Title of Invention: Battery module and battery pack including same
technical field
[One]
Cross-Citation with Related Application(s)
[2]
This application claims the benefit of priority based on Korean Patent Application No. 10-2020-0048650 dated April 22, 2020, 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 for improving cooling performance and a battery pack including the same.
background
[4]
Secondary batteries are receiving a lot of attention as an energy source in various product groups such as mobile devices and electric vehicles. Such a secondary battery is a powerful energy resource that can replace the use of conventional products using fossil fuels, and is in the spotlight as an eco-friendly energy source because no by-products are generated due to energy use.
[5]
Recently, as the need for a high-capacity secondary battery structure, including the use of secondary batteries as an energy storage source, increases, the demand for a battery pack having a multi-module structure in which a plurality of secondary batteries are assembled in series/parallel connected battery pack is increasing. .
[6]
On the other hand, when configuring a battery pack by connecting a plurality of battery cells in series/parallel, a battery module composed of battery cells is configured, and other components are added using at least one battery module to configure the battery pack. How to do it is common
[7]
Such a battery module includes a battery cell stack in which a plurality of battery cells are stacked, a module frame accommodating the battery cell stack, and a heat sink for cooling the plurality of battery cells.
[8]
1 is a view showing a battery module combined with a conventional heat sink. FIG. 2 is a plan view illustrating a flow path structure of the heat sink of FIG. 1 . 3 is a view illustrating a state in which a refrigerant flows in the flow path structure of FIG. 2 .
[9]
1 to 3 , a conventional battery module includes a battery cell stack in which a plurality of battery cells 10 are stacked, a module frame for accommodating the battery cell stack, a bottom portion 20 of the module frame and the It includes a thermally conductive resin layer 15 positioned between the battery cell stack. Such a battery module may be formed under the module frame bottom 20 and combined with a heat sink 30 that provides a cooling function to the plurality of battery cells 10 to form a battery pack. At this time, the heat sink 30 includes a cooling plate 31 having an inlet 32 ​​through which the refrigerant flows, an outlet 33 through which the refrigerant flows, and a cooling passage 34 connecting the inlet 32 ​​and the outlet 33 . ), and an upper plate 29 covering the cooling plate 31 . Here, a heat-conducting layer 18 may be further formed between the bottom 20 of the battery module and the heat sink 30 .
[10]
Conventionally, in order to improve the cooling performance of the battery module and/or the battery pack, a separate cooling structure, for example, a heat sink is required in the battery pack unit. Accordingly, the cooling structure tends to be complicated. In addition, the inside of the heat sink adopts a bent flow path structure as shown in FIG. 2 to cover the lower surface of the module frame. Since this is not done naturally, a temperature deviation from other parts of the flow path may occur. When a temperature deviation occurs on the flow path, the cooling of the battery cell stack is not uniformly performed, so that the overall cooling performance of the battery module may be deteriorated.
DETAILED DESCRIPTION OF THE INVENTION
technical challenge
[11]
SUMMARY OF THE INVENTION An object of the present invention is to provide a battery module and a battery pack that improve cooling performance.
[12]
The problems of the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.
means of solving the problem
[13]
A battery module according to an embodiment of the present invention for realizing the above object includes: a battery cell stack in which a plurality of battery cells are stacked; a module frame for accommodating the battery cell stack; and a heat sink formed below the module frame to cool the plurality of battery cells, wherein the heat sink includes a lower plate and a flow path that is a flow path of the refrigerant, and a dimple portion is formed on a surface of the flow path. .
[14]
The dimple part may be formed of a plurality of dimples convex upwardly from the surface of the flow path part.
[15]
The plurality of dimples may be formed to be spaced apart from each other.
[16]
The heat sink may further include an inlet through which the refrigerant flows and an outlet through which the refrigerant flows, and the dimple portion may be formed to be spaced apart from the inlet and the outlet.
[17]
The flow path part may further include a partition wall formed inside the flow path part along a direction in which the flow path part is formed.
[18]
The dimple part may be formed between the partition wall and both side walls of the flow path part.
[19]
The heat sink further includes an inlet through which the refrigerant flows and an outlet through which the refrigerant flows, a start portion of the barrier rib is formed to be spaced apart from the inlet, and the dimple portion is spaced apart from the inlet from the beginning of the barrier rib to the flow path. The portion may be formed along a direction in which it is formed.
