Battery module, battery pack including same, and automobile

Abstract

The present invention discloses a battery module with enhanced safety. The battery module according to one aspect of the present invention includes a cell stack including a plurality of battery cells stacked in at least one direction, and a module case configured to house the cell stack, wherein at least one of the plurality of battery cells has a coating layer on a surface thereof.

Description

[Technical Field]

[0001] The present invention relates to a battery module, a battery pack including the same, and a vehicle, and more particularly to a battery module with enhanced safety, a battery pack including the same, and a vehicle.

[0002] This application claims priority based on Korean Patent Application No. 10-2022-0167707 filed on December 5, 2022 and Korean Patent Application No. 10-2023-0043169 filed on March 31, 2023, and the contents disclosed in the specifications and drawings of those applications are incorporated herein in their entirety. [Background technology]

[0003] As demand for portable electronic products such as laptops, video cameras, and mobile phones rapidly increases and robots, electric vehicles, and other products are becoming more commercially viable, active research efforts are being made on high-performance secondary batteries that can be repeatedly charged and discharged.

[0004] Currently, commercially available secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and lithium secondary batteries. Among these, lithium secondary batteries are attracting attention due to their advantages of being able to be freely charged and discharged since they have almost no memory effect compared to nickel-based secondary batteries, as well as their extremely low self-discharge rate and high energy density.

[0005] Such lithium secondary batteries primarily use lithium-based oxides and carbon materials as the positive and negative electrode active materials, respectively, and include an electrode assembly in which a separator is sandwiched between positive and negative electrode plates coated with the positive and negative electrode active materials, and an exterior material, such as a battery case, that encloses the electrode assembly together with an electrolyte.

[0006] Generally, lithium secondary batteries are classified into can-type secondary batteries in which an electrode assembly is housed in a metal can and pouch-type secondary batteries in which an electrode assembly is housed in a pouch made of an aluminum laminate sheet, depending on the shape of the exterior material.

[0007] In recent years, secondary batteries have been widely used for driving and storing energy not only in small devices such as portable electronic devices but also in medium- to large-sized devices such as electric vehicles and energy storage systems (ESS). A battery module can be formed by electrically connecting multiple secondary batteries and housing them together inside a module case. Furthermore, a battery pack can be formed by connecting multiple such battery modules.

[0008] However, when multiple secondary batteries (battery cells) or multiple battery modules are packed into a small space, they can be vulnerable to thermal events. In particular, if a thermal event occurs in one of the battery cells, heat, fire, sparks, etc. may occur. If this heat is transferred to other battery cells, an explosive chain reaction such as thermal propagation (TP) may occur, potentially causing an explosion or fire in the battery module.

[0009] Furthermore, medium to large battery packs, such as those for electric vehicles, contain multiple battery cells and battery modules to increase output and / or capacity, and users, such as drivers, may be in close proximity, further increasing the risk of thermal chain reactions.

[0010] Therefore, there is a need for a method to improve safety by, for example, delaying heat transfer to other battery cells or battery modules when a thermal event occurs in a specific battery cell or battery module. Summary of the Invention [Problem to be solved by the invention]

[0011] The present invention has been made to solve the above problems, and aims to provide a battery module that can improve safety through thermal conduction delay, a battery pack including the same, and a vehicle.

[0012] Another object of the present invention is to provide a battery pack having improved stability by including such a battery module, and a vehicle including the same.

[0013] However, the technical problems that the present invention aims to solve are not limited to the above-mentioned problems, and other problems not mentioned will be clearly understood by those skilled in the art from the description of the invention given below. [Means for solving the problem]

[0014] To solve the above problems, a battery module according to one aspect of the present invention includes a cell stack including a plurality of battery cells stacked in at least one direction, and a module case configured to house the cell stack.

[0015] At least one of the plurality of battery cells may include a coating layer on a surface thereof.

[0016] The coating layer may be coated on the entire surface of the battery cell.

[0017] The coating layer may be provided on each surface of all battery cells included in the cell stack.

[0018] The cell stack may include a swelling absorption pad disposed between the plurality of battery cells.

[0019] Two battery cells located on both sides of the swelling absorbing pad may have the coating layer at positions corresponding to each other.

