Battery module and battery pack including same

Abstract

A battery module according to the present invention comprises: a cell stack composed of stacked battery cells: a module case having a gas venting hole on a bottom plate and accommodating the cell stack; and a venting induction member including a main body unit, which has a physical property enabling a bend shape caused by heat, and a needle unit coupled to the main body unit, wherein the venting induction member can be arranged on the bottom plate such that the main body unit is bent and the needle unit faces and comes into contact with the battery cell when the temperature of the main body unit is higher than the predetermined temperature.

Description

Battery module and battery pack including same

[0001] The present invention relates to a battery module and a battery pack including the same, and more particularly, to a battery module having improved safety against thermal events and a battery pack including the same.

[0002] This application claims priority to Korean Patent Application No. 10-2024-0029489, filed on February 29, 2024, and all contents disclosed in the specification and drawings of that application are incorporated herein by reference.

[0003] With the rapid growth in technological development and demand for various mobile devices, electric vehicles, and energy storage systems (ESS), interest in and demand for secondary batteries as an energy source are rapidly increasing. While nickel-cadmium and nickel-metal hydride batteries were previously widely used as secondary batteries, lithium secondary batteries are increasingly being used due to their virtually zero memory effect compared to nickel-based batteries, allowing for easy charging and discharging, extremely low self-discharge rates, and high energy density.

[0004] These lithium secondary batteries primarily use lithium oxide and carbon materials as the positive and negative electrode active materials, respectively. Lithium secondary batteries comprise an electrode assembly comprising positive and negative plates coated with the positive and negative electrode active materials, respectively, with a separator interposed between them, and an outer case, i.e., a battery case, that seals and encloses the electrode assembly together with an electrolyte.

[0005] In general, secondary batteries can be classified into can-type batteries in which the electrode assembly is built into a metal can and pouch-type batteries in which the electrode assembly is built into a pouch of an aluminum laminate sheet, depending on the shape of the outer packaging material.

[0006] Lithium secondary batteries, widely used today, have an operating voltage of approximately 2.5 V to 4.5 V per battery. Therefore, for electric vehicles or power storage devices requiring large capacity and high output, multiple lithium secondary batteries are connected in series and / or parallel to form battery modules or battery packs, which are then used as an energy source. To meet the output and capacity requirements of electric vehicles, battery modules or battery packs typically contain a significant number of lithium secondary batteries.

[0007] These battery modules or battery packs, for example, can generate gases or flames in the event of a thermal event, causing heat to accumulate internally and rapidly spread between battery cells (thermal propagation). This can result in a chain reaction of battery cell explosions, posing a serious risk to users' lives and property.

[0008] Therefore, when a thermal event occurs, it is necessary to actively discharge the heat and pressure to the outside of the battery module to minimize damage before the heat and pressure inside the battery module explosively increases and causes a chain reaction of battery cell explosions or the battery module to collapse.

[0009] The present invention was created to solve the above technical problems, and its primary purpose is to provide a battery module that can effectively disperse or relieve heat and pressure when a thermal event occurs.

[0010] The technical problems to be solved by the present invention are not limited to the problems described above, and other problems not mentioned will be clearly understood by those skilled in the art from the description of the invention described below.

[0011] According to one aspect of the present invention, a battery module may be provided, comprising: a cell stack formed of stacked battery cells; a module case having a gas venting hole in a bottom plate and accommodating the cell stack; and a venting inducing member including a main body having a property of being bent by heat and a needle part coupled to the main body part, wherein the venting inducing member is arranged on the bottom plate such that when the main body part becomes higher than a predetermined temperature, the main body part bends and the needle part faces and contacts the battery cell.

[0012] The above main body part may include a first metal part and a second metal part that are overlapped vertically and made of different metals having different thermal expansion rates.

[0013] The second metal portion has a higher thermal expansion coefficient than the first metal portion, and the venting induction member can be placed on the bottom plate of the module case so that the second metal portion faces the bottom plate of the module case.

[0014] The above main body may include a needle insertion hole into which the needle part can be inserted; and an elastic member disposed in the needle insertion hole and coupled with the needle part.

[0015] The bottom plate of the above module case may include a needle blocking portion configured to block the front of the needle portion inserted into the needle insertion hole to prevent the needle portion from protruding while compressing the elastic member.

[0016] The above main body part includes a rotating shaft part formed protruding on the side, and the bottom plate of the module case may have a shaft mounting part that is fit-fitted with the rotating shaft part.

