Battery pack and electric vehicle

Abstract

The utility model relates to the field of batteries, in particular to a battery pack and an electric vehicle, and the battery pack comprises a box body, a battery cell stacking body, a glue blocking part and at least two glue structures. A mounting space is formed in the box body; the battery cell stacking body comprises a plurality of soft package battery cells, and the battery cell stacking body is arranged in the mounting space; the colloid structure is arranged in the mounting space, and the colloid structure is directly connected between the battery cell stacking body and the box body; the glue blocking part is arranged between the two colloid structures so as to isolate the two colloid structures. According to the battery pack, the colloid structures can be utilized to construct more comprehensive support for the battery core stacking body, and mutual interference among different colloid structures can be prevented.

Description

[0001] This application claims priority to Chinese patent application No. 202311785202.7, the contents of which are referenced herein. Technical Field

[0002] The utility model relates to the technical field of power batteries, in particular to a battery pack and an electric vehicle integrated with the battery pack. Background Art

[0003] The operating voltage of a single secondary battery is about 2.5V to 4.5V. In electric vehicles or energy storage systems that require large capacity and high voltage output, it is usually necessary to connect multiple battery cells in series and / or in parallel to form a battery module, and then connect the battery modules in series and / or in parallel to form a battery pack, and further use the battery pack as an energy system for powering electric vehicles or as an energy storage system. The number and shape of the battery modules used to build the battery pack and the number and shape of the battery cells used to form the battery module can be flexibly changed according to actual needs.

[0004] In the field of power batteries used in electric vehicles, in order to improve the full-charge endurance and charging speed of electric vehicles, it is necessary to further enhance the energy density and cooling performance of the battery pack. As a solution to improve energy density, the CTP (cell to pack) type battery pack omits the step of connecting the battery cells in series and / or in parallel to form a battery module, and directly integrates the battery cells into a battery pack, thereby eliminating the structural parts and electrical connectors required to form a battery module, so that the space left for the battery cells themselves can be increased.

[0005] At present, common battery cells are divided into cylindrical cells, square-shell cells and soft-pack cells according to their structures. CTP battery packs using square-shell cells have been widely promoted and used, but soft-pack cells still face a series of problems in the process of integration into CTP battery packs because they are not easy to withstand external impacts and have poor assembly properties. Utility Model Content

[0006] The utility model solves at least one of the multiple problems faced by the prior art in which soft-pack battery cells are integrated into a soft-pack CTP battery pack.

[0007] The first aspect of the utility model provides a battery pack, comprising a box, a battery cell stack, a glue blocking part and at least two colloid structures. The box has an installation space; the battery cell stack comprises a plurality of soft-pack battery cells, and the battery cell stack is arranged in the installation space; the colloid structure is arranged in the installation space, and the colloid structure is directly connected between the battery cell stack and the box; the glue blocking part is arranged between the two colloid structures to isolate the two colloid structures.

[0008] Optionally, the box body includes a lower shell body, the lower shell body includes a lower shell body bottom plate and a beam structure, the battery cell stack is arranged on the lower shell body bottom plate, and the colloid structure is filled between the battery cell stack body and the lower shell body bottom plate and between the battery cell stack body and the beam structure.

[0009] Optionally, one colloid structure is constructed as a first glue layer and is filled and bonded between the bottom of the battery cell stack and the bottom plate of the lower shell, and the other colloid structure is constructed as a second glue layer and is filled and bonded between the ear side of the battery cell stack and the beam structure.

[0010] Optionally, the first adhesive layer is a thermally conductive structural adhesive, and the second adhesive layer is a foaming adhesive.

[0011] Optionally, the glue blocking portion extends along the stacking direction of the battery cell stack, and in the length direction of the soft-pack battery cell, the glue blocking portion is arranged at both ends of the soft-pack battery cell.

[0012] Optionally, the beam structure includes a first beam structure parallel to the rubber blocking portion and a second beam structure perpendicular to the rubber blocking portion, and the rubber blocking portion extends to abut against the second beam structure.

[0013] Optionally, foamed rubber is filled between the rubber blocking portion and the first beam structure.

[0014] Optionally, the rubber blocking portion is made of elastic material.

[0015] Optionally, the glue blocking portion includes a bottom portion that is in contact with the bottom plate of the lower shell and a top portion that is pressed and fitted with the soft-pack battery cell and matches the shape of the soft-pack battery cell.

[0016] Optionally, the top includes a plurality of teeth arranged at intervals along the length direction of the rubber blocking portion, and each tooth accommodates a corresponding soft-pack battery cell.

[0017] Optionally, the maximum height of the teeth is higher than the top of the thermally conductive structural adhesive.

[0018] Optionally, the bottom of the adhesive stop portion is bonded to the bottom plate of the lower shell body by adhesive.

[0019] Optionally, the battery pack further includes a limiting portion, which is arranged on the bottom plate of the lower shell in the form of protruding by a specified height from the bottom plate of the lower shell provided with the thermal conductive structural adhesive.

[0020] Optionally, the specified height of the limiting portion is lower than the thickness of the thermal conductive structural adhesive or is the same as the thickness of the thermal conductive structural adhesive.

[0021] Optionally, the limiting portion is arranged at an end position corresponding to the length direction of the soft-pack battery cell.

