Battery module filling and sealing device and filling and sealing method thereof and battery module

Abstract

The invention provides a battery module filling and sealing device which can simultaneously carry out multi-station pouring, ensures that a filling and sealing material is completely poured before foaming is started, greatly improves the filling efficiency, can be suitable for various different battery module designs, and is low in part replacement cost, easy to clean and high in practicability. The encapsulating material is consistent in height, good in uniformity and free of defects such as bubbles and foam holes. The invention also provides a battery module encapsulation method and a battery module obtained by the battery module encapsulation method, and the battery module encapsulation method is particularly suitable for an electric automobile as a power source of the electric automobile.

Description

Technical Field

[0001] The invention relates to a battery module potting device, a potting method thereof and a battery module obtained thereby. Background Art

[0002] Polyurethane materials are widely used in automotive interior, building insulation, central air conditioning, incubator, chemical tanks, etc. due to their excellent energy absorption, high strength and high adhesion, excellent thermal insulation, excellent environmental compatibility, excellent durability, high flame retardancy, moisture resistance, high temperature resistance and other properties. In particular, its thermal insulation, flame retardancy and high bonding strength to the substrate have attracted widespread attention and research interest from battery cell bonding manufacturers and electric vehicle manufacturers.

[0003] Electric vehicle batteries have gone through a process of research and development from battery module design, cell and car box integration (CTP) to cell and car body integration (CTC). In this process of development and development, the performance development of polyurethane systems combined with efficient processing methods of polyurethane resin systems are becoming increasingly important in the research and development of cell and car box integration CTP and cell and car body integration CTC.

[0004] The development of electric vehicles and these technologies has resulted in an increasing number of cells in a single battery module and a more compact arrangement. It also requires that the rigidity and strength of the entire battery pack be consistent with the vehicle body integration (CTC), thus posing higher challenges to the cell potting process.

[0005] The traditional cell potting method uses a single or multiple pouring guns to fill the gaps between cells one by one, resulting in low potting efficiency. Often, the potting material in front has already started to bubble before the back pouring point has been poured, resulting in uneven foam, hollowing, creases, etc. There are also single or multiple spray guns for mobile pouring, which is also very likely to cause uneven foam, hollowing, etc.

[0006] WO 2022 / 188050 discloses a method for encapsulating a battery, comprising injecting a reaction mixture into a void around the battery, causing the reaction mixture to react, expand and solidify. However, the method does not involve a method for improving the encapsulation efficiency while ensuring that the encapsulation material is highly consistent and that there are no cavities or bubbles in the foam.

[0007] WO 2019 / 161292 discloses a method for encapsulating battery cells, comprising applying an encapsulating composition as a liquid so that the encapsulating composition flows through gaps between adjacent battery cells and between the battery cells and the walls of the battery housing, the liquid encapsulating composition having sufficient fluidity to stabilize at a substantially uniform height before curing to form an encapsulating compound, the encapsulating composition hardens into a solid after application and forms an encapsulating compound, and the encapsulating composition includes at least 15% by weight of a liquid flame retardant. This method relies on the fluidity of the encapsulating composition to achieve uniform distribution of the encapsulating compound, but is not applicable to other encapsulating composition formulations.

[0008] Existing battery potting methods are mainly used for battery modules fully covered with potting materials, but they cannot meet the requirements of electric vehicle manufacturers that the upper surface of the battery cell does not contact the potting material, and it is difficult to achieve a flat, defect-free, and uniform foam density surface after the potting material is cured.

[0009] Therefore, it is urgent to develop a battery core encapsulation method suitable for industrial large-scale production. Summary of the invention

[0010] In one aspect, the present invention provides a battery module potting device, comprising a potting material mixing and output device (110) connected to at least one split flow casting device (100);

[0011] The potting material mixing and output device (110) has an outlet having an outlet inner cross-sectional area S 出 ,

[0012] The split-flow pouring device comprises at least one main pipe (115) and at least two branch pipes (120), each branch pipe (120) having an outlet having an outlet inner cross-sectional area S 支 , the outlet cross-sectional area of ​​each branch pipe is S 支 Can be the same or different,

[0013] The main pipe (115) is connected to each branch pipe (120), and the flow-dividing pouring device is connected to the outlet of the potting material mixing output device (110) through the main pipe (115).

[0014] The sum of the inner cross-sectional areas of the outlets of all branch pipes (120) ∑S 支 Should meet:

[0015] S 出 *15%≤∑S 支 ≤S 出 ,

[0016] The potting material mixing output device (110) is configured as an output device with an output flow rate greater than or equal to 100 g / s.

[0017] Preferably, the battery module potting device further comprises a cover plate made of a material comprising at least one foamed board, which is used to cover and contact the upper surface of the battery cell, preferably to cover and contact the upper surface of all the battery cells. The cover plate preferably has at least one through hole, which is used to allow the outlet of the potting material and / or the branch pipe to pass through the through hole. The foamed board (or foam board) is preferably selected from silicone foam board, polyethylene foam board, polystyrene foam board, polyurethane foam board or a combination thereof.

[0018] On the other hand, the present invention also provides a battery module potting method, which comprises:

[0019] (i) providing a casing and placing the battery cell in the casing with gaps and spaces therein;

[0020] (ii) using the battery module potting device of the present invention, pouring the potting material into a portion of the gaps between the battery cells and / or a portion of the space between the battery cells and the housing of the battery module,

[0021] (iii) the poured potting material flows to all remaining voids and spaces, and

[0022] (iv) the potting material is foamed and solidified,

[0023] Preferably, the total number of the gaps and the spaces cast by the potting material is equal to the number of the outlets of the branch pipes of the battery module potting device.

[0024] In a preferred embodiment of the present invention, a battery module potting method is provided, comprising:

[0025] (1) placing the battery cell in the housing of the battery module and leaving gaps and spaces therein;

[0026] (2) Covering the upper surface of the battery cell with at least one cover plate, wherein the cover plate has at least one through hole, and the through hole is arranged to be located above the gap or space; and the lower surface of the cover plate is the surface in contact with the battery cell;

[0027] (3) using the battery module potting device to pour the potting material into a portion of the gaps between the battery cells and / or a portion of the space between the battery cells and the housing through the through hole;

[0028] (4) The potting material flows to all the remaining gaps and spaces;

[0029] (5) The potting material foams and solidifies.

[0030] Preferably, the total number of the gaps and the spaces cast by the potting material is equal to the total number of the through holes on the cover plate; and / or the total number of the gaps and the spaces cast by the potting material is equal to the number of the outlets of the branch pipe of the battery module potting device; and / or

[0031] Preferably, before the curing is completed, the cover plate does not move in its vertical direction.

[0032] On the other hand, the present invention further provides a battery module, which includes a shell and a plurality of battery cells arranged in the shell, and there is a solidified potting material obtained by potting using the battery module potting method of the present invention between the battery cells and between the battery cells and the shell.

[0033] On the other hand, the present invention also provides an electric vehicle, which comprises at least one battery module as described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of a preferred battery module potting device of the present invention.

[0035] Figure 2 It is a cross-sectional view of a branch pouring device 200 of the present invention, wherein the branch pipe is semi-n-shaped.

[0036] Figure 3 It is a cross-sectional view of a three-way pipe type flow dividing pouring device of the present invention.

[0037] Figure 4 is a schematic diagram of a four-way pipe type diversion pouring device of the present invention, Figure 4 b is Figure 4 Top view of a.

[0038] Figure 5 is a schematic diagram of a five-way pipe type flow-dividing pouring device of the present invention, Figure 5 b is Figure 5 Top view of a.

[0039] Figure 6 It is a schematic diagram of a five-way pipe type flow-dividing pouring device of the present invention.

[0040] Figure 7 It is a schematic diagram of a nine-way pipe type diversion pouring device of the present invention.

[0041] Figure 8 8a and 8b are schematic diagrams of a seven-way pipe type diversion pouring device of the present invention.

[0042] Fig. 9 It is a schematic diagram of a battery module of the present invention.

[0043] Fig.10 It is a partial schematic diagram of a battery cell and a pouring port in a battery module of the present invention.

[0044] Fig.11 It is a partial schematic diagram of a battery cell and a pouring port in a battery module of the present invention.

[0045] Fig.12 This is a photo of the battery module obtained after potting in Example 9.

[0046] Fig.13 This is a photo of the battery module obtained after potting in Comparative Example 1.

[0047] Fig.14 This is a photo of the battery module obtained after potting in Comparative Example 2. DETAILED DESCRIPTION

[0048] General Definitions and Terminology

[0049] Unless otherwise indicated, all publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety.

[0050] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In the event of a conflict, the definitions provided herein shall prevail.

[0051] Unless otherwise stated, all percentages, parts, ratios, etc. are by weight. It will be appreciated by those skilled in the art that the sum of all components in the composition can be suitably 100%. When providing quantity, concentration or other values ​​or parameters as scope, preferred range or preferred upper limit and lower limit or specific value, it should be understood as specifically disclosing all ranges formed by paired values ​​from any upper limit range or preferred value and any lower limit range or preferred value, and no matter whether scope is disclosed individually. Unless otherwise stated, when numerical range is quoted herein, described scope refers to and includes its endpoints and integers and fractions in all such scopes.

[0052] The terms "about" and "approximately" when used with a numerical variable generally refer to the value of that variable and all values ​​of that variable are within experimental error (e.g., within a 95% confidence interval for the mean) or within ±10% of the specified value, or a wider range.

[0053] The term "optional" or "optionally" as used herein means that the event or situation described subsequently may or may not occur, and the description includes the occurrence of the event or situation and the non-occurrence of the event or situation, and also includes the situation where the content described subsequently is arbitrarily selected. For example, when the content of a certain ingredient in this article is 0%-5%, it means that the component can be optionally present, that is, it covers the situation of absence (0%) and presence (>0-5%).

[0054] The terms "include", "comprising", "having", "containing" or "involving" and other variations thereof herein are inclusive or open-ended and do not exclude other unlisted elements or method steps. It will be understood by those skilled in the art that the above terms such as "comprising" encompass the meaning of "consisting of". The expression "consisting of" excludes any element, step or ingredient not specified. The expression "consisting essentially of" means that the scope is limited to the specified elements, steps or ingredients, plus the optional presence of elements, steps or ingredients that do not substantially affect the basic and new features of the claimed subject matter. It should be understood that the expression "comprising" encompasses the expressions "consisting essentially of" and "consisting of". The term "selected from..." refers to one or more elements in the groups listed later, independently selected, and may include combinations of two or more elements therein.

[0055] As used herein, the terms "one or more" or "at least one" refer to one, two, three, four, five, six, seven, eight, nine or more.

[0056] The term "and / or" as used herein encompasses "and" and "or". A plurality of elements, components or steps defined with "and / or" represent any one of the elements, components or steps and any combination thereof. For example, A and / or B encompasses A, B and A+B; A, B and / or C encompasses A, B, C, A+B, A+C, B+C and A+B+C.

