Battery module, manufacturing method thereof, and battery pack

Abstract

The present invention relates to a battery module and a battery pack including the same that can reduce the number of parts, simplify the assembly process, improve production efficiency, and efficiently prevent heat transfer between cells. The battery module of the present invention includes a cell unit assembly including a plurality of cell units, and end frames that cover both ends of the cell unit assembly based on the longitudinal direction of the cell unit, and the cell unit includes a cell stack in which at least one cell is stacked, and a cell cover that surrounds both widthwise sides and the top of the cell stack.

Description

[Technical Field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0100240, filed August 10, 2022, Korean Patent Application No. 10-2022-0100241, filed August 10, 2022, and Korean Patent Application No. 10-2023-0062426, filed May 15, 2023, and all contents disclosed in the documents of said Korean patent applications are incorporated herein by reference.

[0002] The present invention relates to a battery module, a manufacturing method thereof, and a battery pack, and more particularly to a battery module of a secondary battery including a plurality of cells, a manufacturing method thereof, and a battery pack including the battery module. [Background technology]

[0003] In recent years, with the depletion of fossil fuels causing rising energy prices and increasing concerns about environmental pollution, the demand for environmentally friendly alternative energy sources has become an essential factor for future life. Therefore, research into various electricity production technologies such as solar, wind, and tidal power has continued, and there has also been great interest in power storage devices such as batteries to more efficiently use the electrical energy produced in this way.

[0004] Furthermore, with the increasing technological development and demand for battery-based electronic mobile devices and electric vehicles, the demand for batteries as an energy source is rapidly increasing, and as a result, much research is being conducted on batteries that can meet various demands.

[0005] Generally, batteries that store electrical energy can be divided into primary batteries and secondary batteries. While primary batteries are disposable, secondary batteries are rechargeable batteries made using materials that can undergo repeated oxidation and reduction processes between electric current and materials. That is, when an electric current causes a reduction reaction on a material, the power source is charged, and when an oxidation reaction on a material occurs, the power source is discharged. Electricity is generated by repeating this charge-discharge cycle.

[0006] Meanwhile, in recent years, as the need for large-capacity structures, including those used as energy storage sources, has increased, the demand for battery packs, which are made up of a plurality of secondary batteries or battery modules, has also increased, leading to an increase in the demand for battery modules. For example, to increase output and electrical storage capacity, secondary batteries installed in vehicles, ESSs (Energy Storage Systems), etc., are combined in multiple units to form battery modules, and multiple battery modules are combined to form battery packs.

[0007] Conventional battery modules can be manufactured by arranging multiple cells inside a frame and assembling them by closing the openings in the frame with stack plates and end plates.

[0008] 1, which shows a conventional battery module in its exploded state, each secondary battery is stacked to form a rectangular parallelepiped cell stack, and of the six sides of the rectangular parallelepiped, the sides from which the positive and negative leads do not protrude are covered (selectively as needed) with stack plates 2, and the two sides from which the positive and negative leads protrude are covered with bus bar frames 3. The positive and negative leads are electrically connected to terminals (negative and positive terminals) provided on the bus bar frame 3, respectively.

[0009] Then, a monoframe 4 formed in a cylindrical shape with both sides open is connected to cover the outside of the stack plate 2. After the monoframe 4 is fitted so that the bus bar frame 3 is exposed, an end plate 5 is connected to cover the bus bar frame 3. The end plates 5 and the monoframe 4 are made of metal, and are assembled by welding.

[0010] However, the conventional battery module 1 manufactured in this way has a structure in which all the cells are sealed, so if any one cell releases gas or generates a fire, it can lead to an explosion. In other words, the conventional battery module has a problem in that it cannot effectively prevent thermal propagation between the cells arranged inside.

[0011] In addition, there is a problem that the number of assembly steps is increased because the end plates 5 are joined after the bus bar frame 3 is joined. That is, the conventional battery module has a large number of parts, which makes assembly complicated and reduces the efficiency of the manufacturing process.

[0012] Therefore, in order to solve these problems, there is a need for a battery module and a battery pack including the same that can reduce the number of parts, simplify the assembly process, and efficiently prevent heat transfer between cells. Summary of the Invention [Problem to be solved by the invention]

[0013] The present invention has been made to solve the above problems, and an object of the present invention is to provide a battery module and a battery pack including the same that can reduce the number of parts, simplify the assembly process, improve production efficiency, and efficiently prevent heat transfer between cells. [Means for solving the problem]

[0014] The battery module of the present invention includes a cell unit assembly including a plurality of cell units, and end frames that cover both ends of the cell unit assembly based on the longitudinal direction of the cell unit, and the cell unit includes a cell stack in which at least one cell is stacked, and a cell cover that surrounds both widthwise sides and the top of the cell stack.

