Battery module

Abstract

To provide a technique of discharging gas generated inside a battery module to the outside as appropriate.SOLUTION: A battery module 100 includes a multilayer body 101 where a plurality of battery cells 110 are stacked, an accommodation body that accommodates the multilayer body 101, and a plurality of fixed layers 500 that fix a surface of the accommodation body that faces a side surface (cell side surface 113) of the battery cell 110, and the cell side surface 113 of the battery cell 110. The fixed layers 500 extend in a direction of intersecting with the cell side surface 113 of the battery cell 110. In a direction (Y direction, stacking direction) where the battery cells 110 are arranged, an end part of a first fixed layer 501 overlaps with a second fixed layer 502 existing next to the first fixed layer 501.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a battery module. [Background technology]

[0002] In recent years, various battery modules have been developed. A battery module includes a plurality of battery cells stacked in a predetermined direction and a housing that houses the plurality of battery cells.

[0003] Patent Documents 1 and 2 describe battery modules. The battery module is a stack of multiple battery cells. Both the upper and lower surfaces of the stack are fixed to a housing that houses the stack with a thermally conductive adhesive. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Chinese Utility Model No. 215816165 [Patent Document 2] Chinese Utility Model No. 213026370 Summary of the Invention [Problem to be solved by the invention]

[0005] In battery modules, gas is generated due to deterioration inside the battery, overcharging, and over-discharging, and the generated gas needs to be properly released to the outside.

[0006] An example of an object of the present invention is to provide a technique for appropriately releasing gas generated inside a battery module to the outside. [Means for solving the problem]

[0007] The present invention provides the following techniques. 1. A stack of multiple battery cells; a container that contains the stack; a plurality of fixing layers that fix a surface of the housing that faces a side surface of the battery cell to the side surface of the battery cell; and the plurality of fixing layers extend in a direction intersecting the side surface of the battery cell, In the direction in which the plurality of battery cells are arranged, an end of a first fixing layer overlaps with a second fixing layer located adjacent to the first fixing layer. 2. The battery module described in 1., wherein, in the direction in which the plurality of battery cells are arranged, the opening area of ​​the fixing layer that is located closest to the housing in the extension direction of the side surface of the battery cell overlaps with a gas release port provided in the housing. 3. The battery module according to 2., wherein the length of the open region is 80% or less of the length of the region where the fixing layer is formed. 4. The battery module according to 2. or 3., wherein a plurality of the opening areas are formed in one of the fixing layers. 5. The battery module according to 2. or 3., wherein the positions of the open areas in the extending direction of the fixing layers are the same for every other fixing layer. [Effects of the Invention]

[0008] According to the above aspect of the present invention, it is possible to provide a technique for appropriately releasing gas generated inside a battery module to the outside. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 2 is an exploded top perspective view of the battery module according to the embodiment. [Figure 2] FIG. 2 is a cross-sectional view focusing on the cell side surfaces of adjacent battery cells according to the embodiment. [Figure 3] 4A to 4C are diagrams illustrating examples of the arrangement of fixing layers provided on the upper surface of the stacked body according to the embodiment. [Figure 4] 1A and 1B are diagrams illustrating a fixing layer and an opening region according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, similar components are designated by similar reference numerals, and the description thereof will be omitted as appropriate.

[0011] First Embodiment <Battery module overview> Fig. 1 is an exploded perspective view of the top of a battery module 100 according to an embodiment. Fig. 2 is an enlarged view of a cell side surface 113 of a battery cell.

[0012] For the sake of explanation, the X, Y, and Z directions are shown in FIG. 1 and FIG. 2, which will be described later. The X direction indicates the front-to-rear direction of the battery module 100. The Y direction is perpendicular to the X direction. The Y direction indicates the left-to-right direction of the battery module 100. The Z direction is perpendicular to both the X and Y directions. The Z direction indicates the up-down direction of the battery module 100. An arrow pointing to the X direction, an arrow pointing to the Y direction, and an arrow pointing to the Z direction indicate the front, left, and up directions of the battery module 100, respectively. Hereinafter, as necessary, the tip side of an arrow indicating the X direction will be referred to as the +X side, the opposite side of the tip of the arrow indicating the X direction will be referred to as the -X side, the tip side of an arrow indicating the Y direction will be referred to as the +Y side, the opposite side of the tip of the arrow indicating the Y direction will be referred to as the -Y side, the tip side of an arrow indicating the Z direction will be referred to as the +Z side, and the opposite side of the tip of the arrow indicating the Z direction will be referred to as the -Z side. The relationship between the X direction, Y direction, and Z direction and the front-rear direction, left-right direction, and up-down direction of the battery module 100 is not limited to the above example.

[0013] The battery module 100 includes a plurality of battery cells 110, a plurality of compression pads 120, a first voltage detection device 130, a second voltage detection device 140, a container 200, an adhesive 300, and a fixing layer 500.

