Battery module

Abstract

To provide a battery module of which uniformity of restraining pressure applied to a battery is high.SOLUTION: There is provided a battery module including: a battery including a plurality of electrodes layered in a first direction; a pair of elastic members arranged on both surfaces of the battery, respectively; a pair of plate member arranged to sandwich the battery and the pair of elastic members in the first direction; a pair of restraining members that applies a restraining pressure to the battery, the pair of elastic members, and the pair of plate members in the first direction, and is arranged to face to each other in a second direction orthogonal to the first direction. In the battery module, a specified plate member is included.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This disclosure relates to a battery module. [Background technology]

[0002] As plate members to be placed on both sides of a battery, plate members made by stacking multiple members are known. For example, Patent Document 1 discloses an end plate having a three-layer structure in which a first metal plate layer / resin plate layer / second metal plate layer is stacked in that order, and an end plate having a four-layer structure in which a first metal plate layer / resin plate layer / second metal plate layer / carbon fiber reinforced plastic plate layer is stacked in that order. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-047573 [Overview of the project] [Problems that the invention aims to solve]

[0004] For example, as shown in Patent Document 1, the weight of the plate member can be reduced by combining a resin plate with a metal plate to construct the plate member. On the other hand, in the case of a plate member made by laminating multiple members, each laminated member must be sufficiently fixed. If the fixing is insufficient, when the plate member is bent to restrain the battery with a restraining member, adjacent members in the plate member may shift in the shear direction (direction perpendicular to the thickness direction).

[0005] When adjacent plate members shift in the shear direction, regions with sufficient and insufficient restraining pressure from the restraining members occur, resulting in uneven restraining pressure applied to the battery. In particular, with large batteries, the amount of deflection of the plate members due to the restraining members is large, making uneven restraining pressure on the battery more likely.

[0006] This disclosure is made in view of the above circumstances and primarily aims to provide a battery module with high uniformity of the constraining pressure applied to the battery. [Means for solving the problem]

[0007] [1] A battery comprising multiple electrodes stacked in a first direction, A pair of elastic members are arranged on each side of the above-mentioned battery, A pair of plate members are arranged to sandwich the above-mentioned battery and the pair of above-mentioned elastic members in the above-mentioned first direction, In the first direction described above, a restraining pressure is applied to the battery, the pair of elastic members, and the pair of plate members, and a pair of restraining members are arranged to face each other in a second direction perpendicular to the first direction, A battery module having, The plate member has a plurality of core members extending in the second direction, and a first plate member arranged on the battery-side surface of the plurality of core members. In the plate member described above, the core member and the first plate member have through holes extending in the first direction, and are fastened in the first direction by a first fastening member positioned in the through holes. A battery module having, viewed from the first direction, the plate member is positioned inward from the outer edge of the core member, restricts the relative movement of the core member and the first plate member in the second direction, and has a first fixing member that does not fasten the core member and the first plate member in the first direction.

[0008] [2] A battery comprising multiple electrodes stacked in a first direction, A pair of elastic members are arranged on each side of the above-mentioned battery, A pair of plate members are arranged to sandwich the above-mentioned battery and the pair of above-mentioned elastic members in the above-mentioned first direction, In the first direction described above, a restraining pressure is applied to the battery, the pair of elastic members, and the pair of plate members, and a pair of restraining members are arranged to face each other in a second direction perpendicular to the first direction, A battery module having, The plate member has a plurality of core members extending in the second direction, and a first plate member arranged on the battery-side surface of the plurality of core members. In the plate member described above, the core member and the first plate member have through holes extending in the first direction, and are fastened in the first direction by a first fastening member positioned in the through holes. Viewed from the first direction described above, the plate member is positioned inward from the outer edge of the core member and has a first fixing member that restricts the relative movement of the core member and the first plate member in the second direction described above. The first fixing member has higher strength in the second direction than the first fastening member, in the battery module.

[0009] [3] A battery comprising multiple electrodes stacked in a first direction, A pair of elastic members are arranged on each side of the above-mentioned battery, A pair of plate members are arranged to sandwich the above-mentioned battery and the pair of above-mentioned elastic members in the above-mentioned first direction, In the first direction described above, a restraining pressure is applied to the battery, the pair of elastic members, and the pair of plate members, and a pair of restraining members are arranged to face each other in a second direction perpendicular to the first direction, A battery module having, The plate member has a plurality of core members extending in the second direction, and a first plate member arranged on the battery-side surface of the plurality of core members. In the plate member described above, the core member and the first plate member have through holes extending in the first direction, and are fastened in the first direction by a first fastening member positioned in the through holes. When viewed from the first direction, the plate member is disposed inside the outer edge of the core member, and has a first fixing member that restricts relative movement of the core member and the first plate member in the second direction. The battery module, wherein a clearance in the second direction between the first fixing member and side surfaces of holes formed in the core member and the first plate member is smaller than a clearance in the second direction between the first fastening member and side surfaces of the through holes.

[0010] [4] The battery module according to any one of [1] to [3], wherein when viewed from the second direction, the first fixing member is disposed so as to overlap a boundary between the core member and the first plate member.

[0011] [5] The battery module according to any one of [1] to [4], wherein the first fixing member fits into holes formed in the core member and holes formed in the first plate member respectively, and restricts relative movement of the core member and the first plate member in the second direction.

[0012] [6] The plate member has a second plate member disposed on a surface of the plurality of core members opposite to the battery. In the plate member, the core member and the second plate member have through holes extending in the first direction, and are fastened in the first direction by a second fastening member disposed in the through holes. The battery module according to any one of [1] to [5], wherein when viewed from the first direction, the plate member is disposed inside the outer edge of the core member, restricts relative movement of the core member and the second plate member in the second direction, and has a second fixing member that does not fasten the core member and the second plate member in the first direction.

