KR20220051776A - Battery module and battery pack including the same - Google Patents

Abstract

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 busbar frame coupled to each of the front and rear ends of the battery cell stack; a frame member for accommodating a cell block including the battery cell stack and the busbar frame; a pad unit positioned at one end of the bottom unit of the frame member; and a film unit connected to the pad unit and protruding toward the busbar frame.

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 having improved assembly and insulation properties, 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.

In addition, there is a problem in that an insulation problem that may occur between the battery cell stack 12 and a frame member accommodating the battery cell stack 12 such as the mono frame 20 must be reinforced.

SUMMARY OF THE INVENTION An object of the present invention is to provide a battery module having improved assembly and insulation properties, 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 bus bar frame coupled to front and rear ends of the battery cell stack, respectively, and the battery cell stack and the bus bar. A frame member accommodating a cell block including a frame, a pad portion positioned at one end of a bottom portion of the frame member, and a film portion connected to the pad portion and protruding toward the bus bar frame.

The bottom portion of the frame member includes a first portion and a second portion, the first portion is located at an edge in the longitudinal direction of the battery cell, the second portion is located inside the first portion, the A thickness of the first portion may be smaller than a thickness of the second portion.

A thermally conductive resin layer positioned between the second part and the battery cell stack may be further included, and the pad part may be positioned between the thermally conductive resin layer and the first part.

The pad part may be positioned on the second part, and the film part may be positioned on the first part.

The film part may be formed to be in close contact with the step part connecting the first part and the second part of the bottom part of the frame member.

The frame member has open sides opposite to each other based on a direction in which the electrode leads of the battery cell stack protrude, and the bus bar frame is connected to the battery cell stack at both open sides of the frame member. The bus bar frame may include a main frame disposed perpendicular to a direction in which the electrode leads protrude and a bending portion extending from a lower portion of the main frame, and the bending portion may be located on a first portion of a bottom portion of the frame member. .

The film part may cover between the bending part of the bus bar frame and the second part of the bottom part of the frame member.

The battery module may further include a protruding film part positioned between the bending part of the bus bar frame and the first part of the bottom part of the frame member.

A sum of the thickness of the bending portion and the thickness of the first portion may be thinner than the thickness of the second portion.

The battery cell may include a protrusion formed in a width direction, and the protrusion may be positioned on the bending part.

The pad part and the film part may be integrally formed.

The film part may be attached to a lower end of the pad part.

The frame member may further include an end plate coupled to both sides of the frame member, and the open sides of the frame member may face each other based on a direction in which the electrode leads of the battery cell stack protrude.

The frame member includes a module frame that accommodates the cell block and has an open top, and an upper plate that covers the cell block from an upper portion of the module frame, and the module frame includes a bottom of the frame member and two opposing parts. It may include a side part.

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 modifying the structure of the existing mono frame.

In addition, it is possible to prevent the thermal conductive resin from flowing into an unintended space when the cell block is inserted by using the pad, which is an overflow prevention structure.

In addition, by integrally forming the pad and the insulating film, which are the overflow prevention structures, the insulating performance between the battery cell and the module frame can be reinforced while assembling is simplified.

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 illustrating a state in which 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 bus bar frame in the battery module of FIG. 2 .
6 is a cross-sectional view taken along the xz plane in the longitudinal direction of the battery cell stack in FIG. 3 .
7 is a perspective view illustrating a module frame in the battery module of FIG. 2 .
8 is a perspective view illustrating a state in which a cell block is inserted into the module frame of FIG. 7 .
9 is a cross-sectional view of a battery module corresponding to the comparative example of FIG. 6 .
FIG. 10 is a modified embodiment of FIG. 6 , and is a cross-sectional view taken along the xz plane in the longitudinal direction of the battery cell stack in FIG. 3 .
11 is a perspective view of a battery module including the film unit of FIG. 10 .
FIG. 12 is a modified embodiment of FIG. 6 , and is a cross-sectional view taken along the xz plane in the longitudinal direction of the battery cell stack in FIG. 3 .

