Battery module and battery pack including the same

Abstract

A battery module according to one embodiment of the present invention includes a battery cell stack in which a plurality of battery cells are stacked, a module frame surrounding the battery cell stack, and a first heat transfer member and a second heat transfer member located on a bottom of the module frame, wherein the second heat transfer member is formed on an outer periphery of the first heat transfer member.

Description

Technical Field

[0001] [Cross - Reference to Related Applications] This application claims the benefit of priority based on Korean Patent Application No. 10 - 2021 - 0120125, filed on September 9, 2021, 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 and a battery pack including the same, and more specifically, to a battery module and a battery pack having a novel cooling structure.

Background Art

[0003] Due to the technological development and increasing demand for mobile devices, the demand for secondary batteries as an energy source has been rapidly increasing. In particular, secondary batteries have attracted much attention not only as an energy source for mobile devices such as mobile phones, digital cameras, notebook computers, and wearable devices, but also for power devices such as electric bicycles, electric vehicles, and hybrid electric vehicles.

[0004] For small mobile devices and the like, one or two to four battery cells or the like are used per device, while for medium - to - large - sized devices such as automobiles, high output and large capacity are required. Therefore, medium - to - large - sized battery modules in which a large number of battery cells are electrically connected are used.

[0005] Medium - to - large - sized battery modules are preferably manufactured with the smallest possible size and weight, so square batteries, pouch - type batteries, etc. that can be stacked with a high degree of integration and have a small weight - to - capacity ratio are mainly used as the battery cells of medium - to - large - sized battery modules. Such a battery module has a structure in which a number of cell assemblies including a plurality of unit battery cells are connected in series to obtain high output. And the battery cell includes a positive electrode and a negative electrode current collector, a separator, an active material, an electrolyte, etc., and can be repeatedly charged and discharged by an electrochemical reaction between components.

[0006] On the one hand, recently, as the need for large-capacity structures has increased, including their use as energy storage sources, the demand for a number of battery modules in which a number of secondary batteries are connected in series and / or in parallel and battery packs with a multi-module structure in which said battery modules are assembled has been increasing.

[0007] Also, when configuring a battery pack by connecting a plurality of battery cells in series / parallel, it is common to first configure a battery module consisting of at least one battery cell and then use such at least one battery module to add other components to configure the battery pack.

[0008] Generally, when the temperature of a secondary battery becomes higher than the appropriate temperature, the performance of the secondary battery may deteriorate, and in severe cases, there is also a risk of explosion or ignition. In particular, a number of secondary batteries, that is, a battery module or a battery pack equipped with battery cells, have heat generated from a number of battery cells in a narrow space added together, and the temperature may rise more rapidly and excessively. In other words, in the case of a battery module in which a number of battery cells are stacked and a battery pack to which such a battery module is attached, high output can be obtained, but it is not easy to remove the heat generated in the battery cells during charging and discharging. If the heat dissipation of the battery cells is not properly carried out, the deterioration of the battery cells will speed up, the life will be shortened, and the possibility of explosion or ignition will increase.

[0009] Furthermore, in the case of a battery module included in a vehicle battery pack, it is often exposed to direct sunlight and may be placed in high-temperature conditions such as in summer or desert areas.

[0010] Recently, the needs for high capacity, high energy, rapid charging, etc. have been continuously increasing, and the heat generated in battery cells tends to increase. Accordingly, a heat dissipation layer can be formed in a battery module for discharging the heat generated in the battery cells to the outside. Further, the heat dissipation layer can be formed by applying a substance having a heat dissipation function to necessary portions in the battery module. However, when applying the heat dissipating substance, it may be impossible to apply it to a desired site due to structural reasons, and there is a possibility of damaging the battery cell due to structural characteristics. As a result, the cooling performance may decrease, and the stable performance of the battery module may decrease. Therefore, a new structure capable of ensuring cooling performance and stability is required.

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0011] The problem to be solved by the present invention is to provide a battery module capable of solving the heat generation problem of a battery cell and a battery pack including the same.

