Battery module

Abstract

To easily detect a voltage of a lead part folded back between different battery cells.SOLUTION: The first voltage detection device 30 detects a voltage of the lead part 150 folded between different battery cells 100. The first voltage detection device 30 includes a first voltage detector 410, a first voltage detection line 420 electrically connected to the first voltage detector 410, and a first holding member 300 that holds the first voltage detector 410 and the first voltage detection line 420.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a voltage detection device and a battery module. [Background technology]

[0002] A battery module such as a lithium-ion secondary battery includes multiple stacked battery cells. In such a battery module, the multiple battery cells are electrically connected to each other by positive and negative electrode leads drawn from the battery cells. In addition, multiple battery cells connected in parallel may be connected in series to other multiple battery cells connected in parallel.

[0003] An example of a battery module is described in Patent Document 1. In this example, the positive and negative electrode leads of each battery cell are electrically connected via a bus bar.

[0004] Patent Document 2 describes an example of a method for manufacturing a battery module. In this example, the positive electrode lead of a single battery cell is joined to the negative electrode lead of another single battery cell by ultrasonic welding. In addition, the lead portion is folded back between the different battery cells. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 2020-524375 [Patent Document 2] Japanese Patent Application Publication No. 2018-152223 Summary of the Invention [Problem to be solved by the invention]

[0006] For example, when the lead portions are folded back between different battery cells as described in Patent Document 2, lead wires may be connected to each lead portion in order to detect the voltage of the lead portion. However, connecting lead wires to each lead portion can be a relatively complicated task.

[0007] One example of an object of the present invention is to easily detect the voltage of lead portions folded back between different battery cells. 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 A voltage detection device that detects the voltage of lead portions folded back between different battery cells, A voltage detection unit; a voltage detection line connected to the voltage detection unit; a holder that holds the voltage detection unit and the voltage detection line; The voltage detection device is provided with:

[0009] Another aspect of the present invention is A plurality of battery cells; a voltage detection device that detects the voltage of lead portions folded back between different battery cells; Equipped with The voltage detection device is A voltage detection unit; a voltage detection line connected to the voltage detection unit; a holder that holds the voltage detection unit and the voltage detection line; The battery module has: [Effects of the Invention]

[0010] According to the above aspect of the present invention, the voltage of the lead portion folded back between different battery cells can be easily detected. [Brief explanation of the drawings]

[0011] [Figure 1]FIG. 2 is an exploded front perspective view of the battery module according to the embodiment. [Figure 2] FIG. 2 is a rear perspective view of the battery module according to the embodiment. [Figure 3] FIG. 2 is a side view of a portion of a plurality of battery cells according to an embodiment. [Figure 4] 5A to 5C are diagrams illustrating a first example of a method for manufacturing a battery module according to an embodiment. [Figure 5] 5A to 5C are diagrams illustrating a first example of a method for manufacturing a battery module according to an embodiment. [Figure 6] 5A to 5C are diagrams illustrating a first example of a method for manufacturing a battery module according to an embodiment. [Figure 7] 5A to 5C are diagrams illustrating a first example of a method for manufacturing a battery module according to an embodiment. [Figure 8] 5A to 5C are diagrams illustrating a first example of a method for manufacturing a battery module according to an embodiment. [Figure 9] FIG. 2 is a diagram illustrating a first example of a method for stacking a plurality of cell groups. [Figure 10] FIG. 10 is a diagram illustrating a second example of a method for stacking a plurality of cell groups. [Figure 11] 10A and 10B are diagrams illustrating a second example of the method for manufacturing the battery module according to the embodiment. [Figure 12] 10A and 10B are diagrams illustrating a second example of the method for manufacturing the battery module according to the embodiment. [Figure 13] 10A and 10B are diagrams illustrating a second example of the method for manufacturing the battery module according to the embodiment. [Figure 14] FIG. 10 is a front perspective view of a portion of a battery module according to a first modification. [Figure 15] FIG. 10 is an exploded perspective view of a first voltage detecting device according to a second modification. [Figure 16] FIG. 10 is a front perspective view of a portion of a first voltage detecting device according to a second modification. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments and modifications of the present invention will be described with reference to the drawings. In all the drawings, like components are denoted by like reference numerals, and descriptions thereof will be omitted where appropriate.

[0013] In this specification, ordinal numbers such as "first," "second," and "third" are used merely to distinguish between similarly named configurations, unless otherwise specified, and do not imply any particular characteristics (e.g., order or importance) of the configurations.

[0014] In this specification, "A and B are substantially equal" does not only mean that A and B are strictly equal, but also means, for example, that A is 90% or more and 110% or less of B, or that B is 90% or more and 110% or less of A.

[0015] Fig. 1 is an exploded front perspective view of a battery module 10 according to an embodiment. Fig. 2 is a rear perspective view of the battery module 10 according to an embodiment. Fig. 3 is a side view of a portion of a plurality of battery cells 100 according to an embodiment.

[0016] 1 to 3, the first direction X is a direction parallel to the longitudinal direction of the battery cell 100. The second direction Y is perpendicular to the first direction X and parallel to the thickness direction of the battery cell 100. The third direction Z is perpendicular to both the first direction X and the second direction Y and parallel to the lateral direction of the battery cell 100. The arrows indicating the first direction X, the second direction Y, or the third direction Z indicate that the direction from the base end to the tip of the arrow is the positive direction of the direction indicated by the arrow, and that the direction from the tip to the base end of the arrow is the negative direction of the direction indicated by the arrow. The white circle with a black dot indicating the first direction X, the second direction Y, or the third direction Z indicates that the direction from the back of the page to the front of the page is the positive direction of the direction indicated by the white circle with a black dot, and that the direction from the front of the page to the back of the page is the negative direction of the direction indicated by the white circle with a black dot. The same applies to subsequent figures in FIGS. 1 to 3.

[0017] 1 to 3 , the positive direction of the first direction X is parallel to the direction from the front to the rear of the battery module 10, and the negative direction of the first direction X is parallel to the direction from the rear to the front of the battery module 10. The positive direction of the second direction Y is parallel to the direction from right to left as viewed from the front of the battery module 10, and the negative direction of the second direction Y is parallel to the direction from left to right as viewed from the front of the battery module 10. The positive direction of the third direction Z is parallel to the direction from bottom to top in the vertical direction, and the negative direction of the third direction Z is parallel to the direction from top to bottom in the vertical direction. The relationship between the first direction X, second direction Y, third direction Z, and the vertical direction is not limited to the above example. The relationship between the first direction X, second direction Y, third direction Z, and the vertical direction varies depending on the arrangement of the battery module 10. For example, the battery module 10 may be arranged so that the first direction X or the second direction Y is parallel to the vertical direction.

[0018] The battery module 10 will be described with reference to FIGS.

[0019] The battery module 10 includes a plurality of battery cells 100, a housing 200, a first voltage detection device 30, and a second voltage detection device 50. The first voltage detection device 30 includes a first holder 300, a plurality of first voltage detection units 410, and a plurality of first voltage detection wires 420. The second voltage detection device 50 includes a second holder 500, a plurality of second voltage detection units 610, and a plurality of second voltage detection wires 620.