[0013] [7] The battery module according to any one of [1] to [6], wherein the first fixing member is disposed outside the first fastening member disposed at a position farthest from the center of the core member in the second direction when viewed from the first direction.

[0014] [8] The battery module according to any one of [1] to [7], wherein the first fixing members are respectively disposed at both ends of the core member in the second direction.

[0015] [9] The battery module according to any one of [1] to [8], wherein the core member is a hollow member having a hollow portion extending in the second direction.

[0016] [[ID=;16]]

[10] The battery module according to any one of [1] to [9], wherein the shape of the outer edge of the core member is a quadrilateral when viewed from the second direction.

[0017]

[11] The battery module according to any one of [1] to

[10] , wherein adjacent core members are disposed with a gap in a third direction orthogonal to the first direction and the second direction in the plate member.

[0018]

[12] The battery module according to any one of [1] to

[11] , wherein the shape of the battery is a quadrilateral when viewed from the first direction, and the length of each side constituting the quadrilateral is 20 cm or more.

[0019]

[13] The battery module according to any one of [1] to

[12] , wherein the restraint pressure applied by the restraint member is 10 kN or more and 500 kN or less. [Effect of the Invention]

[0020] The battery module in the present disclosure has an effect that the uniformity of the restraint pressure applied to the battery is high. [Brief explanation of the drawing]

[0021] [Figure 1] This is a schematic cross-sectional view illustrating an example of a battery module in this disclosure. [Figure 2] These are schematic perspective views and schematic cross-sectional views illustrating the plate members in this disclosure. [Figure 3] This is a schematic cross-sectional view illustrating the issues discussed in this disclosure. [Figure 4] This is a magnified view of region Z in Figure 3(b). [Figure 5] This is a schematic cross-sectional view illustrating an example of a fixing member in this disclosure. [Figure 6] This is a schematic side view illustrating a plate member in this disclosure. [Figure 7] This is a schematic side view illustrating a plate member in this disclosure. [Figure 8] These are schematic plan views and schematic cross-sectional views illustrating the fastening members and fixing members in this disclosure. [Figure 9] This is a schematic cross-sectional view illustrating an example of a fastening member in this disclosure. [Figure 10] This is a schematic cross-sectional view illustrating an example of a fixing member in this disclosure. [Figure 11] This is a schematic plan view illustrating the fastening members and fixing members in this disclosure. [Figure 12] This is a schematic plan view illustrating a battery in this disclosure. [Figure 13] This is a schematic cross-sectional view illustrating a battery in this disclosure. [Figure 14] This is a schematic cross-sectional view illustrating the battery manufacturing method described in this disclosure. [Figure 15] These are schematic plan and side views illustrating the restraint members in this disclosure. [Figure 16] This is a schematic cross-sectional view illustrating an example of a plate member in this disclosure. [Figure 17] This is a schematic cross-sectional view illustrating the fixing members and fastening members in this disclosure. [Modes for carrying out the invention]

[0022] Embodiments in this disclosure will be described in detail below with reference to the drawings. The following figures are schematic representations, and the size and shape of each part are exaggerated as appropriate for ease of understanding. In addition, in this specification, when describing a manner in which one member is positioned relative to another member, the terms "above" or "below" include, unless otherwise specified, both cases in which one member is positioned directly above or below another member so as to be in contact with that member, and cases in which one member is positioned above or below another member via another member.

[0023] A. First Embodiment Figure 1(a) is a schematic cross-sectional view illustrating a battery module in the first embodiment, Figure 1(b) is an enlarged view of region X in Figure 1(a), and Figure 1(c) is an enlarged view of region Y in Figure 1(a). As shown in Figure 1(a), the battery module 100 includes a battery 10, a pair of elastic members 20 (elastic member 20a and elastic member 20b) arranged on both sides of the battery 10, a pair of plate members 30 (plate member 30a and plate member 30b) arranged to sandwich the battery 10 and the pair of elastic members 20 in a first direction D1, and a pair of restraint members 40 (restraint member 40α and restraint member 40β) arranged to apply restraint pressure to the battery 10, the pair of elastic members 20 and the pair of plate members 30 in the first direction D1, and to face each other in a second direction D2 perpendicular to the first direction D1. Note that Figures 1(a) to 1(c) show a state in which no restraining pressure is applied to the battery 10 by the restraining member 40, unlike Figure 3(b) which will be described later.

[0024] Figure 2(a) is a schematic perspective view (exploded view) illustrating the plate member in the first embodiment, Figure 2(b) is a schematic perspective view illustrating the plate member in the first embodiment, and Figure 2(c) is a schematic cross-sectional view of the plate member along the D1-D2 plane including the line XX shown in Figure 2(b). Note that the fixing member 36y in Figure 2(c) is covered by the plate member 32y, but in Figure 2(b), the fixing member 36y is shown on the plate member 32y for convenience.

[0025] As shown in Figures 2(a) to (c), the plate member 30 includes a plurality of core members 31 extending in a second direction D2, and plate members 32 (first plate member 32x, second plate member 32y) arranged on both sides of the core members 31, respectively. In the plate member 30, the core members 31 and the plate members 32 have through holes extending in a first direction D1, and are fastened in the first direction D1 by fastening members 35 arranged in the through holes. Furthermore, as viewed from the first direction D1, the plate member 30 is positioned inward from the outer edge of the core members 31, and has fixing members 36 that restrict the relative movement of the core members 31 and the plate members 32 in the second direction D2, and do not fasten the core members 31 and the plate members 32 in the first direction D1.

