Battery pack, electric equipment, battery module and assembling method thereof

Abstract

The invention provides a battery pack, electric equipment, a battery module and an assembling method thereof, and relates to the technical field of batteries. The assembling method of the battery module comprises the following steps: providing a plurality of battery cells; a gap is formed between every two adjacent battery cells; an initial expansion structure is installed in the gap; the initial expansion structure comprises a vacuum bag and an expansion piece, a containing cavity in a negative pressure state is formed in the vacuum bag, and the expansion piece is located in the containing cavity; an air inlet is formed in the vacuum bag, so that the accommodating cavity sucks air through the air inlet, and the expansion piece expands in the accommodating cavity and abuts against the first battery cell and the second battery cell. According to the assembling method of the battery module provided by the embodiment of the invention, in the battery cell stacking process, the restraining force can be reduced, meanwhile, the matching complexity of the filling materials is reduced, the relative positions of the battery cells are stable, the welding precision is improved, and the overall performance, safety and production efficiency of a battery pack are guaranteed.

Description

Technical Field

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

[0002] Battery modules are widely used in electric vehicles, energy storage systems, portable electronic devices and other fields. Through reasonable cell stacking design, the overall performance of the battery pack can be optimized to meet the requirements of different application scenarios for battery energy, power and cycle life.

[0003] In related technologies, the cell stacking process primarily involves placing filler material between the cells to provide insulation and cushioning. These cells are then stacked to form a module, and pressure is applied from both sides using electric cylinders to constrain the modules to a predetermined length. Next, glue is applied to the top and bottom surfaces of the module, and tie bars are affixed. Once the glue has cured, the electric cylinders are removed. Finally, the modules are assembled and placed on a tray, with glue being poured into the gap between the tray and the modules, completing the stacking process.

[0004] However, when the battery cell is too thick, the restraint force will be too large and the pull rod may fail. At the same time, the filling material needs to be carefully matched to achieve the thickness management of the battery cell stacking. The tolerance accumulation of the battery cell position affects the welding accuracy and affects the performance and safety of the battery pack. Summary of the Invention

[0005] The embodiments of the present application provide a battery pack, an electrical device, a battery module, and an assembly method thereof, which are used to reduce the restraint force during the stacking of battery cells, while reducing the complexity of matching filling materials, stabilizing the relative position of the battery cells, improving welding accuracy, and ensuring the overall performance, safety, and production efficiency of the battery pack.

[0006] In a first aspect, the present application provides a battery module, comprising:

[0007] A plurality of battery cells, wherein the plurality of battery cells include a first battery cell and a second battery cell adjacent to each other, and a gap is provided between the first battery cell and the second battery cell;

[0008] an expansion structure disposed in the gap, the expansion structure comprising a vacuum bag and an expansion member; the vacuum bag forming a receiving cavity, the vacuum bag being provided with an air inlet capable of communicating with the receiving cavity;

[0009] The expansion member is disposed in the accommodating cavity, and a first surface of the expansion member can abut against the first battery core through a first portion of the vacuum bag, and a second surface of the expansion member can abut against the second battery core through a second portion of the vacuum bag.

[0010] As an optional embodiment, when the expansion member is located in the gap, the expansion member is in a compressed state;

[0011] After the expansion member is moved out of the gap, the thickness of the expansion member is greater than or equal to the width of the gap.

[0012] As an optional embodiment, the first portion of the vacuum bag is provided with a first adhesive layer, and the surface of the first adhesive layer away from the vacuum bag is connected to the surface of the first battery cell facing the second battery cell;

[0013] And / or, the second portion of the vacuum bag is provided with a second adhesive layer, and a surface of the second adhesive layer away from the vacuum bag is connected to a surface of the second battery core facing the first battery core.

[0014] As an optional embodiment, the material of the expansion member is at least one of foam and aerogel;

[0015] And / or, the vacuum bag is made of plastic packaging material.

[0016] As an optional embodiment, in the arrangement direction of the first battery cell and the second battery cell, at least some of the plurality of battery cells are arranged in sequence at intervals to form a battery cell assembly including the first battery cell and the second battery cell.

[0017] As an optional embodiment, the battery cell assembly is provided with a connector, the extension direction of the connector is parallel to the arrangement direction of the battery cells, and the connector can connect the battery cells in the same battery cell assembly.

[0018] As an optional implementation manner, the connecting member is configured as a pull rod, the pull rod is provided with a glue layer, and the pull rod is bonded and fixed to the battery core through the glue layer.

[0019] As an optional implementation, the connecting member is configured as a rubber limiting strip.

[0020] As an optional implementation, in the battery cell assembly, the gap is provided between two adjacent battery cells, and the widths of the gaps are the same or approximately the same.

[0021] As an optional implementation manner, in the battery core assembly, the expansion structure is provided in each of the gaps.

[0022] In a second aspect, the present application provides a method for assembling a battery module, comprising:

[0023] Providing a plurality of battery cells; the plurality of battery cells include a first battery cell and a second battery cell adjacent to each other, with a gap being provided between the first battery cell and the second battery cell;

[0024] An initial expansion structure is installed in the gap; the initial expansion structure includes a vacuum bag and an expansion member, the vacuum bag forms a receiving cavity in a negative pressure state, and the expansion member is located in the receiving cavity;

[0025] An air inlet is formed in the vacuum bag and is communicated with the accommodating cavity; the accommodating cavity inhales air through the air inlet, and the expansion member expands in the accommodating cavity;

[0026] The first surface of the expansion member abuts against the first battery core through the first portion of the vacuum bag, and the second surface of the expansion member abuts against the second battery core through the second portion of the vacuum bag.

[0027] As an optional implementation, an initial expansion structure is installed in the gap, and the thickness of the initial expansion structure is less than or equal to the width of the gap.

[0028] As an optional embodiment, before the air inlet capable of communicating with the accommodating cavity is formed in the vacuum bag, the method includes:

[0029] fixing the first battery cell and the second battery cell;

[0030] An air inlet that can communicate with the accommodating cavity is formed in the vacuum bag, and the width of the gap remains unchanged during the expansion of the expansion member in the accommodating cavity.

