Battery pack, battery module and automobile including same

Abstract

The present invention discloses a battery pack etc. capable of ensuring excellent safety when a thermal event occurs. A battery pack according to one aspect of the present invention may include a plurality of pouch-type battery cells, a pack case that houses the pouch-type battery cells in an internal space, and a cell cover that includes two unit covers that are at least partially spaced apart from each other and is provided to at least partially enclose at least some of the pouch-type battery cells in the internal space of the pack case, and is configured to allow vent gas to be discharged into the space between the two unit covers.

Description

[Technical field]

[0001] The present invention relates to a battery pack, a battery module, and an automobile including the same, and more particularly, to a battery pack, a battery module, and an automobile including the same, which have excellent safety against thermal events.

[0002] This application claims priority to Korean Patent Application No. 10-2022-0110387 filed on August 31, 2022 and Korean Patent Application No. 10-2023-0029360 filed on March 6, 2023, the entire contents of which are incorporated herein by reference in their entirety in the specification and drawings. [Background technology]

[0003] The development of technology and the increase in demand for various mobile devices, electric vehicles, energy storage systems (ESS), etc. are remarkable, and as a result, interest in and need for secondary batteries as an energy source is growing rapidly. Traditionally, nickel-cadmium batteries and nickel-metal hydride ion batteries were widely used as secondary batteries, but recently lithium secondary batteries have been widely used because they have almost no memory effect compared to nickel-based batteries, can be charged and discharged freely, have a very low self-discharge rate, and have a high energy density.

[0004] Such a lithium secondary battery mainly uses a lithium-based oxide and a carbon material as a positive electrode active material and a negative electrode active material, respectively, and includes an electrode assembly in which a positive electrode plate and a negative electrode plate, to which the positive electrode active material and the negative electrode active material are applied, are arranged with a separator sandwiched therebetween, and an exterior material, such as a battery case, that encloses the electrode assembly together with an electrolyte.

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

[0006] Recently, battery packs have been widely used for driving and storing energy in medium- to large-sized devices such as electric vehicles and energy storage systems (ESS). A conventional battery pack includes one or more battery modules and a control unit, for example, a battery management system (BMS), for controlling charging and discharging of the battery pack inside a pack case. Here, the battery module is configured to include a plurality of battery cells inside a module case. That is, in the case of a conventional battery pack, a plurality of battery cells (secondary batteries) are accommodated inside a module case to configure each battery module, and one or more such battery modules are accommodated inside a pack case to configure a battery pack.

[0007] In particular, pouch-type batteries have various advantages such as being lightweight and having little dead space when stacked, but they have problems such as being vulnerable to external impacts and being somewhat difficult to assemble. Therefore, a battery pack is usually manufactured in such a form that a plurality of battery cells are first modularized and then housed inside a pack case.

[0008] However, in the case of a conventional battery pack, modularization may be disadvantageous in terms of energy density, ease of assembly, cooling performance, etc. Specifically, in a process of modularizing a plurality of battery cells by accommodulating them inside a module case, various components such as a module case or a frame for stacking may increase the volume of the battery pack or reduce the space occupied by the battery cells. First, since it is necessary to go through a process of accommodating the battery module in a pack case after modularizing a plurality of battery cells to form a battery module, there is a problem that the manufacturing process of the battery pack becomes complicated. Since a module case is accommodated inside a pack case and battery cells are accommodated inside the module case, when heat from the battery cells accommodated inside the module case is discharged to the outside of the pack case through the module case, the cooling efficiency may decrease and the cooling structure may become complicated.

[0009] Recently, the need for battery packs applied to electric vehicles and the like is increasing. Such battery packs have multiple cells, and safety must be managed more strictly. If thermal runaway, fire, explosion, etc. occurs in some cells in any one battery module, the generated high-temperature gas, flame, or high-temperature internal material may be ejected and propagated to other adjacent battery modules, causing secondary thermal runaway, secondary fire, explosion, etc., and there is a risk that thermal runaway, fire, or explosion may be caused in a chain reaction in cells in multiple battery modules one after another. Therefore, when a thermal event such as thermal runaway occurs, a means capable of suppressing or delaying the spread of a flame between battery modules is very necessary. However, conventional battery packs and battery modules are vulnerable to thermal events. In particular, when a thermal event occurs inside a battery module or battery pack, thermal runaway may occur, causing a flame, and in severe cases, an explosion may occur. Summary of the Invention [Problem to be solved by the invention]

[0010] Therefore, the present invention has been devised to solve the above-mentioned problems, and a technical problem that the present invention aims to solve is to provide a battery pack, a battery module, and an automobile including the same, which have excellent energy density, ease of assembly, and / or cooling performance.

[0011] Another technical problem to be solved by the present invention is to provide a battery pack, a battery module, and an automobile including the same, which can ensure excellent safety when a thermal event occurs.

[0012] However, the technical problems that the present invention aims to solve are not limited to the problems described above, and other problems not mentioned will be clearly understood by those skilled in the art from the description of the invention described below. [Means for solving the problem]

[0013] A battery pack according to one aspect of the present invention may include a plurality of pouch-type battery cells, a pack case that accommodates the pouch-type battery cells in an internal space, and a cell cover having two unit covers that are at least partially spaced apart and configured to at least partially enclose at least some of the pouch-type battery cells in the internal space of the pack case, and configured to allow venting gas to be discharged into the space between the two unit covers.

[0014] Here, the cell cover may be configured to support the plurality of pouch-type battery cells in an upright state.

[0015] In addition, the cell cover may be formed in a shape that partially encloses the pouch-type battery cell such that at least one side of the enclosed pouch-type battery cell is exposed toward the pack case.

[0016] Furthermore, the pouch-type battery cell may include an accommodation portion in which an electrode assembly is accommodated and an edge portion provided around the accommodation portion, and the cell cover may be configured to enclose both sides of the accommodation portion and a portion of the edge portion of the enclosed pouch-type battery cell.

[0017] Furthermore, the cell cover may be provided to cover both side surfaces and an edge portion on an upper side of the receiving portion of the enclosed pouch-type battery cell.

[0018] Here, the two unit covers may be a first cover configured to enclose a left surface and one side edge of the enclosed pouch-type battery cell, and a second cover configured to enclose a right surface and the other side edge of the enclosed pouch-type battery cell.

[0019] The first cover includes a first upper cover portion configured to wrap around an upper portion of an edge portion on an upper side of the pouch-type battery cell, and a first side cover portion extending downward from one end of the first upper cover portion and wrapping around an outside of an accommodating portion on one side of the encapsulated pouch-type battery cell, and the second cover includes a second upper cover portion configured to wrap around an upper portion of an edge portion on an upper side of the pouch-type battery cell, and a second side cover portion extending downward from one end of the second upper cover portion and wrapping around an outside of an accommodating portion on the other side of the encapsulated pouch-type battery cell, and the second upper cover portion may be separated from the first upper cover portion in the direction of the edge portion on the upper side of the pouch-type battery cell.

[0020] Furthermore, the first side cover portion and the pouch-type battery cell may be adhered to each other, and the second side cover portion and the pouch-type battery cell may be adhered to each other.

[0021] Furthermore, the second side cover portion may have a longer length in the up-down direction than the first side cover portion.

[0022] Furthermore, vent gas can move between the first upper cover part and the second side cover part to a venting channel defined as a space between the first upper cover part and the second upper cover part, and can be discharged between the second upper cover part and the first side cover part.

[0023] Furthermore, the first upper cover portion and the second upper cover portion may have a bending part to bend the vent channel.

[0024] Furthermore, the two unit covers may be formed with one end portion bent toward each other.

[0025] Furthermore, the two unit covers may be stacked vertically on top of each other with the folded ends at least partially spaced apart to allow the vent gas to be discharged.

[0026] Each of the two unit covers may be formed in a folded shape from a single plate.

[0027] Also, the cell cover may have a mesh structure in the space between the two unit covers.

[0028] Further, the cell cover may have bent portions formed in the two unit covers so as to increase a movement path of the gas discharged to the space between the two unit covers.

[0029] The battery pack according to the present invention may further include a control module accommodated in an internal space of the pack case and configured to control charging and discharging of the pouch-type battery cells.

[0030] Furthermore, a battery module according to another aspect of the present invention may include a battery module accommodated in an internal space of a pack case, the battery module including a plurality of pouch-type battery cells, a module case that accommodates the pouch-type battery cells in the internal space, and a cell cover having two unit covers that are at least partially spaced apart and configured to at least partially enclose at least some of the pouch-type battery cells in the internal space of the module case, and configured to allow vent gas to be discharged into the space between the two unit covers.

[0031] Furthermore, a vehicle according to yet another aspect of the present invention may include a battery pack or battery module according to the present invention. Effect of the Invention

[0032] According to one aspect of the present invention, a cell to pack (CTP) concept is adopted, and a module case, etc. are omitted, thereby improving cooling performance and energy density, etc.

[0033] According to one aspect of the present invention, a plurality of pouch-type battery cells can be stably accommodated inside a pack case without components such as a frame for stacking, such as a plastic cartridge, or a separate module case.

