Battery pack and automobile including same

Abstract

The battery pack of the present invention includes a plurality of pouch-type battery cells, a pack case that stores the plurality of pouch-type battery cells in an internal space, and a cell cover configured to partially surround an exterior of at least one of the plurality of pouch-type battery cells to form an opening, and the pack case is characterized in that it has a flame retardant portion on a side where the opening is located.

Description

[Technical Field]

[0001] The present invention relates to a battery pack and a vehicle including the same, and more particularly to a battery pack with improved stability, etc. This application claims priority to Korean Patent Application No. 10-2022-0070539 filed on June 10, 2022, and Korean Patent Application No. 10-2023-0055776 filed on April 27, 2023, the entire contents of which are incorporated herein by reference in their entirety. [Background technology]

[0002] As technological development and demand for various mobile devices, electric vehicles, and energy storage systems (ESS) increases dramatically, interest in and demand for secondary batteries as an energy source is rapidly increasing.

[0003] Conventionally, nickel-cadmium batteries or nickel-metal hydride batteries have been widely used as secondary batteries, but recently lithium secondary batteries have become more widely used because they have almost no memory effect compared to nickel-based secondary batteries, can be charged and discharged freely, have a very low self-discharge rate, and have a high energy density.

[0004] Such lithium secondary batteries mainly use lithium-based oxides and carbon materials as the positive and negative electrode active materials, respectively, and include an electrode assembly in which a separator is sandwiched between positive and negative electrode plates coated with the positive and negative electrode active materials, and an exterior material, i.e., a battery case, that seals and houses the electrode assembly together with an electrolyte.

[0005] Generally, secondary batteries are classified according to the shape of the exterior material into can-type batteries in which the electrode assembly is incorporated into a metal can, and pouch-type batteries in which the electrode assembly is incorporated into a pouch made of an aluminum laminate sheet.

[0006] Recently, battery modules have been widely used for driving and storing energy in medium to large-sized devices such as electric vehicles and energy storage systems.

[0007] A conventional battery pack includes one or more battery modules housed within a pack case and a control unit that controls the charging and discharging of the battery modules. Here, the battery module is configured to include multiple battery cells housed within a module case. That is, in a conventional battery pack, multiple battery cells (secondary batteries) are housed within a module case to form each battery module, and one or more such battery modules are housed within a pack case to form a battery pack. In particular, pouch-type batteries have many advantages, such as light weight and little dead space when stacked, but suffer from issues such as vulnerability to external impacts and somewhat poor assembly. Therefore, battery packs are generally manufactured by modularizing multiple cells and then housing them within a pack case.

[0008] However, conventional battery packs may be disadvantaged in terms of energy density, ease of assembly, cooling, etc., due to modularization, etc. In particular, pouch-type battery cells may experience swelling, and conventional battery packs have difficulty in dealing with this swelling situation.

[0009] In addition, conventional battery packs may be disadvantaged in terms of energy density, ease of assembly, and cooling due to modularization.

[0010] Furthermore, conventional battery modules and battery packs are vulnerable to thermal events. In particular, if a thermal event occurs inside a battery module or battery pack, thermal runaway can cause a fire, and in severe cases, an explosion can occur. Summary of the Invention [Problem to be solved by the invention]

[0011] The present invention has been made to solve the above problems, and an object of the present invention is to provide a battery pack that is excellent in many aspects, including swelling resistance, and a vehicle including the same.

[0012] Another problem to be solved by the present invention is to provide a battery pack and a vehicle including the same that can ensure excellent stability when a thermal event occurs.

[0013] In particular, the present invention aims to provide a battery pack and a vehicle including the same that can prevent heat propagation to adjacent battery cells by reducing the intensity of the flame and controlling backflow when a thermal event occurs inside the battery pack.

[0014] However, the technical problems that the present invention aims to solve are not limited to the above problems, and other problems not mentioned will be clearly understood by those skilled in the art from the description of the invention provided below. [Means for solving the problem]

[0015] A battery pack according to one aspect of the present invention for solving the above-described problems includes a plurality of pouch-type battery cells, a pack case that houses the plurality of pouch-type battery cells in an internal space, and a cell cover configured to partially surround the exterior of at least one pouch-type battery cell of the plurality of pouch-type battery cells to form an opening.

[0016] The pack case may include a flame retardant portion on the side where the opening is located.

[0017] The flame retardant portion may be configured to reduce the directivity of gas and flame generated in the at least one battery cell and allow the gas and flame to pass through.

[0018] The internal space of the pack case may include a storage space that stores the plurality of pouch-type battery cells, and a vent space around the storage space.

[0019] The internal space of the pack case can exhaust the gas and flame that have passed through the flame delay portion to the outside of the pack case through the vent space.

[0020] There may be a plurality of cell covers.

[0021] The flame retardant portion may include a separator provided at a position corresponding to a gap between adjacent cell covers, and a collector provided at a position corresponding to an opening of each of the cell covers.

[0022] The isolation portion may be at least partially located between the storage space and the vent space.

[0023] The collection portion may be located within the vent space.

[0024] The pack case may include a housing configured to house the flame retardant portion.

[0025] The flame retardant portion may include a coupling portion configured to be coupled to the pack case.

[0026] The flame retardant portion may be a wedge-shaped structure having a wave shape in cross section at least at one end thereof.

[0027] The cell cover may include a first cover portion covering one side of the surrounded pouch-type battery cell, a second cover portion covering the other side of the surrounded pouch-type battery cell, and an upper cover portion connecting the first cover portion and the second cover portion and covering one side of the surrounded pouch-type battery cell.

[0028] The plurality of pouch-type battery cells may each include an electrode lead.

[0029] The cell cover may have the opening at an end of the first cover portion on which the electrode lead is provided and at an end of the second cover portion on which the electrode lead is provided.

[0030] The battery pack may further include a side assembly that covers the opening.

[0031] The side assembly may be at least partially inserted into the cell cover.

[0032] The side assembly may include a bus bar assembly configured to electrically connect the electrode leads, and an end cover configured to cover one side of the bus bar assembly and to exhaust gas generated in at least a portion of the enclosed pouch-type battery cell.

[0033] The side assembly may include an intermediate cover between the bus bar assembly and the end cover for insulation.

[0034] The side assemblies may include a mesh portion.

