Battery module

Abstract

To provide a battery module that discharges gas generated inside to the outside as appropriate.SOLUTION: A battery module 100 includes a multilayer body 101 where a plurality of rectangular battery cells 110 are stacked in a thickness direction (Y direction), an accommodation body 200 that accommodates the multilayer body 101, and a plurality of fixed layers 500 that fix a surface of the accommodation body 200 that faces a cell side surface of the battery cell 110, and the cell side surface of the battery cell 110. The fixed layers 500 extend in a direction of intersecting by 30° or less with an extension direction of the cell side surface of the battery cell 110. A gas layer is formed between the adjacent fixed layers 500.SELECTED DRAWING: Figure 1

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 laminate in which multiple battery cells are stacked in the thickness direction; 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 fixing layer extends in a direction intersecting the extending direction of the side surface of the battery cell at an angle of 30° or less, A battery module, wherein a gas layer is formed between adjacent fixed layers. 2. The directions in which the plurality of fixing layers extend are parallel to each other; 1. The battery module according to 1, wherein the longest fixing layer among the plurality of fixing layers intersects with two or more of the battery cells. 3. A battery module according to 1., wherein when the target surface of the laminate corresponding to the side surface of the battery cell is divided into a plurality of regions, the extending direction of the fixing layer differs for each divided region. 4. A battery module described in 3., in which when the target surface is divided into a first region and a second region in the extension direction of the side surface of the battery cell, the extension direction of the fixing layer in the first region is different from the extension direction of the fixing layer in the second region. 5. The battery module according to 4., wherein the gas layer located in the first region and the gas layer located in the second region are connected to each other. 6. The battery module described in 1., wherein the fixing layer is provided between the side surfaces of adjacent battery cells and is in contact with both of the side surfaces of the two battery cells. 7. The battery cell has a cell body and a sealing edge protruding from the side surface of the cell body, the sealing edge is bent so as to be parallel to a plane formed by the assembly of side surfaces of the battery cells, The battery module according to 1. or 6., wherein the fixing layer is in contact with the sealing edge. 8. The battery module according to 1, wherein the fixing layer has a width that increases from one end to the other end in the extension direction. 9. The battery module according to 8., wherein the other end of the fixing layer in the extension direction is in contact with the other end of the adjacent fixing layer. 10. The fixing layer comprises: a region having a first fixing layer whose width increases from one end toward the other end in the extension direction; a second region having a second fixing layer whose width increases from the other end side toward the one end side in the extension direction; The battery module according to 1., 11. The battery module according to claim 10, wherein the other ends of adjacent first fixing layers are in contact with each other, and the one ends of adjacent second fixing layers are in contact with each other. [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 perspective view of the upper side of the battery module according to the first embodiment. [Figure 2] FIG. 2 is a view focusing on the cell side surfaces of adjacent battery cells according to the first embodiment. [Figure 3] 3A to 3C are diagrams illustrating examples of the arrangement of fixing layers provided on the upper surface of the stack according to the first embodiment. [Figure 4] 10A and 10B are diagrams illustrating an example of the arrangement of a fixing layer provided on the upper surface of a stack according to a second embodiment. [Figure 5] 10A and 10B are diagrams illustrating an example of the arrangement of a fixing layer provided on the upper surface of a stack according to a third embodiment. [Figure 6] FIG. 10 is an enlarged cross-sectional view showing the upper surface and fixing layer of the stack according to the third embodiment. [Figure 7] 10A and 10B are diagrams illustrating an example of the arrangement of a fixing layer provided on the upper surface of a stack according to a fourth embodiment. [Figure 8] 10A and 10B are diagrams illustrating an example of the arrangement of a fixing layer provided on the upper surface of a stack according to a fifth 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.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] <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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] <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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] <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.

[0036] <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.

[0037] 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.

[0038] 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.

[0039] The third plate 230 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 (ie, the stack side surface 103).

[0040] 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.

[0041] 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.

[0042] 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.

[0043] <Outline of the upper and lower fixing structure of the stack 101 (battery cells 110)>

[0044] 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.

[0045] 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.

[0046] 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 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] The third step will be explained. An uncured adhesive is applied to the +Z side surface of the fifth plate 250 (i.e., the inner surface of the housing 200). Next, the -Z side surface 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.

