Battery pack with mechatronic fixing structure of battery module

Abstract

According to the present invention, a battery pack includes a plurality of battery modules and a battery pack shell, wherein the battery modules can be fixedly installed in the battery pack shell, wherein the battery pack shell may include: a battery pack tray, which supports the lower portion of the battery module; and a battery pack cover, which is connected to the battery pack tray to cover the battery module, and the battery pack cover has a terminal connecting portion on its upper inner surface, which is connected to at least one side of each battery module and electrically connects the electrode terminals of adjacent battery modules.

Description

Technical Field

[0001] The present disclosure relates to a battery pack, and more particularly, to a battery pack having a mechatronic fixing structure of a battery module.

[0002] This application claims priority to Korean Patent Application No. 10-2019-0096283 filed in Korea on August 7, 2019, the disclosure of which is incorporated herein by reference. Background Art

[0003] Unlike primary batteries that cannot be charged, secondary batteries refer to batteries that can be charged and discharged, and are used not only as power sources for small high-tech electronic devices such as mobile phones, PDAs, or laptop computers, but also as power sources for energy storage systems (ESS), electric vehicles (EV), or hybrid electric vehicles (HEV).

[0004] Currently widely used secondary batteries include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, etc. The operating voltage of a unit secondary battery cell, i.e., a unit battery cell, is about 2.5V to 4.2V. Therefore, if a higher output voltage and a larger energy capacity are required, a plurality of battery cells can be connected in series to construct a battery module, or two or more battery modules can be connected in series or in parallel and other components can be added to construct a battery pack. For example, a battery module may refer to a device in which a plurality of secondary batteries are connected in series or in parallel, and a battery pack may refer to a device in which battery modules are connected in series or in parallel to increase capacity and output.

[0005] In addition to the battery modules, the battery pack may further include a cooling device for appropriately maintaining the temperature of the battery modules, a control device for monitoring the operating state of the battery modules, and a battery pack case for packaging them.

[0006] Meanwhile, in the case of a battery pack for an electric vehicle, since the installation space of the battery pack is limited depending on the overall length and width of the electric vehicle, it is important to increase energy density by mounting battery modules and other components inside the battery pack housing in as space-efficient a manner as possible.

[0007] When assembling the battery pack, in a conventional housing, such as Figure 1As shown, the battery module 2 is arranged on the upper surface of the battery pack tray 1, which corresponds to the bottom surface of the battery pack case, and bolts are fastened to the battery pack tray 1 to mechanically fix the battery module 2. Generally, most battery modules 2 are fixed to the upper surface of the battery pack tray 1 by inserting long bolts in four positions at the front corners and rear corners thereof. As an electrical connection structure between battery modules, in many cases, both ends of an internal bus bar 3 having a metal rod shape are placed on the upper surface of the positive terminal 2a of one battery module 2 and the negative terminal 2b of another battery module 2, and the two ends of the internal bus bar 3 are fixed using two bolts. There are also many examples: a radiator for cooling is further provided below each battery module 2.

[0008] However, some problems have been pointed out recently with the assembly structure of conventional battery packs. Among them, the assembly process is inefficient and the cost is increased because too many bolts are used to fix the battery modules and internal bus bars. In addition, since a large number of bolt points are required on the battery pack tray, the utilization rate of the lower space of the battery pack housing is reduced (when the radiator is installed below the battery module, the bolt fastening structure may be disturbed, which makes the cooling water inlet and outlet pipes complicated).

[0009] Therefore, development of a battery pack to which an assembly structure capable of solving the above-mentioned problems is applied is becoming an issue. Summary of the invention

[0010] Technical issues

[0011] The present disclosure is designed to solve the problems of the related art, and therefore, the present disclosure aims to provide a battery pack that can improve energy density and the freedom of space for installing battery modules and other components by simplifying the mechanical fixing and electrical connection structure of the battery modules inside the battery pack housing and improving space utilization.

[0012] These and other purposes and advantages of the present disclosure can be understood from the following detailed description, and will become more fully apparent from the exemplary embodiments of the present disclosure. In addition, it will be easily understood that the purposes and advantages of the present disclosure can be achieved by the means shown in the appended claims and their combinations.

