Battery module

Abstract

A battery module (100) comprises: a battery cell (110) that has a positive electrode tab (114) or a negative electrode tab (116); and an accommodation body (200) that accommodates therein the battery cell (110). The accommodation body (200) has a first metal part (212), and a first resin part (214) that is at least partially positioned between the battery cell (110) and the first metal part (212). The first resin part (214) includes a second resin protrusion (214c) protruding toward a first voltage detection terminal (132) that is electrically connected to the positive electrode tab (114) or the negative electrode tab (116).

Description

Battery module

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

[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 an example of a battery pack. The battery pack includes a battery unit, a positive electrode output terminal and a negative electrode output terminal electrically connected to the battery unit, and a holder that holds the positive electrode output terminal and the negative electrode output terminal. The holder has an uneven surface between the positive electrode output terminal and the negative electrode output terminal.

[0004] Patent Document 2 describes an example of a fuel cell stack. The fuel cell stack includes a plurality of fuel cell power generation units arranged in a predetermined direction, a pair of terminal plates located on either side of the plurality of fuel cell power generation units in the predetermined direction, a pair of insulating sheets located on either side of the pair of terminal plates in the predetermined direction, and a pair of end plates located on either side of the pair of insulating sheets in the predetermined direction. Bolts pass through the plurality of fuel cell power generation units, the pair of terminal plates, the pair of insulating sheets, and the pair of end plates. The inner surface of the through hole in the insulating sheet through which the bolt passes is stepped.

[0005] JP 2007-220391 A JP 2020-170631 A

[0006] The housing that houses the battery cells may have a conductive part such as a metal plate. The housing may have a conductive part inside, such as a tab of the battery cell or a conductive member electrically connected to the tab. When the voltage between the conductive part of the housing and the conductive part inside the housing is relatively high, it may be difficult to suppress discharges such as creeping discharges and space discharges between the conductive part of the housing and the conductive part inside the housing. When it is difficult to suppress discharges between the conductive part of the housing and the conductive part inside the housing, it may be difficult to ensure electrical insulation between the battery cells and the housing.

[0007] One object of the present invention is to ensure electrical insulation between the battery cell and the housing. Other objects of the present invention will become apparent from the description herein.

[0008] 1. A battery module comprising: a battery cell having an output terminal; and a housing that houses the battery cell, wherein the housing has a first conductive part and an insulating part located at least partially between the battery cell and the first conductive part, and the insulating part includes a protrusion that protrudes toward a second conductive part that includes at least one of the output terminal and a conductive member electrically connected to the output terminal. 2. The battery module described in 1., wherein the protrusion protrudes toward a portion of the second conductive part that is positioned offset toward the center of the second conductive part with respect to an end of the second conductive part. 3. The battery module described in 1. or 2., wherein the insulating part includes a resin part including the protrusion and a heat-resistant part located between the first conductive part and the resin part. 4. The battery module described in any one of 1. to 3., wherein the second conductive part includes a voltage detection terminal electrically connected to the output terminal. 5. 5. A battery module comprising: a battery cell having an output terminal; and a housing that houses the battery cell, wherein the housing has a first conductive portion and an insulating portion located at least partially between the battery cell and the first conductive portion, and the insulating portion includes an uneven surface located between the first conductive portion and a second conductive portion that includes at least one of the output terminal and a conductive member electrically connected to the output terminal. 6. The battery module described in 5., wherein the insulating portion includes a resin portion including the uneven surface and a heat-resistant portion located between the first conductive portion and the resin portion. 7. The battery module described in 5. or 6., wherein the second conductive portion includes a voltage detection terminal electrically connected to the output terminal.

[0009] According to the above aspect of the present invention, electrical insulation between the battery cell and the housing can be ensured.

[0010] Fig. 4 is an exploded upper perspective view of a battery module according to an embodiment. Fig. 5 is a front perspective view of a first plate according to an embodiment. Fig. 6 is a rear perspective view of a first plate according to an embodiment. Fig. 7 is a cross-sectional view of a position corresponding to cross section A-A in Fig. 1 in an assembled state of the battery module. Fig. 8 is a view showing a first modified example of Fig. 4. Fig. 9 is a view showing a second modified example of Fig. 4. Fig. 10 is a cross-sectional view of a portion of a battery module according to a modified example.

[0011] Hereinafter, embodiments and modifications of the present invention will be described with reference to the drawings. In all the drawings, like components are designated by like reference numerals, and descriptions thereof will be omitted as appropriate.

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

[0013] For the purpose of explanation, the X, Y, and Z directions are shown in each figure. 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. The arrows pointing to the X direction, the Y direction, and 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 .

[0015] The multiple battery cells 110 and the multiple compression pads 120 are stacked alternately in the Y direction. Each compression pad 120 is arranged between adjacent battery cells 110 in the Y direction and on both sides of the multiple battery cells 110 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.

