Voltage detection device and battery module

Abstract

To easily detect the voltage of a lead part folded back between different battery cells.SOLUTION: A first voltage detection device 30 detects the voltage of a lead part 150 folded back between different battery cells 100. The first voltage detection device 30 includes a first voltage detection unit 410, a first voltage detection line 420 electrically connected to the first voltage detection unit 410, and a first holder 300 that holds the first voltage detection unit 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 a plurality of stacked battery cells. In such a battery module, the plurality of battery cells are electrically connected to each other by positive and negative electrode leads drawn out from the battery cells. In addition, a plurality of battery cells connected in parallel may be connected in series to other plurality of 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 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 and the negative electrode lead of another single battery cell are joined by ultrasonic bonding. In addition, the lead portions are folded back between the different battery cells. [Prior art documents] [Patent documents]

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

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

[0007] One example of an object of the present invention is to easily detect the voltage of a lead portion 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 for detecting a voltage of a lead portion 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 includes:

[0009] Another aspect of the present invention is A plurality of battery cells; a voltage detection device that detects the voltage of the lead portion that is 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 the following features: Effect of the Invention

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

[0011] [Figure 1]FIG. 2 is an exploded front perspective view of the battery module according to the embodiment; [Diagram 2] FIG. 2 is a rear perspective view of the battery module according to the embodiment. [Diagram 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 manufacturing method for a battery module according to an embodiment. [Diagram 5] 5A to 5C are diagrams illustrating a first example of a manufacturing method for a battery module according to an embodiment. [Figure 6] 5A to 5C are diagrams illustrating a first example of a manufacturing method for a battery module according to an embodiment. [Figure 7] 5A to 5C are diagrams illustrating a first example of a manufacturing method for a battery module according to an embodiment. [Figure 8] 5A to 5C are diagrams illustrating a first example of a manufacturing method for 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. 11 is a diagram for explaining a second example of a method for stacking a plurality of cell groups. [Figure 11] 6A to 6C are diagrams illustrating a second example of a manufacturing method for a battery module according to an embodiment. [Figure 12] 6A to 6C are diagrams illustrating a second example of a manufacturing method for a battery module according to an embodiment. [Figure 13] 6A to 6C are diagrams illustrating a second example of a manufacturing method for a battery module according to an embodiment. [Figure 14] FIG. 11 is a front perspective view of a portion of a battery module according to a first modified example. [Figure 15] FIG. 11 is an exploded perspective view of a first voltage detecting device according to a second modified example. [Figure 16] 11 is a front perspective view of a portion of a first voltage detecting device according to a second modified example. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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

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

[0014] In this specification, A being substantially equal to B does not only mean that A and B are strictly equal to each other, 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] In Figs. 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 of the arrow to the tip is the positive direction of the direction indicated by the arrow, and that the direction from the tip of the arrow to the base end 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 paper to the front of the paper 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 paper to the back of the paper is the negative direction of the direction indicated by the white circle with a black dot. The same applies to the subsequent figures of Figs. 1 to 3.

[0017] In FIG. 1 to FIG. 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, the second direction Y, the third direction Z, and the vertical direction is not limited to the above example. The relationship between the first direction X, the second direction Y, the 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. 1 to 3.

[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 sections 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 sections 610, and a plurality of second voltage detection wires 620.

[0020] The multiple 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 material 102 contains 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 exterior material 102 in the second direction Y. Alternatively, the positive electrode, the negative electrode, and the separator may be wound in the exterior material 102.

[0022] The positive electrode lead 110 is drawn out from one end of the exterior material 102 on the positive side and the negative side in the first direction X. The positive electrode lead 110 is electrically connected to a positive electrode in the exterior 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 a negative electrode inside 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 multiple battery cells 100 stacked in the second direction Y include multiple cell groups 100G stacked in the second direction Y. Each cell group 100G includes multiple battery cells 100 connected in parallel and adjacent to each other in the second direction Y. The multiple cell groups 100G are connected in series from a cell group 100G located at an end of the multiple cell groups 100G on the negative side of the second direction Y to a cell group 100G located at an end of the multiple 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 on the negative side in the first direction X of a first cell group 100Ga and a second cell group 100Gb among the multiple cell groups 100G.

