Battery module, battery and electric device

Abstract

The utility model provides a battery module, a battery and an electric device. The battery module comprises multiple layers of battery packs which are stacked in the first direction and arranged at intervals through structural adhesive layers, each layer of battery pack comprises multiple cylindrical battery monomers which are arranged side by side in the second direction and arranged at intervals through the structural adhesive layers, each battery monomer comprises a tab, and the tabs extend out of the battery monomers in the third direction to be distributed; the first direction, the second direction and the third direction are intersected pairwise; wherein two adjacent battery monomers are bonded through the structural adhesive layer, the structural adhesive layer has preset elastic deformation force, and gap deformation stress between the two adjacent battery monomers can be buffered and absorbed. According to the invention, weight and cost can be reduced and energy density can be increased.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery module, a battery and an electrical device. Background Art

[0002] With the development of new energy technology, batteries are used more and more widely, for example, in mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes and electric tools, etc.

[0003] Compared with square-shell battery cells, the layout of cylindrical battery cells is more flexible, so cylindrical battery cells are more suitable for various vehicle chassis or batteries. However, in the related art, cylindrical battery cells usually adopt the following two layout schemes: a vertical layout scheme of single-sided output ear and pole, which is not suitable for battery chassis with limited layout size; a horizontal layout scheme, which uses a large number of structural parts to fix the battery cells. Therefore, the above layout schemes will not only increase the BOM cost and weight of the battery module, but also reduce the energy density of the battery module.

[0004] Therefore, how to reduce weight and increase efficiency at a lower cost is an urgent problem to be solved in the horizontal arrangement of cylindrical battery cells. Utility Model Content

[0005] In view of the above problems, the present application provides a battery module, a battery and an electrical device that can reduce weight, reduce cost and increase energy density.

[0006] In a first aspect, an embodiment of the present application provides a battery module, which includes: a multi-layer battery group, which is stacked along a first direction and spaced apart by a structural adhesive layer, each layer of the battery group includes a plurality of cylindrical battery cells arranged side by side along a second direction and spaced apart by a structural adhesive layer, the battery cell includes a pole ear, and the pole ear extends out of the battery cell distribution in a third direction, and the first direction, the second direction and the third direction intersect with each other; wherein, two adjacent battery cells are bonded by the structural adhesive layer, and the structural adhesive layer has a preset elastic deformation force, which can buffer and absorb the gap deformation stress between two adjacent battery cells.

[0007] In the above technical solution, the multi-layer battery pack and the multiple battery cells are spaced apart by the structural adhesive layer, and the two adjacent battery cells are bonded by the structural adhesive layer, so that the multiple battery cells of the multi-layer battery pack form a battery module. On the one hand, the design redundancy of the connection structure of the battery cell can be avoided, thereby reducing the weight of the battery module and reducing the cost and volume of the connection structure of the battery cell. The reduction in the volume of the connection structure of the battery cell can increase the number of battery cells without changing the volume of the battery module, thereby achieving the purpose of increasing the energy density of the battery module. On the other hand, since the structural adhesive layer has a preset elastic deformation force, it can buffer and absorb the gap deformation stress between two adjacent battery cells. Therefore, the expansion generated during the charging process of the battery cell will squeeze the structural adhesive layer to cause the structural adhesive layer to produce elastic compression deformation, thereby providing expansion space for the expansion of the battery cell.

[0008] In some embodiments of the first aspect, the plurality of battery cells of two adjacent battery groups are staggered in the second direction.

[0009] In the above technical solution, since the multiple battery cells of two adjacent battery groups are staggered in the second direction, on the one hand, the total height of the battery module can be made smaller than the envelope height, and on the other hand, the space utilization can be improved to increase the energy density of the battery module.

[0010] In some embodiments of the first aspect, the total height of the battery module is less than the sum of the thicknesses of the multi-layer battery module.

[0011] The above technical solution can further improve space utilization to increase the energy density of the battery module.

[0012] In some embodiments of the first aspect, on a cross section parallel to the first direction and the second direction, lines connecting the centers of three adjacent battery cells form an equilateral triangle and satisfy the following formula:

[0013] H=L(n-1)√3 / 2+2r;

[0014] Wherein, H is the total height of the battery module, L is the distance between the centers of two adjacent battery cells, r is the radius of the battery cell, n is the number of layers of the battery pack, and n is an integer not less than 2.