[0035] The battery pack may include a thermal resin in at least a portion of a space between the cell cover and the pack case and a space between the plurality of pouch-type battery cells and the pack case.

[0036] The cell cover may be configured to support the pouch-type battery cell in an upright state between the first cover portion and the second cover portion.

[0037] The cell cover may include an insulating coating layer on at least a portion of an inner surface of the first cover portion and an inner surface of the second cover portion.

[0038] The cell cover may include an adhesive member on at least a portion of an outer surface of the first cover portion and an outer surface of the second cover portion.

[0039] A motor vehicle according to the present invention may include a battery pack according to the present invention. [Effects of the Invention]

[0040] According to one aspect of the present invention, a plurality of pouch-type battery cells can be stably housed inside a pack case without using a stacking frame such as a plastic cartridge or a separate module case.

[0041] Furthermore, a CTP (Cell To Pack) type battery pack using pouch-type battery cells can be more efficiently realized. That is, instead of accommodating pouch-type battery cells inside a separate module case and then accommodating the module case inside a pack case, the battery pack can be provided in a form in which the pouch-type battery cells are directly accommodated inside the pack case.

[0042] According to this configuration of the present invention, when a thermal event occurs inside the battery pack, the flame and gas generated are directed toward the flame delay section through the opening, and the flame and gas collide continuously between some spaces formed in the flame delay section. Therefore, the flame and gas do not travel as directly as the flame and gas, and can be discharged with reduced intensity. In addition, by providing the flame delay section in a position that makes it easy to discharge the flame and gas, it is possible to discharge the gas in a desired direction.

[0043] According to another aspect of the present invention, the cell cover and the side assembly can be efficiently coupled together due to a structure in which the side assembly is inserted into the cell cover, and the end cover can cover the portion of the pouch-type battery cell that is not surrounded by the cell cover, thereby providing more stable protection.

[0044] According to another aspect of the present invention, if gas and / or flame occurs due to swelling or thermal runaway in a pouch-type battery cell, the gas and / or flame can be discharged to the outside of the cell unit through the first vent. Therefore, by introducing a side vent, it is possible to prevent the gas and / or flame from being randomly discharged through the open portion of the cell cover.

[0045] According to another aspect of the present invention, the flow of a flame that may occur in a pouch-type battery cell can be temporarily blocked by the middle cover, thereby reducing the intensity of the flame and preventing the flame from rapidly escaping to the first vent portion, and also preventing a short circuit caused by contact between the bus bar assembly and the end cover.

[0046] As described above, the present invention provides a battery pack and a vehicle including the same that are excellent in many aspects, such as swelling resistance, and also provides a battery pack and a vehicle including the same that can ensure excellent safety when a thermal event occurs.

[0047] The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention, serve to further understand the technical concepts of the present invention. Therefore, the present invention should not be interpreted as being limited to only the matters described in the drawings. [Brief explanation of the drawings]

[0048] [Figure 1] 1 is a diagram showing a battery pack according to the present invention; [Figure 2] 1 is an exploded perspective view of a battery pack according to the present invention; [Figure 3] 1 is a diagram showing a pouch-type battery cell and a cell cover included in a battery pack according to the present invention. [Figure 4] 1 is a diagram showing some components included in a battery pack according to the present invention. [Figure 5] 1A and 1B illustrate exemplary configurations of flame retardants included in battery packs according to the present invention. [Figure 6] FIG. 2 is a diagram showing the paths of gases and flames generated in a cell unit included in a battery pack according to the present invention. [Figure 7] 1 is a partial cross-sectional view of a battery pack according to the present invention; [Figure 8] FIG. 8 is an enlarged view of a part of FIG. 7. [Figure 9] 1 is a diagram showing some components of a battery pack according to the present invention. [Figure 10] 1 is a diagram showing a busbar assembly included in a battery pack according to the present invention. [Figure 11] 10A and 10B are diagrams showing end covers included in a battery pack according to the present invention. [Figure 12] 10A and 10B are diagrams illustrating an intermediate cover included in a battery pack according to the present invention. [Figure 13] 1 is a partial cross-sectional view of a battery pack according to the present invention; [Figure 14] 1 shows a motor vehicle according to the invention; DETAILED DESCRIPTION OF THE INVENTION

[0049] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, the terms and words used in the specification and claims should not be construed as being limited to their ordinary and dictionary meanings, but should be construed as having meanings and concepts corresponding to the technical ideas of the present invention, in accordance with the principle that the inventors themselves can appropriately define the concepts of terms in order to best describe the invention.

[0050] Therefore, it should be understood that the configurations shown in the embodiments described in this specification are merely the most desirable embodiments of the present invention and do not represent the entire technical idea of ​​the present invention, and that there may be various equivalents and modifications that can be substituted for them at the time of this application.

[0051] The same reference numerals refer to the same elements, and in the drawings, the thickness, proportions and dimensions of the elements are exaggerated for the purpose of effectively explaining the technical contents.

[0052] Although terms indicating directions such as up, down, left, right, front, back, etc. are used in this specification, it will be obvious to those skilled in the art that these terms are used for convenience of explanation and may change depending on the position of the object of interest, the position of the observer, etc.

[0053] Fig. 1 is a diagram showing a battery pack according to the present invention, Fig. 2 is a diagram showing some components of the battery pack according to the present invention in isolation, and Fig. 3 is a diagram showing a pouch-type battery cell and a cell cover included in the battery pack according to the present invention.

[0054] 1 to 3, a battery pack 10 according to the present invention includes a plurality of pouch-type battery cells 100, a pack case 300, and a cell cover 200.

[0055] The pouch-type battery cell 100 may include an electrode assembly, an electrolyte, and a pouch exterior material. The pouch-type battery cell 100 may include a storage portion 110 that stores the electrode assembly and a seal portion 120 that extends outward from the periphery of the storage portion 110. The pouch-type battery cell 100 may include electrode leads 111. The electrode leads 111 may be extended in both directions of the pouch exterior material or extended from only one side. In the illustrated example, the electrode leads 111 are extended in both directions of the pouch-type battery cell 100 (Y-axis direction). The direction in which the electrode leads 111 are extended can be defined as the longitudinal direction of the pouch-type battery cell 100; in other words, the electrode leads 111 are extended forward and backward along the longitudinal direction of the pouch-type battery cell 100.

[0056] 2 and 3, such a pouch-type battery cell 100 can be surrounded by a cell cover 200 to form a cell unit U.

