Battery module and battery pack including same

Abstract

The battery module according to the present invention includes a battery cell assembly in which two or more battery cells, each having a lead formed on both ends in the longitudinal direction, are arranged in a row in the longitudinal direction to form a longitudinal unit cell, and the longitudinal unit cells are stacked in two or more rows in the thickness direction of the battery cell; a module case that houses the battery cell assembly; a sensing line that is electrically connected to an electrode lead of a battery cell included in the battery cell assembly, and has one end exposed to the outside of the module case; and a sensing plate that is coupled to one end of the sensing line exposed to the outside.

Description

[Technical field]

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

[0002] More particularly, the present invention relates to a battery module that is configured to be expandable and that can easily sense electrical characteristics between battery modules.

[0003] The present invention also relates to a battery pack including the battery module.

[0004] This application claims the benefit of priority based on Korean Patent Application No. 10-2021-0143922 filed on October 26, 2021, and all contents disclosed in the documents of that Korean patent application are incorporated herein by reference. [Background technology]

[0005] Recently, rechargeable secondary batteries have been widely used as energy sources for wireless mobile devices. Secondary batteries are also attracting attention as energy sources for electric vehicles and hybrid electric vehicles, which are being proposed as a solution to address air pollution caused by existing gasoline and diesel vehicles that use fossil fuels. Therefore, the types of applications that use secondary batteries are becoming increasingly diverse due to the advantages of secondary batteries, and it is expected that secondary batteries will be applied to more fields and products in the future.

[0006] In addition, there is an increasing demand for battery modules housing a number of secondary batteries electrically connected in series or parallel and battery packs including the battery modules as power sources for energy storage systems (ESS) and electric vehicles.

[0007] Such a battery module or battery pack includes an external housing made of a metal material to protect a plurality of secondary batteries from external impact and to accommodate and store them.

[0008] 1(a) is a partial perspective view of a conventional battery module 1, and FIG. 1(b) shows a connection structure of battery modules for inter-module sensing of the conventional battery modules. Such a conventional battery module has the following problems.

[0009] First, since single battery cells are stacked only in the thickness direction, the space utilization rate of the battery cell arrangement is low and the degree of freedom in design is low, so there is a limit to bundling such modules to form a battery pack. That is, it is difficult to form a battery module or battery pack that fits into a limited space such as an automobile or into various spaces. In addition, since a large number of battery cells, about several tens of cells, are stacked in one module, if one battery cell catches fire, the flame easily spreads to other battery cells, and there is a risk that the module will burn down in a short time.

[0010] Secondly, as shown in Fig. 1(a), since the sensing line 2 is connected to the connector 3, and the connector 3 is connected to a mating external connector to sense the electrical characteristics of the battery module, a connector with a complex structure had to be installed for each module. In addition, a separate external connector having a spigot connection structure with the connector installed in the module was required. Since such a connector with a spigot connection structure has a complex shape, the terminal connection structure (structure of the spigot type connector) for sensing the electrical characteristics of the battery module was complicated. In addition, the connector with a complex structure was difficult to mold, which caused an increase in manufacturing costs.

[0011] Thirdly, as shown in Fig. 1(b), inter-bank sensing of adjacent battery modules 1 required the work of connecting the modules with bus bars 4 and harnesses 5 that connect the sensing connectors. Therefore, conventional inter-module sensing required the work of connecting the modules with a complex assembly structure and fixing the components by laser welding or the like.

[0012] Therefore, there is a demand for the development of battery module-related technology that not only increases the design freedom of battery modules and battery packs, but also enables easy sensing of each unit module as well as between modules with a simple structure. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] Korean Patent Registration No. 10-2259416 Summary of the Invention [Problem to be solved by the invention]

[0014] The present invention has been devised to solve the above problems, and an object of the present invention is to provide an expandable battery module in which battery cells are connected in the length direction as well as the thickness direction to improve space utilization of the battery module and the battery pack.

[0015] Another object of the present invention is to provide a battery module having a structure that allows direct sensing of the module by eliminating the need for a connector with a complicated spigot-joint structure as in the conventional expandable module.

[0016] Another object of the present invention is to provide a battery pack having a structure that enables simple direct sensing between a plurality of battery modules without a complex assembly structure. [Means for solving the problem]

[0017] To solve the above problems, a battery module according to the present invention includes a battery cell assembly in which two or more battery cells, each having a lead formed on both ends in the longitudinal direction, are arranged in a row in the longitudinal direction to form a longitudinal unit cell, and the longitudinal unit cells are stacked in two or more rows in a thickness direction of the battery cell; a module case that houses the battery cell assembly; a sensing line that is electrically connected to an electrode lead of a battery cell included in the battery cell assembly, and has one end exposed to the outside of the module case; and a sensing plate that is coupled to one end of the sensing line exposed to the outside.

[0018] For example, the sensing plate may include a coupling portion coupled to one end of the sensing line and a plate portion connected to an external terminal.

[0019] Specifically, the plate portion may have a larger area than the coupling portion.

[0020] As an example, the sensing plate may be arranged alongside a side of the module case where one end of the sensing line is exposed, and the exposed surface of one end of the sensing line may be located at the same height as the side of the module case, so that the sensing plate may be closely attached to the side of the module case when the sensing plate is coupled to one end of the sensing line.

[0021] Also, the module case may have an opening at a position corresponding to one end of the sensing line, and the sensing line may be exposed to the outside through the opening.

