Battery module and battery pack including the same

Abstract

A battery module according to the present invention includes a first battery cell assembly in which battery cells are stacked in a thickness direction of the battery cells, a second battery cell assembly in which the battery cells stacked in the first battery cell assembly and the battery cells arranged in a row in the length direction of the battery cells are stacked in the thickness direction of the battery cells in the same number as the number of battery cells stacked in the first battery cell assembly, and a module case that houses the first and second battery cell assemblies, wherein the battery cells of the first battery cell assembly are electrically connected to each other and the battery cells of the second battery cell assembly are electrically connected to each other, but the battery cells between the first and second battery cell assemblies are not electrically connected to each other. The present invention also includes a battery pack configured with the battery module.

Description

[Technical Field]

[0001] The present invention relates to a battery module and a battery pack including the same.

[0002] More particularly, the present invention relates to a battery module and a battery pack that can prevent an internal electrical short circuit from occurring due to a simple electrical connection structure.

[0003] This application claims the benefit of priority based on Korean Patent Application No. 10-2021-0144831 dated October 27, 2021, and all contents disclosed in the documents of the relevant Korean patent application are incorporated herein by reference. [Background technology]

[0004] Recently, rechargeable secondary batteries have been widely used as a power source for wireless mobile devices. Secondary batteries are also attracting attention as a power source 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 using secondary batteries are becoming increasingly diverse due to the advantages of secondary batteries, and secondary batteries are expected to be applied to more fields and products in the future.

[0005] In addition, there is an increasing demand for battery modules that house a number of secondary batteries electrically connected in series or parallel and battery packs that are configured with the battery modules as power sources for energy storage systems (ESS) and electric vehicles.

[0006] 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.

[0007] FIG. 1 is a plan view (FIG. 1(a)) showing an example of the structure of an expandable battery module 100′ proposed by the present applicant, and a plan view (FIG. 1(b)) of a battery module stack 1000′ formed by stacking the battery modules 100′, and FIG. 2 is a schematic diagram showing the electrical paths of the battery module stack 1000′ formed by the battery modules of FIG. 1.

[0008] The present applicant has developed a battery module 100' in which a battery cell assembly consisting of a first battery cell assembly 10' in which a plurality of battery cells 1' are stacked in the thickness direction of the battery cells and a second battery cell assembly 20' facing the first battery cell assembly 10' in the length direction of the battery cells and consisting of a plurality of battery cells in the same thickness direction as the first battery cell assembly 10' is housed in a module case 30' in the length direction of a rectangular parallelepiped. This battery module 100' houses a relatively small number of battery cells in each module case 30', and the battery modules can be stacked like Lego blocks in the length direction or thickness direction of the battery cells to freely configure a battery pack taking into account the installation space of the battery module 100' or the installation space of the battery pack. The battery module 100' proposed by the present applicant can thus be called an expandable battery module because it can be manufactured into an unlimited number of battery packs depending on the stacking (design) method.

[0009] However, in the case of expandable battery modules proposed so far, the first and second battery cell assemblies 10', 20' that face each other in the longitudinal direction have been electrically connected to each other. Referring to Figure 1, the battery cells in the bottom two rows of the first and second battery cell assemblies 10', 20' are not connected to each other, but the battery cells in the top two rows are electrically connected to each other between the first and second battery cell assemblies 10', 20' (see electrical connection portion A in Figure 1(a)).

[0010] However, the expandable battery module having such an electrical connection structure has the following problems.

[0011] Since the first and second battery cell assemblies 10' and 20' are electrically connected to each other, the electrical connection structure of the battery module itself becomes complicated. Therefore, when stacking battery modules including the first and second battery cell assemblies 10' and 20', a total of three high-voltage bus bars (a, b, c) are required to electrically connect the battery cell assemblies of each battery module, as shown in FIG. 1(b).

