Battery pack

Abstract

A battery pack (1) is provided with: a lower holder (10) having an insulating property, the lower holder (10) including a plurality of housing chambers (11) in each of which at least a portion of a battery (5) in a height direction is housed and a side surface (16a) having at least a height direction component; and a lower collector member (30) having conductivity, the lower collector member (30) including a positioning part (33) extending along the side surface (16a) and a shoulder connection part (35) electrically connected to a shoulder (5a) of the battery (5) housed in the housing chamber (11).

Description

Battery pack

[0002]

[0001] The present disclosure relates to a battery pack including a battery holder and a current collecting member.

[0002] Conventionally, there is a battery pack described in Patent Document 1. This battery pack includes a plurality of cylindrical batteries. The cylindrical battery has an electrode body, an outer can that houses the electrode body, and a sealing body that closes the opening of the outer can via a gasket. The outer can has a cylindrical portion including a groove portion and a shoulder portion. The groove portion is formed by recessing a part of the cylindrical portion inward in the radial direction over the entire circumference in the circumferential direction. The shoulder portion is formed when the tip portion on the opening side of the cylindrical portion is bent inward and caulked to the peripheral edge portion of the sealing body, and extends inward in the radial direction. The sealing body is fixed to the outer can by being sandwiched between the shoulder portion and the groove portion via a gasket by caulking. In this battery pack, a first current collecting member is joined to the shoulder portion of the outer can of each cylindrical battery, and a second current collecting member is joined to the sealing body of each cylindrical battery. The plurality of cylindrical batteries are connected in series or in parallel by using the first current collecting member and the second current collecting member.

[0003] Japanese Patent Publication No. 2024-524061

[0004] When the electrical connection structure of a plurality of batteries is arranged only on one side in the height direction of the battery as in the battery pack of Patent Document 1, it is easy to achieve space saving and easy to promote high energy density. In addition, since a cooling structure can be installed on the other side in the height direction of the battery, a high-performance and compact battery pack capable of controlling the battery temperature can be constructed. However, since the battery shoulder is a small area, there is a risk of poor joining if the positioning of the current collecting member with respect to the shoulder is not performed with high precision during the joining of the current collecting member. Therefore, an object of the present disclosure is to provide a battery pack in which the electrical connection structure of a plurality of batteries can be arranged only on one side in the height direction of the battery, and the positioning of the current collecting member with respect to the shoulder can be easily performed with high precision.

[0005] To solve the above problems, the battery pack according to the present disclosure comprises a plurality of housing chambers, each housing chamber housing at least a portion of the battery in the height direction, an insulating holder having at least a height component, a positioning portion extending along the side, and a shoulder connecting portion electrically connected to the shoulder of the battery housed in the housing chamber, and a conductive lower current collecting member.

[0006] In this specification, the side on which the lower current collector, which is joined to the shoulder of the outer casing, is located relative to the center of the battery in the height direction is defined as the upper side. The battery may be a cylindrical battery, a consumer-grade prismatic battery, or the like.

[0007] According to the battery pack disclosed herein, the electrical connection structure of multiple batteries can be arranged on only one side in the height direction of the battery, and the positioning of the current collector relative to the shoulder portion can be performed with high precision.

[0008] This is a perspective view of a battery pack according to one embodiment of the present disclosure, viewed from diagonally above. This is a perspective view of the upper part of the battery pack, showing the internal structure of the upper part of the battery pack. This is a cross-sectional view taken along line A-A in Figure 2, and is a cross-sectional view including the height direction, the row direction, and the central axis of the battery. This is a perspective view of the upper part of the lower holder, viewed from diagonally above. This is a perspective view of the upper part of the lower holder, in which a battery is housed in the housing chamber, viewed from diagonally above. This is a perspective view of the upper part of the lower holder, in which a battery is housed in the housing chamber, and the lower current collector member joined to the battery, viewed from diagonally above. This is a perspective view of the structure in which the upper holder is fixed to the upper part of the lower holder in the assembly shown in Figure 6, viewed from diagonally above. This is a perspective view of the upper part of the battery pack, viewed from diagonally above. This is a perspective view of a modified lower holder, in which a battery is housed in the housing chamber, and the modified lower current collector member, viewed from diagonally above. This is a perspective view showing the relative position of the modified lower current collector member with respect to the battery.