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 , front and rear ends of the battery cell stack 120 . and a frame member 500 accommodating the cell block 140 including the bus bar frame 130 , the battery cell stack 120 and the bus bar frame 130 respectively coupled to each other. The frame member 500 may include a module frame 300 on which the cell block 140 is mounted and an open top thereof, and an upper plate 400 covering the cell block 140 on the module frame 300 . . The module frame 300 includes two side parts facing each other and a bottom part connecting the two side parts. The two side portions and the bottom portion may be integrally formed. The module frame 300 may be U-shaped.

The frame member 500 may be opened on both sides opposite to each other based on the direction in which the electrode leads of the battery cell stack 120 protrude, and the battery module 100 according to this embodiment is the frame member 500 . It may further include an end plate 150 coupled to the cell block at both open sides.

The battery module 100 according to the present embodiment includes a thermally conductive resin layer 310 positioned between the module frame 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. The end plate 150 may be formed of a metal material.

When the open sides of the module frame 300 are referred to as the first side and the second side, respectively, the module frame 300 except for the side of the cell block 140 corresponding to the first side and the second side. Among the remaining outer surfaces, the plate-shaped structure is bent so as to continuously surround the left side, the lower side, and the right side adjacent to each other. The upper portion corresponding to the bottom of the module frame 300 is open.

The upper plate 400 has a single plate-shaped structure covering the remaining upper portions except for the left side, the lower side, and the right side surrounded by the module frame 300 . The module frame 300 and the upper plate 400 may form a structure surrounding the cell block 140 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 module frame 300 and the upper plate 400 may have a coupling portion CP formed at a corner portion corresponding to each other by a bonding 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 the same as a direction in which two side surfaces of the module frame 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 and a connecting portion connecting both ends 114a and 114b of the battery case 114 . A space between 115 may be defined in the width 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 cell stack 120 is stacked in the y-axis direction, is accommodated in the module frame 300 in the z-axis direction, and may be cooled by a thermally conductive resin layer to be described later. 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.

2 and 7 , the module frame 300 according to the present embodiment includes a bottom part 300a and two side parts 300b facing each other connected by the bottom part 300a. Before the battery cell stack 120 is mounted on the bottom portion 300a of the module frame 300 , a thermally conductive resin is applied to the bottom of the module frame 300 , and the thermally conductive resin is cured to form a thermally conductive resin layer 310 may be formed. The thermally conductive resin layer 310 is positioned between the bottom part 300a of the module frame 300 and the battery cell stack 120 , and heats the battery cells 110 to the bottom of the battery module 100 . It may serve to transfer and fix the battery cell stack 120 .

According to the present embodiment, the thermally conductive resin layer 310 includes a plurality of application lines extending long in a direction perpendicular to the direction in which the plurality of battery cells 110 are stacked. The plurality of application lines may form two groups, and an insulating film 330 may be formed between the two groups. The insulating film 330 may function to maintain insulating performance between the battery cell 110 and the module frame 300 , and at least a portion of a thermal conductive resin may be applied on the insulating film 330 .

According to this embodiment, as shown in FIG. 2 , on the bottom of the module frame 300 , an insulation reinforcement member 345 for reinforcing insulation performance between the battery cell stack 120 and the frame member 500 . is formed The insulation reinforcement member 345 will be described in detail below.

5 is a perspective view illustrating a bus bar frame in the battery module of FIG. 2 .

Referring to FIG. 5 , the bus bar frame 130 according to the present embodiment includes a main frame 130a disposed perpendicular to the direction in which the electrode leads 111 and 112 described with reference to FIG. 4 protrude, and the main frame 130a. and a bending part 130b extending from the lower part of the . The bus bar frame 130 is connected to the battery cell stack 120 as described with reference to FIGS. 2 and 3 . In the main frame 130a, an electrode lead may pass through a slit to form a structure coupled with a bus bar. The bending part 130b may be bent at about 90 degrees with respect to the main frame 130a and positioned on the bottom of the module frame 300 of FIG. 2 . The bending portion 130b and the surrounding configuration will be further described with reference to FIG. 6 .

6 is a cross-sectional view taken along the xz plane in the longitudinal direction of the battery cell stack in FIG. 3 . 7 is a perspective view illustrating a module frame in the battery module of FIG. 2 . 8 is a perspective view illustrating a state in which a cell block is inserted into the module frame of FIG. 7 .

