Battery pack

Abstract

PURPOSE: To provide a battery pack that has a high spatial usage and high energy density, and that can be easily attached by changing a structure inside the battery pack.SOLUTION: A battery pack of the present invention includes a case including a lower part housing, a cell stack including a plurality of pouch type battery cells and installed inside the lower part housing, a thermal conductive adhesive that directly attaches and fixes between the cell stack and the bottom plate of the lower part housing, a foamed adhesive connected by filling a space between the tab side of the cell stack and the lower part housing, and a flexible circuit board assembly including a flexible circuit board and an insulating connecting sheet, in which the flexible circuit board is connected and fixed onto the cell stack through the insulating connecting sheet.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to the technical field of power batteries, and particularly to battery packs.

Background Art

[0002] The operating voltage of a single secondary battery is about 2.5V to 4.5V. In electric vehicles and energy storage systems that require high-capacity and high-voltage output, usually, a plurality of cells are connected in series and / or in parallel to form a battery module, and then the battery modules are connected in series and / or in parallel to form a battery pack. Further, the battery pack is used as an energy source system for supplying energy to an electric vehicle or as an energy storage system. The quantity and shape of the battery modules used in the construction of the battery pack, and the quantity and shape of the cells used in the configuration of the battery modules, etc. can be flexibly changed according to actual needs.

[0003] In the field of power batteries used in electric vehicles, in order to improve the full charge driving range and charging speed of electric vehicles, it is necessary to further enhance the energy density and cooling performance of the battery pack. As one method of improving the energy density, the CTP (cell to pack) type battery pack omits the step of forming a battery module from cells and integrates the cells directly into the battery pack, so that the structural parts and electrical connection parts required for the formation of the battery module can be omitted, and thus the space used for the cells themselves can be increased.

[0004] Currently, general cells are classified into cylindrical cells, rectangular cells, pouch-type battery cells, etc. based on structural differences. The CTP-type battery pack using rectangular cells has already been widely popularized. However, since pouch-type battery cells are vulnerable to external impacts and difficult to assemble, they still face a series of problems in the process of integrating into the CTP-type battery pack. In the existing technology, it is difficult to directly install the stack of pouch-type battery cells into the battery pack, and the low space utilization rate causes a decrease in the energy density of the battery pack.

Summary of the Invention

Problems to be Solved by the Invention

[0005] In consideration of the above-mentioned drawbacks of the existing technology, an object of the present invention is to provide a battery pack with high space utilization rate, large energy density, and easy installation.

Means for Solving the Problems

[0006] To achieve the above object and other related objects, the present invention provides a battery pack including a case including a lower housing, a cell stack including a plurality of pouch-type battery cells installed in the lower housing, a thermally conductive structural adhesive for directly adhesively fixing between the cell stack and the bottom plate of the lower housing, a foaming adhesive filled and connected between the tab side of the cell stack and the lower housing, and a flexible circuit board assembly including a flexible circuit board and an insulating connection sheet, wherein the flexible circuit board is connected and fixed on the cell stack via the insulating connection sheet.

[0007] In one embodiment of the present invention, the flexible circuit board includes a flexible circuit board body, and a plurality of sampling sheets distributed along the stacking direction of the pouch-type battery cells are provided on the flexible circuit board body, and the sampling sheets are welded and fixed to the tabs of the corresponding pouch-type battery cells.

[0008] In one embodiment of the present invention, the insulating connection sheet includes a plastic sheet.

[0009] In one embodiment of the present invention, the flexible circuit board body is located on the tab side of the cell stack. The plastic sheet includes a first fixing surface and a second fixing surface connected to each other. The second fixing surface is bonded and connected to the flexible circuit board body, and the first fixing surface is bonded and connected to the upper surface of the cell stack to fix the flexible circuit board body.

[0010] In one embodiment of the present invention, a plurality of first openings are provided on the first fixing surface. The first openings are close to the connection portion between the first fixing surface and the second fixing surface and correspond to the sampling sheet.

[0011] In one embodiment of the present invention, the angle between the first fixing surface and the second fixing surface is equal to the angle formed between the upper surface of the cell stack and the surface of the tab side.

[0012] In one embodiment of the present invention, the flexible circuit board body is adhesively fixed to the plastic sheet, and the plastic sheet is adhesively fixed to the cell stack.

[0013] In one embodiment of the present invention, the insulating connection sheet includes a thermocompression bonding film.

[0014] In one embodiment of the present invention, the thermocompression bonding film includes a first thermocompression bonding film and a second thermocompression bonding film. At least a part of the flexible circuit board body and at least a part of the sampling sheet are pressed between the first thermocompression bonding film and the second thermocompression bonding film.

[0015] In one embodiment of the present invention, the flexible circuit board body is located on the upper surface side of the cell stack. One end of the sampling sheet is connected and fixed to the flexible circuit board body, and the other end of the sampling sheet is bent to form a vertical portion. The vertical portion extends to the tab side of the cell stack, and a part of the vertical portion extends outside the first thermocompression bonding film and the second thermocompression bonding film and is welded and fixed to the tab of the corresponding pouch-type battery cell.

[0016] In one embodiment of the present invention, both the first thermocompression bonding film and the second thermocompression bonding film include a first thermocompression bonding surface and a second thermocompression bonding surface, and the included angle between the first thermocompression bonding surface and the second thermocompression bonding surface is equal to the angle formed between the upper surface of the cell stack and the surface of the tab side.

[0017] In one embodiment of the present invention, a plurality of first protrusions are provided on the flexible circuit board body, and temperature sampling terminals are provided on the first protrusions. The first thermocompression bonding film and the second thermocompression bonding film are respectively located outside and inside the circuit board body, and second protrusions corresponding to the first protrusions are provided on the first thermocompression bonding film. By pressing the first protrusion against the second protrusion, the temperature sampling terminal is installed on the upper surface of the cell stack, and through holes corresponding to the temperature sampling terminals are provided on the second protrusion.

