Battery module

Abstract

To suppress ignition of a battery cell in an abnormal situation.SOLUTION: The battery module 100 includes: a battery cell 110; a casing 200 for housing the battery cell 110; an extending thermal expansion material 310 located at least partially in a space inside the casing 200; first, second, and third interposed thermal expansion materials 322, 324, and 326; and a surrounding thermal expansion material 330.SELECTED DRAWING: Figure 2

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 battery cells and a housing that houses the battery cells.

[0003] Patent Document 1 describes a battery module. The battery module includes a plurality of batteries and a thermal expansion member. The thermal expansion member is interposed between the wide surfaces of the plurality of batteries.

[0004] Patent Document 2 describes a battery module. The battery module includes a plurality of battery cells, an elastic member positioned between adjacent battery cells, and a thermally expandable resin composition disposed on the elastic member. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2022-169135 [Patent Document 2] Japanese Patent Publication No. 2022-187202 Summary of the Invention [Problem to be solved by the invention]

[0006] A battery cell in which an abnormality occurs may generate relatively high-temperature gas, so it is necessary to suppress the risk of fire when an abnormality occurs in the battery cell.

[0007] One example of an object of the present invention is to suppress the ignition of a battery cell in the event of an abnormality. Other objects of the present invention will become apparent from the description of this specification. [Means for solving the problem]

[0008] One aspect of the present invention is as follows. 1. A battery cell; a housing that houses the battery cell; a thermal expansion material at least partially located in a space present within the housing; A battery module comprising: 2. An adhesive is further provided to bond the battery cell and the housing together, 1. The battery module according to claim 1, wherein the space exists at least partially between the portions of the battery cell and the housing that are bonded to each other by the adhesive. 3. A plurality of the battery cells have terminals joined together; 3. The battery module according to 1. or 2., wherein the space exists at least partially around the terminal. 4. Further comprising a voltage detection device for detecting the voltage of the battery cell; The battery module according to any one of 1. to 3., wherein the space exists at least partially between the battery cell and the voltage detection device. 5. The battery module according to any one of 1. to 4., wherein the thermal expansion material at least partially contains a foam material. [Effects of the Invention]

[0009] According to the above aspect of the present invention, it is possible to suppress the ignition of a battery cell when an abnormality occurs. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 2 is an exploded top perspective view of the battery module according to the embodiment. [Figure 2] 1 is a top view of a battery module according to an embodiment in a state where a first voltage detection device, a second voltage detection device, and a fifth plate are removed. FIG. [Figure 3] FIG. 2 is a perspective view of a portion of the battery module according to the embodiment with the first plate removed. DETAILED DESCRIPTION OF THE INVENTION

[0011] 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.

[0012] FIG. 1 is an exploded perspective view of a battery module 100 according to an embodiment.

[0013] For the sake of explanation, the X, Y, and Z directions are shown in FIG. 1 and in FIGS. 2 and 3 described below. 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.

[0014] 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, and a housing 200. For the sake of explanation, an extended thermal expansion material 310, a first intervening thermal expansion material 322, a second intervening thermal expansion material 324, a third intervening thermal expansion material 326, and a surrounding thermal expansion material 330, which will be described later, have been removed from FIG.

[0015] The multiple battery cells 110 and the multiple compression pads 120 are stacked alternately in the Y direction. Hereinafter, as necessary, the multiple battery cells 110 and the multiple compression pads 120 stacked alternately in the Y direction will be referred to as a stack of battery cells 110. The dimension of each battery cell 110 in the X direction is the dimension in the longitudinal direction of each battery cell 110. The dimension of each battery cell 110 in the Z direction is the dimension in the lateral direction of each battery cell 110. The dimension of each battery cell 110 in the Y direction is the dimension in the thickness direction of each battery cell 110. The shape of each battery cell 110 is not limited to this example. In the example shown in FIG. 1, when viewed from the Y direction, each compression pad 120 has a substantially rectangular shape having a pair of long sides extending in the X direction and a pair of short sides extending in the Z direction. The shape of each compression pad 120 is not limited to the example shown in FIG. 1.

