Battery module

Abstract

A battery module according to an embodiment of the present invention may include a case that forms an accommodation space therein, a plurality of battery cells positioned in the accommodation space, a fixing portion provided on an inner lower surface of the case, a cell adhesion portion positioned between the plurality of battery cells, and a connecting portion including a fixing adhesion portion that is connected to the cell adhesion portion and adhered to the fixing portion.

Description

Technical Field

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0077843 filed on June 24, 2022, and all the contents disclosed in the literature of the Korean patent application are incorporated herein by reference in their entirety.

[0002] The present invention relates to a battery module.

Background Art

[0003] Generally, types of secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, lithium-ion batteries, and lithium-ion polymer batteries. Such secondary batteries are used not only in small products such as digital cameras, P-DVDs, MP3Ps, mobile phones, PDAs, portable game devices, power tools, and e-bikes, but also in large products that require high power such as electric vehicles and hybrid vehicles, power storage devices that store surplus generated power and renewable energy, and backup power storage devices.

[0004] To manufacture such secondary batteries, first, an electrode active material slurry is applied to a positive electrode current collector and a negative electrode current collector to manufacture a positive electrode and a negative electrode, and these are laminated on both sides of a separator to form an electrode assembly of a predetermined shape. Then, the electrode assembly is housed in a battery case, an electrolyte is injected, and then sealed.

[0005] Secondary batteries are classified into a pouch type and a can type depending on the material of the case that houses the electrode assembly. The pouch type houses the electrode assembly in a pouch made of a flexible polymer material. And the can type houses the electrode assembly in a case made of a material such as metal or plastic.

[0006] Generally, a pouch-shaped battery case is manufactured by performing press working on a flexible pouch film to form a cup portion. Then, when the cup portion is formed, an electrode assembly is housed inside the cup portion, and a secondary battery is manufactured by sealing a corner portion, which is a peripheral portion of the cup portion.

[0007] Furthermore, a plurality of such secondary batteries are combined and placed in a case to manufacture a battery module. The secondary battery, that is, the battery cell is housed inside the case and is connected and fixed to the inner surface of the case via an adhesive of a resin component.

[0008] When a swelling phenomenon of the battery cell occurs in a state where the battery cell is coupled to the inner side surface of the case via an adhesive, a tensile force acts greatly on the case of the battery cell. Here, swelling means a phenomenon in which the lithium-ion electrolyte in the pouch vaporizes and the battery swells due to the pressure. In particular, as described above, the pouch-shaped battery cell is composed of a cup portion that forms an inner accommodation space and a corner portion that is a sealing section around the cup portion. However, in the press molding process of the pouch, the reduction in the thickness of the raw material of the corner portion is larger than that of the cup portion. Therefore, when a tensile force is generated on the outer surface of the pouch, more tensile force acts on the corner portion.

[0009] As a result, when the battery cell connected to the adhesive is pushed due to swelling, a large tensile force concentrates on the corner portion, and problems such as the battery cell exploding or gas leaking may occur. In order to prevent this, there is a situation where a battery module with an improved connection structure between the adhesive and the battery cell is required. SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION

[0010] One problem to be solved by the present invention is to provide a battery module that prevents damage to a battery cell by improving the structure of a connecting portion that connects a fixing portion and the battery cell. MEANS FOR SOLVING THE PROBLEM

[0011] The battery module according to an embodiment of the present invention may include a case forming an accommodation space therein, a plurality of battery cells located in the accommodation space, a fixing portion provided on the inner lower surface of the case, a cell adhesion portion located between the plurality of battery cells, and a connecting portion including a fixing adhesion portion connected to the cell adhesion portion and adhered to the fixing portion.

[0012] The plurality of battery cells are stacked in a direction parallel to the lower surface of the case, and the cell adhesion portion can be perpendicular to the lower surface of the case.

[0013] The longitudinal direction of the fixing adhesion portion can be perpendicular to the longitudinal direction of the cell adhesion portion.

[0014] The plurality of battery cells and the fixing portion can be spaced apart from each other at a constant interval.

[0015] The fixing adhesion portion can be located between the battery cell and the fixing portion.

[0016] The upper surface of the fixing adhesion portion can be spaced apart from the lower surface of the battery cell.

[0017] The connecting portion is provided between the cell adhesion portion and the fixing adhesion portion, and can further include an inclined portion formed to be inclined.

[0018] The battery module can further include an adhesive pad for adhering the plurality of battery cells along the stacking direction of the plurality of battery cells.