[0051] <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 Fig. 3. Fig. 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. 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 of the fifth plate 250.

[0052] A plurality of fixing layers 500 are provided in a long shape. The cell side surface 113 of the battery cell 110 is in contact with one of the fixing layers 500. The fixing layer 500 extends in a direction intersecting the extension direction (i.e., the X direction) of the cell side surface 113 of the battery cell 110 at an angle of not more than a certain degree. The angle of not more than a certain degree is, for example, not more than 30 degrees, preferably not more than 25 degrees, and more preferably not more than 20 degrees. The fixing layer 500 extends so as to contact the cell side surfaces 113 of at least two battery cells 110. In other words, the fixing layer 500 does not intersect with the cell side surfaces 113 of some of the battery cells 110.

[0053] In this embodiment, the fixing layer 500 extends at an angle of 7.5° with respect to the extension direction of the cell side surface 113 of the battery cell 110. More specifically, the extension direction of the fixing layer 500 is inclined at an angle of 7.5° in the −Y direction with respect to the +X direction. In this case, the fixing layer 500 intersects with the cell side surfaces 113 of multiple (two or more) battery cells 110.

[0054] The longest fixed layer 500 intersects, for example, three cell side surfaces 113. The reason why the above conditions are applied to the longest fixed layer 500 is that, depending on the position where the fixed layer 500 is provided and the angle, the fixed layer 500 may become short and may not be able to intersect with multiple cell side surfaces 113. For example, in FIG. 3, the two fixed layers 500 at both ends in the Y direction are half the length of the other fixed layers 500.

[0055] Adjacent fixing layers 500 are arranged parallel to each other and spaced apart at a certain interval. That is, the extending directions of the fixing layers 500 are parallel to each other. The spaced apart area between adjacent fixing layers 500 constitutes a gas layer 550. In other words, the gas layer 550 is formed in an area where the uncured adhesive used to form the fixing layer 500 was not applied. Note that the fixing layers 500 do not have to be completely parallel to each other, and may be arranged at a certain angle, with one end narrowing or widening, or these may appear alternately.

[0056] <Gas flow> Gas generated in the battery cells 110 flows through the gas layer 550 and is released from the gas release parts 155, 255 to the outside of the housing 200. In other words, it can be said that the gas is guided to the gas release parts 155, 255 by the fixing layer 500. Because the gas layer 550 does not have a structure that blocks the flow path up to the gas release parts 155, 255, gas does not accumulate in the space between the stack side surface 103 and the fifth plate 250. In other words, it is possible to prevent the accumulated gas from causing an excessive increase in pressure or a sudden increase in temperature inside the housing 200.

[0057] As described above, the fixing layer 500 intersects with the cell side surfaces 113 of the plurality of battery cells 110. In other words, it can be said that the gas layer 550 intersects with the plurality of cell side surfaces 113. With this configuration, not only is it possible for gas generated in a certain battery cell 110 to be guided to the gas release portions 155, 255 by one gas layer 550, but also for adjacent gas layers 550 to be guided to the gas release portions 155, 255, so that gas accumulation can be suppressed and the gas can be smoothly released to the outside.

[0058] On the other hand, if the fixing layer 500 intersects with many cell side surfaces 113, the gas will move to other battery cells 110 via many gas layers 550. When one gas layer 550 intersects with many battery cells 110, the high-temperature gas may affect other normal battery cells 110 via the gas layers 550. Therefore, by limiting the number of battery cells 110 intersected by the fixing layer 500, i.e., the gas layers 550, it is possible to prevent the gas from affecting many battery cells 110. On the other hand, if the width (length in the short direction) of the fixing layer 500 is large, it is possible that the fixing layer 500 may intersect with multiple battery cells 110 (cell side surfaces 113). Taking these factors into consideration, the upper limit of the number of battery cells 110 intersecting with the fixing layer 500 is, for example, 5 or less, preferably 4 or less, and more preferably 3 or less. As a result, even if the gas becomes excessively hot and a battery cell 110 is overheated and damaged, the time until the symptom spreads to another battery cell 110 can be extended. For example, even if a malfunction occurs in a vehicle equipped with the battery module 100, causing the battery module 100 to catch fire, the time from the occurrence of the malfunction to the ignition can be made sufficiently long, and the time required for the vehicle's occupants to evacuate (for example, the time specified by laws and regulations, etc.) can be sufficiently secured.