[0057] 2 and 3, the battery pack 10 may include a plurality of such cell units U, thereby including a plurality of pouch-type battery cells 100 in the battery pack 10. The plurality of pouch-type battery cells 100 may be stacked in at least one direction. The plurality of pouch-type battery cells 100 may be stacked in the left-right direction (X-axis direction). Referring to FIG. 3, two pouch-type battery cells 100 are stacked in the left-right direction to form one cell unit U, and referring to FIG. 2, three such cell units U are arranged in the left-right direction and are arranged in a 1 x 3 array within the pack case 300.

[0058] The cell cover 200 may be configured to partially surround the exterior of at least one pouch-type battery cell 100 to form an opening O. The cell cover 200 may be configured to surround a portion of a plurality of pouch-type battery cells 100 stacked in the left-right direction. The cell cover 200 may be configured to form the opening O on the side where the electrode lead 111 is provided.

[0059] The cell cover 200 can be configured to group and unitize multiple pouch-type battery cells 100 included in the battery pack 10. One cell cover 200 can constitute one cell unit U. For example, one cell unit U is shown in FIG. 3, and multiple cell units U are shown in FIG. 2. The cell cover 200 can surround at least three sides of the pouch-type battery cell 100.

[0060] The battery pack 10 includes a plurality of cell units U, in which case a plurality of cell covers 200 may be included in the battery pack 10. When the cell covers 200 surround two or more pouch-type battery cells 100, the battery pack 10 may include a number of cell covers 200 that is less than the number of pouch-type battery cells 100.

[0061] The cell unit U can also be expressed as a cell bank. According to the present invention, the cell cover 200 separates the cell banks, thereby preventing thermal runaway and explosion for each cell bank.

[0062] The cell cover 200 may be made of various materials to ensure rigidity. In particular, the cell cover 200 may be made of a metal material. Such a metal material can more stably maintain the stacked state of the pouch-type battery cells 100 and more safely protect the pouch-type battery cells 100 from external impacts. The cell cover 200 may be made of a stainless steel material. For example, the entire cell cover 200 may be made of a stainless steel material.

[0063] A thermal barrier (not shown) may be further included between adjacent cell covers 200. The thermal barrier may be configured in the form of a pad made of a heat insulating material or a flame retardant material, and may preferably be configured of a compressible material. Preferably, the thermal barrier may be configured to be in close contact with the cell covers 200 between adjacent cell covers 200. As a result, the thermal barrier may be configured to suppress swelling that may occur in the pouch-type battery cell 100. In addition, the thermal barrier delays the spread of flame due to thermal runaway, blocks heat propagation, and suppresses swelling that may occur in the pouch-type battery cell 100, thereby further ensuring the structural stability of the battery pack 10.

[0064] The cell cover 200 may be made of various materials to ensure rigidity. In particular, the cell cover 200 may be made of a metal material. Such a metal material can more stably maintain the stacked state of the pouch-type battery cells 100 and more safely protect the pouch-type battery cells 100 from external impacts. The cell cover 200 may be made of a stainless steel material. For example, the entire cell cover 200 may be made of a stainless steel material.

[0065] When the cell cover 200 is made of steel, it has excellent mechanical strength and rigidity, and therefore can more stably support the stacked state of the pouch-type battery cells 100. Furthermore, in this case, damage or breakage of the pouch-type battery cells 100 due to external impact, for example, a needle-shaped object, can be more effectively prevented. Furthermore, in this case, the pouch-type battery cells 100 can be more easily handled. Furthermore, due to its high melting point, the overall structure can be stably maintained even if a flame breaks out from a battery cell 100. Because of its higher melting point compared to aluminum materials, it does not melt even when a flame breaks out from the battery cell 100, and its shape can be stably maintained. Therefore, excellent flame propagation prevention and delay effects and vent control effects can be ensured between the battery cells 100.

[0066] In addition, by surrounding the battery cells 100 with the cell covers 200, the battery cells 100 can be easily made strong, and a configuration in which the battery cells 100 are directly stacked inside the pack case 300 can be more easily realized. Therefore, the ease of assembly and mechanical stability of the battery pack 10 can be improved.

[0067] According to this configuration of the present invention, a plurality of pouch-type battery cells 100 can be stably housed inside the pack case 300 without using a stacking frame such as a plastic cartridge or a separate module case.

[0068] Furthermore, in the present invention, a CTP (Cell To Pack) type battery pack 10 using the pouch-type battery cells 100 can be more efficiently realized. That is, instead of accommodating the pouch-type battery cells 100 inside a separate module case and then accommodating the module case inside the pack case 300, the battery pack 10 can be provided in a form in which the pouch-type battery cells 100 are directly accommodated inside the pack case 300. In this case, at least one side of the pouch-type battery cells 100 can be exposed to the outside of the cell cover 200 and disposed directly facing the pack case 300.

[0069] Therefore, according to this aspect of the present invention, the battery pack 10 does not need to further include a module case, a stacking frame, or fastening members such as bolts for maintaining the stacked state of the cells. Therefore, the space occupied by other components such as the module case and the stacking frame and the space required to ensure tolerances can be eliminated. Therefore, the battery cells 100 can occupy the space equivalent to the space removed by the other components, thereby further improving the energy density of the battery pack 10.

[0070] Furthermore, according to this aspect of the present invention, since a module case, stacking frame, bolts, etc. are not provided, the volume and weight of the battery pack 10 can be reduced and the manufacturing process can be simplified.

[0071] Furthermore, according to this aspect of the present invention, handling of the pouch-type battery cells 100 can be made easier. For example, when storing multiple pouch-type battery cells 100 inside the pack case 300, the pouch-type battery cells 100 can be held by a jig or the like. In this case, the jig can hold the cell cover 200 surrounding the pouch-type battery cell 100 without directly holding the pouch-type battery cell 100. This makes it possible to prevent the pouch-type battery cell 100 from being damaged or broken by the jig.

[0072] Furthermore, it is possible to further improve the cooling efficiency of the battery pack 10. In particular, in the case of an embodiment of the present invention, a portion of each battery cell 100 is directly exposed to the pack case 300, so that heat from each battery cell 100 can be effectively discharged to the outside through the pack case 300.