[0015] In the above technical solution, the lines connecting the centers of the circles of three adjacent battery cells form an equilateral triangle, which requires that the spacing between any two adjacent battery cells in the battery module is the same. Therefore, on the one hand, it is beneficial to further reduce the overall height of the battery module, and on the other hand, it is beneficial to further increase the energy density of the battery module.

[0016] In some embodiments of the first aspect, on a cross section parallel to the first direction and the second direction, a line connecting the centers of three adjacent battery cells forms an isosceles triangle and satisfies the following formula:

[0017] H = (n-1) L*tanβ / 2+2r;

[0018] Wherein, H is the total height of the battery module, L is the distance between the centers of two adjacent battery cells in the same layer, β is the angle of the base angle of the isosceles triangle, r is the radius of the battery cell, n is the number of layers of the battery pack, and n is an integer not less than 2.

[0019] The above technical solution, on the one hand, is conducive to further reducing the overall height of the battery module, and on the other hand, is conducive to further increasing the energy density of the battery module.

[0020] In some embodiments of the first aspect, a maximum elastic compression deformation value of the structural adhesive layer at a minimum distance between two adjacent battery cells is not less than a sum of maximum safety expansion values ​​of the two adjacent battery cells.

[0021] The above technical solution can prevent the battery cells of the battery module from being scattered due to the destruction of the structural adhesive layer before the battery cells reach the maximum safe expansion value.

[0022] In some embodiments of the first aspect, the initial thickness of the structural adhesive layer at the minimum distance between two adjacent battery cells is d, the ultimate thickness of the structural adhesive layer after extreme compression at the minimum distance between two adjacent battery cells is d1, and the ratio of d to d1 is 1.03 to 1.30.

[0023] In some embodiments of the first aspect, an initial minimum distance between two adjacent battery cells is 1-2 mm.

[0024] In the above technical solution, the initial minimum spacing between two adjacent battery cells is 1 to 2 mm. On the one hand, it can ensure that the maximum elastic compression deformation value of the structural adhesive layer at the minimum distance between two adjacent battery cells is not less than the sum of the maximum safe expansion values ​​of the two adjacent battery cells. On the other hand, it can make the structure of the battery module more compact, which is beneficial to increase the energy density of the battery module.

[0025] In a second aspect, the present application provides a battery, comprising at least one battery module and a box provided in any embodiment of the first aspect, wherein the at least one battery module is disposed in the box.

[0026] In some embodiments of the second aspect, the box body includes a bottom plate, two end plates spaced apart along a second direction, and two CCS assemblies spaced apart along a third direction, the battery module is connected to the bottom plate on one side along the first direction, the battery module is connected to the end plate, and the CCS assembly electrically connects the tab to the external circuit.

[0027] In a third aspect, the present application provides an electrical device, comprising a battery module provided by any embodiment of the first aspect, wherein the battery module is used to provide electrical energy.

[0028] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Also, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0030] Figure 1 A schematic diagram of the structure of a battery module provided in some embodiments of the present application;

[0031] Figure 2 for Figure 1 An enlarged view of part a of the battery module shown;

[0032] Figure 3 for Figure 1 A schematic diagram of the structure of a battery cell in the battery module shown;

[0033] Figure 4 for Figure 1 A cross-sectional view of section AA of the battery module shown;

[0034] Figure 5 for Figure 4 An enlarged view of part b of the battery module shown;

[0035] Figure 6 A schematic diagram of a structure in which the lines connecting the centers of three adjacent battery cells in a battery module provided in other embodiments of the present application form an isosceles triangle;

[0036] Figure 7 A schematic diagram of the structure of a battery provided in some embodiments of the present application;

[0037] Figure 8 for Figure 7 A schematic diagram of the exploded structure of the battery shown;

[0038] Fig. 9 A schematic diagram of the structure of a vehicle provided in some embodiments of the present application.

[0039] The reference numerals in the specific implementation manner are as follows:

[0040] 1. Vehicle; 2. Battery; 21. Battery module; 211. Battery pack; 213. Battery cell; 215. Tab; 218. Positive tab; 219. Negative tab; 217. Structural adhesive layer; 23. Box; 231. Bottom plate; 233. End plate; 235. CCS assembly; 3. Controller; 4. Motor;

[0041] P, center of circle; M, equilateral triangle; K, isosceles triangle; X, first direction; Y, second direction; Z, third direction. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0043] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as those commonly understood by technicians in the technical field to which this application belongs; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship.