[20]
An end portion of the barrier rib may be formed to be spaced apart from the outlet, and the dimple portion may be formed from a start portion of the barrier rib to an end portion of the barrier rib to be spaced apart from the outlet.
[21]
The flow path part is formed in a structure recessed downward from the lower plate, the upper side of the flow path part is covered by the bottom part of the module frame, and the refrigerant can flow into the space between the flow path part and the bottom part of the module frame. have.
[22]
A battery pack according to another embodiment of the present invention includes the battery module.
Effects of the Invention
[23]
According to embodiments of the present invention, the dimple portion is formed on the surface of the flow path to reduce the thermal resistance of the refrigerant and reduce the temperature deviation of the refrigerant, thereby improving the cooling performance of the battery module.
[24]
In addition, the cooling structure can be simplified through a cooling structure in which the module frame and the heat sink are integrated.
[25]
Effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.
Brief description of the drawing
[26]
1 is a view showing a battery module combined with a conventional heat sink.
[27]
FIG. 2 is a plan view illustrating a flow path structure of the heat sink of FIG. 1 .
[28]
3 is a view illustrating a state in which a refrigerant flows in the flow path structure of FIG. 2 .
[29]
4 is an exploded perspective view of a battery module according to an embodiment of the present invention.
[30]
FIG. 5 is a view showing a state in which the components of the battery module of FIG. 4 are assembled.
[31]
6 is a view of the battery module assembled in FIG. 5 centered on the heat sink formed on the lower part.
[32]
7 is a cross-sectional view illustrating the heat sink of FIG. 6 cut in a horizontal direction and viewed in a direction AA.
[33]
FIG. 8 is a diagram illustrating a state in which a refrigerant flows through the heat sink of FIG. 7 .
[34]
FIG. 9 is a view showing a modified example of the heat sink of FIG. 7 .
[35]
FIG. 10 is a diagram illustrating a state in which a partition wall is formed in a flow path as a modified example of the heat sink of FIG. 7 .
Modes for carrying out the invention
[36]
It should be understood that the embodiments described below are illustratively shown to help understanding of the invention, and that the present invention may be implemented with various modifications different from the embodiments described herein. However, in the description of the present invention, if it is determined that a detailed description of a related known function or component may unnecessarily obscure the gist of the present invention, the detailed description and specific illustration thereof will be omitted. In addition, the accompanying drawings are not drawn to scale in order to help understanding of the invention, but dimensions of some components may be exaggerated.
[37]
The first and second terms used in the present application may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.
[38]
In addition, the terms used in the present application are only used to describe specific embodiments, and are not intended to limit the scope of rights. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present application, terms such as "comprises", "consists of" or "consisting It should be understood that it does not preclude the possibility of addition or existence of further other features or numbers, steps, operations, components, parts, or combinations thereof.
[39]
Hereinafter, a configuration of a battery module according to an embodiment of the present invention will be described with reference to FIGS. 4 and 5 .
[40]
4 is an exploded perspective view of a battery module according to an embodiment of the present invention. FIG. 5 is a view showing a state in which the components of the battery module of FIG. 4 are assembled.
[41]
4 and 5 , the battery module 200 according to an embodiment of the present invention includes a battery cell stack 100 in which a plurality of battery cells are stacked, and a module for accommodating the battery cell stack 100 . The frame 205 and a heat sink 300 formed below the module frame 205 to cool the plurality of battery cells is included.
[42]
The battery cell according to this embodiment is a secondary battery, and may be configured as a pouch-type secondary battery. The battery cells may be configured in plurality, and the plurality of battery cells may be stacked to each other so as to be electrically connected to each other to form the battery cell stack 100 . Each of the plurality of battery cells may include an electrode assembly, a cell case, and an electrode lead protruding from the electrode assembly.
[43]
The module frame 205 accommodates the battery cell stack 100 . According to an embodiment of the present invention, the module frame 205 includes a lower frame 210 that covers the lower surface and both sides of the battery cell stack 100 , and an upper plate that covers the upper surface of the battery cell stack 100 ( 220) may be included. However, the structure of the module frame 205 is not limited thereto, and may be in the form of a mono frame surrounding on four surfaces except for the front and rear surfaces of the battery cell stack 100 .
