KR102931490B1 - Battery module and battery pack including the same - Google Patents

Abstract

A battery module according to one embodiment of the present invention comprises: a battery cell stack having a plurality of battery cells stacked thereon; a module frame accommodating the battery cell stack; a compression pad disposed between the plurality of battery cells; and a thermally conductive resin layer formed between the battery cell stack and a bottom portion of the module frame, wherein the compression pad is formed to be in contact with the bottom portion of the module frame.

Description

Battery module and battery pack including the same {BATTERY MODULE AND BATTERY PACK INCLUDING THE SAME}

The present invention relates to a battery module and a battery pack including the same, and more particularly, to a battery module with improved durability and a battery pack including the same.

Secondary batteries are attracting significant attention as an energy source for a wide range of products, including mobile devices and electric vehicles. These batteries are a promising energy source that can replace the use of existing fossil fuels. They are also gaining recognition as an environmentally friendly energy source, as they produce no byproducts from energy use.

Recently, as the need for large-capacity secondary battery structures has increased, including the use of secondary batteries as energy storage sources, the demand for battery packs with multi-module structures that assemble battery modules in which a number of secondary batteries are connected in series/parallel is increasing.

Meanwhile, when configuring a battery pack by connecting multiple battery cells in series/parallel, it is common to configure a battery module composed of at least one battery cell, and then configure a battery pack by adding other components using at least one battery module.

These battery modules include a battery cell stack in which a plurality of battery cells are stacked, a module frame that accommodates the battery cell stack, and a compression pad disposed between the plurality of battery cells.

Fig. 1 is a cross-sectional view showing a conventional battery module. Fig. 2 is an enlarged view of part A of Fig. 1. Fig. 3 is a drawing showing the portion where the compression pad of Fig. 2 receives force.

Referring to FIGS. 1 to 3, a conventional battery module may include a battery cell stack in which a plurality of battery cells (10) are stacked, a module frame (20) that accommodates the battery cell stack, a compression pad (30) arranged between the plurality of battery cells, and a thermally conductive resin layer (40) formed between the battery cell stack and the bottom of the module frame.

A swelling phenomenon may occur in which the battery cells (10) expand as the electrolyte inside the battery cells (10) vaporizes. When the swelling phenomenon occurs, the battery cells (10) swell and can pressurize the compression pad (30) formed between the battery cells (10).

At this time, as illustrated in Fig. 3, a phenomenon in which stress is concentrated on the lower portions on both sides of the compression pad (30) due to the swelling phenomenon may occur. The lower portions on both sides of the compression pad (30) where stress is concentrated may have a cured thermally conductive resin layer (40) positioned on the lower side, and battery cells (10) positioned on both sides. At this time, as the battery cells (10) positioned on both sides of the compression pad (30) swell, stress may be concentrated on the lower portions on both sides of the compression pad (30).

If stress is concentrated on the lower portions of both sides of the compression pad (30), there is a risk that the area where the stress is concentrated may be damaged, and the durability of the inside of the module may deteriorate during long-term use of the battery module.

The problem to be solved by the present invention is to provide a battery module and a battery pack including the same that improves the durability of the battery module by eliminating a stress concentration area inside the battery module.

The tasks of the present invention are not limited to the tasks mentioned above, and other tasks not mentioned will be clearly understood by those skilled in the art from the description below.

According to one embodiment of the present invention for realizing the above task, a battery module includes a battery cell stack having a plurality of battery cells stacked on top of each other; a module frame accommodating the battery cell stack; a compression pad disposed between the plurality of battery cells; and a thermally conductive resin layer formed between the battery cell stack and a bottom portion of the module frame, wherein the compression pad is formed to be in contact with the bottom portion of the module frame.

The above compression pad divides the space between the module frame bottom and the battery cell stack, and the thermally conductive resin layer can be separately applied to each space divided from the compression pad.

The above compression pad and the plurality of battery cells can be fixed by an adhesive member.

The thermally conductive resin layer formed by applying a thermally conductive resin can be cured to fix the module frame and the plurality of battery cells.

The above compression pads can be placed between the outermost battery cell of the battery cell stack and both sides of the module frame.

The above compression pad can be placed at the center of the battery cell stack.

The above plurality of battery cells can be fixed to each other through an adhesive member.

The above plurality of battery cells can be arranged in a direction facing each other with the compression pad as the center.

The lower center portion of the above compression pad can be joined to the bottom portion of the above module frame through an adhesive member.

A battery pack according to another embodiment of the present invention includes the battery module.

A battery module and a battery pack including the same according to one embodiment of the present invention provide an effect of eliminating a stress concentration area and improving the durability of the battery module by forming a compression pad extended to touch the bottom of the module frame.

