KR20220033855A - Battery module and battery pack including the same - Google Patents

Abstract

The present invention relates to a battery module to minimize the use amount of thermally conductive resin and a battery pack including the same. According to one embodiment of the present invention, the battery module comprises: a battery cell stack in which a plurality of battery cells are stacked; a frame member accommodating the battery cell stack and including an open upper part; a thermally conductive resin layer disposed between the bottom part of the frame member and the battery cell stack; and an upper plate covering the battery cell stack on the upper end of the frame member. The frame member includes two side parts facing each other and the bottom part connecting the two side parts. A press-formed protruding pattern is formed on the bottom of the frame member in a direction toward the battery cell stack and is formed outside an edge of the thermally conductive resin layer.

Description

A battery module and a 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 that improves space utilization and minimizes the amount of thermal conductive resin used, and a battery pack including the same.

Secondary batteries that are easy to apply according to product groups and have electrical characteristics such as high energy density are universally applied to electric vehicles or hybrid vehicles driven by an electric drive source, as well as portable devices, and power storage devices. These secondary batteries are attracting attention as a new energy source for improving eco-friendliness and energy efficiency in that not only the primary advantage of being able to dramatically reduce the use of fossil fuels but also the fact that no by-products are generated from the use of energy.

While one or two or three battery cells are used per device in small mobile devices, medium and large-sized devices such as automobiles require high output and high capacity. Accordingly, a medium or large-sized battery module in which a plurality of battery cells are electrically connected is used.

Since it is desirable to manufacture the mid-to-large-sized battery module as small as possible in size and weight, a prismatic battery, a pouch-type battery, etc. that can be stacked with a high degree of integration and have a small weight to capacity are mainly used as battery cells of the mid- to large-sized battery module. Meanwhile, in order to protect the cell stack from external shock, heat, or vibration, the battery module may include a frame member having front and rear surfaces open to accommodate the battery cell stack in an internal space.

1 is a perspective view showing a battery module having a conventional mono frame.

Referring to FIG. 1 , the battery module includes a battery cell stack 12 formed by stacking a plurality of battery cells 11 , a mono frame 20 with front and rear surfaces open to cover the battery cell stack 12 , and An end plate 60 covering the front and rear surfaces of the mono frame 20 may be included. In order to form such a battery module, horizontal assembly is required so that the battery cell stack 12 is inserted into the open front or rear surface of the mono frame 20 along the x-axis direction as shown by the arrow shown in FIG. 1 . However, sufficient clearance must be secured between the battery cell stack 12 and the mono frame 20 so that the horizontal assembly can be stably performed. Here, the clearance refers to a gap generated by fitting or the like.

A thermally conductive resin layer (not shown) may be formed between the battery cell stack 12 and the mono frame 20 . The thermally conductive resin layer may serve to transfer heat generated from the battery cell stack to the outside of the battery module, and to fix the battery cell stack in the battery module. If the tolerance is increased, the amount of the thermally conductive resin layer used may be increased more than necessary.

In addition, the height of the mono frame 20 should be designed to be large in consideration of the maximum height of the battery cell stack 12 and assembly tolerances during the insertion process, and thus an unnecessary wasted space may occur.

SUMMARY OF THE INVENTION An object of the present invention is to provide a battery module that improves space utilization and minimizes the amount of thermal conductive resin used, and a battery pack including the same.

However, the problems to be solved by the embodiments of the present invention are not limited to the above problems and may be variously expanded within the scope of the technical idea included in the present invention.

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 frame member accommodating the battery cell stack and an open top, and a bottom portion of the frame member and the battery cell stack a thermal conductive resin layer positioned between the sieves, and an upper plate covering the battery cell stack on an upper portion of the frame member, wherein the frame member has two side parts facing each other and the bottom connecting the two side parts and a protrusion pattern press-molded in a direction toward the battery cell stack is formed on the bottom of the frame member, and the protrusion pattern is formed outside the edge of the thermally conductive resin layer.

The bottom portion includes a first portion in which the thermally conductive resin layer is positioned and a second portion in which the bottom portion is exposed without being covered with the thermally conductive resin layer, and the protrusion pattern is formed between the first portion and the second portion. can be located in

A thickness of the protrusion pattern may be the same as at least one of a thickness of the first portion and a thickness of the second portion.

