Battery pack and electric vehicle

Abstract

To provide a battery pack that can support a cell stack structure more thoroughly using an adhesive structure, and can prevent mutual interference between different adhesive structures.SOLUTION: A battery pack 300 includes a box body 1, a cell stack 2, an adhesive blocking part, and at least two adhesive structures. Inside the box body, an attachment space is provided. The cell stack includes a plurality of soft pack cells, and the cell stack is disposed inside the attachment space. The adhesive structure is installed in the attachment space, and the adhesive structure is directly connected between the cell stack and the box body. The adhesive blocking part is disposed between the two adhesive structures and separates the two adhesive structures. The battery pack can support the cell stack structure more thoroughly using the adhesive structure, and can prevent mutual interference between the different adhesive structures.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to the technical field of power batteries, and more particularly to a battery pack and an electric vehicle incorporating the battery pack. [Background technology]

[0002] The operating voltage of a single secondary battery is approximately 2.5V to 4.5V. In an electric vehicle or energy storage system requiring large capacity and high voltage output, it is usually necessary to connect multiple cells in series and / or in parallel to form a battery module, then connect the battery modules in series and / or in parallel to form a battery pack, and then use the battery pack as an energy system or energy storage system that supplies power to the electric vehicle. The number and shape of the battery modules used to form the battery pack and the number and shape of the cells used to form the battery module can be flexibly changed according to actual needs.

[0003] In the field of power batteries used in electric vehicles, there is a need to further improve the energy density and cooling performance of battery packs to increase the full charge duration and charging speed of electric vehicles. As a solution to increase energy density, CTP (cell-to-pack) battery packs eliminate the process of connecting cells in series and / or parallel to form a battery module, and directly integrate the cells into the battery pack, thereby eliminating the structural components and electrical connectors required to form a battery module and leaving more space for the cells themselves.

[0004] Currently, common battery cells are classified into cylindrical cells, prismatic cells, soft pack cells, etc. based on their structure. CTP battery packs using prismatic cells are widely used, but soft pack cells still face a series of problems during the process of integrating them into CTP battery packs because they are difficult to withstand external impacts and have poor assembly performance. Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention solves at least one of several problems faced by soft pack cells integrated into soft pack CTP type battery packs in the prior art. [Means for solving the problem]

[0006] A first aspect of the present invention provides a battery pack including a housing, a cell stack, an adhesive barrier, and at least two adhesive structures. The housing has an installation space within it. The cell stack includes a plurality of soft-pack cells, and the cell stack is disposed within the installation space. The adhesive structures are disposed within the installation space, and the adhesive structures are directly connected between the cell stack and the housing. The adhesive barrier is disposed between the at least two adhesive structures to separate the at least two adhesive structures.

[0007] Optionally, the box includes a lower housing, the lower housing including a lower housing bottom plate and a beam structure, the cell stack is disposed on the lower housing bottom plate, and the adhesive structure is filled between the cell stack and the lower housing bottom plate and between the cell stack and the beam structure.

[0008] Optionally, one adhesive structure is configured as a first adhesive layer that is filled and adhered between the bottom of the cell stack and the lower housing bottom plate, and the other adhesive structure is configured as a second adhesive layer that is filled and adhered between the tab side of the cell stack and the beam structure.

[0009] Optionally, the first adhesive layer comprises a thermally conductive structural adhesive and the second adhesive layer comprises a foamable adhesive.

[0010] Optionally, the adhesive barriers extend along the stacking direction of the cell stack, with the adhesive barriers being located at opposite ends of the soft pack cell along the length of the soft pack cell.

[0011] Optionally, the beam structure includes a first beam structure parallel to the glue barrier and a second beam structure perpendicular to the glue barrier, the glue barrier extending to abut the second beam structure.

[0012] Optionally, a foamable adhesive is filled between the adhesive barrier and the first beam structure.

[0013] Optionally, the adhesive barrier comprises an elastic material.

[0014] Optionally, the adhesive barrier includes a bottom portion that is bonded to the lower housing bottom plate, and a top portion that is pressed against and bonded to the soft pack cell to conform to the shape of the soft pack cell.

[0015] Optionally, the top portion includes a plurality of teeth spaced along the length of the adhesive barrier, each tooth receiving a corresponding soft pack cell.

[0016] Optionally, the maximum height of the teeth is greater than the top of the thermally conductive structural adhesive.

[0017] Optionally, the bottom of the adhesive barrier is adhered to the lower housing base plate via a backside adhesive.

[0018] Optionally, the battery pack further includes a restriction portion disposed on the lower housing bottom plate so as to protrude beyond a predetermined height of the lower housing bottom plate on which the thermally conductive structural adhesive is disposed.

[0019] Optionally, the predetermined height of the restriction is less than or equal to the thickness of the thermally conductive structural adhesive.

[0020] Optionally, the restrictions are located at corresponding longitudinal ends of the soft-pack cell.

[0021] Optionally, the restriction is a frame structure.

[0022] Optionally, the restriction and the lower housing bottom plate are integrally formed.

[0023] Optionally, the surface of the restriction is coated with an insulating coating, or the surface of the restriction is coated with an insulating film.

