Battery Module

Abstract

A battery module is provided, comprising: a cell stack having a plurality of battery cells each having electrode leads; a module housing that accommodates the cell stack; and a busbar assembly having an electrically conductive busbar electrically connected to the electrode leads; wherein the busbar assembly has a gas outlet formed therein for discharging gas generated from the battery cells toward the outside of the cell stack; and the module housing has a venting member for discharging the gas discharged from the gas outlet to the outside of the module housing.

Description

Technology Field

[0001] The present invention relates to a battery module having a cell stack in which a plurality of battery cells are stacked, and more specifically, to a battery module capable of discharging gas generated internally to the outside. Background Technology

[0002] Unlike primary batteries, secondary batteries can be charged and discharged, so they can be applied in various fields such as digital cameras, mobile phones, laptops, hybrid cars, and electric vehicles. Examples of secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-hydrogen batteries, and lithium secondary batteries.

[0003] Among these secondary batteries, extensive research is currently underway on lithium-ion batteries, which possess high energy density and discharge voltage. Recently, lithium-ion batteries are being manufactured and used as flexible pouch-type battery cells or rigid prismatic or cylindrical can-type battery cells. Furthermore, multiple battery cells are electrically connected to form a stacked cell matrix, which is placed inside a module housing to constitute a battery module.

[0004] Meanwhile, electrolyte gas may leak to the outside of the battery cell when various events occur, such as when the battery cell reaches the end of its lifespan, when swelling occurs in the battery cell, when the battery cell is overcharged, when the battery cell is exposed to heat, when a sharp object such as a nail penetrates the outer material of the battery cell, or when an external impact is applied to the battery cell. In particular, in the case of high-capacity pouch-type lithium secondary batteries, a problem may arise in which a large amount of electrolyte gas is exposed through the sealing area of ​​the pouch (outer material) when the above-mentioned events occur. A technology has been proposed to install venting holes (venting parts, gas exhaust ports, gas passage ports) on the walls of the module housing to release electrolyte gas generated in the internal space of the battery module to the outside of the battery pack.

[0005] Meanwhile, in a battery module according to the prior art, multiple spaces are formed due to the shape of the battery cell, the connection structure between the battery cell and the busbar, and the arrangement structure of the battery cell accommodated inside the module housing. When ignition occurs in a battery cell, high-temperature electrolyte gas, flames and / or combustible materials are ejected and fill the aforementioned spaces.

[0006] However, battery modules according to the prior art do not have a structure sufficient to induce the rapid discharge of gases generated inside the module housing (in this specification, 'gas' is defined to include electrolyte gas, flame, and combustible material) to the outside of the module housing through venting holes. Consequently, there are limitations in preventing the phenomenon of thermal propagation, in which high-temperature gases and heat propagating after the ignition of a battery cell propagate to adjacent battery cells, thereby causing instantaneous ignition of adjacent battery cells. Prior art literature

[0008] (Patent Document 0001) KR 2020-0143977 A (Published Dec. 28, 2020)(Patent Document 0002) KR 2020-0110081 A (Published Sep. 23, 2020) The problem to be solved

[0009] In one aspect, the present invention aims to provide a battery module capable of minimizing heat propagation by inducing rapid external discharge of gas generated in a battery cell.

[0010] In addition, as one aspect, the present invention aims to provide a battery module having a structure that induces gas emitted from a portion where the electrode leads of a battery cell are arranged to be rapidly discharged to the outside of the module housing.

[0011] In addition, the present invention aims to provide, in one aspect, a battery module capable of minimizing heat propagation between adjacent battery cells. means of solving the problem

[0013] As one aspect for achieving at least some of the above-mentioned objectives, the present invention provides a battery module comprising: a cell stack having a plurality of battery cells each having electrode leads; a module housing that accommodates the cell stack inside; and a busbar assembly having an electrically conductive busbar electrically connected to the electrode leads; wherein the busbar assembly has a gas outlet formed therein for discharging gas generated from the battery cells toward the outside of the cell stack, and the module housing has a venting member for discharging the gas discharged from the gas outlet to the outside of the module housing.

[0014] Here, a flow space is formed between the outer surface of the busbar assembly and the inner surface of the module housing through which gas discharged from the gas outlet flows, and the venting member may be provided at a position within the module housing corresponding to the flow space.

[0015] Additionally, the busbar assembly further comprises an insulating support plate on which the busbar is installed, and the gas outlet may be formed by penetrating at least a portion of the support plate and the busbar. In this case, the gas outlet may include an insulating outlet formed in the support plate and a busbar outlet formed in the busbar that communicates with the insulating outlet. A coupling hole to which the electrode lead is coupled is formed in the busbar, and the busbar outlet may have a shape with a width greater than that of the coupling hole. Additionally, the busbar outlet may be formed integrally with the coupling hole.

[0016] In addition, a through hole is formed in the support plate through which the electrode lead passes so that the electrode lead can be coupled to the bus bar, and the insulator outlet can be formed integrally with the through hole.

[0017] The above fluid space extends along a first plane perpendicular to the longitudinal direction of the battery cell, and the venting member may be provided on one or both sides of the fluid space within the module housing.

[0018] In addition, the venting member may be provided on the surface of the module housing facing the gas outlet.

[0019] Meanwhile, a battery module according to one embodiment of the present invention may further include a filling member covering at least a portion of the cell stack. The filling member may be accommodated in at least a portion of a first space formed between the cell stack and the inner surface of the busbar assembly. In this case, the electrode leads are located at both longitudinal ends of the battery cell, the busbar assembly is coupled to the electrode leads at both longitudinal ends of the battery cell, and the first space may be located at both longitudinal ends of the battery cell.

[0020] Additionally, the filling member may be accommodated in at least a portion of the second space formed between the upper side of the cell stack and the inner surface of the module housing opposite thereto.