[0073] The pack case 300 may form a space therein to accommodate the pouch-type battery cells 100. For example, the pack case 300 may include a first case 310, a second case 320, and a top cover 330. The first case 310 is configured in the form of a box with an open top and may accommodate a plurality of pouch-type battery cells 100 in the internal space. The second case 320 is configured in the form of a box with an open top and may accommodate the first case 310 in the internal space. The top cover 330 may be configured in the form of a cover that covers the open top portions of the first case 310 and the second case 320. Meanwhile, the pack case 300 is not limited to the above structure and may have a double-wall structure in which the first case 310 and the second case 320 are integrally coupled together, with the portion corresponding to the first case 310 forming an inner wall and the portion corresponding to the second case 320 forming an outer wall. However, in the following description, the pack case 300 is limited to being composed of a first case 310 and a second case 320.

[0074] Fig. 4 is a diagram showing some components included in a battery pack 10 according to the present invention. Fig. 5 is a diagram showing an exemplary configuration of a flame retardant included in a battery pack according to the present invention.

[0075] 4 and 5, the pack case 300 may include a flame retardant portion 340. The flame retardant portion 340 may be provided on the side where the opening O is located. The flame retardant portion 340 may be provided on one side of the first case 310 facing the opening O. Here, the opening O may refer to the side of the cell unit U that is located in the extension direction of the Y axis.

[0076] The flame retardant portion 340 may be configured to reduce the linearity of flame and gas generated in at least one pouch-type battery cell 100. The flame retardant portion 340 may not be simply plate-shaped, but may have a shape with regularly-spaced convex and concave shapes toward the direction of flame and gas discharge. Therefore, spaces may be formed between the regularly-spaced convex and concave portions of a substantially flat plate. Flame and gas may be trapped in the spaces. For example, as shown in FIG. 4 , the flame retardant portion 340 may have a wedge-shaped structure whose cross section (cross section perpendicular to the Z-axis direction) at one end includes a wave shape. The flame retardant portion 340 may be provided at a position corresponding to a cell unit U housed inside the first case 310. The wedge-shaped structure may include a plurality of wedge structures, and each wedge structure may be configured to form a space between itself and the outer surface of the first case 310 at a position corresponding to the cell unit U.

[0077] As shown in FIG. 5, the flame retardant portion 340 may be a plate having a shape similar to an egg container, with a regularly-spaced convex portion 340a and a regularly-spaced concave portion 340b. The concave portion 340b may be recessed inward, and the convex portion 340a may protrude from the concave portion 340b. The flame retardant portion 340 is not limited to the shape shown in FIG. 5 as long as it has regularly-spaced convex and concave portions. The regularly-spaced convex and concave portions may be configured to form a space between the outer surface of the first case 310. For example, various three-dimensional structures, such as sound-absorbing wedges, that are used inside anechoic chambers may be used for the flame retardant portion 340. As is well known, an anechoic chamber is a room designed to have conditions similar to a free sound field by installing sound-absorbing materials or blocks with high sound absorption coefficients on the walls, ceiling, and / or floor of the room to prevent sound generated within the room from reflecting through the walls, ceiling, and / or floor. A typical sound absorbing material used in an anechoic chamber is a sound absorbing wedge with a triangular cross section that protrudes into the inside of the anechoic chamber. The flame retardant 340 may also have a protruding triangular cross section.

[0078] The flame retardant portion 340 may be made of various materials to withstand high heat and pressure, particularly metal materials, which can effectively reduce the intensity of flames and gases.

[0079] The flame retardant portion 340 may be configured to allow passage of gas and flame generated in at least one pouch-type battery cell 100. The flame retardant portion 340 may have holes to allow passage of gas and flame. For example, the holes may be a plurality of regularly arranged holes formed by the flame retardant portion 340 being configured as a perforated plate.

[0080] FIG. 6 is a diagram showing the paths of gas and flame generated in a cell unit included in a battery pack according to the present invention.

[0081] The effect of the flame retardant 340 of the present invention will be described in detail with reference to FIG.

[0082] When a thermal event occurs inside the battery pack 10, the flame and gas generated pass through the opening O of the cell cover 200 toward the flame delay portion 340. Some of the flame and gas are discharged through holes formed in the flame delay portion 340, as indicated by the dotted arrows in FIG. 6 , while the remaining portion collide continuously between certain spaces formed in the flame delay portion 340, as indicated by the solid arrows in FIG. 6 . Therefore, the flame and gas are not discharged all at once through the flame delay portion 340, but are discharged at different times along the discharge path, which may reduce the intensity of the flame and gas. Furthermore, the flame and gas collide continuously between certain spaces formed between the flame delay portion 340 and the first case 310, reducing the linearity of the flame and gas, allowing the flame and gas to be discharged with reduced intensity. Furthermore, the flame delay portion 340 may also serve to guide the flame path. Furthermore, by providing the flame delay section 340 at a position where the flame and gas can be easily discharged, the gas can be discharged in a desired direction.

[0083] Referring again to FIG. 3, the cell cover 200 may include a first cover portion 210, a second cover portion 220, and an upper cover portion 230.

[0084] 3, the first cover part 210 may be configured to cover one side of the enclosed pouch-type battery cell 100. The first cover part 210 may be configured to cover the right side (the side located in the positive direction of the X-axis) of the enclosed pouch-type battery cell 100. The first cover part 210 may cover the storage part 110 and the sealing part 120 of the enclosed pouch-type battery cell 100. The first cover part 210 may be plate-shaped.

[0085] The second cover part 220 may face the first cover part 210. The second cover part 220 may cover the other side of the enclosed pouch-type battery cell 100. The second cover part 220 may be configured to cover the left side (the side located in the negative direction of the X-axis) of the enclosed pouch-type battery cell 100. The second cover part 220 may cover the storage part 110 and the sealing part 120 of the enclosed pouch-type battery cell 100. The second cover part 220 may be plate-shaped.

[0086] The cell cover 200 may be configured to support the pouch-type battery cells 100 in an upright state between the first cover part 210 and the second cover part 220. The first cover part 210 and the second cover part 220 may be arranged side by side. This allows the pouch-type battery cells 100 to be stably stacked side by side in the left-right direction in an upright state.

[0087] The upper cover part 230 may connect the first cover part 210 and the second cover part 220. The upper cover part 230 may cover one side of the enclosed pouch-type battery cell 100. The upper cover part 230 may cover the upper part (positive direction of the Z axis) of the receiving part 110 of the enclosed pouch-type battery cell 100. The upper cover part 230 may be plate-shaped.