[0024] A second aspect of the present invention provides an electric vehicle having a battery pack provided by the first aspect of the present invention. [Effects of the Invention]

[0025] In some technical solutions provided by the present invention, adhesive structures can be used to more fully support the cell stack structure and prevent mutual interference between different adhesive structures. [Brief explanation of the drawings]

[0026] [Figure 1] 1 is a schematic diagram of a stack distribution of a soft-pack CTP battery pack provided by some embodiments of the present invention. [Figure 2] FIG. 2 is a schematic diagram of a stack distribution according to a modification of the embodiment of FIG. 1. [Figure 3] FIG. 2 is an exploded view of a soft-pack type CTP battery pack employing a stack distribution method corresponding to FIG. 1. [Figure 4] 1 is a schematic diagram (top view) of the structure of a side panel according to some embodiments of the present invention. [Figure 5] 5 is a structural schematic diagram of the outer surface of the side plate in the embodiment of FIG. 4. [Figure 6] 10A and 10B are structural schematic diagrams of the outer surface of the side panel provided in some other embodiments of the present invention. [Figure 7] 7 is a schematic view of the cooperating structure between the side plates and the long side beams of the box in the assembled state in the embodiment of FIG. 6; [Figure 8] FIG. 1 is an exploded schematic view of a soft-pack CTP battery pack with a restriction in place according to some embodiments. [Figure 9] 9 is a top view of the box to which the restriction is attached in the embodiment of FIG. 8. FIG. [Figure 10] 9 is a schematic diagram of the relative positions of the soft-pack cell bottom and the restrictor when installation is complete in the embodiment of FIG. 8. FIG. [Figure 11]1 is a structural schematic diagram (exploded view) of a soft-pack type CTP battery pack according to some other embodiments of the present invention. [Figure 12] 11 is a schematic diagram showing the installation position of a limiting portion at the bottom of the box in the embodiment of FIG. 10. FIG. [Figure 13] FIG. 10 is a schematic diagram (cross-sectional view) showing the relative positional relationship between a soft-pack cell, a lower housing bottom plate, and a restrictor in another embodiment. [Figure 14] 1 is a schematic diagram of a foamable adhesive loading location in some embodiments of the present invention. [Figure 15] 15 is a schematic diagram (partial cross-sectional view along the XY plane) of a foam adhesive filling structure between a soft-pack cell and a short side beam in the embodiment of FIG. 14. FIG. [Figure 16] 15 is a schematic diagram (partial cross section along the XZ plane) of the foamable adhesive fill height between the soft-pack cell and the short side beam in the embodiment of FIG. 14. FIG. [Figure 17] 1 is a structural schematic (exploded view) of a soft-pack CTP battery pack with an adhesive barrier in accordance with some embodiments. [Figure 18] 18 is a schematic diagram of the structure of the adhesive barrier in the embodiment of FIG. 17 after compression. [Figure 19] 18 is a structural schematic diagram of each member inside the box in the embodiment of FIG. 17 (a top view after removing the upper cover). [Figure 20] FIG. 20 is a partially enlarged cross-sectional view of region A in FIG. 19. DETAILED DESCRIPTION OF THE INVENTION

[0027] The technical solutions in the embodiments of the present invention are clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but are not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts fall within the scope of protection of the present invention.

[0028] <Cell stack distribution>

[0029] FIG. 1 is a schematic diagram of a stack distribution of a soft-pack CTP battery pack 100 provided by some embodiments of the present invention.

[0030] 1, in some embodiments of the present invention, a soft-pack CTP battery pack 100 includes a square box 1 and a square cell stack 2. The interior space of the box 1 can accommodate two cell stacks 2 arranged side by side.

[0031] The two cell stacks 2 are a first cell stack 21 and a second cell stack 22. The first cell stack 21 has a first output positive electrode 311 and a first output negative electrode 312 arranged at both ends of the side adjacent to the second cell stack 22. Correspondingly, the second cell stack 22 has a second output positive electrode 321 and a second output negative electrode 322 arranged at both ends of the side adjacent to the first cell stack 21. Here, the positions of the first output positive electrode 311 and the second output negative electrode 322 correspond to each other, and the positions of the first output negative electrode 312 and the second output positive electrode 321 correspond to each other, thereby shortening the wiring length and facilitating electrical series connection between the two cell stacks 2.

[0032] The first cell stack 21 further includes a third output positive electrode 331 and a third output negative electrode 332 disposed adjacent to each other at one end thereof remote from the second cell stack 22. The first output positive electrode 311, the first output negative electrode 312, the second output positive electrode 321, and the second output negative electrode 322 are used as electrodes electrically connected in series within the two cell stacks 2, and the third output positive electrode 331 and the third output negative electrode 332 are used as output electrodes for the entire soft-pack CTP battery pack 100. In some embodiments, the third output positive electrode 331 and the third output negative electrode 332 are electrically connected to a battery pack disconnection unit (BDU) and supply power to the entire vehicle through the battery pack disconnection unit.

[0033] The output electrodes provided by the above-described distribution and electrical connection method, i.e., the third output positive electrode 331 and the third output negative electrode 332, are adjacent to each other. In some cases, if it is necessary to separate the output electrodes of the entire soft-pack CTP battery pack 100 from each other, the first cell stack 21 can be rotated 180° with respect to FIG. 1 and placed in the box 1, thereby obtaining the assembled structure of the soft-pack CTP battery pack 200 shown in FIG. 2.

