Battery cell packaging structure, battery cell and secondary battery

Abstract

The utility model belongs to the technical field of batteries, and particularly relates to a battery cell packaging structure, a battery cell and a secondary battery, the battery cell packaging structure comprises a first coating surface, a second coating surface and at least two side covers; the side cover is arranged between the first covering surface and the second covering surface; each side sealing surface comprises a side sealing edge, a first bent connecting section and a second bent connecting section; the first bent connecting section is arranged between the side sealing edge and the second bent connecting section; the side sealing edge comprises a first area overlapped with the first bent connecting section, the first bent connecting section comprises a second area overlapped with the side sealing edge, and the second bent connecting section comprises a third area overlapped with the first bent connecting section; the thickness of the first area is H1, the thickness of the second area is H2, the thickness of the third area is H3, H1 is larger than or equal to H2, and H2 is smaller than H3. The overall thickness of the battery cell packaging structure can be reduced, and the protection performance of the battery cell packaging structure can be ensured; and the energy density of the battery cell can be improved.

Description

Technical Field

[0001] This utility model belongs to the field of battery technology, and in particular relates to a battery cell packaging structure, a battery cell, and a secondary battery. Background Technology

[0002] Lithium-ion power batteries, due to their excellent power output characteristics and long lifespan, have been widely used in various products after continuous development, boasting high energy density and superior adaptability to high and low temperature environments. However, the performance of lithium-ion power batteries is quite sensitive to temperature changes, especially the high-capacity, high-power lithium iron phosphate batteries used in electric vehicles. Lithium batteries generate high temperatures after prolonged use, leading to a gradual shift in packaging from rigid aluminum shells to aluminum-plastic film packaging. This aluminum-plastic film is composed of high-barrier aluminum foil and a chemically resistant, heat-resistant, and flexible plastic film.

[0003] However, most existing battery cell packaging structures are too wide, taking up too much battery volume, which leads to a decrease in the overall energy density of the battery and affects its efficiency. Utility Model Content

[0004] The purpose of this utility model is to provide a battery cell packaging structure that addresses the shortcomings of existing technologies and solves the technical problem of excessive width in existing technologies.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A battery cell packaging structure includes a first covering surface, a second covering surface, and at least two side covers; the side covers are disposed between the first covering surface and the second covering surface; each side cover includes a side sealing edge, a first bent connecting segment, and a second bent connecting segment; the side sealing edge and the first bent connecting segment are sequentially connected to the first covering surface; the second bent connecting segment is connected to the second covering surface.

[0007] The first bent connecting segment is disposed between the side sealing edge and the second bent connecting segment; the side sealing edge includes a first region overlapping with the first bent connecting segment, the first bent connecting segment includes a second region overlapping with the side sealing edge, and the second bent connecting segment includes a third region overlapping with the first bent connecting segment; the thickness of the first region is H1, the thickness of the second region is H2, and the thickness of the third region is H3, wherein H1≥H2 and H2<H3.

[0008] Preferably, a placement cavity is provided between the first covering surface, the second covering surface, and the side cover.

[0009] The side sealing edge is located on the inner side of the first bent connecting section facing the placement cavity; the second bent connecting section is located on the outer side of the first bent connecting section away from the placement cavity.

[0010] Preferably, the thickness of both the first covering surface and the second covering surface is H4; wherein, H4 > H3.

[0011] Preferably, the first region has a three-layer structure; and the first region includes a first heat-sealing layer, a first adhesive layer and a first metal layer stacked sequentially.

[0012] And / or, the second region has a three-layer structure; and the second region includes a second heat-sealing layer, a second adhesive layer and a second metal layer stacked sequentially.

[0013] Preferably, both the first and second covering surfaces have a five-layer structure; and both the first and second covering surfaces include a fourth heat-sealing layer, a fifth adhesive layer, a fourth metal layer, a sixth adhesive layer, and a second nylon layer stacked sequentially.

