[One]Cross-Citation with Related Application(s)
[2]This application claims the benefit of priority based on Korean Patent Application No. 10-2019-0125307 dated October 10, 2019, and all contents disclosed in the literature of the Korean patent application are incorporated as a part of this specification.
[3]
The present invention relates to a battery module and a battery pack including the same, and more particularly, to a battery module having an improved fixing method for a plurality of battery cells and a battery pack including the same.
background
[4]
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.
[5]
Currently commercialized secondary batteries include nickel cadmium batteries, nickel hydride batteries, nickel zinc batteries, and lithium secondary batteries. Among them, lithium secondary batteries do not have much memory effect compared to nickel-based secondary batteries, so charging and discharging are possible freely. , the self-discharge rate is very low and the energy density is high.
[6]
These lithium secondary batteries mainly use a lithium-based oxide and a carbon material as a positive electrode active material and a negative electrode active material, respectively. A lithium secondary battery includes an electrode assembly in which a positive electrode plate and a negative electrode plate to which the positive electrode active material and the negative electrode active material are applied, respectively, are disposed with a separator interposed therebetween, and a casing for sealing and housing the electrode assembly together with an electrolyte, that is, a battery case.
[7]
In general, a lithium secondary battery may be classified into a prismatic secondary battery in which an electrode assembly is embedded in a metal can, and a pouch-type secondary battery in which an electrode assembly is embedded in a pouch of an aluminum laminate sheet, depending on the shape of the exterior material.
[8]
While one to three battery cells per device are used in small mobile devices, medium and large devices such as automobiles require high output and high capacity. Therefore, a medium or large-sized battery module in which a plurality of battery cells are electrically connected is used.
[9]
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.
[10]
Meanwhile, the battery module may include a module frame for accommodating a stack of battery cells in an internal space in order to protect the plurality of battery cells from external impact, heat, or vibration.
[11]
1 is a perspective view of a conventional battery module 10 . However, the illustration of the module frame is omitted to explain the fixing method for the battery cells.
[12]
Referring to FIG. 1 , the conventional battery module 10 includes a battery cell stack 20 in which a plurality of battery cells 11 are stacked.
[13]
When the battery cells 11 are stacked along the Y-axis direction, an adhesive 30 such as a double-sided tape is disposed between each of the battery cells 11 to form the battery cell stack 20 ( 11) are fixed. Furthermore, although not specifically illustrated, a compression pad may be further disposed on the battery cell 11 located at the outermost portion, and an adhesive may also be located between the compression pad and the battery cell 11 .
[14]
However, as the number of battery cells 11 constituting the battery cell stack 20 increases, the number of adhesives 30 to be disposed therebetween increases, and thus the number of repeated processes increases. That is, in order to implement a high-output, large-capacity battery module, a plurality of battery cells 11 are required, but the conventional fixing method using the adhesive 30 has a problem in that unnecessary repetitive processes are required.
[15]
In addition, in the process of laminating the battery cells 11, if misalignment occurs or the tolerance condition is not satisfied, rework of the lamination is required. there is.
[16]
Accordingly, there is a need to improve the fixing method of the battery cells constituting the battery cell stack to simplify the process procedure and to facilitate the rework of the stack.
DETAILED DESCRIPTION OF THE INVENTION
technical challenge
[17]
Embodiments of the present invention have been proposed to solve the above problems of the conventionally proposed methods, and an object of the present invention is to improve the fixing method of the battery cells constituting the battery cell stack.
[18]
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.
means of solving the problem
[19]
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; and a wrap film surrounding the upper surface, the lower surface and both sides of the battery cell stack, wherein the wrap film continues continuously on the upper surface, the lower surface and both sides of the battery cell stack.
[20]
Between each of the battery cells, the adhesive or tape is removed so that neighboring battery cells can directly contact each other.
[21]
The wrap film may cover all portions of the upper surface, the lower surface, and both side surfaces of the battery cell stack.
[22]
The wrap film may include at least one of polycarbonate (PC) and polyethylene terephthalate (PET).
[23]
The battery cells may be stacked parallel to both sides of the battery cell stack.
[24]
The battery cell may include an electrode lead, and the electrode lead may be positioned on the front and rear surfaces of the battery cell stack.