[0026] According to the first embodiment, by providing a fixing member to a plate member having a core member and a plate member, a battery module with high uniformity of the restraining pressure applied to the battery is obtained. Here, Figure 3(a) shows a state in which no restraining pressure is applied to the battery 10 by the restraining member 40, and Figure 3(b) shows a state in which restraining pressure is applied to the battery 10 by the restraining member 40. Specifically, the restraining member 40 has a pair of restraining plates 41, a connecting member 42 that connects the pair of restraining plates 41, and an adjusting member 43 connected to the connecting member 42 that adjusts the distance between the pair of restraining plates 41, and the pair of restraining plates 41, the connecting member 42 and the adjusting member 43 apply restraining pressure to the battery 10. As shown in Figure 3(b), there are cases in which the plate member 30 is bent using the restraining member 40 to apply restraining pressure to the battery 10. The core member 31 and the plate member 32 that constitute the plate member 30 need to be sufficiently fixed.

[0027] One possible method for fixing the core member 31 and the plate member 32 is welding. While welding firmly fixes the core member 31 and the plate member 32, welding distortion (distortion caused by thermal shrinkage during welding) can cause waviness on the surface of the plate member 32, potentially reducing the uniformity of the restraining pressure applied to the battery. Removing this waviness would require machining, for example, which would decrease productivity. In particular, for large batteries, the plate member is also larger, increasing the area required to remove the waviness, resulting in a significant decrease in productivity. In contrast, in the first embodiment, as shown in Figure 1(b), the core member 31 and the plate member 32 are fixed using fastening members 35 (e.g., rivets). When fastening members 35 are used, unlike when welding is used as described above, there is an advantage in that waviness is less likely to occur on the plate member.

[0028] On the other hand, as shown in Figure 1(b), when the fastening member 35 is used, the fixing of the core member 31 and the plate member 32 tends to be insufficient. If the fixing of the core member 31 and the plate member 32 is insufficient, as shown in Figures 3(b) and 4, when the plate member 30 is bent, the core member 31 and the plate member 32 may shift in the shear direction (direction perpendicular to the thickness direction). When the core member 31 and the plate member 32 shift in the shear direction, regions with sufficient restraining pressure applied by the restraining member 30 and regions with insufficient restraining pressure (or regions where no restraining pressure is applied at all) occur, resulting in uneven restraining pressure applied to the battery 10. In particular, in the case of large batteries, the amount of deflection of the plate member by the restraining member is large, so the restraining pressure applied to the battery tends to be uneven.

[0029] In contrast, in the first embodiment, as shown in Figure 5, by providing a fixing member 36 to a plate member 30 having a core member 31 and a plate member 32, a battery module with high uniformity of the restraining pressure applied to the battery is obtained. Specifically, by arranging the side surface SS1 of the fixing member 36 and the side surfaces SS2 of the core member 31 and plate member 32 to face each other, the fixing member 36 acts as resistance to shear displacement. Therefore, a battery module with high uniformity of the restraining pressure applied to the battery is obtained. In the first embodiment, unlike the fastening member 35, the fixing member 36 is a member that does not fasten the core member 31 and the plate member 32 in the first direction D1.

[0030] 1. Plate Member As shown in Figure 1(a), the battery module in the first embodiment has a pair of plate members 30 (30a, 30b) arranged to sandwich a battery 10 and a pair of elastic members 20 (20a, 20b) in a first direction D1.

[0031] As shown in Figures 1(b) and 6(a), the plate member 30 has a plurality of core members 31 extending in the second direction D2, and a first plate member 32x arranged on the battery-side (lower side in the drawing) surface of the plurality of core members 31. As shown in Figure 6(a), the plate member 30 may have a second plate member 32y in addition to the first plate member 32x, arranged on the surface of the plurality of core members 31 opposite to the battery (upper side in the drawing). On the other hand, as shown in Figure 6(b), the plate member 30 does not have a plate member on the surface of the plurality of core members 31 opposite to the battery (upper side in the drawing).

[0032] (1) Core member As shown in Figure 1(a), the core member 31 is a member that extends in the second direction D2. As shown in Figure 2(a), multiple core members 31 are arranged along a third direction D3 that is perpendicular to the first direction D1 and the second direction D2. Also, as shown in Figure 2(b), the core members 31 and the plate members 32 may be in contact. On the other hand, although not specifically shown, other members may be arranged between the core members and the plate members. The material of the core members is not particularly limited, but examples include metals such as stainless steel and aluminum.

[0033] As shown in Figure 2(c), the core member 31 may have a hollow portion 31a extending in the second direction D2. Having a hollow portion 31a in the core member 31 makes it possible to reduce the weight of the plate member 30. Preferably, the hollow portion 31a extends from one end to the other end of the core member 31 in the second direction D2. On the other hand, although not specifically shown, the core member may be a member without a hollow portion (a solid member).

[0034] The shape of the outer edge of the core member as viewed from the second direction is not particularly limited. For example, as shown in Figure 7(a), the shape of the outer edge of the core member 31 as viewed from the second direction D2 may be quadrilateral. Examples of such quadrilaterals include squares and rectangles. The core member 31 shown in Figure 7(a) has a top surface portion 31b and a bottom surface portion 31c that extend in the third direction D3 as viewed from the second direction D2 and are opposite to each other. It is preferable that fastening members and fixing members, which will be described later, are arranged on the top surface portion 31b and the bottom surface portion 31c, respectively.

[0035] Furthermore, as shown in Figure 7(b), the shape of the outer edge of the core member 31 when viewed from the second direction D2 may be circular. Examples of such circular shapes include a perfect circle and an ellipse. Also, as shown in Figure 7(c), the shape of the outer edge of the core member 31 when viewed from the second direction D2 may be I-shaped, having a top surface portion 31d extending in the third direction D3, a bottom surface portion 31e extending in the third direction D3, and a connecting portion 31f extending in the first direction D1 and connected to the top surface portion 31d and the bottom surface portion 31e.