[0031] As an optional embodiment, fixing the first battery cell and the second battery cell includes:

[0032] Connect multiple

[0033] A battery cell, wherein the first portion of the connector is connected to the first battery cell, and the second portion of the connector is connected to the second battery cell;

[0034] and / or, placing a plurality of the battery cells on a tray;

[0035] A glue filling layer is formed between the plurality of battery cells and the tray, and the first battery cell and the second battery cell are fixed to the tray through the glue filling layer.

[0036] As an optional embodiment, before installing the initial expansion structure in the gap, forming the initial expansion structure includes:

[0037] Providing a vacuum bag having a receiving cavity, wherein the receiving cavity has an opening;

[0038] placing the expansion member in the accommodating cavity;

[0039] Air is sucked from the accommodating chamber to form a negative pressure state in the accommodating chamber and close the opening.

[0040] In a third aspect, the present application provides a battery pack comprising any one of the above-mentioned battery modules.

[0041] In a fourth aspect, the present application provides an electrical device comprising any one of the above-mentioned battery modules or battery packs.

[0042] The embodiments of the present application provide a battery pack, an electrical device, a battery module, and an assembly method thereof. The assembly method of the battery module includes: providing a plurality of battery cells, the plurality of battery cells including a first battery cell and a second battery cell adjacent to each other, and a gap is set between the first battery cell and the second battery cell; installing an initial expansion structure in the gap, the initial expansion structure including a vacuum bag and an expansion piece, the vacuum bag forming a receiving cavity in a negative pressure state, and the expansion piece is located in the receiving cavity; forming an air inlet that can communicate with the receiving cavity in the vacuum bag, the receiving cavity inhaling air through the air inlet, the expansion piece expanding in the receiving cavity, the first surface of the expansion piece abutting against the first battery cell through the first part of the vacuum bag, and the second surface of the expansion piece abutting against the second battery cell through the second part of the vacuum bag.

[0043] The battery module assembly method provided in the embodiment of the present application provides a stable and controllable way to fill the gaps between the battery cells during the battery cell stacking process by setting an initial expansion structure between the battery cells and utilizing the design of vacuum bags and expansion pieces. This can avoid the problems of limited selection of pull rod materials and increased equipment costs in traditional methods, simplify the production process, and reduce the difficulty of material preparation management. At the same time, the relative positions between the battery cells are fixed, which improves the welding speed and accuracy, and ensures the performance and safety of the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0045] Figure 1 A schematic diagram of the structure of a battery module provided in an embodiment of the present application;

[0046] Figure 2 for Figure 1 Enlarged view of part A;

[0047] Figure 3 for Figure 2 A schematic structural diagram of a battery module without the second battery cell;

[0048] Figure 4 for Figure 2 An exploded view of the first battery cell, the second battery cell, and the expansion structure;

[0049] Figure 5 for Figure 4 An exploded view of the first battery cell, the second battery cell, and the expansion structure at another viewing angle;

[0050] Figure 6 A schematic diagram of the process structure of the battery module assembly method provided in an embodiment of the present application.

[0051] Description of reference numerals:

[0052] 100-battery cells;

[0053] 101-gap;

[0054] 110-first battery cell;

[0055] 120-second battery cell;

[0056] 200-expansion structure;

[0057] 210-vacuum bag;

[0058] 211-first adhesive layer;

[0059] 212- second adhesive layer;

[0060] 220- expansion piece;

[0061] 300-connector;

[0062] 400-pallet;

[0063] 500-Glue filling layer.

[0064] The above drawings illustrate specific embodiments of the present application, which will be described in more detail below. These drawings and the textual description are not intended to limit the scope of the present application in any way, but rather to illustrate the concepts of the present application to those skilled in the art by reference to specific embodiments. DETAILED DESCRIPTION

[0065] To make the purpose, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions 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 them. Based on the embodiments in the embodiments of the present application, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the embodiments of the present application.

[0066] In the embodiments of the present application, the terms "upper", "lower", "inner", "middle", "outer", "front", "back", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. These terms are primarily intended to better describe the embodiments of the present application and its embodiments, and are not intended to limit the indicated devices, elements, or components to having a specific orientation, or to be constructed and operated in a specific orientation. Moreover, in addition to being used to indicate orientations or positional relationships, some of the above terms may also be used to indicate other meanings. For example, the term "upper" may also be used to indicate a certain dependency or connection relationship in certain circumstances. For those of ordinary skill in the art, the specific meanings of these terms in the embodiments of the present application can be understood based on the specific circumstances.

[0067] Furthermore, the terms "disposed," "connected," and "fixed" should be interpreted broadly. For example, "connected" can mean a fixed connection, a removable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection, an indirect connection through an intermediary, or an internal connection between two devices, elements, or components. Those skilled in the art will understand the specific meanings of these terms in the embodiments of this disclosure based on the specific circumstances.

[0068] The terms "first," "second," "third," "fourth," and so on (if any) in the description and claims of the embodiments of the present application and in the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a particular order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of the present application described herein, for example, can be implemented in an order other than those illustrated or described herein.

[0069] In the embodiments of this application, words such as "exemplarily" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplarily" or "for example" in the embodiments of this application should not be interpreted as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplarily" or "for example" is intended to present the relevant concepts in a concrete manner.

[0070] As can be seen from the background, the process of stacking battery cells into modules in related technologies typically involves filling the gaps between the cells with foam or aerogel to increase insulation and cushioning. These cells are then stacked into modules, and pressure is applied to the modules from both sides using electric cylinders to constrain them to a predetermined length. To ensure the stability of the module structure, glue is applied to the top and bottom surfaces of the modules and tie bars are attached. After the glue cures, the restraining force of the electric cylinders is removed, and the modules now rely primarily on the tie bars to maintain their shape. The modules, now restrained by tie bars, are then spliced ​​together and loaded onto a tray.

[0071] In order to further enhance the bonding strength between the module and the tray, glue is poured into the gap between the tray and the large surface of the module to fill and solidify the gap, thereby completing the assembly process of the entire battery module.

[0072] However, there are some problems with the above-mentioned battery cell stacking method.