[0059] <Second embodiment> <Upper fixing structure 2 of stacked body 101 (battery cells 110)> A second embodiment will be described with reference to Fig. 4. Fig. 4 is a diagram illustrating an example of the arrangement of a fixing layer 500 provided on the upper surface of the laminate 101 of this embodiment. In this embodiment, when the laminate side surface 103 formed by stacking the cell side surfaces 113 of the battery cells 110 in the laminate 101 is divided into a plurality of regions, the extending direction of the fixing layer 500 differs for each divided region.

[0060] In the following, an example will be described in which the laminate side surface 103 is divided into two regions: a first side surface region 103a on the front side (+X side) and a second side surface region 103b on the rear side (-X side).

[0061] Pinning layer 500 has first region pinning layer 511 provided in first side surface region 103a and second region pinning layer 512 provided in second side surface region 103b. In other words, the region where first region pinning layer 511 is provided can be said to be first side surface region 103a, and the region where second region pinning layer 512 is provided can be said to be second side surface region 103b.

[0062] The first region fixed layer 511 and the second region fixed layer 512 are formed by dividing the fixed layer 500 of the first embodiment into halves, and their extending directions are symmetrical with respect to the boundary line between the first side region 103a and the second side region 103b.

[0063] The extension direction of first region fixing layer 511 is inclined at 7.5° toward the +Y direction with respect to the +X direction. At this time, first region fixing layer 511 intersects with cell side surfaces 113 of two battery cells 110. The region between adjacent first region fixing layers 511 is first gas layer 551.

[0064] The extension direction of second region fixing layer 512 is inclined at 7.5° in the −Y direction with respect to the +X direction. At this time, second region fixing layer 512 intersects with cell side surfaces 113 of two battery cells 110. The region between adjacent second region fixing layers 512 is second gas layer 552.

[0065] The -X-direction end of first region fixing layer 511 and the +X-direction end of second region fixing layer 512 may be in contact with or spaced apart from each other. That is, first region fixing layer 511 and second region fixing layer 512 may be integrally connected or disconnected at the boundary between first side surface region 103a and second side surface region 103b. In the example of FIG. 4, first region fixing layer 511 and second region fixing layer 512 are slightly spaced apart and disconnected.

[0066] In this embodiment, the first gas layer 551 and the second gas layer 552 are connected. When the first region fixing layer 511 and the second region fixing layer 512 are connected, one first gas layer 551 and one second gas layer 552 form one independent gas layer 550, and multiple gas layers 550 are arranged side by side. When the first region fixing layer 511 and the second region fixing layer 512 are not connected, the first gas layer 551 and the second gas layer 552 join together in the boundary region between the first side region 103a and the second side region 103b.

[0067] When the first region fixation layer 511 and the second region fixation layer 512 are connected, as in the first embodiment, it is possible to prevent the gas from affecting other battery cells 110. On the other hand, when the first region fixation layer 511 and the second region fixation layer 512 are not connected, it is possible to promote diffusion of the gas.

[0068] In this embodiment, the region of the laminate side surface 103 is divided into two in the front-to-back direction (X direction), but this is not intended to be limiting, and for example, it may be divided into two in the left-to-right direction (Y direction), or it may be divided into four in the front-to-back and left-to-right directions. Furthermore, the number of fixing layers 500 in each region may be the same or different.

[0069] <Third embodiment> <Upper fixing structure 3 of stacked body 101 (battery cells 110)> A third embodiment will be described with reference to Figures 5 and 6. Figure 5 is a diagram illustrating an example of the arrangement of a fixing layer 500 provided on the upper surface of the stack 101 of this embodiment. Figure 6 is an enlarged cross-sectional view showing the periphery of the upper surface (cell side surface 113) of a battery cell 110. In this embodiment, the fixing layer 500 is provided between the cell side surfaces 113 of adjacent battery cells 110. Furthermore, the fixing layer 500 is in contact with both of the cell side surfaces 113 of the two battery cells 110. Therefore, a gas layer 550 is formed directly above the stack side surface 103 of each battery cell 110.