[0016] Each battery cell 110 includes a battery element (not shown), a housing 112, a positive electrode tab 114, and a negative electrode tab 116. In one example, the battery element includes multiple positive electrodes and multiple negative electrodes (not shown) stacked alternately in the Y direction, and a separator (not shown) positioned between adjacent positive electrodes and negative electrodes in the Y direction. The housing 112 includes a storage section 112a that stores the battery element and an electrolyte (not shown), and a pair of drawn-out edges 112b extending from the storage section 112a toward both sides in the X direction. The housing 112 is sealed at least in part around the storage section 112a in the X direction and at the pair of drawn-out edges 112b by, for example, heat sealing the laminate film that constitutes the housing 112. The positive electrode tab 114 is electrically connected to the positive electrode of the battery element. The positive electrode tab 114 is drawn out from one of the pair of drawn-out edges 112b. 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 pair of pulled-out sides 112b. 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 series-parallel combination. Specifically, a cell group 110G including at least two battery cells 110 adjacent to each other in the Y direction and connected in parallel is stacked in the Y direction and connected in series. In the example shown in FIG. 1 , the cell group 110G includes two battery cells 110. The number of battery cells 110 in the cell group 110G is not limited to two. On the +X side of the stack of battery cells 110, a positive electrode tab 114 drawn from a battery cell 110 of one cell group 110G and a negative electrode tab 116 drawn from a battery cell 110 of another cell group 110G are electrically connected to each other, forming a tab group 118 including the positive electrode tab 114 and the negative electrode tab 116. The positive electrode tab 114 and the negative electrode tab 116 in the tab group 118 are joined to each other by, for example, laser welding. A tab group 118 is also located on the −X side of the stack of battery cells 110. Therefore, multiple cell groups 110G are connected in series from the cell group 110G located on one end side in the Y direction of the stack of battery cells 110 to the cell group 110G located on the other end side in the Y direction of the stack of battery cells 110. Hereinafter, as necessary, the tab group 118 located on the +X side of the stack of 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 of battery cells 110 will be referred to as the -X-side tab group 118.

[0019] The electrical connection of the plurality of battery cells 110 is not limited to the above example. For example, a stack of battery cells 110 may be formed by connecting single battery cells 110 in series.

[0020] 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.

[0021] The first protector 131 covers the +X side portion of the stack of battery cells 110. The first protector 131 is, for example, an insulator 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. In the example shown in FIG. 1, when viewed from the X direction, each of the first openings 131a has a substantially rectangular shape having a pair of sides extending in the X direction and another pair of sides extending in the Y direction. The shape of each of the first openings 131a is not limited to the example shown in FIG. 1.

[0022] 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 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.

[0023] 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.

[0024] 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 110G located at the end portion on the +Y side of the stack 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.

[0025] 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.

[0026] The second protector 141 covers the -X side portion of the stack 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. In the example shown in FIG. 1, when viewed from the X direction, each second opening 141a has a substantially rectangular shape having a pair of sides extending in the X direction and another pair of sides extending in the Y direction. The shape of each second opening 141a is not limited to the example shown in FIG. 1.

[0027] 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 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.

[0028] 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.

[0029] 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 110G located at the end portion on the -Y side of the stack 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.

[0030] 1 , the positive electrode tabs 114 at the ends of the multiple cell groups 110G connected in series are drawn out toward the +X side from the battery cells 110 of the cell group 110G located at the end portion on the +Y side of the stack of battery cells 110, and the negative electrode tabs 116 at the ends of the multiple cell groups 110G connected in series are drawn out toward the -X side from the battery cells 110 of the cell group 110G located at the end portion on the -Y side of the stack of battery cells 110. Thus, the first bus bar 135 is disposed on the +X side and the +Y side of the stack of battery cells 110, and the second bus bar 145 is disposed on the -X side and the -Y side of the stack 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 cell groups 110G connected in series may differ depending on the number of battery cells 110 included in the stack of battery cells 110. For example, there may be a case where the positive electrode tab 114 at the end of a plurality of serially connected cell groups 110G is pulled out toward the +X side from the battery cell 110 of the cell group 110G located at the end portion on the +Y side of the stack of battery cells 110, and the negative electrode tab 116 at the end of a plurality of serially connected cell groups 110G is pulled out toward the +X side from the battery cell 110 of the cell group 110G located at the end portion on the -Y side of the stack 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 of battery cells 110, and the second bus bar 145 is arranged on the +X side and the -Y side of the stack of battery cells 110.