[0015] The cell cover may include a top plate that is placed on top of the cell stack and covers the top surface of the cell stack, and a side plate that is folded and connected to the top plate and covers the side surface of the cell stack.

[0016] The side plates can be positioned to contact the sides of the cell stack. The upper plate may have gas exhaust holes formed at both ends in the longitudinal direction. The cell stack can have up to three cells stacked together.

[0017] The cell cover may be made of a metal material. The cell cover can be positioned in contact with the end frame. The cell cover can be welded to the end frame at the portion where it comes into contact with the end frame.

[0018] The cell unit assembly may further include an insulating plate disposed between adjacent cell units and including an insulating material. The heat insulating plate can be arranged so that both ends thereof contact the end frames in the longitudinal direction.

[0019] A battery pack according to the present invention includes a battery module according to the present invention and a cooling plate disposed under a plurality of battery modules, and the cooling plate can cover the open lower portions of the battery modules.

[0020] The battery module according to the present invention may include a cell stack in which a plurality of cells are stacked along a longitudinal direction, with electrode leads protruding from both ends thereof, and an end frame in which end plates coupled to both ends of the cell stack and bus bar assemblies coupled to the end plates and electrically connecting the electrode leads of each cell are combined.

[0021] The end frames can be coupled such that the end plates are located closer to the cell stack than the bus bar assemblies. The end plates are formed with openings through which electrode leads pass, and the electrode leads can be connected to the bus bar assemblies through the openings.

[0022] The bus bar assembly may have a plurality of first holes drilled therein, and the electrode leads may pass through the first holes and be electrically connected to terminals provided on the bus bar assembly.

[0023] The bus bar assembly may further include a second hole spaced apart from the first hole and through which the electrode lead does not pass. The first hole may be formed to a size that allows an empty space to be provided after the electrode lead passes through.

[0024] The busbar assembly may be made of a synthetic resin material having a relatively lower rigidity, and the end plates may be made of a metal material having a relatively higher rigidity.

[0025] The bus bar assembly may have one side bent to form a bent portion, and the end plate may have an opposite side bent to form a bent portion.

[0026] A method for manufacturing a battery module according to the present invention may include a cell stack manufacturing step of manufacturing a cell stack by stacking cells, each having an electrode lead protruding from both ends thereof along a longitudinal direction, and a cell cover made of a metal material; an end frame manufacturing step of manufacturing an end frame, each having an end plate made of a metal material and a bus bar assembly connected to the end plate and electrically connecting the electrode leads of each cell; and a joining step of welding the end plate and the cell cover to join the end frame to the cell stack. [Effects of the Invention]

[0027] The battery module of the present invention includes a cell unit assembly including a plurality of cell units, and end frames that cover both ends of the cell unit assembly based on the longitudinal direction of the cell unit, and the cell unit includes a cell stack in which at least one cell is stacked, and a cell cover that surrounds both widthwise sides and the top of the cell stack.

[0028] This reduces the number of parts required to manufacture the battery module, improving the economy of the manufacturing process. In addition, the assembly process of the battery module can be simplified, thereby improving the efficiency of the manufacturing process. Furthermore, heat transfer between cell units can be effectively prevented, improving the stability of the battery module.

[0029] It also prevents secondary damage caused by gas leaks or flames leading to thermal propagation. Furthermore, the reduction in wasted space makes it possible to increase the energy density per unit volume of the battery module.

[0030] In addition, in conventional structures, a welding jig had to be set up separately when welding the busbar assembly and electrode lead, and when welding the monoframe and end plate after the electrode lead welding was completed (the welding jig had to be set up at least twice).However, in the present invention, the busbar assembly and electrode lead can be welded simultaneously when welding the cell cover and end plate, thereby reducing the number of times the welding jig needs to be set up and disassembled. The effects of the present invention are not limited to the above-mentioned examples, and various other effects may be included within the present specification. [Brief explanation of the drawings]

[0031] [Figure 1] 1A and 1B are a perspective view and an exploded perspective view schematically showing a conventional battery module. [Figure 2] 1 is a perspective view schematically showing a battery module according to a first embodiment of the present invention. [Figure 3] 1 is an exploded perspective view schematically showing a battery module according to a first embodiment of the present invention. [Figure 4] 1 is a perspective view schematically showing a cell cover of a battery module according to a first embodiment of the present invention. [Figure 5] 1 is a perspective view schematically showing an end frame of a battery module according to a first embodiment of the present invention. [Figure 6] FIG. 3 is a front view schematically showing the battery module shown in FIG. 2. [Figure 7] FIG. 4 is a perspective view schematically showing a battery module according to a second embodiment of the present invention. [Figure 8] FIG. 10 is a perspective view schematically showing a cell cover of a battery module according to a second embodiment of the present invention. [Figure 9] FIG. 10 is a perspective view schematically showing an end frame of a battery module according to a second embodiment of the present invention. [Figure 10] FIG. 10 is an exploded perspective view schematically showing a battery pack according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0032] The present invention will now be described in detail with reference to the accompanying drawings, so that those skilled in the art can easily understand and practice the preferred embodiments of the present invention. However, the present invention may be embodied in various different forms and is not limited to the following embodiments.