[0012] In particular, referring to FIG. 2, if thermal runaway (hereinafter abbreviated as "TR") occurs in some battery cells of stacked battery modules 100', an internal short circuit can be formed. In other words, in FIG. 2(a), adjacent battery modules are only electrically connected by the high-voltage bus bar described above, and the battery cells between each module are not directly connected to each other. However, if thermal runaway occurs in one battery cell 1', the battery cell 1' melts and adheres to the module case 30' of the adjacent module, causing the thermal runaway to spread to the module case 30' of the other adjacent module and the battery cells 1' located within that module case. As a result, as shown in FIG. 2(b), the thermal runaway progresses along the stacking direction of the battery modules, spreading between the first battery cell assemblies 10' of the left-hand battery module. However, because the first battery cell assembly 10' of the battery module is electrically connected to the second battery cell assembly 20' of each battery module, a short circuit is formed up to the second battery cell assembly 20', resulting in an internal short circuit being formed electrically in the entire battery module 100' or battery module stack 1000' (see FIG. 2(c)). When an internal short circuit is formed in a battery module or battery pack, gas is rapidly generated and overheating occurs, increasing the risk of the battery pack exploding.

[0013] Therefore, there is a need for the development of technology that can simplify the electrical connection structure in an expandable battery module and a battery pack configured therewith, thereby maximizing the utilization of internal space, while preventing or delaying the generation of an internal short circuit during thermal runaway. [Prior art documents] [Patent documents]

[0014] [Patent Document 1] Korean Patent Publication No. 10-2020-0131500 Summary of the Invention [Problem to be solved by the invention]

[0015] The present invention has been devised to solve the above problems, and aims to provide a battery module and a battery pack that eliminates electrical connection between two battery cell assemblies that constitute an expandable module, thereby simplifying the electrical connection structure and preventing the occurrence of internal short circuits. [Means for solving the problem]

[0016] To solve the above problems, a battery module according to the present invention includes: a first battery cell assembly in which battery cells are stacked in a thickness direction of the battery cells; a second battery cell assembly in which the stacked battery cells in the first battery cell assembly and the battery cells arranged in a row in the length direction of the battery cells are stacked in the thickness direction of the battery cells in the same number as the number of stacked battery cells in the first battery cell assembly; and a module case that houses the first battery cell assembly and the second battery cell assembly, wherein the battery cells of the first battery cell assembly are electrically connected to each other and the battery cells of the second battery cell assembly are electrically connected to each other, but the battery cells between the first battery cell assembly and the second battery cell assembly are not electrically connected to each other.

[0017] As an example, the battery cells constituting the first battery cell assembly and the second battery cell assembly may be pouch cells having electrode leads of different polarities extending from both ends.

[0018] As an example, the number of stacked battery cells in the first battery cell assembly and the second battery cell assembly is an even number.

[0019] Specifically, the electrode leads of adjacent battery cells included in the first battery cell assembly and the second battery cell assembly are electrically connected to form an electrical path that is connected in a zigzag direction, and both ends of the electrical path may be electrode leads at both ends of the battery cells included in the first battery cell assembly and the second battery cell assembly, respectively, that are led out toward between the first battery cell assembly and the second battery cell assembly.

[0020] In addition, the electrode leads of the battery cells included in the first battery cell assembly and the second battery cell assembly, respectively, extending between the first battery cell assembly and the second battery cell assembly, have opposite polarities.

[0021] In addition, a terminal bus bar may be coupled to the electrode leads extending from the first battery cell assembly and the second battery cell assembly toward a space between the first battery cell assembly and the second battery cell assembly, respectively.

[0022] For example, to form the electrical paths connected in the zigzag direction, the electrode leads of adjacent battery cells may be directly coupled to each other through an inter-bus bar or by being bent to each other.

[0023] As another example, a first partition wall extending in a thickness direction of the battery cells may be installed between the first battery cell assembly and the second battery cell assembly.

[0024] A second partition wall may be provided in a middle portion of the battery cells stacked in the thickness direction of the first battery cell assembly and the second battery cell assembly, and extend in the length direction of the module case.

[0025] In another aspect of the present invention, a battery pack includes a battery module stack formed by stacking a plurality of the above-described battery modules in a thickness direction of the battery cells, wherein first battery cell assemblies of the battery modules stacked in the thickness direction are electrically connected to each other to form a first electric block, and second battery cell assemblies of the battery modules stacked in the thickness direction are electrically connected to each other to form a second electric block, and the first battery cell assemblies and second battery cell assemblies constituting the first electric block and the second electric block are not electrically connected to each other except for the first battery cell assembly and second battery cell assembly of the battery module stacked in the uppermost layer of the battery module stack.

