Soft package cylindrical battery packaging structure

Abstract

The utility model discloses a soft package cylindrical battery packaging structure which comprises a cylindrical roll core and a cylindrical soft package shell for packaging the roll core, the roll core comprises a first end part and a second end part which are oppositely arranged, a positive pole lug extends outwards from the first end part and penetrates out of the soft package shell, and a negative pole lug extends outwards from the second end part and penetrates out of the soft package shell; the soft package shell comprises a first shell body and a second shell body, first sealing edges which are attached to each other are arranged at the two ends of the first shell body and the two ends of the second shell body respectively, the first sealing edges are bent in the radial direction of the soft package shell to form flat folded edges, and the corners of the flat folded edges are horizontally bent in the end plane of the soft package shell to form corner bent parts. The edges of the two sides of the first shell and the second shell are provided with second sealing edges which are attached to each other respectively, and the second sealing edges are bent in the circumferential direction of the soft package shell to form arc-shaped folded edges. The sealing performance and the reliability of the edge sealing structure can be effectively improved, and meanwhile, the structural compactness and the attractiveness of the cylindrical battery are improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of secondary batteries, and in particular relates to a soft-package cylindrical battery packaging structure. Background Art

[0002] Lithium-ion batteries, an essential energy source for modern portable electronic devices, are widely used due to their high energy density, long lifespan, and excellent rechargeability. Cylindrical lithium-ion batteries, in particular, are favored in numerous applications, such as portable computing devices, power tools, and electric vehicles, due to their low manufacturing costs and high structural stability.

[0003] Despite the significant market share of cylindrical lithium-ion batteries, traditional steel-cased batteries still present a number of design and safety challenges. The steel casing not only increases the overall weight of the battery, but also limits the flexibility of the battery's internal design due to its packaging density and rigidity. Furthermore, the steel casing structure can cause a sharp increase in gas pressure in the event of overheating or internal short circuits, increasing the risk of explosion. Furthermore, the high density and thick walls of the steel casing negatively impact the battery's overall energy density.

[0004] Therefore, the inventors of this application have developed a soft-pack cylindrical battery to solve the above problems. However, the inventors found in actual applications that soft-pack cylindrical batteries also face some challenges, among which the soft-pack packaging structure is a key issue. In soft-pack cylindrical batteries, the soft-pack shell is generally sealed using a heat sealing process. However, the existing heat sealing structure has some shortcomings. First, the edges of the existing soft-pack shell sealing structure are warped outward, occupying more external space, affecting the aesthetics and compactness of the battery. Secondly, the existing edge sealing structure has problems with poor sealing and insufficient reliability, which affects the performance and safety of the battery.

[0005] In view of this, it is indeed necessary to provide a technical solution to the above problems. Utility Model Content

[0006] The purpose of the present invention is to provide a soft-pack cylindrical battery packaging structure to address the deficiencies of the existing technology, which can effectively improve the sealing and reliability of the edge sealing structure, while enhancing the structural compactness and aesthetics of the cylindrical battery.

[0007] To achieve the above objectives, the present invention provides the following technical solutions:

[0008] A soft-pack cylindrical battery packaging structure includes a cylindrical winding core and a cylindrical soft-pack shell encapsulating the winding core, wherein the winding core includes a first end and a second end disposed opposite each other, the first end being connected to a positive electrode tab, and the second end being connected to a negative electrode tab; the positive electrode tab extends outward from the first end and passes through the soft-pack shell, and the negative electrode tab extends outward from the second end and passes through the soft-pack shell;

[0009] The soft package shell includes a first shell and a second shell, the first shell is heat-sealed and connected to the second shell, and the two ends of the first shell and the second shell are respectively provided with first sealed edges that fit together, and the first sealed edges are bent along the radial direction of the soft package shell to form a flat folded edge, and the corners of the flat folded edge are horizontally bent along the end plane of the soft package shell to form a corner bending portion; the two side edges of the first shell and the second shell are respectively provided with second sealed edges that fit together, and the second sealed edges are bent along the circumference of the soft package shell to form an arc-shaped folded edge.