[0033] In order to clearly explain the present invention, detailed descriptions of parts that are not relevant to the explanation or related known technologies that may unnecessarily obscure the gist of the present invention will be omitted, and in this specification, when assigning reference symbols to components in each drawing, the same or similar reference symbols will be assigned to the same or similar components throughout the specification.

[0034] Furthermore, the terms and words used in this specification and claims should not be interpreted in a limited way to their ordinary or dictionary meanings, but should be interpreted in a way that is consistent with the technical idea of the present invention, based on the principle that inventors can appropriately define the concepts of terms in order to best explain their inventions.

[0035] First embodiment The present invention provides a battery module 10 as a first embodiment. FIG. 2 is a perspective view that schematically shows the battery module 10 according to the first embodiment of the present invention, and FIG. 3 is an exploded perspective view that schematically shows the battery module 10 according to the first embodiment of the present invention.

[0036] Referring to FIGS. 2 and 3, a battery module 10 according to a first embodiment of the present invention may include a cell unit assembly 100 and an end frame 200.

[0037] The cell unit assembly 100 of the battery module 10 according to the first embodiment of the present invention may include a plurality of cell units 110. Specifically, the battery module 10 may include the cell unit assembly 100 having a substantially rectangular parallelepiped shape including the plurality of cell units 110, and end frames 200 assembled to the front and rear surfaces of the cell unit assembly 100.

[0038] 2 and 3, the cell unit assembly 100 of the battery module 10 according to the first embodiment of the present invention may include four cell units 110. Therefore, the cell unit assembly 100 may be formed by stacking the four cell units 110 side by side.

[0039] FIG. 4 is a perspective view schematically showing the cell cover 120 of the battery module 10 according to the first embodiment of the present invention. As an example of a configuration for efficiently preventing heat transmission between cells, the cell unit 110 included in the cell unit assembly 100 of the battery module 10 according to the first embodiment of the present invention may include a cell stack 111 and a cell cover 120.

[0040] The cell stack 111 of the cell unit 110 can be formed by stacking at least one cell. Preferably, in order to prevent heat transfer between cells within the battery module 10, the cell stack 111 constituting the cell unit 110 may include three or less cells. That is, the number of cells constituting the cell stack 111 may be one or more and three or less.

[0041] The cell stack 111 according to the first embodiment of the present invention can be formed by stacking three cells side by side, where the cells may be pouch cells.

[0042] 4, the cell cover 120 of the cell unit 110 may be disposed to surround the cell stack 111. Specifically, it may be disposed to surround both widthwise sides and the top of the cell stack 111. Therefore, the cell stack 111 of the cell unit 110 may be disposed inside the cell cover 120 with both longitudinal ends and the bottom open.

[0043] The cell cover 120 of the cell unit 110 according to the first embodiment of the present invention may have a rectangular parallelepiped shape with three sides open. Therefore, the cell unit assembly 100 formed by stacking the roughly rectangular parallelepiped cell units 110 side by side may also have a roughly rectangular parallelepiped shape.

[0044] As an example of a configuration surrounding the cell stack 111 , the cell cover 120 of the cell unit 110 according to the first embodiment of the present invention can include an upper plate 121 and a side plate 122 .

[0045] The upper plate 121 of the cell cover 120 may cover the upper surface of the cell stack 111. Specifically, the upper plate 121 may be disposed on top of the cell stack 111 and cover the upper surface of the cell stack 111. In addition, the upper plate 121 may have a plate shape with a substantially rectangular cross section.

[0046] The side plates 122 of the cell cover 120 may cover the sides of the cell stack 111. Specifically, the side plates 122 may be bent and connected to both ends of the upper plate 121 in the width direction and disposed on both sides of the cell stack 111. In this case, the upper plate 121 and the side plates 122 may be connected to each other substantially perpendicularly. The cell cover 120 including the top plate 121 and the side plate 122 can be shared and used for various types of battery modules.

[0047] As an example of a configuration for fixing the cell stack 111, the side plate 122 of the cell cover 120 according to the first embodiment of the present invention can come into contact with the side of the cell stack 111. Specifically, the side plate 122 can be arranged so that the outer surface of the cell stack 111 and the inner surface of the side plate 122 come into contact with each other.

[0048] The cell cover 120 may include a pair of side plates 122, and a space may be formed between the pair of side plates 122. When the cell stack 111 made up of three cells is placed in this space in contact with the side plates 122, the cell stack 111 can be sandwiched between the pair of side plates 122. Therefore, the cell stack 111 can be easily fixed between the pair of side plates 122.

