Battery unit, and battery pack and vehicle including same

Abstract

A battery unit according to the present invention may comprise: a cell stack including a plurality of battery cells stacked in a first direction; a bus bar assembly, which includes a bus bar frame covering one surface of the cell stack and a bus bar fixed on the bus bar frame and coupled to an electrode lead of the battery cell, the bus bar frame and / or the bus bar having an injection hole; and a filler, which is located in an inner space formed between the bus bar assembly and the cell stack and suppresses the discharge of venting gas.

Description

Battery unit, battery pack including the same, and automobile

[0001] The present invention relates to a battery unit, a battery pack including the same, and an automobile.

[0002] This application is a priority application for Korean Patent Application No. 10-2025-0013251 filed on February 3, 2025, and all contents disclosed in the specification and drawings of said application are incorporated into this application by reference.

[0003]

[0004] Secondary batteries, which possess electrical characteristics such as high energy density and high applicability across product categories, are widely applied not only to portable devices but also to electric vehicles (EVs) or hybrid electric vehicles (HEVs) powered by electric sources.

[0005] These secondary batteries are attracting attention as a new energy source for improving eco-friendliness and energy efficiency, not only for the primary advantage of being able to drastically reduce the use of fossil fuels, but also because they do not generate any by-products from the use of energy.

[0006] Currently, widely used types of secondary batteries include lithium-ion batteries, lithium-polymer batteries, nickel-cadmium batteries, nickel-hydrogen batteries, and nickel-zinc batteries. When a high output voltage is required, multiple battery cells are connected in series to form a battery unit or battery pack. Additionally, to increase charge / discharge capacity, multiple battery cells are connected in parallel to form a battery unit or battery pack. Therefore, the number of battery cells included in the battery unit or pack can be varied depending on the required output voltage or charge / discharge capacity.

[0007] When configuring a battery pack by connecting multiple battery cells in series or parallel, it is common practice to first construct a battery unit containing at least one battery cell, and then use this at least one battery unit to add other components to form a battery pack or battery rack. Alternatively, recently, battery packs in the form of a "Cell-to-Pack," in which multiple battery cells are directly housed in a pack housing without modularization, are also being manufactured.

[0008] However, when multiple battery units are contained within a battery pack in this manner, it may be vulnerable to thermal chain reactions between the units. For example, if an event such as thermal runaway occurs within a single battery unit, this runaway can propagate to other battery units. If the propagation of thermal runaway between battery units is not properly suppressed, an event originating in a specific battery unit can trigger a chain reaction across multiple units, potentially causing major problems such as explosions or fires.

[0009] In particular, when a battery unit contains multiple battery cells, high-temperature gases, flames, or sparks generated during thermal runaway in a specific battery cell are highly likely to be ejected forward and backward toward the battery cells where the electrode leads of that battery unit are located. Consequently, this can cause thermal damage to components located at both ends of the battery unit, such as end plates or adjacent parts of busbar frames, and lead to structural collapse.

[0010] Therefore, there is a need to develop a structure capable of delaying thermal runaway between battery cells or battery units by preventing the emission of high-temperature gases or flames from a battery cell or by appropriately controlling the direction of emission when a thermal event occurs in a single battery cell.

[0011]

[0012] Therefore, the problem that the present invention aims to solve is to provide a battery unit with improved safety and reliability by appropriately controlling the venting direction of high-temperature gases or flames generated in battery cells during abnormal situations of the battery unit, thereby effectively preventing heat propagation between battery cells or battery units.

[0013] In addition, the problem that the present invention aims to solve is to provide a battery unit that can minimize design errors to shorten process time and more effectively control the venting direction.

[0014] Another technical objective of the present invention is to provide a battery pack including a battery unit of an improved structure, and a vehicle including the battery pack.

[0015] The technical problems that the present invention aims to solve are not limited to those described above, and other unmentioned problems will be clearly understood by a person skilled in the art from the description of the invention below.

[0016]

[0017] To solve the above problem, a battery unit according to the present invention may include a cell stack comprising a plurality of battery cells stacked in a first direction, a busbar frame covering one side of the cell stack, a busbar fixed on the busbar frame and coupled to an electrode lead of the battery cell, a busbar assembly having a liquid injection hole formed in at least one of the busbar frame and the busbar, and a filler located in an internal space formed between the busbar assembly and the cell stack and configured to suppress the discharge of venting gas.

[0018] The above filler may be configured to be injected into the internal space through the injection hole and to fill the internal space.

[0019] The busbar frame is positioned on the front of the cell stack, and the filler may fill the entire internal space.

[0020] The above injection holes are provided in multiple numbers, and the multiple injection holes may be spaced apart in the first direction.

[0021] At least a portion of the above internal space includes a plurality of partitioned spaces partitioned in the first direction by the electrode lead, and the plurality of injection holes may be formed at positions corresponding to each of the plurality of partitioned spaces.

[0022] The cell stack may be provided with a plurality of cell banks each containing at least one battery cell, and the injection hole may include a first injection hole formed at a position corresponding to the cell bank and a second injection hole located between the cell banks arranged side by side.

[0023] The cell stack may further comprise a barrier member disposed between the cell banks, and the second injection hole may be formed at a position facing the barrier member.

[0024] The above injection holes may be provided as a pair spaced apart in a second direction perpendicular to the first direction in the busbar assembly.

[0025] The above filler may be configured to cover the injection hole.

[0026] The busbar frame is positioned on the front and rear of the cell stack, and a filler located between the busbar frame positioned on the rear of the cell stack and the cell stack may fill a portion of the internal space.

[0027] A battery unit assembly method according to the present invention may include a first step of drawing out an electrode lead of a battery cell to the outside of a busbar frame through a slit formed in a busbar frame; a second step of assembling a busbar assembly comprising a cell stack including a plurality of battery cells, a busbar frame, and a busbar fixed on the busbar frame and coupled to the electrode lead of the battery cell, wherein an injection hole is formed in at least one of the busbar frame and the busbar; and a third step of injecting a filler through the injection hole.