[0088] A side assembly (see S in FIG. 9 described later) may be inserted between a portion where the first cover part 210 covers the sealing part 120 and a portion where the second cover part 220 covers the sealing part 120. The first cover part 210 and the second cover part 220 may have a portion that protrudes further toward the electrode lead 111 than the upper cover part 230. That is, the cell cover 200 may be shaped like the letter "n" surrounding at least three sides of the receiving part 110, and portions of the first cover part 210 and the second cover part 220 may protrude from the upper cover part 230 so that only portions of the first cover part 210 and the second cover part 220 cover the sealing part 120.

[0089] At least some of the first cover part 210, the second cover part 220, and the upper cover part 230 may be integrally formed. The first cover part 210, the second cover part 220, and the upper cover part 230 may be formed by bending a single plate. The formation of a bent part in a single plate to form the cell cover 200 can be achieved by various methods, such as pressing or roll forming. This embodiment of the present invention may simplify the manufacture of the cell cover 200. Alternatively, the first cover part 210, the second cover part 220, and the upper cover part 230 may be manufactured separately and then joined to each other by adhesive bonding, fitting, welding, bolting, etc.

[0090] A plurality of cell covers 200 may be included in the battery pack 10. In this case, an adhesive member may be interposed between the cell covers 200. For example, an adhesive member may be interposed between the first cover part 210 and / or the second cover part 220, which are portions of the two cell covers 200 facing each other, to adhesively fix them. This adhesive structure may make the connection structure between the plurality of cell covers 200 more solid. The adhesive member may be insulating so as to insulate the cell covers 200 made of a metal material from each other. The adhesive member may also be thermally conductive. This adhesion allows the cell cover 200 to be firmly attached to the battery cell 100 and may be useful for dissipating heat generated in the battery cell 100 to the outside of the battery cell 100.

[0091] The cell cover 200 may include an insulating coating layer on its inner surface. The insulating coating layer may be coated on the inner surface of the first cover part 210 and / or the inner surface of the second cover part 220. The insulating coating layer may be formed by coating, applying, or attaching an insulating material selected from the group consisting of silicone resin, polyamide, and rubber. The insulating coating layer may maximize the insulating coating effect with a minimum amount of coating. In addition, since the insulating coating layer is applied to the inner surface of the cell cover 200, the insulation between the pouch-type battery cell 100 and the cell cover 200 may be enhanced.

[0092] 3 shows a case where one cell cover 200 surrounds two pouch-type battery cells 100. By adjusting the width of the cell cover 200, particularly the width of the upper cover portion 230, the number of pouch-type battery cells 100 surrounded by one cell cover 200 can be adjusted to one or three or more as needed. This allows the cell unit U, also called an SPU (scalable pouch unit), to advantageously accommodate the pouch-type battery cells 100 in a variably and expandably manner according to the capacity of the battery pack 10.

[0093] FIG. 7 is a partial cross-sectional view of a battery pack 10 according to the present invention.

[0094] Referring to FIG. 7, the pack case 300 may include a storage space V1 and a vent space V2.

[0095] The storage space V1 can store a plurality of pouch-type battery cells 100. The storage space V1 can be the internal space of the first case 310.

[0096] The vent space V2 may be located around the storage space V1. The vent space V2 may be the internal space of the second case 320 excluding the space occupied by the first case 310. The vent space V2 may be provided on only one side of the storage space V1 or around the entire periphery of the storage space V1. Flame and gas that have passed through the flame delay unit 340 can be discharged to the outside of the pack case 300 through the vent space V2. The storage space V1 and the vent space V2 may be configured to communicate with each other via the flame delay unit 340. By separating the storage space V1 and the vent space V2, it is possible to advantageously control the vent direction to a desired direction.

[0097] FIG. 8 is an enlarged view of a part of FIG.

[0098] Referring to FIG. 8, the flame retardant portion 340 may include a separating portion 341, a collecting portion 342, and a connecting portion 343.

[0099] When there are multiple cell covers 200, the separator 341 may be provided at a corresponding position between adjacent cell covers 200. At least a portion of the separator 341 may be located between the storage space V1 and the vent space V2. At least a portion of the separator 341 may be located within the first case 310, which separates the storage space V1 from the vent space V2.

[0100] The collection portion 342 may be provided at a position corresponding to the opening O of each cell cover 200. Here, the opening O may refer to a side surface of the cell unit U that is located in the extension direction of the Y axis. The collection portion 342 may be located within the vent space V2. The collection portion 342 may be configured to provide a certain space between the collection portion 342 and the first case 310.

[0101] The coupling portion 343 may be configured to be coupled to the pack case 300. The coupling portion 343 may be configured to abut against the inner surface of the first case 310. The coupling may be performed by welding or bolting, for example.

[0102] Referring to FIG. 8, the pack case 300 may include a receiving portion 311 .

[0103] 8 and 4, the receiving portion 311 may be configured to receive the flame retardant portion 340. The receiving portion 311 may be provided on the side of the first case 310 on which the flame retardant portion 340 is provided. The receiving portion 311 may be an opening formed so that the flame retardant portion 340 can be inserted.

[0104] The flame retardant portion 340 may be accommodated in the accommodating portion 311 by first inserting it into the inner space of the first case 310 toward the accommodating portion 311. In this case, the coupling portion 343 may be coupled to the inner surface of the first case 310 by being engaged therewith.

[0105] According to this structure of the present invention, the isolation portion 341 can block the movement of flame and gas between adjacent cell units U. Therefore, this structure can prevent backflow of flame and gas. This is because the flame and gas that have already been discharged from the battery cells 100 are less likely to return to the battery cells 100, preventing backflow. Therefore, when a thermal event occurs inside the battery pack 10, heat propagation from one cell unit U where the thermal event occurred to another battery cell 100 in the other cell unit U can be effectively prevented. In addition, the flame retardant portion 340 and the pack case 300 can be easily coupled to each other.

[0106] FIG. 9 is a diagram showing some components of a battery pack according to the present invention.

[0107] Referring to FIG. 9, the battery pack 10 may further include a side assembly S.