[0036] As shown in Figures 7(a) to 7(c), adjacent core members 31 may be arranged with a gap I in a third direction D3 that is perpendicular to the first direction D1 and the second direction D2. By providing a gap I, the weight of the plate member 30 can be reduced. On the other hand, although not specifically shown, adjacent core members may be arranged without a gap. For example, adjacent core members may be in contact with each other.

[0037] (2) Plate members As shown in Figures 1(b) and 6(a), the plate member 30 has at least a first plate member 32x positioned on the battery-side (lower side in the drawing) of the plurality of core members 31. Also, as shown in Figure 6(a), in addition to the first plate member 32x, the plate member 30 may have a second plate member 32y positioned on the opposite side (upper side in the drawing) of the plurality of core members 31 from the battery. In the first embodiment, the first plate member and the second plate member may be simply referred to as plate members. The material of the plate members is not particularly limited, but examples include metals such as stainless steel and aluminum.

[0038] As shown in Figure 6(a), the thickness of the core member 31 (length in the first direction D1) is T1, and the thickness of the plate member 32 (first plate member 32x) is T2. The ratio of T2 to T1 (T2 / T1) is not particularly limited, but for example it may be 0.5 or less, 0.3 or less, or 0.1 or less.

[0039] (3) Fastening members As shown in Figure 1(b), the plate member 30 has a first fastening member 35x that fastens the core member 31 and the first plate member 32x in a first direction D1. Similarly, as shown in Figure 1(c), the plate member 30 may have a second fastening member 35y that fastens the core member 31 and the second plate member 32y in a first direction D1. In the first embodiment, the first fastening member and the second fastening member may be simply referred to as fastening members. The material of the fastening members is not particularly limited, but metal is one example.

[0040] Figure 8(a) is a schematic plan view illustrating the fastening member and fixing member in the first embodiment, Figure 8(b) is a cross-sectional view along line XX of Figure 8(a), and Figure 8(c) is a drawing of Figure 8(b) with the fastening member and fixing member removed. As shown in Figure 8(c), the core member 31 and the plate member 32 have a through hole H extending in the first direction D1. Also, as shown in Figures 8(a) and (b), the fastening member 35 is positioned in the through hole H in Figure 8(c). The fastening member 35 has a shaft portion 35a inserted into the through hole H, and flange portions 35b positioned at both ends of the shaft portion 35a, each having a diameter larger than the diameter of the through hole H. Because the diameter of the flange portions 35b is larger than the diameter of the through hole H, the core member 31 and the plate member 32 are restricted from moving relative to each other in the first direction D1. Furthermore, since the fastening member 35 has a shaft portion 35a, its relative movement in a direction perpendicular to the first direction D1 is also restricted.

[0041] The shape of the fastening member as viewed from the first direction is not particularly limited, but examples include circular shapes such as perfect circles and ellipses. A specific example of a fastening member is a rivet.

[0042] As shown in Figure 9(a), in the first direction D1, the top 35t of the fastening member 35 may protrude beyond the top 32t of the plate member 32. On the other hand, as shown in Figure 9(b), in the first direction D1, the top 35t of the fastening member 35 does not have to protrude beyond the top 32t of the plate member 32. In Figure 9(b), the plate member 32 has a thin-walled portion a around the through hole, so that in the first direction D1, the top 35t of the fastening member 35 is located on the core member 31 side of the top 32t of the plate member 32.

[0043] (4) Fixing member As shown in Figure 1(b), the plate member 30 has a first fixing member that is positioned inside the outer edge of the core member 31, restricts the relative movement of the core member 31 and the first plate member 32x in the second direction D2, and does not fasten the core member 31 and the first plate member 32x in the first direction D1. Similarly, as shown in Figure 1(c), the plate member 30 may have a second fixing member that is positioned inside the outer edge of the core member 31, restricts the relative movement of the core member 31 and the second plate member 32y in the second direction D2, and does not fasten the core member 31 and the second plate member 32y in the first direction D1. In the first embodiment, the first fixing member and the second fixing member may be simply referred to as fixing members. The material of the fixing members is not particularly limited, but examples include metal.

[0044] As shown in Figure 8(c), the core member 31 and the plate member 32 have a space S for housing the fixing member. The space S shown in Figure 8(c) is composed of a hole 31h formed in the core member 31 and a hole 32h formed in the plate member 32. The core member 31 and the plate member 32 also have a side surface SS2 that faces the space S in the second direction D2. The side surface SS2 is a surface flush with the boundary B between the core member 31 and the plate member 32. By positioning the side surface SS1 of the fixing member, as shown in Figure 5, opposite the side surface SS2, the fixing member 36 becomes resistant to shear displacement. As a result, the battery module has high uniformity of the restraining pressure applied to the battery. Furthermore, as shown in Figure 5, it is preferable that the fixing member 36 is positioned so as to overlap with the boundary B between the core member 31 and the plate member 32 when viewed from the second direction D2. The fixing member 36 fits into the hole 31h formed in the core member 31 and the hole 32h formed in the plate member 32, respectively, thereby restricting the relative movement of the core member 31 and the plate member 32 in the second direction D2.

[0045] As shown in Figure 8(b), in the second direction D2, the length of the shaft portion 35a of the fastening member 35 is L1, and the length of the fixing member 36 is L2. It is preferable that L2 is greater than L1. The ratio of L2 to L1 (L2 / L1) is, for example, 1.2 or more, may be 1.5 or more, may be 2 or more, or may be 3 or more. On the other hand, L2 / L1 is, for example, 5 or less.