[0028] In the second step above, the filler is injected into the injection hole through an injection gun, and the shape of the end of the injection gun may be formed to be identical to the shape of the injection hole.

[0029] In addition, the present invention provides a battery pack characterized by including a battery unit according to the present invention.

[0030] And, the present invention provides an automobile characterized by including a battery unit according to the present invention.

[0031]

[0032] According to one aspect of the present invention, a battery unit having a directional vent structure capable of stably discharging gas or flame in an intended direction when a battery cell ignites may be provided.

[0033] According to one aspect of the present invention, high-temperature gases or flames generated in a battery cell within a battery unit can be rapidly discharged to the outside by inducing directional venting toward the rear. This ensures the safety and reliability of the battery unit.

[0034] In addition, according to another aspect of the present invention, high-temperature gas or flames discharged to the outside of the battery unit can be prevented from flowing back into the interior of the battery unit.

[0035] Furthermore, according to another aspect of the present invention, even in a battery pack unit comprising a plurality of battery units, high-temperature gases or flames, etc., can be directionally vented and rapidly discharged to the outside of the battery pack.

[0036] In addition, according to another aspect of the present invention, events such as fire or explosion caused by thermal runaway phenomena in a battery pack including a plurality of battery units or a device equipped with them can be prevented or delayed.

[0037] In addition to the above, the present invention may have various other effects, which are described in each embodiment, or effects that can be easily inferred by those skilled in the art, etc., will be omitted.

[0038]

[0039] The following drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further enhance understanding of the technical concept of the present invention together with the detailed description of the invention provided below; therefore, the present invention should not be interpreted as being limited only to the matters described in such drawings.

[0040] FIG. 1 is a front perspective view of a battery unit according to one embodiment of the present invention.

[0041] FIG. 2 is an exploded perspective view of a battery unit according to one embodiment of the present invention.

[0042] FIG. 3 is a side view of a battery cell included in a battery unit according to one embodiment of the present invention.

[0043] FIG. 4 is a front view of a busbar assembly of a battery unit according to one embodiment of the present invention.

[0044] FIG. 5 is a perspective view showing the front of a battery unit according to one embodiment of the present invention, and is a drawing showing a state in which the case is omitted.

[0045] Figure 6 is a cross-sectional view of Figure 5 cut along line A-A'.

[0046] Figure 7 is a drawing showing an enlarged portion of Figure 6.

[0047] Figure 8 is an enlarged view of another part of Figure 6.

[0048] FIG. 9 is a front view of a busbar assembly of a battery unit according to another embodiment of the present invention.

[0049] FIG. 10 is a front view of a busbar assembly of a battery unit according to another embodiment of the present invention.

[0050] FIG. 11 is a cross-sectional view showing a portion of the rear of a battery unit according to another embodiment of the present invention.

[0051] FIG. 12 is a front view of a busbar assembly of a battery unit according to another embodiment of the present invention.

[0052] FIG. 13 is a cross-sectional view of FIG. 5 cut along line A-A' according to another embodiment of the present invention.

[0053] FIG. 14 is a drawing showing a method of assembling a battery unit according to one embodiment of the present invention.

[0054] FIG. 15 is a drawing for explaining a battery pack including a battery unit according to one embodiment of the present invention.

[0055] FIG. 16 is a drawing for explaining a vehicle including the battery pack of FIG. 15.

[0056]

[0057] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the present invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention.

[0058] Therefore, 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 of the technical ideas of the present invention; thus, it should be understood that various equivalents and modifications that can replace them may exist at the time of filing this application.

[0059] In addition, the present invention includes various embodiments. For each embodiment, redundant descriptions of substantially identical or similar configurations are omitted, and the focus is on the differences.

[0060] Additionally, to aid in understanding the invention, the attached drawings are not drawn to actual scale, and the dimensions of some components may be exaggerated. Furthermore, the same reference numerals may be assigned to identical components in different embodiments.

[0061] Although terms such as "first," "second," etc., are used to describe various components, it goes without saying that these components are not limited by these terms. These terms are used merely to distinguish one component from another, and unless specifically stated otherwise, the first component may also be the second component.

[0062] Throughout the specification, unless specifically stated otherwise, each component may be singular or plural.

[0063] In the following, the statement that any configuration is placed on the "upper (or lower)" of a component or on the "upper (or lower)" of a component may mean not only that any configuration is placed in contact with the upper (or lower) surface of said component, but also that another configuration may be interposed between said component and any configuration placed on (or below) said component.

[0064] In addition, where it is stated that one component is "connected," "combined," or "connected" to another component, it should be understood that while the components may be directly connected or connected to each other, another component may be "interposed" between each component, or each component may be "connected," "combined," or "connected" through another component.

[0065] Singular expressions used in this specification include plural expressions unless the context clearly indicates otherwise. In this application, terms such as "composed of" or "comprising" should not be interpreted as necessarily including all of the various components or steps described in the specification, and should be interpreted as meaning that some of the components or steps may be omitted or additional components or steps may be included.

[0066] Throughout the specification, "A and / or B" means A, B, or A and B unless specifically stated otherwise, and "C to D" means C or more and D or less unless specifically stated otherwise.

[0067] Meanwhile, although terms indicating directions such as up, down, left, right, front, and back may be used in the present invention, these terms are used merely for convenience of explanation and may vary depending on the position of the object or the position of the observer, as is obvious to those skilled in the art of the present invention.

[0068] For example, in an embodiment of the present invention, the X-axis direction shown in the drawing may mean the left-right direction, the Y-axis direction may mean the front-back direction perpendicular to the X-axis direction on the horizontal plane (XY plane), i.e., the length direction of the battery cell, and the Z-axis direction may mean the up-down direction (vertical direction), i.e., the height direction of the battery cell, which is perpendicular to both the X-axis direction and the Y-axis direction.

[0069] FIG. 1 is a front perspective view of a battery unit according to an embodiment of the present invention. FIG. 2 is an exploded perspective view of a battery unit according to an embodiment of the present invention. FIG. 3 is a side view of a battery cell included in a battery unit according to an embodiment of the present invention.

