Title of Invention: Top Cooling Battery Pack
technical field
[One]
The present invention relates to a battery pack, and more particularly, to a cooling and assembly structure of the battery pack.
[2]
This application is a priority claim application for Korean Patent Application No. 10-2019-0096284 filed on August 07, 2019, and all contents disclosed in the specification and drawings of the application are incorporated herein by reference.
background
[3]
A secondary battery refers to a battery that can be charged and discharged, unlike a primary battery that cannot be charged. It is used as a power source for hybrid vehicles (HEVs).
[4]
The types of secondary batteries currently widely used include a lithium ion battery, a lithium polymer battery, a nickel cadmium battery, a nickel hydrogen battery, a nickel zinc battery, and the like. The operating voltage of such a unit secondary battery cell, that is, a unit battery cell, is about 2.5V to 4.2V. Therefore, when higher output voltage and energy capacity are required, a battery module is configured by connecting a plurality of battery cells in series, or two or more battery modules are connected in series or parallel and other components are added to form a battery pack. make up For example, a battery module may refer to a device in which a plurality of secondary cells are connected in series or parallel, and a battery pack may refer to a component in which battery modules are connected in series or in parallel to increase capacity and output.
[5]
The battery pack may further include a cooling device for properly maintaining the temperature of the battery modules including the battery modules, a control device for monitoring the operating state of the battery modules, and a pack case for packaging them. .
[6]
On the other hand, in the case of a battery pack for an electric vehicle, since the installation space of the battery pack is limited according to the overall length and width of the electric vehicle, it is important to increase the energy density by mounting the battery modules and other components in the pack case as space-efficiently as possible. .
[7]
In the conventional case of assembling the battery pack, as shown in FIG. 1 , the battery modules 2 are placed on the upper surface of the pack tray 1 corresponding to the bottom surface of the pack case and bolted to the pack tray 1 , Mechanically fix the battery modules (2). In general, the battery module (2) inserts long bolts in a total of four places of the front and rear corners, and there are many things that are fixed to the upper surface of the pack tray (1). The electrical connection structure between the battery modules spans both ends of the metal bar-shaped inter-bus bar 3 on the upper surface of the positive terminal 2a of one battery module 2 and the negative terminal 2b of the other battery module 2 Many structures are employed in which two bolts are used to place and fix them.
[8]
In addition, as a cooling configuration of the battery pack, a heat sink 4 is installed on the bottom surface of the pack tray 1 and a cooling water supply pipe is connected thereto to circulate cooling water in and out of the pack case.
[9]
However, recently, several problems have been pointed out with respect to the assembly structure of the conventional battery pack. Among them, the problem of inefficiency and cost increase of the assembly process due to the use of too many bolts to fix the battery modules and the inter-bus bars. Wow, space loss, such as in the 'O' region of FIG. 1, energy density decrease due to heat sink installation, coolant leakage, and problems in securing reliability of sealing of pipes and cooling ports have been pointed out a lot.
[10]
Therefore, the development of a battery pack to which a cooling and assembly structure that can solve the above problems is applied has become an issue.
DETAILED DESCRIPTION OF THE INVENTION
technical challenge
[11]
The present invention has been devised to solve the above problems, and an object of the present invention is to provide a battery pack capable of eliminating risks due to coolant leakage, improving energy density, and improving assembly process efficiency.
[12]
Other objects and advantages of the present invention may be understood by the following description, and will become more clearly understood by the examples of the present invention. Further, it will be readily apparent that the objects and advantages of the present invention can be realized by the means and combinations thereof indicated in the claims.
means of solving the problem
[13]
According to the present invention, there is provided a battery pack comprising a plurality of battery modules and a pack case in which the battery modules can be fixedly installed therein,
[14]
a pack case comprising: a pack tray supporting lower portions of the battery modules; and a pack cover covering the battery modules and provided in contact with upper surfaces of the battery modules; and a heat sink installed on an upper portion of the pack cover may be provided.
[15]
The heat sink may be provided integrally with the pack cover.
[16]
The heat sink may be provided to be pre-mountable to a predetermined external structure.
[17]
The pack cover may be provided with a terminal connecting portion for electrically connecting the electrode terminals of the battery modules to each other on an inner surface of the upper end.
[18]
In the battery modules, when the top is covered by the pack cover, the electrode terminal of one of the battery modules and the electrode terminal of the other adjacent battery module respectively contact the terminal connection part in the vertical direction to be electrically connected. can
[19]
Each of the battery modules may include battery cells and a module case for accommodating the battery cells, and the electrode terminal may be provided to protrude from one side of the module case in a square plate shape.