[0022] Optionally, the limiting portion is a frame structure.

[0023] Optionally, the limiting portion is integrally formed with the bottom plate of the lower shell.

[0024] Optionally, the surface of the limiting portion is coated with an insulating coating, or the surface of the limiting portion is covered with an insulating film.

[0025] A second aspect of the present invention provides an electric vehicle having the battery pack provided by the first aspect of the present invention.

[0026] <Beneficial Effects>

[0027] In some technical solutions provided by the present invention, the colloid structure can be used to construct a more comprehensive support for the battery cell stack, and mutual interference between different colloid structures can be prevented. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the stacking distribution of soft-pack CTP battery packs provided in some embodiments of the present invention.

[0029] Figure 2 yes Figure 1 A schematic diagram of stacking body distribution of a variation of an implementation method.

[0030] Figure 3 Is to use Figure 1 Exploded diagram of the soft-pack CTP battery pack with corresponding stacking distribution.

[0031] Figure 4 It is a schematic structural diagram (top view) of the side panels in some embodiments of the present invention.

[0032] Figure 5 yes Figure 4 A schematic structural diagram of the outer surface of the side panel in an embodiment.

[0033] Figure 6 It is a schematic structural diagram of the outer surface of the side panel provided in other embodiments of the present utility model.

[0034] Figure 7 yes Figure 6 A schematic diagram of the matching structure between the side panels and the long side beams of the box body in the assembled state in the implementation manner.

[0035] Figure 8 Schematic diagram of an explosion of a soft-pack CTP battery pack with a limiting portion in some embodiments.

[0036] Fig. 9 yes Figure 8 A top view of a box body equipped with a limiting portion in an embodiment.

[0037] Fig.10 yes Figure 8 Schematic diagram of the relative position relationship between the bottom of the soft-pack battery cell and the limiting portion when assembly is completed in the implementation manner.

[0038] Fig.11 It is a structural schematic diagram (explosion diagram) of a soft-pack CTP battery pack in other embodiments of the present invention.

[0039] Fig.12 yes Fig.10 A schematic diagram of the position of the limiter at the bottom of the box in an implementation manner.

[0040] Fig.13 It is a schematic diagram (cross-sectional view) of the relative position relationship between the soft-pack battery cell, the bottom plate of the lower shell, and the limiting part of another embodiment.

[0041] Fig.14 It is a schematic diagram of the foam filling position in some embodiments of the utility model.

[0042] Fig.15 yes Fig.14 Schematic diagram of the foam filling structure between the soft-pack battery cell and the short side beam in an embodiment (partial cross-sectional view along the XY plane).

[0043] Fig.16 yes Fig.14 Schematic diagram of the foam filling height between the soft-pack battery cell and the short side beam in an implementation manner (partial cross-sectional view along the XZ plane).

[0044] Fig.17 2. It is a schematic structural diagram (explosion diagram) of a soft-pack CTP battery pack provided with a glue blocking portion in some embodiments.

[0045] Fig.18 yes Fig.17 A schematic diagram of the structure after the rubber stopper is compressed in an implementation manner.

[0046] Fig.19 yes Fig.17 Schematic diagram of the structure of each component in the box in an embodiment (top view after removing the upper cover).

[0047] Fig. 20 yes Fig.19 A partial enlarged cross-sectional view of area A in the middle.

[0048] Reference numerals:

[0049] Soft-pack CTP battery pack 100, 200, 300, 400, 500, 600; box 1; lower shell 11; upper cover 12; lower shell bottom plate 13; side beam 14; long side beam 141; short side beam 142; box middle beam 15; chamber 16; first chamber 161; second chamber 162; insulating sheet 17; battery cell stack 2; soft-pack battery cell 23; pole ear 231; pole ear lap surface 232; side plate 24; groove 241; inner surface 242; outer surface 243; outer edge limit portion 244; flat surface 245; first A reinforcing rib 246; a second reinforcing rib 247; a positioning column 248; a positioning groove 249; a thermally conductive structural adhesive 25; a limiting portion 26; an insulating film 261; an adhesive stop portion 27; a tooth 271; a flexible circuit board 28; a foam adhesive 29; a first battery cell stack 21; a second battery cell stack 22; a first output positive electrode 311; a first output negative electrode 312; a second output positive electrode 321; a second output negative electrode 322; a third output positive electrode 331; a third output negative electrode 332; an end output electrode base 34; a middle adapter base 35; an adapter copper bar 36. DETAILED DESCRIPTION

[0050] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0051] <Battery cell stack distribution>

[0052] Figure 1 Schematic diagram of the stacking distribution of the soft-pack CTP battery pack 100 provided in some embodiments of the present invention.

[0053] refer to Figure 1 In some embodiments of the present invention, the soft-pack CTP battery pack 100 includes a square box body 1 and a square battery cell stack 2. The internal space of the box body 1 can accommodate two battery cell stacks 2 placed side by side.

[0054] The two battery cell stacks 2 are the first battery cell stack 21 and the second battery cell stack 22. The first battery cell stack 21 is provided with a first output positive electrode 311 and a first output negative electrode 312 at both ends of a side adjacent to the second battery cell stack 22. Correspondingly, the second battery cell stack 22 is provided with a second output positive electrode 321 and a second output negative electrode 322 at both ends of a side adjacent to the first battery cell stack 21. The positions of the first output positive electrode 311 and the second output negative electrode 322 correspond, and the positions of the first output negative electrode 312 and the second output positive electrode 321 correspond, thereby reducing the wiring length and facilitating the series electrical connection between the two battery cell stacks 2.

