technical field
[One]
The present invention relates to a battery pack, and more particularly, to a battery pack incorporating a mechanical and electrical fixing structure of a battery module.
[2]
This application is a priority claim application for Korean Patent Application No. 10-2019-0096283 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]
Types of secondary batteries currently widely used include lithium ion batteries, lithium polymer batteries, nickel cadmium batteries, nickel hydrogen batteries, nickel zinc batteries, 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 top 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. Although not shown in FIG. 1 , there are many examples in which a heat sink for cooling is further disposed under each of the battery modules 2 .
[8]
However, recently, several problems have been pointed out with respect to the assembly structure of the conventional battery pack. Among them, too many bolts are used to fix the battery modules and the inter-bus bars, so that the inefficiency of the assembly process, cost increase, and the pack tray Problems such as a decrease in the space utilization rate under the pack case due to the large number of bolted points on the top (when the heat sink is installed at the bottom of the battery module, the bolted structure may interfere, complicating the coolant inflow and outflow lines) are pointed out.
[9]
Therefore, the development of a battery pack to which an assembly structure capable of solving the above problems is applied has become an issue.
DETAILED DESCRIPTION OF THE INVENTION
technical challenge
[10]
The present invention was devised to solve the above problems, and by improving the simplification and space efficiency of the mechanical fixing and electrical connection structures of the battery modules in the pack case, the degree of freedom and energy density of the mounting space of the battery modules and other components. The purpose is to provide a battery pack that can be improved.
[11]
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
[12]
According to the present invention, there is provided a battery pack having a plurality of battery modules and a pack case capable of fixing and installing the battery modules therein, the pack case comprising: a pack tray supporting lower portions of the battery modules; and a pack cover provided on the upper inner surface of the pack tray to cover the battery modules, and a terminal connector for coupling with at least one side of each of the battery modules and electrically connecting the electrode terminals of the battery modules. can
[13]
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
[14]
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.
[15]
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.
[16]
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. .
[17]
The electrode terminal may be positioned above the through-hole of the terminal support part and provided to allow the mounting bolt to pass therethrough.
[18]
At least one of the mounting bolt and the mounting nut may be made of an insulating material.
[19]
The terminal connection unit may include: an inter-bus bar having a fastening hole through which the mounting bolt can pass and in surface contact with the electrode terminal; and a bracket member that supports the inter-bus bar and is fixedly coupled to the inner surface of the pack cover.
[20]
The bracket member may be shape-fitted with the mounting nut and attached to the inner surface of the pack cover.
[21]
The module case may include a base plate positioned below the battery cells to support the battery cells, and a flow path through which a refrigerant may flow may be provided in the base plate.
[22]
The pack cover further includes a cooling pipe embedded therein along an edge region, and the base plate has a cooling water port that communicates with the flow path and extends in a vertical direction, and the cooling water port is directly connected to the cooling pipe in a vertical direction. can be
[23]
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.
[24]
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
[25]
According to one aspect of the present invention, the fastening structure can be simplified by integrating the mechanical fixing and electrical connection structures of the battery modules in the pack case.
[26]
According to another aspect of the present invention, since each battery module is fastened and fixed on the pack cover, the space utilization rate and the degree of freedom on the pack tray may be increased.
[27]
According to another aspect of the present invention, by utilizing the base plate of the top cover and the module case as a cooling water circulation space, it is possible to simplify the configuration of the cooling device and improve the energy density.
[28]
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
[29]
1 is a view schematically showing an assembly example of a battery pack according to the prior art.
[30]
2 is a schematic perspective view of a battery pack according to an embodiment of the present invention.
[31]
3 is a partially exploded perspective view of the battery pack of FIG. 2 ;
[32]
4 is a schematic perspective view of a battery module according to an embodiment of the present invention.
[33]
FIG. 5 is a schematic cross-sectional view taken along line II′ of FIG. 2 .
[34]
6 is a schematic cross-sectional view taken along line II-II' of FIG. 2 .
[35]
7 is an enlarged view of area A of FIG. 6 .
[36]
8 is an exploded cross-sectional view taken along line III-III' of FIG. 2 .
[37]
9 is a schematic perspective view of a terminal connection part and a mounting nut according to an embodiment of the present invention.
[38]
FIG. 10 is a cross-sectional view corresponding to FIG. 9 .
[39]
11 is a view for explaining a structure for fixing and electrically connecting a battery module according to an embodiment of the present invention.
Modes for carrying out the invention
[40]
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.
[41]
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.
