Battery Module

Abstract

The present invention relates to a battery module in which a first insulating part in the form of an insulating pad is arranged between individual battery cells, and a second insulating part made of a thermal expansion material is arranged between individual electrode leads, thereby blocking the transfer of heat and high-temperature particles between the individual battery cells and the bus bar plate, thereby effectively reducing the risk of fire and explosion.

Description

[Technical field]

[0001] This application claims priority based on Korean Patent Application No. 10-2021-0150268 dated November 4, 2021, and all contents disclosed in the documents of the Korean patent application are incorporated herein by reference.

[0002] The present invention relates to a battery module, and more specifically, to a battery module in which a first insulating part in the form of an insulating pad is arranged between individual battery cells, and a second insulating part made of a thermal expansion material is arranged between a plurality of individual electrode leads, thereby blocking the transfer of heat and high-temperature particles between the individual battery cells and the bus bar plate, thereby effectively reducing the risk of fire and explosion. [Background technology]

[0003] As environmental concerns grow, efforts to reduce carbon emissions are spreading around the world. In order to reduce carbon emissions, the production of automobiles with combustion engines that are powered by burning fossil fuels is decreasing, while the production of electric vehicles that are powered by electricity is increasing.

[0004] Demand for secondary batteries, which are installed in these electric vehicles to store electricity, is increasing. Meanwhile, as the use of personal mobile devices such as smartphones and tablet PCs has become commonplace, the demand for secondary batteries that supply electricity to these mobile devices is also increasing.

[0005] Due to the increasing demand for these secondary batteries, research and development into secondary batteries has been actively carried out.

[0006] At this time, in order to improve the capacity and efficiency of secondary batteries, there is an increasing demand for battery packs with a multi-module structure in which battery modules are assembled in which a plurality of secondary batteries are connected in series / parallel.

[0007] When constructing a battery pack by connecting multiple battery cells in series / parallel, a commonly used method is to construct a battery module consisting of at least one battery cell, and then use this at least one battery module to add other components to construct the battery pack.

[0008] In constructing a frame to protect the inside of each battery module, a battery module formed with a U-frame structure has been developed that can improve the quality of parts and increase space utilization.

[0009] These battery modules having a U-frame structure can be configured to include a battery cell stack in which a number of battery cells are stacked, a lower frame with a U-shaped structure formed on the bottom and both sides and covering the lower surface and both sides of the battery cell stack, and an upper frame covering the upper surface of the battery cell stack.

[0010] Meanwhile, when power is supplied to a battery cell stack, heat is inevitably generated, and if the heat generation cannot be effectively regulated, the efficiency of the battery cell stack may rapidly decrease, and in some cases, there may be a risk of fire or explosion.

[0011] These fires and explosions typically start in one of the battery cells, spreading heat and hot particles to adjacent battery cells.

[0012] In order to prevent these fires and explosions, Patent Document 1 discloses a battery module in which, as shown in FIG. 1, a heat insulating pad 60 is placed in the gap formed between adjacent battery cells 11 to prevent heat or particles from transferring to the adjacent battery cells 11.

[0013] As shown in the figure, assuming that overheating occurs in the first battery cell 11 arranged on the far left, the heat and high-temperature particles generated in the first battery cell 11 can be prevented from moving to the other battery cells 11 arranged to the right of the fourth battery cell 11 by the insulating pad 60 arranged between the fourth battery cell 11 and the fifth battery cell 11.

[0014] However, according to the configuration described in Patent Document 1, the space between the front end or rear end of the individual battery cell 11 and the bus bar plate 50 is formed so as to be an open space that is not blocked across the first battery cell 11 and the 24th battery cell 11.

[0015] Therefore, the heat and high-temperature particles generated in the first battery cell 11 can diffuse throughout these open spaces, so the effectiveness of using the insulating pad 60 to prevent fires and explosions is limited to being halved. [Prior art documents] [Patent documents]

[0016] [Patent Document 1] Korean Patent Publication No. 10-2020-0106378 Summary of the Invention [Problem to be solved by the invention]

[0017] The present invention has been devised to solve the problems of the conventional technology described above, and has as its first object to provide a battery module that effectively reduces the risk of fire and explosion by arranging a first insulation part in the form of an insulation pad between individual battery cells and a second insulation part made of a thermal expansion material between a plurality of individual electrode leads, thereby blocking the transfer of heat and high-temperature particles between the individual battery cells and the bus bar plate.

