Battery module, battery pack and installation method

Abstract

The invention relates to a battery module, a battery pack and an installation method, and relates to the technical field of power battery design, and discloses a battery module which comprises a battery cell assembly, a battery pack and a battery module, the module frame comprises two first plate-shaped structural members and two second plate-shaped structural members, and the two first plate-shaped structural members are symmetrically arranged on two side end surfaces of the battery cell assembly in the first direction; the two second plate-shaped structural members are symmetrically arranged on the other two side end faces of the battery cell assembly in the second direction; at least one column-groove matching structure is arranged at each lap joint of the two plate-like structural members, and each column-groove matching structure comprises a convex column and a tapered groove; when the battery cell assembly circulates to the later period of the service life, the protruding columns slide along the gradual change grooves under the action of the expansion force of the battery cell assembly and gradually become tight till being limited. According to the battery module, the battery pack and the mounting method, the technical problem of diving or service life shortening caused by the fact that the battery core assembly cannot fully expand when the cycle reaches the later period of the service life is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of power battery design, and particularly relates to a battery module, a battery pack and an installation method. Background Art

[0002] As battery modules can power electronic devices, the safety of battery modules seriously affects the service life of electronic devices. Among them, the expansion of battery modules has a particularly great impact on their own safety performance. And basically all battery modules will experience expansion problems when they reach the end of their life cycles. A battery module generally includes a module frame and a number of battery cells connected in series. The module frame plays the roles of protection, sealing, support, and insulation.

[0003] In related technologies, the module frames all use connection methods such as welding, screwing, and riveting, and the positions of components are fixed. The module frame not only bears the weight support function but also withstands the huge expansion force generated during the cycling of the battery cells. Therefore, the module frame needs to be enhanced in design to prevent problems such as fracture due to the expansion force.

[0004] However, the enhanced module frame also limits the expansion space of the battery cells. When the battery cells reach the end of their life cycles, due to the limitation of the frame fixation, the battery cells cannot fully expand, and the battery cells are under huge external pressure, posing a risk of voltage drop or reduced life. Summary of the Invention

[0005] This application provides a battery module, a battery pack and an installation method to solve the technical problem that the battery cell assembly cannot fully expand at the end of its life cycle, resulting in voltage drop or reduced life.

[0006] In a first aspect, this application discloses a battery module, comprising:

[0007] A battery cell assembly;

[0008] A module frame, comprising two first plate-like structural members and two second plate-like structural members. The two first plate-like structural members are symmetrically arranged along a first direction on two of the side end faces of the battery cell assembly; the two second plate-like structural members are symmetrically arranged along a second direction on the other two side end faces of the battery cell assembly;

[0009] Each lap joint of the two types of plate-like structural members has at least one post-groove fitting structure. The post-groove fitting structure comprises a raised post arranged on one type of plate-like structural member and a tapered groove arranged on the other type of plate-like structural member. The length of the tapered groove is arranged along the second direction; when the battery cell assembly reaches the end of its life cycle, the raised post slides along the tapered groove under the action of the expansion force of the battery cell assembly and gradually tightens until it is limited.

[0010] In combination with the first aspect, in one embodiment, the protruding post extends along a first direction and is disposed at a side end of the second plate-like structural member; the tapered groove is disposed at an edge of the first plate-like structural member; the protruding post passes through the tapered groove;

[0011] When the battery cell assembly reaches the late stage of its life cycle, the protruding post slides relative to the tapered groove in a direction away from the battery cell assembly under the action of the expansion force of the battery cell assembly.

[0012] In combination with the first aspect, in one embodiment, the edge of the second plate-like structural member has a flanging structure, the tapered groove is disposed in the flanging structure along a second direction, and the protruding post extends along the first direction and is disposed at an edge of the first plate-like structural member; the protruding post passes through the tapered groove;

[0013] When the battery cell assembly reaches the late stage of its life cycle, the protruding post slides relative to the tapered groove, and the second plate-like structural member moves away from the battery cell assembly under the action of the expansion force of the battery cell assembly.