[0055] In addition, the first battery cell stack 21 is also provided with a third output positive electrode 331 and a third output negative electrode 332 adjacent to each other at one end away from the second battery 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 inside the two battery cell stacks 2, and the third output positive electrode 331 and the third output negative electrode 332 are used as output electrodes of 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 the battery pack disconnecting unit (BDU), and then the whole vehicle is powered by the battery pack disconnecting unit.

[0056] The output electrodes provided by the above distribution and electrical connection, namely the third output positive electrode 331 and the third output negative electrode 332 are adjacent to each other. In some cases, when the output electrodes of the entire soft-pack CTP battery pack 100 need to be separated from each other, the first battery cell stack 21 can be relatively Figure 1 Rotate 180° and place it in the box 1, so as to obtain the following Figure 2 The assembly structure of the soft-pack CTP battery pack 200 is shown.

[0057] refer to Figure 2 , by rotating 180° and then putting it into the box, the third output positive electrode 331 and the third output negative electrode 332 will be located adjacent to the second battery cell stack 22, and the third output positive electrode 331 and the second output negative electrode 322 are electrically connected through the adapter copper bar 36, and the third output negative electrode 332 and the second output positive electrode 321 are electrically connected through another adapter copper bar 36, thereby realizing the high-voltage electrical connection between the first battery cell stack 21 and the second battery cell stack 22. The first output positive electrode 311 and the first output negative electrode 312 can be used as the output electrodes of the entire soft-pack CTP battery pack 200. By using the first battery cell stack 21 and the adapter copper bar 36 with the above-mentioned electrode distribution, the installation angle of the first battery cell stack 21 can be flexibly adjusted to meet the needs of different output electrode positions.

[0058] The above examples illustrate the distribution mode and electrical connection mode of the first battery cell stack 21 and the second battery cell stack 22 in some embodiments of the present invention. It can be understood that the above description is only exemplary and should not be understood as a limitation on the distribution mode and electrical connection mode. In other embodiments of the present invention, the first battery cell stack 21 and the second battery cell stack 22 can also be integrated into a single-row battery cell stack 2, and the setting position of each output electrode of the battery cell stack 2 can also be flexibly adjusted according to actual needs.

[0059] Figure 3 Is to use Figure 1 An exploded view of the soft-pack CTP battery pack 100 with a corresponding stacking distribution.

[0060] refer to Figure 3 The square box 1 includes a lower shell 11 and an upper cover 12. The lower shell 11 includes a rectangular lower shell bottom plate 13 and four side beams 14. The four side beams 14 are respectively vertically fixed to the four sides of the rectangular lower shell bottom plate 13. The four side beams 14, the lower shell bottom plate 13 and the upper cover 12 are enclosed together to define a chamber 16 for accommodating the battery cell stack 2. In addition to the four side beams 14, the box 1 also includes a box middle beam 15 arranged in the center of the length direction of the box 1. The box middle beam 15 divides the chamber 16 into a first chamber 161 and a second chamber 162. The first chamber 161 is used to accommodate the first battery cell stack 21, and the second chamber 162 is used to accommodate the second battery cell stack 22.

[0061] The bottom of the battery cell stack 2 and the bottom plate 13 of the lower shell are connected by structural glue or heat conductive structural glue 25 ( Figure 3 Not shown, refer to Figure 8 In order to stabilize the battery stack 2, enhance the overall strength and rigidity of the battery pack, and take into account thermal runaway protection, a foaming glue 29 is also filled between the battery stack 2 and the side beam 14 or the middle beam 15 of the box body.

[0062] A structural adhesive or a heat-conducting structural adhesive or an elastomer component (not shown) is provided on the top of the battery cell stack 2 to fill the gap between the battery cell stack 2 and the upper cover 12. By using the structural adhesive, heat-conducting structural adhesive 25, foaming adhesive 29 between the bottom of the battery cell stack 2 and the bottom plate 13 of the lower shell, and the structural adhesive, heat-conducting structural adhesive or elastomer component on the top of the battery cell stack 2, a stable and buffering support can be formed for the battery cell stack 2 from all directions around. In some embodiments, the elastomer component can be composited with fireproof materials such as foam and mica, and a double-sided adhesive or hot melt adhesive is provided between the elastomer component and the battery cell stack 2.

[0063] In some embodiments, a liquid cooling circuit (not shown) may be provided in the lower shell bottom plate 13 and the upper cover 12 , and the heat dissipated by the battery cell stack 2 may be quickly transferred to the liquid cooling circuit using the thermal conductive structural adhesive 25 , thereby improving the cooling capacity of the battery cell stack 2 .

[0064] 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 on the inner middle side of the short side beam 142 adjacent to the first battery cell stack 21. A copper bar (not shown) connected to the third output positive pole 331 and a copper bar (not shown) connected to the third output negative pole 332 are both arranged on the end output pole base 34.