[0026] The first and second battery cell assemblies of the battery module stacked on the topmost level of the battery module stack are electrically connected by a high-voltage bus bar, thereby electrically connecting the first and second electric blocks.

[0027] As an example, to form the first electrical block and the second electrical block, a first high-voltage bus bar electrically connecting the first battery cell assemblies and a second high-voltage bus bar electrically connecting the second battery cell assemblies may be installed on the battery modules in the stacking direction of the battery modules.

[0028] Specifically, the first high-voltage bus bar is connected to a terminal bus bar coupled to the electrode leads of the battery cells extending from the first battery cell assembly toward a gap between the first and second battery cell assemblies of each battery module, and the second high-voltage bus bar is connected to a terminal bus bar coupled to the electrode leads of the battery cells extending from the second battery cell assembly toward a gap between the first and second battery cell assemblies of each battery module.

[0029] For example, the electrical connection structure of the first battery cell assembly and the second battery cell assembly may be a 1PNS structure, where N is an even number. [Effects of the Invention]

[0030] According to the present invention, it is possible to significantly simplify the electrical connection structure of an expandable battery module including two battery cell assemblies and a battery pack constructed by stacking these battery modules.

[0031] In addition, since each battery cell assembly independently forms an electrical circuit, the formation of an internal short circuit can be controlled to be delayed as much as possible or to be formed sequentially, thereby further improving the safety of the battery pack. [Brief explanation of the drawings]

[0032] [Figure 1] 1A and 1B are a plan view showing an example of the structure of an expandable battery module proposed by the present applicant, and a plan view of a battery module stack formed by stacking the battery modules. [Figure 2] 2 is a schematic diagram showing electrical paths in a battery module stack configured with the battery modules of FIG. 1. FIG. [Figure 3] 1A and 1B are a plan view and an enlarged view of a main part of a battery module according to the present invention; [Figure 4] 1 is a perspective view showing a configuration of an electrode assembly of a battery module according to the present invention; [Figure 5] 5 is an exploded perspective view showing an assembly process of the battery module of FIG. 4. [Figure 6] 3 is a schematic diagram illustrating an electrical path when stacking battery modules according to the present invention in comparison with the electrical path in FIG. 2. FIG. [Figure 7] 1 is a plan view showing an electrical connection structure of a battery module stack in which battery modules are stacked according to the present invention; [Figure 8] 1 is a perspective view of a battery pack including a battery module stack constructed using the battery module of the present invention; [Figure 9]3 is an example showing another stacking structure of the battery module of the present invention and a battery module stack constituted by the battery module. DETAILED DESCRIPTION OF THE INVENTION

[0033] 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 is consistent with 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 or her invention.

[0034] As used throughout the present specification, the terms "comprise" or "have" and the like are intended to specify the presence of any feature, number, step, operation, component, part, or combination thereof described in the specification, and should be understood as not precluding the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0035] Furthermore, when a layer, film, region, plate, or other portion is described as being "on" another portion, this includes not only the case where it is "directly on top" of the other portion, but also the case where there is another portion in between. Conversely, when a layer, film, region, plate, or other portion is described as being "under" another portion, this includes not only the case where it is "directly below" the other portion, but also the case where there is another portion in between. Furthermore, in the specification of the present invention, being "located on" can include not only the case where it is located at the top, but also the case where it is located at the bottom.

[0036] (battery module) A battery module according to the present invention includes a first battery cell assembly in which battery cells are stacked in the thickness direction of the battery cells; a second battery cell assembly in which the stacked battery cells in the first battery cell assembly and the battery cells arranged in a row in the length direction of the battery cells are stacked in the thickness direction of the battery cells in the same number as the number of stacked battery cells in the first battery cell assembly; and a module case that houses the first and second battery cell assemblies, wherein the battery cells of the first battery cell assembly are electrically connected to each other and the battery cells of the second battery cell assembly are electrically connected to each other, but the battery cells between the first and second battery cell assemblies are not electrically connected to each other.