[0034] Referring to FIG. 2 , after rotating the first cell stack 21 by 180° and placing it inside the box, the third output positive electrode 331 and the third output negative electrode 332 are positioned adjacent to the second cell stack 22. The third output positive electrode 331 and the second output negative electrode 322 are electrically connected via a copper bus bar 36, and the third output negative electrode 332 and the second output positive electrode 321 are electrically connected via another copper bus bar 36. This achieves a high-voltage electrical connection between the first cell stack 21 and the second cell stack 22. The first output positive electrode 311 and the first output negative electrode 312 can be used as output electrodes for the entire soft-pack CTP battery pack 200. By combining the first cell stack 21 having the above-described electrode distribution and the copper bus bar 36, the installation angle of the first cell stack 21 can be flexibly adjusted to meet different output electrode position requirements.

[0035] The above examples illustrate distribution and electrical connection methods for the first cell stack 21 and the second cell stack 22 in some embodiments of the present invention. It should be understood that the above explanations are merely examples and should not be construed as limiting the distribution and electrical connection methods. In other embodiments of the present invention, the first cell stack 21 and the second cell stack 22 can be integrated into a single row of cell stacks 2, and the arrangement positions of each output electrode of the cell stack 2 can also be flexibly adjusted according to actual requirements.

[0036] FIG. 3 is an exploded view of a soft-pack CTP battery pack 100 employing a stack distribution method corresponding to FIG.

[0037] Referring to FIG. 3 , the square box 1 includes a lower housing 11 and an upper cover 12. The lower housing 11 includes a rectangular lower housing bottom plate 13 and four side beams 14, which are fixed perpendicularly to the four sides of the rectangular lower housing bottom plate 13. The four side beams 14, the lower housing bottom plate 13, and the upper cover 12 are enclosed together to define a chamber 16 for accommodating a cell stack 2. In addition to the four side beams 14, the box 1 further includes a box center beam 15 disposed in the center of the box 1 in the longitudinal direction. The box center beam 15 divides the chamber 16 into a first chamber 161 and a second chamber 162. The first chamber 161 is used to accommodate a first cell stack 21, and the second chamber 162 is used to accommodate a second cell stack 22.

[0038] The bottom of the cell stack 2 and the lower housing bottom plate 13 are directly bonded together using a structural adhesive or a thermally conductive structural adhesive 25 (not shown in FIG. 3; see FIG. 8). To stabilize the cell stack 2, increase the strength and rigidity of the entire battery pack, and protect it from thermal runaway, a foam adhesive 29 is further filled between the cell stack 2 and the side beams 14 or the central beam 15 of the box body.

[0039] A structural adhesive, a thermally conductive structural adhesive, or an elastic member (not shown) is placed on top of the cell stack 2 to fill the gap between the cell stack 2 and the upper cover 12. By using a structural adhesive, a thermally conductive structural adhesive 25, or a foam adhesive 29 between the bottom of the cell stack 2 and the lower housing bottom plate 13, and a structural adhesive, a thermally conductive structural adhesive, or an elastic member on the top of the cell stack 2, it is possible to provide stable, cushioning support for the cell stack 2 from all directions around it. In some embodiments, the elastic member can be formed by combining a fire-resistant material such as foam or mica, and double-sided tape or hot melt adhesive is placed between the elastic member and the cell stack 2.

[0040] In some embodiments, a liquid cooling channel (not shown) can be arranged within the lower housing bottom plate 13 and the upper cover 12, and a thermally conductive structural adhesive 25 can be used to quickly transfer heat dissipated from the cell stack 2 to the liquid cooling channel, thereby increasing the cooling capacity of the cell stack 2.

[0041] The four side beams 14 include two long side beams 141 and two short side beams 142. An end output pole base 34 is arranged inside the center of the short side beam 142 adjacent to the first cell stack 21, and a copper bus bar (not shown) connected to the third output positive electrode 331 and a copper bus bar (not shown) connected to the third output negative electrode 332 are both arranged on the end output pole base 34.

[0042] A central adapter base 35 is disposed on the box central beam 15. The copper bus bar connected to the first output positive electrode 311 and the copper bus bar connected to the second output negative electrode 322 are both disposed on the central adapter base 35, and one end of each of the two copper bus bars is also disposed on the central adapter base 35 and is electrically connected to the corresponding copper bus bar, thereby achieving electrical connection between the first cell stack 21 and the second cell stack 22.

[0043] <Cell stack>

[0044] 3, in this embodiment, the cell stack 2 is formed by stacking and adhering a plurality of soft-pack cells 23, and the stacking direction is the thickness direction of the soft-pack cells 23, i.e., the width direction of the box body 1. The length direction of the soft-pack cells 23 is parallel to the length direction of the box body 1. The top and bottom of each soft-pack cell 23 are completely insulated and protected by insulating tape (not shown).

[0045] The soft pack cell 23 is a cell that uses a plastic or flexible material, such as an aluminum-plastic film, as a packaging material, and has the advantages of being lightweight, not easily exploded, and flexible in design. The aluminum-plastic film may be, for example, an aluminum-plastic film including a nylon layer, an aluminum layer, and a PP / CPP layer.