[0014] <Laminate 101> The multiple battery cells 110 and the multiple compression pads 120 are stacked alternately in the Y direction. Each compression pad 120 is disposed between adjacent battery cells 110 in the Y direction and on both sides of the multiple battery cells 110 in the Y direction. Hereinafter, the multiple battery cells 110 and the multiple compression pads 120 stacked alternately in the Y direction will be referred to as a stack 101 of battery cells 110. The laminate 101 is a rectangular parallelepiped as a whole. Here, the rectangular parallelepiped does not only refer to a perfect rectangular parallelepiped, but also allows for the existence of irregularities and curves on each face and edge that are due to the shapes of the battery cells 110, compression pads 120, and the like that make up the laminate 101. In this embodiment, the surface on the +Z side of the laminate 101 will be referred to as the laminate side surface 103.

[0015] <Battery cell 110> The battery cell 110 has a thin rectangular parallelepiped shape with a rectangular surface (main surface) when viewed from the Y direction. Here, "rectangle" does not mean a perfect rectangle, but rather allows for unevenness, curved surfaces, etc. on each side that constitutes the rectangle. "Rectangular parallelepiped" does not only mean a perfect rectangular parallelepiped, but also allows for unevenness, curved surfaces, etc. on each face and side that constitutes the rectangular parallelepiped. The X-direction dimension of each battery cell 110 is the longitudinal dimension of each battery cell 110. The Z-direction dimension of each battery cell 110 is the lateral dimension of each battery cell 110. The Y-direction dimension of each battery cell 110 is the thickness dimension of each battery cell 110. The shape of each battery cell 110 is not limited to this example. In this embodiment, the surface visible from the +Z side of the battery cell 110 will be referred to as the cell side surface 113. The above-mentioned stack side surface 103 can also be said to be a surface formed by an assembly of the cell side surfaces 113. In other words, in the stack 101, the target surface corresponding to the cell side surface 113 of the battery cell 110 is the stack side surface 103.

[0016] The battery cell 110 includes a battery element (not shown), an exterior material 112, a positive electrode tab 114, and a negative electrode tab 116. In one example, the battery element includes a plurality of positive electrodes and a plurality of negative electrodes (not shown) stacked alternately in the Y direction, and a separator (not shown) positioned between the positive electrodes and negative electrodes adjacent in the Y direction. The battery element and an electrolyte (not shown) are sealed in the exterior material 112. The positive electrode tab 114 is electrically connected to the positive electrode of the battery element. On the side of the exterior material 112, a sealing edge 119 is provided as a structure associated with sealing (so-called sealing margin), extending from the cell body 111. For example, FIG. 2 shows the sealing edge 119 on the +Z side. The sealing edge 119 on the +Z side is bent so as to be parallel to the laminate side surface 103. In other words, it can be said that at least a portion of the sealing edge 119 is included in the laminate side surface 103. The bending directions of the sealing edges 119 may be the same direction or may be alternately different directions (+Y direction, -Y direction). The positive electrode tab 114 is pulled out from one of the two sides in the X direction of the exterior material 112. The negative electrode tab 116 is electrically connected to the negative electrode of the battery element. The negative electrode tab 116 is pulled out from the other of the two sides in the X direction of the exterior material 112. However, the structure of each battery cell 110 is not limited to this example.

[0017] Each battery cell 110 may be an all-solid-state battery. In an all-solid-state battery, a solid electrolyte layer is provided in the portion corresponding to the separator. An all-solid-state battery does not contain an electrolyte solution. Hereinafter, unless otherwise specified, each battery cell 110 will be described as a battery cell containing an electrolyte solution.

[0018] The multiple battery cells 110 are electrically connected in a combination of series and parallel. Specifically, cell groups including at least two battery cells 110 adjacent to each other in the Y direction and connected in parallel are stacked in the Y direction and connected in series.

[0019] On the +X side of the stack 101 of battery cells 110, a positive electrode tab 114 drawn out from a battery cell 110 of one cell group connected in parallel and a negative electrode tab 116 drawn out from a battery cell 110 of another cell group connected in parallel are electrically connected to each other, forming a tab group 118 including the positive electrode tab 114 and the negative electrode tab 116.

[0020] The positive electrode tabs 114 and the negative electrode tabs 116 in the tab group 118 are joined to each other by, for example, laser welding. The tab group 118 is similarly located on the -X side of the stack 101 of battery cells 110. Therefore, multiple cell groups are connected in series from the cell group located at one end side of the stack 101 of battery cells 110 in the Y direction to the cell group located at the other end side of the stack 101 of battery cells 110 in the Y direction. Hereinafter, as necessary, the tab group 118 located on the +X side of the stack 101 of the battery cells 110 will be referred to as the +X side tab group 118, and the tab group 118 located on the -X side of the stack 101 of the battery cells 110 will be referred to as the -X side tab group 118.

[0021] The electrical connection of the plurality of battery cells 110 is not limited to the above example. For example, the stack 101 of battery cells 110 may be configured by connecting single battery cells 110 in series.