[0012] However, the problem to be solved by the present invention is not limited to the above-mentioned problems, and other problems not mentioned will be clearly understood by those having ordinary knowledge in the technical field to which the present invention pertains from the present specification and the accompanying drawings.

MEANS FOR SOLVING THE PROBLEMS

[0013] A battery module according to an embodiment of the present invention includes a battery cell stack in which a plurality of battery cells are stacked, a module frame surrounding the battery cell stack, and a first heat transfer member and a second heat transfer member located on the bottom of the module frame, wherein the second heat transfer member is formed on an outer peripheral portion of the first heat transfer member.

[0014] The second heat transfer member and the first heat transfer member may be formed of different substances.

[0015] The first heat transfer member includes a thermally conductive resin layer, and the second heat transfer member may include a heat transfer pad.

[0016] The second heat transfer member may be in contact with the first heat transfer member.

[0017] The second heat transfer member may be in contact with the lower part of the battery cell laminate.

[0018] The second heat transfer member may be formed so as to be adjacent to the front surface or the rear surface of the battery cell laminate.

[0019] The second heat transfer member may be formed so as to be in contact with the terrace portion of the battery cell.

[0020] The second heat transfer member may be formed higher than the height of the first heat transfer member.

[0021] The second heat transfer member may be formed of a material having thermal conductivity and softness.

[0022] The second heat transfer member may be formed of a material containing silicone.

[0023] The second heat transfer member may include a foam material.

[0024] The second heat transfer member may have a lower hardness than the first heat transfer member.

[0025] The heat transferred from the battery cell may be continuously transferred and released through the second heat transfer member and the module frame.

[0026] The battery pack according to still another embodiment of the present invention may include the battery module.

Advantages of the Invention

[0027] The battery module according to an embodiment of the present invention can solve the problem of battery cell heat generation in an environment of high current and rapid charging by including first and second heat transfer members. Further, by solving the heat generation problem, the stability of the battery module can be improved.

[0028] In addition, by including thermal conductivity and softness, the second heat transfer member can minimize damage to the battery cell due to vibration shock.

[0029] Also, the second heat transfer member can prevent the first heat transfer member from overflowing.

[0030] The effects of the present invention are not limited to the above-described effects and the like, and effects not mentioned will be clearly understood by those having ordinary knowledge in the technical field to which the present invention pertains from this specification and the accompanying drawings.

Brief Description of the Drawings

[0031]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Modes for Carrying Out the Invention

[0032] Hereinafter, 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 embodied in various different forms and is not limited to the embodiments described herein.

[0033] To clearly explain the present invention, parts not related to the explanation will be omitted, and the same reference numerals will be assigned to the same or similar components throughout the specification.

[0034] Also, the sizes and thicknesses of the respective components shown in the drawings are arbitrarily shown for convenience of explanation, so the present invention is not necessarily limited to what is shown in the drawings. The thickness is enlarged to clearly represent various layers and regions in the drawings. And in the drawings, for convenience of explanation, the thicknesses of some layers and regions are exaggerated.

[0035] Also, when a part such as a layer, film, region, or plate is said to be "on" or "above" another part, this includes not only the case where it is "directly above" the other part but also the case where there are additional other parts in between. Conversely, when a part is said to be "directly above" another part, it means that there are no other parts in between. Also, being "on" or "above" a reference part means being located above or below the reference part and does not necessarily mean being located "on" or "above" in the opposite direction of gravity.

[0036] Also, throughout the specification, when a part "includes" a certain component, this means that other components may be further included, rather than excluding other components, unless otherwise stated to the contrary.

[0037] Also, throughout the specification, when it is said to be "on a plane", this means when the target part is viewed from above, and when it is said to be "in a cross-section", this means when the cross-section cut out perpendicularly of the target part is viewed from the side.

[0038] The first and second terms used in this application can be used to describe various components and the like, but the components and the like should not be limited by the terms and the like. The terms and the like are only used for the purpose of distinguishing one component from another component.