[0016] Each 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 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 exterior material 112 seals the battery element and an electrolyte (not shown). 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 both sides of the exterior material 112 in the X direction. The negative electrode tab 116 is electrically connected to the negative electrode of the battery element. The negative electrode tab 116 is drawn out from the other side of the exterior material 112 in the X direction. However, the structure of each battery cell 110 is not limited to this example. For example, in an embodiment, the output terminal of each battery cell 110 is the positive electrode tab 114 or the negative electrode tab 116. The potential of the battery element included in the battery cell 110 is output from the output terminal of each battery cell 110. However, the output terminal of each battery cell 110 is not limited to tabs such as the positive electrode tab 114 and the negative electrode tab 116.

[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 a portion corresponding to a separator. An all-solid-state battery does not contain an electrolyte solution. Unless otherwise specified, the following description will be given assuming that each battery cell 110 is a battery cell containing an electrolyte solution.

[0018] The multiple battery cells 110 are electrically connected in a series-parallel combination. 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. 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 connected in parallel and a negative electrode tab 116 drawn 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. 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. Thus, multiple cell groups are connected in series from the cell group located at one end of the stack of battery cells 110 in the Y direction to the cell group located at the other end of the stack of battery cells 110 in the Y direction. 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 configured by connecting single battery cells 110 in series.

[0020] The first voltage detection device 130 detects the voltages of the plurality of +X side tab groups 118. The first voltage detection device 130 includes a first protector 131, a plurality of first voltage detection terminals 132, a plurality of first voltage detection 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.

[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 placing 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. Thus, the first voltage detection terminals 132 and the first connectors 134 are electrically connected to each other via the 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 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 detection device 140 detects the voltages of the plurality of −X side tab groups 118. The second voltage detection device 140 includes a second protector 141, a plurality of second voltage detection terminals 142, a plurality of second voltage detection 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.

[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 placing 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. Thus, 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 that is 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 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 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 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 of battery cells 110. Thus, the first bus bar 135 is disposed on the +X side and +Y side of the stack of battery cells 110, and the second bus bar 145 is disposed on the −X side and −Y side of the stack of battery cells 110. However, the arrangement of the positive electrode tab 114 and the negative electrode tab 116 at the end of a group of multiple cells 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 group of multiple cells connected in series is pulled 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 of battery cells 110, and the negative electrode tab 116 at the end of a group of multiple cells connected in series is pulled 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 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 container 200 includes 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 and the +X side portion of the first voltage detection device 130. The second plate 220 covers the −X side portion of the stack of battery cells 110 and the −X side portion of the second voltage detection device 140. 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. The sixth plate 260 covers the −Z side portion of the stack of battery cells 110. A thermally conductive adhesive 270 is disposed between the +Z side surface of the sixth plate 260 and the −Z side surface of the stack of battery cells 110. Therefore, heat generated from the stack of battery cells 110 can be dissipated downwards in the battery module 100 through the thermally conductive adhesive 270.

[0033] Fig. 2 is a front perspective view of the first plate 210 according to the embodiment. Fig. 3 is a rear perspective view of the first plate 210 according to the embodiment. Fig. 4 is a cross-sectional view of the battery module 100 in an assembled state, taken along the line AA in Fig. 1 .

[0034] The first plate 210 according to the embodiment will be described with reference to Figures 2 to 4, and also with reference to Figure 1 as needed. The matters described below regarding the first plate 210 according to the embodiment can also be similarly applied to the second plate 220 according to the embodiment.

[0035] As shown in Figures 2 to 4, the first plate 210 includes a first metal portion 212, a first resin portion 214, and a first fire-resistant portion 216. The first metal portion 212 includes a first metal plate 212a, a first metal protrusion 212b, and a second metal protrusion 212c. The first metal plate 212a defines a first notch 212a1 and a second notch 212a2. The first resin portion 214 includes a first resin plate 214a, a plurality of first resin protrusions 214b, and a plurality of second resin protrusions 214c. The first fire-resistant portion 216 includes a first fire-resistant sheet 216a, a first fire-resistant extending sheet 216b1, and a second fire-resistant extending sheet 216b2.

[0036] The first metal portion 212 is a conductive portion. The first metal portion 212 is made of a metal such as aluminum or stainless steel. The rigidity of the first metal portion 212 can be made higher than the rigidity of resin. Therefore, when the first plate 210 has the first metal portion 212, the strength of the first plate 210 can be improved compared to when the first plate 210 does not have the first metal portion 212 and is made of only resin.

[0037] The first metal plate 212a has a thickness that is approximately parallel to the X direction. Specifically, the first metal plate 212a has a substantially rectangular shape with a pair of long sides that are approximately parallel to the Y direction and a pair of short sides that are approximately parallel to the Z direction, excluding the first notch 212a1 and the second notch 212a2.