[0070] Referring to FIGS. 1 to 3, a battery unit (10) according to one embodiment of the present invention may include a cell stack (100), a busbar assembly (200), and a filler (300). In addition to the components described above, the battery unit (10) may additionally include a case (400). Here, the battery unit (10) may refer to a battery module or a cell assembly, etc.

[0071] First, referring mainly to FIG. 2, the cell stack (100) may include battery cells (110). The battery cells (110) may be provided in multiple numbers. At this time, the multiple battery cells (110) may be electrically connected to each other.

[0072] Multiple battery cells (110) can be stacked along one direction. For example, as shown in FIG. 2, multiple battery cells (110) can be arranged side by side in the left-right direction (X-axis direction) while standing upright in the vertical direction (Z-axis direction).

[0073] More specifically, with reference to FIG. 3, a plurality of battery cells (110) may include an electrode assembly and a cell case (111) that accommodates the electrode assembly. The cell case (111) may be a laminate sheet comprising a resin layer and a metal layer.

[0074] Referring to FIG. 3, when the battery cell (110) of the present invention is provided as a pouch-type battery cell (110), the cell case (111) may include a storage portion (111a) and a sealing portion (111b).

[0075] The storage portion (111a) may be configured to accommodate an electrode assembly. The storage portion (111a) is an internal space with a concave shape on the surface facing the electrode assembly, and the electrode assembly may be mounted in this internal space. In the embodiment illustrated in FIG. 3, the storage portion (111a) may be a double cup shape formed on both sides of the cell case (111). The storage portion (111a) may be configured to extend in one direction. That is, the storage portion (111a) may be configured to extend in the longitudinal direction (Y-axis direction) of the battery cell (110).

[0076] The rim around the storage portion (111a) can be heat-fused to form a sealing portion (111b). That is, the sealing portion (111b) can be provided by sealing the outer periphery of the storage portion (111a). At this time, the sealing portion (111b) can be configured to protrude in one direction from the storage portion (111a). The sealing portion (111b) can be configured to protrude beyond the storage portion (111a) along one direction. At the end portion of the battery cell (110), the storage portions (111a) are provided in close contact with each other, and a predetermined space can be formed between the sealing portions (111b). Meanwhile, the battery cell (110) can be provided in an upright state with the side not containing the sealing portion (111b) facing downward.

[0077] Additionally, a plurality of battery cells (110) may each be provided with an electrode lead (112). The electrode lead (112) is connected to an electrode assembly and can be drawn out to the outside of the cell case (111) to function as an electrode terminal.

[0078] The electrode leads (112) may be provided as a pair, and the pair of electrode leads (112) may be drawn out at both ends of the battery cell (110), i.e., in the longitudinal direction (±Y direction). The electrode leads (112) may be configured to protrude toward the front and / or rear side of the sealing portion (111b) of the battery cell (110). At this time, the pair of electrode leads (112) may be a positive lead and a negative lead.

[0079] Meanwhile, the present invention is not limited by the specific type or shape of such battery cell (110), and various battery cells (110) known at the time of filing the present invention may be employed to constitute the battery unit (10) of the present invention. In this embodiment, a pouch-type secondary battery with high energy density and easy stacking is used as shown in the drawing, but it is understood that cylindrical or prismatic secondary batteries may also be applied as battery cells (110).

[0080] Referring to FIG. 2, the busbar assembly (200) may include a busbar frame (210) and a busbar (220).

[0081] The busbar frame (210) can cover one side of the cell stack (100). The busbar frame (210) can serve to support a busbar (220) connected to an electrode lead (112) provided in a plurality of battery cells (110). The busbar frame (210) can be formed from a material having electrical insulation properties, such as plastic.

[0082] The busbar frame (210) may be provided with a front frame (210a) covering the front of the cell stack (100) and a rear frame (210b) covering the rear of the cell stack (100). The front frame (210a) and the rear frame (210b) may be arranged to face each other.

[0083] The busbar frame (210) may be provided with a slit (240). The slit (240) may be configured to allow at least a portion of the electrode leads (112) of a plurality of battery cells (110) to pass through. The slit (240) may be provided to allow the plurality of electrode leads (112) to pass through in the +Y-axis or -Y-axis direction (front-back direction). The slit (240) may be provided in multiple numbers so as to be spaced apart from each other along the stacking direction (X-axis direction) of the battery cells (110). At this time, the plurality of electrode leads (112) that have passed through the slit (240) may be bent and attached to the busbar (220). The plurality of battery cells (110) whose electrode leads (112) are in contact with each other on the busbar (220) may be electrically connected to each other.

[0084] The busbar (220) can be fixed on the busbar frame (210). The busbar (220) can be provided between a plurality of slits (240). The busbar (220) can be coupled with the electrode leads (112) of the battery cells (110). The busbar (220) can be electrically connected to at least a portion of the electrode leads (112). The busbar (220) can be configured to be in direct contact with the electrode leads (112) passing through the slits (240) of the busbar frame (210). Specifically, the electrode leads (112) of the battery cells (110) pass through the slits (240) of the busbar frame (210) and are drawn out to the outside of the first busbar frame (210), and the drawn-out portion can be attached to the surface of the busbar (220) by means such as welding.

[0085] And, through this electrical connection, the busbar (220) can be configured to transmit status information about the battery cell (110) to an external component. For example, the busbar (220) can be configured to transmit voltage information of the battery cell (110) to an external control device such as a Battery Management System (BMS).

[0086] The busbar (220) may be made of an electrically conductive material for transmitting electrical signals. For example, the busbar (220) may be made of a material such as copper, nickel, or aluminum.

[0087] The busbar (220) may be located on the inner side of the electrode lead (112). For example, the electrode lead (112), which is bent at the front side of the battery unit (10), may have the busbar (220) located on the rear side.

[0088] The busbar (220) can be configured in a shape that ensures a sufficient contact area with the electrode lead (112). For example, the busbar (220) may have a flat surface and be formed in a shape that extends long in the vertical direction (Z-axis direction).