[0039] Hereinafter, with reference to FIGS. 1 to 5, a battery module according to an embodiment of the present invention will be described.

[0040] FIG. 1 is an exploded perspective view of the battery module of the present invention. FIG. 2 is a perspective view showing the battery module assembled from the components of FIG. 1. FIG. 3 is an enlarged view showing a state cut out along the P1 plane of FIG. 2. FIG. 4 is a cross-sectional view of a battery module according to another embodiment of the present invention. FIG. 5 is a perspective view showing a battery cell included in the battery module of the present invention.

[0041] Referring to FIGS. 1 and 2, the battery module 100 according to the present embodiment includes a battery cell stack 120 in which a plurality of battery cells 110 are stacked and a module frame 200 surrounding the battery cell stack 120.

[0042] First, the battery cell 110 is preferably a pouch-type battery cell and may be formed in a rectangular sheet-like structure. For example, referring to FIG. 5, the battery cell 110 according to the present embodiment has a structure in which two electrode leads 111 and 112 face each other and protrude from one end portion 114a and the other end portion 114b of the cell body 113, respectively. That is, the battery cell 110 includes electrode leads 111, 112, etc. protruding in a direction facing each other. More specifically, the electrode leads 111 and 112 are connected to an electrode assembly (not shown) and protrude outside the battery cell 110 from the electrode assembly (not shown).

[0043] On the one hand, the battery cell 110 may be manufactured by bonding one end portion 114a and the other end portion 114b of the cell case 114 and one side portion 114c connecting them in a state where an electrode assembly (not shown) is received in the cell case 114. In other words, the battery cell 110 according to the present embodiment has a total of three sealing portions 114sa, 114sb, and 114sc, and the sealing portions 114sa, 114sb, and 114sc are structured to be sealed by a method such as heat fusion, and the other side portion may consist of a connecting portion 115. The cell case 114 may be made of a laminate sheet including a resin layer and a metal layer.

[0044] Further, the connecting portion 115 may extend long along one edge of the battery cell 110, and a battery ear 110p may be formed at an end of the connecting portion 115. Further, the cell case 114 may be sealed with the protruding electrode leads 111 and 112 interposed therebetween, and a terrace portion 116 may be formed between the electrode leads 111 and 112 and the cell body 113. That is, the battery cell 110 may include a terrace portion 116 extending from the cell case 114 in a direction in which the electrode leads 111 and 112 protrude.

[0045] Such battery cells 110 may be composed of a plurality of cells, and the plurality of battery cells 110 are stacked so as to be electrically connected to each other to form a battery cell laminate 120. In particular, as shown in FIG. 1, a plurality of battery cells 110 may be stacked along a direction parallel to the y-axis. Thereby, the electrode leads 111, 112, etc. may protrude in the +x-axis direction and the -x-axis direction, respectively.

[0046] On the other hand, heat is generated when charging and discharging of the battery cell 110 is repeated. Among them, a large amount of heat is generated in a portion adjacent to the electrode leads 111 and 112. That is, more heat can be generated by charging and discharging as it approaches the terrace portion 116 than in the central portion of the cell body 113, so a structure for cooling this portion is required.

[0047] The module frame 200 includes a frame member 300 that has an open upper surface, front surface, and rear surface and covers the lower and both side portions of the battery cell stack 120, and an upper plate 400 that covers the upper portion of the battery cell stack 120. However, the module frame 200 is not limited thereto and may be replaced with other shaped frames such as an L-shaped frame or a monoframe that surrounds the battery cell stack 120 except for the front and rear surfaces. The battery cell stack 120 accommodated inside the module frame 200 can be physically protected through the module frame 200. At this time, the frame member 300 may include a bottom portion 300a that supports the lower portion of the battery cell stack 120 and side portions 300b that extend upward at both ends of the bottom portion 300a, respectively.