[0022] As an example, one end of the sensing line may be bent horizontally to form a counter coupling plate parallel to the sensing plate.

[0023] As an example, the sensing line may be connected to a terminal bus bar coupled to an electrode lead of a battery cell included in the battery cell assembly, and the sensing line may be electrically connected to the battery cell of the battery cell assembly through the terminal bus bar.

[0024] Specifically, the other end of the sensing line may be welded to the terminal bus bar.

[0025] Alternatively, the other end of the sensing line and the terminal bus bar may be coupled to each other via the same sensing plate as the sensing plate coupled to one end of the sensing line.

[0026] As a specific example, the terminal bus bar may be located between electrode leads of battery cells opposed in the longitudinal direction of the longitudinal unit cell, and the electrode leads of the battery cells opposed in the longitudinal direction may be coupled to the terminal bus bar.

[0027] More specifically, the terminal bus bar may include a first terminal bus bar coupled to one of the electrode leads of the battery cells facing each other in the length direction, and a second terminal bus bar coupled to the other electrode lead, the sensing lines may include a first sensing line coupled to the first terminal bus bar and a second sensing line coupled to the second terminal bus bar, and the sensing plates may include first and second sensing plates coupled to the first and second sensing lines, respectively.

[0028] For example, a ventilation plate extending in the length direction of the battery cell and having a ventilation channel formed therein may be installed between rows of the same number of length direction unit cells on both sides of the length direction of the battery cell, and the terminal bus bar and the sensing line may be supported by the ventilation plate.

[0029] According to another aspect of the present invention, a battery pack may include the battery module. In addition, the battery modules of the battery pack may be stacked in a thickness direction of the battery cells. Effect of the Invention

[0030] According to the present invention, an expandable battery module can be obtained in which battery cells are connected in the length direction as well as the thickness direction to improve space utilization of the battery module and the battery pack.

[0031] Furthermore, the present invention can realize a direct sensing structure suitable for such an expandable battery module.

[0032] In addition, the present invention can provide a battery pack having a structure that allows simple direct sensing between a plurality of battery modules without a complex assembly structure. [Brief description of the drawings]

[0033] [Figure 1] 1A is a partial perspective view of a conventional battery module 1. FIG. 1B shows a connection structure of battery modules for inter-module sensing of the conventional battery modules. [Diagram 2] FIG. 2 is an exploded perspective view of the battery module of the present invention; [Diagram 3] 3 is a plan view showing an electrical connection structure of a battery cell assembly included in the battery module of FIG. 2. [Figure 4] 1 is a schematic diagram showing an example of a sensing plate according to the present invention. [Diagram 5] 3A and 3B are a perspective view and a front view showing the structure of a ventilation plate included in the battery module of FIG. 2. [Figure 6] 4 is a perspective view showing a coupling structure of a middle part of a battery module excluding a sensing line and a module case according to the present invention; FIG. [Figure 7]1 is a perspective view showing a coupling structure of an end portion of a battery module according to an embodiment of the present invention; [Figure 8] 2 is a perspective view showing a coupling structure of a middle portion of a battery module according to an embodiment of the present invention; FIG. [Figure 9] FIG. 13 is a perspective view showing a coupling structure of a middle portion of a battery module according to another embodiment of the present invention. [Figure 10] 4 is a schematic diagram showing a cross section of a coupling between a sensing line and a sensing plate. FIG. [Figure 11] 2 is a view showing an upper surface of a battery module stack in which battery modules according to the present invention are stacked and bonded; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0034] The present invention will be described in detail below. Prior to this, the terms and words used in the specification and claims should not be interpreted in a limited manner based on their ordinary or dictionary meanings, but should be interpreted in a meaning and concept that corresponds to the technical idea of ​​the present invention, based on the principle that the inventor can appropriately define the concept of the term in order to best describe his / her invention.

[0035] As used throughout the present specification, terms such as "comprise" or "have" are intended to specify the presence of any feature, number, step, operation, component, part, or combination thereof described in the specification, but are to be understood as not precluding the possibility of the presence or addition of one or more other features, number, step, operation, component, part, or combination thereof.

[0036] In addition, when a layer, film, region, plate, or other part is described as being "on" another part, this includes not only the case where it is "directly on" the other part, but also the case where there is another part in between. Conversely, when a layer, film, region, plate, or other part is described as being "under" another part, this includes not only the case where it is "directly under" the other part, but also the case where there is another part in between. In addition, in the specification of the present invention, being "on" can include not only the case where it is upper, but also the case where it is lower.

[0037] The battery module according to the present invention includes a battery cell assembly in which two or more battery cells, each having a lead formed on both ends in the longitudinal direction, are arranged in a row in the longitudinal direction to form a longitudinal unit cell, and the longitudinal unit cells are stacked in two or more rows in the thickness direction of the battery cell; a module case that houses the battery cell assembly; a sensing line that is electrically connected to an electrode lead of a battery cell included in the battery cell assembly, and has one end exposed to the outside of the module case; and a sensing plate that is coupled to one end of the sensing line exposed to the outside.

[0038] FIG. 2 is an exploded perspective view of a battery module of the present invention, FIG. 3 is a plan view showing the electrical connection structure of a battery cell assembly included in the battery module of FIG. 2, and FIG. 4 is a perspective view showing the structure of a ventilation plate included in the battery module of FIG. 2.