[0014] In combination with the first aspect, in one embodiment, an outer cap is provided at the protruding end of the protruding post, and the dimension of the outer cap along a third direction is greater than the maximum dimension of the tapered groove along the third direction.

[0015] In combination with the first aspect, in one embodiment, the dimension of the tapered groove in the second direction is greater than the dimension of the protruding post; the tapered groove includes a large groove end and a small groove end, the dimension of the large groove end in the third direction is greater than the dimension of the protruding post; the dimension of the small groove end in the third direction is less than the dimension of the protruding post;

[0016] In the initial state of the post-groove fitting structure, the protruding post is in clearance fit with the large groove end; during expansion, the protruding post slides from the large groove end to the small groove end under the action of the expansion force of the battery cell assembly.

[0017] In combination with the first aspect, in one embodiment, the battery cell assembly is formed by stacking a plurality of battery cells along a second direction, and the positive and negative electrode tabs of the plurality of battery cells are connected in series by a plurality of metal strips; a bending structure is provided in the middle of the metal strip, and the bending structure unfolds under the action of the expansion force of the battery cell assembly.

[0018] In combination with the first aspect, in one embodiment, foamed silicone rubber is filled between two adjacent battery cells and between the battery cell and the second plate-like structural member; both the second plate-like structural member and the first plate-like structural member are made of extruded six-series aluminum alloy.

[0019] In combination with the first aspect, in one embodiment, each lap joint of the two plate-like structural members has five post-groove fitting structures, and the outer cap of the protruding post of the post-groove fitting structure is at least 1 mm away from the outer surface of the first plate-like structural member; the hardness of the protruding post is higher than the hardness of the periphery of the tapered groove.

[0020] In a second aspect, the present application discloses a battery pack formed by connecting a plurality of the above battery modules in series and parallel.

[0021] In a third aspect, the present application discloses an installation method for the above battery module, comprising the following steps:

[0022] The battery cell assembly and the second plate-like structural member are stacked under the tooling pressure as designed;

[0023] Maintain the tooling pressure and install the first plate-like structural member. Pass the protruding column through the tapered slot to form a column-slot matching structure. After installation in place, release the tooling pressure, and process the protruding end of the protruding column to form an anti-disengagement outer cap.

[0024] The beneficial effects brought by the technical solutions provided in the embodiments of the present application at least include:

[0025] 1. The battery module of the present application has a simple structure. There is at least one column-slot matching structure at each lap joint of the two types of plate-like structural members. The column-slot matching structure includes a protruding column provided on one type of plate-like structural member and a tapered slot provided on the other type of plate-like structural member. When the battery cell assembly reaches the end of its life cycle and expands, the second plate-like structural member is subjected to the expansion force. The protruding column slides along the tapered slot to expand the internal space, and the mating portion between the protruding column and the tapered slot gradually tightens until positioning is completed. Through the column-slot matching structure, the present application can ensure that in the later stage of the cycle, as the expansion force increases, the internal space of the battery cell assembly gradually expands, ensuring that the external pressure on the battery cell assembly is always at a reasonable level, and avoiding premature battery cell failure or reduced life caused by excessive pressure.

[0026] 2. In the column-slot matching structure of the battery module of the present application, the protruding column extends along a first direction at the side end of the second plate-like structural member, and the tapered slot is provided at the edge of the first plate-like structural member. When the battery cell assembly reaches the end of its life cycle and expands, the second plate-like structural member is subjected to the expansion force. The protruding column slides along the tapered slot to expand the internal space, and the mating portion between the protruding column and the tapered slot gradually tightens until positioning is completed. Through the column-slot matching structure, the column-slot matching structure ensures that the second plate-like structural member can provide appropriate pressure to the battery cell assembly, avoiding capacity degradation of the battery cell assembly due to excessive stress or excessive expansion deformation.

[0027] 3. For the battery module of the present application, the size of the tapered groove in the second direction is greater than that of the raised post. The tapered groove includes a large groove end and a small groove end. The size of the large groove end in the third direction is greater than that of the raised post; the size of the small groove end in the third direction is smaller than that of the raised post; in the initial state of the post-groove fitting structure, the raised post is in clearance fit with the large groove end; when the battery cell assembly reaches the late stage of its life cycle, under the action of the expansion force of the battery cell assembly, the raised post slides from the large groove end to the small groove end, and the post-groove fit becomes tighter and tighter until the raised post is completely limited. The surplus space of the post-groove fit can prevent the battery cell from being subjected to excessive pressure.