[0046] As shown in Figure 10(a), the core member 31 typically has a hole 31h for positioning the fixing member 36. Similarly, the plate member 32 typically has a hole 32h for positioning the fixing member 36. The holes 31h and 32h shown in Figure 10(a) are grooves with bottoms. As shown in Figure 10(a), if the core member 31 has a groove-like hole 31h and the plate member 32 has a groove-like hole 32h, the fixing member 36 is positioned in the space formed by the holes 31h and 32h before fastening the core member 31 and the plate member 32 with a fastening member (not shown).

[0047] On the other hand, as shown in Figure 10(b), the hole 32h formed in the plate member 32 may be a through-hole. When the hole 32h is a through-hole, it is preferable that the fixing member 36 is held by a holding portion 37 positioned in the through-hole. As shown in Figure 10(b), when the core member 31 has a hole 31h which is a groove, and the plate member 32 has a hole 32h which is a through-hole, the core member 31 and the plate member 32 can be fastened together with a fastening member (not shown), the fixing member 36 can be placed in the space formed by the holes 31h and 32h, and then the holding portion 37 can be formed. Examples of materials for the holding portion 37 include resin. In addition, although not specifically shown, the core member may have a hole that is a through-hole, and the plate member may have a hole that is a groove. Also, as shown in Figure 10(c), the hole 31h formed in the core member 31 and the hole 32h formed in the plate member 32 may each be through-holes. The hole 31h has, in order from the plate member 32 side, a large-diameter portion 31h1 and a small-diameter portion 31h2 which has a smaller diameter than the large-diameter portion 31h1. The fixing member 36 also has a stepped structure that fits into the large-diameter portion 31h1 and the small-diameter portion 31h2, respectively.

[0048] The shape of the fixing member as viewed from the first direction is not particularly limited, but examples include circles such as perfect circles and ellipses, and quadrilaterals such as squares and rectangles. A concrete example of a fixing member is a solid pin.

[0049] Figures 11(a) to 11(e) are schematic plan views illustrating the fastening member and fixing member in the first embodiment. In Figures 11(a) to 11(e), the fixing member 36 is shown on the plate member 32 for convenience, similar to Figure 2(b). As shown in Figures 11(a) to 11(e), it is preferable that the fixing member 36 is positioned outside the fastening member 35, which is located at the position furthest from the center C of the core member 31 in the second direction D2 when viewed from the first direction D1. Also, as shown in Figures 11(a) to 11(e), it is preferable that fixing members 36 are positioned at both ends of a single core member 31 in the second direction D2.

[0050] As shown in Figure 11(a), multiple fastening members 35 may be arranged along the second direction D2 in a single core member 31. Also, adjacent fastening members 35 may be arranged along the third direction D3 in adjacent core members 31. Furthermore, as shown in Figure 11(b), a single fastening member 35 may be arranged along the second direction D2 in a single core member 31.

[0051] As shown in Figure 11(c), it is preferable that the fixing member 36 is positioned inward from the fastening member 35, which is located at the position furthest from the center C of the core member 31 in the second direction D2, when viewed from the first direction D1. Also, as shown in Figure 11(c), the fastening member 35 and the fixing member 36 may be arranged regularly in the second direction D2. In Figure 11(c), the fastening member 35 and the fixing member 36 are arranged alternately in the second direction D2. On the other hand, although not specifically shown, one or more fastening members and one or more fixing members may be arranged alternately in the second direction. Also, as shown in Figure 11(d), when viewed from the first direction D1, multiple fixing members 36 may be arranged along the third direction D3 on a single core member 31. Also, as shown in Figure 11(e), the shape of the fixing member 36 when viewed from the first direction D1 may be a rectangle.

[0052] 2.Battery The battery module in the first embodiment has a battery including a plurality of electrodes stacked in a first direction. The electrodes also include a current collector and an active material layer (positive electrode active material layer or negative electrode active material layer) disposed on at least one surface of the current collector.

[0053] As shown in Figure 12, the battery 10 includes a plurality of electrodes E stacked in a first direction D1. The battery 10 shown in Figure 12 has a bipolar electrode BP1, a bipolar electrode BP2, a positive electrode end electrode CA, and a negative electrode end electrode AN as electrodes E. The bipolar electrode BP1 and bipolar electrode BP2 each have a current collector 1, a positive electrode active material layer 2 disposed on one surface of the current collector 1, and a negative electrode active material layer 3 disposed on the other surface of the current collector 1. The positive electrode end electrode CA has a current collector 1 and a positive electrode active material layer 2 disposed on one surface of the current collector 1. The negative electrode end electrode AN has a current collector 1 and a negative electrode active material layer 3 disposed on one surface of the current collector 1.

[0054] As shown in Figure 12, the battery 10 may have a bipolar electrode BP as an electrode E, which includes a current collector 1, a positive electrode active material layer 2 disposed on one surface of the current collector 1, and a negative electrode active material layer 3 disposed on the other surface of the current collector 1. The battery in the first embodiment may have only one bipolar electrode BP, or it may have two or more. On the other hand, the battery in the first embodiment is not particularly limited as long as it includes a plurality of electrodes stacked in a first direction, and may not have a bipolar electrode.

[0055] As shown in Figure 12, the battery 10 comprises power generation units U (U1, U2, U3). Each power generation unit U has a positive electrode active material layer 2, a negative electrode active material layer 3, and a separator 4 disposed between the positive electrode active material layer 2 and the negative electrode active material layer 3. The positive electrode active material layer 2, the negative electrode active material layer 3, and the separator 4 are each impregnated with an electrolyte (not shown). Furthermore, the battery in the first embodiment may have one power generation unit or two or more units.