[0018] A second object of the present invention is to provide a battery module that can effectively maintain cooling performance when operating within a normal temperature range, by forming the second insulation portion to have a smaller volume than the space formed between the individual battery cell and the bus bar plate when the second insulation portion is not expanded, and configuring the space formed between the individual battery cell and the bus bar plate to function as an air passage.

[0019] The object of the present invention is not limited to the object mentioned above, and other objects and advantages of the present invention not mentioned can be understood from the following description and can be more clearly understood from the embodiments of the present invention. In addition, it is easy to understand that the object and advantages of the present invention can be realized by the means and combinations thereof described in the claims. [Means for solving the problem]

[0020] A battery module according to one embodiment of the present invention includes a battery cell stack formed by stacking a first battery cell and a second battery cell arranged adjacent to each other; a plurality of electrode leads electrically connected to the first battery cell and the second battery cell, respectively; a first insulation portion arranged between the first battery cell and the second battery cell; and a second insulation portion arranged between the plurality of electrode leads; and the second insulation portion is made of a material having a thermal expansion coefficient greater than that of the first insulation portion.

[0021] The second insulating portion may be made of a thermally expandable material that increases in volume when a predetermined critical temperature is reached.

[0022] The thermally expandable material may include an expanding paper.

[0023] The first heat insulating portion may be made of a silicon-based material.

[0024] The battery module may further include a bus bar plate electrically connecting the plurality of electrode leads.

[0025] The second heat insulating portion may be configured in a pad shape with one side surface fixed to the bus bar plate.

[0026] The second insulating section may be disposed in a state separated from the first insulating section before expansion starts.

[0027] When the second insulating part reaches the predetermined critical temperature and starts to expand, the other side of the second insulating part may come into contact with the first insulating part.

[0028] The second insulating portion may be disposed in a state separated from each of the plurality of electrode leads before expansion starts.

[0029] When the second insulating portion reaches the predetermined critical temperature and starts to expand, both sides of the second insulating portion may come into contact with the electrode leads, respectively.

[0030] When the expansion of the second insulating portion is completed, the spaces formed between the multiple electrode leads may be closed. Effect of the Invention

[0031] The battery module according to the present invention has a first insulation part in the form of an insulating pad disposed between individual battery cells, and a second insulation part made of a thermal expansion material disposed between a plurality of individual electrode leads, thereby blocking the transfer of heat and high-temperature particles between the individual battery cells and the bus bar plate, thereby effectively reducing the risk of fire and explosion.

[0032] In addition, in the battery module according to the present invention, the second insulation part is formed to have a smaller volume than the space formed between the individual battery cell and the bus bar plate when not expanded, and the space formed between the individual battery cell and the bus bar plate is configured to function as an air passage, thereby effectively maintaining cooling performance when operating within a normal temperature range.

[0033] The above-mentioned effects and specific effects of the present invention will be described in conjunction with the following description of the preferred embodiment of the invention. [Brief description of the drawings]

[0034] [Figure 1] 1 is a schematic cross-sectional view of a battery cell according to the prior art; [Diagram 2] 1 is an exploded perspective view of a battery module according to an embodiment of the present invention; [Diagram 3] 3 is a schematic cross-sectional view of the battery module shown in FIG. 2. [Figure 4] 3 is a rear perspective view showing a state in which a second heat insulating portion is disposed on the first bus bar plate shown in FIG. 2. FIG. [Diagram 5] FIG. 4 is a partially enlarged view of FIG. 3, showing a state in which the second insulating portion is not expanded. [Figure 6] FIG. 4 is a partially enlarged view of FIG. 3, illustrating a process in which the second insulating part expands upon reaching a critical temperature. [Figure 7] FIG. 4 is a partially enlarged view of FIG. 3, illustrating a process in which the second insulating part expands upon reaching a critical temperature. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] The above-mentioned objects, features and advantages will be described in detail below with reference to the accompanying drawings, so that a person having ordinary skill in the art to which the present invention pertains can easily implement the technical idea of ​​the present invention. In describing the present invention, if a detailed description of a known technology according to the present invention is deemed to obscure the gist of the present invention, the detailed description will be omitted. Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings. The same reference numerals in the drawings are used to indicate the same or similar components.