[0022] <First Voltage Detector 130> The first voltage detecting device 130 detects the voltages of the plurality of +X side tab groups 118. The first voltage detecting device 130 has a first protector 131, a plurality of first voltage detecting terminals 132, a plurality of first voltage detecting lines 133, a first connector 134, and a first bus bar 135.

[0023] The first protector 131 covers the +X side portion of the stack 101 of battery cells 110. The first protector 131 is, for example, an insulating material such as resin. The first protector 131 defines a plurality of first openings 131a. Each of the plurality of +X side tab groups 118 is exposed toward the +X side through each of the plurality of first openings 131a.

[0024] Each of the multiple first voltage detection terminals 132 is located on the +X side of each of the multiple +X side tab groups 118. Each first voltage detection terminal 132 is made of a conductive material such as metal. The -X side surface of each first voltage detection terminal 132 and the +X side surface of each +X side tab group 118 are joined to each other by a joining method such as laser welding. Therefore, each first voltage detection terminal 132 and each +X side tab group 118 are electrically connected to each other. Therefore, the first voltage detection device 130 can detect the voltage of each +X side tab group 118 using each first voltage detection terminal 132. The multiple first voltage detection terminals 132 are held together by a first protector 131. Therefore, by installing the first protector 131 at an appropriate position relative to the stack 101 of battery cells 110, each of the multiple first voltage detection terminals 132 can be positioned appropriately relative to each of the multiple +X side tab groups 118.

[0025] One end of each first voltage detection line 133 is electrically connected to each first voltage detection terminal 132. The other end of each first voltage detection line 133 is electrically connected to each first connector 134. Therefore, the multiple first voltage detection terminals 132 and the first connector 134 are electrically connected to each other via the multiple first voltage detection lines 133. Each first voltage detection line 133 is routed between one end of the first voltage detection line 133 and the other end of the first voltage detection line 133 via the first protector 131.

[0026] The first bus bar 135 is disposed at the end portion on the +Y side of the first protector 131. The first bus bar 135 is electrically connected to the positive electrode tab 114 drawn out to the +X side from the battery cell 110 of the cell group located at the end portion on the +Y side of the stack 101 of battery cells 110. The first bus bar 135 functions as an external terminal for electrically connecting the battery module 100 to an external device such as another battery module.

[0027] <Second Voltage Detector 140> The second voltage detecting device 140 detects the voltages of the plurality of -X side tab groups 118. The second voltage detecting device 140 has a second protector 141, a plurality of second voltage detecting terminals 142, a plurality of second voltage detecting lines 143, a second connector 144, and a second bus bar 145.

[0028] The second protector 141 covers the -X side portion of the stack 101 of battery cells 110. The second protector 141 is, for example, an insulator such as resin. The second protector 141 defines a plurality of second openings 141a. Each of the plurality of -X side tab groups 118 is exposed toward the -X side through each of the plurality of second openings 141a.

[0029] Each of the multiple second voltage detection terminals 142 is located on the -X side of each of the multiple -X side tab groups 118. Each second voltage detection terminal 142 is made of a conductive material such as metal. The +X side surface of each second voltage detection terminal 142 and the -X side surface of each -X side tab group 118 are joined to each other by a joining method such as laser welding. Therefore, each second voltage detection terminal 142 and each -X side tab group 118 are electrically connected to each other. Therefore, the second voltage detection device 140 can detect the voltage of each -X side tab group 118 using each second voltage detection terminal 142. The multiple second voltage detection terminals 142 are held together by a second protector 141. Therefore, by installing the second protector 141 at an appropriate position relative to the stack 101 of battery cells 110, each of the multiple second voltage detection terminals 142 can be positioned appropriately relative to each of the multiple -X side tab groups 118.

[0030] One end of each second voltage detection line 143 is electrically connected to each second voltage detection terminal 142. The other end of each second voltage detection line 143 is electrically connected to each second connector 144. Therefore, the second voltage detection terminals 142 and the second connector 144 are electrically connected to each other via the second voltage detection lines 143. Each second voltage detection line 143 is routed between one end of the second voltage detection line 143 and the other end of the second voltage detection line 143 via the second protector 141.

[0031] The second bus bar 145 is disposed at the end portion on the -Y side of the second protector 141. The second bus bar 145 is electrically connected to the negative electrode tab 116 drawn out to the -X side from the battery cell 110 of the cell group located at the end portion on the -Y side of the stack 101 of battery cells 110. The second bus bar 145 functions as an external terminal for electrically connecting the battery module 100 to an external device such as another battery module.