[0049] As an example of a configuration for preventing heat propagation between the cell stacks 111, the cell cover 120 of the cell unit 110 according to the first embodiment of the present invention may be made of a metal material. Specifically, the cell cover 120 may be made of a highly heat-resistant metal material.

[0050] Because the cell cover 120 is made of a metal material, it is possible to prevent flames and high-temperature gases generated in the cell stack 111 of one cell unit 110 from spreading to other adjacent cell units 110, allowing the cell unit 110 to withstand internal fire. In this case, the open ends of the cell cover 120 are blocked from spreading by the end frames 200, and the open bottom of the cell cover 120 is blocked from spreading by the cooling plate 20 of the battery pack 1. This will be described in detail later.

[0051] As an example of a configuration for delaying heat conduction between the cell units 110, the cell unit assembly 100 of the battery module 10 according to the first embodiment of the present invention may further include a heat insulating plate 130. That is, the heat insulating plate 130 may be selectively disposed between adjacent cell units 110 to reduce temperature, improve insulation performance, and cushion impacts during stacking.

[0052] The heat insulating plate 130 is disposed between adjacent cell units 110 and may contain a heat insulating material. The heat insulating plate 130 may have a plate shape with a substantially rectangular cross section and may have the same cross-sectional area as the side plate 122 of the cell cover 120. The heat insulating plate 130 may include a material with excellent heat insulating properties, such as silicon, aerogel, and the like.

[0053] As an example of a configuration for efficiently delaying heat conduction between cell units 110, the heat insulating plate 130 according to the first embodiment of the present invention may be arranged so that both ends thereof contact the end frame 200 in the longitudinal direction. Therefore, the heat insulating plate 130 prevents adjacent cell units 110 from contacting each other, thereby efficiently maintaining the heat insulating effect.

[0054] The cell unit assembly 100 of the battery module 10 according to the first embodiment of the present invention includes the heat insulating plate 130, thereby making it possible to efficiently delay heat conduction between the cell units 110.

[0055] Meanwhile, the cell unit 110 is provided to have an overall hexahedral shape as a cell stack 111 including one or more cells and a cell cover 120 combined together, and a positive electrode lead 11 and a negative electrode lead 12 may protrude from each cell stack 111 on both sides.

[0056] The end frame 200 may be provided by integrally combining a busbar assembly 210, which electrically connects the electrode leads (positive and negative leads) of each cell stack 111 to terminals 213 and 214, and an end plate 220 for protecting and finishing the cell stack 111 (especially the electrode lead portion) from external physical impact.

[0057] FIG. 5 is a perspective view schematically showing an end frame 200 of the battery module 10 according to the first embodiment of the present invention, and FIG. 6 is a front view schematically showing the battery module 10 shown in FIG.

[0058] As an example of a configuration for fixing the cell unit assembly 100, the battery module 10 according to the first embodiment of the present invention can include an end frame 200.

[0059] The end frames 200 of the battery module 10 can cover both ends of the cell unit assembly 100. Specifically, they can cover both ends of the cell unit assembly 100 based on the longitudinal direction of the cell units 110. Therefore, the end frames 200 can prevent the spread of fire through the open ends of the cell unit assembly 100.

[0060] Referring to FIG. 5, the end frame 200 according to the first embodiment of the present invention is arranged so that the end plate 220 is positioned on the inside and can be coupled to be positioned closer to the cell stack 111 than the bus bar assembly 210.

[0061] Thus, the end plates 220 may be formed with a plurality of openings 221 through which the electrode leads 11 and 12 pass, so that the positive electrode leads 11 and the negative electrode leads 12 protruding from the individual cell stacks 111 can pass through the end plates 220 without detouring and extend to the bus bar assembly 210. The number, size, and arrangement of the openings 221 may be determined according to the positions and number of the electrode leads 11 and 12. Therefore, the electrode leads 11 and 12 can be connected to the bus bar assembly 210 through the openings 221.

[0062] The bus bar assembly 210 is also provided with a plurality of first holes 211 through which the electrode leads 11 and 12 pass, and the electrode leads 11 and 12 may pass through the first holes 211 and be electrically connected to terminals 213 and 214 provided on the bus bar assembly 210. That is, the ends of the electrode leads 11 and 12 may be connected to the terminals 213 and 214 by welding or soldering.

[0063] Meanwhile, second holes 212, which are spaced apart from the first holes 211 and through which the electrode leads 11 and 12 do not penetrate, may be further formed separately from the first holes 211. The second holes 212 allow gas and flame to leak to the outside to prevent explosion when gas leakage or fire occurs in the cell, and may be provided to adjust the direction of leakage.