[0018] In one embodiment of the present invention, side plates are further installed in the lower housing. The side plates are located on both sides along the stacking direction of the pouch-type battery cells of the cell stack, and both ends of the flexible circuit board body are bent in the same direction to form fixing portions that are hooked on the side plates.

[0019] In one embodiment of the present invention, the flexible circuit board assembly further includes a first connector. The first connector is installed on the fixing portion and is suitable for electrical connection with a battery management system.

[0020] In one embodiment of the present invention, the battery pack further includes a temperature sampling terminal and a fixing plate. The temperature sampling terminal is connected and fixed onto the cell stack via the fixing plate.

[0021] In one embodiment of the present invention, both ends of the fixing plate extend along the stacking direction of the pouch-type battery cells in the cell stack and are connected and fixed to the corresponding side plates.

[0022] In one embodiment of the present invention, the flexible circuit board body is located on the tab side of the cell stack, and the temperature sampling terminal is located on the upper surface side of the cell stack. The flexible circuit board further includes a plurality of extension structures, and both ends of the extension structure are respectively connected to the flexible circuit board body and the temperature sampling terminal.

[0023] In one embodiment of the present invention, a reinforcing plate is installed at one end of the extension structure connected to the temperature sampling terminal. The reinforcing plate and the temperature sampling terminal are located on opposite sides of the extension structure, and the reinforcing plate faces the upper surface of the cell stack. A second opening corresponding to the temperature sampling terminal is provided on the fixing plate. The fixing plate is crimped onto the extension structure and / or the reinforcing plate and is bonded to the upper surface of the cell stack.

[0024] In one embodiment of the present invention, both ends of the fixing plate are bent in the same direction to form a curved structure, and the curved structure is fixedly connected to the side plate.

Advantages of the Invention

[0025] The present invention provides a battery pack that can prevent a flexible circuit board from shaking greatly during use by installing a plastic sheet to fix and position a flexible circuit board assembly. Compared with the method of using plastic brackets or upper and lower covers of modules for fixing, the plastic sheet can not only play the role of positioning and fixing the flexible circuit board, but also the plastic sheet is relatively inexpensive, easy to process, lightweight, and can save material costs, so that the cost of the battery pack can be reduced, the space utilization rate can be improved, the energy density can be increased, and furthermore, the assembly process can be simplified, and the welding jig for the tab can be avoided by the opening of the fixing sheet.

[0026] The present invention provides a battery pack that installs a fixing plate to fix a temperature sampling terminal. When installing the sensor, since the temperature sampling terminals can be installed one by one and only the fixing plate needs to be directly installed, the process can be simplified, and the fixing plate can ensure that the position of the temperature sampling terminal is more accurate and improve the sampling accuracy, and furthermore, it can also ensure that the temperature sampling terminal does not shift during use.

[0027] The present invention provides a battery pack that can omit the plastic brackets and the upper and lower covers of the module by limiting the positions of the flexible circuit board and the sampling sheet with a thermocompression bonding film, can greatly reduce the cost, and at the same time, can play the roles of fixing and insulating the flexible circuit board and the sampling sheet. During installation, the assembly process can be simplified, and since the circuits of the temperature sampling terminals are all thermocompression bonded in the thermocompression bonding film, the accuracy of the position can be guaranteed and no alignment by the assembly operator is required.

Brief Description of the Drawings

[0028]

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Embodiments for Carrying out the Invention

[0029] Hereinafter, embodiments of the present invention will be described with reference to specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied by other different specific embodiments, and various modifications or changes can be made to the details of each item in this specification without departing from the spirit of the present invention based on different viewpoints and applications.

[0030] It should be noted that the drawings provided in this embodiment are merely schematic ways to explain the basic concept of the present invention. Therefore, only the components related to the present invention are shown in the drawings, and they are not drawn according to the number, shape, and dimensions of the components in actual implementation. When actually implementing, the form, quantity, and ratio of each component can be arbitrarily changed, and the layout form of the components may become more complex.

[0031] In recent years, the development of new energy vehicles has been remarkable, and the penetration rate has become increasingly high. As a result, the renewal of related components and technologies has also accelerated. The power battery system is an important component of new energy vehicles. Under fierce market competition, the requirements for product performance, safety, and cost are also increasing. The power battery system is an important component of new energy vehicles. The power battery system mainly includes a battery pack formed by connecting several cells in series and parallel, which can provide a power source for the normal driving of the vehicle.

[0032] Referring to FIG. 1, in one embodiment of the present invention, a battery pack includes a case, a cell stack 102, a thermally conductive structural adhesive, a foam adhesive 105, and a flexible circuit board assembly 200. The case includes a lower housing 101. The cell stack 102 includes a plurality of pouch-type battery cells and includes two opposing tab sides and sides adjacent to the tab sides. The cell stack 102 is installed in the lower housing 101, and the space between the cell stack 102 and the bottom plate of the lower housing 101 is directly adhesively fixed with a thermally conductive structural adhesive. In other words, the space between the cell stack 102 and the bottom plate of the lower housing 101 is directly adhesively fixed with a thermally conductive structural adhesive. The foam adhesive 105 is filled and connected between the tab side of the cell stack 102 and the lower housing 101. The flexible circuit board assembly 200 includes a flexible circuit board 201 and an insulating connection sheet. The flexible circuit board 201 is connected and fixed on the cell stack 102 through the insulating connection sheet. Here, the thickness and the occupied volume of the insulating connection sheet are smaller than those of a conventional bracket for connecting and fixing the flexible circuit board 201. That is, the battery pack includes the lower housing 101 and the cell stack 102 installed in the lower housing 101, and the cell stack 102 is sequentially installed in the lower housing 101. A chamber may be formed between the lower housing 101 and the upper cover 106 on the upper part of the cell stack 102 to provide a closed accommodation space for the cell stack 102. Each cell stack 102 includes a plurality of pouch-type battery cells, and the plurality of pouch-type battery cells are sequentially stacked in the thickness direction of the cell to form the cell stack 102. When manufacturing the battery pack, the number of cell stacks 102 in each battery pack can be set according to the user's requirements. The higher the requirement for the power supply capacity of the battery pack, the more cell stacks 102 of the corresponding number need to be installed in the lower housing 101.