[0034] In particular, according to one embodiment of the present invention, a configuration in which a plurality of pouch-type battery cells are stacked in a vertically upright state and aligned horizontally can be easily realized.

[0035] According to one aspect of the present invention, the energy density of a battery pack can be improved. Furthermore, according to one embodiment of the present invention, a battery pack can be manufactured that does not require a module case for a battery module because the battery cells are directly accommodated in the pack case without being modularized. Therefore, it is possible to reduce the space occupied by such a module case and arrange more battery cells inside the pack case. This has the effect of further improving the energy density of the battery pack. By directly assembling the pouch-type battery cells in the pack case of the battery pack, the space utilization rate of the battery pack can be maximized and the energy capacity can be significantly improved.

[0036] Furthermore, according to one aspect of the present invention, a pouch-type battery cell having a case made of a flexible material can be easily and firmly formed, and a configuration in which the pouch-type battery cell is directly stacked inside a pack case or a module case can be easily realized, thereby improving the ease of assembly and mechanical stability of a battery pack or a battery module.

[0037] According to one aspect of the present invention, the cooling efficiency of the battery pack can be further improved. In particular, in one embodiment of the present invention, a portion of each pouch-type battery cell is directly exposed to the pack case, so that heat of each pouch-type battery cell can be effectively dissipated to the outside through the pack case.

[0038] Furthermore, according to one aspect of the present invention, when a thermal runaway occurs in a specific battery cell, it is possible to effectively respond to a thermal event. In particular, in the case of the present invention, among the three elements that cause a flame (fuel, oxygen, and ignition source), the accumulation and discharge of heat that corresponds to the ignition source can be blocked or appropriately controlled. Furthermore, in the case of the present invention, in order to block the accumulation of heat and prevent the discharge of a flame, it is possible to realize control of the discharge of vent gas, directional venting, and blocking of sparks.

[0039] Furthermore, according to one aspect of the present invention, even when a thermal event occurs, it is possible to effectively prevent internal short circuits, structural collapse, and the like.

[0040] According to the present invention, there are provided a battery pack and a battery module with improved safety against thermal runaway, fire, explosion, etc., i.e., thermal safety. When some battery cells or battery modules in a battery module including a plurality of battery cells and a battery pack including a plurality of battery modules generate heat, the heat can be stably blocked from being transmitted to surrounding battery cells or battery modules.

[0041] Also, according to one aspect of the present invention, the safety of the battery pack can be improved. In particular, according to one embodiment of the present invention, gas, etc. discharged from each battery cell can be smoothly discharged to the outside. Furthermore, according to one embodiment of the present invention, the discharge direction of gas, flame, etc. discharged from the battery cell can be controlled. Therefore, the propagation of thermal runaway between adjacent battery cells can be effectively prevented.

[0042] The following drawings attached to this specification are intended to illustrate preferred embodiments of the present invention and serve to facilitate a further understanding of the technical ideas of the present invention as well as the contents of the invention. Therefore, the present invention should not be interpreted as being limited to only the matters described in the drawings. [Brief description of the drawings]

[0043] [Figure 1] 1 is a schematic exploded perspective view showing some components of a battery pack according to an embodiment of the present invention. [Diagram 2] FIG. 2 is an exploded perspective view illustrating a configuration of a pouch-type battery cell and a cell cover accommodated inside a battery pack according to an embodiment of the present invention. [Diagram 3]1 is a perspective view illustrating a coupling configuration between a pouch-type battery cell and a cell cover housed inside a battery pack according to an embodiment of the present invention; FIG. [Figure 4] FIG. 4 is a YZ cross-sectional view of FIG. [Diagram 5] 11 is a cross-sectional view illustrating a coupling configuration between a pouch-type battery cell and a cell cover housed inside a battery pack according to another embodiment of the present invention. FIG. [Figure 6] 13 is a cross-sectional view illustrating a schematic configuration of a combination of a pouch-type battery cell and a cell cover housed in a battery pack according to yet another embodiment of the present invention. FIG. [Figure 7] FIG. 13 is a schematic diagram illustrating a cross-sectional configuration of a portion of a battery pack according to yet another embodiment of the present invention. [Figure 8] FIG. 13 is a schematic diagram illustrating a cross-sectional configuration of a portion of a battery pack according to yet another embodiment of the present invention. [Figure 9] 1 is a diagram illustrating a schematic configuration of a battery module according to an embodiment of the present invention; [Figure 10] 1 is a diagram showing a schematic configuration of a vehicle according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0044] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings. The terms and words used in this specification and claims are not to be construed as being limited to their ordinary or dictionary meanings, but are to be construed as being in accordance with the meaning and concept of the technical idea of ​​the present invention, in accordance with the principle that the inventor himself can appropriately define the concept of the term in order to best describe the invention. Therefore, it should be understood that the embodiment described in this specification and the configuration shown in the drawings are merely the most preferred embodiment of the present invention, and do not represent the entire technical idea of ​​the present invention, and therefore there may be various equivalents and modifications that can be substituted therefor at the time of this application.

[0045] In the drawings, the size of each component or a specific part constituting each component is somewhat exaggerated, omitted, or illustrated in a schematic manner for ease of explanation and clarity. Therefore, the size of each component does not entirely reflect the actual size. If a detailed description of related publicly known functions or configurations is deemed to be likely to unnecessarily obscure the gist of the present invention, the detailed description will be omitted.

[0046] Fig. 1 is a schematic perspective view showing an exploded view of some components of a battery pack according to an embodiment of the present invention. Fig. 2 is an exploded perspective view showing a schematic configuration of a pouch-type battery cell and a cell cover housed in a battery pack according to an embodiment of the present invention. Fig. 3 is a perspective view showing a schematic coupling configuration of a pouch-type battery cell and a cell cover housed in a battery pack according to an embodiment of the present invention. Fig. 4 is a YZ cross-sectional view of Fig. 3.

[0047] 1 to 4, a battery pack 10 according to one embodiment of the present invention includes a plurality of pouch-type battery cells 100, a pack case 300, and a cell cover 200.

[0048] The pouch-type battery cell 100 is a pouch-type secondary battery and may include an electrode assembly, an electrolyte, and a pouch exterior material. A plurality of such pouch-type battery cells 100 may be included in the battery pack 10. The plurality of such pouch-type battery cells 100 may be stacked in at least one direction. For example, as shown in Figs. 1 to 4, the plurality of pouch-type battery cells 100 may be stacked in a horizontal direction, for example, in a left-right direction (Y-axis direction in the figure). Furthermore, the plurality of pouch-type battery cells 100 may be arranged in a front-back direction (X-axis direction in the figure) as shown in Fig. 1. Furthermore, the plurality of pouch-type battery cells 100 may be arranged in a horizontal direction, but may be arranged in a shape that forms a plurality of rows in the left-right and horizontal directions. For example, as shown in Fig. 1, the plurality of pouch-type battery cells 100 may be stacked in a shape in which two rows of cells arranged in the left-right direction are arranged in the front-back direction.

[0049] The battery pack according to the present invention may employ various types of pouch-type battery cells 100 known at the time of filing of the present invention, and therefore, detailed description of the configuration of such pouch-type battery cells 100 will be omitted.

[0050] The pack case 300 may have an empty space formed therein and may accommodate a plurality of pouch-type battery cells 100. For example, as shown in FIG. 1, the pack case 300 may include an upper case 310 and a lower case 320. More specifically, the lower case 320 may be formed in a box shape with an open upper end and may accommodate a plurality of battery cells in the internal space. The upper case 310 may be formed in a lid shape that covers the open upper end of the lower case 320. In this case, the upper case 310 may be formed in a box shape with an open lower end. In addition, the cell cover 200 may be accommodated in the internal space of the pack case 300 together with the plurality of pouch-type battery cells 100. The pack case 300 may include a plastic or metal material. In addition, the pack case 300 may adopt various types of exterior materials of battery packs known at the time of filing of the present invention.

[0051] The cell cover 200 may be configured to encase the pouch-type battery cell 100 in the internal space of the pack case 300. That is, the cell cover 200 may be configured to encase at least some of the pouch-type battery cells 100 included in the battery pack 10. Furthermore, the cell cover 200 may be provided to at least partially encase the pouch-type battery cell 100.

[0052] The cell cover 200 may be configured to encase one or more pouch-type battery cells 100. In one example, in the embodiment of Figures 1-4, one cell cover 200 is shown encasing two pouch-type battery cells 100. The cell cover 200 may also be configured to encase two or more pouch-type battery cells 100 together.

[0053] 5 is a cross-sectional view that shows a schematic configuration of a connection between a pouch-type battery cell and a cell cover housed inside a battery pack according to another embodiment of the present invention. In FIG. 5, one cell cover 200 is shown in a shape that encases one pouch-type battery cell 100. In this manner, one cell cover 200 may be configured to encase only one pouch-type battery cell 100. In this case, it can be said that the cell cover 200 is individually connected to each pouch-type battery cell 100 among the plurality of pouch-type battery cells 100.

