Battery module

Abstract

To make it easy and reliable for a voltage detector and a container to be fixed to each other.SOLUTION: A battery module 1A includes a plurality of battery cells 100, a front voltage detector 20A detecting voltages of the plurality of battery cells 100, and a container 30A housing the plurality of battery cells 100 and the front voltage detector 20A therein. One of the front voltage detector 20A and the container 30A has a plurality of protrusions lined up in a predetermined direction. The other of the front voltage detector 20A and the container 30A has a plurality of alignment structures aligning the plurality of protrusions.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] In recent years, various battery modules including multiple battery cells have been developed. For example, a battery module described in Patent Document 1 includes a pair of bus bar assemblies, a pair of end covers, and a pair of side plates. The pair of bus bar assemblies are arranged in front of and behind the multiple battery cells. The pair of end covers are arranged in front of and behind the pair of bus bar assemblies. The side plates are arranged on both sides of the multiple battery cells. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2020-520067 Summary of the Invention [Problem to be solved by the invention]

[0004] For example, as described in Patent Document 1, battery cells may be housed in a housing having plates such as end covers and side plates. The battery cells may be provided with a voltage detection device such as a bus bar assembly. In this case, it is desirable to make it easy to securely fix the voltage detection device and the housing to each other.

[0005] One object of the present invention is to make it easier to securely fasten a voltage detection device and a housing to each other. Other objects of the present invention will become apparent from the description herein. [Means for solving the problem]

[0006] One aspect of the present invention is as follows. [1] A plurality of battery cells; a voltage detection device that detects the voltages of the plurality of battery cells; a housing that houses the plurality of battery cells and the voltage detection device; Equipped with one of the voltage detection device and the housing has a plurality of protrusions arranged in a predetermined direction, The other of the voltage detection device and the housing has a plurality of alignment structures for aligning the plurality of protrusions. [2] the housing has an exposure structure that exposes at least a portion of a tab of one of the plurality of battery cells, The battery module according to [1], wherein the exposure structure and the plurality of alignment structures are aligned in the predetermined direction. [3] The battery module according to [1] or [2], wherein the voltage detection device and the housing have a locking structure that locks the voltage detection device and the housing to each other. [Effects of the Invention]

[0007] According to the above aspect of the present invention, the voltage detection device and the housing can be easily and reliably fixed to each other. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is an exploded perspective view of a battery module according to a first embodiment. [Figure 2] 1 is an enlarged view of a portion of a battery module according to Embodiment 1. FIG. [Figure 3] FIG. 3 is a view of FIG. 2 with the front plate removed. [Figure 4] FIG. 10 is an enlarged view of a portion of a battery module according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, similar components are designated by similar reference numerals, and the description thereof will be omitted as appropriate.

[0010] FIG. 1 is an exploded perspective view of a battery module 1A according to the first embodiment.

[0011] For ease of explanation, arrows indicating the X, Y, and Z directions are shown in each figure. The X direction is the front-to-rear direction of the battery module 1A. Hereinafter, unless otherwise specified, the tip of an arrow indicating the X direction will be referred to as the rear side of the battery module 1A. Hereinafter, unless otherwise specified, the base end of an arrow indicating the X direction will be referred to as the front side of the battery module 1A. The Y direction is perpendicular to the X direction. The Y direction is the left-to-right direction of the battery module 1A. Hereinafter, unless otherwise specified, the tip of an arrow indicating the Y direction will be referred to as the left side of the battery module 1A. Hereinafter, unless otherwise specified, the base end of an arrow indicating the Y direction will be referred to as the right side of the battery module 1A. The Z direction is perpendicular to both the X and Y directions. The Z direction is the up-down direction of the battery module 1A. Hereinafter, unless otherwise specified, the tip of an arrow indicating the Z direction will be referred to as the upper side of the battery module 1A. Hereinafter, unless otherwise specified, the base end of an arrow indicating the Z direction will be referred to as the lower side of the battery module 1A. Hereinafter, where necessary, the direction perpendicular to the X direction will be referred to as the YZ plane direction. Hereinafter, where necessary, the direction perpendicular to the Y direction will be referred to as the ZX plane direction. Hereinafter, where necessary, the direction perpendicular to the Z direction will be referred to as the XY plane direction. Note that the relationship between each of the X direction, Y direction, and Z direction and each of the front-rear direction, left-right direction, and up-down direction of the battery module 1A is not limited to the example described above.