[0021] The above-mentioned filling member may be formed of a heat-resistant material having a heat resistance temperature of 100 degrees or higher. The above-mentioned filling member may include at least some of ceramic, graphite, alumina, and heat-resistant plastic.

[0022] Meanwhile, the cell stack may be provided with a thermal diffusion blocking member that blocks the diffusion of at least one of heat and flame between the battery cells. The thermal diffusion blocking member may be made of a fire-resistant and thermal insulating material. Additionally, the thermal diffusion blocking member may be composed of at least a portion of mica, kaolin, aerogel, silicone, and ceramic.

[0023] And, the heat diffusion blocking member can be coupled to the busbar assembly across a first space formed between the cell stack and the inner surface of the busbar assembly.

[0024] Additionally, the venting member may include a venting hole formed in the module housing. The venting member may include a venting hole formed in the module housing and a venting unit installed in the venting hole, and the venting member may have a structure that opens when gas is discharged.

[0025] The battery cell may be composed of a pouch-type secondary battery comprising an electrode receiving portion that accommodates an electrode assembly inside, a sealing portion that seals at least a portion of the circumference of the electrode receiving portion, and an electrode lead that is electrically connected to the electrode assembly. Effects of the invention

[0027] According to one embodiment of the present invention having such a configuration, the effect of minimizing heat / flame propagation phenomena can be obtained by inducing rapid external discharge of gas generated in the battery cell.

[0028] In addition, according to one embodiment of the present invention, the gas emitted from the portion where the electrode lead of the battery cell is placed is induced to be rapidly discharged to the outside of the module housing.

[0029] In addition, according to one embodiment of the present invention, the effect of minimizing heat propagation between adjacent battery cells can be obtained. Brief explanation of the drawing

[0031] FIG. 1 is a perspective view of a battery module according to one embodiment of the present invention. FIG. 2 is a cross-sectional view along the line I-I' of FIG. 1. Figure 3 is an enlarged view of part A of Figure 2. FIG. 4 is a cross-sectional view along the line II-II' of FIG. 2. Figure 5 is a schematic diagram of a busbar assembly viewed from B in Figure 4. FIG. 6 is a perspective view illustrating the connection state of the cell stack and the busbar shown in FIG. 2. FIG. 7 is a perspective view of a battery cell according to an embodiment of the present invention. FIG. 8 is a perspective view of a busbar according to an embodiment of the present invention. FIG. 9 is a perspective view illustrating the assembled state of a cell stack and a busbar assembly according to an embodiment of the present invention. FIGS. 10 and FIGS. 11 are cross-sectional views illustrating variations of the battery module shown in FIGS. 2. FIG. 12 is a perspective view of a battery module according to another embodiment of the present invention. FIG. 13 is a cross-sectional view along the line III-III' of FIG. 12. Fig. 14 is an enlarged view of section C of Fig. 13. FIG. 15 is a cross-sectional view along the line IV-IV' of FIG. 13. FIG. 16 is a cross-sectional view illustrating a modified example of the battery module shown in FIG. 13. Fig. 17 is an enlarged view of section D of Fig. 16. FIG. 18 is a perspective view of a battery module according to another embodiment of the present invention. FIG. 19 is a cross-sectional view along the V-V' line of FIG. 18. FIG. 20 is a cross-sectional view along the line VI-VI' of FIG. 19. Specific details for implementing the invention

[0032] Prior to the detailed description of the present invention, the terms and words used in the specification and claims described below should not be interpreted as being limited to their ordinary or dictionary meanings. Instead, they should be interpreted in a sense and concept consistent with the technical spirit of the present invention, based on the principle that the inventor may appropriately define the concept of the terms to best describe his invention. Accordingly, the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present invention and do not represent all aspects of the technical spirit of the present invention. Therefore, it should be understood that various equivalents and modifications capable of replacing them may exist at the time of filing this application.

[0033] Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that identical components in the accompanying drawings are indicated by the same reference numerals whenever possible. Furthermore, detailed descriptions of known functions and configurations that could obscure the essence of the invention will be omitted. For the same reason, some components in the accompanying drawings may be exaggerated, omitted, or schematically depicted, and the size of each component does not entirely reflect its actual size.

[0035] First, a battery module (100) according to one embodiment of the present invention will be described with reference to FIGS. 1 to 11.

[0036] FIG. 1 is a perspective view of a battery module (100) according to an embodiment of the present invention. Referring to FIG. 1, a battery module (100) according to an embodiment of the present invention comprises a module housing (150).

[0037] The module housing (150) may be provided with a housing body (151) having open ends and a space formed inside for accommodating components such as a battery cell (120 in FIG. 2), and end plates (153) covering the open ends of the housing body (151). Although FIG. 1 shows the housing body (151) having an integrated structure with a tubular shape, the housing body (151) may also be manufactured by dividing it into two or more plates and then integrating them, and various modifications are possible.

[0038] A venting member (155) for discharging gas generated inside the module housing (150) to the outside may be provided on the outside of the module housing (150). In this specification, 'gas' is defined to include all of the electrolyte gas, flame, combustion material, etc., and the venting member (155) performs the function of discharging the electrolyte gas, flame, combustion material to the outside of the module housing (150). In addition, the module housing (150) may be provided with an external connection terminal (TC) that is electrically connected to a bus bar (140 in FIG. 2).

[0039] FIG. 2 is a cross-sectional view along the line I-I' of FIG. 1, FIG. 3 is an enlarged view of part A of FIG. 2, and FIG. 4 is a cross-sectional view along the line II-II' of FIG. 2.

[0040] Referring to FIGS. 2 to 4, a battery module (100) according to one embodiment of the present invention accommodates a cell stack (110) and a busbar assembly (130) inside a module housing (150).