[0054] The cell cover 200 may be at least partially adhered to the outer surface of the battery cell 100. For example, the cell cover 200 may be adhered to the inner surface of the receiving portion of the pouch-type battery cell 100. The member for adhesion may be thermally conductive. Through such adhesion, the cell cover 200 is firmly bonded to the battery cell 100 and helps to dissipate heat generated from the battery cell 100 to the outside of the battery cell 100.

[0055] One or more cell covers 200 may be included in the battery pack. When multiple cell covers 200 are included, the multiple cell covers 200 may be separated from each other. For example, the multiple cell covers 200 may be separated from each other in the X-axis direction. Direct heat transfer between the cell covers 200 can be blocked through the separated space. In addition, a separate member required to configure the battery pack 10 can be inserted through the separated space. Alternatively, a heat insulating pad, a fire suppression pad, or the like may be interposed at least partially between the multiple cell covers 200. Such a heat insulating pad or fire suppression pad can prevent heat or flame that may occur in any one cell unit from being propagated to the other cell units and affecting other battery cells 100. The fire suppression pad may be formed from a heat-resistant resin such as polyvinyl chloride resin, a material such as silicon or ceramic, a complex of a heat-resistant resin and a ceramic or glass filler, or a metal plate with an insulating coating, but these are merely exemplary and may be any flame-retardant material. It is preferable that the pouch-type battery cell 100 be made of a material that does not decompose, melt, or ignite at least up to a temperature at which the pouch-type battery cell 100 experiences thermal runaway (for example, 150° C. to 200° C.).

[0056] In addition, when the battery pack 10 includes a plurality of stacked cell covers 200, an adhesive member may be interposed between the cell covers 200. For example, an adhesive member may be interposed between the two cell covers 200 at portions where the two cell covers 200 face each other, thereby adhesively fixing the two cell covers 200 to each other. Through such an adhesive configuration, the connection between the plurality of cell covers 200 can be made even stronger.

[0057] In particular, the cell cover 200 may be configured to group and unitize a plurality of pouch-type battery cells 100 included in the battery pack. In this case, one cell cover 200 may constitute one cell unit. One cell unit may include one or a plurality of pouch-type battery cells 100. For example, one cell unit is shown as indicated by "U1" in FIG. 2, and a plurality of cell units are shown in FIG. 1. In this manner, the battery pack 10 may include a plurality of cell units, and in this case, a plurality of cell covers 200 may be included in the battery pack. For example, when the cell cover 200 is formed into a shape that envelops one pouch-type battery cell 100, the battery pack may include the same number of cell covers 200 as the number of pouch-type battery cells 100. As another example, when the cell cover 200 is formed into a shape that encases two or more pouch-type battery cells 100, the battery pack may include a number of cell covers 200 that is less than the number of pouch-type battery cells 100. Meanwhile, each cell group enclosed by the cell cover 200 may be referred to as a cell bank unit in addition to being called a cell unit. The pouch-type battery cells 100 in the cell unit or cell bank may include a direct and / or parallel electrical connection configuration via a bus bar or the like.

[0058] The cell cover 200 may be configured to support a plurality of pouch-type battery cells 100 in an upright state. As shown in FIG. 2, each pouch-type battery cell 100 has two wide surfaces, and a sealed portion or a folded portion of the pouch exterior material may be present at the edge portion of the wide surfaces. Therefore, it is generally difficult to stack the pouch-type battery cells 100 in a vertically upright shape with the narrow surface facing down. However, in the battery pack according to the present invention, the cell cover 200 may be configured to support the upright state, i.e., the upright state, of the wrapped pouch-type battery cells 100 while wrapping one or more pouch-type battery cells 100.

[0059] In particular, the cell cover 200 may be configured so that a plurality of pouch-type battery cells 100 can be stacked horizontally in a vertically standing state. For example, as in the embodiment configurations shown in Figs. 1 and 3, a plurality of cell covers 200 may be stacked on top of each other in a horizontal direction, and each cell cover 200 may be formed in a shape that encases one or more pouch-type battery cells 100. In this case, the cell cover 200 may stably maintain a configuration in which a plurality of pouch-type battery cells 100 are stacked horizontally in a vertically standing state.

[0060] In particular, the cell cover 200 may be configured to be self-supporting in the internal space of the pack case 300. That is, the cell cover 200 may be configured to maintain an upright state by itself without the aid of other components arranged in the battery pack, such as the pack case 300 or the pouch-type battery cell 100.

[0061] The cell cover 200 may be formed in a shape that partially envelops the pouch-type battery cell such that at least one side of the enclosed pouch-type battery cell is exposed to the outside. That is, the cell cover 200 may be formed in a shape that envelops only a portion of the pouch-type battery cell 100 without completely enveloping the entire pouch-type battery cell 100. In particular, the cell cover 200 may be configured such that at least one side of the pouch-type battery cell 100 is exposed toward the pack case 300. From this perspective, the cell cover 200 may be referred to as a cell sleeve or the like.

[0062] For example, referring to the embodiment of Fig. 2 to Fig. 4, the cell cover 200 is formed in a shape that encases two pouch-type battery cells 100, but the encased pouch-type battery cells 100, i.e., the lower parts of the battery cells 100 accommodated in the internal space, may not be encased by the cell cover 200. Therefore, the lower parts of the battery cells 100 may be exposed toward the pack case 300 and directly face the pack case 300. In particular, referring to the embodiment of Fig. 1, the lower parts of the battery cells 100 may be exposed toward the bottom surface of the lower case 320.

[0063] In the present invention, the pouch type battery cell 100 and the cell cover 200 may be directly placed on the pack case 300. Furthermore, the lower ends of the pouch type battery cell 100 and the cell cover 200 may be placed on the upper surface of the bottom surface of the pack case 300. For example, the cell cover 200 may be directly placed on the bottom surface of the lower case 320 in the embodiment of FIG. 1. At this time, a part of the cell cover 200, for example, the lower end of the cell cover 200 indicated by "C1" in FIG. 2, may be placed in direct contact with the bottom surface of the lower case 320. And, the cell cover 200 may be configured so that the placed state is stably maintained when the lower end is placed in this manner. At this time, when the cell cover 200 is made of a metal material having excellent rigidity such as steel, particularly stainless steel (SUS), the self-supporting state may be more stably maintained. Therefore, in this case, the upright state of the pouch type battery cell 100 can be more firmly supported.

[0064] The cell cover 200 may be configured to support the battery cells housed therein. In particular, the cell cover 200 may be configured to stably support the upright state of the battery cells housed therein. The cell cover 200 may be configured to support the stacked state of the plurality of pouch-type battery cells 100 inside the pack case 300 through a structure that envelops the battery cells in this way. For example, the plurality of pouch-type battery cells 100 may be stacked in the horizontal direction (Y-axis direction in the drawings) as shown in Figs. 1 to 4. At this time, the cell cover 200 may be configured to stably maintain the stacked state of the plurality of pouch-type battery cells 100 stacked in the horizontal direction in this way.

[0065] According to this aspect of the present invention, a plurality of pouch-type battery cells 100 can be directly placed and housed inside the pack case 300 without a module case. In particular, in the case of the pouch-type battery cell 100, the exterior material is made of a soft material, which is weak against external impact and has low hardness. Therefore, it is not easy to house the pouch-type battery cell 100 itself inside the pack case 300 without housing it in a module case. However, in the case of the present invention, the plurality of pouch-type battery cells 100 are combined with the cell cover 200 in a state where at least a portion of the pouch-type battery cells 100 is wrapped by the cell cover 200, and are directly housed inside the pack case 300, and the stacked state can be stably maintained.

[0066] Furthermore, in the present invention, a CTP (Cell To Pack) type battery pack using the pouch-type battery cell 100 can be more efficiently realized. That is, in the present invention, the pouch-type battery cell 100 is not accommodated inside a separate module case and the module case is not accommodated inside the pack case 300, but the battery pack 10 may be provided in a form in which the pouch-type battery cell 100 is directly accommodated inside the pack case 300. In this case, at least one side of the pouch-type battery cell 100 may be exposed to the outside of the cell cover 200 and disposed to directly face the pack case 300.

[0067] Therefore, according to this aspect of the present invention, there is no need to further provide a module case, a frame for stacking, or fastening members such as bolts for maintaining the stacked state of the cells in the battery pack 10. Therefore, it is possible to eliminate the space occupied by other components such as the module case and the frame for stacking, and the space required to ensure the tolerances therefor. As a result, the battery cells can occupy the additional space corresponding to the eliminated space, thereby further improving the energy density of the battery pack.

[0068] In addition, according to this aspect of the present invention, since a module case, stacking frame, bolts, etc. are not required, the volume and weight of the battery pack can be reduced and the manufacturing process can be simplified.

[0069] According to the present invention, it is possible to improve the ease of assembly of the battery pack 10. In particular, according to one embodiment of the present invention, it is not necessary to perform a process of accommodating pouch-type battery cells in a module case to provide a battery module, and a process of accommodating one or more battery modules thus provided in a pack case, etc. Therefore, it is possible to simplify the manufacturing process and shorten the manufacturing time.