[25]
The wrap film may wrap the battery cell laminate once or twice.
[26]
It may further include a module frame for accommodating the battery cell stack and an end plate covering the front and rear surfaces of the module frame.
[27]
The module frame may be a mono frame with open front and rear surfaces, and an upper surface, a lower surface, and both sides integrated therein.
[28]
The module frame may include a U-shaped frame having an open front, rear, and upper surface, and an upper cover covering the open upper surface of the U-shaped frame.
[29]
A plurality of through holes may be formed in the wrap film.
[30]
The plurality of through-holes may be formed in the wrap film located at the lower end of the battery cell stack.
[31]
The battery module may further include a thermally conductive resin layer positioned under the battery cell stack.
[32]
The thermally conductive resin layer may include at least one of a silicone material, a urethane material, and an acrylic material.
Effects of the Invention
[33]
According to embodiments of the present invention, through the wrap film structure surrounding the battery cell stack, even if the number of battery cells constituting the battery cell stack increases, it is possible to simply fix the battery cells.
[34]
In addition, even if misalignment occurs during the lamination process or the tolerance condition is not satisfied, the lamination can be reworked more easily.
[35]
In addition, since electrical insulation between the battery cell stack and the module frame is possible by the wrap film, it is unnecessary to insert other members for insulation.
[36]
In addition, by suppressing the expansion of the battery cell stack according to the swelling phenomenon of the battery cell, it is possible to minimize the change in the external shape of the battery module, it is possible to improve the structural safety of the battery module and the battery pack including the same.
Brief description of the drawing
[37]
1 is a perspective view illustrating a conventional battery module by omitting the illustration of the module frame.
[38]
Figure 2 is a perspective view showing the module frame for the battery module according to an embodiment of the present invention is omitted.
[39]
3 is an exploded perspective view of a battery module including a mono frame.
[40]
4 is an exploded perspective view of a battery module including a U-shaped frame.
[41]
5 is a view of the battery cell stack as viewed from below in order to describe a wrap film in which a through hole is formed.
Modes for carrying out the invention
[42]
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.
[43]
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 elements throughout the specification.
[44]
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 is exaggerated.
[45]
Also, when a part of a layer, film, region, plate, etc. is said to be “on” or “on” another part, this 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 gravity not.
[46]
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.
[47]
In addition, throughout the specification, when referring to "planar", it means when the target part is viewed from above, and "in cross-section" means when viewed from the side when a cross-section of the target part is vertically cut.
[48]
2 is a perspective view showing the module frame for the battery module 100 according to an embodiment of the present invention, omitting the illustration.
[49]
Referring to FIG. 2 , the battery module 100 according to an embodiment of the present invention includes a battery cell stack 200 in which a plurality of battery cells 110 are stacked and an upper surface Z of the battery cell stack 200 . axial direction), the lower surface (opposite to the Z-axis) and both sides (the opposite to the Y-axis direction) of a wrap film (Wrap film, 300).
[50]
In addition, the wrap film 300 is continuously connected on the upper surface (Z-axis direction), the lower surface (opposite the Z-axis direction) and both sides (the Y-axis direction and the opposite direction) of the battery cell stack 200 .
[51]
In the conventional battery module 10 in FIG. 1 , the adhesive 30 is positioned between the plurality of battery cells 11 to fix the battery cells 11 . Accordingly, as the number of battery cells 11 increases, the number of adhesives 30 to be disposed between them increases. ), there was a problem that the process of attaching had to be repeated. In other words, there was a problem in that excessive time and cost were incurred due to the repeated process.
[52]
Accordingly, the battery module 100 according to the present embodiment includes a wrap film 300 covering the outer peripheral surface of the battery cell stack 200 , that is, the upper surface, the lower surface and both sides, so that the battery cells 110 can be fixed. there is. Accordingly, an adhesive or tape between each battery cell 110 is unnecessary and thus removed, and adjacent battery cells 110 may directly contact each other.
[53]
Since the outer circumferential surface of the battery cell stack 200 may be wrapped with the wrap film 300 without interposing an adhesive between the respective battery cells 110 , even if the number of battery cells 110 increases, the conventional repetition Since no process is required, time and cost can be saved.