[0056] As shown in Figure 12, the battery 10 may have a plurality of power generation units U(U1, U2, U3) stacked in a first direction D1. As shown in Figure 12, the plurality of power generation units U(U1, U2, U3) may be connected in series with each other. Although not specifically shown, the plurality of power generation units may also be connected in parallel with each other. The plurality of power generation units are independent of each other so that electrolyte does not flow between them. In Figure 12, the plurality of power generation units U(U1, U2, U3) are independent of each other so that electrolyte does not flow between them. For example, power generation unit U1 and power generation unit U2 are separated by a current collector 1 and a seal part 5, and are independent of each other.

[0057] As shown in Figure 12, it is preferable that a frame-shaped sealing portion 5 is arranged along the outer edge of the current collector 1 when viewed from the first direction D1. The sealing portion is preferably made of resin. Examples of the resin include thermoplastic resins. Examples of thermoplastic resins include olefin resins such as polyethylene and polypropylene.

[0058] The shape of the battery as viewed from the first direction is not particularly limited, but examples include a square, rectangle, or other quadrilateral. As viewed from the first direction, the length of each side constituting the outer edge of the battery is, for example, 20 cm or more, may be 50 cm or more, or may be 100 cm or more. On the other hand, the length of each of the above sides is, for example, 200 cm or less.

[0059] As shown in Figure 13(a), multiple batteries 10 may be stacked between a pair of elastic members 20 (20a, 20b). In Figure 13(a), multiple batteries 10 are stacked via a conductive plate 50 having a flow path 51 through which a coolant flows. Also, as shown in Figure 13(b), multiple batteries 10 may be stacked between a pair of elastic members 20 (20a, 20b), with an elastic member 20c placed between adjacent batteries 10.

[0060] The method for manufacturing the battery is not particularly limited. Figure 14 is a schematic cross-sectional view (exploded view) illustrating a method for manufacturing the battery in the first embodiment. As shown in Figure 14, bipolar electrodes BP1 and BP2 are prepared. The bipolar electrode BP1 has a positive electrode active material layer 2 disposed on one side of the current collector 1 and a negative electrode active material layer 3 disposed on the other side of the current collector 1.

[0061] Furthermore, the bipolar electrode BP1 has a frame member 5a for forming a seal, which is positioned along the outer edge of the current collector 1. Viewed from the first direction D1, the frame member 5a is usually positioned along the entire circumference of the outer edge of the current collector 1. For example, if the outer edge shape of the current collector 1 is rectangular, the frame member 5a is positioned along the entire circumference of the outer edge of that rectangle. Also, as shown in Figure 14, the frame member 5a usually covers a portion of one main surface p of the current collector 1, a portion of the other main surface q of the current collector 1, and the entire side surface r that constitutes the outer edge of the current collector 1.

[0062] As shown in Figure 14, the bipolar electrode BP2 has a positive electrode active material layer 2 disposed on one side of the current collector 1 and a negative electrode active material layer 3 disposed on the other side of the current collector 1. Furthermore, the bipolar electrode BP2 has a frame member 5a for forming a seal portion, which is disposed along the outer edge of the current collector 1. The details of the bipolar electrode BP2 are the same as those of the bipolar electrode BP1 described above.

[0063] As shown in Figure 14, the negative electrode active material layer 3 of the bipolar electrode BP1 and the positive electrode active material layer 2 of the bipolar electrode BP2 are placed opposite each other via a separator 4. At this time, at least a portion of the outer edge of the separator 4 is placed between adjacent frame members 5a. Also, a frame member (spacer) 5b is placed between the frame member 5a of the bipolar electrode BP1 and the frame member 5b of the bipolar electrode BP2. Next, the positive electrode end electrode CA is stacked on the bipolar electrode BP2 via the separator 4, and the negative electrode end electrode AN is stacked on the bipolar electrode BP1 via the separator 4. After that, a seal portion is formed by welding the stacked frame members together. Although not specifically shown, when stacking each electrode, an insert is placed between adjacent frame members, and after the seal portion is formed, the insert is removed to form a supply hole for supplying electrolyte. Electrolyte is supplied to the inside of the battery through the supply hole, and then the supply hole is sealed. This results in a battery.

[0064] 3. Elastic members The battery module in the first embodiment has a pair of elastic members, each positioned on both sides of the battery. The elastic members and the battery may be in contact or stacked with other members in between.

[0065] Examples of materials for the elastic member include polymer materials. Examples of polymer materials include silicone rubber, fluororubber, epichlorohydrin rubber, acrylic rubber, ethylene acrylic rubber, urethane rubber, nitrile rubber, hydrogenated nitrile rubber, chlorosulfonated polyethylene, chloroprene rubber, EPDM (ethylene-propylene-diene rubber), ethylene rubber, propylene rubber, butyl rubber, butadiene rubber, styrene-butadiene rubber, natural rubber, polyisobutylene, chloride polyethylene, isoprene rubber, foamed polypropylene, foamed polyethylene, and foamed polyurethane. Examples of shapes for the elastic member include layered and porous structures. The thickness of the elastic member is not particularly limited, but is, for example, 1 mm to 5 cm.

[0066] 4. Restraining member The restraining members in the first embodiment are a pair of restraining members that apply restraining pressure to the battery, the pair of elastic members, and the pair of plate members in the first direction, and are arranged to face each other in a second direction perpendicular to the first direction.

[0067] As shown in Figures 15(a) and (b), the restraining member 40 is a member that applies restraining pressure to the battery 10, a pair of elastic members 20 (20a, 20b), and a pair of plate members 30 (30a, 30b) in the first direction D1. Also, as shown in Figure 15(a), the pair of restraining members 40 (40α, 40β) are arranged to face each other in the second direction D2. Furthermore, as viewed from the first direction D1, the pair of restraining members 40 (40α, 40β) are positioned to overlap with the plate member 30.