[0048] The upper plate 400 can cover the open upper surface of the module frame 200. The end plate 150 can cover the front and rear surfaces of the battery cell stack 120 that are open in the module frame 200. The end plate 150 can be joined by welding to the corner portions of the front and rear ends of the upper plate 400 and the corner portions of the front and rear ends of the module frame 200.

[0049] A bus bar frame 130 may be formed between the end plate 150 and the front and rear surfaces of the battery cell stack 120. A plurality of bus bars 160 attached to the bus bar frame 130 may protrude from the battery cells 110 or the like and may be brought into contact with electrode leads 111, 112 or the like attached on the bus bar frame 130.

[0050] In the conventional battery module, the heat generated in the battery cell was released through the thermally conductive resin layer formed at the bottom of the battery cell. However, the thermally conductive resin layer had a problem in that it could not efficiently cool the electrode leads and the terrace portions on the front and rear surfaces of the battery cell. In addition, in the conventional battery module, due to the vibration applied to the battery module, there was a high possibility of cracks occurring on the front and rear surfaces of the battery cell, but there was no structure to prevent this. Therefore, in a situation where a high current flow causes high heat generation in a short time in the electrode leads and the terrace portions of the battery cell, such as rapid charging, a cooling structure that can minimize the temperature rise of the battery cell is required, and a structure that can minimize the possibility of damage to the battery cell is required.

[0051] Therefore, referring to FIGS. 1 and 3, the battery module 100 according to the present embodiment includes a first heat transfer member 310 and a second heat transfer member 500 located on the bottom of the module frame 200, that is, on the bottom 300a of the frame member 300. At this time, the second heat transfer member 500 is formed on the outer peripheral portion of the first heat transfer member 310.

[0052] At this time, the outer peripheral portion of the first heat transfer member 310 may be the peripheral edge of the first heat transfer member 310 located in the direction in which the electrode leads 111 and 112 of the battery cell 110 are formed. Therefore, the second heat transfer member 500 may be formed to be located on the peripheral edge of the first heat transfer member 310. In addition, the second heat transfer member 500 may be in contact with the first heat transfer member 310 by being formed on the outer peripheral portion of the first heat transfer member 310.

[0053] The second heat transfer member 500 and the first heat transfer member 310 may be formed of different substances. Specifically, the first heat transfer member 310 may include a thermally conductive resin layer, and the second heat transfer member 500 may include a heat transfer pad.

[0054] For the formation of the first heat transfer member 310, various methods may be used. Specifically, it may include applying a thermally conductive resin to the bottom 300a of the frame member 300 and curing the thermally conductive resin to form a thermally conductive resin layer. At this time, the second heat transfer member 500 can achieve the effect of guiding the application position of the thermally conductive resin or preventing the thermally conductive resin from overflowing outside the bottom 300a.

[0055] On the other hand, the second heat transfer member 500 according to this embodiment may be formed on the bottom 300a of the frame member 300 and may be in contact with the lower part of the battery cell laminate 120.

[0056] In particular, as described above, the second heat transfer member 500 may be formed at the periphery of the first heat transfer member 310, and the periphery may be adjacent to the front or rear surface of the battery cell laminate 120. Therefore, the second heat transfer member 500 may be formed so as to be adjacent to the front or rear surface of the battery cell laminate 120. That is, the second heat transfer member 500 may be in contact with the lower part of the battery cell laminate 120 corresponding to the front and rear surfaces of the battery cell laminate 120.

[0057] As described above, in the case of the battery cell 110, more heat is generated in the terrace portion 116 and the electrode leads 111 and 112 than in the central portion of the battery cell 110. Therefore, the second heat transfer member 500 may be formed so as to be in contact with the terrace portion 116 of the battery cell 110. Thus, the heat generated in the battery cell 110 can be cooled and transferred through the second heat transfer member 500. The second heat transfer member 500 can improve the heat dissipation function of the battery cell and the temperature deviation between different parts of the battery cell by forming a cooling path in direct contact with the terrace portion 116. The temperature deviation between different parts of the battery cell causes a decrease in the performance of the battery cell. Therefore, the effect of maintaining the performance and ensuring the safety of the battery cell can be achieved through the second heat transfer member 500.