[54]
In addition, even when misalignment occurs during the lamination process of the battery cells 110 or the tolerance condition is not satisfied, the wrapped wrap film 300 is removed and the battery cells 110 are stacked again, and a new wrap film 300 is removed. Rework is easier because it can be wrapped with In the case of the conventional battery cell stack 20 in which the respective battery cells 11 have already been adhered to each other, this embodiment has a great advantage in that the rework process is extremely difficult.
[55]
On the other hand, the wrap film 300 in this embodiment, as in FIG. 2 , the upper surface (Z-axis direction), the lower surface (opposite to the Z-axis direction) and both sides (the Y-axis direction and the It is desirable to wrap the entire part in the opposite direction).
[56]
Accordingly, it is possible to effectively fix the battery cells 110 constituting the battery cell stack 200 , and furthermore, it is possible to perform electrical insulation between the battery cell stack 200 and the module frame (not shown). .
[57]
Since the module frame in which the battery cell stack 200 is accommodated usually includes a metal material for rigidity, electrical insulation from the battery cell stack 200 is required.
[58]
Accordingly, the wrap film 300 surrounding the entire portion of the upper surface (Z-axis direction), the lower surface (the opposite direction of the Z-axis) and both sides (the opposite direction to the Y-axis direction) of the battery cell stack 200 is, the battery cell In addition to fixing the 110 , it may serve as an electrical insulation of the battery cell stack 200 . Accordingly, there is no need to dispose a separate additional member for securing insulation performance.
[59]
At this time, the wrap film 300 is at least one of polycarbonate (PC) and polyethylene terephthalate (PET) for fixing the battery cells 110 and for electrical insulation of the battery cell stack 200 . may contain one. In other words, the wrap film 300 has a thin sheet structure including at least one of polycarbonate and polyethylene terephthalate, and may implement fixing of the battery cells 110 and electrical insulation of the battery cell stack 200 .
[60]
Meanwhile, the battery cells 110 in this embodiment are stacked in parallel with both sides of the battery cell stack 200 . That is, they are stacked along the Y-axis direction in FIG. 2 .
[61]
In this case, the battery cell 110 may be configured as a pouch-type secondary battery. In such a pouch-type secondary battery, an electrode may be thickened during repeated charging and discharging, or an internal electrolyte may be decomposed due to a side reaction to generate gas. In this case, a phenomenon in which the pouch-type secondary battery cell swells due to electrode expansion and/or generated gas is referred to as a swelling phenomenon. When the swelling phenomenon of the battery cell 110 intensifies, the external shape of the battery module 100 may be changed to adversely affect the structural stability of the battery module 100 or a battery pack including the same.
[62]
The wrap film 300 tightly wrapping the upper surface, the lower surface and both sides of the battery cell stack 200 so that the wrap film 300 is connected not only fixes the battery cell 110 , but also causes swelling of the battery cell 110 . It is possible to effectively suppress the expansion of the battery cell stack 200 according to the development.
[63]
In particular, when the stacked battery cells 110 are strongly pressed from the beginning of assembly, it is known that the thickness expansion due to swelling is relatively small, so the wrap film 300 may be more effective in suppressing expansion.
[64]
Meanwhile, the wrap film 300 in this embodiment may wrap the battery cell stack 200 once or twice. When wrapped less than once, the fixing of the battery cells 110 may not be smooth, and when wrapping more than two times, the height or width of the battery cell stack 200 becomes thick due to the wrap film 300 more than necessary. There may be a problem in that the battery capacity is lowered.
[65]
Referring back to FIG. 2 , the battery cells 110 include an electrode lead 120 connected to an electrode assembly (not shown), and the electrode lead 120 is the front surface (X-axis direction) of the battery cell stack 200 . ) and the rear (direction opposite to the X-axis).
[66]
In embodiments of the present invention, the battery cell stack is embedded in a module frame, such a module frame may be a mono frame or a U-shaped frame. 3 and 4 are diagrams for explaining a mono frame and a U-shaped frame, respectively. Hereinafter, it will be described together with FIGS. 3 and 4 .