[0012] The battery module 1A includes a cell stack 10, a front voltage detector 20A, a rear voltage detector 20A', and a housing 30A.

[0013] The cell stack 10 has a plurality of battery cells 100 and a plurality of compression pads 110. The plurality of battery cells 100 and the plurality of compression pads 110 are arranged alternately in the Y direction. A compression pad 110 is arranged on both sides of each battery cell 100 in the Y direction. The plurality of battery cells 100 and the plurality of compression pads 110 are compressed in the Y direction by a right plate 330A and a left plate 340A, which will be described later. This makes it possible to suppress displacement of the battery cells 100 in the ZX plane direction.

[0014] The longitudinal direction of each battery cell 100 is approximately parallel to the X direction. The lateral direction of each battery cell 100 is approximately parallel to the Z direction. The thickness direction of each battery cell 100 is approximately parallel to the Y direction. The multiple battery cells 100 are stacked in the Y direction. Note that the shape of each battery cell 100 is not limited to this example.

[0015] Each battery cell 100 includes a battery element (not shown), an outer casing 102, a positive electrode tab 104, and a negative electrode tab 106. The battery element includes a plurality of positive electrodes and a plurality of negative electrodes (not shown) alternately stacked in the Y direction, and a separator (not shown) positioned between adjacent positive electrodes and negative electrodes in the Y direction. The outer casing 102 seals the battery element and an electrolyte (not shown). The positive electrode tab 104 is electrically connected to the positive electrode of the battery element. The positive electrode tab 104 is pulled out from one of both sides of the outer casing 102 in the X direction. The negative electrode tab 106 is electrically connected to the negative electrode of the battery element. The negative electrode tab 106 is pulled out from the other side of the outer casing 102 in the X direction. However, the structure of each battery cell 100 is not limited to this example.

[0016] In the first embodiment, a plurality of cell groups 100G are connected in series from a cell group 100G located at one end in the Y direction to a cell group 100G located at the other end in the Y direction. Each cell group 100G includes a plurality of battery cells 100 connected in parallel. In the first embodiment, each cell group 100G includes two battery cells 100 adjacent to each other in the Y direction. Two positive electrode tabs 104 drawn from the two battery cells 100 included in each cell group 100G face the same side in the X direction. Two negative electrode tabs 106 drawn from the two battery cells 100 included in each cell group 100G face the same side in the X direction. The positive electrode tab 104 and the negative electrode tab 106 drawn from one of the cell groups 100G adjacent to each other in the Y direction face opposite each other in the X direction. Two cell groups 100G adjacent to each other in the Y direction include tab groups 108 located in front of or behind the two cell groups 100G. The tab groups 108 include positive electrode tabs 104 and negative electrode tabs 106 joined to each other. The positive electrode tabs 104 and negative electrode tabs 106 included in the tab groups 108 are joined to each other by, for example, laser welding. As a result, the multiple tab groups 108 located in front of the cell stack 10 and the multiple tab groups 108 located in the rear of the cell stack 10 are arranged alternately.

[0017] In the first embodiment, a positive electrode tab 104 extends forward from the battery cell 100 located at the right end of the cell stack 10. Hereinafter, as needed, this positive electrode tab 104 will be referred to as a terminal positive electrode tab 104T. Also, a negative electrode tab 106 extends backward from the battery cell 100 located at the left end of the cell stack 10. Hereinafter, as needed, this negative electrode tab 106 will be referred to as a terminal negative electrode tab 106T.

[0018] The configuration of the cell stack 10 is not limited to the above example. For example, each cell group 100G may include three or more battery cells 100 connected in parallel. Alternatively, multiple single battery cells 100 may be connected in series from a battery cell 100 located at one end in the Y direction to a battery cell 100 located at the other end in the Y direction. Furthermore, the positions of the terminal positive electrode tabs 104T and terminal negative electrode tabs 106T are not limited to the above example. The positions of the terminal positive electrode tabs 104T and terminal negative electrode tabs 106T vary depending on the number of cell groups 100G. For example, depending on the number of cell groups 100G, both the terminal positive electrode tabs 104T and terminal negative electrode tabs 106T may be located at the front or rear of the cell stack 10.

[0019] The front voltage detection device 20A has a front holder 210A, a plurality of front voltage detection parts 220A, a plurality of front voltage detection lines 222A, a front connector 224A, and a positive bus bar 230A.