[0073] First, attaching the tie strips requires the use of UV-curing adhesive, which requires specialized UV lamps to cure. This necessitates transparent materials, limiting the choice of materials. Second, because the module relies on the tie strips to maintain their shape, higher requirements are placed on their strength and elastic modulus, which also limits the choice of materials. Furthermore, the use of UV-curing adhesive increases the equipment investment required for both the glue applicator and the UV curing machine, raising production costs.

[0074] Furthermore, if the incoming batch of battery cells is too thick, removing the electric cylinder restraint will result in excessive restraint force on the tie bars, which may not be able to withstand it, causing the module to rebound too long and prevent smooth loading on the pallet. To avoid this problem, related technologies use a mix of foam or aerogel and battery cells of varying thicknesses. However, this process is complex and requires real-time updates of stock quantities, which increases management difficulties.

[0075] Finally, due to changes in foam thickness and tolerance accumulation, the relative positions of the battery cells will change. As a result, when welding the connecting pieces, the robotic arm may move according to a fixed offset, and the laser may not be aligned with the battery cell pole, causing welding deviation and affecting the performance and safety of the battery pack.

[0076] In summary, the technology of stacking battery cells into modules has technical problems such as limited selection of pull rod materials, the need for additional equipment to increase costs, cumbersome production processes, complex and error-prone management of battery cell thickness, and tolerance accumulation that affects welding accuracy.

[0077] In view of this, the present application provides a battery pack, an electrical device, a battery module and an assembly method thereof, wherein the assembly method of the battery module includes: providing a plurality of battery cells, the plurality of battery cells including an adjacent first battery cell and a second battery cell, and a gap is set between the first battery cell and the second battery cell; installing an initial expansion structure in the gap, the initial expansion structure including a vacuum bag and an expansion piece, the vacuum bag forms a accommodating cavity in a negative pressure state, and the expansion piece is located in the accommodating cavity; forming an air inlet that can communicate with the accommodating cavity in the vacuum bag, the accommodating cavity inhales air through the air inlet, and the expansion piece expands in the accommodating cavity; the first surface of the expansion piece abuts against the first battery cell through the first part of the vacuum bag, and the second surface of the expansion piece abuts against the second battery cell through the second part of the vacuum bag.

[0078] The battery module assembly method provided in the embodiment of the present application provides a stable and controllable way to fill the gaps between the battery cells during the battery cell stacking process by setting an initial expansion structure between the first battery cell and the second battery cell and utilizing the design of a vacuum bag and an expansion piece.

[0079] In the initial expansion structure, the expansion part is in the vacuum bag and is in a negative pressure state. Therefore, the overall thickness of the initial expansion structure is relatively stable. When the battery cells are stacked, the initial expansion structure has no force on the battery cells or only has a small force. Therefore, no restraint operation is required, and there is no problem of excessive or insufficient restraint force. Therefore, the use of pull rods can be avoided, or replaced with other limit strips with lower strength and material to ensure the stability of the battery cell position. This helps to solve the problems of limited selection of pull rod materials and increased equipment costs.

[0080] Moreover, when the thickness of the battery cell is relatively thick, the thickness of the expansion structure can be easily adjusted according to the actual width of the gap between the battery cells, eliminating the need to match the thickness of the filling material, and helping to simplify the production process and reduce the difficulty of material preparation management.

[0081] Furthermore, the stable thickness of the expansion structure ensures a constant gap width between the first and second cells, thus maintaining a fixed relative position between the cells. This ensures a stable distance between the terminals and avoids offset issues caused by tolerance accumulation. When welding the connecting tabs, the robotic arm can operate within a fixed offset, improving welding speed and accuracy, ensuring the performance and safety of the battery pack.

[0082] After the stacked battery cells are loaded into the tray, the accommodating cavity of the vacuum bag can inhale air through the air inlet to expand the expansion piece in the accommodating cavity. The expansion piece abuts against both the first battery cell and the second battery cell, thereby providing pre-tightening force for the battery cells.

[0083] The technical solution of the present application is described in detail below with reference to the accompanying drawings and specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0084] Combine Figures 1 to 3As shown, the first aspect of an embodiment of the present application provides a battery module, including: a plurality of battery cells 100, the plurality of battery cells 100 including adjacent first battery cells 110 and second battery cells 120, a gap 101 is provided between the first battery cell 110 and the second battery cell 120; an expansion structure 200, arranged in the gap 101, the expansion structure 200 including a vacuum bag 210 and an expansion piece 220; the vacuum bag 210 forms a accommodating cavity, the vacuum bag 210 is provided with an air inlet that can be communicated with the accommodating cavity; the expansion piece 220 is arranged in the accommodating cavity, the first surface of the expansion piece 220 can abut against the first battery cell 110 through the first part of the vacuum bag 210, and the second surface of the expansion piece 220 can abut against the second battery cell 120 through the second part of the vacuum bag 210.

[0085] It is understandable that in the conventional method of stacking the battery cells 100 , foam or aerogel is filled between the battery cells 100 and squeezed. The deformation of the foam or aerogel after compression is uncertain, which may cause the relative positions of the battery cells 100 to be unstable.

[0086] The expansion structure 200 provided in the embodiment of the present application includes a vacuum bag 210 and an expansion piece 220. In the initial state, the expansion piece 220 is in the vacuum bag 210, and the accommodating cavity of the vacuum bag 210 is in a negative pressure state. The expansion piece 220 is compressed and its thickness is relatively stable, which can avoid the uneven thickness problem of traditional filling materials.

[0087] When the battery cells 100 are stacked, the thickness of the expansion structure 200 is relatively stable. When stacked with the first battery cell 110 and the second battery cell 120, it has no force or only a small force on the battery cell 100. Therefore, no restraint operation is required, and there is no problem of excessive or insufficient restraint force. The use of pull rods can be avoided, or replaced with other limit rods with lower strength and material to ensure the stability of the position of the battery cell 100, which helps to solve the problems of limited selection of pull rod materials and increased equipment costs.