[0017] The bottom plate of the above module case includes a groove formed in a concave shape corresponding to the main body, and the venting induction member can be inserted into the groove.

[0018] The above needle portions are plural, and the spacing between the needle portions can be configured to correspond to the thickness of the battery cell.

[0019] The module case may include a top plate covering the upper portion of the cell stack; a bottom plate covering the lower portion of the cell stack and formed on the floor plate; a pair of side plates covering each of the two side portions of the cell stack; and a pair of end covers covering the front and rear portions of the cell stack, respectively.

[0020] The above battery cells are pouch-type battery cells, and the gas venting holes are provided at predetermined intervals along the width direction of the bottom plate, and the gas venting holes can be provided at positions corresponding vertically to cell terraces formed by heat-sealing a pouch sheet in the pouch-type battery cells.

[0021] The above venting induction member can be arranged on the bottom plate along the width direction of the bottom plate alternately with the gas venting hole.

[0022] The battery further comprises: a busbar electrically connected to electrode leads provided in the battery cells; and a busbar frame that supports the busbars and has a lead slot through which the electrode leads can pass, and is mounted on a front or rear portion of the cell stack; wherein the busbars include a first busbar and a second busbar that are overlapped with the electrode leads interposed therebetween, and the electrode leads can be press-fixed between the first busbar and the second busbar.

[0023] The battery cells are pouch-type battery cells, each having a wide surface that is upright and stacked in one direction, and the cell stack includes a plurality of barrier plates that are inserted between the battery cells at predetermined intervals along the one direction to limit the movement of heat or gas between the battery cells, and each of the plurality of barrier plates can have an end portion that is fitted into the busbar frame so that the battery cells and the gas venting holes are divided into a predetermined number of units.

[0024] According to another aspect of the present invention, a battery pack including the above-described battery module can be provided.

[0025] According to the present invention, a battery module capable of effectively dispersing or relieving heat and pressure when a thermal event occurs can be provided.

[0026] In particular, according to the venting induction member according to the present invention, a hole is formed in a trigger battery cell having thermal abnormality signs, and high-temperature gas, particles, etc. emitted from the trigger battery cell can be discharged to the outside of the module case through a gas venting hole formed in the bottom plate of the module case.

[0027] In addition, the present invention may have various other effects, which will be described in each embodiment configuration, or the description of effects that can be easily inferred by those skilled in the art will be omitted.

[0028] FIG. 1 is a schematic perspective view of a battery module according to one embodiment of the present invention.

[0029] Figure 2 is an exploded perspective view of the battery module of Figure 1.

[0030] Figure 3 is a perspective view of the cell stack of Figure 2.

[0031] Fig. 4 is a drawing showing the bottom plate of the module case of Fig. 2.

[0032] FIG. 5 is a drawing showing a main body and a needle part partially inserted into the main body as a venting induction member according to one embodiment of the present invention.

[0033] FIG. 6 is a drawing showing a main body and a needle portion protruding from the main body as a venting induction member according to one embodiment of the present invention.

[0034] Fig. 7 is a schematic cross-sectional view of a venting induction member along A-A' of Fig. 6.

[0035] FIG. 8 is an enlarged view of a portion of a bottom plate according to one embodiment of the present invention.

[0036] Fig. 9 is a drawing showing a venting induction member mounted on the bottom plate of Fig. 8.

[0037] Fig. 10 is a drawing showing a state before operation of a venting induction member according to one embodiment of the present invention.

[0038] Fig. 11 is a drawing showing the operating state of a venting induction member according to one embodiment of the present invention.

[0039] FIG. 12 is a drawing for explaining an assembly example of a cell laminate and a busbar frame according to one embodiment of the present invention.

[0040] Fig. 13 is a drawing showing a busbar frame in which a frame cover and a compression busbar are combined in Fig. 12.

[0041] FIG. 14 is a schematic cross-sectional view of a mutually assembled cell stack and busbar frame according to one embodiment of the present invention.

[0042] FIG. 15 is a schematic drawing of a vehicle including a battery pack according to one embodiment of the present invention.

[0043] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Terms or words used in this specification and claims should not be interpreted as limited to their conventional or dictionary meanings, but should be interpreted with meanings and concepts that conform to the technical idea of ​​the present invention based on the principle that the inventor can appropriately define the concept of the term to best explain his or her own invention. Therefore, it should be understood that the embodiments described in this specification and the configurations illustrated in the drawings are only the most preferred embodiments of the present invention and do not represent all of the technical idea of ​​the present invention, and various equivalents and modifications may exist as of the time of this application.