[0033] Referring to FIG. 1, in one embodiment of the present invention, two cell stacks 102, namely, a first cell stack 1021 and a second cell stack 1022, are installed in the lower housing 101, and one tab side of the first cell stack 1021 faces one tab side of the second cell stack 1022. The two cell stacks 102 are separated by a case intermediate beam 103. The foam adhesive 105 is installed on both sides of the cell stack 102 and is located between the cell stack 102 and the lower housing 101. Specifically described, the foam adhesive 105 can be installed between one side where the tab of the cell stack 102 is installed and the side beam of the lower housing 101, and between one side where the tab of the cell stack 102 is installed and the case intermediate beam 103. The cell stack 102 and the bottom plate of the lower housing 101 are adhesively fixed with a direct thermal conductivity structural adhesive. Side plates 104 are further installed inside the lower housing 101 and on both sides of the cell stack 102. That is, the side plates 104 are located on the side surfaces of the cell stack 102, and the side surfaces are the side surfaces adjacent to the tab side of the cell stack 102. In other words, since the side plates 104 are located on the side surfaces perpendicular to the case intermediate beam 103 of the cell stack 102, the cell stack 102 can be compressed to a predetermined size by tightening the side plates 104 with a jig and then inserted into the lower housing 101.

[0034] Referring to FIGS. 1 and 2, in one embodiment of the present invention, a flexible circuit board assembly 200 is further installed in the battery pack. The flexible circuit board assembly 200 includes a flexible circuit board 201, a sampling sheet 202, a first connector 203, and an insulating connection sheet. In this embodiment, the insulating connection sheet is a plastic sheet 204, and the flexible circuit board 201 is fixedly connected onto the cell stack 102 through the insulating connection sheet. Specifically, the plastic sheet 204 can be made of materials such as polyethylene glycol terephthalate (PET) or polycarbonate (PC). Here, one flexible circuit board 201 is installed on each of the two tab sides of each cell stack 102, and information such as the voltage, temperature, and current output of the cell stack 102 can be monitored in real time.

[0035] Referring to FIGS. 2, 3, and 4, in one embodiment of the present invention, the flexible circuit board 201 is in a foldable sheet form. The flexible circuit board 201 includes a flexible circuit board body 2011. The flexible circuit board body 2011 can be located on the tab side of the cell stack 102 and is bonded to the tab side of the cell stack 102. In this application, both ends of the flexible circuit board body 2011 are bent in the same direction, and fixing portions 2012 are formed at both ends of the flexible circuit board body 2011, and the fixing portions 2012 can be hooked onto the side plates 104. When the flexible circuit board 201 is attached onto the cell stack 102, the flexible circuit board body 2011 is bonded to the tab side close to the foaming adhesive 105 of the cell stack 102, and the fixing portions 2012 at both ends of the flexible circuit board body 2011 are bonded to the side surfaces close to the side plates 104 of the cell stack 102.

[0036] Referring to FIG. 2, in one embodiment of the present invention, the insulating connection sheet includes a plastic sheet 204. On each flexible circuit board 201, a plurality of sampling sheets 202 are installed. The plurality of sampling sheets 202 are distributed along the stacking direction of the pouch-type battery cells, and the plurality of sampling sheets 202 are welded in parallel on the flexible circuit board 201. Also, the plurality of sampling sheets 202 are located on one side of the flexible circuit board body 2011, and the other side of the flexible circuit board body 2011 is adhered to the plastic sheet 204. That is, the flexible circuit board body 2011 is adhesively fixed to the plastic sheet 204, and the plastic sheet 204 is further adhesively fixed to the cell stack 102. The number of sampling sheets 202 is the same as the number of pouch-type battery cells in each cell stack 102. When the flexible circuit board 201 is attached to the tab side of the cell stack 102, the sampling sheets 202 are welded and fixed corresponding to the tabs on the pouch-type battery cells. Here, the sampling sheet 202 can be made of metal, for example, it can be made of a nickel plate.

[0037] Referring to FIGS. 2, 5, and 6, in one embodiment of the present invention, a first connector 203 is further installed on the fixing portion 2012 of the flexible circuit board 201. Through the first connector 203 and the connection line, the flexible circuit board 201 is electrically connected to the battery management system 108. Thereby, monitoring of the pouch-type battery cells is realized. When the flexible circuit board 201 is attached to the tab side of the cell stack 102, the fixing portion 2012 of the flexible circuit board 201 is hooked on the buckle 107 of the side plate 104. At this time, the first connector 203 on the fixing portion 2012 engages with the buckle 107 on the side plate 104, so that the position of the flexible circuit board 201 can be limited.

[0038] Referring to FIGS. 2 and 3, in one embodiment of the present invention, the plastic sheet 204 includes a first fixing surface 2041 and a second fixing surface 2042. The first fixing surface 2041 and the second fixing surface 2042 are connected to each other, and the first fixing surface 2041 and the second fixing surface 2042 are installed at a preset angle. The plastic sheet 204 can be manufactured using plastic, and the first fixing surface 2041 and the second fixing surface 2042 are integrally formed. The angle between the first fixing surface 2041 and the second fixing surface 2042 is equal to the angle formed between the upper surface of the cell stack 102 and the surface on the tab side. When installing, it can be guaranteed that the first fixing surface 2041 is bonded and connected to the upper surface of the cell stack 102, and the second fixing surface 2042 is bonded and connected to the flexible circuit board body 2011 attached to the tab side of the cell stack 102 to fix the flexible circuit board body 2011. In this embodiment, the first fixing surface 2041 and the second fixing surface 2042 are installed at a right angle, for example. Here, in the present application, the upper surface of the cell stack 102 is the surface facing the upper cover of the cell stack 102.