[0039] For convenience of illustration, FIG. 2 omits the illustration of the sensing line inside the battery module and the sensing plate coupled thereto, and illustrates only the remaining parts in an exploded view.

[0040] As shown in Fig. 2, the present invention includes a battery cell assembly 100 including a lengthwise unit cell 110, and a module case 200 in which the battery cell assembly 100 is housed. In Fig. 2, based on a typical pouch-type battery cell 10 having leads 11, 12 formed at both ends and extending long in the lengthwise direction, the X direction is the length direction of the battery cell 10 or module (case), the Y direction is the thickness direction of the battery cell 10 or module case 200 (stacking direction of the battery cells), and the Z direction is the up-down direction.

[0041] The battery cell 10 of the present invention is a battery cell having electrode leads formed on both ends in the length direction (a so-called bidirectional battery cell (bidirectional pouch cell)). With this configuration, the positive electrode lead 11 and the negative electrode lead 12 are respectively extended from both ends of a single battery cell 10, eliminating interference between the leads and increasing the area of ​​the electrode leads, making it easier to connect the electrode leads to a bus bar.

[0042] The battery cell assembly 100 of the present invention includes a bundle of battery cells, in which two or more such bidirectional battery cells are arranged in a row in the length direction and the electrode leads of the battery cells facing each other in the length direction are electrically connected to each other, as a length direction unit cell 110. In FIG. 2, two battery cells are connected in the length direction to form the length direction unit cell 110, but two or more battery cells may be connected in the length direction. In principle, the number of battery cells 10 connected in the length direction is not limited as long as the space of the battery pack in which the battery module case 200 or the battery module 1000 is installed is allowed. However, since the space of the battery module 1000 or the battery pack that can be installed in an automobile or the like is actually limited, it is preferable to connect about two to four battery cells 10 in the length direction. In addition, the number of battery cells 10 connected in the length direction may vary depending on the size (length) of the battery cells 10 to be connected. As described above, in this specification, a combination of two or more battery cells 10, each having leads 11, 12 formed at both ends in the longitudinal direction, is referred to as a longitudinal unit cell 110, in which the leads 11, 12 at the ends of opposing battery cells are electrically connected to each other.

[0043] The battery cell assembly 100 included in the battery module 1000 of the present invention is formed by stacking the lengthwise unit cells 110 in two or more rows in the thickness direction (X direction) of the battery cell 10. The number of rows in which the lengthwise unit cells 110 are stacked also depends on the allowable space of the battery module 1000 and the battery pack, the size of the battery cell 10, and the like. In addition, the number of battery cells 10 in the length direction and the number of rows can be determined in consideration of the required capacity of the required electric device. In this way, the present invention can adjust the number of battery cells in the length direction and the number of rows of the battery cell assembly 100 housed in the module case 200, thereby improving the design freedom. In addition, the battery cell assembly 100 can be configured more compactly by stacking, for example, about 2 to 4 battery cell assemblies 100 in the length direction and about 2 to 6 rows in the thickness direction of the battery cell, instead of stacking several tens of battery cell assemblies 100 as in the conventional case. In addition, by accommodating the battery cell assemblies 100 each composed of a small number of battery cells 10 in separate module cases 200 and stacking the battery modules 1000 including the module cases 200 in the length direction or thickness direction of the battery cells 10 like Lego blocks, a battery pack can be freely configured in consideration of the space in which the battery modules 1000 are installed or the installation space of the battery pack. For example, by stacking the battery modules 1000 in the length direction, the same effect can be achieved without connecting the battery cells of the length direction unit cells 110 further in the length direction. This allows the individual battery modules (unit modules) to be configured more compactly. In addition, the battery modules 1000 can be stacked as many as necessary in the thickness direction of the battery cells, thereby improving the degree of freedom in design. In the structure in which several tens of battery cells are stacked in one module case as shown in FIG. 1, it is difficult to configure a battery pack as desired. That is, since the minimum unit of the battery cells included in the battery modules constituting the battery pack is different, the degree of freedom in design of the conventional battery module 1 is inevitably reduced accordingly.

[0044] Also, for example, if a fire occurs in one of the battery cells 10 included in the battery module, the fire can easily spread to adjacent battery cells 10 in the battery module 1 of Fig. 1. However, the structure of the battery module 1000 of Fig. 2 or a battery pack including the same has a small number of battery cell assemblies 100 housed separately in the battery module 1000, so that even if a fire occurs in a battery cell 10 in one battery module 1000, the fire is unlikely to spread to other battery modules 1000.

[0045] As described above, the battery cell assemblies 100 of the present invention are connected in the length direction and thickness direction of the battery cells, and each battery cell assembly 100 consisting of a specific number of battery cells 10 is housed in a module case. Therefore, since any number of different battery packs can be manufactured depending on the stacking (design) method of the battery module 1000 including such battery cell assemblies 100, the battery module 1000 of the present invention can be called an expandable module.

[0046] The battery cell assembly 100 of this embodiment shown in FIGS. 2 and 3 has two battery cells 10 connected in the lengthwise direction, and the lengthwise unit cells 110 are stacked in four rows, forming a so-called 2P4S connection structure, with a total of eight battery cells 10 making up the battery cell assembly 100.