[0057] Unless otherwise specified, the terms "combination thereof", "any combination thereof" and "mixture thereof" mean a multi-component mixture of the elements, such as a mixture of two, three, four and up to the maximum possible multi-component mixture.

[0058] In addition, if the number of parts or components of the present invention is not indicated before, it means that there is no limit to the number of occurrences (or existence) of the parts or components. Therefore, it should be interpreted as including one or at least one, and the singular form of the parts or components also includes the plural form, unless the numerical value obviously represents the singular.

[0059] In this article, "multiple" or "several" means two or more, and there is no special requirement for which specific ones, unless otherwise clearly specified. Unless the context clearly indicates, "one" can include singular references as well as plural references.

[0060] Herein, a "cell" is a single electrochemical cell containing a positive electrode and a negative electrode, and may also be referred to as a battery cell. A "battery module" includes a plurality of cells, which are packaged together in the same housing. The cells and battery modules described in the present invention are mainly used in electric vehicles. The number of cells in a battery module may be 10-1000, preferably 100-900.

[0061] Herein, "cross section" refers to a cross section perpendicular to the length direction of the main pipe or branch pipe. Since the main pipe and branch pipe described in the present invention are hollow pipes, they have an inner cross section and an outer cross section. Herein, unless otherwise specified, the cross section refers to the inner cross section. Accordingly, unless otherwise specified, the cross-sectional area refers to the inner cross-sectional area.

[0062] Herein, "dimensions" include length, width, height, area and volume. The dimensions of a cross section include width, length, diameter, side length and area, etc. When the cross section is circular or quasi-circular, the dimensions include diameter, maximum diameter and area; when the cross section is square, the dimensions include length, width and area; when the cross section is triangular, the dimensions include side length and area; when the cross section is polygonal or irregular, the dimensions include maximum width and area.

[0063] In the present invention, the main pipe or branch pipe may be in the form of a pipe fitting or a pipeline, or in the form of a channel, as long as the potting material can flow and transport therein. For example, a channel may be formed by removing a portion of the structure from a solid body. Although it is not in the shape of a pipeline in appearance, it may have the function of a pipeline.

[0064] In the present invention, the flow rate refers to the weight of the potting material passing through the inner cross-section of the outlet of the potting material mixing and output device within one second, expressed in units of g / s.

[0065] The present invention provides a battery module potting device, which comprises:

[0066] a potting material mixing and output device (110) and at least one diversion pouring device (100),

[0067] The potting material mixing and output device (110) has an outlet having an outlet inner cross-sectional area S 出 ;

[0068] The split-flow pouring device comprises at least one main pipe (115) and at least two branch pipes (120), each branch pipe (120) having an outlet having an outlet inner cross-sectional area S 支 , the internal cross-sectional area S of each branch pipe 支 Can be the same or different,

[0069] The main pipe (115) is connected to each branch pipe (120), and the flow-dividing pouring device is connected to the outlet of the potting material mixing output device (110) through the main pipe (115).

[0070] The sum of the inner cross-sectional areas of the outlets of all branch pipes (120) ∑S 支 Should meet:

[0071] S 出 *15%≤∑S 支 ≤S 出 ,

[0072] The potting material mixing output device (110) is configured as an output device with an output flow rate greater than or equal to 100 g / s.

[0073] In the present invention, the sum of the inner cross-sectional areas of the outlets of all branch pipes ∑S 支 Should meet: S 出 *15%≤∑S 支 ≤S 出 , preferably S 出 *15%≤∑S 支 ≤S 出 *90%. By controlling the inner cross-sectional area of ​​the outlets of all branch pipes, the pore size in the solidified potting material can be made uniform, without the problem of local discoloration and blackening, so that the strength of the foam remains consistent.

[0074] In a preferred embodiment of the present invention, the battery module potting device further comprises a cover plate, the cover plate is made of a material comprising at least one foamed board, and is used to cover and contact the upper surface of the battery cell (usually the positive electrode surface of the battery cell), preferably covering and contacting the upper surface of all the battery cells. The cover plate can be removed after curing is completed. The cover plate can help guide the flow of the potting material, protect the battery cell, and obtain a solidified potting material with a smooth surface and no defects. In the present invention, the foamed board (or foam board) is preferably selected from silicone foam board, polyethylene foam board, polystyrene foam board, polyurethane foam board or a combination thereof.

[0075] The polyurethane foam board is preferably provided with a film layer on the surface in contact with the battery core, and the film is preferably selected from one or more of polyhexafluoropropylene, polytetrafluoroethylene, polytrifluoroethylene, polychlorotrifluoroethylene, polyvinylidene fluoride, polyvinyl fluoride, polyethylene and polypropylene, or their copolymers, and more preferably one or more of polyhexafluoropropylene, polytetrafluoroethylene, polytrifluoroethylene, polychlorotrifluoroethylene, polyvinylidene fluoride and polyvinyl fluoride, or their copolymers.

[0076] In the present invention, the cover plate has a thickness greater than or equal to 3 mm, preferably 3 mm-10 cm, and more preferably 1 cm-5 cm. By selecting the thickness of the cover plate and the material, a solidified potting material with a smooth surface, no defects, and uniform density can be obtained.

[0077] In the present invention, the cover plate may also be a combination of a foam plate and a rigid material, wherein the portion in contact with the upper surface of the battery cell is the foam plate. The rigid material may be selected from one or more of metals, alloys and plastics.

[0078] In a more preferred embodiment of the present invention, the cover plate has at least one through hole for allowing the potting material and / or the outlet of the branch pipe to pass through the through hole. The number of the through holes is preferably equal to the number of the outlets of the branch pipe.

[0079] In the present invention, the number of the branch pipes is not particularly limited and can be changed and adjusted according to the design structure of the battery module. The number of the branch pipes can be 2-100, preferably 2-50, and more preferably 2-30. In the present invention, the number of the branch pipes is preferably equal to or matches the number of pouring ports, and more preferably the number of pouring ports is equal to the number of branch pipes, or is a multiple of the number of branch pipes, preferably 2-4 times.

[0080] In the present invention, the number of the through holes is preferably 2-100, more preferably 2-50, and most preferably 2-30.

[0081] In the present invention, there is no special requirement for the size of the outer cross-section of the outlet of the branch pipe, and it is preferably configured so that the outlet of the branch pipe can pour the potting material into the gap formed between the battery cells.

[0082] In the present invention, the size of the outlet outer cross section of the branch pipe is preferably set so that the outlet of the branch pipe can be inserted into the gap formed between the battery cells to pour the potting material, for example, the maximum width of the outlet outer cross section of the branch pipe is less than the spacing between the battery cells. When the outer cross section of the branch pipe is circular, the maximum width is its diameter. In this case, the upper surface of the battery cell is prevented from being contaminated by the potting material to the greatest extent, while the potting efficiency can be guaranteed, thereby avoiding the situation where the potting material has begun to foam or solidify before it is completely poured.

[0083] Of course, the size of the outer cross-section of the outlet of the branch pipe in the present invention can also be set to be larger than the spacing between the battery cells. In this case, the outlet of the branch pipe does not need to be inserted into the gap formed between the battery cells, but is cast from above the battery cells. For battery modules that require the upper surface of the battery cell to be partially covered by the potting material, this size of the outer cross-section of the outlet of the branch pipe can be used.

[0084] In the present invention, at least a portion of at least one of the branch pipes is preferably a bendable flexible tube, and more preferably, the portion (outlet portion) of at least one of the branch pipes including the outlet is a bendable flexible tube. The bendable flexible tube described in the present invention is a pipe that can be deformed under the action of external force at room temperature. There is no special selection of the material of the bendable flexible tube, as long as it is not obviously detrimental to the polyurethane potting material. The optional materials include metal, rubber and plastic, preferably plastic, such as polyester, polycarbonate, polyurethane, polyamide, polyolefin, polychloroolefin, etc. The bendable flexible tube is preferably a transparent or partially transparent flexible tube, which is convenient for observing the flow or blockage state of the potting material in the tube. The use of a bendable flexible tube can adapt to the design requirements of different battery modules, is easy to replace, and can reduce the risk of damage to the battery cell caused by the collision between the branch pipe and the battery cell.

[0085] In the present invention, it is preferred that at least a portion of all branch pipes is a bendable flexible pipe, and it is more preferred that a portion of all branch pipes including the outlet (outlet portion) is a bendable flexible pipe.

[0086] In the present invention, at least a portion of the branch pipe is a rigid pipe. The material of the rigid pipe is not particularly limited, including but not limited to metal and plastic, preferably a thermosetting or thermoplastic plastic. Thermosetting plastics may include epoxy resins and / or polyurethane resins, and thermoplastic plastics may include polyesters, polycarbonates, polyurethanes, polyamides, polyolefins, polychloroolefins, liquid crystal polymers, acrylonitrile-butadiene-styrene plastics (ABS), polyetheretherketone, polysulfone, polyethersulfone and / or polyphenylene sulfide, etc.

[0087] In a preferred embodiment of the present invention, the branch pipe includes a rigid pipe and a bendable flexible pipe, and the rigid pipe is connected to the main pipe.

[0088] In a preferred embodiment of the present invention, the branch pipe includes a rigid pipe and a bendable flexible pipe, and the bendable flexible pipe is connected to the main pipe.

[0089] In a preferred embodiment of the present invention, the rigid pipe member of the branch pipe has the same cross-sectional shape as that of the bendable flexible pipe.

[0090] In the present invention, the inner cross-sectional areas of the outlets of the branch pipes may be the same or different, and the outer cross-sectional areas of the outlets of the branch pipes may be the same or different.

[0091] In the present invention, the cross-sectional shape of the branch pipe is not particularly limited, including but not limited to circular, elliptical, quasi-circular, triangular, pentagonal and hexagonal shapes, etc., preferably circular, quasi-circular and triangular.

[0092] In the present invention, the cross-sectional shape of the bendable flexible pipe or the rigid pipe of the branch pipe is not particularly limited, including but not limited to circular, elliptical, quasi-circular, triangular, pentagonal, hexagonal, etc., preferably circular, quasi-circular and triangular.

[0093] In a preferred embodiment of the present invention, the size of the branch pipe, such as its inner diameter, may vary along its length, or may have the same size. The size change, such as the change in inner diameter, may be a continuous gradual change, or may be a step-wise change. Preferably, the inlet and outlet of the branch pipe have the same size, such as the inner diameter, or the inlet size of the branch pipe is greater than or equal to the outlet size, such as the inner diameter of the inlet is greater than or equal to the inner diameter of the outlet.

[0094] In the present invention, the length difference between the branches is preferably less than or equal to 30%, preferably less than or equal to 20%, based on the length of the shortest branch among all the branches. The length difference refers to the difference between the branch length of any branch and the shortest branch among all the branches. The branch length includes the path length from the branch inlet to the branch outlet.

