Battery module and battery pack containing the same

Abstract

The battery module of the present invention includes a battery cell stack including a plurality of battery cells, a module frame including a bottom and two opposing side surfaces and accommodating the battery cell stack inside, a thermally conductive resin layer disposed between one surface of the module frame and the battery cell stack, a pad disposed at least at one end of the one surface of the module frame, and a complementary material disposed between the battery cell stack and the pad, the complementary material filling the space between the battery cell stack and the pad.

Description

[Technical Field]

[0001] [Cross-Reference to Related Applications] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0107114 filed on August 16, 2023 and Korean Patent Application No. 10-2024-0097888 filed on July 24, 2024. All contents disclosed in the documents of the said Korean patent applications are incorporated herein by reference.

[0002] The present invention relates to a battery module and a battery pack including the same, and more particularly to a battery module capable of preventing overflow of a thermally conductive resin and a battery pack including the same. [Background Art]

[0003] Secondary batteries, which have high applicability to different product groups and electrical characteristics such as high energy density, are widely applied not only to portable devices but also to electric vehicles driven by electric drive sources, hybrid vehicles, power storage devices and the like. Such secondary batteries are attracting attention as a new energy source for being environmentally friendly and improving energy efficiency, not only because they have the primary advantage of being able to dramatically reduce the use of fossil fuels, but also because they do not generate any by-products from energy use.

[0004] While small mobile devices use one, two, three or four battery cells per device, medium and large devices such as automobiles require high output and large capacity. Therefore, medium and large-sized battery modules in which a plurality of battery cells are electrically connected are used.

[0005] Medium- and large-sized battery modules are preferably manufactured to be as small in size and weight as possible, allowing for high-density stacking. Prismatic batteries and pouch-type batteries, which have a small weight relative to their capacity, are mainly used as battery cells in medium- and large-sized battery modules. On the other hand, battery modules may include a frame member that houses the battery cell stack in an internal space, with the front and rear sides open to protect the cell stack from external shocks, heat, or vibrations.

[0006] Figure 1 is an exploded perspective view showing a conventional battery module.

[0007] Figure 2 is a perspective view of a conventional battery cell stack, seen from below.

[0008] Figure 3 is a cross-sectional view showing the battery module of Figure 1 cut along the YZ plane.

[0009] Figure 4 is a cross-sectional view showing an enlarged portion of Figure 3.

[0010] Referring with Figures 1 and 2, a conventional battery module 100c includes a battery cell stack 12 containing a plurality of battery cells 11 and a module frame 30 that houses the battery cell stack 12 inside. The battery cell stack 12 may further include compression pads 10 positioned between the plurality of battery cells 11, as shown in Figure 3.

[0011] The battery module 100c may further include an upper plate (not shown) which is coupled with the module frame 30 to cover the top of the battery cell stack 120, end plates (not shown) located on the front and rear surfaces of the battery cell stack 12, respectively, and a busbar frame 13 located between the battery cell stack 12 and the end plates (not shown).

[0012] A conventional module frame 30 includes a bottom portion 30a and two opposing side portions 30b. The bottom portion 30a may have a shape in which the front and rear surfaces are open along the X-axis direction and the top is open along the Z-axis direction. The side portions 30b may extend along the Z-axis direction on both sides of the bottom portion 30a. The bottom portion 30a and the side portions 30b form a space for housing the battery cell stack 12.

[0013] On the other hand, a thermally conductive resin layer 31 can be formed between the module frame 30 and the battery cell stack 12 before the battery cell stack 12 is attached to the module frame 30. The thermally conductive resin layer 31 can transfer heat generated from the battery cell stack 12 to the outside of the battery module and fix the battery cell stack inside the battery module.

[0014] The thermally conductive resin layer 31 can be formed by applying and curing a thermally conductive resin to the bottom 30a of the module frame 30. Alternatively, pads 32 can be placed on the bottom 30a to prevent the thermally conductive resin from overflowing outside the required area during application. The pads 32 are positioned at both ends of the bottom 30a to control the application direction of the thermally conductive resin. However, during the process of spreading the thermally conductive resin, it may spread beyond the pads 32 to areas other than the application site.

[0015] Referring to Figures 3 and 4, after the battery cell stack 12 is attached to the module frame 30, there is an incompletely filled space SP between the pad 32 and the battery cell stack 12. The thermal conductive resin may overflow from the pad 32 through this space SP during the coating process. In this case, the battery cell stack 12 may be damaged, potentially leading to a decrease in the performance of the battery cell stack 12 and safety issues.