[0070] Furthermore, according to this aspect of the present invention, the pouch-type battery cell 100 can be handled even more easily. For example, when a plurality of pouch-type battery cells 100 are housed inside a pack case, the pouch-type battery cell 100 can be gripped by a jig or the like. At this time, the jig can grip the cell cover 200 enclosing the pouch-type battery cell 100 without directly gripping the pouch-type battery cell 100. Therefore, it is possible to prevent the pouch-type battery cell 100 from being damaged or broken by the jig.

[0071] Furthermore, according to this aspect of the present invention, the cell cover 200 is coupled to the battery cell 100, so that the battery cell 100 can be effectively protected without a module case.

[0072] According to this embodiment of the present invention, the cooling performance of the battery pack can be more effectively ensured. In particular, according to the above embodiment, the pouch type battery cell 100 and the pack case 300 can be directly face-to-face and in contact with each other through the open end of the cell cover 200. That is, one side of the pouch type battery cell 100 arranged adjacent to the open end of the cell cover 200 can directly face or be in contact with the pack case 300. Therefore, the heat released from each pouch type battery cell 100 is directly transferred to the pack case 300, and the cooling performance can be improved. In addition, in this case, since a separate cooling structure does not need to be provided between the pouch type battery cell 100 and the pack case 300, efficient cooling performance can be achieved. In addition, in this case, a space for a coolant such as air to flow in may not be provided between the pouch type battery cells 100.

[0073] In this case, at least one side of the cell cover 200 is open, which may be advantageous for reducing the weight of the battery pack. For example, when the cell cover 200 is made of a material such as steel, if the lower end of the cell cover 200 is formed in an open shape, the weight of the cell cover 200 can be reduced by an amount corresponding to the lower plate. Furthermore, as shown in FIG. 1, the battery pack 10 may include many cell covers 200, and if all the cell covers 200 are formed in an open shape without the lower plate, the weight of the battery pack 10 can be significantly reduced.

[0074] Furthermore, according to one aspect of the present invention, it becomes possible to more easily provide a long cell configuration in which the length in a specific direction is long.

[0075] For example, in the case of a conventional prismatic cell, if the length in a specific direction is formed to be long, it may be difficult to perform the process of fitting the electrode assembly into the prismatic case. In particular, there is a concern that the electrode assembly may be damaged during the process of fitting the electrode assembly. However, according to one embodiment of the present invention, it is possible to easily lengthen the length of the pouch-type battery cell 100 and the cell cover 200 in one direction during the molding of the pouch exterior material, the manufacturing of the electrode assembly, and the manufacturing stage of the cell cover 200. In addition, the process of fitting the long cell, which is manufactured to be long in one direction, through the open side (e.g., the lower end) of the cell cover 200 is easily performed. Therefore, according to this aspect of the present invention, excellent assembly, processability, productivity, etc. can be ensured even when manufacturing the battery pack 10 using the long cell.

[0076] As shown in FIG. 2, each pouch-type battery cell 100 may have a receiving portion indicated by "R" and edge portions indicated by "E1" to "E4". Here, the receiving portion R may be a portion that receives an electrode assembly formed by stacking a positive electrode plate and a negative electrode plate with a separator interposed therebetween. Also, an electrolyte may be received in the receiving portion R. The edge portions E1 to E4 may be arranged in a shape that surrounds the receiving portion R.

[0077] In particular, the edge portion may be a seal portion where a pouch exterior material, which is a case of a pouch-type battery cell, is sealed. For example, in the embodiment of FIG. 2, four edge portions are provided, and it can be said that they are located at the upper edge portion, the lower edge portion, the front edge portion, and the rear edge portion, respectively, based on the storage portion R. In this case, the four edge portions E1 to E4 may all be seal portions. Alternatively, some of the four edge portions E1 to E4 may be formed in a folded shape, rather than being seal portions. For example, in the embodiment of FIG. 2, the upper edge portion E1, the front edge portion E3, and the rear edge portion E4 are all seal portions, but the lower edge portion E2 may be a portion where the pouch exterior material is folded. For example, the upper edge portion E1 may be a sealed portion of the pouch-type battery cell 100 that is folded twice, a so-called double side folding (DSF) portion, and the lower edge portion E2 may be an unsealed portion of the pouch-type battery cell 100.

[0078] Here, a battery cell in which all four edge portions E1 to E4 are sealed may be referred to as a four-side sealed cell, and a battery cell in which three edge portions E1, E3, and E4 are sealed may be referred to as a three-side sealed cell. In this configuration, the cell cover 200 may be configured to enclose both sides of the housing portion R of the pouch-type battery cell 100, which may be a four-side sealed cell or a three-side sealed cell, and a part of the edge portions E1 to E4. For example, as shown in FIG. 5, when one cell cover 200 is formed in a shape that encloses one pouch-type battery cell 100, the cell cover 200 may be configured to enclose both surfaces of the housing portion R of the same pouch-type battery cell 100 (e.g., the left and right surfaces of the same housing portion R) and a part of the edge portion of the battery cell 100 from the outside. As another example, when one cell cover 200 is formed in a shape that encloses a plurality of pouch-type battery cells 100, for example, a plurality of battery cells arranged in the left-right direction, it may be formed in a shape that encloses the outer surface of the housing part of the outermost battery cell and one-side edge parts of all the battery cells. As a more specific example, as shown in Figs. 2 to 4, one cell cover 200 may be formed in a shape that encloses two pouch-type battery cells 100 stacked in the left-right direction. In this case, the cell cover 200 may be formed in a shape that encloses the left surface of the left battery cell, one-side edge parts of the two battery cells, and the right surface of the right battery cell.

[0079] According to this embodiment, a configuration in which one cell cover 200 supports and protects one or more pouch-type battery cells 100 can be easily realized. In addition, according to the above embodiment, the process of handling one or more pouch-type battery cells 100 through the cell cover 200 can be easily and safely performed. Furthermore, according to the above embodiment, one cell cover 200 can face the surfaces of two storage parts R with respect to the pouch-type battery cell 100 stored therein. Therefore, the cooling performance can be further improved between the storage parts R and the cell cover 200. Particularly in this case, surface cooling is realized through the wide surface of the storage part R, and the cooling efficiency is improved.

[0080] In particular, the cell cover 200 may be formed in a shape that envelops an edge portion on which no electrode lead is provided, among a plurality of edge portions of the pouch-type battery cell 100 housed therein. For example, referring to the embodiment shown in FIG. 2, the pouch-type battery cell 100 may include two electrode leads 110, i.e., a positive electrode lead and a negative electrode lead. In this case, the two electrode leads may be located at the front edge portion E3 and the rear edge portion E4, respectively. In this case, the cell cover may be formed in a shape that envelops one of the remaining two edge portions E1 and E2 excluding the front edge portion E3 and the rear edge portion E4.

[0081] Furthermore, the cell cover 200 may be provided in a shape that covers both side surfaces and an upper edge portion E1 of the receiving portion R of one or more pouch-type battery cells 100 that are received and wrapped therein. For example, as shown in FIG. 5, the cell cover 200 may be formed in a shape that surrounds both the left and right surfaces of the receiving portion R and the upper edge portion E1 of one pouch-type battery cell 100. As another example, as shown in FIGS. 2 to 4, when the cell cover 200 is formed in a shape that surrounds two pouch-type battery cells 100 stacked in the left-right direction, the cell cover 200 may be formed in a shape that surrounds the left surface of the receiving portion of the left battery cell, the upper edge portions E1 of the two battery cells, and the right surface of the receiving portion of the right battery cell.

[0082] According to this embodiment of the present invention, it is possible to easily realize a configuration in which one or more battery cells are supported and protected by one cell cover 200. In particular, according to the above embodiment, the lower edge portion E2 is located adjacent to the open end of the cell cover 200, and faces the pack case 300 without being enclosed by the cell cover 200, and can be in direct face-to-face contact with the pack case 300. Therefore, heat from the pouch-type battery cell 100 enclosed by the cell cover 200 can be quickly and smoothly discharged to the lower pack case 300 side. Therefore, the cooling performance of the battery pack 10 can be more effectively ensured.

[0083] In particular, this configuration can be more effectively adopted when cooling is mainly performed in the lower part of the pack case 300. For example, in the case of a battery pack mounted on an electric vehicle, since it is mounted on the lower part of the vehicle body, cooling can mainly be performed in the lower part of the pack case 300. At this time, when the edge part E2 on the lower side of each battery cell 100 faces and contacts the pack case 300 as in the above embodiment, heat is rapidly transferred from each battery cell 100 to the pack case 300 side, and the cooling performance can be further improved.

[0084] In the pouch-type battery cell 100, the upper edge portion E1 as a sealed portion may be more vulnerable to the discharge of high-temperature gas or flame than the lower edge portion E2 as an unsealed portion. However, according to the above embodiment, the upper edge portion E1 as a sealed portion is disposed to face the cell cover 200, which may be more advantageous for directional venting.

[0085] The cell cover 200 may be made of a wide variety of materials to ensure rigidity. In particular, the cell cover 200 may be made of a metal material. In the case of such a metal material, the stacked state of the pouch-type battery cells 100 can be more stably maintained and the pouch-type battery cells 100 can be more safely protected from external impacts. In particular, the cell cover 200 may include a steel material and / or a SUS material. For example, the cell cover 200 may be entirely made of a SUS material. The cell cover 200 made of a SUS material may have a thickness of approximately 2 mm.