[0041] A cell stack (110) is formed by stacking a plurality of battery cells (120). A battery cell (120) may have an electrode lead (125) exposed to the outside. As an example, the battery cell (120) may be configured as a pouch-type secondary battery in which the electrode lead (125) is exposed to the outside through a sealing portion (123). An insulating portion (126) made of an insulating material, such as an insulating film, may be disposed between the electrode lead (125) and the sealing portion (123).

[0042] Additionally, at least one cushioning pad (112) may be disposed in the cell stack (110). The cushioning pad (112) may be disposed between the battery cells (120) and between the battery cells (120) and the side wall of the module housing (150). Since this cushioning pad (112) can be compressed and elastically deformed when a specific battery cell (120) expands due to a swelling phenomenon, it can suppress the expansion of the entire volume of the cell stack (110). The cushioning pad (112) may be composed of a polyurethane foam, but the material is not limited thereto.

[0043] The busbar assembly (130) may include an electrically conductive busbar (140) electrically connected to an electrode lead (125) and a support plate (131) made of an insulating material for insulation between the busbars (140).

[0044] A coupling hole (142) through which an electrode lead (125) passes and is coupled may be formed in the bus bar (140). The coupling of the electrode lead (125) and the bus bar (140) may be performed by welding in a state where the electrode lead (125) passes through the coupling hole (142), that is, in a state where the electrode lead (125) protrudes to the outside of the coupling hole (142).

[0045] A support plate (131) is positioned between a bus bar (140) and a battery cell (120) to support the bus bar (140), and a through hole (133) may be formed in the support plate (131) to allow an electrode lead (125) to pass through. The support plate (131) may be provided with a partition projection (137) to electrically separate adjacent bus bars (140).

[0046] A flow space (SF) through which gas discharged from the battery cell (120) flows can be formed between the outer surface of the busbar assembly (130) and the inner surface of the module housing (150).

[0047] Additionally, the venting member (155) is provided at a position corresponding to the flow space (SF) within the module housing (150), and the gas discharged from the battery cell (120) can flow through the flow space (SF) and then be discharged to the outside of the module housing (150) through the venting member (155).

[0048] As an example, the fluid space (SF) may extend along a first plane (X2-X3 plane) perpendicular to the longitudinal direction (X1) of the battery cell (120). Additionally, the battery cell (120) may have electrode leads (125) at each end of the longitudinal direction (X1), and the fluid space (SF) may be positioned at both ends of the longitudinal direction (X1) of the battery cell (120) to correspond to each electrode lead (125).

[0049] A venting member (155) may be provided at a position corresponding to the flow space (SF) within the module housing (150) so as to discharge gas flowing through the flow space (SF) to the outside of the module housing (150). As shown in FIGS. 1 and 2, the venting member (155) may be provided at both ends of the flow space (SF), but is not limited thereto and may be provided only at one end of the flow space (SF) (see FIG. 10). Additionally, the flow space (SF) may be arranged at each end of the longitudinal direction (X1) of the battery cell (120), and in this case, at least one venting member (155) may be installed in each flow space (SF).

[0050] The venting member (155) may consist of a venting hole (156) formed on the wall surface of the module housing (150). The venting hole (156) may have an open structure. Alternatively, the venting member (155) may have a venting hole (156) formed on the wall surface and a venting unit (157) installed in the venting hole (156). The venting unit (157) may have a structure that is fixed to the venting hole (156), but may also have a structure that is detachably coupled. The venting unit (157) may have a certain length in the discharge direction to facilitate the external discharge of gas, and for this purpose, it may have a structure that extends outward from the module housing (150). In addition, the venting unit (157) may always have an open structure. However, the venting unit (157) may have a structure that is normally closed to prevent external air from easily entering the interior of the module housing (150), and opens when gas is discharged, that is, when the internal pressure of the module housing (150) rises. Since the structure of the venting unit (157) that opens when gas is discharged is known in various forms, such as flaps and valve structures, a detailed description will be omitted.

[0051] Although FIGS. 1 and 2 show that the venting member (155) is provided on the end plate (153), the installation location of the venting member (155) is not limited to the aforementioned configuration and can be varied as long as communication between the venting member (155) and the flow space (SF) is possible. For example, the venting member (155) may be provided on at least a portion of the front and rear surfaces, the top and bottom surfaces, and both sides of the module housing (150). That is, the venting member (155) may be installed at a location within the module housing (150) that corresponds to the flow space (SF). In addition, the number of venting members (155) installed may also be varied.

[0052] Meanwhile, the battery module (100) according to an embodiment of the present invention may additionally include a filler (160) that covers at least a portion of the cell stack (110). This filler (160) may perform the function of preventing gas generated from the battery cell (120) from flowing into any space inside the module housing (150) or propagating to an adjacent battery cell (120). That is, the filler (160) may perform the function of guiding electrolyte gas, flames, and combustion materials discharged from the battery cell (120) where an event such as ignition has occurred to minimize the effect on neighboring battery cells (120) by remaining in the space around the cell stack (110), and to facilitate discharge to the space outside the cell stack (110). In addition, the filler (160) may perform the function of minimizing or delaying the phenomenon of the sealing portion (123) opening up.

[0053] Referring to FIGS. 2 and 3, a first space (S1) is formed between the inner surface of the busbar assembly (130) and the cell stack (110). In an embodiment of the present invention, the electrode lead (125) is located at both ends in the longitudinal direction (X1) of the battery cell (120), and the busbar assembly (130) is coupled to the electrode lead (125) at both ends in the longitudinal direction (X1) of the battery cell (120), so the first space (S1) can be located on both sides in the longitudinal direction (X1) of the battery cell (120).