[0064] 6, four first holes 211 may be formed in the bus bar assembly 210 of the end frame 200 according to the first embodiment of the present invention. In this case, the first holes 211 may be formed to a size that allows an empty space to be left after the electrode leads 11 and 12 have passed through so that gas or flame can also be ejected into the first holes 211 when gas or flame is generated. Furthermore, the first holes 211 may be formed in portions of the bus bar assembly 210 corresponding to portions where the cell units 110 are arranged.

[0065] That is, the bus bar assembly 210 according to the first embodiment of the present invention may be formed with a first hole 211 and a second hole 212 to prevent the cell unit 110 from exploding.

[0066] The first holes 211 and the second holes 212 may be formed in various shapes to facilitate gas discharge, and the first holes 211 and the second holes 212 of the bus bar assembly 210 according to the first embodiment of the present invention may be formed to have a substantially rectangular cross section. Also, the first holes 211 and the second holes 212 may be formed to penetrate from one side of the bus bar assembly 210 to the opposite side.

[0067] The first hole 211 and the second hole 212 are formed in the bus bar assembly 210 of the end frame 200 according to the first embodiment of the present invention, thereby preventing an explosion due to an increase in pressure inside the cell unit 110. In addition, secondary damage caused by gas leakage or fire leading to thermal runaway can be prevented.

[0068] Meanwhile, the bus bar assembly 210 may be made of a synthetic resin material having a relatively low rigidity so that the remaining portions of the bus bar assembly 210, excluding the terminals 213 and 214, have electrical insulation properties and are relatively light in weight. In contrast, the end plates 220 may be made of a metal material having a relatively high rigidity so that the end plates 220 can protect the cell stack from external loads and impacts.

[0069] Two end frames 200 are coupled to cover both sides of the cell stack 111 where the electrode leads 11 and 12 protrude, and in this case, the end plates 220 may be coupled to face the electrode leads 11 and 12.

[0070] Although either the end plate 220 or the bus bar assembly 210 may be connected to the cell stack via other connecting means, this embodiment provides a structure that allows the cell stack and the end frame to be firmly connected.

[0071] That is, the cell cover 120 provided in this embodiment is manufactured from a metal material that can be welded, and the end plate 220 can be joined by welding the parts that contact the cell cover 120 in an abutting or temporarily fixed state.

[0072] In this case, as shown in FIG. 5, one side of the busbar assembly 210 may be bent to form a bent portion 215, and the end plate 220 may be bent at the side opposite to the bent portion 215 to form a bent portion 222 so that the cell stack can be fitted into the end frame and temporarily fixed before welding.

[0073] The end frame 200 of the battery module 10 according to the first embodiment of the present invention may further include components such as bus bars for electrical connection between the cell units 110 .

[0074] As an example of a method for connecting the cell unit assemblies 100 and the end frames 200, the battery module 10 according to the first embodiment of the present invention can use welding.

[0075] The cell cover 120 of the cell unit 110 included in the cell unit assembly 100 may be arranged to contact the end frame 200. Specifically, both longitudinal ends of the cell cover 120 may contact the end frame 200. In this case, the contacting portions of the cell cover 120 and the end frame 200 may be joined to each other by welding.

[0076] Therefore, both ends of the cell cover 120 are arranged to contact the end frame 200 and the contacting portions are welded, so that the cell unit assembly 100 can be fixed and coupled to the end frame 200 .

[0077] When the cell unit assembly 100 is joined to the end frame 200 by welding, both open longitudinal sides of the cell unit 110 can be covered by the end frame 200 .

[0078] As described above, the battery module 10 can include a cell unit assembly 100 and an end frame 200, and the cell unit assembly 100 can include a plurality of cell units 110 and a heat insulating plate 130. Furthermore, each cell unit 110 can include a cell stack 111 and a cell cover 120 surrounding it.

[0079] As described above, the battery module 10 according to the first embodiment of the present invention is made up of a relatively small number of parts, thereby improving the economy of the manufacturing process, and the simple assembly process improves the efficiency of the manufacturing process. Furthermore, the battery module 10 prevents explosion of the cell units 110 due to pressure buildup, and also prevents or delays the spread of flames and heat propagation between the cell units 110, thereby improving the stability of the battery module 10. Furthermore, the cell units 110 of a fixed shape allow the manufacture of battery module structures with various capacities and sizes.

[0080] A method for manufacturing the battery module 10 according to the first embodiment of the present invention will be described in detail below. The manufacturing method of the battery module 10 can include a step of manufacturing a cell stack, a step of manufacturing an end frame, and a bonding step.

[0081] In the cell stack manufacturing step, the cell unit 110 can be manufactured by stacking the cell stack 111 having electrode leads 11, 12 protruding from both ends along the longitudinal direction and a cell cover 120 made of a metal material.