[0032] <Arrangement of Positive Electrode Tab 114 and Negative Electrode Tab 116> 1 , the positive electrode tabs 114 at the ends of the multiple serially connected cell groups are drawn out toward the +X side from the battery cells 110 of the cell groups located at the end portion on the +Y side of the stack 101 of battery cells 110, and the negative electrode tabs 116 at the ends of the multiple serially connected cell groups are drawn out toward the -X side from the battery cells 110 of the cell groups located at the end portion on the -Y side of the stack 101 of battery cells 110. Thus, the first bus bar 135 is disposed on the +X side and the +Y side of the stack 101 of battery cells 110, and the second bus bar 145 is disposed on the -X side and the -Y side of the stack 101 of battery cells 110. However, the arrangement of the positive electrode tabs 114 and the negative electrode tabs 116 at the ends of the multiple serially connected cell groups may differ depending on the number of battery cells 110 included in the stack 101 of battery cells 110. For example, there may be cases where the positive electrode tab 114 at the end of a group of multiple cells connected in series is drawn out toward the +X side from the battery cell 110 of the cell group located at the end portion on the +Y side of the stack 101 of battery cells 110, and the negative electrode tab 116 at the end of a group of multiple cells connected in series is drawn out toward the +X side from the battery cell 110 of the cell group located at the end portion on the -Y side of the stack 101 of battery cells 110. In this case, the first bus bar 135 is arranged on the +X side and the +Y side of the stack 101 of battery cells 110, and the second bus bar 145 is arranged on the -X side and the -Y side of the stack 101 of battery cells 110.

[0033] <Container 200 (Housing)> The container 200 has a first plate 210, a second plate 220, a third plate 230, a fourth plate 240, a fifth plate 250, and a sixth plate 260.

[0034] The first plate 210 is a metal plate such as an aluminum plate, and covers the +X side portion of the stack 101 of battery cells 110 and the +X side portion of the first voltage detection device 130. The first plate 210 is provided with a plurality of gas release portions 155 that penetrate the first plate 210 in the thickness direction and provide communication between the inside and outside of the housing 200. The shape of the gas release portions 155 is, for example, circular when viewed from the +X side. The shape of the gas release portions 155 is not limited to circular, and various shapes can be used as long as they have a gas release function. Furthermore, the shapes and sizes of all the gas release portions 155 may be the same or different.

[0035] The second plate 220 is a metal plate such as an aluminum plate, and covers the -X side portion of the stack 101 of battery cells 110 and the -X side portion of the second voltage detection device 140. The second plate 220 is provided with a plurality of gas release portions 255 that penetrate through the second plate 220 in the thickness direction and provide communication between the inside and outside of the housing 200. The shape of the gas release portions 255 is, for example, circular when viewed from the -X side. The shape of the gas release portions 255 is not limited to circular, and various shapes can be used as long as they have a gas release function. The shapes and sizes of all the gas release portions 255 may be the same or different.

[0036] The third plate 230 is, for example, a metal plate such as an aluminum plate, and covers the portion of the stack 101 of the battery cells 110 on the +Y side (ie, the stack side surface 103).

[0037] The fourth plate 240 is, for example, a metal plate such as an aluminum plate, and covers the portion of the stack 101 of battery cells 110 on the -Y side.

[0038] The fifth plate 250 is, for example, a metal plate such as an aluminum plate, and covers the +Z side portion of the stack 101 of battery cells 110.

[0039] The sixth plate 260 is, for example, a metal plate such as an aluminum plate, and covers the portion of the stack 101 of battery cells 110 on the -Z side.

[0040] <Outline of the upper and lower fixing structure of the stack 101 (battery cells 110)>

[0041] In the laminate 101, the -Z side portion is fixed to the sixth plate 260 by adhesive 300, and the +Z side portion, i.e., the laminate side surface 103, is fixed to the fifth plate 250 by fixing layer 500.

[0042] The adhesive 300 has thermal conductivity. The adhesive 300 is, for example, a thermally conductive adhesive such as a silicone adhesive or a urethane adhesive. The adhesive 300 is at least partially located between the -Z side surface of the stack 101 of battery cells 110 and the +Z side surface of the sixth plate 260 in the Z direction. Therefore, heat generated from the stack 101 of battery cells 110 can be released toward the sixth plate 260 via the adhesive 300. However, the adhesive 300 does not have to have thermal conductivity.

[0043] The fixing layer 500 is a thermally conductive adhesive such as a silicone adhesive or a urethane adhesive. In the Z direction, the fixing layer 500 is partially located between the +Z side surface (stack side surface 103) of the stack 101 of battery cells 110 and the -Z side surface 251 of the fifth plate 250 (i.e., the inner surface of the housing 200). This structure allows heat generated from the stack 101 of battery cells 110 to be released toward the fifth plate 250 via the fixing layer 500. However, the fixing layer 500 does not have to be thermally conductive. Hereinafter, the adhesive 300 and the fixing layer 500 are formed by curing an adhesive in a liquid or gel state before curing (hereinafter referred to as uncured adhesive). The specific shape, arrangement, etc. of the fixed layer 500 will be described later.

[0044] A method for fixing the stack 101 to the container 200 will be described. In this embodiment, a first step is performed in which the stack 101 is fixed to the sixth plate 260, which will be the bottom surface of the housing body 200, using adhesive 300. Next, a second step is performed in which the first plate 210, the second plate 220, the third plate 230, and the fourth plate 240 are bonded around the periphery of the sixth plate 260. Furthermore, a third step is performed in which the fifth plate 250, which will be the lid of the housing body 200, is fixed to the top surface (stack body side surface 103) of the stack 101 using a fixing layer 500.