[0054] In the battery cell (120), since the thickness of the sealing portion (123) is thinner than the thickness of the electrode receiving portion (122 in FIG. 7) in which the electrode assembly (127 in FIG. 7) is received, a space may be formed between the sealing portions (123). The first space (S1) corresponds to the space formed between the sealing portions (123) of the battery cell (120). Additionally, since the adhesive strength of the sealing portion (123) in the battery cell (120) is weakest at the electrode lead (125) portion, gas discharge from the battery cell (120) mainly occurs at the sealing portion (123) where the electrode lead (125) is installed.

[0055] The filling member (160) can function to prevent gas discharged from the battery cell (120) from remaining in the first space (S1) by filling at least a portion of the first space (S1). For example, the filling member (160) is filled in the first space (S1) between the sealing portion (123; 123a in FIG. 7) of the battery cell (120) and between the inner surface of the busbar assembly (130) and the cell stack (110), so that gas discharged from the battery cell (120) does not remain in the first space (S1) but is discharged into the flow space (SF). In addition, since the filling member (160) is filled between the sealing portions (123), it can apply pressure when deformation of the sealing portions (123) occurs, thereby performing the function of preventing the sealing portions (123) from opening up.

[0056] Referring to FIG. 4, a second space (S2) is formed between the upper side of the cell stack (110) and the inner side (151a) of the module housing (150) facing it. A filling member (160) can function to prevent gas discharged from the battery cell (120) from moving into the second space (S2) by filling at least a portion of the second space (S2). Meanwhile, a sealing portion (123) is formed on the upper side of the pouch-type battery cell (120), so when the pressure inside the battery cell (120) rises, a phenomenon may occur where the upper sealing portion (123; 123b in FIG. 7) opens up. At this time, when the filling member (160) fills at least a portion of the second space (S2), it acts as a resistance against deformation of the upper sealing portion (123), thereby minimizing gas discharge through the upper sealing portion (123).

[0057] The filling member (160) may have sufficient heat resistance and / or fire resistance to respond to event situations such as ignition of the battery cell (120). For example, the filling member (160) may have a heat resistance temperature of 100 degrees Celsius or higher so as not to melt or burn even at high temperatures. In addition, the filling member (160) may be made of an insulating material. The filling member (160) may include at least some of ceramic, graphite, alumina, and heat-resistant plastic, but the material is not limited thereto. Meanwhile, the method of installing the filling member (160) around the cell stack (110) may be to produce the filling member (160) in a shape corresponding to at least a part of the first space (S1) and / or the second space (S2) using injection molding and then install it in the first space (S1) and / or the second space (S2), or to apply a gel-type raw material to at least a part of the first space (S1) and / or the second space (S2), but is not limited thereto.

[0058] In this way, according to an embodiment of the present invention, by installing a filling member (160) in a first space (S1) and / or a second space (S2) corresponding to the periphery of a cell stack (110), the gas discharged from the battery cell (120) can be guided to be easily discharged to the flow space (SF) side through a gas outlet (HG) described later, without remaining in the first space (S1) and / or the second space (S2).

[0059] Referring to FIG. 4 together with FIG. 2 and FIG. 3, a gas outlet (HG) may be formed in the busbar assembly (130) to discharge gas generated from the battery cell (120) in the outer direction of the cell stack (110), that is, outward in the longitudinal direction (X1) of the battery cell (120). The gas generated from the battery cell (120) is mainly discharged through the sealing portion (123) where the electrode lead (125) is placed, and a gas outlet (HG) may be formed in the busbar assembly (130) in the direction of extension of the sealing portion (123) / electrode lead (125), that is, the direction of gas discharge. Accordingly, the gas discharged through the sealing portion (123) of the battery cell (120) can be easily discharged into the flow space (SF) through the gas outlet (HG) formed in the busbar assembly (130). Additionally, since the filling member (160) can be configured to fill at least a portion of the first space (S1), the gas discharged from the battery cell (120) can be easily discharged into the flow space (SF) through the gas outlet (HG) without remaining in the first space (S1).

[0060] Gas that has moved from the battery cell (120) to the flow space (SF) through the gas outlet (HG) can be discharged to the outside of the module housing (150) through a venting member (155) provided in communication with the flow space (SF). In this way, since the gas outlet (HG) is directly formed in the busbar assembly (130), it is possible to guide the easy discharge of gas from the battery cell (120).

[0061] A gas outlet (HG) may be formed by penetrating at least a portion of the support plate (131) and the bus bar (140). That is, the gas outlet (HG) may be provided in both the support plate (131) and the bus bar (140), but it is also possible to provide it in only one of them. For example, since the area of ​​the support plate (131) is larger than that of the bus bar (140), it is possible to form the gas outlet (HG) only in the support plate (131). Additionally, the gas outlet (HG) may have a hole shape penetrating the support plate (131) and / or the bus bar (140), but is not limited thereto, and it may also be formed in a groove shape.

[0062] The gas outlet (HG) may include an insulator outlet (135) formed in the support plate (131) and a busbar outlet (145) formed in the busbar (140) that communicates with the insulator outlet (135).

[0063] FIG. 5 is a schematic diagram of a busbar assembly (130) viewed from B in FIG. 4. Referring to FIG. 4 and FIG. 5 together, a coupling hole (142) is formed in the busbar (140) to which an electrode lead (125) is coupled. The busbar outlet (145) may have a structure formed integrally with the coupling hole (142) and communicating with the coupling hole (142). The busbar outlet (145) may have a shape in which the width (W2) of the busbar outlet (145) is larger than the width (W1) of the coupling hole (142) so that gas discharge can be easily achieved. That is, the busbar outlet (145) may have a shape that is expanded in the width direction compared to the coupling hole (142). However, it is also possible for the busbar outlet (145) and the coupling hole (142) to have a structure in which they are separated from each other and are not integrally connected.

[0064] In this way, since the busbar outlet (145) is installed adjacent to the coupling hole (142), the gas discharged from the sealing portion (123) around the electrode lead (125) can be easily discharged into the flow space (SF) through the busbar outlet (145) located in the extension direction of the electrode lead (125).