[0020] The plurality of battery cells 100 are stacked in the second direction Y. Each battery cell 100 has an exterior material 102. Each battery cell 100 is provided with a positive electrode lead 110 and a negative electrode lead 120.

[0021] The exterior packaging 102 accommodates a positive electrode, a negative electrode, and a separator (not shown) together with an electrolyte (not shown). In one example, the positive electrode, the negative electrode, and the separator are stacked in the second direction Y within the exterior packaging 102. Alternatively, the positive electrode, the negative electrode, and the separator may be wound within the exterior packaging 102.

[0022] The positive electrode lead 110 is drawn out from one end of the exterior packaging material 102 on the positive side and one end on the negative side in the first direction X. The positive electrode lead 110 is electrically connected to a positive electrode inside the exterior packaging material 102. In one example, the positive electrode lead 110 is made of a metal such as aluminum.

[0023] The negative electrode lead 120 is drawn out from the other end of the exterior material 102 on the positive side and the negative side in the first direction X. The negative electrode lead 120 is electrically connected to the negative electrode in the exterior material 102. In one example, the negative electrode lead 120 is made of a metal different from the metal constituting the positive electrode lead 110, such as copper.

[0024] The plurality of battery cells 100 stacked in the second direction Y includes a plurality of cell groups 100G stacked in the second direction Y. Each cell group 100G includes a plurality of battery cells 100 connected in parallel and adjacent to each other in the second direction Y. The plurality of cell groups 100G are connected in series from the cell group 100G located at the end of the plurality of cell groups 100G on the negative side of the second direction Y to the cell group 100G located at the end of the plurality of cell groups 100G on the positive side of the second direction Y.

[0025] The cell group 100G will be described in detail with reference to Fig. 3. Fig. 3 shows the ends of the first cell group 100Ga and the second cell group 100Gb on the negative side in the first direction X, among the plurality of cell groups 100G.

[0026] The first cell group 100Ga includes a plurality of battery cells 100 connected in parallel and adjacent to each other in the second direction Y, i.e., a plurality of first battery cells 100a. The second cell group 100Gb includes a plurality of battery cells 100 connected in parallel and adjacent to each other in the second direction Y, i.e., a plurality of second battery cells 100b.

[0027] The first cell group 100Ga is provided with a plurality of positive electrode leads 110 bundled together. The second cell group 100Gb is provided with a plurality of negative electrode leads 120 bundled together. The plurality of positive electrode leads 110 of the first cell group 100Ga and the plurality of positive electrode leads 110 (not shown in FIG. 3) of the second cell group 100Gb are oriented in opposite directions to each other in the first direction X. The plurality of negative electrode leads 120 (not shown in FIG. 3) of the first cell group 100Ga and the plurality of negative electrode leads 120 of the second cell group 100Gb are oriented in opposite directions to each other in the first direction X.

[0028] At least a portion, specifically, the distal end portions, of the positive electrode leads 110 of the first cell group 100Ga and at least a portion, specifically, the distal end portions, of the negative electrode leads 120 of the second cell group 100Gb are joined to each other. The positive electrode leads 110 of the first cell group 100Ga and the negative electrode leads 120 of the second cell group 100Gb are folded back from one of the first cell group 100Ga and the second cell group 100Gb to the other of the first cell group 100Ga and the second cell group 100Gb, via at least a portion of the positive electrode leads 110 of the first cell group 100Ga and at least a portion of the negative electrode leads 120 of the second cell group 100Gb. Therefore, the first cell group 100Ga and the second cell group 100Gb can be electrically connected without the use of a conductive member such as a bus bar. In this case, the structure for connecting the first cell group 100Ga and the second cell group 100Gb in series can be simplified compared to when a conductive member such as a bus bar is used.

[0029] The lead section 150, which includes the positive electrode leads 110 of the first cell group 100Ga and the negative electrode leads 120 of the second cell group 100Gb, includes a first region 152, a second region 154, and a third region 156. The lead section 150 is folded between different battery cells 100, specifically between the first cell group 100Ga and the second cell group 100Gb. The first region 152 is a region in which the distance in the second direction Y between the positive electrode leads 110 of the first cell group 100Ga decreases with increasing distance from the first cell group 100Ga. The second region 154 is a region in which the distance in the second direction Y between the negative electrode leads 120 of the second cell group 100Gb decreases with increasing distance from the second cell group 100Gb. The third region 156 is located between the first region 152 and the second region 154, and is a region where the multiple positive electrode leads 110 bundled together of the first cell group 100Ga and the multiple negative electrode leads 120 bundled together of the second cell group 100Gb are joined to each other.

[0030] 3, of the multiple positive electrode leads 110 in the first cell group 100Ga, two positive electrode leads 110 located at both ends in the second direction Y have substantially the same length from the exterior packaging material 102 to the first bent portion 158a between the first region 152 and the third region 156. In this case, bending of one of the two positive electrode leads 110 can be suppressed compared to when the lengths of the two positive electrode leads 110 are different from each other. Note that the lengths of the two positive electrode leads 110 may be different from each other.

[0031] 3, of the plurality of negative electrode leads 120 in the second cell group 100Gb, two negative electrode leads 120 located at both ends in the second direction Y have substantially the same length from the exterior packaging material 102 to the second bent portion 158b between the second region 154 and the third region 156. In this case, bending of one of the two negative electrode leads 120 can be suppressed compared to when the lengths of the two negative electrode leads 120 are different from each other. Note that the lengths of the two negative electrode leads 120 may be different from each other.

[0032] 3, the third region 156 between the first bent portion 158a and the second bent portion 158b is flat in parallel to the second direction Y and the third direction Z. In this case, it is easier to join the first voltage detection unit 410 or the second voltage detection unit 610 (described later) to the third region 156 compared to when the third region 156 is curved or otherwise non-flat. Note that the third region 156 may also be curved or otherwise non-flat.

[0033] 1 to 3 again, the battery module 10 will be described.

[0034] As shown in FIG. 1 , in a region where the positive electrode leads 110 and the negative electrode leads 120 of each lead portion 150 located on the negative side in the first direction X of a plurality of cell groups 100G stacked in the second direction Y are joined to one another, the negative electrode leads 120 are located on the negative side in the first direction X of the plurality of positive electrode leads 110. Also, as shown in FIG. 2 , in a region where the positive electrode leads 110 and the negative electrode leads 120 of each lead portion 150 located on the positive side in the first direction X of a plurality of cell groups 100G stacked in the second direction Y are joined to one another, the positive electrode leads 110 are located on the positive side in the first direction X of the plurality of negative electrode leads 120. However, the structure of each lead portion 150 is not limited to the example shown in FIGS. 1 and 2 .

[0035] Hereinafter, as necessary, each lead portion 150 located on the negative side in the first direction X of a plurality of cell groups 100G stacked in the second direction Y will be referred to as a first lead portion 150a. Also, each lead portion 150 located on the positive side in the first direction X of a plurality of cell groups 100G stacked in the second direction Y will be referred to as a second lead portion 150b.