[0108] The side assembly S may cover the opening O of the cell cover 200. The side assembly S may be configured to cover the opening O of the cell cover 200 formed on the side where the electrode leads 111 are provided. At least a portion of the side assembly S may be inserted into the cell cover 200. The side assembly S may be provided on the side of each cell unit U that is not surrounded by the cell cover 200. In this embodiment, the cell cover 200 surrounds at least three sides of the pouch-type battery cell 100, exposing the front and rear sides of the pouch-type battery cell 100 where the electrode leads 111 are provided, and the bottom of the pouch-type battery cell 100. Therefore, the side assemblies S may be provided on the front and rear parts of the cell cover 200 where the electrode leads 111 are provided. At least a portion of the side assembly S may be inserted inside the cell cover 200.

[0109] In the cell cover 200, a portion of the first cover part 210 and a portion of the second cover part 220 may protrude from the upper cover part 230. A portion of the side assembly S may protrude from the upper cover part 230, and the remaining portion may be inserted into and in contact with the inside of the first cover part 210 and the second cover part 220 of the portion protruding from the upper cover part 230.

[0110] According to this configuration of the present invention, the cell cover 200 and the side assembly S can be efficiently coupled together by the structure in which the side assembly S is inserted into the cell cover 200.

[0111] Fig. 10 is a diagram showing a bus bar assembly included in a battery pack according to the present invention, Fig. 11 is a diagram showing an end cover included in a battery pack according to the present invention, and Fig. 12 is a diagram showing a middle cover included in a battery pack according to the present invention.

[0112] 10-12 and 9, the side assembly S may include a bus bar assembly 400, a middle cover 500, and an end cover 600.

[0113] The bus bar assembly 400 may be configured to electrically connect the electrode leads 111. The bus bar assembly 400 may include a bus bar terminal 410 to be connected to the electrode leads 111, and a bus bar frame 420 configured to seat the bus bar terminal 410 and having a lead receiving portion 421 to receive the electrode leads 111.

[0114] The busbar assembly 400 may include a groove 422 for coupling with the intermediate cover 500. The groove 422 may have a concave shape on an outer surface of the busbar assembly 400 located in the negative direction of the Y axis.

[0115] The end cover 600 may cover one side of the bus bar assembly 400. The end cover 600 may be configured to be able to exhaust gas generated in at least a portion of the enclosed pouch-type battery cell 100. The end cover 600 may include a first vent portion 610. The first vent portion 610 may be configured to be able to exhaust gas and flame generated in at least a portion of the pouch-type battery cell 100 enclosed by the cell cover 200.

[0116] The first vent portion 610 may be in the form of a simple hole that penetrates the end cover 600. It may also be in a form that is completely open, or may be a specific device that is not completely open but is normally closed and can be opened in response to changes in pressure, temperature, etc. The first vent portion 610 may be, for example, a one-way valve. The description of the first vent portion 610 may also be applied to the second vent portion 301 (see 301 in FIG. 1) of the pack case 300, which will be described later.

[0117] The first vent portion 610 may include a mesh member M. The mesh member M may be provided in the form of a plurality of overlapping porous metal plates and configured to function as a flame arrester. However, the mesh member M may also be provided in the form of a mesh plate between the middle cover 500 and the end cover 600.

[0118] According to this configuration of the present invention, if gas and flame are generated due to swelling or thermal runaway in the pouch-type battery cell 100, they can be discharged to the outside of the cell unit U through the first vent portion 610 of the end cover 600. Therefore, by introducing the side vent, it is possible to prevent gas and flame from being randomly discharged through the open portion of the cell cover 200. By including the cell cover 200 having the open portion O and the end cover 600 coupled to this open portion O, it is possible to guide the direction of gas and flame in a specific direction, thereby providing a battery pack 10 with excellent swelling resistance.

[0119] In addition, since the first vent portion 610 is formed in the end cover 600 that covers the open portion of the cell cover 200, the first vent portion 610 has an area smaller than the open portion of the cell cover 200 or the area covered by the end cover 600. Therefore, when the end cover 600 is provided, the discharge angle of the vent gas or flame can be minimized, and the propagation of the flame can be minimized, compared to when the end cover 600 is not provided.

[0120] Therefore, the gas or flame discharged through the first vent portion 610 is directed toward the flame delay portion 340, thereby maximizing the gas or flame flow retarding effect of the flame delay portion 340. As described above, a portion of the gas or flame discharged through the first vent portion 610 passes immediately through the flame delay portion 340 and is discharged, while the remaining portion continuously impinges on the flame delay portion 340 in a portion of the space formed between the first case 310 and the flame delay portion 340, thereby delaying discharge.

[0121] The end cover 600 may include a guide portion 620. The guide portion 620 may have a shape that protrudes in the positive direction of the Y axis to form a surface having a predetermined width from an end of an inner surface located in the positive direction of the Y axis of the end cover 600. The guide portion 620 may be inserted between the cell cover 200 and the bus bar assembly 400 and coupled thereto.

[0122] 9 and 12, the middle cover 500 may be provided on one side of the bus bar assembly 400. The middle cover 500 may be provided between the bus bar assembly 400 and the end cover 600. The middle cover 500 may have a communication portion 510. The middle cover 500 may have a hook 501. The hook 501 may have a shape that protrudes from an inner surface of the middle cover 500 that is located in the positive direction of the Y axis.

[0123] The middle cover 500 may include an insulating material, which may interrupt the electrical connection between the bus bar assembly 400 and the end cover 600.

[0124] According to this configuration of the present invention, the flow of a flame that may occur in the pouch-type battery cell 100 is temporarily blocked by the middle cover 500, thereby reducing the intensity of the flame and preventing the flame from rapidly escaping to the first vent portion 610. In addition, a short circuit caused by contact between the bus bar assembly 400 and the end cover 600 can be prevented.

[0125] To explain the assembly process of the battery pack 10 according to the above embodiment, after the battery cells 100 are surrounded by the cell cover 200, the bus bar assembly 400 is inserted into the open portion of the cell cover 200 for assembly. The electrode leads 111 of the battery cells 100 are passed through the lead receiving portions 421, bent, and fixed to the bus bar terminals 410 by a known joining method such as welding. The middle cover 500 is assembled to the bus bar assembly 400. The end cover 600 is assembled to the middle cover 500. The end cover 600 is then welded. The unique joining structure of the bus bar assembly 400, middle cover 500, and end cover 600 allows for easy and efficient joining among them.

[0126] FIG. 13 is a partial cross-sectional view of a battery pack according to the present invention.