[0047] However, by varying the number of rows of lengthwise unit cells connected in pairs in the length direction, battery cell assemblies such as 2-row stacking (1P4S), 6-row stacking (3P4S), 8-row stacking (4P4S), etc., in which an even number of rows are stacked are also possible. Also, structures in which three cells are connected in the length direction instead of two (1P6S, 2P6S, 3P6S, ...), structures in which four cells are connected (1P8S, 2P8S, 3P8S, ...), and structures in which more than two cells are connected are also possible. In short, it is an advantage of the present invention that the stacking structure of the lengthwise unit cells and battery cell assemblies can be changed to be diverse and scalable according to the design requirements of the battery module and battery pack described above.

[0048] For convenience of illustration, FIG. 3 does not show the vent plate 300, and only shows the electrical connection structure of the battery cell assembly 100.

[0049] In FIG. 3, in the four rows of lengthwise unit cells 110, the electrode leads 11, 12 of the battery cells facing each other in the lengthwise direction in the top two rows are not coupled to each other but are coupled to terminal bus bars of different polarities. However, the electrode leads 11, 11, 12 of the battery cells adjacent to each other in the thickness direction of the battery cells in the top two rows may be coupled to each other, and the coupled electrode leads may be coupled to the terminal bus bar. On the other hand, in the bottom two rows of lengthwise unit cells 110 that are not coupled to the terminal bus bar, the electrode leads 11, 12 of the battery cells facing each other in the lengthwise direction are coupled to each other. Specifically, in the bottom two rows of lengthwise unit cells 110, the electrode leads 11, 11, 12 of the battery cells adjacent to each other in the thickness direction of the battery cells are coupled to each other, and then the electrode leads 12, 12, 11, 11 of the other battery cells in the bottom two rows facing each other in the lengthwise direction may be coupled to each other.

[0050] Meanwhile, the leads 11, 12 of the battery cells included in the longitudinal unit cells 110 in adjacent rows at the front and rear ends in the longitudinal direction are bent in the thickness direction of the battery cells and welded together.

[0051] The present invention also includes a module case 200 in which the battery cell assembly 100 is housed.

[0052] That is, as shown in Fig. 2, the present invention includes a module case 200 that surrounds and houses the battery cell assembly 100. The module case 200 has a rectangular parallelepiped structure that is elongated in the length direction to house the battery cell assembly specific to the present invention. In Fig. 2, the module case 200 is formed by combining a C-shaped wall 210 and an I-shaped wall 220, but is not limited thereto. For example, a form in which two C-shaped walls arranged on the left and right or above and below are combined is also possible, and a form in which the upper, lower, left and right cases are each separated and combined by welding, hooking, or a fastening member is also possible.

[0053] The module case 200 of the present invention also includes a front end plate 230 and a rear end plate 240. The front end plate 230 and the rear end plate 240 are respectively coupled to the C-wall-I-wall combination to close the front and rear of the module.

[0054] The module case 200 may have an opening 211 at a position corresponding to one end of a sensing line so that one end of the sensing line, which will be described later, may be exposed to the outside. The sensing line may be exposed to the outside through the opening, and one end of the sensing line may be coupled to a sensing plate, which will be described later.

[0055] The battery module of the present invention also includes a sensing line 400 electrically connected to an electrode lead of a battery cell included in the battery cell assembly. The sensing line 400 may be a conductive sensing metal wire or a sensing cable in which a predetermined coating is applied to the sensing metal wire. Preferably, the sensing line 400 is flexible, and more preferably, the sensing line 400 is a plastically deformable sensing cable that can be bent or folded and maintains its shape in a bent state. If the sensing line 400 is made of such a material, the path of the sensing line connected to the electrode lead part or the bus bar or sensing member connected thereto in the battery module can be freely changed to match the space inside the module and led out to the outside of the module case.

[0056] The sensing line 400 of the present invention is for sensing electrical characteristics of a battery module, i.e., voltage, current, resistance, etc. Therefore, the sensing line 400 may be connected to a sensing device outside the module, for example, a sensing cable, and may ultimately be connected to a BMS, ECU, or a predetermined controller installed in a battery pack to measure electrical characteristics of a unit battery module or between a plurality of battery modules. In order to measure electrical characteristics of a battery module stage, the sensing line 400 must be electrically connected to electrode leads of all battery cells 10 included in the battery cell assembly 100. However, the sensing line 400 does not necessarily need to be directly connected to each electrode lead, and may be electrically connected to the electrode leads through a terminal bus bar 500 coupled to the electrode leads.

[0057] A characteristic feature of the present invention is that one end of the sensing line 400 is exposed to the outside of the module case 200. That is, unlike the conventional battery module, a connector with a spigot-joint structure for sensing is not installed, but the sensing line 400 electrically connected to the battery cell inside the module is turned toward the outside, and one end of the sensing line 400 is exposed to the outside of the module case 200. When one end of the exposed sensing line 400 is coupled to a sensing plate 600 described below, the electrical characteristics of the battery module can be easily sensed. The specific shape of the sensing line 400 and its coupling relationship with other members will be described later.

[0058] The present invention includes a sensing plate 600 coupled to one end of the sensing line 400 exposed to the outside. The sensing plate 600 is coupled to one end of the sensing line 400 to sense the electrical characteristics of the battery module stage. The sensing plate 600 may be connected to an adjacent battery module or to a BMS or the like through a sensing cable. As described above, the sensing structure of the present invention is a simple combination of the sensing terminal 400 and the sensing plate 600, not a connector structure, so that electrical connection with an external terminal is very easy. Also, there is no need to form a complicated connector. The sensing plate 600 may use a commonly used electrical connection member, but it is necessary to provide a plate portion 620 with a large area for connection with an external terminal.