At least one block pattern may be formed at a boundary portion where the bottom portion and the side portion are connected, and the block pattern may have a structure press-molded into the frame member.

The block pattern may include a first block portion positioned in the first portion and a second block portion positioned in the second portion based on the protrusion pattern.

The protrusion pattern may extend long in a stacking direction of the battery cells.

The thermally conductive resin layer includes a first thermally conductive resin layer and a second thermally conductive resin layer, and the battery module further includes an insulating film positioned between the first thermally conductive resin layer and the second thermally conductive resin layer. may include

The battery module may further include an additional protruding pattern positioned between the first thermally conductive resin layer and the insulating film and between the second thermally conductive resin layer and the insulating film.

The bottom part and the side part included in the frame member may be integrally formed.

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

According to embodiments, the space utilization rate may be improved by reducing the tolerance between the battery cell stack and the frame member compared to the prior art by implementing a frame member having a bottom portion and side portions extending upward from both ends of the bottom portion.

In addition, by utilizing the overflow prevention structure of the thermal conductive resin, it is possible to prevent the thermal conductive resin from flowing into an unintended space when the battery cell stack is inserted.

In addition, since the frame member is press-molded to form the overflow prevention structure, it is possible to reduce the influence on the overflow prevention performance by the performance of the material when the overflow prevention structure is separately formed using an additional material.

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.

1 is an exploded perspective view showing a battery module having a conventional mono frame.
2 is an exploded perspective view illustrating a battery module according to an embodiment of the present invention.
3 is a perspective view showing a state in which the components of the battery module of FIG. 2 are combined.
4 is a perspective view illustrating one battery cell included in the battery cell stack of FIG. 2 .
5 is a perspective view illustrating a frame member according to a comparative example of the present invention.
6 is a perspective view illustrating a frame member included in the battery module of FIG. 2 .
7 is a partial perspective view showing an enlarged area A of FIG. 6 .
8 is a cross-sectional view taken along the cutting line X-X' of FIG.
9 is a perspective view illustrating a thermally conductive resin layer positioned on the frame member of FIG. 6 .
10 is a perspective view illustrating a frame member according to another embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings, various embodiments of the present invention will be described in detail so that those of ordinary skill in the art can easily carry out the present invention. The present invention may be embodied in several different forms and is not limited to the embodiments described herein.

In order to clearly explain the present invention, parts irrelevant to the description are omitted, and the same reference numerals are assigned to the same or similar components throughout the specification.

In addition, since the size and thickness of each component shown in the drawings are arbitrarily indicated for convenience of description, the present invention is not necessarily limited to the illustrated bar. In order to clearly express various layers and regions in the drawings, the thicknesses are enlarged. And in the drawings, for convenience of description, the thickness of some layers and regions are exaggerated.

Further, when a part of a layer, film, region, plate, etc. is said to be “on” or “on” another part, it includes not only cases where it is “directly on” another part, but also cases where another part is in between. . Conversely, when we say that a part is "just above" another part, we mean that there is no other part in the middle. In addition, to be "on" or "on" the reference part means to be located above or below the reference part, and to necessarily mean to be located "on" or "on" in the direction opposite to the gravity not.

In addition, 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.

In addition, throughout the specification, when referring to "planar", it means when the target part is viewed from above, and "cross-sectional" means when viewed from the side when a cross-section of the target part is vertically cut.

2 is an exploded perspective view illustrating a battery module according to an embodiment of the present invention. 3 is a perspective view showing a state in which the components of the battery module of FIG. 2 are combined. 4 is a perspective view illustrating one battery cell included in the battery cell stack of FIG. 2 .

2 and 3 , the battery module 100 according to the present embodiment includes a battery cell stack 120 including a plurality of battery cells 110, and a frame member ( 300), the upper plate 400 covering the upper portion of the battery cell stack 120, the end plate 150 and the battery cell stack 120 and the end respectively positioned on the front and rear surfaces of the battery cell stack 120, respectively. and a bus bar frame 130 positioned between the plates 150 . In addition, the battery module 100 includes a thermally conductive resin layer 310 positioned between the frame member 300 and the battery cell stack 120 . The thermally conductive resin layer 310 is a kind of heat dissipation layer, and may be formed by coating a material having a heat dissipation function.