[0009] The embodiments relating to this disclosure will be described in detail below with reference to the accompanying drawings. Note that if multiple embodiments or modifications are included below, it is intended from the outset that new embodiments may be constructed by appropriately combining their characteristic features. Furthermore, in the following embodiments, the same reference numerals are used for the same components in the drawings, and redundant explanations are omitted. Also, multiple drawings include schematic diagrams, and the dimensional ratios such as length, width, and height of each component do not necessarily match between different drawings. Furthermore, among the components described below, components not described in the independent claim indicating the highest-level concept are optional components and not essential components. In this specification, the word "omitted" may be used to allow for manufacturing tolerances (manufacturing variations), and may also be used to describe the general shape of a component.

[0010] In the following description, the height direction refers to the height direction of the battery pack, and coincides with the height direction of the battery pack's housing. The orthogonal direction refers to the direction perpendicular to the height direction. Furthermore, as described above, in this specification, the side on which the lower current collector, which is joined to the shoulder of the outer casing, is located relative to the height center of the battery is defined as the upper side, and the side on which the lower current collector is not located relative to the height center is defined as the lower side.

[0011] In the following embodiment, we will describe the case where the battery is a cylindrical battery 5, with the shoulder portion 5a of the cylindrical battery 5 being the negative electrode and the sealing body 5b of the cylindrical battery 5 being the positive electrode. However, the battery may also be a cylindrical battery where the shoulder portion is the positive electrode and the sealing body of the cylindrical battery is the negative electrode. Furthermore, the battery may also be a prismatic battery.

[0012] Figure 1 is a perspective view of a battery pack 1 according to one embodiment of the present disclosure, viewed from an oblique angle above, and Figure 2 is a perspective view of the upper part of the battery pack, showing the internal structure of the upper part of the battery pack. As shown in Figure 1, the battery pack 1 comprises an insulating resin lower holder 10 and an insulating resin upper holder 20 positioned above the lower holder 10. The lower holder 10 has a bottomed, rectangular parallelepiped shape. As shown in Figure 2, when N is a natural number of 1 or more and M is a natural number of 2 or more, the lower holder 10 has substantially circular storage chambers 11 arranged in a matrix of N rows and M columns in a top view seen from above.

[0013] The upper holder 20 is an example of an insulating member. The upper holder 20 is fixed to the lower holder 10 by fixing means, such as screws or adhesive. In the top view, the upper holder 20 has a rectangular plate shape and has substantially cylindrical through holes 21 arranged in a matrix of N rows and M columns. The central axis of the housing chamber 11 and the central axis of the through holes 21 are located on substantially the same straight line. The lower holder 10 and the upper holder 20 are each formed, for example, by injection molding. The lower holder 10 and the upper holder 20 may each be made of a thermoplastic resin such as polyethylene terephthalate (PET), polypropylene (PP), fluororesin (FR), or polyamide (PA), or they may be made of a thermosetting resin such as urea resin or phenolic resin.

[0014] As shown in Figure 2, the battery pack 1 includes a shoulder connection portion 35 that is electrically connected to the shoulder portion 5a of a cylindrical battery (hereinafter simply referred to as "battery") 5 housed in a housing chamber 11, and also includes a conductive lower current collector member 30. In this embodiment, the housing chamber 11 is arranged in a matrix with multiple rows and multiple columns, and the battery pack 1 includes the same number of lower current collector members 30 as the number of columns, each lower current collector member 30 includes the same number of shoulder connection portions 35 as the number of rows, and the negative electrodes of the same number of batteries 5 as the number of rows are connected in parallel by one lower current collector member 30.