[0068] As shown in Figure 15(b), the restraining member 40α may include a first restraining plate 41a positioned on the side of the plate member 30a opposite to the elastic member 20a and extending in the third direction D3, a second restraining plate 41b positioned on the side of the plate member 30b opposite to the elastic member 20b and extending in the third direction D3, a connecting member 42 connecting the first restraining plate 41a and the second restraining plate 41b, and an adjusting member 43 (43a, 43b) connected to the connecting member 42 for adjusting the distance between the first restraining plate 41a and the second restraining plate 41b. It is also preferable that the restraining member 40β has a structure similar to that of the restraining member 40α.

[0069] The restraining pressure applied by the pair of restraining members may be, for example, 10kN or more and 500kN or less, or 20kN or more and 400kN or less.

[0070] 5. Battery Module Applications of the battery module in the first embodiment include, for example, powering vehicles such as hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), battery electric vehicles (BEVs), gasoline cars, and diesel cars. In particular, it is preferable to use it as a power source for hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), or battery electric vehicles (BEVs). Furthermore, the battery module in the first embodiment may be used as a power source for mobile devices other than vehicles (e.g., railways, ships, aircraft), or as a power source for electrical products such as information processing devices.

[0071] B. Second Embodiment The battery module in the second embodiment comprises a battery including a plurality of electrodes stacked in a first direction, a pair of elastic members disposed on both sides of the battery, a pair of plate members disposed to sandwich the battery and the pair of elastic members in the first direction, and a pair of restraining members that apply restraining pressure to the battery, the pair of elastic members and the pair of plate members in the first direction and are disposed to face each other in a second direction perpendicular to the first direction, wherein the plate members have a plurality of cores extending in the second direction The device comprises a core member and a first plate member positioned on the battery-side surface of the plurality of core members, wherein the plate member has through holes extending in the first direction and is fastened in the first direction by first fastening members positioned in the through holes, and as viewed from the first direction, the plate member is positioned inward from the outer edge of the core member and has a first fixing member that restricts relative movement of the core member and the first plate member in the second direction, and the first fixing member has greater strength in the second direction than the first fastening member.

[0072] According to the second embodiment, by providing a specific fixing member (a fixing member having higher strength in the second direction than a fastening member) to a plate member having a core member and a plate member, a battery module with high uniformity of the restraining pressure applied to the battery is obtained. Furthermore, the fixing member in the second embodiment may be a member that fastens the core member and the plate member in the first direction. On the other hand, the fixing member in the second embodiment may be a member that does not fasten the core member and the plate member in the first direction. Details of each component constituting the battery module are the same as those described in "A. First Embodiment" above, so a detailed explanation is omitted here.

[0073] FIG. 16 is a schematic cross-sectional view of the plate member taken along the plane D1-D2 including the X-X line shown in FIG. 2(b), similar to FIG. 2(c). As shown in FIG. 16, in the second embodiment, the fixing member 36 has higher strength in the second direction D2 than the fastening member 35. "Higher strength in the second direction" means higher shear strength in the second direction. For example, the material (typically metal) used for the fixing member 36 may have higher shear strength than the material (typically metal) used for the fastening member 35. Also, as shown in FIG. 16, let the length in the second direction D2 of the through-hole H for arranging the fastening member 35 be L H and let the length in the second direction D2 of the hole 31h formed in the core member 31 and the hole 32h formed in the plate member 32 be L A as well. L A is preferably larger than L H . The ratio of L H to L A (L A / L H ) is, for example, 1.2 or more, and may be 1.5 or more, or may be 3 or more. On the other hand, L A / L H is, for example, 5 or less.

[0074] C. Third Embodiment The battery module in the third embodiment comprises a battery including a plurality of electrodes stacked in a first direction, a pair of elastic members disposed on both sides of the battery, a pair of plate members disposed to sandwich the battery and the pair of elastic members in the first direction, and a pair of restraint members that apply restraint pressure to the battery, the pair of elastic members and the pair of plate members in the first direction and are disposed to face each other in a second direction perpendicular to the first direction, wherein the plate members include a plurality of core members extending in the second direction and disposed on the battery-side surface of the plurality of core members. The plate member comprises a core member and a first plate member, wherein the core member and the first plate member have through holes extending in the first direction and are fastened in the first direction by a first fastening member positioned in the through holes, and as viewed from the first direction, the plate member is positioned inward from the outer edge of the core member and has a first fixing member that restricts the relative movement of the core member and the first plate member in the second direction, and the clearance in the second direction between the first fixing member and the side surface of the hole formed in the core member and the first plate member is smaller than the clearance in the second direction between the first fastening member and the side surface of the through hole.

[0075] According to the third embodiment, by providing a specific fixing member (a fixing member whose clearance in the second direction between the side surface of the hole formed in the core member and the plate member is smaller than the clearance in the second direction between the fastening member and the side surface of the through hole) to the plate member having a core member and a plate member, a battery module with high uniformity of the restraining pressure applied to the battery is obtained. Furthermore, the fixing member in the third embodiment may be a member that fastens the core member and the plate member in the first direction. On the other hand, the fixing member in the third embodiment may be a member that does not fasten the core member and the plate member in the first direction. Furthermore, the fixing member in the third embodiment may have higher strength in the second direction than the fastening member. Details of each component constituting the battery module are the same as those described in "A. First Embodiment" and "B. Second Embodiment" above, so a detailed explanation is omitted here.