When the open both sides of the frame member 300 are referred to as a first side and a second side, respectively, the frame member 300 is the surface of the battery cell stack 120 corresponding to the first side and the second side. Among the remaining outer surfaces, it has a bent plate-shaped structure so as to continuously cover the adjacent front, lower, and rear surfaces. The upper surface corresponding to the lower surface of the frame member 300 is open. The frame member 300 includes a bottom portion 300a and side portions 300b extending upward from both ends of the bottom portion 300a, respectively. In this case, the bottom portion 300a and the two side portions 300b may be integrally formed.

The upper plate 400 has a single plate-shaped structure in which the battery cell stack 120 covers the remaining upper surfaces except for the front, lower, and rear surfaces of which the battery cell stack 120 is covered by the frame member 300 . The frame member 300 and the upper plate 400 may form a structure surrounding the battery cell stack 120 by being coupled by welding or the like in a state in which corresponding corner portions are in contact with each other. That is, the frame member 300 and the upper plate 400 may have a coupling portion CP formed at a corner portion corresponding to each other by a coupling method such as welding.

The battery cell stack 120 includes a plurality of battery cells 110 stacked in one direction, and the plurality of battery cells 110 may be stacked in the y-axis direction as shown in FIG. 2 . In other words, a direction in which the plurality of battery cells 110 are stacked may be parallel to a direction in which the two side portions 300b of the frame member 300 face each other.

The battery cell 110 is preferably a pouch-type battery cell. For example, referring to FIG. 4 , in the battery cell 110 according to the present embodiment, two electrode leads 111 and 112 face each other, so that one end 114a and the other end 114b of the battery body 113 are opposite to each other. ) has a structure protruding from each other. The battery cell 110 is to be manufactured by adhering both ends 114a and 114b of the case 114 and both side surfaces 114c connecting them in a state in which an electrode assembly (not shown) is accommodated in the battery case 114 . can In other words, the battery cell 110 according to the present embodiment has a total of three sealing parts 114sa, 114sb, 114sc, and the sealing parts 114sa, 114sb, 114sc are sealed by a method such as thermal fusion. , the other one side may be formed of a connection part 115 . Between both ends 114a and 114b of the battery case 114 is defined in the longitudinal direction of the battery cell 110 , and one side portion 114c connecting both ends 114a and 114b of the battery case 114 and a connection part A space between 115 may be defined in the height direction of the battery cell 110 .

The connector 115 is a region extending along one edge of the battery cell 110 , and a protrusion 110p of the battery cell 110 may be formed at an end of the connector 115 . The protrusion 110p may be formed on at least one of both ends of the connecting unit 115 and may protrude in a direction perpendicular to the extending direction of the connecting unit 115 . The protrusion 110p may be positioned between one of the sealing parts 114sa and 114sb of both ends 114a and 114b of the battery case 114 and the connection part 115 .

The battery case 114 generally has a laminate structure of a resin layer/metal thin film layer/resin layer. For example, when the battery case surface is made of an O (oriented)-nylon layer, when stacking a plurality of battery cells to form a medium or large-sized battery module, it tends to slide easily due to an external impact. Therefore, in order to prevent this and maintain a stable laminated structure of the battery cells, an adhesive member such as an adhesive such as a double-sided tape or a chemical adhesive bonded by a chemical reaction during adhesion is attached to the surface of the battery case to form a battery cell laminate (120) can be formed. In this embodiment, the battery cells 110 included in the battery cell stack 120 are stacked in the y-axis direction, and the battery cell stack 120 is accommodated in the frame member 300 in the z-axis direction to be described later. Heat transfer may be performed by the thermally conductive resin layer. As a comparative example to this, there is a case where the battery cells are formed as cartridge-shaped parts, and the fixing between the battery cells is made by assembling the battery module frame. In this comparative example, there is little or no cooling action due to the presence of the cartridge-shaped part, or it may proceed in the direction of the surface of the battery cell, and the cooling is not well in the direction of the height of the battery module.

5 is a perspective view illustrating a frame member according to a comparative example of the present invention.

Referring to FIG. 5 , the frame member 30 according to this comparative example includes a bottom part 30a and two side parts 30b facing each other. Before the battery cell stack 120 described in FIG. 2 is mounted on the bottom part 30a of the frame member 30 , a thermal conductive resin is applied to the bottom part 30a of the frame member 30 , and the thermal conductive resin may be cured to form the thermally conductive resin layer 31 .