[0065] A middle adapter base 35 is provided on the middle beam 15 of the box body. The copper bar connected to the first output positive electrode 311 and the copper bar connected to the second output negative electrode 322 are both provided on the middle adapter base 35, and one end of the two adapter copper bars are also provided on the middle adapter base 35 and are respectively electrically connected to the corresponding copper bars, thereby realizing the electrical connection between the first battery cell stack 21 and the second battery cell stack 22.

[0066] <Battery cell stack>

[0067] Continue to refer Figure 3 In this embodiment, the battery stack 2 is formed by stacking and bonding a plurality of soft-packed batteries 23, and the stacking direction is the thickness direction of the soft-packed batteries 23, that is, the width direction of the box 1. The length direction of the soft-packed batteries 23 is parallel to the length direction of the box 1. The top and bottom of each soft-packed battery 23 are insulated and protected by full-covering insulating tape (not shown in the figure).

[0068] The soft-pack battery 23 is a battery using plastic or flexible materials such as aluminum-plastic film as packaging materials, which has the advantages of light weight, non-explosion, flexible design, etc. The aluminum-plastic film can be an aluminum-plastic film including a nylon layer, an aluminum layer and a PP / CPP layer.

[0069] In some embodiments of the present invention, the size range of the soft-pack battery cell 23 used in the soft-pack CTP battery pack is: length 300-700 mm, width 100-120 mm, thickness 10-20 mm. Fig.14 , 15 ) has a thickness of 0.2 to 0.6 mm and a width of 40 to 80 mm.

[0070] <Side panel>

[0071] How to install the battery cell stack 2 into the box and apply pre-tightening force to the battery cell stack 2 in the initial state is a technical problem to be solved in the assembly process of the soft-pack CTP battery pack 100.

[0072] To solve the above problems, continue to refer to Figure 3 In some embodiments of the utility model, each cell stack 2 of the soft-pack CTP battery pack 100 has two opposite side panels 24, which are respectively arranged on the inner side of the long side beams 141 at both ends of the width direction of the box body 1 (i.e., the two ends of the cell stack 2 in the stacking direction), and are bonded and fixed to the main body surfaces of the two soft-pack cells 23 at both ends of the cell stack 2 in the stacking direction.

[0073] Figure 4 2 is a schematic diagram (top view) of the structure of the side plate 24 in some embodiments of the present invention. Figure 4 The outer surface 243 of the side plate 24 has a groove 241 that cooperates with the external fixture. The external fixture (not shown) can use the groove 241 to clamp the side plate 24 and apply a pre-tightening force to the battery stack 2 from both ends of the stacking direction of the battery stack 2, so that the battery stack 2 is squeezed to a size that can be easily entered into the box 1. Applying the pre-tightening force can enhance the cycle performance of the battery. In addition, the groove 241 can also facilitate the withdrawal of the fixture after the battery stack 2 is put into the box.

[0074] In order to ensure that the preload force is more evenly distributed to each position of the soft-pack battery cell 23 and avoid the occurrence of local stress concentration, the portion where the inner surface 242 of the side plate 24 contacts the main surface of the soft-pack battery cell 23 is formed as a flat surface 245. In other words, the area of ​​the inner surface 242 of the side plate 24 formed as the flat surface 245 is greater than the area of ​​the plane portion of the main surface of the soft-pack battery cell 23.

[0075] The outer edge of the inner surface 242 of the side plate 24 protrudes to form an outer edge limiting portion 244 for limiting the relative position relationship between the side plate 24 and the soft-pack battery cell 23 when the flat surface 245 in the center of the inner surface 242 abuts against the main surface of the soft-pack battery cell 23.

[0076] The structure of the outer surface 243 of the side plate 24 is as follows: Figure 5 Reference Figure 5 The second reinforcing rib 247 is provided at the groove 241 provided on the outer surface 243 of the side plate 24, and the first reinforcing rib 246 is provided at the position where the groove 241 is not provided. The number of the 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, so as to improve the strength of the part that cooperates with the fixture. The rib height of the second reinforcing rib 247 is lower than that of the first reinforcing rib 246, so as to form the groove 241.

[0077] Optionally, the wall thickness of the side panel 24 is 1.5-5 mm, and the overall width is 5-25 mm. The material of the side panel 24 can be plastic materials such as PA6, PA66, PPE, PBT, etc.

[0078] Figure 6 It is a schematic structural diagram of the outer surface 243 of the side panel 24 provided in some other embodiments of the present invention. Figure 7 Schematic diagram of the matching structure between the side plate 24 and the long side beam 141 of the box body 1 in the assembled state. Figure 6 and Figure 7 The inner wall of the long side beam 141 of the box body 1 is provided with a positioning column 248, and the outer surface 243 of the side panel 24 is provided with a positioning groove 249. The shapes and sizes of the positioning column 248 and the positioning groove 249 match each other. The positioning column 248 can be inserted into the positioning groove 249 in a matching manner to limit the relative movement between the side panel 24 and the long side beam 141 along the length direction of the soft-pack battery cell 23, so as to conveniently and accurately complete the positioning and installation of the battery cell stack 2 during assembly.