[0026] The first cell group 100Ga includes a plurality of battery cells 100 connected in parallel 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 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 a tip portion, of the positive electrode leads 110 of the first cell group 100Ga and at least a portion, specifically a tip portion, 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 using 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 including 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 back 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 between the positive electrode leads 110 of the first cell group 100Ga in the second direction Y decreases as the distance increases from the first cell group 100Ga. The second region 154 is a region in which the distance between the negative electrode leads 120 of the second cell group 100Gb in the second direction Y decreases as the distance increases 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 of the first cell group 100Ga that are bundled together and the multiple negative electrode leads 120 of the second cell group 100Gb that are bundled together 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 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 a case in which the lengths of the two positive electrode leads 110 are different from each other. The lengths of the two positive electrode leads 110 may be different from each other.

[0031] 3, the lengths from the exterior material 102 to the second bent portion 158b between the second region 154 and the third region 156 of the two negative electrode leads 120 located at both ends in the second direction Y among the multiple negative electrode leads 120 of the second cell group 100Gb are substantially equal. In this case, it is possible to suppress the occurrence of bending of one of the two negative electrode leads 120 compared to a case in which 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 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 below to the third region 156 compared to a case in which the third region 156 is non-flat, such as curved. Note that the third region 156 may be non-flat, such as curved.

[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 the lead parts 150 located on the negative side of the first direction X of the cell groups 100G stacked in the second direction Y are joined to each other, the negative electrode leads 120 are located on the negative side of the first direction X relative to the 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 the lead parts 150 located on the positive side of the first direction X of the cell groups 100G stacked in the second direction Y are joined to each other, the positive electrode leads 110 are located on the positive side of the first direction X relative to the negative electrode leads 120. However, the structure of each lead part 150 is not limited to the example shown in FIG. 1 and FIG. 2.

[0035] Hereinafter, as necessary, each lead portion 150 located on the negative side in the first direction X of the multiple 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 the multiple 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 first direction X of the housing body 200. 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 parts 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 of the second direction Y is connected to an end of the first mounting body 310 on the positive side of the third direction Z. An end of the third mounting body 330 on the positive side of the second direction Y is connected to an end of the second mounting body 320 on the positive side of the third direction Z.

[0038] The first attachment body 310 has a first alignment portion 352 that fits into the first guide portion 252 provided in the first cover member 210. The second attachment body 320 has a second alignment portion 354 that fits into the second guide portion 254 provided in the second cover member 220. Each of the first guide portion 252 and the second guide portion 254 defines 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 housing 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, the first bus bar 314 provided on the first mounting body 310 is electrically connected to 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 located at 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. In addition, the second bus bar 324 provided on the second mounting body 320 is electrically connected to 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 located at 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 is substantially L-shaped when viewed from the first direction X. As a result, the first bus bar 314 includes a portion extending in the third direction Z and electrically connected to the positive electrode lead 110, and a portion extending from the upper end of the portion extending in the third direction Z toward the positive direction of the second direction Y. The upper surface of the portion of the first bus bar 314 extending 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 extending in the second direction Y serves as a terminal for connecting to an external device. Therefore, when the portion of the first bus bar 314 extending in the second direction Y is provided, it is easier to connect the first bus bar 314 to an external device than when the portion of the first bus bar 314 extending in the second direction Y is not provided.

[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 extending in the third direction Z and electrically connected to the negative electrode lead 120, and a portion extending from the upper end of the portion extending in the third direction Z toward the negative direction of the second direction Y. The upper surface of the portion of the second bus bar 324 extending 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 extending in the second direction Y serves as a terminal for connecting to an external device. Therefore, when the portion of the second bus bar 324 extending in the second direction Y is provided, it is easier to connect the second bus bar 324 to an external device than when the portion of the second bus bar 324 extending in the second direction Y is not provided.