[0127] Referring to FIG. 13, the battery pack 10 may include a thermal resin R.

[0128] 13 and 2, the thermal resin R may be interposed in at least a portion of the space between the cell cover 200 and the pack case 300 and the space between the plurality of pouch-type battery cells 100 and the pack case 300. That is, the thermal resin R may be interposed in at least a portion of the space between the cell unit U and the pack case 300. The thermal resin R may improve heat transfer performance between different components. The thermal resin R is intended to reduce contact thermal resistance between different components. The inclusion of the thermal resin R may further improve the heat dissipation performance of the pouch-type battery cell 100 and further improve the cooling performance of the battery pack 10.

[0129] Referring again to FIG. 1, the pack case 300 may include a second vent portion 301 .

[0130] The second vent portion 301 may be configured to communicate with the first vent portion 610 of the end cover 600 described with reference to FIG. 11 and the like, and to exhaust gas and / or flame generated in at least one of the cell units U housed inside the pack case 300 to the outside of the battery pack 10. The second vent portion 301 may be provided at a position farthest from the first vent portion 610, thereby maximizing the travel path of the gas and flame and effectively reducing the intensity of the gas and flame. In the illustrated example, the first vent portion 610 may be located at both ends of the pack case 300 in the Y-axis direction, and therefore the farthest position from the first vent portion 610 is the middle position of the pack case 300 in the Y-axis direction. The speed and temperature of the gas and flame exhausted from the first vent portion 610 decrease as they travel within the vent space V2 to the position of the second vent portion 301, allowing them to be ultimately exhausted to the outside of the battery pack 10 in a less dangerous manner. The detailed description of the second vent portion 301 can be replaced with the description of the first vent portion 610.

[0131] As described above, when a battery cell 100 ignites, the cell cover 200 controls the initial flame direction. The flame retardant portion 340 reduces the intensity of the gas and flame exhausted from the opening O of the cell cover 200 and prevents them from flowing back to other adjacent battery cells 100. The gas and flame exhausted through the flame retardant portion 340 have a minimized exhaust angle due to the end cover 600, further minimizing the propagation of the flame. In this way, the battery pack 10 of the present invention can ensure excellent safety when a thermal event occurs.

[0132] The battery pack 10 according to the present invention may further include a battery management system (BMS) and a battery disconnect unit (BDU). The BMS may be installed in the interior space of the pack case 300 and configured to generally control the charging and discharging operations and data transmission and reception operations of the pouch-type battery cells 100. The BMS may be provided for each battery pack 10 rather than for each battery module. More specifically, the BMS may be configured to control the charging and discharging state, power state, and performance state of the pouch-type battery cells 100 according to the pack voltage and pack current. The BMS estimates the state of the battery cells 100 in the battery pack 10 and manages the battery pack 10 using the estimated state information. For example, the BMS estimates and manages state information of the battery pack 10, such as the SOC (State of Charge), SOH (State of Health), maximum input / output power allowance, and output voltage of the battery pack 10. The BMS may also use such state information to control charging and discharging of the battery pack 10 and estimate when the battery pack 10 should be replaced. The BDU may be configured to control the electrical connection of the battery cells 100 to manage the power capacity and function of the battery pack 10. For this purpose, the BDU may include a power relay, a current sensor, a fuse, etc. The BDU is also configured to be provided for each battery pack 10 rather than for each battery module, and may employ various shutoff units known at the time of filing of the present invention.

[0133] In addition, the battery pack 10 according to the present invention may further include various components of the battery pack 10 that are known at the time of filing of the present invention. For example, the battery pack 10 according to an embodiment of the present invention may further include a manual service disconnector (MSD) that allows an operator to manually disconnect the service plug to cut off the power supply. Also, the battery pack 10 may further include flexible bus bars or cables for connecting the plurality of battery cells 100 having the n×n arrangement as described above to each other.

[0134] However, the present invention can apply the structure applied to the above-described battery pack 10 to a battery module. That is, the structure of the pack case 300 can be applied to a module case, and a battery module can be constructed by accommodating a plurality of cell units U in the module case and providing a vent portion in the module case. Such a battery module is a battery module in which one or more battery cells are accommodated in the internal space of the pack case 300, and can include a module case (the structure of the pack case 300 of the battery pack 10 according to the present invention as described above can be used as is) that includes a plurality of pouch-type battery cells 100 and cell covers 200 as described above and accommodates the pouch-type battery cells 100 in the internal space.

[0135] The battery pack 10 according to the present invention or the battery module described herein can be applied to various devices. Typical examples of such devices include transportation means such as electric bicycles, electric vehicles, and hybrid vehicles, but the present invention is not limited thereto. The battery pack 10 is particularly suitable for use as a battery pack 10 for electric vehicles. It can also be used as an energy source for an ESS.

[0136] FIG. 14 shows a vehicle according to the present invention.

[0137] 14, an automobile 1 may include the battery pack 10 according to the present invention described above. Furthermore, the automobile 1 according to the present invention may further include, in addition to the battery pack 10, various other components included in the automobile 1. For example, the automobile 1 according to the present invention may further include, in addition to the battery pack 10 according to the present invention, a vehicle body, a motor, a control device such as an ECU (electronic control unit), and the like.

[0138] The battery pack 10 can be placed at a predetermined position inside the vehicle 1. The battery pack 10 can be used as an electric energy source that provides driving force to a motor of the electric vehicle 1 to drive the vehicle 1. In this case, the battery pack 10 has a high nominal voltage of 100 V or more.

[0139] The battery pack 10 can be charged and discharged by an inverter in response to the driving of the motor and / or the internal combustion engine. The battery pack 10 can be charged by a regenerative charging device coupled to the brake. The battery pack 10 can be electrically connected to the motor of the automobile 1 by the inverter.

[0140] In this way, the battery pack 10 provided in the automobile 1 can provide the electrical energy necessary for many operations of the automobile 1. Furthermore, since the battery pack 10 has the various effects described above, the automobile 1 including the battery pack 10 can also have those effects.