[0082] More specifically, an electrode assembly in which a positive electrode, a separator, and a negative electrode are repeatedly stacked is placed in a pouch together with an electrolyte, and individual cells are manufactured through charge / discharge processes, aging processes, test processes, etc. using a known cell manufacturing method. One or more cells are then attached with a cell cover 120 and stacked to manufacture the cell unit 110.

[0083] In this case, the cell has a positive electrode lead 11 protruding from one end of the pouch and a negative electrode lead 12 protruding from the other end, and the cell unit 110, in which one or more cells and cell covers 120 are stacked, can be manufactured to have an overall hexahedral shape.

[0084] The end frame may be manufactured such that the end plate 220 made of a metal material and the bus bar assembly 210 made of a synthetic resin material are integrally formed.

[0085] The end plate 220 made of a metal material can be manufactured by a metal processing method such as casting, forging, cutting, rolling, milling, etc. Then, the previously manufactured end plate 220 can be integrally manufactured with the bus bar assembly 210 by an insert molding method in which a polymer resin is injected onto the outside of the end plate 220 after being inserted into an injection mold.

[0086] The polymer resin injected onto the end plate 220 is cooled to form the outer appearance of the bus bar assembly 210, and after cooling, the terminals 213, 214, etc. may be further attached to complete the bus bar assembly 210.

[0087] Alternatively, the end frame 200 may be manufactured by other manufacturing methods such as integral molding of a metal material and a synthetic resin material, and if the end plate 220 is manufactured using a synthetic resin material instead of a metal material, it may be manufactured using a method such as two-shot molding, in which different types of synthetic resin materials are manufactured into one unit. Of course, the end frame 200 can also be manufactured by manufacturing the end plate 220 using a metal material, separately manufacturing the bus bar assembly 210 using a synthetic resin material, and then bonding the two together with an adhesive.

[0088] Then, a joining step may be performed in which the end plate 220 and the cell cover 120 are welded together to join the end frame 200 to the cell unit assembly 100 .

[0089] The end plate 220 and the cell cover 120 provided in this embodiment are made of a metal material that can be welded to each other, and therefore, the end plate 220 can be joined to the cell cover 120 by welding them together while the end plate 220 is in contact with the cell cover 120.

[0090] In this case, even if there is only one cell cover 120, it is possible to weld it to the end plate 220, but it is preferable that the cell cover 120 is provided attached to each cell stack 111 so that welding can be performed as continuously as possible along the edge of the end plate 220.

[0091] Therefore, in the conventional structure, the end plate is positioned on the outermost side and the bus bar assembly and the end plate are individually connected to each other. However, in the present invention, the end plate 220 and the bus bar assembly 210 are manufactured integrally, and then the end plate 220 is fixed to the cell stack, thereby shortening the assembly process.

[0092] In the present invention having the above-described configuration, the end plate 220 and the bus bar assembly 210 are combined and provided as a single end frame 200, which simplifies the assembly process and further increases production efficiency compared to the conventional structure in which the bus bar assembly 210 and the end plate 220 are attached separately. In addition, the monoframe and stack plate are eliminated from the conventional structure, further simplifying the assembly process and reducing weight.

[0093] The end frame 200 is coupled such that the end plate 220 is positioned closer to the cell stack than the bus bar assembly 210, and the fixing points of the end plate 220 and the cell stack are positioned relatively inward, eliminating wasted space and further increasing the energy density per volume of the battery module.

[0094] An opening hole 221 is formed in the end plate 220, and a first hole 211 and a second hole 212 are formed in the busbar assembly 210, so that even if a gas leak or flame occurs in the cell unit assembly 100, the gas is discharged to the outside through the opening hole 221, the first hole 211, and the second hole 212, thereby preventing problems that could lead to thermal runaway.

[0095] One or more cell covers 120 are stacked on the cell unit 110 together with the cell stack 111, thereby increasing the rigidity of the cell unit 110 itself. Furthermore, the cell covers 120 and the end plates 220 are each manufactured from metal materials and joined by welding, which simplifies the assembly process.

[0096] For example, in conventional structures, a welding jig was required to be set up separately when welding the busbar assembly and the electrode lead, and when welding the monoframe and the end plate after the electrode lead welding was completed (the welding jig was required to be set up at least twice).However, in the present invention, when welding the cell cover 120 and the end plate 220, welding the busbar assembly 210 and the electrode leads 11, 12 can also be performed simultaneously, thereby reducing the number of times the welding jig needs to be set up and disassembled.

[0097] Second embodiment The present invention provides another type of battery module 10' as a second embodiment. The battery module 10' according to the second embodiment of the present invention may differ from the battery module 10 according to the first embodiment in the number of cells forming the cell stack, the number of cell units 110' forming the cell unit assembly 100', the shape of the end frame 200', and the assembly method of the cell cover 120' and the end frame 200'.

[0098] Hereinafter, detailed description of the same configuration as that of the battery module 10 according to the first embodiment of the present invention will be omitted. FIG. 5 is a perspective view schematically showing a battery module 10' according to a second embodiment of the present invention.

