Battery pack

Abstract

To provide a battery pack.SOLUTION: A battery pack according to the present disclosure includes a plurality of battery cells 11a-11d, a first inter-cell connecting film 21, and a second inter-cell connecting film 22. Each of the plurality of battery cells 11a-11d includes a conductive exterior body and an electrode body housed inside the exterior body. The exterior body is electrically connected to the electrode body to form a positive electrode terminal and a negative electrode terminal. The first inter-cell connecting film 21 and the second inter-cell connecting film 22 have a first conductive pattern 21a and a second conductive pattern 22a, respectively. One of the positive electrode terminal and the negative electrode terminal is in contact with the first conductive pattern 21a, and the other is in contact with the second conductive pattern 22a, so that each of the battery cells 11a-11d is sandwiched by the first inter-cell connecting film 21 and the second inter-cell connecting film 22. Thus, via the first conductive pattern 21a and the second conductive pattern 22a, the battery cells 11a-11d each are electrically connected in parallel and / or in series with each other.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present disclosure relates to a battery pack.

Background Art

[0002] A battery pack in which a plurality of battery cells are electrically connected has been studied.

[0003] Patent Document 1 discloses a battery system assembled to a battery block, in which a battery block formed by stacking a plurality of battery cells and electrodes of the battery cells are electrically connected to bus bars provided on a flexible printed wiring board.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Conventionally, as a method for electrically connecting a plurality of battery cells, a fastening structure using bolts has been studied. In contrast, the present inventor has found that it is preferable to connect between battery cells with a film.

Means for Solving the Problems

[0006] <Aspect 1> A battery pack includes a plurality of battery cells, a first inter - cell connection film, and a second inter - cell connection film, [[ID=5()]]each of the plurality of battery cells includes a conductive exterior and an electrode body housed inside the exterior, the exterior has a positive - electrode terminal portion electrically connected to the positive electrode of the electrode body and a negative - electrode terminal portion electrically connected to the negative electrode of the electrode body, the first inter - cell connection film has a first conductive pattern, The second inter-cell connecting film has a second conductive pattern, Each of the plurality of battery cells is sandwiched between the first cell-to-cell connecting film and the second cell-to-cell connecting film such that one of the positive terminal portion and the negative terminal portion of the outer casing of each of the plurality of battery cells is in contact with the first conductive pattern and the other is in contact with the second conductive pattern, thereby electrically connecting each of the plurality of battery cells to one another in parallel and / or in series via the first conductive pattern and the second conductive pattern. Battery pack. <Aspect 2> The positive electrode terminal portion of the outer casing of the plurality of battery cells is in contact with the first conductive pattern, and The negative terminal portion of the outer casing of the plurality of battery cells comes into contact with the second conductive pattern. As a result, each of the plurality of battery cells is electrically connected in parallel with one another. A battery pack according to embodiment 1. <Aspect 3> The positive electrode terminal portion of the casing of the battery cell of the first group of the plurality of battery cells, and the negative electrode terminal portion of the casing of the battery cell of the second group of the plurality of battery cells are in contact with the first conductive pattern, The positive electrode terminal portion of the casing of the battery cell of the second group of the plurality of battery cells, and the negative electrode terminal portion of the casing of the battery cell of the first group of the plurality of battery cells, are in contact with the second conductive pattern. As a result, at least some of the plurality of battery cells are electrically connected in series with each other. A battery pack according to embodiment 1. <Aspect 4> The battery pack according to embodiment 1, wherein the cross-sectional shape of the casing on the positive electrode side and / or the casing on the negative electrode side of the battery cell is U-shaped. <Aspect 5> A battery pack according to any of embodiments 1 to 4, wherein the first inter-cell connecting film has a first conductive pattern and a first insulating substrate supporting the first conductive pattern, and the second inter-cell connecting film has a second conductive pattern and a second insulating substrate supporting the second conductive pattern. <Aspect 6> A battery pack according to embodiment 5, wherein the first conductive pattern and the second conductive pattern are made of metal, and the first insulating substrate and the second insulating substrate are made of resin. <Aspect 7> A battery pack according to any of embodiments 1 to 6, wherein a cooling layer is laminated on one or both of the following surfaces: the surface of the first inter-cell connecting film opposite to the surface in contact with the positive or negative terminal portion, and the surface of the second inter-cell connecting film opposite to the surface in contact with the positive or negative terminal portion. <Aspect 8> A battery pack according to any of embodiments 1 to 7, wherein one or both of the first inter-cell connecting film and the second inter-cell connecting film have a positioning portion, and each of the plurality of battery cells is positioned by the positioning portion. [Effects of the Invention]

