Filling structure and battery pack

Abstract

A filling structure (1) and a battery pack. A gap is formed between a battery cell module (2) and a module end plate (3), and the filling structure (1) is adapted to be filled in the gap; the filling structure (1) comprises a vacuum bag (101) and an elastic filler (103), and the vacuum bag (101) is internally provided with an accommodating cavity; the elastic filler (103) is filled in the accommodating cavity; the elastic filler (103) has a compressed state when the vacuum bag (101) is vacuumized, and a natural state of returning to an original shape when the vacuum bag (101) is subjected to vacuum breaking, wherein the vacuum bag (101) is adapted to be subjected to vacuum breaking when the filling structure (1) is arranged in the gap. The filling structure (1) can be conveniently filled in the gap in place, thereby improving the cycle effect, and reducing the cycle attenuation speed of an end battery cell located at the gap.

Description

Filling structure and battery pack

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the China Patent Office on June 28, 2023, with application number 202321669951.9 and invention name “Filling structure and battery pack”, the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the field of battery technology, and in particular to a filling structure and a battery pack. Background Art

[0004] With the continuous development of the new energy industry, people are increasingly looking forward to new energy and energy-saving travel. To achieve "carbon neutrality" as soon as possible, improving battery energy density has become a key indicator of battery development. Battery packs in related technologies increase in size as the number of battery modules connected in series increases. This also increases the size of the individual cells within the modules, such as blade cells and poleless cells. As the size of individual cells increases, the challenge of creating module assembly technology that can accommodate the size of the battery pack becomes a pressing issue.

[0005] Battery modules such as blade modules are generally hoisted into PACK (packaging box) through a hoisting structure. When the robotic arm of the hoisting mechanism grabs the battery module and puts it into the box, it is usually affected by the position tolerance of the robotic arm itself and the tolerance of the box, resulting in a gap between the battery module and the side of the box after it is put into the box. This gap causes the cycle attenuation of the end battery cells of the battery module located in the gap to be accelerated, and the cycle life is reduced, forming a "short board in the barrel" effect on the cycle life of the battery module.

[0006] Summary of the Invention

[0007] In view of this, the present application provides a filling structure and a battery pack to solve the problem of the gap between the battery cell module and the side of the box after being placed in the box, and the problem of reduced cycle life of the end battery cells caused by the gap.

[0008] In the first aspect, the present application provides a filling structure, wherein a gap is provided between a battery cell module and a module end plate, and the filling structure is suitable for filling in the gap; the filling structure includes a vacuum bag and an elastic filler, and a receiving cavity is provided inside the vacuum bag; the elastic filler is filled in the receiving cavity; the elastic filler has a compressed state when the vacuum bag is evacuated, and a natural state of returning to its original state after the vacuum bag is broken; wherein, the vacuum bag is suitable for breaking the vacuum after the filling structure is set in the gap.

[0009] Beneficial effects: The elastic filler has a compressed state and a natural state. When the elastic filler is in the compressed state, the filling structure is thinner as a whole and can be placed more conveniently in the gap between the battery cell module and the module end plate. After the filling structure is set in the gap, the vacuum state of the vacuum bag is broken, and the elastic filler can return to its natural state and fill in the gap. The filling structure fills the gap conveniently and accurately, improves the cycle effect, reduces the cycle attenuation rate of the end battery cells of the battery cell module located in the gap, increases its cycle life, and avoids affecting the overall cycle life of the battery cell module due to the barrel effect.

[0010] In an optional embodiment, the elastic filler is made of foam material.

[0011] Beneficial effects: The foam material is soft and light, easy to deform, and can be quickly compressed by vacuuming.

[0012] In an optional embodiment, the elastic filler is made of foam.

[0013] Beneficial effects: Foam has good elasticity, is lightweight, can be quickly pressure-sensitively fixed or vacuum-compressed, is easy to use and has low cost.

[0014] In an optional embodiment, the elastic filler is made of felt.

[0015] Beneficial effects: The felt can be a membrane made of animal hair or chemical fiber, has good resilience, can be quickly vacuumed and compressed, is light in weight, easy to use and has low cost.

[0016] In an optional embodiment, the vacuum bag is made of polyimide material.