[0019] In the stacking direction of the plurality of battery cells, the adhesive pad and the cell adhesion portion can be alternately stacked with each other.

[0020] A plurality of the connecting portions can be provided.

[0021] The thermal conductivity of the connecting portion can be greater than the thermal conductivity of the battery cell.

[0022] The thermal conductivity of the fixing portion can be greater than the thermal conductivity of the battery cell.

Advantages of the Invention

[0023] According to a preferred embodiment of the present invention, by improving the structure of the connecting portion that connects the fixing portion and the battery cell and preventing damage and explosion of the battery cell, the stability and lifespan of the battery module can be improved.

[0024] In addition, it can include effects that can be easily predicted by those skilled in the art from the configuration according to the preferred embodiment of the present invention.

Brief Description of the Drawings

[0025] The following drawings attached to this specification illustrate the preferred embodiments of the present invention and, together with the detailed description of the invention described later, serve to better understand the technical idea of the present invention. Therefore, the present invention should not be construed as being limited only to the matters described in these drawings.

Figure 1

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Figure 4

Modes for Carrying Out the Invention

[0026] Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those having ordinary knowledge in the technical field to which the present invention pertains can easily implement it. However, the present invention can be realized in various different forms and is not limited to the following embodiments.

[0027] To clearly explain the present invention, detailed descriptions of parts not related to the explanation or related known technologies that may obscure the gist of the present invention are omitted. In this specification, when adding reference numerals to the components of each drawing, the same or similar reference numerals are assigned to the same or similar components throughout the specification.

[0028] Also, the terms and words used in this specification and the claims should not be construed as being limited to their ordinary and dictionary meanings. In accordance with the principle that the inventor can appropriately define the concept of the terms in order to explain his or her invention in the best way, they should be construed in a meaning and concept that conforms to the technical idea of the present invention.

[0029] FIG. 1 is a cross-sectional view of a battery module according to a comparative example.

[0030] Referring to FIG. 1, the battery module according to the comparative example may include a case C1 and battery cells C2 provided inside the case C1. For example, the battery module according to the comparative example includes an adhesive layer C3 on the inner lower surface of the case C1, and a plurality of battery cells C2 can be adhered and fixed via the adhesive layer C3.

[0031] FIG. 2 is a cross-sectional view showing a state where swelling occurs in the battery cell C2 according to the comparative example.

[0032] Referring to FIG. 2, in the structure of such a comparative example, when a swelling phenomenon of the battery cell C2 occurs due to internal vaporization and damage of the battery cell C2, referring to FIG. 2, with the lower surfaces of the plurality of battery cells C2 fixed to the adhesive layer C3, the battery cell C2 will receive an external force on one side along the arrow direction in FIG. 2.

[0033] When the battery cell C2 is a pouch-type battery composed of a cup portion and a corner portion, during the press-forming process of the pouch, the reduction in the thickness of the raw material of the corner portion is greater than that of the cup portion. Therefore, when tension occurs at the connection portion between the pouch and the adhesive layer C3, a large tensile force can act on the corner portion connected to the adhesive layer C3.

[0034] Therefore, according to the structure of such a comparative example, when swelling occurs, there is a high risk that the corner portion of the battery cell C2, which is weak to tension, may be damaged. As a result, due to the damage and breakage of the battery cell C2, there is a risk of an accident in which the battery module explodes due to the discharge of internal gas and flames.

[0035] To complement such problems, the battery module 1 according to an embodiment of the present invention can have the following structure and functions.

[0036] FIG. 3 is a cross-sectional view of the battery module 1 according to an embodiment.

[0037] Referring to FIG. 3, the battery module 1 can accommodate a plurality of battery cells 11 inside a case 10, accumulate electrical energy, be connected to an external terminal, and output the accumulated electrical energy to the outside. For example, the battery module 1 includes a case 10 that forms an accommodation space inside, and a plurality of battery cells 11 can be stacked on each other and positioned and fixed within the accommodation space. In this case, the battery cell 11 can include a pouch composed of a cup portion and a corner portion, and an electrode assembly accommodated inside the pouch. The cup portion means a portion recessed in the central portion of the pouch through the press-forming process of the pouch, and the corner portion can mean a side seal portion formed along the edge of the cup portion.

[0038] The battery module 1 can prevent the plurality of battery cells 11 from being damaged due to the swelling phenomenon by means of a connection structure in which the plurality of battery cells 11 are connected to the inner surface of the case 10. In other words, the battery module 1 can improve the connection structure in order to reduce damage to the corner portions of the pouches of the battery cells 11. Further, the battery module 1 can more effectively discharge the heat generated by the plurality of battery cells 11 to the outside by means of the connection structure.