[0036] The housing 200 houses a plurality of cell groups 100G stacked in the second direction Y. The housing 200 has a first cover member 210, a second cover member 220, a third cover member 230, and a fourth cover member 240. The first cover member 210 covers the negative side of the plurality of cell groups 100G stacked in the second direction Y in the second direction Y. The second cover member 220 covers the positive side of the plurality of cell groups 100G stacked in the second direction Y in the second direction Y. The third cover member 230 covers the negative side of the plurality of cell groups 100G stacked in the second direction Y in the third direction Z. The fourth cover member 240 covers the positive side of the plurality of cell groups 100G stacked in the second direction Y in the third direction Z. The housing 200 also has a fifth cover member (not shown) that covers the negative side in the first direction X of the multiple cell groups 100G stacked in the second direction Y and the first holder 300. The housing 200 also has a sixth cover member (not shown) that covers the positive side in the first direction X of the multiple cell groups 100G stacked in the second direction Y and the second holder 500. In the example shown in FIG. 1, the fifth cover member has been removed. In the example shown in FIG. 2, the sixth cover member has been removed.

[0037] The first holding body 300 is attached to the negative side of the housing 200 in the first direction X. The first holding body 300 has a first mounting body 310, a second mounting body 320, and a third mounting body 330. In this embodiment, the first mounting body 310 and the second mounting body 320 extend parallel to the third direction Z. The third mounting body 330 extends parallel to the second direction Y on the side of the positive side of the third direction Z of the multiple first lead portions 150a between the first mounting body 310 and the second mounting body 320. An end of the third mounting body 330 on the negative side in the second direction Y is connected to an end of the first mounting body 310 on the positive side in the third direction Z. An end of the third mounting body 330 on the positive side in the second direction Y is connected to an end of the second mounting body 320 on the positive side in the third direction Z.

[0038] The first mounting body 310 has a first alignment portion 352 that fits into the first guide portion 252 provided on the first cover member 210. The second mounting body 320 has a second alignment portion 354 that fits into the second guide portion 254 provided on the second cover member 220. The first guide portion 252 and the second guide portion 254 each define a recess that opens upward. The first alignment portion 352 fits into the recess defined in the first guide portion 252 from above the first guide portion 252. The second alignment portion 354 fits into the recess defined in the second guide portion 254 from above the second guide portion 254. The first holding body 300 is aligned with the container 200 by the first alignment portion 352 and the second alignment portion 354 fitting into the recess defined in the first guide portion 252 and the recess defined in the second guide portion 254, respectively. The first alignment portion 352 may define a recess into which a protrusion provided on the first guide portion 252 fits. The second alignment portion 354 may define a recess into which a protrusion provided on the second guide portion 254 fits.

[0039] In this embodiment, a first bus bar 314 provided on the first mounting body 310 is electrically connected to a positive electrode lead 110 extended to the negative side in the first direction X of a cell group 100G located at an end on the negative side in the second direction Y among the multiple cell groups 100G stacked in the second direction Y. The first bus bar 314 is made of, for example, copper or aluminum. Furthermore, a second bus bar 324 provided on the second mounting body 320 is electrically connected to a negative electrode lead 120 extended to the negative side in the first direction X of a cell group 100G located at an end on the positive side in the second direction Y among the multiple cell groups 100G stacked in the second direction Y. The second bus bar 324 is made of, for example, copper or aluminum.

[0040] Specifically, the first bus bar 314 has a substantially L-shape when viewed from the first direction X. As a result, the first bus bar 314 includes a portion that extends in the third direction Z and is electrically connected to the positive electrode lead 110, and a portion that extends in the positive direction of the second direction Y from the upper end of the portion that extends in the third direction Z. The upper surface of the portion of the first bus bar 314 that extends in the second direction Y is a surface that is substantially perpendicular to the third direction Z. The portion of the first bus bar 314 that extends in the second direction Y serves as a terminal for connecting to an external device. Therefore, when the first bus bar 314 has a portion that extends in the second direction Y, it is easier to connect the first bus bar 314 to an external device than when the first bus bar 314 does not have a portion that extends in the second direction Y.

[0041] Similarly, the second bus bar 324 is substantially L-shaped when viewed from the first direction X. As a result, the second bus bar 324 includes a portion that extends in the third direction Z and is electrically connected to the negative electrode lead 120, and a portion that extends in the negative direction of the second direction Y from the upper end of the portion that extends in the third direction Z. The upper surface of the portion of the second bus bar 324 that extends in the second direction Y is a surface that is substantially perpendicular to the third direction Z. The portion of the second bus bar 324 that extends in the second direction Y serves as a terminal for connecting to an external device. Therefore, when the second bus bar 324 has a portion that extends in the second direction Y, it is easier to connect the second bus bar 324 to an external device than when the second bus bar 324 does not have a portion that extends in the second direction Y.

[0042] The tip of the positive electrode lead 110 drawn to the negative side in the first direction X of the cell group 100G located at the end of the cell group 100G on the negative side in the second direction Y among the multiple cell groups 100G extends in the negative direction in the first direction X without being bent in a direction approximately perpendicular to the first direction X. The tip of the positive electrode lead 110 is joined to a surface of the first bus bar 314 on the negative side in the second direction Y of a portion extending in the third direction Z. However, the tip of the positive electrode lead 110 may also be joined to a surface of the first bus bar 314 on the positive side in the second direction Y of the portion extending in the third direction Z. Similarly, the tip of the negative electrode lead 120 drawn to the negative side in the first direction X of the cell group 100G located at the end of the cell group 100G on the positive side in the second direction Y extends in the negative direction in the first direction X without being bent in a direction approximately perpendicular to the first direction X. Furthermore, the tip of the negative electrode lead 120 is joined to a surface of the second bus bar 324 on the positive side in the second direction Y of a portion extending in the third direction Z. However, the tip of the negative electrode lead 120 may also be joined to a surface of the second bus bar 324 on the negative side in the second direction Y of a portion extending in the third direction Z. This configuration is preferable because it increases the volumetric energy density of the portion accommodating the plurality of cell groups 100G, i.e., the volumetric energy density of the battery module 10, without increasing the length dimension of the plurality of cell groups 100G in the second direction Y. Note that, depending on the number of stacked cell groups 100G, the orientation of the tip of the positive electrode lead 110 and the tip of the negative electrode lead 120 in the first direction X may be reversed.

[0043] Depending on the total number of the cell groups 100G stacked in the second direction Y, the negative electrode lead 120 of the cell group 100G located at the end of the cell group 100G on the positive side in the second direction Y among the cell groups 100G stacked in the second direction Y may be drawn out to the positive side in the first direction X. In this case, the second mounting body 320 may not be provided. Also, in this case, the negative electrode lead 120 drawn out to the positive side in the first direction X of the cell group 100G located at the end of the cell group 100G on the positive side in the second direction Y among the cell groups 100G stacked in the second direction Y may be electrically connected to a second bus bar 324 provided at a corner of the accommodating body 200 on the positive side in the first direction X and on the positive side in the second direction Y.

[0044] The third attachment body 330 has a second connection portion 356 that mechanically connects to the first connection portion 256 provided on the fourth cover member 240. In this embodiment, the second connection portion 356 has a protrusion that fits into a recess defined in the first connection portion 256. The protrusion provided on the second connection portion 356 is mechanically connected to the recess defined in the first connection portion 256 by, for example, snap fitting. In this manner, the first holding body 300 is attached to the housing 200. Furthermore, by inserting a positioning pin 358 attached to the third attachment body 330 into an attachment hole 258 provided in the fourth cover member 240, the first holding body 300 can be more firmly fixed to the housing 200. Note that the second connection portion 356 may define a recess into which the protrusion provided on the first connection portion 256 fits.