[0065] Additionally, a through hole (133) through which the electrode lead (125) passes may be formed in the support plate (131) so that the electrode lead (125) can be coupled to the bus bar (140). The insulator outlet (135) may be formed integrally with the through hole (133) and may have a structure that communicates with the through hole (133). However, it is also possible for the insulator outlet (135) and the through hole (133) to have a structure that is separated from each other. The through hole (133) may have a width greater than that of the coupling hole (142) for the passage of the electrode lead (125), and accordingly, the insulator outlet (135) may have a width equal to or similar to that of the through hole (133).

[0066] FIG. 6 is a perspective view illustrating the connection state of the cell stack (110) and the bus bar (140) shown in FIG. 2, and shows the state excluding the support plate (131) of the bus bar assembly (130) to clearly illustrate the structure of the bus bar (140). As shown in FIG. 6, a plurality of battery cells (120) are stacked to form a cell stack (110), and a cushioning pad (112) may be provided in the cell stack (110). The bus bar (140) may be provided with a first bus bar (140a) that electrically connects a plurality of battery cells (120) and a second bus bar (140b) that connects the battery cells (120) to an external connection terminal (TC in FIG. 1), and the electrode leads (125) of the battery cells (120) may be connected to the bus bar (140).

[0067] FIG. 7 is a perspective view of a battery cell (120) according to an embodiment of the present invention. In an embodiment of the present invention, the battery cell (120) may be composed of a pouch-type secondary battery and may have a structure in which an electrode lead (125) protrudes outward.

[0068] The battery cell (120) may have a structure in which an electrode assembly (127) is housed within a pouch (121) that forms an outer casing, and a portion of an electrode lead (125) is exposed to the outside of the pouch (121).

[0069] The pouch (121) may be divided into an electrode receiving portion (122) and a sealing portion (123). The electrode receiving portion (122) is formed in the shape of a container and provides a space for containing an electrode assembly (127) and an electrolyte inside. The electrode assembly (127) is equipped with a plurality of electrode plates (not shown) and electrode tabs (not shown) and is housed within the pouch (121). Here, the electrode plates consist of a positive plate and a negative plate, and the electrode assembly (127) may be configured such that the positive plate and the negative plate face each other, with the positive plate and the negative plate stacked in the thickness direction (X2) with a separator in between. Each of the plurality of positive plates and the plurality of negative plates is equipped with an electrode tab, and the electrode tabs may be connected to electrode leads (125) of the same polarity by contacting each other with the same polarity. That is, the electrode lead (125) can be electrically connected to the electrode plate of the electrode assembly (127) through the electrode tab.

[0070] The sealing portion (123) is a part of the pouch (121) that is joined to seal the circumference of the receiving portion (122). Accordingly, the sealing portion (123) is formed in the shape of a flange that extends outward from the receiving portion (122), which is formed in the shape of a container, and is arranged along the outer edge of the receiving portion (122). A heat fusion method may be used for joining the pouch (121) to form the sealing portion (123), but is not limited thereto. In this embodiment, the sealing portion (123) may be divided into a first sealing portion (123a) where the electrode lead (125) is placed and a second sealing portion (123b) where the electrode lead (125) is not placed. At this time, the electrode lead (125) may be covered by an insulating portion (126) so that the sealing degree of the first sealing portion (123a) can be increased at the location where the electrode lead (125) is drawn out, and at the same time, an electrical insulation state can be secured.

[0071] In this embodiment, the pouch (121) can be formed by forming a single sheet of outer material. More specifically, one or two storage compartments can be formed by forming a single sheet of outer material, and then the outer material can be folded so that the storage compartments form a single space {i.e., a receiving compartment (122)} to complete the pouch (121).

[0072] In this embodiment, the receiving portion (122) may be formed in a square shape. A sealing portion (123) formed by joining an exterior material is provided on the outer edge of the receiving portion (122). However, as described above, there is no need to form a sealing portion (123) on the surface where the exterior material is folded. Therefore, in this embodiment, the sealing portion (123) is formed on the outer edge of the receiving portion (122), but is provided only on three sides of the receiving portion (122), and the sealing portion (123) may not be placed on any one of the outer sides of the receiving portion (122) (the lower side in FIG. 7).

[0073] In this embodiment, electrode leads (125) are positioned on both sides of the longitudinal direction (X1) of the battery cell (120) so as to face in opposite directions. An electrode lead (125) of the first polarity (e.g., positive) is positioned on one side of the longitudinal direction of the battery cell (120), and an electrode lead (125) of the second polarity (e.g., negative) is positioned on the other side of the longitudinal direction. The two electrode leads (125) are positioned in sealing portions (123) formed on different sides. Accordingly, the sealing portion (123) of this embodiment consists of two first sealing portions (123a) where the electrode leads (125) are positioned, and one second sealing portion (123b) where the electrode leads (125) are not positioned. In FIG. 7, the second sealing portion (123b) is shown as being formed on the upper surface of the pouch (121), but the second sealing portion (123b) can also be formed on the lower surface of the pouch (121).

[0074] Meanwhile, the pouch (121) used in the embodiment of the present invention is not limited to a structure in which a single outer material is folded to form sealing portions (123) on three sides as shown in FIG. 7. For example, it is also possible to form a receiving portion (122) by overlapping two outer materials and to form sealing portions (123) on all four sides around the receiving portion (122). In this case, the sealing portions (123) may be composed of two first sealing portions (123a) where electrode leads (125) are placed, and two second sealing portions (123b) where electrode leads (125) are not placed. At this time, the second sealing portions (123b) may be formed on the upper and lower surfaces of the battery cell (120).