[0095] In the present invention, the main pipe is mainly used to connect the branch pipe and the outlet of the potting material mixing output device. The length of the main pipe is not particularly limited, as long as it can achieve the connection function. It can be a pipe with a certain length, or a fastener, such as a nut, as the main pipe. In some cases, if the outlet of the potting material mixture output device can be connected to each branch pipe in an integrally formed manner, the outlet of the potting material mixing output device also realizes the function of the main pipe, which is also included in the scope of the present invention. Other structures with the same function as the main pipe should also be included in the scope of the present invention.

[0096] In a preferred embodiment of the present invention, the main pipe is a pipe. The inner diameter of the main pipe may vary along its length, or may have the same inner diameter. The inner diameter change may be a continuous gradual change, or a step-wise change. Preferably, the inlet and outlet of the main pipe have the same inner diameter, or the inlet inner diameter of the main pipe is greater than or equal to the outlet inner diameter.

[0097] In the present invention, the main pipe can be a rigid pipe or a flexible pipe, or a combination of the two, preferably a rigid pipe. The material of the rigid pipe is not particularly limited, including but not limited to metal and plastic, preferably a thermosetting or thermoplastic plastic. Thermosetting plastics may include epoxy resins and / or polyurethane resins, and thermoplastic plastics may include polyesters, polycarbonates, polyurethanes, polyamides, polyolefins, polychloroolefins, liquid crystal polymers, acrylonitrile-butadiene-styrene plastics (ABS), polyetheretherketone, polysulfone, polyethersulfone and / or polyphenylene sulfide, etc.

[0098] In a preferred embodiment of the present invention, the size of the main pipe may vary in its length direction, or may have the same size. The size change may be a continuous gradual change, or a step-wise change. Preferably, the inlet size of the main pipe is larger than the outlet size.

[0099] In a preferred embodiment of the present invention, the combination of the rigid pipes of the main pipe and the branch pipe can be replaced by a multi-way pipe, including but not limited to a three-way pipe, a four-way pipe, a five-way pipe or more pipes or a combination thereof, in which the main pipe is the inlet pipe and the branch pipe is the outlet pipe.

[0100] In the present invention, if the outlet of the potting material mixing output device is a straight tube structure, in order to conveniently connect with the output pipe, the main pipe of the split flow pouring device can also be a straight tube structure.

[0101] In a preferred embodiment of the present invention, the number of the branch pipes is an even number greater than 2, such as 2, 4, 6, 8, 10, 12, 14, etc., preferably 4, 6, 8 or 10. In this case, the branch pipes are preferably distributed around the main pipe in an axisymmetric manner, with the center line of the main pipe as the axis.

[0102] In a preferred embodiment of the present invention, the number of the branch pipes is an odd number greater than 3, such as 3, 5, 7, 9, 11, 13, 15, etc., preferably 3, 5 or 7. In this case, the branch pipes are preferably evenly distributed radially with the center line of the main pipe as the axis.

[0103] In the present invention, the shape of the branch pipe, especially the shape of the rigid pipe in the branch pipe can be selected according to needs, including but not limited to a straight pipe structure, a bent pipe structure, and a semi-n-shaped structure. The bent pipe structure can be a right-angle bent pipe structure.

[0104] In the present invention, at least one air inlet pipe is further provided on the main pipe and / or at least one of the branch pipes, for introducing high-pressure gas into the diversion pouring device to clear the potting material or foam formed by the potting material remaining in the diversion pouring device. Preferably, at least one valve may be further provided on the air inlet pipe to control the high-pressure gas. The pressure of the high-pressure gas in the air inlet pipe may be 2-20 bar, preferably 8-15 bar, and the flow rate of the gas may be 5-50 Nm 3 / h, preferably 30-50Nm 3 / h.

[0105] In the present invention, the connection between the main pipe and the potting material mixing output device can be a fixed connection or a detachable connection, preferably a detachable connection. In this way, the shunt pouring device can be easily replaced to prevent the situation that, for example, the potting material blocks the pipe mouth and causes the pouring to fail. The shunt pouring device that is more suitable for the pouring requirements can also be replaced according to different battery module designs. The detachable connection method is various conventional methods in the field, such as threaded connection, flange connection, socket connection, clamp connection or self-locking connection, etc., preferably a self-locking connection.

[0106] In the present invention, the connection mode between the main pipe and the branch pipe or the connection mode between the rigid pipe fittings of the main pipe and the branch pipe can be a fixed connection or a detachable connection, preferably a detachable connection. The detachable connection mode is various conventional modes in the art, such as threaded connection, flange connection, socket connection, clamp connection or self-locking connection, etc., preferably a self-locking connection.

[0107] In the present invention, the connection method between the rigid pipe fitting of the branch pipe and the bendable flexible pipe is preferably a detachable connection. The detachable connection method is various conventional methods in the art, such as threaded connection, flange connection, socket connection, clamp connection or self-locking connection, etc., preferably a self-locking connection.

[0108] The threaded connection described in the present invention refers to a detachable connection in which the connected parts are connected into one piece by a threaded part (or a threaded part of the connected parts). Commonly used threaded connecting parts include bolts, studs, screws and set screws.

[0109] The socket connection described in the present invention refers to a connection method in which the withdrawal port at one end of the pipe fitting is inserted into the socket of the part to be connected, and the annular gap is sealed with a filling material (such as hemp or asbestos rope).

[0110] The clamp connection described in the present invention refers to a connection method in which a sealing ring is sandwiched between the clamp joints at both ends, and then a tube bundle is put on and locked and fixed.

[0111] In the present invention, the self-locking connection refers to a connection method that can achieve the locking of two connecting parts without using additional fasteners, adhesives or components, and its examples include but are not limited to two-pronged quick self-locking joints, three-pronged quick self-locking joints, single-linked expansion-type self-locking quick joints, double-linked expansion-type self-locking quick joints, metal push-pull self-locking connections, etc. Since the self-locking connection method is quick and easy to install and remove, the self-locking connection is preferably used for the detachable connection.

[0112] In the present invention, the main pipe and the outlet of the potting material mixing and outputting device, the main pipe and the branch pipe, or the outlet of the potting material mixing and outputting device, the main pipe and the branch pipe can also be integrally formed, thereby eliminating the need for fixed connection or detachable connection.

[0113] In a preferred embodiment of the present invention, the battery module potting device includes a potting material mixing output device and at least one shunt pouring device, the shunt pouring device includes a main pipe and two or more branch pipes, the branch pipe includes a rigid pipe and a bendable flexible pipe connected to the rigid pipe, the main pipe is connected to the bendable flexible pipe through the rigid pipe, and the size of the outlet outer cross-section of the branch pipe is set so that the outlet of the branch pipe can be inserted into the gap formed between the battery cells for pouring.

[0114] In the present invention, the inner diameters of various parts of the main pipe may be the same or different, and preferably the inner diameters are the same or gradually narrow from the inlet to the outlet.

[0115] In the present invention, the inner diameters of various parts of the branch pipe may be the same or different, and preferably the inner diameters are the same or gradually narrow from the inlet to the outlet.

[0116] In the present invention, the battery module potting device may further include at least one raw material tank for storing and premixing potting materials, and the raw material tanks are respectively connected to the potting material mixing and outputting devices.

[0117] In the present invention, a pump is respectively arranged between the raw material tank and the potting material mixing and outputting device. The battery module potting device may also not include a pump. In this case, the raw material tank can be arranged above the potting outputting device, and the potting material can flow into the potting material mixing and outputting device by gravity.

[0118] In a preferred embodiment of the present invention, the battery module potting device includes an A raw material tank and a B raw material tank, which can be used to store the isocyanate component A and the isocyanate reactive component B, respectively. Preferably, a pump is provided between the A raw material tank and the potting material mixing and outputting device, and a pump is provided between the B raw material tank and the potting material mixing and outputting device.

[0119] In a preferred embodiment of the present invention, the battery module potting device may further include a C raw material tank for storing and mixing potting material components other than the isocyanate component A and the isocyanate reactive component B.

[0120] In a preferred embodiment of the present invention, the battery module potting device comprises a raw material tank, in which the components of the potting material are premixed and then enter the potting material mixing and output device for full mixing.

[0121] In the present invention, the potting material mixing and output device can use the mixing equipment used in the polyurethane processing industry. These equipment include but are not limited to single-component equipment, two-component equipment or multi-component equipment, preferably using high-pressure two-component casting equipment, including but not limited to Hennecke HK135, HK270, HK450, HK540, HK650 high-pressure casting machines or Kanglong A-Compact 10, A-Compact 20, A-Compact 40, A-Compact60, A-Compact 100, A-LAB 10H high-pressure casting machines.

[0122] In the present invention, when the potting material mixing and outputting device is a pouring machine, the outlet of the potting material mixing and outputting device is generally the pouring gun head of the pouring machine, and the S 出 That is, the inner cross-sectional area of ​​the pouring gun head of the pouring machine.

[0123] The potting material of the present invention can be selected from various commonly used foam potting materials in the art, preferably a polyurethane potting material.

[0124] The polyurethane potting material of the present invention comprises an isocyanate component A, an isocyanate reactive component B and a foaming agent.

[0125] From the perspective of chemical structure, polyurethane is a polymer containing repeating urethane units. In the sense of the present invention, it includes addition products (sometimes, although not completely correct, also referred to as condensation products) of polyfunctional isocyanates and polyols. In addition to the above-mentioned polyurethane basic structure, polyurethane products usually also contain other structures, such as structures with urea bonds. Polyurethanes that simultaneously contain these structures that are different from the pure polyurethane basic structure and the polyurethane basic structure are also included in the scope of the polyurethane of the present invention and do not deviate from the scope of the present invention.

[0126] In the present invention, the term "isocyanate component" includes one or more of all isocyanates known to the person skilled in the art in polyurethane chemistry, such as, in particular, toluene diisocyanate (TDI; prepared from toluenediamine TDA), diisocyanates and polyisocyanates of the diphenylmethane series (MDI; prepared from diamines and polyamines MDA of the diphenylmethane series), pentane-1,5-diisocyanate (PDI; prepared from 1,5-pentanediamine PDA), hexamethylene diisocyanate (HDI; prepared from 1,6-pentanediamine PDA), 1,5-pentane-1,5-diisocyanate (PDI; prepared from 1,5-pentanediamine PDA), 1,5-pentane-2,5-diisocyanate (HDI; prepared from 1,6-pentanediamine PDA), 1,5-pentane-2,5-diisocyanate (PDI; prepared from 1,6-pentanediamine PDA), 1,5-pentane-1,5-diisocyanate (PDI; prepared from 1,6-pentanediamine PDA), 1,5-pentane-2,5-diisocyanate (HDI; prepared from 1,6-pentanediamine PDA), 1,5-pentane-2,5-diisocyanate (P ... -hexamethylenediamine HAD), 1,5-naphthalene diisocyanate (NDI; prepared from 1,5-naphthalene diamine NDA), isophorone diisocyanate (IPDI; prepared from isophorone diamine IPDA), p-phenylene diisocyanate (XDI; prepared from p-phenylene diamine XDA), methylcyclohexyl diisocyanate (HTDI), 4,4'-dicyclohexylmethane diisocyanate, p-phenylene diisocyanate (PPDI) or tetramethyl dimethylene diisocyanate (TMXDI).