[0028] When the expansion force further increases, the tapered groove of the post-groove fitting structure collapses and deforms under the extrusion of the raised post, which can further expand the accommodation space of the module frame. The surplus space of the post-groove fit and the space margin of the collapse deformation cooperate with each other to ensure that the external pressure on the battery cell is always at a reasonable level, and to prevent the battery cell from diving or reducing its life due to excessive pressure.

[0029] 4. For the battery module of the present application, on the basis of the post-groove fit, specific materials are used. Both the second plate-shaped structural member and the first plate-shaped structural member are made of extruded 6xxx series aluminum alloy. After the post-groove fit reaches the limit position, it can further collapse and deform, ensuring that the external pressure on the battery cell is always at a reasonable level, and preventing the battery cell from diving or reducing its life due to excessive pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0031] Figure 1 It is a schematic diagram of the battery module provided by the embodiment of the present application;

[0032] Figure 2 is Figure 1 an exploded view of;

[0033] Figure 3 It is a schematic diagram of the initial state of the raised post and the tapered groove provided by the embodiment of the present application;

[0034] Figure 4 It is a schematic diagram of the limited state of the raised post and the tapered groove provided by the embodiment of the present application;

[0035] Figure 5 It is a schematic diagram of the outer cap of the raised post provided by the embodiment of the present application;

[0036] In the figure: 1. First plate-shaped structural member; 2. Second plate-shaped structural member; 3. Compressible material; 4. Battery cell; 5. Metal strip; 11. Gradual change groove; 21. Protruding column. Detailed implementation manner

[0037] In order to enable those skilled in the art to better understand the solution of this application, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of this application.

[0038] This application provides a battery module, which solves the technical problem that the battery cell assembly cannot fully expand in the later stage of the cycle life, resulting in voltage drop or reduced life, so that the battery cell assembly can expand safely and fully in the later stage of the cycle life and extend the service life.

[0039] As Figure 2 shown, the width direction of the battery cell assembly is the first direction x, the length direction of the battery cell assembly is the second direction y, and the height direction of the battery cell assembly is the third direction z.

[0040] As Figure 1 and Figure 2 shown, in the first aspect, an embodiment of a battery module disclosed in this application, the battery module includes a battery cell assembly and a module frame. The battery cell assembly includes a plurality of battery cells 4, and the module frame includes two first plate-shaped structural members 1 and two second plate-shaped structural members 2. The two first plate-shaped structural members 1 and the two second plate-shaped structural members 2 enclose a rectangular accommodation cavity for accommodating a plurality of battery cells 4.

[0041] The two first plate-shaped structural members 1 are symmetrically arranged on two side end faces of the battery cell assembly along the first direction (i.e., Figure 2 the x direction in Figure 2 ). The two second plate-shaped structural members 2 are symmetrically arranged on the other two side end faces of the battery cell assembly along the second direction (i.e.,

[0042] the y direction in

[0043] Each lap joint of the two types of plate-shaped structural members has at least one column-groove matching structure, and the column-groove matching structure can enable the module frame to expand the volume of the internal cavity when subjected to an expansion force.The post-groove matching structure includes a convex post 21 provided on a plate-like structural member of one type and a tapered groove 11 provided on a plate-like structural member of another type. The tapered groove 11 is strip-shaped and its length is set along the second direction. When the battery cell assembly reaches the late stage of its life cycle, the battery cell assembly will inevitably expand. Under the action of the expansion force of the battery cell assembly, the second plate-like structural member 2 moves away from the battery cell assembly along the second direction. The convex post 21 slides along the tapered groove 11 under the action of the expansion force of the battery cell assembly, and the convex post 21 gradually tightens during sliding in the tapered groove 11 until the limit is reached, that is, when the convex post 21 starts to slide relative to the tapered groove 11, there is basically no resistance, and then the resistance gradually increases until the limit is reached.