[0013] Technical Solution

[0014] In one aspect of the present disclosure, a battery pack is provided, which includes a plurality of battery modules and a battery pack case for fixedly mounting the battery modules in the battery pack case, wherein the battery pack case includes: a battery pack tray configured to support the lower portion of the battery modules; and a battery pack cover connected to the battery pack tray to cover the battery modules, and the battery pack cover has a terminal connection unit connected to at least one side of each battery module and arranged to the inner surface of the top of the battery pack cover to electrically connect the electrode terminals of the battery modules.

[0015] The battery modules may be configured such that, when an upper portion of the battery modules is covered by the battery pack cover, electrode terminals of any one battery module and electrode terminals of another battery module adjacent to the any one battery module contact the terminal connection units in upper and lower directions, respectively, to be electrically connected.

[0016] Each battery module may include a battery cell and a module case for accommodating the battery cell, and the electrode terminal may have a rectangular plate shape and may be disposed to protrude on one side of the module case.

[0017] The module case may include a terminal supporter formed to protrude on one side of the module case to support a lower portion of the electrode terminal, the terminal supporter having a penetration hole formed in a vertical direction.

[0018] The battery pack cover may further include a mounting nut disposed at an inner surface of a top portion of the battery pack cover, and each battery module may be fixed to the battery pack cover using a mounting bolt that is vertically inserted into a through hole of the terminal support and fastened to the mounting nut.

[0019] The electrode terminal may be located above the penetration hole of the terminal supporter and configured such that the mounting bolt passes through the electrode terminal.

[0020] At least one of the mounting bolt and the mounting nut may be made of an insulating material.

[0021] The terminal connection unit may include: an inner bus bar configured to form surface contact with the electrode terminal and having a fastening hole through which the mounting bolt passes; and a bracket member configured to support the inner bus bar and fixedly coupled to an inner surface of the battery pack cover.

[0022] The bracket member may be form-fitted with the mounting nut and attached to an inner surface of the battery pack cover.

[0023] The module case may include a base plate located at a lower portion of the battery cell to support the battery cell, and the base plate has a flow path provided therein so that a coolant flows through the flow path.

[0024] The battery pack cover may further include a cooling pipe embedded in the battery pack cover along an edge area of ​​the battery pack cover, the substrate may include a cooling water port configured to communicate with the flow path and formed to extend vertically, and the cooling water port may be directly connected to the cooling pipe in an up and down direction.

[0025] The plurality of battery modules may be arranged in two rows such that electrode terminals of the plurality of battery modules are arranged to face each other based on a center portion of the pack case.

[0026] In another aspect of the present disclosure, a vehicle including the battery pack is provided. The vehicle may include an electric vehicle (EV) or a hybrid electric vehicle (HEV).

[0027] Beneficial effects

[0028] According to one embodiment of the present disclosure, a fastening structure may be simplified by integrating mechanical fixing and electrical connection structures of a battery module in a battery pack case.

[0029] According to another embodiment of the present disclosure, since the battery module is fastened and fixed to the battery pack cover, space utilization and freedom on the battery pack tray may be increased.

[0030] According to still another embodiment of the present disclosure, by using a top cover and a base plate of a module case as a cooling water circulation space, it is possible to simplify the configuration of a cooling device and improve energy density.

[0031] Other effects of the present disclosure can be understood through the following description and will be more clearly understood through the embodiments of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a view schematically showing an example in which a conventional battery pack is assembled.

[0033] Figure 2 is a perspective view schematically showing a battery pack according to an embodiment of the present disclosure.

[0034] Figure 3 It is shown Figure 2 A partially exploded perspective view of a battery pack.

[0035] Figure 4is a perspective view schematically showing a battery module according to an embodiment of the present disclosure.

[0036] Figure 5 It is along Figure 2 Schematic cross-sectional view taken along line II'.

[0037] Figure 6 It is along Figure 2 Schematic cross-sectional view taken along line II-II'.

[0038] Figure 7 It is shown Figure 6 Magnified view of area A.

[0039] Figure 8 It is along Figure 2 Exploded cross-sectional view taken along line III-III'.