[0088] When the battery cells 100 are relatively thick, the thickness of the expansion structure 200 can be easily adjusted based on the actual width of the gaps 101 between the battery cells 100. For example, a thinner expansion member 220 can be used directly, or the negative pressure in the vacuum bag 210 cavity can be increased to reduce the compressed thickness of the expansion member 220. This eliminates the need to adjust the thickness of the filler material and helps simplify the production process. The expansion member 220 can be of a single type and a fixed quantity during stock preparation, reducing the difficulty of stock preparation and management.

[0089] Furthermore, the relatively stable thickness of the expansion structure 200 ensures a constant width of the gap 101 between the first and second battery cells 110, 120. This maintains the relative position of the battery cells 100, ensuring a stable distance between the terminals and avoiding offset issues caused by tolerance accumulation. When welding the connecting tabs, the robotic arm can operate within a fixed offset, improving welding speed and accuracy, ensuring the performance and safety of the battery pack.

[0090] By providing an air inlet in the vacuum bag 210, air can be introduced into the vacuum bag 210 as needed to adjust the expansion of the expansion member 220. After the stacked battery cells 100 are loaded into the tray 400, air can be drawn into the accommodating cavity of the vacuum bag 210 through the air inlet, causing the expansion member 220 to expand within the accommodating cavity. The expansion member 220 abuts against both the first battery cell 110 and the second battery cell 120, providing preload force for the battery cells 100.

[0091] Specifically, the battery module provided in the embodiment of the present application provides a stable and controllable method for filling the gaps 101 between the battery cells 100 by introducing an expansion structure 200 between the battery cells 100 and utilizing the design of a vacuum bag 210 and an expansion piece 220. This arrangement not only avoids the problems of uneven filling material and unstable positioning of the battery cells 100 that may occur when stacking the battery cells 100 in traditional methods, but also improves the stability and precision of the battery cell 100 stacking, thereby helping to enhance the performance and safety of the battery module.

[0092] In some embodiments, when the expansion member 220 is located in the gap 101 , the expansion member 220 is in a compressed state; after the expansion member 220 moves out of the gap 101 , the thickness of the expansion member 220 is greater than or equal to the width of the gap 101 .

[0093] It can be understood that when the expansion member 220 is in a compressed state, it can be conveniently placed in the gap 101 between the battery cells 100 .

[0094] During the assembly of the battery cells 100, the expansion member 220 must first be placed in the gap 101 between the battery cells 100. By designing the expansion member 220 to be initially compressed, it can be ensured to smoothly enter the gap 101 without requiring a restrained operation or applying excessive force to adjust the position of the battery cells 100.

[0095] The expansion member 220 is placed in the gap 101 in a compressed state. After removal or expansion, its thickness can be restored to a value greater than or equal to the width of the gap 101. This design ensures that the expansion member 220 has sufficient elasticity and recovery ability to completely fill the gap 101 when needed, providing the necessary support and fixation to prevent the battery cell 100 from moving or vibrating during use.

[0096] Combine Figure 5 As shown, in some embodiments, a first adhesive layer 211 is provided on the first portion of the vacuum bag 210 , and the surface of the first adhesive layer 211 away from the vacuum bag 210 is connected to the surface of the first battery cell 110 facing the second battery cell 120 .

[0097] During the assembly process of the battery cell 100, an adhesive layer is provided on the first portion of the vacuum bag 210 to increase the adhesion between the battery cell 100 and the expansion structure 200, thereby ensuring a tight connection between the first battery cell 110 and the expansion structure 200 and improving the structural stability of the battery cell 100 stack.

[0098] Combine Figure 4 As shown, in some embodiments, the second portion of the vacuum bag 210 is provided with a second adhesive layer 212 , and the surface of the second adhesive layer 212 away from the vacuum bag 210 is connected to the surface of the second battery cell 120 facing the first battery cell 110 .

[0099] Similar to the first adhesive layer 211 , the second adhesive layer 212 can ensure a stable connection between the second battery cell 120 and the expansion structure 200 by providing adhesion, further improving the stability of the battery cell 100 stack and helping to prevent the battery cell 100 from being displaced due to vibration or other external forces during operation.

[0100] In some embodiments, the expansion member 220 is made of at least one of foam and aerogel.

[0101] By selecting foam or aerogel as the material of the expansion member 220 , excellent elasticity and cushioning properties are provided, the gaps 101 between the battery cells 100 can be effectively filled, and stable supporting properties can be provided after expansion.

[0102] It can be understood that the foam has good elasticity and compressibility, and is suitable for being placed in the gap 101 of the battery cell 100 in an initial compressed state, and recovering to fill the gap 101 after expansion.

[0103] Aerogel is lightweight and has excellent thermal insulation properties, and can reduce heat conduction between battery cells 100 while providing support.

[0104] In some embodiments, the material of the vacuum bag 210 is plastic packaging material.

[0105] It should be noted that plastic packaging materials are widely used in the packaging industry due to their easy processing, low cost and good sealing properties. Plastic packaging materials can be made of plastics such as polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyester (PET) or nylon (PA).

[0106] Using plastic packaging material as the material of the vacuum bag 210 can provide excellent airtightness and flexibility, can effectively maintain the negative pressure state of the vacuum bag 210, and expand through the air inlet when needed, which helps to achieve controllable expansion of the expansion piece 220 and effective filling of the gap 101 of the battery cell 100.

[0107] It should be noted that when the expansion structure 200 is arranged in the gap 101, in the arrangement direction of the first battery cell 110 and the second battery cell 120, the first part of the vacuum bag 210 is located within the projection area of ​​the first battery cell 110; the second part of the vacuum bag 210 is located within the projection area of ​​the second battery cell 120.

[0108] As will be appreciated, the expansion structure 200 is located within the gap 101 and does not extend outside the gap 101. By controlling the boundaries of the expansion structure 200 and limiting its range within the gap 101, interference with the external packaging of the battery cell 100 is avoided, thereby ensuring the packaging integrity and sealing of the battery cell 100 and safeguarding the overall structure and functionality of the battery module.

[0109] In some embodiments, in the arrangement direction of the first battery cell 110 and the second battery cell 120 , the area of ​​the first surface of the expansion member 220 may be no less than half of the projected area of ​​the first battery cell 110 ; the area of ​​the second surface of the expansion member 220 may be no less than half of the projected area of ​​the second battery cell 120 .

