Battery module production method

Abstract

This invention provides a technology for producing battery modules that can be easily disassembled as needed, while properly positioning the battery cells and heat exchange components. [Solution] The battery module production method comprises a first step #1 of arranging a heat exchange member 2 adjacent to a battery cell 1, a second step #2 of pressing the battery cell 1 and the heat exchange member 2 in the alignment direction X, which is the direction in which the battery cell 1 and the heat exchange member 2 are aligned, and a third step #3 of fixing the positional relationship between the battery cell 1 and the heat exchange member 2.

Description

Technical Field

[0001] The present invention relates to a method for producing a battery module.

Background Art

[0002] Japanese Patent Publication No. 2022-506553 discloses a battery module (21) including a battery cell (30), a heat exchange member (50 / 230) that exchanges heat with the battery cell (30), and a potting material (231) that fixes the positional relationship between the battery cell (30) and the heat exchange member (50). (In the background art, the reference numerals in parentheses refer to those in the cited documents.) The potting material (231) functions as an adhesive that fixes the battery cell (30) and the heat exchange member (50 / 230) while bringing them into close contact. The battery module (21) is formed through a process of arranging a plurality of battery cells (30) at predetermined positions, a process of arranging a flexible heat exchange member (50 / 230) between the plurality of battery cells (30), a process of flowing a fluid through the heat exchange member (50 / 230) to expand the heat exchange member (50 / 230) and bring it into contact with the plurality of battery cells (30), and a process of fixing the positional relationship between the plurality of battery cells (30) and the heat exchange member (50 / 230) in at least a partial region by the potting material (231) in a state where the heat exchange member (50 / 230) is expanded.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the battery module described above, when the battery cells and heat exchanger are positioned, they are not in contact with each other; contact is achieved by the fluid expanding the heat exchanger. If the fluid does not spread evenly due to twisting of the heat exchanger, contact may be insufficient. The use of guide members has been proposed to prevent this, but this may increase the number of steps in production and lead to higher production costs. Furthermore, after the production of the battery module, the fluid is discharged from the heat exchanger, and even if the positional relationship is fixed in at least some areas by the potting material, it is not guaranteed that the contact state between the battery cells and the heat exchanger can be properly maintained.

[0005] Furthermore, in recent years, in order to reduce the environmental impact, there is a demand for improved environmental performance in battery modules as described above. For example, when disposing of a battery module, it is preferable that each component of the battery module be separable. Also, if the battery module has multiple battery cells, it is preferable that partial battery cells can be replaced. As described above, if the components of a battery module are bonded together, it is not easy to disassemble the battery module, and sorting for disposal and maintenance such as replacing battery cells are also not easy.

[0006] In light of the above background, there is a need for technology to produce battery modules that can be appropriately positioned with respect to the heat exchange components and can be easily disassembled as needed. [Means for solving the problem]

[0007] A battery cell production method in view of the above is a battery module production method for producing a battery module comprising at least one battery cell and a heat exchange member having a flow path formed inside through which a heat transfer medium flows, comprising: a first step of arranging the heat exchange member adjacent to the battery cell along the alignment direction, with the direction in which the battery cell and the heat exchange member are aligned being defined as the alignment direction; a second step of pressing the battery cell and the heat exchange member in the alignment direction; and a third step of fixing the positional relationship between the battery cell and the heat exchange member.

[0008] This production method allows the battery cells and heat exchange members to be pressed together in the alignment direction, thereby fixing the positional relationship between the battery cells and the heat exchange members. This enables the production of battery modules with proper positioning of the battery cells and heat exchange members without the need for adhesives or fillers. Furthermore, since the need to insert adhesives or fillers between the battery cells and heat exchange members is reduced, disassembly of the battery module is also made easier. Thus, this production method makes it possible to produce battery modules that can be properly positioned between the battery cells and heat exchange components while being easily disassembled as needed.

[0009] Further features and advantages of the battery module production method will become clear from the following description of exemplary and non-limiting embodiments illustrated with reference to the drawings. [Brief explanation of the drawing]

[0010] [Figure 1] Exploded perspective view of the first example of the basic structure of a battery module. [Figure 2] Perspective view of the first example of the basic structure of a battery module. [Figure 3] Cross-sectional view of the first example of the basic structure of a battery module (section III-III in Figure 2) [Figure 4] Perspective view of the heat exchange component [Figure 5] Cross-sectional view of the heat exchange component (VV cross-sectional view in Figure 4) [Figure 6] Disassembled cross-sectional view of the second example of the basic structure of a battery module. [Figure 7] Cross-sectional view of a second example of the basic structure of a battery module. [Figure 8] Exploded perspective view of a third example of the basic structure of a battery module. [Figure 9] Disassembled cross-sectional view of the fourth example of the basic structure of a battery module. [Figure 10] A diagram illustrating an example of the battery module production process. [Figure 11] Diagram illustrating the first step [Figure 12] An explanatory diagram showing an example of the second and third steps. [Figure 13] A perspective view showing an example of a battery module produced through the process shown in Figure 12. [Figure 14] Diagram illustrating other examples of the second and third steps. [Figure 15] Figure 14 shows a perspective view illustrating an example of a battery module produced through the process described. [Figure 16] Figure 14 provides a schematic diagram illustrating a specific example of the process. [Modes for carrying out the invention]

[0011] The following describes embodiments of the battery module production method with reference to the drawings. Figures 1 to 9 illustrate the basic structure of a battery module 5 produced by the battery module production method according to this embodiment. Since the basic structure alone can function as a battery module 5, these basic structures will be simply referred to as battery module 5 unless otherwise specified. The battery module 5 is preferably used as a DC power source to supply power to a rotating electric machine (traction motor) that serves as the driving force source for a vehicle in electric vehicles or hybrid vehicles, but its use is not limited to such vehicles. As shown in Figure 1, etc., the battery module 5 comprises at least one battery cell 1 and a heat exchange member 2. The following describes the battery module 5 with reference to several embodiments. In this specification, in all embodiments illustrated, the battery module 5 is shown to be equipped with multiple battery cells 1 in order to increase the storage capacity of the battery module 5 or to enable a high output voltage. However, the battery module 5 may be equipped with a single battery cell 1. That is, the battery module 5 is equipped with at least one battery cell 1.

[0012] The battery cell 1 may contain relatively expensive raw materials or raw materials that have a large environmental impact when discarded. Therefore, in many cases, it is required to extract such raw materials from the used battery module 5 after replacement due to performance degradation. In addition, for components other than the battery cell 1 in the battery module 5 (such as the heat exchange member 2 and the holding member 3 described later), it is preferable to be appropriately separated in consideration of reducing the environmental impact after disposal. Also, when the battery module 5 includes a plurality of battery cells 1, the performance of the battery module 5 may be restored by replacing the battery cell 1 with deteriorated performance. That is, it is required to consider environmental friendliness, economy, and maintainability for the battery module 5. On the other hand, assuming a case where the battery module 5 is mounted on an automobile, each component constituting the battery module 5, including the relationship between the battery cell 1 and the heat exchange member 2, is required to maintain an appropriately positioned state even in an environment where vibrations occur. The battery module 5 of the present embodiment has a configuration that can appropriately position the battery cell 1 and the heat exchange member 2 and can be easily disassembled as needed. And the battery module production method of the present embodiment includes steps for appropriately producing the battery module 5 having such a configuration.

[0013] First, the structure of the battery module 5 as a product will be described. The battery module 5 of the present embodiment includes at least one battery cell 1, a heat exchange member 2 in which a flow path 24 (see FIGS. 4 and 5) through which a heat medium flows is formed inside, and a holding member 3 that holds at least the battery cell 1. The holding member 3 can also be said to be a member that maintains the positional relationship between the battery cell 1 and the heat exchange member 2 in the state where the battery module 5 is formed. As the heat medium, a fluid such as cooling water, oil, or a refrigerant of an air conditioner can be used. Although details will be described later, the holding member 3 does not adhere the battery cell 1 and the heat exchange member 2 like an adhesive. Therefore, the battery module 5 can be easily disassembled into the battery cell 1, the heat exchange member 2, and the holding member 3.

[0014] When explaining the configuration of the battery module 5, first, directions are defined. Here, the direction in which the battery cell 1 and the heat exchange member 2 are arranged side by side is defined as the arrangement direction X. One side in the arrangement direction X is referred to as the first side X1 in the arrangement direction, and the other side in the arrangement direction X is referred to as the second side X2 in the arrangement direction. Also, as shown in FIG. 1 and the like, the direction orthogonal to the arrangement direction X is referred to as the width direction Y. The width direction Y is the direction in which a plurality of battery cells 1 are arranged when the battery module 5 includes a plurality of battery cells 1, and can also be referred to as the "cell arrangement direction". Further, the direction orthogonal to the arrangement direction X and the width direction Y (cell arrangement direction) is conveniently referred to as the vertical direction Z. For example, when the battery module 5 is mounted on a vehicle, the direction along the vertical direction in the standard posture (the posture in which the vehicle is located on a horizontal plane) is the vertical direction Z, and the upper side is referred to as the upper side Z1 and the lower side is referred to as the lower side Z2. Of course, this is a convenient direction, and when the battery module 5 is mounted on a vehicle, the vertical direction and the vertical direction Z do not have to coincide. As shown in FIG. 1 and the like, in this embodiment, a cylindrical battery cell 1 is exemplified. In this case, the vertical direction Z coincides with the height direction or the extending direction of the columnar battery cell 1. Note that the columnar battery cell 1 is not limited to a cylindrical shape, and the bottom surface may be a polygonal shape such as a triangular prism, a quadrangular prism, a hexagonal prism, or an octagonal shape.

[0015] Here, a plurality of battery cells 1 arranged side by side along the direction orthogonal to the arrangement direction X (width direction Y, cell arrangement direction) are referred to as a cell array 10 (battery cell array). Here, an example is shown in which one cell array 10 has a configuration in which the battery cells 1 are arranged in a single row along the width direction Y, but the battery cells 1 may be arranged in a plurality of rows (for example, two rows) to form one cell array 10. For example, it is also possible to use one cell array 10 in which two sets of a plurality of battery cells 1 arranged in a single row in the width direction Y are provided, the two sets are arranged offset in the width direction Y, and the battery cells 1 are arranged in a staggered pattern in two rows in the vertical direction Z.

[0016] As shown in Figure 1, the battery cell 1 (cell array 10), the heat exchange member 2, and the holding member 3 are arranged in a line along the alignment direction X. The battery cell 1 (cell array 10), whose position is fixed in the battery module 5, has a facing surface 8 that faces some member constituting the battery module 5 on both the first side X1 and the second side X2 in the alignment direction. Here, of the facing surfaces 8, the surface of the battery cell 1 facing the first side X1 in the alignment direction is called the first side facing surface 8a, and the surface of the battery cell 1 facing the second side X2 in the alignment direction is called the second side facing surface 8b. In addition, of the facing surfaces 8, the surface of the battery cell 1 facing the heat exchange member 2 is called the heat exchange member side facing surface 8c. The heat exchange member side facing surface 8c does not necessarily have to directly face the heat exchange member 2, but may face it with other members (other battery cells 1 or cell array 10, heat-conducting members described later, etc.) in between. The first side opposing surface 8a and the second side opposing surface 8b may become the heat exchange member side opposing surface 8c, depending on the arrangement position of the battery cell 1 (cell array 10).

[0017] The heat exchange member-side opposing surface 8c has an uneven shape in the alignment direction X, and the amount of protrusion in the alignment direction X differs depending on the position in the width direction Y. Even when the battery cell 1 is triangular or rectangular prism-shaped, if the edges (corners) between two adjacent sides, rather than the sides (surfaces other than the bottom surface of the column), are positioned facing the alignment direction X, the heat exchange member-side opposing surface 8c will have an uneven shape in the alignment direction X. Furthermore, even when the triangular or rectangular prism-shaped battery cell 1 is positioned with its sides facing the alignment direction X, if the edges (corners) are chamfered or grooves or protrusions are provided on the sides, it can be said that it has an uneven shape. In addition, in this embodiment, opposing surfaces 8 other than the heat exchange member-side opposing surface 8c also have an uneven shape in the alignment direction X. That is, the first side opposing surface 8a and the second side opposing surface 8b have an uneven shape in the alignment direction X, regardless of whether or not they are the heat exchange member-side opposing surface 8c.