[0089] Referring to FIG. 2, a filler (300) may be positioned between the busbar assembly (200) and the cell stack (100). At this time, the filler (300) may surround the sealing portion (111b) of the battery cell (110). The filler (300) may be configured to suppress the discharge of venting gas when a thermal event occurs in the battery cell (110).

[0090] The filler (300) may include a material of the type that undergoes a phase change into a solid after curing from a liquid state. That is, the filler (300) may be a material that facilitates application and curing after application. The liquid filler (300) may additionally include a viscosity modifier, for example, a thixotropic agent, a diluent, a dispersant, a surface treatment agent, or a coupling agent, in order to control the viscosity in the liquid state.

[0091] For example, the filler (300) may be provided in the form of foam. The filler (300) may include, for example, silicone foam. The filler (300) may include, for example, a urethane-based material or a silicone-based material. The filler (300) may include, for example, a material having heat resistance and / or flame retardancy.

[0092] According to an embodiment of the present invention, the filler (300) may be configured to suppress the discharge of venting gas when a thermal event occurs in the battery cell (110). Additionally, it may prevent or delay the transfer of heat to another battery cell (110) adjacent to the battery cell (110) where the thermal event occurred.

[0093] In addition, according to the above embodiment of the present invention, the filler (300) is configured to pressurize the sealing portion (111b) (or terrace portion) so as to prevent the sealing portion (111b) from opening up when pressure is applied to the sealing portion (111b) of the battery cell (110), and to disperse the pressure applied to the sealing portion (111b).

[0094] Furthermore, according to the above embodiment of the present invention, the filler (300) may serve to more firmly secure the positions of the battery cells (110).

[0095] Referring to FIGS. 1 and 2, a case (400) may be configured to accommodate a cell stack (100). Specifically, the case (400) may be configured to have a receiving space formed therein and to accommodate the cell stack (100) in the receiving space. Such a case (400) may be made of a metal material having rigidity and heat resistance to physically or chemically protect the accommodated cell stack (100).

[0096] More specifically, the case (400) may include a case body (410), a front end cover (420), and a rear end cover (430).

[0097] The case body (410) may include a U-frame (411) and a top plate (412). The U-frame (411) may include a pair of side plates covering the left and right sides of the cell stack (100) and a base plate covering the bottom surface of the cell stack (100). The pair of side plates and the base plate may be formed integrally.

[0098] The top plate (412) may be configured to cover the upper surface of the cell stack (100). This top plate (412) may be joined to the U-frame (411) by welding. This case body (410) may be formed in a rectangular tubular shape with the front and rear open. As an alternative to the present embodiment, a monoframe-type case (400) in which the U-frame (411) and the top plate (412) are integrated may be adopted.

[0099] The front end cover (420) and the rear end cover (430) can be attached to the open front and rear of the case body (410), respectively. The front end cover (420) and the rear end cover (430) can be attached to the case body (410) by welding or a snap-fit ​​structure.

[0100] A venting hole (not shown) may be formed in the rear end cover (430). The venting hole may be configured to allow venting gas generated from the battery cell (110) to be discharged to the outside of the case.

[0101] A venting hole provided in the rear end cover (330) can be configured to discharge gas or flame generated inside the battery unit (10) to the outside of the battery unit (10) when thermal runaway of the battery unit (10) occurs. The remaining part of the case (400) excluding the venting hole is sealed, and the gas or flame can be discharged in a straight line toward the venting hole.

[0102] According to an embodiment of the present invention, even if a thermal event occurs at any location of the battery cell (110), gas or flame generated in the battery cell (110) is discharged to the outside of the battery unit (10) through specific venting holes provided at the rear of the battery cell (110), thereby facilitating venting. Thus, directional venting in one direction may be possible in the battery unit (10) according to one embodiment of the present invention. For example, directional venting to the rear of the battery unit (10) may be possible through the venting holes.

[0103] FIG. 4 is a front view of a busbar assembly of a battery unit according to an embodiment of the present invention. FIG. 5 is a perspective view showing the front of a battery unit according to an embodiment of the present invention, with the case omitted. FIG. 6 is a cross-sectional view of FIG. 5 cut along line A-A'. FIG. 7 is an enlarged view of a part of FIG. 6. FIG. 8 is an enlarged view of another part of FIG. 6. However, FIG. 7 and FIG. 8 only show a part of the filler (300) for convenience of explanation.

[0104] A filler hole (H) may be formed in at least one of the busbar frame (210) and the busbar (220). The filler hole (H) may be a hole configured to inject a filler (300) into the inside of the busbar assembly (200). By injecting the filler (300) through this filler hole (H), the space between the busbar frame (210) and the cell stack (100) can be filled with the filler (300). The filler hole (H) may be circular or elliptical in shape. However, the shape of the filler hole (H) is not limited by the embodiment and may be designed in various ways.

[0105] The filler (300) can be configured to be injected into the internal space (S) through the injection hole (H) and can be configured to fill the internal space (S). Referring to part B of FIG. 4, the filler (300) can be configured to cover the injection hole (H). That is, when the filler (300) is injected and then hardened, it can cover the injection hole (H). In other words, the injection hole (H) can be in a blocked state.

[0106] Referring to FIGS. 4 and 5, the injection holes (H) are provided in a plurality, and the plurality of injection holes (H) may be spaced apart in the first direction, that is, the width direction (X-axis direction), which is the stacking direction of the battery cell (110). These plurality of injection holes (H) may be provided at regular intervals from each other. However, this is not limited by the embodiment, and the spacing of the injection holes (H) may be adjusted as needed.

[0107] According to an embodiment of the present invention, a plurality of sealing portions (111b) (or terrace portions) provided in a plurality of battery cells (110) stacked in the width direction (X-axis direction) may each be surrounded by a filler (300). Even if a thermal event occurs in any one of the battery cells (110) among the plurality of battery cells (110) accommodated in the battery unit (10), venting gas may be prevented from being discharged near the filler (300), and heat transfer to an adjacent battery cell (110) may be prevented or delayed.