[0086] In this way, when the cell cover 200 is made of a steel material, it has excellent mechanical strength and rigidity, and can more stably support the stacked state of the pouch-type battery cells 100. In this case, damage or breakage of the pouch-type battery cells 100 from external impacts, such as needle-shaped objects, can be more effectively prevented. Furthermore, in this case, the pouch-type battery cells 100 become easier to handle.

[0087] Also, when the cell cover 200 is made of a steel material as in the above embodiment, the high melting point allows the overall structure to be stably maintained when a flame breaks out from the battery cell 100. In particular, since the steel material has a higher melting point than the aluminum material, it is not melted by the flame ejected from the battery cell 100 and its shape can be stably maintained. Therefore, the effect of preventing or delaying the propagation of flame between the battery cells 100, the effect of vent control, etc. can be satisfactorily ensured.

[0088] Here, the cell cover 200 is a unit cover and may include a first cover 210 and a second cover 220 as shown in Figs. 2 to 5. Also, the cell cover 200 may be configured to allow vent gas to be discharged to a space S between the two unit covers 210, 220. For example, referring to Figs. 4 and 5, the cell cover 200 may allow vent gas to be discharged as indicated by the arrows through the space S formed between the two unit covers 210, 220.

[0089] The pouch-type battery cell 100 has the advantages of being lightweight, having a low possibility of electrolyte leakage, and being flexible in shape, allowing a secondary battery of the same capacity to be realized with a smaller volume and mass. However, since there is a risk of explosion when it overheats, ensuring safety is one of the important issues. Overheating of the pouch-type battery cell 100 occurs due to various reasons, one of which is when an overcharge beyond a limit flows through the pouch-type battery cell 100. When an overcurrent flows, the pouch-type battery cell 100 generates heat due to Joule heat, and the temperature inside the pouch-type battery cell 100 rises rapidly. The sudden rise in temperature may cause a decomposition reaction of the electrolyte, which may generate gas. This may cause a swelling phenomenon, which is a type of bulging phenomenon, due to an increase in pressure inside the pouch exterior material, which may cause serious problems such as an explosion of the secondary battery. When gas is generated inside the pouch-type battery cell 100 due to not only such an overcurrent but also exposure to high temperature, an external impact, and the like, it is necessary to effectively exhaust the gas to ensure the safety of the secondary battery. The exhaust of gas generated inside the secondary battery to the outside is called venting. The cell cover 200 included in the battery pack 10 according to the embodiment of the present invention is configured to be able to exhaust vent gas to the separation space S between the two unit covers 210, 220, thereby making it possible to ensure the safety of the secondary battery.

[0090] The first cover 210 may be configured to enclose a left surface and one edge of the enclosed pouch-type battery cell 100. And, the second cover 220 may be configured to enclose a right surface and the other edge of the enclosed pouch-type battery cell 100. Here, the first cover 210 and the second cover 220 are each formed in an L-shape, and it can be said that the cell cover 200 according to this embodiment of the present invention is formed in a shape in which two L-shaped unit covers 210, 220 are combined with each other.

[0091] In particular, the first cover 210 and the second cover 220 can be configured to wrap around the upper edge of the pouch-type battery cell 100.

[0092] 1 and 2, only a shape in which the upper edges of the first cover 210 and the second cover 220 are spaced apart from each other is disclosed, but such a space S may be provided with a support portion for supporting the space S between the two unit covers 210, 220. In addition, such two unit covers 210, 220 may be fastened to each other by a variety of fastening methods such as welding, adhesion, fitting, and hooking.

[0093] In addition, the two unit covers 210, 220 may be formed with one end bent toward each other. For example, as shown in Figs. 2 to 5, the upper end of the first cover 210 may be bent toward the right, and the upper end of the second cover 220 may be bent toward the left. Here, the upper end of the first cover 210 and the upper end of the second cover 220 may be stacked vertically while being at least partially separated from each other.

[0094] Each of the two unit covers 210, 220 may be formed by bending a single plate. For example, each of the two unit covers 210, 220 may be formed by bending one end of a single plate material by about 90° to a shape that encloses one or more pouch-type battery cells 100.

[0095] The cell cover 200 may be configured to enclose both side surfaces and the edge of the upper side of at least a portion of the pouch-type battery cell 100. For example, the cell cover 200 composed of two unit covers 210, 220 may be said to have two side cover parts enclosing both left and right side surfaces of the pouch-type battery cell 100 housed therein and an upper cover part enclosing the edge of the upper side, as shown in Figs. 2 to 5. In this case, the upper cover part may be said to be at least partially double-layered. In this case, the cross-sectional shape of the cell cover 200 viewed from the front side may be said to be roughly similar to the letter "n". Therefore, in this case, the cell cover 200 may be called "n-fin". Also, the cross-sectional shapes of the first cover 210 and the second cover 220 viewed from the front side may be roughly similar to the letter "L". Therefore, in this case, the first cover 210 and the second cover 220 may be referred to as an "L-fin." And the cell cover 200 can be said to be an n-fin formed from two L-fins.

[0096] More specifically, the first cover 210 includes a first upper cover part 212 configured to enclose an upper part of the edge part E1 on the upper side of the pouch-type battery cell 100, and a first side cover part 214 extending downward from one end of the first upper cover part 212 and enclosing the outside of the storage part on one side of the encased pouch-type battery cell 100. The second cover 220 includes a second upper cover part 222 configured to enclose an upper part of the edge part E1 on the upper side of the pouch-type battery cell 100, and a second side cover part 224 extending downward from one end of the second upper cover part 222 and enclosing the outside of the storage part on the other side of the encased pouch-type battery cell 100. The first upper cover part 212 and the second upper cover part 222 are spaced apart in the vertical direction. In this embodiment, the second upper cover portion 222 is spaced from the first upper cover portion 212 in the direction of the upper edge portion E1 of the pouch-type battery cell 100.

[0097] Here, the first upper cover part 212 and the second upper cover part 222 may be configured to enclose the upper part of the edge part E1 on the upper side of the pouch type battery cell 100 housed therein. In particular, a part located between the two side cover parts 214, 224 in the cell cover 200 and a side of the pouch type battery cell 100 facing the part may be spaced apart from each other by a predetermined distance. And, such a space may be formed in a hollow shape. According to such an embodiment of the present invention, a path for vent gas to move can be provided by an empty space formed between the side part (edge ​​part) of the pouch type battery cell 100 and the cell cover 200. For example, when vent gas is generated in the battery cell 100 housed inside the cell cover 200 due to thermal runaway or the like, the generated vent gas can move in the front-rear direction (X-axis direction) through an empty space between the edge part E1 on the upper side adjacent to the first upper cover part 212 and the first upper cover part 212 and the first side cover part 214. Therefore, regardless of where a component for discharging vent gas to the outside of the cell cover 200, such as a through hole or a cutout portion as described below, is located in the cell cover 200 or another component, the vent gas can move smoothly and quickly to the portion where the component related to the discharge is located. This makes it possible to prevent the internal pressure of the cell cover 200 from increasing and to perform efficient vent control, such as guiding the discharge direction of the vent gas.

[0098] Meanwhile, the first upper cover part 212 may be formed in a shape that contacts the edge part E1 on the upper side of the pouch-type battery cell 100.

[0099] Also, the first upper cover part 212 may be formed in a flat shape. In this case, the first upper cover part 212 may have a cross section formed in a horizontal straight line and may wrap the upper edge part E1 of the pouch-type battery cell 100 from the outside in a straight line.

[0100] The first side cover part 214 may be formed in a shape extending downward from one end of the first upper cover part 212. For example, the first side cover part 214 may be formed in a shape extending in an elongated shape from the left end part of the first upper cover part 212 downward (in the -Z axis direction in the figure). Furthermore, the first side cover part 214 may be formed in a flat shape. In this case, the first side cover part 214 may be formed in a shape bent from the first upper cover part 212.

[0101] The first side cover part 214 may be configured to enclose the outside of one side of the accommodation part of the pouch-type battery cell 100 accommodated therein. For example, when one pouch-type battery cell 100 is accommodated in the cell cover 200, the first side cover part 214 may be configured to enclose the left surface of the accommodation part of the accommodated pouch-type battery cell 100 from the left side. Here, the first side cover part 214 may be in direct contact with the outer surface of the accommodation part.

[0102] The second side cover part 224 may be positioned so as to be horizontally spaced apart from the first side cover part 214. The second side cover part 224 may be formed in a shape extending downward from one end of the second upper cover part 222. For example, the second side cover part 224 may be formed in a shape extending elongatedly downward from the right end part of the second upper cover part 222. Furthermore, the second side cover part 224 may also be formed in a planar shape, similar to the first side cover part 214. In this case, it can be said that the second side cover part 224 and the first side cover part 214 are arranged parallel to each other while being horizontally spaced apart. The second side cover part 224 may be formed in a shape bent from the second upper cover part 222.