[0127] The term "isocyanate" of course also includes embodiments in which two or more different isocyanates (e.g. a mixture of MDI and TDI) are used in the production of polyurethanes. This is also the case within the class of isocyanates (thus also for example different MDI types). All isocyanates used to produce polyurethanes are collectively referred to as isocyanate components of the polyurethanes. The isocyanate component contains at least one isocyanate. The isocyanates may contain different isomers, for example the isomers 2,4-TDI and 2,6-TDI of TDI, the isomers 2,4'-MDI and 4,4'-MDI of MDI.

[0128] In the present invention, the term "isocyanate reactive component" includes at least one polyol, or is composed of one or more polyols. All polyols used to prepare polyurethane are all referred to as the polyol component of polyurethane. The polyol component comprises at least one polyol. The term "polyol" includes all polyols known to those skilled in the art in polyurethane chemistry, such as polyether polyols, polyester polyols, polyether ester polyols and polyether carbonate polyols. The statement "polyol" certainly also includes an embodiment in which two or more different polyols are used in the production of polyurethane. This is also the case in the polyol category. Therefore, if, for example, "polyether polyol" (or "polyester polyol" etc.) is mentioned below, the term certainly also includes an embodiment in which two or more different polyether polyols (or two or more different polyester polyols etc.) are used in the production of polyurethane.

[0129] The polyether polyol can be prepared by a known process, for example, by reacting an olefin oxide with an initiator in the presence of a catalyst. The catalyst includes, but is not limited to, an alkaline hydroxide, an alkaline alcohol salt, antimony pentachloride, boron fluoride etherate, or a combination thereof. The olefin oxide includes, but is not limited to, tetrahydrofuran, ethylene oxide, propylene oxide, 1,2-butylene oxide, 2,3-butylene oxide, styrene oxide, or a combination thereof, with ethylene oxide and / or propylene oxide being particularly preferred. The initiator can be adjusted according to the properties of the polyether polyol such as functionality and viscosity, preferably but not limited to polyhydroxy compounds or polyamine compounds. Polyhydroxy compounds include, but are not limited to, sorbitol, water, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, diethylene glycol, trimethylolpropane, glycerol, bisphenol A, bisphenol S, or a combination thereof. Polyamine compounds include, but are not limited to, ethylenediamine, propylenediamine, butylenediamine, hexamethylenediamine, diethylenetriamine, toluenediamine, or a combination thereof. The molecular weight of the polyether polyol can be the conventional range of polyether polyols used in polyurethane potting materials in the art, preferably 200-20000, more preferably 200-10000, and the molecular weight is determined by GPC high performance liquid chromatography, and the test method can refer to GB / T 21863-2008. The functionality of the polyether polyol is preferably 2-6. The hydroxyl value of the polyether polyol is preferably 16-1200 mgKOH / g; the hydroxyl value refers to the number of milligrams of potassium hydroxide equivalent to the hydroxyl group in 1g of the sample, and the test method can refer to ISO 14900-2017.

[0130] Polyester polyol can be aliphatic or aromatic polyester polyol, preferably aliphatic polyester polyol.Polyester polyol can be made by dicarboxylic acid or dicarboxylic anhydride and polyol reaction.Dicarboxylic acid includes but is not limited to aliphatic carboxylic acid containing 2-12 carbon atoms, and the aliphatic carboxylic acid containing 2-12 carbon atoms includes but is not limited to succinic acid, malonic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, dodecyl carboxylic acid, maleic acid, fumaric acid, phthalic acid, isophthalic acid, terephthalic acid or its combination.Dicarboxylic anhydride includes but is not limited to phthalic anhydride, tetrachlorophthalic anhydride, maleic anhydride or its combination. The polyols reacted with dicarboxylic acids or dicarboxylic anhydrides include, but are not limited to, ethylene glycol, diethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, dipropylene glycol, 1,3-methylpropanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 1,10-decanediol, glycerol, trimethylolpropane, or a combination thereof. Polyester polyols may also include polyester polyols prepared from lactones. The polyester polyols prepared from lactones are preferably, but not limited to, ε-caprolactone. The molecular weight of the polyester polyols may be the conventional range of polyester polyols used in polyurethane potting materials in the art, preferably 200-6000, more preferably 200-5000, and the molecular weight is determined by GPC high performance liquid chromatography, and the test method may refer to GB / T21863-2008. The functionality of the polyether polyols is preferably 2-4. The hydroxyl value of the polyether polyol is preferably 18-800 mgKOH / g; the hydroxyl value refers to the number of milligrams of potassium hydroxide equivalent to the hydroxyl groups in 1 g of the sample, and the test method can refer to ISO 14900-2017.

[0131] The polyurethane potting material includes one or more foaming agents, including but not limited to water, fluorocarbons, hydrochlorocarbons, chlorofluorocarbons, hydrofluorocarbons and hydrocarbons, preferably water.

[0132] In the present invention, the volume ratio of the isocyanate component A to the isocyanate reactive component B in the potting material is preferably 1:10 to 10:1, more preferably 5:1 to 1:5, for example 3:1, 2:1, 1:1, 1:2, 1:3.

[0133] In the present invention, the isocyanate component A or the isocyanate reactive component B may also include various additives conventional in the art, including but not limited to catalysts, foam stabilizers, light stabilizers, crosslinking agents, antioxidants, pore openers, colorants, fillers, flame retardants, smoke suppressants, antistatic agents, diluents, coupling agents, surface wetting agents, leveling agents, thixotropic agents, plasticizers, foam leveling agents, free radical reaction inhibitors or combinations thereof.

[0134] In a preferred embodiment of the present invention, the isocyanate component A and / or the isocyanate reactive component B may include a flame retardant. When the application of the battery module does not need to meet the flame retardant requirements, the flame retardant may not be included. The flame retardant may be any conventional flame retardant in the art, including but not limited to additive flame retardants and reactive flame retardants. Halogenated phosphate flame retardant is a commonly used flame retardant in polyurethane foam. Most halogenated phosphates are liquid at room temperature and have good compatibility with polyols, including tris(2-chloropropyl) phosphate (TCPP), tris(2-chloroethyl) phosphate (TCEP), tris(dichloropropyl) phosphate (TDCPP), tris(dibromopropyl) phosphate, tetra(2-chloroethyl) ethylene diphosphate, bis[di(2-chloroethyl)] diethylene glycol phosphate, 2,2-dimethyl-3-chloropropyl bis(1,3-dichloro-2-propyl) phosphate, 2,2-dimethyl-3-bromo-propyl-β-bromoethyl phosphate, dimer or polyphosphate, etc. The flame retardant can also use phosphonate flame retardants, including dimethyl methylphosphonate (DMMP), diethyl ethylphosphonate, dimethyl propylphosphonate, triisopropylphenyl phosphate, triethyl phosphate, etc. Inorganic solid flame retardants can also be used in the present invention, such as melamine and its derivatives, red phosphorus and its complexes, aluminum hydroxide powder, etc. The content of the flame retardant in the system generally needs to reach a certain amount to achieve a flame retardant effect. The amount of the flame retardant is preferably 5-50% by weight relative to the potting material, preferably 15-40% by weight.

[0135] The polyurethane potting material of the present invention can be foamed to form a flexible polyurethane foam or a rigid polyurethane foam. The density of the foam can be 100-600 kg / m 3 , preferably 150-500kg / m 3 .

[0136] The present invention also provides a battery module potting method, which comprises:

[0137] (i) providing a casing and placing the battery cell in the casing with gaps and spaces therein;

[0138] (ii) using the battery module potting device of the present invention, pouring the potting material into a portion of the gaps between the battery cells and / or a portion of the space between the battery cells and the housing of the battery module, and the poured potting material flows to all the remaining gaps and spaces,

[0139] (iii) the potting material is foamed and solidified,

[0140] Preferably, the total number of the gaps and the spaces cast by the potting material is equal to the number of the outlets of the branch pipes of the battery module potting device.

[0141] In a preferred embodiment of the present invention, the battery module potting method includes using the battery module potting device of the present invention, inserting each branch pipe into a portion of the gaps between the battery cells and / or a portion of the space between the battery cells and the outer shell of the battery module and pouring the potting material, the poured potting material flows to all the remaining gaps and spaces, foams and solidifies, wherein the total number of the gaps and spaces poured with the potting material is equal to the number of the outlets of the branch pipes of the battery module potting device.

[0142] In the present invention, according to the actual size of the battery module, the pouring step can be repeated to allow the potting material to flow to all gaps and spaces. At this time, the total number of the gaps and spaces poured with the potting material does not need to be equal to the number of the outlets of the branch pipes, and can be a multiple of the outlets of the branch pipes.

[0143] In the present invention, the position where the branch pipe pours the potting material is called a pouring point. When the outlet of the branch pipe is inserted into the gap and / or the space, the insertion point is the pouring point; when the branch pipe is poured from above the battery cell, the position where the potting material is injected is the pouring point. The choice of pouring points can be selected according to the design of the battery module, the number and arrangement of battery cells, etc. Generally, the more battery cells there are, the more pouring points there are, so as to ensure that the potting material can flow to each gap and space. The pouring points described in the present invention can be 2-100, preferably 2-50, and more preferably 2-30.

[0144] In a preferred embodiment of the present invention, a battery module potting method is provided, comprising:

[0145] (1) placing the battery cell in the housing of the battery module and leaving gaps and spaces therein;

[0146] (2) Covering the upper surface of the battery cell with at least one cover plate, wherein the cover plate has at least one through hole, and the through hole is arranged to be located above the gap or space; and the lower surface of the cover plate is the surface in contact with the battery cell;

[0147] (3) using the battery module potting device to pour the potting material into a portion of the gaps between the battery cells and / or a portion of the space between the battery cells and the housing through the through hole;

[0148] (4) The potting material flows to all the remaining gaps and spaces;

[0149] (5) The potting material foams and solidifies.

[0150] Preferably, the total number of the gaps and the spaces cast by the potting material is equal to the total number of the through holes on the cover plate; and / or the total number of the gaps and the spaces cast by the potting material is equal to the number of the outlets of the branch pipe of the battery module potting device; and / or

[0151] Preferably, before the curing is completed, the cover plate does not move in the vertical direction z, wherein the vertical direction z refers to a direction perpendicular to the upper surface or the lower surface of the cover plate.

[0152] In the above preferred embodiment, the potting material is output from the mixing output device at a flow rate greater than or equal to 100 g / s, preferably at an output flow rate of 100 g / s-250 g / s, and more preferably at an output flow rate of 100 g / s-200 g / s.