[0016] Therefore, it is necessary to develop a structure that can control the overflow of the thermally conductive resin during the formation process of the thermally conductive resin layer. [Overview of the Initiative] [Problems that the invention aims to solve]

[0017] The problem that this invention aims to solve is to provide a battery module and a battery pack including the same in which the overflow of thermally conductive resin is prevented.

[0018] However, the problems that the embodiments of the present invention aim to solve are not limited to those described above, and can be broadly expanded within the scope of the technical ideas included in the present invention. [Means for solving the problem]

[0019] The battery module of the present invention includes a battery cell stack comprising a plurality of battery cells; a module frame comprising a bottom and two opposing side portions, which houses the battery cell stack internally; a thermally conductive resin layer disposed between one surface of the module frame and the battery cell stack; a pad disposed at at least one end of the one surface of the module frame; and a complementary material disposed between the battery cell stack and the pad, wherein the complementary material fills the space between the battery cell stack and the pad.

[0020] In one embodiment, the aforementioned surface may be the upper surface of the bottom portion.

[0021] In one embodiment, the one surface may be the inner surface of the side surface.

[0022] In one embodiment, the complementary material may include a resin.

[0023] In one embodiment, the thermally conductive resin layer may not overflow to the outside of the pad and the complementary material.

[0024] In one embodiment, the complementary material may first be provided to one surface of the battery cell stack in an uncured state, and then compressed and cured between the battery cell stacks and the pad when the battery cell stack is housed in the module frame.

[0025] In one embodiment, the complementary material may be a polyurethane foam (PU foam).

[0026] In one embodiment, the complementary material may be silicone.

[0027] In one embodiment, a plurality of the pads may be disposed at both ends of the one surface of the module frame, and the heat-conductive resin layer may be disposed between the pads.

[0028] The battery pack of the present invention includes the battery module described above. Effects of the Invention

[0029] The battery module of the present invention includes the complementary material filling a space between the battery cell stack and the pad, which can prevent the heat-conductive resin from flowing into an unintended space when inserting the battery cell stack into the module frame. Brief Description of the Drawings

[0030] [Figure 1] Figure 1 is an exploded perspective view showing a conventional battery module. [Figure 2] Figure 2 is a bottom perspective view showing a conventional battery cell stack. [Figure 3] Figure 3 is a cross-sectional view showing a cross-section of the battery module of Figure 1 taken along the YZ plane. [Figure 4] Figure 4 is an enlarged cross-sectional view showing a part of Figure 3. [Figure 5] Figure 5 is a plan view showing a battery pack according to one embodiment. [Figure 6] Figure 6 is an exploded perspective view showing a battery module according to one embodiment. [Figure 7] Figure 7 is an assembled perspective view showing a battery module in which the components shown in Figure 6 are assembled. [Figure 8] Figure 8 is a bottom perspective view showing the battery module of Figure 6. [Figure 9]Figure 9 is a cross-sectional view showing the battery module of Figure 7 cut along the YZ plane. [Figure 10] Figure 10 is a cross-sectional view showing an enlarged portion of Figure 9. [Modes for carrying out the invention]

[0031] The following describes in detail, with reference to the attached drawings, various embodiments of the present invention so that those with ordinary skill in the art to which the present invention pertains can easily implement them. The present invention can be embodied in a variety of different forms and is not limited to the embodiments described herein.

[0032] To clearly explain the present invention, unnecessary explanatory parts have been omitted, and the same or similar reference numerals are used throughout the specification for identical or similar components.

[0033] Furthermore, the dimensions and thicknesses of each component shown in the drawings are arbitrarily shown for the sake of explanation and are not necessarily limited to those shown in the present invention. The thicknesses are shown enlarged in the drawings to clearly represent various layers and regions. In addition, the thicknesses of some layers and regions are exaggerated in the drawings for the sake of explanation.

[0034] Furthermore, when a layer, membrane, region, plate, or other part is said to be "on top of" another part, this includes not only the case where it is "directly above" the other part, but also the case where the other part is in between. Conversely, when one part is said to be "directly above" another part, it means that there is no other part in between. Also, being "on top of" a reference part means being located above or below the reference part, and does not necessarily mean being located "up" in the opposite direction of gravity.