Before forming the thermally conductive resin layer 31 , that is, before the applied thermally conductive resin is cured, the battery cell stack 120 moves in a direction perpendicular to the bottom 30a of the frame member 30 . While the frame member 30 may be mounted on the bottom (30a). Thereafter, the thermally conductive resin layer 31 formed by curing the thermally conductive resin is positioned between the bottom portion 30a of the frame member 30 and the battery cell stack 120 . In this case, the battery module according to the comparative example may further include a pad part 32 formed on the bottom part 30a of the frame member 30 . A thermally conductive resin layer 31 is positioned inside the pad part 32 . The pad part 32 may guide the application position of the thermal conductive resin or prevent the thermal conductive resin from overflowing to the outside of the bottom part 30a, and at least one may be formed. In addition, if there is no pad part 32 according to the present embodiment, the thermal conductive resin overflows excessively, and if the thermal conductive resin is formed to an unnecessary portion and then hardens, an unintended failure mode may be formed. In FIG. 5 , one pad part 32 is formed at both ends of the bottom part 30a based on the x-axis direction, but the size, position and The number and the like can be modified and designed. The pad part 32 may be formed of an insulating film. In this case, the pad part 32 may be formed of a material such as polyurethane foam or rubber so that the thermal conductive resin can be compressed by contacting the battery cell 110 on the bottom part 300a.

However, in order to form the pad part 32 in this way, the cost increases because an additional material is used to form a separate structure, and in the case of the pad part 32 formed of polyurethane foam, etc., since it is a porous material, the thermal conductive resin is can penetrate. Accordingly, despite the formation of the pad part 32 , the thermal conductive resin may be extended to a portion other than the intended area.

In contrast, the battery module according to the present embodiment is different from the pad part according to the comparative example in order to prevent overflow of the thermal conductive resin, that is, the thermal conductive resin extending to a portion other than the intended area. contain different structures.

Hereinafter, a frame member included in the battery module according to an embodiment of the present invention described with reference to FIGS. 2 to 4 with reference to FIGS. 6 to 8 will be described in detail.

6 is a perspective view illustrating a frame member included in the battery module of FIG. 2 . 7 is a partial perspective view showing an enlarged area A of FIG. 6 . 8 is a cross-sectional view taken along the cutting line X-X' of FIG. 9 is a perspective view illustrating a thermally conductive resin layer positioned on the frame member of FIG. 6 .

6 and 7 , the frame member 300 according to the present embodiment includes two side parts 300b facing each other and a bottom part 300a connecting the two side parts 300b. A protrusion pattern 300p press-molded in the z-axis direction, which is the direction toward the battery cell stack, is formed on the bottom portion 300a of the frame member 300 .

7 to 9 , the bottom portion 300a of the frame member 300 is not covered with the first portion P1 where the thermally conductive resin layer 310 is located and the thermally conductive resin layer 310 . The bottom portion 300a includes the exposed second portion P2. The protrusion pattern 300p may be formed outside the edge of the thermally conductive resin layer 310 . Specifically, the protrusion pattern 300p may be positioned between the first part P1 and the second part P2 of the bottom part 300a. As shown in FIG. 8 , the protrusion pattern 300p according to the present embodiment is formed by a press molding method, and in this case, the thickness of the protrusion pattern 300p is the thickness of the first part P1 and the thickness of the second part P2. ) may be equal to at least one of the thicknesses. The press-formed protrusion pattern 300p may be formed such that a specific portion of the bottom portion 300a rises while substantially maintaining the thickness of the bottom portion 300a. Since the frame member 300 is manufactured by a press process, when the protrusion pattern 300p is generated by press molding, there is no additional equipment or additional process, which may be advantageous in terms of cost.

As shown in FIG. 9 , the protrusion pattern 300p may be formed to extend long along the y-axis direction, which is the stacking direction of the battery cells. The protrusion pattern 300p may serve as the pad part 320 described with reference to FIG. 5 to guide the application position of the thermal conductive resin or to prevent the thermal conductive resin from overflowing out of the area to be applied.