[0036] Although the terms "first", "second", etc. are used to indicate various components, it is understood that these components are not limited by these terms. These terms are used merely to distinguish one component from another, and it is understood that a first component may also be a second component unless otherwise specified.

[0037] Throughout the specification, unless otherwise specified to the contrary, each element may be singular or plural.

[0038] Hereinafter, when an arbitrary structure is arranged on the "top (or bottom)" of a component or "above (or below)" a component, it means that the arbitrary structure is not only arranged in contact with the upper surface (or lower surface) of the component, but also that other structures may be interposed between the component and the arbitrary structure arranged on (or below) the component.

[0039] In addition, when a component is described as being "coupled," "coupled," or "connected" to another component, it should be understood that the components may be directly coupled or connected to each other, but that there may be other components "intervening" between each component, or each component may be "coupled," "coupled," or "connected" via other components.

[0040] As used herein, singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "include" should not be interpreted as including all of the components or steps described in the specification, but should be interpreted as including some components or steps that may not be included, or may further include additional components or steps.

[0041] In addition, the singular expressions used in this specification include the plural expressions unless the context clearly indicates otherwise. The terms "comprise" or "include" in this application should not be interpreted as including all of the components or steps described in the specification, but should be interpreted as including some components or steps that may not be included, or may further include additional components or steps.

[0042] In the entire specification, "A and / or B" means A, B, or A and B, unless otherwise specified, and "C to D" means C or more and D or less, unless otherwise specified.

[0043] Hereinafter, the present invention will be described with reference to the drawings showing the configuration of a battery module 1 according to an embodiment of the present invention.

[0044] [General structure of battery module] Hereinafter, the overall structure of a battery module 1 according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0045] FIG. 2 is an exploded perspective view of a battery module 1 according to one embodiment of the present invention.

[0046] Referring to FIG. 2 , a battery module 1 according to an embodiment of the present invention may include a frame 200 including a lower frame 210 and an upper frame 220, a battery cell stack 100 housed inside the frame 200, a pair of end plates 300 coupled to an open front surface and an open rear surface of the frame 200, an insulating cover 400 disposed between the end plate 300 and the frame 200 to provide insulation between the end plate 300 and the frame 200, and a bus bar plate 500 disposed between the insulating cover 400 and the battery cell stack 100.

[0047] As shown in the figure, a plurality of battery cells 110 can be closely arranged in a stacked state to form a battery cell stack 100.

[0048] As described later, a first heat insulating section 600 in the form of a heat insulating pad may be disposed between adjacent battery cells 110. The first heat insulating section 600 may be disposed with one to several battery cells 110 interposed therebetween. In the embodiment shown in FIG. 3, a structure in which the first heat insulating section 600 is disposed with four battery cells 110 interposed therebetween is illustrated.

[0049] The frame 200 can include a lower frame 210 having a structure that encases the lower surface and both side surfaces of the battery cell stack 100 so as to accommodate the battery cell stack 100 therein, and an upper frame 220 that is arranged on the upper surface side of the battery cell stack 100, so as to form a case or housing for the battery module 1.

[0050] As shown in the figure, the lower frame 210 may include a bottom frame 220 constituting the bottom surface, and a pair of side frames 210 constituting two side walls. For example, the bottom frame 220 and the pair of side frames 210 may be integrally formed by pressing a metal plate having a predetermined strength.

[0051] The upper frame 220 serves to cover the upper surface of the battery cell stack 100, and like the lower frame 210, may be formed of a metal plate having a certain strength.

[0052] The upper frame 220 may be assembled to the lower frame by being coupled to the upper ends of the pair of side frames 210 .

[0053] The bottom surfaces of both ends of the upper frame 220 and the upper ends of the side frames 210 can be joined by laser welding (L).