[0108] As illustrated in FIGS. 5 and 6, the filler (300) may be located in an internal space (S) formed between the busbar assembly (200) and the cell stack (100). Here, the internal space (S) may be defined as the space between the busbar assembly (200) and the cell stack (100) when the busbar assembly (200) and the cell stack (100) are spaced apart in the longitudinal direction (Y-axis direction). The internal space (S) may be formed by extending in the width direction (X-axis direction).

[0109] According to a comparative example, a solid (block-shaped) filler to suppress venting can be attached before the busbar assembly (200) and the cell stack (100) are assembled. In this case, a separate attachment process must be added, and since this is done manually, there is a problem that design errors are likely to occur.

[0110] According to the present invention, when the busbar assembly (200) and the cell stack (100) are assembled, the filler (300) can be injected through the injection hole (H). That is, the filler (300) can be injected in liquid form and then hardened. According to the embodiment of the present invention, design errors may not occur, and the internal space (S) between the busbar assembly (200) and the cell stack (100) can be configured to fill the space more tightly, thereby suppressing the discharge of venting gas more efficiently.

[0111] At this time, as shown in FIGS. 5 and 6, a busbar frame (210) with an injection hole (H) formed therein is placed on the front of the cell stack (100), and the filler (300) can fill the entire internal space (S). Here, the busbar frame (210) with the injection hole (H) formed therein may mainly refer to the front frame (front frame (210a) in FIG. 2). Additionally, the filler (300) may be placed between the front frame (210a) and the cell stack (100). For example, the injection hole (H) may be formed in the front frame (210a), but not in the rear frame (210b), and the filler (300) may not be injected between the rear frame (210b) and the cell stack (100). However, the location and placement of the injection hole (H) are not limited by the above embodiment and can be designed in various ways.

[0112] Additionally, the meaning of the filler (300) filling the entire internal space (S) may be that it fills the space spaced apart in the longitudinal direction (Y-axis direction) between the busbar assembly (200) and the cell stack (100). Furthermore, the meaning of the filler (300) filling the entire internal space (S) may be that it fills the space so as to extend in the width direction (X-axis direction) to correspond to all the battery cells (110) stacked in the width direction (X-axis direction). That is, the filler (300) can face all the battery cells (110) stacked in the width direction (X-axis direction).

[0113] According to an embodiment of the present invention, a directional venting structure that induces venting in a desired direction can be easily implemented through the appropriate arrangement of the filler (300). Specifically, the internal space (S) formed in the front direction of the battery unit (10) can be completely filled with the filler (300) to suppress venting toward the front and induce venting toward the rear. That is, directional venting toward the rear of the battery unit (10) (e.g., rear venting) can be implemented. Furthermore, another battery unit (10) may be placed on the front side of the battery unit (10), or an electrical connection configuration, such as a module terminal, for connecting to another battery unit (10) may exist. However, when front venting is blocked or suppressed as in the above embodiment, high-temperature gas or flames may be prevented or reduced from heading toward another battery unit (10) or the electrical connection configuration. In this case, the safety and reliability of the battery unit (10) including multiple battery cells (110) can be further improved.

[0114] Specifically, referring to FIGS. 5 and 6, at least a portion of the internal space (S) may include a plurality of partitioned spaces (e.g., S1, S2) partitioned in a first direction (X-axis direction) by electrode leads (112). At this time, a plurality of injection holes (H) may be formed at positions corresponding to each of the plurality of partitioned spaces. That is, the partitioned spaces (e.g., S1, S2) may be arranged in a first direction (X-axis direction). Each partitioned space may be surrounded by a sealing portion (111b) and / or a storage portion (111a) and / or a busbar frame (210). For example, the partitioned space may have a shape in which electrode leads (112) protruding from sealing portions (111b) provided on both sides come closer together, or an shape in which electrode leads (112) provided on both sides move away from each other.

[0115] The partition space can generally be divided into a first partition space (S1) and a second partition space (S2). The first partition space (S1) and the second partition space (S2) can be arranged alternately.

[0116] Referring primarily to FIG. 7, when each electrode lead (112) protruding from two battery cells (110) arranged side by side is drawn out through a single slit (240), each electrode lead (112) may become closer to each other as it approaches the busbar frame (210). The space surrounded by the electrode leads (112) that become closer to each other in this way can be defined as a first partition space (S1). The first partition space (S1) may be surrounded by electrode leads (112) and a storage portion (111a) provided on each side. In this case, the first partition space (S1) may generally have a roughly triangular shape.

[0117] Referring primarily to FIG. 8, when each electrode lead (112) protruding from two battery cells (110) arranged side by side is drawn out into each slit (240), each electrode lead (112) may move further apart from each other toward the busbar frame (210). The space enclosed by the electrode leads (112) that move further apart from each other in this way can be defined as a second compartment space (S2). The second compartment space (S2) may be enclosed by the electrode leads (112), the storage portion (111a), and the busbar frame (210) provided on both sides. In this case, the second compartment space (S2) may generally have a trapezoidal shape.

[0118] According to an embodiment of the present invention, since the internal space (S) can be partially separated by the electrode lead (112), injection holes (H) are arranged to correspond to all partially separated compartment spaces (S1, S2), so that a certain amount of filler (300) can be applied to all compartment spaces (S1, S2).

[0119] Referring to FIGS. 4 to 8, the cell stack (100) may be provided with a plurality of cell banks (CB) each containing at least one battery cell (110). For example, when 16 battery cells (110) are stacked in the cell stack (100), the cell bank (CB) may have 2 battery cells (110), and the cell stack (100) may have 8 cell banks (CB). According to the above embodiment of the present invention, the battery cells (110) can be grouped into small units to improve assembly.

[0120] Additionally, the electrode leads (112) of the battery cells (110) constituting a cell bank (CB) may be drawn out through a single slit (240) and overlapped on the outside of the busbar frame (210). That is, the cell bank (CB) may be a subunit of battery cells (110) configured so that the electrode leads (112) overlap.