[0046] In some embodiments of the present invention, the size range of the soft-pack cell 23 used in the soft-pack CTP battery pack is 300-700 mm in length, 100-120 mm in width, and 10-20 mm in thickness. The tab 231 (see FIGS. 14 and 15) is 0.2-0.6 mm in thickness and 40-80 mm in width.

[0047] <Side panel>

[0048] How to install the cell stack 2 inside the box and how to apply temporary tightening force to the cell stack 2 in the initial state are technical issues that must be resolved during the assembly process of the soft-pack type CTP battery pack 100.

[0049] 3, in order to solve the above problems, each cell stack 2 of a soft-pack CTP battery pack 100 provided in some embodiments of the present invention has two side plates 24 arranged opposite each other. The two side plates 24 are respectively arranged inside the long side beams 141 at both ends in the width direction of the box 1 (i.e., at both ends in the stacking direction of the cell stack 2), and are adhesively fixed to the main body surfaces of the two soft-pack cells 23 at both ends in the stacking direction of the cell stack 2.

[0050] 4 is a schematic diagram (top view) of the structure of the side plate 24 in some embodiments of the present invention. Referring to FIG. 4, the outer surface 243 of the side plate 24 has a groove 241 that fits into an external jig. The external jig (not shown) clamps the side plate 24 via the groove 241 and applies a temporary clamping force to the cell stack 2 from both ends in the stacking direction of the cell stack 2, compressing the cell stack 2 to a size that is easy to insert into the box 1. By applying the temporary clamping force, the cycle performance of the cell can be improved. The groove 241 also makes it easy to remove the jig after the cell stack 2 is placed in the box.

[0051] In order to more uniformly distribute the temporary tightening force to each position of the soft-pack cell 23 and avoid localized stress concentrations, the portion where the inner surface 242 of the side plate 24 contacts the main body surface of the soft-pack cell 23 is formed into a flat surface 245. In other words, the inner surface 242 of the side plate 24 is configured so that the area of ​​the flat surface 245 is larger than the area of ​​the flat portion of the main body surface of the soft-pack cell 23.

[0052] The outer edge of the inner surface 242 of the side plate 24 protrudes to form an outer edge limiting portion 244 so as to limit the relative positional relationship between the side plate 24 and the soft pack cell 23 when the flat surface 245 in the center of the inner surface 242 abuts against the main body surface of the soft pack cell 23.

[0053] The structure of the outer surface 243 of the side plate 24 is as shown in Figure 5. Referring to Figure 5, second reinforcing ribs 247 are arranged in the grooves 241 arranged on the outer surface 243 of the side plate 24, and first reinforcing ribs 246 are arranged in the positions where no grooves 241 are arranged. The number of second reinforcing ribs 247 is greater than that of the first reinforcing ribs 246, and the density is also greater than that of the first reinforcing ribs 246, thereby improving the strength of the portion that comes into contact with the jig. The height of the second reinforcing ribs 247 is lower than that of the first reinforcing ribs 246, and the grooves 241 are formed.

[0054] Optionally, the wall thickness of the side plate 24 is 1.5-5 mm, the overall width is 5-25 mm, and the material of the side plate 24 can be plastic material such as PA6, PA66, PPE, PBT, etc.

[0055] FIG. 6 is a structural schematic diagram of the outer surface 243 of the side panel 24 provided in another embodiment of the present invention. FIG. 7 is a schematic diagram of the cooperative structure between the side panel 24 and the long side beam 141 of the box body 1 in an assembled state. Referring to FIGS. 6 and 7, a positioning post 248 is arranged on the inner wall of the long side beam 141 of the box body 1, and a positioning groove 249 is arranged on the outer surface 243 of the side panel 24. The positioning post 248 and the positioning groove 249 have matching shapes and sizes, and the positioning post 248 can be inserted into the positioning groove 249 to limit relative movement between the side panel 24 and the long side beam 141 along the length of the soft-pack cell 23, thereby conveniently and accurately completing the positioning and installation of the cell stack 2 during assembly.

[0056] It should be noted that in other embodiments of the present invention, the groove 241 is merely one form for fitting with an external jig. In other embodiments of the present invention, other suitable forms of jig fitting portions can be arranged on the outer surface 243 of the side plate depending on the type of jig, as long as they can be used in conjunction with the jig and the jig can stably clamp the cell stack 2.

[0057] The side plates 24 having the above structure allow a uniform temporary tightening force to be applied to the cell stack 2 in the initial state, effectively improving the grouping ability of the soft-pack cells 23 and making it easier to group the soft-pack cells 23 and box the cell stack 2.

[0058] <Thermal conductive structural adhesive 25-restriction part 26>

[0059] During the assembly process, it is necessary to apply a thermally conductive structural adhesive 25 between the bottom of the cell stack 2 and the bottom plate 13 of the lower housing. The thermally conductive structural adhesive 25 is usually applied evenly by applying pressure from the outside to fill gaps, but due to reasons such as uneven pressure, the thermally conductive structural adhesive 25 in some areas is usually too thin or too thick, which may affect heat dissipation efficiency and insulation performance.