[0045] Each of the multiple first voltage detection units 410 is provided for each of the multiple first lead portions 150a. The first voltage detection device 30 detects the voltages of the multiple first lead portions 150a using the multiple first voltage detection units 410. The first voltage detection units 410 are chip-shaped. Each first voltage detection unit 410 is electrically connected to at least one of the multiple positive electrode leads 110 and the multiple negative electrode leads 120 in each first lead portion 150a. Each first voltage detection unit 410 is joined to the multiple positive electrode leads 110 and the multiple negative electrode leads 120 in the first lead portion 150a by, for example, laser welding.

[0046] The first voltage detection unit 410 is held by the first holding body 300. Specifically, the first holding body 300 has a first holding portion 302 provided on the third mounting body 330. The first holding portion 302 holds a protrusion provided on the end of the first voltage detection unit 410 in the third direction Z. Therefore, when the first holding body 300 is attached to the housing 200, the first voltage detection unit 410 can be positioned appropriately with respect to the first lead portion 150a. Furthermore, when the first holding body 300 is attached to the housing 200, the first voltage detection unit 410 is located on the opposite side of the first lead portion 150a from the side where the cell group 100G is located. In this case, the first voltage detection unit 410 can be laser-welded to the first lead portion 150a by irradiating the first voltage detection unit 410 with a laser from the side opposite the side where the first lead portion 150a is located. Therefore, for example, it is easier to weld the first voltage detection unit 410 to the first lead portion 150a compared to when the first voltage detection unit 410 is located between the first lead portion 150a and the cell group 100G.

[0047] The first voltage detection unit 410 is provided on a flat portion of the first lead portion 150a that is parallel to the second direction Y and the third direction Z. In this case, it is easier to join the first voltage detection unit 410 to the first lead portion 150a compared to when the first voltage detection unit 410 is provided on a non-flat portion such as a bent portion of the first lead portion 150a or when the entire first lead portion 150a is curved.

[0048] The first voltage detection unit 410 may be movable in at least one of a direction toward the first lead portion 150a and a direction away from the first lead portion 150a. In this case, by moving the first voltage detection unit 410 in the first direction X, the first voltage detection unit 410 can be positioned at an appropriate position in the first direction X with respect to the first lead portion 150a.

[0049] In one example, the first voltage detection unit 410 includes, for example, the same material as the material included in the portion of the first lead portion 150a that contacts the first voltage detection unit 410, i.e., the negative electrode lead 120. In this example, the material included in the first voltage detection unit 410 is easier to bond to the negative electrode lead 120 compared to when the material included in the first voltage detection unit 410 is different from the material included in the negative electrode lead 120.

[0050] The first voltage detection line 420 is, for example, a wire harness. The first voltage detection line 420 is electrically connected to the first voltage detection unit 410. The first voltage detection line 420 is supported by the first holding body 300. Specifically, the first holding body 300 has a second holding portion 304 provided on the third attachment body 330. The second holding portion 304 defines a groove for routing the first voltage detection line 420 along the second direction Y. The second holding portion 304 holds the first voltage detection line 420 by means of this groove. Therefore, the first voltage detection line 420 can be routed along the third attachment body 330 without being physically floating. Therefore, the first voltage detection line 420 can be routed more stably than when the first voltage detection line 420 is physically floating. Note that the first voltage detection line 420 may be in a physically floating state.

[0051] In this embodiment, the first holding body 300 holds the first voltage detection unit 410 and the first voltage detection wire 420. As a result, the first voltage detection unit 410 and the first voltage detection wire 420 are integrated. Furthermore, by attaching the first holding body 300 to the housing 200, the first voltage detection unit 410 can be positioned appropriately with respect to the first lead portion 150a. In this case, it is easier to connect the first voltage detection unit 410 to each of the first lead portions 150a than when lead wires are connected to each of the first lead portions 150a. Therefore, it is easier to detect the voltage of the first lead portion 150a than when lead wires are connected to each of the first lead portions 150a.

[0052] The second holding body 500 is attached to the positive side of the housing 200 in the first direction X. At least a portion of the second holding body 500 extends laterally on the positive side of the third direction Z of the plurality of second lead portions 150b. Similar to the first holding body 300, the second holding body 500 is mechanically connected to the housing 200 by, for example, a snap fit.

[0053] Each of the multiple second voltage detection units 610 is provided for each of the multiple second lead portions 150b. The second voltage detection device 50 detects the voltages of the multiple second lead portions 150b using the multiple second voltage detection units 610. The second voltage detection units 610 are chip-shaped. Each second voltage detection unit 610 is electrically connected to at least one of the multiple positive electrode leads 110 and the multiple negative electrode leads 120 in each second lead portion 150b. Each second voltage detection unit 610 is joined to the multiple positive electrode leads 110 and the multiple negative electrode leads 120 in the second lead portion 150b by, for example, laser welding.

[0054] The second voltage detection unit 610 is held by the second holder 500. Specifically, the second holder 500 has a third holder 502. The third holder 502 holds a protrusion provided at the end of the second voltage detection unit 610 in the third direction Z. Therefore, when the second holder 500 is attached to the housing 200, the second voltage detection unit 610 can be positioned appropriately with respect to the second lead portion 150b. Furthermore, when the second holder 500 is attached to the housing 200, the second voltage detection unit 610 is located on the opposite side of the second lead portion 150b from the side where the cell group 100G is located. In this case, the second voltage detection unit 610 can be laser-welded to the second lead portion 150b by irradiating the second voltage detection unit 610 with a laser from the side opposite the side where the second lead portion 150b is located. Therefore, for example, it is easier to weld the second voltage detection unit 610 to the second lead portion 150b compared to when the second voltage detection unit 610 is located between the second lead portion 150b and the cell group 100G.

[0055] The second voltage detection unit 610 is provided on a flat portion of the second lead portion 150b that is parallel to the second direction Y and the third direction Z. In this case, it is easier to join the second voltage detection unit 610 to the second lead portion 150b compared to when the second voltage detection unit 610 is provided on a non-flat portion such as a bent portion of the second lead portion 150b or when the entire second lead portion 150b is curved.

[0056] The second voltage detection unit 610 may be movable in at least one of a direction toward the second lead portion 150b and a direction away from the second lead portion 150b. In this case, by moving the second voltage detection unit 610 in the first direction X, the second voltage detection unit 610 can be positioned appropriately in the first direction X with respect to the second lead portion 150b.

[0057] In one example, the second voltage detection unit 610 includes, for example, the same material as the material included in the portion of the second lead portion 150b that contacts the second voltage detection unit 610, i.e., the positive electrode lead 110. In this example, the material included in the second voltage detection unit 610 is easier to bond to the positive electrode lead 110 compared to when the material included in the second voltage detection unit 610 is different from the material included in the positive electrode lead 110.