[0059] FIG. 4 is a schematic diagram showing an example of a sensing plate according to the present invention.

[0060] As shown, the sensing plate 600 includes a coupling part 610 coupled to one end of the sensing line 400 and a plate part 620 connected to an external terminal. The coupling part 610 may be coupled to one end of the sensing line 400 by welding or screw coupling, but the coupling method is not limited thereto, and other coupling methods may be used as long as the sensing line 400 and the sensing plate 600 can be efficiently coupled. The sensing plate 600 of FIG. 4(a) includes a coupling part 610 for welding, and the sensing plate 600 of FIG. 4(b) includes a coupling part 610' having a fastening hole formed therein so that the sensing plate 600 can be coupled to a fastening member such as a screw. The plate part 620 has a larger area than the coupling parts 610, 610' for connection with an external terminal. The sensing plate 600 has a flat plate shape, so that it can be coupled to the outer surface of the module case 200 in close contact. For example, the coupling portion 610 is coupled to one end of the exposed sensing line, and the rear surface of the plate portion 620 is coupled to the outer surface of the module case, thereby making it possible to more firmly couple the sensing plate 600 to the module case. A specific coupling form between the sensing plate and the sensing line will be described later.

[0061] The battery module of the present invention may also include a venting plate 300 for supporting the battery cell assemblies 100, the sensing lines 400, and the terminal bus bars 500 described below, and for venting gas within the module.

[0062] 5 is a perspective view and a front view showing the structure of a venting plate included in the battery module of FIG.

[0063] 2 and 5, a venting plate 300 is installed between the rows of the lengthwise unit cells 110 constituting the battery cell assembly 100, extending in the lengthwise direction of the battery cell from the front end to the rear end of the module case 200. The venting plate 300 is disposed between the rows of the lengthwise unit cells 110, and can prevent the propagation of heat and flame in the thickness direction of the battery cell when a fire occurs inside the battery cell due to overheating. Preferably, the same number of rows of the lengthwise unit cells 110 are disposed on both sides of the venting plate 300 based on the lengthwise direction of the battery cell 10. In this embodiment, two rows of the lengthwise unit cells 110 are disposed on the left and right sides of the venting plate 300. The venting plate 300 is preferably larger than the battery cell so as to cover the entire area of ​​the battery cell as much as possible. That is, the width of the venting plate 300 is preferably large enough to cover the entire width of the battery cell. The length of the venting plate 300 may be extended in the length direction of the battery cells across the front and rear ends of the module case 200 to an extent that the length direction unit cells 110 can be entirely covered.

[0064] In particular, the venting plate 300 has a hollow structure in which a gas venting channel 311 is formed to exhaust gas and flames.

[0065] Most of the gas inside the battery module is generated around the leads of the battery cells, and around the gas pockets, which are terraces between the leads and the battery cell body when the pouch cell is used as a reference. Therefore, it is preferable that the venting channel 311 has a gas inlet E (venting through holes 312 or an opening communicating therewith) communicating with the inside of the battery module at a position of the venting plate 300 corresponding to the gas pocket. Referring to FIG. 5, the venting plate 300 has a total of four venting through holes 312 at positions corresponding to the gas pockets of the battery cells included in the battery cell assembly 100, and the venting through holes 312 communicate with the gas venting channel 311.

[0066] In addition, the gas venting channel 311 has an outlet O through which the gas and flame can be discharged. Since the gas and flame flowing in through the gas inlet corresponding to the gas pocket are at high temperature, the outlet O of the venting channel must be located far away from the gas inlet E to lower the temperature of the gas and discharge it to the outside. For this reason, the gas venting channel 311 of the present invention has a flow path that extends long from the gas inlet E to the outlet O.

[0067] Specifically, the gas venting channel 311 may include a lengthwise channel 311a extending in the length direction of the venting plate 300 and a widthwise channel 311b communicating with the lengthwise channel 311a and opening to the outside of the venting plate 300. In this case, it is preferable that the widthwise channel 311b is formed at a position corresponding to a midpoint between the leads at both ends of the battery cell included in the lengthwise unit cell 110 when the battery cell assembly is combined with the venting plate 300. As a result, as shown in Fig. 5, gas from a gas pocket near the lead at the end of the battery cell moves to a position corresponding to the midpoint through the lengthwise channel 311a, and the gas and flames can be easily exhausted from this position through the widthwise channel 311b.

[0068] The gas venting channels, particularly the lengthwise channels 311a, may be formed in a plurality of numbers along the length of the venting plate 300. Referring to the front view of Fig. 5, the venting plate 300 has five lengthwise channels 311a separated by partitions (W). Gas passing through the lengthwise channels 311a may join together in the widthwise channels 311b and be discharged to the outside toward at least one of the upper and lower portions of the width of the venting plate 300.

[0069] Meanwhile, the venting plate 300 of this embodiment includes a body part 310 extending in the length direction of the battery cell, and a heat conduction prevention plate 320 installed perpendicular to the body part 310. The heat conduction prevention plate 320 is installed at a position corresponding to between electrode leads of battery cells facing each other in the length direction of the lengthwise unit cell 110. Therefore, the heat conduction prevention plate 320 can block heat conduction between the battery cells arranged in the length direction of the lengthwise unit cell 110.