[0044] The battery module of the present application has a simple structure and has at least one post-groove matching structure at each lap joint of two types of plate-like structural members. The post-groove matching structure includes a convex post 21 provided on a plate-like structural member of one type and a tapered groove 11 provided on a plate-like structural member of another type. When the battery cell assembly reaches the late stage of its life cycle and expands, the second plate-like structural member 2 is subjected to an expansion force, and the convex post 21 slides along the tapered groove 11 to expand the internal space, and the mating portion of the convex post 21 and the tapered groove 11 gradually tightens until the limit is reached. Through the post-groove matching structure, the present application can ensure that in the later stage of the cycle of the battery cell assembly, the internal space gradually expands with the increase of the expansion force, ensure that the external pressure on the battery cell assembly is always at a reasonable level, and avoid premature failure or reduced life of the battery cell caused by excessive pressure. The battery module of the present application is suitable for various types of battery packs such as vehicle-mounted battery packs, energy storage battery packs, and transportation tools.

[0045] Regarding the post-groove matching structure, in one embodiment, the convex post 21 extends along the first direction and is provided at the side end of the second plate-like structural member 2. The tapered groove 11 is provided at the edge of the first plate-like structural member 1. The convex post 21 passes through the tapered groove 11.

[0046] When the battery cell assembly reaches the late stage of its life cycle, the second plate-like structural member 2 is subjected to an outward expansion force, and the convex post 21 slides relative to the tapered groove 11 along the direction away from the battery cell assembly under the action of the expansion force of the battery cell assembly.

[0047] Specifically, in this embodiment, the groove is stationary and the post moves. In the initial state, the convex post 21 of the post-groove matching structure is located at the innermost side of the tapered groove 11. After being subjected to the expansion force, the convex post 21 moves outward relative to the tapered groove 11 along the second direction.

[0048] In the battery module of the present application, in the column-groove matching structure, the protruding column 21 extends along the first direction and is arranged at the side end of the second plate-like structural member 2, and the tapered groove 11 is arranged at the edge of the first plate-like structural member 1. When the two are matched, when the battery cell assembly reaches the later stage of its life cycle and the battery cell assembly expands, the second plate-like structural member 2 is subjected to the expansion force, and the protruding column 21 slides along the tapered groove 11 to expand the internal space, and the mating part of the protruding column 21 and the tapered groove 11 gradually tightens until the limit is completed; through the column-groove matching structure of the present application, the column-groove matching structure ensures that the second plate-like structural member 2 can provide appropriate pressure to the battery cell assembly, avoiding capacity drop of the battery cell assembly due to excessive stress or excessive expansion and deformation.

[0049] Preferably, the edge of the second plate-like structural member 2 has a flanging structure, and the protruding column 21 is arranged along the second direction on the flanging structure.

[0050] Regarding the column-groove matching structure, in another embodiment, the edge of the second plate-like structural member 2 has a flanging structure, and the tapered groove 11 is arranged along the second direction on the flanging structure. The protruding column 21 extends along the first direction and is arranged at the edge of the first plate-like structural member 1. The protruding column 21 passes through the tapered groove 11.

[0051] When the battery cell assembly reaches the later stage of its life cycle, the protruding column 21 slides relative to the tapered groove 11, and the second plate-like structural member 2 moves away from the battery cell assembly under the action of the expansion force of the battery cell assembly.

[0052] Specifically, in this embodiment, the column is stationary and the groove moves. In the initial state, the protruding column 21 of the column-groove matching structure is located at the outermost side of the tapered groove 11. After being subjected to the expansion force, along the second direction, the tapered groove 11 moves outward relative to the protruding column 21.

[0053] In the battery module of the present application, in the column-groove matching structure, the edge of the second plate-like structural member 2 has a flanging structure, the tapered groove 11 is arranged along the second direction on the flanging structure, and the protruding column 21 extends along the first direction and is arranged at the edge of the first plate-like structural member 1. When the two are matched, when the battery cell assembly reaches the later stage of its life cycle and the battery cell assembly expands, the second plate-like structural member 2 is subjected to the expansion force, and the protruding column 21 slides along the tapered groove 11 to expand the internal space, and the mating part of the protruding column 21 and the tapered groove 11 gradually tightens until the limit is completed; through the column-groove matching structure of the present application, the column-groove matching structure ensures that the second plate-like structural member 2 can provide appropriate pressure to the battery cell assembly, avoiding capacity drop of the battery cell assembly due to excessive stress or excessive expansion and deformation.

