery 30, including the end face on the tab 60b side. The tip portion of the battery 30 is covered by the housing sections 40ai and 40bi, while the central portion of the battery 30 is not covered by the housing sections 40ai and 40bi and is exposed to the air cooling channel 44.

[0104] The through-hole H1 is provided with a tapered inner surface in the direction of extension of the through-hole H1. The diameter of the opening 41A is smaller than the diameter of the opening 42A. The through-hole H1 is provided with an inner surface in which the diameter of the through-hole H1 continuously widens as it moves from the opening 41A to the opening 42A. The through-hole H1 is provided with an inner surface in which the diameter of the through-hole H1 widens linearly as it moves from the opening 41A to the opening 42A.

[0105] One spacer 50 is provided for each housing section 40i. The spacer 50 consists of a spacer 50a provided in the housing section 40ai and a spacer 50b provided in the housing section 40bi.

[0106] Spacer 50a is made of an elastic member having a tapered circumferential surface that can fill the gap between the circumferential surface S3 of the battery 30 and the inner surface of the through-hole H1 of the housing 40ai. Spacer 50a is made of a hollow frustoconical elastic member that can fill the gap between the circumferential surface S3 of the battery 30 and the inner surface of the through-hole H1 of the housing 40ai. Spacer 50a makes surface contact with the circumferential surface S3 of the battery 30 and also makes surface contact with the inner surface of the through-hole H1 of the housing 40ai. Spacer 50b is made of an elastic member having a tapered circumferential surface that can fill the gap between the circumferential surface S3 of the battery 30 and the inner surface of the through-hole H1 of the housing 40bi. Spacer 50b is made of a hollow frustoconical elastic member that can fill the gap between the circumferential surface S3 of the battery 30 and the inner surface of the through-hole H1 of the housing 40bi. The spacer 50b makes surface contact with the circumferential surface S3 of the battery 30, and also makes surface contact with the inner surface of the through hole H1 of the housing portion 40bi.

[0107] Spacers 50a and 50b both have a common structure. Spacers 50a and 50b each have end faces 51 and 52 that face each other in the extending direction of the battery 30, for example, as shown in Figure 15(B). An opening 51A is provided on the end face 51 of spacers 50a and 50b at a location facing the positive electrode 31 or negative electrode 32 of the battery 30. Therefore, the positive electrode 31 or negative electrode 32 is exposed at the opening 51A. An opening 52A is provided on the end face 52 of spacers 50a and 50b at a location facing the positive electrode 31 or negative electrode 32 of the battery 30. Therefore, the positive electrode 31 or negative electrode 32 is exposed at the opening 52A. The end face 52 of spacer 50a and the end face 52 of spacer 50b are arranged facing each other via an air cooling channel 44.

[0108] Spacers 50a and 50b are provided with through holes H2 connected to openings 51A and 52A, respectively. The tip portion of the battery 30 is housed in the through holes H2. A portion of the battery 30, including the end face on the tab 60a side, is housed in the through hole H2 of spacer 50a. A portion of the battery 30, including the end face on the tab 60b side, is housed in the through hole H2 of spacer 50b. In other words, the tip portion of the battery 30 is covered by spacers 50a and 50b, while the central portion of the battery 30 is not covered by spacers 50a and 50b and is exposed to the air cooling channel 44.

[0109] Spacers 50a and 50b are provided with tapered circumferential surfaces with respect to the extending direction of the through hole H2. The diameter of the end face 51 of spacers 50a and 50b is smaller than the diameter of the end face 52 of spacers 50a and 50b. Spacers 50a and 50b are provided with circumferential surfaces in which the diameter of spacers 50a and 50b continuously widens from end face 51 to end face 52. Spacers 50a and 50b are provided with circumferential surfaces in which the diameter of spacers 50a and 50b widens linearly from end face 51 to end face 52.

[0110] In this modified example, the housing section 40i is provided with a through-hole H1 capable of housing the battery 30, and the through-hole H1 has a tapered inner surface in the direction of extension of the through-hole H1. The spacer 50 is made of an elastic member having a tapered circumferential surface that can fill the gap between the circumferential surface S3 of the battery 30 and the inner surface of the through-hole H1. As a result, heat generated in the battery 30 can be efficiently transferred to the battery holder 40 via the spacer 50, compared to the case where there is an air gap between the circumferential surface S3 of the battery 30 and the inner surface of the housing section 40i. Consequently, the heat accumulated in the battery pack 1 can be efficiently released to the outside. Therefore, it is possible to make maximum use of the performance of the battery 30.