[0054] The plurality of battery cells 110 may be pouch-type battery cells, and may be bidirectional battery cells in which the positive and negative electrode leads constituting the electrode leads 111 protrude in opposite directions.

[0055] The electrode leads 111 of the multiple battery cells 110 may be electrically connected using a bus bar plate 500 so that the multiple battery cells 110 are connected in series or in parallel depending on the desired output and capacity of the battery module 1. Depending on the specifications of the applied product, the battery cell stack 100 may further include a cartridge that houses the battery cells 110, a buffer member, a cooling means, or the like.

[0056] Based on the illustrated state, the front and rear surfaces of the frame 200 are open, and the electrode leads 111 of the battery cell stack 100 may be exposed to the outside through the open front and rear surfaces.

[0057] A pair of insulating covers 400, arranged to face the electrode leads 111, a pair of end plates 300, and a pair of bus bar plates 500 may be arranged on the open front and rear surfaces of the frame 200.

[0058] The end plate 300 may be mounted on the frame 200 together with the battery cell stack 100 in a state in which the end plate 300 is connected to the battery cell stack 100 and the bus bar plate 500. Alternatively, the battery cell stack 100 and the bus bar plate 500 may first be mounted on the frame 200, and the end plate 300 may be coupled to the frame 200 in a state in which the upper frame 220 is coupled to the frame 200.

[0059] The end plate 300 may be manufactured by casting using a metal material, preferably an iron or alloy material, so as to maintain a predetermined strength and rigidity.

[0060] The insulating cover 400 is disposed between the end plate 300 and the bus bar plate 500 and serves to physically separate and insulate at least the end plate 300 and the bus bar plate 500, and may be configured to include a first insulating cover 420 disposed on the front side and a second insulating cover 420 disposed on the rear side.

[0061] Therefore, the insulating cover 400 can be manufactured by injection molding a plastic material that has low electrical conductivity but can maintain a certain rigidity.

[0062] [Detailed structure of the first and second insulation sections] Hereinafter, with reference to FIG. 3, detailed structures of the first and second insulation parts 600 and 700 of the battery module 1 according to an embodiment of the present invention will be described in detail.

[0063] As shown in FIG. 2, the battery module 1 according to an embodiment of the present invention may further include a first insulation part 600 in the form of an insulation pad or sheet disposed between each of the battery cells 110 .

[0064] The first heat insulating portion 600 serves to prevent heat, flames, or high-temperature particles generated in any one battery cell 110 from being transferred to an adjacent battery cell 110 .

[0065] In order to prevent the movement of heat, flames, or high-temperature particles, the first insulation section 600 may be made by processing a silicon material having excellent thermal insulation performance and electrical insulation properties into a pad or sheet shape and placing it between the battery cells 111.

[0066] In addition, the first insulating part 600 may be formed to have a predetermined elasticity, so that when the volume of the battery cell 110 expands due to heat or a swelling phenomenon or contracts due to cooling, the first insulating part 600 may effectively expand or contract accordingly.

[0067] The first insulation part 600 is disposed so as to entirely cover one side of the battery cell 110, but is preferably disposed so as not to extend beyond the front and rear ends of the battery cell 110 as shown in the drawing. If the first insulation part 600 is disposed beyond the front and rear ends of the battery cell 110, it will be difficult to ensure a space for connecting the multiple electrode leads 111 to the bus bar plate 500.

[0068] Thus, an open space that is not blocked but communicates may be formed between the front end of the individual battery cell 110 and the bus bar plate 500, and between the rear end of the individual battery cell 110 and the bus bar plate 500. These open spaces function as cooling channels through which air can flow.

[0069] The first heat insulating portion 600 may be disposed continuously between all the battery cells 111 or may be disposed intermittently between some of the battery cells 111.

[0070] 3 shows a configuration in which a total of five first heat insulating sections 600 are intermittently arranged. Although the present invention is not limited thereto, the present invention will be described based on the embodiment in which a total of five first heat insulating sections 600 are intermittently arranged as shown as an example.