[0018] Furthermore, if sufficient pressing force can be secured in the alignment direction X, or if sufficient frictional force can be secured between the battery cell 1 (cell array 10) and the adjacent member in the alignment direction X, the heat exchange member side opposing surface 8c does not need to have irregularities in the alignment direction X. Similarly, the first side opposing surface 8a and the second side opposing surface 8b do not need to have irregularities in the alignment direction X, regardless of whether or not they are the heat exchange member side opposing surface 8c. For example, if the battery cell 1 is triangular or rectangular prism-shaped, its side surface may be arranged facing the alignment direction X.

[0019] In the cell array 10, there are as many opposing surfaces 8 as there are battery cells 1 arranged in the width direction Y (cell arrangement direction). Although the symbols in the figure are omitted, the cell array 10 can be said to have a "group of opposing surfaces" which is a collection of the opposing surfaces 8 of multiple battery cells 1. Similarly, although the symbols in the figure are omitted, the group of surfaces within the group of opposing surfaces that face the first side X1 in the arrangement direction of the cell array 10 can be called the "first side group of opposing surfaces," and the group of surfaces that face the second side X2 in the arrangement direction of the cell array 10 can be called the "second side group of opposing surfaces." Furthermore, the group of "heat exchange member side opposing surfaces 8c" within the "group of opposing surfaces" can be called the "heat exchange member side group of opposing surfaces 80." That is, the surfaces in the cell array 10 that face the heat exchange member 2 can be called the "heat exchange member side group of opposing surfaces 80." The first side group of opposing surfaces and the second side group of opposing surfaces can become the heat exchange member side group of opposing surfaces 80 depending on the arrangement position of the cell array 10. The heat exchange member side opposing surface group 80 has a shape with irregularities in the alignment direction X, and the amount of protrusion in the alignment direction X differs depending on the position in the width direction Y. In this embodiment, opposing surface groups other than the heat exchange member side opposing surface group 80 also have a shape with irregularities in the alignment direction X. That is, the first side opposing surface group and the second side opposing surface group also have a shape with irregularities in the alignment direction X, regardless of whether or not they are the heat exchange member side opposing surface group 80.

[0020] Furthermore, when a cell array 10 is formed by arranging battery cells 1 with gaps in the width direction Y, the opposing surfaces 8 of the battery cells 1 and the gaps can be considered together as a "group of opposing surfaces." Therefore, the group of opposing surfaces of a cell array 10, in which multiple triangular or rectangular prism-shaped battery cells 1 without grooves or protrusions on their sides are arranged with their sides facing the alignment direction X and with gaps in the width direction Y, can also be considered to have an uneven shape.

[0021] As will be explained in more detail later, as shown in Figures 6 and 7, when one cell array 10 (first cell array 11 or second cell array 12) faces one heat exchange member 2 in the direction X, one of the two opposing surface groups of the cell array 10 becomes the "heat exchange member side opposing surface group 80". As shown in Figures 1 to 3, when two cell arrays 10 (a pair of the first cell array 11 and the second cell array 12, or a pair of the third cell array 13 and the fourth cell array 14) face one heat exchange member 2, one of the two opposing surface groups of each cell array 10 becomes the "heat exchange member side opposing surface group 80". For example, in a pair of a first cell array 11 and a second cell array 12, when distinguishing between the heat exchange member-side opposing surface groups 80 in each cell array 10, the heat exchange member-side opposing surface group 80 in the first cell array 11 is referred to as the "first heat exchange member-side opposing surface group 81," and the heat exchange member-side opposing surface group 80 in the second cell array 12 is referred to as the "second heat exchange member-side opposing surface group 82."

[0022] The heat exchange member 2 has greater flexibility than the heat exchange member-side opposing surface 8c. The hardness of the heat exchange member 2 (hardness of the outer wall portion 20, described later) is, for example, 20 to 80 degrees, more preferably 40 to 70 degrees. For this reason, the heat exchange member 2 is pressed against the heat exchange member-side opposing surface 8c (group of heat exchange member-side opposing surfaces 80) by the holding member 3 in a state in which it is deformed to follow the shape of the heat exchange member-side opposing surface 8c (group of heat exchange member-side opposing surfaces 80).

[0023] A battery module 5 comprising at least one battery cell 1, a heat exchange member 2 having a flow path through which a heat transfer medium flows, and a holding member 3 that maintains the positional relationship between the battery cell 1 and the heat exchange member 2 can be produced by the following procedure. In the first step, the heat exchange member 2 is placed adjacent to the battery cell 1. Specifically, the battery cell 1 and the heat exchange member 2, which has greater flexibility than the heat exchange member side facing surface (8c), are placed side by side in the alignment direction X, such that the heat exchange member side facing surface 8c has an uneven shape in the alignment direction X. In the first step, the holding members 3 are placed on the first side X1 and the second side X2 in the alignment direction, respectively, with respect to the battery cell 1 and the heat exchange member 2. In the second step, the heat exchange member 2 is pressed toward the heat exchange member side facing surface 8c by the holding members 3 so that the heat exchange member 2 deforms to conform to the shape of the heat exchange member side facing surface 8c. Furthermore, when producing a battery module 5 equipped with a cell array 10, it is preferable to configure the cell array 10 by arranging a plurality of battery cells 1 in the width direction (arrangement direction) in the first step, preferably in a step preceding the first step.

[0024] The heat exchange member 2 has greater flexibility than the heat exchange member-side opposing surface 8c of the battery cell 1, and is pressed against the heat exchange member-side opposing surface 8c so that it deforms to conform to the shape of the heat exchange member-side opposing surface 8c. Therefore, even if there are errors in the position or shape of the battery cell 1, it is easier to improve the heat transfer efficiency between the battery cell 1 and the heat exchange member 2 while determining the positional relationship between the battery cell 1 and the heat exchange member 2. In addition, the holding member 3 is structured to press the heat exchange member 2 against the heat exchange member-side opposing surface 8c so that it deforms to conform to the shape of the heat exchange member-side opposing surface 8c, thus reducing the need to insert adhesives or fillers between the battery cell 1 and the heat exchange member 2. Consequently, if it becomes necessary to disassemble the battery module 5, the battery cell 1, the heat exchange member 2, and the holding member 3 can be easily separated.

[0025] As shown in Figure 1, the holding member 3 comprises a first holding member 31 positioned on the first side X1 in the alignment direction with respect to the battery cell 1 (cell array 10) and the heat exchange member 2, and a second holding member 32 positioned on the second side X2 in the alignment direction with respect to the battery cell 1 (cell array 10) and the heat exchange member 2. The battery cell 1 (cell array 10) and the heat exchange member 2 are held by being sandwiched between the first holding member 31 and the second holding member 32 in the alignment direction X.

[0026] By holding the battery cell 1 and the heat exchange member 2 between the first holding member 31 and the second holding member 32 in the alignment direction X, the pressing force in the alignment direction X and the frictional force between adjacent members in the alignment direction X maintain the proper positioning of the components constituting the battery module 5. Therefore, the need to insert adhesives, fillers, etc., between the battery cell 1 and the heat exchange member 2, between the battery cell 1 and any of the holding members 3, and between the heat exchange member 2 and any of the holding members 3 can be reduced. Consequently, the battery module 5 can be easily disassembled.

[0027] Furthermore, it is preferable that the heat exchange member 2 is made of, for example, silicone rubber or elastomer and has electrical insulation properties. The entire heat exchange member 2 may have insulating properties, or only a part of the heat exchange member 2, such as only the surface of the heat exchange member 2, may have electrical insulation properties. Because the heat exchange member 2 has electrical insulation properties, it is not necessary to separately arrange a member to ensure electrical insulation between the battery cell 1 and the heat exchange member 2, and a simple configuration can be realized. In addition, if another insulating member is arranged to ensure electrical insulation, there is a possibility that the heat conductivity between the battery cell 1 and the heat exchange member 2 may be impaired, but this possibility can be reduced, and it is easier to improve the heat transfer efficiency between the battery cell 1 and the heat exchange member 2. Although it is preferable that the heat exchange member 2 has insulating properties, this does not prevent the heat exchange member 2 and the battery cell 1 (cell array 10) from being arranged in the direction X with another member with high thermal conductivity (such as a heat transfer sheet) in between.

[0028] The basic concept of the battery module 5 of this embodiment has been described above. Specific configuration examples will be described below. Figures 1 to 3 show a first example of the battery module 5. Figure 3 is a cross-sectional view taken along line III-III in Figure 2. Figures 6 and 7 show a second example of the battery module 5. In the second example, perspective views and exploded perspective views are omitted, and exploded cross-sectional views and cross-sectional views are shown. Figures 4 and 5 show configuration examples of the heat exchange member 2 common to the first and second examples. Figure 5 is a cross-sectional view taken along line VV in Figure 4.

[0029] Since it is common to both the first and second examples, the configuration of the flexible heat exchange member 2 will be described first. As shown in Figure 4, the heat exchange member 2 is a plate-shaped member. The heat exchange member 2, which has a flow path 24 through which a heat transfer medium flows, comprises a pair of outer wall portions 20 (first outer wall portion 25, second outer wall portion 26) arranged to face each other in the direction X, as shown in Figures 4 and 5, and a partition wall portion 23 which is arranged in the region sandwiched between the pair of outer wall portions 20 and has a higher hardness than the pair of outer wall portions 20. The flow path 24 is formed in the space where the pair of outer wall portions 20 face each other, partitioned by the partition wall portion 23. The pair of outer wall portions 20 are softer than the partition wall portion 23 and have high flexibility. Both the outer wall portions 20 and the partition wall portion 23 are more flexible than the heat exchange member side facing surface 8c, and the heat exchange member 2 as a whole deforms according to the uneven shape of the heat exchange member side facing surface 8c. However, the outer wall portion 20 is more conformable to the uneven shape than the partition portion 23, so even if the heat exchange member 2 as a whole deforms, the flow path 24 is less likely to be crushed and blocked in the direction X, and the flow path 24 through which the heat transfer medium flows can be secured.

[0030] The flow path 24, partitioned by the partition wall 23, has defined inlet and outlet points for the heat transfer medium. In this embodiment, the heat exchange member 2 is equipped with multiple partition wall sections 23, and multiple independent flow paths 24 are formed in the heat exchange member 2. That is, as shown in the figure, multiple flow paths 24 arranged in parallel are positioned in a direction (here, the width direction Y) that intersects the vertical direction Z, which is the longitudinal direction of the columnar battery cell 1.

[0031] In both the first and second examples, the battery module 5 includes a cell array 10. However, as mentioned above, the battery module 5 may be configured with a single battery cell 1 instead of a cell array 10. Also, in both the first and second examples, the battery module 5 is configured with multiple (in this case, two) unit module sections 50, each equipped with a heat exchange member 2. However, the battery module 5 may be configured with a single unit module section 50. If one unit module section 50 is configured with one battery cell 1, and the battery module 5 is configured with a single unit module section 50, then the battery module 5 has a minimum configuration consisting of one battery cell 1.

[0032] The following describes the battery module 5 of the first example. As shown in Figure 1, the battery module 5 of the first example is composed of four cell arrays 10 (first cell array 11, second cell array 12, third cell array 13, fourth cell array 14), two heat exchange members 2 (first heat exchange member 21, second heat exchange member 22), and three holding members 3 (first side holder 41, intermediate holder 42, second side holder 43). Specifically, the battery module 5 of the first example is composed of a first side holder 41, a first cell array 11, a first heat exchange member 21, a second cell array 12, an intermediate holder 42, a third cell array 13, a second heat exchange member 22, a fourth cell array 14, and a second side holder 43, arranged from the first side X1 in the alignment direction toward the second side X2 in the alignment direction.