[0040] Fig. 9 is a schematic perspective view showing a terminal connection unit and a mounting nut according to an embodiment of the present disclosure.

[0041] Fig.10 is corresponding to Fig. 9 Cross-sectional view of .

[0042] Fig.11 is a view for illustrating a structure for fixing and electrically connecting a battery module according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0043] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Before the description, it should be understood that the terms used in the specification and the appended claims should not be interpreted as limited to the general meaning and dictionary meaning, but are interpreted based on the meaning and concept corresponding to the technical aspects of the present disclosure based on the principle of allowing the inventor to appropriately define the terms for the best interpretation. Therefore, the descriptions presented herein are only preferred examples for the purpose of illustration only and are not intended to limit the scope of the present disclosure, so it should be understood that other equivalents and modifications may be made thereto without departing from the scope of the present disclosure.

[0044] Figure 2 is a perspective view schematically showing a battery pack according to an embodiment of the present disclosure, Figure 3 It shows Figure 2 A partially exploded perspective view of a battery pack. Figure 4 is a perspective view schematically showing a battery module according to an embodiment of the present disclosure.

[0045] Referring to these drawings, a battery pack 10 according to an embodiment of the present disclosure includes a plurality of battery modules 100 and a battery pack case 200 for accommodating the battery modules 100. The battery pack case 200 includes: a battery pack tray 210 for supporting the lower portions of the plurality of battery modules 100; and a battery pack cover 220 coupled to the battery pack tray 210 to cover the entire battery module 100.

[0046] As will be described later, the battery pack 10 according to the present disclosure can reduce the number of fastening components and fastening points, and is configured to simultaneously mechanically fix and electrically connect the battery module 100 to the pack cover 220 , thereby improving space utilization or spatial freedom of the pack tray 210 .

[0047] Among the main components of the battery pack 10 , each battery module 100 will be described first.

[0048] The battery module 100 includes a battery cell 110 , a module case 120 for accommodating the battery cell 110 in an inner space thereof, and electrode terminals 150 a and 150 b exposed at an outer side of the module case 120 .

[0049] The battery cell 110 is a pouch-type secondary battery cell known in the art. The pouch-type secondary battery cells can be stacked in the internal space of the module housing, which is conducive to increasing the energy density. Of course, the battery cell 110 is not necessarily limited to a pouch-type battery cell. For example, a cylindrical secondary battery cell or a prismatic secondary battery cell can be used instead of a pouch-type secondary battery cell.

[0050] like Figure 4 and Figure 5 As shown, the module housing 120 may include: a substrate 121 and a top plate 122, which are respectively used to cover the lower part and the upper part of the battery cell 110; a pair of side plates 123, which are arranged at the outermost part of the battery cell 110 according to the arrangement direction of the battery cell 110; and a front cover 124 and a rear cover 125, which are respectively used to cover the front side and the rear side of the battery cell 110.

[0051] In particular, the function of the substrate 121 forming the bottom surface of the module housing 120 is similar to that of a conventional heat sink. For example, a flow path through which cooling water can flow is provided inside the substrate 121 so that the substrate 121 can directly cool the battery cells 110, and a cooling water port 121a is provided at the edge of the substrate 121 to allow cooling water to flow into and out of the flow path.

[0052] The cooling water port 121a may vertically extend from one side of the edge of the base plate 121 to be directly connected to a cooling pipe of the pack cover 220 explained later. With the cooling water supply and discharge structure, cooling water may be supplied to the base plate 121 of each battery module 100.

[0053] Most conventional battery packs 10 have a cooling configuration in which a thermal pad and a heat sink are sequentially arranged below the battery module 100. However, in the present disclosure, a heat sink is coupled to the base plate 121 of the module housing 120, thereby reducing the heat transfer path, reducing the number of components, and saving the installation space of the cooling device compared to conventional technologies.

[0054] The front cover 124 and the rear cover 125 are located in front and rear of the battery cell 110 so that the electrode lead or components such as an internal connection plate (ICB) of the battery cell 110 are not exposed to the outside. The electrode terminals 150a, 150b include a positive terminal 150a and a negative terminal 150b, and the electrode terminals 150a, 150b are located outside the top of the front cover 124 to have a rectangular plate shape so that the wide surfaces of the electrode terminals 150a, 150b are placed horizontally, and the electrode terminals 150a, 150b have holes formed therein so that bolts can be inserted in the up-down direction.