[0044] Reference to "embodiment" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0045] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "attached" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0046] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0047] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0048] The term "plurality" used in the present application refers to two or more (including two).

[0049] In the present application, the term "parallel" includes not only the absolutely parallel situation, but also the roughly parallel situation conventionally recognized in engineering; meanwhile, "vertical" includes not only the absolutely vertical situation, but also the roughly vertical situation conventionally recognized in engineering.

[0050] In the embodiment of the present application, the battery cell may be a secondary battery cell, which refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0051] The battery cells can be lithium-ion battery cells, sodium-ion battery cells, sodium-lithium-ion battery cells, lithium metal battery cells, sodium metal battery cells, lithium-sulfur battery cells, magnesium-ion battery cells, nickel-hydrogen battery cells, nickel-cadmium battery cells, lead-acid battery cells, etc., which are not limited in the embodiments of the present application.

[0052] A battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode and a negative electrode. During the charge and discharge process of the battery cell, active ions (such as lithium ions) are inserted and removed back and forth between the positive electrode and the negative electrode.

[0053] The electrode assembly is provided with a tab, which can lead the current out of the electrode assembly. The tab includes a positive tab and a negative tab.

[0054] In some embodiments, the electrode assembly further includes a separator, which is disposed between the positive electrode and the negative electrode to prevent the positive and negative electrodes from short-circuiting while allowing active ions to pass through.

[0055] In some embodiments, the positive electrode may be a positive electrode sheet, and the positive electrode sheet may include a positive electrode current collector and a positive electrode active material layer disposed on at least one surface of the positive electrode current collector.

[0056] As an example, the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active material layer is disposed on any one or both of the two facing surfaces of the positive electrode current collector.

[0057] As an example, the positive electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, stainless steel, copper, aluminum, nickel, silver-surface-treated aluminum, silver-surface-treated stainless steel, carbon electrode, carbon, nickel or titanium, etc. may be used. The composite current collector may include a polymer material base and a metal layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0058] As an example, the positive electrode active material layer includes a positive electrode active material. The positive electrode active material may include at least one of the following materials: lithium-containing phosphates, lithium transition metal oxides, and their respective modified compounds. However, the present application is not limited to these materials, and other traditional materials that can be used as positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more. Among them, examples of lithium-containing phosphates may include but are not limited to lithium iron phosphate (such as LiFePO 4 (also referred to as LFP), composite materials of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO 4 ), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon. Examples of lithium transition metal oxides may include but are not limited to lithium cobalt oxide (such as LiCoO 2 ), lithium nickel oxide (such as LiNiO 2 ), lithium manganese oxide (such as LiMnO 2 、LiMn 2 O 4 ), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O 2 (Also referred to as NCM 333 )、LiNi 0.5 Co 0.2 Mn 0.3 O 2 (Also referred to as NCM 523 )、LiNi 0.5 Co 0.25 Mn 0.25 O 2 (Also referred to as NCM 211 )、LiNi0.6 Co 0.2 Mn 0.2 O 2 (Also referred to as NCM 622 )、LiNi 0.8 Co 0.1 Mn 0.1 O 2 (Also referred to as NCM 811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.80 Co 0.15 Al 0.05 O 2 ) and at least one of its modified compounds.

[0059] In some embodiments, the positive electrode may be carbon foam or metal foam. The metal foam may be nickel foam, copper foam, aluminum foam or alloy foam. When the metal foam is used as the positive electrode, the positive electrode active material may not be provided on the surface of the metal foam, but the positive electrode active material may also be provided. As an example, lithium source material, potassium metal or sodium metal may be filled or / and deposited in the metal foam, and the lithium source material is lithium metal and / or lithium-rich material.

[0060] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector and a negative electrode active material layer disposed on at least one surface of the negative electrode current collector.

[0061] As an example, the negative electrode current collector may be a metal foil, a foamed metal, a foamed carbon or a composite current collector. For example, as a metal foil, stainless steel, copper, aluminum, nickel, silver-surface-treated aluminum, silver-surface-treated stainless steel, a carbon electrode, carbon, nickel or titanium, etc. may be used. The foamed metal may be a foamed nickel, a foamed copper, a foamed aluminum or a foamed alloy, etc. The composite current collector may include a polymer material base and a metal layer. The composite current collector may be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0062] As an example, the negative electrode active material may adopt the negative electrode active material for battery cells known in the art. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, etc. The silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, the present application is not limited to these materials, and other traditional materials that can be used as negative electrode active materials for batteries may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0063] In some embodiments, the negative electrode may be foamed carbon or foamed metal. The foamed metal may be foamed nickel, foamed copper, foamed aluminum or foamed alloy, etc. When the foamed metal is used as the negative electrode sheet, the surface of the foamed metal may not be provided with a negative electrode active material, but of course, a negative electrode active material may also be provided.