[0054] In one embodiment, an outer cap is provided at the protruding end of the protruding column 21, and the dimension of the outer cap along the third direction is larger than the maximum dimension of the tapered groove 11 along the third direction.

[0055] Such as Figure 5As shown, specifically, the width of the outer cap is greater than the maximum width of the tapered groove 11, which can effectively prevent the column-groove fit from coming out, making it safer and more reliable.

[0056] In one embodiment, the dimension of the tapered groove 11 in the second direction is greater than the dimension of the protruding post 21, that is, there is a sliding margin reserved in the second direction for the tapered groove 11.

[0057] The tapered groove 11 includes a large groove end and a small groove end, as Figure 3 and Figure 4 , the left side is the large groove end of the tapered groove 11, and the right side is the small groove end of the tapered groove 11.

[0058] The dimension of the large groove end in the third direction is greater than the dimension of the protruding post 21; the dimension of the small groove end in the third direction is less than the dimension of the protruding post 21.

[0059] In the initial state of the column-groove fit structure, the protruding post 21 is in clearance fit with the large groove end; when the battery cell assembly reaches the later stage of its life cycle, under the action of the expansion force of the battery cell assembly, the protruding post 21 slides from the large groove end to the small groove end, and the column-groove fit becomes tighter and tighter until the protruding post 21 is completely limited.

[0060] Furthermore, when the expansion force further increases, the tapered groove 11 of the column-groove fit structure collapses and deforms under the extrusion of the protruding post 21, which can further expand the accommodation space of the module frame. The surplus space of the column-groove fit and the space margin of the collapse deformation cooperate with each other to ensure that the external pressure on the battery cell is always at a reasonable level, avoiding excessive pressure causing the battery cell to dive or reducing its life.

[0061] For the battery module of the present application, the dimension of the tapered groove 11 in the second direction is greater than the dimension of the protruding post 21. The tapered groove 11 includes a large groove end and a small groove end. The dimension of the large groove end in the third direction is greater than the dimension of the protruding post 21; the dimension of the small groove end in the third direction is less than the dimension of the protruding post 21. In the initial state of the column-groove fit structure, the protruding post 21 is in clearance fit with the large groove end; when the battery cell assembly reaches the later stage of its life cycle, under the action of the expansion force of the battery cell assembly, the protruding post 21 slides from the large groove end to the small groove end, and the column-groove fit becomes tighter and tighter until the protruding post 21 is completely limited. The surplus space of the column-groove fit can prevent the battery cell from being subjected to excessive pressure.

[0062] When the expansion force further increases, the tapered groove 11 of the column-groove fit structure collapses and deforms under the extrusion of the protruding post 21, which can further expand the accommodation space of the module frame. The surplus space of the column-groove fit and the space margin of the collapse deformation cooperate with each other to ensure that the external pressure on the battery cell is always at a reasonable level, avoiding excessive pressure causing the battery cell to dive or reducing its life.

[0063] In one embodiment, the battery cell assembly is formed by stacking a plurality of battery cells 4 in the second direction, and the positive and negative tabs of the plurality of battery cells 4 are connected in series through a plurality of metal strips 5. The middle of the metal strip 5 has a bending structure, and the bending structure unfolds under the expansion force of the battery cell assembly. The bending structure of the metal strip 5 can prevent the metal strip 5 from being torn and damaged when the battery cells expand.

[0064] Specifically, two second plate-like structural members 2 are stacked outside the two outermost battery cells of the battery cell assembly.

[0065] Preferably, the edge of the first plate-like structural member 1 extends beyond the second plate-like structural member 2 to reserve more movement margin.