[0058] Referring to FIG. 3, the second heat transfer member 500 according to this embodiment may be formed in a pad form or may be formed side by side so as to contact the first heat transfer member 310. In particular, the second heat transfer member 500 may be formed to be the same height as the first heat transfer member 310 so as to contact the terrace portion 116 of the battery cell 110. Further, it can function to prevent the first heat transfer member 310 from overflowing.

[0059] The second heat transfer member 500 according to another embodiment of the present invention may be formed higher than the height of the first heat transfer member 310. That is, referring to FIG. 5, the second heat transfer member 500 according to this embodiment may be formed to surround the terrace portion 116 of the battery cell 110. Thereby, the second heat transfer member 500 can improve the stability of the battery module by protecting the terrace portion 116 of the battery cell 110 and the front and rear surfaces of the battery cell 110 that may be damaged by vibration shock. Further, by being formed higher than the height of the first heat transfer member 310, it is possible to prevent the first heat transfer member 310 from being formed and overflowing, and to guide the first heat transfer member 310 to be formed at a desired position.

[0060] At this time, since the height indicates the lengths of the first heat transfer member 310 and the second heat transfer member 500 grasped in cross section, it can be used in the same meaning as the thickness. Therefore, the second heat transfer member 500 may be formed thicker than the thickness of the first heat transfer member 310.

[0061] On the other hand, the second heat transfer member 500 according to this embodiment may be formed of a material having thermal conductivity and softness. Specifically, by being formed of a material having better softness than the first heat transfer member 310, it is possible to prevent breakage of the battery cell 110 due to vibration shock, and in particular, to prevent breakage of the terrace portion 116 of the battery cell 110. That is, since the second heat transfer member 500 has softness, it can absorb the shock applied to the battery cell 110.

[0062] The second heat transfer member 500 according to this embodiment may be formed of a material containing silicone. Also, the second heat transfer member 500 according to this embodiment may be formed in the form of a heat transfer pad containing silicone. At this time, the second heat transfer member 500 may include a foam material. Generally, a foam material has a large surface area by having a low-density permeable structure. Therefore, effective cooling performance can be ensured based on the large surface area. Therefore, the second heat transfer member 500 according to this embodiment may specifically be formed of a silicone foam material.

[0063] The second heat transfer member 500 according to this embodiment may have a lower hardness than the first heat transfer member 310. Specifically, the second heat transfer member 500 may have a numerical value of 20 to 50 based on the shore hardness, which has a lower hardness compared to 100 of the numerical value of the first heat transfer member 310, and can prevent the occurrence of cracks in the battery cell 110 as described above.

[0064] The second heat transfer member 500 according to this embodiment may have a thermal conductivity of at least 3.0 W / m·K or more. Therefore, the second heat transfer member 500 may include a material selected from various materials having the above thermal conductivity numerical value, and specifically may include a silicone material.

[0065] The second heat transfer member 500 according to this embodiment may be formed of a material having thermal conductivity and flexibility, include silicone, and be formed to have a lower hardness than the first heat transfer member 310. Therefore, not only can cooling performance be ensured, but also cracks generated when the battery cell 110 collides with the second heat transfer member 500 or due to external impact can be prevented. In particular, by being formed of a material containing silicone, thermal conductivity, flexibility, and hardness having the above-described characteristics can be ensured.

[0066] In addition, the battery module according to this embodiment includes the second heat transfer member 500, so that the heat generated in the battery cell 110 can be transferred to the first heat transfer member 310 and the second heat transfer member 500 and released to the outside of the battery module. Therefore, the heat transferred from the battery cell 110 can be continuously transferred and released through the second heat transfer member 500 and the module frame 200.

[0067] Hereinafter, with reference to FIG. 6, a battery pack according to still another embodiment of the present invention will be described.

[0068] FIG. 6 is a diagram showing a battery pack according to still another embodiment of the present invention.