[0064] As an example, a lithium source material, potassium metal or sodium metal may be filled or / and deposited in the negative electrode current collector, and the lithium source material is lithium metal and / or lithium-rich material.

[0065] In some embodiments, the material of the positive electrode current collector may be aluminum, and the material of the negative electrode current collector may be copper.

[0066] In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode sheet and the negative electrode sheet.

[0067] In some embodiments, the separator is a separator. The present application has no particular limitation on the type of separator, and any known separator with a porous structure having good chemical stability and mechanical stability can be selected.

[0068] As an example, the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator can be a single-layer film or a multi-layer composite film, without special restrictions. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without special restrictions. The separator can be a separate component located between the positive and negative electrodes, or it can be attached to the surface of the positive and negative electrodes.

[0069] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode sheet and the negative electrode sheet and plays the role of transmitting ions and isolating the positive and negative electrodes.

[0070] In some embodiments, the battery cell further includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. The present application has no specific restrictions on the type of electrolyte, which can be selected according to needs. The electrolyte can be liquid, gel or solid.

[0071] In some embodiments, the liquid electrolyte includes an electrolyte salt and a solvent.

[0072] In some embodiments, the electrolyte salt can be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalatoborate, lithium dioxalatoborate, lithium difluorodioxalatophosphate, and lithium tetrafluorooxalatophosphate.

[0073] In some embodiments, the solvent can be selected from at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, cyclopentane, dimethyl sulfone, methyl ethyl sulfone and diethyl sulfone. The solvent can also be selected from ether solvents. Ether solvents can include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyltetrahydrofuran, diphenyl ether and crown ether.

[0074] The gel electrolyte includes a polymer-based electrolyte skeleton network combined with an ionic liquid-lithium salt.

[0075] Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0076] As an example, the polymer solid electrolyte may be polyether (polyethylene oxide), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, a single ion polymer, polyionic liquid-lithium salt, cellulose, and the like.

[0077] As an example, the inorganic solid electrolyte can be an oxide solid electrolyte (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON film), a sulfide solid electrolyte (crystalline lithium superion conductor (lithium germanium phosphosulfide, silver germanium sulfide), amorphous sulfide) and one or more of a halide solid electrolyte, a nitride solid electrolyte and a hydride solid electrolyte.

[0078] As an example, the composite solid electrolyte is formed by adding an inorganic solid electrolyte filler to a polymer solid electrolyte.

[0079] In some embodiments, the electrode assembly is a wound structure, wherein the positive electrode sheet and the negative electrode sheet are wound into a wound structure.

[0080] In some embodiments, the electrode assembly is a laminate structure.

[0081] As an example, a plurality of positive electrode sheets and a plurality of negative electrode sheets may be provided respectively, and the plurality of positive electrode sheets and the plurality of negative electrode sheets may be alternately stacked.

[0082] As an example, a plurality of positive electrode sheets may be provided, and the negative electrode sheet may be folded to form a plurality of stacked folded segments, with a positive electrode sheet being sandwiched between adjacent folded segments.

[0083] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form a plurality of folded sections that are stacked.

[0084] As an example, a plurality of separators may be provided, each of which is provided between any adjacent positive electrode sheets or negative electrode sheets.

[0085] As an example, the separator may be disposed continuously, and may be disposed between any adjacent positive electrode sheets or negative electrode sheets by folding or winding.

[0086] In some embodiments, the battery cell may include a housing. The housing is used to encapsulate components such as the electrode assembly and the electrolyte. The housing may be a steel housing, an aluminum housing, a plastic housing (such as polypropylene), a composite metal housing (such as a copper-aluminum composite housing), or an aluminum-plastic film.

[0087] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery modules to provide higher voltage and capacity.

[0088] In some embodiments, the battery may be a battery pack, which includes a case and a battery module, wherein the battery module is accommodated in the case.