[0007] According to this disclosure, a battery pack can be provided in which battery cells are connected by a film. [Brief explanation of the drawing]

[0008] [Figure 1] This figure shows a schematic of the battery cells included in the battery pack of this disclosure. [Figure 2] This figure shows an example of the degree of freedom in the overall shape of the battery pack in this disclosure. [Figure 3] This figure shows a schematic of the conductive pattern in the battery pack of the present disclosure. [Figure 4] This figure shows a schematic of the positioning section in the battery pack of the present disclosure. [Figure 5] This figure shows a schematic of the first connection configuration of the battery pack of this disclosure. [Figure 6] It is a diagram showing an outline of a second connection mode of the assembled battery of the present disclosure. [Figure 7] It is a diagram showing an outline of a third connection mode of the assembled battery of the present disclosure. [Figure 8] It is a diagram showing an outline of a fourth connection mode of the assembled battery of the present disclosure. [Figure 9] It is a diagram showing an example of the arrangement of battery cells in the plane direction in the assembled battery of the present disclosure. [Figure 10] It is a diagram showing another example of the arrangement of battery cells in the plane direction in the assembled battery of the present disclosure.

Mode for Carrying Out the Invention

[0009] Hereinafter, the present disclosure will be specifically described with reference to the drawings, but the present disclosure is not limited to this embodiment.

[0010] The assembled battery of the present disclosure includes a plurality of battery cells, a first inter-cell connection film, and a second inter-cell connection film.

[0011] In this assembled battery of the present disclosure, a plurality of exterior bodies have a positive electrode terminal portion electrically connected to the positive electrode of the electrode body and a negative electrode terminal portion electrically connected to the negative electrode of the electrode body, the first inter-cell connection film has a first conductive pattern, and the second inter-cell connection film has a second conductive pattern.

[0012] Further, in the assembled battery of the present disclosure, among the positive electrode terminal portions and the negative electrode terminal portions of the exterior bodies of each of the plurality of battery cells, one contacts the first conductive pattern and the other contacts the second conductive pattern, so that each of the plurality of battery cells is sandwiched between the first inter-cell connection film and the second inter-cell connection film, whereby each of the plurality of battery cells is electrically connected in parallel and / or in series with each other via the first conductive pattern and the second conductive pattern.

[0013] According to the battery pack of this disclosure, multiple battery cells can be electrically connected without using bolts, nuts, or the like, by directly contacting and connecting them to a film having a conductive pattern. As a result, the space occupied by the battery pack can be reduced, and the structural efficiency of the battery pack can be improved. Furthermore, since bolts, nuts, etc. are not required, the weight of the battery pack can be reduced. However, the battery pack of this disclosure may include bolts, nuts, etc., if necessary.

[0014] Furthermore, in the battery of this disclosure, multiple battery cells can be freely connected in series, parallel, or a combination of series and parallel connections.

[0015] The following describes the configuration of the battery pack, the connection method of the battery cells, and the planar arrangement of the battery cells of this disclosure.