[0015] The lower current collector 30 has a linear portion 31 that extends in a straight line, and at least a portion of each of the multiple locations 32 within the linear portion 31 that are spaced apart in the direction of extension is included in the shoulder connection portion 35. Alternatively, the lower current collector may have a linear portion that extends in a straight line, and each of the multiple locations within the linear portion that are spaced apart in the direction of extension is electrically connected to the shoulder connection portion by a conductive part. Furthermore, the multiple storage chambers of the lower holder may be arranged randomly when viewed from above in the height direction. In addition, the lower current collector may have extensions that are not linear when viewed from above in the height direction, for example, curved or folded extensions, and multiple batteries 5 may be connected in parallel by these extensions.

[0016] The battery pack 1 further includes an upper conductive portion 41 positioned above the upper holder 20, and lead portions 45 that electrically connect the upper conductive portion 41 to the sealing body 5b of the battery 5, as well as an upper current collector 40 that is conductive. In this embodiment, the upper conductive portion 41 extends linearly substantially parallel to the straight portion 31, and the lead portions 45 extend from each of a plurality of locations 42 on the upper conductive portion 41 that are spaced apart in the direction of its extension to the sealing body 5b of the battery 5 and are joined to the sealing body 5b.

[0017] The battery pack 1 is provided with an upper current collector 40 equal to the number of rows, and each upper current collector 40 includes a lead portion 45 equal to the number of rows, and the positive electrodes of the batteries 5 equal to the number of rows are connected in parallel by one upper current collector 40. The battery pack 1 is further provided with a number of connecting portions 50 that is one less than the number of rows, and each connecting portion 50 extends in a direction including a height component and electrically connects the lower current collector 30 and the upper current collector 40. In this embodiment, the connecting portion 50 extends substantially in the height direction. As a result, a plurality of battery groups connected in parallel equal to the number of rows are connected in series equal to the number of rows. In this embodiment, the connecting portion 50 is a part of the upper current collector 40, but the connecting portion 50 may also be a part of the lower current collector 30, or may be a different member from both the lower current collector 30 and the upper current collector 40.

[0018] Figure 3 is a cross-sectional view taken along line A-A in Figure 2, and is a cross-sectional view including the height direction, the row direction, and the central axis of the battery 5. As shown in Figure 3, the lower holder 10 has a protruding portion 16 that projects upward along the cylindrical outer surface of the outer casing 5c ​​of the battery 5. The protruding portion 16 has a side surface 16a on the side opposite to the battery 5 that has at least a height component. The lower current collector member 30 has a positioning portion 33 that extends along the side surface 16a, and the upper end of the positioning portion 33 is connected to the shoulder connection portion 35 via a bent portion 34. The side surface 16a has a shape corresponding to the side surface 33a of the positioning portion 33 on the shoulder connection portion 35 side. In this embodiment, the side surface 16a is a plane that extends in the height direction and is a plane that is substantially perpendicular to the extending direction of the straight portion 31.

[0019] The side of the protruding portion 16 opposite to the battery side only needs to have a height component. The side of the protruding portion opposite to the battery side may be, for example, a plane that slopes in the height direction, or a curved surface. As will be described later, it is preferable that the side of the protruding portion opposite to the battery side has a shape that corresponds to the side of the positioning portion on the shoulder connection side, in order to position the lower current collector with high precision and ease.

[0020] In this embodiment, the bent portion 34 bends toward the shoulder portion 5a in a direction substantially perpendicular to the height direction. The lower current collector member 30 may have a conductive portion that is bent in multiple stages. Specifically, the lower current collector member 30 may have a bottom plate portion 37 that extends from the lower end of the positioning portion 33 along the upper surface 18 of the lower holder 10. The upper surface 18 of the lower holder 10 may also have a recess 29 having a shape corresponding to the bottom plate portion 37, and the bottom plate portion 37 may be positioned by fitting into the recess 29.

[0021] Next, an example of a manufacturing method for the battery pack 1 will be described. First, a lower holder 10 is prepared. As shown in Figure 4, the lower holder 10 has the same number of protrusions 16 as the number of rows, the protrusions 16 extend in the row direction, and the multiple protrusions 16 are arranged at approximately equal intervals in the row direction. A part of the side surface 16b of the protrusion 16 constitutes a part of the inner circumferential surface of the housing chamber 11. Therefore, if the straight section 31 is arranged to extend along the upper surface of the protrusion 16, a part of the straight section 31 can be easily brought into contact with the shoulder 5a of the battery 5 in the height direction.