[0044] In the drawings, the sizes of each component or specific parts of that component are exaggerated, omitted, or schematically illustrated for convenience and clarity of explanation. Therefore, the size of each component does not entirely reflect its actual size. If a detailed description of a related known function or configuration is deemed to unnecessarily obscure the gist of the present invention, such description will be omitted.

[0045] FIG. 1 is a schematic perspective view of a battery module according to one embodiment of the present invention, FIG. 2 is an exploded perspective view of the battery module of FIG. 1, FIG. 3 is a perspective view of a cell stack of FIG. 2, and FIG. 4 is a drawing illustrating a bottom plate of a module case of FIG. 2.

[0046] Referring to FIGS. 1 to 4, a battery module (10) according to one embodiment of the present invention includes a cell stack (100) made of stacked battery cells (110), a module case (200) having a gas venting hole (201) in a bottom plate and accommodating the cell stack (100), and a venting induction member (300) that operates when the temperature rises above a certain temperature.

[0047] The above cell stack (100) may be an assembly of battery cells (110) in which a plurality of battery cells (110) are erected and stacked in a horizontal direction (X direction), as shown in FIGS. 2 and 3. In the present embodiment, the battery cell (110) is a pouch-type battery cell (110). The pouch-type battery cell (110) may include an electrode assembly, an electrolyte, a pouch case for sealingly storing the electrode assembly and the electrolyte, and an electrode lead (111).

[0048] The above pouch case may be composed of two pouch sheets, at least one of which may have an electrode assembly receiving groove formed therein. An electrode assembly and an electrolyte are placed in the electrode assembly receiving groove, covered with another pouch sheet, and the edges of the two pouch sheets are heat-sealed. In such a pouch-type battery cell (110), a portion where the pouch sheets are heat-sealed and sealed is referred to as a sealing portion. The electrode lead (111) has one end connected to the electrode assembly inside the pouch case, the other end protruding outside the pouch case, and a portion between the one end and the other end is fixed within the sealing portion when the pouch sheet is heat-sealed. A portion of the electrode lead (111) exposed to the outside of the pouch case may function as an electrode terminal of the pouch-type battery cell (110).

[0049] For reference, a pouch-type battery cell (110) in which an electrode assembly is packaged with two pouch sheets has four sealing portions. Here, the four sealing portions refer to a front sealing portion, a rear sealing portion, from which an electrode lead (111) protrudes, and two side sealing portions extending in the longitudinal direction of the electrode assembly. On the other hand, a pouch-type battery cell (110) in which an electrode assembly is packaged by folding one pouch sheet has three sealing portions. Here, the three sealing portions refer to a front sealing portion, a rear sealing portion, from which an electrode lead (111) protrudes, and one side sealing portion. In particular, in the pouch-type battery cell (110), the front sealing portion and the rear sealing portion are referred to as cell terraces (112).

[0050] The above cell stack (100) may further include a barrier plate (120) positioned between the battery cells (110). The barrier plate (120) may be formed in a plate shape using a material with excellent thermal insulation and fire resistance. This barrier plate (120) may serve to prevent heat transfer between the battery cells (110) and absorb pressure when the battery cells (110) swell.

[0051] The above module case (200) may be composed of a case body and a pair of end covers (250, 260) as shown in FIGS. 1 and 2.

[0052] The case body may include a top plate (210) covering the upper portion of the cell stack (100), a bottom plate (220) covering the lower portion of the cell stack (100), and a pair of side plates (230, 240) covering both side portions of the cell stack (100), respectively.

[0053] The bottom plate (220) and the pair of side plates (230, 240) may be formed integrally. The bottom plate (220) and the pair of side plates (230, 240) provided integrally are also referred to as a U-frame. The U-frame and the top plate (210) may be joined by a method such as bolting, welding, or adhesion. Meanwhile, unlike the present embodiment, the top plate (210), the bottom plate (220), and the pair of side plates (230, 240) may be formed integrally in a square tube shape. The end cover (250, 260) may be opened from the case body and joined to the front and rear.

[0054] In the present embodiment, the top plate (210) may be provided with a terminal through hole through which the terminal bus bar of the battery module (10) can be extended upward. The terminal bus bar includes a positive terminal bus bar (410a) and a negative terminal bus bar (410b). However, unlike the present embodiment, the terminal bus bar may be designed to face forward, for example, by penetrating the end cover (250, 260).