[0039] Referring to FIGS. 2 and 3, in one embodiment of the present invention, a plurality of first openings 2043 are further installed on the first fixing surface 2041 of the plastic sheet 204. The plurality of first openings 2043 are installed in parallel on the first fixing surface 2041, and the first openings 2043 are close to the connection portion between the first fixing surface 2041 and the second fixing surface 2042. The quantity of the first openings 2043 is equal to the quantity of the sampling sheets 202, and the first openings 2043 are installed corresponding to the sampling sheets 202. When welding the sampling sheet 202 and the tab, the jig can enter from the first openings 2043. The present application does not limit the shape and dimensions of the first openings 2043. The first openings 2043 only need to be able to avoid the entry of the jig during welding. The first openings 2043 can be set in a rectangular shape, a circular shape, an elliptical shape, or any other arbitrary shape.

[0040] Referring to FIG. 3, in one embodiment of the present invention, an adhesive (not shown) is installed on the first fixing surface 2041 and the second fixing surface 2042, and on the inner side where the first fixing surface 2041 and the second fixing surface 2042 are bent. The adhesive is a double-sided tape, which adhesively fixes the first fixing surface 2041 of the plastic sheet 204 to the upper surface of the cell stack 102, and adhesively fixes the second fixing surface 2042 of the plastic sheet 204 to the flexible circuit board 201.

[0041] Referring to FIGS. 2 to 6, in one embodiment of the present invention, when assembling the flexible circuit board assembly 200, a plurality of sampling sheets 202 are welded to one side of the flexible circuit board 201, the first connector 203 is assembled on the fixing portion 2012 of the flexible circuit board 201, and the second fixing surface 2042 of the plastic sheet 204 is fixed to the flexible circuit board body 2011 with an adhesive. After the assembly of the flexible circuit board assembly 200 is completed, the flexible circuit board assembly 200 is mounted on the cell stack 102. Specifically, first, the first fixing surface 2041 of the plastic sheet 204 is fixed to the upper surface of the cell stack 102 with an adhesive. Then, the sampling sheet 202 is welded to the tab of each pouch-type battery cell on the cell stack 102 through the first opening 2043. Finally, the fixing portion 2012 of the flexible circuit board 201 is engaged through the opening on the side plate, and the first connector 203 on the fixing portion 2012 is engaged with the buckle 107 on the side plate.

[0042] Referring to FIGS. 3, 7 to 11, in one embodiment of the present invention, the battery pack further includes a temperature sampling terminal 205 and a fixing plate 207. The temperature sampling terminal 205 is connected and fixed onto the cell stack 102 via the fixing plate 207. In order to collect the temperature of each pouch-type battery cell, a temperature sampling terminal 205 is further installed in the battery pack. The flexible circuit board body 2011 is located on the tab side of the cell stack 102, the temperature sampling terminal 205 is located on the upper surface side of the cell stack 102, and the temperature sampling terminal 205 is electrically connected to the flexible circuit board 201. In the present application, the flexible circuit board 201 further includes a plurality of extension structures 2013, and the plurality of extension structures 2013 are connected to the flexible circuit board body 2011. That is, both ends of the extension structure 2013 are respectively connected to the flexible circuit board body 2011 and the temperature sampling terminal 205. Based on the collection requirements and the overall structure of the battery pack, the position of the extension structure 2013 can be limited. In this embodiment, the plurality of extension structures 2013 are installed in parallel on the plane where the first fixing surface 2041 of the plastic sheet 204 is located, or installed on the upper surface of the cell stack 102, and one end of the extension structure 2013 is connected to the flexible circuit board body 2011, and the other end is connected to the temperature sampling terminal 205. Further, a reinforcing plate 206, a temperature sampling terminal 205, and a fixing plate 207 are installed in the flexible circuit board assembly 200. The fixing plate 207 is crimped onto the extension structure 2013 and / or the reinforcing plate 206 and can be bonded to the upper surface of the cell stack 102.

[0043] Referring to FIGS. 7 to 9, in one embodiment of the present invention, the temperature sampling terminal 205 is connected onto the flexible circuit board 201 and is located at the other end of the extension structure 2013. The temperature sampling terminal 205 contacts the pouch-type battery cells in the cell stack 102 to collect the temperature of the pouch-type battery cells, and transmits it to the battery management system 108 via the flexible circuit board 201, so as to realize the monitoring of the temperature of the pouch-type battery cells and ensure the safe operation of the system.

[0044] Referring to FIGS. 8 and 11, in one embodiment of the present invention, a reinforcing plate 206 is installed on the stretching structure 2013 of the flexible circuit board 201. The reinforcing plate 206 is installed at one end connected to the temperature sampling terminal 205 of the stretching structure 2013. The reinforcing plate 206 and the temperature sampling terminal 205 are located on both sides of the stretching structure 2013, and the reinforcing plate 206 is close to the pouch-type battery cell. That is, the reinforcing plate 206 and the temperature sampling terminal 205 are located on opposite sides of the stretching structure 2013, and the reinforcing plate 206 faces the upper surface of the cell stack 102. Both ends of the reinforcing plate 206 extend outward from the temperature sampling terminal 205 to facilitate connection with the fixing plate 207.