[0033] As described above, the battery module 5 of the first example is configured with two unit module sections 50. One unit module section 50, the first unit module section 51, is composed of a first side holder 41, a first cell array 11, a first heat exchange member 21, a second cell array 12, and an intermediate holder 42. The other unit module section 50, the second unit module section 52, is composed of an intermediate holder 42, a third cell array 13, a second heat exchange member 22, a fourth cell array 14, and a second side holder 43. The intermediate holder 42 is used in common by the first unit module section 51 and the second unit module section 52. However, the intermediate holder 42 may be composed of different members (for example, a first intermediate holder and a second intermediate holder) and used in each unit module section 50. That is, the battery module 5 may be formed by connecting multiple independently usable unit module sections 50. The direction of connection can be any direction in the alignment direction X, width direction Y, and vertical direction Z.

[0034] In the first example, one unit module section 50 of the battery module 5 comprises at least two cell arrays 10 (battery cell arrays). That is, the first unit module section 51 and the second unit module section 52 each comprise at least two cell arrays 10 (battery cell arrays). In the first unit module section 51, a heat exchange member 2 (first heat exchange member 21) is positioned between the first battery cell array (first cell array 11), which is one of the two cell arrays 10, and the second battery cell array (second cell array 12), which is the other, in the direction X of alignment. In the second unit module section 52, a heat exchange member 2 (second heat exchange member 22) is positioned between the first battery cell array (third cell array 13), which is one of the two cell arrays 10, and the second battery cell array (fourth cell array 14), which is the other, in the direction X of alignment. For simplification, the reference numerals are representative of the first unit module section 51, and some reference numerals are omitted for the second unit module section 52.

[0035] Furthermore, each first battery cell array is positioned on the first side X1 in the alignment direction relative to the second battery cell array. In the first unit module 51, the first cell array 11 (first battery cell array) is positioned on the first side X1 in the alignment direction relative to the second cell array 12 (second battery cell array). The first cell array 11 and the second cell array 12 are offset in the width direction Y, and the multiple battery cells 1 are arranged in a staggered pattern when viewed in the vertical direction Z. By arranging them in a staggered pattern, it is easier to suppress an increase in the dimension of the battery module 5 in the alignment direction X. In the second unit module 52, the third cell array 13 (first battery cell array) is positioned on the first side X1 in the alignment direction relative to the fourth cell array 14 (second battery cell array). The third cell array 13 and the fourth cell array 14 are also offset in the width direction Y, and the multiple battery cells 1 are arranged in a staggered pattern when viewed in the vertical direction Z.

[0036] Furthermore, each unit module 50 includes, as a holding member 3, a first holding member 31 positioned on the first side X1 in the alignment direction with respect to the first battery cell array, and a second holding member 32 positioned on the second side X2 in the alignment direction with respect to the second battery cell array. In the first unit module 51, the first side holder 41 corresponds to the first holding member 31, and the intermediate holder 42 corresponds to the second holding member 32. That is, the first unit module 51 includes a first side holder 41 (first holding member 31) positioned on the first side X1 in the alignment direction with respect to the first cell array 11, and an intermediate holder 42 (second holding member 32) positioned on the second side X2 in the alignment direction with respect to the second cell array 12. In the second unit module 52, the intermediate holder 42 corresponds to the first holding member 31, and the second side holder 43 corresponds to the second holding member 32. Specifically, the second unit module 52 includes an intermediate holder 42 (first holding member 31) positioned on the first side X1 in the alignment direction with respect to the third cell array 13, and a second side holder 43 (second holding member 32) positioned on the second side X2 in the alignment direction with respect to the fourth cell array 14.

[0037] As described above, the set of heat exchange member-side opposing surfaces 8c of the multiple battery cells 1 constituting the first battery cell array (first cell array 11, third cell array 13) is the heat exchange member-side first opposing surface group 81, and the set of heat exchange member-side opposing surfaces 8c of the multiple battery cells 1 constituting the second battery cell array (second cell array 12, fourth cell array 14) is the heat exchange member-side second opposing surface group 82. The heat exchange member-side first opposing surface group 81 and the heat exchange member-side second opposing surface group 82 have a shape with irregularities in the alignment direction X. As shown in Figures 2 and 3, the positional relationship between the first holding member 31 and the second holding member 32 in the alignment direction X is fixed. As is clear from a comparison of the heat exchange member 2 shown in Figure 1 with the heat exchange member 2 shown in Figures 2 and 3, the heat exchange member 2 (first heat exchange member 21, second heat exchange member 22) is sandwiched between the first opposing surface group 81 and the second opposing surface group 82 on the heat exchange member side, in a state where it has deformed to follow the shape of the first opposing surface group 81 and the second opposing surface group 82 on the heat exchange member side.

[0038] As shown in Figure 1, the support surface 3s of the holding member 3, which faces the alignment direction X, also has irregularities formed on it with different amounts of protrusion in the alignment direction X. Specifically, the first support surface 31s of the first holding member 31, which faces the second side X2 in the alignment direction, has irregularities in the alignment direction X corresponding to the shape of the first opposing surface 8a (the "group of first opposing surfaces" in the case of the cell array 10). Similarly, the second support surface 32s of the second holding member 32, which faces the first side X1 in the alignment direction, has irregularities in the alignment direction X corresponding to the shape of the second opposing surface 8b (the "group of second opposing surfaces" in the case of the cell array 10).

[0039] In the first example shown in Figures 1 to 3, in the first unit module section 51, the support surface 3s of the first side holder 41 (first holding member 31) facing the second side X2 in the alignment direction is the first support surface 31s having irregularities in the alignment direction X, and the support surface 3s of the intermediate holder 42 (second holding member 32) facing the first side X1 in the alignment direction is the second support surface 32s having irregularities in the alignment direction X. Also, although the symbols in the figures are omitted for simplification, in the second unit module section 52, the support surface 3s of the intermediate holder 42 (first holding member 31) facing the second side X2 in the alignment direction is the first support surface 31s having irregularities in the alignment direction X, and the support surface 3s of the second side holder 43 (second holding member 32) facing the first side X1 in the alignment direction is the second support surface 32s having irregularities in the alignment direction X.

[0040] The first side holder 41, intermediate holder 42, and second side holder 43 (collectively referred to as "holders" as appropriate), which correspond to the holding member 3, are equipped with walls that surround the battery cell 1. The shape of the walls changes along the width direction Y according to the shape of the battery cell 1, thereby forming irregularities on the support surface 3s. Specifically, the first support surface 31s is provided to cover the first side X1 in the direction of arrangement of the battery cell 1, and the second support surface 32s is provided to cover the second side X2 in the direction of arrangement of the battery cell 1. In addition, the first side holder 41, intermediate holder 42, and second side holder 43 are equipped with bottoms 39 that support the battery cell 1 on the lower side Z2 in the vertical direction Z (see Figures 1 and 3). By placing the battery cell 1 on the bottoms 39 and surrounding the battery cell 1 with the walls, the holders can accommodate the battery cell 1 within the holders.

[0041] Thus, in this embodiment, the support surface 3s of the holding member 3 has an uneven shape, and the holding member 3 is configured to accommodate the battery cell 1. However, the holding member 3 is not limited to having an uneven shape on the support surface 3s, as long as it can hold the battery cell 1, and the support surface 3s may be flat.

[0042] In the first unit module 51, a heat exchange member 2 (first heat exchange member 21) is positioned between the battery cell 1 (first cell array 11) housed in the first side holder 41 (first holding member 31) and the battery cell 1 (second cell array 12) housed in the intermediate holder 42 (second holding member 32) in the direction of alignment X. In the second unit module 52, a heat exchange member 2 (second heat exchange member 22) is positioned between the battery cell 1 (third cell array 13) housed in the intermediate holder 42 (first holding member 31) and the battery cell 1 (fourth cell array 14) housed in the second side holder 43 (second holding member 32) in the direction of alignment X.

[0043] In other words, in the first unit module section 51 of the battery module 5, a heat exchange member 2 (first heat exchange member 21) is positioned between the battery cell 1 (battery cell array (e.g., second cell array 12)) in the alignment direction X and the first holding member 31 (e.g., first side holder 41). In the configuration shown in Figures 1 to 3, a battery cell 1 (battery cell array (here, first cell array 11)) is further positioned between the first holding member 31 (first side holder 41) and the heat exchange member 2 (first heat exchange member 21). Similarly, in the second unit module section 52, a heat exchange member 2 (second heat exchange member 22) is positioned between the battery cell 1 (battery cell array (e.g., fourth cell array 14)) in the alignment direction X and the first holding member 31 (e.g., intermediate holder 42). In the configurations shown in Figures 1 to 3, a battery cell 1 (battery cell array (here, the third cell array 13)) is further positioned between the first holding member 31 (intermediate holder 42) and the heat exchange member 2 (second heat exchange member 22). The heat exchange member 2 has greater flexibility than the first opposing surface 8a (group of first opposing surfaces) and is pressed against the first opposing surface 8a (group of first opposing surfaces) while deformed to conform to the shape of the first opposing surface 8a (group of first opposing surfaces).

[0044] By the way, in the above explanation, the first side X1 and the second side X2 in the alignment direction were fixed in the directions shown in the figure, but it is also possible to consider that the first unit module 51 and the second unit module 52 are configured with their arrangements in the alignment direction X reversed, with the intermediate holder 42 as the axis of symmetry. That is, the second unit module 52 can also be considered as having the first side X1 and the second side X2 in the alignment direction swapped in the first unit module 51. As mentioned above, one side in the alignment direction X is the first side X1, and the other side in the alignment direction X is the second side X2, so there is no problem in considering the first side X1 and the second side X2 in the alignment direction swapped in the first unit module 51 and the second unit module 52. In this case, in the second unit module 52, the second side holder 43 corresponds to the first holding member 31, and the intermediate holder 42 corresponds to the second holding member 32.

[0045] As shown in Figure 2, the battery module 5 is equipped with a fixing member 6 that fixes the positional relationship of the holding members 3 in the alignment direction X. When producing the battery module 5, a third step is performed after the second step in which the fixing member 6 fixes the positional relationship of the holding members 3 in the alignment direction X. In Figure 2, only the fixing member 6 (lower case 66) positioned on the lower side Z2 in the vertical direction Z is shown as an example, but it is preferable that a similar fixing member 6 (second fixing member) is also positioned on the upper side Z1 in the vertical direction Z. The fixing member 6 fixes the relative positions of the battery cells 1 (cell array 10), heat exchange members 2, and holding members 3, which are the main components constituting the battery module 5, in the alignment direction X. Preferably, the fixing member 6 also fixes the position of the main components in the battery module 5 in the width direction Y. More preferably, the fixing member 6 also fixes the position of the main components in the battery module 5 in the vertical direction Z. Furthermore, the fixing member 6 may be a belt-shaped member that fixes the relative positions of the main components in the alignment direction X between the upper Z1 and lower Z2 of the battery module 5. Although not shown in Figure 6, the fixing member 6 is the same for the battery module 5 of the second example described later.

[0046] Considering the unit module section 50, one unit module section 50 can be said to be equipped with a fixing member 6 that fixes the positional relationship in the alignment direction X between the first holding member 31 and the second holding member 32. In the configuration shown in Figures 1 to 3, the first unit module section 51 is equipped with a fixing member 6 that fixes the positional relationship in the alignment direction X between the first side holder 41 and the intermediate holder 42, and the second unit module section 52 is equipped with a fixing member 6 that fixes the positional relationship in the alignment direction X between the intermediate holder 42 and the second side holder 43. The fixing member 6 in the first unit module section 51 and the fixing member 6 in the second unit module section 52 are made of a common material. The battery module 5, which includes the first unit module section 51 and the second unit module section 52, can be said to be equipped with a fixing member 6 that fixes the positional relationship in the alignment direction X between the first holding member 31 (first side holder 41, intermediate holder 42) and the second holding member 32 (intermediate holder 42 and second side holder 43). In other words, in the third step, which is performed after the second step, the positional relationship between the first holding member 31 and the second holding member 32 in the direction X is fixed by the fixing member 6.

[0047] The following describes the battery module 5 of the second example. Since the elements common to the first example (such as the cell array 10, the unit module section 50, the functional definition of the opposing surface 8, and the fixing member 6) can be easily understood from the above description, the corresponding symbols and explanations in the figures will be omitted as appropriate. As shown in Figures 6 and 7, the battery module 5 of the second example comprises two cell arrays 10 (first cell array 11, second cell array 12), two heat exchange members 2 (first heat exchange member 21, second heat exchange member 22), and three holding members 3 (first side holder 41, intermediate holder 42, second side holder 43). Specifically, the battery module 5 of the second example comprises the first side holder 41, the first heat exchange member 21, the first cell array 11, the intermediate holder 42, the second cell array 12, the second heat exchange member 22, and the second side holder 43, arranged from the first side X1 in the alignment direction toward the second side X2 in the alignment direction.