[0038] As shown in Fig. 2, the first notch 212a1 is located on the +Y side of the long side on the +Z side of the first metal plate 212a. As shown in Figs. 1 and 2, the space defined by the first notch 212a1 and the first bus bar 135 at least partially overlap in the X direction. The first bus bar 135 is a conductive member electrically connected to the battery cell 110. Therefore, electrical insulation between the first metal plate 212a and the first bus bar 135 can be ensured compared to when the first notch 212a1 is not defined in the first metal plate 212a.

[0039] As shown in Fig. 2, the second notch 212a2 is located on the -Y side of the long side on the +Z side of the first metal plate 212a. As shown in Figs. 1 and 2, the space defined by the second notch 212a2 and the first connector 134 at least partially overlap in the X direction. The first connector 134 is a conductive member electrically connected to the battery cell 110. Therefore, electrical insulation between the first metal plate 212a and the first connector 134 can be ensured compared to when the first metal plate 212a does not define the second notch 212a2.

[0040] The first metal plate 212a may define a notch instead of or in addition to the first notch 212a1 and the second notch 212a2. The space defined by the notch and the conductive member electrically connected to the battery cell 110 may at least partially overlap in the X direction. When the space and the conductive member at least partially overlap in the X direction, electrical insulation between the first metal plate 212a and the conductive member can be ensured compared to when the first metal plate 212a does not define the notch.

[0041] The first metal protrusion 212b is located at the end portion on the -Z side of the -X side surface of the first metal plate 212a. The first metal protrusion 212b protrudes toward the -X side. The first metal protrusion 212b extends along the edge of the first metal plate 212a on the -Z side. The first metal plate 212a and the first metal protrusion 212b are integral with each other.

[0042] The second metal protrusion 212c is located at the end portion on the +Z side of the -X side surface of the first metal plate 212a. The second metal protrusion 212c protrudes toward the -X side. The second metal protrusion 212c extends along the +Z side edge of the first metal plate 212a, excluding the first notch 212a1 and the second notch 212a2. The first metal plate 212a and the second metal protrusion 212c are integral with each other.

[0043] The first resin portion 214 serves as an insulating portion and is made of resin such as polypropylene (PP).

[0044] The first resin plate 214a has a thickness that is approximately parallel to the X direction. Specifically, the first resin plate 214a has a substantially rectangular shape with a pair of long sides that are approximately parallel to the Y direction and a pair of short sides that are approximately parallel to the Z direction. As shown in FIGS. 3 and 4, the -Z side long side of the first resin plate 214a and the +Z side surface of the first metal protrusion 212b are spaced apart from each other in the Z direction. Therefore, a portion of the first fire-resistant sheet 216a (described later) is exposed toward the -X side between the -Z side long side of the first resin plate 214a and the +Z side surface of the first metal protrusion 212b.

[0045] The first resin plate 214a has electrical insulation properties. The first resin plate 214a covers substantially the entire surface of the −X side of the first metal portion 212. Therefore, in the X direction, the first resin plate 214a is at least partially located between the −X side surface of the first metal plate 212a and the +X side surfaces of the +X side tab group 118, the first voltage detection terminal 132, and the first bus bar 135. Therefore, the first resin plate 214a can suppress short circuits between the first metal plate 212a and the +X side tab group 118, the first voltage detection terminal 132, and the first bus bar 135.

[0046] The plurality of first resin protrusions 214b are provided on the +X side surface of the first resin plate 214a. For example, the first resin plate 214a and the plurality of first resin protrusions 214b are integrally formed by resin molding. The first metal plate 212a and the first resin plate 214a are joined to each other by thermally caulking the plurality of first resin protrusions 214b, with a first fire-resistant sheet 216a (described later) at least partially disposed between the −X side surface of the first metal plate 212a and the +X side surface of the first resin plate 214a. Specifically, when the first metal plate 212a and the first resin plate 214a are joined to each other, each of the first resin protrusions 214b penetrates in the X direction through a through-hole provided in the first fire-resistant sheet 216a and a through-hole provided in the first metal plate 212a. The dimension of the +X side end of each first resin protrusion 214b in the direction perpendicular to the X direction is larger than the dimension of the through hole provided in the first metal plate 212a in the direction perpendicular to the X direction by heat caulking the +X side end of each first resin protrusion 214b. Therefore, the first metal plate 212a and the first resin plate 214a are joined to each other in a state where the first metal plate 212a does not come loose from the first resin plate 214a toward the +X side. However, the method of joining the first metal plate 212a and the first resin plate 214a is not limited to heat caulking the +X side end of each first resin portion 214.