[0042] The tip of the positive electrode lead 110 drawn out to the negative side of the first direction X of the cell group 100G located at the end of the negative side of the second direction Y among the multiple cell groups 100G is not bent in a direction substantially perpendicular to the first direction X and extends in the negative direction of the first direction X. In addition, the tip of the positive electrode lead 110 is joined to a surface on the negative side of the second direction Y of the portion of the first bus bar 314 extending in the third direction Z. However, the tip of the positive electrode lead 110 may be joined to a surface on the positive side of the second direction Y of the portion of the first bus bar 314 extending in the third direction Z. Similarly, the tip of the negative electrode lead 120 drawn out to the negative side of the first direction X of the cell group 100G located at the end of the positive side of the second direction Y among the multiple cell groups 100G is not bent in a direction substantially perpendicular to the first direction X and extends in the negative direction of the first direction X. Further, the tip of the negative electrode lead 120 is joined to a surface on the positive side in the second direction Y of the portion of the second bus bar 324 extending in the third direction Z. However, the tip of the negative electrode lead 120 may be joined to a surface on the negative side in the second direction Y of the portion of the second bus bar 324 extending in the third direction Z. This configuration is preferable because it is possible to increase the volumetric energy density of the portion accommodating the multiple cell groups 100G, i.e., the volumetric energy density of the battery module 10, without increasing the length dimension of the multiple 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 or the tip of the negative electrode lead 120 in the first direction X may be reversed.

[0043] Depending on the total number of the multiple 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 multiple cell groups 100G stacked in the second direction Y on the positive side 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. 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 multiple cell groups 100G stacked in the second direction Y on the positive side in the second direction Y may be electrically connected to a second bus bar 324 provided at a corner of the container 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 is mechanically connected to the first connection portion 256 provided on the fourth cover member 240. In this embodiment, the second connection portion 356 has a convex portion that fits into a recess defined in the first connection portion 256. The convex portion provided in 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. In addition, by inserting the positioning pin 358 attached to the third attachment body 330 into the mounting hole 258 provided in the fourth cover member 240, the first holding body 300 can be fixed to the housing 200 more firmly. Note that the second connection portion 356 may define a recess into which the convex portion provided in 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 parts 150a. The first voltage detection device 30 detects the voltage of the multiple first lead parts 150a by the multiple first voltage detection units 410. The first voltage detection units 410 are chip-shaped. Each of the first voltage detection units 410 is electrically connected to at least one of the multiple positive electrode leads 110 and the multiple negative electrode leads 120 in each of the first lead parts 150a. Each of the first voltage detection units 410 is joined to the multiple positive electrode leads 110 and the multiple negative electrode leads 120 in the first lead part 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 disposed at an appropriate position with respect to the first lead portion 150a. Also, 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 side where the cell group 100G is located with respect to the first lead portion 150a. 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 opposite side of the side where the first lead portion 150a is located. Therefore, for example, it is easier to weld the first voltage detection portion 410 to the first lead portion 150a compared to when the first voltage detection portion 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 a case in which 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 a case in which 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 disposed 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, a portion of the first lead portion 150a that contacts the first voltage detection unit 410, i.e., the same material as that included in 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 a case in which 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 section 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 section 304 provided on the third attachment body 330. The second holding section 304 defines a groove for routing the first voltage detection line 420 along the second direction Y. The second holding section 304 holds the first voltage detection line 420 by 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 stably routed compared to a case where the first voltage detection line 420 is physically floating. 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 line 420. As a result, the first voltage detection unit 410 and the first voltage detection line 420 are integrated. In addition, by attaching the first holding body 300 to the housing 200, the first voltage detection unit 410 can be disposed at an appropriate position relative 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 the 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 the 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 first direction X of the housing 200. At least a portion of the second holding body 500 extends laterally on the positive side of the third direction Z of the multiple second lead portions 150b. The second holding body 500 is mechanically connected to the housing 200 in the same manner as the first holding body 300, for example by a snap fit.