[0048] The battery module 5 of the second example is also configured with two unit module sections 50 (a first unit module section 51 and a second unit module section 52). As shown in Figure 6, the first unit module section 51 is composed of a first side holder 41, a first heat exchange member 21, a first cell array 11, and an intermediate holder 42. The second unit module section 52 is composed of an intermediate holder 42, a second cell array 12, a second heat exchange member 22, and a second side holder 43. The intermediate holder 42 is used in common by the first unit module section 51 and the second unit module section 52. However, the intermediate holder 42 may be composed of different materials (for example, a first intermediate holder and a second intermediate holder) and used in each unit module section 50. Also, similar to the battery module 5 of the first example, the battery module 5 of the second example only needs to be configured with at least one unit module section 50.

[0049] In the second example, one unit module 50 of the battery module 5 comprises at least one cell array 10 (battery cell array). The unit module 50 includes, as holding members 3, a first holding member 31 positioned on the first side X1 in the alignment direction with respect to the cell array 10, and a second holding member 32 positioned on the second side X2 in the alignment direction with respect to the cell array 10. The positional relationship between the first holding member 31 and the second holding member 32 in the alignment direction X is fixed, and the heat exchange member 2 is positioned between the cell array 10 and the first holding member 31 in the alignment direction X. The support surface 3s of the first holding member 31, which faces the heat exchange member 2, has a shape with irregularities in the alignment direction X. Also, the group of heat exchange member-side opposing surfaces 80 of the cell array 10 has a shape with irregularities in the alignment direction X. The heat exchange member 2 is sandwiched between the heat exchange member-side opposing surfaces 80 and the support surface 3s in a state that deforms to follow the shapes of the heat exchange member-side opposing surfaces 80 and the support surface 3s.

[0050] In the first unit module 51 of the second example battery module 5 having two unit module sections 50, the first side holder 41 corresponds to the first retaining member 31, and the intermediate holder 42 corresponds to the second retaining member 32. The first unit module 51 includes, as retaining members 3, a first side holder 41 (first retaining member 31) positioned on the first side X1 in the alignment direction with respect to the first cell array 11, and an intermediate holder 42 (second retaining member 32) positioned on the second side X2 in the alignment direction with respect to the first cell array 11. The positional relationship between the first side holder 41 and the intermediate holder 42 in the alignment direction X is fixed, and the first heat exchange member 21 is positioned between the first cell array 11 and the first side holder 41 in the alignment direction X. The support surface 3s (first support surface 31s) of the first side holder 41 as the first retaining member 31 has a shape with irregularities in the alignment direction X. Furthermore, the heat exchange member-side opposing surface group 80 of the first cell array 11 has a shape with irregularities in the alignment direction X. The first heat exchange member 21 is sandwiched between the heat exchange member-side opposing surface group 80 and the support surface 3s (first support surface 31s) in a state that deforms to follow the shape of the heat exchange member-side opposing surface group 80 and the support surface 3s (first support surface 31s).

[0051] Next, the second unit module 52 will be described. As mentioned above, the first unit module 51 and the second unit module 52 can be considered as being configured with their arrangements in the alignment direction X reversed, with the intermediate holder 42 as the axis of symmetry. In the second example, the second unit module 52 will be described as being configured with its arrangement in the alignment direction X reversed from that of the first unit module 51. That is, the second unit module 52 in the second example is configured by swapping the first alignment direction X1 and the second alignment direction X2 in the first unit module 51. As mentioned above, one side in the alignment direction X is the first alignment direction X1, and the other side in the alignment direction X is the second alignment direction X2, so there is no problem in considering the first alignment direction X1 and the second alignment direction X2 to be swapped in the first unit module 51 and the second unit module 52.

[0052] In the second example of the second unit module 52, in which the first alignment direction X1 and the second alignment direction X2 are swapped, the second side holder 43 corresponds to the first holding member 31, and the intermediate holder 42 corresponds to the second holding member 32. The second unit module 52 includes, as holding members 3, a second side holder 43 (first holding member 31) positioned on the first alignment direction X1 (second alignment direction X2 in the figure) with respect to the second cell array 12, and an intermediate holder 42 (second holding member 32) positioned on the second alignment direction X2 (first alignment direction X1 in the figure) with respect to the second cell array 12. The positional relationship between the second side holder 43 and the intermediate holder 42 in the alignment direction X is fixed, and the second heat exchange member 22 is positioned between the second cell array 12 and the second side holder 43 in the alignment direction X. The support surface 3s (first support surface 31s) of the second side holder 43, which serves as the first holding member 31, has a shape with irregularities in the alignment direction X. Also, the heat exchange member side opposing surface group 80 of the second cell array 12 has a shape with irregularities in the alignment direction X. The second heat exchange member 22 is sandwiched between the heat exchange member side opposing surface group 80 and the support surface 3s (first support surface 31s) in a state that deforms to follow the shapes of the heat exchange member side opposing surface group 80 and the support surface 3s (first support surface 31s).

[0053] In both the first and second examples, the above-described embodiments illustrate the holding member 3 as a pre-molded product, specifically a first-side holder 41, an intermediate holder 42, and a second-side holder 43. Synthetic resins and foamed resins are preferred as the molding material. Foamed resins, in particular, are suitable for reducing the weight of the battery module 5. In this embodiment, the support surface 3s is not flexible, and even when a pressing force is applied to the holding member 3, the shape of the support surface 3s does not change before and after the pressing. However, the holding member 3 is not limited to such a molded product (solid), and may be potted using a foaming agent that does not have adhesive properties. That is, the support surface 3s may be flexible, and the shape of the support surface 3s may change before and after the pressing force is applied to the holding member 3.

[0054] Furthermore, the above description illustrates a configuration in which the heat exchange member-side opposing surface 8c of the battery cell 1 (the heat exchange member-side opposing surface group 80 of the cell array 10) and the heat exchange member 2 are in close contact. When considering heat exchange between the battery cell 1 and the heat exchange member 2, it is preferable that the battery cell 1 and the heat exchange member 2 are in close contact without any gaps. However, the heat exchange member-side opposing surface 8c (the heat exchange member-side opposing surface group 80) and the heat exchange member 2 may be in contact with a partial gap. Even if such a gap occurs, with the configuration of this embodiment, it is easy to reduce the distance between the heat exchange member-side opposing surface 8c (the heat exchange member-side opposing surface group 80) of the battery cell 1 (cell array 10) and the heat exchange member 2 along the alignment direction X.

[0055] Furthermore, in the above description, an example was given in which the heat exchange member-side opposing surface 8c of the battery cell 1 (the group of heat exchange member-side opposing surfaces 80 of the cell array 10) and the heat exchange member 2 are adjacent to each other in the alignment direction X and in direct contact. However, the heat exchange member-side opposing surface 8c (the group of heat exchange member-side opposing surfaces 80) and the heat exchange member 2 may be adjacent to each other in the alignment direction X and in contact via a non-adhesive heat transfer sheet or other material (heat transfer material). In other words, another material may be placed between the heat exchange member-side opposing surface 8c (the group of heat exchange member-side opposing surfaces 80) and the heat exchange member 2 in the alignment direction X. Here, if the heat exchange member 2 does not have insulating properties, it is preferable that the other material has insulating properties. When producing a battery module 5 equipped with such a heat transfer material, it is preferable to place the heat transfer material 7 between the battery cell 1 and the heat exchange member 2 in the alignment direction X in the first step.

[0056] Figures 8 and 9 illustrate an example in which a heat transfer member 7 is positioned between the heat exchange member-side opposing surface 8c (heat exchange member-side opposing surface group 80) and the heat exchange member 2 in the alignment direction X. Figure 8 illustrates a third example of the battery module 5 in which a heat transfer member 7 is added to the first example described above. Figure 8 is an exploded perspective view corresponding to Figure 1, but unlike Figure 1, only the first unit module section 51 is shown, and the second unit module section 52 is omitted. Figure 9 illustrates a fourth example of the battery module 5 in which a heat transfer member 7 is added to the second example described above. In the third and fourth examples, the heat exchange member 2 does not need to be flexible, and may be formed from a molded product, for example, similar to the holding member 3, or from a material with high thermal conductivity such as metal. Figures 8 and 9 illustrate an example in which the heat exchange member 2 is a resin molded product. Furthermore, since matters common to the first example (such as the functional definitions of the cell array 10, unit module section 50, and opposing surface 8, and the fixing member 6) can be easily understood from the above explanation, the reference numerals and explanations in the figures are omitted as appropriate. Also, for simplification, the reference numerals in Figures 8 and 9 are omitted for points that can be understood from the first and second examples described above by referring to Figures 1 to 7.

[0057] As shown in Figures 8 and 9, in a battery module 5 in which a heat exchange member 2 is arranged between the battery cells 1 (including the cell array 10) and the first holding member 31 in the alignment direction X, a heat-conductive heat transfer member 7 is arranged between the battery cells 1 (cell array 10) and the heat exchange member 2 in the alignment direction X. Here, a sheet-like heat transfer member 7 is shown as an example, but the heat transfer member 7 is not limited to a sheet-like member and may be a non-adhesive gel or the like.

[0058] The battery-side opposing surface 2s of the heat exchange member 2, which faces the battery cell 1 (cell array 10), has irregularities in the alignment direction X corresponding to the shape of the heat exchange member-side opposing surface 8c (group of heat exchange member-side opposing surfaces 80) on the battery cell 1 (cell array 10). The heat transfer member 7 has higher flexibility than the battery-side opposing surface 2s and the heat exchange member-side opposing surface 8c (group of heat exchange member-side opposing surfaces 80). The heat transfer member 7 is sandwiched between the battery-side opposing surface 2s and the heat exchange member-side opposing surface 8c (group of heat exchange member-side opposing surfaces 80) in a state where it has deformed to follow the shape of the battery-side opposing surface 2s and the heat exchange member-side opposing surface 8c (group of heat exchange member-side opposing surfaces 80).

[0059] As shown in Figure 8, in the third example, heat transfer members 7 are arranged between the battery cell 1 (first cell array 11) and the heat exchange member 2 in the arrangement direction X, and between the battery cell 1 (second cell array 12) and the heat exchange member 2. Specifically, a first heat transfer member 71 is arranged between the first cell array 11 and the heat exchange member 2, and a second heat transfer member 72 is arranged between the second cell array 12 and the heat exchange member 2.

[0060] As shown in Figure 8, in the third example, battery cells 1 (cell array 10) are arranged on both sides of the heat exchange member 2 in the alignment direction X. Therefore, in the third example, the battery-side opposing surface 2s of the heat exchange member 2 consists of two surfaces: a battery-side first opposing surface 2a facing the first cell array 11, and a battery-side second opposing surface 2b facing the second cell array 12 (the notation "2s" for the battery-side first opposing surface 2a is omitted). The battery-side first opposing surface 2a and the battery-side second opposing surface 2b each have irregularities in the alignment direction X corresponding to the shape of the heat exchange member-side opposing surface 8c (heat exchange member-side opposing surface group 80) of the opposing battery cell 1 (cell array 10). In other words, the battery-side first opposing surface 2a has irregularities in the alignment direction X corresponding to the shape of the heat exchange member-side first opposing surface group 81 of the opposing first cell array 11. Furthermore, the second opposing surface 2b on the battery side has irregularities in the alignment direction X corresponding to the shape of the second opposing surface group 82 on the heat exchange member side of the opposing second cell array 12.