[42]
Referring to these drawings, the battery pack 10 according to an embodiment of the present invention includes a plurality of battery modules 100 and a pack case accommodating the battery modules 100 (200) is included. The pack case 200 includes a pack tray 210 supporting the lower portions of the plurality of battery modules 100, and a pack cover 220 that is coupled to the pack tray 210 to cover all the battery modules 100. includes
[43]
As will be described later, the battery pack 10 according to the present invention can reduce the number of fastening parts and fastening locations, and each battery module 100 is mounted on the pack cover 220 so as to increase the space utilization rate or space freedom of the pack tray 210 . ) are configured to simultaneously mechanically fix and electrically connect them.
[44]
Among the main components of the battery pack 10 , each battery module 100 will be described first.
[45]
The battery module 100 includes the battery cells 110 , the module case 120 for accommodating the battery cells 110 in the internal space, and the electrode terminals 150a and 150b exposed to the outside of the module case 120 . include
[46]
The battery cells 110 are pouch-type secondary battery cells widely known in the art. The pouch-type secondary battery cells can be stacked in the inner space of the module case, 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.
[47]
As shown in FIGS. 4 and 5 , the module case 120 has a base plate 121 and a top plate 122 covering the lower and upper portions of the battery cells 110 , respectively, and the arrangement direction of the battery cells 110 . It may be configured to include a pair of side plates 123 and a front cover 124 and a rear cover 125 that cover the front and rear of the battery cells 110, respectively, which are disposed on the outermost side.
[48]
In particular, the base plate 121 forming the bottom surface of the module case 120 also functions as a conventional heat sink. For example, a flow path through which cooling water can flow is provided inside the base plate 121 so that the base plate 121 can directly cool the battery cells 110, and a cooling water port ( 121a) is provided at the edge of the base plate 121 .
[49]
The cooling water port 121a may extend in a vertical direction from one edge of the base plate 121 to be directly connected to a cooling pipe of the pack cover 220 to be described later. With this cooling water supply and discharge structure, cooling water may be supplied to the base plate 121 of each battery module 100 .
[50]
Most of the battery pack 10 according to the prior art has a cooling configuration in which a heat conduction pad and a heat sink are sequentially disposed under the battery module 100 , but in the present invention, the heat sink is a base plate forming the module case 120 . (121) reduced the heat transfer path, reduced the number of parts, and reduced the space for installing the cooling device compared to the prior art.
[51]
The front cover 124 and the rear cover 125 are positioned in front of the battery cells 110 to prevent the electrode leads of the battery cells 110 or components such as 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.
[52]
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 bolt fastening place for the battery module 100 .
[53]
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 drawings, the through-holes may be formed to coincide vertically with the holes of the electrode terminals 150a and 150b.
[54]
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
[55]
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 .
[56]
Next, with reference to FIGS. 5 to 11 , a mechanical fixation, electrical connection, and cooling structure for each of the battery modules 100 inside the pack case 200 will be described in detail.
[57]
A cooling structure of the battery pack 10 of the present invention will be described first.
[58]
Basically, the battery pack 10 of the present invention is water-cooled, and the coolant is provided to be supplied to each battery module 100 while circulating along the circumference of the pack cover 220 .
[59]
In particular, in the battery module 100 of the present invention, the heat sink serves as a part of the module case 120 , that is, the base plate 121 . In other words, as shown in FIG. 5 , the base plate 121 having a flow path through which the cooling water can flow is configured as the bottom surface of the module case 120 .
[60]
A cooling pipe 224 for supplying cooling water to each of the battery modules 100 is embedded therein along the edge region of the pack cover 220, and is vertically connected to the cooling water port 121a of each battery module 100. available to be
[61]
Specifically, as shown in FIGS. 6 to 7 , the pack cover 220 includes an uneven portion 222 that is forcibly fitted to the edge of the pack tray 210 and the pack cover 220 in the uneven portion 222 . A cooling pipe mounting part 223 extending in an inward direction is provided.
[62]
An O-ring 230 made of a rubber material for enhancing sealing properties may be further interposed between the pack cover 220 and the pack tray 210 in combination.
[63]
The cooling pipe 224 may be located in the cooling pipe mounting part 223 . As an alternative embodiment, the cooling pipe may be omitted by forming one region of the cooling pipe mounting part 223 in a hollow structure.
[64]
The base plate 121 of each battery module 100 includes a port assembly part 121b provided to further extend outward with respect to the vertical surface of the cell rear cover 125 . The cooling water port 121a may be vertically mounted on the port assembly 121b.