[0053] Each of the second voltage detection units 610 is provided for each of the second lead portions 150b. The second voltage detection device 50 detects the voltages of the second lead portions 150b by the second voltage detection units 610. The second voltage detection units 610 are chip-shaped. Each of the second voltage detection units 610 is electrically connected to at least one of the positive electrode leads 110 and the negative electrode leads 120 in each of the second lead portions 150b. Each of the second voltage detection units 610 is joined to the positive electrode leads 110 and the 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 holding body 500. Specifically, the second holding body 500 has a third holding portion 502. The third holding portion 502 holds a protrusion provided at the end of the second voltage detection unit 610 in the third direction Z. Therefore, when the second holding body 500 is attached to the housing 200, the second voltage detection unit 610 can be disposed at an appropriate position with respect to the second lead portion 150b. Also, when the second holding body 500 is attached to the housing 200, the second voltage detection unit 610 is located on the opposite side of the cell group 100G with respect to the second lead portion 150b. 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 opposite side of the side where the second lead portion 150b is located. Therefore, for example, it is easier to weld the second voltage detection portion 610 to the second lead portion 150b compared to when the second voltage detection portion 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 a case in which 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 a case in which 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 disposed at an appropriate position 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, a portion of the second lead portion 150b that contacts the second voltage detection unit 610, i.e., the same material as that included in 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 a case in which 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 contained in the second voltage detection unit 610 may be the same as the material contained 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 contained in the second voltage detection unit 610 is the same as the material contained in the first voltage detection unit 410, the material contained in the second voltage detection unit 610 may be different from the material contained in the portion of the second lead portion 150b that contacts the second voltage detection unit 610, that is, the material contained 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 direction side of the first direction X, the multiple positive electrode leads 110 may be cut out at the 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] In addition, 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 the 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 on the positive side of the first direction X from 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 made the same. Therefore, compared to the case where the multiple positive electrode leads 110 are located on the positive side of the first direction X from the multiple negative electrode leads 120 in the 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 possible to easily laser weld the second voltage detection unit 610 to the negative electrode lead 120 from the positive side of 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 holding body 500. Specifically, the second holding body 500 has a fourth holding portion 504. The fourth holding portion 504 defines a groove for routing the second voltage detection line 620 along the second direction Y. The fourth holding portion 504 holds the second voltage detection line 620 by this groove. Therefore, the second voltage detection line 620 can be routed along the second holding body 500 without being physically floating. Therefore, the second voltage detection line 620 can be stably routed compared to a case where the second voltage detection line 620 is physically floating. 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 line 620. As a result, the second voltage detection unit 610 and the second voltage detection line 620 are integrated. In addition, by attaching the second holding body 500 to the housing body 200, the second voltage detection unit 610 can be disposed at an appropriate position 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 the lead wires are connected to each of the second lead portions 150b. Therefore, it is easier to detect the voltage of the second lead portion 150b than when the lead wires are connected to each of the second lead portions 150b.

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

[0063] 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 is true in Figs. 9 and 10 described below.

[0064] First, as shown in FIG. 4, a cell group 100G having a plurality of battery cells 100 is formed. Specifically, a first tape 132 is provided on the negative side of the first direction X of the upper surface of the battery cell 100 located at the lower of the two battery cells 100. A second tape 134 is provided on the positive side of the first direction X of the upper surface of the battery cell 100 located at the lower of the two battery cells 100. A compression pad 136 is provided on the upper surface of the battery cell 100 located at the lower of the two battery cells 100 via the first tape 132. Next, another battery cell 100 is provided on the battery cell 100 located at the lower of the two battery cells 100 via the second tape 134 and the compression pad 136. In this manner, the cell group 100G is formed. Note that the method of 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 arranged 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. Also, 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 arranged in this order from the positive direction 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 irradiated 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. As a result, a lead portion 150 including the multiple positive electrode leads 110 and the multiple negative electrode leads 120 joined to each other is formed. 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 bonding are used. 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 bonding.