[0039] Specifically, the battery module 1 can further include a fixing portion 12 and a connecting portion 13.

[0040] The fixing portion 12 can fix the plurality of battery cells 11 inside the case 10. For example, the fixing portion 12 is provided on the inner lower surface of the case 10 and can be connected to the plurality of battery cells 11. Specifically, the lower surface of the fixing portion 12 is connected to the inner lower surface of the case 10, and the upper surface of the fixing portion 12 can be connected to the plurality of battery cells 11. More specifically, the upper surface of the fixing portion 12 can be connected to the plurality of battery cells 11 via the connecting portion 13 described later.

[0041] The fixing portion 12 can include an adhesive material. For example, the fixing portion 12 includes a resin material, and after being applied to the inner lower surface of the case 10, it is solidified in a state of being adhered and connected to the connecting portion 13 described later, thereby connecting the inner lower surface of the case 10 and the plurality of battery cells 11 to each other.

[0042] The connecting portion 13 is connected to the plurality of battery cells 11 and the fixing portion 12, and can connect the plurality of battery cells 11 and the fixing portion 12 to each other. For example, the connecting portion 13 is provided between the plurality of battery cells 11 and is combined with the plurality of battery cells 11, and protrudes from the plurality of battery cells 11 to one side and is connected to the fixing portion 12, thereby connecting the plurality of battery cells 11 and the fixing portion 12. In this case, the plurality of battery cells 11 are connected to the fixing portion 12 only via the connecting portion 13, and the plurality of battery cells 11 can be prevented from coming into contact with the fixing portion 12. That is, the plurality of battery cells 11 and the fixing portion 12 can be arranged at a certain interval from each other.

[0043] The connecting portion 13 can include a cell adhesion portion 130 and a fixed adhesion portion 131.

[0044] The cell adhesion portion 130 can be located between a plurality of battery cells 11. For example, the cell adhesion portion 130 can be located between a plurality of battery cells 11 along the direction in which the plurality of battery cells 11 are stacked. In this case, the plurality of battery cells 11 can be stacked in a direction parallel to the lower surface of the case 10. That is, by the cell adhesion portion 130 being located in the space between the plurality of battery cells 11 while they are stacked, the cell adhesion portion 130 can have a structure in which the battery cells 11 are coupled and connected on both sides.

[0045] Specifically, the longitudinal direction of the cell adhesion portion 130 can be perpendicular to the lower surface of the case 10. In other words, based on a side view, the cell adhesion portion 130 can have a structure that extends toward the upper and lower surfaces of the case 10. While being located and connected between a plurality of battery cells 11, the cell adhesion portion 130 can protrude from the plurality of battery cells 11 toward the lower surface of the case 10 and be connected to the fixed adhesion portion 131.

[0046] The fixed adhesion portion 131 can be connected to the cell adhesion portion 130 and adhered to the fixing portion 12. For example, the upper surface of the fixed adhesion portion 131 can be connected to the lower portion of the cell adhesion portion 130, and the lower surface of the fixed adhesion portion 131 can be adhered to the upper surface of the fixing portion 12. That is, the fixed adhesion portion 131 is located between the plurality of battery cells 11 and the fixing portion 12 and can be connected to the cell adhesion portion 130 and the fixing portion 12.

[0047] In this case, the fixed adhesion portion 131 can be non-contact with the plurality of battery cells 11. By the fixed adhesion portion 131 not being in contact with the plurality of battery cells 11, even if the plurality of battery cells 11 are pushed due to the occurrence of swelling, in such a spaced-apart arrangement structure between the fixed adhesion portion 131 and the plurality of battery cells 11, the fixed adhesion portion 131 can prevent a phenomenon in which a tensile force acts on the battery cells 11 or the battery cells 11 are damaged.

[0048] The longitudinal direction of the fixed bonding portion 131 can be perpendicular to the longitudinal direction of the cell bonding portion 130. In other words, the fixed bonding portion 131 can be vertically connected to the cell bonding portion 130 and arranged to be aligned with the lower surface of the case 10. For example, due to the structures of the cell bonding portion 130 and the fixed bonding portion 131, the connecting portion 13 can have an "L" - shaped form. Specifically, with reference to a side view, the bonding length of the fixed bonding portion 131 with the fixing portion 12 can be made longer than the width length of the cell bonding portion 130.