[0058] The material included in the second voltage detection unit 610 may be the same as the material included in the first voltage detection unit 410. In this case, it is not necessary to use different materials for the first voltage detection unit 410 and the second voltage detection unit 610. On the other hand, when the material included in the second voltage detection unit 610 is the same as the material included in the first voltage detection unit 410, the material included in the second voltage detection unit 610 may be different from the material included in the portion of the second lead portion 150b that contacts the second voltage detection unit 610, i.e., the material included in the positive electrode lead 110. In this case, if it is difficult to laser-weld the second voltage detection unit 610 to the positive electrode lead 110 from the positive side of the first direction X, the positive electrode leads 110 may be cut out at a portion of the second lead portion 150b that overlaps with the second voltage detection unit 610 in the first direction X, and the second voltage detection unit 610 may be laser-welded to the negative electrode lead 120.

[0059] When the material contained in the second voltage detection unit 610 is the same as the material contained in the first voltage detection unit 410, in a region of each second lead portion 150b where the multiple positive electrode leads 110 and the multiple negative electrode leads 120 are joined to each other, the multiple negative electrode leads 120 may be located closer to the positive side in the first direction X than the multiple positive electrode leads 110. In this case, the material contained in the second voltage detection unit 610 and the portion of the second lead portion 150b that contacts the second voltage detection unit 610, i.e., the material contained in the negative electrode lead 120, can be the same. Therefore, compared to a case where the multiple positive electrode leads 110 are located closer to the positive side in the first direction X than the multiple negative electrode leads 120 in a region of each second lead portion 150b where the multiple positive electrode leads 110 and the multiple negative electrode leads 120 are joined to each other, it is not necessary to cut out the multiple positive electrode leads 110, and it is therefore easier to laser-weld the second voltage detection unit 610 to the negative electrode lead 120 from the positive side in the first direction X.

[0060] The second voltage detection line 620 is, for example, a wire harness. The second voltage detection line 620 is electrically connected to the second voltage detection unit 610. The second voltage detection line 620 is held by the second holder 500. Specifically, the second holder 500 has a fourth holder 504. The fourth holder 504 defines a groove for routing the second voltage detection line 620 along the second direction Y. The fourth holder 504 holds the second voltage detection line 620 by means of this groove. Therefore, the second voltage detection line 620 can be routed along the second holder 500 without being physically floating. Therefore, the second voltage detection line 620 can be routed more stably than when the second voltage detection line 620 is physically floating. Note that the second voltage detection line 620 may be in a physically floating state.

[0061] In this embodiment, the second holding body 500 holds the second voltage detection unit 610 and the second voltage detection wire 620. As a result, the second voltage detection unit 610 and the second voltage detection wire 620 are integrated. Furthermore, by attaching the second holding body 500 to the housing 200, the second voltage detection unit 610 can be positioned appropriately with respect to the second lead portion 150b. In this case, it is easier to connect the second voltage detection unit 610 to each of the second lead portions 150b than when lead wires are connected to each of the second lead portions 150b. Therefore, it is easier to detect the voltage at the second lead portion 150b than when lead wires are connected to each of the second lead portions 150b.

[0062] 4 to 8 are diagrams illustrating a first example of a method for manufacturing the battery module 10 according to the embodiment. The battery module 10 is manufactured as follows.

[0063] In Figures 4 to 8, the positive direction of the second direction Y is parallel to the vertical direction from bottom to top. The negative direction of the second direction Y is parallel to the vertical direction from top to bottom. The first direction X and the third direction Z are parallel to the horizontal direction perpendicular to the vertical direction. The same applies to Figures 9 and 10 described below.

[0064] First, as shown in FIG. 4, a cell group 100G including a plurality of battery cells 100 is formed. Specifically, a first tape 132 is provided on the negative side of the first direction X on the upper surface of the lower of the two battery cells 100. A second tape 134 is provided on the positive side of the first direction X on the upper surface of the lower of the two battery cells 100. A compression pad 136 is provided on the upper surface of the lower of the two battery cells 100, with the first tape 132 interposed therebetween. Next, another battery cell 100 is provided on the lower of the two battery cells 100, with the second tape 134 and compression pad 136 interposed therebetween. In this manner, the cell group 100G is formed. Note that the method for forming the cell group 100G is not limited to the example shown in FIG. 4.

[0065] Next, as shown in FIG. 5, the multiple cell groups 100G are aligned in a line along the first direction X so that the thickness direction of each cell group 100G, i.e., the second direction Y, is parallel to the vertical direction. The multiple positive electrode leads 110 of each cell group 100G are oriented toward the positive side of the first direction X. The multiple negative electrode leads 120 of each cell group 100G are oriented toward the negative side of the first direction X. Furthermore, between adjacent cell groups 100G, the multiple positive electrode leads 110 and the multiple negative electrode leads 120 overlap in the second direction Y so that the multiple positive electrode leads 110 are located above the multiple negative electrode leads 120. In the example shown in FIG. 5, the first cell group 100Ga, the second cell group 100Gb, the third cell group 100Gc, and the fourth cell group 100Gd are aligned in this order from the positive to the negative direction of the first direction X. Furthermore, the multiple cell groups 100G are moved from the negative direction to the positive direction of the first direction X by a moving mechanism such as a conveyor.

[0066] Next, a laser is applied from above the multiple positive electrode leads 110 and the multiple negative electrode leads 120 between adjacent cell groups 100G to laser-weld at least a portion of the multiple positive electrode leads 110 and at least a portion of the multiple negative electrode leads 120. In this manner, at least a portion of the multiple positive electrode leads 110 and at least a portion of the multiple negative electrode leads 120 are joined to each other. This forms a lead portion 150 including the multiple positive electrode leads 110 and the multiple negative electrode leads 120 joined to each other. When laser welding is used, the time required to join the multiple positive electrode leads 110 and the multiple negative electrode leads 120 can be shortened compared to when other methods such as ultrasonic welding are used. Note that the multiple positive electrode leads 110 and the multiple negative electrode leads 120 may be joined to each other by a method other than laser welding, for example, ultrasonic welding.

[0067] In one example, laser welding involves irradiating the laser while wobbling. When the laser is wobbled, it becomes easier to finely adjust the size of the intermetallic compound at the interface between the different materials between the positive electrode lead 110 and the negative electrode lead 120, compared to when the laser is irradiated linearly without wobbling, thereby enabling the positive electrode lead 110 and the negative electrode lead 120 to be bonded with high strength. The laser may also be irradiated linearly, for example, without wobbling. Furthermore, when the positive electrode lead 110 and the negative electrode lead 120 are welded before stacking multiple cell groups 100G or before bending the lead portion 150, it becomes easier to adjust the size of the gap between the positive electrode lead 110 and the negative electrode lead 120 when they are overlapped before welding, compared to when the positive electrode lead 110 and the negative electrode lead 120 are welded after stacking multiple cell groups 100G or after bending the lead portion 150. The positive electrode lead 110 and the negative electrode lead 120 may be welded after stacking a plurality of cell groups 100G or after bending the lead portion 150.

[0068] 6, the lead portion 150 between the second cell group 100Gb and the third cell group 100Gc is moved upward relative to the first cell group 100Ga and the fourth cell group 100Gd. Also, the lead portion 150 between the second cell group 100Gb and the third cell group 100Gc is bent so as to fold back from one of the second cell group 100Gb and the third cell group 100Gc to the other of the second cell group 100Gb and the third cell group 100Gc.