[65]
The port assembly part 121b is located just below the cooling pipe mounting part 223 of the pack cover 220 so that the cooling water port 121a can be directly connected to the cooling pipe of the pack cover 220 . Although not shown, a fixing connector and a sealing member may be further used to secure fastening and sealing properties between the cooling water port 121a and the cooling pipe.
[66]
With this configuration, the coolant may be supplied to the base plate 121 of each battery module 100 while circulating along the cooling pipe 224 of the pack cover 220 in the circumferential direction of the pack cover 220 .
[67]
In particular, in the present invention, since the cooling pipe 224 is in the pack cover 220 and the cooling water port 121a of the base plate 121 is simply connected to the cooling pipe 224 by the shortest distance, the cooling water supply No additional connecting pipes or hoses are required for this. In addition, since there is no connecting pipe or hose on the pack tray 210 , the battery module 100 and other electronic components may be more easily mounted.
[68]
Next, a mechanical fixing and electrical connection structure of the battery pack 10 of the present invention will be described with reference to FIGS. 8 to 11 .
[69]
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 based on the center of the pack case 200 . . This 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.
[70]
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 .
[71]
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 .
[72]
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 attached to the pack cover.
[73]
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-shaped interconnect 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 .
[74]
The rear portion of the bracket member 221a is provided to be shape-fitted with the mounting nut 225 , and the front portion 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.
[75]
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 may be attached in another method such as a combination of bolts and nuts.
[76]
With this configuration, as shown in FIG. 11 , each battery module 100 attaches the 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 . In this case, 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 .
[77]
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.
[78]
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.
[79]
Finally, an assembly example of the battery pack 10 of the present invention will be briefly described as follows.
[80]
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.
[81]
That is, turn the pack cover 220 upside down and connect or contact the cooling water port 121a and the electrode terminals 150a and 150b of the battery module 100 to the cooling pipe and the terminal connection part 221 of the pack cover 220, respectively. Position each battery module 100 .
[82]
Next, the mounting bolt 201 may be fastened to a fastening portion between each battery module 100 and the pack cover 220 . As described above, by placing each battery module 100 at a predetermined position and fastening the mounting bolt 201, the mechanical fixing operation and the serial and/or parallel connection operation of the battery modules 100 can be easily solved at once. .
[83]
Next, if the O-ring is interposed in the concave-convex portion 222 of the pack cover 220 and the concave-convex portion 222 is aligned with the edge of the pack tray 210 , the main assembly process can be completed.
[84]
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 10 may be applied to a power storage device or other IT products.
[85]
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.
[86]
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 and installing the battery modules therein, the pack case comprising: a pack tray supporting lower portions of the battery modules; and a pack cover provided on the inner surface of the upper end of the pack tray to cover the battery modules, but to be coupled to at least one side of each of the battery modules and to electrically connect the electrode terminals of the battery modules A battery pack, characterized in that.
[Claim 2]
According to claim 1, wherein the battery modules, when the top is covered by the pack cover, the electrode terminal of any one of the battery module and the electrode terminal of the other adjacent to the battery module in the vertical direction to the terminal connector, respectively A battery pack, characterized in that it is electrically connected by contact.
[Claim 3]
The method according to claim 1, 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 4]
The battery pack according to claim 3, 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 5]
The pack according to claim 4, wherein the pack cover further includes a mounting nut on an 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 6]
The battery pack according to claim 5, wherein the electrode terminal is positioned above the through hole of the terminal support part and provided through which the mounting bolt passes.
[Claim 7]
The battery pack according to claim 5, wherein at least one of the mounting bolt and the mounting nut is made of an insulating material.
[Claim 8]
[7] The device of claim 6, wherein the terminal connection unit comprises: an inter-bus bar having a fastening hole through which the mounting bolt can pass and in surface contact with the electrode terminal; and a bracket member that supports the inter-bus bar and is fixedly coupled to an inner surface of the pack cover.
[Claim 9]
The battery pack according to claim 8, wherein the bracket member is shape-fitted with the mounting nut and is attached to an inner surface of the pack cover.
[Claim 10]
The battery according to claim 1, wherein the module case includes a base plate positioned under the battery cells to support the battery cells, wherein the base plate has a flow path through which a refrigerant can flow therein. pack.
[Claim 11]
The cooling water port of claim 10, wherein the pack cover further includes a cooling pipe embedded therein along an edge region, and the base plate communicates with the flow path and includes a cooling water port extending in a vertical direction. A battery pack, characterized in that it is directly connected to the pipe in the vertical direction.
[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 comprising the battery pack according to claim 1 .