[0099] A battery module 10' according to the second embodiment of the present invention may include a cell unit assembly 100' and an end frame 200'. Here, the cell unit assembly 100' may include 12 cell units 110'.

[0100] FIG. 6 is a perspective view schematically showing a cell cover 120' of a battery module 10' according to a second embodiment of the present invention. The cell unit 110' according to the second embodiment of the present invention may include a cell and a cell cover 120'. Specifically, the cell unit 110' may include one cell and a cell cover 120' surrounding the cell. Here, the cell may be arranged such that an extra space is formed between the outer surface of the cell and the inner surface of the cell cover 120'.

[0101] The cell cover 120' may include an upper plate 121' and a side plate 122' that is bent and connected to the upper plate 121'. In this case, the upper plate 121' may cover the top of the cell, and the side plate 122' may cover both sides of the cell. As in the first embodiment, the cell cover 120' has an approximately rectangular parallelepiped shape with three open sides.

[0102] As an example of a configuration for preventing explosion of the cell unit 110', a gas exhaust hole 123 may be formed in the upper plate 121' of the cell cover 120' according to the second embodiment of the present invention.

[0103] 6, the gas exhaust holes 123 may be formed at both ends of the upper plate 121′ in the longitudinal direction. Therefore, two gas exhaust holes 123 may be formed in the upper plate 121′ of the cell cover 120′ according to the second embodiment of the present invention.

[0104] The gas exhaust holes 123 may be formed in various shapes to facilitate gas exhaust, and the gas exhaust holes 123 of the upper plate 121′ according to the second embodiment of the present invention may be formed to have an approximately circular cross section.

[0105] The gas exhaust holes 123 may be formed to penetrate from one side of the upper plate 121' facing the cells to the other side of the opposite side, so that high-temperature gas generated by ignition of the cells in the cell unit 110' can be exhausted from inside the cell unit 110' to the outside of the cell unit 110'.

[0106] The upper plate 121' of the cell cover 120' according to the second embodiment of the present invention has a gas exhaust hole 123 formed therein, which can prevent an explosion due to an increase in pressure inside the cell unit 110'. In addition, secondary damage caused by gas leakage or fire leading to thermal runaway can be prevented.

[0107] FIG. 7 is a perspective view schematically showing an end frame 200' of a battery module 10' according to a second embodiment of the present invention. As an example of a configuration for fixing the cell unit assembly 100', the battery module 10' according to the second embodiment of the present invention may include an end frame 200'. In addition, since the cell unit assembly 100' according to the second embodiment includes more cell units 110' than the first embodiment, the horizontal length of the end frame 200' according to the second embodiment may be longer than the horizontal length of the end frame 200 according to the first embodiment.

[0108] As an example of a method for connecting the cell unit assembly 100' and the end frame 200', the cell unit assembly 100' according to the second embodiment of the present invention can be sandwiched between the bent portion 222' of the end plate 220' and the bent portion 215' of the busbar assembly 210'.

[0109] A space may be formed between the bent portion 222' and the bent portion 215', which extend parallel to each other. In this case, the cell unit assembly 100' may have the same height as the height of this space. Therefore, when both ends are arranged to contact the end plates 220' of the end frame 200', the cell unit assembly 100' is sandwiched in the space between the bent portion 222' and the bent portion 215', and the cell unit assembly 100' may be fixed to the end frame 200'.

[0110] The battery module 10' according to the second embodiment of the present invention can prevent explosion of the cell units 110' due to pressure buildup and prevent or delay the spread of fire between the cell units 110', thereby improving the stability of the battery module 10' and simplifying the connection between the cell unit assemblies 100' and the end frames 200', thereby improving the efficiency of the manufacturing process of the battery module 10'. In addition, the cell units 110' of a fixed shape can be used to manufacture battery module structures with various capacities and sizes.

[0111] Third embodiment The present invention provides a battery pack 1 as a third embodiment. FIG. 8 is an exploded perspective view schematically showing a battery pack 1 according to a third embodiment of the present invention.

[0112] The battery pack 1 according to the third embodiment of the present invention can include a battery module 10 and a cooling plate 20. In order to provide a large amount of electrical energy, a battery pack 1 comprising an assembly of a plurality of battery modules 10 can be used. Therefore, the battery pack 1 according to the third embodiment of the present invention can include a plurality of the battery modules 10 according to the first embodiment. Specifically, the battery pack 1 can include six battery modules 10.

[0113] The cooling plate 20 of the battery pack 1 may be disposed below the plurality of battery modules 10. In this case, the cooling plate 20 may have a plate shape with a substantially rectangular cross section, and the cooling plate 20 may cover the open bottom of the battery modules 10.