[0060] FIG. 8 is an exploded schematic diagram of a soft-pack CTP battery pack 300 having a limiting portion 26 according to some embodiments. Referring to FIG. 8 , in response to the above-described problem, some embodiments of the present invention provide a limiting portion 26 of a predetermined height attached to the lower housing bottom plate 13. When the box 1 is placed horizontally, the height of the upper portion of the limiting portion 26 is equal to or slightly lower than the height of an appropriate amount of thermally conductive structural adhesive 25 when the box 1 is placed horizontally. In this manner, an operator or an automatic adhesive application system can determine whether the amount of adhesive applied is appropriate based on the relative height between the liquid level of the thermally conductive structural adhesive 25 and the upper portion of the limiting portion 26. That is, if the applied thermally conductive structural adhesive 25 becomes flat and the liquid level is essentially flush with the upper portion of the limiting portion 26, or if the liquid level is slightly higher than the upper portion of the limiting portion 26, the amount of applied thermally conductive structural adhesive 25 is appropriate. Otherwise, the amount of applied thermally conductive structural adhesive 25 needs to be adjusted. By using the limiting portion 26, the thickness of the thermally conductive structural adhesive 25 between the cell stack 2 and the box 1 can be accurately controlled to a predetermined thickness value within the range of 0.5 mm to 5 mm.

[0061] In some embodiments of the present invention, the restriction portion 26 has a strip shape, i.e., the shape of a limiting strip. The restriction portion 26 is preferably made of an insulating material such as a foam, an elastic material such as silicone rubber, or a plastic such as PP or PPF. In other embodiments, the restriction portion 26 is made of a high-strength metal material such as an aluminum alloy or stainless steel, and insulation can be achieved by attaching an insulating film to the surface of the metal restriction portion 26 or by thermally spraying an insulating material.

[0062] In some embodiments, the restriction portion 26 may be formed by combining multiple restriction strips or by integrally forming multiple restriction strips. In other embodiments, the restriction portion 26 may be formed integrally with the lower housing bottom plate 13.

[0063] On the other hand, the limiting portion 26 helps control the amount of thermally conductive structural adhesive 25 added, improves the uniformity of the thermally conductive structural adhesive 25 at the bottom of the cell stack 2, increases the heat dissipation capacity of the cell stack 2, and improves safety under high current operating conditions. On the other hand, the limiting portion 26 can also separate the cell stack 2 from the lower housing bottom plate 13 to prevent the bottom of the cell stack 2 from coming into direct contact with the lower housing bottom plate 13 and affecting insulation.

[0064] 8 , in some embodiments, the restriction portions 26 may be independent members. After the restriction portions 26 are fixed to the lower housing bottom plate 13, the areas between the restriction portions 26 are filled with thermally conductive structural adhesive 25 to the same height as the restriction portions 26 (or slightly higher than the height of the restriction portions 26). The cell stack 2 is then placed in the box 1, and the thermally conductive structural adhesive 25 is pressed against the cell stack 2 so that all of the soft-pack cells 23 are in uniform contact with the restriction portions 26 and the thermally conductive structural adhesive 25. In this embodiment, the restriction portions 26 are made of a combination of multiple foams or rubber cones. The surface of the lower housing bottom plate 13 is flat, and the restriction portions 26 are bonded to the surface of the lower housing bottom plate 13.

[0065] Fig. 9 is a top view of the box body 1 to which the limiting portion 26 is attached. Referring to Fig. 9, in the embodiment of Fig. 8, the limiting portion 26 is an independently produced frame structure including a rectangular limiting portion 26 that forms an outer frame, a limiting portion 26 that connects diagonals of the rectangle, and a limiting portion 26 that is parallel to the short side beams 142.

[0066] The height of each of the restriction portions 26 is the same, and is substantially equal to the rated adhesive application height. Figure 10 is a schematic diagram of the relative positional relationship between the bottom of the soft-pack cell 23 and the restriction portion 26 after assembly is complete. Referring to Figures 9 and 10, the restriction portion 26 extends in the width direction of the box 1, and its extension range covers the extension range of the cell stack 2 in the width direction of the box 1. Therefore, by arranging the restriction portion 26 in this manner, each soft-pack cell 23 of the cell stack 2 can be effectively pressed against the restriction portion 26.

[0067] 11 is a structural schematic diagram (exploded view) of a soft-pack CTP battery pack 400 according to some other embodiments of the present invention. Referring to FIG. 11, the limiting portion 26 may be formed integrally with the lower housing bottom plate 13. Specifically, the limiting portion 26 may be formed by punching the surface of the lower housing bottom plate 13, or by punching a hole in the surface of the lower housing bottom plate 13 to form an adhesive application groove. The sidewalls of the adhesive application groove are higher than the bottom of the adhesive application groove; that is, the sidewalls of the adhesive application groove correspond to the limiting portion 26.

[0068] FIG. 12 is a schematic diagram of the installation position of the limiting portion 26 at the bottom of the box 1 in the embodiment of FIG. 10. FIG. 13 is a schematic diagram (cross-sectional view) of the relative positional relationship between the soft-pack cell 23, the lower housing bottom plate 13, and the limiting portion 26 in the embodiment of FIG. 10. Referring to FIGS. 12 and 13, the limiting portion 26 extends along the width direction of the box 1. The limiting portion 26 is formed integrally with the box 1 and is made of the same metal material. To insulate the limiting portion 26, an insulating paint may be sprayed onto the surface of the limiting portion 26 or the limiting portion 26 may be covered with an insulating film 261. By forming the limiting portion 26 integrally, a separate process for positioning and attaching the limiting portion 26 can be omitted, shortening the process flow and improving production efficiency.