[0076] Figure 17(a) is a schematic cross-sectional view of the plate member by the D1-D2 plane including the XX line shown in Figure 2(b), similar to Figure 2(c). Figures 17(b) and (c) are enlarged views of the fastening member 35 and the fixing member 36 in Figure 17(a). As shown in Figures 17(b) and (c), in the third embodiment, the clearance C2 in the second direction D2 between the fixing member 36 and the side surface of the holes (holes 31h and 32h) formed in the core member 31 and the plate member 32 is smaller than the clearance C1 in the second direction D2 between the fastening member 35 and the side surface of the through hole H. The ratio of C2 to C1 (C2 / C1) is, for example, 0.8 or less, and may be 0.6 or less. On the other hand, C2 / C1 is, for example, 0.3 or more.

[0077] This disclosure is not limited to the embodiments described above. The embodiments described above are illustrative, and any configuration that is substantially identical to the technical idea described in the claims of this disclosure and achieves similar effects is included within the technical scope of this disclosure. [Explanation of symbols]

[0078] 1... Current collector 2...Cathode active material layer 3...Negative electrode active material layer 4... Separator 5...Seal part 10...Battery 20…Elastic member 30...Plate component 31... Core component 32...Plate member 35… Fastening member 36… Fixing member 40…Restraining member 50... Conductive plate 100...Battery module

Claims

1. A battery including multiple electrodes stacked in a first direction, A pair of elastic members are arranged on both sides of the aforementioned battery, A pair of plate members are arranged to sandwich the battery and the pair of elastic members in the first direction, In the first direction, a restraining pressure is applied to the battery, the pair of elastic members, and the pair of plate members, and a pair of restraining members are arranged to face each other in a second direction perpendicular to the first direction, A battery module having, The plate member comprises a plurality of core members extending in the second direction, and a first plate member disposed on the battery-side surface of the plurality of core members. In the plate member, the core member and the first plate member have through holes extending in the first direction, and are fastened in the first direction by a first fastening member positioned in the through holes. A battery module having, viewed from the first direction, the plate member is positioned inward from the outer edge of the core member, restricts the relative movement of the core member and the first plate member in the second direction, and has a first fixing member that does not fasten the core member and the first plate member in the first direction.

2. A battery including multiple electrodes stacked in a first direction, A pair of elastic members are arranged on both sides of the aforementioned battery, A pair of plate members are arranged to sandwich the battery and the pair of elastic members in the first direction, In the first direction, a restraining pressure is applied to the battery, the pair of elastic members, and the pair of plate members, and a pair of restraining members are arranged to face each other in a second direction perpendicular to the first direction, A battery module having, The plate member comprises a plurality of core members extending in the second direction, and a first plate member disposed on the battery-side surface of the plurality of core members. In the plate member, the core member and the first plate member have through holes extending in the first direction, and are fastened in the first direction by a first fastening member positioned in the through holes. Viewed from the first direction, the plate member is positioned inward from the outer edge of the core member and has a first fixing member that restricts the relative movement of the core member and the first plate member in the second direction. The first fixing member has higher strength in the second direction than the first fastening member, in a battery module.

3. A battery including multiple electrodes stacked in a first direction, A pair of elastic members are arranged on both sides of the aforementioned battery, A pair of plate members are arranged to sandwich the battery and the pair of elastic members in the first direction, In the first direction, a restraining pressure is applied to the battery, the pair of elastic members, and the pair of plate members, and a pair of restraining members are arranged to face each other in a second direction perpendicular to the first direction, A battery module having, The plate member comprises a plurality of core members extending in the second direction, and a first plate member disposed on the battery-side surface of the plurality of core members. In the plate member, the core member and the first plate member have through holes extending in the first direction, and are fastened in the first direction by a first fastening member positioned in the through holes. Viewed from the first direction, the plate member is positioned inward from the outer edge of the core member and has a first fixing member that restricts the relative movement of the core member and the first plate member in the second direction. A battery module in which the clearance in the second direction between the first fixing member and the side surface of the hole formed in the core member and the first plate member is smaller than the clearance in the second direction between the first fastening member and the side surface of the through hole.

4. The battery module according to any one of claims 1 to 3, wherein, when viewed from the second direction, the first fixing member is arranged to overlap with the boundary between the core member and the first plate member.

5. The battery module according to any one of claims 1 to 3, wherein the first fixing member fits into a hole formed in the core member and a hole formed in the first plate member, respectively, to restrict the relative movement of the core member and the first plate member in the second direction.

6. The plate member has a second plate member that is arranged on the side of the plurality of core members opposite to the battery, In the plate member, the core member and the second plate member have through holes extending in the first direction, and are fastened in the first direction by a second fastening member positioned in the through holes. The battery module according to claim 1, wherein, viewed from the first direction, the plate member is positioned inward from the outer edge of the core member, restricts relative movement of the core member and the second plate member in the second direction, and has a second fixing member that does not fasten the core member and the second plate member in the first direction.

7. The battery module according to any one of claims 1 to 3, wherein, when viewed from the first direction, the first fixing member is positioned outside the first fastening member which is positioned at the position furthest from the center of the core member in the second direction.

8. The battery module according to any one of claims 1 to 3, wherein a first fixing member is disposed at both ends in the second direction of a single core member.

9. The battery module according to any one of claims 1 to 3, wherein the core member is a hollow member having a hollow portion extending in the second direction.

10. The battery module according to any one of claims 1 to 3, wherein, when viewed from the second direction, the shape of the outer edge of the core member is rectangular.

11. The battery module according to any one of claims 1 to 3, wherein, in the plate member, adjacent core members are arranged with a gap between them in a third direction perpendicular to the first and second directions.

12. The battery module according to any one of claims 1 to 3, wherein, when viewed from the first direction, the shape of the battery is rectangular, and the length of each side constituting the rectangle is 20 cm or more.

13. The battery module according to any one of claims 1 to 3, wherein the restraining pressure applied by the restraining member is 10 kN or more and 500 kN or less.

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