[0089] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0090] In some embodiments, the battery may be an energy storage device, which includes an energy storage container, an energy storage cabinet, and the like.

[0091] With the development of new energy technology, batteries are used more and more widely, for example, in mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes and electric tools, etc.

[0092] Compared with square-shell battery cells, the layout of cylindrical battery cells is more flexible, so cylindrical battery cells are more suitable for various vehicle chassis or batteries. However, in the related art, cylindrical battery cells usually adopt the following two layout schemes: a vertical layout scheme of single-sided output ear and pole, which is not suitable for battery chassis with limited layout size; a horizontal layout scheme, which uses a large number of structural parts to fix the battery cells, including fixed brackets, fixed sheet metal parts, upper and lower pressure plates, foam glue, etc. Therefore, the above layout scheme will not only increase the BOM cost and weight of the battery module, but also reduce the energy density of the battery module.

[0093] Based on the above considerations, the present application designs a battery module.

[0094] Figure 1 A schematic diagram of the structure of a battery module provided in some embodiments of the present application; Figure 2 for Figure 1 An enlarged view of part a of the battery module shown; Figure 3 for Figure 1 A schematic diagram of the structure of a battery cell in the battery module shown; Figure 4 for Figure 1 A cross-sectional view of section AA of the battery module shown; Figure 5 for Figure 4 An enlarged view of part b of the battery module shown; Figure 6 This is a schematic structural diagram of an isosceles triangle formed by connecting the centers of three adjacent battery cells in a battery module provided in other embodiments of the present application.

[0095] like Figures 1 to 6 As shown, the battery module 21 of the present application includes a multi-layer battery pack 211. The multi-layer battery pack 211 is stacked along a first direction X and spaced apart by a structural adhesive layer 217. Each layer of the battery pack 211 includes a plurality of cylindrical battery cells 213 arranged side by side along a second direction Y and spaced apart by a structural adhesive layer 217. The battery cells 213 include tabs 215. The tabs 215 extend out of the battery cells 213 in a third direction Z. The first direction X, the second direction Y, and the third direction Z intersect each other.

[0096] The two adjacent battery cells 213 are bonded together via a structural adhesive layer 217 . The structural adhesive layer 217 has a preset elastic deformation force, which can buffer and absorb the gap deformation stress between the two adjacent battery cells 213 .

[0097] The two adjacent battery cells 213 include two adjacent battery cells 213 in the first direction X and two adjacent battery cells 213 in the second direction Y. That is, the two adjacent battery cells 213 are bonded via the structural adhesive layer 217 so that multiple battery cells 213 in the same layer of the battery group 211 are connected via the structural adhesive layer 217, and the two adjacent battery cells 213 in two adjacent battery groups 211 are connected via the structural adhesive layer 217.

[0098] The number of layers of the battery pack 211 and the number of battery cells 213 in each battery pack 211 can be set according to requirements; the number of battery cells 213 in each battery pack 211 can be the same or different.

[0099] In the above technical solution, the multi-layer battery pack 211 and the multiple battery cells 213 are arranged at intervals by the structural adhesive layer 217, and the adjacent two battery cells 213 are bonded by the structural adhesive layer 217, so that the multiple battery cells 213 of the multi-layer battery pack 211 form a battery module 21. On the one hand, the design redundancy of the connection structure of the battery cell 213 can be avoided, thereby reducing the weight of the battery module 21, reducing the cost and volume of the connection structure of the battery cell 213, and reducing the volume of the connection structure of the battery cell 213 can increase the number of battery cells 213 without changing the volume of the battery module 21, thereby achieving the purpose of increasing the energy density of the battery module 21; on the other hand, because the structural adhesive layer 217 has a preset elastic deformation force, it can buffer and absorb the gap deformation stress between the adjacent two battery cells 213. Therefore, the expansion generated during the charging process of the battery cell 213 will squeeze the structural adhesive layer 217 to make the structural adhesive layer 217 produce elastic compression deformation, thereby providing expansion space for the expansion of the battery cell 213.

[0100] In some embodiments, the first direction X, the second direction Y, and the third direction Z intersect each other perpendicularly.

[0101] The first direction X is the thickness direction of the battery module, the second direction Y is the length direction of the battery module, and the third direction Z is the width direction of the battery module.

[0102] In some embodiments, the battery cells 213 of two adjacent battery groups 211 are staggered in the second direction Y.