[0141] As a specific example, the battery pack 10 can have a high energy density by including the cell cover 200, eliminating the need for a module case. Energy density refers to the amount of energy stored per unit weight. As the energy density of the battery pack 10 increases, the amount of energy stored in the battery pack 10 increases even if the weight remains the same. Therefore, a vehicle 1 including such a battery pack 10 can be used in a variety of ways, such as extending the driving distance per charge, increasing acceleration, allowing for more cargo to be carried, and expanding the interior space. Furthermore, as the energy density of the battery pack 10 increases, the battery pack 10 becomes lighter even if the energy is the same. A lighter battery pack 10, and therefore a lighter vehicle 1 including the battery pack 10, offers many advantages, such as improved acceleration, energy efficiency, and durability.

[0142] As another specific example, the battery pack 10 can have high safety. Since the automobile 1 is directly related to human life, safety is absolutely essential. The pouch-type battery cell 100 always has a risk of fire due to the physical properties of lithium. However, the battery pack 10 according to the present invention includes the cell cover 200, so that even if a thermal event occurs in the pouch-type battery cell 100, it can be prevented from spreading to other parts. Therefore, the automobile 1 including the battery pack 10 can ensure safety against fire.

[0143] While the present invention has been described above with reference to the accompanying drawings, focusing on the preferred embodiments, it will be apparent to those skilled in the art that many obvious modifications can be made from such description without departing from the scope of the present invention. Therefore, the scope of the present invention should be interpreted by the claims, which are set forth to include all such modifications. [Explanation of symbols]

[0144] 1: Automobiles 10: Battery pack U: Cell unit 100: Battery cells 111: Electrode lead 110: Storage area 120: Seal part 200: Cell cover 210: First cover part 220: Second cover part 230: Upper cover part 300: Pack case 301: Second vent section 310: Case 1 311: Storage unit V1: Storage space 320: Second case V2: Vent space 330: Top cover 340: Flame retardation section 341: Isolation Department 342: Collection section 343:Joining part S: Side assembly 400: Busbar assembly 410: Busbar terminal 420: Busbar frame 421: Lead storage section 422: Groove 500: Intermediate cover 510: Communication part 501: Hook 600: End cover 610: First vent 620: Guide section M: Mesh material R: Thermal resin O:Open part

Claims

1. a plurality of pouch-type battery cells; a pack case that houses the plurality of pouch-type battery cells in its internal space; a cell cover configured to partially surround an exterior of at least one pouch-type battery cell of the plurality of pouch-type battery cells to form an opening; The pack case is A battery pack comprising a flame retardant portion on the side where the opening is located, the flame retardant portion including a plate having a regularly-spaced convex and concave shape.

2. The flame delay section is The battery pack according to claim 1 , wherein the pouch-type battery cell is configured to reduce the linearity of gas and flame generated in the at least one pouch-type battery cell and allow the gas and flame to pass through the pouch-type battery cell.

3. The internal space of the pack case is a storage space for storing the plurality of pouch-type battery cells; a vent space around the storage space, The battery pack according to claim 2 , wherein the gas and flame that have passed through the flame delay portion are discharged to the outside of the pack case through the vent space.

4. A plurality of pouch-type battery cells; a pack case that houses the plurality of pouch-type battery cells in its internal space; a cell cover configured to partially surround an exterior of at least one pouch-type battery cell of the plurality of pouch-type battery cells to form an opening; The pack case is a flame retardant section on the side where the opening is located; The flame delay section is The pouch-type battery cell is configured to reduce the linearity of gas and flame generated in the at least one pouch-type battery cell and allow the gas and flame to pass through the pouch-type battery cell, The internal space of the pack case is a storage space for storing the plurality of pouch-type battery cells; a vent space around the storage space, The gas and flame that have passed through the flame delay section are discharged to the outside of the pack case through the vent space, the cell covers are plural; The flame delay section is A battery pack comprising: a separator provided at a position corresponding to a gap between adjacent cell covers; and a collector provided at a position corresponding to an opening of each of the cell covers.

5. The isolation unit is At least a portion of the storage space is located between the storage space and the vent space, The battery pack according to claim 4 , wherein the collector is located within the vent space.

6. The pack case is The battery pack according to claim 1 , further comprising a housing configured to house the flame retardant.

7. The flame delay section is The battery pack according to claim 4 , further comprising a coupling portion configured to be coupled to the pack case.

8. The battery pack according to claim 3 , wherein the flame retardant portion is a wedge-shaped structure having a wave-like cross section at least at one end thereof.

9. A plurality of pouch-type battery cells; a pack case that houses the plurality of pouch-type battery cells in its internal space; a cell cover configured to partially surround an exterior of at least one pouch-type battery cell of the plurality of pouch-type battery cells to form an opening; The pack case is a flame retardant section on the side where the opening is located; The cell cover is a first cover portion that covers one side of the enclosed pouch-type battery cell; a second cover portion that covers the other side of the enclosed pouch-type battery cell; an upper cover portion connecting the first cover portion and the second cover portion and covering one side of the enclosed pouch-type battery cell.

10. Each of the plurality of pouch-type battery cells includes an electrode lead; The cell cover is 10. The battery pack according to claim 9, wherein the openings are formed at an end of the first cover portion on which the electrode lead is provided and at an end of the second cover portion on which the electrode lead is provided.

11. The battery pack The battery pack according to claim 10, further comprising a side assembly for covering the opening.

12. The side assembly includes: The battery pack according to claim 11, characterized in that at least a portion of the battery pack is inserted into the cell cover.

13. The side assembly includes: a bus bar assembly configured to electrically connect the electrode leads; an end cover configured to cover one side of the bus bar assembly and to allow gas generated in at least a portion of the enclosed pouch-type battery cell to be discharged.

14. The side assembly includes:

14. The battery pack according to claim 13, further comprising an intermediate cover between the bus bar assembly and the end cover for insulation.

15. The side assembly includes: The battery pack according to claim 11, further comprising a mesh member.

16. The battery pack 2. The battery pack according to claim 1, further comprising a thermal resin in at least a portion of a space between the cell cover and the pack case and a space between the plurality of pouch-type battery cells and the pack case.

17. The cell cover is The battery pack according to claim 9, wherein the pouch-type battery cell is configured to be supported in an upright state between the first cover part and the second cover part.

18. The cell cover is The battery pack according to claim 9, wherein an insulating coating layer is provided on at least a portion of an inner surface of the first cover part and an inner surface of the second cover part.

19. The cell cover is The battery pack of claim 9 , wherein an adhesive member is provided on at least a portion of an outer surface of the first cover part and an outer surface of the second cover part.

20. 20. A motor vehicle comprising a battery pack according to any one of claims 1 to 19.

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