[0110] By ensuring that the first surface of the expansion member 220 covers at least half of the projected area of ​​the battery cell 100 and the second surface of the expansion member 220 covers at least half of the projected area of ​​the battery cell 100, sufficient mechanical support is provided, which helps to provide necessary buffering and protection when the battery cell 100 undergoes thermal expansion or mechanical stress.

[0111] In some embodiments, in the arrangement direction of the first battery cell 110 and the second battery cell 120 , at least some of the battery cells 100 are sequentially arranged to form a battery cell assembly including the first battery cell 110 and the second battery cell 120 .

[0112] By spacing the cells 100 and forming a cell assembly, a modular design is achieved. This modular design allows the cells 100 to be combined and connected in a standardized manner, simplifying the production and assembly process. Forming a cell assembly also makes it easier to standardize and replace the cells 100, improving the overall reliability and maintainability of the battery module.

[0113] In some embodiments, multiple battery cell assemblies are spliced ​​together, and the spliced ​​multiple battery cell assemblies are loaded into the tray 400 to form a battery module.

[0114] In some embodiments, the battery cell assembly is provided with a connector 300 , the extension direction of the connector 300 is parallel to the arrangement direction of the battery cells 100 , and the connector 300 can connect the battery cells 100 in the same battery cell assembly.

[0115] By setting a connector 300 in the battery cell assembly, the connector 300 can connect the battery cells 100 in the same battery cell assembly, provide unified structural support for the battery cells 100 in the battery cell assembly, and effectively fix the individual battery cells 100 together to ensure that the relative position of the battery cells 100 in the assembly remains stable, preventing the battery cells 100 from shifting or loosening due to vibration or external force during transportation, installation or use.

[0116] By making the extension direction of the connector 300 parallel to the arrangement direction of the battery cells 100 , the structural strength of the connector 300 can be utilized to the maximum extent to support the arrangement of the battery cells 100 , ensuring that the connector 300 can effectively withstand the mechanical stress from the arrangement direction of the battery cells 100 .

[0117] In some embodiments, the connector 300 is configured as a pull rod, the pull rod is provided with a glue layer, and the pull rod is bonded and fixed to the battery cell 100 through the glue layer.

[0118] It can be understood that the tie rod, as a simple and effective structural element, can provide effective mechanical connection in the battery cell assembly.

[0119] By designing the connector 300 as a pull rod with an adhesive layer and bonding and fixing it to the battery cell 100 through the adhesive layer, linear and uniform support and fixation can be provided in the arrangement direction of the battery cell 100 to maintain the stacking shape of the battery cell 100.

[0120] The setting of the rubber layer enhances the adhesion between the pull rod and the battery cell 100, ensures that the pull rod can be firmly fixed on the battery cell 100, enhances the connection strength between the pull rod and the battery cell 100, and also increases the reliability of the connection, preventing the battery cell 100 from loosening due to vibration or external force during operation or use.

[0121] In some embodiments, the connecting member 300 is configured as a rubber limiting strip.

[0122] It can be understood that the glue limiting strip, as a specially designed connector 300, can limit the flow and diffusion of glue during the gluing process, ensuring that the glue layer forms a uniform coverage on the surface of the battery cell 100, so as to facilitate the effective connection between the packaging shell and the battery cell 100 after packaging, thereby ensuring the overall performance and service life of the battery module.

[0123] Designing connector 300 as a limited adhesive strip effectively controls the thickness and distribution of the adhesive layer, ensuring uniformity of the adhesive layer between battery cells 100. This design helps improve bonding reliability and consistency, and prevents connection problems caused by excessively thick or uneven adhesive layers.

[0124] Since in the initial state, the expansion piece 220 in the expansion structure 200 is inside the vacuum bag 210, and the accommodating cavity of the vacuum bag 210 is in a negative pressure state, the expansion piece 220 is compressed and its thickness is relatively stable. When stacked with the battery cell 100, it has no force or only a small force on the battery cell 100. Therefore, there is no need for restraint operation, nor is there a need to use high-strength pull rods to ensure the stability of the position of the battery cell 100. The strength and material requirements of the pull rods are lower.

[0125] When setting the glue limit strip, the glue limit strip can be directly pasted with the adhesive backing, without the need for a glue coating machine and a UV curing machine, which can reduce costs.

[0126] In some embodiments, in the battery cell assembly, a gap 101 is provided between two adjacent battery cells 100 , and the widths of the gaps 101 are the same or approximately the same.

[0127] The gap 101 is provided to accommodate an expandable structure 200 , such as foam or aerogel, which can fill the gap 101 and provide mechanical support when expanded.

[0128] By providing a gap 101 between each pair of adjacent battery cells 100 , the mechanical stability of the entire battery cell assembly can be ensured.

[0129] Maintaining consistency in the width of the gaps 101 can ensure that the expansion structure 200 can play the same role in each gap 101 , that is, provide the same or approximately the same pre-tightening force for the battery cell 100 .

[0130] In addition, this consistent design also facilitates the use of expansion structures 200 of the same specifications, reduces the complexity of materials and processes, and simplifies the production and assembly process.

[0131] In some embodiments, in the battery cell assembly, an expansion structure 200 is disposed in each gap 101 .

[0132] Providing an expansion structure 200 in each gap 101 can ensure that the gaps 101 between all battery cells 100 can be effectively filled and supported, thereby enhancing the overall stability and safety of the battery cell assembly.

[0133] In addition, by providing an expansion structure 200 such as foam or aerogel in each gap 101, not only mechanical support can be provided, but also heat conduction between the battery cells 100 can be reduced through the thermal insulation material such as aerogel, thereby improving the thermal management performance of the battery module.