[0037] FIG. 3 is a plan view and an enlarged view of a main part of a battery module according to the present invention, FIG. 4 is a perspective view showing the configuration of an electrode assembly of the battery module according to the present invention, and FIG. 5 is an exploded perspective view showing the assembly process of the battery module of FIG. 4.

[0038] As shown in FIG. 3, the battery module of the present invention includes a first battery cell assembly 10 in which battery cells 1 are stacked in the thickness direction of the battery cells, and a second battery cell assembly 20 in which the stacked battery cells 1 in the first battery cell assembly 10 and the battery cells 1 arranged in a row in the length direction of the battery cells are stacked in the thickness direction of the battery cells in the same number as the stacked battery cells of the first battery cell assembly 10. In this embodiment, the first and second battery cell assemblies 10 and 20 are stacked four by four in the thickness direction of the battery cells. The battery cells in the same layer of the first and second battery cell assemblies 10 and 20 are arranged to face each other in the length direction. Because the two battery cell assemblies are arranged longitudinally as described above, the module case 30 that houses the battery cell assemblies also has a rectangular parallelepiped shape that is elongated in the length direction. As shown in the enlarged view of Figure 3, the battery cells of the first and second battery cell assemblies are connected to terminal bus bars TB1 and TB2 located between the first and second battery cell assemblies 10 and 20, respectively, but are not electrically connected to each other between the first and second battery cell assemblies 10 and 20. The terminal bus bars are labeled TB1 and TB2 according to polarity.

[0039] The battery cells constituting the first and second battery cell assemblies 10 and 20 may be pouch cells, so-called bidirectional pouch cells, in which electrode leads with opposite polarities are led out from both ends of the battery cell. In addition, the number of battery cells 1 stacked in the thickness direction of the battery cells in the expandable module of the present invention is an even number.

[0040] A first partition wall 40 extending in the thickness direction of the battery cells may be provided between the first and second battery cell assemblies 10, 20. This first partition wall 40 prevents heat transfer between the first and second battery cell assemblies 10, 20. However, for convenience of illustration, the first partition wall 40 is not shown in FIGS. 4 and 5. In addition, since the number of battery cells 1 stacked in the thickness direction of the battery cells is an even number, the same number of battery cells may be divided into upper and lower sections. That is, a second partition wall 50 extending in the length direction of the module case 30 is provided in the middle of the battery cells stacked in the thickness direction of the first and second battery cell assemblies 10, 20 (between two battery cells on each side in the example of FIG. 3). This second partition wall 50 prevents heat transfer in the thickness direction.

[0041] The battery module 100 of the present invention includes terminal bus bars TB1 and TB2 between the first and second battery cell assemblies 10 and 20. Specifically, when electrically connecting the stacked battery cells, the terminal bus bars TB1 and TB2 are coupled to the ends of the electrical paths. As will be described later, the terminal bus bars TB1 and TB2 are coupled to high-voltage bus bars and electrically connected to the terminal bus bars TB1 and TB2 of adjacent battery modules.

[0042] 4(b) and 4(c) are perspective views of the first and second battery cell assemblies constituting the battery module 100 of the present invention, as seen from the front and rear, respectively, and FIG. 4(a) is a perspective view showing the sides where the first and second battery cell assemblies are arranged facing each other. Referring to FIG. 4, it can be seen that the leads of battery cells 1 that are not connected to terminal bus bars TB1 and TB2 are electrically connected by inter-bus bars IB. In FIG. 4, inter-bus bars IB are connected to a support plate between the terminal bus bars TB1 and TB2 (see FIG. 4(a)), and the leads of battery cells located at the longitudinal ends of the first and second battery cell assemblies 10 and 20 are connected by inter-bus bars IB (see FIGS. 4(b) and 4(c)).