[0031] The housing 200 houses a stack of battery cells 110. The housing 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.

[0032] The first plate 210 covers the +X side portion of the stack of battery cells 110, with the first voltage detection device 130 located between the stack of battery cells 110 and the first plate 210. The second plate 220 covers the -X side portion of the stack of battery cells 110, with the second voltage detection device 140 located between the stack of battery cells 110 and the second plate 220. The third plate 230 covers the +Y side portion of the stack of battery cells 110. The fourth plate 240 covers the -Y side portion of the stack of battery cells 110. The fifth plate 250 covers the +Z side portion of the stack of battery cells 110, with multiple structural adhesives 252 located between the stack of battery cells 110 and the fifth plate 250. In the example shown in FIG. 1 , the multiple structural adhesives 252 extend in the Y direction. The arrangement of the structural adhesives 252 is not limited to the example shown in FIG. 1 . The stack of battery cells 110 and the fifth plate 250 are bonded to each other via a plurality of structural adhesives 252. The sixth plate 260 covers the -Z side portion of the stack of battery cells 110, with the thermally conductive adhesive 262 positioned between the stack of battery cells 110 and the sixth plate 260. The stack of battery cells 110 and the sixth plate 260 are bonded to each other via the thermally conductive adhesive 262. The stack of battery cells 110 and the sixth plate 260 are thermally coupled to each other via the thermally conductive adhesive 262. The thermal conductivity of the thermally conductive adhesive 262 is higher than the thermal conductivity of each structural adhesive 252. Therefore, heat generated from the stack of battery cells 110 can be more easily conducted to the thermally conductive adhesive 262 than to the structural adhesive 252.

[0033] 2 is a top view of the battery module 100 according to the embodiment, with the first voltage detection device 130, the second voltage detection device 140, and the fifth plate 250 removed. In FIG. 2, the white circle with a black dot indicating the Z direction indicates that the tip of the arrow indicating the Z direction is facing towards the front of the page.

[0034] A battery module 100 according to an embodiment will be described with reference to FIGS.

[0035] 1 and 2 , when viewed from the Z direction, the multiple structural adhesives 252 and the multiple extended thermal expansion materials 310 arranged alternately in the X direction each extend in the Y direction between the +Z side surface of the stack of battery cells 110 and the −Z side surface of the fifth plate 250. Therefore, each extended thermal expansion material 310 is at least partially located in the space between the +Z side surface of the stack of battery cells 110 and the −Z side surface of the fifth plate 250. When viewed from the Z direction, the X direction dimension of each extended thermal expansion material 310 is approximately equal to the X direction distance between the −X side edge of the structural adhesive 252 located on the +X side of each extended thermal expansion material 310 and the +X side edge of the structural adhesive 252 located on the −X side of each extended thermal expansion material 310. Therefore, the ratio of the X direction dimension of each extended thermal expansion material 310 to the distance can be increased compared to when the X direction dimension of each extended thermal expansion material 310 is less than the distance.

[0036] In the embodiment, even if a relatively high-temperature gas is generated from a battery cell 110 in which an abnormality has occurred, the gas causes each extended thermal expansion material 310 to thermally expand in the space between the +Z side surface of the battery cell 110 and the -Z side surface of the fifth plate 250. The thermal expansion of the extended thermal expansion material 310 causes the space to be at least partially filled with the extended thermal expansion material 310. By at least partially filling the space with the extended thermal expansion material 310, oxygen in the space can be depleted. Therefore, compared to when the extended thermal expansion material 310 is not provided, fire in the event of an abnormality in the battery cell 110 can be suppressed.

[0037] In the embodiment, the extended thermal expansion material 310 is exemplified as a thermal expansion material at least partially located in a space that exists at least partially between portions of the battery cells 110 and the housing 200 that are bonded to each other with an adhesive. However, the thermal expansion material that is at least partially located in a space that exists at least partially between portions of the battery cells 110 and the housing 200 that are bonded to each other with an adhesive is not limited to the exemplified thermal expansion material. For example, an extended thermal expansion material may also be at least partially located in a space that exists between the stack of battery cells 110 and the sixth plate 260.