[0020] The coating layer may be a fire-resistant coating layer.

[0021] The coating layer may include a silica material.

[0022] The swelling absorbing pad may be disposed between each adjacent battery cell.

[0023] The swelling absorbing pad may be a thermal pad having elasticity and heat resistance.

[0024] The swelling absorbent pad may comprise silicone.

[0025] The swelling absorption pad may have an area larger than the opposing surface of the battery cell.

[0026] A battery pack according to the present invention may include a battery module according to the present invention.

[0027] A motor vehicle according to the invention may include a battery pack according to the invention. [Effects of the Invention]

[0028] According to one aspect of the present invention, the swelling absorption pad can absorb or suppress pressure generated by swelling of a battery cell, prevent the acceleration of thermal runaway caused by swelling, and delay or prevent a thermal chain reaction in which flame and / or heat generated by a thermal event occurring in a specific battery cell spreads to other adjacent battery cells.

[0029] In particular, pouch-type secondary batteries are relatively vulnerable to flames and / or heat compared to can-type batteries due to the characteristics of the exterior material. However, according to the present invention, by forming a coating layer on the surface of the pouch exterior material, it is possible to enhance the effect of delaying or preventing the above-mentioned thermal chain reaction.

[0030] According to another aspect of the present invention, the swelling absorption pad can more effectively absorb or suppress pressure generated by swelling of the battery cell because the swelling absorption pad is stably fixed by being accommodated in the accommodation portions of the module case and the bus bar frame. [Brief explanation of the drawings]

[0031] [Figure 1] 1 is a diagram showing the appearance of a battery module according to the present invention; [Figure 2] 1 is an exploded perspective view of a battery module according to the present invention; [Figure 3] 1 is a diagram showing a battery cell included in a battery module according to the present invention; [Figure 4] 4 is a diagram showing an exemplary form of a cross section taken along line BB' in FIG. 3. FIG. [Figure 5] 1 is a diagram showing a swelling absorbing pad included in a battery module according to the present invention and two battery cells located on both sides thereof. FIG. [Figure 6] 2 is a diagram showing an exemplary form of a cross section taken along line AA' in FIG. 1. FIG. [Figure 7] 2 is a diagram showing an exemplary form of a cross section taken along line AA' in FIG. 1. FIG. [Figure 8] 1 is a diagram showing a busbar assembly included in a battery module according to the present invention. FIG. [Figure 9] 1 shows a battery pack according to the present invention; [Figure 10] 1 shows a motor vehicle according to the invention; DETAILED DESCRIPTION OF THE INVENTION

[0032] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention, serve to further understand the technical concepts of the present invention. Therefore, the present invention should not be interpreted as being limited to only the matters shown in the drawings. The same reference numerals refer to the same components. Furthermore, in the drawings, the thickness, ratio, and dimensions of components may be exaggerated to effectively explain the technical content.

[0033] The terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted as having meanings and concepts corresponding to the technical ideas of the present invention, in accordance with the principle that the inventor can appropriately define the concepts of terms himself / herself in order to best explain the invention.

[0034] In this specification, directional terms such as up, down, left, right, front, and rear are used, but these terms are used merely for ease of explanation, and it will be obvious to those skilled in the art of the present invention that they may differ depending on the position of the object in question, the position of the observer, etc.

[0035] Therefore, it should be understood that the embodiments described in this specification and the configurations shown in the drawings are merely preferred embodiments of the present invention and do not represent the entire technical idea of ​​the present invention, and that there may be various equivalents and modifications that can be substituted therefor at the time of this application.

[0036] Fig. 1 is a diagram showing the appearance of a battery module according to the present invention. Fig. 2 is an exploded perspective view of a battery module according to the present invention. Fig. 3 is a diagram showing a battery cell included in a battery module according to the present invention. Fig. 4 is a diagram showing an exemplary cross section taken along line B-B' in Fig. 3.

[0037] Referring to FIGS. 1 to 4, a battery module 10 according to the present invention may include a cell stack 100 and a module case 200.

[0038] The cell stack 100 may include a plurality of battery cells 110 stacked in at least one direction.