[0067] In one example, in laser welding, the laser is irradiated while being wobbled. 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, as compared with the case where the laser is irradiated, for example, linearly without being wobbled, and the positive electrode lead 110 and the negative electrode lead 120 can be joined with high strength. The laser may be irradiated, for example, linearly without being wobbled. In addition, when the positive electrode lead 110 and the negative electrode lead 120 are welded before stacking the 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 the positive electrode lead 110 and the negative electrode lead 120, as compared with the case where the positive electrode lead 110 and the negative electrode lead 120 are welded after stacking the 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 be folded 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 toward the positive direction of the first direction X. Also, the lead portion 150 between the first cell group 100Ga and the second cell group 100Gb is 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. 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 direction 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 in 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. Also, 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 a plurality of first voltage detection units 410 and a plurality of first voltage detection lines 420 are attached is attached to the housing 200. Also, a second holder 500 to which a plurality of second voltage detection units 610 and a plurality of second voltage detection lines 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. Also, 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 multiple 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, the first cell group 100Ga, the second cell group 100Gb, and the 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 with respect to the rotating portion 912. The second engaging portion 916 is rotatable along a circumference centered on the rotating portion 912 with the distance between the rotating portion 912 and the first engaging portion 914 as the radius. In addition, the second engaging portion 916 is capable of engaging 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 with respect to the rotating portion 912, the lead portion 150 between the first cell group 100Ga and the second cell group 100Gb is folded back, and the lead portion 150 between the second cell group 100Gb and the third cell group 100Gc is folded back. In this manner, 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 becomes 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 a plurality of 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 plurality of 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 plurality of cell groups 100G in the third direction Z. The second guide member 924 extends parallel to the second direction Y. Therefore, the plurality of cell groups 100G are stacked along the first guide member 922 and the second guide member 924 between the first guide member 922 and the second guide member 924.

[0081] When the second jig 920 is used, it becomes 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 for explaining a second example of the manufacturing method of 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 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 arranged 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. As a result, the first cell group 100Ga, the second cell group 100Gb, and the third cell group 100Gc are 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 each cell group 100G in the third direction Z due to the weight of each cell group 100G.

[0088] In the second example shown in Fig. 11 to Fig. 13, four cell groups 100G are joined in a row along the first direction X in the stage shown in Fig. 11. However, the number of cell groups 100G joined in advance is not limited to this, and may be two or three or more. For example, the first cell group 100Ga and the second cell group 100Gb may be joined 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 joined 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-back 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 arranged in either the positive direction of the first direction X or the negative direction 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 is referred to as a stacked cell group 100G as necessary.

[0089] In view of the above, depending on whether the cell group 100G to be next 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 cell group 100G to be next stacked on the stacked cell group 100G can 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 in the second direction Y on the positive side of the first direction X of the stacked cell group 100G or the negative side of the first direction X of the stacked cell group 100G, each time the next cell group 100G is stacked on the stacked cell group 100G, the cell groups 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 detection device 30A has a first protruding portion 302Aa provided on the negative side of the first direction X of the first holding body 300A. The first protruding portion 302Aa penetrates the first voltage detection portion 410A in the first direction X. The first protruding portion 302Aa is, for example, a pin. The first voltage detection portion 410A is movable in the first direction X along the first protruding portion 302Aa. As a result, the first voltage detection portion 410A is movable in at least one of a direction approaching the first lead portion 150a and a direction away from the first lead portion 150a. Therefore, when the first voltage detection portion 410A is joined 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 a through hole provided in the portion of the first voltage detection portion 410A through which the first convex portion 302Aa penetrates, 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 an 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 includes 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 a surface of the first bus bar 314B on 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 on the positive side in the third direction Z, but also at least a portion of the first bus bar 314B on the negative side in the second direction Y and at least a portion of the first bus bar 314B on 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 on 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 on the positive side in the third direction Z, but also at least a portion of the second bus bar 324B on the positive side in the second direction Y and at least a portion of the second bus bar 324B on the negative side in the first direction X.

[0098] The third attachment body 330B can be separated into a plurality of extension bodies 332B along the second direction Y. The adjacent extension bodies 332B are mechanically connected by the connector 334B. That is, the third attachment body 330B has a plurality of parts connected to each other, that is, a plurality of extension bodies 332B. Each of the plurality of extension bodies 332B has at least one, for example, a plurality of first holding parts 302B. In this case, when the first voltage detection device 30B is attached to the container 200 as shown in FIG. 1, the number of extension bodies 332B included in the third attachment body 330B can be adjusted according to the total number of the plurality of lead parts 150 arranged in the first direction X, thereby adjusting the length of the first voltage detection device 30B in the second direction Y.