[0038] As shown in FIG. 2 , a first intermediate thermal expansion material 322 is located inside each of the spaces at least partially surrounded in the Z direction by the +X-side drawn-out edge 112b of each cell group 110G and the spaces at least partially surrounded in the Z direction by the −X-side drawn-out edge 112b of each cell group 110G. In one example, the Z-direction dimension of each first intermediate thermal expansion material 322 may be substantially equal to the Z-direction dimension of each battery cell 110 or may be smaller than the Z-direction dimension of each battery cell 110. When viewed from the Z direction, the shape of each first intermediate thermal expansion material 322 and the shape of each space in which each first intermediate thermal expansion material 322 is located are substantially similar. Therefore, compared to when these shapes are different from each other when viewed from the Z direction, it is easier to increase the ratio of the area perpendicular to the Z direction of each first intermediate thermal expansion material 322 to the area perpendicular to the Z direction of each space in which each first intermediate thermal expansion material 322 is located. However, when viewed from the Z direction, the shape of each of the first intermediate thermal expansion materials 322 and the shape of each of the spaces in which each of the first intermediate thermal expansion materials 322 is located may be different from each other.

[0039] The multiple first intermediate thermal expansion materials 322 provided on the +X side of the stack of battery cells 110 may be separate from each other, or may be integrated with each other via an extension body (not shown) that extends in the Y direction. The same applies to the multiple first intermediate thermal expansion materials 322 provided on the -X side of the stack of battery cells 110.

[0040] The first intervening thermal expansion material 322 may be at least partially located in a space that is shifted in the Z direction relative to a space that is at least partially surrounded in the Z direction by the +X side draw-out edge 112b or the -X side draw-out edge 112b of each cell group 110G. For example, the first intervening thermal expansion material 322 may be at least partially located in a space that is shifted to the +X side or the -X side relative to the accommodating section 112a and to the +Z side or the -Z side relative to the draw-out edge 112b.

[0041] As shown in FIG. 2 , a second intervening thermal expansion material 324 is located inside each of the spaces at least partially surrounded in the Z direction by the +X-side tab groups 118 and the spaces at least partially surrounded in the Z direction by the -X-side tab groups 118. In one example, the Z-direction dimension of each second intervening thermal expansion material 324 may be approximately equal to the Z-direction dimension of each battery cell 110, or may be less than the Z-direction dimension of each battery cell 110. When viewed from the Z direction, the shape of each second intervening thermal expansion material 324 and the shape of each space in which each second intervening thermal expansion material 324 is located are approximately similar. Therefore, compared to when these shapes are different from each other when viewed from the Z direction, it is easier to increase the ratio of the area perpendicular to the Z direction of each second intervening thermal expansion material 324 to the area perpendicular to the Z direction of each space in which each second intervening thermal expansion material 324 is located. However, when viewed from the Z direction, the shape of each second intervening thermal expansion material 324 and the shape of each space in which each second intervening thermal expansion material 324 is located may be different from each other.

[0042] As shown in FIG. 2 , a third intervening thermal expansion material 326 is located inside each of the spaces between adjacent tab groups 118 on the +X side in the Y direction and the spaces between adjacent tab groups 118 on the −X side in the Y direction. In one example, the Z-direction dimension of each third intervening thermal expansion material 326 may be approximately equal to the Z-direction dimension of each battery cell 110, or may be less than the Z-direction dimension of each battery cell 110. When viewed from the Z direction, the shape of each third intervening thermal expansion material 326 and the shape of each space in which each third intervening thermal expansion material 326 is located are approximately similar. Therefore, compared to when these shapes are different from each other when viewed from the Z direction, it is easier to increase the ratio of the area perpendicular to the Z direction of each third intervening thermal expansion material 326 to the area perpendicular to the Z direction of each space in which each third intervening thermal expansion material 326 is located. However, when viewed from the Z direction, the shape of each third intermediate thermal expansion material 326 and the shape of each space in which each third intermediate thermal expansion material 326 is located may be different from each other.