[0070] As described above, the battery cell 110 has a sealing edge 119 that protrudes from the side surface of the cell body 111. The sealing edge 119 is bent so as to be parallel to the stack side surface 103. In addition, a compression pad 120 is provided between adjacent cell bodies 111.

[0071] When the fixing layer 500 is provided between the cell side surfaces 113 of adjacent battery cells 110, the fixing layer 500 is in contact with the sealing edge 119. In this case, the fixing layer 500 is also formed in the lower region of the sealing edge 119. This is because when the uncured adhesive is applied to the fifth plate 250 and attached to the stack side surface 103, it flows around to the lower region of the sealing edge 119 due to the weight or pressing operation of the fifth plate 250.

[0072] With this configuration, the gas generated in the battery cell 110 is guided by the gas layer 550 to the gas release sections 155, 255 and is released to the outside.

[0073] <Fourth embodiment> <Upper fixing structure 4 of stacked body 101 (battery cells 110)> The fourth embodiment will be described with reference to Fig. 7. Fig. 7 is a diagram illustrating an example of the arrangement of a fixing layer 500 provided on the upper surface of the laminate 101 of this embodiment.

[0074] In this embodiment, the fixed layer 500 increases in width from one end (rear end 521) to the other end (front end 522) in the extension direction when viewed from above (i.e., when viewed from the Z direction). That is, the fixed layer 500 has a rectangular shape with the front end 522 being wider than the rear end 521. The front end 522 has a length equivalent to two cell side surfaces 113 of the battery cell 110. The rear end 521 has a length equivalent to one cell side surface 113 of the battery cell 110.

[0075] The lower (+Y side) side of the fixed layer 500 is inclined in the -Y direction with respect to the extension direction (+X direction) of the cell side surface 113. The upper (-Y side) side of the fixed layer 500 is inclined in the -Y direction with respect to the extension direction (+X direction) of the cell side surface 113. In this case, the upper (-Y side) side is inclined more than the lower (+Y side) side. More specifically, when extending from the rear end 521 to the front end 522, the end of the lower (+Y side) side is located one cell side surface 113 above (-Y) in the Y direction. When extending from the rear end 521 to the front end 522, the end of the upper (-Y side) side is located two cell side surfaces 113 above (-Y) in the Y direction.

[0076] The fixing layers 500 are arranged so that the front ends 522 of adjacent fixing layers 500 are in contact with each other. As a result, the gas layer 550 formed by adjacent fixing layers 500 has a triangular shape that is elongated in the +X direction when viewed from above (when viewed from the Z direction). That is, the end of the gas layer 550 on the +X direction side is closed, and the width increases as it approaches the -X direction. Gas generated in the battery cell 110 is guided in the -X direction and released to the outside from the release portion 225 of the second plate 220.

[0077] Such a fixing layer 500 is effective when a component (high-voltage line, etc.) that should not be exposed to gas is present in the configuration (for example, the first voltage detection device 130, etc.) on the +X side of the laminate 101. That is, the fixing layer 500 can prevent gas from flowing into the region where the component that should not be exposed to gas is located.

[0078] <Fifth embodiment> <Upper fixing structure 5 of stacked body 101 (battery cells 110)> The fifth embodiment will be described with reference to Fig. 8. Fig. 8 is a diagram illustrating an example of the arrangement of a fixing layer 500 provided on the upper surface of the laminate 101 of this embodiment.

[0079] In this embodiment, the fixing layer 500 of the fourth embodiment is arranged in a different direction for each of the regions obtained by dividing the side surface 103 of the stacked body into a plurality of regions. Specifically, the fixed layer 500 has a region (first fixed layer region 541) having a first fixed layer 531 that widens from one end (rear end 521a) in the extension direction toward the other end (front end 522a), and a second region (second fixed layer region 542) having a second fixed layer 532 that widens from the other end (front end 522b) in the extension direction toward one end (rear end 521b). The +Y half of stack side surface 103 (the lower half in the drawing) is first fixed layer region 541, and the −Y half (the upper half in the drawing) is first fixed layer region 541.