[0016] 《Each configuration》 (Battery cell) The battery pack of this disclosure has a plurality of battery cells, each of which comprises a conductive outer casing and an electrode body housed inside the outer casing. The outer casing also has a positive electrode terminal portion electrically connected to the positive electrode of the electrode body and a negative electrode terminal portion electrically connected to the negative electrode of the electrode body.

[0017] Specifically, as shown in Figure 1, for example, the battery cell 11 comprises an outer casing and an electrode body 112 housed inside the outer casing. The outer casing 111a on the positive electrode side of the electrode body has a conductive positive electrode terminal portion electrically connected to the positive electrode of the electrode body, and the outer casing 111b on the negative electrode side of the electrode body has a conductive negative electrode terminal portion electrically connected to the negative electrode of the electrode body.

[0018] Multiple battery cells may be, for example, lithium-ion battery cells and nickel-metal hydride battery cells. The outer casings 111a and 111b may be made of metal, for example, gold, silver, copper, aluminum, nickel, iron, zinc, or an alloy containing one or more of these, such as stainless steel or brass.

[0019] Insulating portions 113a and 113b may be provided between the positive electrode side outer casing 111a and the negative electrode side outer casing 111b of the electrode body, and on the side surface of the electrode body 112, in order to insulate the positive electrode side outer casing 111a, the negative electrode side outer casing 111b, and the side surface of the electrode body 112, and to seal the electrode body 112. The insulating portions 113a and 113b may be made of resin, for example.

[0020] In the embodiment shown in Figure 1, both the positive electrode side casing 111a and the negative electrode side casing 111b of the electrode body have a U-shaped or concave cross-sectional shape. However, either one of these casings 111a or 111b may have a U-shaped or concave cross-sectional shape, while the other has a straight cross-sectional shape. By making the cross-sectional shape U-shaped or concave, it is possible to prevent the intrusion of moisture. In particular, since sulfide solid-state batteries may generate hydrogen sulfide when they react with moisture, it is preferable that moisture does not permeate through the resin portion between the stacked metal plates.

[0021] The following provides a more detailed explanation of preventing moisture intrusion. The metals used in the outer casings 111a and 11b are impermeable to moisture, but if the insulating parts 113a and 113b are made of resin, the resin will allow a small amount of moisture to pass through. Since the amount of moisture that passes through is proportional to the cross-sectional area and inversely proportional to the length through which it passes, making the cross-sectional shape of the outer casings U-shaped or concave is advantageous in preventing moisture intrusion by making the gaps between the outer casings where the resin is placed narrower and longer.

[0022] Therefore, as shown in Figure 1, by making the cross-sectional shape of both the positive electrode side outer casing 111a and the negative electrode side outer casing 111b of the electrode body U-shaped, and by creating a portion where the outer casings 111a and 111b overlap on the side of the battery cell, the gap between the outer casings where the resin is placed can be made narrower and longer, thereby more effectively preventing the intrusion of moisture.

[0023] The size of the battery cell is not particularly limited. For example, it can be 20mm x 20mm or larger, 30mm x 30mm or larger, 40mm x 40mm or larger, or 50mm x 50mm or larger. The shape is not limited to a square. Also, the size of the battery cell can be, for example, 200mm x 500mm or smaller, 200mm x 300mm or smaller, 200mm x 200mm or smaller, 150mm x 150mm or smaller, or 100mm x 100mm or smaller. The thickness of the battery cell can be, for example, 2.0mm or larger, 2.5mm or larger, or 3.0mm or larger. Also, the thickness of the battery cell can be, for example, 30.0mm or smaller, 20mm or smaller, 10mm or smaller, or 5.0mm or smaller. The spacing between battery cells can be, for example, 0.1mm or larger, 0.3mm or larger, or 0.5mm or larger. Furthermore, the spacing between battery cells can be, for example, 5.0 mm or less, 4.0 mm or less, or 3.0 mm or less.