[0017] Advantages: Vacuum bags made of polyimide material can accommodate elastic fillers, have high insulation properties, and are resistant to high temperatures. Vacuum bags are bag-shaped structures made of polyimide film through hot melting or other methods.

[0018] In an optional embodiment, the vacuum bag is made of polyamide resin material.

[0019] Advantages: Vacuum bags made of polyamide resin can accommodate elastic fillers, have high insulation properties, and are resistant to high temperatures. Vacuum bags are bag-shaped structures made of polyamide resin film formed by hot-melt methods.

[0020] In an optional embodiment, the accommodating cavity of the vacuum bag is a flat rectangular structure, and the two oppositely arranged rectangular end faces of the vacuum bag are respectively suitable for abutting the side faces of the battery cell module and the module end plate, and an easy-tear opening is provided on the strip side face of the vacuum bag.

[0021] Beneficial Effects: The rectangular end faces of the vacuum bag are larger, providing greater contact area with the sides of the cell module and the module end plates, filling more space within the gap and providing better elastic support. Furthermore, the strip-shaped side of the vacuum bag is provided with an easy-tear notch, which allows for easy tearing after the filling structure is placed in the gap, thereby breaking the vacuum.

[0022] In an optional embodiment, the vacuum bag includes a film-shaped bag body, which is bent into a U-shaped shell with a rectangular cross-section. The side of the U-shaped shell is provided with three openings, and the elastic filler is filled in the U-shaped shell through the openings. The openings are suitable for being hot-melt sealed to form a hot-melt edge after the elastic filler is in the compressed state.

[0023] Advantages: The membrane-like bag body is flexible, lightweight, and easy to manufacture. The U-shaped shell features three openings, facilitating rapid filling with elastic fillers. These openings also allow for rapid vacuuming and compression. After the openings are sealed with heat-melt edges, the vacuum bag achieves a superior seal.

[0024] In an optional embodiment, the elastic filler is a rectangular membrane structure, the first thickness of the elastic filler in the compressed state is d, the second thickness of the elastic filler in the natural state is D, and the ratio d / D of the first thickness to the second thickness satisfies 20%≤d / D≤80%.

[0025] Advantageous effect: The smaller the first thickness, the easier it is to place the filling structure with the elastic filler in a compressed state in the gap. The larger the first thickness, the easier it is for the elastic filler to return to its natural state.

[0026] On the second aspect, the present application also provides a battery pack, including a shell, a battery cell module, a module end plate and the above-mentioned filling structure, the battery cell module is stacked with multiple battery cells, and the battery cell module is arranged in the shell; the module end plate is connected in the shell, located on the side of the battery cell module, and a gap is provided between the battery cell located at the end of the battery cell module; the above-mentioned filling structure is filled in the gap.

[0027] Beneficial effects: The elastic filler has a compressed state and a natural state. When the elastic filler is in the compressed state, the filling structure is thinner as a whole and can be placed more conveniently in the gap between the battery cell module and the module end plate. After the filling structure is set in the gap, the vacuum state of the vacuum bag is broken, and the elastic filler can return to its natural state and fill in the gap, thereby conveniently achieving precise filling of the filling structure.

[0028] In an optional embodiment, the module end plate is integrally formed with the bottom of the shell.

[0029] Beneficial Effects: The integrally formed module end plate and the housing can simplify the connection and positioning steps and simplify the structure. Moreover, the module end plate can serve as both a module side beam on the side of the battery module and also has the function of a module end plate.

[0030] In an optional embodiment, the width W of the gap satisfies 1 mm ≤ W ≤ 12 mm.

[0031] In an optional embodiment, the module end plate is made of metal material.

[0032] In an optional embodiment, the module end plates are made of polymer plastic particles. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the specific implementation methods or the description of the prior art. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0034] FIG1 is a schematic diagram of a battery pack from a first perspective according to an embodiment of the present application;

[0035] FIG2 is a schematic diagram of a battery pack according to an embodiment of the present application from a second viewing angle;

[0036] FIG3 is a schematic diagram of a filling structure (when the elastic filler is in a compressed state) according to an embodiment of the present application;

[0037] FIG4 is a cross-sectional view of a filling structure (when the elastic filler is in a compressed state) according to an embodiment of the present application from a first perspective;

[0038] FIG5 is an enlarged view of portion A of FIG4 ;

[0039] FIG6 is a cross-sectional view of a filling structure (when the elastic filler is in a compressed state) according to an embodiment of the present application from a second viewing angle;

[0040] FIG7 is an enlarged view of portion B of FIG6 .