[0069] <Foaming adhesive>

[0070] In order to increase the overall strength and rigidity of the soft pack CTP battery pack 500 and ensure the structural safety performance of the soft pack CTP battery pack 500, in some embodiments of the present invention, a foam adhesive 29 is further filled between the short side beam 142 and the cell stack 2.

[0071] 14 is a schematic diagram of the filling position of the foamable adhesive 29 in a soft-pack CTP battery pack 500 according to some embodiments of the present invention. Referring to FIG. 14, the foamable adhesive 29 is filled at both ends of the soft-pack cell 23 in the longitudinal direction, specifically, between the short side beams 142 and the cell stack 2, and between the box center beam 15 and the cell stack 2.

[0072] The soft-pack cells 23 are stacked perpendicularly in the thickness direction, and the length direction of the soft-pack cells 23 is the length direction of the box body 1. Tabs 231 protrude from both ends of the soft-pack cells 23 in the length direction, and the positive electrode tab 231 and the negative electrode tab 231 are located at both ends of the soft-pack cells 23 in the length direction. The positive electrode tab 231 and the negative electrode tab 231 of adjacent cells are rolled and folded, directly overlapped, and welded to be fixed. In some embodiments, the cell stack 2 may further include a flexible circuit board 28 (see FIG. 3 ). The main body of the flexible circuit board 28 is arranged parallel to the tab 231, and a sampling piece (not shown) of the flexible circuit board 28 is welded to the tab 231.

[0073] FIG. 15 is a schematic diagram (partial cross-sectional view along the XY plane of FIG. 14) of the structure of filling the foamable adhesive 29 between the soft-pack cell 23 and the short side beam 142. FIG. 16 is a schematic diagram (partial cross-sectional view along the XZ plane of FIG. 14) of the filling height of the foamable adhesive 29 between the soft-pack cell 23 and the short side beam 142. Referring to FIGS. 15 and 16, adjacent tabs 231 are directly overlapped and welded. After welding the tabs 231, the foamable adhesive 29 is injected between the soft-pack cell 23 and the short side beam 142 and the box central beam 15. After foaming and hardening, the foamable adhesive 29 is filled in the gaps between the cell stack 2 and the short side beam 142 and the gaps between the cell stack 2 and the box central beam 15.

[0074] The height of the foamable adhesive 29 obtained after hardening and molding is greater than the height of the tabs 231. In this way, the foamable adhesive 29 can completely encase the tabs 231 inside the foamable adhesive 29, and the tabs 231 are electrically insulated from each other by the foamable adhesive 29, which effectively prevents overlapping short circuits between the tabs 231, improves thermal runaway prevention performance, and increases safety and stability.

[0075] In addition to completely immersing the tab 231, it is preferable that the height H1 of the foamable adhesive be equal to or less than the height H3 of the soft-pack cell. That is, it is preferable that the height H2 of the tab 231 is equal to or less than the height H1 of the foamable adhesive and equal to or less than the height H3 of the soft-pack cell. Because the foamable adhesive 29 can completely immerse the tab 231, if thermal runaway occurs, high-temperature gas generated inside the soft-pack cell 23 is not released from the tab 231 but is discharged from the top of the tab 231 of the soft-pack cell 23 above the foamable adhesive 29, thereby effectively preventing the expansion of thermal runaway.

[0076] In some embodiments of the present invention, the distance between the tab overlap surface 232 connecting the tabs 231 and the short side beam 142 or the box body central beam 15 is 3 to 10 mm, and an insulating sheet 17 is arranged on the inner surface of the short side beam 142 and the box body central beam 15, the insulating sheet 17 having a thickness of 0.1 to 0.5 mm, and the insulating sheet 17 can further ensure electrical insulation between the tab 231 and the box body 1.

[0077] The foamable adhesive 29 after hardening has a density of 0.1 to 0.3 g / cm3, an elastic modulus of 10 to 30 MPa, adhesive performance, shear strength, and tensile strength in the range of 1 to 3 MPa, an elongation at break of ≥ 8%, a compressive elastic modulus of ≥ 30 MPa, and a storage elastic modulus of ≥ 20 MPa. The material of the foamable adhesive 29 also has insulating properties, and the volume resistivity is ≥ 1 × 10 15 Ω·cm, flame retardant grade complies with UL94 V0.

[0078] By using the above method, on the one hand, the foamable adhesive 29 can fix the cell stack 2 and increase the rigidity and strength of the soft pack type CTP battery pack 500, and on the other hand, it can isolate the tabs 231, for example, by isolating the tabs 231 from the high-temperature gas generated during thermal runaway and by providing electrical insulation between the tabs 231 and between the tabs 231 and the box body 1.

[0079] <Adhesive blocking part>

[0080] In order to prevent the foamable adhesive 29 from penetrating between the cell stack 2 and the thermally conductive structural adhesive 25 and affecting the heat dissipation capability of the cell stack 2 or degrading the mechanical properties of the battery pack, in some embodiments of the present invention, an adhesive blocking portion 27 is further arranged at a position where the foamable adhesive 29 and the thermally conductive structural adhesive 25 may come into contact.

[0081] FIG. 17 is a structural schematic (exploded view) of a soft-pack CTP battery pack 600 having an adhesive barrier 27 disposed therein in some embodiments, and FIG. 18 is a structural schematic view of the battery pack 600 after the adhesive barrier 27 has been compressed.