[0080] The other ends (front ends 522a) of adjacent first fixed layers 531 are in contact with each other, and the one ends (rear ends 521b) of adjacent second fixed layers 532 are in contact with each other.

[0081] First fixed layer 531 and gas layer 550a of first fixed layer region 541 have the same shapes as those in the fourth embodiment. When viewed from above (i.e., when viewed from the Z direction), the width increases from one end (rear end 521) toward the other end (front end 522) in the extension direction. That is, first fixed layer region 541 has a rectangular shape with front end 522 being wider than rear end 521.

[0082] The front ends 522 of adjacent first fixing layer regions 541 are in contact with each other. Therefore, gas layer 550a formed by adjacent first fixing layer regions 541 has a triangular shape that is elongated in the +X direction in top view (when viewed from the Z direction). That is, the end of gas layer 550a on the +X direction side is closed, and the width increases toward the -X direction. Gas generated in battery cell 110 is guided in the -X direction and released to the outside from release portion 225 of second plate 220.

[0083] Second fixed layer 532 and gas layer 550b in second fixed layer region 542 have a shape obtained by left-right inverting first fixed layer 531 and gas layer 550a in first fixed layer region 541. When viewed from above (i.e., when viewed from the Z direction), the width increases from the other end (522) in the extension direction toward one end (rear end 521). That is, first fixed layer 531 has a quadrangular shape with rear end 521 being wider than front end 522.

[0084] The rear ends 521 of adjacent second fixed layer regions 542 are in contact with each other. The gas layer 550b formed by adjacent second fixed layer regions 542 has a triangular shape that is elongated in the -X direction in top view (when viewed from the Z direction). That is, the end of the gas layer 550b on the -X direction side is closed, and the width increases as it approaches the +X direction. Gas generated in the battery cell 110 is guided in the +X direction and released to the outside from the gas release portion 155 of the first plate 210.

[0085] The first fixing layer 531 is effective when the lower region of the +X-direction end of the laminate side surface 103 (e.g., the first voltage detection device 130, etc.) contains components (high-voltage lines, etc.) that should not come into contact with gas. The second fixing layer 532 is effective when the upper region configuration (e.g., the second voltage detection device 140, etc.) at the -X direction end of the laminate side surface 103 contains components (high-voltage lines, etc.) that should not come into contact with gas. That is, depending on the location of components (such as high-voltage lines) that should not come into contact with gas, the shapes of the fixed layer 500 and the gas layer 550 can be adapted to prevent gas from flowing toward those components, thereby protecting those components from being exposed to gas.

[0086] 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.