[0045] Referring to FIGS. 8, 9, and 10, in one embodiment of the present invention, the fixing plate 207 is installed on the upper surface of the cell stack 102 and is arranged along the thickness direction of the pouch-type battery cell. The fixing plate 207 is fixedly connected to the reinforcing plate 206 on one side of each temperature sampling terminal 205, thereby fixing a plurality of temperature sampling terminals 205 on the fixing plate 207. Both ends of the fixing plate 207 are bent to the same side to form a curved structure 2071. When the fixing plate 207 is attached to the upper surface of the cell stack 102, the curved structure 2071 is attached to both side surfaces of the cell stack 102. Since through holes are installed on the curved structure 2071, a fixing structure 208 can be used to fixedly connect the fixing plate 207 to the side plates on both sides of the cell stack 102 to fix a plurality of temperature sampling terminals 205. That is, both ends of the fixing plate 207 extend along the stacking direction of the pouch-type battery cells in the cell stack 102 and are connected and fixed to the corresponding side plates 104. Specifically, the curved structure 2071 is fixedly connected to the side plate 104. The fixing structure 208 is, for example, a rivet or other fixing structure.

[0046] Referring to FIGS. 8 and 9, in one embodiment of the present invention, a plurality of second openings 2072 are provided on the fixing plate 207. The number of the second openings 2072 is the same as the number of the temperature sampling terminals 205, and the positions of the second openings 2072 correspond to the positions of the temperature sampling terminals 205. When the fixing plate 207 is disposed on the upper surface of the cell stack 102, the temperature sampling terminals 205 penetrate through the second openings 2072 and reach the surface of the fixing plate 207.

[0047] Referring to FIGS. 8 to 11, in one embodiment of the present invention, an adhesive (not shown) is provided on the fixing plate 207. On the one hand, the adhesive on the fixing plate 207 can be fixedly connected to both sides of the reinforcing plate 206. That is, the fixing plate 207 is crimped onto the reinforcing plate 206, so that the temperature sampling terminals 205 can be fixed on the reinforcing plate 206, and the temperature sampling terminals 205 penetrate through the second openings 2072 on the fixing plate 207 and reach the surface of the fixing plate 207. On the other hand, after the fixing plate 207 is fixedly connected to the temperature sampling terminals 205, the adhesive on the fixing plate 207 can be used to fixedly connect to the pouch-type battery cell. That is, the fixing plate 207 can be bonded to the upper surface of the cell stack 102.

[0048] Referring to FIGS. 7 to 11, in one embodiment of the present invention, when the flexible circuit board assembly 200 is mounted, after the sampling sheet 202, the first connector 203 and the flexible circuit board 201 are assembled, the reinforcing plate 206 and the temperature sampling terminals 205 on the reinforcing plate 206 are assembled onto the flexible circuit board 201. Then, the fixing plate 207 is fixedly connected to the reinforcing plate 206 with an adhesive, and finally, the flexible circuit board assembly 200 is mounted on the cell stack 102. The fixing plate 207 is fixed to the cell stack 102 through the adhesive, and the sampling sheet 202 can be welded to the tabs of each pouch-type battery cell on the cell stack 102. Finally, the fixing portion 2012 of the flexible circuit board 201 is engaged through the opening on the side plate 104, and the first connector 203 on the fixing portion 2012 is engaged with the buckle 107 on the side plate.

[0049] Referring to FIGS. 12 to 16, in another embodiment of the present invention, furthermore, another type of flexible circuit board assembly 200 is provided. The insulating connection sheet includes a thermocompression bonding film 209. The sampling sheet 202 is fixed on the flexible circuit board 201. The thermocompression bonding film 209 includes a first thermocompression bonding film 2091 and a second thermocompression bonding film 2092. At least a part of the flexible circuit board 201 and at least a part of the sampling sheet 202 are pressed against each other between the first thermocompression bonding film 2091 and the second thermocompression bonding film 2092. The first thermocompression bonding film 2091 and the second thermocompression bonding film 2092 fix and insulate the flexible circuit board 201 and the sampling sheet 202.

[0050] Referring to FIGS. 12 to 14, in another embodiment of the present invention, the flexible circuit board body 2011 is bonded to the upper surface of the cell stack 102. Both ends of the flexible circuit board body 2011 are bent in the same direction, and fixing portions 2012 are formed at both ends of the flexible circuit board body 2011. When the flexible circuit board 201 is attached onto the cell stack 102, the flexible circuit board body 2011 is bonded to the upper surface of the cell stack 102, and the fixing portions 2012 at both ends of the flexible circuit board body 2011 are bonded to the side surface of the cell stack 102.

[0051] Referring to FIGS. 12 and 13, in another embodiment of the present invention, a first connector 203 is further installed on the fixing portion 2012 of the flexible circuit board 201. The flexible circuit board 201 is electrically connected to the battery management system 108 via the first connector 203 and a connection line. Thereby, monitoring of the pouch-type battery cell is realized. Referring also to FIG. 6, when the flexible circuit board 201 is attached to the upper surface of the cell stack 102, the fixing portion 2012 of the flexible circuit board 201 is hooked on the buckle 107 of the side plate 104. At this time, since the first connector 203 on the fixing portion 2012 engages with the buckle 107 on the side plate, the position of the flexible circuit board 201 can be limited.