[0014] And / or, the third region has a five-layer structure; and the third region includes a third heat-sealing layer, a third adhesive layer, a third metal layer, a fourth adhesive layer and a first nylon layer stacked sequentially; the third heat-sealing layer is bonded to the second heat-sealing layer.

[0015] Preferably, the relationship between the thickness h1 of the first heat-sealing layer and the thickness h2 of the second heat-sealing layer satisfies: h1≥h2.

[0016] Preferably, the relationship between the thickness h4 of the fourth heat-sealing layer and the thickness h1 of the first heat-sealing layer satisfies: 20um≤h4-h1≤35um;

[0017] And / or, the relationship between the thickness h4 of the fourth heat-sealing layer and the thickness h2 of the second heat-sealing layer satisfies: 20um≤h4-h2≤35um;

[0018] And / or, the relationship between the thickness h4 of the fourth heat-sealing layer and the thickness h3 of the third heat-sealing layer satisfies: 20um≤h4-h3≤35um.

[0019] Preferably, a seventh adhesive layer is provided between the first metal layer and the second metal layer;

[0020] And / or, an eighth adhesive layer is provided between the third heat-sealing layer and the second heat-sealing layer.

[0021] This utility model also discloses a battery cell, including a bare battery cell body and the battery cell packaging structure; the bare battery cell body is connected inside between the first covering surface, the second covering surface and the side cover.

[0022] This utility model also discloses a secondary battery, including the aforementioned battery cell.

[0023] The beneficial effects of this utility model are that, by using a side cover formed by combining a side seal with a thin side edge and a first bent connecting section with a thin side edge and a second bent connecting section with a thick side edge in the width direction, the thickness of the side end of the battery cell packaging structure can be effectively reduced, thereby reducing the overall thickness of the battery cell packaging structure and ensuring its protective performance; furthermore, it can reduce the overall width of the battery cell and improve the energy density of the battery cell. Attached Figure Description

[0024] The following will refer to the appendix. Figures 1-5 This section describes the features, advantages, and technical effects of exemplary embodiments of the present invention.

[0025] Figure 1 This is a schematic diagram of the battery cell packaging structure according to an embodiment of the present invention;

[0026] Figure 2 This is a schematic diagram of the side cover of a battery cell packaging structure in an unbent state according to an embodiment of the present invention;

[0027] Figure 3 This is a partial cross-sectional view of the heat-sealed side cover of a battery cell packaging structure according to an embodiment of the present invention.

[0028] Figure 4 This is a partial cross-sectional view of the heat-sealed side cover of a battery cell packaging structure according to an embodiment of the present invention.

[0029] Figure 5 This is a schematic diagram of the structure of a battery cell according to an embodiment of the present invention.

[0030] In the diagram: 1-First covering surface; 101-Placement cavity; 2-Second covering surface; 3-Side cover; 31-Side sealing edge; 311-First heat-sealing layer; 312-First adhesive layer; 313-First metal layer; 32-First bending connection section; 321-Second heat-sealing layer; 322-Second adhesive layer; 323-Second metal layer; 33-Second bending connection section; 331-Third heat-sealing layer; 332-Third adhesive layer; 333-Third metal layer; 334-Fourth adhesive layer; 335-First nylon layer; 401-Fourth heat-sealing layer; 402-Fifth adhesive layer; 403-Fourth metal layer; 404-Sixth adhesive layer; 405-Second nylon layer; 51-Seventh adhesive layer; 52-Eighth adhesive layer; 6-Bare battery cell body; A-First direction. Detailed Implementation

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0032] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0033] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0034] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or multiple situations existing alone. In addition, the character " / " in this document generally indicates that the related objects before and after are in an "or" relationship.

[0035] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0036] The following is in conjunction with the appendix Figures 1-5 The present invention will be described in further detail, but this is not intended to limit the scope of the present invention.