[0020] The front holder 210A is disposed in front of the cell stack 10. The front holder 210A has a plurality of front openings 210aA. Each of the plurality of tab groups 108 located in front of the cell stack 10 is exposed forward through each of the plurality of front openings 210aA. The front holder 210A integrally holds a plurality of front voltage detection units 220A and a plurality of front voltage detection wires 222A.

[0021] The multiple front voltage detection units 220A are attached to the front holder 210A. Each of the multiple front voltage detection units 220A is joined, for example by laser welding, to the front surface of each of the multiple tab groups 108 located in the front of the cell stack 10. The multiple front voltage detection units 220A are electrically connected to the front connector 224A via multiple front voltage detection wires 222A. The multiple front voltage detection wires 222A are routed through the front holder 210A. In the first embodiment, by installing the front holder 210A in an appropriate position relative to the cell stack 10, each of the multiple front voltage detection units 220A can be disposed in an appropriate position relative to each of the multiple tab groups 108 located in the front of the cell stack 10.

[0022] The positive bus bar 230A is disposed at the right end of the front holding body 210A. The positive bus bar 230A is substantially L-shaped. Specifically, the positive bus bar 230A includes a front horizontal conductor 232A and a front vertical conductor 234A. The front horizontal conductor 232A extends substantially parallel to the Y direction. The front vertical conductor 234A extends downward from the right end of the front horizontal conductor 232A substantially parallel to the Z direction.

[0023] The front horizontal conductor 232A functions as a terminal for electrically connecting to an external device such as another battery module. Specifically, a fastening hole 232aA is provided at the left end of the front horizontal conductor 232A. A fastener (not shown) can be installed in the fastening hole 232aA to fasten a bus bar (not shown) that is electrically connected to an external device (not shown) such as another battery module.

[0024] The front vertical conductor 234A is electrically connected to the terminal positive electrode tab 104T. The terminal positive electrode tab 104T is located to the right of the front vertical conductor 234A. In the first embodiment, the terminal positive electrode tab 104T and the front vertical conductor 234A are joined by laser welding. However, the joining method of the terminal positive electrode tab 104T and the front vertical conductor 234A is not limited to laser welding.

[0025] The rear voltage detection device 20A' is similar to the front voltage detection device 20A except for the following points: The rear voltage detection device 20A' includes a rear holder 210A', a plurality of rear voltage detection units 220A', a plurality of rear voltage detection lines 222A', a rear connector 224A', and a negative bus bar 230A'.

[0026] The rear holding body 210A' is disposed at the rear of the cell stack 10. A plurality of rear openings 210aA' are provided in the rear holding body 210A'. Each of the plurality of tab groups 108 located at the rear of the cell stack 10 is exposed rearward through each of the plurality of rear openings 210aA'. The rear holding body 210A' integrally holds a plurality of rear voltage detection units 220A' and a plurality of rear voltage detection wires 222A'.

[0027] The multiple rear voltage detection units 220A' are attached to the rear support 210A'. Each of the multiple rear voltage detection units 220A' is joined to the rear surface of each of the multiple tab groups 108 located at the rear of the cell stack 10, for example, by laser welding. The multiple rear voltage detection units 220A' are electrically connected to the rear connector 224A' via multiple rear voltage detection wires 222A'. The multiple rear voltage detection wires 222A' are routed through the rear support 210A'. In the first embodiment, by placing the rear support 210A' at an appropriate position relative to the cell stack 10, each of the multiple rear voltage detection units 220A' can be disposed at an appropriate position relative to each of the multiple tab groups 108 located at the rear of the cell stack 10.

[0028] The negative bus bar 230A' is disposed at the left end of the rear holding body 210A'. The negative bus bar 230A' is substantially L-shaped. The negative bus bar 230A' includes a rear vertical conductor 232' and a rear vertical conductor 234A'. The rear vertical conductor 232' extends substantially parallel to the Y direction. The rear vertical conductor 234A' extends downward from the left end of the rear vertical conductor 232' substantially parallel to the Z direction.

[0029] The rear vertical conductor 232' functions as a terminal for electrical connection to an external device such as another battery module.

[0030] The rear vertical conductor 234A' is electrically connected to the terminating negative electrode tab 106T. The terminating negative electrode tab 106T is located to the left of the rear vertical conductor 234A'. In the first embodiment, the terminating negative electrode tab 106T and the rear vertical conductor 234A' are joined by laser welding. However, the method for joining the terminating negative electrode tab 106T and the rear vertical conductor 234A' is not limited to laser welding.