[0055] The electrode terminals 150a, 150b may be placed on and supported by the terminal support 126. Here, the terminal support 126 is a portion protruding from the front cover 124 and may serve as a location where lower portions of the electrode terminals 150a, 150b are supported and bolts of the battery module 100 are fastened.

[0056] The terminal support 126 may be provided to extend along the width direction of the front cover 124, and a through hole into which a bolt may be inserted may be formed in the vertical direction at the location of the positive terminal 150a and the negative terminal 150b. The through hole is not shown in the drawings, but may be formed to overlap with the holes of the electrode terminals 150a and 150b in the up-down direction.

[0057] For reference, although the front cover 124 and the terminal support 126 are described as being separately provided, the front cover 124 and the terminal support 126 may also be manufactured in an integral form. In addition, although not shown, a perforation may be provided to allow the mounting bolt 201 to be inserted into a position other than where the electrode terminals 150a, 150b are located. In this way, the mounting bolt 201 may be fastened to the battery pack cover 220.

[0058] The pair of side plates 123 may serve to externally compress and support the battery cells 110 at the outermost battery cells 110 in the arrangement direction of the battery cells 110 .

[0059] Next, refer to Figures 5 to 11 , the mechanical fixing and electrical connection structure for each battery module 100 inside the battery pack housing 200 will be described in detail.

[0060] First, the cooling structure of the battery pack 10 according to the present disclosure will be described.

[0061] Basically, the battery pack 10 of the present disclosure is of a water-cooling type, and cooling water is supplied to each battery module 100 while circulating along the edge of the pack cover 220 .

[0062] Specifically, in the battery module 100 of the present invention, the heat sink serves as a part of the module housing 120, that is, serves as the base plate 121. In other words, Figure 5 As shown, a base plate 121 having a flow path through which cooling water can flow is configured as a bottom surface of the module case 120 .

[0063] A cooling pipe 224 for supplying cooling water to each battery module 100 is embedded in the pack cover 220 along an edge region of the pack cover 220 and may be vertically connected to the cooling water port 121 a of each battery module 100 .

[0064] Specifically, Figure 6 to Figure 7 As shown, the battery pack cover 220 includes an uneven portion 222 that is fitted into an edge of the battery pack tray 210 , and a cooling pipe installation portion 223 that extends from the uneven portion 222 into the battery pack cover 220 .

[0065] An O-ring 230 may be further disposed at a coupling portion between the pack cover 220 and the pack tray 210 , the O-ring 230 being made of rubber and configured to enhance sealing performance.

[0066] The cooling pipe 224 may be located inside the cooling pipe installation portion 223. As an alternative embodiment, the cooling pipe may be omitted by forming the region of the cooling pipe installation portion 223 in a hollow structure.

[0067] The base plate 121 of each battery module 100 includes a port assembling portion 121b configured to further extend outward based on a vertical surface of the rear cover 125. The cooling water port 121a may be vertically mounted to the port assembling portion 121b.

[0068] The port assembly portion 121b is located directly below the cooling pipe mounting portion 223 of the battery pack cover 220, so that the cooling water port 121a can be directly connected to the cooling pipe of the battery pack cover 220. Although not shown, a fixing connector and a sealing member can also be used to ensure the fastening performance and sealing performance between the cooling water port 121a and the cooling pipe.

[0069] Through this configuration, cooling water 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 .

[0070] In particular, in the present disclosure, since the cooling pipe 224 is included in the battery pack cover 220 and the cooling water port 121a of the base plate 121 is simply connected to the cooling pipe 224 at the shortest distance, additional connection pipes or hoses such as for supplying cooling water are not necessary. In addition, since there are no connection pipes or hoses on the battery pack tray 210, the battery module 100 and other electronic components can be installed more easily.

[0071] Next, we will refer to Figures 8 to 11 The mechanical fixing and electrical connection structure of the battery pack 10 of the present disclosure is described.