[0153] In a more preferred embodiment of the present invention, the battery module potting method comprises the following steps:

[0154] (1) placing the battery cells in the housing of the battery module, leaving gaps between the battery cells and leaving space between the battery cells and the housing;

[0155] (2) Covering the upper surface of the battery cell with at least one cover plate, wherein the cover plate has through holes equal in number to the outlets of the branch pipes;

[0156] (3) inserting the outlet of the branch pipe through the through hole into the part of the gap and / or the part of the space, and then pouring the potting material; or placing the outlet of the branch pipe above the through hole, and then pouring the potting material, so that the potting material passes through the through hole and flows into the part of the gap and / or the part of the space;

[0157] The potting material is output from the potting material mixing and output device at an output flow rate greater than or equal to 100 g / s, preferably at an output flow rate of 100 g / s-250 g / s, and more preferably at an output flow rate of 100 g / s-200 g / s, and is poured into a portion of the gap and / or a portion of the space through the outlet of the branch pipe;

[0158] (4) the poured potting material flows to all the remaining voids and spaces, foams and solidifies; and

[0159] (5) Preferably, the cover plate is removed;

[0160] In which, during the period from the completion of pouring in step (3) to the completion of curing in step (4), a pressure is always applied to the cover plate so that the cover plate does not move in the vertical direction z during the period.

[0161] In another preferred embodiment of the present invention, the battery module potting method includes covering at least one cover plate on the upper surface of the battery cell after pouring the potting material, and applying pressure to the cover plate so that the cover plate does not produce vertical displacement before the curing is completed.

[0162] In a more preferred embodiment of the present invention, the battery module potting method comprises the following steps:

[0163] (1) placing all the battery cells in the housing of the battery module, leaving gaps between the battery cells and leaving space between the battery cells and the housing;

[0164] (2) inserting the outlet of the branch pipe into a part of the gap and / or a part of the space, and then pouring the potting material; or placing the outlet of the branch pipe above a part of the gap and / or a part of the space, and then pouring the potting material so that the potting material flows into the part of the gap and / or a part of the space, and covering the upper surface of the battery cell with at least one cover plate, and the cover plate may not have the through hole;

[0165] The potting material is output from the potting material mixing and output device at an output flow rate greater than or equal to 100 g / s, preferably at an output flow rate of 100 g / s-250 g / s, and more preferably at an output flow rate of 100 g / s-200 g / s, and is poured into a part of the gap and / or a part of the space through the outlet of the branch pipe;

[0166] (3) the poured potting material flows to all the remaining gaps and spaces, foams and solidifies, and (4) preferably, the cover plate is removed;

[0167] In which, during the period from after the pouring in step (2) is completed to before the curing in step (3) is completed, a pressure is always applied to the cover plate so that the cover plate does not move in its vertical direction (z) during the period.

[0168] In a more preferred embodiment of the present invention, the number of the through holes is 2-100, more preferably 2-50, and most preferably 2-30.

[0169] In a preferred embodiment of the present invention, if the outlet portion of the branch pipe or the portion including the outlet of the branch pipe is a bendable flexible pipe, the bendable flexible pipe is inserted into the pouring nozzle.

[0170] In the present invention, after pouring is completed, high-pressure gas can be introduced into the air inlet pipe on the main pipe and / or the branch pipe. The pressure of the high-pressure gas is preferably 2-20 bar, more preferably 8-15 bar, and the flow rate of the gas is preferably 5-50 Nm 3 / h, preferably 30-50Nm 3 / h. The step of introducing high-pressure gas does not affect the flow, foaming or curing of the potting material, and can be carried out simultaneously or not.

[0171] In a more preferred embodiment of the present invention, a pouring point is set for every 10-50 battery cells, and more preferably, a pouring point is set for every 20-40 battery cells.

[0172] In the aforementioned embodiment, the cover plate has a thickness greater than or equal to 3 mm, preferably 3 mm-10 cm, and more preferably 1 cm-5 cm.

[0173] The cover plate is made of a material comprising at least one foam board. In the present invention, the foam board (or foam board) is preferably selected from silicone foam board, polyethylene foam board, polystyrene foam board, polyurethane foam board or a combination thereof.

[0174] The polyurethane foam board is preferably provided with a film layer on the surface in contact with the battery core, and the film is preferably selected from one or more of polyhexafluoropropylene, polytetrafluoroethylene, polytrifluoroethylene, polychlorotrifluoroethylene, polyvinylidene fluoride, polyvinyl fluoride, polyethylene and polypropylene, or their copolymers, and more preferably one or more of polyhexafluoropropylene, polytetrafluoroethylene, polytrifluoroethylene, polychlorotrifluoroethylene, polyvinylidene fluoride and polyvinyl fluoride, or their copolymers.

[0175] In the present invention, the cover plate may also be a combination of a foam plate and a rigid material, wherein the portion in contact with the upper surface of the battery cell is the foam plate. The rigid material may be selected from one or more of metals, alloys and plastics.

[0176] In another embodiment of the present invention, the battery module potting method includes using the battery module potting device of the present invention to pour the potting material downwardly from each branch pipe at the upper position of the plurality of battery cells, and the poured potting material flows to all gaps and spaces, foams and solidifies. The upper position is the space above any battery cell, indicating the upper and lower position relationship between the branch pipe and the battery cell, and is not required to be directly above the battery cell, and can be the upper left, upper right, or obliquely above. This method can be used for battery modules whose battery cells are completely potted, and can greatly improve the potting efficiency.

[0177] The present invention also provides a battery module, which includes a shell and a plurality of battery cells arranged in the shell, wherein the battery cells and the battery cells and the shell are provided with a solidified potting material obtained by potting using the battery module potting method of the present invention, namely, polyurethane foam. The height of the solidified potting material is preferably less than or equal to the height of the battery cell, so that the upper surface of the battery cell does not have the potting material, thereby reducing the possibility of short circuit of the battery cell.

[0178] In the present invention, the battery module preferably further includes a top cover.

[0179] The number of the battery cells in the battery module is preferably 10-1000, more preferably 100-900. The spacing between adjacent battery cells is preferably 0.5-10 mm, preferably 0.5-5 mm.

[0180] The present invention also provides an electric vehicle, which comprises at least one battery module according to the present invention.

[0181] Beneficial Effects

[0182] The existing potting device cannot perform multi-station potting at the same time. When the size of the pouring gun head is very small, a low-flow pouring machine needs to be used accordingly, which is not suitable for the field of electric vehicles with an increasing number of battery cells. The battery module potting device of the present invention can achieve fast and efficient pouring, ensuring that the potting material is poured before the foaming begins. The present invention adopts a bendable flexible tube as a pouring port, which can be widely used in the design of various battery cells, has low replacement cost, flexible application, and avoids damage to the battery cells when colliding with the battery cells. Controlling the ratio between the cross-sectional area of ​​the branch pipe outlet and the main pipe outlet can ensure that the solidified potting material obtained after pouring, that is, polyurethane foam, is highly consistent, uniform, and free of defects such as bubbles and pores, greatly improving the efficiency of the potting.

[0183] Example

[0184] The present invention will be further described below in conjunction with specific examples. However, it should be understood that these examples are only used to illustrate the present invention and do not constitute a limitation to the scope of the present invention.

[0185] The test methods in the following examples without specifying specific conditions are usually carried out under conventional conditions or under conditions recommended by the manufacturer. Unless otherwise specified or conflicting, percentages and parts used herein are by weight.

[0186] Materials, instruments and test methods

[0187] Material A is Desmodur 44V20 (polymeric MDI) purchased from Covestro;

[0188] Material B is Baysafe BEF (polyol) purchased from Covestro.

[0189] Potting material mixing output equipment:

[0190] Hennecke HK135, pouring flow rate is more than 100g / s, pouring gun head outer diameter 18mm, inner diameter 12mm, inner cross-sectional area 113.04mm 2 ; The pouring gun head is the outlet of the potting material mixing output device.

[0191] HK270 from Hennecke, pouring flow rate is 200g / s, pouring gun tip outer diameter is 40mm, inner diameter is 18mm, inner cross-sectional area is 254.34mm 2 ; The pouring gun head is the outlet of the potting material mixing output device.

[0192] A-LAB 10H from Cannon SpA, pouring flow rate 120g / s, pouring gun tip outer diameter 15mm, inner diameter 10mm, inner cross-sectional area 78.5mm 2 ; The pouring gun head is the outlet of the potting material mixing output device.

[0193] Cream time: the time difference from the start of mixing of the polyol-containing component and the polyisocyanate component (counted as 0 seconds) to the time when the polyurethane composition starts to turn creamy white.

[0194] Gel time: The time from the start of mixing of the polyol-containing component and the polyisocyanate component (counted as 0 seconds) to the time period during which the polyurethane composition is cured (the time until the composition begins to become viscous and can be pulled out into filaments when touched with a stick-like solid).

[0195] Tack-free time: The time that elapses from the mixing of the polyol-containing component and the polyisocyanate component until the foam surface no longer feels tacky.

[0196] Viscosity: measured at 25°C according to DIN 53019-1-3.

[0197] Free foam density: tested according to ISO845 standard.

[0198] Molded Density: Tested according to ASTM C303.

[0199] Compression strength: Tested according to ASTM D1621 standard.

[0200] Tensile strength: tested according to DIN53571 standard.

[0201] Tensile elongation at break: tested according to DIN53571 standard.

[0202] Flame retardant grade: tested according to UL94 standard, sample thickness = 7mm.

[0203] like Figure 1 As shown, the battery module potting device of the present invention includes an A raw material tank 130, a B raw material tank 140, a potting material mixing output device 110, a diversion pouring device and a cover plate 190. The A raw material tank and the B raw material tank are respectively connected to the potting material mixing output device 110 through a pump 150 arranged downstream. The diversion pouring device includes at least one main pipe and two branch pipes, the main pipes are respectively connected to the branch pipes, and the diversion pouring device is connected to the potting material mixing output device 110 through the main pipe. The diversion pouring device 100, 200, 300, 400, 500, 600, 700, 800 can have the following Figure 1-Figure 8 The main pipe and the branch pipe may be provided with an air inlet pipe with an air inlet valve, which is not shown in the figure, so as to introduce high-pressure gas into the main pipe or the branch pipe to clean the main pipe and the branch pipe.

[0204] Example 1

[0205] Use Figure 1 The battery module potting device, the potting material mixing and output device 110 is HK135, wherein the diversion pouring device 100 is as follows Figure 1 The main pipe 115 and two branch pipes are shown, each branch pipe includes a connected rigid pipe 120 and a bendable flexible pipe 160, each rigid pipe is a right-angle bend pipe, and the outlet inner cross-sectional area of ​​the bendable flexible pipe 160 of each branch pipe is 8.5mm 2 ,∑S 支 =17mm 2 The cross-sectional area of ​​the main pipe outlet is 113 mm 2 The main pipe is fixedly connected to the pouring gun head and the branch pipe of the potting material mixing output device, and the bendable flexible pipe 160 is self-lockingly connected to the rigid pipe 120. The total length of the two branch pipes is the same.