[20]
The module case may include a terminal support part formed to protrude from one side to support a lower portion of the electrode terminal and having a through hole in a vertical direction.
[21]
The pack cover may further include a mounting nut on the top inner surface, and each of the battery modules may be fixed to the pack cover by a mounting bolt that is inserted into the through hole of the terminal support part and is vertically fastened to the mounting nut. .
[22]
At least one of the mounting bolt and the mounting nut may be made of an insulating material.
[23]
The terminal connection unit may include: an inter-bus bar in surface contact with the electrode terminal and having a fastening hole through which the mounting bolt can pass; and a bracket member that supports the inter-bus bar and is fixedly coupled to the inner surface of the pack cover.
[24]
The bracket member may be shape-fitted with the mounting nut and attached to the inner surface of the pack cover.
[25]
The plurality of battery modules may be arranged in two rows, and electrode terminals may be arranged to face each other with respect to the center of the pack case.
[26]
According to another aspect of the present invention, a vehicle including the above-described battery pack may be provided. The vehicle may include an electric vehicle (EV) or a hybrid vehicle (HEV).
Effects of the Invention
[27]
According to one aspect of the present invention, since the heat sink is installed outside the pack case, it is free from the risk of coolant leakage, and it is possible to simplify the assembly structure inside the pack case and improve the energy density.
[28]
According to another aspect of the present invention, the assembly process efficiency can be promoted by integrating the mechanical fixing and electrical connection structures of the battery modules in the pack case.
[29]
Other effects of the present invention can be understood by the following description, and will be more clearly understood by the examples of the present invention.
Brief description of the drawing
[30]
1 is a view schematically showing an assembly example of a battery pack according to the prior art.
[31]
2 is a schematic perspective view of a battery pack according to an embodiment of the present invention.
[32]
3 is a partially exploded perspective view of the battery pack of FIG. 2 ;
[33]
4 is a schematic perspective view of a battery module according to an embodiment of the present invention.
[34]
FIG. 5 is a schematic cross-sectional view taken along II′ of FIG. 2 .
[35]
6 is a schematic cross-sectional view taken along line II-II' of FIG. 2 .
[36]
7 is a schematic cross-sectional view taken along line III-III' of FIG. 2 .
[37]
8 is a schematic perspective view of a terminal connection part and a mounting nut according to an embodiment of the present invention.
[38]
FIG. 9 is a cross-sectional view corresponding to FIG. 8 .
[39]
10 is a view for explaining a structure for fixing and electrically connecting a battery module according to an embodiment of the present invention.
[40]
11 is a view corresponding to FIG. 7 and is a view for explaining another embodiment of the present invention.
Modes for carrying out the invention
[41]
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, the terms or words used in the present specification and claims should not be construed as being limited to their ordinary or dictionary meanings, and the inventor should properly understand the concept of the term in order to best describe his invention. Based on the principle that it can be defined, it should be interpreted as meaning and concept consistent with the technical idea of ​​the present invention. Accordingly, the embodiments described in the present specification and the configurations shown in the drawings are only some of the most preferred embodiments of the present invention and do not represent all the technical spirit of the present invention. It should be understood that there may be equivalents and variations.
[42]
2 is a schematic perspective view of a battery pack according to an embodiment of the present invention, FIG. 3 is a partially exploded perspective view of the battery pack of FIG. 2 , and FIG. 4 is a schematic perspective view of a battery module according to an embodiment of the present invention.
[43]
Referring to these drawings, the battery pack 10 according to an embodiment of the present invention includes a plurality of battery modules 100 , a pack case 200 accommodating the battery modules 100 , and the pack case It includes a heat sink 300 installed on the upper portion of the 200 .
[44]
2 and 3 , the pack case 200 includes a pack tray 210 and a pack cover 220 coupled to each other. The pack tray 210 is provided in the shape of a plate-shaped body having a large area to support the lower portions of the battery modules 100 , and the pack cover 220 is combined with the pack tray 210 to support the entire battery modules 100 . provided to cover the
[45]
In particular, as will be described later, each battery cell 110 is electrically connected and mechanically fixed at the same time through the terminal connection part 221 provided on the upper inner surface of the pack cover 220 .
[46]
Among the main components constituting the battery pack 10 , the heat sink 300 corresponding to the cooling component will be first examined, and then the internal assembly structure of the battery pack 10 will be examined.
[47]
The heat sink 300 of this embodiment has a flow path (not shown) through which the refrigerant can circulate therein. The refrigerant flowing in the flow passage is not particularly limited as long as it flows easily in the flow passage and has excellent cooling properties.