[0082] Referring to Figures 17 and 18, the extension direction of the adhesive blocking portion 27 is perpendicular to the longitudinal direction of the soft pack cell 23, and both ends of the adhesive blocking portion 27 in the longitudinal direction each extend so as to abut against the inside of the long side beam 141.

[0083] Two adhesive blocking sections 27 are arranged inside each of the first chamber 161 and the second chamber 162, and the area where the conductive structural adhesive 25 is applied is located between the two adhesive blocking sections 27, and the foamable adhesive 29 is filled between the adhesive blocking section 27 and the short side beam 142, and between the adhesive blocking section 27 and the box body central beam 15.

[0084] The length of the adhesive blocking portion 27 is equal to or greater than the length in the stacking direction of the cell stack 2 and less than the width of the box 1. The width of the adhesive blocking portion 27 is 1 to 30 mm. The top of the adhesive blocking portion 27 is higher than the top of the thermally conductive structural adhesive 25 so as to limit the application area of ​​the thermally conductive structural adhesive 25 and prevent the thermally conductive structural adhesive 25 from overflowing.

[0085] The adhesive blocking portion 27 is preferably made of an insulating material with a certain degree of elasticity, such as foam, silicone rubber, or other elastic material, in order to effectively fill the gap, isolate the foam adhesive 29 from the thermally conductive structural adhesive 25, and prevent the two adhesives from coming into contact with each other.

[0086] The adhesive barrier 27 has a flat bottom that can be bonded to the lower housing bottom plate 13 via adhesive disposed on the underside of the bottom. The top can be formed as a flat, elastic surface, with a certain gap between the soft-pack cells 23. When the soft-pack cells 23 press against the flat top surface of the elastic adhesive barrier 27, a plurality of teeth 271 can be formed on the top of the adhesive barrier 27 at equal intervals along its length. The tooth spacing between adjacent teeth 271 is equal to the thickness of one or a group of soft-pack cells 23. By correspondingly extending each tooth 271 between adjacent soft-pack cells 23, the adhesive barrier 27 can be adhesively fixed to the cell stack 2. As described above, the maximum height of each tooth 271 is higher than the top of the thermally conductive structural adhesive 25 to limit the application area of ​​the thermally conductive structural adhesive 25 and prevent the thermally conductive structural adhesive 25 from overflowing.

[0087] Fig. 19 is a schematic diagram (top view) of the structure of each member in the box 1 in the embodiment of Fig. 17. Fig. 20 is a partially enlarged cross-sectional view of region A in Fig. 19.

[0088] 17, 19 and 20, after the cell stack 2 is installed in place, the soft-pack cells 23 and the adhesive barriers 27 are sufficiently compressed together, with essentially no gap between the bottom of the soft-pack cells 23 and the adhesive barriers 27. This effectively isolates the foamable adhesive 29 from the thermally conductive structural adhesive 25, preventing contact between them.

[0089] In this manner, the adhesive blocking portion 27 is in close contact with the bottom of the cell stack 2 and can fill the gap between the soft-pack cells 23, effectively isolating the foamable adhesive 29 and the thermally conductive structural adhesive 25 and preventing the foamable adhesive 29 from penetrating between the thermally conductive structural adhesive 25 and the cell stack 2, thereby ensuring the heat dissipation performance of the cell stack 2 and the mechanical performance of the soft-pack CTP battery pack 600.

[0090] In other embodiments of the present invention, adhesive blocking methods of the adhesive blocking section 27 include filling the gaps between adjacent soft-pack cells 23, filling the gaps between the box body 1 and the cell stack 2, and covering the sides of the soft-pack cells 23, but are not limited to these, and any method that can assist in isolating the thermally conductive structural adhesive 25 and the foamable adhesive 29 will suffice.

[0091] <Assembly process>

[0092] The assembly process of the soft pack type CTP battery pack provided by some embodiments of the present invention will be introduced below.

[0093] First, the lower housing 11 of the box 1 is provided. If the lower housing 11 is integrated with the limiting portion 26 or adhesive blocking portion 27, the thermally conductive structural adhesive 25 is applied directly between the limiting portion 26 of the lower housing 11 and the limiting portion 26. If the lower housing 11 is not integrated with the limiting portion 26, the limiting portion 26 or adhesive blocking portion 27 is arranged separately, and the thermally conductive structural adhesive 25 is applied to the area between the limiting portion 26 or adhesive blocking portion 27 and the added limiting portion 26 or adhesive blocking portion 27.

[0094] After applying an appropriate amount of thermally conductive structural adhesive 25, an external jig is connected to the grooves 241 of the side plates 24, and the two cell stacks 2 are placed inside the box. Before being placed inside the box, the cell stacks 2 are compressed to a certain size under the clamping action of the jig, so that the overall width of the cell stack 2, including the side plates 24, is equal to or less than the width of the chamber 16 inside the box 1. After the cell stacks 2 are placed inside the box, the jig can be removed from the grooves 241 of the side plates 24, and the cell stacks 2 slowly rebound until the first reinforcing rib 246 of the side plates 24 comes into contact with the long side beams 141, after which the rebounding stops.