[0079] It should be noted that the groove 241 is only a form of cooperation with the external tooling fixture in this embodiment. In other embodiments of the present invention, depending on the type of the tooling fixture, the outer surface 243 of the side panel may also be provided with any other suitable form of fixture cooperation portion, as long as the fixture cooperation portion can be used in conjunction with the tooling fixture so that the tooling fixture can stably clamp the battery cell stack 2.

[0080] The side plates 24 of the above structure can apply uniform pre-tightening force to the battery stack 2 in the initial state, effectively improving the grouping capability of the soft-pack battery cells 23 and facilitating the grouping of the soft-pack battery cells 23 and the boxing of the battery stack 2.

[0081] <Thermal conductive structural adhesive 25-limiting portion 26>

[0082] During the assembly process, it is necessary to apply a thermally conductive structural adhesive 25 between the bottom of the battery cell stack 2 and the bottom plate 13 of the lower shell. The thermally conductive structural adhesive 25 is generally spread evenly by external extrusion to fill the gap. However, due to uneven extrusion force and other reasons, the thermally conductive structural adhesive 25 in some areas is usually too thin or too thick, which affects the heat dissipation efficiency and may affect the insulation performance.

[0083] Figure 8 FIG. 2 is an exploded view of a soft-pack CTP battery pack 300 with a limited position portion 26 in some embodiments. Figure 8In view of the above problems, in some embodiments of the present invention, a limiter 26 of a specified height is also provided in the form of being attached to the bottom plate 13 of the lower shell. When the box body 1 is placed horizontally, the top height of the limiter 26 is equal to or slightly lower than the height reached when a reasonable amount of the thermally conductive structural adhesive 25 is leveled. In this way, the staff or the automated glue coating system can judge whether the amount of glue coating is appropriate based on the relative height relationship between the liquid level height and the top of the limiter 26 when the thermally conductive structural adhesive 25 is leveled. That is, when the liquid level of the added thermally conductive structural adhesive 25 is basically flush with the top of the limiter 26, or the liquid level is slightly higher than the top of the limiter 26, the amount of the added thermally conductive structural adhesive 25 is appropriate, otherwise the amount of the added thermally conductive structural adhesive 25 needs to be adjusted. By using the limiter 26, the thickness of the thermally conductive structural adhesive 25 between the battery cell stack 2 and the box body 1 can be more accurately controlled within a certain specified thickness value within the range of 0.5mm to 5mm.

[0084] In some embodiments of the present invention, the limiting portion 26 is in the shape of a strip, i.e., a limiting strip. The limiting portion 26 is preferably made of an insulating material, such as an elastomer such as foam or silicone rubber, or a plastic such as PP or PPF. In other embodiments, the limiting portion 26 may also be made of a metal material with a high strength such as aluminum alloy or stainless steel, and insulation is achieved by pasting an insulating film or spraying an insulating material on the surface of the metal limiting portion 26.

[0085] In some embodiments, the limiting portion 26 may be formed by splicing a plurality of limiting strips, or may be formed by integrally molding a plurality of limiting strips. In other embodiments, the limiting portion 26 may also be integrally molded with the bottom plate 13 of the lower housing.

[0086] On the one hand, the limiting portion 26 can assist in controlling the amount of thermally conductive structural adhesive 25 added, improve the uniformity of the thermally conductive structural adhesive 25 at the bottom of the battery cell stack 2, enhance the heat dissipation capacity of the battery cell stack 2, and improve the safety under high current use conditions; on the other hand, the limiting portion 26 can also separate the battery cell stack 2 and the lower shell bottom plate 13 to ensure that the bottom of the battery cell stack 2 will not directly contact the lower shell bottom plate 13 and affect the insulation.

[0087] refer to Figure 8 In some embodiments, the limiter 26 can be an independent component. After the limiter 26 is fixed to the bottom plate 13 of the lower shell, the area between the limiters 26 is filled with a thermal conductive structural adhesive 25 of the same height as the limiter 26 (or slightly higher than the limiter 26), and then the battery stack 2 is placed in the box 1, and the thermal conductive structural adhesive 25 is squeezed through the battery stack 2, so that all soft-pack batteries 23 are evenly in contact with the limiter 26 and the thermal conductive structural adhesive 25. In this embodiment, the limiter 26 is formed by a combination of multiple foams or silicone rubbers, the surface of the bottom plate 13 of the lower shell is flat, and the limiter 26 is pasted on the surface of the bottom plate 13 of the lower shell.

[0088] Fig. 9 2 is a top view of the box body 1 with the limit portion 26 installed. Fig. 9 ,exist Figure 8 In the implementation, the limiting portion 26 is a separately manufactured frame structure, including a rectangular limiting portion 26 constituting an outer frame, a limiting portion 26 connecting the rectangular diagonal, and a limiting portion 26 parallel to the short side beam 142 .

[0089] The heights of the various limiting portions 26 are equal and are substantially equal to the rated glue coating height. Fig.10 2 is a schematic diagram of the relative position relationship between the bottom of the soft-pack battery cell 23 and the limiting portion 26 when the assembly is completed. Fig. 9 and Fig.10 Because the limiting portion 26 extends in the width direction of the box body 1, and the extension range covers the extension range of the battery cell stack 2 in the width direction of the box body 1, the limiting portion 26 set in this way can effectively ensure that each soft-pack battery cell 23 of the battery cell stack 2 can be pressed against the limiting portion 26.