[0111] In this modified example, the housing section 40i is composed of housing sections 40ai and 40bi. The housing section 40ai is provided with a frustoconical through-hole H1 capable of accommodating the tip portion of the battery 30. The housing section 40bi is provided with a frustoconical through-hole H1 capable of accommodating the tip portion of the battery 30. The spacer 50 is composed of a hollow frustoconical spacer 50a capable of filling the gap between the circumferential surface S3 of the battery 30 and the inner surface of the through-hole H1 of the housing section 40ai, and a hollow frustoconical spacer 50b capable of filling the gap between the circumferential surface S3 of the battery 30 and the inner surface of the through-hole H1 of the housing section 40bi. As a result, compared to the case where there is an air gap between the circumferential surface S3 of the battery 30 and the inner surface of the housing section 40i, the heat generated in the battery 30 can be efficiently transferred to the battery holder 40 via the spacers 50a and 50b. As a result, the heat accumulated in the battery pack 1 can be efficiently released to the outside. Therefore, it becomes possible to make full use of the performance of battery 30.

[0112] In this modified example, the through-holes H1 of the housing sections 40ai and 40bi are provided with an inner surface in which the diameter of the through-hole H1 increases linearly from the opening 41A toward the opening 42A. This allows the housing sections 40ai and 40bi to be resin parts formed by injection molding. Furthermore, in this modified example, the spacers 50a and 50b are provided with a circumferential surface in which the diameter of the spacers 50a and 50b increases linearly from the end face 51 toward the end face 52. This allows the inner surfaces of the housing sections 40ai and 40bi to be in surface contact with the circumferential surfaces S3 of the spacers 50a and 50b. As a result, the heat accumulated inside the battery pack 1 can be efficiently released to the outside. Therefore, it becomes possible to maximize the performance of the battery 30.

[0113] In this modified example, the through-holes H1 of the housing sections 40ai and 40bi are provided with an inner surface in which the diameter of the through-hole H1 increases linearly from the opening 41A towards the opening 42A, and the spacers 50a and 50b are provided with a circumferential surface in which the diameter of the spacers 50a and 50b increases linearly from the end face 51 towards the end face 52. This makes it easy to remove the spacers 50a and 50b from the housing sections 40ai and 40bi. In addition, in the event of an external impact, the stress from the housing sections 40ai and 40bi to the spacers 50a and 50b can be evenly distributed. Furthermore, since both the inner surfaces of the housing sections 40ai and 40bi and the circumferential surfaces of the spacers 50a and 50b are linear in shape, there is also the advantage that it is easier to process and control the dimensions of the housing sections 40ai and 40bi and the spacers 50a and 50b.

[0114] [Differentiation K] Figure 16(A) shows one modified example of the cross-sectional configuration of the housing 40i, battery 30, and spacers 50a and 50b when the battery 30 and spacers 50 are housed in the housing 40i. Figure 16(B) shows one modified example of the unfolded configuration of the housing 40i, battery 30, and spacers 50a and 50b shown in Figure 16(A).

[0115] In modified example J, for example, as shown in Figures 16(A) and 16(B), the through-hole H1 may be provided with an inner surface in which the diameter of the through-hole H1 narrows linearly from the opening 41A toward the opening 42A. In this case, the spacers 50a and 50b are provided with circumferential surfaces in which the diameter of the spacers 50a and 50b narrows linearly from the end face 51 toward the end face 52. The spacers 50a and 50b are in surface contact with the circumferential surface S3 of the battery 30 and also in surface contact with the inner surface of the through-hole H1. As a result, compared to the case where there is an air gap between the circumferential surface S3 of the battery 30 and the inner surface of the housing 40i, the heat generated in the battery 30 is efficiently transferred to the battery holder 40 via the spacers 50a and 50b. As a result, the heat accumulated in the battery pack 1 can be released to the outside more efficiently.