[0022] Next, as shown in Figure 5, the battery 5 is placed in the housing chamber 11 (see Figure 4). Subsequently, as shown in Figure 6, the lower current collector 30 is positioned relative to the lower holder 10, and then the shoulder connection portion 35 is joined to the shoulder portion 5a. Referring to Figure 3, the positioning of the lower current collector 30 relative to the lower holder 10 is performed by pressing the side surface 33a of the positioning portion 33 on the shoulder connection portion 35 side against the side surface 16a of the protruding portion 16 having a shape corresponding to the side surface 33a using a jig (not shown), and bringing the shoulder connection portion 35 into contact with the shoulder portion 5a. The joining of the shoulder connection portion 35 to the shoulder portion 5a can be performed, for example, by laser welding, or more specifically, by irradiating the shoulder connection portion 35 with laser light from above in the height direction. According to this embodiment, since the joining can be performed from above in the height direction, the workability of the joining can be improved.

[0023] As shown in Figure 6, the shoulder connection portion 35 has a circular portion 35a that is approximately circular when viewed from the height direction, and this circular portion 35a is in contact with the upper surface of the annular shoulder portion 5a around its entire circumference. This allows the cross-sectional area through which the current passes to be enlarged, thereby reducing electrical resistance. The welding points by laser welding can be, for example, the parts of the shoulder connection portion 35 that are included in the straight portion 31. In this way, all batteries 5 can be welded mechanically and quickly, shortening the cycle time and improving mass productivity.

[0024] Once the lower current collector 30 is joined to the lower holder 10, the upper holder 20 is positioned above the lower holder 10, as shown in Figure 7, and the upper holder 20 is fixed to the lower holder 10, for example, by screw fastening. This screw fastening prevents the battery 5 from being removed from the housing chamber 11 (see Figure 4). In order to securely fix the upper holder 20 to the lower holder 10, it is preferable that the lower surface of the upper holder 20 has a recess 24 for housing the lower current collector 30.

[0025] Next, as shown in Figure 8, the upper current collector 40 is joined to the battery 5. As shown in Figure 3, the lead portion 45 has a first portion 45a that extends substantially perpendicularly from the upper conductive portion 41 toward the through hole 21, a second portion 45b that extends from the end of the first portion 45a opposite to the upper conductive portion 41 through the through hole 21 toward the sealing body 5b, and a third portion 45c that extends substantially perpendicularly from the end of the second portion 45b opposite to the first portion 45a and is joined to the sealing body 5b. By joining the third portion 45c to the sealing body 5b, the upper conductive portion 41 becomes inseparable from the lower holder 10 via the battery 5, which is inseparable from the housing chamber 11. Finally, the lower end of the connecting portion 50 is joined to one end of the straight portion 31 by welding or the like, and the upper end of the connecting portion 50 is joined to one end of the straight-extending upper conductive portion 41 by welding or the like, thereby manufacturing the battery pack 1.

[0026] As described above, the battery pack 1 includes a plurality of housing chambers 11, each housing a portion of the battery 5 in the height direction, and a side surface 16a having at least a height component, and also includes an insulating lower holder 10. The battery pack 1 also includes a positioning portion 33 extending along the side surface 16a and a shoulder connecting portion 35 electrically connected to the shoulder portion 5a of the battery 5 housed in the housing chamber 11, and includes a conductive integrated lower current collector member 30.

[0027] According to this disclosure, the shoulder connection portion 35 of the lower current collector member 30 is joined to the shoulder portion 5a of the battery 5, which is located on the same height side as the sealing body 5b of the battery 5. Therefore, the electrical connection structure of multiple batteries 5 can be arranged on only one side (upper side) in the height direction, making it easier to save space and promote high energy density. Furthermore, by providing a through hole on the lower side of the lower holder, it becomes possible to install a cooling structure on the other side (lower side) in the height direction of the battery, making it possible to construct a high-performance, compact battery pack that can control the battery temperature.