[0045] The first step will be explained. An uncured adhesive is applied to the +Z side surface of the sixth plate 260. Next, the stack 101 of battery cells 110 is placed on the +Z side surface of the sixth plate 260 via the uncured adhesive. Next, the uncured adhesive is cured to change the uncured adhesive into adhesive 300. There are no particular limitations on the method for curing the uncured adhesive, and examples include drying, heating, and light irradiation. In this way, the stack 101 is fixed to the sixth plate 260.

[0046] The second step will be described. After the laminate 101 is fixed to the +Z side surface of the sixth plate 260 with the adhesive 300, the first plate 210, the second plate 220, the third plate 230 and the fourth plate 240 are joined around the periphery of the sixth plate 260. Specifically, the -Z side end of the first plate 210 and the +X side end of the sixth plate 260 are joined to each other by a joining method such as laser welding, and the -Z side end of the second plate 220 and the +X side end of the sixth plate 260 are joined to each other by a joining method such as laser welding. Furthermore, the -Z side end of the third plate 230 and the +Y side end of the sixth plate 260 are joined to each other by a joining method such as laser welding, and the -Z side end of the fourth plate 240 and the -Y side end of the sixth plate 260 are joined to each other by a joining method such as laser welding.

[0047] The third step will be explained. An uncured adhesive is applied to the +Z side surface 251 of the fifth plate 250 (i.e., the surface on the inner side of the housing 200). Next, the -Z side surface 251 of the fifth plate 250 to which the uncured adhesive has been applied is placed on the stack side surface 103 of the stack 101 of battery cells 110. Next, the uncured adhesive is cured to form the fixing layer 500. The method for curing the uncured adhesive is not particularly limited, and examples include drying, heating, and light irradiation. As a result, the stack side surface 103 of the stack 101 is fixed to the fifth plate 250.

[0048] <Upper fixing structure 1 of stacked body 101 (battery cells 110)> The fixing structure between the upper surface (laminate side surface 103) of the laminate 101 and the fifth plate 250 will be described in more detail with reference to Figures 3 and 4. Figure 3 is a diagram illustrating an example of the arrangement of a fixing layer 500 provided on the laminate side surface 103 of the laminate 101. Figure 4 is a diagram illustrating the fixing layer 500 and the opening region. Here, the figure focuses on the second fixing layer, the third fixing layer, and the second gas layer 552 between them. The shape and arrangement of the fixing layer 500 can also be said to be the arrangement formed when uncured adhesive is applied to the -Z side surface 251 of the fifth plate 250.

[0049] In this embodiment, a plurality of fixed layers 500 are provided. First to eighth fixed layers 501 to 508 are provided as the fixed layers 500. The first to eighth fixed layers 501 to 508 are arranged in order from the first plate 210 side (+X side) to the second plate 220 side (-X side). When the first to eighth fixed layers 501 to 508 are not to be distinguished from one another, they will be simply referred to as "fixed layers 500." Adjacent fixed layers 500 are spaced apart in the X direction, and the space between the two fixed layers is a gas layer 550.

[0050] When viewed from the Z direction, each of the first to eighth fixed layers 501 to 508 has an elongated (or strip-like) shape with its longitudinal direction being a horizontal direction (Y direction) perpendicular to the extension direction (X direction) of the cell side surface 113. In other words, the multiple fixed layers 500 (first to eighth fixed layers 501 to 508) extend in a direction intersecting the cell side surface 113 of the battery cell 110.

[0051] Each of the multiple fixing layers 500 (first to eighth fixing layers 501 to 508) is provided partially in the extension direction (Y direction), and the portions where no fixing layer 500 is provided are open regions. Adjacent gas layers 550 communicate with each other through the open regions, allowing gas to flow. The open regions of adjacent fixing layers 500 do not overlap in the direction in which the multiple battery cells 110 are lined up (Y direction, stacking direction). In other words, in the direction in which the multiple battery cells 110 are lined up (Y direction, stacking direction), the end of a certain fixing layer 501 can be said to be located between the ends of the fixing layer 502 located adjacent to that fixing layer 501. In other words, the ends of the fixing layers 500 are staggered in the direction in which the multiple battery cells 110 are lined up.

[0052] The structures of the fixed layer 500 and the gas layer 550 will be described in more detail below. First fixed layer 501 is located at the end most side in the +X direction and faces first voltage detection device 130 provided on the +X direction side at a distance. First fixed layer 501 has an opening region 591 in the center in its extension direction (Y direction) and is separated. First fixed layer 501 has first fixed layer (A) 501a on the +Y direction side and first fixed layer (B) 501b on the -Y direction side.