[0075] In an embodiment of the present invention, the battery cell (120) may have the sealing portion (123) formed in a folded shape at least once to increase the bonding reliability of the sealing portion (123) and minimize the volume / area of ​​the sealing portion (123). More specifically, among the sealing portions (123) according to the present embodiment, the second sealing portion (123b) in which the electrode lead (125) is not placed may be fixed by an adhesive member (124) after being folded twice. For example, the second sealing portion (123b) may be folded 180° along the first bending line (C1) and then folded again along the second bending line (C2) shown in FIG. 3. At this time, the interior of the second sealing portion (123b) may be filled with an adhesive member (124), and the second sealing portion (123b) may maintain a shape folded twice by the adhesive member (124). The adhesive member (124) may be formed from an adhesive with high thermal conductivity. For example, the adhesive member (124) may be formed from epoxy or silicone, but is not limited thereto.

[0076] The battery cell (120) configured in this way may be a nickel metal hydride (Ni-MH) battery or a lithium ion (Li-ion) battery capable of charging and discharging.

[0077] These battery cells (120) are placed in the internal space of the module housing (150), and a plurality of battery cells (120) are vertically positioned in the internal space of the module housing (150) and stacked in the left-right direction to form a cell stack (110 in FIG. 6). However, in the embodiment of the present invention, the battery cells (120) are not limited to the aforementioned pouch-type secondary batteries, and it is also possible to configure them as prismatic or cylindrical secondary batteries in which electrode leads are connected to the busbar assembly (130).

[0078] FIG. 8 is a perspective view of a busbar (140) according to an embodiment of the present invention. The busbar (140) has a configuration in which a coupling hole (142) and a busbar outlet (145) are formed in a busbar body (141). To facilitate gas discharge through the busbar outlet (145), the busbar outlet (145) may have a shape that is expanded in the width direction compared to the coupling hole (142). That is, the width (W2) of the busbar outlet (145) may have a shape that is larger than the width (W1) of the coupling hole (142). Additionally, the busbar outlet (145) may have a shape formed integrally with the coupling hole (142) at the lower part of the coupling hole (142).

[0079] FIG. 9 is a perspective view illustrating the assembled state of a cell stack (110) and a busbar assembly (130) according to an embodiment of the present invention. A plurality of battery cells (120) are stacked in the width direction (X2) of the cell stack (110), and a busbar assembly (130) is connected in the length direction (X1) of the cell stack (110). The busbar assembly (130) may be provided with an insulating support plate (131) and a busbar (140) to which the electrode lead (125) of the battery cell (120) is electrically connected. The busbar (140) may be provided with a first busbar (140a) and a second busbar (140b). The busbar (140) may be provided with a busbar outlet (145) adjacent to the part where the electrode lead (125) is joined, which discharges gas discharged from the battery cell (120) toward the outside of the cell stack (110).

[0080] FIGS. 10 and FIGS. 11 are cross-sectional views illustrating a modified example of the battery module (100) illustrated in FIG. 2. The modified example illustrated in FIG. 10 differs from the embodiment of the battery module (100) illustrated in FIG. 2 only in that a thermal propagation blocking member (115) is installed in the cell stack (110) and a venting member (155) is placed only on one side of the flow space (SF). Additionally, the modified example illustrated in FIG. 11 differs from the embodiment of the battery module (100) illustrated in FIG. 2 only in that a thermal propagation blocking member (115) is installed in the cell stack (110). Therefore, the configuration of the battery module (100) described through FIGS. 1 to 9 can be applied to the modified examples illustrated in FIG. 10 and FIG. 11, except for the aforementioned differences.

[0081] Therefore, in order to avoid unnecessary duplication, a detailed description of the variations shown in FIGS. 10 and 11 will be omitted and replaced by the description provided in FIGS. 1 to 9. Additionally, for the variations shown in FIGS. 10 and 11, the same reference numerals will be assigned to components that are identical or corresponding to those in FIGS. 1 to 9, and only the differences will be described.

[0082] A variation of FIGS. 10 and 11 has a configuration in which a heat diffusion blocking member (115) is disposed between battery cells (120). The heat diffusion blocking member (115) is disposed between battery cells (120) to block at least one of the heat and flame generated in one battery cell (120) from propagating to another battery cell (120). The heat diffusion blocking member (115) may be made of a planar structure. While such a heat diffusion blocking member (115) may be disposed between individual battery cells (120) as shown in FIG. 11, it may also be installed between a plurality of grouped battery cells (120) as shown in FIG. 10. For example, the heat diffusion blocking member (115) may be disposed between each group of two battery cells (120) as a group. At this time, the number of battery cells (120) partitioned by the heat diffusion blocking member (115) may be two or more. The number of battery cells (120) partitioned by the heat diffusion blocking member (115) may be set by considering the amount of heat generated by the battery cells (120), the performance and thickness of the heat diffusion blocking member (115), etc.

[0083] The heat diffusion blocking member (115) may be made of a fire-resistant and thermal insulating material to block heat / flame propagation between adjacent battery cells (120) or groups of battery cells (120). For example, it may be made of a material that can withstand high temperatures of 1000 degrees or higher without igniting. This heat diffusion blocking member (115) may be composed of at least some of mica, kaoline, aerogel, silicone, and ceramic, and may also include known heat diffusion blocking materials such as various mineral fibers and glass fibers.

[0084] Meanwhile, in the modified example illustrated in FIG. 10, since the venting member (155) is installed only on one side of the flow space (SF), the gas discharged from the battery cell (120) and moved into the flow space (SF) can be discharged to the outside of the module housing (150) through the venting member (155) on one side of the flow space (SF).

[0086] Next, a battery module (100) according to another embodiment of the present invention will be described with reference to FIGS. 12 to 15.

[0087] FIG. 12 is a perspective view of a battery module (100) according to another embodiment of the present invention, FIG. 13 is a cross-sectional view along the line III-III' of FIG. 12, FIG. 14 is an enlarged view of part C of FIG. 13, and FIG. 15 is a cross-sectional view along the line IV-IV' of FIG. 13.