[0070] Adjacent battery cells of the battery cell assembly 100 that are not coupled to a terminal bus bar (described later) may be directly connected to each other through their electrode leads. The bending plate 300 includes a separate through hole 321 for coupling with such an electrode lead or for supporting the coupled electrode lead portion. In the present embodiment, the separate through hole 321 is formed on one side of the heat conduction prevention plate 320. Also, in order to provide a space for bending and welding the electrode lead of the battery cell at the front or rear end of the lengthwise unit cell 110, a lead coupling through hole 313 through which the electrode lead of the battery cell can pass is formed at the front and rear ends of the bending plate 300. The size of the lead coupling through hole 313 may be changed in various ways according to the purpose, such as a size that allows easy coupling between the leads or a size that can support the coupled leads.

[0071] As described above, the sensing line 400 is electrically connected to the electrode leads of the battery cell assembly 100. In order to sense the electrical characteristics of a module stage, it is more efficient to connect the sensing line 400 to the terminal bus bar 500, which is electrically connected to the electrode leads, rather than connecting the sensing line 400 to the electrode leads of each battery cell one by one. Since the terminal bus bar 500 is a terminal that is electrically connected to all the battery cells in the battery module and connected to an external terminal, by connecting the sensing line 400 to the terminal bus bar 500, it is possible to sense the electrical characteristics of all the battery cells in the battery module, i.e., the module stage.

[0072] In one embodiment of the present invention, the sensing line 400 is connected to a terminal bus bar 500 which is coupled with an electrode lead of a battery cell included in the battery cell assembly 100, thereby electrically connecting the sensing line 400 to the battery cell 10 through the terminal bus bar 500. Prior to describing the connection structure between the sensing line 400 and the terminal bus bar 500, the connection structure between the terminal bus bar 500 and the battery cell assembly 100 in an expandable battery module such as the present invention will be described first. This clarifies the electrical connection structure of the battery module represented by the terminal bus bar 500, and it will be easily understood that sensing can be easily performed at the module level of the battery module by simply connecting the sensing line 400 to the terminal bus bar 500.

[0073] FIG. 6 is a perspective view showing a connection structure of an intermediate portion of a battery module excluding a sensing line and a module case according to the present invention, and FIG. 7 is a perspective view showing a connection structure of an end portion of a battery module according to the present invention.

[0074] 6(a) illustrates the connection between electrode leads of battery cells facing each other in the length direction corresponding to the middle of a length direction unit cell 110. Terminal bus bars 500, 500' are connected to main body parts 310 located on the left and right sides of a heat conduction prevention plate 320 on one side (front side) of the venting plate 300, and the leads of the battery cells in the front two rows are connected to the terminal bus bars 500, 500', respectively. To facilitate the connection of the terminal bus bars 500, 500' to the venting plate, terminal bus bar support blocks 510, 510' are installed on the venting plate, and the terminal bus bars can be inserted into the support blocks 510, 510' for connection (see FIG. 6(a)). However, the electrode leads 11, 12 of battery cells facing each other in the length direction in the front two rows of battery cells are not connected to each other.

[0075] 6(b) shows the other side (rear side) of the ventilation plate 300, and illustrates that the electrode leads 11, 12 of the battery cells facing each other in the longitudinal direction are welded together through lead connection through holes 321 formed in a heat conduction prevention plate 320 of the ventilation plate 300. However, the connection of the electrode leads 11, 12 is not limited to direct welding, and for example, they may be connected by interposing an inter-bus bar (not shown) between the electrode leads.

[0076] FIG. 7 illustrates the electrode lead connection relationship of a battery cell located at the end of a length-direction unit cell 110, where FIG. 7(a) shows the state before connection and FIG. 7(b) shows the state after connection.

[0077] In FIG. 7(a), the electrode leads 12, 12 of the two rows of lengthwise unit cells 110 on one side (front side) of the bending plate 300 are bent toward the bending plate 300 in the thickness direction of the battery cells, and the electrode leads 11, 11 of the battery cells of the two rows of lengthwise unit cells 110 on the other side (rear side) are also bent toward the bending plate 300.

[0078] 7(b) shows that the electrode leads 11, 12 of the bent battery cell are welded together through lead connection through holes 313 formed in the bending plate 300. However, even in this case, the connection of the electrode leads 11, 12 is not limited to a direct welding connection, and for example, the electrode leads can be connected by interposing an inter-bus bar between them.

[0079] As shown in Fig. 3, Fig. 6 and Fig. 7, the battery cell assembly 100 of the present invention is electrically connected in a 2P4S structure, and the terminal bus bar 500 is located between the leads of the battery cells 10 facing each other in the length direction and is connected to the leads, respectively. More specifically, the terminal bus bar 500 is composed of a first terminal bus bar 500 connected to one of the electrode leads of the battery cells facing each other in the length direction, and a second terminal bus bar 500' connected to the other electrode lead. The first and second terminal bus bars 500, 500' are respectively connected to electrode leads of different polarities. As will be described later, the sensing line is also composed of a first sensing line 400 connected to the first terminal bus bar 500 and a second sensing line 400' connected to the second terminal bus bar 500', and can sense the electrical characteristics of the module stage. The sensing plate also includes first and second sensing plates 600 and 600' coupled to the first and second sensing lines, respectively.