[0061] The first heat-conducting member 71 and the second heat-conducting member 72 have higher flexibility than the battery-side opposing surface 2s (battery-side first opposing surface 2a, battery-side second opposing surface 2b) and the heat exchange member-side opposing surface 8c (heat exchange member-side opposing surface group 80), respectively. The first heat-conducting member 71 is sandwiched between the battery-side first opposing surface 2a and the heat exchange member-side opposing surface 8c (heat exchange member-side first opposing surface group 81) in a state in which it deforms to follow the shape of the battery-side first opposing surface 2a and the heat exchange member-side opposing surface 8c (heat exchange member-side first opposing surface group 81). The second heat-conducting member 72 is sandwiched between the battery-side second opposing surface 2b and the heat exchange member-side opposing surface 8c (heat exchange member-side second opposing surface group 82) in a state in which it deforms to follow the shape of the battery-side second opposing surface 2b and the heat exchange member-side opposing surface 8c (heat exchange member-side second opposing surface group 82).

[0062] Considering the direction in the alignment direction X, in the first unit module 51, the heat-conducting member 7 has greater flexibility than the battery-side opposing surface 2s and the first side opposing surface 8a (first side facing surface group), and can be said to be sandwiched between the battery-side opposing surface 2s and the first side opposing surface 8a (first side facing surface group) in a state where it has deformed to follow the shape of the battery-side opposing surface 2s and the first side opposing surface 8a (first side facing surface group). As described above, the second unit module 52 can be considered by swapping the first side X1 and the second side X2 in the alignment direction of the first unit module 51, so a detailed explanation is omitted.

[0063] In the fourth example battery module 5 shown in Figure 9, a heat exchange member 2 is positioned between the battery cells 1 (cell array 10) and the first holding member 31 in the alignment direction X, and a heat-conductive heat transfer member 7 is positioned between the battery cells 1 (cell array 10) and the heat exchange member 2 in the alignment direction X. The battery-side opposing surface 2s of the heat exchange member 2, which faces the battery cells 1 (cell array 10), has irregularities in the alignment direction X corresponding to the shape of the heat exchange member-side opposing surface 8c (group of heat exchange member-side opposing surfaces 80). The heat transfer member 7 has higher flexibility than the heat exchange member-side opposing surface 8c (group of heat exchange member-side opposing surfaces 80) and the battery-side opposing surface 2s. The heat-conducting member 7 is sandwiched between the heat exchange member side opposing surface 8c (heat exchange member side opposing surface group 80) and the battery side opposing surface 2s, in a state where it has deformed to conform to the shape of the heat exchange member side opposing surface 8c (heat exchange member side opposing surface group 80) and the battery side opposing surface 2s.

[0064] The fourth example battery module 5 also comprises two unit module sections 50: a first unit module section 51 and a second unit module section 52. In the first unit module section 51, the heat-conducting member 7 (first heat-conducting member 71) has greater flexibility than the first opposing surface 8a (group of first opposing surfaces) and the battery-side opposing surface 2s, and is sandwiched between the first opposing surface 8a (group of first opposing surfaces) and the battery-side opposing surface 2s in a state where it deforms to conform to the shape of the first opposing surface 8a (group of first opposing surfaces) and the battery-side opposing surface 2s. Although some symbols have been omitted, in the second unit module section 52, the heat-conducting member 7 (second heat-conducting member 72) has greater flexibility than the second side opposing surface 8b (group of second side opposing surfaces) and the battery side opposing surface 2s, and is sandwiched between the second side opposing surface 8b (group of second side opposing surfaces) and the battery side opposing surface 2s in a state in which it has deformed to follow the shape of the second side opposing surface 8b (group of second side opposing surfaces) and the battery side opposing surface 2s.

[0065] As described above, the first unit module 51 and the second unit module 52 can be considered to be configured in a state in which their arrangement in the alignment direction X is reversed with respect to the intermediate holder 42 as the axis of symmetry. In the fourth example as well, the second unit module 52 can be considered to be configured in a state in which its arrangement in the alignment direction X is reversed with that of the first unit module 51. That is, in the second unit module 52 as well, the heat-conducting member 7 has higher flexibility than the first side opposing surface 8a (group of first side opposing surfaces) and the battery side opposing surface 2s, and can be considered to be sandwiched between the first side opposing surface 8a (group of first side opposing surfaces) and the battery side opposing surface 2s in a state in which it deforms to follow the shape of the first side opposing surface 8a (group of first side opposing surfaces) and the battery side opposing surface 2s.

[0066] The following describes the battery module production method, showing an example of the configuration of the battery module 5, including the fixing member 6, with reference to Figures 10 to 16. Figure 10 shows an example of the flow of production for the battery module 5. As described above with an example of the basic structure of the battery module 5, the battery module production method comprises a first step #1, a second step #2, and a third step #3.

[0067] Step 1 #1 comprises a first step #11 and a second step #12. As will be described later, the execution order of the first step #11 and the second step #12 does not matter. Step 1 #11 is the step of placing the heat exchange member 2 adjacent to the battery cell 1. Figure 10 illustrates a configuration in which a cell array 10 is arranged, having a plurality of cylindrical battery cells 1 arranged along a direction (width direction Y) perpendicular to the alignment direction X. In this example, in step 1 #11, the heat exchange member 2 is placed between the first cell array 11 and the second cell array 12 in the alignment direction X.

[0068] The second first step #12 is the step of placing the holding members 3 on the first side X1 and the second side X2 in the alignment direction with respect to the battery cell 1 and the heat exchange member 2, respectively. When the cell array 10 is arranged in the alignment direction X, in the second first step #12, the heat exchange member side first opposing surface group 81 and the heat exchange member side second opposing surface group 82, which have irregularities in the alignment direction X, are arranged with the heat exchange member 2 in between, with the recesses and protrusions facing each other in the alignment direction X. Note that the first first step #11 and the second first step #12 may be performed simultaneously.

[0069] Step 2 is performed after Step 1. Step 2 is the process of pressing the first retaining member 31, which is a retaining member 3 located on the first side X1 in the alignment direction, toward the second side X2 in the alignment direction, and pressing the second retaining member 32, which is a retaining member 3 located on the second side X2 in the alignment direction, toward the first side X1 in the alignment direction. When the cell array 10 is arranged in the alignment direction X, Step 2 is the process of pressing the first retaining member 31 and the second retaining member 32 so that the heat exchange member 2 deforms to follow the shape of the heat exchange member side first opposing surface group 81 and the heat exchange member side second opposing surface group 82. In Step 1, the members may be spaced apart in the alignment direction X to make it easier to arrange the members. In Step 2, the heat exchange member 2 is compressed and deformed in the alignment direction X by pressing the first retaining member 31 and the second retaining member 32 so that the distance between them in the alignment direction X is shortened.

[0070] Step 3 is the process of fixing the positional relationship between the first retaining member 31 and the second retaining member 32 while the battery cell 1, heat exchange member 2, and retaining member 3 are pressed in the alignment direction X. Figure 10 shows an example of a sub-assembly 55, which is an intermediate assembly pressed in step 2, with the lower case 66 and upper bracket 67 acting as fixing members 6.

[0071] Figure 11 shows an example of the first step #1. When the battery module 5 is composed of a pair of battery cells 1 (a pair of cell arrays 10: first cell array 11, second cell array 12), one heat exchange member 2, and a pair of holding members 3 (first holding member 31, second holding member 32), as shown in Figure 10, the first holding member 31 is positioned on the first side X1 in the alignment direction, and the second holding member 32 is positioned on the second side X2 in the alignment direction. However, the battery module 5 may be composed of three or more (preferably an even number, preferably four or more) battery cells 1 (cell arrays 10) arranged in the alignment direction X. In this case, the holding members 3 are positioned on the first side X1 and the second side X2 in the alignment direction, respectively, of the unit module section 50 (see Figures 1, 6, 7, etc.) which is composed of a pair of battery cells 1 (a pair of cell arrays 10) and one heat exchange member 2.

[0072] Figure 11 illustrates a configuration in which each heat exchange member 2 is provided with an external flow path 28 that connects the internal flow paths 24 (see Figures 4 and 5) formed inside each heat exchange member 2. When a pressing force is applied in the alignment direction X in the second step #2, the external flow paths 28 of adjacent heat exchange members 2 in the alignment direction X (adjacent with a battery cell 1 or holding member 3 in between) are connected. Figure 11 and others illustrate a configuration in which the heat exchange member 2 is provided with an external flow path 28 on only one side in the width direction Y, but external flow paths 28 may be provided on both sides in the width direction Y. Also, Figure 11 and others illustrate a configuration in which each heat exchange member 2 is provided with two external flow paths 28, but it may be provided with three or more external flow paths 28. Figures 4 and 5 illustrate a configuration in which each flow path 24 penetrates the heat exchange member 2 in the width direction Y, but depending on the relationship with the external flow path 28, the flow path 24 may be in a configuration other than penetrating, such as folding back inside.

[0073] Figure 11 illustrates a configuration in which four cell arrays 10 are arranged. In the first step #11, the four cell arrays 10 are arranged in the order of first cell array 11, second cell array 12, third cell array 13, and fourth cell array 14, from the first side X1 in the arrangement direction toward the second side X2 in the arrangement direction. In addition, in the first step #11, one heat exchange member 2 (first heat exchange member 21) is placed adjacent to the first cell array 11 and the second cell array 12, and another heat exchange member 2 (second heat exchange member 22) is placed adjacent to the third cell array 13 and the fourth cell array 14. That is, in the first step #11, the cell arrays are arranged in the order of first cell array 11, first heat exchange member 21, second cell array 12, third cell array 13, second heat exchange member 22, and fourth cell array 14, from the first side X1 in the arrangement direction toward the second side X2 in the arrangement direction. If five or more battery cells 1 (cell array 10) (preferably an even number, and preferably six or more) are arranged in the direction X, the battery cells 1 (cell array 10) and heat exchange members 2 should be arranged in the same manner.

[0074] In the second first step #12, the holding members 3 are placed on the first side X1 and the second side X2 in the alignment direction for the set of the first cell array 11, the first heat exchange member 21, and the second cell array 12, respectively, and the holding members 3 are also placed on the first side X1 and the second side X2 in the alignment direction for the set of the third cell array 13, the second heat exchange member 22, and the fourth cell array 14. No heat exchange member 2 is placed between the second cell array 12 and the third cell array 13. Therefore, the holding member 3 placed on the second side X2 in the alignment direction for the second cell array 12 and the holding member 3 placed on the first side X1 in the alignment direction for the third cell array 13 can be a common member. As shown in Figure 10, the holding member 3 includes a first-side holder 41 placed on the first side X1 in the alignment direction, a second-side holder 43 placed on the second side X2 in the alignment direction, and an intermediate holder 42 placed in the middle in the alignment direction X. In the second first step #12, for the set of the first cell array 11, the first heat exchange member 21, and the second cell array 12, the first side holder 41 is placed on the first side X1 in the alignment direction and the intermediate holder 42 is placed on the second side X2 in the alignment direction. Similarly, for the set of the third cell array 13, the second heat exchange member 22, and the fourth cell array 14, the same intermediate holder 42 is placed on the first side X1 in the alignment direction and the second side holder 43 is placed on the second side X2 in the alignment direction.

[0075] As described above, the first step #11 and the second step #12 may be executed in the order of the first step #11 followed by the second step #12, or they may be executed simultaneously. Furthermore, if they are executed simultaneously, a part of the first step #11 and a part of the second step #12 may be executed alternately. For example, in the embodiment illustrated in Figure 11, the first step #1 and the second step #12 may be executed simultaneously in one process, and the first side holder 41, the first cell array 11, the first heat exchange member 21, the second cell array 12, the intermediate holder 42, the third cell array 13, the second heat exchange member 22, the fourth cell array 14, and the second side holder 43 may be arranged in the order described, from the first side X1 in the alignment direction to the second side X2 in the alignment direction.

[0076] Alternatively, for example, the first step #11 and the second step #12 may be repeatedly performed as follows until the arrangement is as illustrated in Figure 11. First, the first cell array 11, the first heat exchange member 21, and the second cell array 12 are arranged in the order described, from the first side X1 in the alignment direction toward the second side X2 in the alignment direction (first step #1). Next, the first side holder 41 is placed on the first side X1 in the alignment direction relative to the first cell array 11, and the intermediate holder 42 is placed on the second side X2 in the alignment direction relative to the second cell array 12 (second step #12). Next, the third cell array 13, the second heat exchange member 22, and the fourth cell array 14 are arranged on the second side X2 in the alignment direction relative to the intermediate holder 42, from the first side X1 in the alignment direction toward the second side X2 in the alignment direction (part of the second step #12 and the first step #11). Finally, the second side holder 43 is positioned on the second side X2 in the alignment direction relative to the fourth cell array 14 (second first step #12).