[0066] Further, compressible materials 3 are filled between two adjacent battery cells 4 and between the battery cell 4 and the second plate-like structural member 2, and the compressible materials 3 are made of foamed silicone rubber. The foamed silicone rubber can expand as the battery cell assembly expands.

[0067] Both the second plate-like structural member 2 and the first plate-like structural member 1 are made of extruded 6xxx series aluminum alloy. The extruded 6xxx series aluminum alloy has relatively high strength and can withstand the expansion pressure of the battery cells. The extruded 6xxx series aluminum alloy is an aluminum alloy with magnesium and silicon as the main alloying elements, belonging to wrought aluminum alloy, with medium strength and good plasticity, so it is widely used as extruded aluminum materials.

[0068] Preferably, the structural member 5 is made of 1xxx series aluminum alloy.

[0069] In other embodiments, the tapered groove and its surrounding area should be made of metal material and have excellent ductility.

[0070] Further, when the first plate-like structural member 1 is grooved and the surrounding material deforms, no debris with a diameter exceeding 0.1 mm should be generated. The first plate-like structural member 1 should have relatively high tensile strength and excellent extensibility, and can withstand a tensile force of 0.6 times the expansion pressure of the battery cells.

[0071] For the battery module of the present application, on the basis of the column-groove cooperation, specific materials are used. Both the second plate-like structural member 2 and the first plate-like structural member 1 are made of extruded 6xxx series aluminum alloy. After the column-groove cooperation reaches the limit position, it can further undergo a collapse deformation to ensure that the external pressure on the battery cells is always at a reasonable level, avoiding excessive pressure causing the battery cells to experience a voltage drop or reduced lifespan.

[0072] In one embodiment, each lap joint of the two plate-like structural members has five column-groove cooperation structures, and the outer cap of the protruding column 21 of the column-groove cooperation structure is at least 1 mm away from the outer surface of the first plate-like structural member 1.

[0073] The hardness of the protruding column 21 is higher than the hardness of the periphery of the tapered groove 11. The protruding column 21 can squeeze the tapered groove 11, causing the tapered groove 11 to undergo a collapsible deformation within a safe range. During extrusion, the tapered groove 11 deforms while the protruding column 21 remains unchanged.

[0074] Specifically, the protruding column 21 can be a cylinder or in other forms. The tapered groove 11 does not produce debris with a diameter exceeding 0.1 mm during compression deformation.

[0075] In a second aspect, a battery pack is formed by connecting a plurality of the above-mentioned battery modules in series and parallel.

[0076] Regarding the column-groove fitting structure, in one embodiment, the protruding column 21 extends along a first direction and is disposed at the side end of the second plate-like structural member 2. The tapered groove 11 is disposed at the edge of the first plate-like structural member 1. The protruding column 21 passes through the tapered groove 11. When the battery cell assembly reaches the end of its life cycle, the second plate-like structural member 2 is subjected to an outward expansion force, and the protruding column 21 slides relative to the tapered groove 11 in a direction away from the battery cell assembly under the action of the expansion force of the battery cell assembly. Specifically, in this embodiment, the groove remains stationary while the column moves. In the initial state, the protruding column 21 of the column-groove fitting structure is located at the innermost side of the tapered groove 11. After being subjected to the expansion force, the protruding column 21 moves outward relative to the tapered groove 11 along a second direction.

[0077] In the battery module of the present application, in the column-groove fitting structure, the protruding column 21 extends along a first direction and is disposed at the side end of the second plate-like structural member 2, and the tapered groove 11 is disposed at the edge of the first plate-like structural member 1. When the battery cell assembly expands at the end of its life cycle, the second plate-like structural member 2 is subjected to an expansion force, and the protruding column 21 slides along the tapered groove 11 to expand the internal space, and the fitting portion between the protruding column 21 and the tapered groove 11 gradually tightens until the limit is completed; through the column-groove fitting structure of the present application, the column-groove fitting structure ensures that the second plate-like structural member 2 can provide appropriate pressure to the battery cell assembly, avoiding capacity drop of the battery cell assembly due to excessive stress or excessive expansion deformation.

