KR102187056B1 - Battery Module having improved energy density and simplified assembly process - Google Patents

Abstract

According to an aspect of the present invention, a cell stack composed of a plurality of pouch-type secondary battery cells stacked in one direction; And a mono frame having an opening in at least one of the front and rear sides in the form of a box, and in which the cell stack is provided to be accommodated in the inner space, and adhesive resin on at least one side of both sides of the mono frame A resin injection hole capable of injecting is formed, and at least one side portion of the cell stack may be provided with a battery module that is adhesively fixed in the mono frame.

Description

Battery Module having improved energy density and simplified assembly process}

The present invention relates to a battery module, and more particularly, to a battery module that can increase the energy density of battery cells per unit volume and simplify the assembly process.

The secondary battery has high applicability to various product groups and has electrical characteristics with high energy density. Such secondary batteries are applied not only to portable electronic devices, but also to electric vehicles or hybrid vehicles driven by an electric drive source, and power storage devices.

Currently, the types of secondary batteries widely used include lithium ion batteries, lithium polymer batteries, nickel cadmium batteries, nickel hydride batteries, and nickel zinc batteries. This unit secondary battery cell, that is, the operating voltage of the unit battery cell is about 2.5V ~ 4.2V. Therefore, when a higher output voltage is required, a battery module may be configured by connecting a plurality of secondary batteries in series. In addition, a plurality of battery modules may be connected in parallel according to the required charge/discharge capacity. That is, the battery module may be variously designed by connecting battery cells in series/parallel according to an output voltage or charge/discharge capacity required for an electric vehicle or the like.

In particular, pouch-type secondary batteries are widely used in electric vehicles due to the advantage of high energy density due to easy stacking. The pouch-type secondary battery generally refers to a form in which an electrode assembly is packaged with a battery case made of a laminate sheet of aluminum and polymer resin. Pouch-type secondary batteries do not have high mechanical stiffness, so when constructing a battery module including a plurality of pouch-type secondary batteries, a structure to protect the secondary batteries from external shocks, prevent the flow and facilitate stacking In many cases, a cell cover or a frame for stacking is used. These cell covers or frames for stacking may be generally referred to in the art as cartridges.

For example, a conventional cartridge includes a lower frame and an upper frame, and is configured to stack two secondary batteries on the upper surface of the lower frame, and then place the upper frame on the upper frame and combine the upper frame and the lower frame.

And in the conventional battery module, the unit cartridges are combined in a snap-fit method and stacked in one direction to form a cell/cartridge assembly, and an end plate (plate-shaped metal structure) on the top or bottom of the cell/cartridge assembly It is configured to include an additional module case for receiving and supporting them after being added.

However, such a conventional battery module has a large number of components other than a secondary battery, and thus is placed in the trend of reducing the weight of battery modules, and the energy density per unit volume is low. In addition, since the conventional battery module is designed to fasten components using, for example, bolting, snap fit, and welding, the assembly process is complicated and the manufacturing cost is increased.

Republic of Korea Patent Publication No. 10-2016-0111217, 2016.09.26, LG Chem Co., Ltd.

An object of the present invention is to provide a battery module capable of improving energy density of a battery module and simplifying an assembly process, and a battery pack including the same, in order to solve the above-described problems.

However, the technical problem to be achieved by the present invention is not limited to the above-described problems, and other problems that are not mentioned will be clearly understood by those skilled in the art from the description of the invention described below.

According to an aspect of the present invention, a cell stack composed of a plurality of pouch-type secondary battery cells stacked in one direction; And a mono frame having an opening in at least one of the front and rear sides in the form of a box, and in which the cell stack is provided to be accommodated in the inner space, and adhesive resin on at least one side of both sides of the mono frame A resin injection hole capable of injecting is formed, and at least one side portion of the cell stack may be provided with a battery module that is adhesively fixed in the mono frame.

The cell guide frame may further include a cell guide frame that supports at least one side portion of the cell stack and has a resin passage hole inserted into the inner space facing the inner wall of the mono frame and communicating with the resin injection hole.

The cell guide frame is formed at a position spaced apart from the resin passage hole, so that the adhesive resin is filled in the gap between the cell guide frame and the inner wall of the mono frame, thereby inducing the flow of the adhesive resin. A hole may be further provided.