[0043] The plurality of second intermediate thermal expansion materials 324 and the plurality of third intermediate thermal expansion materials 326 provided on the +X side of the stack of battery cells 110 may be separate from each other, or may be integrated with each other via an extension body (not shown) extending in the Y direction. The plurality of second intermediate thermal expansion materials 324 and the plurality of third intermediate thermal expansion materials 326 provided on the +X side of the stack of battery cells 110 may be integrated with the plurality of first intermediate thermal expansion materials 322 provided on the +X side of the stack of battery cells 110 via an extension body (not shown) extending in the Y direction. The same applies to the plurality of second intermediate thermal expansion materials 324 and the plurality of third intermediate thermal expansion materials 326 provided on the -X side of the stack of battery cells 110.

[0044] In the embodiment, even if a relatively high-temperature gas is generated from a battery cell 110 in which an abnormality has occurred, the thermal expansion materials, including the first interposed thermal expansion material 322, the second interposed thermal expansion material 324, and the third interposed thermal expansion material 326, in the space surrounding the tab group 118 are thermally expanded by the gas. The thermal expansion of the thermal expansion materials causes the space to be at least partially filled with the thermal expansion material. By at least partially filling the space with the thermal expansion material, oxygen in the space can be depleted. Therefore, compared to a case in which the first interposed thermal expansion material 322, the second interposed thermal expansion material 324, and the third interposed thermal expansion material 326 are not provided, fire in the event of an abnormality in the battery cell 110 can be suppressed.

[0045] In the embodiment, the first intervening thermal expansion material 322, the second intervening thermal expansion material 324, and the third intervening thermal expansion material 326 are exemplified as thermal expansion materials at least partially located in the space at least partially existing around the tab group 118. However, the thermal expansion materials at least partially located in the space at least partially existing around the tab group 118 are not limited to these exemplified thermal expansion materials. The intervening thermal expansion materials at least partially located in the space at least partially existing around the tab group 118 can be disposed in locations that are likely to reach a temperature at which the intervening thermal expansion material thermally expands. An example of a location that is likely to reach a temperature at which the intervening thermal expansion material thermally expands is the path through which gas generated from an abnormal battery cell 110 passes. By disposing the intervening thermal expansion material in this location, it is possible to suppress the release of gas generated from the battery cell 110 to the outside, and to isolate the battery cell 110 from the external space, thereby depleting oxygen in the space around the battery cell 110 and suppressing fire. It is not necessary to provide all of the first intervening thermal expansion material 322, the second intervening thermal expansion material 324, and the third intervening thermal expansion material 326. For example, the second intervening thermal expansion material 324 and the third intervening thermal expansion material 326 may be provided without providing the first intervening thermal expansion material 322.

[0046] FIG. 3 is a perspective view of a portion of the battery module 100 according to this embodiment with the first plate 210 removed.

[0047] A battery module 100 according to an embodiment will be described with reference to FIGS.

[0048] As shown in FIG. 3 , the surrounding thermal expansion material 330 is at least partially located in the space between the +X-side tab group 118 and the inner peripheral surface of the first opening 131a in the Z direction, as viewed from the X direction. The outer peripheral surface of the surrounding thermal expansion material 330 in the Z direction and the inner peripheral surface of the first opening 131a in the Z direction may be attached to each other, for example, via an adhesive. As viewed from the X direction, the shapes of the first opening 131a and the surrounding thermal expansion material 330 are substantially similar. Therefore, compared to when these shapes are different from each other as viewed from the X direction, it is easier to increase the ratio of the area perpendicular to the X direction of the surrounding thermal expansion material 330 to the area perpendicular to the X direction of the space between the +X-side tab group 118 and the inner peripheral surface of the first opening 131a in the Z direction. However, as viewed from the X direction, the shapes of the first opening 131a and the surrounding thermal expansion material 330 may be different from each other.

[0049] When viewed from the X direction, a thermal expansion material equivalent to the surrounding thermal expansion material 330 may be located in the space between the tab group 118 on the -X side and the inner surface around the Z direction of the second opening 141a, similar to the space between the tab group 118 on the +X side and the inner surface around the Z direction of the first opening 131a.

[0050] In the embodiment, even if a relatively high-temperature gas is generated from an abnormal battery cell 110, the thermal expansion material including the surrounding thermal expansion material 330 in the space between the battery cell 110 and the first voltage detection device 130 thermally expands due to the gas. The thermal expansion of the thermal expansion material causes the space to be at least partially filled with the thermal expansion material. By at least partially filling the space with the thermal expansion material, the space can be depleted of oxygen. Therefore, compared to when the surrounding thermal expansion material 330 is not provided, it is possible to suppress ignition when an abnormality occurs in the battery cell 110.