[0024] (First inter-cell connecting film and second inter-cell connecting film) The battery pack of this disclosure comprises a first inter-cell connecting film and a second inter-cell connecting film. The first inter-cell connecting film has a first conductive pattern, and the second inter-cell connecting film has a second conductive pattern. In the following description, the first inter-cell connecting film and the second inter-cell connecting film will be collectively referred to simply as the "inter-cell connecting film." Similarly, the first conductive pattern and the second conductive pattern will be collectively referred to simply as the "conductive pattern."

[0025] The inter-cell connection film may consist only of a conductive pattern. Alternatively, the first inter-cell connection film may have a first conductive pattern and a first insulating substrate supporting the first conductive pattern, and the second inter-cell connection film may have a second conductive pattern and a second insulating substrate supporting the second conductive pattern. In the following description, the first insulating substrate and the second insulating substrate will be collectively referred to simply as the "insulating substrate." Furthermore, the conductive pattern may be formed only on a part of the surface of the insulating substrate, or on the entire surface of the insulating substrate. Having an insulating substrate allows the battery pack to be electrically insulated from the outside, thus reducing the possibility of leakage current and enabling it to have superior electrical performance.

[0026] The first conductive pattern and the second conductive pattern may be metals, such as gold, silver, copper, aluminum, or alloys containing one or more of these. The first insulating substrate and the second insulating substrate may be resins, such as polyethylene terephthalate, nylon, polymethyl methacrylate, polypropylene, polycarbonate, polyalkylene terephthalate, polyimide, epoxy resin, etc.

[0027] Furthermore, by making the inter-cell connecting film flexible, the overall shape of the battery pack can be freely changed. As a result, there are fewer restrictions on where the battery pack can be placed. Figure 2 shows an example of changing the overall shape of the battery pack according to this disclosure. By making the inter-cell connecting film of the battery pack according to this disclosure flexible, it can be folded as shown in Figures 2(a) and (b). Furthermore, it can be folded into a zigzag shape as shown in Figures 2(c) and (d). When folding into a zigzag shape, the outer film needs to stretch as shown in Figure 2(c), but by providing irregularities on the inter-cell connecting film as shown in Figure 4(b), which will be described later, it is possible to create a shape in which the outer film does not stretch when folded into a zigzag shape, as shown in Figure 2(d).

[0028] The size of the inter-cell connection film is not limited as long as it is large enough to sandwich the battery cells. It does not need to be extremely large compared to the battery cells, so for example, it can be sized to be 0.1 to 5.0 mm from the edge of the battery cell. If the battery casing can be insulated by means other than the inter-cell connection film, the size of the inter-cell connection film may be smaller than the battery cells. If terminals are provided at the edge of the inter-cell connection film, the inter-cell connection film may be made longer as needed.

[0029] The thickness of the inter-cell connecting film should be set appropriately, taking into consideration the balance between the required degree of flexibility and strength. The thickness of the conductive side may be, for example, 0.005 mm or more, 0.01 mm or more, or 0.02 mm or more. Alternatively, the thickness of the conductive side may be, for example, 0.10 mm or less, 0.09 mm or less, or 0.08 mm or less. The thickness of the insulating side may be, for example, 0.005 mm or more, 0.01 mm or more, or 0.02 mm or more. Alternatively, the thickness of the insulating side may be, for example, 0.10 mm or less, 0.09 mm or less, or 0.08 mm or less.

[0030] Methods for bringing the battery cells into contact with the inter-cell connecting film include using shrink film, restraint bands, adhesives, ultrasonic welding, laser welding, or electric welding. Alternatively, the battery cells may be secured by sandwiching them between plates or other means from the outside of the inter-cell connecting film. Alternatively, the battery cells may be brought into contact with the inter-cell connecting film using springs or the like.

[0031] Figure 3 shows an example in which a conductive pattern is formed on one side of an inter-cell connecting film. Figure 3(a) shows an example in which the conductive pattern is formed on the entire surface of the insulating substrate, while (b) to (d) show examples in which the conductive pattern is formed on a part of the surface of the insulating substrate. Note that the insulating substrate is not shown in Figure 3.