[0069] 7, the lead portion 150 between the second cell group 100Gb and the third cell group 100Gc is moved in the positive direction of the first direction X. The lead portion 150 between the first cell group 100Ga and the second cell group 100Gb is also bent so as to fold back from one of the first cell group 100Ga and the second cell group 100Gb to the other of the first cell group 100Ga and the second cell group 100Gb. In this way, the first cell group 100Ga, the second cell group 100Gb, and the third cell group 100Gc are stacked in order from the negative to the positive direction of the second direction Y.

[0070] 6 and 7, the lead portion 150 between adjacent cell groups 100G can be bent using, for example, a clamp. In this case, by appropriately adjusting the clamp, the third region 156 of the lead portion 150 can be flattened as shown in FIG.

[0071] By performing the steps shown in FIGS. 5 to 7 an appropriate number of times, a predetermined number of cell groups 100G are stacked from the negative direction to the positive direction of the second direction Y.

[0072] 8, a first cover member 210 is provided on the negative side of the second direction Y of the multiple cell groups 100G stacked in the second direction Y, and a second cover member 220 is provided on the positive side of the second direction Y of the multiple cell groups 100G stacked in the second direction Y. Next, the multiple cell groups 100G stacked in the second direction Y are compressed in the second direction Y by the first cover member 210 and the second cover member 220. This adjusts the length in the second direction Y of the multiple cell groups 100G stacked in the second direction Y to a desired length.

[0073] Next, a third cover member 230 is provided on the negative side in the third direction Z of the multiple cell groups 100G stacked in the second direction Y. A fourth cover member 240 is provided on the positive side in the third direction Z of the multiple cell groups 100G stacked in the second direction Y. Next, a first holder 300, to which multiple first voltage detection units 410 and multiple first voltage detection wires 420 are attached, is attached to the housing 200. A second holder 500, to which multiple second voltage detection units 610 and multiple second voltage detection wires 620 are attached, is attached to the housing 200. Next, each first voltage detection unit 410 is joined to each first lead portion 150a by, for example, laser welding. Each second voltage detection unit 610 is joined to each second lead portion 150b by, for example, laser welding. Next, a fifth cover member (not shown) is provided on the negative side in the first direction X of the multiple cell groups 100G stacked in the second direction Y. In addition, a sixth cover member (not shown) is provided on the positive side in the first direction X of the plurality of cell groups 100G stacked in the second direction Y.

[0074] In this manner, the battery module 10 is manufactured.

[0075] FIG. 9 is a diagram for explaining a first example of a method for stacking a plurality of cell groups 100G.

[0076] In the example shown in FIG. 9, a first cell group 100Ga, a second cell group 100Gb, and a third cell group 100Gc are stacked using a first jig 910. The first jig 910 has a rotating portion 912, a first engaging portion 914, and a second engaging portion 916. The first engaging portion 914 is located on the positive side of the first direction X relative to the rotating portion 912. The second engaging portion 916 is rotatable around the rotating portion 912, with the distance between the rotating portion 912 and the first engaging portion 914 as its radius. The second engaging portion 916 is also engageable with the first engaging portion 914 from above the first engaging portion 914.

[0077] The first cell group 100Ga is fixed between the rotating portion 912 and the first engaging portion 914. The second cell group 100Gb is fixed between the rotating portion 912 and the second engaging portion 916. In this state, by rotating the second engaging portion 916 relative to the rotating portion 912, the lead portions 150 between the first cell group 100Ga and the second cell group 100Gb are folded back, and the lead portions 150 between the second cell group 100Gb and the third cell group 100Gc are also folded back. In this way, the first cell group 100Ga, the second cell group 100Gb, and the third cell group 100Gc are stacked in the second direction Y.

[0078] When the first jig 910 is used, it is easier to stack the multiple cell groups 100G while aligning them in the first direction X, compared to when the first jig 910 is not used.

[0079] FIG. 10 is a diagram for explaining a second example of a method for stacking a plurality of cell groups 100G.

[0080] In the example shown in FIG. 10 , a second jig 920 is used to stack multiple cell groups 100G in the second direction Y. The second jig 920 has a first guide member 922 and a second guide member 924. The first guide member 922 is provided on the negative side of the multiple cell groups 100G in the third direction Z. The first guide member 922 extends parallel to the second direction Y. The second guide member 924 is provided on the positive side of the multiple cell groups 100G in the third direction Z. The second guide member 924 extends parallel to the second direction Y. Therefore, the multiple cell groups 100G are stacked between the first guide member 922 and the second guide member 924 along the first guide member 922 and the second guide member 924.

[0081] When the second jig 920 is used, it is easier to stack the multiple cell groups 100G while aligning them in the third direction Z, compared to when the second jig 920 is not used.

[0082] 11 to 13 are diagrams illustrating a second example of the method for manufacturing the battery module 10 according to the embodiment. The battery module 10 is manufactured as follows.

[0083] 11 to 13, the positive direction of the third direction Z is parallel to the vertical direction from bottom to top. The negative direction of the third direction Z is parallel to the vertical direction from top to bottom. The first direction X and the second direction Y are parallel to the horizontal direction that is perpendicular to the vertical direction.

[0084] First, as shown in FIG. 11, the first cell group 100Ga, the second cell group 100Gb, the third cell group 100Gc, and the fourth cell group 100Gd are aligned in a row along the first direction X so that the short side direction of each cell group 100G, i.e., the third direction Z, is parallel to the vertical direction.

[0085] 12, the lead portion 150 between the first cell group 100Ga and the second cell group 100Gb is folded back, and the first cell group 100Ga is rotated toward the positive side of the second cell group 100Gb in the second direction Y. This causes the first cell group 100Ga and the second cell group 100Gb to be stacked in the second direction Y.

[0086] 13, the lead portion 150 between the second cell group 100Gb and the third cell group 100Gc is folded back, and the first cell group 100Ga and the second cell group 100Gb are rotated toward the negative side of the third cell group 100Gc in the second direction Y. This causes the first cell group 100Ga, the second cell group 100Gb, and the third cell group 100Gc to be stacked in the second direction Y.

[0087] In the example shown in FIGS. 11 to 13, the cell groups 100G can be stacked in the second direction Y while aligning the cell groups 100G in the third direction Z due to the weight of the cell groups 100G.

[0088] 11 to 13, four cell groups 100G are pre-bonded in a row along the first direction X at the stage shown in FIG. 11. However, the number of pre-bonded cell groups 100G is not limited to this and may be two, three, or more. For example, the first cell group 100Ga and the second cell group 100Gb may be pre-bonded in a row along the first direction X, the lead portion 150 between the first cell group 100Ga and the second cell group 100Gb may be folded back to stack the first cell group 100Ga and the second cell group 100Gb in the second direction Y, and then the third cell group 100Gc may be bonded to the first cell group 100Ga or the second cell group 100Gb from the positive side of the first direction X or the negative side of the first direction X. Depending on whether the folded lead portion 150 between the first cell group 100Ga and the second cell group 100Gb stacked in the second direction Y is positioned on the positive side of the first direction X or the negative side of the first direction X, the third cell group 100Gc stacked in the second direction Y next to the first cell group 100Ga and the second cell group 100Gb stacked in the second direction Y can be positioned either in the positive side of the first direction X or in the negative side of the first direction X of the first cell group 100Ga and the second cell group 100Gb stacked in the second direction Y. Hereinafter, the cell group 100G stacked in the second direction Y will be referred to as a stacked cell group 100G as necessary.