[0028] Furthermore, as described above, the positioning portion 33 of the lower current collector 30 can be pressed against the side surface 16a of the lower holder 10, allowing the shoulder connection portion 35 of the lower current collector 30 to be joined to the shoulder portion 5a of the battery 5. Therefore, the lower current collector 30 can be positioned with high precision on the lower holder 10, and consequently, the lower current collector 30 can be positioned with high precision relative to the battery 5 housed in the housing chamber 11 of the lower holder 10. Thus, a good connection of the lower current collector 30 to the battery 5 can be achieved.

[0029] The battery pack 1 may also include an insulating upper holder 20 positioned above the lower holder 10 so as to cover the shoulder connection portion 35, an upper conductive portion 41 positioned above the upper holder 20, a lead portion 45 that electrically connects the upper conductive portion 41 to the sealing body 5b of the battery 5, an integral conductive upper current collector member 40, and a connecting portion 50 that electrically connects the lower current collector member 30 and the upper current collector member 40.

[0030] With this configuration, a two-layer insulating structure can be constructed using the lower holder 10 and the upper holder 20, and the upper holder 20 can be interposed between the upper current collector 40 and the lower current collector 30. Therefore, short circuits between the upper current collector 40 and the lower current collector 30 can be reliably prevented, ensuring the safety of the battery pack 1. In addition, the degree of freedom in the placement of the upper current collector 40 can be increased.

[0031] In the battery pack 1, the side surface 16a extends in the height direction, and the shoulder connection portion 35 may extend in a direction substantially perpendicular to the height direction. With this configuration, the positioning portion 33 of the lower current collector 30 can be easily brought into close contact with the side surface 16a of the lower holder 10, and the positioning of the lower current collector 30 relative to the lower holder 10 can be made even more precise.

[0032] The shoulder connection portion 35 may include a circular portion 35a that extends along the annular shoulder portion 5a when viewed from above in the height direction. This configuration allows for a larger cross-sectional area through which current flows, thereby reducing the electrical resistance of the battery pack 1. Furthermore, the lower current collector 30 may connect multiple batteries 5 in parallel, thereby increasing the capacity of the battery pack 1.

[0033] The lower current collector 30 has a linear portion 31 that extends in a straight line, and at least a portion of each of the multiple locations 32 within the linear portion 31 that are spaced apart in the direction of extension may be included in the shoulder connection portion 35. With this configuration, multiple batteries 5 can be connected in parallel easily and reliably.

[0034] The lower current collector 30 has a linear portion 31 that extends in a straight line, and at least a portion of each of the multiple locations 32 of the linear portion 31 that are spaced apart in the direction of its extension are included in the shoulder connection portion 35, or each of the multiple locations may have a conductive portion that electrically connects to the shoulder connection portion. The upper conductive portion 41 extends substantially parallel to the linear portion 31 and includes an upper linear portion that extends in a straight line, and the upper linear portion may be electrically connected to a plurality of sealing bodies 5b via a plurality of lead portions 45. With this configuration, a compact battery pack 1 can be realized.

[0035] This disclosure is not limited to the above embodiments and their variations, and various improvements and modifications are possible within the scope of the claims of this application and their equivalents. For example, in the above embodiments, the lower holder 10 had a plurality of storage chambers 11 arranged in a matrix when viewed from above. However, when viewed from above, the plurality of storage chambers do not have to be arranged in a matrix in the lower holder.

[0036] Figure 9 is a perspective view from diagonally above of a modified lower holder 110 in which batteries 5 are housed in a housing chamber 111, and a modified lower current collector member 130 in which multiple batteries 5 are connected in parallel. Note that in order to show the groove structure for positioning the lower current collector member 130 relative to the lower holder 110, Figure 9 shows the state in which not all of the lower current collector members 130 are attached to the lower holder 110.

[0037] As shown in Figure 9, when viewed from above, the insulating lower holder 110 may have a plurality of staggered housing chambers 111. The insulating lower current collector member 130 may have a linear portion 131 extending in a straight line, and a first battery 5d with its central axis on one side in the width direction of the linear portion 131 and a second battery 5e with its central axis on the other side in the width direction of the linear portion 131 may be alternately electrically connected to the linear portion 131.