The cell guide frame includes the resin through hole and the resin filling guide hole, and is intersected with the first side plate supporting one side of the cell stack and the first side plate to be connected to the rear surface of the cell stack. It may include a back plate to support.

The resin injection holes are respectively formed on both sides of the mono frame, one side of the cell stack is adhesively fixed to the first side plate, and the other side of the cell stack is adhesively fixed to the inner wall of the mono frame Can be.

A plurality of the resin through holes and the resin filling induction holes may be provided along a direction in which the cell stack is arranged in layers, and the resin through holes and the resin filling induction holes may be alternately disposed therebetween.

The cell guide frame may further include a second side plate having the resin passage hole and the resin filling guide hole, and being cross-connected to the rear plate to support the other side of the cell stack.

The cell guide frame may include a plurality of cell guide ribs protruding in a horizontal direction with a predetermined interval therebetween along a height direction.

According to another aspect of the present invention, a battery pack including the battery module according to the present invention described above may be provided.

According to an aspect of the present invention, a battery module in which pouch-type secondary batteries (cell stack) can be stably fixed inside a mono frame without a separate storage component (cartridge) may be provided. Accordingly, the number of components constituting the battery module is reduced compared to the previous one, thereby reducing manufacturing cost, and increasing the energy density by maximizing the volume occupied by secondary battery cells per unit volume inside the battery module.

According to another aspect of the present invention, the assembly process of the battery module can be greatly simplified compared to the conventional one, and the fixing force of the cell stack inside the mono frame can be strengthened.

According to another aspect of the present invention, secondary batteries can be more easily and safely located inside the mono frame by using the cell guide frame, and vibration, shock, etc., by integrally bonding the mono frame, the cell guide frame and the secondary battery cells. It is possible to secure enough mechanical durability.

The effects of the present invention are not limited to the above-described effects, and effects that are not mentioned will be clearly understood by those of ordinary skill in the art from the present specification and the accompanying drawings.

The following drawings attached to the present specification illustrate preferred embodiments of the present invention, and serve to further understand the technical idea of the present invention together with the detailed description of the present invention to be described later. It is limited only to and should not be interpreted.
1 is an exploded perspective view schematically showing the configuration of a battery module according to an embodiment of the present invention.
2 is a combined perspective view of FIG. 1.
3 is an exploded perspective view schematically showing the configuration of a battery module according to another embodiment of the present invention.
4 is a perspective view showing a state in which the cell guide frame and the cell stack of FIG. 3 are assembled.
5 is a combined perspective view of FIG. 3.
6 is a cross-sectional view taken along line I-I' of FIG. 5.
7 is an enlarged view of area A of FIG. 6.
8 is a cross-sectional view taken along line II-II' of FIG. 5.
9 is an enlarged view of area B of FIG. 8.
10 is a perspective view illustrating a state in which an ICB assembly is additionally mounted in FIG. 5.
11 is a perspective view showing a cell guide frame according to another embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms or words used in the specification and claims should not be construed as being limited to their usual or dictionary meanings, and the inventors appropriately explain the concept of terms in order to explain their own invention in the best way. Based on the principle that it can be defined, it should be interpreted as a meaning and concept consistent with the technical idea of the present invention.

Therefore, the embodiments described in the present specification and the configurations shown in the drawings are only the most preferred embodiments of the present invention, and do not represent all of the technical spirit of the present invention, and thus various equivalents that can replace them at the time of application It should be understood that there may be water and variations.

Since the embodiments of the present invention are provided to more completely describe the present invention to a person skilled in the art, the shape and size of components in the drawings may be exaggerated, omitted, or schematically illustrated for a more clear description. Therefore, the size or ratio of each component does not entirely reflect the actual size or ratio.

Referring to FIGS. 1 and 2, a battery module 10 according to an embodiment of the present invention includes a cell stack 100 composed of cells of a plurality of pouch-type secondary batteries 110, and the cell stack 100 ) And a mono frame 200 for packaging in the inner space. Although it will be described later in detail, the battery module 10 according to the present invention does not use components other than the cell stack 100 or uses only a minimum of guide parts to directly insert the cell stack 100 into the mono frame 200 Then, it is configured to increase the energy density of the battery module 10 by bonding it to the inner wall of the mono frame.