[0052] Referring to FIGS. 12 to 14, in another embodiment of the present invention, a plurality of sampling sheets 202 are installed on each flexible circuit board 201, and the plurality of sampling sheets 202 are welded in parallel on the flexible circuit board body 2011. The plurality of sampling sheets 202 are located on one side of the flexible circuit board body 2011. In this embodiment, the flexible circuit board body 2011 is located on the upper surface side of the cell stack 102, one end of each sampling sheet 202 is fixedly connected on the flexible circuit board body 2011, and the other end is bent in the same direction to form a vertical portion 2021. When the flexible circuit board body 2011 is adhesively bonded to the upper surface of the cell stack 102 through the thermocompression bonding film 209 in an insulated manner, a part of each sampling sheet 202 is adhesively bonded to the upper surface of the cell stack 102 through the thermocompression bonding film 209 in an insulated manner, and another part is adhesively bonded to the tab side of the cell stack 102 through the thermocompression bonding film 209 in an insulated manner. The other end of the sampling sheet 202 is bent and extends to a position where there is a tab of the pouch-type battery cell. That is, the vertical portion 2021 extends to the tab side of the cell stack 102, and a part of the vertical portion 2021 extends out of the first thermocompression bonding film 2091 and the second thermocompression bonding film 2092 and is welded and fixed to the tab of the corresponding pouch-type battery cell. The number of the sampling sheets 202 is the same as the number of the pouch-type battery cells in each cell stack 102. When the flexible circuit board 201 is attached to the upper surface of the cell stack 102, the other end of the sampling sheet 202 corresponds to the tab on the pouch-type battery cell. The sampling sheet 202 is made of metal, for example, made of a nickel plate.

[0053] Referring to FIGS. 13 and 16, in another embodiment of the present invention, a plurality of first protrusions 2014 are provided on each flexible circuit board 201. The first protrusions 2014 and the sampling sheet 202 are located on opposite sides of the flexible circuit board body 2011. A temperature sampling terminal 205 is attached onto the first protrusion 2014. By installing the temperature sampling terminal 205 onto the first protrusion 2014, the temperature of the pouch-type battery cell can be detected. The number of the first protrusions 2014 is the same as the number of the temperature sampling terminals 205, and the position of the first protrusion 2014 is installed corresponding to the position of the temperature sampling terminal 205. That is, the temperature sampling terminal 205 is installed on the upper surface of the cell stack 102. When the temperature sampling terminal 205 is attached onto the first protrusion 2014, temperature sampling can be performed on the pouch-type battery cell that requires sampling.

[0054] Referring to FIGS. 13 and 16, in another embodiment of the present invention, the shapes of the first thermocompression bonding film 2091 and the second thermocompression bonding film 2092 correspond to the shapes of the flexible circuit board 201 and the sampling sheet 202. In this embodiment, the first thermocompression bonding film 2091 is installed outside the vertical portion 2021 of the sampling sheet 202 and the flexible circuit board body 2011, and the second thermocompression bonding film 2092 is installed inside the vertical portion 2021 of the sampling sheet 202 and the flexible circuit board body 2011. The first thermocompression bonding film 2091 and the second thermocompression bonding film 2092 include a first thermocompression bonding surface 2093 and a second thermocompression bonding surface 2094. The first thermocompression bonding surface 2093 and the second thermocompression bonding surface 2094 are installed at a preset angle, and the included angle between the first thermocompression bonding surface 2093 and the second thermocompression bonding surface 2094 is equal to the angle of the vertical portion 2021 on the sampling sheet 202 and the angle formed between the upper surface of the cell stack 102 and the surface of the tab side. When the first thermocompression bonding film 2091 and the second thermocompression bonding film 2092 are pressed against the flexible circuit board 201 and the sampling sheet 202, the edge of the first thermocompression bonding surface 2093 overlaps the edge of the flexible circuit board body 2011, and the edge of the second thermocompression bonding surface 2094 exposes the other end of the sampling sheet 202. Also, in order to protect the temperature sampling terminal 205, a plurality of second protrusions 2095 are installed on the first thermocompression bonding film 2091. The second protrusions 2095 on the first thermocompression bonding film 2091 correspond to the first protrusions 2014 on the flexible circuit board 201. When the first thermocompression bonding film 2091 is bonded to the flexible circuit board 201, the second protrusions 2095 on the first thermocompression bonding film 2091 are bonded to the first protrusions 2014 on the flexible circuit board 201. That is, by pressing the first protrusions 2014 against the second protrusions 2095, the temperature sampling terminal 205 is installed on the upper surface of the cell stack 102, and temperature sampling can be performed on the pouch-type battery cell that requires sampling. Also, a plurality of through holes are installed on the second protrusions 2095, and the through holes expose the temperature sampling terminals 205 installed on the first protrusions 2014.

[0055] Referring to FIGS. 12 to 16, in another embodiment of the present invention, when attaching the flexible circuit board assembly 200, a plurality of sampling sheets 202 are welded to one side of the flexible circuit board 201. After assembling the first connector 203 on the fixing portion 2012 of the flexible circuit board 201, the first thermocompression bonding film 2091 and the second thermocompression bonding film 2092 are pressed against the flexible circuit board 201 and the sampling sheet 202. Then, the sampling sheet 202 is bent to form a vertical portion 2021 on each sampling sheet 202. And the thermocompression bonding film 209 is fixed to the upper surface of the cell stack 102 through an adhesive. The other end of the sampling sheet 202 exposed from the thermocompression bonding film 209 is welded to the tab of each pouch-type battery cell on the cell stack 102. Finally, the fixing portion 2012 of the flexible circuit board 201 is engaged through the opening on the side plate, and the first connector 203 on the fixing portion 2012 is engaged with the buckle 107 on the side plate.

[0056] Referring to FIGS. 1 and 4 together with FIGS. 17 to 21, in one embodiment of the present invention, the battery pack further includes a connection component 300, a battery management system 108, and a side plate 104. The flexible circuit board 201 is communicatively connected to the battery management system 108 via the connection component 300. The side plate 104 is fixed to the side surface of the cell stack 102, and the connection component 300 is connected and fixed on the side plate 104. The connection component 300 includes a flexible flat cable 301 and an adapter sheet 303. The flexible flat cable 301 is installed on the side surface of the cell stack 102 and is connected and fixed on the side plate 104 via the adapter sheet 303. That is, the flexible flat cable 301 is installed corresponding to the side surface of the cell stack 102. The connection component 300 is also provided. One end of the connection component 300 is electrically connected to the first connector 203 of the flexible circuit board 201, and the other end is connected to the battery management system 108, thereby realizing signal transmission. Here, the connection component 300 includes a flexible flat cable 301, a second connector 302, and an adapter sheet 303. The flexible flat cable 301 is fixed on the side plate 104 via the adapter sheet 303.