[0010] Preferably, the positive electrode tab extends outward from the first end portion and passes through the soft-pack shell along the first sealed edge. The portion of the positive electrode tab passing through the soft-pack shell is bent in reverse along the edge of the flat folded edge to form a first bending section. A first protective paper is provided between the first bending section and an end plane of the soft-pack shell, and the first protective paper covers the corner bending portion.

[0011] Preferably, the negative electrode tab extends outward from the second end portion and passes through the soft-pack shell along the first sealed edge. The portion of the negative electrode tab passing through the soft-pack shell is bent in reverse along the edge of the flat folded edge to form a second bending section. A second protective paper is provided between the second bending section and the other end plane of the soft-pack shell, and the second protective paper covers the corner bending portion.

[0012] Preferably, an adhesive layer is provided on one surface of the first protective paper and the second protective paper respectively.

[0013] Preferably, the two end portions of the soft package shell are respectively provided with fixing tape for fixing the first bending section and the second bending section, the fixing tape respectively covers the bending surface of the first bending section and the bending surface of the second bending section, and the two ends of the fixing tape are respectively fixed to the circumferential side walls of the soft package shell.

[0014] Preferably, the outer surface of the soft package shell is tightly covered with a heat shrink film, and the heat shrink film is pressed tightly against both ends of the fixing tape.

[0015] Preferably, the soft package shell is an aluminum-plastic film, and the thickness of the aluminum-plastic film is 0.05 to 0.15 mm.

[0016] Preferably, a first tab glue is provided between the positive electrode tab and the first edge seal, and a second tab glue is provided between the negative electrode tab and the first edge seal.

[0017] Compared with the prior art, the present invention has at least the following beneficial effects:

[0018] 1) The packaging structure of the present invention has good sealing and reliability. The present invention proposes a soft-pack cylindrical battery packaging structure, wherein the soft-pack shell includes a first shell and a second shell, which are connected by heat sealing; a first sealing edge that fits each other is provided at both ends of the first shell and the second shell, and the first sealing edge is bent along the radial direction of the soft-pack shell to form a flat folded edge, and the corners of the flat folded edge are horizontally bent along the end plane of the soft-pack shell to form a corner bending portion; this multiple folding edge structure can effectively increase the edge sealing path and improve the sealing performance of the edge sealing structure. At the same time, the design of the corner bending portion can alleviate the stress concentration during the heat sealing process, avoid cracking or delamination of the edge sealing, and improve the reliability of the edge sealing structure.

[0019] 2) The packaging structure of this utility model improves the compactness and aesthetics of soft-pack cylindrical batteries. In this soft-pack packaging structure, the edges of the first and second shells are provided with a second sealing edge that fits together. The second sealing edge is bent along the circumference of the soft-pack shell to form an arc-shaped fold. This arc-shaped fold effectively reduces the outer protrusion of the sealing edge, making the overall battery structure more compact and saving external space. At the same time, the arc-shaped fold coordinates with the cylindrical battery's appearance, improving the battery's aesthetics and consistency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic structural diagram of a soft-pack cylindrical battery packaging structure according to an embodiment of the present invention;

[0021] Figure 2 This is an exploded view of the soft-pack cylindrical battery packaging structure according to one embodiment of the present invention;

[0022] Figure 3 This is a schematic structural diagram of a soft-pack cylindrical battery packaging structure according to another embodiment of the present invention;

[0023] Figure 4 This is an exploded view of the soft-pack cylindrical battery packaging structure of another embodiment of the present invention;

[0024] Figure 5 This is a structural diagram of a soft-pack cylindrical battery packaging structure according to another embodiment of the present invention;

[0025] Figure 6 This is a structural exploded view of a soft-pack cylindrical battery packaging structure according to another embodiment of the present invention.