[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 on the housing 200 as shown in FIG. 1, the wall portion 340B is located on the opposite side of the first voltage detection unit 410B relative to the first lead portion 150a. By arranging the wall portion 340B in this manner, when the first lead portion 150a and the first voltage detection unit 410B are laser-welded by irradiating a laser from the opposite side of the side where the wall portion 340B is located relative to the first voltage detection unit 410B, even if the laser penetrates the first lead portion 150a, the laser is irradiated to the wall portion 340B, so that the laser can be prevented from being irradiated to the cell group 100G. In addition, when the first voltage detection device 30B is assembled, transported, etc. with the first voltage detection unit 410B held by the first holding portion 302B, it is possible to prevent damage to the first voltage detection unit 410B due to contact with tools, equipment, transport containers, packaging materials, etc. from the side opposite to the side where the first voltage detection unit 410B is located relative to the wall portion 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 portion 410B in the first direction X. Therefore, similar to the first voltage detection portion 410A according to the first modification, the first voltage detection portion 410B according to the second modification is movable in the first direction X along the first convex portion 302Ba.

[0102] The two second convex portions 302Bb are located on both sides of the first voltage detection unit 410B in the second direction Y. The second convex portions 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 only on one of the positive and negative sides of the second direction Y of the first voltage detection unit 410B. By providing the second convex portions 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 prevent the first voltage detection unit 410B from being aligned in the second direction Y or from rotating.

[0103] A first voltage detection line 420B is connected to an end of the first voltage detection part 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 part 304B provided in a third attachment body 330B.

[0104] Although the embodiment and modified examples 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 other two battery cells 100 connected in parallel. However, three or more battery cells 100 connected in parallel may be connected in series to other three or more battery cells 100 connected in parallel. In addition, the number of the multiple 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 other three battery cells 100 connected in parallel.

[0106] Furthermore, the method of stacking 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 such that the lead portions 150 folded back between the cell groups 100G adjacent to each other in the second direction Y are alternately arranged in the positive direction of the first direction X and the negative direction of the first direction X.

[0107] 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 a lead portion that is 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 according to 1., A voltage detection device, wherein the voltage detection portion 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 to 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 parts 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 container that houses the battery cell. 7. A plurality of battery cells; a voltage detection device that detects the voltage of the lead portion that is 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 a 8. The battery module according to 7., The battery pack further includes a housing that houses the plurality of battery cells. The holder has a connection portion that mechanically connects to the container, the battery module.

[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 Cell Group 4 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 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 protrusion 302B 1st holding part 302Ba 1st protrusion 302Bb 2nd convex part 304 Second holding part 304B 2nd holding part 310 First mounting body 310B First mounting body 312B 1st Protector 314 First bus bar 314B 1st bus bar 316B 1st Vis 318B 1st protector cover 320 Second mounting body 320B Second mounting body 322B Second Protector 324 2nd bus bar 324B 2nd bus bar 326B 2nd Vis 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 section 410B First voltage detection unit 420 First voltage detection line 420A 1st 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 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; Equipped with The holder has a plurality of parts connected to each other, Each of the plurality of portions has a holding portion that holds at least one of the voltage detection units, A voltage detection device, wherein the holder is configured so that the length of the holder can be adjusted by adjusting the number of the portions included in the holder.

2. 2. The voltage detection device according to claim 1, A voltage detection device, wherein the voltage detection unit is movable in at least one of a direction toward a lead portion to which the voltage detection unit is electrically connected and a direction away from the lead portion.

3. 3. The voltage detection device according to claim 2, The holding body has a wall portion located on the opposite side to the lead portion from the side on which the voltage detection portion is located.

4. The voltage detection device according to claim 2 or 3, 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.

5. The voltage detection device according to any one of claims 1 to 4, The holder has a connection portion that mechanically connects to a container that contains the battery cells.

6. A plurality of battery cells; a voltage detection device that detects the voltage of the lead portion that is 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; having The carrier includes a plurality of portions connected to each other, Each of the plurality of portions has a holding portion that holds at least one of the voltage detection units, The battery module, wherein the holder is configured so that a length of the holder can be adjusted by adjusting the number of the portions included in the holder.

7. The battery module according to claim 6, The battery pack further includes a housing that houses the plurality of battery cells. The holder has a connection portion that mechanically connects to the housing, the battery module.

Images