[0037] like Figure 1 As shown, in one embodiment of this utility model, the battery cell packaging structure includes a first covering surface 1, a second covering surface 2, and at least two side covers 3; the side covers 3 are disposed between the first covering surface 1 and the second covering surface 2; each side cover 3 includes a side sealing edge 31, a first bent connecting section 32, and a second bent connecting section 33; the side sealing edge 31 and the first bent connecting section 32 are sequentially connected to the first covering surface 1; the second bent connecting section 33 is connected to the second covering surface 2;

[0038] When the battery cell packaging structure is in a heat-sealed state, the first bending connection section 32 is bent and positioned between the side seal edge 31 and the second bending connection section 33; the side seal edge includes a first region overlapping with the first bending connection section; the first bending connection section includes a second region overlapping with the side seal edge, and the second bending connection section includes a third region overlapping with the first bending connection section; the thickness of the first region is H1, the thickness of the second region is H2, and the thickness of the third region is H3, wherein H1 ≥ H2, and H2 < H3. For example... Figure 1 As shown, in some embodiments, the end of the second bent connecting segment 33 away from the first bent connecting segment 32 is connected to one side end face of the second covering surface 2; the end of the side sealing edge 31 away from the first bent connecting segment 32 is connected to one side end face of the first covering surface 1; and the orthographic projection of one side end face of the second covering surface 2 toward the first covering surface 1 coincides with one side end face of the first covering surface 1. Specifically, the end of the second bent connecting segment 33 away from the first bent connecting segment 32 is connected to the second covering surface 2; and the end of the side sealing edge 31 away from the first bent connecting segment 32 is connected to the first covering surface 1.

[0039] The technical solution of this utility model uses a side cover formed by combining a side seal with a thin side edge and a thin first bent connecting section with a thick second bent connecting section in the width direction. This helps to reduce the thickness of the side end of the battery cell packaging structure, thereby reducing the overall thickness of the battery cell packaging structure and ensuring its protective performance. Furthermore, it can reduce the overall width of the battery cell and improve the energy density of the battery cell.

[0040] Specifically, in some implementations, such as Figure 1 As shown, a placement cavity 101 is provided between the first covering surface 1, the second covering surface 2, and the side cover 3. When the battery cell packaging structure is in a heat-sealed state, the side sealing edge 31 is bent and disposed on the inner side of the first bent connecting section 32 facing the placement cavity 101; the second bent connecting section 33 is bent and disposed on the outer side of the first bent connecting section 32 away from the placement cavity 101. That is, the side sealing edge 31 is disposed relatively inside the overall battery cell packaging structure; the second bent connecting section 33 is disposed relatively outside the overall battery cell packaging structure. In other words, by using a thinner inner side sealing edge 31 and a first bent connecting section 32, the thickness of the protective layer that is tightly attached to the bare battery cell placed in the placement cavity 101 is reduced, and the outermost and thicker second bent connecting section 33 ensures the protective performance of the battery cell packaging structure, thereby reducing the overall width of the battery cell and increasing the energy density of the battery cell.

[0041] Specifically, in some implementations, such as Figure 1 and 2 As shown, the thickness of the first covering surface 1 facing the placement cavity 101 and the thickness of the second covering surface 2 facing the placement cavity 101 are both H4, and the thickness of the third region is H3; where H4 > H3. That is to say, to ensure the orderly realization of protection performance, a relatively thin second bending connection section 33 is selected; thereby directly reducing the width of the battery cell and increasing the energy density of the battery cell.

[0042] Specifically, in some implementations, such as Figure 1 and 2 As shown, the first covering surface 1 and the second covering surface 2 have a five-layer structure, each including a fourth heat-sealing layer 401, a fifth adhesive layer 402, a fourth metal layer 403, a sixth adhesive layer 404, and a second nylon layer 405, which are stacked sequentially. The fourth heat-sealing layer 401 is made of PP (polypropylene) or EAA (ethylene acrylate copolymer), etc. The fifth adhesive layer 402 and the sixth adhesive layer 404 are made of polyimide adhesive resin, solvent-free polyurethane adhesive, or benzene-free polyurethane adhesive, etc.