[0039] Each battery cell 110 may represent a secondary battery. The battery cell 110 may include an electrode assembly, electrode leads 113 connected to the electrode assembly, and a sealed battery case that houses the electrode assembly and allows the electrode leads 113 to extend to the outside. An electrolyte may be housed inside the battery case. In particular, the battery cell 110 provided in the cell stack 100 may be a pouch-type secondary battery. The cell stack 100 may have a configuration in which a plurality of pouch-type secondary batteries are arranged horizontally in an upright state with their wide surfaces facing each other.

[0040] At least one of the plurality of battery cells 110 may have a coating layer C on its surface. The coating layer C may be coated on the entire surface of the battery cell 110. The coating layer C may be provided on the surface of each of all the battery cells 110.

[0041] The battery case may include a receiving portion 111 that receives the electrode assembly, and a sealing portion 112 that extends outward from the periphery of the receiving portion 111 and is configured to seal the receiving portion 111. The coating layer C may be provided over the entire remaining surface of the battery cell 110 except for the electrode leads 113. That is, the coating layer C may be configured to cover both the receiving portion 111 and the sealing portion 112 of the pouch case. In this way, when the coating layer C is provided over the entire remaining area of ​​the battery cell 110 except for the electrode leads 113 for electrical connection, the fire resistance of the battery cell 110 itself can be improved without affecting the electrical connection.

[0042] In another embodiment, the coating layer C may be provided on a portion of the electrode lead 113. The coating layer C may be configured to cover the entire area of ​​the electrode lead 113, excluding the surface that is coupled to other components (e.g., a bus bar, an electrode lead of an adjacent battery cell, a terminal, or other components). In this case, the fire resistance of the battery cell 110 can be further improved. However, the present invention is not limited thereto, and the coating layer C may be provided only on the housing portion 111 of the pouch case.

[0043] The coating layer C may be formed by spraying paint onto the surface of the battery cell 110. However, the coating layer C may also be formed on the surface of the battery cell 110 by various other methods.

[0044] The coating layer C may be a refractory coating layer C. The coating layer C may include a silica material. The coating layer C may include an alumina material. The coating layer C may include a magnesia material.

[0045] The swelling absorbent pad 120 may be disposed between a plurality of battery cells 110. The swelling absorbent pad 120 may be disposed between two adjacent battery cells 110. The swelling absorbent pad 120 may be disposed between every two adjacent battery cells 110. The swelling absorbent pad 120 may be formed in a plate shape.

[0046] The swelling absorbent pad 120 may be formed from an elastic material. The swelling absorbent pad 120 may be formed from a heat-resistant material that can withstand a certain amount of flame or heat. The swelling absorbent pad 120 may include a polyurethane material. The swelling absorbent pad 120 may include a silicone material.

[0047] According to this configuration of the present invention, the swelling absorption pad 120 can absorb or suppress pressure generated by the swelling phenomenon of the battery cell 110. In another embodiment, according to this configuration of the present invention, it is possible to prevent the acceleration of a thermal runaway phenomenon caused by the swelling phenomenon. In yet another embodiment, according to this configuration of the present invention, it is possible to delay or prevent a thermal chain reaction in which a flame and / or heat generated by a thermal event occurring in a specific battery cell 110 spreads to other adjacent battery cells 110.

[0048] In particular, pouch-type secondary batteries are relatively vulnerable to flames and / or heat compared to can-type batteries due to the characteristics of the exterior material. However, according to the present invention, by forming a coating layer C on the surface of the pouch exterior material, it is possible to enhance the effect of delaying or preventing the above-mentioned thermal chain reaction.

[0049] The module case 200 can be configured to house the cell stack 100. The module case 200 can be configured to have a housing space capable of housing the cell stack 100. The module case 200 can include a case main body 210 made up of four covers, each of whose faces forms a substantially quadrangular prism, and a pair of end covers 220 that cover the front and rear faces of the cell stack 100.

[0050] FIG. 5 is a diagram showing a swelling absorbing pad and two battery cells located on both sides thereof included in a battery module according to the present invention.

[0051] Referring to FIG. 5, each of the two battery cells 110 located on both sides of the swelling-absorbing pad 120 may have a coating layer C at a position corresponding to each other.