[0072] In this embodiment, a total of eight battery modules 100 can be accommodated inside the battery pack housing 200, that is, two rows of four battery modules each. At this time, a group of battery modules 100 in the first row and a group of battery modules 100 in the second row (see Figure 3 ) may be positioned so that the electrode terminals 150a, 150b of the battery modules 100 face each other based on the central portion of the battery pack case 200. Such an arrangement of the battery modules 100 may be advantageous in minimizing the electrical connection distance between the battery modules 100. Of course, such an arrangement of the battery modules 100 is an example, and the total number or arrangement structure of the battery modules 100 may be changed as needed.

[0073] The eight battery modules 100 may be placed on and supported by the bottom of the battery pack tray 210, and may be fixed to a terminal connection unit 221 provided at the inner surface of the top of the battery pack cover 220 by bolt connection. In addition, the electrode terminals 150a, 150b of adjacent battery modules 100 may contact the terminal connection unit 221 to be electrically connected to each other.

[0074] For example, when the upper portion of the module housing 120 is covered by the battery pack cover 220 , the electrode terminals 150 a , 150 b of one battery module 100 and the electrode terminals 150 a , 150 b of another battery module 100 may be electrically connected to each other by contacting the terminal connection unit 221 in the up and down directions.

[0075] like Figure 8 and Fig. 9 As shown, the battery cover 220 may further include a mounting nut 225 located at the inner surface of the top of the battery cover 220. The mounting nut 225 may be pre-attached to the battery cover 220 by welding. The terminal connection unit 221 is form-fitted with the mounting nut 225 and attached to the battery cover.

[0076] The terminal connection unit 221 has: a metal rod-shaped internal bus bar 221b having a fastening hole 221c, through which the mounting bolt 201 can pass, and the internal bus bar 221b forms a surface contact with the electrode terminals 150a, 150b of the battery module 100; and a bracket member 221a, which is made of an insulating material, supports the internal bus bar 221b, and is fixedly connected to the inner surface of the top of the battery pack cover 220.

[0077] The bracket member 221a has a rear surface that matches the shape of the mounting nut 225, and the front surface of the bracket member 221a is configured so that the internal bus bar 221b is detachably attached to the front surface of the bracket member 221a, so that the fastening hole 221c of the internal bus bar 221b and the mounting nut 225 overlap each other in the up and down direction.

[0078] The bracket member 221a can be simply attached to the battery pack cover 220 by attaching a double-sided adhesive tape 221d to the rear surface of the bracket member 221a. Of course, the bracket member can also be attached in other ways, such as a bolt and nut combination.

[0079] Using this construction, Fig.11 As shown, each battery module 100 can be fixed to the battery pack cover 220 by passing the mounting bolt 201 from the through hole of the terminal support 126 through the holes of the electrode terminals 150a, 150b and the fastening hole 221c of the internal bus bar 221b to the mounting nut 225. At this time, because the positive terminal 150a and the negative terminal 150b contact the internal bus bar 221b of the terminal connection unit 221, respectively, two adjacent battery modules 100 can be electrically connected to each other.

[0080] At least one of the mounting bolt 201 and the mounting nut 225 may be an insulating bolt and an insulating nut. By using the insulating bolt and the insulating nut, even if the battery module 100 is mechanically fixed and electrically connected to the pack cover 220 at the same time, a short circuit can be prevented.

[0081] As described above, the battery pack 10 of the present disclosure can be assembled very easily because the mechanical fixing and electrical connection structure of the battery module 100 are integrated. In addition, by fixing each battery module 100 to the battery pack cover 220 instead of fixing each battery module 100 to the battery pack tray 210 with bolts, the space utilization or degree of freedom of the battery pack tray 210 can be improved.

[0082] Finally, an example of assembling the battery pack 10 of the present disclosure will be briefly described below.

[0083] For the battery pack 10 of the present disclosure, contrary to the assembly method of the general battery pack 10 , it is preferred that the battery pack cover 220 be inverted, the battery modules 100 be placed in the battery pack cover 220 , and then they be fixed.

[0084] That is, in a state where the pack cover 220 is inverted, each battery module 100 is positioned so that the cooling water port 121 a and the electrode terminals 150 a , 150 b of the battery module 100 approach or contact the cooling pipe and the terminal connection unit 221 of the pack cover 220 , respectively.