[0077] The second step #2 and the third step #3 will be explained below with reference to a specific example of the battery module 5. The first embodiment will be described with reference to Figures 12 and 13, and the second embodiment will be described with reference to Figures 14 to 16.

[0078] The first embodiment is a configuration in which, in the third step #3, a fixing member 6 is used to fix the positional relationship of the battery cell 1 (cell array 10), the heat exchange member 2, and the holding member 3, and the holding member 3 is pressed in the second step #2. The exploded perspective view in Figure 12 illustrates the arrangement and assembly method of each component in the second step #2 and the third step #3. The perspective view in Figure 13 shows the appearance of the battery module 5 produced according to the first embodiment.

[0079] As shown in Figure 12, the fixing member 6 comprises at least a first bracket 61 (first fixing member), a second bracket 62 (second fixing member), and a lower plate 63 (third fixing member). Here, an example is shown in which an upper plate 64 and a third bracket 65 are also included. The first bracket 61 is positioned on the first side X1 in the alignment direction with respect to the first retaining member 31. When the battery module 5 comprises multiple unit module sections 50, the first bracket 61 is positioned on the first side X1 in the alignment direction with respect to the first retaining member 31 located furthest to the first side X1 in the alignment direction. The second bracket 62 is positioned on the second side X2 in the alignment direction with respect to the second retaining member 32. When the battery module 5 comprises multiple unit module sections 50, the second bracket 62 is positioned on the second side X2 in the alignment direction with respect to the second retaining member 32 located furthest to the second side X2 in the alignment direction. The lower plate 63 is a member to which the first bracket 61 and the second bracket 62 are connected. By connecting to the lower plate 63, the positional relationship between the first bracket 61 and the second bracket 62 in the direction X is fixed.

[0080] In the second step #2, the first bracket 61 is pressed toward the second side X2 in the alignment direction, and the second bracket 62 is pressed toward the first side X1 in the alignment direction. At this time, an assembly jig may be used that presses the first bracket 61 from the first side X1 in the alignment direction toward the second side X2 in the alignment direction, and presses the second bracket 62 from the second side X2 in the alignment direction toward the first side X1 in the alignment direction. Although not shown in the figures, this assembly jig may be the same as the assembly jig 9 (see Figure 16) used in the second embodiment described later with reference to Figures 14 to 16.

[0081] In the third step #3, the first bracket 61 and the second bracket 62 are fixed to the lower plate 63 while maintaining the pressing state from the second step #2, that is, while maintaining the positional relationship between the first bracket 61 and the second bracket 62. Specifically, the first bracket 61 and the lower plate 63 are fastened together with fastening members 69 such as screws, and the second bracket 62 and the lower plate 63 are fastened together with fastening members 69. The third step #3 includes at least the step of fixing the first bracket 61 and the second bracket 62 to the lower plate 63. In the first embodiment, the following steps are further performed.

[0082] In the first embodiment illustrated in Figure 12, a flow path bracket 68 for holding the external flow path 28 is also provided in the heat exchange member 2 where the external flow path 28 is formed, and this flow path bracket 68 is also fastened to the lower plate 63. Furthermore, an upper plate 64 covering the subassembly 55 is connected to the first bracket 61 and the second bracket 62 from the opposite side of the lower plate 63 in the vertical direction Z (upper side Z1). In Figure 12, the third bracket 65, which is located on the rear side, is fixed to the lower plate 63 as a vibration damping bracket to suppress vibration of the subassembly 55 in the width direction Y.

[0083] The second embodiment is a method of producing the battery module 5 in the second step #2 and third step #3 using an assembly jig 9 (see Figure 16) that contacts the first holding member 31 from the first side X1 in the alignment direction and contacts the second holding member 32 from the second side X2 in the alignment direction. The exploded perspective view in Figure 14 illustrates the arrangement of each component and the assembly method in the second step #2 and third step #3. The perspective view in Figure 15 shows the appearance of the battery module 5 produced according to the second embodiment. Figure 16 is a schematic explanatory diagram illustrating the second step #2 and third step #3 using the assembly jig 9.

[0084] As shown in Figure 16, the assembly jig 9 includes a first contact portion 91 that contacts the first holding member 31 located on the first side X1 in the alignment direction in the subassembly 55 from the first side X1 in the alignment direction, and a second contact portion 92 that contacts the second holding member 32 located on the second side X2 in the alignment direction in the subassembly 55 from the second side X2 in the alignment direction. In this embodiment, the assembly jig 9 also includes a third contact portion 93 that contacts the subassembly 55 from the upper side Z1 in the vertical direction Z.

[0085] As shown in Figure 14, in the second embodiment, the fixing member 6 includes a lower case 66 having a first fixing portion 6a, a second fixing portion 6b, and a connecting portion 6c that connects the first fixing portion 6a and the second fixing portion 6b, and an upper bracket 67 that is positioned on the opposite side of the lower case 66 in the vertical direction Z from the connecting portion 6c, with the subassembly 55 in between. In the embodiment shown in Figure 14, one battery module 5 is provided with two upper brackets 67. The first fixing portion 6a in the lower case 66 is the part that is positioned on the first side X1 in the alignment direction relative to the first retaining member 31, which is positioned on the first side X1 in the alignment direction in the subassembly 55 when the battery module 5 is formed. The second fixing portion 6b in the lower case 66 is the part that is positioned on the second side X2 in the alignment direction relative to the second retaining member 32, which is positioned on the second side X2 in the alignment direction in the subassembly 55 when the battery module 5 is formed. The connecting portion 6c is located on the lower side Z2 of the subassembly 55 when the battery module 5 is formed, and connects the first fixing portion 6a and the second fixing portion 6b. The lower case 66 has a housing portion 6e in the space enclosed by the first fixing portion 6a, the second fixing portion 6b and the connecting portion 6c. The subassembly 55 is housed in this housing portion 6e, and the battery module 5 is formed as shown in Figure 15.

[0086] As shown in Figure 16, in the second step #2, the assembly jig 9 is used to press the first retaining member 31 toward the second side X2 in the alignment direction with the first contact portion 91, and to press the second retaining member 32 toward the first side X1 in the alignment direction with the second contact portion 92. At this time, it is preferable that the assembly jig 9 presses such that the length in the alignment direction X from the end of the first contact portion 91 toward the first side X1 in the alignment direction to the end of the second contact portion 92 toward the second side X2 in the alignment direction (length between jigs) is shorter than the length in the alignment direction X between the inner surface of the first fixing portion 6a of the lower case 66 facing the second side X2 in the alignment direction and the inner surface of the second fixing portion 6b facing the first side X1 in the alignment direction (length of the housing portion).

[0087] In the third step #3, the battery cell 1, heat exchange member 2, and holding member 3 are pressed in the alignment direction X by the assembly jig 9 and housed in the housing section 6e along the first fixing part 6a and the second fixing part 6b (#31). Because the subassembly 55 is pressed such that the length between the jigs is shorter than the length of the housing section, the subassembly 55 can be housed in the housing section 6e without the first contact part 91 and the first fixing part 6a, and the second contact part 92 and the second fixing part 6b coming into contact. With the subassembly 55 housed in the housing section 6e, the third contact part 93 is brought into contact with the upper side Z1 of the subassembly 55 and pressed downwards Z2, and the first contact part 91 and the second contact part 92 are moved upwards Z1, allowing the assembly jig 9 to be withdrawn from the housing section 6e without dragging the subassembly 55 (#32). Subsequently, the third contact portion 93 is moved to the upper Z1 (#32). Alternatively, in step "#31", the first contact portion 91 and the second contact portion 92 may be moved to the upper Z1 while the third contact portion 93 presses the subassembly 55 to the lower Z2 and houses it in the housing portion 6e.

[0088] The subassembly 55 housed in the housing 6e can expand in the alignment direction X until it contacts the first fixing part 6a and the second fixing part 6b, since the pressing force in the alignment direction X has been removed. The positional relationship between the first holding member 31 and the second holding member 32 is fixed by the first fixing part 6a and the second fixing part 6b. That is, the battery cell 1 (cell array 10), the heat exchange member 2, and the holding member 3 are pressed in the alignment direction X by the first fixing part 6a and the second fixing part 6b that constitute the fixing member 6, and the positional relationship between the first holding member 31 and the second holding member 32 is fixed.

[0089] In the third step #3, the upper bracket 67 is attached to the lower case 66 so as to connect the first fixing part 6a and the second fixing part 6b. The upper bracket 67 fixes the subassembly 55 inside the lower case 66 so that it does not move from the housing part 6e to the upper part Z1.

[0090] Furthermore, referring to Figures 12 and 13, the assembly jig 9 of the second embodiment may be used in the second step #2 and third step #3 of the first embodiment described above. For example, in the second step #2, the assembly jig 9 is used to press the first bracket 61 from the first side X1 in the alignment direction toward the second side X2 in the alignment direction with the first contact portion 91, and to press the second bracket 62 from the second side X2 in the alignment direction toward the first side X1 in the alignment direction with the second contact portion 92. In the third step #3, in this state, the first bracket 61 and the second bracket 62 are brought into contact with the lower plate 63 for positioning, and the first bracket 61 and the second bracket 62 are fastened to the lower plate 63.

[0091] As described above, a battery module production method for producing a battery module 5 comprising at least one battery cell 1, a heat exchange member 2 having a flow path 24 through which a heat transfer medium flows, and a holding member 3 that maintains the positional relationship between the battery cell 1 and the heat exchange member 2, can include: a first step #1 of arranging the heat exchange member 2 adjacent to the battery cell 1 and arranging the holding members 3 on the first side X1 and second side X2 in the alignment direction relative to the battery cell 1 and the heat exchange member 2, respectively; a second step #2 of pressing the first holding member 31 on the first side X1 toward the second side X2 in the alignment direction and pressing the second holding member 32 positioned on the second side X2 toward the first side X1 in the alignment direction; and a third step #3 of fixing the positional relationship between the first holding member 31 and the second holding member 32 while the battery cell 1, the heat exchange member 2, and the holding member 3 are pressed toward the alignment direction X.

[0092] According to this production method, the battery cell 1 and the heat exchange member 2 are held in place in the alignment direction X by holding members 3 positioned on the first side X1 and the second side X2 in the alignment direction, respectively. By fixing the relative positions of the holding members 3 while maintaining this state, the battery module 5 can be produced with the battery cell and heat exchange member properly positioned without using adhesives or fillers. Furthermore, since the need to insert adhesives or fillers between the battery cell 1 and the heat exchange member 2, between the battery cell 1 and either of the holding members 3, and between the heat exchange member 2 and either of the holding members 3 is reduced, the battery module 5 can be easily disassembled.

[0093] In the above, a method for producing a battery module 5 comprising a battery cell 1, a heat exchange member 2, and a holding member 3 was illustrated and explained with reference to Figures 10 to 16. However, the production method of this embodiment can also be applied to the production of a battery module 5 comprising a battery cell 1 and a heat exchange member 2, without the holding member 3.

[0094] That is, a battery module production method for producing a battery module 5 comprising at least one battery cell 1 (or at least one cell array 10) and a heat exchange member 2 having a flow path through which a heat transfer medium flows may include a first step #1 of arranging the heat exchange member 2 adjacent to the battery cell 1 (cell array 10) along the alignment direction X, a second step #2 of pressing the battery cell 1 (cell array 10) and the heat exchange member 2 in the alignment direction X, and a third step #3 of fixing the positional relationship between the battery cell 1 (cell array 10) and the heat exchange member 2. That is, as the first step #1, only the first step #11 of the first first step #11 and the second first step #12 may be executed. In the second step #2, the battery cell 1 (cell array 10) and the heat exchange member 2, the member located furthest to the first side X1 in the alignment direction (referred to as the "first side member") is pressed toward the second side X2 in the alignment direction, and the member located furthest to the second side X2 in the alignment direction (referred to as the "second side member") is pressed toward the first side X1 in the alignment direction. In the third step #3, the relative positions of the battery cell 1 (cell array 10) and the heat exchange member 2 are fixed while they are pressed toward the alignment direction X.

