Z-shaped laminated cell and secondary battery

Abstract

The utility model provides a Z-shaped laminated battery cell and a secondary battery, and relates to the technical field of battery structures. The Z-shaped laminated cell comprises a cell body, an external reinforcing structure and a shell, the external reinforcing structure comprises a fixed framework and a packaging film, the fixed framework is provided with an accommodating space and a top opening communicated with the accommodating space, the cell body is accommodated in the accommodating space, and the packaging film is used for sealing the top opening, so that the cell body is packaged in the accommodating space. The external reinforcing structure and the core body located in the containing space are contained in the shell, and the external reinforcing structure is made of an insulating material, so that on one hand, the core body can be reinforced through the external reinforcing structure, the external reinforcing structure is assembled in the shell along with the movement of the core body, and normal movement of the external reinforcing structure in the assembly section is guaranteed; and on the other hand, the external reinforcing structure is made of an insulating material, and can replace an insulating sheet in the battery cell in the prior art to play a role in insulating the cell body.

Description

Technical Field

[0001] The utility model relates to the technical field of battery structure, in particular to a Z-shaped laminated battery cell and a secondary battery. Background Art

[0002] At present, with the continuous increase in the penetration rate of new energy, the large-scale energy storage industry is also booming. In recent years, stacked cells have received more and more attention as a development direction of energy storage cells. Stacked cells can enable the system to achieve the optimal arrangement (CTR), realize a very simple system arrangement, minimize the use of auxiliary materials, and integrate highly integrated battery clusters. Using stacked batteries, the energy of the battery compartment is increased by 50%, the area density is increased by 10%, and the cost is reduced by about 35%. Stacked cells use double-sided poles to increase the volume energy density of the cell and reduce the overall cost of the cell. Reduce stress concentration at winding corners, reduce crack risks, and improve cell safety.

[0003] However, the current laminated battery cells are lacking in structural rigidity. When the length of the laminated battery becomes longer, the structural rigidity problem becomes more obvious, which will lead to many problems in the laminated battery cell assembly section, such as assembly difficulties, process delays, and poor battery consistency. However, there are relatively few ways to optimize the structural rigidity of laminated batteries in the prior art. How to improve the structural rigidity of laminated batteries to ensure the normal flow of laminated batteries in the assembly section has become a technical problem that needs to be solved in this field. Utility Model Content

[0004] A brief summary of one or more aspects is given below to provide a basic understanding of these aspects. This summary is not an exhaustive overview of all conceived aspects, and is neither intended to identify the key or critical elements of all aspects nor to define the scope of any or all aspects. Its only purpose is to give some concepts of one or more aspects in a simplified form as a prelude to a more detailed description that will be given later.

[0005] The utility model aims to provide a Z-shaped laminated battery core, which can improve the structural rigidity of the laminated battery core to ensure the normal flow of the laminated battery core in the assembly section.

[0006] The utility model also aims to provide a secondary battery, which can improve the structural rigidity of the laminated battery core.

[0007] The embodiments of the present invention can be implemented in the following ways:

[0008] A Z-type laminated battery core, the Z-type laminated battery core comprising:

[0009] Core;

[0010] an external reinforcement structure, the external reinforcement structure having a fixed frame and a packaging film, the fixed frame having a receiving space and a top opening communicated with the receiving space, the receiving space being used to receive the core, and the packaging film being used to close the top opening; and

[0011] A shell, wherein the external reinforcement structure and the core located in the accommodating space are accommodated in the shell;

[0012] Wherein, the external reinforcement structure is made of insulating material to play the role of insulating the core.

[0013] Optionally, the fixed skeleton includes a first reinforcing plate, a second reinforcing plate and a third reinforcing plate connected in sequence, and the first reinforcing plate and the third reinforcing plate are arranged relatively spaced apart to form the accommodating space between the first reinforcing plate, the second reinforcing plate and the third reinforcing plate, and the top opening is opposite to the second reinforcing plate.

[0014] Optionally, the first reinforcing plate, the second reinforcing plate and the third reinforcing plate are an integrally formed structure.