[0103] It should be noted that the staggered arrangement of the multiple battery cells 213 of two adjacent battery groups 211 in the second direction Y means that: in the cross section AA, the center point P of each of the multiple battery cells 213 of the battery group 211 on the -X direction side is offset by a distance D1 in the -Y direction relative to the center point P of each of the multiple battery cells 213 of the battery group 211 on the +X direction side, and the center point P of each of the multiple battery cells 213 of the battery group 211 on the -X direction side is offset by a distance D2 in the +X direction relative to the center point P of each of the multiple battery cells 213 of the battery group 211 on the +X direction side. Among them, since a gap is formed between the multiple battery cells 213 of the battery group 211 on the +X direction side, the center P of each of the multiple battery cells 213 of the battery group 211 on the -X direction side is offset by a distance D1 in the -Y direction relative to the center P of each of the multiple battery cells 213 of the battery group 211 on the +X direction side, and the multiple battery cells 213 of the battery group 211 on the -X direction side can be moved in the gap direction, so the center P of each of the multiple battery cells 213 of the battery group 211 on the -X direction side can be offset by a distance D2 in the +X direction relative to the center P of each of the multiple battery cells 213 of the battery group 211 on the +X direction side. Therefore, the multiple battery cells 213 of two adjacent battery groups 211 are staggered in the second direction, so that the total height of the battery module can be less than the envelope height, so that the battery module 21 can be miniaturized to improve space utilization and increase the energy density of the battery module. In some embodiments, the total height of the battery module 21 is less than the sum of the thicknesses of the multi-layer battery group 211. The thickness of the multi-layer battery group 211 is equal to the diameter of the battery cell 213 .

[0104] In some embodiments, on a cross section AA parallel to the first direction X and the second direction Y, a line connecting the centers P of three adjacent battery cells 213 forms an equilateral triangle M, and satisfies the following formula:

[0105]

[0106] Wherein, H is the total height of the battery module 21 , L is the distance between the centers of two adjacent battery cells 213 , r is the radius of the battery cell 213 , n is the number of layers of the battery module 211 , and n is an integer not less than 2.

[0107] in, is the height of the equilateral triangle M; It is the sum of the distances in the first direction X between the centers of two adjacent battery cells 213 in each two adjacent layers of the multi-layer battery group 211 .

[0108] Illustratively, n includes but is not limited to 2, 3, 4, 5, 6, 7, 8, 9 or 10, etc.

[0109] Among them, the lines connecting the centers P of the three adjacent battery cells 213 form an equilateral triangle M, which requires that the spacing between any two groups of adjacent battery cells 213 in the battery module 21 are the same, that is, the initial minimum spacing between two adjacent battery cells 213 is d, d=L-2r, that is, the initial thickness of the structural adhesive layer 217 at the minimum distance between two adjacent battery cells 213 is d. Therefore, on the one hand, it is beneficial to further reduce the envelope height of the battery module 21, and on the other hand, it is beneficial to increase the energy density of the battery module 21.

[0110] In some embodiments, on a cross section AA parallel to the first direction X and the second direction Y, a line connecting the centers P of three adjacent battery cells 213 forms an isosceles triangle K and satisfies the following formula:

[0111] H = (n-1) L*tanβ / 2+2r;

[0112] Wherein, H is the total height of the battery module 21, L is the distance between the centers of two adjacent battery cells 213 in the same layer, β is the angle of the base angle of the isosceles triangle K, r is the radius of the battery cell 213, n is the number of layers of the battery pack 211, and n is an integer not less than 2.

[0113] Wherein, L*tanβ / 2 is the height of the isosceles triangle K; (n-1)L*tanβ / 2 is the sum of the distances in the first direction X between the centers of two adjacent battery cells 213 in each two adjacent layers of the multi-layer battery pack 211 .

[0114] In some embodiments, the maximum elastic compression deformation value of the structural adhesive layer 217 at the minimum distance between two adjacent battery cells 213 is not less than the sum of the maximum safety expansion values ​​of the two adjacent battery cells 213 .

[0115] In some embodiments, the initial thickness of the structural adhesive layer 217 at the minimum distance between two adjacent battery cells 213 is d, the ultimate thickness of the structural adhesive layer 217 after being compressed to the limit at the minimum distance between two adjacent battery cells 213 is d1, and the ratio of d to d1 is 1.03 to 1.30. That is, the difference between d and d1 is the maximum elastic compression deformation value of the structural adhesive layer 217 at the minimum distance between two adjacent battery cells 213.