Referring to FIG. 6 , the battery cell 110 according to the present embodiment includes a protrusion 110p formed in the width direction, and the protrusion 110p is positioned on the bending part 130b. Here, the width direction of the battery cell 110 may be the z-axis direction of FIG. 6 . The bottom portion 300a of the module frame according to the present embodiment includes a first portion 300a1 and a second portion 300a2 , and the first portion 300a1 is an edge with respect to the longitudinal direction of the battery cell 110 . , and the second part 300a2 is positioned inside the first part 300a1 . In this case, the thickness of the first part 300a1 is preferably thinner than the thickness of the second part 300a2 . Here, the longitudinal direction of the battery cell 110 may be the x-axis direction of FIG. 6 .

5 and 6 , in the present embodiment, the bending part 130b of the bus bar frame 130 is located on the first part 300a1 of the bottom part 300a of the module frame. In this case, the sum of the thickness of the bending portion 130b and the thickness of the first portion 300a1 is preferably thinner than the thickness of the second portion 300a2 . This is because the protrusion 110p of the battery cell 110 is caught by the step difference between the first part 300a1 and the second part 300a2 and can be prevented from flowing due to an external shock. In addition, it is possible to reduce the gap between the battery cell 110 and the frame member through the processing of the bottom portion 300a of the module frame, and such a gap reducing effect is increased by the gap reducing effect obtained through the height direction assembly. effect to maximize overall space efficiency. The processing of the bottom portion 300a of the module frame may be performed while forming the module frame structure. Press molding or NC (numerical control work) processing may be used to form the step of the bottom portion 300a of the module frame.

The pad part 320 is positioned between the second part 300a2 of the bottom part 300a and the battery cell 110 , and the thermal conductive resin layer 310 is positioned inside the pad part 320 . That is, the pad part 320 may be positioned between the thermal conductive resin layer 310 and the first portion 300a1 of the bottom part 300a to define a position where the thermal conductive resin layer 310 is formed. The battery module according to the present embodiment includes a film part 340 connected to the pad part 320 and protruding toward the bus bar frame 130 . The pad part 320 may be positioned on the second part 300a2 , and the film part 340 may be positioned on the first part 300a1 . In this case, the pad part 320 and the film part 340 may be integrally formed to constitute the insulating reinforcing member 345 . The insulation reinforcing member 345 not only reinforces the insulation between the battery cell 110 or the protrusion 110p of the battery cell 110 and the module frame 300 , but is also integrally formed with the pad portion 320 to form the module frame ( 300) and assembly can be simplified. In a modified embodiment, the film unit 340 may be attached to the lower end of the pad unit 320 . Both the pad part 320 and the film part 340 are insulating parts, and may be flexible and compressively deformable members. For example, the pad part 320 may be formed of polyurethane, and the film part 340 may be formed of polyethylene terephthalate (PET). Alternatively, both the pad part 320 and the film part 340 may be formed of polyurethane or polyethylene terephthalate.

7 and 8 , before the cell block 140 is mounted on the module frame 300 , an insulating reinforcing member 345 may be formed on the bottom portion 300a of the module frame 300 .

9 is a cross-sectional view of a battery module corresponding to the comparative example of FIG. 6 .

Referring to FIG. 9 , in the insulating reinforcing member according to the comparative example, the insulating film part 340 ′ may be formed to be spaced apart from the pad part 320 . The insulating film part 340' may be formed between the second part 300a2 of the bottom part 300a of the module frame and the bending part 130b of the bus bar frame. According to the comparative example, alignment is required through an attachment process to form the insulating film part 340', and between the insulating film part 340' and the pad part 320 and/or the insulating film part 340' It is difficult to guarantee insulation of the exposed portion between the bending portions 130b.

FIG. 10 is a modified embodiment of FIG. 6 , and is a cross-sectional view taken along the xz plane in the longitudinal direction of the battery cell stack in FIG. 3 . 11 is a perspective view of a battery module including the film unit of FIG. 10 .