[0051] In the embodiment, the surrounding thermal expansion material 330 is exemplified as the thermal expansion material at least partially located in the space at least partially existing between the battery cell 110 and the first voltage detection device 130. However, the thermal expansion material at least partially located in the space at least partially existing between the battery cell 110 and the first voltage detection device 130 is not limited to the exemplified thermal expansion material. The same applies to the thermal expansion material at least partially located in the space at least partially existing between the battery cell 110 and the second voltage detection device 140.

[0052] In the embodiment, as described with reference to FIGS. 1 to 3 , thermal expansion materials including the extended thermal expansion material 310, the first intervening thermal expansion material 322, the second intervening thermal expansion material 324, the third intervening thermal expansion material 326, and the surrounding thermal expansion material 330 are at least partially located in the space present inside the housing 200. Therefore, even if a relatively high-temperature gas is generated from a battery cell 110 in which an abnormality has occurred, the thermal expansion material thermally expands due to the gas. The thermal expansion of the thermal expansion material at least partially fills the space with the thermal expansion material. By at least partially filling the space with the thermal expansion material, oxygen in the space can be depleted. Therefore, compared to when a thermal expansion material is not provided, fire in the event of an abnormality in the battery cell 110 can be suppressed.

[0053] In the embodiment, the extended thermal expansion material 310, the first intervening thermal expansion material 322, the second intervening thermal expansion material 324, the third intervening thermal expansion material 326, and the surrounding thermal expansion material 330 are exemplified as thermal expansion materials at least partially located in the space present inside the housing 200. However, the thermal expansion materials at least partially located in the space present inside the housing 200 are not limited to these exemplified thermal expansion materials.

[0054] In the embodiment, the thermal expansion materials, such as the extended thermal expansion material 310, the first intervening thermal expansion material 322, the second intervening thermal expansion material 324, the third intervening thermal expansion material 326, and the surrounding thermal expansion material 330, at least partially contain a foam material such as foam rubber. The thermal expansion materials are electrically insulating. Therefore, even if the thermal expansion materials are heated by gas generated from a battery cell 110 in which an abnormality has occurred, the thermal expansion materials are more likely to foam than melt. Therefore, in the embodiment, even if the thermal expansion materials are heated by gas generated from a battery cell 110 in which an abnormality has occurred, the electrical insulation of the thermal expansion materials can be more easily ensured than if the thermal expansion materials melt. However, the thermal expansion materials may be other thermal expansion materials than foam materials.

[0055] 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. [Explanation of symbols]

[0056] 100 battery module, 110 battery cell, 110G cell group, 112 exterior material, 112a housing section, 112b pull-out edge, 114 positive electrode tab, 116 negative electrode tab, 118 tab group, 120 compression pad, 130 first voltage detection device, 131 first protector, 131a first opening, 132 first voltage detection terminal, 133 first voltage detection line, 134 first connector, 135 first bus bar, 140 second voltage detection device, 141 second protector, 141a second opening, 142 second voltage detection terminal, 143 second voltage detection line, 144 second connector, 145 second bus bar, 200 housing, 210 first plate, 220 second plate, 230 third plate, 240 fourth plate, 250 fifth plate, 252 Structural adhesive, 260 Sixth plate, 262 Thermal conductive adhesive, 310 Extended thermal expansion material, 322 First intervening thermal expansion material, 324 Second intervening thermal expansion material, 326 Third intervening thermal expansion material, 330 Surrounding thermal expansion material

Claims

1. A battery cell; a housing that houses the battery cell; a thermal expansion material at least partially located in a space present within the housing; A battery module comprising:

2. an adhesive that bonds the battery cell and the housing together; The battery module according to claim 1 , wherein the space exists at least partially between the portions of the battery cells and the housing that are bonded to each other by the adhesive.

3. A plurality of the battery cells have terminals joined to each other, The battery module according to claim 1 , wherein the space exists at least partially around the terminal.

4. a voltage detection device for detecting the voltage of the battery cell; The battery module according to claim 1 , wherein the space exists at least partially between the battery cells and the voltage detection device.

5. The battery module according to claim 1 , wherein the thermal expansion material at least partially includes a foam material.

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