[67]
3 is an exploded perspective view of the battery module 100a including the mono frame 400 . Referring to FIG. 3 , the battery module 100a of the present invention may include a mono frame 400 in which the battery cell stack 200 is accommodated.
[68]
Mono frame 400 has an open front (X-axis direction) and rear (X-axis direction), the upper surface (Z-axis direction), the lower surface (opposite the Z-axis direction) and both sides (the opposite direction to the Y-axis direction) This may be an integrated metal plate structure. An end plate 600 may be coupled to the open front and rear surfaces of the mono frame 400 .
[69]
The battery cell stack 200 may be inserted into the open front or rear surface of the mono frame 400 , and the wrap film 300 surrounding the battery cell stack 200 functions as a guide member in this insertion process. can be responsible for That is, the upper surface, the lower surface and both sides of the battery cell stack 200 are wrapped with the wrap film 300 to prevent jamming during the insertion process, so that the battery cell stack 200 is easily monolithic. It may be inserted into the open front or back of the frame 400 .
[70]
In addition, compression pads (not shown) may be disposed on both sides of the battery cell stack 200 . In the process of inserting the wrap film 300 , the compression pad is rolled into the battery cell stack 200 . that can be prevented
[71]
4 is an exploded perspective view of the battery module 100b including the U-shaped frame 500 . Referring to Figure 4, the U-shaped frame 500, the front (X-axis direction), the rear (X-axis direction) and the upper surface (Z-axis direction) are open, the bottom portion 501 and the bottom portion (501) It may have a structure having both side portions 502 extending upwardly from opposite ends of the .
[72]
The open upper surface of the U-shaped frame 500 may be coupled to the upper cover 510 , and the open front and rear surfaces of the U-shaped frame 500 may be coupled to the end plate 600 , respectively.
[73]
The electrode leads 120 may be positioned on the front and rear surfaces of the battery cell stack 200 , and the electrode leads 120 may be electrically connected to the bus bar 710 mounted on the bus bar frame 700 .
[74]
The battery cell stack 200 may be inserted into the open upper surface of the U-shaped frame 500, and the wrap film 300 surrounding the battery cell stack 200 functions as a guide member in this insertion process. can be in charge That is, since both sides of the battery cell stack 200 are wrapped with the wrap film 300, it is possible to prevent jamming by both side parts 502 during the insertion process, so that the battery cell stack 200 is easy can be inserted
[75]
In addition, compression pads (not shown) may be disposed on both sides of the battery cell stack 200 . In the process of inserting the wrap film 300 , the battery cell stack 200 , the compression pads are formed on both side portions. It can be prevented from being rolled up by (502)
[76]
Referring back to FIG. 3 , the battery module 100a may include a thermally conductive resin layer 800 positioned under the battery cell stack 200 . More specifically, the thermally conductive resin layer 800 may be positioned between the battery cell stack 200 and the bottom of the mono frame 400 .
[77]
The thermally conductive resin layer 800 is formed by injecting a thermally conductive resin (Thermal Resin), and may include a thermally conductive adhesive material, specifically, by injecting a thermally conductive resin having fluidity, and then the thermally conductive resin is the battery It may be formed by being solidified while in contact with the cell stack 200 . That is, it may serve to transfer heat generated from the battery cell stack 200 to the bottom of the battery module 100a.
[78]
Although not specifically shown, after accommodating the battery cell stack 200 in the mono frame 400 , a thermal conductive resin is injected through an injection hole formed in the lower portion of the mono frame 400 to form the thermal conductive resin layer 800 . can be formed
[79]
Referring back to FIG. 4 , the battery module 100b may include a thermally conductive resin layer 800 positioned under the battery cell stack 200 . More specifically, the thermally conductive resin layer 800 may be positioned between the battery cell stack 200 and the bottom 501 of the U-shaped frame 500 .
[80]
As in FIG. 3 , the thermally conductive resin layer 800 is formed by applying a thermally conductive resin, and may serve to transfer heat generated from the battery cell stack 200 to the bottom of the battery module 100b. .
[81]
A thermally conductive resin is applied to the bottom 501 of the U-shaped frame 500 and the battery cell stack 200 is placed thereon, and then the thermally conductive resin is solidified to form a thermally conductive resin layer 800 . can do.