[0206] Example 2

[0207] Use Figure 1 The battery module potting device, wherein the potting material mixing and output device 110 is HK135, and the split-flow casting device 100 is replaced by a split-flow casting device 200. Figure 2The main pipe 215 and two branch pipes are shown, each branch pipe includes a rigid pipe 220 and a flexible pipe 260, and an air inlet pipe (not shown) is provided on the main pipe. Each rigid pipe 220 is semi-n-shaped and has the same pipe diameter, and is axially symmetrically distributed with the center line of the main pipe 215 as the axis. The flexible pipe 260 is a polyolefin hose. The inner cross-sectional area of ​​the outlet of the flexible pipe 260 of the branch pipe is 50.5mm 2 ,∑S 支 =101mm 2 , the inner cross-sectional area of ​​the outlet of main pipe 215 is 113mm 2 The inner diameter of the main pipe decreases in a step-like manner from the inlet to the outlet. The main pipe is fixedly connected to the pouring gun head and the branch pipe of the potting material mixing and output device, and the bendable flexible pipe 260 is connected to the rigid pipe 220 by a clamp. The lengths of the two rigid pipes 220 are the same, and the lengths of the two bendable flexible pipes 260 are the same. The main pipe and each branch pipe of the diversion pouring device can have different cross-sectional shapes, pipe shapes and pipe diameters.

[0208] Example 3

[0209] Use Figure 1 The battery module potting device, wherein the potting material mixing and output device 110 is HK270, and the split-flow casting device 100 is replaced by a split-flow casting device 300. The split-flow casting device 300 is as follows Figure 3 The main pipe 315 and two branch pipes are shown, each branch pipe includes a rigid pipe 320 and a bendable flexible pipe 360. Each rigid pipe 320 is a straight pipe with the same pipe diameter, and is symmetrically distributed with the center line of the main pipe 315 as the axis. The bendable flexible pipe 360 ​​is a TPU hose. The outlet inner cross-sectional area of ​​the bendable flexible pipe 360 ​​of the branch pipe is 78.5mm 2 ,∑S 支 =157mm 2 , the inner cross-sectional area of ​​the outlet of main pipe 315 is 254mm 2 . The inner diameter of the main pipe gradually decreases from the inlet to the outlet. The main pipe and the branch pipe are fixedly connected, and the bendable flexible pipe 360 ​​and the rigid pipe fitting 320 are self-lockingly connected. The lengths of the two rigid pipe fittings 320 are the same, and the lengths of the two bendable flexible pipes 360 are the same, and can be adjusted as needed. The main pipe and each branch pipe of the diversion casting device can have different cross-sectional shapes, pipe fitting shapes and pipe diameters, and the angle between the rigid pipe fitting and the center line of the main pipe can be adjusted between 0-90° according to actual needs.

[0210] Example 4

[0211] Use Figure 1The battery module potting device, wherein the potting material mixing and output device 110 is A-LAB 10H, and the diversion pouring device 100 is replaced by a diversion pouring device 400. The diversion pouring device 400 is a four-way pipe, such as Figure 4 As shown. It has a main pipe 415 and three branch pipes, each branch pipe includes a rigid pipe 420 and a bendable flexible pipe 460 connected. Each rigid pipe 420 is a straight pipe with the same pipe diameter, and is radially distributed with the center line of the main pipe 415 as the axis. The bendable flexible pipe 460 is a PE hose. The outlet inner cross-sectional area of ​​the bendable flexible pipe 460 of the branch pipe is 20mm 2 ,∑S 支 =60mm 2 , the outlet inner cross-sectional area of ​​main pipe 415 is 79mm 2 . The main pipe and the branch pipe are fixedly connected, and the bendable flexible pipe 460 and the branch pipe 420 are connected by a clamp. The lengths of the three rigid pipe fittings 420 are consistent, and the lengths of the three bendable flexible pipes 460 are consistent and can be adjusted as needed. The main pipe and each branch pipe of the diversion casting device can have different cross-sectional shapes, pipe fitting shapes and pipe diameters. The angle α formed by the projections of adjacent rigid pipe fittings on the horizontal plane can be adjusted according to actual needs, and the angles α are preferably the same. The angle between the rigid pipe fitting and the main pipe can be adjusted between 0-90° according to actual needs.

[0212] Example 5

[0213] Use Figure 1 The battery module potting device, wherein the potting material mixing and output device 110 is HK270, and the diversion pouring device 100 is replaced by a diversion pouring device 500. The diversion pouring device 500 is a five-way pipe, such as Figure 5 As shown. It has a main pipe 515 and 4 branch pipes, each branch pipe includes a rigid pipe 520 and a bendable flexible pipe 560, the main pipe is provided with an air inlet pipe 570, and the air inlet pipe 570 is provided with a valve (not shown). Each rigid pipe 520 is a straight pipe with the same pipe diameter, and is axially symmetrically distributed with the center line of the main pipe 515 as the axis. The bendable flexible pipe 560 is a polyurethane TPU hose. The outlet inner cross-sectional area of ​​the bendable flexible pipe 560 of the branch pipe is 52.8mm 2 ,∑S 支 =211.2mm 2 , the inner cross-sectional area of ​​the outlet of main pipe 515 is 254mm 2. The main pipe and the branch pipe are connected by a clamp, and the bendable flexible pipe 560 and the rigid pipe fitting 520 are connected by a self-locking connection. The four bendable flexible pipes 560 have the same length, and the four rigid pipe fittings 520 have the same length and can be adjusted as needed. The main pipe and each branch pipe of the diversion casting device can have different cross-sectional shapes, pipe fitting shapes and pipe diameters. The angles α and α' formed by the projection of the rigid pipe fitting on the horizontal plane can be adjusted according to actual needs, and preferably the angles α' and α are the same. The angle between the rigid pipe fitting and the main pipe can be adjusted between 0-90° according to actual needs.

[0214] Example 6

[0215] Use Figure 1 The battery module potting device, wherein the potting material mixing and output device 110 is HK270, and the diversion pouring device 100 is replaced by a diversion pouring device 600. The diversion pouring device 600 is a five-way pipe, such as Figure 6 As shown. It has a main pipe 615 and 4 branch pipes, each branch pipe includes rigid pipe fittings 620 and 620', and each rigid pipe fitting 620 is connected to two rigid pipe fittings 620' respectively. Each rigid pipe fitting 620 is a right-angle bend pipe structure and has the same pipe diameter, and is axially symmetrically distributed with the center line of the main pipe 615 as the axis. Each rigid pipe fitting 620' is axially symmetrically distributed with the center line of the rigid pipe fitting 620 as the axis. Each rigid pipe diameter 620' is a right-angle bend pipe structure and has the same pipe diameter. At a position close to the outlet of the rigid pipe diameter 620', the pipe diameter gradually narrows along the direction of the outlet. The inner cross-sectional area of ​​the outlet of the rigid pipe fitting 620' is 32.2mm 2 ,∑S 支 =128.8mm 2 , the inner cross-sectional area of ​​the outlet of main pipe 615 is 254mm 2 The main pipe and the branch pipe are connected by a clamp. The two rigid pipes 620 have the same length, and the four rigid pipes 620' have the same length and can be adjusted as needed. The main pipe and each branch pipe of the split casting device can have different cross-sectional shapes, pipe shapes and pipe diameters.

[0216] Example 7

[0217] Use Figure 1 The battery module potting device, wherein the potting material mixing and output device 110 is HK270, and the diversion pouring device 100 is replaced by a diversion pouring device 700. The diversion pouring device 700 is a nine-way pipe, such as Figure 7As shown. It has a main pipe 715 and 8 branch pipes, each branch pipe includes a rigid pipe 720, 720' and a bendable flexible pipe 760, and the four branch pipes 720' are integrated together and connected to the rigid pipe 720. The rigid pipe 720 is axially symmetrically distributed with the center line of the main pipe 715 as the axis, or it can be non-symmetrically distributed. The bendable flexible pipe 760 is a polyurethane TPU hose. The outlet inner cross-sectional area of ​​the bendable flexible pipe 760 of the branch pipe is 19.6mm 2 ,∑S 支 =156.8mm 2 , the outlet inner cross-sectional area of ​​main pipe 715 is 254mm 2 The main pipe and the rigid pipe 720 are integrally formed, the rigid pipes 720 and 720' are detachably connected, and the bendable flexible pipe 760 and the rigid pipe 720' are self-lockingly connected. The two rigid pipes 720 are of the same length, the four rigid pipes 720' are of the same length, and the four bendable flexible pipes 760 are of the same length, but can be adjusted as needed. The main pipe and each branch pipe of the diversion casting device can have different cross-sectional shapes, pipe shapes and pipe diameters.

[0218] Example 8

[0219] Use Figure 1 The battery module potting device, wherein the potting material mixing and output device 110 is HK270, and the diversion pouring device 100 is replaced by a diversion pouring device 800. The diversion pouring device 800 is a seven-way pipe, such as Figure 8 It has a main pipe 815 and 6 branch pipes, each branch pipe includes a rigid pipe 820 and a bendable flexible pipe 860 connected thereto. Figure 8 In a, six rigid pipe fittings 820 are integrated together and connected to the main pipe 815; Figure 8 In b, the six rigid pipes 820 are formed by forming six through holes on a solid piece 870, and the solid piece 870 is connected to the main pipe 815. The rigid pipes 820 are axially symmetrically distributed with the center line of the main pipe 815 as the axis, or they may be non-symmetrically distributed. The bendable flexible pipe 860 is a polyester hose. The inner cross-sectional area of ​​the outlet of the bendable flexible pipe 860 of the branch pipe is 13.8 mm 2 ,∑S 支 =82.8mm 2 , the outlet inner cross-sectional area of ​​main pipe 815 is 254mm 2The main pipe is connected to the rigid pipe 820 by a slot, and the bendable flexible pipe 860 is connected to the rigid pipe 820 by a clamp. The six rigid pipes 820 are of the same length, and the six bendable flexible pipes 860 are of different lengths. The length difference between the longest bendable flexible pipe 860 and the shortest bendable flexible pipe 860 is 30% of the sum of the lengths of the shortest bendable flexible pipe and any rigid pipe, but can be adjusted to the same length as needed. The main pipe and each branch pipe of the diversion casting device can have different cross-sectional shapes, pipe shapes and pipe diameters.

[0220] Example 9

[0221] (1) Place 128 battery cells in the housing 170 of the battery module 1, leaving space between the battery cells.