[0087] <Summary of the embodiment> The features of this embodiment can be summarized as follows: 1. A stack 101 in which multiple rectangular battery cells 110 are stacked in the thickness direction (Y direction), a container 200 for accommodating the stack 101; a plurality of fixing layers 500 that fix a surface of the housing 200 that faces the cell side surface 113 of the battery cell 110 (i.e., an inner surface 251 of the fifth plate 250) and the cell side surface 113 of the battery cell 110; and the fixing layer 500 extends in a direction intersecting the extending direction of the cell side surface 113 of the battery cell 110 at an angle of 30° or less; The battery module 100 has a gas layer 550 formed between adjacent fixed layers 500. 2. The extension directions of the plurality of fixed layers 500 are parallel to each other, 1. The battery module (100) according to 1, wherein the longest fixing layer (501) of the plurality of fixing layers (500) intersects with two or more of the battery cells (110). 3. The battery module 100 described in 1, wherein when the target surface (laminated body side surface 103) corresponding to the side surface of the battery cell of the laminated body 101 is divided into a plurality of regions (in the second embodiment, a first side surface region 103a and a second side surface region 103b), the extension direction of the fixing layer 500 is set for each divided region. 4. A battery module 100 as described in 3., wherein when the symmetry plane (laminated body side surface 103) is divided into a first region (first side surface region 103a) and a second region (second side surface region 103b) in the extension direction of the cell side surface 113 of the battery cell 110, the extension direction of the fixing layer 500 (i.e., first region fixing layer 511) in the first region (first side surface region 103a) is different from the extension direction of the fixing layer 500 (i.e., second region fixing layer 512) in the second region (second side surface region 103b). 5. The battery module 100 described in 4., wherein the gas layer 550a formed by the fixing layer 500 (first region fixing layer 511) in the first region (first side region 103a) and the gas layer 550b formed by the fixing layer 500 (second region fixing layer 512) in the second region (second side region 103b) are connected. 6. A battery module 100 as described in 1., wherein the fixing layer 500 is provided between the side surfaces (cell side surfaces 113) of adjacent battery cells 110 and is in contact with both of the side surfaces (cell side surfaces 113) of the two battery cells 110. 7. The battery cell 110 has a cell body 111 and a sealing edge 119 protruding from the side surface 111a of the cell body 111; The sealing edge 119 is bent so as to be parallel to the surface (the stack side surface 103) formed by the assembly of the cell side surfaces 113 of the battery cells 110, The battery module (100) according to any one of (1) to (6), wherein the fixing layer (500) is in contact with the sealing edge (119). 8. The battery module 100 according to 1, wherein the fixing layer 500 increases in width from one end (rear end 521) in the extension direction toward the other end (front end 522). 9. The battery module according to 8., wherein the other end (front end 522) of the fixing layer 500 in the extension direction is in contact with the other end (front end 522) of the adjacent fixing layer 500. 10. The fixed layer 500 is a region (first fixed layer region 541) having a first fixed layer 531 whose width increases from one end (rear end 521) to the other end (front end 522) in the extension direction; a second region having a second fixed layer (second fixed layer region 542) that increases in width from the other end side (front end 522) in the extension direction toward the one end side (rear end 521); 1. The battery module 100 having: 11. The battery module 100 described in 10., wherein the other ends (front ends 522) of adjacent first fixing layers 531 are in contact with each other, and the one ends (rear ends 521) of adjacent second fixing layers 532 are in contact with each other. [Explanation of symbols]

[0088] 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 Containment Unit 210 Plate 1 220 Second Plate 230 Third Plate 240 4th Plate 250 5th Plate 260 6th Plate 300 Adhesive 500 fixed layer 511 1st area fixed layer 512 2nd area fixed layer 550, 550a, 550b Gas layer 551 First gas layer 552 Second gas layer

Claims

1. a stack in which a plurality of battery cells are stacked in the thickness direction; 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 fixing layer extends in a direction intersecting with an extension direction of the side surface of the battery cell at an angle of 30° or less, A gas layer is formed between adjacent fixed layers. Battery module.

2. The directions in which the plurality of fixing layers extend are parallel to each other, The battery module according to claim 1 , wherein the longest fixing layer among the plurality of fixing layers intersects with two or more of the battery cells.

3. 2 . The battery module according to claim 1 , wherein when a target surface of the stack corresponding to a side surface of the battery cell is divided into a plurality of regions, the extending direction of the fixing layer differs for each divided region.

4. 4. The battery module according to claim 3, wherein when the target surface is divided into a first region and a second region in an extension direction of the side surface of the battery cell, the extension direction of the fixing layer in the first region is different from the extension direction of the fixing layer in the second region.

5. The battery module according to claim 4 , wherein the gas layer located in the first region and the gas layer located in the second region are connected to each other.

6. The battery module according to claim 1 , wherein the fixing layer is provided between the side surfaces of the adjacent battery cells and is in contact with both of the side surfaces of the two battery cells.

7. The battery cell has a cell body and a sealing edge that protrudes from a side surface of the cell body. the sealing edge is bent so as to be parallel to a plane formed by the assembly of the side surfaces of the battery cells, The battery module according to claim 1 , wherein the fixing layer is in contact with the sealing edge.

8. The battery module according to claim 1 , wherein the fixing layer has a width that increases from one end side to the other end side in the extension direction.

9. The battery module according to claim 8 , wherein the other end of the fixing layer in the extending direction is in contact with the other end of the adjacent fixing layer.

10. a region in which the fixing layer has a first fixing layer whose width increases from one end toward the other end in the extension direction; a second region including a second fixing layer whose width increases from the other end side toward the one end side in the extension direction; The battery module of claim 1 ,

11. The battery module according to claim 10 , wherein the other ends of the adjacent first fixing layers are in contact with each other, and the one ends of the adjacent second fixing layers are in contact with each other.

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