[0052] Referring to FIG. 5, the swelling-absorbing pad 120 may have an area larger than the opposing surface of the battery cell 110 .

[0053] When the battery case provided in the battery cell 110 includes a receiving portion 111 that receives the electrode assembly and a sealing portion 112 that seals the receiving portion 111, the two battery cells 110 located on both sides of the swelling absorbent pad 120 may have a coating layer C in an area corresponding to the receiving portion 111. The swelling absorbent pad 120 may have an area larger than the receiving portion 111. The swelling absorbent pad 120 may be configured to cover the entire receiving portion 111.

[0054] 6 and 7 are diagrams showing exemplary cross-sectional shapes taken along line AA' in FIG.

[0055] 6 and 7, the module case 200 may include a first receiving portion 201 for receiving the swelling absorbent pad 120. The module case 200 may include the first receiving portion 201 on an inner surface of the case body 210.

[0056] 6, the first receiving portions 201 may be provided at positions corresponding to the swelling absorbent pads 120. The first receiving portions 201 may be provided on the inner surface of at least one of the upper and lower portions of the module case 200. The first receiving portions 201 may be groove-shaped and extend substantially linearly from one end of the module case 200 to the other end. The first receiving portions 201 may be provided to correspond in number to the swelling absorbent pads 120.

[0057] According to this configuration of the present invention, the swelling absorbent pad 120 can more effectively absorb or suppress pressure generated due to the swelling phenomenon of the battery cell 110. This is because the swelling absorbent pad 120 is stably accommodated and fixed in the first accommodating portion 201 of the module case 200. In another embodiment, according to this configuration, thermal propagation between adjacent battery cells 110 can be more effectively prevented because it is possible to prevent an empty space from being formed between the swelling absorbent pad 120 and the inner surface of the module housing 200.

[0058] Also, referring to Figure 2, when the assembly of the stacked cell stack 100 and the swelling absorption pad 120 is accommodated in the module case 200, a part of the swelling absorption pad 120 is accommodated in one end of the first accommodation section 201, and then the entire pad can be accommodated in a sliding manner by pushing it toward the other end.

[0059] 7 , the battery module 10 may include an additional swelling absorption pad 121 disposed between the cell stack 100 and the module case 200. The battery module 10 may include two additional swelling absorption pads 121, one between the left side (negative direction of the X axis) of the cell stack 100 and the left side (negative direction of the X axis) inner surface of the module case 200, and one between the right side (positive direction of the X axis) of the cell stack 100 and the right side (positive direction of the X axis) inner surface of the module case 200. The module case 200 may include a second receiving portion 202 in which the additional swelling absorption pad 121 is received. The second receiving portion 202 may be provided at a position corresponding to the additional swelling absorption pad 121. In this case, the first receiving portion 201 may be selectively provided.

[0060] According to this configuration of the present invention, the additional swelling absorption pad 121 can delay or prevent a thermal chain reaction in which flames and / or heat generated due to a thermal runaway phenomenon occurring in the battery cell 110 are transferred to the module case 200. Referring also to FIG. 2, when the assembly of the stacked cell assembly 100, the swelling absorption pad 120, and the additional swelling absorption pad 121 is accommodated in the module case 200, a portion of the additional swelling absorption pad 121 is accommodated in one end of the second accommodating portion 202, and then the entire pad can be accommodated in a sliding manner by pushing it toward the other end.

[0061] FIG. 8 is a diagram showing a busbar assembly 400 included in a battery module 10 according to the present invention.

[0062] Referring to FIG. 8 , the battery module 10 may include a bus bar assembly 400.

[0063] The bus bar assembly 400 may include a bus bar 420 that electrically connects the plurality of battery cells 110 and a bus bar frame 410 to which the bus bar 420 is attached.

[0064] The bus bar frame 410 may include a bus bar attachment portion 411 , an electrode lead accommodating portion 412 in which the electrode lead 113 is accommodated, and a third accommodating portion 413 .