[0116] The initial minimum spacing between two adjacent battery cells 213 is set to increase with the increase of the radius of the battery cell 213 so that the structural adhesive layer 217 can be deformed within the range of the maximum elastic compression deformation value when the battery cell 213 expands.

[0117] In some embodiments, the initial minimum distance between two adjacent battery cells 213 is 1-2 mm, that is, the value of d is 1-2 mm.

[0118] For example, the initial minimum spacing between two adjacent battery cells 213 may be 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm or 2 mm.

[0119] In some embodiments, the tabs 215 include a positive tab 218 and a negative tab 219 , and the positive tab 218 and the negative tab 219 are respectively extended out of the battery cell 213 in the third direction Z. This facilitates the connection of the tabs 215 with an external circuit.

[0120] The battery module is prepared in the following manner.

[0121] The bracket fixture is used to fix multiple battery cells 213 to form a battery pack 211. The bracket fixture is used to ensure that the multiple battery cells 213 are arranged at a preset interval d along the second direction Y, the flatness of the battery pack 211, and the tabs 215 extend out of the battery cells 213 in the third direction Z.

[0122] Structural adhesive is applied on each battery pack 211. The structural adhesive is applied on the battery pack 211 with a preset adhesive application area and adhesive application amount to prevent the structural adhesive from being connected to the bracket tooling.

[0123] The plurality of brackets for fixing the battery pack 211 are stacked in the first direction X so that two adjacent battery cells 213 are connected via structural adhesive. The brackets also ensure that two adjacent battery cells 213 in the first direction X are spaced apart by a preset spacing d.

[0124] After the structural adhesive solidifies to form a structural adhesive layer 217 , the support fixture is removed to obtain the battery module 21 .

[0125] The battery module 21 is suitable for use in batteries and electrical devices using the batteries.

[0126] The electrical device may be a vehicle, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, an electric tool, and the like. The vehicle may be a fuel vehicle, a gas vehicle, or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle, and the like; the spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, and the like; the electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, and the like; the electric tool may include a metal cutting electric tool, a grinding electric tool, an assembly electric tool, and an electric tool for railways, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact drill, a concrete vibrator, and an electric planer, and the like. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical devices.

[0127] It should be understood that the technical solutions described in the embodiments of the present application are not limited to the batteries and electrical devices described above, but can also be applied to all batteries including a box and electrical devices using batteries. However, for the sake of simplicity of description, the following embodiments are explained using the vehicle as an electrical device as an example.

[0128] Figure 7 A schematic diagram of the structure of a battery provided in some embodiments of the present application; Figure 8 for Figure 7 Schematic diagram of the exploded structure of the battery shown.

[0129] like Figure 7 and Figure 8 As shown, the battery 2 includes at least one battery module 21 and a box 23 , and the at least one battery module 21 is disposed in the box 23 .

[0130] The box 23 is used to accommodate the battery module 21, and the box 23 can be of various structures. In some embodiments, the box 23 includes a bottom plate 231, two end plates 233 spaced apart along the second direction Y, and two CCS assemblies 235 spaced apart along the third direction Z. The battery module 21 is connected to the bottom plate 231 on one side along the first direction X, the battery module 21 is connected to the end plate 233, and the CCS assembly 235 electrically connects the tab 215 to the external circuit. The bottom plate 231, the two end plates 233, and the two CCS assemblies 235 together define a receiving space for accommodating the battery module 21.

[0131] In some embodiments, the battery module 21 may only have one battery module 21 , and the two ends of the battery module 21 along the second direction Y are respectively connected to the two end plates 233 , and the two CCS assemblies 235 are respectively connected to the positive electrode ear 218 and the negative electrode ear 219 .

[0132] In the battery 2 , the multiple battery cells 213 in the battery module 21 can be connected in series, in parallel, or in mixed connection. Mixed connection means that the multiple battery cells 213 are connected in series and in parallel.

[0133] In some embodiments, the battery module 21 can be provided with at least two battery modules 21, and at least two battery modules 21 can be arranged in a sequentially connected manner along the second direction Y, and at least two battery modules 21 can be connected in series, in parallel, or in mixed connection. Mixed connection means that at least two battery modules 21 are connected in series and in parallel.

[0134] In some embodiments, the CCS assembly 235 may include a bar, a bus bar, a signal acquisition harness, a temperature sensor, a sampling circuit board, etc.