[0114] The cooling plate 20 may further include a cooling channel through which cooling water passes for cooling. Therefore, the cooling plate 20 can efficiently reduce the temperature of the cells arranged inside through the open bottom of the battery module 10.

[0115] The battery pack 1 according to the third embodiment of the present invention may further include a case for covering the upper part of the battery modules 10, and additional components for electrically connecting the battery modules 10 to each other.

[0116] The battery pack 1 according to the third embodiment of the present invention is merely an example, and the effects of the present invention can be achieved by battery packs of various structures including battery modules of other types or different numbers of battery modules.

[0117] Although the present invention has been described above using limited embodiments and drawings, the present invention is not limited thereby, and various implementations are possible within the scope equivalent to the technical concept of the present invention and the claims described below by a person having ordinary skill in the art to which the present invention pertains. [Explanation of symbols]

[0118] 1: Battery pack 10, 10': Battery module 11: Positive lead 12: Negative electrode lead 20: Cooling plate 100, 100': Cell unit assembly 110, 110': Cell unit 111: Cell stack 120, 120': Cell cover 121, 121': Upper plate 122, 122': Side plate 123: Gas exhaust hole 130: Heat insulating board 200, 200': End frame 210, 210': Busbar assembly 211: 1st hole 212: 2nd hole 213, 214: Terminals 215, 215': Bending section 220, 220': End plate 221: Opening hole 222, 222': Folded part

Claims

1. a cell unit assembly including a plurality of cell units; end frames that cover both ends of the cell unit assembly with respect to the longitudinal direction of the cell units; Including, The cell unit comprises: a cell stack in which at least one cell is stacked; a cell cover surrounding both widthwise sides and an upper portion of the cell stack; a battery module including:

2. The cell cover is an upper plate disposed on the upper portion of the cell stack and covering the upper surface of the cell stack; The battery module of claim 1 , further comprising: a side plate bent from the top plate and connected to the top plate to cover a side surface of the cell stack.

3. The side panel is The battery module according to claim 2 , wherein the battery module is disposed so as to contact a side surface of the cell stack.

4. The upper plate is The battery module according to claim 2 , wherein gas exhaust holes are formed at both ends of the battery module in the longitudinal direction.

5. The cell stack is The battery module according to claim 1 , comprising one to three of the cells.

6. The cell cover is The battery module according to claim 1, wherein the battery module is made of a metal material.

7. The cell cover is The battery module according to claim 1 , wherein the battery module is disposed so as to be in contact with the end frame.

8. The cell cover is 8. The battery module according to claim 7, wherein the portions in contact with the end frames are welded.

9. The cell unit assembly is The battery module according to claim 1 , further comprising an insulating plate disposed between adjacent cell units and including an insulating material.

10. The heat insulating board is The battery module according to claim 9 , wherein both ends of the battery module are in contact with the end frames in the longitudinal direction.

11. The battery module according to any one of claims 1 to 10; a cooling plate disposed below the plurality of battery modules; Including, The battery pack, wherein the cooling plate covers the open bottom of the battery module.

12. A battery module, a cell stack in which a plurality of cells are stacked, each having an electrode lead protruding from both ends along the longitudinal direction; and an end frame including end plates coupled to both ends of the cell stack and bus bar assemblies coupled to the end plates and electrically connecting electrode leads of each cell; a battery module including:

13. The battery module of claim 12 , wherein the end frame is coupled such that the end plate is positioned closer to the cell stack than the bus bar assembly.

14. The battery module of claim 13 , wherein the end plates have openings through which the electrode leads pass, and the electrode leads are connected to a bus bar assembly through the openings.

15. 15. The battery module of claim 14, wherein the bus bar assembly has a plurality of first holes, and the electrode leads pass through the first holes and are electrically connected to terminals provided on the bus bar assembly.

16. The battery module of claim 15 , wherein the bus bar assembly further includes a second hole spaced apart from the first hole and through which the electrode lead does not pass.

17. The battery module of claim 15 , wherein the first holes are formed to have a size that leaves a space after the electrode leads pass through.

18. The battery module of claim 13 , wherein the bus bar assembly is made of a synthetic resin material having a relatively low rigidity, and the end plates are made of a metal material having a relatively high rigidity.

19. The battery module of claim 12 , wherein one side of the bus bar assembly is bent to form a bent portion, and the end plate is bent at a side opposite to the bent portion to form a bent portion.

20. A method for manufacturing a battery module, comprising: a cell stack manufacturing step of manufacturing a cell stack by stacking cells having electrode leads protruding from both ends along the longitudinal direction and cell covers made of a metal material; an end frame manufacturing step of manufacturing an end frame in which an end plate made of a metal material and a bus bar assembly coupled to the end plate and electrically connecting electrode leads of each cell are combined; a joining step of joining the end frame to the cell stack by welding the end plate and the cell cover; A method for manufacturing a battery module, comprising:

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