[0121] At this time, the injection hole (H) may be provided with a first injection hole (H1) formed at a position corresponding to a cell bank (CB) and a second injection hole (H2) located between two cell banks (CB) arranged side by side. The first injection hole (H1) and the second injection hole (H2) may be arranged alternately with respect to the first direction (X-axis direction).

[0122] Referring primarily to FIG. 7, the first injection hole (H1) may be formed in a portion facing the area where the cell bank (CB) is placed in the busbar assembly (200). A plurality of first injection holes (H1) may correspond to a plurality of cell banks (CB), respectively. A plurality of first injection holes (H1) may correspond to a plurality of cell banks (CB) in a 1:1 ratio. For example, the number of first injection holes (H1) may be substantially the same as the number of cell banks (CB).

[0123] For example, the first injection hole (H1) may be formed in a portion corresponding to the slit (240) of the busbar frame (210) from which the electrode lead (112) of the battery cell (110) constituting the cell bank (CB) is drawn out. Referring to FIG. 4, the first injection hole (H1) may be positioned parallel to the slit (240) in a vertical direction (Z-axis direction, second direction). For example, the first injection hole (H1) may be positioned above and / or below the slit (240).

[0124] The first injection hole (H1) can be configured to fill the first compartment space (S1) with filler (300). The filler (300) can be injected into the first compartment space (S1) through the first injection hole (H1).

[0125] Referring primarily to FIG. 8, the second injection hole (H2) may be formed at the boundary of cell banks (CB) arranged side by side in the busbar assembly (200). For example, the second injection hole (H2) may be positioned between a plurality of slits (240) formed in the busbar frame (210). The second injection hole (H2) may be located in the busbar (220). Generally, since the busbar (220) is coupled between the plurality of slits (240), the second injection hole (H2) may be located in the busbar (220) coupled between the slits (240). Additionally, the second injection hole (H2) may be formed in the busbar frame (210) formed between the slits (240). That is, the second injection hole (H2) may be formed in both the busbar frame (210) and the busbar (220). For example, the number of second injection holes (H2) can be formed to be one less than the number of cell banks (CB).

[0126] For example, generally, the first injection hole (H1) may be located in the busbar frame (210), and the second injection hole (H2) may be located in the busbar (220). For example, generally, the size of the first injection hole (H1) may be larger than the size of the second injection hole (H2). For example, since there is generally more extra area in the busbar frame (210) than in the busbar (220), the size of the first injection hole (H1) may be formed to be relatively larger than the size of the second injection hole (H2). However, the size and location of the first injection hole (H1) and the second injection hole (H2) are not limited by the embodiment and can be designed in various ways.

[0127] According to an embodiment of the present invention, a plurality of injection holes (H) are provided at regular intervals based on a battery cell (110) or cell bank (CB), so that the filler (300) can be injected without gaps.

[0128] Meanwhile, referring to FIGS. 2, 5, and 6, the cell stack (100) of a battery unit (10) according to one embodiment of the present invention may further comprise a barrier member (120). The barrier member (120) may be configured to be provided between battery cells (110) to partition between a plurality of battery cells (110). In particular, at least one barrier member (120) may be included in one battery unit (10). A plurality of barrier members (120) may be provided along one direction in which the battery cells (110) are arranged.

[0129] A barrier member (120) may be placed between cell banks (CB). The barrier member (120) may be provided in a form that is placed for at least one battery cell (110). For example, as shown in FIG. 6, in a battery unit (10) according to one embodiment of the present invention, a barrier member (120) may be placed for each cell bank (CB) composed of two battery cells (110).

[0130] The barrier member (120) may be provided as an insulating pad that is thinner than the battery cell (110). The barrier member (120) may be provided as a material with excellent heat resistance and / or fire resistance. Alternatively, the barrier member (120) may be provided as a pad with compressible force, for example, made of a material such as silicone or aerogel.

[0131] At this time, referring to FIG. 8, the second injection hole (H2) may be formed in a position facing the barrier member (120). The second injection hole (H2) may be located between cell banks (CB) and may be positioned to face the barrier member (120) inserted between the cell banks (CB).

[0132] According to an embodiment of the present invention, battery cells (110) can be partitioned or separated to prevent gas or flames from passing over to an adjacent barrier member (120) and preventing heat from propagating to another battery cell (110). Additionally, according to an embodiment of the present invention, the barrier member (120) can contribute to the structural rigidity of the battery cells (110) by compressing the battery cell (110) during the swelling phenomenon of the battery cell (110).

[0133] The injection holes (H) may be provided as a pair spaced apart in a second direction (Z-axis direction) that is perpendicular to the first direction in the busbar assembly (200). In other words, the injection holes (H) may be provided as a pair in the upper and lower parts. Both the first injection hole (H1) and the second injection hole (H2) may have an injection hole (H) positioned on the upper side and an injection hole (H) positioned on the lower side. For example, the injection hole (H) positioned on the upper side and the injection hole (H) positioned on the lower side may be located on the upper and lower sides with respect to the electrode lead (112) coupled on the busbar assembly (200).

[0134] According to the embodiment of the present invention, the problem of an excessive amount of filler (300) flowing to the lower side of the battery cell (110) or hardening unevenly between the upper and lower sides within the internal space (S) can be resolved. As a result, the filler (300) can be configured to be injected evenly in a certain amount from the upper and lower sides.

[0135] FIG. 9 is a front view of a busbar assembly of a battery unit according to another embodiment of the present invention.

[0136] According to one embodiment, the size of the injection hole (H) positioned on the upper side may be formed to be larger than the size of the injection hole (H) positioned on the lower side. For example, the size of the injection hole (H) positioned on the upper side may be formed to be approximately 1.2 times larger than the size of the injection hole (H) positioned on the lower side. For example, the size of the injection hole (H) positioned on the upper side may be approximately 1.2 times larger and 2 times smaller than the size of the injection hole (H) positioned on the lower side.