[0080] Hereinafter, a specific embodiment of a coupling structure of the sensing line and the sensing plate when the terminal bus bar is disposed between battery cells facing each other in the longitudinal direction of the longitudinal unit cell will be described.

[0081] (First embodiment) FIG. 8 is a perspective view showing a coupling structure of a middle part of a battery module according to an embodiment of the present invention.

[0082] The terminal bus bars 500, 500' are located between the leads on both sides of the battery cells facing each other in the length direction, and include first and second terminal bus bars 500, 500' respectively coupled to the leads on both sides. Also shown in Fig. 8 is a rectangular parallelepiped module case 200 surrounding the battery cell assemblies and the terminal bus bars. Fig. 8 shows sensing lines 400, 400' coupled to terminal bus bars 500, 500' inside the module case 200 and sensing plates 600, 600' positioned outside the module case, respectively. That is, the other ends of the sensing lines 400, 400' are horizontally bent toward the sensing plates 600, 600' and welded to the sensing plates. The sensing lines 400, 400' also include first and second sensing lines 400, 400' corresponding to the terminal bus bars 500, 500', and one end of the first and second sensing lines is bent toward the module case 200. One end of the sensing lines 400, 400' is exposed to the outside of the module case through an opening formed in the module case, and a connecting portion of the sensing plates 600, 600' may be connected to the exposed portion by welding or a fastening member.

[0083] Second embodiment FIG. 9 is a perspective view showing a coupling structure of a middle portion of a battery module according to another embodiment of the present invention.

[0084] The basic connection structure of the sensing line and the sensing plate in this embodiment is the same as that in the first embodiment, except that the other end of the sensing line is not directly connected to the terminal bus bar, but is connected to the terminal bus bar through the same sensing plate as that installed outside the module case.

[0085] In the first embodiment, the sensing lines 400, 400' extending vertically are bent horizontally toward the terminal busbars 500, 500' so as to be coupled with the terminal busbars 500, 500'. In this case, the sensing lines 400, 400' are bent abruptly, and therefore the bent parts may be subjected to a bending load and may be damaged during long-term use. In addition, since the position of the terminal busbars 500, 500' in the battery module may change depending on the type, shape, and internal structure of the battery module, it is inefficient to change and form the shape (path) of the sensing lines in accordance with the position of the terminal busbars 500, 500'. For example, when the sensing lines 400, 400' are formed using a conductive metal plate, this problem becomes more serious. In this embodiment, the sensing plate 600, 600' is positioned between the other end of the sensing line 400, 400' and the terminal bus bar, and even if the path of the sensing line 400, 400' and the position of the terminal bus bar 500, 500' are different, the sensing plate 600, 600' is used as a kind of bridge to easily connect the sensing line and the terminal bus bar. Therefore, there is no need to forcibly bend or reshape the sensing line 400, 400'. In other words, there is an advantage that the sensing line 400, 400' and the terminal bus bar 500, 500' can be electrically connected to each other in accordance with various types of internal structures of modules by appropriately installing the sensing plate in consideration of the shape and position of the sensing line and the position of the terminal bus bar.

[0086] Meanwhile, one end of the sensing lines 400, 400' may be exposed by protruding to the outside. However, in order to reduce the space occupied by the sensing part and to form a more compact battery module by closely contacting the sensing plate to the module case, it is preferable that the sensing lines 400, 400' do not protrude completely outside the module case 200. If the exposed surface of the sensing lines 400, 400' is positioned at the same height as the side of the module case 210, one end 410 of the sensing line does not protrude to the outside, and the sensing plate 600, 600' can be coupled to the exposed surface. FIG. 10 is a schematic diagram showing a coupling section of the sensing line 400 and the sensing plate 600. As shown in the figure, one end 410 of the sensing line 400 is exposed through an opening of the module case 400, but the exposed surface of the one end 410 is positioned at the same height as the side of the module case 210, so that the sensing line 400 does not protrude to the outside of the case. Therefore, the sensing plate 600 arranged alongside the side of the module case may have its coupling portion 610 closely coupled to an exposed surface of one end of the sensing line, and accordingly, the plate portion 620 of the sensing plate 600 is also closely coupled to the side of the module case 210. Therefore, the entire sensing plate 600 is closely coupled to the module case, making it possible to configure the battery module more compact.

[0087] Meanwhile, one end 410 of the sensing line 400 is bent horizontally to form a portion parallel to the sensing plate 600. That is, the horizontal bent portion forms a coupling plate facing the sensing plate 600 so as to be coupled with the coupling portion 610 of the sensing plate 600 with a sufficient contact area.

[0088] FIG. 11 is a view showing an upper surface of a battery module stack in which battery modules according to the present invention are stacked and bonded.

[0089] This drawing shows a case where two battery modules are stacked in the thickness direction of the battery cell.

[0090] The terminal bus bars 500, 500' of each battery module 1000 protrude outward to be connected to external terminals. Sensing plates 600, 600' are positioned on both sides of the terminal bus bars 500, 500' on the module case. The coupling portions of the sensing plates 600, 600' are coupled to one ends 410 of the sensing lines 400, 400' exposed to the outside through openings 211 formed in the upper side of the module case. By connecting a sensing cable to the plate portions 620 of the sensing plates 600, 600', it is possible to easily sense electrical characteristics at the module stage.