[0055] The bottom plate of the module case (200) may be formed of the bottom plate (220). A thermal resin (TR) may be applied to the upper surface of the bottom plate (220), and the cell stack (100) may be placed on the thermal resin (TR). At this time, the lower edges of the battery cells (110) may be in contact with the thermal resin (TR). In this case, the thermal conductivity and fixation between the battery cells (110) and the bottom plate (220) may be increased. In particular, the heat generated from each battery cell (110) during charging and discharging may be effectively transferred to the bottom plate (220) through the thermal resin (TR) and dissipated. Although not shown, if a heat sink (not shown) is additionally mounted on the lower surface of the bottom plate (220), the heat of the battery cells (110) may be absorbed more quickly.

[0056] In the pouch-type battery cell (110), for example, when overcharging occurs, a large amount of gas is generated as a side reaction, causing a swelling phenomenon, and if this worsens, the bonding strength of the heat-sealed sealing portion may weaken, causing the portion to tear and releasing gas. At this time, among the sealing portions of the pouch-type battery cell (110), the cell terrace (112) generates relatively more heat and has a lower bonding strength than other portions because the electrode lead (111) is interposed therebetween. Due to this, the pouch-type battery cell (110) is most likely to be damaged in the cell terrace (112) portion when the internal pressure increases.

[0057] Accordingly, in accordance with one embodiment of the present invention, the battery module (10) has gas venting holes (201) configured in the edge areas on both sides of the bottom plate (220) corresponding vertically to the cell terrace (112) so that gases emitted when the cell terrace (112) is damaged can be immediately discharged to the outside of the battery module (10).

[0058] Specifically, the gas venting holes (201) according to the present embodiment may be provided at predetermined intervals along the width direction (X direction) of the bottom plate (220), as illustrated in FIG. 2 or FIG. 4. In addition, the gas venting holes (201) may be provided at positions corresponding vertically to the cell terraces (112) of the pouch-type battery cells (110) when the cell stack (100) is housed in the module case (200). In the present embodiment, the pouch-type battery cells (110) each have cell terraces (112) at the front and rear. The gas venting holes (201) may be provided at the front and rear sides of the bottom plate (220) to correspond to the cell terraces (112) of the pouch-type battery cells (110).

[0059] That is, a plurality of gas venting holes (201) may be provided along the same direction as the stacking direction of the pouch-type battery cells (110). In addition, the plurality of gas venting holes (201) may be provided at positions adjacent to the front sealing portion and the rear sealing portion of the pouch-type battery cells (110) in the bottom plate (220).

[0060] The above gas venting hole (201) can serve to prevent a pressure difference between the inside and outside of the module case (200) under normal circumstances. In addition, the gas venting hole (201) serves to prevent excessive heat accumulation inside the battery module (10) and to prevent the internal pressure of the battery module (10) from rapidly increasing by discharging high-temperature gases, etc., emitted from the battery cell (110) to the outside when a thermal event occurs.

[0061] In particular, according to an embodiment of the present invention as shown in FIG. 2 or FIG. 4, when a high-temperature gas or the like is emitted from a trigger battery cell (110) among the battery cells (110) in which a thermal event has occurred, the high-temperature gas or the like may not diffuse into the interior of the module case (200) but may be guided and discharged in a downward direction of the module case (200) through the gas venting hole (201). In this case, other battery cells (110) adjacent to the trigger battery cell (110) may not suffer significant thermal damage. In addition, since a large amount of gas may be discharged more quickly to the exterior of the battery module (10), the internal pressure of the battery module (10) may be prevented from rapidly increasing.

[0062] Meanwhile, the battery module (10) according to the present invention includes not only the gas venting hole (201) but also a venting induction member (300) as a means for removing gas from the battery cell (110) and relieving internal pressure by making a hole in the battery cell (110) when a thermal event occurs.

[0063] As shown in FIGS. 5 and 6, the venting induction member (300) may include a main body (310) and a needle part (320) coupled to the main body (310).

[0064] The main body (310) may be provided with a property that allows its shape to be bent by heat. In the present embodiment, the main body (310) may include a first metal part (311) and a second metal part (312) made of different metals with different thermal expansion rates, which are overlapped vertically to form a layered structure. The first metal part (311) and the second metal part (312) may be joined into one body by mechanical fastening, such as welding or riveting.