[0049] According to such a structure of the connecting portion 13, with reference to a side view, in a state where the connecting portion 13 is coupled between a plurality of battery cells 11 stacked, the lower surface of the connecting portion 13, that is, the lower surface of the fixed bonding portion 131, can be in contact with and connected to the fixing portion 12 over a wider area. In other words, the connecting portion 13 is coupled to the battery cell 11 over a wider area via the cell bonding portion 130 and connected to the fixing portion 12 over a wider area via the fixed bonding portion 131, so that the bonding force and fixing force between the plurality of battery cells 11 and the fixing portion 12 can be increased.

[0050] More specifically, the cell bonding portion 130 is not limited to bonding only to a specific region of the pouch of the battery cell 11, but is bonded to the battery cell 11 over a wide area including the cup portion and the corner portion of the pouch of the battery cell 11. Therefore, the tensile force due to swelling can be dispersed over a wide area of the pouch of the battery cell 11. Similarly, even if the battery cell 11 is pushed due to swelling, since the fixed bonding portion 131 is bonded to the fixing portion 12 over a wide area, the tensile force generated between the fixed bonding portion 131 and the fixing portion 12 can be dispersed over a wide area.

[0051] Therefore, such a structure of the connecting portion 13 can prevent the problem that the tensile force generated due to the swelling phenomenon concentrates on the relatively weak corner portion and the pouch is damaged. As a result, secondary problem situations such as an explosion of the battery module 1 can be prevented.

[0052] Furthermore, when high-temperature heat is generated in the battery cell 11 due to swelling, in order to more effectively discharge the heat of the battery cell 11, the thermal conductivity of the fixing part 12 and the connecting part 13 can be higher than the thermal conductivity of the battery cell 11. Specifically, the fixing part 12 can include an adhesive of a resin material having a thermal conductivity higher than that of the battery cell 11. Also, the connecting part 13 can have a plate shape made of a metal material having a thermal conductivity higher than that of the battery cell 11.

[0053] Due to the structural features of the cell adhesion part 130 and the fixed adhesion part 131 described above, the connecting part 13 can transfer the heat generated in the battery cell 11 to the outside more effectively. In other words, in the case of a comparative example where the connecting part 13 does not exist, the battery cell C2 is directly connected to the adhesive layer C3, and the high-temperature heat generated by internal vaporization can be transferred to the adhesive layer C3. In this process, the heat on one side of the battery cell C2 directly connected to the adhesive layer C3 is immediately discharged through the adhesive layer C3, but on the other side of the battery cell C2 not connected to the adhesive layer C3, the heat may not be effectively discharged. Different from the comparative example, the connecting part 13 of the present invention is located between a plurality of battery cells 11 and is connected to a plurality of battery cells 11 with a larger area, and is connected to the other side of the battery cell 11 relatively far from the fixing part 12, so that the high-temperature heat generated in the battery cell 11 can be discharged more effectively.

[0054] Furthermore, in order to increase the damage prevention effect and heat discharge effect of the battery cell 11 of the connecting part 13, the connecting part 13 can be composed of a plurality so as to be respectively arranged between a plurality of battery cells 11. That is, the fixing part 12 is integrally formed on the inner lower surface of the case 10, while the connecting part 13 is provided in a plurality, so as to prevent damage to each battery cell 11 and effectively transfer the heat generated in each battery cell 11 to the fixing part 12.

[0055] Subsequently, the pad 14 can bond a plurality of battery cells 11 along the stacking direction of the plurality of battery cells 11. For example, the adhesive pad 14 can be positioned between the stacked battery cells 11 and can bring the plurality of battery cells 11 into contact with and bond to each other. That is, similar to the cell bonding portion 130, the adhesive pad 14 can have a longitudinal direction perpendicular to the lower surface of the case 10. Specifically, with the battery cells 11 provided between the cell bonding portion 130 and the adhesive pad 14, the adhesive pad 14 and the cell bonding portion 130 can be alternately stacked with each other in the stacking direction of the plurality of battery cells 11. In other words, the battery cells 11, the cell bonding portion 130, the battery cells 11, and the adhesive pads can be repeatedly stacked in this order.

[0056] Due to the function of such an adhesive pad 14, the bonding force between the plurality of battery cells 11 can be increased, the plurality of battery cells 11 can be further fixed inside the case 10, and damage to the battery cells 11 due to swelling can be more effectively inhibited.