[44]
The battery module 200 according to the present embodiment may further include an end plate 230 covering the front and rear surfaces of the battery cell stack 100 . It is possible to physically protect the battery cell stack 100 accommodated therein through the module frame 205 described above.
[45]
The heat sink 300 may be formed under the module frame 205 . The heat sink 300 is formed on one side of the cooling plate 310 forming the skeleton of the heat sink 300 and in contact with the bottom of the module frame 205 and the heat sink 300 from the outside. ) The inlet 320 for supplying the refrigerant to the inside, the outlet 330 formed on one side of the heat sink to allow the refrigerant flowing inside the heat sink to flow out of the heat sink, and the inlet 320 and the outlet 330 are connected and a flow path part 340 through which the refrigerant flows.
[46]
Specifically, the flow path 340 may refer to a structure in which the cooling plate 310 in contact with the lower surface of the lower frame 210 corresponding to the bottom of the module frame 205 is depressed downward. The upper side of the flow path part 340 is opened to form a flow path between the flow path part 340 and the bottom of the module frame 205 , and a refrigerant may flow through the flow path. In other words, the battery module 200 according to the present embodiment may have a cooling-integrated structure in which the bottom of the module frame 205 serves to correspond to the upper plate of the heat sink 300 .
[47]
Conventionally, a structure in which a refrigerant flows is separately formed on the lower side of the module frame, so that the module frame has to be indirectly cooled, so cooling efficiency is lowered and a separate refrigerant flow structure is formed on the battery module and the battery pack equipped with the battery module. There was a problem in that the space utilization rate was lowered. However, according to an embodiment of the present invention, by adopting a structure in which the heat sink 300 is integrated in the lower part of the module frame 205 , the refrigerant flows directly between the flow path part 340 and the bottom part of the module frame 205 . As a result, the cooling efficiency according to direct cooling is increased, and the space utilization rate on the battery module and the battery pack in which the battery module is mounted is further improved through the structure in which the heat sink 300 is integrated with the bottom of the module frame 205 . can do it
[48]
A dimple part 350 may be formed on the surface of the flow path part 340 . In the conventional flow path structure having a flat surface, a temperature deviation occurs in a portion where a sudden change in flow occurs, such as a corner portion of a bent flow passage or both ends of the flow passage, so that the cooling of the battery module is not performed smoothly in that portion. there was. In addition, in the case of a large-area battery module in which the number of battery cells stacked in the battery cell stack increases significantly compared to the prior art, the width of the flow path may be formed to be wider, so that the temperature deviation may be more severe.
[49]
Accordingly, according to an embodiment of the present invention, by forming the dimple part 350 on the surface of the flow path part 340 , the flow rate of the refrigerant can be adjusted to uniformly cool all parts of the flow path part 340 . Accordingly, it is possible to decrease the maximum rising temperature, to minimize the cooling temperature deviation between flow passage parts, and to improve thermal resistance, so that the overall battery module and the battery pack including the same can be improved in cooling performance. The effect of reducing the temperature deviation and improving the cooling performance may be more effectively shown in a large-area battery module in which the channel width is formed wider as an embodiment of the present invention.
[50]
Hereinafter, a heat sink structure in which a dimple portion is formed according to embodiments of the present invention will be described in more detail with reference to FIGS. 6 to 9 .
[51]
6 is a view of the battery module assembled in FIG. 5 centered on the heat sink formed on the lower part. 7 is a cross-sectional view illustrating the heat sink of FIG. 6 cut in a horizontal direction and viewed in a direction AA. FIG. 8 is a diagram illustrating a state in which a refrigerant flows through the heat sink of FIG. 7 . FIG. 9 is a view showing a modified example of the heat sink of FIG. 7 .
[52]
6 to 8 , in the heat sink 300 according to an embodiment of the present invention, the cooling plate 310 may be formed to correspond to the bottom of the module frame 205 . The bottom portion of the module frame 205 corresponds to the bottom portion of the lower frame 210 , and the bottom portion of the cooling plate 310 and the lower frame 210 may be coupled by welding, and the battery module may be coupled through the cooling plate 310 . The overall rigidity can be reinforced. The cooling plate 310 and the bottom of the lower frame 210 are sealed through welding, so that the refrigerant can flow through the flow path 340 formed inside the cooling plate 310 without leakage.