[0065] Referring also to FIG. 2 , the third accommodating portion 413 may accommodate one end of the swelling absorbent pad 120 in the longitudinal direction (extension direction of the Y axis). The third accommodating portion 413 may be a groove having a shape extending along the height direction of the bus bar frame 410 (extension direction of the Z axis). The third accommodating portion 413 may be provided on the inner surface of the bus bar frame 410. The third accommodating portion 413 may be groove-shaped, recessed from the substantially flat inner surface of the bus bar frame 410 in the positive direction of the Y axis so as to correspond to the shape of the swelling absorbent pad 120. The third accommodating portion 413 may be groove-shaped, recessed from a protrusion formed in the shape of a substantially trapezoidal pillar on the inner surface of the bus bar frame in the positive direction of the Y axis so as to correspond to the shape of the swelling absorbent pad 120. However, the third accommodating portion 413 is not limited to a groove shape and may be formed in the shape of a hole through which the swelling absorbent pad 120 can pass.

[0066] According to this configuration of the present invention, the swelling absorption pad 120 can be more reliably fixed not only by the first receiving portion 201 of the module case 200 but also by the third receiving portion 413 of the bus bar frame 410 .

[0067] FIG. 9 is a diagram showing a battery pack according to the present invention.

[0068] 9, a battery pack 2 may include one or more battery modules 10 according to the present invention described above. In addition to the battery module 10, the battery pack 2 according to the present invention may further include various other components, such as a battery management system (BMS), bus bars, a pack case, a relay, a current sensor, and other components of a battery pack 2 known at the time of filing of the present invention.

[0069] FIG. 10 shows a vehicle according to the present invention.

[0070] 10, an automobile 1 may include one or more battery packs 2 according to the present invention described above. In addition to the battery pack 2, the automobile 1 according to the present invention may further include various other components included in the automobile 1. For example, in addition to the battery pack 2 according to the present invention, the automobile 1 according to the present invention may further include a vehicle body, a motor, a control device such as an electronic control unit (ECU), and the like.

[0071] While the present invention has been described above with reference to the accompanying drawings focusing on preferred embodiments, it will be apparent to those skilled in the art that many different and obvious modifications can be made from such description without departing from the scope of the present invention. Therefore, the scope of the present invention should be construed by the claims which are written to include such many modified embodiments. [Explanation of symbols]

[0072] 1. Automobiles 2 battery packs 10 Battery Module 100 cell stack 110 battery cells 111 Storage unit 112 Seal part 113 Electrode Lead 120 Swelling Absorbent Pads 121 Extra Swelling Absorbent Pad 200 Module Case 201 First Storage Unit 202 Second Storage Unit 210 Case body 220 End cover 400 Busbar Assembly 410 Busbar Frame 411 Busbar mounting part 412 Electrode lead housing 413 Third Storage Unit 420 Busbar C coating layer

Claims

1. a cell stack including a plurality of battery cells stacked in at least one direction; a module case configured to house the cell stack; Including, At least one of the plurality of battery cells A battery module having a coating layer on its surface.

2. The coating layer is The battery module according to claim 1 , wherein the coating is applied to the entire surface of the battery cells.

3. The coating layer is The battery module according to claim 1 , wherein the insulating film is provided on a surface of each of all battery cells included in the cell stack.

4. The cell stack is The battery module according to claim 1 , further comprising a swelling absorption pad disposed between the plurality of battery cells.

5. Each of the two battery cells located on both sides of the swelling absorbing pad is The battery module according to claim 4 , wherein the coating layers are provided at positions corresponding to each other.

6. The coating layer is The battery module according to claim 1 , wherein the insulating layer is a fire-resistant coating layer.

7. The coating layer is The battery module of claim 1 comprising a silica material.

8. The swelling absorbent pad is The battery module according to claim 4 , wherein the battery module is disposed between adjacent battery cells.

9. The swelling absorbent pad is The battery module according to claim 4 , which is a thermal pad having elasticity and heat resistance.

10. The swelling absorbent pad is 5. The battery module of claim 4, comprising silicon.

11. The swelling absorbent pad is The battery module according to claim 4 , having an area larger than the opposing surfaces of the battery cells.

12. A battery pack comprising the battery module according to any one of claims 1 to 11.

13. A motor vehicle comprising the battery pack of claim 12.

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