[0041] Explanation of the accompanying reference numerals: 1. Filling structure; 101. Vacuum bag; 102. Easy-tear notch; 103. Elastic filler; 104. Hot-melt edge; 2. Battery cell module; 3. Module end plate. DETAILED DESCRIPTION

[0042] 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 the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of this application.

[0043] The following describes an embodiment of the present application with reference to FIG. 1 to FIG. 7 .

[0044] According to an embodiment of the present application, on the one hand, a filling structure 1 is provided, wherein a gap is provided between the battery cell module 2 and the module end plate 3, and the filling structure 1 is suitable for filling in the gap; as shown in Figures 3 to 7, the filling structure 1 includes a vacuum bag 101 and an elastic filler 103, and a receiving cavity is provided inside the vacuum bag 101; the elastic filler 103 is filled in the receiving cavity; the elastic filler 103 has a compressed state when the vacuum bag 101 is evacuated, and a natural state of returning to its original state after the vacuum bag 101 is broken; wherein, the vacuum bag 101 is suitable for breaking the vacuum after the filling structure 1 is set in the gap.

[0045] The elastic filler 103 has a compressed state and a natural state. When the elastic filler 103 is in the compressed state, the filling structure 1 is thinner as a whole and can be placed more conveniently in the gap between the battery cell module 2 and the module end plate 3. After the filling structure 1 is set in the gap, the vacuum state of the vacuum bag 101 is broken, and the elastic filler 103 can be restored to its natural state and filled in the gap. The filling structure 1 fills the gap conveniently and accurately, improves the cycle effect, reduces the cycle attenuation rate of the end battery cells of the battery cell module 2 located in the gap, increases its cycle life, and avoids affecting the overall cycle life of the battery cell module 2 due to the barrel effect.

[0046] In one embodiment, the elastic filler 103 is made of foam material.

[0047] Beneficial effects: The foam material is soft and light, easy to deform, and can be quickly compressed by vacuuming.

[0048] In an optional embodiment, the elastic filler 103 is made of foam.

[0049] Beneficial effects: Foam has good elasticity, is lightweight, can be quickly pressure-sensitively fixed or vacuum-compressed, is easy to use and has low cost.

[0050] In an optional embodiment, the elastic filler 103 is made of felt.

[0051] Beneficial effects: The felt can be a membrane made of animal hair or chemical fiber, has good resilience, can be quickly vacuumed and compressed, is light in weight, easy to use and has low cost.

[0052] In an optional embodiment, the vacuum bag 101 is made of polyimide material.

[0053] Advantageous Effects: The vacuum bag 101 made of polyimide material can accommodate the elastic filler 103, has high insulation performance, and is resistant to high temperatures. The vacuum bag 101 is a bagged structure formed by hot-melting a film made of polyimide material.

[0054] In an optional embodiment, the vacuum bag 101 is made of polyamide resin material.

[0055] Advantageous Effects: The vacuum bag 101 made of polyamide resin material can accommodate the elastic filler 103, has high insulation performance, and is resistant to high temperatures. The vacuum bag 101 is a bagged structure formed by hot-melting a film made of polyamide resin material.

[0056] In an optional embodiment, the accommodating cavity of the vacuum bag 101 is a flat rectangular structure, and the two oppositely arranged rectangular end faces of the vacuum bag 101 are respectively suitable for abutting the side of the battery cell module 2 and the module end plate 3, and an easy-tear opening 102 is provided on the strip side of the vacuum bag 101.

[0057] Beneficial Effects: The rectangular end faces of the vacuum bag 101 are larger, providing a greater contact area with the sides of the cell module 2 and the module end plate 3, filling more space within the gap and providing better elastic support. Furthermore, the strip-shaped side faces of the vacuum bag 101 are provided with an easy-tear notch 102, which allows for easy tearing of the notch 102 after the filling structure 1 is placed within the gap, thereby breaking the vacuum.