[0031] The housing 30A has a front plate 310A, a rear plate 320A, a right plate 330A, a left plate 340A, a lower plate 350A, and an upper plate 360A. The housing 30A has a front bracket 372A and a rear bracket 374A. The housing 30A does not necessarily have at least one of the lower plate 350A and the upper plate 360A.

[0032] The front plate 310A covers the cell stack 10 and the front voltage detection device 20A from the front direction. The front plate 310A is, for example, a laminate of a resin plate and a metal plate. In this example, the metal plate is laminated in front of the resin plate.

[0033] The rear plate 320A covers the cell stack 10 and the rear voltage detection device 20A' from the rear direction. The rear plate 320A is, for example, a laminate of a resin plate and a metal plate. In this example, the metal plate is laminated behind the resin plate.

[0034] The right plate 330A covers the cell stack 10, the front voltage detector 20A, and the rear voltage detector 20A' from the right side. The right plate 330A is made of a metal such as aluminum.

[0035] The left plate 340A covers the cell stack 10, the front voltage detector 20A, and the rear voltage detector 20A' from the left side. The left plate 340A is made of a metal such as aluminum.

[0036] The lower plate 350A covers the cell stack 10, the front voltage detection device 20A, and the rear voltage detection device 20A' from below. The lower plate 350A is made of a metal such as aluminum. A thermally conductive adhesive 352A is disposed between the upper surface of the lower plate 350A and the lower end of the cell stack 10. This allows heat generated from the cell stack 10 to escape downwards from the battery module 1A through the thermally conductive adhesive 352A.

[0037] The upper plate 360A covers from above the cell stack 10, the front voltage detection device 20A, and the rear voltage detection device 20A'. The upper plate 360A is made of a metal such as aluminum.

[0038] The front bracket 372A is disposed at the corner between the right end of the front plate 310A and the front end of the right plate 330A of the housing 30A. When viewed from the Z direction, the front bracket 372A is substantially L-shaped. Specifically, when viewed from the Z direction, the front bracket 372A includes a portion extending substantially parallel to the Y direction and a portion extending substantially parallel to the X direction. The portion of the front bracket 372A extending substantially parallel to the Y direction is joined to the right end of the front plate 310A, for example, by welding. The portion of the front bracket 372A extending substantially parallel to the X direction is joined to the front end of the right plate 330A, for example, by welding. In this way, the front bracket 372A serves as a connecting member that connects the front plate 310A and the right plate 330A to each other.

[0039] The rear bracket 374A is disposed at the corner between the left end of the rear plate 320A of the housing 30A and the rear end of the left plate 340A. When viewed from the Z direction, the rear bracket 374A is generally L-shaped. Specifically, when viewed from the Z direction, the rear bracket 374A includes a portion extending generally parallel to the Y direction and a portion extending generally parallel to the X direction. The portion of the rear bracket 374A extending generally parallel to the Y direction is joined to the left end of the rear plate 320A, for example, by welding. The portion of the rear bracket 374A extending generally parallel to the X direction is joined to the rear end of the left plate 340A, for example, by welding. In this way, the rear bracket 374A serves as a connecting member that connects the rear plate 320A and the left plate 340A to each other.

[0040] Fig. 2 is an enlarged view of a portion of the battery module 1A according to embodiment 1. Fig. 3 is a view in which the front plate 310A has been removed from Fig. 2. For the sake of explanation, the front bracket 372A has been removed from Fig. 2.

[0041] The right plate 330A defines a first lower notch 331A, a first upper notch 332A, a central notch 333A, a lower locking hole 334A, an upper locking hole 335A, a second lower notch 336A, and a second upper notch 337A. The front retainer 210A has a first lower protrusion 211A, a first upper protrusion 212A, a lower locking protrusion 214A, and an upper locking protrusion 215A. The front plate 310A has a second lower protrusion 316A and a second upper protrusion 317A.

[0042] The first lower notch 331A and the first upper notch 332A are provided on the front edge of the front end portion of the right plate 330A. The first lower notch 331A and the first upper notch 332A are aligned substantially parallel to the Z direction. The first lower notch 331A and the first upper notch 332A are open toward the front. The first lower protrusion 211A and the first upper protrusion 212A protrude toward the right from the right end portion of the front holding body 210A. The first lower protrusion 211A and the first upper protrusion 212A fit into the first lower notch 331A and the first upper notch 332A, respectively. As a result, the first lower protrusion 211A and the first upper protrusion 212A are aligned by the first lower notch 331A and the first upper notch 332A, respectively. That is, the first lower cutout 331A and the first upper cutout 332A are alignment structures that align the first lower protrusion 211A and the first upper protrusion 212A, respectively.