[0137] Referring to FIG. 9, when the diameter of the injection hole (H) positioned on the upper side is R1 and the diameter of the injection hole (H) positioned on the lower side is R2, the diameter (R1) of the injection hole (H) positioned on the upper side may be formed larger than the diameter (R2) of the injection hole (H) positioned on the lower side. At this time, the injection hole (H) positioned on the upper side may be the first injection hole (H1) positioned on the upper side or the second injection hole (H2) positioned on the upper side. The injection hole (H) positioned on the lower side may be the first injection hole (H1) positioned on the lower side or the second injection hole (H2) positioned on the lower side. For example, the size of the first injection hole (H1) positioned on the upper side may be formed larger than the size of the first injection hole (H1) positioned on the lower side. For example, the size of the second injection hole (H2) positioned on the upper side may be formed to be larger than the size of the second injection hole (H2) positioned on the lower side.

[0138] Since the filler (300) has the property of flowing downward before hardening, it moves downward even when injected into the injection hole (H) located on the upper side. According to the above embodiment of the present invention, the size of the injection hole (H) located on the lower side is made relatively small, thereby solving the problem of the upper and lower sides hardening unevenly within the internal space (S). As a result, the filler (300) can be configured to be injected evenly in a certain amount from the upper and lower sides.

[0139] FIG. 10 is a front view of a busbar assembly of a battery unit according to another embodiment of the present invention. FIG. 11 is a cross-sectional view showing a portion of the rear of a battery unit according to another embodiment of the present invention.

[0140] A busbar frame (210) may be placed on the front and rear of a cell stack (100). At this time, a busbar frame (210) placed on the rear of the cell stack (100) (e.g., the rear frame (210b) of FIG. 2) and a filler (300) located between the cell stack (100) may be configured to fill a portion of the internal space (S).

[0141] The filler (300) can be placed on both the front and rear sides. Here, the filler (300) placed on the front side may be substantially the same as the filler (300) of FIGS. 1 to 9. Below, the description will focus on the filler (300) placed on the rear side.

[0142] At this time, the pillar (300) placed on the front may fill the entire internal space (S), and the pillar (300) placed on the rear may fill a part of the internal space (S). That is, the pillar (300) placed on the rear may not be configured to surround all of the multiple battery cells (110), but may be placed only in the part corresponding to some of the battery cells (110). Multiple pillars (300) placed on the rear may be spaced apart. That is, the pillar (300) placed on the front may be provided with a higher density than the pillar (300) placed on the rear.

[0143] For example, the rear-mounted filler (300) may be placed only in the second compartment space (S2) and not in the first compartment space (S1). For example, the rear-mounted filler (300) may be interposed on both sides of the barrier member (120). Multiple rear-mounted fillers (300) may be provided and spaced apart from each other. Accordingly, a space may be provided between adjacent rear-mounted fillers (300) to vent the venting gas or flame generated from the battery cell (110). However, the placement of the rear-mounted filler (300) is not limited by the above embodiment, and the position and amount may be varied in design as long as they fill a part of the internal space (S).

[0144] According to an embodiment of the present invention, when a thermal event occurs, the venting direction of venting gas or flames, etc., can be induced to the rear. Specifically, when a thermal event occurs, the internal pressure of the sealing portion (111b) of the battery cell (110) can increase. At this time, the venting gas can be suppressed or blocked from being discharged through the front. Furthermore, the pressure of the venting gas can be concentrated at the rear side sealing portion (111b) of the battery cell (110). As a result, the venting gas can be discharged through the rear side sealing portion (111b) of the battery cell (110).

[0145] FIG. 12 is a front view of a busbar assembly of a battery unit according to another embodiment of the present invention.

[0146] According to one embodiment, the injection hole (H) may be formed extending in a first direction (X-axis direction). For example, the injection hole (H) may be in the form of a bar extending in the first direction. For example, the injection hole (H) may be in the form of a thin slit. For example, the injection hole (H) may be formed extending in the first direction on the upper and / or lower side of the busbar frame (210). The injection hole (H) may be located on the upper and / or lower side of the busbar (220). The injection hole (H) may be positioned perpendicular to the slit (240) formed in the busbar frame (210).

[0147] According to the embodiment of the present invention, since it is not necessary to form multiple injection holes (H), the design time can be shortened and the manufacturing speed can be improved. In addition, since the filler (300) can be injected into the entire internal space (S) with a single injection, it can be simpler and the design time can be effectively shortened.

[0148] FIG. 13 is a cross-sectional view of FIG. 5 cut along line A-A' according to another embodiment of the present invention.

[0149] The barrier member (120) may be in direct vertical contact with the busbar assembly (200). The barrier member (120) may be extended so as to protrude in the front direction (+Y-axis direction) beyond the storage portion (111a) of the battery cell (110). At this time, the barrier member (120) may serve to partition the internal space (S). The barrier member (120) may partially divide the second partitioned space (S2).

[0150] The barrier member (120) may partially contact the second injection hole (H2). The barrier member (120) may cover at least a portion of the second injection hole (H2). For example, the diameter of the second injection hole (H2) may be formed to be larger than the width of the barrier member (120). That is, when injecting filler (300) into the second injection hole (H2), the filler (300) may be injected into both sides of the barrier member (120).

[0151] According to an embodiment of the present invention, the barrier member can partially divide the second partition space (S2), which has a relatively larger area than the first partition space (S1), to guide the filler (300) to be injected evenly on both sides. Additionally, it can serve as a guide to allow the filler (300) to flow down along the barrier member inside.

[0152] Below, we will explain the battery unit assembly method.

[0153] FIG. 14 is a drawing showing a method of assembling a battery unit according to one embodiment of the present invention.

[0154] The method for assembling the battery unit (10) may include the following first, second, and third steps.

[0155] The first step may be to pull the electrode lead (112) of the battery cell (110) out to the outside of the busbar frame (210) through a slit (240) formed in the busbar frame (210).

[0156] The second step may be a step of assembling the cell stack (100) and the busbar assembly (200). The filler (300) may be injected into the injection hole (H) through an injection gun (G). At this time, with reference to part C of FIG. 14, the shape of the end of the injection gun (G) may be formed to be identical to the shape of the injection hole (H). The shape and size of the end of the injection gun (G) may be substantially identical to the shape and size of the injection hole (H). Multiple injection guns (G) may be provided.