[0065] For example, steel may be used as the first metal part (311), and copper or brass may be used as the second metal part (312). Copper or brass is a metal having a higher thermal expansion rate than steel. In other words, the second metal part (312) is a metal having a higher thermal expansion rate than the first metal part (311). In this way, when the main body part (310) made of different metals having different thermal expansion rates is heated, the second metal part (312) expands more than the first metal part (311). However, since the first metal part (311) and the second metal part (312) are firmly coupled to each other, the main body part (310) may bend toward the first metal part (311).

[0066] In this embodiment, the main body (310) may further include a needle insertion hole (313) therein and an elastic member (314) disposed inside the needle insertion hole (313), one end of which is coupled to the inside of the needle insertion hole (313) and the other end of which is coupled to the needle portion (320).

[0067] For example, as shown in FIG. 7, the needle insertion hole (313) may be defined as a space or passage provided inside the main body (310) so that the needle portion (320) can be inserted into the inside of the main body (310). In addition, the elastic member (314) may be defined as a means for providing force so that the needle portion (320) can be elastically protruded from the inside to the outside of the main body (310). For example, a spring may be employed as the elastic member (314).

[0068] The main body (310) may further include a rotation shaft portion (315) protruding from a side. The rotation shaft portion (315) is a portion that is fitted into an axis mounting portion (225) provided on the bottom plate of the module case (200), which will be described later. The venting guide member (300) may be installed on the bottom plate of the module case (200) so as to be rotatable about the rotation shaft portion (315).

[0069] The needle portion (320) may be provided with an end shaped like a nail or a needle as a means for making a hole in the battery cell (110). There may be a plurality of needle portions (320), and the spacing between the needle portions (320) may be configured to correspond to the thickness of the battery cell (110).

[0070] As illustrated in FIGS. 5 and 6, the needle portion (320) may include a first needle portion (321) and a second needle portion (322) that are joined in a protruding form from the main body portion (310) and spaced apart from each other by approximately the thickness of the battery cell (110). As will be described later, two adjacent different battery cells (110) may be perforated by contacting the first needle portion (321) and the second needle portion (322).

[0071] In the present embodiment, the venting guide member (300) may be arranged on the bottom plate of the module case (200) so that the second metal portion (312) faces the bottom plate of the module case (200). In addition, the venting guide member (300) may be arranged on the bottom plate of the module case (200), i.e., the bottom plate (220), along the width direction of the bottom plate (220), alternately with the gas venting hole (201) described above. In addition, the venting guide member (300) may be arranged adjacent to the front sealing portion or the rear sealing portion of the battery cell (110).

[0072] When the venting induction member (300) receives heat from the bottom plate (220) or becomes hotter than a certain temperature due to the influence of high-temperature particles or flames, the main body (310) is bent at a predetermined angle or more with respect to the bottom plate and faces the battery cell (110), and at this time, the needle part (320) comes into contact with the battery cell (110) so that a hole can be formed in the battery cell (110).

[0073] Hereinafter, with reference to FIGS. 8 to 11, an installation example and an operation example of a venting induction member (300) according to an embodiment of the present invention will be described in more detail. Hereinafter, the bottom plate of the module case (200) refers to the bottom plate (220) described above.

[0074] First, referring to FIG. 8, the bottom plate of the module case (200) according to one embodiment of the present invention may further include a groove portion (221), a needle blocking portion (223), and an axis mounting portion (225).

[0075] The above-mentioned groove (221) may be provided in an engraved shape corresponding to the main body (310) of the venting guide member (300). The groove (221) may be provided between the aforementioned gas venting holes (201). The venting guide member (300) may be inserted into this groove (221). At this time, the venting guide member (300) is inserted into the groove (221) such that the second metal part (312) among the first metal part (311) and the second metal part (312) in the main body (310) faces downward. By configuring the groove (221) in the bottom plate of the module case (200) in this way, it is easy to install the venting guide member (300) in the correct position and the movement of the venting guide member (300) can be suppressed.

[0076] The above needle blocking portion (223) (see FIG. 6) blocks the front of the needle portion (320) inserted into the needle insertion hole (313) of the main body portion (310) to prevent the needle portion (320) from protruding from the needle insertion hole (313).