[0069] Referring to FIG. 6, the battery pack according to this embodiment includes the battery module described above. Further, it may further include a heat sink 600, and may further include a thermally conductive resin layer formed between the bottom portion 300a of the module frame and the heat sink 600.

[0070] Therefore, as described above, by being transferred to the heat sink 600 formed in the battery pack transferred from the battery cell 110 and cooled, effective cooling of a large amount of heat generated in a rapid charging situation is possible.

[0071] In addition, the battery pack of the present invention may have a structure in which one or more battery modules according to this embodiment are assembled, and a battery management system (Battery Management System, BMS) for managing the temperature and voltage of the battery, a cooling device, etc. are added and packed.

[0072] The battery pack is applicable to various devices. Such devices are applicable to transportation means such as electric bicycles, electric vehicles, and hybrid vehicles, but the present invention is not limited thereto, and is applicable to various devices using battery modules, which also belongs to the scope of rights of the present invention.

[0073] In the above, the preferred embodiments of the present invention have been illustrated and described. However, the present invention is not limited to the specific embodiments described above, and it goes without saying that various modifications can be made by those having ordinary knowledge in the technical field to which the present invention pertains without departing from the gist of the present invention claimed in the claims. Such modifications and the like should not be individually understood from the technical idea and perspective of the present invention.

Explanation of Signs

[0074] 1: Device 100: Battery module 110: Battery cell 110p: Battery ear 111: Electrode lead 112: Electrode lead 113: Cell body 114: Cell case 114a: One end portion 114b: The other end portion 114c: One side portion 114sa: Sealing portion 114sb: Sealing portion 114sc: Sealing portion 115: Connecting portion 116: Terrace portion 120: Battery cell laminate 130: Bus bar frame 150: End plate 160: Bus bar 200: Module frame 300: Frame member 300a: Bottom portion 300b: Side surface portion 310: First heat transfer member 400: Upper plate 500: Second heat transfer member

Claims

1. A battery cell stack in which a plurality of battery cells are stacked, A module frame that surrounds the battery cell stack, covers the upper, lower, and both side portions of the battery cell stack, and opens the front and rear surfaces of the battery cell stack, A battery module including a first heat transfer member and a second heat transfer member located on the bottom of the module frame that supports the lower portion of the battery cell stack, The battery cell has a cell body, a first electrode lead protruding from one end of the cell body located on the front surface of the battery cell stack, and a second electrode lead protruding from the other end of the cell body located on the rear surface of the battery cell stack, The second heat transfer member is formed on the outer peripheral portion of the first heat transfer member, contacts the lower portion of the battery cell stack, and is formed so as to be adjacent to the front or rear surface of the battery cell stack.

2. The battery module according to claim 1, wherein the second heat transfer member and the first heat transfer member are formed of different substances.

3. The battery module according to claim 2, wherein the first heat transfer member includes a thermally conductive resin layer, and the second heat transfer member includes a heat transfer pad.

4. The battery module according to claim 1, wherein the second heat transfer member contacts the first heat transfer member.

5. The battery module according to claim 1, wherein the second heat transfer member is formed so as to contact the terrace portion of the battery cell.

6. A battery cell stack in which a plurality of battery cells are stacked, A module frame surrounding the battery cell stack, A battery module including a first heat transfer member and a second heat transfer member located on the bottom of the module frame, The second heat transfer member is formed on the outer peripheral portion of the first heat transfer member, The battery module, wherein the second heat transfer member is formed higher than the height of the first heat transfer member.

7. The battery module according to claim 1, wherein the second heat transfer member is formed of a material having thermal conductivity and flexibility.

8. The battery module according to claim 1, wherein the second heat transfer member is formed of a material containing silicone.

9. The battery module according to claim 6, wherein the second heat transfer member includes a foam material.

10. The battery module according to claim 1, wherein the second heat transfer member has a lower hardness than the first heat transfer member.

11. The heat transmitted from the battery cell is continuously transmitted and released through the second heat transfer member and the module frame. The battery module according to claim 1.

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

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