[0053] The second fixing layer 502 is provided at a position spaced apart from the first fixing layer 501 in the −X direction. The second fixing layer 502 has two opening regions 592a and 592b arranged side by side in its extension direction (Y direction) and separated from each other. The second fixing layer 502 has, in order from the +Y direction side, a second fixing layer (A) 502a, a second fixing layer (B) 502b, and a second fixing layer (C) 502c. The opening region 592a is provided at a position approximately one-quarter of the way from the end of the stack body side surface 103 in the Y direction (stacking direction of the battery cells 110) in the +Y direction. The opening region 592b is provided at a position approximately one-quarter of the way from the end of the stack body side surface 103 in the Y direction (stacking direction of the battery cells 110) in the −Y direction.

[0054] Third fixed layer 503 is provided at a position spaced apart in the -X direction from second fixed layer 502. Third fixed layer 503 has an opening region 593 in the center in its extension direction (Y direction) and is separated. Third fixed layer 503 has third fixed layer (A) 503a on the +Y direction side and third fixed layer (B) 503b on the -Y direction side.

[0055] Fourth fixing layer 504 is provided at a position spaced apart from third fixing layer 503 in the −X direction. Fourth fixing layer 504 has two opening regions 594a and 594b aligned in its extension direction (Y direction) and separated from each other. Fourth fixing layer 504 has, in order from the +Y direction side, fourth fixing layer (A) 504a, fourth fixing layer (B) 504b, and fourth fixing layer (C) 504c. Opening region 594a is provided at a position approximately one-quarter of the way from the end of stack body side surface 103 in the Y direction (stacking direction of battery cells 110) in the +Y direction. Opening region 594b is provided at a position approximately one-quarter of the way from the end of stack body side surface 103 in the Y direction (stacking direction of battery cells 110) in the −Y direction.

[0056] Fifth fixed layer 505 is provided at a position spaced apart in the -X direction from fourth fixed layer 504. Fifth fixed layer 505 has an opening region 595 in the center in its extension direction (Y direction) and is separated. Fifth fixed layer 505 has fifth fixed layer (A) 505a on the +Y direction side and fifth fixed layer (B) 505b on the -Y direction side.

[0057] Sixth fixing layer 506 is provided at a position spaced apart from fifth fixing layer 505 in the −X direction. Sixth fixing layer 506 has two opening regions 596a, 596b side by side in its extension direction (Y direction) and separated from each other. Sixth fixing layer 506 has, from the +Y direction side, sixth fixing layer (A) 506a, sixth fixing layer (B) 506b, and sixth fixing layer (C) 506c. Opening region 596a is provided at a position approximately one-quarter of the way from the end of stack body side surface 103 in the Y direction (stacking direction of battery cells 110). Opening region 596b is provided at a position approximately one-quarter of the way from the end of stack body side surface 103 in the Y direction (stacking direction of battery cells 110).

[0058] Seventh fixed layer 507 is provided at a position spaced apart in the -X direction from sixth fixed layer 604. Seventh fixed layer 507 has an opening region 597 in the center in its extension direction (Y direction) and is separated. Seventh fixed layer 507 has seventh fixed layer (A) 507a on the +Y direction side and seventh fixed layer (B) 507b on the -Y direction side.

[0059] The eighth fixed layer 508 is located at the endmost position in the -X direction and faces the second voltage detection device 140 provided on the -X direction side, with a gap therebetween. The eighth fixed layer 508 has two opening regions 598a and 598b arranged side by side in its extension direction (Y direction), and is separated from the other. The eighth fixed layer 508 has, in order from the +Y direction side, an eighth fixed layer (A) 508a, an eighth fixed layer (B) 508b, and an eighth fixed layer (C) 508c. Opening region 598a is located approximately one-quarter of the way from the endmost position in the +Y direction on the stacked body side surface 103 in the Y direction (stacking direction of the battery cells 110). Opening region 598b is located approximately one-quarter of the way from the endmost position in the -Y direction on the stacked body side surface 103 in the Y direction (stacking direction of the battery cells 110).

[0060] The gas layer 550 is provided as a space between adjacent fixed layers 500 . First gas layer 551 is the space between first fixed layer 501 and second fixed layer 502. First gas layer 551 communicates with the region on the +X direction side, i.e., the region where first voltage detection device 130 is provided, through opening region 591 of first fixed layer 501. Furthermore, first gas layer 551 communicates with the region on the −X direction side, i.e., second gas layer 552, through opening regions 592a and 592b of second fixed layer 502.

[0061] Second gas layer 552 is the space between second fixed layer 502 and third fixed layer 503. Second gas layer 552 communicates with the region on the +X direction side, i.e., first gas layer 551, through opening regions 592a and 592b of second fixed layer 502. Furthermore, second gas layer 552 communicates with the region on the −X direction side, i.e., third gas layer 553, through opening region 593 of third fixed layer 503.

[0062] Third gas layer 553 is the space between third fixed layer 503 and fourth fixed layer 504. Third gas layer 553 communicates with the region on the +X direction side, i.e., second gas layer 552, through opening region 593 of third fixed layer 503. Furthermore, third gas layer 553 communicates with the region on the −X direction side, i.e., fourth gas layer 554, through opening regions 594a and 594b of fourth fixed layer 504.