[0090] Fig.11 Schematic diagram (explosion diagram) of the structure of the soft-pack CTP battery pack 400 in other embodiments of the present invention. Fig.11 The limiting portion 26 can be integrally formed with the bottom plate 13 of the lower shell body. Specifically, the limiting portion 26 can be made on the surface of the bottom plate 13 of the lower shell body by punching ribs, or a glue groove can be punched on the surface of the bottom plate 13 of the lower shell body by punching holes. The side wall of the glue groove is higher than the bottom of the glue groove, that is, the side wall of the glue groove is equivalent to the limiting portion 26.

[0091] Fig.12 yes Fig.10 Schematic diagram of the position of the limiting portion 26 at the bottom of the box body 1 in the embodiment. Fig.13 yes Fig.10 Schematic diagram (cross-sectional view) of the relative position relationship between the soft-pack battery 23, the bottom plate 13 of the lower shell, and the limiting portion 26 in the embodiment. Fig.12 and 13 The limiting portion 26 is a limiting portion 26 extending along the width direction of the box body 1. The limiting portion 26 is integrally formed with the box body 1 and is made of the same metal material. In order to insulate the limiting portion 26, an insulating coating may be sprayed on the surface of the limiting portion 26 or covered with an insulating film 261. By manufacturing the limiting portion 26 in an integrally formed manner, the steps of separately positioning and installing the limiting portion 26 can be omitted, the process flow can be shortened, and production efficiency can be improved.

[0092] <Foaming glue>

[0093] In order to improve 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 glue 29 is also filled between the short side beam 142 and the battery cell stack 2.

[0094] Fig.14 Schematic diagram of the filling position of the foam glue 29 of the soft-pack CTP battery pack 500 in some embodiments of the present invention. Fig.14 The foam glue 29 is filled at both ends of the soft-pack battery cell 23 in the length direction, specifically between the short side beam 142 and the battery cell stack 2 , and between the box body middle beam 15 and the battery cell stack 2 .

[0095] The soft-packed battery cells 23 are stacked in an upright position in the thickness direction, and the length direction of the soft-packed battery cells 23 is the length direction of the box body 1. The two ends of the soft-packed battery cells 23 in the length direction have tabs 231 extending therefrom, and the positive tab 231 and the negative tab 231 are respectively located at the two ends of the length direction of the soft-packed battery cells 23. The positive tabs 231 and the negative tabs 231 of the adjacent battery cells are rolled and bent and directly overlapped and welded to fix. In addition, in some embodiments, the battery stack 2 may also include a flexible circuit board 28 (see Figure 3 ), the body of the flexible circuit board 28 is arranged in parallel with the pole ear 231, and the sampling piece (not shown) of the flexible circuit board 28 is welded to the pole ear 231.

[0096] Fig.15 is a schematic diagram of the filling structure of the foam glue 29 between the soft-pack battery cell 23 and the short side beam 142 ( Fig.14 A cross-sectional view of a part along the XY plane). Fig.16 Schematic diagram of the filling height of the foam glue 29 between the soft-pack battery cell 23 and the short side beam 142 ( Fig.14 A cross-sectional view of a part along the XZ plane). Fig.15 and Fig.16 Adjacent pole ears 231 are directly overlap-welded. After the pole ears 231 are welded, foam glue 29 is poured between the soft-pack battery cell 23 and the short side beam 142 and the middle beam 15 of the box body. After foaming and curing, the gap between the battery cell stack 2 and the short side beam 142, and the gap between the battery cell stack 2 and the middle beam 15 of the box body will be filled with the foam glue 29.

[0097] After curing and molding, the height of the foam glue 29 is higher than the height of the pole ear 231. In this way, the foam glue 29 can completely wrap the pole ear 231 inside the foam glue 29, and the pole ears 231 are electrically isolated by the foam glue 29, thereby effectively preventing overlapping short circuits between the pole ears 231, and can improve the thermal runaway protection performance, safety and stability.

[0098] In addition to completely immersing the tab 231, the height H1 of the foam glue is preferably less than or equal to the height H3 of the soft-pack battery cell, that is, preferably, the tab height H2 ≤ the foam glue height H1 ≤ the soft-pack battery cell height H3. Since the foam glue 29 can completely immerse the tab 231, when thermal runaway occurs, the high-temperature gas generated inside the soft-pack battery cell 23 will no longer be released from the tab 231, but will be released from the top of the tab 231 of the soft-pack battery cell 23 above the foam glue 29, thereby effectively preventing the spread of thermal runaway.

[0099] In some embodiments of the utility model, the distance between the pole ear lap surface 232 connected to each other between the pole ears 231 and the short side beam 142 or the middle beam 15 of the box body is 3 to 10 mm, and the inner surfaces of the short side beam 142 and the middle beam 15 of the box body are provided with an insulating sheet 17, and the thickness of the insulating sheet 17 is 0.1 to 0.5 mm. The insulating sheet 17 can further ensure the electrical insulation between the pole ear 231 and the box body 1.

[0100] The density of the foam glue 29 after curing is 0.1~0.3g / cm 3 , elastic modulus 10~30MPa, adhesive performance, shear strength and tensile strength range from 1~3MPa, elongation at break ≥8%, compression modulus ≥30MPa, storage modulus ≥20MPa. In addition, the material of foam glue 29 also has insulation properties, volume resistivity ≥1×10 15 Ω·cm, and the flame retardant grade meets UL94 V0.