[0032] One or both of the first and second inter-cell connecting films may optionally have positioning sections, and each of the multiple battery cells may be positioned by these positioning sections. Figure 4 is a schematic diagram of a battery pack 1 in which the first inter-cell connecting film 21 is provided with positioning sections 31. This allows for accurate positioning of the battery cells, resulting in a battery pack with superior performance such as durability. The positioning sections may be made of resin, for example, as shown in Figure 4(a). Alternatively, instead of using resin, notches may be made in the inter-cell connecting film, or the inter-cell connecting film may be bent into an uneven shape, as shown in Figure 4(b), to form the positioning sections. When the inter-cell connecting film is bent into an uneven shape to form the positioning sections, adjustments can be made so that the outer film does not need to stretch when folding the battery pack in a zigzag pattern, as shown in Figure 2(d) above. The thickness of the positioning sections only needs to be thinner than the battery cells, but can be, for example, 0.02 mm or more, 0.03 mm or more, or 0.05 mm or more. Furthermore, the thickness of the positioning part can be, for example, 0.50 mm or less, 0.40 mm or less, or 0.30 mm or less.

[0033] (cooling layer) The battery pack of this disclosure may optionally have a cooling layer laminated on one or both of the following surfaces: the surface of the first inter-cell connecting film opposite to the surface in contact with the positive or negative terminal portion, and the surface of the second inter-cell connecting film opposite to the surface in contact with the positive or negative terminal portion. As the cooling layer, for example, an aluminum plate may be provided integrated on the outside of the inter-cell connecting film. This makes it possible to obtain a battery pack with excellent cooling performance.

[0034] Connection format In the battery pack of this disclosure, each of the multiple battery cells is sandwiched between a first inter-cell connecting film and a second inter-cell connecting film such that one of the positive terminal portion and negative terminal portion of the outer casing of each of the multiple battery cells contacts a first conductive pattern and the other contacts a second conductive pattern. The multiple battery cells are then electrically connected in parallel and / or in series to each other via the first and second conductive patterns. The ends of the inter-cell connecting films may be provided with holes and serve as terminals.

[0035] The following will explain the electrical connections of battery cells in the battery pack of this disclosure, using diagrams illustrating specific embodiments. The electrical connections of this disclosure are not limited to the following embodiments.

[0036] <Parallel connection> First, we will describe an example in which multiple battery cells are electrically connected in parallel to one another.

[0037] In the battery pack of this disclosure, the positive terminal portions of the casings of multiple battery cells may be in contact with the first conductive pattern, and the negative terminal portions of the casings of multiple battery cells may be in contact with the second conductive pattern, thereby electrically connecting each of the multiple battery cells in parallel.

[0038] (First connection mode (parallel connection)) Figure 5 shows a schematic of the first connection configuration of the present disclosure, in which each of the multiple battery cells is electrically connected in parallel with one another. Figure 5(a) is a schematic side view of the battery pack 1 of the present disclosure, and Figure 5(b) is a schematic top view of the battery pack 1 of the present disclosure.

[0039] In the battery pack 1 shown in Figure 5, the first inter-cell connecting film 21 and the second inter-cell connecting film 22 are composed only of a first conductive pattern 21a and a second conductive pattern 22a, respectively, and the four battery cells 11a, 11b, 11c, and 11d are electrically connected to the first conductive pattern 21a and the second conductive pattern 22a. Holes 21c are provided at the ends of the first conductive pattern 21a and the second conductive pattern 22a (in Figure 5(b), only the holes of the first conductive pattern 21a are shown), and they function as terminals. In the configuration shown in Figure 5, the upper side of each battery cell 11 (the side labeled "+" in Figure 5(a)) is the positive electrode, and the lower side (the side labeled "-" in Figure 5(a)) is the negative electrode, and each of the battery cells is connected to the others in parallel.