[0058] In a specific embodiment, one end of the module end plate 3 is connected to the bottom of the battery case, and the easy-tear notch 102 is provided at the top of the vacuum bag 101, providing a large operating space and facilitating the tearing of the easy-tear notch 102. The easy-tear notch 102 can be provided in the form of a plurality of rectangular teeth provided on the strip-shaped side surface of the vacuum bag 101, or at least one U-shaped notch provided on the strip-shaped side surface of the vacuum bag 101.

[0059] In an optional embodiment, the vacuum bag 101 includes a film-shaped bag body, which is bent into a U-shaped shell with a rectangular cross-section. The side of the U-shaped shell is provided with three openings, and the elastic filler 103 is filled in the U-shaped shell through the openings. The openings are suitable for hot-melt sealing to form a hot-melt edge 104 after the elastic filler 103 is in a compressed state.

[0060] The membrane-like bag body is flexible, thin, and easily accessible. The U-shaped shell features three openings, facilitating rapid filling with elastic filler 103. These openings also allow for rapid vacuuming and compression. After the openings are heat-sealed to form heat-fused edges 104, the vacuum bag 101 achieves a superior seal, as shown in Figures 4 and 5.

[0061] In one embodiment, the elastic filler 103 is a rectangular membrane structure, the first thickness of the elastic filler 103 in a compressed state is d, the second thickness of the elastic filler 103 in a natural state is D, and the ratio d / D of the first thickness to the second thickness satisfies 20%≤d / D≤80%.

[0062] The smaller the first thickness, the easier it is to place the filling structure 1 with the elastic filler 103 in a compressed state in the gap. The larger the first thickness, the easier it is for the elastic filler 103 to return to its natural state.

[0063] In a specific embodiment, the elastic filler 103 is a rectangular membrane structure, the first thickness of the elastic filler 103 in a compressed state is d, the second thickness of the elastic filler 103 in a natural state is D, and the ratio d / D of the first thickness to the second thickness is 20%.

[0064] In another specific embodiment, the elastic filler 103 is a rectangular membrane structure, the first thickness of the elastic filler 103 in the compressed state is d, the second thickness of the elastic filler 103 in the natural state is D, and the ratio d / D of the first thickness to the second thickness is 80%.

[0065] The operator can select the elastic filler 103 of corresponding thickness according to the actually measured width of the gap, and can make the selection with reference to the ratio between the first thickness and the second thickness.

[0066] In this embodiment, the forming method of the filling structure 1 includes: folding the membrane-shaped bag body into a U-shaped shell, filling the elastic filler 103 into the U-shaped shell, quickly achieving vacuuming and compression through three openings, and hot-melting and sealing the openings to form a hot-melt edge 104 after the vacuuming and compression are completed.

[0067] According to an embodiment of the present application, on the other hand, a battery pack is also provided, as shown in Figures 1 to 2, including a shell, a battery cell module 2, a module end plate 3 and the above-mentioned filling structure 1, the battery cell module 2 is stacked with multiple battery cell units, and the battery cell module 2 is arranged in the shell; the module end plate 3 is connected in the shell, located on the side of the battery cell module 2, and a gap is provided between the battery cell units at the end of the battery cell module 2; the above-mentioned filling structure 1 is filled in the gap.

[0068] The elastic filler 103 has a compressed state and a natural state. When the elastic filler 103 is in the compressed state, the filling structure 1 is thinner as a whole and can be placed more conveniently in the gap between the battery cell module 2 and the module end plate 3. After the filling structure 1 is set in the gap, the vacuum state of the vacuum bag 101 is broken, and the elastic filler 103 can be restored to its natural state and filled in the gap, thereby conveniently achieving precise filling of the filling structure 1.

[0069] Specifically, a connection portion for fixing an external connection member may be provided on the module end plate 3. The battery cell modules 2 may be provided in one group or in multiple groups, and both ends of each group of battery cell modules 2 are provided with module end plates 3 and filling structures 1 respectively.