[0038] Furthermore, the lower holder 110 may have a plurality of linear grooves 118 that are spaced apart from each other and are substantially parallel to one another, and one side surface 118a of the linear grooves 118 may have at least a height component. Also, the lower current collector member 130 may have a positioning portion 133 (see Figure 10) that extends along the side surface 118a, and a plurality of shoulder connection portions 135 that are spaced apart. The shoulder connection portions 135 may be electrically connected to the shoulder portion 5a of the battery 5 housed in the housing chamber 111. Also, the shoulder connection portions 135 may have an arc-shaped portion 135a that extends in an arc along the shoulder portion 5a when viewed from above in the height direction.

[0039] By using the modified lower holder 110 in which multiple storage chambers 111 are arranged in a staggered pattern, the arrangement density of the batteries 5 can be increased, and the energy density efficiency of the battery pack 101 can be increased. In addition, by making the shoulder connection portion 135 include an arc-shaped portion 135a, the cross-sectional area through which the current passes can be increased, and the electrical resistance of the battery pack 101 can be reduced.

[0040] Figure 10 is a perspective view showing the relative position of the lower current collector 130 in a modified example with respect to the battery 5. As shown in Figure 10, the lower current collector 130 does not necessarily have a positioning portion 133 in the region between the batteries 5 connected in parallel by it, and may have a notch 139 in the region between the batteries 5 connected in parallel. In this way, the battery pack 101 can be made lighter and manufacturing costs can be reduced.

[0041] Although the upper holder 20, which constitutes the insulating member, is made of a molded resin product, the resin member positioned above the lower holder 10 may be made of a sheet material such as an insulating resin sheet or an insulating tape. Furthermore, the lower current collector 30 and the shoulder portion 5a of the battery 5 are electrically connected by joining. However, for example, when fixing the upper holder 20 to the lower holder 10 by fastening, the lower current collector may be pressed towards the shoulder portion 5a of the battery 5, thereby bringing the lower current collector into contact with the shoulder portion 5a and electrically connecting the lower current collector to the shoulder portion 5a of the battery 5.

[0042] The case described is when the side surface 16a of the lower holder 10 that positions the positioning unit 33 is a plane extending in the height direction. However, the side surface of the lower holder that positions the positioning unit does not have to be a plane extending in the height direction; it may be a plane inclined in the height direction, or a curved surface, etc. Also, the case described is when the battery pack 1 is made by connecting multiple battery groups connected in parallel in series, but the battery pack may simply be made by connecting multiple batteries in series.

[0043] Furthermore, the battery pack of this disclosure may have the following configurations: Configuration 1: A battery pack comprising a plurality of housing chambers, each housing chamber housing at least a portion of a battery in the height direction, an insulating holder having at least a height component, a positioning portion extending along the side, and a shoulder connection portion electrically connected to the shoulder of the battery housed in the housing chamber, and a conductive lower current collector member. Configuration 2: The battery pack according to Configuration 1, comprising an insulating member disposed above the holder so as to cover the shoulder connection portion and having insulating properties, an upper conductive portion disposed above the insulating member, a lead portion electrically connecting the upper conductive portion to the sealing body of the battery, and a conductive upper current collector member, and a connecting portion electrically connecting the lower current collector member and the upper current collector member. Configuration 3: The battery pack according to Configuration 1 or 2, wherein the side extends in the height direction, and the shoulder connection portion extends in a direction substantially perpendicular to the height direction. Configuration 4: The battery pack according to any one of Configurations 1 to 3, wherein the shoulder connection portion includes a circular or arc-shaped portion that extends along the shoulder portion in a top view taken from the height direction. Configuration 5: The battery pack according to any one of Configurations 1 to 4, wherein the lower current collector member connects a plurality of the batteries in parallel. Configuration 6: The battery pack according to any one of Configurations 1 to 5, wherein the lower current collector member has a linear portion that extends in a straight line, and at least a portion of each of a plurality of locations within the linear portion that are spaced apart in the direction of extension is included in the shoulder connection portion, or has a conductive portion that electrically connects each of the plurality of locations to the shoulder connection portion. Configuration 7: The battery pack according to Configuration 6, wherein, in a top view taken from above in the height direction of the holder, the plurality of storage chambers are arranged in a staggered pattern, and a first battery with its central axis on one side in the width direction of the linear portion and a second battery with its central axis on the other side in the width direction of the linear portion are alternately electrically connected to the linear portion.Configuration 8: The battery pack according to Configuration 2, wherein the lower current collector has a linear portion extending in a straight line, and at least a portion of each of a plurality of locations of the linear portion that are spaced apart in the direction of extension is included in the shoulder connection portion, or each of the plurality of locations has a conductive portion that electrically connects to the shoulder connection portion, and the upper conductive portion includes an upper linear portion that extends substantially parallel to the linear portion and in a straight line, and the upper linear portion is electrically connected to a plurality of sealing bodies via a plurality of lead portions.