[0043] The central notch 333A is provided on the front edge of the front end portion of the right plate 330A. The central notch 333A is located between the first lower notch 331A and the first upper notch 332A in a direction substantially parallel to the Z direction. The width of the central notch 333A in the Z direction is wider than both the width of the first lower notch 331A in the Z direction and the width of the first upper notch 332A in the Z direction. The central notch 333A is open toward the front. At least a portion of the terminal positive electrode tab 104T is exposed toward the right through the central notch 333A.

[0044] The pair of the lower locking projection 214A and the lower locking hole 334A, and the pair of the upper locking projection 215A and the upper locking hole 335A, form at least a part of a locking structure that locks the right end of the front holding body 210A and the front end of the right plate 330A together. Specifically, the lower locking projection 214A and the lower locking hole 334A can be locked together by a snap fit. Similarly, the upper locking projection 215A and the upper locking hole 335A can be locked together by a snap fit. In the embodiment, these snap fits have a cantilever structure. This prevents the right end of the front holding body 210A and the front end of the right plate 330A from detaching in the X direction.

[0045] The second lower notch 336A and the second upper notch 337A are provided at the lower and upper corners, respectively, of the front end of the right plate 330A. The second lower protrusion 316A and the second upper protrusion 317A protrude rearward from the right end of the front plate 310A. The second lower protrusion 316A and the second upper protrusion 317A are recessed into the second lower notch 336A and the second upper notch 337A, respectively. The lower surface of the second lower protrusion 316A and the upper surface of the front end of the lower plate 350A can be joined to each other by, for example, laser welding. Therefore, compared to when the second lower protrusion 316A is not provided, it is easier to ensure a sufficient joining area between the front plate 310A and the lower plate 350A. Similarly, the upper surface of the second upper protrusion 317A and the lower surface of the front end of the upper plate 360A can be joined to each other by, for example, laser welding. Therefore, compared to when the second upper protrusion 317A is not provided, it is easier to ensure the bonding area between the front plate 310A and the upper plate 360A. However, the second lower protrusion 316A and the second upper protrusion 317A do not necessarily have to be provided.

[0046] Next, an example of a method for assembling the battery module 1A according to embodiment 1 will be described with reference to Figures 1 to 3. In this example, the battery module 1A is assembled as follows.

[0047] First, the cell stack 10 is manufactured. The cell stack 10 includes a plurality of battery cells 100 and a plurality of compression pads 110.

[0048] Next, the cell stack 10 is pressed in the Y direction by the right plate 330A and the left plate 340A to hold the cell stack 10 in place.

[0049] Next, the front voltage detection device 20A is placed in front of the cell stack 10. In this state, the right end of the front support body 210A and the front end of the right plate 330A are fixed to each other. Similarly, the left end of the front support body 210A and the front end of the left plate 340A are fixed to each other. As a result, each of the multiple front voltage detection units 220A is placed in front of each of the multiple tab groups 108 located in the front of the cell stack 10. In addition, the terminal positive electrode tab 104T is placed to the right of the front vertical conductor 234A.

[0050] When the right end of the front holder 210A and the front end of the right plate 330A are fixed to each other, the first downward protrusion 211A and the first upper protrusion 212A fit into the first downward notch 331A and the first upper notch 332A, respectively, from the front. This allows the front holder 210A and the right plate 330A to be aligned with each other in the Z direction. Furthermore, it is possible to suppress rotation or swinging of the front holder 210A in a direction substantially perpendicular to the Y direction. This makes it easier to reliably fix the front holder 210A and the right plate 330A to each other.

[0051] When the right end of the front holding body 210A and the front end of the right plate 330A are fixed to each other, the lower locking protrusion 214A enters the lower locking hole 334A from the left. This causes the lower locking protrusion 214A and the lower locking hole 334A to be locked to each other by a snap fit. Similarly, the upper locking protrusion 215A enters the upper locking hole 335A. This causes the upper locking protrusion 215A and the upper locking hole 335A to be locked to each other by a snap fit. This prevents the right end of the front holding body 210A and the front end of the right plate 330A from coming apart in the X direction.

[0052] The above-described structure for fixing the right end of the front holding body 210A and the front end of the right plate 330A to each other can be similarly applied to the structure for fixing the left end of the front holding body 210A and the front end of the left plate 340A to each other.