[0101] Through the above method, the foam glue 29 can, on the one hand, fix the battery cell stack 2 and increase the rigidity and strength of the soft-pack CTP battery pack 500; on the other hand, it can isolate the pole ear 231, including isolating the pole ear 231 from the high-temperature gas generated during thermal runaway, and achieving electrical insulation between the pole ears 231 and between the pole ears 231 and the box body 1.

[0102] <Glue blocking section>

[0103] In order to prevent the foam glue 29 from invading between the battery cell stack 2 and the thermally conductive structural glue 25, affecting the heat dissipation capacity of the battery cell stack 2 or reducing the mechanical properties of the battery pack, in some embodiments of the utility model, a glue blocking portion 27 is also provided at a position where the foam glue 29 and the thermally conductive structural glue 25 may come into contact.

[0104] Fig.17 2 is a schematic structural diagram (explosion diagram) of a soft-pack CTP battery pack 600 provided with a glue blocking portion 27 in some embodiments. Fig.18 It is a schematic diagram of the structure after the rubber blocking portion 27 is compressed.

[0105] refer to Fig.17 and Fig.18The extending direction of the rubber blocking portion 27 is perpendicular to the length direction of the soft-pack battery core 23 , and both ends of the length direction of the rubber blocking portion 27 extend to abut against the inner side of the long side beam 141 .

[0106] Two rubber blocking parts 27 are respectively provided inside the first chamber 161 and the second chamber 162. The area for applying the thermal conductive structural adhesive 25 is located between the two rubber blocking parts 27, and the foaming adhesive 29 is filled between the rubber blocking part 27 and the short side beam 142, and between the rubber blocking part 27 and the middle beam 15 of the box body.

[0107] The length of the adhesive stopper 27 is greater than or equal to the length of the battery cell stack 2 along the stacking direction, and less than the width of the box 1. The width of the adhesive stopper 27 is 1-30 mm. The top of the adhesive stopper 27 is higher than the top of the thermal conductive structural adhesive 25 to limit the adhesive coating area of ​​the thermal conductive structural adhesive 25 and prevent the thermal conductive structural adhesive 25 from overflowing.

[0108] The rubber blocking portion 27 is preferably made of an insulating material with a certain elasticity, such as foam, silicone rubber and other elastic materials, so as to effectively fill the gap, isolate the foaming glue 29 and the thermal conductive structural glue 25, and prevent the two glues from contacting each other.

[0109] The bottom of the adhesive stopper 27 is a plane, which fits with the bottom plate 13 of the lower shell, and can be adhered to the bottom plate 13 of the lower shell by the adhesive provided at the bottom. The top can be formed into a flat surface with elasticity. Since there is a certain gap between the soft-packed cells 23, when the soft-packed cells 23 squeeze the top plane of the elastic adhesive stopper 27, a plurality of teeth 271 arranged at equal intervals along the length direction can be formed on the top of the adhesive stopper 27. The tooth spacing between adjacent teeth 271 is equal to the thickness of one or a group of soft-packed cells 23, and the adhesive stopper 27 can be bonded and fixed to the cell stack 2 by each tooth 271 extending into the space between the adjacent soft-packed cells 23. As mentioned above, the maximum height of each tooth 271 is higher than the top of the thermal conductive structural adhesive 25 to limit the adhesive coating area of ​​the thermal conductive structural adhesive 25 and prevent the thermal conductive structural adhesive 25 from overflowing.

[0110] Fig.19 yes Fig.17 A schematic diagram of the structures of the components in the housing 1 in the embodiment (top view). Fig. 20 yes Fig.19 A partial enlarged cross-sectional view of area A in the middle.

[0111] refer to Fig.17 , Fig.19 and Fig. 20 After the battery cell stack 2 is installed in place, the soft-pack battery cell 23 and the rubber blocking portion 27 are fully pressed together, and there is basically no gap between the bottom of the soft-pack battery cell 23 and the rubber blocking portion 27, thereby effectively isolating the foam glue 29 and the thermal conductive structural glue 25 to avoid contact between the two.

[0112] Through the above method, the glue blocking part 27 can form a close contact with the bottom of the battery cell stack 2, fill the gap between the soft-pack battery cells 23, so that the foam glue 29 and the thermally conductive structural glue 25 are effectively isolated, preventing the foam glue 29 from invading between the thermally conductive structural glue 25 and the battery cell stack 2, thereby ensuring the heat dissipation performance of the battery cell stack 2 and the mechanical properties of the soft-pack CTP battery pack 600.

[0113] In other embodiments of the utility model, the glue blocking method of the glue blocking portion 27 includes but is not limited to filling the gap between adjacent soft-pack battery cells 23, filling the gap between the box body 1 and the battery cell stack 2, and wrapping the side of the soft-pack battery cell 23, etc., as long as it can help isolate the thermal conductive structural glue 25 and the foam glue 29.

[0114] <Assembly Process>

[0115] The above introduces the assembly process of the soft-pack CTP battery pack provided in some embodiments of the present invention.