[0091] As described above, according to the present invention, it is possible to easily perform sensing in a module stage and connection of sensing units between adjacent battery modules without the need for preparing a complex connector structure, inter-bus bar, harness, etc. That is, a sensing unit for sensing and a battery module including the sensing unit can be configured more compactly to match the structure of an expandable module. Also, since the sensing line and the sensing plate are exposed to the outside and a plurality of battery modules can be directly connected to a sensing cable, etc., a direct sensing structure can be realized in a simple form.

[0092] 11 illustrates two battery modules stacked together, but two or more battery modules 1000 may be stacked together in the thickness direction of the battery cells, for example. Also, such battery modules may be housed in a pack case to form a battery pack.

[0093] A battery pack having a direct sensing structure can be easily implemented by connecting the sensing plate of the battery module to a BMS of a battery pack.

[0094] The drawings disclosed in the present invention are for the purpose of explanation and not for the purpose of limiting the technical idea of ​​the present invention, and the scope of the technical idea of ​​the present invention is not limited by such drawings. The scope of protection of the present invention should be interpreted according to the following claims, and all technical ideas within the equivalent range should be interpreted as being included in the scope of the present invention.

[0095] Meanwhile, although terms indicating directions such as up, down, left, right, front, and back are used in this specification, it is obvious that such terms are used merely for convenience of explanation and may change depending on the position of the object of interest, the position of the observer, etc. [Explanation of symbols]

[0096] 10: Battery cell 11, 12: Lead 100: Battery cell assembly 110: Lengthwise unit cell 200: Module case 210: C-shaped wall 220: I-shaped wall 211: Opening 230: Front end plate 240: Rear end plate 300: Venting plate 310: Main body 311: Gas venting channel 320: Heat conduction prevention plate 400, 400´: Sensing line (1st sensing line, 2nd sensing line) 410: One end of the sensing line 500, 500´: Terminal busbar (1st terminal busbar, 2nd terminal busbar) 510, 510´: Terminal busbar support block 600: Sensing plate 610, 610´: Joint part 620: Plate section 1000: Battery module

Claims

1. a battery cell assembly in which two or more battery cells, each having a lead formed on both ends in the length direction, are arranged in a row in the length direction to form a length direction unit cell, and the length direction unit cells are stacked in two or more rows in the thickness direction of the battery cell; a module case that houses the battery cell assembly; a sensing line electrically connected to an electrode lead of a battery cell included in the battery cell assembly, the sensing line having one end exposed to the outside of the module case; and a sensing plate coupled to one end of the sensing line exposed to the outside, one end of the longitudinal unit cell of the first row is coupled to one end of the longitudinal unit cell of the second row, the other end of the longitudinal unit cell of the first row is coupled to the other end of the second longitudinal unit cell of the second row, and a first battery cell and a second battery cell in the longitudinal unit cells of the first row are not coupled to each other. Battery module.

2. The battery module of claim 1 , wherein the sensing plate comprises a coupling portion coupled to one end of the sensing line and a plate portion connected to an external terminal.

3. The battery module according to claim 2 , wherein the plate portion has a larger area than the coupling portion.

4. the sensing plate is disposed next to a side of the module case where one end of the sensing line is exposed, 2. The battery module of claim 1, wherein an exposed surface of one end of the sensing line is located at the same height as a side surface of the module case, and the sensing plate is in close contact with the side surface of the module case when the sensing plate is coupled to the one end of the sensing line.

5. The battery module of claim 1 , wherein the module case has an opening at a position corresponding to one end of the sensing line, and the sensing line is exposed to the outside through the opening.

6. The battery module of claim 1 , wherein one end of the sensing line is horizontally bent to form an opposing coupling plate parallel to the sensing plate.

7. 2. The battery module of claim 1, wherein the sensing lines are connected to a terminal bus bar coupled to electrode leads of battery cells included in the battery cell assembly, and the sensing lines are electrically connected to the battery cells of the battery cell assembly through the terminal bus bar.

8. The battery module according to claim 7 , wherein the other end of the sensing line is welded to the terminal bus bar.

9. The battery module of claim 7 , wherein the other end of the sensing line and the terminal bus bar are coupled to each other via a sensing plate that is the same as a sensing plate coupled to one end of the sensing line.

10. 8. The battery module according to claim 7, wherein the terminal bus bar is positioned between electrode leads of battery cells opposed in the longitudinal direction of the longitudinal unit cell, and the electrode leads of the battery cells opposed in the longitudinal direction are coupled to the terminal bus bar.

11. the terminal bus bar includes a first terminal bus bar coupled to one of the electrode leads of the battery cells facing each other in a longitudinal direction, and a second terminal bus bar coupled to the other electrode lead, the sensing lines include a first sensing line coupled to the first terminal bus bar and a second sensing line coupled to the second terminal bus bar; The battery module of claim 10 , wherein the sensing plate comprises first and second sensing plates coupled to the first and second sensing lines, respectively.

12. a venting plate extending in a longitudinal direction of the battery cell and having a venting channel formed therein is installed between rows of unit cells in the longitudinal direction of the battery cell, the rows having the same number of unit cells on both sides of the longitudinal direction of the battery cell; The battery module according to claim 7 , wherein the terminal bus bars and the sensing lines are supported by the bending plate.

13. A battery pack comprising the battery module according to any one of claims 1 to 12.

14. The battery pack according to claim 13 , wherein a plurality of the battery modules are stacked in a thickness direction of the battery cells.

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