[0063] Fourth gas layer 554 is the space between fourth fixed layer 504 and fifth fixed layer 505. Fourth gas layer 554 communicates with the region on the +X direction side, i.e., third gas layer 553, through opening regions 594a and 594b of fourth fixed layer 504. Furthermore, fourth gas layer 554 communicates with the region on the −X direction side, i.e., fifth gas layer 555, through opening region 595 of fifth fixed layer 505.

[0064] The fifth gas layer 555 is the space between the fifth fixed layer 505 and the sixth fixed layer 506. The fifth gas layer 555 communicates with the region on the +X direction side, i.e., the fourth gas layer 554, through an opening region 595 of the fifth fixed layer 505. The fifth gas layer 555 also communicates with the region on the −X direction side, i.e., the sixth gas layer 556, through opening regions 596a and 596b of the sixth fixed layer 506.

[0065] The sixth gas layer 556 is the space between the sixth fixed layer 506 and the seventh fixed layer 507. The sixth gas layer 556 communicates with the region on the +X direction side, i.e., the fifth gas layer 555, through opening regions 596a and 596b of the sixth fixed layer 506. The sixth gas layer 556 also communicates with the region on the −X direction side, i.e., the seventh gas layer 557, through opening region 597 of the seventh fixed layer 507.

[0066] Seventh gas layer 557 is the space between seventh fixed layer 507 and eighth fixed layer 508. Seventh gas layer 557 communicates with the region on the +X direction side, i.e., sixth gas layer 556, through opening region 597 of seventh fixed layer 507. Furthermore, seventh gas layer 557 communicates with the region on the −X direction side, i.e., the region where second voltage detection device 140 is provided, through opening regions 598a and 598b of eighth fixed layer 508.

[0067] In this way, the first to seventh gas layers 557 are interconnected by the opening areas provided in the fixed layer 500, and gas can be released from the gas release section 155 of the first plate 210 at the +X side end, and gas can be released from the gas release section 255 of the second plate 220 at the -X side end.

[0068] The opening regions that communicate the first to seventh gas layers 557 are provided at positions on the +X direction side of the fixed layer 500 in the Y direction different from those on the -X side of the fixed layer 500. More specifically, the positions of the opening regions in the extension direction (Y direction) of the fixed layer 500 are the same for every other fixed layer 500.

[0069] Referring to FIG. 4, second fixed layer 502, third fixed layer 503, and second gas layer 552 therebetween are illustrated.

[0070] Opening region 592a of second fixed layer 502, which is fixed layer 500 on the +X side, is located 1 / 4 of the way along the Y direction length (L20, L30) of stack side surface 103 from the +Y direction end (i.e., third plate 230), and opening region 592b is located 1 / 4 of the way from the -Y direction end (i.e., fourth plate 240). Opening region 593 of third fixed layer 503, which is fixed layer 500 on the -X side, is located in the center in the Y direction.

[0071] The length of second fixed layer (A) 502a is L21, the length of second fixed layer (B) 502b is L23, and the length of second fixed layer (C) 502c is L25. The third fixed layer (A) 503a has a length L31, and the third fixed layer (B) 503b has a length L33.

[0072] The opening region 592a is a region (length L22) between an end 502a1 in the −Y direction of the second fixed layer (A) 502a and an end 502b1 in the +Y direction of the second fixed layer (B) 502b. The open region 592b is a region (length L24) between an end 502b2 in the +Y direction of the second fixed layer (B) 502b and an end 502c1 in the +Y direction of the second fixed layer (C) 502c. The open region 593 is a region (length L32) between an end 503a1 of the third fixed layer (A) 503a in the −Y direction and an end 503b1 of the third fixed layer (B) 503b in the +Y direction.

[0073] In the Y direction (that is, when viewed from the +X direction), the opening regions 592a and 592b of the second fixed layer 502 and the opening region 593 of the third fixed layer 503 do not overlap. That is, end 502a1 of second fixed layer (A) 502a and end 502b1 of second fixed layer (B) 502b, which are the positions of both ends of opening region 592a, are located in the region where third fixed layer (A) 503a is provided when viewed from the X direction. End 502b2 of second fixed layer (B) 502b and end 502c1 of second fixed layer (C) 502c, which are the positions of both ends of opening region 592b, are located in the region where third fixed layer (B) 503b is provided when viewed from the X direction. End 503a1 of third fixed layer (A) 503a and end 503b1 of third fixed layer (B) 503b, which are the positions of both ends of opening region 593, are located in the region where second fixed layer (B) 502b is provided when viewed from the X direction.

[0074] By applying the fixed layer 500 having such a configuration to the first to seventh gas layers 557, the gas path formed by connecting the first to seventh gas layers 557 is not linear but zigzag.

[0075] As a result, the path (gas release path) that gas generated inside the battery module 100 (i.e., the battery cells 110) takes to be released to the outside is not linear, but rather detoured. As a result, the time it takes for the gas to be released to the outside of the battery module 100 can be delayed. Compared to the case of a linear gas release path, the temperature of the released gas can be lowered.