[0047] The multiple second resin protrusions 214c are provided on the -X side surface of the first resin plate 214a. For example, the first resin plate 214a and the multiple second resin protrusions 214c are integrally formed by resin molding. The -X side surface of each second resin protrusion 214c and the +X side surface of each first voltage detection terminal 132 face each other in the X direction when the first plate 210 covers the +X side portion of the stack of battery cells 110 and the +X side portion of the first voltage detection device 130. Instead of the multiple second resin protrusions 214c, a single second resin protrusion 214c extending in the Y direction may be provided. When a single second resin protrusion 214c is provided, the -X side surface of the second resin protrusion 214c and the +X side surface of each first voltage detection terminal 132 face each other in the X direction when the first plate 210 covers the +X side portion of the stack of battery cells 110 and the +X side portion of the first voltage detection device 130.

[0048] The formability of the first resin portion 214 is higher than the formability of the first fire-resistant portion 216. Therefore, in the embodiment, the degree of freedom in the shape of the −X side of the first plate 210 can be improved compared to when the first plate 210 does not include the first resin portion 214. However, the first plate 210 may include the first metal portion 212 and the first fire-resistant portion 216 without including the first resin portion 214.

[0049] The first refractory portion 216 is an insulating portion and includes a refractory material such as silicon fiber.

[0050] The first fire-resistant sheet 216a has a thickness that is approximately parallel to the X direction. Specifically, the first resin plate 214a, excluding the first fire-resistant extending sheet 216b1 and the second fire-resistant extending sheet 216b2, has a substantially rectangular shape with a pair of long sides that are approximately parallel to the Y direction and a pair of short sides that are approximately parallel to the Z direction.

[0051] The first fire-resistant sheet 216a has electrical insulation properties. The first fire-resistant sheet 216a covers substantially the entire −X side of the first metal portion 212, except for the first metal protrusion 212b and the second metal protrusion 212c. Therefore, in the X direction, the first fire-resistant sheet 216a is at least partially located between the −X side surface of the first metal plate 212a and the +X side surfaces of the +X side tab group 118, the first voltage detection terminal 132, and the first bus bar 135. Therefore, the first fire-resistant sheet 216a can prevent short circuits between the first metal plate 212a and the +X side tab group 118, the first voltage detection terminal 132, and the first bus bar 135.

[0052] The first fire-resistant sheet 216a does not have to cover substantially the entire −X side of the first metal plate 212a. For example, the first fire-resistant sheet 216a may partially cover portions of the −X side surface of the first metal plate 212a that overlap in the X direction with the +X side tab group 118, the first voltage detection terminal 132, and the first bus bar 135. When the first fire-resistant sheet 216a partially covers these portions of the −X side surface of the first metal plate 212a, the first fire-resistant sheet 216a can suppress short circuits between the first metal plate 212a and the +X side tab group 118, the first voltage detection terminal 132, and the first bus bar 135. When the first fire-resistant sheet 216a partially covers the -X side surface of the first metal plate 212a, the material cost of the first fire-resistant sheet 216a can be reduced compared to when the first fire-resistant sheet 216a covers almost the entire -X side surface of the first metal plate 212a.

[0053] The first fire-resistant sheet 216a is disposed between the +Z side surface of the first metal protrusion 212b and the −Z side surface of the second metal protrusion 212c. This prevents the −Z side end of the first fire-resistant sheet 216a from entering the gap between the −Z side end of the first plate 210 and the +Z side surface of the +X side end of the sixth plate 260. This allows the −Z side end of the first plate 210 and the +X side end of the sixth plate 260 to be more reliably joined by a joining method such as laser welding, compared to when the −Z side end of the first fire-resistant sheet 216a enters the gap. Similarly, this prevents the +Z side end of the first fire-resistant sheet 216a from entering the gap between the +Z side end of the first plate 210 and the +Z side surface of the +X side end of the fifth plate 250. Therefore, compared to when the +Z side end of the first fire-resistant sheet 216a enters the gap, the +Z side end of the first plate 210 and the +X side end of the fifth plate 250 can be more reliably joined by a joining method such as laser welding.

[0054] As shown in FIG. 2 , the first fire-resistant extension sheet 216b1 is folded back toward the −Z side, with at least a portion of the first fire-resistant extension sheet 216b1 covering at least a portion of the edge of the first notch 212a1 of the first metal plate 212a. In the example shown in FIG. 2 , the first fire-resistant extension sheet 216b1 covers the edge of the first notch 212a1 of the first metal plate 212a facing the +Z side. Therefore, compared to when the first fire-resistant extension sheet 216b1 does not cover the edge of the first metal plate 212a, electrical insulation between the first metal plate 212a and the conductive member arranged around the first notch 212a1 can be ensured. For example, a connecting bus bar (not shown) may be arranged around the first notch 212a1 to electrically connect the first bus bar 135 to a bus bar of an external device such as another battery module. In the embodiment, even if the connection bus bar falls toward the edge of the first metal plate 212a, the first fire-resistant extension sheet 216b1 can prevent a short circuit between the connection bus bar and the first metal plate 212a.