[48]
The heat sink 300 is located on the top outer surface of the pack cover 220 . That is, in the battery pack 10 of the present invention, the electrical element and the cooling element are separated by providing the heat sink 300 outside the pack case 200 . Therefore, it is free from the risk of coolant leakage due to external shocks, etc. In addition, since the heat sink 300 is removed from the inside of the pack case 200 , it is possible to achieve the effect of simplifying the assembly structure and increasing the energy density.
[49]
As a method of installing the heat sink 300 on the top of the pack cover 220, there is a method of manufacturing the heat sink 300 separately from the pack cover 220, placing it on the pack cover 220 and fixing it, In this case, due to the difference in surface roughness between the heat sink 300 and the pack cover 220 , the thermal contact resistance is large, and cooling efficiency may be reduced.
[50]
Accordingly, in this embodiment, the pack cover 220 and the heat sink 300 are integrally configured. For example, it can be said that the heat sink 300 is integrated as a part of the pack cover 220 to minimize the thermal contact resistance and the thermal conduction path. By absorbing heat inside the pack case 200 with the heat sink 300 integrated pack cover 220 , the cooling performance may not decrease even if the heat sink 300 is outside the pack case 200 .
[51]
As an alternative example of this embodiment, an example in which a thermal interface material (TIM) is placed on the upper outer surface of the pack cover 220 and the heat sink 300 is disposed thereon can be considered. The TIM fills a gap between the pack cover 220 and the heat sink 300 to reduce thermal contact resistance. As the TIM, a thermal pad or resin having high thermal conductivity may be employed.
[52]
As shown in FIGS. 4 and 5 , each battery module 100 accommodated in the pack case 200 includes battery cells 110 and for accommodating the battery cells 110 in an internal space. It includes a module case 120 and electrode terminals 150a and 150b provided to be exposed to the outside of the module case 120 .
[53]
The battery cells 110 are pouch-type secondary battery cells widely known in the art. The pouch-type secondary battery can be stacked in the inner space of the module case 120, which is advantageous in increasing energy density. Of course, the battery cell 110 does not necessarily have to be the pouch-type battery cell 110 . For example, it may be replaced with a cylindrical secondary battery cell or a prismatic secondary battery cell.
[54]
The module case 120 includes a base plate 121 and a top plate 122 covering the lower and upper portions of the battery cells 110 , respectively, and a pair of side surfaces disposed at the outermost sides along the arrangement direction of the battery cells 110 . The plate 123 and the battery cells 110 may be configured to include a front cover 124 and a rear cover 125 respectively covering the front and rear.
[55]
The top plate 122 of the module case 120 may be provided in surface contact with the inner surface of the pack cover 220 . A thermal pad may be further interposed between the top plate 122 and the inner surface of the pack cover 220 .
[56]
The front cover 124 and the rear cover 125 are positioned in front of the battery cells 110 to prevent components such as electrode leads of the battery cells 110 or an inter connection board (ICB) from being exposed to the outside. The electrode terminals 150a and 150b include a positive terminal 150a and a negative terminal 150b, are located outside the top of the front cover 124, have a wide surface in the form of a square plate, and have a hole in the vertical direction. It is provided to insert a bolt.
[57]
The electrode terminals 150a and 150b may be supported by being placed on the terminal support 126 . Here, the terminal support 126 is a portion protruding from the front cover 124 , and may be used as a lower support for the electrode terminals 150a and 150b and a bolting place for the battery module 100 .
[58]
The terminal support part 126 may be provided to extend along the width direction of the front cover 124 , and in places where the positive terminal 150a and the negative terminal 150b are placed, a through hole through which a bolt can be inserted is vertical one by one. direction can be formed. Although not shown in the drawing, the through-holes may be formed to coincide vertically with the holes of the electrode terminals 150a and 150b.
[59]
For reference, although the front cover 124 and the terminal support 126 have been separately described, they may be integrally manufactured. In addition, although not shown, a through hole is provided so that the mounting bolt 201 can be inserted in another place where the electrode terminals 150a and 150b are not located to fasten the mounting bolt 201 to the pack cover 220 . may be
[60]
The pair of side plates 123 may serve to press and support the battery cells 110 from the outside of the outermost battery cells 110 in the arrangement direction of the battery cells 110 .
[61]
Next, with reference to FIGS. 6 to 10 , a mechanical fixing structure and an electrical connection structure for each of the battery modules 100 and 100 inside the pack case 200 will be described in detail.