6 to 9 , at least one block pattern 300bp may be formed at a boundary where the bottom part 300a and the side part 300b are connected. The block pattern 300bp has a structure press-molded inside the frame member 300 . The block pattern 300bp includes a first block portion 300bp1 positioned in the first portion P1 of the bottom portion 300a based on the protrusion pattern 300p and a second portion P2 of the bottom portion 300a. It may include a second block portion (300bp2) located in the. It is difficult to exclude the possibility that the thermal conductive resin will leak to both sides of the bottom part 300a only with the protrusion pattern 300p alone, but the block pattern 300bp according to the present embodiment can compensate for this. In addition, since the block pattern 300bp includes the first block portion 300bp1 and the second block portion 300bp2, it is possible to limit the thermal conductive resin from exceeding at least the second block portion 300bp2.

Referring to FIG. 9 , the thermally conductive resin layer 310 includes a first thermally conductive resin layer 310a and a second thermally conductive resin layer 310b, and a first thermally conductive resin layer 310a and a second thermally conductive resin layer 310a. An insulating film 330 may be positioned between the conductive resin layers 310b. The insulating film 330 may function to maintain insulating performance between the battery cell 110 and the frame member 300 , and at least a portion of a thermally conductive resin may be coated on the insulating film 330 .

The thermally conductive resin layer 310 may serve to transfer heat generated in the battery cell 110 of FIG. 2 to the bottom of the battery module 100 and to fix the battery cell stack 120 .

10 is a perspective view illustrating a frame member according to another embodiment of the present invention.

9 and 10 , the frame member 300 according to the present embodiment is formed between the first thermally conductive resin layer 310a and the insulating film 330 and between the second thermally conductive resin layer 310b and the insulating film ( 330) may further include an additional protrusion pattern (300pp) positioned between. The additional protrusion pattern 300pp may extend in parallel to the protrusion pattern 300p. An additional block pattern 300bp may be formed at a boundary where the bottom portion 300a adjacent to both ends of the additional protrusion pattern 300pp and the side portion 300b are connected. The additional block pattern (300bp) has a structure press-molded into the frame member 300 .

Meanwhile, one or more battery modules according to an embodiment of the present invention may be packaged in a pack case to form a battery pack.

The battery module or battery pack according to the present embodiment described above may be applied to various devices. Such a device may be applied to transportation means such as an electric bicycle, an electric vehicle, and a hybrid vehicle, but the present invention is not limited thereto and is applicable to various devices that can use a battery module and a battery pack including the same, and this It belongs to the scope of the invention.

Although preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the present invention as defined in the following claims are also provided. is within the scope of the

300: frame member
300a: bottom
300b: side part
300bp: block pattern
300p: Extrusion pattern
330: insulating film
400: upper plate

Claims (10)

A battery cell laminate in which a plurality of battery cells are stacked;
A frame member accommodating the battery cell stack and having an open top;
A thermally conductive resin layer positioned between the bottom of the frame member and the battery cell stack, and
and an upper plate covering the battery cell stack on an upper portion of the frame member,
The frame member includes two side parts facing each other and the bottom part connecting the two side parts,
A protrusion pattern press-molded in a direction toward the battery cell stack is formed on the bottom of the frame member,
The protrusion pattern is a battery module formed outside the edge of the thermally conductive resin layer. In claim 1,
The bottom portion includes a first portion in which the thermally conductive resin layer is located and a second portion in which the bottom portion is exposed without being covered with the thermally conductive resin layer, and the protrusion pattern is formed between the first portion and the second portion. The battery module located in . In claim 2,
A thickness of the protrusion pattern is the same as at least one of a thickness of the first part and a thickness of the second part. In claim 2,
At least one block pattern is formed at a boundary where the bottom part and the side part are connected,
The block pattern is a battery module having a structure press-molded inside the frame member. In claim 4,
The block pattern may include a first block portion positioned in the first portion and a second block portion positioned in the second portion based on the protrusion pattern. In claim 1,
The protrusion pattern is a battery module extending long along the stacking direction of the battery cells. In claim 1,
The thermally conductive resin layer includes a first thermally conductive resin layer and a second thermally conductive resin layer, and the battery module further comprising an insulating film positioned between the first thermally conductive resin layer and the second thermally conductive resin layer . In claim 7,
The battery module further comprising an additional protruding pattern positioned between the first thermally conductive resin layer and the insulating film and between the second thermally conductive resin layer and the insulating film. In claim 1,
A battery module in which the bottom part and the side part included in the frame member are integrally formed. A battery pack comprising the battery module according to claim 1 .

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