[0044] 1,101 Battery pack, 5 Battery, 5a Shoulder portion, 5b Sealing body, 5c Outer can, 5d First battery, 5e Second battery, 10,110 Lower holder, 11,111 Storage chamber, 16 Protruding portion, 16a Side surface, 18 Upper surface of lower holder, 20 Upper holder, 21 Through hole of upper holder, 24 Recess on the lower surface of upper holder, 27 Bent portion, 29 Recess on the upper surface of lower holder, 30,130 Lower current collector, 31,131 Straight portion, 32,42 Multiple locations, 33,133 Positioning portion, 33a Side surface of positioning portion on the shoulder connection portion side, 34 Bent portion, 35,135 Shoulder connection portion, 35a Circular portion, 37 Bottom plate portion, 40 Upper current collector member, 41 Upper conductive part, 45 Lead part, 45a First part, 45b Second part, 45c Third part, 50 Connecting part, 118 Straight groove, 118a Side surface, 135a Arc-shaped part, 139 Notch.

Claims

1. A battery pack comprising: a plurality of housing chambers, each housing chamber housing at least a portion of a battery in the height direction; an insulating holder including a side having at least a height component; a positioning portion extending along the side, and a shoulder connecting portion electrically connected to the shoulder of the battery housed in the housing chamber; and a conductive lower current collecting member.

2. The battery pack according to claim 1, comprising: an insulating member having insulating properties and positioned above the holder so as to cover the shoulder connection portion; an upper conductive portion positioned above the insulating member; a lead portion that electrically connects the upper conductive portion and the sealing body of the battery, and an upper current collector member having conductivity; and a connecting portion that electrically connects the lower current collector member and the upper current collector member.

3. The battery pack according to claim 1 or 2, wherein the side surface extends in the height direction, and the shoulder connection portion extends in a direction substantially perpendicular to the height direction.

4. The battery pack according to claim 1 or 2, wherein the shoulder connection portion includes a circular or arc-shaped portion that extends along the shoulder portion when viewed from above in the height direction.

5. The lower current collector member connects a plurality of the batteries in parallel, as described in claim 1 or 2.

6. The battery pack according to claim 5, wherein the lower current collector has a linear portion extending in a straight line, and at least a portion of each of a plurality of locations of the linear portion that are spaced apart in the direction of extension is included in the shoulder connection portion, or each of the plurality of locations has a conductive portion that electrically connects to the shoulder connection portion.

7. The battery pack according to claim 6, wherein, in a top view of the holder viewed from above in the height direction, the plurality of housing chambers are arranged in a staggered pattern, and a first battery having its central axis on one side in the width direction of the straight section and a second battery having its central axis on the other side in the width direction of the straight section are alternately electrically connected to the straight section.

8. The battery pack according to claim 2, wherein the lower current collector has a linear portion extending in a straight line, at least a portion of each of a plurality of locations of the linear portion that are spaced apart in the direction of extension is included in the shoulder connection portion, or each of the plurality of locations has a conductive portion that electrically connects to the shoulder connection portion, the upper conductive portion includes an upper linear portion that extends substantially parallel to the linear portion and in a straight line, and the upper linear portion is electrically connected to a plurality of sealing bodies via a plurality of lead portions.

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