[0157] The third step may be a step of injecting filler (300) through injection holes (H). Referring to FIG. 13, injection may be performed simultaneously in multiple injection holes (H). For example, filler (300) may be injected simultaneously into multiple injection holes (H) through multiple injection guns (G).

[0158] According to the above embodiment of the present invention, since the liquid injection proceeds simultaneously, production can be easy and simple. In addition, production time can be shortened and production speed can be increased. Furthermore, compared to manual production, the internal space (S) can be filled more effectively.

[0159] FIG. 15 is a drawing for explaining a battery pack (1) including a battery unit according to an embodiment of the present invention. FIG. 16 is a drawing for explaining a vehicle (V) including the battery pack (1) of FIG. 15.

[0160] Referring to FIG. 15, the battery pack (1) according to the present invention may include at least one battery unit (10) according to the present invention as described above. The battery pack (1) according to the present invention may further include a pack case (2) for accommodating components such as a Battery Management System (BMS) for integrated control of charging and discharging of one or more battery units (10), a current sensor, a fuse, etc., as described above. As illustrated, the battery pack (1) may be constructed using a battery unit (10) which is an intermediate form of assembly, or it may directly accommodate a cell stack (100) without a battery unit (10). For example, the battery pack (1) of the present invention may be manufactured by a cell-to-pack process. For example, the battery pack (1) of the present invention may be manufactured by a cell-to-chassis process. Here, the battery unit (10) may refer to a battery module, a cell assembly, etc.

[0161] Referring to FIG. 15, a plurality of battery units (10) can be arranged such that one side having a front frame (210a) and a filler (300) located inside the front frame (210a) faces the inside of the pack case (2). Thus, the other side (e.g., rear) of the battery unit (10) having a venting hole can be arranged such that it faces the outside of the pack case (2).

[0162] According to an embodiment of the present invention, when a thermal event occurs in a battery cell (110) inside a battery unit (10), venting gas or flames, etc., can be directionally vented toward the rear side of the battery unit (10). Accordingly, venting gas or flames, etc., discharged toward the rear side can be rapidly discharged to the outside of the battery pack (1).

[0163] Referring to FIG. 16, the automobile (V) according to the present invention may include at least one battery pack (1) according to the present invention.

[0164] The battery cell (110) according to the present invention can be applied to a vehicle such as an electric vehicle or a hybrid vehicle. That is, the vehicle (V) according to the present invention may include the battery cell (110) according to the present invention, the battery unit (10) according to the present invention, or the battery pack (1) according to the present invention. The vehicle (V) according to the present invention may be, for example, an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle. The vehicle (V) includes four-wheeled vehicles and two-wheeled vehicles. The vehicle (V) operates by receiving power from the battery pack (1) to the battery unit (10) and the cell stack (100) according to one embodiment of the present invention.

[0165] Although the present invention has been described above by 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 spirit of the present invention and the equivalent scope of the claims described below by those skilled in the art to which the present invention belongs.

Claims

1. A cell stack comprising a plurality of battery cells stacked in a first direction; A busbar assembly comprising a busbar frame covering one side of the cell stack and a busbar fixed on the busbar frame and coupled to an electrode lead of the battery cell, wherein a liquid injection hole is formed in at least one of the busbar frame and the busbar; and A battery unit comprising: a filler located in the internal space formed between the busbar assembly and the cell stack and configured to suppress the discharge of venting gas.

2. In Paragraph 1, A battery unit characterized by the above filler being configured to be injected into the internal space through the injection hole and configured to fill the internal space.

3. In Paragraph 1, The above busbar frame is positioned on the front of the cell stack, and A battery unit characterized by the above-mentioned filler filling the entire internal space.

4. In Paragraph 1, A battery unit characterized in that the above-mentioned injection holes are provided in plurality, and the plurality of injection holes are spaced apart in the first direction.

5. In Paragraph 1, At least a portion of the above internal space includes a plurality of partitioned spaces partitioned in the first direction by the electrode lead, and A battery unit characterized in that the plurality of injection holes are formed at positions corresponding to each of the plurality of compartment spaces.

6. In Paragraph 1, The cell stack is provided with a plurality of cell banks, each containing at least one battery cell, and A battery unit characterized in that the above-mentioned injection hole comprises a first injection hole formed at a position corresponding to the cell bank and a second injection hole located between the cell banks arranged side by side.

7. In Paragraph 6, The cell stack further comprises a barrier member disposed between the cell banks, A battery unit characterized in that the second injection hole is formed in a position facing the barrier member.

8. In Paragraph 1, A battery unit characterized in that the above injection holes are provided as a pair spaced apart in a second direction perpendicular to the first direction in the busbar assembly.

9. In Paragraph 1, A battery unit characterized in that the above filler is configured to cover the above injection hole.

10. In Paragraph 9, The above busbar frame is positioned on the front and rear of the cell stack, and A battery unit characterized by a busbar frame positioned on the rear of the cell stack and a filler located between the cell stack and the busbar frame, which fills a portion of the internal space.

11. Regarding the battery unit assembly method, A first step of drawing the electrode lead of a battery cell out to the outside of the busbar frame through a slit formed in the busbar frame; A second step of assembling a busbar assembly comprising a cell stack including a plurality of battery cells, a busbar frame, and a busbar fixed on the busbar frame and coupled to the electrode lead of the battery cell, wherein a liquid injection hole is formed in at least one of the busbar frame and the busbar; and A battery unit assembly method comprising a third step of injecting a filler through the injection hole.

12. In Paragraph 11, A battery unit assembly method characterized in that, in the second step above, the filler is injected into the injection hole through an injection gun, and the shape of the end of the injection gun is formed to be identical to the shape of the injection hole.

13. A battery pack characterized by including at least one battery unit described in any one of claims 1 to 10.

14. An automobile characterized by comprising at least one battery unit described in any one of claims 1 to 10.

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