[0116] In this modified example, the through-holes H1 of the housing sections 40ai and 40bi are provided with an inner surface in which the diameter of the through-hole H1 narrows linearly from the opening 41A towards the opening 42A, and the spacers 50a and 50b are provided with a circumferential surface in which the diameter of the spacers 50a and 50b narrows linearly from the end face 51 towards the end face 52. This allows the heat generated by the battery 30 to be efficiently dissipated towards the end face 41 of the housing sections 40ai and 40bi. Furthermore, the spacers 50a and 50b can be easily removed from the housing sections 40ai and 40bi. In addition, in the event of an external impact, the stress from the housing sections 40ai and 40bi to the spacers 50a and 50b can be evenly distributed. Moreover, since both the inner surfaces of the housing sections 40ai and 40bi and the circumferential surfaces of the spacers 50a and 50b are linear in shape, there is also the advantage that processing and dimensional control of the housing sections 40ai and 40bi and the spacers 50a and 50b are easier.

[0117] In this modified example, if the volume occupied by the housing section 40i is greater than the volume occupied by the spacers 50a and 50b, the overall durability of the battery pack 1 can be improved.

[0118] [Modified version L] Figure 17(A) shows one modified example of the cross-sectional configuration of the housing 40i, battery 30, and spacers 50a and 50b when the battery 30 and spacers 50 are housed in the housing 40i. Figure 17(B) shows one modified example of the unfolded configuration of the housing 40i, battery 30, and spacers 50a and 50b shown in Figure 17(A).

[0119] In modified example J, for example, as shown in Figures 17(A) and 17(B), a cover 53 having a through hole H3 may be provided on the end faces 51 of the housing sections 40ai and 40bi. The cover 53 of housing section 40ai corresponds to a specific example of the "first housing section" according to one embodiment of the present disclosure. The cover 53 of housing section 40bi corresponds to a specific example of the "second housing section" according to one embodiment of the present disclosure. The through hole H3 of the cover 53 of housing section 40ai exposes at least a portion of one terminal of the battery 30. The through hole H3 of the cover 53 of housing section 40bi exposes at least a portion of the other terminal of the battery 30. This prevents moisture and foreign matter from entering from the end face S1 of the battery 30. It also improves the airtightness between the end face S1 of the battery 30 and the housing section 40i. It also prevents the battery 30 from shifting from its predetermined position.

[0120] [Differentiation M] Figure 18(A) shows one modified example of the cross-sectional configuration of the housing 40i, battery 30, and spacers 50a and 50b when the battery 30 and spacers 50 are housed in the housing 40i. Figure 18(B) shows one modified example of the unfolded configuration of the housing 40i, battery 30, and spacers 50a and 50b shown in Figure 18(A).

[0121] In modified example J, for example, as shown in Figures 18(A) and 18(B), a cover 53 having a through hole H3 may be provided on the end faces 51 of the housing sections 40ai and 40bi. The cover 53 of housing section 40ai corresponds to a specific example of the "first housing section" according to one embodiment of the present disclosure. The cover 53 of housing section 40bi corresponds to a specific example of the "second housing section" according to one embodiment of the present disclosure. The through hole H3 of the cover 53 of housing section 40ai exposes at least a portion of one terminal of the battery 30. The through hole H3 of the cover 53 of housing section 40bi exposes at least a portion of the other terminal of the battery 30. This prevents moisture and foreign matter from entering from the end face S1 of the battery 30. It also improves the airtightness between the end face S1 of the battery 30 and the housing section 40i. It also prevents the battery 30 from shifting from its predetermined position.

[0122] Although the present technology has been described above with reference to several embodiments and their variations, the present technology is not limited to the embodiments described above, and various modifications are possible. Furthermore, the effects described herein are merely illustrative, and the effects of the present technology are not limited to those described herein. Therefore, other effects may be obtained with respect to the present technology. [Explanation of Symbols]

[0123] 1...Battery pack, 10...Outer case, 10a...Lower case, 10b...Upper case, 11...External terminal, 20...Battery module, 30, 30a, 30b...Battery, 31...Positive electrode, 32...Negative electrode, 40...Battery holder, 40a, 40b...Holder, 40i, 40ai, 40bi...Housing section, 41, 42...End face, 41A, 42A...Opening, 43...Support section, 44...Air cooling channel, 50, 50a, 50b...Spacer, 51, 52...End face, 53...Lid, 60a, 60b...Tab, 70...Control board, H1, H2, H3...Through hole, S1, S2...End face, T, Ta, Tb...Average thickness, λ, λa, λb...Thermal conductivity.