[62]
In the present embodiment, there are eight battery modules 100 in total and may be accommodated in the pack case 200 in two rows of four each. At this time (see FIG. 3 ), in the battery module 100 group in the first row and the battery module 100 group in the second row, the electrode terminals 150a and 150b may be positioned to face each other with respect to the center of the pack case 200 . . The arrangement of the battery modules 100 may be advantageous in minimizing the electrical connection distance between the respective battery modules 100 . Of course, since such an arrangement of the battery modules 100 is an example, the total number or arrangement structure of the battery modules 100 may vary.
[63]
The eight battery modules 100 may be supported by being placed on the bottom of the pack tray 210 , and may be fixed by bolting to the terminal connector 221 provided on the top inner surface of the pack cover 220 . In addition, the electrode terminals 150a and 150b of the adjacent battery modules 100 may be electrically connected to each other by contacting the terminal connection part 221 .
[64]
For example, when the top of the module case 120 is covered by the pack cover 220, the electrode terminals 150a and 150b of any one battery module 100 and the electrode terminals of the other battery module 100 ( 150a and 150b may be electrically connected to each other by vertically contacting the terminal connection part 221 .
[65]
As shown in FIGS. 8 and 9 , the pack cover 220 may further include a mounting nut 225 on the upper inner surface thereof. The mounting nut 225 may be pre-attached to the pack cover 220 by welding. The terminal connection part 221 may be coupled to the mounting nut 225 and may be attached to the pack cover 220 .
[66]
The terminal connection part 221 is provided with a fastening hole 221c through which the mounting bolt 201 can pass, and has a metal bar shape that can be in surface contact with the electrode terminals 150a and 150b of the battery module 100 - It may include a bus bar 221b and a bracket member 221a formed of an insulating material that supports the inter-bus bar 221b and is fixedly coupled to the top inner surface of the pack cover 220 .
[67]
The rear part of the bracket member 221a is provided to be shape-fitted with the mounting nut 225, and the front part of the bracket member 221a is inter-connected so that the fastening hole 221c of the inter-bus bar 221b is vertically aligned with the mounting nut 225. - The bus bar (221b) is provided to be detachably attached.
[68]
The bracket member 221a may be simply attached to the pack cover 220 by attaching a double-sided tape 221d to the rear portion thereof. Of course, the bracket member 221a may be attached in another method such as a combination of bolts and nuts.
[69]
With this configuration, as shown in FIG. 10, each battery module 100 has a mounting bolt 201 from the through hole of the terminal support 126 to the hole of the electrode terminals 150a and 150b, and the inter-bus bar ( By passing it through the fastening hole 221c of 221b) and fastening it to the mounting nut 225, it may be fixed to the pack cover 220 . At this time, the two adjacent battery modules 100 may be electrically connected to each other because the positive terminal 150a and the negative terminal 150b respectively contact the inter-bus bar 221b of the terminal connection part 221 .
[70]
At least one of the mounting bolt 201 and the mounting nut 225 may be an insulating bolt and an insulating nut. By using an insulating bolt and an insulating nut, a short circuit can be prevented even when mechanical fixing and electrical connection of each battery module 100 to the pack cover 220 are simultaneously made.
[71]
As described above, in the battery pack 10 of the present invention, the mechanical fixing of the battery modules 100 and the electrical connection structure are integrated, so the assembly process is very easy. In addition, by fixing each battery module 100 to the pack cover 220 instead of fixing the battery modules 100 to the pack tray 210 with bolts, the space utilization rate or the degree of freedom of the pack tray 210 may be improved.
[72]
An assembly example of the battery pack 10 of the present invention will be briefly described as follows.
[73]
In the battery pack 10 of the present invention, contrary to the assembly method of the general battery pack 10, it is preferable to turn the pack cover 220 upside down and arrange the battery modules 100 therein and then fix them.
[74]
That is, turn the pack cover 220 upside down and place each battery module 100 so that the electrode terminals 150a and 150b of the battery module 100 face the cooling pipe and the terminal connection part 221 of the pack cover 220, respectively. make it
[75]
Next, the mounting bolt 201 may be fastened to a fastening portion between each battery module 100 and the pack cover 220 . That is, by placing each battery module 100 at a predetermined position and fastening the mounting bolt 201 , the mechanical fixing operation of the battery modules 100 and the serial and/or parallel connection operation can be easily solved at once.
[76]
Then, the main assembly process can be completed by inserting the O-ring 230 into the concave-convex portion of the pack cover 220 and aligning the concave-convex portion with the edge of the pack tray 210 .
[77]
Next, a battery pack 10 according to another embodiment of the present invention will be briefly described with reference to FIG. 11 .