[0043] FIG. 5 shows that the first and second battery cell assemblies 10 and 20 are housed in a module case 30. The module case 30 includes a U-shaped frame 31 with an open top and an upper frame 32 coupled thereto, but is not limited to this. For example, a C-shaped frame with an open side and an I-shaped frame coupled thereto are also possible. Other types of module case 30 are also possible as long as they can stably accommodate the battery cell assemblies. The module case 30 includes a front end plate 33 and a rear end plate 34 coupled to the front and rear ends of the battery cell assemblies. A recess is formed in the center of the upper frame 32, and a through-hole 32a is formed through this recess so that the terminal portion of a terminal bus bar coupled to the battery cell assemblies can protrude. The terminal portion of the terminal bus bar protruding through the through-hole 32a is coupled to a high-voltage bus bar, which will be described later.

[0044] FIG. 6 is a schematic diagram showing electrical paths when the battery modules of the present invention are stacked, in comparison with the electrical paths in FIG.

[0045] As shown in Fig. 6, a battery module stack may be formed by stacking a plurality of battery modules in the thickness direction of the battery cells. The detailed structure of the battery module stack will be described later in connection with the battery pack.

[0046] The electrical connection structure of the battery cell assembly and the battery module stack provided in the battery pack of the present invention will be described with reference to FIGS.

[0047] FIG. 6(a) illustrates the electrical path of the electrical connection structure of the stacked battery module structure consisting of the first and second battery cell assemblies of FIG. 2, and FIG. 6(b) illustrates the electrical path of the electrical connection structure of the stacked battery module structure consisting of the first and second battery cell assemblies of the present invention.

[0048] In the battery cell assembly of Fig. 6, the electrode leads R of adjacent battery cells are electrically connected to form electrical paths that connect four battery cells 1 and 1' stacked in the thickness direction in a zigzag pattern. To form the electrical paths that connect the four battery cells 1 and 1' in the zigzag pattern, the electrode leads R of adjacent battery cells 1 and 1' may be bent together and directly joined by, for example, welding, or may be electrically connected through an inter-bus bar IB as shown in Fig. 4.

[0049] The ends of the electrical path connected in a zigzag direction are electrode lead portions of the battery cells included in the first and second battery cell assemblies (10', 20') (10, 20) that are respectively led toward the space between the first and second battery cell assemblies. In this case, the polarities of the electrode lead portions led from the first and second battery cell assemblies (10', 20') (10, 20) are opposite. The terminal bus bars described above are connected to the electrode lead portions at both ends of the electrical path.

[0050] The difference between Figures 4(a) and 4(b) is that one of the electrode leads extending between the first and second battery cell assemblies connects the first and second battery cell assemblies 10' and 20' in the example of Figure 4(a), whereas in the example of the present invention shown in Figure 4(b), it is disconnected and does not connect the first and second battery cell assemblies 10 and 20. In Figure 6, a first partition wall 40 extending in the thickness direction of the battery cells is formed between the first and second battery cell assemblies, and although the electrode lead appears to be disconnected in the example of Figure 6(a), it is actually connected through the first partition wall 40. When battery modules with such an electrical connection structure are stacked to form a battery pack, a complex structure is created, such as connecting three high-voltage bus bars as shown in Figure 1, which can lead to the problem of internal short circuits. This will be explained in more detail in connection with the battery pack of the present invention below.

[0051] (battery pack) According to another aspect of the present invention, a battery pack includes a battery module stack 1000 formed by stacking a plurality of the above-described battery modules 100 in the thickness direction of the battery cells, wherein first battery cell assemblies 10 of the battery modules 1000 stacked in the thickness direction are electrically connected to each other to form a first electric block P, and second battery cell assemblies 20 of the battery modules 1000 stacked in the thickness direction are electrically connected to each other to form a second electric block Q, and the first battery cell assemblies 10 and second battery cell assemblies 20 constituting the first electric block P and the second electric block Q are not electrically connected to each other except for the first and second battery cell assemblies 10 and 20 of the battery module stacked on the topmost level of the battery module stack 1000.