[0040] (Second connection method (parallel connection)) Figure 6 shows a second connection configuration of the present disclosure in which each of a plurality of battery cells is electrically connected in parallel to one another. In the configuration shown in Figure 6, the first inter-cell connection film 21 is composed of a first conductive pattern 21a and a first insulating substrate 21b, and the second inter-cell connection film 22 is composed of a second conductive pattern 22a and a first insulating substrate 22b. The four battery cells 11a, 11b, 11c, and 11d are connected in parallel to one another, as in the first configuration.

[0041] <Series connection, or series and parallel connection> Next, we will describe examples where multiple battery cells are electrically connected in series with each other, and examples where series and parallel connections are mixed.

[0042] In the battery pack of the present disclosure, the positive terminal portion of the casing of the battery cells of the first group of the plurality of battery cells and the negative terminal portion of the casing of the battery cells of the second group of the plurality of battery cells are in contact with the first conductive pattern, and the positive terminal portion of the casing of the battery cells of the second group of the plurality of battery cells and the negative terminal portion of the casing of the battery cells of the first group of the plurality of battery cells are in contact with the second conductive pattern, thereby each of the plurality of battery cells may be electrically connected to each other in series, or in series and parallel.

[0043] (Third connection method (series connection)) Figure 7 shows a third connection configuration of this disclosure in which each of the multiple battery cells is electrically connected in series with respect to the others.

[0044] In the embodiment schematically shown in Figure 7, the first conductive pattern 21a is in contact with the positive terminal portion of the casing of the battery cells 11a and 11c of the first group, and the negative terminal portion of the casing of the battery cells 11b and 11d of the second group. The second conductive pattern 22b is in contact with the positive terminal portion of the casing of the battery cells 11b and 11d of the second group, and the negative terminal portion of the casing of the battery cells 11a and 11c of the first group. As shown in Figure 7, in the battery pack of this disclosure, the first conductive pattern and the second conductive pattern do not have to be continuous. In the embodiment shown in Figure 7, the first conductive pattern 21a and the second conductive pattern 22a are not continuous, but by changing the orientation of the battery cell 11 and bringing it into contact with the respective conductive patterns, the battery cells 11a, 11b, 11c, and 11d are electrically connected continuously. In the battery pack shown in Figure 7, each of the battery cells is connected in series with the others.

[0045] (Fourth connection method (series connection and parallel connection)) Figure 8 shows a fourth connection configuration of this disclosure in which each of the multiple battery cells is electrically connected to one another in series and in parallel.

[0046] As schematically shown in Figure 8, series and parallel connections may be mixed. In the embodiment shown in Figure 8, the positive terminal portions of the casings of the battery cells 11a and 11b of the first group and the negative terminal portions of the casings of the battery cells 11c and 11d of the second group are in contact with the first conductive pattern 21a. The second conductive pattern 22b is in contact with the positive terminal portions of the casings of the battery cells 11c and 11d of the second group and the negative terminal portions of the casings of the battery cells 11a and 11b of the first group. In the embodiment shown in Figure 8, the battery cells 11a and 11b of the first group are connected in parallel, and the battery cells 11c and 11d of the second group are connected in parallel. Then, each group of battery cells connected in parallel is connected in series.

[0047] Planar arrangement of battery cells The battery pack of this disclosure is constructed by sandwiching multiple battery cells between inter-cell connecting films. Therefore, the number of battery cells to be connected is not limited, and any number of battery cells can be connected. Figure 9(a) is a schematic diagram of an example in which three battery cells are connected, and Figure 9(b) is a schematic diagram of an example in which six battery cells are connected.