[0116] First, provide the lower shell 11 of the box body 1. If the lower shell 11 is integrated with the limiting part 26 or the rubber stop part 27, the thermal conductive structural adhesive 25 is directly applied between the limiting parts 26 of the lower shell 11; if the lower shell 11 is not integrated with the limiting part 26, an additional limiting part 26 or the rubber stop part 27 is provided, and the thermal conductive structural adhesive 25 is applied in the area between the additional limiting parts 26 or the rubber stop part 27.

[0117] After applying a reasonable amount of thermal conductive structural adhesive 25, the external fixture is connected to the groove 241 of the side plate 24, and the two battery stacks 2 are placed in the box. Before being placed in the box, the battery stack 2 is compressed to a certain size under the clamping action of the fixture, so that the overall width of the battery stack 2 including the side plate 24 is less than or equal to the width of the internal chamber 16 of the box body 1. After the battery stack 2 is placed in the box, the fixture can be withdrawn through the groove 241 of the side plate 24, and the battery stack 2 slowly rebounds until the first reinforcing rib 246 of the side plate 24 contacts the long side beam 141 and stops rebounding.

[0118] After the installation of some electrical connectors is completed, the foam glue 29 is poured between the short side beam 142 and the battery stack 2, and between the middle beam 15 of the box body and the battery stack 2. After the foam glue 29 is cured and formed, and other electrical connectors and the battery management system (if any) are installed, the structural glue is applied on the battery stack 2, and the upper cover 12 is closed to complete the assembly of the soft pack CTP battery pack.

[0119] The above multiple embodiments provided by the utility model can be combined with each other. In some embodiments, the soft-pack CTP battery pack can also be directly integrated into the chassis of the electric vehicle, which is not limited in the embodiments of the utility model.

[0120] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A battery pack, characterized in that: include: A box body, wherein the box body has an installation space; A battery cell stack, the battery cell stack comprising a plurality of soft-pack battery cells, the battery cell stack being arranged in the installation space; at least two colloid structures, the colloid structures being arranged in the installation space and directly connected between the battery cell stack and the box; The glue blocking part is arranged between the two colloid structures to isolate the two colloid structures.

2. The battery pack according to claim 1, characterized in that: The box body includes a lower shell, the lower shell includes a lower shell bottom plate and a beam structure, the battery cell stack is arranged on the lower shell bottom plate, and the colloid structure is filled between the battery cell stack and the lower shell bottom plate and between the battery cell stack and the beam structure.

3. The battery pack according to claim 2, characterized in that: One colloid structure is constructed as a first glue layer and is filled and bonded between the bottom of the battery cell stack and the bottom plate of the lower shell, and the other colloid structure is constructed as a second glue layer and is filled and bonded between the ear side of the battery cell stack and the beam structure.

4. The battery pack according to claim 3, characterized in that: The first adhesive layer is a thermally conductive structural adhesive, and the second adhesive layer is a foam adhesive.

5. The battery pack according to claim 4, characterized in that: The glue blocking portion extends along the stacking direction of the battery cell stack, and in the length direction of the soft-pack battery cell, the glue blocking portion is arranged at two ends of the soft-pack battery cell.

6. The battery pack according to claim 5, characterized in that: The beam structure includes a first beam structure parallel to the rubber blocking portion and a second beam structure perpendicular to the rubber blocking portion, and the rubber blocking portion extends to abut against the second beam structure.

7. The battery pack according to claim 6, characterized in that: The foam glue is filled between the glue blocking portion and the first beam structure.

8. The battery pack according to claim 7, characterized in that: The rubber blocking part is made of elastic material.

9. The battery pack according to claim 8, characterized in that: The rubber blocking portion comprises: A bottom portion that fits the bottom plate of the lower housing; and The top portion is pressed and adhered to the soft-pack battery core and matches the shape of the soft-pack battery core.

10. The battery pack according to claim 9, characterized in that: The top portion includes a plurality of teeth arranged at intervals along the length direction of the rubber blocking portion, and each of the teeth accommodates a corresponding soft-pack battery cell.

11. The battery pack according to claim 10, characterized in that: The maximum height of the teeth is higher than the top of the thermal conductive structural adhesive.

12. The battery pack according to claim 9, characterized in that: The bottom of the adhesive blocking portion is bonded to the bottom plate of the lower shell body by adhesive.

13. The battery pack according to claim 4, characterized in that: It also includes a limiting portion, which is arranged on the bottom plate of the lower shell body in the form of protruding to a specified height from the bottom plate of the lower shell body on which the thermal conductive structural adhesive is arranged.

14. The battery pack according to claim 13, wherein: The specified height of the limiting portion is lower than the thickness of the thermally conductive structural adhesive or is the same as the thickness of the thermally conductive structural adhesive.

15. The battery pack according to claim 14, characterized in that: The limiting portion is arranged at an end position corresponding to the length direction of the soft-pack battery core.

16. The battery pack according to claim 14 or 15, characterized in that: The limiting part is a frame structure.

17. The battery pack according to claim 14 or 15, characterized in that: The limiting portion is integrally formed with the bottom plate of the lower shell.

18. The battery pack according to claim 17, wherein: The surface of the limiting portion is coated with an insulating coating, or the surface of the limiting portion is covered with an insulating film.

19. An electric vehicle, characterized in that: A battery pack according to any one of claims 1 to 18.

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