[0052] The battery pack 2000 of the present invention includes a battery module stack 1000 formed by stacking a plurality of battery modules 100 in the thickness direction of the battery cells, with no electrical connection between the first and second battery cell assemblies. The first battery cell assemblies 10 of the battery modules 10 stacked in the thickness direction of the battery module stack 1000 are electrically connected to each other to form a first electric block P. The second battery cell assemblies 20 of the battery modules stacked in the thickness direction of the battery module stack 1000 are electrically connected to each other to form a second electric block Q. The battery module stack 1000 provided in the battery pack of the present invention essentially prevents electrical connection between the first and second electric blocks P and Q, just as the first and second battery cell assemblies 10 and 20 of each battery module constituting the first and second electric blocks P and Q are not electrically connected to each other. That is, the first and second battery cell assemblies 10 and 20 of each battery module constituting the first and second electric blocks P and Q are not electrically connected to each other. However, since the first and second battery cell assemblies of the battery module stacked in the uppermost layer of the battery module stack are electrically connected by, for example, a high-voltage bus bar H3, the first electric block P and the second electric block Q are electrically connected in the uppermost layer of the battery module stack 1000. Therefore, referring to Fig. 7, of the nine battery modules constituting the first and second electric blocks, the first and second electric blocks P and Q of the bottom eight battery modules are not electrically connected to each other, but the first and second electric blocks P and Q of the ninth battery module are electrically connected.

[0053] An example of the battery module stack is shown in FIGS. 6 and 7. FIG.

[0054] FIG. 6(a) is the same as FIG. 2 and illustrates the formation of an internal short circuit due to thermal runaway. That is, the battery module stack of FIG. 6(a) includes a battery module 100' electrically connected between first and second battery cell assemblies 10', 20'. Therefore, when the first battery cell assemblies and the second battery cell assemblies of adjacent battery modules are connected by high-voltage bus bars to form electrical blocks P and Q, the electrical blocks P and Q are also electrically connected. In the case of FIG. 6(a), if thermal runaway TR occurs in one battery cell 1' of a battery cell assembly, it propagates to the battery cell 1' of an adjacent battery module, resulting in an electrical circuit connection, creating an internal short circuit. In this case, thermal runaway TR does not propagate sequentially, but rather can propagate from the first battery cell assembly 10' to the second battery cell assembly 20', bypassing the thermal runaway TR propagation order. That is, As shown in Figure 1(b), when electricity flows along an inverted U-shaped path, thermal runaway does not spread vertically from the point where thermal runaway occurs, but rather spreads horizontally due to an internal short circuit, accelerating the propagation speed of thermal runaway. This significantly increases the amount of gas generated inside the battery pack, and the risk of explosion also increases.

[0055] 6(b), that is, in the case of the present invention, even if thermal runaway occurs in the first battery cell assembly 10 on the left, the thermal runaway propagates only to the battery modules 100 above and below it, and does not propagate to the second battery cell assembly 20 on the right, specifically to the second electric block Q. This is because, in principle, there is no electrical connection between the first and second battery cell assemblies 10, 20 and the first and second electric blocks P, Q, so no internal short circuit is formed.

[0056] FIG. 7 is a plan view showing the electrical connection structure of a battery module stack in which battery modules according to the present invention are stacked.

[0057] FIG. 7 also clearly illustrates the effects of a battery pack including a battery module stack 1000 according to the present invention. As described above, the battery module stack 1000 according to the present invention is configured such that, except for the battery module 100 stacked at the top of the stack, there is no electrical connection between the first and second electric blocks P and Q, and thus, in the event of thermal runaway, the left and right electric block sections P and Q are propagated separately. However, due to the structure of a battery pack that must be connected to, for example, a vehicle's electrical components, the flow of electricity must be in an inverted U shape as shown in FIG. 7, so the first and second battery cell assemblies 10 and 20 of the battery module 100 stacked at the top of the battery module stack 1000 must be electrically connected. However, even in this case, thermal runaway TR propagates sequentially rather than between the first and second battery cell assemblies 10 and 20 of each battery module 100 until it reaches the top. In addition, the present invention suppresses the occurrence of internal short circuits within the battery pack, preventing rapid propagation of thermal runaway TR and allowing it to propagate sequentially, thereby reducing the amount of gas generated and significantly mitigating the risk of explosion.