[0078] In a third aspect, a method for installing the above-mentioned battery module includes the following steps:

[0079] The battery cell assembly and the second plate-like structural member 2 are stacked under the tooling pressure as designed;

[0080] Maintain the tooling pressure and install the first plate-like structural member 1, pass the protruding column 21 through the tapered groove 11 to form a column-groove fitting structure. After installation in place, release the tooling pressure, and process the protruding end of the protruding column 21 to form an anti-detachment outer cap.

[0081] Further, regarding the post-groove fitting structure, the protruding post 21 extends along the first direction and is disposed at the side end of the second plate-like structural member 2. The tapered groove 11 is disposed at the edge of the first plate-like structural member 1. The protruding post 21 passes through the tapered groove 11. When the battery cell assembly reaches the later stage of its life cycle, the second plate-like structural member 2 is subjected to an outward expansion force, and the protruding post 21 slides relative to the tapered groove 11 in a direction away from the battery cell assembly under the action of the expansion force of the battery cell assembly. Specifically, in this embodiment, the groove remains stationary while the post moves. In the initial state, the protruding post 21 of the post-groove fitting structure is located at the innermost side of the tapered groove 11, and after being subjected to the expansion force, the protruding post 21 moves outward relative to the tapered groove 11 along the second direction.

[0082] Specifically, an outer cap is provided at the protruding end of the protruding post 2, and the dimension of the outer cap along the third direction is greater than the maximum dimension of the tapered groove 11 along the third direction. As Figure 5 shown, specifically, the width of the outer cap is greater than the maximum width of the tapered groove 11, which can effectively prevent the post-groove fitting from coming out, and is safer and more reliable.

[0083] Specifically, the battery cell assembly is formed by stacking a plurality of battery cells 4 along the second direction, and the positive and negative electrode tabs of the plurality of battery cells 4 are connected in series through a plurality of metal strips 5. The metal strip 5 has a bending structure in the middle, and the bending structure unfolds under the action of the expansion force of the battery cell assembly. The bending structure of the metal strip 5 can prevent the metal strip 5 from being torn and damaged when the battery cells expand.

[0084] Further, a compressible material 3 is filled between two adjacent battery cells 4 and between the battery cell 4 and the second plate-like structural member 2, and the compressible material 3 is made of foamed silicone rubber. The foamed silicone rubber can expand as the battery cell assembly expands. Both the second plate-like structural member 2 and the first plate-like structural member 1 are made of extruded 6000 series aluminum alloy.

[0085] On the basis of the post-groove fitting, specific materials are used. Both the second plate-like structural member 2 and the first plate-like structural member 1 are made of extruded 6000 series aluminum alloy. After the post-groove fitting reaches the limit position, it can further undergo a collapse deformation, ensuring that the external pressure on the battery cells is always at a reasonable level and avoiding excessive pressure causing the battery cells to "dive" or reducing their lifespan.

[0086] Further, in one embodiment, each lap joint of the two plate-like structural members has five post-groove fitting structures, and the outer cap of the protruding post 2 of the post-groove fitting structure is at least 1 mm away from the outer surface of the first plate-like structural member 1. The hardness of the protruding post 2 is higher than the hardness of the periphery of the tapered groove 11, and the protruding post 2 can squeeze the tapered groove 11 to cause the tapered groove 11 to undergo a collapse deformation within a safe range. When being squeezed, the tapered groove 11 deforms while the protruding post 2 does not deform. Specifically, the protruding post 2 can be a cylinder or other forms. The tapered groove 11 does not produce debris with a diameter exceeding 0.1 mm during compression deformation.

[0087] In the description of the present application, it should be noted that the orientation or positional relationship indicated by terms such as "upper" and "lower" is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present application. Unless otherwise clearly specified and defined, the terms "installed", "connected", and "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0088] It should be noted that in the present application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprising", "including" or any other variation thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising one..." does not exclude the presence of another identical element in the process, method, article or device including the said element.

[0089] The above are only specific embodiments of the present application, enabling those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features claimed herein.