The cell stack 100 constituting the battery module 10 may be an assembly of cells of the pouch-type secondary battery 110 as shown in FIG. 1. The pouch-type secondary battery 110 cell is an electrode assembly composed of a positive electrode plate, a separator, and a negative electrode plate in a pouch case made of a laminate material composed of aluminum and polymer resin, and a plurality of positive electrode tabs extending from the positive electrode plate and the negative electrode plate of each secondary battery 110 cell. And a negative electrode tab and a positive electrode lead and a negative electrode lead connected to the positive electrode tab and the negative electrode tab, respectively, protruding outside the pouch case. The electrode leads 120 may function as electrode terminals of a cell of the secondary battery 110.

The cells of the pouch-type secondary battery 110 are stacked or arranged in parallel so that one or both sides face the adjacent secondary battery 110 cells to form the cell stack 100. Meanwhile, the cells of the secondary battery 110 constituting the battery module 10 according to the present invention are not limited to the pouch-type secondary battery 110 cells. That is, the cells of the secondary battery 110 may be of any type as long as the cells of the secondary battery 110 are arranged in layers in a plate shape and accommodated in the mono frame 200.

The mono frame 200 has an inner space in which the cell stack 100 can be accommodated, and has an entrance 250 at at least one of the front and rear sides, so that the cell stack 100 is provided to be accommodated in the inner space. It can be provided in the form of a box. Such a mono frame 200 may serve to protect the cell stack 100 from external impacts. Therefore, the mono frame 200 may be made of a metal material such as steel to ensure rigidity.

In the case of the present embodiment, the mono frame 200 is a top plate 210 and a bottom plate 220 facing each other so that an inner space is formed in a rectangular parallelepiped shape as a whole, as shown in FIGS. 1 to 2, and the top plate 210 and the bottom The left side plate 230 and the right side plate 240 connecting the long side edge of the plate 220 up and down, and the rear plate covering the rear of the inner space, and an entrance provided in an open form facing the rear plate It may include (250).

The cell stack 100 may be inserted and disposed in the inner space of the mono frame 200 through the entrance 250. In this case, the electrode lead 120 faces the entrance 250. Meanwhile, in the present embodiment, the mono frame 200 is configured based on the cell of the unidirectional pouch-type secondary battery 110 in which the electrode lead 120 faces the same direction, and the entrance 250 is provided only on the front side, but the electrode lead ( When 120 is configured based on the cells of the bi-directional pouch-type secondary battery 110 facing in opposite directions, the entrance 250 may be provided on both the front and rear sides.

In particular, the mono frame 200 according to the present invention has resin injection holes 232 and 242 through which resin can be injected from the outside to the inside. Referring to FIGS. 1 to 2, resin injection holes 232 and 242 are formed in the left side plate 230 and the right side plate 240 of the mono frame 200. In other words, the left side plate 230 and the right side plate 240 of the mono frame 200 have portions in contact with the folded side portions corresponding to the long sides of the pouch case arranged in layers in the cell stack 100. it means.

A plurality of resin injection holes 232 and 242 may be provided along a layered arrangement direction of the cell stack 100 of the mono frame 200. According to this configuration of the mono frame 200, after the operator inserts the cell stack 100 into the inner space of the mono frame 200, the left side plate 230 and the right side plate 240 of the mono frame 200 The adhesive resin L may be injected into the mono frame 200 through the resin injection holes 232 and 242. For example, the adhesive resin (L) may be a urethane resin, an epoxy resin, or a silicone.

The adhesive resin L may be filled in an empty space between the inner wall of the left side plate 230 of the mono frame 200 and the left side of the cell stack 100 and the gap between the cells of the stacked secondary battery 110. have. The adhesive resin L may be filled in the same shape as the right side of the mono frame 200 and the inner wall of the right side plate 240 of the mono frame 200 and the right side of the cell stack 100. When the adhesive resin filled in the mono frame 200 is cured as described above, the cell stack 100 may be integrally bonded to and fixed to the mono frame 200.