[0222] There is a gap with a spacing of 1.5 mm. Fig. 9 , Fig.10 Shows a partial view of the battery module

[0223] Schematic diagram, the remaining cells are not shown;

[0224] (2) Cover all the cells with an aluminum composite board (silicone foam board) with 6 through holes

[0225] Composite material of aluminum plate, silicone foam plate thickness is 1cm, silicone foam plate

[0226] In contact with the upper surface of the battery cell);

[0227] (3) Using the potting material formula (material A and material B) shown in Table 1 and the battery module potting device described in Example 8, the potting material components in the raw material tank A and the raw material tank B are transferred to the potting material mixing and output device HK270 through the pump 150. The raw materials are mixed in the potting material mixing and output device and transported to the split-flow casting device at a flow rate of 200 g / s. All the flexible hoses 860 in the split-flow casting device are inserted into the six gaps between the battery cells through the through holes on the aluminum composite board. Fig.10 The positions indicated by the middle arrows are two gaps, i.e., pouring ports. The mixed potting material is poured into the pouring ports through a split-flow pouring device, and the pouring height is less than the height of the battery cell. After the pouring is completed, the bendable flexible tube is removed, and a pressure is applied to the aluminum composite plate, so that the aluminum composite plate does not produce a vertical displacement in the z direction;

[0228] (4) The poured potting material flows to all the gaps and spaces, the potting material foams and solidifies, and the aluminum composite plate is removed.

[0229] The photo of the battery module obtained after potting is as follows Fig.12As shown, there are no bubbles or defects between the battery cell and the cured potting material, the surface of the cured potting material is flat and highly uniform, and the battery cell is not stained with potting material. The potted battery module is divided into 4 areas, and the molded density of the foam in each area is tested ρ1, ρ2, ρ3 and ρ4 (each area is tested 3 times and the average value is taken). The average value of the molded density of the 4 areas is calculated as The difference between the maximum density and the minimum density in ρ1, ρ2, ρ3 and ρ4 is lower than the average molding density 10%, indicating that the foam density in each potting area is uniform and the battery cell will not experience foam shrinkage later.

[0230] Table 1

[0231]

[0232]

[0233] Example 10

[0234] (1) 8*8=64 battery cells are placed in the housing of the battery module 1, leaving a gap of 1.5 mm between the battery cells;

[0235] (2) Using the potting material formula (material A and material B) shown in Table 1 and the battery module potting device described in Example 1, the potting material components in the A raw material tank and the B raw material tank are respectively transferred to the potting material mixing output device HK135 through the pump 150, the potting material components are mixed in the potting material mixing output device and transported to the diversion casting device at a speed of 120g / s, and the two flexible hoses 160 in the diversion casting device inject the potting material downward above the gap, and the casting is lower than the height of the battery cell. After the casting is completed, the flexible hose is removed, and a polyurethane foam board with a polyethylene film layer is covered on the battery cell, and a pressure is applied to the polyurethane foam board so that the polyurethane foam board does not produce a displacement in the vertical direction z;

[0236] Among them, the thickness of the polyurethane foam board is 3mm, and the polyethylene film layer is in contact with the battery core;

[0237] (3) Introduce high-pressure gas into the inlet pipe on the main pipe. The pressure is 12 bar and the gas flow rate is 20 Nm 3 / h;

[0238] (4) The poured potting material flows to all the gaps and spaces, the potting material foams and solidifies, and the polyurethane foam board is removed.

[0239] The order of step (3) and step (4) is not critical and they can also be performed simultaneously.

[0240] The battery module obtained after potting has no bubbles or defects between the battery cell and the cured potting material. The surface of the cured potting material is flat and highly uniform, and there is no potting material on the surface of the battery cell. The potted battery module is divided into 4 areas, and the molding density of the foam in each area is tested separately (each area is tested 3 times and the average value is taken). Among the molding densities of the 4 areas, the difference between the maximum density and the minimum density is lower than the average molding density. 10%, indicating that the foam density in each potting area is uniform and the battery cell will not experience foam shrinkage later.

[0241] The battery module potting device in the above-mentioned Example 10 was replaced with the potting device in Example 2-3. The flow rate of the potting material mixing output device in Example 2 was 120 g / s, and that in Example 3 was 200 g / s. A battery module with good potting effect was also obtained. There were no bubbles or defects between the battery cell and the solidified potting material. The solidified potting material was highly uniform and had a smooth surface. The potted battery module was divided into 4 areas on average, and the molding density of the foam in each area was tested separately (each area was tested 3 times and the average value was taken). Among the molding densities of the 4 areas, the difference between the maximum density and the minimum density was lower than the average molding density. 10%, indicating that the foam density in each potting area is uniform and the battery cell will not experience foam shrinkage later.

[0242] Embodiment 11

[0243] (1) Place 256 cells in the housing of the battery module 1, leaving space between the cells.

[0244] The gap from l is 1.5mm, Fig.11 A partial schematic diagram of a battery module is shown, and other battery cells are not shown;

[0245] (2) All cells are covered with an aluminum composite board (polyethylene foam board) with 8 through holes.

[0246] A composite material of aluminum plate, polyethylene foam plate thickness of 2cm, polyethylene foam

[0247] The plate is in contact with the upper surface of the cell);

[0248] (3) Using the potting material formula (material A and material B) shown in Table 1 and the battery module potting device described in Example 7, the potting material components in the raw material tank A and the raw material tank B are transferred to the potting material mixing and output device HK270 through the pump 150. The raw materials are mixed in the potting material mixing and output device and transported to the split-flow casting device at a speed of 200 g / s. All the flexible hoses 760 in the split-flow casting device pass through the through holes on the aluminum composite plate and are inserted into the 8 gaps between the battery cells, i.e., the casting ports. Fig.11The position indicated by the middle arrow is one of the pouring ports. The mixed potting material is poured into the eight gaps through a split-flow pouring device, and the pouring height is less than the height of the battery cell. After the pouring is completed, the bendable flexible tube is removed, and a pressure is applied to the aluminum composite plate so that the aluminum composite plate does not produce a displacement in the vertical direction z;

[0249] (4) The poured potting material flows to all the gaps and spaces, and the potting material foams.

[0250] After curing, remove the aluminum composite panel.

[0251] After potting, the battery module obtained has no bubbles or defects between the battery cell and the potting material. The surface of the cured potting material is flat and highly uniform, and there is no potting material on the battery cell. The potted battery module is divided into 4 areas, and the molding density of the foam in each area is tested separately (each area is tested 3 times and the average value is taken). Among the molding densities of the 4 areas, the difference between the maximum density and the minimum density is lower than the average molding density. 10%, indicating that the foam density in each potting area is uniform and the battery cell will not experience foam shrinkage later.

[0252] Example 12

[0253] (1) 128 battery cells are placed in the housing of the battery module 1, leaving a gap of 1.5 mm between the battery cells;

[0254] (2) All battery cells are covered with an aluminum composite plate (a composite material of a silicone foam plate and an aluminum plate, the silicone foam plate is 1 cm thick, and the silicone foam plate is in contact with the upper surface of the battery cell) having four through holes;

[0255] (3) Using the potting material formula (material A and material B) shown in Table 1 and the battery module potting device described in Example 6, the potting material components in the raw material tank A and the raw material tank B are transferred to the potting material mixing output device HK270 by a pump. The raw materials are mixed in the potting material mixing output device and transported to the split-flow pouring device at a flow rate of 200 g / s. All branch pipes 620' in the split-flow pouring device pass through the through holes on the aluminum composite plate and are inserted into the four gaps between the battery cells, i.e., the pouring ports. The mixed potting material is poured into the pouring port by the split-flow pouring device. The pouring height is less than the battery cell height. After the pouring is completed, the split-flow pouring device is removed, and a pressure is applied on the aluminum composite plate so that the aluminum composite plate

[0256] The plate does not produce vertical displacement;

[0257] (4) The poured potting material flows to all the gaps and spaces, and the potting material foams and solidifies.

[0258] Just remove the aluminum composite panel.

[0259] The battery module with good potting effect was also obtained. There were no bubbles or defects between the battery cell and the potting material. The surface of the solidified potting material was flat and highly uniform, and there was no potting material on the battery cell. The potted battery module was divided into 4 areas, and the molding density of the foam in each area was tested (each area was tested 3 times and the average value was taken). Among the molding densities of the 4 areas, the difference between the maximum density and the minimum density was lower than the average molding density. 10%, indicating that the foam density in each potting area is uniform and the battery cell will not experience foam shrinkage later.

[0260] Embodiment 13

[0261] (1) 128 battery cells are placed in the housing of the battery module 1, with a gap of 1.5 mm between the battery cells;

[0262] (2) Cover all battery cells with a silicone foam board with 4 through holes (the thickness of the silicone foam board is 1 cm);

[0263] (3) Using the potting material formula (material A and material B) shown in Table 1, the battery module potting device described in Example 5, and the potting material mixing and outputting device in Example 4, the potting material components in the A raw material tank and the B raw material tank are transferred to the potting material mixing and outputting device A-LAB 10H (same as in Example 4) and HK270 (same as in Example 5) through pump 150, and the raw materials are mixed in the potting material mixing and outputting device and discharged at 110 g / s (A-LAB 10H) and 200 g / s

[0264] The flow rate of (HK270) is transported to the diversion pouring device, and all the flexible hoses in the diversion pouring device in Example 5 are inserted into the four gaps between the battery cells through the through holes on the organic silicon foam board, i.e., the pouring port. The mixed potting material is poured into the pouring port through the diversion pouring device, and the pouring height is less than the height of the battery cell. After the pouring is completed, the diversion pouring device is removed; and a pressure is applied to the organic silicon foam board so that the organic silicon foam board does not produce vertical displacement;

[0265] (4) The poured potting material flows to all the gaps and spaces, and the potting material foams and solidifies.

[0266] Just remove the silicone foam board.

[0267] The battery module with good potting effect was also obtained. There were no bubbles or defects between the battery cell and the potting material. The potting material was highly uniform and the surface was flat. There was no potting material on the battery cell. The potted battery module was divided into 4 areas, and the molding density of the foam in each area was tested (each area was tested 3 times and the average value was taken). Among the molding densities of the 4 areas, the difference between the maximum density and the minimum density was lower than the average molding density. 10%, indicating that the foam density in each potting area is uniform and the battery cell will not experience foam shrinkage later.

[0268] Comparative Example 1

[0269] Use Figure 1 The battery module potting device, wherein the diversion pouring device 100 is as follows Figure 1 The main pipe 115 and two branch pipes are shown, each branch pipe includes a connected rigid pipe 120 and a bendable flexible pipe 160. The main pipe and the branch pipe are fixedly connected, and the bendable flexible pipe 160 and the rigid branch pipe 120 are self-lockingly connected. The total length of the two branch pipes is the same. The cross-sectional area of ​​the outlet of the main pipe 115 is 160mm 2 The outlet inner cross-sectional area of ​​the bendable flexible tube 160 of the branch pipe is 8 mm 2 The same potting material and potting process as in Example 10 were used. The photo of the battery module obtained after potting is shown in FIG. Fig.13 As shown. Fig.13 Because the total cross-sectional area of ​​the branch pipe outlet of the polyurethane potting material is less than 15% of the cross-sectional area of ​​the pouring gun head of the pouring machine, the foam cells after foaming become significantly coarser, the bubble size is uneven, and the local color becomes darker or even black, which will affect the uneven distribution of the mechanical strength of the potting material and affect the application of the battery module.