The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

Figure 1 is a cross-sectional view showing a conventional battery module.
Figure 2 is an enlarged view of part A of Figure 1.
Figure 3 is a drawing showing the portion where the compression pad of Figure 2 receives force.
Figure 4 is a drawing showing a battery module according to one embodiment of the present invention.
FIG. 5 is a cross-sectional view of a battery module according to one embodiment of the present invention, taken as part DD of FIG. 4.
Figure 6 is an enlarged view showing part B of Figure 5.
Figure 7 is a drawing showing the compression pad of Figure 6 compressed due to the swelling phenomenon of battery cells.
Figure 8 is an enlarged view of part C of Figure 7.

The embodiments described below are provided as examples to aid in understanding the invention, and it should be understood that the present invention can be implemented in various ways other than the embodiments described herein. However, when describing the present invention, if it is determined that a detailed description of a related known function or component may unnecessarily obscure the gist of the present invention, a detailed description and specific illustration thereof will be omitted. In addition, the attached drawings are not drawn to scale to aid in understanding the invention, and the dimensions of some components may be exaggerated.

The first and second terms used in this application may be used to describe various components, but the components should not be limited by the terms. The terms are used solely to distinguish one component from another.

In addition, the terminology used in this application is only used to describe specific embodiments and is not intended to limit the scope of the rights. The singular expression includes the plural expression unless the context clearly indicates otherwise. It should be understood that the terms "comprises," "consists of," or "consists of" in this application are intended to specify the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not preclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

Hereinafter, a battery module according to one embodiment of the present invention will be described with reference to FIGS. 4 and 5.

Fig. 4 is a drawing showing a battery module according to one embodiment of the present invention. Fig. 5 is a cross-sectional view taken along section D-D of Fig. 4 showing a battery module according to one embodiment of the present invention.

Referring to FIGS. 4 and 5, a battery module according to one embodiment of the present invention includes a battery cell stack (100) in which a plurality of battery cells (110) are stacked, a module frame (200) that accommodates the battery cell stack (100), a compression pad (300) arranged between the plurality of battery cells (110), and a thermally conductive resin layer (400) formed between the battery cell stack (100) and the bottom portion (210) of the module frame (200). The compression pad (300) is formed to be in contact with the bottom portion (210) of the module frame (200).

The battery cell (110) is a secondary battery and may be configured as a pouch-type secondary battery. The battery cell (110) may be configured in multiple pieces, and the multiple battery cells (110) may be electrically connected to each other and stacked to form a battery cell stack (100). Each of the multiple battery cells (110) may include an electrode assembly, a battery case, and an electrode lead protruding from the electrode assembly.

The battery cell stack (100) is formed by being surrounded by a module frame (200) covering the lower surface and both sides and an upper plate (230) covering the upper surface. At this time, the battery cell stack (100) is inserted onto the module frame (200), and then the battery cell stack (100) can be mounted inside the module frame (200) by covering the upper surface of the battery cell stack through the upper plate (230).

The module frame (200) and the upper plate (230) are coupled to each other to accommodate the battery cell stack (100) positioned inside the module frame (200). At this time, the module frame (200) and the upper plate (230) can be coupled to each other through welding. More specifically, the upper corners of both sides of the module frame (200) and the lower sides of both sides of the upper plate (230) can be coupled to each other through welding.

A busbar frame (not shown) is formed on each of the front and rear surfaces of the battery cell stack (100). The busbar frame includes a busbar and a cell connection board, and may be formed to cover the front and rear surfaces of the battery cell stack so as to electrically connect electrode leads of a plurality of battery cells (110). An end plate (240) may be mounted on each of the outer surfaces of the busbar frame. The end plate (240) may protect various electrical components provided in the busbar frame from external impact, and at the same time, guide electrical connection between the busbar frame and an external power source. An insulating member (not shown) may be inserted between the end plate (240) and the busbar frame to block electrical connection between the busbar frame and the outside.

As illustrated in FIG. 5, a compression pad (300) is formed between a plurality of battery cells (110). The compression pad (300) can absorb swelling of the battery cells (110) to secure durability within the battery module. The plurality of battery cells (110) can be arranged facing each other with the compression pad (300) as the center. Since the plurality of battery cells (110) are formed symmetrically with the compression pad (300) as the center, the same stress can be applied to both ends of the compression pad (300).

A thermally conductive resin layer (400) may be formed between the battery cell stack (100) and the bottom portion (210) of the module frame (200). The thermally conductive resin layer (400) may transfer heat generated from the battery cell stack (100) to the outside. The thermally conductive resin layer (400) may be formed by applying a thermally conductive resin to the bottom portion (210) of the module frame (200). The applied thermally conductive resin may be cured between the battery cell stack (100) inserted into the module frame (200) and the bottom portion (210) to fix the module frame (200) and the battery cell stack (100).

Hereinafter, a battery module including a compression pad according to one embodiment of the present invention will be described with reference to FIGS. 4 to 8.