[0089] From the above, depending on whether the next cell group 100G to be stacked on the stacked cell group 100G is positioned on the positive side of the first direction X or the negative side of the first direction X of the stacked cell group 100G, the next cell group 100G to be stacked on the stacked cell group 100G can always be joined to the stacked cell group 100G from either the positive side of the first direction X or the negative side of the first direction X of the stacked cell group 100G, and these cell groups 100G can be stacked in the second direction Y. Alternatively, depending on whether the next cell group 100G to be stacked on the stacked cell group 100G is positioned on the positive side of the first direction X or the negative side of the first direction X of the stacked cell group 100G in the second direction Y, each time the next cell group 100G is stacked on the stacked cell group 100G, the next cell group 100G can be joined to the stacked cell group 100G alternately from the positive side of the first direction X of the stacked cell group 100G and the negative side of the first direction X of the stacked cell group 100G, and these cell groups 100G can be stacked in the second direction Y.

[0090] 14 is a front perspective view of a portion of a battery module 10A according to Modification 1. The battery module 10A according to Modification 1 is similar to the battery module 10 according to the embodiment, except for the following points.

[0091] The first holding portion 302A of the first voltage detecting device 30A has a first protrusion 302Aa provided on the negative side of the first holding body 300A in the first direction X. The first protrusion 302Aa penetrates the first voltage detection portion 410A in the first direction X. The first protrusion 302Aa is, for example, a pin. The first voltage detection portion 410A is movable in the first direction X along the first protrusion 302Aa. This allows the first voltage detection portion 410A to move in at least one direction toward or away from the first lead portion 150a. Therefore, when joining the first voltage detection portion 410A to the first lead portion 150a, the first voltage detection portion 410A can be moved to an appropriate position in the first direction X relative to the first lead portion 150a.

[0092] The width of the end of the first convex portion 302Aa on the negative side in the first direction X is wider than the width of the through hole provided in the first voltage detection portion 410A at the portion through which the first convex portion 302Aa passes, thereby preventing the first voltage detection portion 410A from slipping out of the first convex portion 302Aa.

[0093] A first voltage detection line 420A is connected to the end of the first voltage detection unit 410A on the positive side in the third direction Z. The first voltage detection line 420A is held by a first holding body 300A.

[0094] Fig. 15 is an exploded perspective view of the first voltage detecting device 30B according to Modification 2. Fig. 16 is a front perspective view of a portion of the first voltage detecting device 30B according to Modification 2. The first voltage detecting device 30B according to Modification 2 is similar to the first voltage detecting device 30 according to the embodiment, except for the following points.

[0095] The first voltage detecting device 30B includes a first holding body 300B, a plurality of first voltage detecting parts 410B, and a plurality of first voltage detecting lines 420B. The first holding body 300B has a first mounting body 310B, a second mounting body 320B, and a third mounting body 330B.

[0096] The first mounting body 310B includes a first protector 312B, a first bus bar 314B, a first screw 316B, and a first protector cover 318B. A first voltage detection line 420B is attached to the first bus bar 314B by a first screw 316B. At least a portion of the first screw 316B may reach the first protector 312B so that both the first screw 316B and the first bus bar 314B are attached to the first protector 312B. The first protector cover 318B covers the surface of the first bus bar 314B facing the positive side in the third direction Z. The first protector cover 318B may cover not only the surface of the first bus bar 314B facing the positive side in the third direction Z, but also at least a portion of the first bus bar 314B facing the negative side in the second direction Y or at least a portion of the first bus bar 314B facing the negative side in the first direction X.

[0097] The second mounting body 320B includes a second protector 322B, a second bus bar 324B, a second screw 326B, and a second protector cover 328B. The first voltage detection line 420B is attached to the second bus bar 324B by the second screw 326B. At least a portion of the second screw 326B may reach the second protector 322B so that both the second screw 326B and the second bus bar 324B are attached to the second protector 322B. The second protector cover 328B covers the surface of the second bus bar 324B facing the positive side in the third direction Z. The second protector cover 328B may cover not only the surface of the second bus bar 324B facing the positive side in the third direction Z, but also at least a portion of the second bus bar 324B facing the positive side in the second direction Y or at least a portion of the second bus bar 324B facing the negative side in the first direction X.

[0098] The third mounting body 330B can be separated into multiple extension bodies 332B along the second direction Y. Adjacent extension bodies 332B are mechanically connected by connectors 334B. That is, the third mounting body 330B has multiple portions connected to each other, i.e., multiple extension bodies 332B. Each of the multiple extension bodies 332B has at least one, for example, multiple first holding portions 302B. In this case, when the first voltage detecting device 30B is mounted to the housing 200 as shown in FIG. 1 , the length of the first voltage detecting device 30B in the second direction Y can be adjusted by adjusting the number of extension bodies 332B included in the third mounting body 330B in accordance with the total number of multiple lead portions 150 aligned in the first direction X.

[0099] The third mounting body 330B is provided with a plurality of wall portions 340B corresponding to the plurality of first voltage detection units 410B. When the first voltage detection device 30B is mounted to the housing 200 as shown in FIG. 1, the wall portions 340B are located on the side opposite to the side where the first voltage detection unit 410B is located with respect to the first lead portion 150a. By arranging the wall portions 340B in this manner, when laser welding the first lead portion 150a and the first voltage detection unit 410B by irradiating a laser from the side opposite to the side where the wall portions 340B are located with respect to the first voltage detection unit 410B, even if the laser penetrates the first lead portion 150a, the laser is irradiated onto the wall portions 340B, thereby preventing the laser from being irradiated onto the cell group 100G. Furthermore, when the first voltage detection device 30B is assembled, transported, etc. with the first voltage detection unit 410B held by the first holding unit 302B, it is possible to prevent damage to the first voltage detection unit 410B due to jigs, equipment, transport containers, packaging materials, etc. coming into contact with the first voltage detection unit 410B from the side opposite to the side where the first voltage detection unit 410B is located relative to the wall 340B.

[0100] The first holding portion 302B provided on the third attachment body 330B includes a first protrusion 302Ba and two second protrusions 302Bb.

[0101] Similar to the first convex portion 302Aa according to the first modification, the first convex portion 302Ba according to the second modification penetrates the first voltage detection unit 410B in the first direction X. Therefore, similar to the first voltage detection unit 410A according to the first modification, the first voltage detection unit 410B according to the second modification is movable in the first direction X along the first convex portion 302Ba.

[0102] The two second protrusions 302Bb are located on both sides of the first voltage detection unit 410B in the second direction Y. Note that the second protrusions 302Bb do not have to be provided on both sides of the first voltage detection unit 410B in the second direction Y, and may be located on only one of the positive and negative sides of the first voltage detection unit 410B in the second direction Y. By providing the second protrusions 302Bb on at least one of the both sides of the first voltage detection unit 410B in the second direction Y, it is possible to align the first voltage detection unit 410B in the second direction Y and prevent the first voltage detection unit 410B from rotating.