[0088] Compared to the battery module (100) described with reference to FIGS. 1 to 9, the battery module (100) illustrated in FIGS. 12 to 15 differs in that the venting member (155) is provided on the surface facing the gas outlet (HG) within the module housing (150).

[0089] Accordingly, the embodiments illustrated in FIGS. 12 to 15 may be configured with the battery module (100) described through FIGS. 1 to 9, except for the differences mentioned above.

[0090] Therefore, in order to avoid unnecessary duplication, a detailed description of the embodiments illustrated in FIGS. 12 to 15 will be omitted and replaced by the description provided in FIGS. 1 to 9. Additionally, for the embodiments illustrated in FIGS. 12 to 15, the same reference numerals will be assigned to components that are identical or corresponding to those illustrated in FIGS. 1 to 9, and only the differences will be described.

[0091] Referring to FIG. 12, the venting member (155) may be provided on the end plate (153) corresponding to the front and rear of the module housing (150).

[0092] Accordingly, as illustrated in FIGS. 13 to 15, a venting member (155) may be provided on a surface of the module housing (150) facing the gas outlet (HG). Thus, gas discharged through the sealing portion (123) adjacent to the electrode lead (125) of the battery cell (120) is discharged into the flow space (SF) through the gas outlet (HG) installed in the extensional direction of the electrode lead (125), and the gas discharged into the flow space (SF) can be discharged to the outside of the module housing (150) through the venting member (155) provided on the surface facing the gas outlet (HG). In this case, since the gas discharged into the flow space (SF) can be discharged through the venting member (155) adjacent to the gas outlet (HG), rapid gas discharge becomes possible. The venting member (155) may be provided at a height corresponding to the height of the gas outlet (HG) to facilitate smooth gas discharge. Additionally, the number and / or spacing of the venting members (155) provided in the module housing (150) may be set considering the gas discharge pressure, etc.

[0094] Next, with reference to FIGS. 16 and 17, a modified example of the battery module (100) illustrated in FIGS. 12 to 15 will be described. FIG. 16 is a cross-sectional view illustrating a modified example of the battery module (100) illustrated in FIG. 13, and FIG. 17 is an enlarged view of section D of FIG. 16.

[0095] The variants illustrated in FIGS. 16 and 17 differ from the embodiment of the battery module (100) illustrated in FIG. 13 only in that a thermal diffusion blocking member (115) is installed in the cell stack (110). Accordingly, the variants illustrated in FIGS. 16 and 17 may be configured with the battery module (100) described with reference to FIGS. 12 to 15, except for the aforementioned differences.

[0096] Therefore, in order to avoid unnecessary duplication, a detailed description of the variations shown in FIGS. 16 and 17 will be omitted and replaced by the description provided in FIGS. 12 to 15. Additionally, regarding the variations of the embodiments shown in FIGS. 16 and 17, the same reference numerals will be assigned to components that are identical or corresponding to those in FIGS. 12 to 15, and only the differences will be described.

[0097] A variation of FIGS. 16 and 17 has a configuration in which a heat diffusion blocking member (115) is disposed between battery cells (120). The heat diffusion blocking member (115) is disposed between battery cells (120) to block at least one of the heat and flame generated in one battery cell (120) from propagating to another battery cell (120). The heat diffusion blocking member (115) may be made of a planar structure. While it is possible for such a heat diffusion blocking member (115) to be disposed between each battery cell (120), it is also possible to install it between a plurality of grouped battery cells (120) as shown in FIGS. 16 and 17. For example, the heat diffusion blocking member (115) may be disposed between each group of two battery cells (120) as a group. In this case, the number of battery cells (120) partitioned by the heat diffusion blocking member (115) may be two or more.

[0098] Additionally, the heat diffusion blocking member (115) can be coupled to the busbar assembly (130) across a first space (S1) formed between the cell stack (110) and the inner surface of the busbar assembly (130). That is, the heat diffusion blocking member (115) may have a structure that extends beyond the contact surface between the battery cells (120) to the support plate (131). A coupling groove (139) to which the heat diffusion blocking member (115) is coupled may be formed in the support plate (131). When the heat diffusion blocking member (115) is coupled to the support plate (131) across the first space (S1) in this manner, the space between adjacent battery cells (120) or groups of battery cells (120) can be blocked, thereby effectively blocking heat / flame propagation through the first space (S1). That is, the variations of FIGS. 16 and 17 can block heat / flame propagation through the first space (S1) regardless of whether a filling member (160) is installed in the first space (S1).

[0099] The heat diffusion blocking member (115) may be made of a fire-resistant and thermal insulating material to block heat / flame propagation between adjacent battery cells (120) or groups of battery cells (120). For example, it may be made of a material that can withstand high temperatures of 1000 degrees or higher without igniting. This heat diffusion blocking member (115) may be composed of at least some of mica, kaoline, aerogel, silicone, and ceramic, and may also include various mineral fibers, glass fibers, etc.

[0101] Finally, another embodiment of the battery module (100) is described with reference to FIGS. 18 to 20. FIG. 18 is a perspective view of the battery module (100) according to another embodiment of the present invention, FIG. 19 is a cross-sectional view along the line V-V' of FIG. 18, and FIG. 20 is a cross-sectional view along the line VI-VI' of FIG. 19.

[0102] Unlike the battery module (100) illustrated in FIGS. 1 and 12, the battery module (100) illustrated in FIGS. 18 to 20 has a venting member (155) provided on the upper surface of the module housing (150). Accordingly, gas discharged from the battery cell (120) and flowing through the flow space (SF) can be discharged through the venting member (155) on the upper surface of the module housing (150). However, the installation location of the venting member (155) is not limited to the upper surface of the module housing (150), and it is also possible to additionally provide it on at least a part of the side (see FIG. 1) or the front and rear (see FIG. 12) of the module housing (150).