[0053] Next, each of the multiple tab groups 108 located at the front of the cell stack 10 is joined to each of the multiple front voltage detection portions 220A by laser welding. Also, the terminal positive electrode tab 104T and the front vertical conductor 234A are joined by laser welding. This forms a connection between the terminal positive electrode tab 104T and the front vertical conductor 234A. Note that the joining method of each tab group 108 and each front voltage detection portion 220A is not limited to laser welding. Also, the joining method of the terminal positive electrode tab 104T and the front vertical conductor 234A is not limited to laser welding.

[0054] In the first embodiment, when the front voltage detector 20A is disposed in front of the cell stack 10 and the right plate 330A is disposed to the right of the cell stack 10 and the front voltage detector 20A, the connection between the terminal positive electrode tab 104T and the front vertical conductor 234A is exposed to the right through the central notch 333A. That is, the central notch 333A has an exposed structure that exposes at least a portion of the connection to the right. This allows a laser to be irradiated onto the connection from the right through the central notch 333A. Therefore, in the first embodiment, compared to when the connection is covered by the right plate 330A, even when the cell stack 10 and the right plate 330A are brought closer to each other in the Y direction, it is easier to ensure a working space for joining the terminal positive electrode tab 104T and the front vertical conductor 234A. Therefore, in the first embodiment, the volume of the housing 30A can be reduced compared to the above-described case. Therefore, in the first embodiment, the volumetric efficiency of the battery module 1A can be improved compared to the above-mentioned cases.

[0055] The exposure structure that exposes at least a portion of the connection portion between the terminal positive electrode tab 104T and the front vertical conductor 234A toward the right is not limited to the central notch 333A. For example, a hole that exposes the connection portion may be provided in the front end portion of the right plate 330A instead of the central notch 333A.

[0056] Next, the rear voltage detection device 20A' is placed behind the cell stack 10. In this state, the left end of the rear support body 210A' and the rear end of the left plate 340A are fixed to each other. Similarly, the right end of the rear support body 210A' and the rear end of the right plate 330A are fixed to each other. As a result, each of the multiple rear voltage detection units 220A' is placed behind each of the multiple tab groups 108 located at the rear of the cell stack 10. In addition, the terminal negative electrode tab 106T is placed to the left of the rear vertical conductor 234A'.

[0057] The structure for fixing the left end of the rear holding body 210A' and the rear end of the left plate 340A to each other can be similar to the structure for fixing the right end of the front holding body 210A and the front end of the right plate 330A to each other described above. The structure for fixing the right end of the rear holding body 210A' and the rear end of the right plate 330A to each other can be similar to the structure for fixing the right end of the front holding body 210A and the front end of the right plate 330A to each other described above.

[0058] Next, each of the tab groups 108 located at the rear of the cell stack 10 is joined to each of the rear voltage detection units 220A' by laser welding. The terminating negative electrode tab 106T and the rear vertical conductor 234A' are also joined by laser welding. Similar to the laser welding of the terminating positive electrode tab 104T and the front vertical conductor 234A, the laser can be applied through an exposure structure provided at the rear end of the left plate 340A. This forms a connection between the terminating negative electrode tab 106T and the rear vertical conductor 234A'. The joining method of each tab group 108 and each rear voltage detection unit 220A' is not limited to laser welding. The joining method of the terminating negative electrode tab 106T and the rear vertical conductor 234A' is not limited to laser welding.

[0059] Next, the front plate 310A is placed in front of the cell stack 10 and the front voltage detection device 20A. In this state, the second downward protrusion 316A and the second upward protrusion 317A are inserted into the second downward notch 336A and the second upward notch 337A, respectively, from the front. This allows the right end of the front plate 310A and the front end of the right plate 330A to be aligned with each other in the Z direction. Furthermore, rotation or swinging of the front plate 310A in a direction approximately perpendicular to the Y direction can be suppressed. This makes it easier to reliably fix the front plate 310A and the right plate 330A to each other. The structure of the left end of the front plate 310A and the front end of the left plate 340A can be similar to the structure of the right end of the front plate 310A and the front end of the right plate 330A described above.

[0060] Next, the right end of the front plate 310A and the portion of the front bracket 372A extending substantially parallel to the Y direction are joined together by welding. Also, the front end of the right plate 330A and the portion of the front bracket 372A extending substantially parallel to the X direction are joined together by welding. As a result, the right end of the front plate 310A and the front end of the right plate 330A are joined together via the front bracket 372A.