[0095] Furthermore, in the second step #2, the heat exchange member 2 is pressed such that the thickness in the alignment direction X is smaller after the completion of the second step #2 than the thickness before the start of the second step #2. If the battery module 5 has at least two cell arrays 10, in the second step #2, the heat exchange member 2 is pressed such that it deforms to follow the shape of the first opposing surface group 81 and the second opposing surface group 82 on the heat exchange member side.

[0096] The battery module 5 preferably includes at least two battery cells 1 (at least two cell arrays 10) and heat exchange members 2 disposed between the two battery cells 1 (cell arrays 10). In other words, the battery module 5 preferably comprises n battery cells 1 (n cell arrays 10) and n-1 heat exchange members 2 disposed between each battery cell 1 (cell array 10), where n is a natural number. In this case, both the first side member and the second side member can be battery cells 1 (cell arrays 10), and proper pressing can be achieved in the second step #2. Furthermore, in the third step #3, proper fixing can be achieved by suppressing the movement of the first side member toward the first side X1 in the alignment direction and suppressing the movement of the second side member toward the second side X2 in the alignment direction.

[0097] Naturally, the system may be configured with "n+1" heat exchange members 2 and n battery cells 1 (n cell arrays 10) arranged between each heat exchange member 2. In this case, both the first side member and the second side member become heat exchange members 2. The heat exchange members 2 corresponding to the first side member and the second side member are adjacent to the battery cells 1 (cell arrays 10) on only one side in the alignment direction X.

[0098] Furthermore, naturally, the battery module 5 may be configured to include n battery cells 1 (n cell arrays 10) and n heat exchange members 2 that are arranged alternately with the battery cells 1 (cell arrays 10) along the alignment direction X. In this case, one of the first side member and the second side member becomes the battery cells 1 (cell arrays 10), and the other becomes the heat exchange member 2.

[0099] This production method is easily understood from the above explanation with reference to Figures 10 to 16, so illustrations and detailed explanations are omitted. For example, in an example of the production flow for the battery module 5 illustrated in Figure 10, the second first step #12 is omitted, and the second step #2 and third step #3 are reinterpreted as pressing and fixing the product produced by the first first step #11, making it easily understandable. Also, in Figure 11, for example, the first step #1 (first first step #11) in this production method can be easily understood by removing the first side holder 41 and the second side holder 43, and replacing the intermediate holder 42 with the heat exchange member 2. Furthermore, when the holding member 3 is removed from Figure 11 in this way, the first cell array 11 corresponds to the first side member, and the fourth cell array 14 corresponds to the second side member.

[0100] The same applies to the first embodiment (Figures 12 and 13) and the second embodiment (Figures 14 to 16), which describe the second step #2 and the third step #3 with a specific example of the battery module 5. In both the first and second embodiments, the battery cell 1 (cell array 10) or the heat exchange member 2 are used as the first and second side members instead of the holding member 3, preferably the battery cell 1 (cell array 10) as the first and second side members. Furthermore, in the above description, it can be easily understood by substituting the first side member for the first side holder 41 and the second side member for the second side holder 43. Also, common to both the first and second embodiments, the battery module 5 includes a fixing member 6 that fixes the positional relationship between the battery cell 1 and the heat exchange member 2.

[0101] For example, in the first embodiment, the fixing member 6 comprises a first bracket 61 (first fixing member) positioned on the first side X1 in the alignment direction relative to the first side member, a second bracket 62 (second fixing member) positioned on the second side X2 in the alignment direction relative to the second side member, and a lower plate 63 (third fixing member) to which the first bracket 61 and the second bracket 62 are connected. In the second step #2, the first bracket 61 is pressed toward the second side X2 in the alignment direction, and the second bracket 62 is pressed toward the first side X1 in the alignment direction. In the third step #3, the first bracket 61 and the second bracket 62 are fixed to the lower plate 63 while maintaining the relative position of the first bracket 61 and the second bracket 62.

[0102] In the second embodiment, an assembly jig 9 is used, which has a first contact portion 91 that contacts the first side member from the first side X1 in the alignment direction, and a second contact portion 92 that contacts the second side member from the second side X2 in the alignment direction. In the second step #2, the first contact portion 91 presses the first side member toward the second side X2 in the alignment direction, and the second contact portion 92 presses the second side member toward the first side X1 in the alignment direction. In the third step #3, with the battery cell 1 (cell array 10) and the heat exchange member 2 pressed in the alignment direction X, the positional relationship between the battery cell 1 (cell array 10) and the heat exchange member 2 is fixed by the fixing member 6.

[0103] The fixing member 6 of the second embodiment includes a first fixing portion 6a positioned on the first side X1 in the alignment direction relative to the first side member, a second fixing portion 6b positioned on the second side X2 in the alignment direction relative to the second side member, and a connecting portion 6c that connects the first fixing portion 6a and the second fixing portion 6b along the alignment direction X, with the battery module 5 formed. A housing portion 6e is formed in the space enclosed by the first fixing portion 6a, the second fixing portion 6b and the connecting portion 6c. In the third step #3, the battery cell 1 and the heat exchange member 2 are pressed in the alignment direction X by the assembly jig 9 and housed in the housing portion 6e along the first fixing portion 6a and the second fixing portion 6b. The positional relationship between the battery cell 1 (cell array 10) and the heat exchange member 2 is then fixed by the first fixing portion 6a and the second fixing portion 6b.

[0104] The following is a brief summary of the battery module production method described above.

[0105] In one embodiment, a battery module production method is a method for producing a battery module comprising at least one battery cell (1) and a heat exchange member (2) having a flow path (24) through which a heat transfer medium flows, the method comprising: a first step (#1) of positioning the heat exchange member (2) adjacent to the battery cell (1) along the alignment direction (X), with the direction in which the battery cell (1) and the heat exchange member (2) are aligned being defined as the alignment direction (X); a second step (#2) of pressing the battery cell (2) and the heat exchange member (2) in the alignment direction (X); and a third step (#3) of fixing the positional relationship between the battery cell (1) and the heat exchange member (2).

[0106] According to this production method, the battery cells (1) and heat exchange members (2) can be fixed in a state where they are pressed together in the direction of alignment, thereby fixing the positional relationship between the battery cells and the heat exchange members. As a result, the battery modules (5) can be produced with the battery cells and heat exchange members properly positioned without the use of adhesives or fillers. Furthermore, since the need to insert adhesives or fillers between the battery cells (1) and the heat exchange members (2) is reduced, the battery modules (5) can be easily disassembled.

[0107] Furthermore, in the battery module production method, it is preferable that in the second step (#2), the heat exchange member (2) is pressed such that the thickness of the heat exchange member (2) in the alignment direction (X) is smaller after the completion of the second step (#2) than the thickness before the start of the second step (#2).

[0108] This configuration makes it easier to bring the battery cell (1) and the heat exchange component (2) into close contact.

[0109] Furthermore, the battery module production method comprises at least two battery cell arrays (10) each having a plurality of cylindrical battery cells (1) arranged in a direction (Y) perpendicular to the arrangement direction (X), one of the two battery cell arrays (10) being designated as the first battery cell array (11) and the other as the second battery cell array (12), the surface of the first battery cell array (11) facing the heat exchange member (2) being designated as the first heat exchange member side opposing surface group (81), and the surface of the second battery cell array (12) facing the heat exchange member (2) being designated as the second heat exchange member side opposing surface group (82). In the first step (#1), the heat exchange member (2) is positioned between the first battery cell array (11) and the second battery cell array (12) in the alignment direction (X), and the first opposing surface group (81) and the second opposing surface group (82) on the heat exchange member side, which have irregularities in the alignment direction (X), are positioned sandwiching the heat exchange member (2) with the recesses and protrusions facing each other in the alignment direction (X). In the second step (#2), it is preferable to press the heat exchange member (2) so that it deforms to conform to the shapes of the first opposing surface group (81) and the second opposing surface group (82) on the heat exchange member side.

[0110] With this configuration, the heat exchange member (2) deforms to conform to the shape of the first opposing surface group (81) and the second opposing surface group (82) on the heat exchange member side, making it easier to increase the contact area between the heat exchange member (2) and the battery cell (1), and thus easier to improve the cooling performance of the battery cell (1).

[0111] Furthermore, the battery module production method further includes a holding member (3) that holds at least the battery cell (1) in the battery module (5), with one side of the alignment direction (X) designated as the first alignment direction side (X1) and the other side of the alignment direction (X) designated as the second alignment direction side (X2), and in the first step (#1), the holding member (3) is further positioned on the first alignment direction side (X1) and the second alignment direction side (X2) with respect to the battery cell (1) and the heat exchange member (2), and in the second step (#2), the alignment In the third step (#3), it is preferable to press the first retaining member (31), which is the retaining member (3) positioned on the first side (X1), toward the second side (X2) in the alignment direction, and press the second retaining member (32), which is the retaining member (3) positioned on the second side (X2) in the alignment direction, toward the first side (X1) in the alignment direction, and fix the positional relationship of the first retaining member (31) and the second retaining member (32) in the third step (#3) while the battery cell (1), the heat exchange member (2), and the retaining member (3) are pressed toward the alignment direction (X).

[0112] According to this production method, the battery cell (1) and the heat exchange member (2) are held in place in the alignment direction (X) by holding members (3) positioned on the first side (X1) and the second side (X2) of the alignment direction, respectively. By fixing the positional relationship of the holding members (3) while maintaining this state, the battery cell and the heat exchange member can be properly positioned and the battery module (5) can be produced without using adhesives or fillers. Furthermore, the need to insert adhesives or fillers between the battery cell (1) and the heat exchange member (2), between the battery cell (1) and any of the holding members (3), and between the heat exchange member (2) and any of the holding members (3) is reduced, making it easier to disassemble the battery module (5).

[0113] Furthermore, in the battery module production method, it is preferable that in the second step (#2), the heat exchange member (2) is compressed and deformed in the alignment direction (X) by pressing the first holding member (31) and the second holding member (32) so that the distance between them in the alignment direction (X) is shortened.

[0114] This configuration makes it easier to bring the battery cell (1) and the heat exchange component (2) into close contact.

[0115] Furthermore, the battery module production method includes a battery module (5) which comprises a fixing member (6) that fixes the positional relationship of the battery cell (1), the heat exchange member (2), and the holding member (3), and the fixing member (6) comprises a first fixing member (61) positioned on the first side in the alignment direction relative to the first holding member (31), a second fixing member (62) positioned on the second side in the alignment direction relative to the second holding member (32), and the first fixing member (61) and the second fixing member (62) are connected The assembly comprises a third fixing member (63) to which the first fixing member (61) is pressed toward the second side (X2) in the alignment direction and the second fixing member (62) is pressed toward the first side (X1) in the alignment direction. In the third step (3), the first fixing member (61) and the second fixing member (62) are fixed to the third fixing member (63) while maintaining the relative position of the first fixing member (61) and the second fixing member (62).

[0116] With this configuration, the fixing member (6) that constitutes the battery module (5) makes it possible to achieve pressing in the second step (#2) and fixing while maintaining the pressed state in the third step (#3).

[0117] Furthermore, the battery module production method includes a battery module (5) equipped with a fixing member (6) that fixes the positional relationship of the battery cell (1), the heat exchange member (2), and the holding member (3), and uses an assembly jig (9) equipped with a first contact portion (91) that abuts the first holding member (31) from the first side (X1) in the alignment direction, and a second contact portion (92) that abuts the second holding member (32) from the second side (X2) in the alignment direction, and in the second step (#2), the first contact portion (9 1) Therefore, the first retaining member (31) is pressed toward the second side (X2) in the alignment direction, and the second retaining member (32) is pressed toward the first side (X1) in the alignment direction by the second contact portion (92). In the third step (#3), the battery cell (1), the heat exchange member (2), and the retaining member (3) are pressed toward the alignment direction, and the positional relationship of the first retaining member (31) and the second retaining member (32) is fixed by the fixing member (6).