[0070] In an optional embodiment, the module end plate 3 is integrally formed with the bottom of the housing. This integrally formed module end plate 3 and housing simplifies the connection and positioning steps, simplifying the structure. Furthermore, the module end plate 3 serves as both a module side beam on the side of the cell module 2 and also performs the function of the module end plate 3.

[0071] As a convertible embodiment, the module end plate 3 may be welded to the bottom of the shell, or the module end plate 3 may be detachably connected to the bottom of the shell via fasteners.

[0072] In an optional embodiment, the width W of the gap satisfies 1 mm ≤ W ≤ 12 mm. The operator can select a corresponding filling structure 1 according to the actual width of the gap and the second thickness of the elastic filler 103 .

[0073] In a specific embodiment, the width W of the gap is 1 mm.

[0074] In another specific embodiment, the width W of the gap is 12 mm.

[0075] In an optional embodiment, the module end plate 3 is made of metal material; the module end plate 3 can be integrally formed on the bottom of the shell by die-casting.

[0076] In an optional embodiment, the module end plate 3 is made of polymer plastic particles. The module end plate 3 can be integrally formed with the housing by extrusion, injection molding, or film pressing.

[0077] In this embodiment, the forming method of the battery pack includes: placing the battery cell module 2 in the shell, and forming a gap corresponding to the module end plate 3, placing the filling structure 1 with the elastic filler 103 in a compressed state in the gap, tearing the easy-tear opening 102 to break the vacuum bag 101, and the elastic filler 103 returns to its natural state.

[0078] Although the embodiments of the present application have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present application, and such modifications and variations shall fall within the scope defined by the appended claims.

Claims

1. A filling structure, wherein a gap is provided between a battery cell module and a module end plate, and the filling structure is suitable for filling in the gap; characterized in that: include: A vacuum bag having a containing cavity therein; An elastic filler is filled in the accommodating cavity; the elastic filler has a compressed state when the vacuum bag is evacuated, and a natural state of returning to the original state after the vacuum bag is broken; Wherein, the vacuum bag is suitable for breaking the vacuum after the filling structure is arranged in the gap.

2. The filling structure according to claim 1, characterized in that The elastic filler is made of foam material.

3. The filling structure according to claim 2, characterized in that The elastic filler is made of foam; And / or, the elastic filler is made of felt.

4. The filling structure according to any one of claims 1 to 3, characterized in that The vacuum bag is made of polyimide material; And / or, the vacuum bag is made of polyamide resin material.

5. The filling structure according to claim 4, characterized in that: The accommodating cavity of the vacuum bag is a flat rectangular structure. The two oppositely arranged rectangular end faces of the vacuum bag are respectively suitable for abutting against the side faces of the battery cell module and the module end plate. The strip-shaped side faces of the vacuum bag are provided with tearable openings.

6. The filling structure according to claim 5, characterized in that The vacuum bag includes a film-shaped bag body, which is bent into a U-shaped shell with a rectangular cross-section. The side of the U-shaped shell is provided with three openings, and the elastic filler is filled in the U-shaped shell through the openings. The openings are suitable for being hot-melt sealed to form hot-melt edges after the elastic filler is in the compressed state.

7. The filling structure according to any one of claims 1 to 3 or 5 or 6, characterized in that: The elastic filler is a rectangular film-like structure, the first thickness of the elastic filler in the compressed state is d, the second thickness of the elastic filler in the natural state is D, and the ratio d / D of the first thickness to the second thickness satisfies 20%≤d / D≤80%.

8. A battery pack, characterized in that: include: case; A battery cell module, which is stacked with a plurality of battery cell monomers, and the battery cell module is arranged in the shell; A module end plate, connected inside the housing, located at the side of the battery module, and having a gap between the battery cell monomers at the end of the battery module; The filling structure according to any one of claims 1 to 7 is filled in the gap.

9. The battery pack according to claim 8, characterized in that: The module end plate is integrally formed with the bottom of the shell; And / or, the width W of the gap satisfies, 1mm≤W≤12mm.

10. The battery pack according to claim 8, characterized in that: The module end plate is made of metal material; And / or, the module end plate is made of polymer plastic particles.

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