[0270] Comparative Example 2

[0271] Use Figure 1 The battery module potting device, wherein the potting material mixing and output device 110 is HK270, and the diversion pouring device 100 is replaced by Figure 8 a split flow pouring device 800. The bendable flexible tube 860 is a polyester hose. The outlet cross-sectional area of ​​the bendable flexible tube 860 is 6 mm 2 , the outlet cross-sectional area of ​​main pipe 815 is 90mm 2 The main pipe and the branch pipe are fixedly connected, and the bendable flexible pipe 860 and the rigid pipe 820 are connected by a clamp. The rigid pipes of the branch pipes are of the same length. Among the six bendable flexible pipes 860, four bendable flexible pipes are of the same length, and the difference in length between the longest bendable flexible pipe and the shortest bendable flexible pipe is 35% of the length of the shortest bendable flexible pipe. The same potting material and potting process as in Example 9 are used. The photo of the battery module obtained after potting is shown in FIG. Fig.14 As shown. Fig.14As shown in the figure, due to the large difference in branch pipe length, the polyurethane potting material cannot be evenly leveled and produce uniform foaming height within the system's operating time, resulting in voids and defects in the foam-filled battery cell area. The potted battery module was divided into 4 areas, and the molding density of the foam in each area was tested separately (each area was tested 3 times and the average value was taken). Among the molding densities of the 4 areas, the difference between the maximum density and the minimum density was lower than the average molding density This indicates that the foam density in each potting area is uneven, and the battery cell will experience foam shrinkage later.

[0272] Although the specific embodiments of the present invention are described above, it should be understood by those skilled in the art that this is only for illustration and the protection scope of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but these changes and modifications all fall within the protection scope of the present invention.

Claims

1. A battery module potting device, comprising a potting material mixing and output device (110), wherein the device further comprises at least one split flow pouring device (100); The potting material mixing and output device (110) has an outlet having an outlet inner cross-sectional area S 出 , The split-flow pouring device comprises at least one main pipe (115) and at least two branch pipes (120), each branch pipe (120) having an outlet having an outlet inner cross-sectional area S 支 , the outlet cross-sectional area of ​​each branch pipe is S 支 Same or different, The main pipe (115) is connected to each branch pipe (120), and the flow-dividing pouring device is connected to the outlet of the potting material mixing output device (110) through the main pipe (115). The sum of the inner cross-sectional areas of the outlets of all branch pipes (120) ∑S 支 Should meet: S 出 *15%≤∑S 支 ≤S 出 , The potting material mixing output device (110) is an output device with an output flow rate greater than or equal to 100 g / s.

2. The battery module potting device according to claim 1, characterized in that: The battery module potting device also includes a cover plate, which is made of a material containing at least one foam plate and is used to cover and contact the upper surface of the battery cell; the cover plate has a thickness greater than or equal to 3mm, preferably 3mm-10cm, and more preferably 1cm-5cm.

3. The battery module potting device according to claim 2, characterized in that: The foam board is selected from silicone foam board, polyethylene foam board, polystyrene foam board, polyurethane foam board or a combination thereof; the polyurethane foam board is preferably provided with a film layer on the surface in contact with the battery core, and the film preferably includes one or more of polyhexafluoropropylene, polytetrafluoroethylene, polytrifluoroethylene, polychlorotrifluoroethylene, polyvinylidene fluoride, polyvinyl fluoride, polyethylene and polypropylene or their copolymers, and more preferably one or more of polyhexafluoropropylene, polytetrafluoroethylene, polytrifluoroethylene, polychlorotrifluoroethylene, polyvinylidene fluoride and polyvinyl fluoride or their copolymers.

4. The battery module potting device as described in claim 2 or 3 is characterized in that the cover plate has at least one through hole for allowing the potting material and / or the outlet of the branch pipe to pass through the through hole; the number of the through holes is preferably equal to the number of the outlets of the branch pipe.

5. The battery module potting device according to any one of claims 1 to 4, characterized in that: The size of the outer cross-section of the outlet of each branch pipe is set to enable the outlet of the branch pipe to pour the potting material into the gap formed between the battery cells, preferably to be able to be inserted into the gap formed between the battery cells to pour the potting material.

6. The battery module potting device according to any one of claims 1 to 5, characterized in that: At least a portion of at least one of the branch pipes is a bendable flexible pipe, preferably, the portion of at least one of the branch pipes including the outlet is a bendable flexible pipe; more preferably, the branch pipe includes a rigid pipe and the bendable flexible pipe, and the rigid pipe is connected to the main pipe.

7. The battery module potting device according to any one of claims 1 to 6, characterized in that: The length difference between all branch pipes is less than or equal to 30%, based on the length of the shortest branch pipe among all branch pipes.

8. The battery module potting device according to any one of claims 1 to 7, characterized in that: The number of the branch pipes is an even number greater than 2, and the branch pipes are preferably distributed around the main pipe in an axisymmetric manner, with the center line of the main pipe as the axis; or the number of the branch pipes is an odd number greater than 3, and the branch pipes are preferably evenly distributed radially with the center line of the main pipe as the axis.

9. The battery module potting device according to any one of claims 1 to 8, characterized in that: The shape of the branch pipe is a straight pipe structure, a curved pipe structure or a semi-n-shaped structure, and the curved pipe structure is preferably a right-angle curved pipe structure.

10. The battery module potting device according to any one of claims 1 to 9, characterized in that: At least one air inlet pipe is arranged on the main pipe and / or at least one of the branch pipes for introducing high-pressure gas into the diversion pouring device; preferably, at least one valve is also arranged on the air inlet pipe.

11. The battery module potting device according to any one of claims 1 to 10, characterized in that: The battery module potting device further comprises at least one raw material tank, which is connected to the potting material mixing and outputting device; preferably, a pump is respectively arranged between each raw material tank and the potting material mixing and outputting device.

12. A battery module potting method, characterized in that: It includes: (i) providing a housing and placing the battery cell in the housing with gaps and spaces therein; (ii) using the battery module potting device as claimed in any one of claims 1 to 11, pouring the potting material into a portion of the gaps between the battery cells and / or a portion of the space between the battery cells and the housing of the battery module, wherein the poured potting material flows to all the remaining gaps and spaces, (iii) the potting material is foamed and solidified, Preferably, the total number of the gaps and the spaces poured with the potting material is equal to the number of the outlets of the branch pipes of the battery module potting device; wherein the position for pouring the potting material is the pouring point.

13. The battery module potting method according to claim 12, characterized in that: It includes: Step (ii) further comprises: covering the upper surface of the battery cell with at least one cover plate as claimed in claim 2 or 3, wherein the cover plate has at least one through hole, and the position of the through hole is arranged to be located above the gap or space; the lower surface of the cover plate is the surface in contact with the battery cell; using the battery module potting device, pouring the potting material into the gap between a part of the battery cells and / or the space between a part of the battery cell and the shell through the through hole; Preferably, the total number of the gaps and spaces cast by the potting material is equal to the total number of the through holes on the cover plate; Preferably, before the curing is completed, the cover plate is kept from being displaced in its vertical direction.

14. The battery module potting method according to claim 13, characterized in that: It includes the following steps: (1) placing all the battery cells in the housing of the battery module, leaving gaps between the battery cells and leaving space between the battery cells and the housing; (2) Covering the upper surface of the battery cell with at least one cover plate, wherein the cover plate has through holes equal in number to the outlets of the branch pipes; (3) inserting the outlet of the branch pipe through the through hole into the part of the gap and / or the part of the space, and pouring the potting material; or placing the outlet of the branch pipe above the through hole, pouring the potting material, so that the potting material passes through the through hole and flows into the part of the gap and / or the part of the space; The potting material is output from the potting material mixing and output device at an output flow rate greater than or equal to 100 g / s, preferably at an output flow rate of 100 g / s-250 g / s, and more preferably at an output flow rate of 100 g / s-200 g / s, and is poured into a portion of the gap and / or a portion of the space through the outlet of the branch pipe; (4) the poured potting material flows to all the remaining voids and spaces, foams and solidifies; and, (5) Preferably, the cover plate is removed; In which, during the period from the completion of pouring in step (3) to the completion of curing in step (4), a pressure is always applied to the cover plate so that the cover plate does not move in the vertical direction during the period.

15. The battery module potting method according to claim 12, characterized in that: It includes covering the upper surface of the battery cell with at least one cover plate as claimed in claim 2 or 3 after pouring the potting material, and applying an external force to the cover plate so that the cover plate does not produce vertical displacement before the curing is completed.

16. The battery module potting method according to claim 15, characterized in that: It includes the following steps: (1) placing all the battery cells in the housing of the battery module, leaving gaps between the battery cells and leaving space between the battery cells and the housing; (2) inserting the outlet of the branch pipe into a portion of the gap and / or a portion of the space, and then pouring the potting material; or placing the outlet of the branch pipe above the portion of the gap and / or the portion of the space, and then pouring the potting material so that the potting material flows into the portion of the gap and / or the portion of the space, and covering at least one cover plate on the upper surface of the battery cell; The potting material is output from the potting material mixing and output device at an output flow rate greater than or equal to 100 g / s, preferably at an output flow rate of 100 g / s-250 g / s, and more preferably at an output flow rate of 100 g / s-200 g / s, and is poured into a portion of the gap and / or a portion of the space through the outlet of the branch pipe; (3) The poured potting material flows to all the remaining gaps and spaces, foams and solidifies; (4) The cover plate is preferably removed; In which, during the period from the completion of pouring in step (2) to the completion of curing in step (3), a pressure is always applied to the cover plate so that the cover plate does not move in its vertical direction during the period.

17. The battery module potting method according to any one of claims 12 to 16, characterized in that: A pouring point is set for every 10-50 battery cells, preferably a pouring point is set for every 20-40 battery cells.

18. The battery module potting method according to any one of claims 12 to 17, characterized in that: After the pouring is completed, high-pressure gas is introduced into the air inlet pipe. The pressure of the high-pressure gas is 2-20 bar, preferably 8-15 bar, and the gas flow rate is 5-50 Nm 3 / h, preferably 30-50Nm 3 / h.

19. A battery module, comprising a shell and a plurality of battery cells arranged in the shell, wherein there is a solidified potting material obtained by potting using the battery module potting method described in any one of claims 12 to 18 between the battery cells and between the battery cells and the shell; the height of the solidified potting material is preferably less than or equal to the height of the battery cells; the number of the battery cells is preferably 10-1000, more preferably 10-900; the spacing between adjacent battery cells is preferably 0.5-10 mm, more preferably 0.5-5 mm.

20. An electric vehicle, characterized in that: It comprises at least one battery module as claimed in claim 19.

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