[0057] Referring to FIGS. 4, 17, and 18, in one embodiment of the present invention, a second connector 302 is connected to both ends of the flexible flat cable 301. That is, the second connector 302 is connected to both ends of the flexible flat cable 301. The second connector 302 at one end of the flexible flat cable 301 is connected to the first connector 203 on the flexible circuit board 201, and the second connector 302 at the other end of the flexible flat cable 301 is electrically connected to the battery management system 108. In the present application, the number of flexible flat cables 301 may be plural, and the number of flexible flat cables 301 is equal to the number of flexible circuit boards 201. Here, the battery pack includes a first cell stack and a second cell stack. One tab side of the first cell stack faces one tab side of the second cell stack. The battery management system 108 is located on another tab side opposite to the second cell stack of the first cell stack. One end of the plurality of flexible flat cables 301 is connected to the corresponding flexible circuit board 201, and the other end of the plurality of flexible flat cables 301 extends across the side surface of the first cell stack and / or the side surface of the second cell stack and is electrically connected to the same battery management system 108. In this embodiment, when it is necessary to transmit the signals of the four flexible circuit boards 201 in each battery pack, for example, four flexible flat cables 301 are installed. The length and folding method of each flexible flat cable 301 may be folded as required. Here, the second connectors 302 on the plurality of flexible flat cables 301 are arranged offset in the extending direction of the flexible flat cables 301. In this embodiment, the flexible flat cable 301 is installed corresponding to the side surface of the cell stack 102 and extends from the first connector 203 on the flexible circuit board 201 onto the battery management system 108 along the side surface of the cell stack 102. That is, one end of the flexible flat cable 301 is connected to the first connector 203 on the corresponding flexible circuit board 201, and the other end of the flexible flat cable 301 extends onto the battery management system 108.Also, on overlapping paths, a plurality of flexible flat cables 301 are installed overlapping each other. That is, at least a part of the plurality of flexible flat cables 301 are installed overlapping each other and are connected and fixed onto the side plate 104 via the same adapter sheet 303. Specifically speaking, the plurality of flexible flat cables 301 are installed overlapping each other on the same path.

[0058] Referring to FIGS. 17, 19, 20, and 21, in one embodiment of the present invention, the adapter sheet 303 includes a first connection surface 3031 and a second connection surface 3032, and the first connection surface 3031 and the second connection surface 3032 are installed at a preset angle. During installation, the first connection surface 3031 is overlapped and joined on the side plate 104 and fixed via a fixture 304. That is, the first connection surface 3031 can be fixedly connected to the side plate 104. The second connection surface 3032 is fixedly connected to the flexible flat cable 301 via an adhesive. That is, the second connection surface 3032 can be fixedly connected to the flexible flat cable 301. In this embodiment, the first connection surface 3031 and the second connection surface 3032 are installed at a right angle, for example. The fixture 304 may be a fixture such as a rivet, for example.

[0059] Referring to FIGS. 1, 17 to 21, in one embodiment of the present invention, when attaching the connection component 300, first, the second connectors 302 at both ends of each flexible flat cable can be connected to the corresponding first connector 203 and the battery management system. Next, a plurality of layers of flexible flat cables 301 are overlapped and installed, and the adjacent flexible flat cables 301 are fixed with an adhesive. That is, since the adjacent two layers of flexible flat cables 301 can be fixed to each other with an adhesive, a plurality of layers of flexible flat cables 301 can be integrally formed thereby. Finally, the adapter sheet 303 is attached, the second connection surface 3032 of the adapter sheet 303 is fixed to the flexible flat cable 301 with an adhesive, and then the first connection surface 3031 of the adapter sheet 303 is overlapped and joined on the side plate, and the first connection surface 3031 is fixed to the side plate 104 using a fixture or the like.

[0060] As described above, the present application provides a battery pack including a lower housing, a cell stack installed in the lower housing, flexible circuit boards installed on both sides of each cell stack, a connection component including a flexible flat cable, a plastic sheet or a thermocompression bonding film for fixing the flexible circuit board, and a fixing plate for fixing the temperature sampling terminal. The battery pack provided by the present application does not require separately installing an independent bracket structure for components such as the flexible circuit board, so the volume utilization rate and energy density of the battery pack can be improved.

[0061] The above description is only an explanation of the more preferred embodiments of the present application and the applicable technical principles. Those skilled in the art should understand that the scope related to the present application is not limited to the technical solutions formed by the specific combination of the above-described technical features. At the same time, without departing from the concept of the invention, other technical solutions formed by arbitrarily combining the above-described technical features or their equivalent features, for example, technical solutions formed by mutually replacing the above-described features and technical features having similar functions (but not limited thereto) disclosed in the present application, are also included.

[0062] Except for the technical features of the specification, the other technical features are known technologies to those skilled in the art. Therefore, in order to emphasize the innovative features of the present invention, the other technical features will not be repeatedly described here.

Industrial Applicability

[0063] The battery pack of the present invention can be applied in the technical field of power batteries.