[0055] As shown in FIG. 2 , the second fire-resistant extension sheet 216b2 is folded back toward the −Z side, with at least a portion of the second fire-resistant extension sheet 216b2 covering at least a portion of the edge of the second notch 212a2 of the first metal plate 212a. In the example shown in FIG. 2 , the second fire-resistant extension sheet 216b2 covers the edge of the second notch 212a2 of the first metal plate 212a facing the +Z side. Therefore, compared to when the second fire-resistant extension sheet 216b2 does not cover the edge of the first metal plate 212a, electrical insulation between the first metal plate 212a and the conductive member disposed around the second notch 212a2 can be ensured. For example, a harness (not shown) electrically connected to the first connector 134 may be disposed around the second notch 212a2. In the embodiment, even if the harness falls toward the edge of the first metal plate 212a, the second fire-resistant extension sheet 216b2 can prevent a short circuit between the harness and the first metal plate 212a.

[0056] In the embodiment, the first refractory portion 216 covers at least a portion of the edges of the first metal plate 212a, such as the first notch 212a1 and the second notch 212a2. However, the first refractory portion 216 may also cover at least a portion of an edge of the first metal plate 212a that is different from the edges of the notches. For example, the first refractory portion 216 may cover at least a portion of the edge of the first metal plate 212a when the first metal plate 212a does not define any notches. When the first refractory portion 216 covers at least a portion of the edge of the first metal plate 212a, electrical insulation between the first metal plate 212a and a conductive member disposed around the portion of the edge of the first metal plate 212a that is covered by the first refractory portion 216 can be ensured, compared to when the first refractory portion 216 does not cover any portion of the edge of the first metal plate 212a.

[0057] The first refractory portion 216 is a heat-resistant portion having relatively high heat resistance. For example, the electrical insulation of the first refractory portion 216 is maintained after the first refractory portion 216 is exposed to 800°C for 10 minutes, preferably after being exposed to 1000°C for 10 minutes. In the embodiment, even if abnormal heat generation occurs in the battery cell 110, the heat resistance of the first refractory portion 216 can make the first refractory portion 216 less likely to melt. Therefore, even if the first resin portion 214 melts due to abnormal heat generation in the battery cell 110, the first refractory portion 216 can make it less likely to melt. Therefore, even if the first resin portion 214 melts due to abnormal heat generation in the battery cell 110, the first refractory portion 216 can suppress short-circuiting between the first metal portion 212 and each of the +X-side tab group 118, the first voltage detection terminal 132, and the first bus bar 135.

[0058] In one example, the heat resistance of the first fire-resistant portion 216 is higher than the heat resistance of the first resin portion 214. If the heat resistance of the first fire-resistant portion 216 is higher than the heat resistance of the first resin portion 214, the first fire-resistant portion 216 can be made less likely to melt than the first resin portion 214 even if abnormal heat generation occurs in the battery cell 110.

[0059] The first fire-resistant portion 216 also has relatively high fire resistance. Fire resistance is determined by the time it takes for a flame to completely burn a certain component. The longer it takes for the flame to burn a component, the higher the fire resistance, and the shorter it takes for the flame to burn a component, the lower the fire resistance. In the embodiment, even if abnormal heat generation occurs in the battery cell 110, the fire resistance of the first fire-resistant portion 216 can make the first fire-resistant portion 216 less likely to melt. Therefore, even if the first resin portion 214 melts due to abnormal heat generation in the battery cell 110, the first fire-resistant portion 216 can make it less likely to melt. Therefore, even if the first resin portion 214 melts due to abnormal heat generation in the battery cell 110, the first fire-resistant portion 216 can suppress short-circuiting between the first metal portion 212 and each of the +X-side tab group 118, the first voltage detection terminal 132, and the first bus bar 135.

[0060] In one example, the fire resistance of the first fire-resistant portion 216 is higher than the fire resistance of the first resin portion 214. If the fire resistance of the first fire-resistant portion 216 is higher than the fire resistance of the first resin portion 214, the first fire-resistant portion 216 can be made less likely to melt than the first resin portion 214 even if abnormal heat generation occurs in the battery cell 110.

[0061] The first fire-resistant portion 216 may or may not have flame resistance. If the first fire-resistant portion 216 has flame resistance, the first fire-resistant portion 216 may melt without burning at a temperature higher than the heat resistance temperature of the first fire-resistant portion 216. If the first fire-resistant portion 216 does not have flame resistance, the first fire-resistant portion 216 may burn and melt at a temperature higher than the heat resistance temperature of the first fire-resistant portion 216.

[0062] The first plate 210 may have a heat-resistant portion instead of the first fire-resistant portion 216. The heat-resistant portion may or may not have fire resistance. When the first plate 210 has a heat-resistant portion, even if abnormal heat generation occurs in the battery cell 110, the heat resistance of the heat-resistant portion can make the heat-resistant portion less likely to melt.

[0063] 4, the electrical insulation between the first metal portion 212 and the first voltage detection terminal 132 will be described. In the example shown in Fig. 4, the first voltage detection terminal 132 is a conductive member electrically connected to the tab group 118 on the +X side.