[0134] Combine Figure 6 As shown, a second aspect of an embodiment of the present application provides a method for assembling a battery module, comprising the following steps:

[0135] S101 , providing a plurality of battery cells 100 ; the plurality of battery cells 100 include adjacent first and second battery cells 110 and 120 , with a gap 101 provided between the first and second battery cells 110 and 120 ;

[0136] S102, installing an initial expansion structure 200 in the gap 101; the initial expansion structure 200 includes a vacuum bag 210 and an expansion member 220, the vacuum bag 210 forms a receiving cavity in a negative pressure state, and the expansion member 220 is located in the receiving cavity;

[0137] S103. An air inlet that can communicate with the accommodating cavity is formed in the vacuum bag 210; the accommodating cavity sucks in air through the air inlet, and the expansion piece 220 expands in the accommodating cavity; the first surface of the expansion piece 220 abuts against the first battery cell 110 through the first part of the vacuum bag 210, and the second surface of the expansion piece 220 abuts against the second battery cell 120 through the second part of the vacuum bag 210.

[0138] It is understandable that during the stacking process of the battery cells 100 , conventional methods rely on foam or aerogel to fill the gaps 101 . However, these materials are squeezed when constrained by the electric cylinder, and variations in thickness and tolerance may cause the position of the battery cells 100 to be unstable.

[0139] It should be noted that the initial expansion structure 200 is the expansion structure 200 in the initial state. In the initial state, the expansion member 220 is in the vacuum bag 210, the accommodating cavity of the vacuum bag 210 is in a negative pressure state, and the expansion member 220 is compressed and has a stable thickness.

[0140] The introduction of the initial expansion structure 200 provides a controllable way to fill the gaps 101 between the battery cells 100. By using the vacuum bag 210 and the expansion member 220, the gaps 101 can be kept compact and of a constant thickness in the initial state, thus avoiding the uneven thickness problem of traditional filling materials.

[0141] The overall thickness of the initial expansion structure 200 can be adapted to the width of the gap 101 required between the battery cells 100. When the battery cells 100 are stacked, no restraint operation is required, and there is no problem of excessive or insufficient restraint force. The use of pull rods can be avoided, or replaced with other limit rods with lower strength and material to ensure the stability of the position of the battery cells 100. This helps to solve the problems of limited selection of pull rod materials and increased equipment costs.

[0142] Moreover, when the battery cells 100 are relatively thick, the thickness of the expansion structure 200 can be easily adjusted according to the actual width of the gap 101 between the battery cells 100, eliminating the need to match the thickness of the filling material, and helping to simplify the production process and reduce the difficulty of material preparation management.

[0143] Furthermore, the thickness of expansion structure 200 is relatively stable, matching the width of gap 101. This ensures that the relative positions of the battery cells 100 are fixed, ensuring a stable distance between the terminals and avoiding offset issues caused by tolerance accumulation. When welding the connecting tabs, the robotic arm can operate with a fixed offset, improving welding speed and accuracy, ensuring the performance and safety of the battery pack.

[0144] After the stacked battery cells 100 are loaded into the tray 400, the accommodating cavity of the vacuum bag 210 can inhale air through the air inlet to allow the expansion piece 220 to expand in the accommodating cavity. The expansion piece 220 abuts against both the first battery cell 110 and the second battery cell 120, thereby providing pre-tightening force for the battery cell 100.

[0145] It should be noted that the accommodating cavity inhales air through the air inlet, so that after the expansion member 220 is expanded in the accommodating cavity, the pre-tightening force that the expansion member 220 can provide to the battery cell 100 is: F=E×S×(d1-d3) / d1;

[0146] Among them, F is the preload force; E is the elastic modulus of the expansion member 220; S is the area of ​​the first surface of the expansion member 220, or the area of ​​the second surface of the expansion member 220; d1 is the thickness of the expansion member 220 under natural conditions; d3 is the width of the gap 101.

[0147] When the thickness of the battery cells 100 changes, the thickness d1 of the expansion member 220 can be determined based on the actual width of the gap 101 between the battery cells 100 and the required preload force F. This eliminates the need to match the thickness of the filling material, ensures a single type of stock and a fixed quantity, and reduces the difficulty of stock management.

[0148] In some embodiments, the steps of installing the initial expansion structure 200 in the gap 101 are specifically as follows:

[0149] The first adhesive layer 211 on the surface of the vacuum bag 210 is adhered to the first battery cell 110; the first battery cell 110 and the second battery cell 120 are stacked together so that the second adhesive layer 212 on the surface of the vacuum bag 210 is adhered to the second battery cell 120; the above steps are repeated to form an initial expansion structure 200 between each pair of battery cells 100.

[0150] When n battery cells 100 are stacked together in a module, the gap 101 between each cell 100 is constant, and the relative positions of the cells 100 are fixed. This prevents excessive deviations between cells 100 due to accumulated tolerances, which could affect the subsequent installation of the plastic brackets and connectors of the cells 100. Furthermore, since the positions of the cells 100 are fixed, the robotic arm can move in a fixed offset during the connector welding, facilitating the welding of the connectors and increasing the welding speed.

[0151] In some embodiments, an initial expansion structure 200 is installed in the gap 101 , and a thickness of the initial expansion structure 200 is less than or equal to a width d3 of the gap 101 .

[0152] If the thickness of the initial expansion structure 200 is greater than the width d3 of the gap 101 , installation may be difficult or still require restraint and rely on tie bars to maintain the shape.

[0153] The thickness of the initial expansion structure 200 is designed to be less than or equal to the width d3 of the gap 101, which can ensure that the expansion structure 200 can be smoothly installed in the gap 101 and completely fill the gap 101 after expansion to provide sufficient preload force.

[0154] In some embodiments, before the vacuum bag 210 forms an air inlet capable of communicating with the receiving cavity, the following steps are included:

[0155] Fix the first battery cell 110 and the second battery cell 120;

[0156] An air inlet that can communicate with the accommodating cavity is formed in the vacuum bag 210 , and the width of the gap 101 remains unchanged during the expansion of the expansion member 220 in the accommodating cavity.

[0157] It can be understood that fixing the battery cell 100 before the expansion member 220 expands ensures that the battery cell 100 maintains a stable position during the expansion process, thereby preventing the battery cell 100 from moving or deflecting due to external forces during the expansion process.