Claims

1. A plurality of batteries having a pair of end faces on which terminals are provided, and a circumferential surface perpendicular to the pair of end faces, A holder having multiple storage compartments capable of housing each of the aforementioned multiple batteries, A plurality of spacers are provided in each of the aforementioned housing sections, in the gap between the circumferential surface of the battery and the inner surface of the housing section. Equipped with, The housing section is provided with a through hole through which the battery can be housed. The through hole is provided with a tapered inner surface in the direction of extension of the through hole. The spacer is made of an elastic member having a tapered circumferential surface that can fill the gap between the circumferential surface of the battery and the inner surface of the through hole. Battery pack.

2. The aforementioned housing section is A first housing portion is provided, in which a frustoconical first through-hole capable of housing a part of the aforementioned battery is provided as part of the through-hole, A second housing portion is provided as part of the first housing portion, which has a frustoconical shape capable of housing the portion of the battery excluding the portion housed by the first through hole. It has, The previous spacer is A hollow frustoconical first spacer capable of filling the gap between the circumferential surface of the battery and the inner surface of the first through hole, A hollow frustum-shaped second spacer capable of filling the gap between the circumferential surface of the battery and the inner surface of the second through hole, has The battery pack according to claim 1.

3. The aforementioned through hole has a frustum shape. The spacer has a hollow frustum shape that can fill the gap between the circumferential surface of the battery and the inner surface of the through hole. The battery pack according to claim 1.

4. The aforementioned through hole has a shape in which two frustums are connected at the ends with the smaller diameters. The spacer has a shape that can fill the gap between the circumferential surface of the battery and the inner surface of the through hole. The battery pack according to claim 1.

5. In the plurality of spacers, the thermal conductivity of the spacer located on the central side in the arrangement direction of the plurality of batteries is higher than the thermal conductivity of the spacers located at both ends in the arrangement direction of the plurality of batteries. The battery pack according to claim 1.

6. In the plurality of spacers, the average thickness of the spacer provided on the central side in the arrangement direction of the plurality of batteries is thicker than the average thickness of the spacers provided at both ends in the arrangement direction of the plurality of batteries. The battery pack according to claim 1.

7. A plurality of batteries having a pair of end faces on which terminals are provided, and a circumferential surface perpendicular to the pair of end faces, A holder comprising a plurality of first housing sections, each capable of housing a portion of one end face side of the plurality of batteries, and a plurality of second housing sections, each capable of housing a portion of the other end face side of the plurality of batteries, arranged with a predetermined gap between them, A plurality of first spacers are provided in each of the first housing sections, and are provided in the gap between the circumferential surface of the battery and the inner surface of the first housing section, A plurality of second spacers are provided in each of the second housing sections, and are provided in the gap between the circumferential surface of the battery and the inner surface of the second housing section. Equipped with, The first housing section is provided with a first through-hole capable of housing a portion of one of the plurality of batteries, on the end face side. The second housing section is provided with a second through-hole capable of housing a portion of the other end face side of the plurality of batteries. The first through-hole is provided with a tapered inner surface in the direction of extension of the first through-hole. The second through-hole is provided with a tapered inner surface in the direction of extension of the second through-hole. The first spacer is made of an elastic member having a tapered circumferential surface that can fill the gap between the circumferential surface of the battery and the inner surface of the first through hole. The second spacer is made of an elastic member having a tapered circumferential surface that can fill the gap between the circumferential surface of the battery and the inner surface of the second through hole. Battery pack.

8. Both the first through hole and the second through hole are frustum-shaped. The first spacer has a hollow frustum shape that can fill the gap between the circumferential surface of the battery and the inner surface of the first through hole. The second spacer has a hollow frustum shape that can fill the gap between the circumferential surface of the battery and the inner surface of the second through hole. The battery pack according to claim 7.

9. The first spacer has a first cover with a first opening that exposes at least a portion of one terminal of the battery, The second spacer has a second cover provided with a second opening that exposes at least a portion of the other terminal of the battery. The battery pack according to claim 8.

10. The spacer is made of a resin material. The battery pack according to any one of claims 1 to 9.

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