10 and 11 , the film part 340 is a protruding film part 340p positioned between the bending part 130b of the bus bar frame and the first part 300a1 of the bottom part 300a of the frame member. may further include. The protruding film part 340p may vertically overlap the bending part 130b of the bus bar frame. If there is no such overlapping structure, a gap is generated between the film portion 340 and the bending portion 130b, so that the insulation distance and creepage distance between the bottom portion 300a of the frame member and the end of the protrusion portion 110p of the battery cell 110 . (Creepage) may be lacking. Therefore, according to the present embodiment, insulation performance can be improved.

FIG. 12 is a modified embodiment of FIG. 6 , and is a cross-sectional view taken along the xz plane in the longitudinal direction of the battery cell stack in FIG. 3 .

Referring to FIG. 12 , the battery module according to the present embodiment includes a film part 340 connected to the pad part 320 and protruding toward the bus bar frame 130 . The pad part 320 may be positioned on the second part 300a2 , and the film part 340 may be positioned on the first part 300a1 . At this time, as shown in FIG. 12 , the film part 340 may be formed to be in close contact with the step part connecting the first part 300a1 and the second part 300a2 of the bottom part 300a of the module frame. there is. The film part 340 according to the present embodiment may be formed integrally with the pad part 320 to constitute the insulating reinforcing member 345 , or may be attached to the lower end of the pad part 320 . Since the film portion 340 is formed to be in close contact with the step portion, insulation between the protrusion portion 110p of the battery cell 110 and the module frame 300 may be further strengthened.

In addition to the differences described above, all of the contents described with reference to FIG. 6 are applicable to the present embodiment.

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 above-described battery module and battery pack including the same 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

110p: overhang
140: cell block
320: pad part
340: film unit
340p: protruding film part
345: insulation reinforcement member

Claims (15)

A battery cell laminate in which a plurality of battery cells are stacked;
a bus bar frame coupled to each of the front and rear ends of the battery cell stack;
a frame member accommodating a cell block including the battery cell stack and the bus bar frame;
a pad portion located at one end of the bottom portion of the frame member, and
A battery module connected to the pad part and including a film part protruding toward the bus bar frame. In claim 1,
The bottom portion of the frame member includes a first portion and a second portion, the first portion is located at an edge in the longitudinal direction of the battery cell, the second portion is located inside the first portion, the The thickness of the first part is thinner than the thickness of the second part battery module. In claim 2,
A battery module further comprising a thermally conductive resin layer positioned between the second part and the battery cell stack, wherein the pad part is positioned between the thermally conductive resin layer and the first part. In claim 3,
The pad part is positioned on the second part, and the film part is positioned on the first part. In claim 2,
The film part is formed to be in close contact with the step part connecting the first part and the second part of the bottom part of the frame member. In claim 1,
The frame member has open sides opposite to each other based on the direction in which the electrode leads of the battery cell stack protrude, and the bus bar frame is connected to the battery cell stack at both open sides of the frame member,
The bus bar frame includes a main frame disposed perpendicular to a direction in which the electrode leads protrude and a bending portion extending from a lower portion of the main frame,
The bending part is a battery module located on the first portion of the bottom portion of the frame member. In claim 6,
The film part covers between the bending part of the bus bar frame and the second part of the bottom part of the frame member. In claim 7,
The film part further includes a protruding film part positioned between the bending part of the bus bar frame and the first part of the bottom part of the frame member. In claim 6,
The sum of the thickness of the bending part and the thickness of the first part is thinner than the thickness of the second part. In claim 6,
The battery cell includes a protrusion formed in a width direction, and the protrusion is positioned on the bending part. In claim 1,
A battery module in which the pad part and the film part are integrally formed. In claim 1,
The film part is a battery module attached to the bottom of the pad part. In claim 1,
The battery module further includes an end plate coupled to each of the open both sides of the frame member, wherein the open both sides of the frame member are opposed to each other based on a direction in which the electrode leads of the battery cell stack protrude. In claim 1,
The frame member includes a module frame having an open top and accommodating the cell block, and an upper plate covering the cell block from an upper portion of the module frame,
The module frame is a battery module including a bottom portion and two side portions facing each other of the frame member. A battery pack comprising the battery module according to claim 1 .

Images