[0135] The tabs are connected to the tabs of the battery cells 213 so that the multiple battery cells 213 in the battery module 21 can be connected in series, in parallel, or in mixed connection.

[0136] Busbars are used to conduct large currents to achieve electrical connections between battery modules and with external circuits.

[0137] The signal acquisition harness contains the connections of various sensors, which are used to collect voltage, current and other signals and transmit them to the battery management system.

[0138] The temperature sensor is used to monitor the temperature inside the battery box in real time.

[0139] The sampling circuit board integrates circuits for processing and transmitting the collected signals.

[0140] Fig. 9 A schematic diagram of the structure of a vehicle provided in some embodiments of the present application.

[0141] like Fig. 9 As shown, a battery 2 is disposed inside the vehicle 1, and the battery 2 may be disposed at the bottom, head, or tail of the vehicle 1. The battery 2 may be used to power the vehicle 1, for example, the battery 2 may be used as an operating power source for the vehicle 1.

[0142] The vehicle 1 may further include a controller 3 and a motor 4 , wherein the controller 3 is used to control the battery 2 to supply power to the motor 4 , for example, to meet the power requirements of starting, navigating, and driving the vehicle 1 .

[0143] In some embodiments of the present application, the battery 2 can not only serve as an operating power source for the vehicle 1, but also serve as a driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0144] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application may be combined with each other.

[0145] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery module, characterized in that: include: A multi-layer battery pack, stacked in a first direction and spaced apart by a structural adhesive layer, each layer of the battery pack comprises a plurality of cylindrical battery cells arranged side by side in a second direction and spaced apart by the structural adhesive layer, the battery cells comprising tabs, the tabs extending out of the battery cells in a third direction, the first direction, the second direction and the third direction intersecting in pairs; Wherein, two adjacent battery cells are bonded together via the structural adhesive layer, and the structural adhesive layer has a preset elastic deformation force, which can buffer and absorb the gap deformation stress between the two adjacent battery cells.

2. The battery module according to claim 1, characterized in that: The battery cells of two adjacent battery groups are staggered in the second direction.

3. The battery module according to claim 2, characterized in that: The total height of the battery module is less than the sum of the thicknesses of multiple layers of the battery modules.

4. The battery module according to claim 2, characterized in that: On a cross section parallel to the first direction and the second direction, a line connecting the centers of the three adjacent battery cells forms an equilateral triangle and satisfies the following formula: Wherein, H is the total height of the battery module, L is the distance between the centers of two adjacent battery cells, r is the radius of the battery cell, n is the number of layers of the battery pack, and n is an integer not less than 2.

5. The battery module according to claim 2, characterized in that: On a cross section parallel to the first direction and the second direction, a line connecting the centers of the three adjacent battery cells forms an isosceles triangle and satisfies the following formula: H = (n-1) L*tanβ / 2+2r; Wherein, H is the total height of the battery module, L is the distance between the centers of two adjacent battery cells in the same layer, β is the angle of the base angle of the isosceles triangle, r is the radius of the battery cell, n is the number of layers of the battery pack, and n is an integer not less than 2.

6. The battery module according to claim 1, characterized in that: The maximum elastic compression deformation value of the structural adhesive layer at the minimum distance between two adjacent battery cells is not less than the sum of the maximum safety expansion values ​​of the two adjacent battery cells.

7. The battery module according to claim 1, characterized in that: The initial thickness of the structural adhesive layer at the minimum distance between two adjacent battery cells is d, the ultimate thickness of the structural adhesive layer after being compressed to the limit at the minimum distance between two adjacent battery cells is d1, and the ratio of d to d1 is 1.03-1.

30.

8. The battery module according to claim 1, characterized in that: The initial minimum spacing between two adjacent battery cells is 1 to 2 mm.

9. A battery, characterized in that: It comprises at least one battery module and a box as described in any one of claims 1 to 8, wherein the at least one battery module is arranged in the box.

10. The battery according to claim 9, characterized in that The box body includes a bottom plate, two end plates spaced apart along the second direction, and two CCS assemblies spaced apart along the third direction. The battery module is connected to the bottom plate on one side along the first direction, the battery module is connected to the end plates, and the CCS assembly electrically connects the tab to an external circuit.

11. An electrical device, characterized in that: It comprises a battery module as described in any one of claims 1 to 8, wherein the battery module is used to provide electrical energy.

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