As described above, in the case of the present embodiment, the cell stack 100 composed of the pouch-type secondary battery 110 cells without a separate component (cartridge) for fixing the cells of the unit pouch-type secondary battery 110 is inside the mono frame 200. Since it is adhesively fixed, it is possible to suppress the occurrence of unnecessary space inside the module, thereby improving the energy density of the battery module 10. In addition, manufacturing cost can be lowered by reducing the number of parts used for assembly of the battery module 10 compared to the conventional one, and since, for example, fastening means such as bolts and nuts are not used, the assembly process can be simplified.

Hereinafter, a battery module 10 according to another embodiment of the present invention will be described.

3 is an exploded perspective view schematically showing a configuration of a battery module according to another embodiment of the present invention, FIG. 4 is a perspective view showing a state in which the cell guide frame and the cell stack of FIG. 3 are assembled, and FIG. 5 is It is a combined perspective view.

The same reference numerals as in FIGS. 1 and 2 denote the same members, and redundant descriptions of the same members will be omitted.

3 to 5, the battery module 10 according to the present invention further includes a cell guide frame 300.

The cell guide frame 300 supports at least one side of the cell stack 100, protects the cell stack 100 from being damaged when the cell stack 100 is inserted into the mono frame 200, and It may serve as a guide to facilitate insertion of the cell stack 100.

The cell guide frame 300 according to the present embodiment is intersected with a first side plate 310 supporting one side of the cell stack 100 and the first side plate 310 to be cross-connected to the cell stack body ( It may include a rear plate 320 supporting the rear surface of 100). In addition, a cell guide rib 340 for guiding the stacking of cells of the pouch-type secondary battery 110 and holding the stacking position is provided on an inner surface of one of the first side plate 310 and the rear plate 320. do.

As shown in FIGS. 3 and 4, the cell guide frame 300 composed of the first side plate 310 and the rear plate 320 may take an approximately alphabetic “L” shape.

In more detail, a plurality of guide ribs 340 protruding in the horizontal direction at a predetermined distance from each other along the height direction on the first side plate 310 and the rear plate 320 based on FIGS. 3 and 4 It is equipped. With this configuration, the outer peripheries of at least one pouch-type secondary battery 110 may be inserted between the upper and lower neighboring guide ribs 340 (see FIG. 6) to support the pouch-type secondary batteries 110.

When such a cell guide frame 300 is mounted on the cell stack 100, the long side side region of the cell stack 100 may be supported by the first side plate 310, in other words, the rear surface, that is, the electrode lead The short side side area of the cell stack 100 without 120 may be supported by the rear plate 320. For reference, since the first side plate 310 and the rear plate 320 have a size sufficient to support at least the cell stack 100, they must be aligned with the width or length of the cell stack 100. There is no need. Further, the cell guide frame 300 may be a plastic injection product that is relatively easy to manufacture, but may be made of a metal material such as aluminum in consideration of rigidity and thermal conductivity.

When the cell guide frame 300 is used, insertion of the cell stack 100 may be much easier than in the above-described embodiment, and in particular, the pouch case made of a laminate sheet material is directly monolithic during the insertion process of the cell stack 100. Since it does not contact the inner wall of the frame 200, damage to the pouch case may be prevented. In addition, the "L"-shaped cell guide frame 300 serves as an assembly guide and effective support for the pouch-type secondary batteries 110 without significantly lowering the energy density of the battery cells by occupying a minimum space inside the mono frame 200 can do.

Specifically, as shown in FIG. 4, after mounting the cell stack 100 on the cell guide frame 300, for example, the mono frame 200 is erected so that the entrance 250 of the mono frame 200 faces upward. The cell stack 100 and the cell guide frame 300 may be integrated into the mono frame 200. In this case, the cell guide frame 300 supports the cell stack 100 and may slide along the inner wall of the mono frame 200.

In this way, the cell guide frame 300 inserted and arranged in the inner space of the mono frame 200 includes the first side plate 310 and the rear plate 320, respectively, the inner wall and the rear side of the left side plate 230 of the mono frame 200. You face the inner wall of the plate. In addition, the right side of the cell stack 100 faces the inner wall of the right side plate 240 of the mono frame 200.

On the other hand, the cell guide frame 300 has a resin through hole 312 communicating with the resin injection hole 232 of the mono frame 200, and a resin filling guide hole formed at a predetermined distance from the resin through hole 312 It is further provided with 314.