[0085] Afterwards, the mounting bolts 201 are fastened to the fastening portion between each battery module 100 and the battery pack cover 220. As described above, by placing each battery module 100 at a predetermined position and fastening the mounting bolts 201 to each battery module 100, the mechanical fixing work of the battery modules 100 and the series and / or parallel work can be easily solved at one time.

[0086] Then, an O-ring is placed in the uneven portion 222 of the pack cover 220 , and the uneven portion 222 is fitted into the edge portion of the pack tray 210 , thereby completing the main assembly process.

[0087] At the same time, the battery pack according to the present disclosure may also include various devices for controlling the charging and discharging of the battery module, such as a BMS, a current sensor, and a fuse. The battery pack may be applied not only to vehicles such as electric vehicles or hybrid electric vehicles, but also to energy storage systems or other IT products.

[0088] The present disclosure has been described in detail. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the present disclosure, are given by way of illustration only, since various changes and modifications within the scope of the present disclosure will become apparent to those skilled in the art from the detailed description.

[0089] At the same time, even if terms expressing directions such as "up", "down", "left" and "right" are used in the specification, these terms are only for convenience of description and can be expressed differently depending on the position of the observer or the object, which is obvious to those skilled in the art.

Claims

1. A battery pack, comprising a plurality of battery modules and a battery pack housing, wherein the battery pack housing is used to fix the battery modules on a in, in, The battery pack housing comprises: a battery pack tray configured to support a lower portion of the battery module; and a battery pack cover coupled to the battery pack tray to cover the battery modules, and having a terminal connection unit coupled to at least one side of each battery module and provided to an inner surface of a top of the battery pack cover to electrically connect electrode terminals of the battery modules, Each of the battery modules includes a battery cell and a module case for accommodating the battery cell, and the electrode terminal is provided to protrude on one side of the module case.

2. The battery pack according to claim 1, wherein: The battery modules are configured such that when an upper portion of the battery modules is covered by the pack cover, electrode terminals of any one battery module and electrode terminals of another battery module adjacent to the any one battery module contact the terminal connection units in upper and lower directions, respectively, to be electrically connected.

3. The battery pack according to claim 1, wherein: The electrode terminal has a rectangular plate shape.

4. The battery pack according to claim 3, wherein: The module case includes a terminal supporter formed to protrude on one side of the module case to support a lower portion of the electrode terminal, the terminal supporter having a penetration hole formed in a vertical direction.

5. The battery pack according to claim 4, wherein: The battery pack cover further includes a mounting nut disposed at an inner surface of a top portion of the battery pack cover, and Each battery module is fixed to the pack cover using a mounting bolt which is inserted into the penetration hole of the terminal support in a vertical direction and is fastened to the mounting nut.

6. The battery pack according to claim 5, wherein: The electrode terminal is located above the penetration hole of the terminal supporter and is configured to allow the mounting bolt to pass through the electrode terminal.

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.

8. The battery pack according to claim 6, wherein: The terminal connection unit comprises: an inner bus bar configured to make surface contact with the electrode terminal and having a fastening hole through which the mounting bolt passes; and A bracket member is configured to support the inner bus bar and is fixedly coupled to an inner surface of the pack cover.

9. The battery pack according to claim 8, wherein: The bracket member is form-fitted with the mounting nut and is attached to an inner surface of the battery pack cover.

10. The battery pack according to claim 3, wherein: The module housing includes a base plate located at a lower portion of the battery cell to support the battery cell, and The base plate has a flow path provided therein such that a coolant flows through the flow path.

11. The battery pack according to claim 10, wherein: The battery pack cover further includes a cooling pipe embedded in the battery pack cover along an edge region of the battery pack cover, The base plate includes a cooling water port configured to communicate with the flow path and formed to extend vertically, and The cooling water port is directly connected to the cooling pipe in an up-and-down direction.

12. The battery pack according to claim 1, wherein: The plurality of battery modules are arranged in two rows such that the electrode terminals of the plurality of battery modules are arranged to face each other based on a center portion of the pack case.

13. A vehicle comprising the battery pack according to any one of claims 1 to 12.

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