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 that Korean patent application are incorporated herein by reference.

[0002] The present invention relates to a battery module, and more specifically to a battery module that has a first insulating portion in the form of an insulating pad disposed between individual battery cells and a second insulating portion 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. [Background technology]

[0003] As environmental concerns grow, efforts to reduce carbon emissions are spreading around the world. To reduce carbon emissions, the production of cars with combustion engines that burn fossil fuels is declining, while the production of electric cars that use electricity to power them 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, demand for secondary batteries to supply power to these 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, each of which has a plurality of secondary batteries connected in series / parallel.

[0007] When connecting multiple battery cells in series / parallel to form a battery pack, a commonly used method is to form a battery module consisting of at least one battery cell, and then use this at least one battery module to add other components to form a 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, which allows for improved component quality and increased space utilization.

[0009] These battery modules having a U-frame structure may be configured to include a battery cell stack in which a plurality 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 that covers 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 controlled, 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, heat insulating pads 60 are placed in the gaps 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 be diffused throughout the entire battery through 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 prior art described above, and its first object is to provide a battery module that effectively reduces the risk of fire and explosion by arranging a first insulating portion in the form of an insulating pad between individual battery cells and a second insulating portion 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 so that it has a smaller volume than the space formed between the individual battery cell and the bus bar plate when 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 unmentioned objects and advantages of the present invention can be understood from the following description and can be more clearly understood from the embodiments of the present invention. Also, it is clear that the object and advantages of the present invention can be realized by the means and combinations thereof set forth 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 first and second battery cells arranged adjacent to each other; a plurality of electrode leads electrically connected to the first and second battery cells, respectively; a first insulating portion arranged between the first and second battery cells; and a second insulating portion arranged between the plurality of electrode leads, wherein the second insulating portion is made of a material having a thermal expansion coefficient greater than that of the first insulating portion.

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

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

[0023] The first heat insulating section is silicone It can be made of a material based on the above.

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

[0025] The second heat insulating portion may have one side configured in a pad shape that is fixed to the bus bar plate.

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

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

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

[0029] When the second heat insulating portion reaches the predetermined critical temperature and starts to expand, both sides of the second heat 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 plurality of electrode leads may be closed. [Effects of the Invention]

[0031] The battery module according to the present invention has a first insulating portion in the form of an insulating pad disposed between individual battery cells, and a second insulating portion 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, when the second insulation part is not expanded, it has a smaller volume than the space formed between the individual battery cell and the bus bar plate, and the space formed between the individual battery cell and the bus bar plate functions 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 explanation of the drawings]

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

[0035] The above-mentioned objects, features, and advantages will be described in detail below with reference to the accompanying drawings, so that those skilled in the art can easily implement the technical concept of the present invention. In describing the present invention, if a detailed description of known technologies relating to the present invention is deemed to obscure the gist of the present invention, the detailed description will be omitted. Hereinafter, preferred embodiments of 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 terms such as "first" and "second" 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 unless otherwise specified, the first component may also be the second component.

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

[0038] Hereinafter, when an arbitrary structure is arranged "on 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 above (or below) the component.

[0039] Furthermore, 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 other components may be "intervening" between the components, or that each component may be "coupled," "coupled," or "connected" via other components.

[0040] As used herein, singular expressions include plural expressions unless the context clearly dictates otherwise. Terms such as "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 meaning that some components or steps may not be included, or that additional components or steps may be included.

[0041] Furthermore, as used herein, singular expressions include plural expressions unless the context clearly dictates otherwise. Terms such as "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 meaning that some components or steps may not be included, or that additional components or steps may be included.

[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] The present invention will be described below 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 general 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 the open front and open rear surfaces 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 stacked and closely arranged to form a battery cell stack 100.

[0048] As will be described later, a first heat insulating portion 600 in the form of a heat insulating pad may be disposed between adjacent battery cells 110. The first heat insulating portion 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 portion 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 encloses 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 that forms the bottom surface and a pair of side frames 210 that form 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 from a metal plate having a predetermined strength.

[0052] The upper frame 220 can 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 bus bar plates 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 for accommodating 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, 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 so as to face the electrode leads 111.

[0058] The end plate 300 may be mounted on the frame 200 together with the battery cell stack 100 in a state where it 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 where the upper frame 220 is coupled to the frame 200.

[0059] The end plate 300 can be manufactured by casting using a metal material, preferably iron or an 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 can 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 predetermined rigidity.

[0062] [Detailed structure of the first and second insulation sections] Hereinafter, with reference to FIG. 3, the detailed structures of the first heat insulating part 600 and the second heat insulating part 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 heat insulating part 600 in the form of a heat insulating pad or sheet disposed between each of the battery cells 110 .

[0064] The first heat insulating part 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] The first heat insulating part 600 has excellent heat insulating properties and electrical insulation properties so as to prevent the transfer of heat, flames, or high-temperature particles. silicone The material may be processed into a pad or sheet shape and placed 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 swelling or contracts due to cooling, the first insulating part 600 can effectively expand or contract accordingly.

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

[0068] Therefore, an open space that is not blocked and 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 to this, the following description will be given 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 way, the open spaces formed between the front end of the individual battery cell 110 and the bus bar plate 500, and between the rear end and the bus bar plate 500, are not blocked or sealed by the first insulating part 600, so heat, flames, and high-temperature particles can 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 insulating portions 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 thermal expansion coefficient greater than that of the first insulating section 600.

[0074] The second insulating part 700 may be made of a thermal expansion material that expands in volume when it reaches a predetermined critical temperature, and may be made of an expanding paper material, for example.

[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 its 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 as shown in FIG. 6.

[0077] When the open space is closed in this manner, the path (P) through which heat, flames, and high-temperature particles travel to the adjacent battery cells 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 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 prevents 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 portion 700.

[0081] In addition, in order to maximize the blocking effect of heat, flames, and high-temperature particles, the second insulation part 700 may be arranged in line with the first insulation part 600 while being spaced apart from the first insulation part 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 with 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 begins, the second insulating section 700 may be positioned in a state separated from each of the plurality of electrode leads 111, and when the expansion begins upon reaching the aforementioned predetermined critical temperature, both sides of the second insulating section 700 may be configured to come into contact with the plurality of electrode leads 111.

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

[0086] Below, with reference to Figures 5 to 7, the process by which the second insulating section 700 expands and closes 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 insulating section 700 arranged with one end 701 fixed to the second bus bar plate 520.

[0087] As shown in FIG. 5, when the device is operating within the normal temperature range, the other end 701 of the second heat insulating section 700 remains separated from the first heat insulating section 600 in the front-to-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, during operation in the normal temperature range, the width W1 of the second heat insulating part 700 in the left-right direction may be smaller than the distance between adjacent pairs of electrode leads 111. This may minimize interference of the second heat insulating part 700 with the plurality of electrode leads in the normal temperature range.

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

[0091] At this time, the inflation 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 may advance toward the pair of opposing electrode leads 111, and the gap between the second heat insulating portion and the pair of electrode leads may gradually decrease.

[0094] In this way, 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 illustrative drawings, the present invention is not limited to the embodiments and drawings disclosed in this specification, and various modifications may be made by those skilled in the art within the scope of the technical concept of the present invention. Furthermore, 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 cells 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 Second end plate 400 Insulation 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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