[0058] Furthermore, as shown in FIG. 7, if a structure is adopted in which the first and second electrical blocks P and Q are not electrically connected, then when connecting the high-voltage bus bars HB1 and HB2 to the terminal bus bars TB1 and TB2 provided on the first and second battery cell assemblies 10 and 20 of each battery module 100, it is sufficient to provide only two high-voltage bus bars HB1 and HB2 extending in the stacking direction of the battery modules. In other words, there is no need to provide three high-voltage bus bars as shown in FIG. 1. This greatly simplifies the electrical connection structure of the battery pack. As shown in the enlarged view of FIG. 7, the first and second high-voltage bus bars HB1 and HB2 are respectively coupled to terminal bus bars TB1 and TB2 of opposite polarities exposed at the top of the battery modules to electrically connect the battery modules 100.

[0059] Meanwhile, the first and second battery cell assemblies 10 and 20 of the battery module 100 stacked in the uppermost layer of the battery module stack 1000 can be electrically connected to each other by a high-voltage bus bar H3. Specifically, by connecting the high-voltage bus bar H3 (third high-voltage bus bar) to terminal bus bars TB1 and TB2 coupled to electrode leads of battery cells extending between the first and second battery cell assemblies 10 and 20 of the battery module 100 stacked in the uppermost layer, an inverted U-shaped electrical path can be implemented in the battery module stack.

[0060] FIG. 8 is a perspective view of a battery pack 2000 including a battery module stack 1000 constructed from the battery modules of the present invention.

[0061] 7, in which two high-voltage bus bars HB1 and HB2 are coupled side by side in the module stacking direction within the first and second electric blocks P and Q. When this battery module stack 1000 is housed in an appropriate battery pack case 2100, a battery pack 2000 can be obtained that simplifies the electrical connection structure, increases the utilization of space within the pack, and prevents the occurrence of internal short circuits.

[0062] FIG. 9 shows an example of another stacking structure and electrical connection structure of the battery module of the present invention and the battery module stack 1000 configured by the battery module.

[0063] FIG. 9(a) shows a structure in which first and second battery cell assemblies 10 and 20, each formed by stacking two battery cells in the thickness direction within one battery module, are stacked one, two, and four battery modules, each forming a 1P2S battery cell assembly.

[0064] FIG. 9(b) shows a structure in which first and second battery cell assemblies 10 and 20, each formed by stacking six battery cells in the thickness direction within one battery module, are stacked one, two, and four battery modules, each forming a 1P6S battery cell assembly.

[0065] In FIGS. 3 to 6, the electrical connection structure of the first and second battery cell assemblies 10, 20 is shown as a 1P4S structure. However, as shown in FIG. 9, the electrical connection structure of the battery module may be different structures such as 1P2S or 1P6S. For example, although not shown in FIG. 9, a 1P8S electrical connection structure may also be adopted. In other words, the electrical connection structure of the first and second battery cell assemblies 10, 20 may be a 1PNS (N is an even number) structure. Regardless of the structure, the first and second battery cell assemblies 10, 20, the first electrical block P formed by connecting adjacent first battery cell assemblies 10, and the second electrical block Q formed by connecting second battery cell assemblies 20 between stacked battery modules 100 are not electrically connected to each other except for the first and second battery cell assemblies 10, 20 of the terminal battery module 100.

[0066] 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 by the following claims, and all technical ideas within the equivalent range should be interpreted as being included in the scope of the present invention.

[0067] Meanwhile, although terms indicating directions such as up, down, left, right, front, and back are used in this specification, it is obvious that these terms are used merely for convenience of explanation and may vary depending on the position of the object in question, the position of the observer, etc. [Explanation of symbols]

[0068] 1: Battery cell 10: First battery cell assembly 20: Second battery cell assembly 30: Module case 40:First bulkhead 50:Second bulkhead TB1, TB2: Terminal bus bars IB: Interbusbar TR: Thermal runaway battery cell HB1, HB2, HB3: High voltage busbars R: Electrode lead P: 1st electric block Q: Second electric block 100: Battery module 1000: Battery module stack 2100: Battery pack case 2000: Battery pack