[0061] Next, the rear plate 320A is placed behind the cell stack 10 and the rear voltage detection device 20A'. The left end of the rear plate 320A and the rear end of the left plate 340A may have the same structure as the right end of the front plate 310A and the front end of the right plate 330A described above. The right end of the rear plate 320A and the rear end of the right plate 330A may have the same structure as the left end of the front plate 310A and the front end of the left plate 340A described above.

[0062] Next, the left end of the rear plate 320A and the portion of the rear bracket 374A extending substantially parallel to the Y direction are joined together by welding. Also, the rear end of the left plate 340A and the portion of the rear bracket 374A extending substantially parallel to the X direction are joined together by welding. As a result, the left end of the rear plate 320A and the rear end of the left plate 340A are joined together via the rear bracket 374A.

[0063] Next, the lower plate 350A and the upper plate 360A are respectively placed below and above the cell stack 10. The lower plate 350A and the upper plate 360A are then joined to the front plate 310A, the rear plate 320A, the right plate 330A, and the left plate 340A.

[0064] In this manner, the battery module 1A according to the first embodiment is manufactured.

[0065] The structure for fixing the right end of the front holding body 210A and the front end of the right plate 330A to each other is not limited to the structure according to the first embodiment. For example, three or more protrusions provided on the right end of the front holding body 210A may fit into three or more notches provided on the front end of the right plate 330A. The alignment structure for aligning the protrusions is not limited to notches, but may also be holes. In this case, the protrusions are aligned by being inserted into the holes. Furthermore, the number of locking structures including the locking holes provided on the front end of the right plate 330A and the locking protrusions provided on the right end of the front holding body 210A may be one or three or more.

[0066] Fig. 4 is an enlarged view of a portion of the battery module 1B according to embodiment 2. For the sake of illustration, the front bracket has been removed from Fig. 4. The battery module 1B according to embodiment 2 is similar to the battery module 1A according to embodiment 1, except for the following points.

[0067] The right plate 330B defines a lower notch 331B, an upper notch 332B, a central notch 333B, and a locking hole 334B. The front holder 210B has a first lower protrusion 211B, a first upper protrusion 212B, and a locking protrusion 214B. The front plate 310B has a second lower protrusion 311B and a second upper protrusion 312B.

[0068] The lower notch 331B and the upper notch 332B are provided at the lower and upper corners, respectively, of the front end of the right plate 330B. Providing notches at the corners of a plate reduces the cost of forming the notches compared to providing notches on the sides of the plate. Therefore, the lower notch 331B and the upper notch 332B according to the second embodiment can be formed at lower cost than the first lower notch 331A and the first upper notch 332A according to the first embodiment. Similar to the first lower protrusion 211A and the first upper protrusion 212A according to the first embodiment, the first lower protrusion 211B and the first upper protrusion 212B according to the second embodiment are recessed into the lower notch 331B and the upper notch 332B, respectively. Therefore, similar to the first embodiment, the front holder 210B and the right plate 330B can be aligned with each other in the Z direction. Furthermore, it is possible to suppress rotation or swinging of the front holding body 210B in a direction substantially perpendicular to the Y direction. Therefore, it is possible to easily and reliably fix the front holding body 210B and the right plate 330B to each other.

[0069] The second downward protrusion 311B and the second upward protrusion 312B are inserted into the downward notch 331B and the upper notch 332B, respectively. That is, the first downward protrusion 211B and the second downward protrusion 311B are inserted into the same notch. Therefore, the cost of forming the notches can be reduced compared to when the first downward protrusion 211B and the second downward protrusion 311B are inserted into different notches. Similarly, the first upward protrusion 212B and the second upward protrusion 312B are inserted into the same notch. Therefore, the cost of forming the notches can be reduced compared to when the first upward protrusion 212B and the second upward protrusion 312B are inserted into different notches. Furthermore, the lower surface of the second downward protrusion 311B and the upper surface of the front end of the lower plate 350B can be joined to each other by, for example, laser welding. This makes it easier to ensure a sufficient joining area between the front plate 310B and the lower plate 350B. Similarly, the upper surface of the second upper protrusion 312B and the lower surface of the front end portion of the upper plate 360B can be joined to each other by, for example, laser welding, making it easier to ensure a joining area between the front plate 310B and the upper plate 360B.