[0048] Furthermore, the arrangement of battery cells is not limited to a straight line; they can be freely arranged in rectangular, L-shaped, U-shaped, T-shaped, and other configurations. This also reduces the limitations on where the battery pack can be placed. Figure 10(a) shows an example of a rectangular arrangement, Figure 10(b) shows an example of an L-shaped arrangement, Figure 10(c) shows an example of a U-shaped arrangement, and Figure 10(d) shows an example of a T-shaped arrangement. [Explanation of symbols]

[0049] 1 battery pack 11, 11a, 11b, 11c, 11d battery cells 111a, 111b Exterior body 113a, 113b Insulated portion 21 First inter-cell connecting film 21a First conductive pattern 21b First insulating substrate 21c hole 22 Second inter-cell connecting film 22a Second conductive pattern 22b Second insulating substrate 31 Positioning section

Claims

1. The device comprises multiple battery cells, a first inter-cell connecting film, and a second inter-cell connecting film. The first inter-cell connecting film and the second inter-cell connecting film are flexible. Each of the plurality of battery cells comprises a conductive outer casing and an electrode body housed inside the outer casing. The outer casing has a positive electrode terminal portion electrically connected to the positive electrode of the electrode body and a negative electrode terminal portion electrically connected to the negative electrode of the electrode body. The first inter-cell connecting film has a first conductive pattern, The second inter-cell connecting film has a second conductive pattern, Each of the plurality of battery cells is sandwiched between the first cell-to-cell connecting film and the second cell-to-cell connecting film such that one of the positive terminal portion and the negative terminal portion of the outer casing of each of the plurality of battery cells is in contact with the first conductive pattern and the other is in contact with the second conductive pattern, thereby electrically connecting each of the plurality of battery cells to each other in parallel and / or series via the first conductive pattern and the second conductive pattern. It is a battery pack, The aforementioned battery pack has a zigzag shape, The first inter-cell connecting film and the second inter-cell connecting film have positioning portions that are bent into an uneven shape, so that when the battery pack is folded in a zigzag pattern, the outer inter-cell connecting film does not stretch. A battery pack characterized by the following features.

2. The positive electrode terminal portion of the outer casing of the plurality of battery cells is in contact with the first conductive pattern, and The negative terminal portion of the outer casing of the plurality of battery cells comes into contact with the second conductive pattern. As a result, each of the plurality of battery cells is electrically connected in parallel with one another. The battery pack according to claim 1.

3. The positive electrode terminal portion of the casing of the battery cell of the first group of the plurality of battery cells, and the negative electrode terminal portion of the casing of the battery cell of the second group of the plurality of battery cells are in contact with the first conductive pattern, The positive electrode terminal portion of the casing of the battery cell of the second group of the plurality of battery cells, and the negative electrode terminal portion of the casing of the battery cell of the first group of the plurality of battery cells, are in contact with the second conductive pattern. As a result, at least some of the plurality of battery cells are electrically connected in series with each other. The battery pack according to claim 1.

4. The battery pack according to claim 1, wherein the cross-sectional shape of the casing on the positive electrode side and / or the casing on the negative electrode side of the battery cell is U-shaped.

5. The first inter-cell connecting film has a first conductive pattern and a first insulating substrate supporting the first conductive pattern, The second inter-cell connecting film has the second conductive pattern and the second insulating substrate supporting the second conductive pattern. A battery pack according to any one of claims 1 to 4.

6. The first conductive pattern and the second conductive pattern are made of metal, and The first insulating substrate and the second insulating substrate are made of resin. Battery pack according to claim 5.

7. The surface of the first inter-cell connecting film opposite to the surface in contact with the positive electrode terminal portion or the negative electrode terminal portion, and The surface of the second inter-cell connecting film opposite to the surface in contact with the positive terminal portion or the negative terminal portion, A battery pack according to any one of claims 1 to 4, wherein a cooling layer is laminated on one or both of the surfaces.

8. The battery pack according to any one of claims 1 to 4, wherein the positioning portion is made of resin.

9. The battery pack according to any one of claims 1 to 4, wherein the thickness of the positioning portion is 0.02 mm or more and 0.50 mm or less.

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