[0071] In this manner, the open spaces formed between the front ends of the individual battery cells 110 and the bus bar plate 500, and between the rear ends of the individual battery cells 110 and the bus bar plate 500, are not blocked or sealed by the first insulation portion 600, so that heat, flames and high-temperature particles may diffuse through the open spaces.

[0072] As such, as a means for preventing the spread of heat, flames and high-temperature particles through the open space, the battery module 1 according to one embodiment of the present invention may further include a plurality of second insulation parts 700 disposed between adjacent electrode leads 111.

[0073] The second insulating section 700 may be arranged between the electrode leads 111 in the form of a pad or sheet, similar to the first insulating section 600, but may be made of a material having a greater thermal expansion coefficient than the first insulating section 600.

[0074] The second insulating part 700 may be made of a thermal expansion material whose volume expands when a certain critical temperature is reached, for example, an expanding paper material.

[0075] Expanding paper is a material characterized by a sudden increase in volume when it reaches a critical temperature of approximately 100 to 200°C.

[0076] Therefore, when the battery cell 110 is operating within the normal operating temperature range, the volume is maintained in the initial state (unexpanded state). However, when the battery cell 110 overheats and reaches a critical temperature, the expansion paper expands and blocks the open space between the battery cell 110 and the bus bar plate 500 described above, as shown in FIG. 6.

[0077] In this manner, when the open space is closed, the path (P) through which heat, flames and high-temperature particles move to the adjacent battery cell 110 via the open space can be effectively blocked.

[0078] On the other hand, as shown in FIGS. 3 and 4, the second heat insulating section 700 may be disposed with one end portion fixed to the bus bar plate 500.

[0079] That is, the multiple pad-shaped second insulation sections 700 can be configured to be fixed to the rear surface 511 of the first bus bar plate 510 arranged in the front, or the front surface of the second bus bar plate 520 arranged in the rear, respectively.

[0080] This makes it possible to prevent the space required for assembly between the first bus bar plate 510 and the second bus bar plate 520 and the plurality of electrode leads 111 from being reduced by the second heat insulating section 700.

[0081] In addition, in order to maximize the blocking effect of heat, flames and high-temperature particles, the second insulation section 700 may be arranged in line with the first insulation section 600 while being separated and spaced apart from the first insulation section 600 by a predetermined distance.

[0082] Therefore, as shown in the figure, the second insulating section 700 can be arranged intermittently between multiple electrode leads 111, similar to the first insulating section 600, and the second insulating section 700 may be arranged in an alignment on an extension line of the first insulating section 600 in the front-to-rear direction (FR direction).

[0083] As a result, as described below, when the second insulating section expands, the second insulating section 700 comes into direct contact with the front and rear ends of the first insulating section 600, effectively blocking the open space.

[0084] Meanwhile, before expansion starts, the second insulation section 700 may be arranged in a state separated from each of the multiple electrode leads 111, and when the expansion starts upon reaching the above-mentioned predetermined critical temperature, both sides of the second insulation section 700 may be configured to contact the multiple electrode leads 111.

[0085] As a result, the open spaces formed between the multiple electrode leads 111 and between the battery cells 110 and the bus bar plate 500 can be blocked by the at least partially expanded second insulating portion 700.

[0086] Below, with reference to Figures 5 to 7, the process in which the second insulation section 700 expands to close the open spaces formed between the multiple electrode leads 111 and between the battery cells 110 and the bus bar plate 500 will be explained based on the second insulation section 700 arranged with one end 701 fixed to the second bus bar plate 520.

[0087] As shown in FIG. 5, during operation within the normal temperature range, the other end 701 of the second insulation section 700 is maintained separated from the first insulation section 600 in the front-rear direction (FR direction).

[0088] In this case, it is preferable that the front-rear distance (G1) between the other end 701 of the second insulation part 700 and the first insulation part 600 is set to be smaller than or equal to the front-rear width (W2) of the second insulation part 700. This allows the function as a cooling channel for the open space between the battery cells 110 and the second bus bar plate to be maintained at an appropriate level.

[0089] In addition, in a state where the device is operating in a normal temperature range, the left-right width (W1) of the second insulation part 700 may be formed to be smaller than the distance between adjacent pairs of electrode leads 111. This can minimize interference of the second insulation part 700 with the multiple electrode leads in the normal temperature range.