[82]
On the other hand, the thermally conductive resin of the thermally conductive resin layer 800 may include a thermally conductive adhesive material, and specifically, it may include at least one of a silicone material, a urethane material, and an acrylic material. there is. The thermally conductive resin layer 800 has excellent thermal conduction characteristics, so that heat generated from the battery cells can be quickly transferred to prevent overheating of the battery modules 100a and 100b.
[83]
At this time, FIG. 5 is a view for explaining the wrap film 300a in which the through hole 310 is formed, and is a view of the battery cell stack 200a from below.
[84]
Referring to FIG. 5 together with FIGS. 3 and 4 , a plurality of through holes 310 may be formed in the wrap film 300a in the present invention.
[85]
In particular, a plurality of through-holes 310 may be formed in the wrap film 300a located at the lower end of the battery cell stack 200a.
[86]
In addition, the through hole 310 may be formed in all areas of the wrap film 300a, not just the lower end of the battery cell stack 200a.
[87]
As described above, for the transfer of heat generated in the battery cell stack 200a, the thermal conductive resin layer 800 may be positioned between the battery cell stack 200a and the bottom of the module frames 400 and 500 . .
[88]
The plurality of battery cells included in the battery cell stack 200a can directly contact the thermally conductive resin layer 800 by the through-holes 310 formed in the wrap film 300a, and the thermally conductive resin layer 800 . Heat transfer of the battery cell stack 200a through the can be made more effectively.
[89]
One or more battery modules according to the present embodiment described above may be mounted together with various control and protection systems such as a battery management system (BMS) and a cooling system to form a battery pack.
[90]
The battery module or battery pack 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, but is not limited thereto, and may be applied to various devices capable of using a secondary battery.
[91]
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
[92]
Explanation of symbols
[93]
100: battery module
[94]
110: battery cell
[95]
200: battery cell stack
[96]
300: wrap film
[97]
400: mono frame
[98]
500: U-shaped frame
[99]
510: top cover
[100]
600: end plate

WE CLAIMS

a battery cell stack in which a plurality of battery cells are stacked; and a wrap film surrounding the upper surface, the lower surface and both sides of the battery cell stack, wherein the wrap film is continuously connected from the upper surface, the lower surface and both sides of the battery cell stack.
[Claim 2]
The battery module of claim 1, wherein, between each of the battery cells, an adhesive or tape is removed so that adjacent battery cells are in direct contact with each other.
[Claim 3]
The battery module of claim 1 , wherein the wrap film covers all portions of the upper surface, the lower surface, and both sides of the battery cell stack.
[Claim 4]
The battery module of claim 1 , wherein the wrap film includes at least one of polycarbonate (PC) and polyethylene terephthalate (PET).
[Claim 5]
The battery module of claim 1 , wherein the battery cells are arranged parallel to both sides of the battery cell stack and stacked.
[Claim 6]
The battery module of claim 1 , wherein the battery cell includes an electrode lead, and the electrode lead is positioned on the front and rear surfaces of the battery cell stack.
[Claim 7]
The battery module of claim 1 , wherein the wrap film wraps the battery cell stack once or twice.
[Claim 8]
The battery module of claim 1, further comprising: a module frame accommodating the battery cell stack; and an end plate covering the front and rear surfaces of the module frame.
[Claim 9]
The battery module of claim 8, wherein the module frame is a mono frame with open front and rear surfaces, and an upper surface, a lower surface, and both sides integrated.
[Claim 10]
The battery module of claim 8, wherein the module frame includes a U-shaped frame having an open front, rear, and upper surface, and an upper cover covering the open upper surface of the U-shaped frame.
[Claim 11]
The battery module of claim 1, wherein a plurality of through holes are formed in the wrap film.
[Claim 12]
The battery module of claim 11, wherein the plurality of through-holes are formed in the wrap film located at the lower end of the battery cell stack.
[Claim 13]
The battery module of claim 11, further comprising a thermally conductive resin layer positioned under the battery cell stack.
[Claim 14]
The battery module of claim 13 , wherein the thermally conductive resin layer includes at least one of a silicone material, a urethane material, and an acrylic material.
[Claim 15]
A battery pack comprising at least one battery module according to claim 1 .