[0077] As illustrated in FIG. 9, the venting guide member (300) may be placed in the groove (221) with the needle portion (320) inserted into the interior of the main body (310). The needle blocking portion (223) may be provided at the end of the groove (221) or at a position slightly spaced apart from the groove (221) in the direction of the battery cell (110), and may be formed higher than the needle portion (320) of the venting guide member (300) seated in the groove (221). The bottom plate of the module case (200) may have a step. That is, the bottom plate of the module case (200) may have a first layer (S1) on which the venting guide member (300) is placed and a second layer (S2) on which the battery cells (110) are placed, and the second layer (S2) may be provided higher than the first layer (S1). At this time, the step surface between the first layer (S1) and the second layer (S2) can function as the needle blocking portion (223).

[0078] The above needle blocking portion (223) may be formed as a curved surface. When the main body portion (310) is bent upward due to heat in the groove portion (221), the needle portion (320) may be guided along the curved surface of the needle blocking portion (223). In this case, the needle portion (320) may protrude from the main body portion (310) toward the battery cell (110) more smoothly than when the needle blocking portion (223) is flat. In other words, when the needle blocking portion (223) is flat, the frictional force between the tip of the needle portion (320) and the needle blocking portion (223) increases, which may hinder the main body portion (310) from bending upward, and there is a risk that the tip of the needle portion (320) may be damaged. However, the frictional force between the curved needle blocking portion (223) and the tip of the needle portion (320) is relatively small, so the above problem may not occur.

[0079] The above-described shaft mounting portion (225) may be provided with a fitting hole into which the rotational shaft portion (315) of the venting guide member (300) can be fitted, as shown in Fig. 8, and may be provided with a structure protruding upward from the side surface of the groove portion (221). Meanwhile, unlike the present embodiment, if the depth of the groove portion (221) is deep enough to allow the venting guide member (300) to be completely inserted, the shaft mounting portion (225) may be provided on the side surface of the groove portion (221).

[0080] The rotating shaft portion (315) of the venting guide member (300) may be provided on each side of the main body portion (310). Two shaft mounting portions (225) may also be provided to correspond to the two rotating shaft portions (315) of the venting guide member (300). As illustrated in FIG. 9, the venting guide member (300) may be mounted in the groove portion (221) in a state where the two rotating shaft portions (315) are fitted into the two shaft mounting portions (225). In this case, even if an external force is applied, the venting guide member (300) may not be detached and may be stably positioned in the groove portion (221). In addition, when the main body portion (310) is bent due to heat, the venting guide member (300) may be rotated about the rotating shaft portion (315) as an axis.

[0081] In the bottom plate of the module case (200) having the above configuration, venting induction members (300) may be installed, as shown in FIG. 10. In the battery module (10) according to the present embodiment, when a thermal event such as ignition occurs inside, the venting induction members (300) operate, as shown in FIG. 11, to create a hole in the battery cell (110), thereby inducing and discharging high-temperature gases, etc., from the battery cell (110). For example, as described above, when the main body (310) is heated, the thermal expansion coefficient of the second metal part (312) is greater than the thermal expansion coefficient of the first metal part (311), so that the main body (310) bends upward, and at this time, the needle part (320) inserted into the main body (310) protrudes toward the body (113) of the battery cell (110), so that a hole may be formed in the battery cell (110). In particular, the venting induction member (300) according to the present embodiment is configured to make a hole in the body (113) or sealing portion of the battery cell (110) close to the gas venting hole (201), so that high-temperature gas, etc. can be more smoothly and quickly discharged to the outside of the battery module (10).

[0082] FIG. 12 is a drawing for explaining an assembly example of a cell laminate and a busbar frame according to one embodiment of the present invention, FIG. 13 is a drawing showing a busbar frame in which a frame cover and a compression busbar are combined in FIG. 12, and FIG. 14 is a schematic cross-sectional view of a mutually assembled cell laminate and a busbar frame according to one embodiment of the present invention.

[0083] Referring to FIG. 2 and FIG. 12 to FIG. 14, a battery module (10) according to one embodiment of the present invention may further include a plurality of bus bars electrically connected to electrode leads (111) provided in battery cells (110), a bus bar frame (400), a frame cover (500), and a sealing cover (700).

[0084] The above busbars may be formed of a metal such as copper or aluminum having electrical conductivity and provided in the form of a rod.

[0085] The above busbar frame (400) may be provided in a plate shape that supports the busbars and can cover the front and rear portions of the cell stack (100), respectively. Here, the busbar frame (400) may be formed of an electrically insulating material such as plastic. In addition, the busbar frame (400) may be provided with lead slots (420) through which electrode leads (111) may pass. The electrode leads (111) of the battery cells (110) may pass through the lead slots (420) and be attached to the busbars (410) in a predetermined pattern.