[0064] For illustrative purposes, FIG. 4 illustrates the creeping path C between the +Z side surface of the first metal protrusion 212b and the +X side surface of the first voltage detection terminal 132 with a bold line. The longer the overall length of the creeping path C, the easier it is to ensure electrical insulation between the first voltage detection terminal 132 and the first metal portion 212. The creeping path C shown in FIG. 4 runs along the −X side surface of the first fireproof sheet 216a between the +Z side surface of the first metal protrusion 212b and the −Z side surface of the second resin protrusion 214c, and also runs along the −Z side surface of the second resin protrusion 214c between the −X side surface of the first fireproof sheet 216a and the +X side surface of the first voltage detection terminal 132. As shown in FIG. 4, a portion of the creeping path C is formed in the space between the −X side end of the −Z side surface of the second resin protrusion 214c and the +X side surface of the first voltage detection terminal 132. The reason why the portion of the creeping path C is formed in the space is because the −X side surface of the second resin protrusion 214c is located closer to the +X side surface of the first voltage detection terminal 132 than the −X side surface of the first resin plate 214a and the −X side surface of the first fire-resistant sheet 216a. In other words, the position where discharge occurs in the space between the insulating portion including the first resin portion 214 and the first fire-resistant portion 216 and the conductive portion including the +X side tab group 118 and the first voltage detection terminal 132 can be adjusted according to the position of the second resin protrusion 214c in the Z direction.

[0065] The first voltage detection terminal 132 is movable in the X direction. In the example shown in Fig. 4, the +X side surface of the first voltage detection terminal 132 and the -X side surface of the second resin protrusion 214c face each other with a gap between them. However, if the first voltage detection terminal 132 moves toward the +X side, the +X side surface of the first voltage detection terminal 132 and the -X side surface of the second resin protrusion 214c may come into contact with each other.

[0066] In the example shown in FIG. 4 , the second resin protrusion 214c protrudes toward the first voltage detection terminal 132. Therefore, in the example shown in FIG. 4 , even if the first voltage detection terminal 132 moves toward the +X side, the movement of the first voltage detection terminal 132 toward the +X side can be restricted by contact between the −X side surface of the second resin protrusion 214c and the +X side surface of the first voltage detection terminal 132. Therefore, in the example shown in FIG. 4 , it is easier to ensure the distance between the −X side surface of the first fireproof sheet 216a and the +X side surface of the first voltage detection terminal 132 compared to when the second resin protrusion 214c is not provided. Therefore, in the example shown in FIG. 4 , electrical insulation between the first voltage detection terminal 132 and the first metal portion 212 can be ensured compared to when the second resin protrusion 214c is not provided.

[0067] 4, the second resin protrusion 214c protrudes toward a portion of the first voltage detection terminal 132 that is shifted toward the center of the first voltage detection terminal 132 with respect to the −Z side end of the first voltage detection terminal 132. That is, the distance in the Z direction between the −Z side surface of the second resin protrusion 214c and the +Z side surface of the sixth plate 260 is longer than the distance in the Z direction between the −Z side end of the first voltage detection terminal 132 and the +Z side surface of the sixth plate 260. Therefore, in the example shown in FIG. 4, compared to when the −Z side end of the second resin protrusion 214c and the −Z side end of the first voltage detection terminal 132 overlap in the X direction, a creeping path can be formed along the −Z side surface of the second resin protrusion 214c at a position farther toward the +Z side from the +Z side surface of the first metal protrusion 212b. Therefore, in the example shown in Figure 4, compared to when the -Z side end of the second resin protrusion 214c and the -Z side end of the first voltage detection terminal 132 overlap in the X direction, the creeping path along the -X side surface of the first fire-resistant sheet 216a between the +Z side surface of the first metal protrusion 212b and the -Z side surface of the second resin protrusion 214c can be made longer.

[0068] 4, the second resin protrusion 214c protrudes toward a portion of the first voltage detection terminal 132 that is located relatively close to the −Z side end of the first voltage detection terminal 132. Specifically, the second resin protrusion 214c protrudes toward a portion of the first voltage detection terminal 132 that is located between the −Z side end of the first voltage detection terminal 132 and the −Z side end of the +X side tab group 118. Therefore, compared to a case in which the second resin protrusion 214c protrudes toward a portion of the first voltage detection terminal 132 that is located relatively far from the −Z side end of the first voltage detection terminal 132, movement of the −Z side end of the first voltage detection terminal 132 toward the +X side can be more easily restricted by the first voltage detection terminal 132. Therefore, compared to when the second resin protrusion 214c protrudes toward a portion of the first voltage detection terminal 132 that is located relatively far from the -Z side end of the first voltage detection terminal 132, it is easier to suppress discharge in the space between the -Z side end of the first voltage detection terminal 132 and the -X side surface of the first fire-resistant sheet 216a.