Fig. 6 is an enlarged view of part B of Fig. 5. Fig. 7 is a drawing showing the compression pad of Fig. 6 compressed due to the swelling phenomenon of the battery cells. Fig. 8 is an enlarged view of part C of Fig. 7.

According to the present embodiment, the compression pad (300) is formed to be in contact with the bottom portion (210) of the module frame. Conventionally, as illustrated in FIG. 3, the lower portion of the compression pad is spaced apart from the bottom portion of the module frame, and thus, due to swelling of the battery cells, the lower portions on both sides of the compression pad come into contact with the edges of the swelling battery cells and the thermally conductive resin layer, resulting in a phenomenon in which stress is concentrated in the corresponding portion. If stress is concentrated in a specific portion, the durability of the battery module may be reduced.

Accordingly, according to the present embodiment, the lower part of the compression pad (300) is formed to extend and come into contact with the module frame bottom part (210), so that stress is no longer concentrated on the lower part of the compression pad (300) as shown in FIG. 7, thereby solving the problem of reduced durability due to stress concentration.

According to the present embodiment, the compression pad (300) is placed at the center of the battery cell stack (100) to divide the space between the module frame bottom (210) and the battery cell stack (100), and the thermally conductive resin is separately applied to each of the spaces divided from the compression pad (300) to form a separate thermally conductive resin layer (400). The appearance of the thermally conductive resin layer (400) being separately applied can be confirmed in FIGS. 4, 6, and 7.

Since the thermally conductive resin layer (400) is formed by being applied in a divided manner, the thermally conductive resin applied in the direction in which the compression pad (300) is located can penetrate, so that a free space in which the thermally conductive resin layer (400) can be formed can be secured.

Referring to FIG. 6, the compression pad (300) and the plurality of battery cells (110) can be fixed by an adhesive member (500). In addition, the plurality of battery cells (110) can be fixed to each other by an adhesive member (510). Referring to FIG. 5, the compression pad (310) can also be placed between the outermost battery cell of the battery cell stack (100) and both sides of the module frame (200).

Referring to FIG. 8, the lower center portion of the compression pad (300) can be coupled to the bottom portion (210) of the module frame (200) via an adhesive member (520). Through this, the compression pad (300) and the bottom portion (210) of the module frame are coupled, so that the lower portion of the compression pad (300) can be centered without being tilted to one side due to the application of thermally conductive resin. In addition, since the lower surface of the compression pad (300) is adhered face-to-face to the bottom portion (210) of the module frame, the stress acting on the lower portion of the compression pad (300) can be distributed on a surface basis.

The battery modules described above may be included in a battery pack. The battery pack may be structured by packaging one or more battery modules according to the present embodiment, adding a battery management system (BMS) that manages the temperature and voltage of the battery, a cooling device, etc.

The above battery pack can be applied to various devices. These devices include electric bicycles, electric vehicles, hybrid vehicles, and other transportation vehicles. However, the present invention is not limited thereto and can be applied to various devices that utilize battery modules, which also fall within the scope of the present invention.

Although the preferred embodiments of the present invention have been illustrated and described above, the present invention is not limited to the specific embodiments described above, and various modifications may be made by those skilled in the art without departing from the spirit or scope of the present invention as claimed in the claims. Furthermore, such modifications should not be understood individually from the technical idea or prospect of the present invention.

100: Battery cell stack
110: Battery cell
200: Module Frame
210: Module frame bottom
300, 310: Compression pad
400: Thermally conductive resin layer
500, 510, 520: Adhesive member

Claims (10)

A battery cell stack in which multiple battery cells are stacked;
A module frame accommodating the above battery cell stack;
a compression pad disposed between the plurality of battery cells; and
Including a thermally conductive resin layer formed between the battery cell laminate and the bottom of the module frame,
The above compression pad is formed to contact the bottom of the module frame,
The above compression pad divides the space between the bottom of the module frame and the battery cell stack,
A battery module in which the thermally conductive resin layer is applied separately to each space divided from the compression pad. delete In paragraph 1,
A battery module in which the compression pad and the plurality of battery cells are fixed by an adhesive member. In paragraph 1,
A battery module in which the thermally conductive resin layer formed by applying a thermally conductive resin is cured to fix the module frame and the plurality of battery cells. In paragraph 1,
A battery module in which the above compression pad is respectively placed between the outermost battery cell of the battery cell stack and both sides of the module frame. In paragraph 1,
A battery module in which the above compression pad is placed at the center of the above battery cell stack. In paragraph 1,
A battery module in which the above plurality of battery cells are fixed to each other through an adhesive member. In paragraph 1,
A battery module in which the above plurality of battery cells are arranged facing each other with the compression pad as the center. In paragraph 1,
A battery module in which the lower center portion of the above compression pad is connected to the bottom portion of the above module frame through an adhesive member. A battery pack comprising a battery module according to paragraph 1.