[0043] Specifically, in some implementations, such as Figure 1 and 2As shown, the first region has a three-layer structure, including a first heat-sealing layer 311, a first adhesive layer 312, and a first metal layer 313 stacked sequentially. When the battery cell packaging structure is in a heat-sealed state, it is inclinedly connected to the first covering surface; and the first bent connecting section 32 is bent along the first direction A toward the first metal layer 313. That is, the first heat-sealing layer 311 serves as a protective layer that is tightly attached to the bare battery cell placed in the placement cavity 101 to ensure the installation stability of the bare battery cell. The side sealing edge 31 consists only of the first heat-sealing layer 311, the first adhesive layer 312, and the first metal layer 313 to reduce the number of nylon and adhesive layers. The first heat-sealing layer 311 is made of PP (polypropylene) or EAA (ethylene acrylate copolymer), etc. The first adhesive layer 312 is made of polyimide adhesive resin, solvent-free polyurethane adhesive, or benzene-free polyurethane adhesive, etc.

[0044] Specifically, in some implementations, such as Figure 1 and 2 As shown, the second region has a three-layer structure, including a second heat-sealing layer 321, a second adhesive layer 322, and a second metal layer 323 stacked sequentially. When the battery cell packaging structure is in a heat-sealed state, the second metal layer 323 is bent relative to the side seal edge 31 (the first metal layer 313) along the first direction A. That is, the second metal layer 323 is assembled with the first metal layer 313 in the side seal edge 31 as the inner layer, and the protection performance of the side cover 3 is achieved through the second heat-sealing layer 321 of the outer layer. Among them, the first bending connection section 32 consists only of the second heat-sealing layer 321, the second adhesive layer 322, and the second metal layer 323 stacked sequentially, so as to reduce one layer of nylon layer and adhesive layer; the second heat-sealing layer 321 is made of PP (polypropylene) material or PE (polyethylene) material, etc. The second adhesive layer 322 is made of polyimide adhesive resin, solvent-free polyurethane adhesive, or benzene-free polyurethane adhesive, etc.

[0045] Specifically, in some implementations, such as Figure 1 and 2 As shown, the third region has a five-layer structure, including a third heat-sealing layer 331, a third adhesive layer 332, a third metal layer 333, a fourth adhesive layer 334, and a first nylon layer 335 stacked sequentially. When the battery cell packaging structure is in a heat-sealed state, the third heat-sealing layer 331 is bonded to the second heat-sealing layer. In other words, by adding a nylon layer 335 to the outermost layer, the protective performance of the aluminum-plastic film is improved, and the width of the battery cell can be effectively reduced, increasing the energy density of the battery cell. The third heat-sealing layer 331 is made of PP (polypropylene) or PE (polyethylene), etc. The third adhesive layer 332 is made of polyimide adhesive resin, solvent-free polyurethane adhesive, or benzene-free polyurethane adhesive, etc.

[0046] The fourth heat-sealing layer 401, the third heat-sealing layer 331, the second heat-sealing layer 321, and the first heat-sealing layer 311 are all made of the same material and are integrally formed. The first adhesive layer 312, the second adhesive layer 322, the third adhesive layer 332, the fourth adhesive layer 334, the fifth adhesive layer 402, and the sixth adhesive layer 404 are all made of the same material.

[0047] Specifically, in some implementations, such as Figure 1 and 2 As shown, the relationship between the thickness h1 of the first heat-sealing layer 311 and the thickness h2 of the second heat-sealing layer 321 satisfies: h1 ≥ h2. This structure, with its relatively thicker inner first heat-sealing layer 311, ensures the protective performance between the battery cell packaging structure and the bare battery cell. Preferably, h1 = h2. This structure improves the ease of removing the first heat-sealing layer 311 and the second heat-sealing layer 321, avoiding the need for multiple adjustments to processing parameters.