In this embodiment, the resin through hole 312 and the resin filling guide hole 314 are provided in the first side plate 310. The resin through hole 312 is a resin injection hole 232 formed in the left side plate 230 of the mono frame 200 when the first side plate 310 is inserted and disposed inside the mono frame 200 as above. ) In the same position. In addition, the resin filling guide hole 314 is provided only on the cell guide frame 300 to induce the flow of the adhesive resin L between the cell guide frame 300 and the inner wall of the mono frame 200.

4 and 5, a plurality of resin through holes 312 and resin filling guide holes 314 are provided on the first side plate 310 along the direction in which the cell stack 100 is arranged in layers. Can be, and can be arranged alternately with each other. For example, resin filling induction holes 314 may be arranged one by one on both sides of the resin passage hole 312. When the cell guide frame 300 having such a configuration is used, as in the above-described embodiment, resin for adhesion (L) is injected into the resin injection holes 232 and 242 of the mono frame 200, Can be filled.

More specifically, looking at the internal structure of the left side of the battery module 10 with reference to FIGS. 6 and 7, the mono frame 200 through the resin injection holes 232 and the resin through holes 312 communicated with each other. When the adhesive resin (L) is injected from the outside, the adhesive resin (L) flows into the empty space between the first side plate 310 and the left side of the cell stack 100, and thus the introduced adhesive resin (L) ) May spread radially and fill the empty space.

Then, as shown in Figs. 8 and 9, a part of the adhesive resin (L) filled between the cell stack 100 and the first side plate 310 is through the resin filling guide holes 314 It may be discharged from the inside to the outside of the first side plate 310. The discharged resin may permeate and be filled between the first side plate 310 and the inner wall of the mono frame 200.

For reference, in the case of the present embodiment, three resin through holes 312 in the vertical direction and three resin filling induction holes 314 each in the left and right sides of the resin through hole 312 are approximately in the center of the first side plate 310 Although designed to be distributed, the scope of the present invention is not limited to the shape and number of the resin through holes 312 and the resin filling guide holes 314. In other words, the resin through holes 312 and the resin filling induction holes 314 are designed as long as they are in a shape and position in which the adhesive resin (L) can be effectively filled inside the mono frame 200, unlike the present embodiment. It could be changed.

In this way, since the cell guide frame 300 has the resin through hole 312 and the resin filling guide hole 314, a gap between the inner wall of the left side plate 230 and the first side plate 310 of the mono frame 200 And the first side plate 310 and the left side of the cell stack 100 may be filled with an adhesive resin (L) permeating, respectively. Therefore, the left side of the battery module 10 has a structure in which the left side plate 230 of the mono frame 200, the first side plate 310, and the left side of the cell stack 100 are integrally bonded and fixed.

On the other hand, referring to FIGS. 6 and 8 again, looking at the internal structure of the right side of the battery module 10, as described above, the cell guide frame 300 of the present embodiment is approximately an alphabetic "L" shape, so the cell stack 100 There is no structure between the right side of) and the right side plate 240 of the mono frame 200. Therefore, the right side of the battery module 10 has a structure in which the right side plate 240 of the mono frame 200 and the right side of the cell stack 100 are integrally bonded and fixed.

Further, referring to FIG. 10, the cell stack 100 adhered and fixed inside the mono frame 200 may be electrically connected to an ICB (inter connection borad) assembly. The ICB assembly includes an outer frame customized to the shape of the entrance 250 of the mono frame 200, and a plurality of bus bars (not shown) provided inside so as to be electrically connected to the electrode leads 120. I can. For example, the outer frame may be mounted on the mono frame 200 by laser welding along the circumferential direction to the entrance 250 of the mono frame 200.

In the battery module 10 according to the present embodiment, both side portions of the cell stack 100 may be uniformly adhered and fixed inside the mono frame 200, so that mechanical durability against external shock and vibration may be sufficiently secured. have.

11 is a perspective view showing a cell guide frame 300 according to another embodiment of the present invention.

This embodiment differs only in the configuration of the cell guide frame 300 from the above-described embodiment, but the rest of the configuration is the same. Therefore, the overlapping description from the above-described embodiment will be omitted and only differences will be described.