[0103] The first side cover part 214 and the first upper cover part 212 may be made of one plate. The second side cover part 224 and the second upper cover part 222 may also be made of one plate. In this case, it can be said that each of the two unit covers 210, 220 is made of a plurality of components that are integrally formed. Here, each component may be divided through a bent part. In particular, one plate may have one bent part. Then, the first side cover part 214 and the first upper cover part 212 may be divided based on this one bent part, and the second side cover part 224 and the second upper cover part 222 may be divided. In this way, the configuration of forming a bent part in one plate to form the cell cover 200 may be realized by various methods such as pressing or roll forming.

[0104] According to this embodiment of the present invention, the manufacturing process of the cell cover 200 is simplified. Therefore, the manufacturing cost and time of the battery pack can be reduced. In addition, according to this embodiment, the mechanical strength and rigidity of the cell cover 200 can be further improved. Furthermore, in this case, the heat conduction performance through the cell cover 200 is further improved, and the cooling performance can be further improved.

[0105] Also, the second side cover part 224 may be configured to enclose the outside of the other side of the housing part of the pouch-type battery cell 100 housed therein. For example, when one pouch-type battery cell 100 is housed in the cell cover 200, the second side cover part 224 may be configured to enclose the right surface of the housing part of the housed pouch-type battery cell 100 from the right side. Here, the second side cover part 224 may be in direct contact with the outer surface of the housing part.

[0106] In the above-described embodiment, an internal space may be defined by the first and second upper cover parts 212, 222 and the first and second side cover parts 214, 224. The cell cover 200 may then house one or more battery cells in the internal space defined in this manner.

[0107] The two unit covers 210, 220 may be configured such that the folded ends are at least partially spaced from each other to allow the vent gas to be discharged. For example, referring to the embodiment of Fig. 4 and Fig. 5, the folded portions on the upper sides of the two unit covers 210, 220 may be vertically spaced from each other to form a spaced space S. The vent gas may be discharged through the spaced space S.

[0108] The length of the second side cover part 224 in the up-down direction may be longer than that of the first side cover part 214. In Fig. 4, the length of the first side cover part 214 is indicated by L1, and the length of the second side cover part 224 is indicated by L2. In this case, L2 may be greater than L1.

[0109] The lower end portions C1 of the first side cover portion 214 and the second side cover portion 224 may come into contact with the bottom surface of the pack case 300. If the heights of the lower end portions C1 of the first side cover portion 214 and the second side cover portion 224 are the same, the configuration in which the first upper cover portion 212 connected to the first side cover portion 214 and the second upper cover portion 222 connected to the second side cover portion 224 are separated from each other can be achieved simply by making the length L2 of the second side cover portion 224 longer than the length L1 of the first side cover portion 214.

[0110] The vent gas moves to a vent channel defined as a space S between the first upper cover part 212 and the second upper cover part 222 through the gap between the first upper cover part 212 and the second side cover part 224, and can be discharged through the gap between the second upper cover part 222 and the first side cover part 214. That is, it is equivalent to forming an n-fin from two L-fins, and forming a vent channel in the upper gap between the L-fins. The vent gas can be discharged through such a vent channel.

[0111] According to such an embodiment of the present invention, the exhaust direction of flames and the like can be guided to the space S between the two unit covers 210, 220. For example, according to the above embodiment, flames and the like can be exhausted in the Y-axis direction from the upper end of the cell cover 200. It is possible to effectively prevent the exhausted gas or flames from moving toward the upper side (Z-axis direction) and perform directional venting in the desired direction (Y-axis direction).

[0112] If the gas generated inside the secondary battery is discharged in multiple directions instead of in a single direction, the vent gas cannot be easily discharged to the outside, and the time required to discharge the vent gas is prolonged, which may significantly reduce the safety of the secondary battery. According to the present invention, the vent gas can be discharged in a single direction through the two unit covers 210 and 220. According to the above embodiment, when high-temperature gas or flame is discharged from the pouch-type battery cell 100 under a situation such as thermal runaway, the discharged gas or flame can be prevented from moving toward the upper side. In particular, when a passenger is located on the upper side of the battery pack 10, such as an electric vehicle, according to the above embodiment, the gas or flame can be prevented from moving toward the passenger side.

[0113] In this way, according to the present invention, the flame or gas can be guided and discharged in a preset direction. In this case, even if thermal runaway occurs in any one of the battery cells 100, the flame or gas generated in the battery cell 100 can be discharged only in the preset direction through the cell cover 200. If the preset direction is a direction that is not toward the other cell covers 200, the flame or gas can be prevented from propagating to the other battery cells 100 arranged adjacent to the battery cell 100 in which thermal runaway has occurred. In other words, even if thermal runaway occurs in any one of the battery cells 100, the effect of the thermal runaway on the other battery cells 100 is minimized.

[0114] The first side cover part 214 and the pouch-type battery cell 100, and the second side cover part 224 and the pouch-type battery cell 100 may be bonded together. The first side cover part 214 and the pouch-type battery cell 100, and the second side cover part 224 and the pouch-type battery cell 100 may be bonded together directly, but it is preferable that they are bonded together indirectly while further including an insulating member 270, as shown in FIG.

[0115] FIG. 6 is a cross-sectional view illustrating a schematic coupling configuration between a pouch-type battery cell and a cell cover housed in a battery pack according to still another embodiment of the present invention.

[0116] Referring to FIG. 6, the cell cover 200 may further include an insulating member 270. The insulating member 270 may be made of an electrically insulating material and disposed on the inner surface of the cell cover 200 in which the pouch-type battery cell 100 is housed. In particular, the insulating member 270 may be attached to the inner surface of the cell cover 200 by providing an adhesive layer on at least one side. Also, the insulating member 270 may be attached to the inner surface of the cell cover 200 by providing an adhesive layer on both sides, and may also be attached to the pouch-type battery cell 100. In addition, the insulating member 270 may be made of a material having heat resistance. For example, the insulating member 270 may be formed in the shape of a heat-resistant tape in which an adhesive is applied to the surface of a ceramic sheet having heat resistance. The insulating member 270 may be a film made of a polyimide (PI) material. The insulating member 270 may have a thickness of approximately 0.5 mm. Also, the insulating member 270 may be located on both the inner and outer surfaces of the cell cover 200, i.e., on both sides.

[0117] Meanwhile, in the battery pack according to the present invention, a thermal interface material (TIM) may be interposed to improve the heat transfer performance between different components. For example, the TIM may be filled between the battery cell 100 and the cell cover 200, between the cell cover 200 and the pack case 300, and / or between the battery cell 100 and the pack case 300. In this case, the cooling performance of the battery pack may be further improved. The TIM is for reducing the contact thermal resistance between members. In a battery pack in which cooling is important, it is necessary to improve the thermal performance of the entire system by using a material that can reduce the contact thermal resistance as much as possible. As the TIM, various materials such as thermally conductive grease, a thermally conductive sheet, a thermally conductive pad, a thermally conductive adhesive, and a PCM (phase change material) may be used. As a specific example, the TIM may be any one of a thermally conductive silicone-based bond, a thermally conductive silicone pad, and a thermally conductive acrylic bond. The heat dissipating silicone adhesive and the heat dissipating acrylic adhesive are commercially available as one-component or two-component adhesives, and can be applied between different components by coating or injection. The heat dissipating silicone pad includes a base film such as a double-sided tape and release paper on the top and bottom of the base film, and can be applied between different components by adhesion after peeling off the release paper. The heat dissipating silicone adhesive, the heat dissipating silicone pad, and the heat dissipating acrylic adhesive have higher thermal conductivity than a normal adhesive, and can further increase the amount and speed of heat transfer between different components. Therefore, according to this embodiment of the present invention, the heat dissipation performance of the pouch-type battery cell 100 can be further improved, and the cooling performance of the battery pack 10 can be further improved.

[0118] Returning to FIG. 1, the cell units including the pouch-type battery cells 100 and the cell covers 200 may be accommodated in the pack case 300 in a stacked shape. Here, one unit having a shape in which a plurality of cell units are stacked is referred to as a cell unit block. For example, the plurality of cell units may be arranged to be stacked in a horizontal direction in the internal space of the lower case 320 as shown in FIG. 1. At this time, the plurality of cell units may be stacked so that the surfaces of the cell covers 200 face each other. In particular, each cell cover 200 may be stacked in the left-right direction so that the first side cover portion 214 and the second side cover portion 224 face each other. Also, each cell unit may be stacked in the front-rear direction. In this case, a plurality of cell units may be stacked in a shape in which the electrode leads 110 protruding in the front-rear direction from each cell unit face each other. According to the above-mentioned embodiment of the present invention, the module case of the battery module and the like can be removed to further improve space efficiency.