[0057] Hereinafter, a battery module 2 according to another embodiment in which the structure of the connecting portion is partially deformed will be disclosed. The same contents as the configuration and functions of the aforementioned battery module will be omitted hereinafter.

[0058] FIG. 4 is a cross-sectional view of battery cells 21, a connecting portion 23, and a fixing portion 22 of a battery module 2 according to another embodiment.

[0059] Referring to FIG. 4, a battery module 2 according to another embodiment can include a plurality of battery cells 21, a connecting portion 23, and a fixing portion 22 that are the same as the configuration of the aforementioned battery module 1. Further, the connecting portion 23 according to another embodiment can include a cell bonding portion 230 and a fixing adhesive portion 231.

[0060] Furthermore, the connecting portion 23 according to another embodiment can further include an inclined portion 232.

[0061] The inclined portion 232 is provided between the cell adhesion portion 230 and the fixed adhesion portion 231, and can be formed to be inclined. For example, the inclined portion 232 can have a shape inclined in the longitudinal direction of the cell adhesion portion 230 and the fixed adhesion portion 231. In other words, the cell adhesion portion 230 and the fixed adhesion portion 231 have a perpendicular structure to each other, and the inclined portion 232 can have a shape inclined at an angle of 45 degrees with respect to the cell adhesion portion 230 and the fixed adhesion portion 231.

[0062] According to the structure of such an inclined portion 232, even if the battery cell 21 is pushed due to the occurrence of swelling and a tensile force is generated between the fixed adhesion portion 231 and the fixing portion, the inclined portion 232 buffers the external force transmitted from the battery cell 21 to the fixing portion, so that the inclined portion 232 can function to reduce the tensile force between the fixed adhesion portion 231 and the fixing portion 22.

[0063] As a result, by further including the inclined portion 232 in the connecting portion 23 according to other embodiments, damage to the battery cell 21 due to swelling can be further minimized, and secondary problems such as an explosion phenomenon of the secondary battery generated thereby can be further prevented.

[0064] The above description merely exemplarily explains the technical idea of the present invention. Those having ordinary knowledge in the technical field to which the present invention pertains can make various modifications and deformations without departing from the essential characteristics of the present invention.

[0065] Therefore, the embodiments disclosed in the present invention are not for limiting the technical idea of the present invention, but for explanation purposes, and the scope of the technical idea of the present invention is not limited by such embodiments.

[0066] The protection scope of the present invention should be interpreted according to the appended claims, and all technical ideas within the equivalent scope thereof should be interpreted as being included in the scope of rights of the present invention.

Description of Reference Numerals

[0067] 1 Battery module 10 cases 11 battery cells 12 fixing part 13 connecting part 14 adhesive pad 130 cell adhesion part 131 fixing adhesion part 232 inclined part

Claims

1. A case that forms an accommodation space inside; A plurality of battery cells located in the accommodation space; A fixing part provided on the inner lower surface of the case; A battery module including a cell adhesion part located between the plurality of battery cells, and a connection part including a fixing adhesion part connected to the cell adhesion part and adhered to the fixing part.

2. The plurality of battery cells are laminated in a direction parallel to the lower surface of the case, The battery module according to claim 1, wherein the cell adhesion part is perpendicular to the lower surface of the case.

3. The battery module according to claim 2, wherein the longitudinal direction of the fixing adhesion part is perpendicular to the longitudinal direction of the cell adhesion part.

4. The battery module according to claim 1, wherein the plurality of battery cells and the fixing part are spaced apart from each other at a constant interval.

5. The battery module according to claim 4, wherein the fixing adhesion part is located between the battery cell and the fixing part.

6. The battery module according to claim 5, wherein the upper surface of the fixing adhesion part is spaced apart from the lower surface of the battery cell.

7. The battery module according to claim 6, wherein the connection part is provided between the cell adhesion part and the fixing adhesion part and further includes an inclined part formed in an inclined manner.

8. The battery module according to claim 1, further including an adhesive pad for adhering the plurality of battery cells along the stacking direction of the plurality of battery cells.

9. The battery module according to claim 8, wherein the adhesive pad and the cell adhesion part are alternately laminated with each other in the stacking direction of the plurality of battery cells.

10. The battery module according to claim 1, wherein a plurality of the connection parts are provided.

11. The battery module according to claim 1, wherein the thermal conductivity of the connection part is greater than the thermal conductivity of the battery cell.

12. The battery module according to claim 1, wherein the thermal conductivity of the fixing part is greater than the thermal conductivity of the battery cell.

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