The cell guide frame 300 according to the present embodiment is connected to the first side plate 310, the rear plate 320, and the rear plate 320, and is connected to the second side plate 310. A side plate 330 may be further included.

The second side plate 330 has a resin through hole 332, a resin filling guide hole 334, and cell guide ribs 340 inside the same shape as the first side plate 310 described above. That is, in the case of the present embodiment, the cell guide frame 300 may be implemented in an approximately "C" shape. According to the configuration of the cell guide frame 300 of this embodiment, the cell stack 100 can be inserted into the mono frame 200 while the left, rear, and right sides of the cell stack 100 are supported and held. Therefore, it is possible to more safely protect the pouch-type secondary batteries 110 during the insertion process of the cell stack 100 than in the case of the above-described embodiment. In addition, the "c"-type cell guide frame 300 prevents the flow of the cell stack 100 in the left and right directions as well as in the vertical direction, thereby further enhancing the fixing force of the cell stack 100 in the mono frame 200 Can be.

The battery pack according to the present invention may include one or more battery modules 10 according to the present invention. In addition, the battery pack according to the present invention includes, in addition to the battery module 10, a pack case for accommodating the battery module 10, various devices for controlling charge/discharge of the battery module 10, such as BMS, current A sensor, a fuse, etc. may be further included.

The battery pack according to the present invention can be applied to a vehicle such as an electric vehicle or a hybrid vehicle.

As described above, although the present invention has been described by a limited embodiment and drawings, the present invention is not limited thereto, and the technical idea of the present invention and the following by those of ordinary skill in the art to which the present invention pertains. It goes without saying that various modifications and variations are possible within the equivalent range of the claims to be described.

On the other hand, when terms indicating directions such as up, down, left, right, before, and after are used in the specification, these terms are for convenience of description only, depending on the location of the object or the observer. It will be apparent to those skilled in the art that may vary.

10: battery module 100: cell stack
110: pouch type secondary battery 120: electrode lead
200: mono frame 210: top plate
220: bottom plate 230: left side plate
240: right side plate 232,242: resin injection hole
300: cell guide frame 310: first side plate
312,332: resin through hole 314,334: resin filling guide hole
320: rear plate 330: second side plate
340: cell guide rib 400: ICB assembly

Claims (9)

A cell stack composed of a plurality of pouch-type secondary battery cells stacked in one direction;
A mono frame having an entrance opening at least one of the front and rear sides in the form of a box and the cell stack is provided to be accommodated in an inner space; And
A cell guide frame that supports at least one side portion of the cell stack and is disposed to face the inner wall of the mono frame,
The mono frame has a resin injection hole in at least one side plate of both side plates to inject the adhesive resin into the inner space,
The cell guide frame includes a resin passage hole disposed at the same position as the resin injection hole to communicate with the resin injection hole; and a resin filling guide hole formed only on the cell guide frame and facing the inner wall of the mono frame at a predetermined distance from the resin passage hole. Equipped,
At least one side portion of the cell stack and the cell guide frame are adhesively fixed to the inner wall of the mono frame by the adhesive resin. delete delete The method of claim 1,
The cell guide frame,
A first side plate having the resin through hole and the resin filling induction hole, which supports one side of the cell stack, and a rear plate that is intersected with the first side plate and supports the rear surface of the cell stack. Battery module comprising a. The method of claim 4,
The resin injection holes are respectively formed on both side plates of the mono frame,
One side of the cell stack is adhesively fixed to the first side plate, and the other side of the cell stack is adhesively fixed to an inner wall of the mono frame. The method of claim 4,
A battery module, characterized in that a plurality of the resin through holes and the resin filling guide holes are provided along a direction in which the cell stack is arranged in layers, and the resin through holes and the resin filling guide holes are alternately arranged with each other. . The method of claim 4,
The cell guide frame,
The battery module further comprising a second side plate having the resin through hole and the resin filling guide hole, and connected to the rear plate to be cross-connected to support the other side of the cell stack. The method of claim 1,
The cell guide frame comprises a plurality of cell guide ribs protruding in a horizontal direction with a predetermined interval therebetween along a height direction. A battery pack comprising the battery module according to any one of claims 1 and 4 to 8.

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