Claims

1. A battery module, characterized in that: Include: Battery cell components; A module frame comprises two first plate-shaped structural members (1) and two second plate-shaped structural members (2), wherein the two first plate-shaped structural members (1) are symmetrically arranged on two side end surfaces of a battery cell assembly along a first direction; and the two second plate-shaped structural members (2) are symmetrically arranged on the other two side end surfaces of the battery cell assembly along a second direction; Each overlap of the two types of plate-like structural members has at least one column-slot matching structure, the column-slot matching structure comprising a protruding column (21) arranged on one type of plate-like structural member and a gradient groove (11) arranged on another type of plate-like structural member, the length of the gradient groove (11) being arranged along a second direction; when the battery cell assembly reaches the end of its service life after a cycle, the protruding column (21) slides along the gradient groove (11) under the action of the expansion force of the battery cell assembly, and gradually becomes tighter until it reaches a limit position.

2. A battery module according to claim 1, characterized in that: The protruding column (21) is extended along the first direction and arranged at the side end of the second plate-shaped structural member (2); the gradient groove (11) is arranged at the edge of the first plate-shaped structural member (1); the protruding column (21) passes through the gradient groove (11); When the battery cell assembly reaches the end of its service life after cycling, the protruding column (21) slides relative to the gradual groove (11) in a direction away from the battery cell assembly under the action of the expansion force of the battery cell assembly.

3. A battery module according to claim 1, characterized in that: The edge of the second plate-like structural member (2) has a flange structure, the gradient groove (11) is arranged on the flange structure along the second direction, and the protruding column (21) is extended along the first direction and arranged on the edge of the first plate-like structural member (1); the protruding column (21) passes through the gradient groove (11); When the battery cell assembly reaches the end of its service life, the protruding column (21) slides relative to the gradient groove (11), and the second plate-shaped structural member (2) moves away from the battery cell assembly under the action of the expansion force of the battery cell assembly.

4. A battery module according to claim 2 or 3, characterized in that: An outer cap is provided at the protruding end of the protruding column (2), and the dimension of the outer cap along the third direction is greater than the maximum dimension of the gradient groove (11) along the third direction.

5. A battery module according to claim 2 or 3, characterized in that: The dimension of the gradient groove (11) in the second direction is greater than the dimension of the protruding column (21); the gradient groove (11) comprises a large groove end and a small groove end, the dimension of the large groove end in the third direction is greater than the dimension of the protruding column (21); the dimension of the small groove end in the third direction is smaller than the dimension of the protruding column (21); In the initial state of the column-slot matching structure, the protruding column (21) is loosely matched with the large slot end; when expanding, the protruding column (21) slides from the large slot end to the small slot end under the action of the expansion force of the battery cell assembly.

6. A battery module according to claim 1, characterized in that: The battery cell assembly is formed by stacking a plurality of battery cells (4) along a second direction, and the positive and negative tabs of the plurality of battery cells (4) are connected in series via a plurality of metal strips (5); the metal strips (5) have a bent structure in the middle, and the bent structure unfolds under the action of the expansion force of the battery cell assembly.

7. A battery module according to claim 6, characterized in that: Foamed silicone rubber is filled between two connected battery cells (4) and between the battery cell (4) and the second plate-like structural member (2); and the second plate-like structural member (2) and the first plate-like structural member (1) are both made of extruded six-series aluminum alloy.

8. A battery module as claimed in claim 4, characterized in that: Each overlap of the two plate-like structural members has five column-slot matching structures, and the outer cap of the protruding column (21) of the column-slot matching structure is at least 1 mm away from the outer surface of the first plate-like structural member (1); the hardness of the protruding column (21) is higher than the peripheral hardness of the gradient groove (11).

9. A battery pack, characterized in that: The battery module is formed by connecting a plurality of battery modules as claimed in claim 1 in series and in parallel.

10. A method for installing a battery module as claimed in claim 1, characterized in that: Contains steps: The battery core assembly and the second plate-shaped structural member (2) are stacked under tooling pressure as expected in the design; The tooling pressure is maintained and the first plate-like structural member (1) is installed, the raised column (21) is passed through the gradient groove (11) to form a column-groove matching structure, the tooling pressure is released after the installation is in place, and the protruding end of the raised column (21) is processed to form an anti-falling outer cap.

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