[0026] In the figure: 1. Winding core; 11. Positive electrode tab; 12. Negative electrode tab; 13. First tab glue; 14. Second tab glue; 2. Soft package shell; 21. First shell; 22. Second shell; 23. First edge seal; 24. Second edge seal; 25. Corner bend; 3. First protective paper; 4. Second protective paper; 5. Fixing tape; 6. Heat shrink film. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0028] In the description of this application, unless otherwise expressly specified or limited, the terms "first", "second", and "third" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance; the term "plurality" refers to two or more; unless otherwise specified or explained, the terms "connected" and "fixed" should be understood in a broad sense. For example, "connected" can mean a fixed connection, a detachable connection, an integral connection, or an electrical connection; "connected" can mean a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0029] Referring to the accompanying drawings, the present application provides a soft-pack cylindrical battery packaging structure, comprising a cylindrical core 1, an electrolyte, and a cylindrical soft-pack shell 2 encapsulating the core 1 and the electrolyte. The core 1 comprises a positive electrode sheet, a negative electrode sheet, and a separator disposed between the positive and negative electrode sheets. The positive electrode sheet, the separator, and the negative electrode sheet are sequentially stacked and wound to form the core 1. The core 1 comprises a first end and a second end disposed opposite each other. The first end is connected to a positive electrode tab 11, and the second end is connected to a negative electrode tab 12. The positive electrode tab 11 extends outward from the first end and passes through the soft-pack shell 2, and the negative electrode tab 12 extends outward from the second end and passes through the soft-pack shell 2.

[0030] The soft-pack shell 2 includes a first shell 21 and a second shell 22, and the first shell 21 and the second shell 22 are heat-sealed and connected. The two ends of the first shell 21 and the second shell 22 are respectively provided with first sealed edges 23 that fit together, and the first sealed edges 23 are bent along the radial direction of the soft-pack shell 2 to form a flat folded edge, and the corners of the flat folded edge are horizontally bent along the end plane of the soft-pack shell 2 to form a corner bending portion 25; the two side edges of the first shell 21 and the second shell 22 are respectively provided with second sealed edges 24 that fit together, and the second sealed edges 24 are bent along the circumference of the soft-pack shell 2 to form an arc-shaped folded edge.

[0031] Among them, the soft-pack cylindrical battery packaging structure of the present application has a soft-pack shell 2 comprising a first shell 21 and a second shell 22, which are connected by heat sealing. A first sealing edge 23 is provided at both ends of the first shell 21 and the second shell 22, which fits together. The first sealing edge 23 is bent along the radial direction of the soft-pack shell 2 to form a flat folded edge. The corners of the flat folded edge are bent horizontally along the end plane of the soft-pack shell 2 to form a corner bend portion 25. This multiple folded edge structure can effectively increase the edge sealing path and improve the sealing performance of the edge sealing structure. At the same time, the design of the corner bend portion 25 can alleviate stress concentration during the heat sealing process, avoid cracking or delamination of the edge seal, and improve the reliability of the edge sealing structure.

[0032] In the soft-pack packaging structure of this application, the edges of the first shell 21 and the second shell 22 are provided with a second sealing edge 24 that fits together. The second sealing edge 24 is bent along the circumference of the soft-pack shell 2 to form an arc-shaped fold. The arc-shaped fold structure of the present invention can effectively reduce the outer protrusion of the sealing structure, making the overall battery structure more compact and saving external space. At the same time, the arc-shaped fold is coordinated with the shape of the cylindrical battery, improving the battery's aesthetics and consistency.

[0033] In one embodiment of the present application, the positive electrode tab 11 extends outward from the first end and passes through the soft-pack shell 2 along the first sealed edge 23. The portion of the positive electrode tab 11 that passes through the soft-pack shell 2 is bent in the opposite direction along the edge of the flat folded edge to form a first bent section. A first protective paper 3 is provided between the first bent section and the flat surface of one end of the soft-pack shell 2, and the first protective paper 3 covers the corner bent portion 25. This structural design can effectively fix the lead-out position of the positive electrode tab 11, prevent the positive electrode tab 11 from shifting or falling off, and improve the reliability of the lead-out structure of the positive electrode tab 11. At the same time, the first protective paper 3 can isolate the positive electrode tab 11 from direct contact with the soft-pack shell 2, preventing the tab edge burrs from damaging the soft-pack shell 2, while also buffering the stress between the positive electrode tab 11 and the soft-pack shell 2, thereby improving the safety of the battery.