[0069] In the example shown in FIG. 4 , the second resin protrusion 214c partially thickens the X-direction thickness of the first resin part 214. Therefore, movement of the first voltage detection terminal 132 toward the +X side can be restricted without increasing the X-direction thickness of the first resin part 214 throughout the first resin part 214. If the X-direction thickness of the first resin part 214 were to be thick throughout the first resin part 214, the warping stress of the first resin part 214 would be relatively large, and the impact of the warping stress on the components surrounding the first resin part 214 would be relatively large. In contrast, in the example shown in FIG. 4 , the X-direction thickness of the first resin part 214 can be relatively thin, excluding the second resin protrusion 214c. Therefore, compared to when the X-direction thickness of the first resin part 214 is thick throughout the first resin part 214, the impact of the warping stress on the components surrounding the first resin part 214 can be reduced.

[0070] In the example shown in Fig. 4, the second resin protrusion 214c prevents a short circuit between the conductive portion including the first metal portion 212 and the conductive portion including the first voltage detection terminal 132 and the +X-side tab group 118 via the creeping path C of the insulating portion including the first resin plate 214a and the first fireproof sheet 216a. However, the structure to which the protrusion corresponding to the second resin protrusion 214c is applied is not limited to the example shown in Fig. 4. For example, the protrusion may protrude toward the +X-side tab group 118 instead of the first voltage detection terminal 132.

[0071] In the embodiment, the output terminal of each battery cell 110 is a positive electrode tab 114 or a negative electrode tab 116. The output terminal of each battery cell 110 outputs the potential of the battery element included in the battery cell 110. However, the output terminal of each battery cell 110 is not limited to tabs such as the positive electrode tab 114 and the negative electrode tab 116.

[0072] FIG. 5 is a diagram showing a first modified example of FIG.

[0073] The surface path C1 shown in FIG. 5 runs along the -X side surface of the first fire-resistant sheet 216a, the -Z side surface of the first resin plate 214a, and the -X side surface of the first resin plate 214a between the +Z side surface of the first metal protrusion 212b and the -Z side surface of the second resin protrusion 214c, and runs along the -Z side surface of the second resin protrusion 214c between the -X side surface of the first fire-resistant sheet 216a and the +X side surface of the first voltage detection terminal 132.

[0074] In the example shown in Fig. 5 , similar to the example shown in Fig. 4 , the second resin protrusion 214c protrudes toward the first voltage detection terminal 132. Therefore, in the example shown in Fig. 5 , even if the first voltage detection terminal 132 moves toward the +X side, the movement of the first voltage detection terminal 132 toward the +X side can be restricted by the contact between the -X side surface of the second resin protrusion 214c and the +X side surface of the first voltage detection terminal 132. Therefore, in the example shown in Fig. 5 , similar to the example shown in Fig. 4 , electrical insulation between the first voltage detection terminal 132 and the first metal portion 212 can be ensured compared to a case in which the second resin protrusion 214c is not provided.

[0075] 5, similarly to the example shown in Fig. 4, second resin protrusion 214c protrudes toward a portion of first voltage detection terminal 132 that is shifted toward the center of first voltage detection terminal 132 with respect to the -Z side end of first voltage detection terminal 132. Therefore, in the example shown in Fig. 5, similarly to the example shown in Fig. 4, the creeping path along the -X side surface of first fire-resistant sheet 216a between the +Z side surface of first metal protrusion 212b and the -Z side surface of second resin protrusion 214c can be made longer compared to the case where the -Z side end of second resin protrusion 214c and the -Z side end of first voltage detection terminal 132 overlap in the X direction.

[0076] 5, the second resin protrusion 214c protrudes toward a portion of the first voltage detection terminal 132 that is located relatively far from the −Z side end of the first voltage detection terminal 132. Specifically, the second resin protrusion 214c and the +X side tab group 118 at least partially overlap each other in the X direction. Therefore, compared to when the second resin protrusion 214c protrudes toward a portion of the first voltage detection terminal 132 that is located relatively close to the −Z side end of the first voltage detection terminal 132, the creeping path along the −X side surface of the first fireproof sheet 216a, the −Z side surface of the first resin plate 214a, and the −X side surface of the first resin plate 214a can be made longer between the +Z side surface of the first metal protrusion 212b and the −Z side surface of the second resin protrusion 214c.

[0077] FIG. 6 is a diagram showing a second modified example of FIG.

[0078] The surface path C2 shown in FIG. 6 runs along the −X side surface of the first fire-resistant sheet 216a between the +Z side surface of the first metal protrusion 212b and the −Z side surface of the second resin protrusion 214c, and runs along the −Z side surface of the second resin protrusion 214c between the −X side surface of the first fire-resistant sheet 216a and the +X side surface of the first voltage detection terminal 132.