[0086] In particular, the battery module (10) of the present embodiment is configured to secure the electrode leads (111) to the bus bars by compressing them rather than welding them to the bus bars. Accordingly, the assembly time of the battery module (10) can be shortened and the assembly process can be carried out more easily.

[0087] Specifically, a bus bar according to an embodiment of the present invention includes a first bus bar (410) and a second bus bar (600). Referring to FIGS. 12 and 13, the first bus bar (410) and the second bus bar (600) may be overlapped with the electrode lead (111) therebetween. In addition, the electrode lead (111) may be press-fixed between the first bus bar (410) and the second bus bar (600). At this time, the first bus bar (410) and the second bus bar (600) may be firmly coupled by a fastening member (800) such as a bolt.

[0088] The above frame cover (500) is provided in the form of a pad made of a material having low thermal conductivity and excellent heat resistance, such as silicone, aerogel, or mica, and can be coupled to the busbar frame (400) so as to face it, as shown in FIG. 13. The frame cover (500) may include a plurality of cover plates (510). Each cover plate (510) may be provided to correspond to the partition surfaces of the busbar frame (400) partitioned by the partition walls (430) protruding from the busbar frame (400) and the end portions (121) of the barrier plate (120) to be described later. Here, the partition walls (430) and the end portions (121) of the barrier plate (120) may serve to prevent short circuits between the electrode leads (111).

[0089] When the above frame cover (500) is attached to the busbar frame (400), the lead slots (420) of the busbar frame (400) can be covered. With this configuration, when a thermal event occurs, high-temperature gas or flames can be prevented from leaking out to the front or rear of the cell stack (100) through the lead slots (420).

[0090] The electrode leads (111) are bent in a predetermined pattern and placed on the front surface of the corresponding first bus bars (410), and then the frame cover (500) can be attached to the bus bar frame (400). Here, the frame cover (500) has a bus bar insertion hole (H). The second bus bar (600) can be configured to be coupled to the first bus bar (410) with the electrode leads (111) interposed therebetween through the bus bar insertion hole (H).

[0091] The above-mentioned sealing cover (700) is a component for sealing the frame cover (500) to the busbar frame (400) and also sealing the second busbar (600) toward the electrode lead (111) and the first busbar (410).

[0092] The above-described sealing cover (700) may be composed of a plurality of sealing plates (710), as illustrated in FIG. 13. The sealing plates (710) may be provided in a number corresponding to the number of bus bars, and each sealing plate (710) may be fixedly coupled to each corresponding bus bar by a fastening member (800). In addition, the sealing plates (710) may be attached between the end portions (121) of the barrier plates (120) penetrating the bus bar frame (400) and the partition walls (430) protruding from the bus bar frame (400). The sealing plates (710) may be made of a material having high mechanical rigidity and flame retardant properties. For example, the sealing plates (710) may be made of a rigid material having a high melting point, such as SUS, which is insulated, or a rigid material having fire resistance and insulation properties.

[0093] As described above, the cell stack (100) according to one embodiment of the present invention may include a plurality of barrier plates (120) that are interposed between battery cells (110) at predetermined intervals along one direction to limit the movement of heat or gas between the battery cells (110).

[0094] Each of the plurality of barrier plates (120) can be fitted with the terminal portion (121) of the bus bar frame (400) so that the battery cells (110) and the gas venting holes (201) are divided into a predetermined number of units, as shown in FIGS. 13 and 14.

[0095] The above barrier plate (120) may be provided in the form of a compressible pad and made of a material with excellent heat resistance and / or fire resistance, such as silicone, aerogel, mica, etc.

[0096] As illustrated in FIG. 14, the barrier plate (120) can perform a thermal barrier function that blocks heat, such as a flame, generated from an ignited battery cell (110) from spreading in the stacking direction of the battery cells (110). Therefore, heat propagation to neighboring battery cells (110) can be minimized. The barrier plate (120) can block not only heat but also high-temperature gases, flames, discharged substances, etc. generated from the battery cells (110). Accordingly, the barrier member can partition or separate the battery cells (110) to prevent flames, etc. from spreading between the battery cells (110).

[0097] Meanwhile, the battery pack according to the present invention may include one or more of the above-described battery modules (10). The battery pack according to the present invention may further include a master BMS (Battery Management System) for integrated control of charging and discharging of one or more battery modules (10), a current sensor, a fuse, and a pack case for accommodating the above-described components.