Explanation of Reference Numerals

[0064] 101 Lower housing 102 Cell stack 1021 First cell stack 1022 Second cell stack 103 Case intermediate beam 104 Side plate 105 Foam adhesive 106 Upper cover 107 Buckle 108 Battery management system 200 Flexible circuit board assembly 201 Flexible circuit board 2011 Flexible circuit board body 2012 Fixing part 2013 Extension structure 2014 First protrusion 202 Sampling sheet 2021 Vertical part 203 First connector 204 Plastic sheet 2041 First fixing surface 2042 Second fixing surface 2043 First opening 205 Temperature sampling terminal 206 Reinforcing plate 207 Fixing plate 2071 Curved structure 2072 Second opening 208 Fixing structure 209 Thermocompression film 2091 First thermocompression bonding film 2092 Second thermocompression bonding film 2093 First thermocompression bonding surface 2094 Second thermocompression bonding surface 2095 Second protrusion 300 Connecting component 301 Flexible flat cable 302 Second connector 303 Adapter sheet 3031 First connection surface 3032 Second connection surface 304 Fixture

Claims

1. A case including a lower housing, a cell stack including a plurality of pouch-type battery cells and installed in the lower housing, a thermally conductive structural adhesive for directly adhesively fixing between the cell stack and the bottom plate of the lower housing, a foamed adhesive filled and connected between the tab side of the cell stack and the lower housing, a flexible circuit board assembly including a flexible circuit board and an insulating connection sheet, and a battery pack, wherein the flexible circuit board is connected and fixed on the cell stack via the insulating connection sheet.

2. The battery pack according to claim 1, wherein the flexible circuit board includes a flexible circuit board body, a plurality of sampling sheets distributed along the stacking direction of the pouch-type battery cells are provided on the flexible circuit board body, and the sampling sheets are welded and fixed to the tabs of the corresponding pouch-type battery cells.

3. The battery pack according to claim 2, wherein the insulating connection sheet includes a plastic sheet.

4. The battery pack according to claim 3, wherein the flexible circuit board body is located on the tab side of the cell stack, the plastic sheet includes a first fixing surface and a second fixing surface connected to each other, the second fixing surface is connected by being bonded to the flexible circuit board body, and the first fixing surface is connected by being bonded to the upper surface of the cell stack to fix the flexible circuit board body.

5. The battery pack according to claim 4, wherein a plurality of first openings are provided in the first fixing surface, the first openings are close to the connection portion between the first fixing surface and the second fixing surface, and correspond to the sampling sheets.

6. The battery pack according to claim 4 or 5, wherein the angle between the first fixing surface and the second fixing surface is equal to the angle formed between the upper surface of the cell stack and the surface of the tab side.

7. The battery pack according to claim 3, wherein the flexible circuit board body is adhesively fixed to the plastic sheet, and the plastic sheet is adhesively fixed to the cell stack.

8. The battery pack according to claim 2, wherein the insulating connection sheet includes a thermocompression bonding film.

9. The thermal compression bonding film includes a first thermal compression bonding film and a second thermal compression bonding film, and at least a part of the flexible circuit board body and at least a part of the sampling sheet are pressed and contacted between the first thermal compression bonding film and the second thermal compression bonding film. The battery pack according to claim 8.

10. The flexible circuit board body is located on the upper surface side of the cell stack. One end of the sampling sheet is connected and fixed to the flexible circuit board body. The other end of the sampling sheet is bent to form a vertical portion. The vertical portion extends to the tab side of the cell stack. A part of the vertical portion extends out of the first thermal compression bonding film and the second thermal compression bonding film and is welded and fixed to the tab of the corresponding pouch-type battery cell. The battery pack according to claim 9.

11. Both the first thermal compression bonding film and the second thermal compression bonding film include a first thermal compression bonding surface and a second thermal compression bonding surface, and the included angle between the first thermal compression bonding surface and the second thermal compression bonding surface is equal to the angle formed between the upper surface of the cell stack and the surface of the tab side. The battery pack according to claim 10.

12. A plurality of first protrusions are provided on the flexible circuit board body, and temperature sampling terminals are provided on the first protrusions. The first thermal compression bonding film and the second thermal compression bonding film are respectively located outside and inside the circuit board body. A second protrusion corresponding to the first protrusion is provided on the first thermal compression bonding film. By pressing the first protrusion against the second protrusion, the temperature sampling terminal is installed on the upper surface of the cell stack, and a through hole corresponding to the temperature sampling terminal is provided in the second protrusion. The battery pack according to claim 10 or 11.

13. A side plate is further installed in the lower housing. The side plate is located on both sides along the stacking direction of the pouch-type battery cells of the cell stack. Both ends of the flexible circuit board body are bent in the same direction to form fixing portions that are hooked on the side plate. The battery pack according to claim 2.

14. The flexible circuit board assembly further includes a first connector. The first connector is installed on the fixing portion and is suitable for electrical connection with a battery management system. The battery pack according to claim 13.

15. The battery pack according to claim 13, further comprising a temperature sampling terminal and a fixing plate, wherein the temperature sampling terminal is connected and fixed onto the cell stack via the fixing plate.

16. The battery pack according to claim 15, wherein both ends of the fixing plate extend along the stacking direction of the pouch-type battery cells in the cell stack and are connected and fixed to the corresponding side plates.

17. The flexible circuit board body is located on the tab side of the cell stack, the temperature sampling terminal is located on the upper surface side of the cell stack, the flexible circuit board further includes a plurality of extending structures, and both ends of the extending structure are respectively connected to the flexible circuit board body and the temperature sampling terminal. The battery pack according to claim 15.

18. A reinforcing plate is installed at one end of the extending structure connected to the temperature sampling terminal, the reinforcing plate and the temperature sampling terminal are located on opposite sides of the extending structure, the reinforcing plate faces the upper surface of the cell stack, a second opening corresponding to the temperature sampling terminal is provided in the fixing plate, the fixing plate is crimped onto the extending structure and / or the reinforcing plate, and is bonded to the upper surface of the cell stack. The battery pack according to claim 17.

19. The battery pack according to any one of claims 15 to 18, wherein both ends of the fixing plate are bent in the same direction to form a curved structure, and the curved structure is fixedly connected to the side plate.

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