[0118] With this configuration, the positional relationship between the first holding member (31) and the second holding member (32) can be fixed by the fixing member (6) in a state where no reaction force due to pressing acts on the fixing member (6), or in a state where the reaction force of pressing applied to the fixing member (6) is suppressed.

[0119] Furthermore, in the battery module production method, the battery module (5) is equipped with the fixing member (6), and when pressed using the assembly jig (9) in the second step (#2) and the third step (#3), the fixing member (6) is equipped with a first fixing part (6a) positioned on the first side (X1) in the alignment direction with respect to the first holding member (31), a second fixing part (6b) positioned on the second side (X2) in the alignment direction with respect to the second holding member (32), and a connecting part (6c) that connects the first fixing part (6a) and the second fixing part (6b) along the alignment direction (X). In the third step (#3), the battery cell (1), the heat exchange member (2), and the holding member (3) are pressed in the alignment direction (X) by the assembly jig (9) and housed in the housing (6e) along the first fixing part (6a) and the second fixing part (6b), and the positional relationship of the first holding member (31) and the second holding member (32) is preferably fixed by the first fixing part (6a) and the second fixing part (6b).

[0120] With this configuration, the positional relationship between the first retaining member (31) and the second retaining member (32) can be easily fixed in the third step (#3) by using a fixing member (6) in which a housing portion (6e) is formed.

[0121] The following is a brief summary of the battery module (5) produced by the battery module production method described above.

[0122] In one embodiment, the battery module (5) comprises at least one battery cell (1), a heat exchange member (2) having a flow path (24) through which a heat transfer medium flows, and a holding member (3) that maintains the positional relationship between the battery cell (1) and the heat exchange member (2), wherein the direction in which the battery cell (1) and the heat exchange member (2) are aligned is defined as the alignment direction (X), one side of the alignment direction X is defined as the first alignment direction side (X1), and the other side of the alignment direction (X) is defined as the second alignment direction side (X2). The holding member (3) comprises a first holding member (31) positioned on the first side (X1) in the alignment direction relative to the battery cell (1) and the heat exchange member (2), and a second holding member (32) positioned on the second side (X2) in the alignment direction relative to the battery cell (1) and the heat exchange member (2), wherein the battery cell (1) and the heat exchange member (2) are held in a state where they are sandwiched between the first holding member (31) and the second holding member (32) in the alignment direction (X).

[0123] With this configuration, the battery cell (1) and the heat exchange member (2) are held by being sandwiched between the first holding member (31) and the second holding member (32) in the direction of alignment (X), thereby reducing the need to insert adhesives, fillers, etc., between the battery cell (1) and the heat exchange member (2), between the battery cell (1) and any of the holding members (3), and between the heat exchange member (2) and any of the holding members (3). Therefore, the battery module (5) can be easily disassembled.

[0124] Furthermore, it is preferable that the battery module (5) has a first opposing surface (8a) on the battery cell (1) facing the first side (X1) in the alignment direction, and a second opposing surface (8b) on the battery cell (1) facing the second side (X2) in the alignment direction, and that the first opposing surface (8a) and the second opposing surface (8b) have a shape with irregularities in the alignment direction (X), and that the first support surface (31s) on the first holding member (31), which is the surface facing the second side (X2) in the alignment direction, has irregularities in the alignment direction (X) corresponding to the shape of the first opposing surface (8a), and that the second support surface (32s) on the second holding member (32), which is the surface facing the first side (X1) in the alignment direction, has irregularities in the alignment direction (X) corresponding to the shape of the second opposing surface (8b).

[0125] With this configuration, the first support surface (31s) and the second support surface (32s) with uneven surfaces allow the battery cell (1) and the heat exchange member (2), which have first and second opposing surfaces (8a and 8b) with uneven surfaces, to be properly held in a state where they do not move relative to each other.

[0126] Furthermore, it is preferable that the heat exchange member (2) of the battery module (5) is positioned between the battery cell (1) and the first holding member (31) in the alignment direction (X), and that the heat exchange member (2) has greater flexibility than the first opposing surface (8a), and is pressed against the first opposing surface (8a) while deforming to conform to the shape of the first opposing surface (8a).

[0127] With this configuration, the heat exchange member (2) has greater flexibility than the first opposing surface (8a) of the battery cell (1), and is pressed against the first opposing surface (8a) so as to deform to conform to the shape of the first opposing surface (8a). Therefore, even if there are errors in the relative position or relative shape between the first holding member (31) and the battery cell (1), it is easy to appropriately determine the positional relationship between the battery cell (1) and the heat exchange member (2) and to improve the heat transfer efficiency between the battery cell (1) and the heat exchange member (2). Furthermore, because the heat exchange member (2) is pressed against the first opposing surface (8a) using the first holding member (31) so as to deform to conform to the shape of the first opposing surface (8a), the battery cell (1) and the heat exchange member (2) can be properly held without inserting adhesives or fillers between them, and the battery module (5) can be easily disassembled.

[0128] Furthermore, the battery module (5) preferably has the heat exchange member (2) positioned between the battery cells (1) and the first holding member (31) in the alignment direction (X), and a heat-conductive heat transfer member (7) positioned between the battery cells (1) and the heat exchange member (2) in the alignment direction (X), with the side of the heat exchange member (2) facing the battery cells (1) being the battery-side opposing surface (2s), the battery-side opposing surface (2s) having irregularities in the alignment direction (X) corresponding to the shape of the first side opposing surface (8a), and the heat transfer member (7) having greater flexibility than the first side opposing surface (8a) and the battery-side opposing surface (2s), and being sandwiched between the first side opposing surface (8a) and the battery-side opposing surface (2s) in a state where it deforms to follow the shape of the first side opposing surface (8a) and the battery-side opposing surface (2s).

[0129] With this configuration, a heat-conducting member (7) is placed between the battery cell (1) and the heat exchange member (2), and the heat-conducting member (7) has greater flexibility than the first side opposing surface (8a) and the battery side opposing surface (2s). Therefore, it is easy to improve the heat transfer efficiency between the battery cell (1) and the heat exchange member (2) while appropriately determining the positional relationship between the battery cell (1) and the heat exchange member (2). Furthermore, since the heat exchange member (2) and the heat-conducting member (7) are sandwiched between the battery cell (1) and the first holding member (31), the battery cell (1) and the heat exchange member (2) can be properly held without inserting adhesive or filler between them, and the battery module (5) can be easily disassembled.

[0130] Furthermore, the battery module (5) preferably includes a fixing member (6) that fixes the positional relationship between the first holding member (31) and the second holding member (32) in the alignment direction (X).

[0131] With this configuration, the fixing member (6) fixes the positional relationship between the first holding member (31) and the second holding member (32), allowing the battery cell (1) and the heat exchange member (2) to be properly held in a state where they are sandwiched between the first holding member (31) and the second holding member (32). Furthermore, the battery module (5) can be easily disassembled by removing the fixing member (6). [Explanation of Symbols]

[0132] 1: Battery cell, 2: Heat exchange member, 3: Holding member, 5: Battery module, 6: Fixing member, 6a: First fixing part, 6b: Second fixing part, 6c: Connecting part, 6e: Housing part, 9: Assembly jig, 10: Cell array (battery cell array), 24: Flow path, 31: First holding member, 32: Second holding member, 61: First bracket (first fixing member), 62: Second bracket (second fixing member), 63: Lower plate (third fixing member), 64: Upper plate (fixing member), 66: Lower case (fixing member), 67: Upper bracket (fixing member), 81: First opposing surface group on the heat exchange member side, 82: Second opposing surface group on the heat exchange member side, 91: First contact part, 92: Second contact part, X: Alignment direction, X1: First side in the alignment direction, X2: Second side in the alignment direction, Y: Width direction (direction perpendicular to the alignment direction)

Claims

1. At least one battery cell, A method for producing a battery module comprising a heat exchange member having a channel formed inside through which a heat transfer medium flows, The direction in which the battery cell and the heat exchange member are aligned is defined as the alignment direction. A first step is to arrange the heat exchange member adjacent to the battery cell along the aforementioned alignment direction, A second step involves pressing the battery cell and the heat exchange member in the direction of alignment, A third step involves fixing the positional relationship between the battery cell and the heat exchange member, A battery module production method comprising the following features.

2. The battery module production method according to claim 1, wherein in the second step, the heat exchange members are pressed such that the thickness of the heat exchange members in the direction of alignment is smaller after the completion of the second step than the thickness before the start of the second step.

3. The battery cell array comprises at least two arrays, each containing a plurality of cylindrical battery cells arranged in a direction perpendicular to the aforementioned arrangement direction. One of the two battery cell arrays is designated as the first battery cell array, and the other as the second battery cell array. The surfaces in the first battery cell array facing the heat exchange member are designated as the first group of opposing surfaces on the heat exchange member side, and the surfaces in the second battery cell array facing the heat exchange member are designated as the second group of opposing surfaces on the heat exchange member side. In the first step described above, The heat exchange member is positioned between the first battery cell array and the second battery cell array in the direction of alignment, The heat exchange member side first opposing surface group and the heat exchange member side second opposing surface group, which have irregularities in the direction of alignment, are arranged on either side of the heat exchange member such that the recesses and protrusions face each other in the direction of alignment. The battery module production method according to claim 1, wherein in the second step, the heat exchange member is pressed so as to deform in accordance with the shape of the first group of opposing surfaces on the heat exchange member side and the second group of opposing surfaces on the heat exchange member side.

4. The battery module further comprises a retaining member that holds at least the battery cells, Let one side of the aforementioned alignment direction be the first alignment direction, and the other side of the aforementioned alignment direction be the second alignment direction. In the first step, the holding members are further positioned on the first and second sides in the alignment direction with respect to the battery cell and the heat exchange member, respectively. In the second step, the first retaining member, which is the retaining member positioned on the first side in the alignment direction, is pressed toward the second side in the alignment direction, and the second retaining member, which is the retaining member positioned on the second side in the alignment direction, is pressed toward the first side in the alignment direction. The battery module production method according to any one of claims 1 to 3, wherein in the third step, the battery cell, the heat exchange member, and the holding member are pressed in the direction of alignment, and the positional relationship between the first holding member and the second holding member is fixed.

5. The battery module production method according to claim 4, wherein in the second step, the heat exchange member is compressed and deformed in the direction of alignment by pressing it so that the distance between the first holding member and the second holding member in the direction of alignment is shortened.

6. The battery module includes a fixing member that fixes the positional relationship between the battery cell, the heat exchange member, and the holding member. The fixing member comprises a first fixing member positioned on the first side in the alignment direction relative to the first holding member, a second fixing member positioned on the second side in the alignment direction relative to the second holding member, and a third fixing member to which the first fixing member and the second fixing member are connected. In the second step, the first fixing member is pressed toward the second side in the alignment direction, and the second fixing member is pressed toward the first side in the alignment direction. In the third step, the first fixing member and the second fixing member are fixed to the third fixing member while maintaining the relative position of the first fixing member and the second fixing member. The battery module production method according to claim 4.

7. The battery module includes a fixing member that fixes the positional relationship between the battery cell, the heat exchange member, and the holding member. An assembly jig is used which includes a first contact portion that contacts the first holding member from the first side in the alignment direction, and a second contact portion that contacts the second holding member from the second side in the alignment direction. In the second step, the first contact portion presses the first retaining member toward the second side in the alignment direction, and the second contact portion presses the second retaining member toward the first side in the alignment direction. The battery module production method according to claim 4, wherein in the third step, the battery cell, the heat exchange member, and the holding member are pressed in the direction of alignment, and the positional relationship between the first holding member and the second holding member is fixed by the fixing member.

8. The fixing member comprises a first fixing portion positioned on the first side in the alignment direction relative to the first holding member, a second fixing portion positioned on the second side in the alignment direction relative to the second holding member, and a connecting portion connecting the first fixing portion and the second fixing portion along the alignment direction, with a housing portion formed in the space enclosed by the first fixing portion, the second fixing portion and the connecting portion. The battery module production method according to claim 7, wherein in the third step, the battery cell, the heat exchange member, and the holding member are pressed in the alignment direction by the assembly jig and housed in the housing along the first fixing portion and the second fixing portion, and the positional relationship between the first holding member and the second holding member is fixed by the first fixing portion and the second fixing portion.

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