[0090] Meanwhile, as shown in FIG. 6, when the temperature around the second insulating section 700 rises to a certain critical temperature, the second insulating section 700 may start to expand.

[0091] At this time, the expansion can be performed simultaneously in the front-rear direction (FR direction) and the left-right direction (Le-Ri direction).

[0092] Therefore, the other end 702 of the second insulating section 700 gradually advances toward the first insulating section 600, and the front-to-rear distance (G1) between the other end 701 of the second insulating section 700 and the first insulating section 600 can gradually decrease.

[0093] Also, both side surfaces of the second heat insulating portion 700 advance toward the pair of opposing electrode leads 111, and the gap between the second heat insulating portion and the pair of electrode leads can gradually decrease.

[0094] In this manner, as the expansion of the second insulating section 700 continues, the other end 702 of the second insulating section 700 extends to the first insulating section 600, and both side surfaces of the second insulating section 700 extend to the pair of electrode leads 111.

[0095] As a result, when the expansion of the second insulating section 700 is completed, the open spaces formed between the battery cell 110 and the bus bar plate 500 and between the pair of electrode leads 111 can be completely blocked by the second insulating section 700, thereby blocking the path (P) through which heat, flames, and high-temperature particles can move.

[0096] Although the present invention has been described above with reference to the illustrative drawings, the present invention is not limited to the embodiments and drawings disclosed in this specification, and various modifications may be made by ordinary skilled artisans within the scope of the technical concept of the present invention. Even if the effects of the configuration of the present invention are not explicitly described and explained while describing the embodiments of the present invention, it is natural that the effects that can be predicted by the configuration should also be recognized. [Explanation of symbols]

[0097] 1 Battery module 100 Battery cell stack 110 Battery Cell 111 Electrode lead 200 frames 210 Lower Frame 211 Bottom Frame 212 Side Frame 220 Upper Frame 300 End Plate 310 First end plate 320 2nd end plate 400 Insulating Cover 410 First insulating cover 420 Second insulating cover 500 Busbar Plate 600 First insulation section 700 Second insulation section

Claims

1. a battery cell stack formed by stacking first battery cells and second battery cells arranged adjacent to each other; a plurality of electrode leads electrically connected to the first battery cell and the second battery cell, respectively; a bus bar plate that electrically connects the plurality of electrode leads; a first heat insulating portion disposed between the first battery cell and the second battery cell; and a second heat insulating portion disposed between the plurality of electrode leads and spaced apart from the first heat insulating portion; Including, The second heat insulating portion is made of a material having a thermal expansion coefficient greater than that of the first heat insulating portion, an open space exists between the plurality of electrode leads and the battery cell stack; The second insulating portion expands when heated to reach the first insulating portion, thereby closing the open space. Battery module.

2. The second insulating portion is made of a thermally expandable material whose volume increases when a predetermined critical temperature is reached. The battery module according to claim 1 .

3. The thermal expansion material constituting the second heat insulating portion includes expansion paper. The battery module according to claim 2 .

4. The first heat insulating portion is made of a silicone-based material. The battery module according to claim 1 or 3.

5. The second insulating portion has a side facing the bus bar plate configured in a pad shape fixed to the bus bar plate. The battery module according to claim 2 .

6. The second insulating section is disposed in a state separated from the first insulating section before expansion begins. The battery module according to claim 5 .

7. When the predetermined critical temperature is reached and expansion begins, the side of the second insulating part facing the first insulating part comes into contact with the first insulating part. The battery module according to claim 6 .

8. the second heat insulating portion is disposed in a state separated from each of the plurality of electrode leads before expansion begins. The battery module according to any one of claims 5 to 7.

9. When the predetermined critical temperature is reached and expansion begins, both side surfaces of the second heat insulating portion facing the plurality of electrode leads come into contact with the plurality of electrode leads, respectively. The battery module according to claim 8 .

10. When the expansion of the second heat insulating portion is completed, the spaces formed between the plurality of electrode leads are closed. The battery module according to claim 6 .

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