[53]
Both the inlet 320 and the outlet 330 may be formed on one side of the heat sink 300 . In more detail, both the inlet 320 and the outlet 330 may be formed on one side of the heat sink 300 formed in the portion where the end plate 230 is located. The inlet 320 and the outlet 330 may be respectively located at both ends of one side of the heat sink 300 . A refrigerant supply unit and a refrigerant discharge unit are formed on the lower side or upper side of the heat sink 300 , so that the refrigerant supplied through the refrigerant supply unit may flow into the inlet 320 , and the refrigerant discharged through the outlet 330 may be discharged through the refrigerant discharge unit. can be discharged to the outside.
[54]
The flow path portion 340 may be formed to cover the bottom portion of the module frame 205 while being bent along the direction in which the refrigerant flows. The flow path 340 is formed in most regions of the bottom of the module frame 205 , except for the portion where the cooling plate 310 comes into contact with the bottom of the module frame 205 . Accordingly, all parts of the battery cell stack 100 disposed above the bottom of the module frame 205 to occupy most of the area of ​​the bottom of the module frame 205 may be uniformly cooled.
[55]
The dimple part 350 may be formed of a plurality of dimples formed in a hemispherical shape convex upward from the surface of the flow path part 340 . In other words, when the battery module is viewed from the bottom up, the lower surface of the heat sink 300 may have a concave shape. The plurality of dimples may be formed to be spaced apart from each other. Accordingly, as shown in FIG. 8 , the refrigerant flows evenly while passing between the dimple parts 350 formed of a plurality of dimples, so that cooling performance indicators such as maximum cooling temperature, temperature deviation, and thermal resistance can be improved. . The dimple part 350 may be formed to be spaced apart from the inlet 320 and the outlet 330 .
[56]
The dimple part 350 may implement a heat sink having a dimple part structure modified in various forms including the structure shown in FIG. 9 .
[57]
Hereinafter, a heat sink having a barrier rib structure according to a modified embodiment of the present invention will be described with reference to FIGS. 6 and 10 .
[58]
FIG. 10 is a diagram illustrating a state in which a partition wall is formed in a flow path as a modified example of the heat sink of FIG. 7 .
[59]
According to the present embodiment, the partition wall 360 is formed in the flow path part 340 in the direction in which the flow path part 340 is formed. The barrier rib 360 according to the present exemplary embodiment reduces the width of the flow path part 340 without changing the flow path length of the flow path part 340 to minimize the pressure drop and at the same time reduce the temperature deviation between the flow path widths. The upper end of the partition wall 360 and the upper end of the cooling plate 310 may be coupled to the lower surface of the module frame 205 by a method such as welding.
[60]
By the partition wall 360 , it is possible to minimize the pressure drop and temperature deviation of the flowing refrigerant, and in addition to the cooling plate 310 , the partition wall 360 is also combined with the bottom of the module frame 205 to form the module frame 205 . ) and support the load of the battery cell stack accommodated in the module frame 205 and may have the effect of reinforcing the rigidity of the battery module.
[61]
The partition wall 360 may extend from the inlet 320 to the outlet 330 along a central portion of the flow path 340 . Through this, the refrigerant introduced into the inlet 320 may be guided to the outlet 330 along the partition wall 360 .
[62]
The starting point of the partition wall 360 is formed to be spaced apart from the inlet 320 , and the refrigerant introduced through the inlet 320 flows from the starting point of the partition wall 360 to the first flow path portion 341 and the second flow path formed through the partition wall 360 . It can flow by being divided into two flow passages 342 . In this case, the widths of the first flow path part 341 and the second flow path part 342 are formed to be the same, and the widths of the first flow path part 341 and the second flow path part 342 are from the inlet 320 to the outlet 340 . ) can be consistently formed. Accordingly, the flow may not be biased toward any one of the first and second flow passages 341 and 342 , and a flow passage that may occur due to a wider width of one of the first and second flow passages 341 and 342 . It is possible to minimize the difference in temperature difference between each. In addition, since the widths of the flow passages 340 are formed uniformly, the possibility of pressure drop and temperature deviation that may occur when the width is increased or decreased can be minimized.