[0035] Furthermore, when a specification states that a part of it "includes" a certain component, this means that, unless otherwise stated, it does not exclude other components and may include other components.

[0036] Furthermore, throughout the specification, "on a plane" means when the subject is viewed from above, and "on a cross-section" means when the subject is viewed from the side of a cross-section obtained by cutting the subject perpendicularly.

[0037] Figure 5 is a plan view showing a battery pack according to one embodiment.

[0038] Referring to Figure 5, a battery pack 1000 according to one embodiment includes a battery module 100, a pack frame 1100, a busbar assembly 1200, a BDU (battery disconnect unit) module 1300 for controlling the electrical connections of the battery module 100, and a BMS (battery management system) module 1400 for monitoring and controlling the operation of the battery module 100. At least one busbar assembly 1200 according to this embodiment electrically connects at least one of the following: between the battery modules 100, between the battery module 100 and the BDU module 1300, between the battery module 100 and the BMS module 1400, and between the BDU module 1300 and the BMS module 1400. Specifically, multiple battery modules 100 can be housed in the pack frame 1100, and the electric connections between the battery modules 100 and between the battery module 100 and the BDU module 1300 can be made by the busbar assembly 1200. In other words, the busbar assembly 1200 according to this embodiment can handle HV (High Voltage) connections. Here, HV connection refers to the connection of power sources that supply power requiring high voltage, and means connections between battery cells or connections between battery modules.

[0039] On the other hand, the BDU module 1300 is a component for controlling the electrical connection of the battery module 100, and can interrupt the power supply between the power converter and the battery module 100.

[0040] The BDU module 1300 can ensure the safety of the battery pack 1000 by shutting off the power supply to the battery pack 1000 when conditions occur that cause the current to exceed a set range.

[0041] On the other hand, the LV connecting member 1200' according to this embodiment can be responsible for the electrical connection between the battery module 100 and the BMS module 1400. The electrical connection here is an LV (Low voltage) connection, meaning a sensing connection for sensing and controlling the voltage and temperature of the battery module 100. Specifically, sensors such as those inside the battery module 100 are arranged, and real-time temperature and voltage information of the battery module 100 is transmitted to the BMS module 1400 through the LV connecting member 1200'. The real-time operating state of the battery module 100 can be monitored and controlled through the BMS module 1400. Although not specifically shown, an HV current sensor may be integrated into the BMS module 1400. In this case, the busbar assembly according to this embodiment can be responsible for the electrical connection between the battery module 100 and the BMS module 1400 or between the BDU module 1300 and the BMS module 1400.

[0042] A battery module according to one embodiment will be described below with reference to Figures 6 to 10. However, the battery module 100 described later is one example structure of a battery module including a battery cell stack 120, and various forms of battery modules including a battery cell stack 120 can be applied.

[0043] Figure 6 is an exploded perspective view showing a battery module according to one embodiment.

[0044] Figure 7 is a coupled perspective view showing a battery module in which the components shown in Figure 6 are combined.

[0045] Figure 8 is a perspective view of the battery module shown in Figure 6, viewed from below.

[0046] Figure 9 is a cross-sectional view showing the battery module of Figure 7 cut along the YZ plane.

[0047] Figure 10 is a cross-sectional view showing an enlarged portion of Figure 9.

[0048] Referring to both Figures 6 and 7, the battery module 100 according to this embodiment includes a battery cell stack 120 containing a plurality of battery cells 110 and a module frame 300 that houses the battery cell stack 120 inside. The battery cell stack 120 includes a plurality of battery cells 110 stacked in one direction, for example, the plurality of battery cells 110 may be stacked in the Y-axis direction as shown in Figure 6. The battery cells 110 may be pouch-type battery cells, but embodiments of the present invention are not limited thereto. On the other hand, the battery cell stack 120 may further include compression pads 111 placed between the plurality of battery cells 110 as shown in Figure 9. The compression pads 111 include foam foam or the like and can absorb the expansion of the battery cells 110 to improve the structural stability of the battery module 100.

[0049] The battery module 100 may further include an upper plate 400 that is coupled with a module frame 300 to cover the top of the battery cell stack 120, end plates 150 located on the front and rear surfaces of the battery cell stack 120, and a busbar frame 130 located between the battery cell stack 120 and the end plates 150.