Claims

1. a battery module stack formed by stacking a plurality of battery modules in the thickness direction of the battery cells; The battery module includes: a first battery cell assembly in which a plurality of battery cells are stacked in a thickness direction in which the plurality of battery cells are stacked; a second battery cell assembly in which a plurality of battery cells are stacked in a thickness direction of the stacked plurality of battery cells; and a module case that houses the first battery cell assembly and the second battery cell assembly; each of the plurality of stacked battery cells in the first battery cell assembly and each of the plurality of stacked battery cells in the second battery cell assembly face each other in a longitudinal direction in which the first battery cell assembly and the second battery cell assembly face each other; the number of the plurality of stacked battery cells in the first battery cell assembly is the same as the number of the plurality of stacked battery cells in the second battery cell assembly; the battery cells of the first battery cell assembly are electrically connected to each other; the battery cells of the second battery cell assembly are electrically connected to each other; the battery cells constituting the first battery cell assembly and the second battery cell assembly are battery cells having electrode leads of different polarities extending from both ends thereof, The battery cells included in the first battery cell assembly and the second battery cell assembly are electrically connected to each other such that electrode leads of adjacent battery cells form electrical paths that are connected in a zigzag direction, the first battery cell assemblies of the battery modules stacked in the thickness direction are electrically connected to each other to form a first electric block, and the second battery cell assemblies are electrically connected to each other to form a second electric block; a battery pack in which each first battery cell assembly constituting the first electric block and each second battery cell assembly constituting the second electric block are not electrically connected to each other except for the first battery cell assembly and the second battery cell assembly of a battery module stacked in an uppermost layer of the battery module stack.

2. The battery pack according to claim 1 , wherein the number of stacked battery cells in the first battery cell assembly and the second battery cell assembly is an even number.

3. 3. The battery pack of claim 2, wherein both ends of the electrical path are electrode leads at both ends of the battery cells included in the first battery cell assembly and the second battery cell assembly, respectively, that are led out toward a gap between the first battery cell assembly and the second battery cell assembly.

4. 4. The battery pack of claim 3, wherein the electrode leads of the battery cells included in the first battery cell assembly and the second battery cell assembly, respectively, extending between the first battery cell assembly and the second battery cell assembly, have opposite polarities.

5. 5. The battery pack according to claim 4, wherein a terminal bus bar is coupled to the electrode leads extending from the first battery cell assembly and the second battery cell assembly toward a space between the first battery cell assembly and the second battery cell assembly, respectively.

6. The battery pack according to claim 3 , wherein the electrode leads of the adjacent battery cells are directly coupled to each other through an inter-bus bar or by being bent to each other to form the electrical paths connected in the zigzag direction.

7. The battery pack according to claim 1 , wherein a first partition wall extending in a thickness direction of the battery cells is installed between the first battery cell assembly and the second battery cell assembly.

8. 2. The battery pack of claim 1, wherein a second partition wall extending in a length direction of the module case is provided in an intermediate portion of the battery cells stacked in a thickness direction of the first battery cell assembly and the second battery cell assembly.

9. 2. The battery pack of claim 1, wherein the first battery cell assembly and the second battery cell assembly of the battery module stacked in the uppermost stack are electrically connected by a high-voltage bus bar to electrically connect the first electric block and the second electric block.

10. 2. The battery pack of claim 1, wherein a first high-voltage bus bar electrically connecting the first battery cell assemblies and a second high-voltage bus bar electrically connecting the second battery cell assemblies are installed on the battery modules in a stacking direction of the battery modules to form the first electric block and the second electric block.

11. the first high voltage bus bar is connected to a terminal bus bar coupled to an electrode lead of the battery cell extending from the first battery cell assembly toward a position between the first battery cell assembly and the second battery cell assembly of each battery module; 11. The battery pack of claim 10, wherein the second high-voltage bus bar is connected to a terminal bus bar coupled to an electrode lead of the battery cell extending from the second battery cell assembly toward a position between the first battery cell assembly and the second battery cell assembly of each battery module.

12. The battery pack according to claim 1 , wherein an electrical connection structure of the first battery cell assembly and the second battery cell assembly is a 1PNS structure, and N is an even number.

13. The battery pack according to claim 1 , further comprising a battery pack case that houses the battery module stack.

Images