[0095] After the installation of some of the electrical connectors is completed, foam adhesive 29 is injected between the short side beams 142 and the cell stack 2, and between the box center beam 15 and the cell stack 2. After the foam adhesive 29 hardens and forms, and other electrical connectors and the battery management system (if any) are installed, structural adhesive is applied onto the cell stack 2, and the top cover 12 is closed to complete the assembly of the soft-pack CTP battery pack.

[0096] The above-described embodiments provided by the present invention can be combined with each other. In some embodiments, the soft-pack CTP battery pack can be directly integrated into the chassis of the electric vehicle, but the embodiments of the present invention are not limited thereto.

[0097] The above are only preferred embodiments of the present invention, and are not intended to limit the present invention, and any modifications, equivalent replacements and improvements made within the spirit and principle of the present invention shall fall within the protection scope of the present invention. [Industrial Applicability]

[0098] The battery pack of the present invention and the electric vehicle incorporating the battery pack can be applied in the field of power battery technology. [Explanation of symbols]

[0099] 100, 200, 300, 400, 500, 600: Soft pack type CTP battery pack 1: Box body 11: Lower housing 12: Top cover 13: Lower housing bottom plate 14: Side beam 141: Long side beam 142: Short side beam 15: Box center beam 16: Chamber 161: First Chamber 162: Second chamber 17: Insulation sheet 2: Cell stack 23: Soft pack cell 231: Tab 232: Tab overlapping surface 24: Side panel 241: Groove 242:Inner surface 243:Outer surface 244: Outer edge limiting part 245: Flat surface 246: First reinforcing rib 247: Second reinforcing rib 248: Positioning pillar 249: Positioning groove 25: Thermally conductive structural adhesive 26: Restriction section 261: Insulating film 27: Adhesive blocking section 271: Teeth 28: Flexible circuit board 29: Foaming adhesive 21: First cell stack 22: Second cell stack 311: 1st output positive pole 312: First output negative pole 321: Second output positive pole 322: Second output negative pole 331: Third output positive pole 332: Third output negative pole 34: End output pole base 35: Central adapter base 36: Copper busbar

Claims

1. a box having an installation space therein; a cell stack including a plurality of soft-pack cells and disposed within the mounting space; At least two adhesive structures are disposed in the mounting space and directly connected between the cell stack and the box body; an adhesive barrier disposed between the two adhesive structures and separating the two adhesive structures; Including, the box body includes a lower housing, the lower housing including a lower housing bottom plate and a beam structure, the cell stack is disposed on the lower housing bottom plate, and the adhesive structure is filled between the cell stack and the lower housing bottom plate and between the cell stack and the beam structure; One adhesive structure is configured as a first adhesive layer, and is filled and bonded between the bottom of the cell stack and the lower housing bottom plate, and the other adhesive structure is configured as a second adhesive layer, and is filled and bonded between the tab side of the cell stack and the beam structure, The battery pack, wherein the first adhesive layer includes a thermally conductive structural adhesive, and the second adhesive layer includes a foam adhesive.

2. the adhesive-blocking portion extends along the stacking direction of the cell stack, and the adhesive-blocking portion is disposed at both ends of the soft-pack cell in the longitudinal direction of the soft-pack cell.

2. The battery pack according to claim 1, wherein:

3. the beam structure includes a first beam structure parallel to the adhesive barrier and a second beam structure perpendicular to the adhesive barrier, the adhesive barrier extending to abut the second beam structure; 3. The battery pack according to claim 2, wherein:

4. The foamable adhesive is filled between the adhesive barrier and the first beam structure.

4. The battery pack according to claim 3, wherein:

5. the adhesive barrier comprises an elastic material; 5. The battery pack according to claim 1, wherein the battery pack comprises:

6. The adhesive blocking portion is a bottom portion bonded to the bottom plate of the lower housing; an upper portion that is pressed against and adhered to the soft-pack cell and conforms to the shape of the soft-pack cell; The battery pack according to claim 5 , comprising:

7. the top portion includes a plurality of teeth spaced along the length of the adhesive barrier, each tooth receiving a corresponding one of the soft pack cells; 7. The battery pack according to claim 6, wherein:

8. the maximum height of the teeth is greater than the top of the thermally conductive structural adhesive; 8. The battery pack according to claim 7, wherein:

9. The bottom of the adhesive blocking portion is adhered to the bottom plate of the lower housing via a backside adhesive.

7. The battery pack according to claim 6, wherein:

10. a limiting portion disposed on the bottom plate of the lower housing so as to protrude beyond a predetermined height of the bottom plate of the lower housing on which the thermally conductive structural adhesive is disposed; 2. The battery pack according to claim 1, wherein:

11. the predetermined height of the restriction portion is less than or equal to the thickness of the thermally conductive structural adhesive; The battery pack according to claim 10 .

12. The limiting portion is disposed at an end position corresponding to the length direction of the soft-pack cell. The battery pack according to claim 11 .

13. The limiting portion is a frame structure.

13. The battery pack according to claim 11 or 12.

14. The limiting portion and the bottom plate of the lower housing are integrally formed.

13. The battery pack according to claim 11 or 12.

15. The surface of the limiting portion is coated with an insulating coating layer, or the surface of the limiting portion is coated with an insulating film.

15. The battery pack according to claim 14.

16. An electric vehicle comprising the battery pack according to any one of claims 1 to 4.

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