[0103] A first voltage detection line 420B is connected to the end of the first voltage detection unit 410B on the positive side in the third direction Z. The first voltage detection line 420B is held by a groove defined by a second holding portion 304B provided in a third mounting body 330B.

[0104] 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.

[0105] For example, in the embodiment, two battery cells 100 connected in parallel are connected in series to two other battery cells 100 connected in parallel. However, three or more battery cells 100 connected in parallel may be connected in series to three or more other battery cells 100 connected in parallel. Furthermore, the number of the plurality of battery cells 100 and the number of other battery cells 100 connected in series may be different from each other, such as connecting two battery cells 100 connected in parallel in series to three other battery cells 100 connected in parallel.

[0106] Furthermore, the stacking method of the multiple cell groups 100G is not limited to the stacking method of the embodiment, as long as the multiple cell groups 100G are stacked in the second direction Y so that the lead portions 150 folded between adjacent cell groups 100G in the second direction Y are arranged alternately in the positive direction of the first direction X and the negative direction of the first direction X.

[0107] In addition, in the embodiment, the first voltage detection device 30 and the second voltage detection device 50 are used to detect the voltage of the lead section 150 including a plurality of positive electrode leads 110 and a plurality of negative electrode leads 120. However, the first voltage detection device 30 and the second voltage detection device 50 can also be used to detect the voltage of the lead section 150 including a single positive electrode lead 110 and a single negative electrode lead 120.

[0108] Below, examples of reference forms are given. 1. A voltage detection device that detects the voltage of lead sections folded back between different battery cells, A voltage detection unit; a voltage detection line connected to the voltage detection unit; a holder that holds the voltage detection unit and the voltage detection line; A voltage detection device comprising: 2. In the voltage detection device described in 1., The voltage detection device, wherein the voltage detection unit is movable in at least one of a direction toward the lead portion and a direction away from the lead portion. 3. In the voltage detection device according to 1. or 2., The holding body has a wall portion located on the opposite side of the lead portion from the side on which the voltage detection portion is located. 4. In the voltage detection device according to any one of 1. to 3., The holder has a plurality of portions connected to each other, A voltage detection device, wherein each of the plurality of parts has a holding portion that holds at least one of the voltage detection units. 5. In the voltage detection device according to any one of 1. to 4., A voltage detection device, wherein the voltage detection portion includes the same material as that included in the portion of the lead portion that contacts the voltage detection portion. 6. In the voltage detection device according to any one of 1. to 5., The holder has a connection portion that mechanically connects to a housing that houses the battery cell. 7. A plurality of battery cells; a voltage detection device that detects the voltage of lead portions folded back between different battery cells; Equipped with The voltage detection device is A voltage detection unit; a voltage detection line connected to the voltage detection unit; a holder that holds the voltage detection unit and the voltage detection line; A battery module having: 8. The battery module according to 7., Further, a housing that houses the plurality of battery cells is provided. The holder has a connection portion for mechanically connecting to the housing.

[0109] This application claims priority based on Japanese Patent Application No. 2021-004740, filed on January 15, 2021, the disclosure of which is incorporated herein in its entirety. [Explanation of symbols]

[0110] 10 Battery Module 10A battery module 30 First voltage detection device 30A First Voltage Detector 30B First voltage detection device 50 Second voltage detection device 100 battery cells 100G cell group 100Ga 1st cell group 100Gb Second Cell Group 100Gc 3rd cell group 100Gd 4th cell group 100a 1st battery cell 100b Second battery cell 102 Exterior materials 110 Positive lead 120 Negative lead 132 Tape 1 134 Tape 2 136 Compression Pad 150 Lead section 150a First lead part 150b Second lead part 152 1st area 154 Second area 156 Third area 158a 1st bend 158b 2nd bend 200 units 210 first cover member 220 second cover member 230 Third cover member 240 Fourth cover member 252 1st Information Department 254 2nd Information Department 256 First Connection 258 Mounting hole 300 First holding body 300A 1st holding body 300B 1st holding body 302 1st holding part 302A 1st holding part 302Aa First convex part 302B 1st holding part 302Ba 1st convex part 302Bb Second convex part 304 Second holding part 304B 2nd holding part 310 First mounting body 310B First mounting body 312B First Protector 314 No. 1 bus bar 314B 1st bus bar 316B 1st bis 318B 1st protector cover 320 Second mounting body 320B Second mounting body 322B Secondary Protector 324 Second bus bar 324B 2nd bus bar 326B 2nd Visor 328B Second protector cover 330 Third mounting body 330B Third mounting body 332B Stretched body 334B Connector 340B wall section 352 First alignment section 354 Second alignment section 356 Second Connection 358 Locating Pin 410 First voltage detection unit 410A First voltage detection unit 410B First voltage detection unit 420 First voltage detection line 420A First voltage detection wire 420B 1st voltage detection line 500 Second holding body 502 Third holding part 504 4th holding part 610 Second voltage detection unit 620 Second voltage detection line 910 First jig 912 Rotating part 914 First engagement part 916 Second engagement part 920 Second jig 922 1st guide member 924 2nd guide member X 1st direction Y Second direction Z 3rd direction

Claims

1. A plurality of battery cells; a voltage detection device located on one side of the plurality of battery cells; Equipped with The voltage detection device is a first voltage detection unit that detects a voltage of a first lead of at least one first battery cell included in the plurality of battery cells; a first voltage detection line electrically connected to the first voltage detection unit; a second voltage detection unit that detects a voltage of a second lead of at least one second battery cell included in the plurality of battery cells; a second voltage detection line electrically connected to the second voltage detection unit; a holder including a first extension body that holds the first voltage detection unit and the first voltage detection line, and a second extension body that holds the second voltage detection unit and the second voltage detection line; and The first voltage detection line is held by both the first extension body and the second extension body.

2. The battery module according to claim 1 , wherein the second extension body has a groove that accommodates both the first voltage detection wire and the second voltage detection wire.

3. The battery module according to claim 1 , wherein the first elongated body and the second elongated body are mechanically connected by a connector.

4. the first elongated body has a convex portion, 4. The battery module according to claim 1, wherein the first voltage detection portion is movable along the protrusion.

5. the protrusion includes a portion that penetrates a through hole provided in the first voltage detection unit, and a tip portion that is located closer to a tip of the protrusion than the portion, The battery module according to claim 4 , wherein the width of the tip of the protrusion is wider than the width of the through hole.

6. the plurality of battery cells includes at least one third battery cell stacked together with the at least one first battery cell and the at least one second battery cell in a predetermined stacking direction; the first lead is a positive electrode lead joined to a negative electrode lead of the at least one third battery cell; at least a portion of the positive electrode lead, at least a portion of the negative electrode lead, and the first voltage detection unit are arranged and overlapped in this order from the other side of the plurality of battery cells that is located opposite to the one side in a direction perpendicular to the stacking direction, the negative electrode lead, the positive electrode lead, and the first voltage detection unit, The battery module according to claim 1 , wherein the first voltage detection portion and the at least a portion of the positive electrode lead contain the same material.

7. The battery module according to any one of claims 1 to 6, wherein the first voltage detection portion includes a planar portion electrically connected to the first lead, a first protrusion portion protruding from the planar portion, and a second protrusion portion protruding from the first protrusion portion to a side of the first protrusion portion.

Images