[0034] In one embodiment of the present application, the negative electrode tab 12 extends outward from the second end and passes through the soft-pack shell 2 along the first sealed edge 23. The portion of the negative electrode tab 12 that passes through the soft-pack shell 2 is bent in the opposite direction along the edge of the flat folded edge to form a second bent section. A second protective paper 4 is provided between the second bent section and the flat surface of the other end of the soft-pack shell 2, and the second protective paper 4 covers the corner bent portion 25. This structural design can effectively fix the lead-out position of the negative electrode tab 12, prevent the negative electrode tab 12 from shifting or falling off, and improve the reliability of the negative electrode tab 12 lead-out structure. At the same time, the second protective paper 4 can isolate the negative electrode tab 12 from direct contact with the soft-pack shell 2, preventing the tab edge burrs from damaging the soft-pack shell 2, while also buffering the stress between the negative electrode tab 12 and the soft-pack shell 2, thereby improving the safety of the battery.

[0035] In one embodiment of the present application, an adhesive layer is provided on one surface of the first protective paper 3 and the second protective paper 4. The adhesive layer is an acrylic adhesive, a silicone adhesive, a vinyl acrylate adhesive, a nitrile rubber adhesive, or a chloroprene rubber adhesive. Providing an adhesive layer on one surface of the protective paper facilitates the adhesive bonding of the protective paper between the tab and the soft-pack shell 2, ensuring a secure fit between the protective paper and the soft-pack shell 2, providing a long-lasting protective effect, and preventing the protective paper from shifting or falling off.

[0036] In one embodiment of the present application, the first protective paper 3 is red barley paper, and the second protective paper 4 is green barley paper. Both red barley paper and green barley paper have excellent insulation properties and are relatively low-cost paper materials. They can provide good insulation protection while controlling material costs, resulting in a high cost-effectiveness ratio. Furthermore, the positive electrode tab 11 and the negative electrode tab 12 are provided with protective paper of different colors, respectively, which can facilitate the distinction and identification of the positive and negative electrodes.

[0037] In one embodiment of the present application, fixing tape 5 for fixing the first and second bent sections is provided at both ends of the soft-pack shell 2. The fixing tape 5 covers the bend surfaces of the first and second bent sections, respectively, and both ends of the fixing tape 5 are fixed to the circumferential side walls of the soft-pack shell 2. The provision of the fixing tape 5 further secures the tabs, preventing them from shifting or loosening, and improving connection reliability.

[0038] In one embodiment of the present application, a heat shrink film 6 is tightly fitted on the outer surface of the soft package shell 2, and the heat shrink film 6 is pressed against the ends of the adhesive tape 5. The heat shrink film 6 is tightly fitted on the outer surface of the soft package shell 2, which effectively protects the soft package shell 2. At the same time, the heat shrink film 6 is pressed against the ends of the adhesive tape 5, further reinforcing the tab connection structure and improving the stability and reliability of the tab connection structure.

[0039] In one embodiment of the present application, the soft-pack outer shell 2 is an aluminum-plastic film with a thickness of 0.05 to 0.15 mm. Compared with traditional steel shells, the aluminum-plastic film is thinner and lighter, effectively reducing battery weight and increasing energy density. Furthermore, the aluminum-plastic film has high barrier properties and mechanical strength, effectively preventing external water and oxygen intrusion and extending battery life. In the event of thermal runaway, the aluminum-plastic film can also expand and deform to release internal pressure, preventing battery explosion and improving safety.

[0040] In one embodiment of the present application, a first tab glue 13 is provided between the positive electrode tab 11 and the first edge seal 23, and a second tab glue 14 is provided between the negative electrode tab 12 and the first edge seal 23. The tab glue can fill the gap between the tab and the first edge seal 23 to improve the sealing and prevent electrolyte leakage; at the same time, the tab glue can also play a bonding role, improve the connection reliability between the tab and the first edge seal 23, and prevent the tab from falling off or loosening.

[0041] In one embodiment of the present application, the positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer disposed on at least one surface of the positive electrode current collector. A first hollow foil region is disposed in the center of the positive electrode sheet, and a positive electrode tab 11 is disposed in the first hollow foil region. The center of the positive electrode sheet is located between 3 / 8 and 5 / 8 of the length of the positive electrode sheet. Placing the positive electrode tab in the center of the positive electrode sheet can effectively reduce the internal resistance of the battery cell, thereby increasing the output power and energy density of the battery cell. Furthermore, it can effectively disperse the current and temperature within the battery cell, reducing the risk of thermal runaway and explosion within the battery cell, thereby improving the safety of the battery cell.