[78]
The battery pack 10 according to the present embodiment has the same basic mechanical and electrical assembly structure as the battery pack 10 according to the above-described embodiment, but differs in the cooling configuration.
[79]
That is, in the above-described embodiment, the pack cover 220 and the heat sink 300 are integrated, but in the present embodiment, the pack cover 220 and the heat sink 300 are provided as a separate type.
[80]
The heat sink 300 may be provided to be pre-mountable to a predetermined external structure. For example, the upper portion of the heat sink 300 is provided in a form that can be mounted on the vehicle body 20 , and the lower portion of the heat sink 300 is provided to face the upper surface of the pack cover 220 . And, after the heat sink 300 is pre-mounted on the vehicle body 20 , the pack case 200 accommodating the remaining battery modules 100 is installed under the heat sink 300 . In this case, the TIM 400 may be further provided on the upper surface of the pack cover 220 .
[81]
According to this, since the electrical energy component and the cooling component constituting the battery pack 10 are completely separated, the structure of each component can be further simplified, and in particular, the heat sink 300 can be pre-mounted on the vehicle end. By doing so, it can be easy to connect the cooling water pipe required for the cooling configuration and secure sealing properties.
[82]
Meanwhile, the battery pack according to the present invention described above may further include various devices for controlling the charging and discharging of battery modules, such as a BMS, a current sensor, a fuse, and the like. The battery pack may be applied to a vehicle such as an electric vehicle or a hybrid vehicle. Of course, the battery pack may be applied to a power storage device or other IT products.
[83]
In the above, preferred embodiments of the present invention have been illustrated and described, but the present invention is not limited to the specific preferred embodiments described above, and in the technical field to which the present invention pertains without departing from the gist of the present invention as claimed in the claims. Anyone with ordinary skill in the art can implement various modifications, of course, such changes are within the scope of the claims.
[84]
On the other hand, in this specification. Although terms indicating directions such as up, down, left, and right have been used, those skilled in the art are aware that these terms are only for convenience of description and may be expressed differently depending on the viewing position of the observer or the location of the object. self-evident to
Claims
[Claim 1]
A battery pack having a plurality of battery modules and a pack case capable of fixing the battery modules therein, a pack tray supporting lower portions of the battery modules, and covering the battery modules, but upper ends of the battery modules a pack case having a pack cover provided in contact with the surface; and a heat sink installed on the top of the pack cover.
[Claim 2]
The battery pack according to claim 1, wherein the heat sink is provided integrally with the pack cover.
[Claim 3]
The battery pack according to claim 1, wherein the heat sink is pre-mountable to a predetermined external structure.
[Claim 4]
According to claim 1, wherein the pack cover, the battery pack, characterized in that the terminal connecting portion for electrically connecting the electrode terminals of the battery modules to each other is provided on an inner surface of the top.
[Claim 5]
According to claim 4, wherein, when the top of the battery modules is covered by the pack cover, the electrode terminal of one of the battery modules and the electrode terminal of the other adjacent to the battery module are connected to the terminal connector in the vertical direction, respectively. A battery pack, characterized in that it is electrically connected by contact.
[Claim 6]
The method according to claim 4, wherein each of the battery modules includes battery cells and a module case for accommodating the battery cells, and the electrode terminal is provided to protrude from one side of the module case in a square plate shape. to the battery pack.
[Claim 7]
The battery pack according to claim 6, wherein the module case includes a terminal support part protruding from one side to support a lower portion of the electrode terminal and having a through hole in a vertical direction.
[Claim 8]
The pack according to claim 7, wherein the pack cover further includes a mounting nut on the upper inner surface, and each of the battery modules is fitted into the through hole of the terminal support part and is vertically fastened to the mounting nut by a mounting bolt. A battery pack, characterized in that it is fixed to the cover.
[Claim 9]
The battery pack according to claim 8, wherein at least one of the mounting bolt and the mounting nut is made of an insulating material.
[Claim 10]
The inter-bus bar of claim 8, wherein the terminal connection unit is in surface contact with the electrode terminal and has a fastening hole through which the mounting bolt can pass; and a bracket member that supports the inter-bus bar and is fixedly coupled to an inner surface of the pack cover.
[Claim 11]
The battery pack according to claim 10, wherein the bracket member is shape-fitted with the mounting nut and is attached to an inner surface of the pack cover.
[Claim 12]
The battery pack according to claim 1, wherein the plurality of battery modules are arranged in two rows, and electrode terminals are arranged to face each other with respect to the center of the pack case.
[Claim 13]
A motor vehicle, characterized in that it comprises a battery pack according to any one of claims 1 to 12.