[0048] Specifically, in some implementations, such as Figure 1 and 2 As shown, the relationship between the thickness h4 of the fourth heat-sealing layer 401 and the thickness h1 of the first heat-sealing layer 311 satisfies: 20µm ≤ h4 - h1 ≤ 35µm. The relationship between the thickness h4 of the fourth heat-sealing layer 401 and the thickness h2 of the second heat-sealing layer 321 satisfies: 20µm ≤ h4 - h2 ≤ 35µm. The relationship between the thickness h4 of the fourth heat-sealing layer 401 and the thickness h3 of the third heat-sealing layer 331 satisfies: 20µm ≤ h4 - h3 ≤ 35µm. This structure, by thinning all segmented heat-sealing layers on the side cover 3 by 20-35µm, directly reduces the width of the battery cell, increases its energy density, ensures its protective performance, and improves safety in use.

[0049] Specifically, in some implementations, such as Figure 2 and 3 As shown in Figure 4, when the battery cell packaging structure is in a heat-sealed state, a seventh adhesive layer 51 is provided between the first metal layer 313 and the second metal layer 323. The seventh adhesive layer 51 is made of polyimide adhesive resin, solvent-free polyurethane adhesive, or benzene-free polyurethane adhesive, etc. This structure, through the seventh adhesive layer 51, can improve the stability of the battery cell packaging structure after the second sealing operation and enhance its safety in use.

[0050] Specifically, in some implementations, such as Figure 2 and 3As shown in Figure 4, when the battery cell packaging structure is in a heat-sealed state, an eighth adhesive layer 52 is provided between the third heat-sealing layer 331 and the second heat-sealing layer 321. The eighth adhesive layer 52 is made of polyimide adhesive resin, solvent-free polyurethane adhesive, or benzene-free polyurethane adhesive, etc. This structure, through the eighth adhesive layer 52, can improve the stability of the battery cell packaging structure after the second sealing operation and enhance its safety in use.

[0051] This utility model also proposes a battery cell, such as Figure 5 As shown, the battery cell includes a battery cell packaging structure and a bare battery cell body 6; the bare battery cell body 6 is connected inside the cavity 101 between the first covering surface 1, the second covering surface 2, and the side cover 3. The specific structure of the battery cell packaging structure is as described in the above embodiments. Since this battery cell adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0052] The bare cell body 6 includes a positive electrode, a negative electrode, and a separator. The battery cell primarily functions by the movement of metal ions between the positive and negative electrodes. The positive electrode includes a positive current collector and a positive active material layer, the latter coated on the surface of the current collector. The current collector includes a positive coating area and a positive electrode tab connected to the coating area. The coating area is coated with the positive active material layer, while the tab is not. Further, the positive current collector can be made of aluminum, and the positive active material layer includes a positive active material, which can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The negative electrode includes a negative current collector and a negative active material layer, the latter coated on the surface of the current collector. The current collector includes a negative coating area and a negative electrode tab connected to the coating area. The coating area is coated with the negative active material layer, while the tab is not. The negative electrode current collector can be made of copper, and the negative electrode active material layer includes a negative electrode active material, which can be carbon or silicon, etc. The separator can be made of PP (polypropylene) or PE (polyethylene), etc.

[0053] This utility model also proposes a secondary battery, which includes a battery cell. The specific structure of the battery cell is as described in the above embodiments. Since this secondary battery adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0054] A rechargeable battery, also known as a secondary battery or accumulator battery, is a battery that can be recharged after discharge to reactivate its active materials and continue to be used. Utilizing the reversibility of chemical reactions, a new battery can be constructed; that is, after a chemical reaction converts into electrical energy, the electrical energy can be used to repair the chemical system, and then the chemical reaction can be converted back into electrical energy. Therefore, it is called a secondary battery (rechargeable battery). The main types of rechargeable batteries on the market include nickel-metal hydride batteries, nickel-cadmium batteries, lead-acid (or lead-acid) batteries, lithium-ion batteries, and polymer lithium-ion batteries.