[0158] During the expansion process, if the width of the gap 101 changes, it may cause the battery cell 100 to shift or receive uneven force. By maintaining the width of the gap 101 during the expansion process, it is ensured that the expansion of the expansion member 220 is only used to fill the gap 101 without applying additional lateral pressure to the battery cell 100.

[0159] Specifically, by securing the battery cell 100 before expansion and maintaining the width of the gap 101 constant during the expansion process, the positional stability of the battery cell 100 is ensured throughout the expansion and securing process. This approach helps avoid potential positional shifting and uneven stress on the battery cell 100 during the expansion process, thereby improving the assembly accuracy and stability of the battery module.

[0160] In some embodiments, fixing the first battery cell 110 and the second battery cell 120 includes the following steps:

[0161] The plurality of battery cells 100 are connected by a connector 300 , wherein a first portion of the connector 300 is connected to the first battery cell 110 , and a second portion of the connector 300 is connected to the second battery cell 120 ;

[0162] and / or, placing a plurality of battery cells 100 on a tray 400;

[0163] A filler layer 500 is formed between the plurality of battery cells 100 and the tray 400 , and the first battery cell 110 and the second battery cell 120 are fixed to the tray 400 via the filler layer 500 .

[0164] It is understandable that the battery cells 100 are connected together by the connector 300 to form an integral structure, thereby increasing the mechanical stability between the battery cells 100. This connection method helps to maintain the relative position of the battery cells 100 during the expansion and fixing process.

[0165] It can be understood that the tray 400 acts as a supporting structure, which can effectively limit the movement of the battery cell 100 and provide a stable foundation. In particular, when the expansion structure 200 applies force, the tray 400 can help maintain the overall stability of the battery cell 100.

[0166] The stacked battery cell assemblies are assembled together and then placed in a tray 400 . Glue is then poured into the gap between the battery cell assemblies and the tray 400 to form a glue filling layer 500 to fill the gap.

[0167] The filler layer 500 can effectively fill the small gap 101 between the battery cell 100 and the tray 400 , provide additional fixing force and buffering effect, and prevent the battery cell 100 from moving or vibrating under external force.

[0168] The filler layer 500 forms a bonding interface between the battery cell 100 and the tray 400 , further enhancing the fixing effect of the battery cell 100 .

[0169] Specifically, the use of connectors 300 and tray 400, along with the formation of a filler layer 500 between the battery cell 100 and tray 400, provides a multi-step fixation method to ensure the stability of the battery cell 100 during assembly. This method, combining mechanical connection and adhesive fixation, ensures that the battery cell 100 maintains its relative position and overall stability during expansion and fixation, improving the assembly accuracy and reliability of the battery module, and contributing to enhanced battery module performance and safety.

[0170] After the filling layer 500 is cured, the vacuum bag 210 of the initial expansion structure 200 is cut to form an air inlet on the vacuum bag 210. The accommodating cavity of the vacuum bag 210 can inhale air through the air inlet to allow the expansion piece 220 to expand in the accommodating cavity. The first surface of the expansion piece 220 abuts against the first battery cell 110, and the second surface of the expansion piece 220 abuts against the second battery cell 120, thereby providing effective pre-tightening force for the battery cell 100.

[0171] In some embodiments, before installing the initial expansion structure 200 in the gap 101 , forming the initial expansion structure 200 includes the following steps:

[0172] Providing a vacuum bag 210 having a receiving cavity, wherein the receiving cavity has an opening;

[0173] Place the expansion member 220 in the accommodating cavity;

[0174] Air is sucked from the accommodating chamber to form a negative pressure state in the accommodating chamber and close the opening.

[0175] Specifically, the expansion piece 220 with a thickness of d1 under natural conditions can be first placed in the vacuum bag 210, and then the vacuum bag 210 can be evacuated to compress the thickness of the expansion piece 220 in the vacuum bag 210 to a value less than or equal to the width d3 of the gap 101. Finally, the vacuum bag 210 can be heat-sealed to keep the expansion piece 220 in a compressed state. In this way, the initial expansion structure 200 can be prepared.

[0176] The vacuum bag 210 provides a controlled environment for the subsequent expansion of the expansion member 220 and the filling of the gaps 101 between the battery cells 100. Maintaining a negative pressure in the chamber and sealing the opening ensures that the expansion member 220 expands only when needed, thereby improving the accuracy and reliability of the battery module assembly process and enhancing the performance and safety of the battery module.

[0177] In other embodiments, the vacuum bag 210 may be replaced with a packaging bag made of polyethylene terephthalate (PET bag), and the expansion member 220 may be replaced with foam.

[0178] In a specific implementation, a PET bag is inserted between the first battery cell 110 and the second battery cell 120. After the battery cells are stacked and placed on a tray, polyurethane or other similar foam glue is poured into the PET bag. After curing, the foam glue solidifies and expands in the PET bag, providing preload force for the battery cells 100. As can be understood, foam glue has better fluidity in a liquid state and is easily poured into the PET bag.

[0179] A third aspect of the embodiment of the present application provides a battery pack, comprising the battery module provided by any of the above embodiments.

[0180] The battery module has been described in detail in the above embodiments and will not be described again here.

[0181] A fourth aspect of the embodiment of the present application provides an electrical device, including the battery module provided by any of the above embodiments, or the battery pack provided by any of the above embodiments.

[0182] Among them, the battery module and battery pack have been described in detail in the above embodiments and will not be repeated here.

[0183] Illustratively, the electric device may be a new energy vehicle.

[0184] In summary, the battery pack, electrical equipment, battery module and assembly method thereof provided in the embodiments of the present application provide a stable and controllable way to fill the gaps 101 between the battery cells 100 by setting an initial expansion structure 200 between the battery cells 100 and utilizing the design of the vacuum bag 210 and the expansion piece 220 during the stacking process of the battery cells 100. This can avoid the problems of limited selection of pull rod materials and increased equipment costs in traditional methods, simplify the production process, and reduce the difficulty of material preparation management. At the same time, the relative positions between the battery cells 100 are fixed, which improves the welding speed and accuracy, and ensures the performance and safety of the battery pack.