[0042] In one embodiment of the present application, the negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer disposed on at least one surface of the negative electrode current collector. A second hollow foil region is disposed in the middle of the negative electrode sheet, and a negative electrode tab 12 is disposed in the second hollow foil region. The middle of the negative electrode sheet is located between 3 / 8 and 5 / 8 of the length of the negative electrode sheet. Placing the negative electrode tab in the middle of the negative electrode sheet effectively reduces the internal resistance of the battery cell, thereby increasing the output power and energy density of the battery cell. Furthermore, it effectively disperses the current and temperature within the battery cell, reducing the risk of thermal runaway and explosion within the battery cell, thereby improving the safety of the battery cell.

[0043] It should be noted that the contents not described in detail in this specification belong to the existing technology known to professional and technical personnel in this field and will not be repeated here.

[0044] Based on the disclosure and teachings of the above description, those skilled in the art will be able to make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments described above. Any obvious improvements, substitutions, or modifications made by those skilled in the art based on the present invention fall within the scope of protection of the present invention. In addition, although certain specific terms are used in this description, these terms are for convenience only and do not constitute any limitation on the present invention.

Claims

1. A soft-pack cylindrical battery packaging structure, characterized by: The invention comprises a cylindrical winding core and a cylindrical soft-package shell encapsulating the winding core, wherein the winding core comprises a first end and a second end oppositely disposed, the first end being connected to a positive electrode tab, and the second end being connected to a negative electrode tab; the positive electrode tab extends outward from the first end and passes through the soft-package shell, and the negative electrode tab extends outward from the second end and passes through the soft-package shell; The soft package shell includes a first shell and a second shell, the first shell is heat-sealed and connected to the second shell, and the two ends of the first shell and the second shell are respectively provided with first sealed edges that fit together, and the first sealed edges are bent along the radial direction of the soft package shell to form a flat folded edge, and the corners of the flat folded edge are horizontally bent along the end plane of the soft package shell to form a corner bending portion; the two side edges of the first shell and the second shell are respectively provided with second sealed edges that fit together, and the second sealed edges are bent along the circumference of the soft package shell to form an arc-shaped folded edge.

2. The soft-pack cylindrical battery packaging structure according to claim 1, characterized in that: The positive electrode tab extends outward from the first end portion and passes through the soft-pack shell along the first sealed edge. The portion of the positive electrode tab passing through the soft-pack shell is bent in the opposite direction along the edge of the flat folded edge to form a first bending section. A first protective paper is provided between the first bending section and an end plane of the soft-pack shell, and the first protective paper covers the corner bending portion.

3. The soft-pack cylindrical battery packaging structure according to claim 2, characterized in that: The negative electrode tab extends outward from the second end and passes through the soft-pack shell along the first sealed edge. The part of the negative electrode tab that passes through the soft-pack shell is bent in the opposite direction along the edge of the flat folded edge to form a second bending section. A second protective paper is arranged between the second bending section and the other end plane of the soft-pack shell, and the second protective paper covers the corner bending portion.

4. The soft-pack cylindrical battery packaging structure according to claim 3, characterized in that: An adhesive layer is provided on one surface of the first protective paper and the second protective paper respectively.

5. The soft-pack cylindrical battery packaging structure according to claim 3, characterized in that: The two ends of the soft package shell are respectively provided with fixing tape for fixing the first bending section and the second bending section, the fixing tape respectively covers the bending surface of the first bending section and the bending surface of the second bending section, and the two ends of the fixing tape are respectively fixed to the circumferential side wall of the soft package shell.

6. The soft-pack cylindrical battery packaging structure according to claim 5, characterized in that: The outer surface of the soft package shell is tightly covered with a heat shrink film, and the heat shrink film is tightly pressed against the two ends of the fixing tape.

7. The soft-pack cylindrical battery packaging structure according to claim 1, characterized in that: The soft package shell is an aluminum-plastic film, and the thickness of the aluminum-plastic film is 0.05-0.15 mm.

8. The soft-pack cylindrical battery packaging structure according to claim 1, characterized in that: A first tab glue is provided between the positive electrode tab and the first edge seal, and a second tab glue is provided between the negative electrode tab and the first edge seal.

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