[0079] In the example shown in Fig. 6 , similar to the example shown in Fig. 4 , the second resin protrusion 214c protrudes toward the first voltage detection terminal 132. Therefore, in the example shown in Fig. 6 , even if the first voltage detection terminal 132 moves toward the +X side, the movement of the first voltage detection terminal 132 toward the +X side can be restricted by the contact between the -X side surface of the second resin protrusion 214c and the +X side surface of the first voltage detection terminal 132. Therefore, in the example shown in Fig. 6 , similar to the example shown in Fig. 4 , electrical insulation between the first voltage detection terminal 132 and the first metal portion 212 can be ensured compared to a case in which the second resin protrusion 214c is not provided.

[0080] 6, the −Z side end of the second resin protrusion 214c and the −Z side end of the first voltage detection terminal 132 overlap in the X direction. Therefore, compared to a case where the second resin protrusion 214c protrudes toward a portion of the first voltage detection terminal 132 that is shifted toward the center of the first voltage detection terminal 132 with respect to the −Z side end of the first voltage detection terminal 132, it is possible to more easily restrict movement of the −Z side end of the first voltage detection terminal 132 toward the +X side.

[0081] Fig. 7 is a cross-sectional view of a portion of a battery module 100A according to a modified example. The A-A cross section shown in Fig. 7 according to the modified example corresponds to the A-A cross section in Fig. 4 according to the embodiment. The battery module 100A according to the modified example is similar to the battery module 100 according to the embodiment, except for the following points.

[0082] As shown in FIG. 7 , the −X-side surface of the −Z-side end of the first resin plate 214aA of the first resin part 214A according to the modified example includes an uneven surface between the +Z-side surface of the first metal protrusion 212b and the +X-side surface of the first voltage detection terminal 132. For illustrative purposes, the creeping path CA is illustrated in FIG. 7 with a bold line. As indicated by the creeping path CA, in the example shown in FIG. 7 , the total length of the creeping path CA can be increased compared to when the −X-side surface of the −Z-side end of the first resin plate 214aA is a flat surface perpendicular to the X-direction. Therefore, electrical insulation between the first voltage detection terminal 132 and the first metal part 212 can be ensured compared to when the −X-side surface of the −Z-side end of the first resin plate 214aA is a flat surface perpendicular to the X-direction. The shape of the uneven surface is not particularly limited as long as it can increase the total length of the creeping path CA between the +Z-side surface of the first metal protrusion 212b and the +X-side surface of the first voltage detection terminal 132.

[0083] Although the embodiments and modifications of the present invention have been described above with reference to the drawings, these are merely examples of the present invention, and various configurations other than those described above can also be adopted.

[0084] This application claims priority based on Japanese Patent Application No. 2023-172623, filed October 4, 2023, the disclosure of which is incorporated herein by reference in its entirety.

[0085] 100, 100A battery module, 110 battery cell, 112 exterior material, 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, 212 first metal portion, 212a first metal plate, 212a1 first notch, 212a2 second notch, 212b first metal protrusion, 212c Second metal protrusion, 214, 214A First resin portion, 214a, 214aA First resin plate, 214b First resin protrusion, 214c Second resin protrusion, 216 First fire-resistant portion, 216a First fire-resistant sheet, 216b1 First fire-resistant extension sheet, 216b2 Second fire-resistant extension sheet, 220 Second plate, 230 Third plate, 240 Fourth plate, 250 Fifth plate, 260 Sixth plate, 270 Thermally conductive adhesive, C, C1, C2, CA Surface path

Claims

1. A battery module comprising: a battery cell having an output terminal; and a housing that houses the battery cell, wherein the housing has a first conductive portion and an insulating portion located at least partially between the battery cell and the first conductive portion, and the insulating portion includes a protrusion that protrudes toward the output terminal and a second conductive portion that includes at least one of a conductive member electrically connected to the output terminal.

2. The battery module according to claim 1, wherein the projection protrudes toward a portion of the second conductive portion that is offset toward the center of the second conductive portion relative to an end of the second conductive portion.

3. A battery module as described in claim 1 or 2, wherein the insulating portion includes a resin portion including the protrusion, and a heat-resistant portion located between the first conductive portion and the resin portion.

4. A battery module according to any one of claims 1 to 3, wherein the second conductive portion includes a voltage detection terminal electrically connected to the output terminal.

5. A battery module comprising: a battery cell having an output terminal; and a housing that houses the battery cell, wherein the housing has a first conductive portion and an insulating portion located at least partially between the battery cell and the first conductive portion, and the insulating portion includes an uneven surface located between the first conductive portion and a second conductive portion that includes at least one of the output terminal and a conductive member electrically connected to the output terminal.

6. The battery module according to claim 5, wherein the insulating portion includes a resin portion including the uneven surface, and a heat-resistant portion located between the first conductive portion and the resin portion.

7. The battery module according to claim 5 or 6, wherein the second conductive portion includes a voltage detection terminal electrically connected to the output terminal.

Images