[0076] The length of the opening region is 80% or less, preferably 60% or less, and more preferably 50% or less of the length of the region where the fixing layer 500 is formed (i.e., the length of the battery cells 110 in the stacking direction (the length of the laminate 101 in the Y direction)). The length of the opening region refers to the sum of all the opening regions in the extending direction of a certain fixing layer 500, when focusing on that fixing layer 500. For example, in the example of the second fixed layer 502 in Figure 4, when the sum (L22 + L24) of the length L22 of the opening region 592a and the length L24 of the opening region 592b is taken as the length of the region where the fixed layer 500 is formed (L20 = L21 + L22 + L23 + L24 + L25), the value obtained by (L22 + L24) / L20 × 100 (%) is calculated, and the calculated result is 80% or less. Similarly, in the example of the third fixed layer 503, when the length L32 of the opening region 593 is set to the length of the region in which the fixed layer 500 is formed (L30 = L31 + L32 + L33), the value obtained by L32 / L30 × 100 (%) is calculated, and the calculated result is 80% or less. By not widening the opening area too much, the gas release path can be made to zigzag widely and be longer.

[0077] Furthermore, the gas release position can be controlled by adjusting opening region 591 of fixed layer 500 (i.e., first fixed layer 501) on the end-most side in the +X direction (closest to housing 200) of fixed layer 500. For example, opening region 591 is not provided in first voltage detection device 130 in front of a component (such as a high-voltage line) that should not be exposed to gas or a component that is desired to function as a fuse portion (one form of gas release portion) that melts at high temperatures to become an opening, but first fixed layer (A) 501a and first fixed layer (b) 501b are provided. The same applies to opening regions 598a and 598b of fixed layer 500 (i.e., eighth fixed layer 508) on the end-most side in the -X direction (closest to housing 200).

[0078] Although the embodiments of the present invention have been described above with reference to the drawings, these are merely examples of the present invention, and various other configurations can also be adopted.

[0079] <Summary of the embodiment> The features of this embodiment can be summarized as follows: 1. A stacked body 101 in which a plurality of battery cells 110 are stacked; a housing 200 (casing) that houses the stack 101; a plurality of fixing layers 500 that fix a surface 251 of the housing 200 that faces a side surface (cell side surface 113) of the battery cell 110 to the cell side surface 113 of the battery cell 110; and The plurality of fixing layers 500 extend in a direction intersecting the cell side surface 113 of the battery cell 110, A battery module 100 in which, in the direction in which the plurality of battery cells 110 are arranged (Y direction, stacking direction), the end of a first fixing layer 501 overlaps with a second fixing layer 502 located adjacent to the first fixing layer 501. 2. The battery module 100 described in 1., wherein, in the direction in which the plurality of battery cells 110 are arranged (Y direction, stacking direction), the opening area of ​​the fixing layer 500 located closest to the housing 200 in the extension direction of the cell side surface 113 of the battery cell 110 overlaps with a gas release port provided in the housing 200. 3. The battery module 100 according to 2., wherein the length of the open region is 80% or less of the length of the region where the fixing layer 500 is formed. 4. The battery module 100 according to 2. or 3., wherein a plurality of the opening areas are formed in one of the fixing layers 500. 5. The battery module 100 according to 1, wherein the positions of the open areas are the same for every other one of the fixing layers 500 in the extension direction of the fixing layer. [Explanation of symbols]

[0080] 100 Battery Module 1 101 laminate 103 Laminated body side 110 battery cells 111 Cell body 113 Cell side 119 Sealing side 120 compression pad 130 First voltage detection device 1 140 Second voltage detection device 155, 255 Gas release section 200 units 210 First Plate 220 Second Plate 230 Third Plate 240 4th Plate 250 5th Plate 260 6th Plate 300 Adhesive 500 fixed layer 501~508 1st~8th fixed layer 550 Gas Layer 551~557 1st~7th gas layers 591, 592a, 592b, 593, 594a, 594b, 595, 596a, 596b, 597, 598a, 598b opening area

Claims

1. a stacked body in which a plurality of battery cells are stacked; a container that contains the stack; a plurality of fixing layers that fix a surface of the housing that faces a side surface of the battery cell to the side surface of the battery cell; and the plurality of fixing layers extend in a direction intersecting the side surface of the battery cell, a first fixing layer having an end portion overlapping a second fixing layer located adjacent to the first fixing layer in a direction in which the plurality of battery cells are arranged.

2. 2. The battery module according to claim 1, wherein, in a direction in which the plurality of battery cells are arranged, an open region of a fixing layer that is located closest to the housing in an extension direction of the side surface of the battery cell overlaps with a gas release port provided in the housing.

3. The battery module according to claim 2 , wherein the length of the open region is 80% or less of the length of the region where the fixing layer is formed.

4. The battery module according to claim 2 , wherein a plurality of the opening regions are formed in one of the fixing layers.

5. The battery module according to claim 2 , wherein the positions of the open regions are the same for every other one of the fixing layers in the extending direction of the fixing layers.

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