[0050] The battery module 100 includes a thermally conductive resin layer 310 located between the battery cell stack 120 and the module frame 300. The thermally conductive resin layer 310 may be a thermally conductive adhesive. Various organic and / or inorganic resins may be used as the thermally conductive adhesive, such as thermally conductive epoxy adhesive, thermally conductive silicone adhesive, or thermally conductive urethane adhesive. Such a thermally conductive resin layer 310 can serve to bond and fix the battery cell stack 120 within the battery module 100. Furthermore, because the thermally conductive resin layer 310 has a higher thermal conductivity than general adhesives, it can further increase the amount and rate of heat transfer between the battery cell stack 120 and the module frame 30, and can serve as a heat dissipation layer that transfers heat generated from the battery cell stack 120 to the outside of the battery module 100. The thermally conductive resin layer 310 is placed between the battery cell stack 120 and one side of the module frame 300.

[0051] The module frame 300 may have an open shape with its top, front, and rear surfaces. The module frame 300 may also be a U-shaped frame. When the open sides of the module frame 300 are referred to as the first side and the second side, the module frame 300 consists of a plate-like structure that is folded to continuously enclose the adjacent front, bottom, and rear surfaces, excluding the surfaces of the battery cell stack 120 corresponding to the first and second sides. The top surface of the module frame 300, opposite the bottom surface, is open.

[0052] A pad 320 is placed on one surface of the module frame 300, which can guide the application position of the thermal conductive resin during the formation process of the thermal conductive resin layer 310.

[0053] The module frame 300 includes a bottom portion 300a and two side portions 300b facing each other. As described above, the thermal conductive resin layer 310 is disposed between one surface of the module frame 300 and the battery cell stack 120. The surface of the module frame 300 may be either the top surface of the bottom portion 300a or the inner surface of the side portion 300b. The top surface of the bottom portion 300a may be the surface facing the bottom surface of the battery cell stack 120. The inner surface of the side portion 300b may be the surfaces facing the front and rear surfaces of the battery cell stack 120. In one embodiment, the thermal conductive resin layer 310 may be disposed between the top surface of the bottom portion 300a of the module frame 300 and the battery cell stack 120. Alternatively, in another embodiment, the thermal conductive resin layer 310 may be disposed between the inner surface of the side portion 300b of the module frame 300 and the battery cell stack 120.

[0054] In the following explanation, we will describe a case where the thermally conductive resin layer 310 is placed on the upper surface of the bottom 300a of the module frame 300, as an example. In other words, we will explain using a structure in which the thermally conductive resin layer 310, the pad 320, and the complementary material RS (described later) are placed on the bottom 300a as an example.

[0055] However, the embodiments of the present invention are not limited thereto, and the thermally conductive resin layer 310 may be placed on the inner surface of the side portion 300b other than the bottom portion 300a. In this case as well, the explanation of the relationship between the thermally conductive resin layer 310, the pad 32, and the complementary material RS described later applies similarly.

[0056] In one embodiment, referring to Figure 6, the thermally conductive resin layer 310 is formed by coating the bottom portion 300a in a lengthwise direction in the X-axis direction, which is the extension direction of the bottom portion 300a.

[0057] The pad 320 is positioned at least one end of the bottom portion 300a. For example, the pads 320 can be positioned at both ends of the bottom portion 300a to guide the application position of the thermal conductive resin during the formation process of the thermal conductive resin layer 310, or to prevent the thermal conductive resin from overflowing outside the pads 320. Figure 6 shows that one pad 320 is formed at each end of the bottom portion 300a, but the size, position, and number of pads 320 can be modified in design considering the amount of thermal conductive resin to be applied. The pads 320 can be insulating. Furthermore, the pads 320 may be made of a material such as polyurethane foam (PU foam) or rubber so that the pads 320 that come into contact with the bottom surface of the battery cell stack 120 are compressed when the battery cell stack 120 is inserted into the module frame 300.

[0058] The upper plate 400 is a single plate-shaped structure that surrounds the remaining upper surface, excluding the front, bottom, and rear surfaces, which are enclosed by the module frame 300. The module frame 300 and the upper plate 400 can be joined by welding or other means, with their corresponding corner portions in contact with each other, thereby forming a structure that surrounds the battery cell stack 120. In other words, the module frame 300 and the upper plate 400 may have joint portions CP formed by welding or other joining methods at their corresponding corner portions.