[0185] Finally, it should be noted that those skilled in the art will readily conceive of other embodiments of the present invention after considering the specification and practicing the applications disclosed herein. The present invention is intended to encompass any variations, uses, or adaptations of the present invention, which follow the general principles of the present invention and include common knowledge or customary techniques in the art that are not disclosed in the present invention. The specification and examples are to be considered merely as exemplary, and the true scope and spirit of the present invention are indicated by the following claims.

[0186] It should be understood that the embodiments of the present application are not limited to the precise structures described above and shown in the drawings, and various modifications and changes can be made without departing from the scope thereof. The scope of the embodiments of the present application is limited only by the appended claims.

Claims

1. A battery module, characterized in that: include: A plurality of battery cells (100), wherein the plurality of battery cells (100) include adjacent first battery cells (110) and second battery cells (120), and a gap (101) is provided between the first battery cells (110) and the second battery cells (120); An expansion structure (200) is disposed in the gap (101), the expansion structure (200) comprising a vacuum bag (210) and an expansion member (220); the vacuum bag (210) is formed with a receiving cavity, and the vacuum bag (210) is provided with an air inlet capable of communicating with the receiving cavity; The expansion piece (220) is arranged in the accommodating cavity, and a first surface of the expansion piece (220) can abut against the first battery core (110) through a first portion of the vacuum bag (210), and a second surface of the expansion piece (220) can abut against the second battery core (120) through a second portion of the vacuum bag (210).

2. The battery module according to claim 1, wherein: When the expansion member (220) is located in the gap (101), the expansion member (220) is in a compressed state; After the expansion member (220) is moved out of the gap (101), the thickness of the expansion member (220) is greater than or equal to the width of the gap (101).

3. The battery module according to claim 1, wherein: A first adhesive layer (211) is provided on a first portion of the vacuum bag (210), wherein a surface of the first adhesive layer (211) away from the vacuum bag (210) is connected to a surface of the first battery cell (110) facing the second battery cell (120); And / or, the second portion of the vacuum bag (210) is provided with a second adhesive layer (212), and the surface of the second adhesive layer (212) away from the vacuum bag (210) is connected to the surface of the second battery cell (120) facing the first battery cell (110).

4. The battery module according to claim 1, wherein: The expansion member (220) is made of at least one of foam and aerogel; And / or, the material of the vacuum bag (210) is plastic packaging material.

5. The battery module according to any one of claims 1 to 4, characterized in that: In the arrangement direction of the first battery cell (110) and the second battery cell (120), at least some of the battery cells (100) in the plurality of battery cells (100) are sequentially spaced apart to form a battery cell assembly including the first battery cell (110) and the second battery cell (120).

6. The battery module according to claim 5, characterized in that: The battery cell assembly is provided with a connecting piece (300), the extending direction of the connecting piece (300) is parallel to the arrangement direction of the battery cells (100), and the connecting piece (300) can connect the battery cells (100) in the same battery cell assembly.

7. The battery module according to claim 6, characterized in that: The connecting member (300) is configured as a pull rod, the pull rod is provided with a glue coating layer, and the pull rod is bonded and fixed to the battery core (100) via the glue coating layer.

8. The battery module according to claim 6, characterized in that: The connecting piece (300) is configured as a rubber limiting strip.

9. The battery module according to claim 5, characterized in that: In the battery cell assembly, a gap (101) is provided between two adjacent battery cells (100), and the widths of the gaps (101) are the same or approximately the same.

10. The battery module according to claim 9, characterized in that: In the battery core assembly, the expansion structure (200) is provided in each of the gaps (101).

11. A method for assembling a battery module, characterized in that: include: A plurality of battery cells (100) are provided; the plurality of battery cells (100) include adjacent first battery cells (110) and second battery cells (120), with a gap (101) being provided between the first battery cells (110) and the second battery cells (120); An initial expansion structure (200) is installed in the gap (101); the initial expansion structure (200) comprises a vacuum bag (210) and an expansion member (220); the vacuum bag (210) forms a receiving cavity in a negative pressure state, and the expansion member (220) is located in the receiving cavity; An air inlet capable of communicating with the accommodating cavity is formed in the vacuum bag (210); the accommodating cavity inhales air through the air inlet, and the expansion member (220) expands in the accommodating cavity; The first surface of the expansion piece (220) abuts against the first battery core (110) through the first portion of the vacuum bag (210), and the second surface of the expansion piece (220) abuts against the second battery core (120) through the second portion of the vacuum bag (210).

12. The battery module assembly method according to claim 11, wherein: An initial expansion structure (200) is installed in the gap (101), and the thickness of the initial expansion structure (200) is less than or equal to the width of the gap (101).

13. The battery module assembly method according to claim 11, wherein: Before the vacuum bag (210) forms an air inlet capable of communicating with the accommodating cavity, the method comprises: fixing the first battery core (110) and the second battery core (120); An air inlet capable of communicating with the accommodating cavity is formed in the vacuum bag (210), and during the expansion process of the expansion member (220) in the accommodating cavity, the width of the gap (101) remains unchanged.

14. The battery module assembly method according to claim 13, wherein: Fixing the first battery core (110) and the second battery core (120) comprises: Connecting a plurality of the battery cells (100) via a connector (300), wherein a first portion of the connector (300) is connected to the first battery cell (110), and a second portion of the connector (300) is connected to the second battery cell (120); and / or, placing a plurality of the battery cells (100) on a tray (400); A glue filling layer (500) is formed between the plurality of battery cells (100) and the tray (400), and the first battery cell (110) and the second battery cell (120) are fixed to the tray (400) via the glue filling layer (500).

15. The battery module assembly method according to any one of claims 11 to 14, characterized in that: Before installing the initial expansion structure (200) in the gap (101), forming the initial expansion structure (200) includes: Providing a vacuum bag (210) having a receiving cavity, wherein the receiving cavity has an opening; placing the expansion member (220) in the accommodating cavity; Air is sucked from the accommodating chamber to form a negative pressure state in the accommodating chamber and close the opening.

16. A battery pack, characterized in that: Comprising the battery module according to any one of claims 1 to 10.

17. An electrical device, characterized in that: Comprising the battery module according to any one of claims 1 to 10, or the battery pack according to claim 16.

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