[0119] In addition, as in the illustrated example, when arranging a plurality of pouch-type battery cells 100, such as when one cell unit block arranged in the left-right direction is stacked in a shape in which two are arranged in the front-rear direction, when a plurality of cell unit blocks are arranged in rows and columns, the discharge direction of the vent gas from one cell unit block and the discharge direction of the vent gas from the other cell unit blocks may be different from each other. For example, the discharge direction of the vent gas from any one cell unit block may be configured to be a direction toward the pack case 300 without toward the other cell unit blocks. In the illustrated example, the discharge direction of the vent gas from the cell unit blocks CUB1 and CUB2 at the front end on the left side and the rear end on the left side is the Y-axis direction as shown in FIGS. 1 and 3. It is also possible to invert the arrangement configuration as shown in FIGS. 1 and 3 so that the discharge direction of the vent gas from the cell unit blocks CUB3 and CUB4 at the front end on the right side and the rear end on the right side is the -Y-axis direction.

[0120] According to the present invention, when a thermal runaway occurs in a specific battery cell, it is possible to effectively respond to a thermal event. In particular, in the case of the present invention, among the three elements (fuel, oxygen, and ignition source) that cause a flame, it is possible to block or appropriately control the accumulation and discharge of heat that corresponds to the ignition source. Furthermore, in the case of the present invention, it is possible to realize control of the discharge of vent gas via the cell cover 200 and directional venting in order to block the accumulation of heat and prevent the discharge of flames. Furthermore, according to one aspect of the present invention, it is possible to prevent internal short circuits and structural collapse even when a thermal event occurs.

[0121] Also, the battery pack according to the present invention may further include a control module 400 accommodated in the internal space of the pack case 300. Such a control module 400 may include a battery management system (BMS). The control module 400 may be mounted in the internal space of the pack case 300 and configured to generally control the charging and discharging operation and the data transmission and reception operation of the pouch-type battery cell 100. The control module 400 may be arranged in pack units, not in module units. More specifically, the control module 400 may be provided to control the charging and discharging state, power state, and performance state of the pouch-type battery cell 100 using the pack voltage and the pack current. The control module 400 estimates the state of the battery cell 100 in the battery pack 10 and manages the battery pack 10 using the estimated state information. For example, the control module estimates and manages state information of the battery pack 10, such as the state of charge (SOC), state of health (SOH), maximum input / output power allowance, and output voltage of the battery pack 10. Such status information can be used to control the charging or discharging of the battery pack 10, and can also be used to estimate the time to replace the battery pack 10.

[0122] Also, the battery pack 10 according to the present invention may further include a battery disconnect unit, as shown in Fig. 1. The battery disconnect unit 500 (BDU) may be configured to control electrical connection of the battery cells to manage the power capacity and functions of the battery pack 10. To this end, the battery disconnect unit 500 may include a power relay, a current sensor, a fuse, and the like. The battery disconnect unit 500 is also a component that is arranged on a pack basis, not on a module basis, and may employ various disconnect units known at the time of filing of the present invention.

[0123] In addition, the battery pack 10 according to the present invention may further include various battery pack components 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 pull out a service plug to cut off the power supply. In addition, the battery pack 10 may further include flexible bus bars or cables for connecting a plurality of cell unit blocks to each other.

[0124] FIG. 7 is a diagram illustrating a schematic cross-sectional configuration of a portion of a battery pack according to still another embodiment of the present invention.

[0125] The cell cover 200 may have a mesh structure M in the space S between the two unit covers 210 and 220. For example, referring to the embodiment of FIG. 7, a mesh structure as indicated by M may be located in the space S between the first upper cover part 212 of the first cover 210 and the second upper cover part 222 of the second cover 220. The cell cover 200 may be formed so that when the vent gas is discharged to the outside through the space S between the first upper cover part 212 of the first cover 210 and the second upper cover part 222 of the second cover 220, the vent gas passes through the mesh structure M. At this time, the mesh structure M may be configured to have a structure capable of collecting sparks and active material particles contained in the vent gas, for example, a pore size capable of collecting such sparks and active material particles, and a material capable of withstanding a temperature above a certain level.

[0126] It is preferable to include such a mesh structure M so that when a fire or explosion occurs in a part of the pouch-type battery cell 100, high-temperature electrode assembly fragments, flames, and high-temperature gases are not discharged and affect other adjacent pouch-type battery cells 100. The mesh structure M can prevent high-temperature active material from moving to adjacent battery cells 100 even if it is discharged from an exploded battery cell 100 while maintaining the function of ejecting gas and flames generated when the battery cell 100 ignites. As a result, the discharge of vent gas is suppressed while the discharge of ignition sources such as sparks is suppressed. Therefore, the present invention can prevent chain ignition such as thermal runaway, fire, explosion, etc. from spreading to other battery cells 100, thereby significantly improving safety.

[0127] The mesh structure M may be a metal net or a metal plate with many holes. The holes may be formed by cutting out or cutting out a part of the metal plate by punching or etching. The metal net is formed by weaving together many metal wires to form a so-called iron net. As a suitable example, the mesh structure M is formed by forming a metal net of two or more meshes in one or more layers, preferably multiple layers. The mesh is a method of classifying a mesh according to the size of the mesh, and is represented by the number of meshes (squares) per inch of length. In other words, the mesh is a unit that indicates the hole of a sieve or the particle size of a particle, and can be said to be the number of meshes that fit in a square of 1 inch. For example, 200 mesh means that iron wires with a diameter of 2 / 1000 inch are stretched at intervals of 3 / 1000 inch, and there are 200 meshes per inch of length. Therefore, N mesh is N / 25.4mm. For example, if a metal net with 2 meshes or more is used, the diameter of each hole is 12.7x12.7mm. 2 If only flame quenching is taken into consideration, the smaller the mesh spacing, the better, but if the spacing is too narrow, it is likely to be clogged with foreign matter such as dust, so the number should be moderate.

[0128] The mesh structure M is characterized by being made of a non-combustible material. Any material may be used as long as it is not easily flammable. Specifically, any one of copper, aluminum, cast iron, Monel (Ni+Cu), SUS, and steel may be used, but the material is not limited to these. It is preferable to select a material for the mesh structure M that has not only a flame-extinguishing ability to prevent flames, but also mechanical properties to withstand explosion pressure. The mesh structure M may be used purely by itself or may be laminated with a polymer resin layer, but is not limited thereto. The polymer resin layer may be any one selected from the group consisting of polyvinylidene fluoride-hexafluoropropylene, polyvinylidene fluoride-trichloroethylene, polymethyl methacrylate, polyacrylonitrile, polyvinyl pyrrolidone, polyvinyl acetate, polyethylene-vinyl acetate copolymer, polyethylene oxide, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethyl pullulan, cyanoethyl polyvinyl alcohol, cyanoethyl cellulose, cyanoethyl sucrose, pullulan, carboxyl methyl cellulose, acrylonitrile-styrene-butadiene copolymer, polyimide, and mixtures thereof, but is not limited thereto.

[0129] Such a mesh structure M not only breaks the flame into small pieces while passing it, but also induces an endothermic reaction that absorbs the energy of the flame, resulting in a drop in temperature and the effect of extinguishing the flame. More specifically, since the mesh structure M has small holes, gases such as gas and steam can pass through it, but flames cannot easily pass through it. In addition, when a mixture of combustible gas and air inside the secondary battery is ignited, the mesh structure M absorbs and dissipates the heat emitted from the combusted gas mixture, thereby lowering the combustion temperature so that the gas on the opposite side does not rise to the spontaneous ignition temperature. This is because the heated gas with high heat is absorbed by the material constituting the mesh structure M as it passes through the mesh structure M. The mesh structure M is made of a metal material containing many holes, and therefore becomes a heat absorbing plate with a very wide cross-sectional area.

[0130] Therefore, as the flame passes through the mesh structure M, it is possible to remove so much heat that the flame cannot sustain any more, and the explosion can be quelled.

[0131] Since the mesh structure M is a thin plate-like structure, it can be appropriately arranged in the separated space S in the cell cover 200, and an increase in the size of the cell unit can be suppressed. In addition, since the mesh structure M has a large number of holes, an increase in weight can also be suppressed. Thus, according to the present invention, even if a situation occurs in which a flame is ejected from the secondary battery, the ejection of a flame to the outside is prevented while suppressing an increase in the size and weight of the battery pack 10, thereby improving safety. According to such an embodiment of the present invention, it is possible to suppress the discharge to the outside of sparks, flames, high-temperature active material particles, etc. contained in the vent gas. Therefore, the fire suppression performance can be further improved. Thus, according to the present invention, it is possible to realize the blocking of sparks. If the pack case 300 is made of aluminum to reduce weight, if sparks scatter and directly collide with the pack case 300, there is a risk that the pack case 300 will melt and cause structural collapse. According to the embodiment of the present invention, it is possible to prevent sparks from scattering and directly colliding with the pack case 300 side, and therefore such structural collapse can be prevented.

[0132] FIG. 8 is a diagram illustrating a schematic cross-sectional configuration of a portion of a battery pack according to still another embodiment of the present invention.

[0133] Referring to FIG. 8, the cell cover 200 may be configured so that the gas discharged to the space S between the two unit covers 210 and 220 is bent. For example, as shown in FIG. 8, the cell cover 200 may be configured so that the two unit covers 210 and 220 are formed with bent portions B so that the movement path of the gas discharged to the space S between the two unit covers 210 and 220 is increased. The bent portions B may be formed in the first upper cover part 212 and the second upper cover part 222 so that the above-mentioned vent channel may be bent. In addition, the bent portions B may be configured so that an uneven or wavy pattern or a wavy portion is formed. In addition, with this configuration, the vent gas discharged to the space S between the unit covers 210 and 220 may have a shape bent two or more times during the discharge process.