[0055] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style of the specification is merely for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0056] Based on the disclosure and teachings of the above specification, those skilled in the art can make changes and modifications to the above embodiments. Therefore, this utility model is not limited to the specific embodiments described above, and any obvious improvements, substitutions, or modifications made by those skilled in the art based on this utility model are within the protection scope of this utility model. Furthermore, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation on this utility model.

Claims

1. An electric cell packaging structure, characterized by: The first covering surface, the second covering surface and at least two side sealing surfaces; the side sealing surfaces are arranged between the first covering surface and the second covering surface; each of the side sealing surfaces comprises a side sealing edge, a first bending connecting section and a second bending connecting section; the side sealing edge and the first bending connecting section are sequentially connected to the first covering surface; the second bending connecting section is connected to the second covering surface; The first bending connecting section is arranged between the side sealing edge and the second bending connecting section; the side sealing edge comprises a first area overlapping the first bending connecting section, the first bending connecting section comprises a second area overlapping the side sealing edge, and the second bending connecting section comprises a third area overlapping the first bending connecting section; the thickness of the first area is H1, the thickness of the second area is H2, and the thickness of the third area is H3, wherein H1≥H2, H2 2. The battery cell packaging structure of claim 1, wherein: A placing cavity is arranged between the first covering surface, the second covering surface and the side sealing surface; The side sealing edge is located on the inner side of the first bending connecting section facing the placing cavity; The second bending connecting section is located on the outer side of the first bending connecting section away from the placing cavity.

3. The battery cell packaging structure of claim 1, wherein: The thickness of the first covering surface and the second covering surface is H4; wherein H4>H3.

4. The battery cell packaging structure according to claim 1 or 2 or 3, wherein: The first area is a three-layer structure; and the first area comprises a first heat sealing layer, a first adhesive layer and a first metal layer which are sequentially stacked; And / or, the second area is a three-layer structure; and the second area comprises a second heat sealing layer, a second adhesive layer and a second metal layer which are sequentially stacked.

5. The battery cell packaging structure of claim 4, wherein: The first covering surface and the second covering surface are both five-layer structures; and the first covering surface and the second covering surface both comprise a fourth heat sealing layer, a fifth adhesive layer, a fourth metal layer, a sixth adhesive layer and a second nylon layer which are sequentially stacked; And / or, the third area is a five-layer structure; and the third area comprises a third heat sealing layer, a third adhesive layer, a third metal layer, a fourth adhesive layer and a first nylon layer which are sequentially stacked; the third heat sealing layer is bonded to the second heat sealing layer.

6. The battery cell packaging structure of claim 4, wherein: The relationship between the thickness h1 of the first heat sealing layer and the thickness h2 of the second heat sealing layer satisfies: h1≥h2.

7. The battery cell packaging structure of claim 5, wherein: The relationship between the thickness h4 of the fourth heat sealing layer and the thickness h1 of the first heat sealing layer satisfies: 20um≤h4-h1≤35um; And / or, the relationship between the thickness h4 of the fourth heat sealing layer and the thickness h2 of the second heat sealing layer satisfies: 20um≤h4-h2≤35um; And / or, the relationship between the thickness h4 of the fourth heat sealing layer and the thickness h3 of the third heat sealing layer satisfies: 20um≤h4-h3≤35um.

8. The battery cell packaging structure of claim 5, wherein: The first metal layer and the second metal layer are provided with a seventh adhesive layer therebetween; And / or, the third heat sealing layer and the second heat sealing layer are provided with an eighth adhesive layer therebetween.

9. An electric cell characterized by: The bare cell body and the cell packaging structure according to any one of claims 1-8; the bare cell body is connected to the inside between the first covering surface, the second covering surface and the side sealing surface.

10. A secondary battery characterized by comprising: The cell according to claim 9.

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