[0098] Referring to FIG. 15, the battery pack (2) according to the present invention can be used as a driving energy source for an electric vehicle. That is, the battery pack (2) can be used as an electric energy source to provide driving force to a motor to drive the vehicle. The battery pack (2) can be charged or discharged by an inverter according to the operation of the motor and / or internal combustion engine. The battery pack (2) can be charged by a regenerative charging device combined with a brake. The battery pack (2) can be electrically connected to the motor of the vehicle (1) through an inverter.

[0099] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and it is obvious that various modifications and variations are possible within the scope of the technical idea of ​​the present invention and the equivalent scope of the claims to be described below by a person having ordinary skill in the art to which the present invention pertains.

[0100] In addition, although terms indicating directions such as up, down, left, and right are used in this specification, it is obvious to those skilled in the art that these terms are only for convenience of explanation and may vary depending on the location of the target object or the location of the observer.

Claims

1. A cell stack composed of stacked battery cells; A module case having a gas venting hole in the bottom plate and accommodating the cell stack; and It includes a venting induction member including a main body having a property that can be bent into a shape by heat and a needle part coupled to the main body, A battery module characterized in that the above-mentioned venting induction member is arranged on the bottom plate so that when the main body part becomes higher than a predetermined temperature, the main body part bends and the needle part faces and contacts the battery cell.

2. In paragraph 1, A battery module characterized in that the main body includes a first metal part and a second metal part that are overlapped vertically by different metals having different thermal expansion rates.

3. In paragraph 2, The second metal portion has a higher thermal expansion coefficient than the first metal portion, A battery module characterized in that the above-mentioned venting induction member is arranged on the bottom plate of the module case so that the second metal portion faces the bottom plate of the module case.

4. In paragraph 1, The above main body part, A battery module characterized by including a needle insertion hole into which the needle part can be inserted; and an elastic member disposed in the needle insertion hole and coupled with the needle part.

5. In paragraph 4, A battery module characterized in that the bottom plate of the module case includes a needle blocking portion configured to block the front of the needle portion inserted into the needle insertion hole to prevent the needle portion from protruding while compressing the elastic member.

6. In paragraph 1, The above main body part includes a rotating shaft part formed protruding on the side, A battery module characterized in that the bottom plate of the above module case has an axis mounting portion that is fit-fitted with the above rotational axis portion.

7. In paragraph 1, The bottom plate of the above module case includes a groove formed in a concave shape corresponding to the main body portion, A battery module characterized in that the above-mentioned venting induction member is inserted into the above-mentioned home portion.

8. In paragraph 1, A battery module characterized in that the needle portions are plural in number and the spacing between the needle portions corresponds to the thickness of the battery cell.

9. In paragraph 1, The above module case is, A top plate covering the upper portion of the above cell stack; A bottom plate that covers the lower part of the cell laminate and is formed on the floor plate; A pair of side plates each covering both side surfaces of the cell stack; and A battery module characterized by comprising a pair of end covers each covering the front and rear of the cell stack.

10. In paragraph 9, The above battery cells are pouch-type battery cells, The above gas venting holes are provided at regular intervals along the width direction of the bottom plate, A battery module characterized in that the gas venting hole is provided at a position corresponding vertically to a cell terrace formed by heat-melting a pouch sheet in the pouch-type battery cell.

11. In paragraph 10, A battery module characterized in that the venting induction member is arranged on the bottom plate along the width direction of the bottom plate alternately with the gas venting hole.

12. In paragraph 1, Busbars electrically connected to the electrode leads provided in the above battery cells; and Further comprising a busbar frame that supports the busbars and has a lead slot through which the electrode leads can pass, and is mounted on the front or rear portion of the cell stack; A battery module characterized in that the busbars include a first busbar and a second busbar that are arranged to overlap each other with the electrode lead therebetween, and the electrode lead is press-fitted between the first busbar and the second busbar.

13. In paragraph 12, The above battery cells are pouch-type battery cells, and each wide surface is erected and stacked in one direction. The cell stack includes a plurality of barrier plates interposed between the battery cells at predetermined intervals along the one direction to limit the movement of heat or gas between the battery cells, A battery module characterized in that each of the plurality of barrier plates is fitted and connected at the end to the busbar frame so that the battery cells and the gas venting holes are divided into a predetermined number of units.

14. A battery pack comprising a battery module according to any one of claims 1 to 13.

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