[0070] As in the first embodiment, at least a portion of the terminal positive electrode tab 104T is exposed to the right through the central cutout 333B.

[0071] Similar to the pair of lower locking protrusion 214A and lower locking hole 334A, and the pair of upper locking protrusion 215A and upper locking hole 335A in embodiment 1, the pair of locking protrusion 214B and locking hole 334B forms at least a part of a locking structure that locks the right end of front retainer 210B and the front end of right plate 330B to each other.

[0072] In the second embodiment, both the lower notch 331B and the upper notch 332B are provided at the corners of the front end portion of the right plate 330B. However, one of the lower notch 331B and the upper notch 332B may be provided on the front edge of the front end portion of the right plate 330B instead of at the corners of the front end portion of the right plate 330B.

[0073] Although the embodiments of the present invention have been described above with reference to the drawings, these are merely examples of the present invention, and various other configurations can also be adopted.

[0074] For example, in each embodiment, the right plate has multiple alignment structures for aligning multiple protrusions provided on the front retainer. However, the front retainer may also have multiple alignment structures for aligning multiple protrusions provided on the right plate. For example, multiple notches are provided on the right side of the right end of the front retainer. The multiple notches are open toward the right. Multiple protrusions protrude forward from the front end of the right plate. The multiple protrusions provided on the right plate fit into the multiple notches provided in the front retainer. This example also makes it easier to securely fix the front retainer and the right plate to each other. [Explanation of symbols]

[0075] 1A, 1B battery module 10 Cell stack 20A forward voltage detector 30A Housing 100 battery cells 100G cell group 102 Exterior materials 104 Positive electrode tab 104T Termination Positive Tab 106 Negative electrode tab 106T Negative terminal tab 108 Tabs 110 compression pad 210A,210B Front holding body 210aA front opening 211A, 211B 1st downward protrusion 212A,212B 1st upper projection 214A Lower locking protrusion 214B Locking protrusion 215A Upper locking protrusion 220A forward voltage detector 222A forward voltage detection wire 224A Front Connector 230A positive bus bar 232A Front horizontal conductor 232aA fastening hole 234A Front vertical conductor 310A, 310B Front plate 316A,311B 2nd downward protrusion 317A,312B 2nd upper projection 320A Rear Plate 330A, 330B Right Plate 331A 1st lower notch 331B Lower notch 332A 1st upper notch 332B Upper notch 333A,333B center notch 334A Lower locking hole 334B Locking hole 335A Upper locking hole 336A 2nd lower notch 337A 2nd upper notch 340A Left Plate 350A, 350B Lower plate 352A Thermally Conductive Adhesive 360A, 360B Upper plate 372A Front Bracket 374A Rear Bracket

Claims

1. A plurality of battery cells; a voltage detection device that detects the voltages of the plurality of battery cells; a housing that houses the plurality of battery cells and the voltage detection device; Equipped with one of the voltage detection device and the housing has a plurality of protrusions arranged in a predetermined direction, the other of the voltage detection device and the housing has a plurality of alignment structures for aligning the plurality of protrusions, the housing has a plate that covers a portion of the plurality of battery cells; the plate includes an exposure structure that exposes at least a portion of a tab of one of the plurality of battery cells in a direction from a side where the tab is located toward a side where the plate is located; The battery module, wherein the exposure structure and the plurality of alignment structures are aligned in the predetermined direction.

2. The battery module according to claim 1 , wherein the voltage detection device and the plate have a locking structure that locks the voltage detection device and the plate together.

3. A plurality of battery cells; a voltage detection device including a holder positioned on one side of the plurality of battery cells and a voltage detection unit held by the holder and electrically connected to the plurality of battery cells, the voltage detection device detecting the voltages of the plurality of battery cells; a housing that houses the plurality of battery cells and the voltage detection device; Equipped with the housing has a plate that covers the plurality of battery cells and the holder from one side in a direction perpendicular to a direction connecting the plurality of battery cells and the holder, one of the holder and the plate includes a plurality of protrusions aligned in a predetermined direction; the other of the holder and the plate includes a plurality of alignment structures that align the plurality of protrusions.

4. the plate includes an exposure structure that exposes at least a portion of a tab of one of the plurality of battery cells in a direction from a side where the tab is located toward a side where the plate is located; The battery module according to claim 3 , wherein the exposure structure and the plurality of alignment structures are aligned in the predetermined direction.

5. The battery module according to claim 3 or 4, wherein the holder and the plate include a locking structure that locks the holder and the plate together.

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