[0134] In addition, in the case of FIG. 8, the unevenness formed on the two unit covers 210 and 220 is configured to move the vent gas in a vertically bent manner in order to increase the gas path in the vertical direction, but the unevenness may also be configured to move the vent gas in a horizontally bent manner.

[0135] In addition, in the case of Figure 8, the unevenness formed on the two unit covers 210, 220 are made to have conformal shapes with each other, but it is also possible to adopt a case where the unevenness is formed on only one of the two unit covers 210, 220.

[0136] Such an implementation can reduce or delay the emission of flames or sparks with strong linear motion, and can also help reduce the temperature of the vent gas as it is exhausted along its longer travel path.

[0137] Meanwhile, the battery pack may house one or more battery modules, and in this case, the components described in the various embodiments above, particularly the battery cells and cell covers, may be applied to the battery modules.

[0138] FIG. 9 is a diagram illustrating a schematic configuration of a battery module according to an embodiment of the present invention.

[0139] 9, the battery module 20 may be one or more battery modules housed in the internal space of the pack case 300 as shown in Fig. 1. The battery module 20 may include a plurality of pouch-type battery cells 100 as described above.

[0140] The battery module 20 may include a module case that accommodates the pouch-type battery cells 100 in an internal space. The module case may include a body frame MC1 and end plates MC2. The body frame MC1 may be formed in a shape in which the upper, lower, left and right sides are closed and the front and rear are open. In this case, the upper, lower, left and right sides may each be formed in a plate shape, and such four plates may be manufactured in the shape of a tube integrated with one another. The body frame MC1 having such a shape may be called a monoframe. The end plates MC2 may be configured to be coupled to the opening of the body frame MC1.

[0141] In another example, the module case may include a U-frame, a top plate, and an end plate. The left and right plates may be integrated with a base plate to form the U-frame. The top plate may be coupled to an upper portion of the U-frame, and the end plates may be coupled to openings at the front and rear ends of the U-frame, respectively.

[0142] As described above, the battery module 20 may include the cell cover 200, which includes two unit covers 210 and 220 that are at least partially spaced apart from each other and is provided to at least partially enclose at least some of the pouch-type battery cells 100 in the internal space of the module case, and is configured to allow vent gas to be discharged to the space S between the two unit covers 210 and 220. Here, in the case of the plurality of pouch-type battery cells 100 and the cell cover 200, the above description of the battery pack may be applied in the same or similar manner. In addition, the battery module 20 may be configured to include a bus bar for electrically connecting the plurality of pouch-type battery cells 100, a sensing wire for sensing the voltage and temperature of the plurality of pouch-type battery cells 100, and the like.

[0143] The battery pack 10 or the battery module 20 according to an embodiment of the present invention can be applied to various devices. Representative examples of such devices include electric motorcycles, electric vehicles, and hybrid vehicles, but the present invention is not limited to these. The battery pack 10 can be suitably used as a battery pack for electric vehicles. It can also be used as an energy source for an energy storage system (ESS).

[0144] FIG. 10 is a diagram showing a schematic configuration of a vehicle according to an embodiment of the present invention.

[0145] 10, an automobile V according to an embodiment of the present invention may include the battery pack 10 according to the embodiment of the present invention described above. Here, the automobile V may include a specific automobile that uses electricity as a driving source, such as an electric automobile or a hybrid automobile. Furthermore, the automobile V may further include various other components included in the automobile, such as a body and a motor, in addition to the battery pack 10 according to the present invention.

[0146] The battery pack 10 can be disposed at a predetermined position within an automobile V. The battery pack 10 can be used as an electric energy source that provides driving force to a motor of an electric vehicle to drive the automobile V. In this case, the battery pack 10 has a high nominal voltage of 100 V or more.

[0147] The battery pack 10 may be charged or discharged by an inverter in response to driving of a motor and / or an internal combustion engine. The battery pack 10 may be charged by a regenerative charging device coupled to a brake. The battery pack 10 may be electrically connected to a motor of the automobile V via an inverter.

[0148] Meanwhile, in this specification, directional terms such as up, down, left, right, front, and back are used, but these terms are used merely for ease of explanation, and it will be obvious to those skilled in the art of the present invention that they may vary depending on the position of the object in question, the position of the observer, etc.

[0149] Although the present invention has been described above using limited embodiments and drawings, the present invention is not limited thereto, and it goes without saying that various modifications and variations can be made by a person having ordinary knowledge in the technical field to which the present invention pertains within the equivalent scope of the technical concept of the present invention and the scope of the claims. [Explanation of symbols]

[0150] 10 Battery Pack 20 Battery Module 100 pouch type battery cells 200 Cell Cover 210 First Cover 212 first upper cover part 214 First side cover part 220 Second Cover 222 second upper cover part 224 Second side cover part 270 Insulating materials 300 pack case M mesh structure B Bending section V Automobile

Claims

1. A plurality of pouch-type battery cells; a pack case that houses the pouch-type battery cell in an internal space; a cell cover including two unit covers at least partially spaced apart from each other, the cell cover being provided to at least partially enclose at least some of the pouch-type battery cells in the internal space of the pack case, and configured to allow vent gas to be discharged into a space between the two unit covers; Including the battery pack.

2. 2. The battery pack according to claim 1, wherein the cell cover is configured to support the plurality of pouch-type battery cells in an upright position.

3. The battery pack according to claim 1 , wherein the cell cover partially encases the pouch-type battery cell such that at least one side of the encased pouch-type battery cell is exposed toward the pack case.

4. The pouch-type battery cell includes a receiving portion in which an electrode assembly is received and an edge portion provided around the receiving portion, 2. The battery pack according to claim 1, wherein the cell cover is configured to encase both sides and a portion of an edge of a housing portion of the enclosed pouch-type battery cell.

5. The battery pack according to claim 4 , wherein the cell cover is provided to cover both side surfaces and an edge portion on an upper side of the housing portion of the enclosed pouch-type battery cell.

6. 2. The battery pack according to claim 1, wherein the two unit covers are a first cover configured to enclose a left surface and an edge on one side of the enclosed pouch-type battery cell, and a second cover configured to enclose a right surface and an edge on the other side of the enclosed pouch-type battery cell.

7. the first cover includes a first upper cover portion configured to enclose an upper portion of an edge portion on an upper side of the pouch-type battery cell, and a first side cover portion extending downward from one end of the first upper cover portion and enclosing an outer side of a receiving portion on one side of the enclosed pouch-type battery cell; the second cover includes a second upper cover portion configured to enclose an upper portion of an edge portion on an upper side of the pouch-type battery cell, and a second side cover portion extending downward from one end of the second upper cover portion and enclosing an outside of a housing portion on the other side of the enclosed pouch-type battery cell; 7. The battery pack according to claim 6, wherein the second upper cover part is spaced apart from the first upper cover part in a direction toward an edge part of an upper side of the pouch-type battery cell.

8. 8. The battery pack according to claim 7, wherein the first side cover portion and the pouch-type battery cell are adhered to each other, and the second side cover portion and the pouch-type battery cell are adhered to each other.

9. The battery pack according to claim 7 , wherein the second side cover portion has a longer vertical length than the first side cover portion.

10. 8. The battery pack of claim 7, wherein vent gas moves to a vent channel defined as a space between the first upper cover part and the second upper cover part through a gap between the first upper cover part and the second side cover part, and is discharged through a gap between the second upper cover part and the first side cover part.

11. The battery pack according to claim 10 , wherein the vent channel is bent by providing a bent portion in the first upper cover portion and the second upper cover portion.

12. The battery pack according to claim 1 , wherein one end of each of the two unit covers is bent toward each other.

13. 13. The battery pack of claim 12, wherein the two unit covers are stacked vertically on one another with the folded ends at least partially spaced apart from each other to allow the vent gas to be discharged.

14. The battery pack according to claim 12 , wherein each of the two unit covers is formed in a shape obtained by bending a single plate.

15. The battery pack according to claim 1 , wherein the cell cover comprises a mesh structure in the space between the two unit covers.

16. The battery pack according to claim 1 , wherein the cell cover has bent portions formed in the two unit covers to increase a movement path of gas discharged to the space between the two unit covers.

17. 2. The battery pack according to claim 1, further comprising a control module housed in an internal space of the pack case and configured to control charging and discharging of the pouch-type battery cells.

18. A motor vehicle comprising a battery pack according to any one of claims 1 to 17.

19. One or more battery modules are housed in an internal space of a pack case, A plurality of pouch-type battery cells; a module case that houses the pouch-type battery cell in an internal space; a cell cover including two unit covers at least partially spaced apart from each other, the cell cover being provided to at least partially enclose at least some of the pouch-type battery cells in the internal space of the module case, and configured to allow vent gas to be discharged into a space between the two unit covers; a battery module.

20. 20. A motor vehicle comprising the battery module of claim 19.

Images