[63]
The dimple part 350 may be formed between the partition wall 360 and both side walls of the flow path part 340 . That is, the dimple part 350 may be formed on the surfaces of the first flow path part 341 and the second flow path part 342 . The start portion of the partition wall 360 is formed to be spaced apart from the inlet 320 , and the dimple portion 350 is formed along the direction in which the flow path portion 340 is formed from the start portion of the partition wall 360 so as to be spaced apart from the inlet 320 . can be In addition, the end portion of the partition wall 360 is formed to be spaced apart from the outlet 330 , and the dimple portion 350 is formed from the beginning of the partition wall 360 to the end portion of the partition wall 360 so as to be spaced apart from the outlet 330 . can As the dimple parts 350 are formed in each of the first and second flow passages 341 and 342 separated by the partition wall 360 , the temperature deviation in the first and second flow passages 341 and 342 is improved and cooling performance is improved. can be improved
[64]
The battery module described above may be included in the battery pack. The battery pack may have a structure in which one or more battery modules according to the present embodiment are collected and packed by adding a battery management system (BMS) that manages the temperature or voltage of the batteries and a cooling device.
[65]
The 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 vehicle, but the present invention is not limited thereto and can be applied to various devices that can use a battery module, which also falls within the scope of the present invention .
[66]
In the above, preferred embodiments of the present invention have been illustrated and described, but the present invention is not limited to the specific embodiments described above, and it is common in the technical field to which the present invention pertains without departing from the gist of the present invention as claimed in the claims. Various modifications may be made by those having the knowledge of, of course, and these modifications should not be individually understood from the technical spirit or perspective of the present invention.
[67]
Explanation of symbols
[68]
205: module frame
[69]
210: lower frame
[70]
220: upper plate
[71]
230: end plate
[72]
300: heat sink
[73]
310: lower plate
[74]
320: inlet
[75]
330: outlet
[76]
340: Euro
[77]
341: 1st Euro
[78]
342: 2nd Euro
[79]
350: dimple part
[80]
360: bulkhead
Claims
[Claim 1]
a battery cell stack in which a plurality of battery cells are stacked; a module frame for accommodating the battery cell stack; and a heat sink formed under the module frame to cool the plurality of battery cells, wherein the heat sink includes a lower plate and a flow path that is a flow path of the refrigerant, and a dimple part is formed on the surface of the flow path part module.
[Claim 2]
The battery module of claim 1 , wherein the dimple part is formed of a plurality of dimples convex upward from a surface of the flow path part.
[Claim 3]
The battery module of claim 2, wherein the plurality of dimples are spaced apart from each other.
[Claim 4]
The battery module of claim 1 , wherein the heat sink further includes an inlet through which the refrigerant flows and an outlet through which the refrigerant flows, and the dimple portion is formed to be spaced apart from the inlet and the outlet.
[Claim 5]
The battery module of claim 1 , wherein the flow path part further comprises a partition wall formed inside the flow path part along a direction in which the flow path part is formed.
[Claim 6]
The battery module of claim 5 , wherein the dimple part is formed between the partition wall and both side walls of the flow path part.
[Claim 7]
The heat sink of claim 5, wherein the heat sink further includes an inlet through which the refrigerant flows and an outlet through which the refrigerant flows, a start portion of the barrier rib is formed to be spaced apart from the inlet, and the dimple portion of the barrier rib is spaced apart from the inlet. A battery module formed along a direction in which the flow path part is formed from the beginning.
[Claim 8]
The battery module of claim 7 , wherein an end portion of the partition wall is formed to be spaced apart from the outlet, and the dimple portion is formed from a start portion of the partition wall to an end portion of the partition wall to be spaced apart from the outlet.
[Claim 9]
The method of claim 1, wherein the flow path part is formed in a structure recessed downwardly from the lower plate, and an upper side of the flow path part is covered by the bottom part of the module frame, and is formed into a space between the flow path part and the bottom part of the module frame. A battery module in which the refrigerant flows.
[Claim 10]
A battery pack comprising the battery module according to claim 1 .