[0059] Referring to Figures 6, 8, 9, and 10, a complementary material RS is placed between the battery cell stack 120 and the pad 320 in one embodiment. To illustrate the location where the complementary material RS is formed, the pad 320 is omitted in Figure 8. The complementary material RS may be positioned along the Y-axis direction, which is the extension direction of the pad 320. The complementary material RS serves to fill the space SP (see Figure 3) between the battery cell stack 120 and the pad 320 when the battery cell stack 120 is housed in the module frame 300. Space SP (see Figure 3) refers to the gap between the battery cell stack 120 and the pad 320. The complementary material RS prevents the thermally conductive resin layer 310 from overflowing from the pad 320 through space SP (see Figure 3).

[0060] The complementary material RS may include resin. For example, the complementary material RS may be polyurethane foam (PU foam) formed by applying a polyurethane spray or the like to one surface of the battery cell laminate 120, for example, the bottom surface. Alternatively, the complementary material RS may be silicon formed on one surface of the battery cell laminate 120, for example, the bottom surface, using a silicon gun or the like. However, the material of the complementary material RS is not limited to the above, and any material having insulating properties and a predetermined compressibility is acceptable.

[0061] The complementary material RS may first be provided in an uncured state to one surface of the battery cell stack 120, for example, the bottom surface, and then compressed and cured between the battery cell stack 120 and the pad 320 when the battery cell stack 120 is housed in the module frame 300. During the compression process, the complementary material RS can fill the space SP (see Figure 3) between the battery cell stack 120 and the pad 320.

[0062] The battery module 100 of the present invention includes a complementary material RS positioned between the battery cell stack 120 and a pad 320 located at the bottom 300a of the module frame 300. The space between the battery cell stack 120 and the pad 320 is filled with the complementary material RS, effectively controlling the overflow of the thermally conductive resin. This prevents defects in the battery module 100 that occur due to the formation of a thermally conductive resin layer 310 in unintended areas.

[0063] In this embodiment, terms indicating directions such as front, back, left, right, and up and down were used, but such terms are merely for the convenience of explanation and can change depending on the position of the object in question, the observer's position, etc.

[0064] One or more battery modules according to the embodiment described above can be mounted together with various control and protection systems such as a Battery Management System (BMS), Battery Disconnect Unit (BDU), and cooling system to form a battery pack.

[0065] The aforementioned battery modules and battery packs can be applied to a variety of devices. Specifically, they can be applied to means of transportation such as electric bicycles, electric vehicles, and hybrids, as well as ESS (Energy Storage Systems), but are not limited to these, and can be applied to a variety of devices that can use secondary batteries.

[0066] Although preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto. Various modifications and improvements by those skilled in the art, using the basic concepts of the present invention as defined in the following claims, also fall within the scope of the present invention. [Explanation of Symbols]

[0067] 100: Battery Module 120: Battery cell stack 110: Battery cell 111: Compression pad 300: Module Frame 300a: Bottom 300b: Side part 310: Thermally conductive resin layer 320: Pad 400: Top plate RS: Complementary material

Claims

1. A battery cell stack containing multiple battery cells, A module frame comprising a bottom and two opposing side sections, which houses the battery cell stack inside, A thermally conductive resin layer is disposed between one surface of the module frame and the battery cell stack. A pad disposed at at least one end of one surface of the module frame to prevent the thermally conductive resin layer from spilling outwards, and A complementary material is placed between the battery cell stack and the pad. Includes, A battery module in which the complementary material fills the space between the battery cell laminate and the pad, preventing the thermally conductive resin layer from spilling out through the space.

2. The battery module according to claim 1, wherein the aforementioned surface is the upper surface of the bottom.

3. The battery module according to claim 1, wherein the aforementioned surface is the inner surface of the side portion.

4. The battery module according to claim 1, wherein the complementary material includes a resin.

5. The battery module according to any one of claims 1 to 4, wherein the thermally conductive resin layer does not overflow to the outside of the pad and the complementary material.

6. The battery module according to claim 1, wherein the complementary material is first provided in an uncured state to one surface of the battery cell stack, and then compressed and cured between the battery cell stack and the pad when the battery cell stack is housed in the module frame.

7. The battery module according to claim 1, wherein the complementary material is polyurethane foam.

8. The battery module according to claim 1, wherein the complementary material is silicon.

9. Multiple pads are arranged at both ends of one surface of the module frame. The battery module according to claim 1, wherein the thermally conductive resin layer is disposed between the pads.

10. A battery pack comprising the battery module described in claim 1.

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