[0103] The battery module (100) illustrated in FIG. 19 may have a heat diffusion blocking member (115) installed between the battery cells (120), similar to the embodiment illustrated in FIG. 16 and FIG. 17. The structure of the battery module (100) illustrated in FIG. 19 is identical to the structure of the battery module (100) illustrated in FIG. 16 and FIG. 17, except for the location of the venting member (155). Therefore, to avoid unnecessary duplication, a detailed description of the configuration of the heat diffusion blocking member (115) and its installation structure is omitted and replaced by the description above.

[0104] Referring to FIG. 20, the gas discharged from the battery cell (120) can be moved to the flow space (SF) and then discharged to the outside through the venting member (155) located above the flow space (SF).

[0106] Although embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and it will be obvious to those skilled in the art that various modifications and variations are possible within the scope of the technical concept of the present invention as described in the claims.

[0107] For example, some components of the above-described embodiments may be omitted, and each embodiment and variation may be combined with one another. Explanation of the symbols

[0109] 100... battery module 110... cell stack 112... cushioning pad 115... heat diffusion barrier 120... Battery cell 123... Sealing part 125... electrode lead 130... busbar assembly 131... Support plate 133... Through hole 135... Insulator outlet 137... Partition protrusion 139... coupling groove 140... busbar 141... Busbar body 142... Connection hole 145... Busbar outlet 150... Module housing 151... Housing body 153... End plate 155... Venting component 156... Venting hole 157... Venting unit 160... Filling member HG... Gas outlet SF... Flow space S1... First space S2... Second space TC... External connection terminal X1... Longitudinal direction X2... width direction X3... height direction W1... Width of the coupling hole W2... Width of the busbar outlet

Claims

Claim 1 A battery module comprising: a cell stack including a plurality of battery cells having electrode leads; a module housing that accommodates the cell stack inside; and a busbar assembly having an electrically conductive busbar electrically connected to the electrode leads; wherein the busbar assembly has a gas outlet formed therein for discharging gas generated from the battery cells outwardly toward the cell stack, the module housing has a venting member for discharging the gas discharged from the gas outlet to the outside of the module housing, the gas outlet includes a busbar outlet formed in the busbar, a coupling hole formed in the busbar to which the electrode leads are coupled is formed, and the busbar outlet has a shape having a width greater than that of the coupling hole. Claim 2 In claim 1, a flow space is formed between the outer surface of the busbar assembly and the inner surface of the module housing through which gas discharged from the gas outlet flows, and the venting member is provided in a position corresponding to the flow space within the module housing, in a battery module. Claim 3 In claim 1, the busbar assembly further comprises an insulating support plate on which the busbar is installed, and the gas outlet is formed through the support plate and the busbar in a battery module. Claim 4 In paragraph 3, the battery module further comprises a gas outlet formed in an insulator outlet in the support plate. Claim 5 delete Claim 6 In claim 1, the busbar outlet is a battery module formed integrally with the coupling hole. Claim 7 A battery module according to claim 4, wherein the support plate has a through hole formed therein through which the electrode lead passes so that the electrode lead can be coupled to the bus bar, and the insulator outlet is formed integrally with the through hole. Claim 8 In paragraph 2, the fluid space extends onto a first plane perpendicular to the longitudinal direction of the battery cell, and the venting member is provided on one or both sides of the fluid space within the module housing. Claim 9 In paragraph 2, the venting member is a battery module provided on the surface facing the gas outlet in the module housing. Claim 10 A battery module further comprising, in paragraph 2, a filling member covering at least a portion of the cell stack. Claim 11 In claim 10, the filling member is a battery module accommodated in at least a portion of a first space formed between the cell stack and the inner surface of the busbar assembly. Claim 12 In claim 11, the electrode leads are located at both longitudinal ends of the battery cell, the busbar assembly is coupled to the electrode leads at both longitudinal ends of the battery cell, and the first space is a battery module located on both longitudinal sides of the battery cell. Claim 13 In claim 10, the filling member is a battery module accommodated in at least a portion of a second space formed between the upper side of the cell stack and the inner surface of the module housing opposite thereto. Claim 14 In claim 10, the above-mentioned filling member is a battery module formed of a material having a heat resistance temperature of 100 degrees or higher. Claim 15 In claim 10, the above-mentioned filler is a battery module comprising at least a portion of ceramic, graphite, alumina, and heat-resistant plastic. Claim 16 A battery module according to any one of claims 1 to 4 and 6 to 15, wherein the cell stack comprises a heat diffusion blocking member disposed between adjacent battery cells to block the diffusion of at least one of heat and flame. Claim 17 In claim 16, the above-mentioned heat diffusion blocking member is a battery module made of a fire-resistant and thermal insulation material. Claim 18 In claim 16, the above-mentioned thermal diffusion blocking member comprises at least a portion of mica, kaolin, aerogel, silicon, and ceramic, forming a battery module. Claim 19 In claim 16, the thermal diffusion blocking member is a battery module coupled to the busbar assembly across a first space formed between the cell stack and the inner surface of the busbar assembly. Claim 20 In any one of claims 1 to 4 and 6 to 15, the venting member comprises a battery module including a venting hole formed in the module housing. Claim 21 In any one of claims 1 to 4 and 6 to 15, the venting member comprises a venting hole formed in the module housing and a venting unit installed in the venting hole, and the venting member has a structure that opens when gas is discharged, in a battery module. Claim 22 A battery module comprising a pouch-type secondary battery according to any one of claims 1 to 4 and 6 to 15, wherein the battery cell comprises an electrode receiving portion that accommodates an electrode assembly inside, a sealing portion that seals at least a portion of the periphery of the electrode receiving portion, and an electrode lead that is electrically connected to the electrode assembly.

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