[0015] Optionally, at both ends of the second reinforcing plate, the first reinforcing plate, the second reinforcing plate and the third reinforcing plate form a first end opening and a second end opening; the two ends of the core body respectively have a first pole ear and a second pole ear, the first pole ear extends out of the accommodating space from the first end opening, and the second pole ear extends out of the accommodating space from the second end opening.

[0016] Optionally, the material of the fixed frame includes polycarbonate, acrylonitrile-butadiene-styrene, polyimide or polymethyl methacrylate.

[0017] Optionally, the packaging film is made of polypropylene.

[0018] Optionally, the thickness of the fixed frame is 0.1 mm to 0.3 mm; and / or,

[0019] The packaging film has a thickness of 0.1 mm to 0.3 mm.

[0020] Optionally, at least one core is stacked in the accommodating space.

[0021] Optionally, the core includes a PP separator, multiple positive electrode sheets and multiple negative electrode sheets, the multiple positive electrode sheets and the multiple negative electrode sheets are distributed alternately in sequence, the PP separator is folded in a Z shape to form multiple folding parts connected in sequence, and the positive electrode sheet or the negative electrode sheet is arranged between two adjacent folding parts.

[0022] A secondary battery comprises the Z-type laminated battery cell as described above.

[0023] The beneficial effects of the Z-type laminated battery cell and the secondary battery provided by the embodiments of the utility model include:

[0024] The embodiment of the utility model provides a Z-type laminated battery cell, which includes a core body, an external reinforcement structure and a shell, wherein the external reinforcement structure includes a fixed frame and a packaging film, wherein the fixed frame has a storage space and a top opening connected to the storage space, wherein the core body is stored in the storage space, and the packaging film is used to close the top opening, thereby packaging the core body in the storage space. The external reinforcement structure and the core body located in the storage space are accommodated in the shell, and the external reinforcement structure is made of insulating material, so that on the one hand, the core body can be reinforced by the external reinforcement structure, and the external reinforcement structure is transferred with the core body to be assembled in the shell, thereby ensuring its normal flow in the assembly section; on the other hand, the external reinforcement structure is made of insulating material, and when the external reinforcement structure is installed in the shell with the core body, the external reinforcement structure can replace the insulating sheet (i.e., mylar sheet) in the battery cell in the prior art to play the role of insulating the core body, and the external reinforcement structure arranged in this way will not cause additional impact on the assembly of the battery cell, and has strong adaptability.

[0025] The embodiment of the utility model also provides a secondary battery, which includes the above-mentioned Z-type stacked battery cell, and thus has the beneficial effect of enhancing structural rigidity, ensuring normal flow in the assembly section, and at the same time not causing additional impact on the battery cell assembly, and having strong adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The above features and advantages of the present invention can be better understood after reading the detailed description of the embodiments of the present disclosure in conjunction with the following drawings. In the drawings, the components are not necessarily drawn to scale, and components with similar related properties or features may have the same or similar reference numerals.

[0027] Figure 1 A schematic diagram of the internal structure of a Z-type laminated battery cell provided according to one aspect of the utility model is shown;

[0028] Figure 2 A schematic diagram of the structure after the core body and the external reinforcement structure are assembled according to one aspect of the utility model is shown;

[0029] Figure 3 A schematic structural diagram of a core body in a Z-type laminated battery core provided according to one aspect of the utility model is shown;

[0030] Figure 4 A schematic structural diagram of a fixed frame provided according to one aspect of the utility model is shown;

[0031] Figure 5A process diagram of packaging a core body in a containing space in a Z-type laminated battery core provided according to one aspect of the utility model is shown.

[0032] Reference numerals:

[0033] 100-Z-type stacked battery cell; 110-core; 111-positive electrode sheet; 112-negative electrode sheet; 113-diaphragm; 114-first pole ear; 115-second pole ear; 116-folding portion; 120-external reinforcement structure; 121-fixed skeleton; 122-first reinforcement plate; 123-second reinforcement plate; 124-third reinforcement plate; 125-top opening; 126-first end opening; 127-second end opening; 128-accommodating space; 129-packaging film; 130-shell; 131-shell; 132-top cover. DETAILED DESCRIPTION

[0034] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. Note that the aspects described below in conjunction with the accompanying drawings and specific embodiments are only exemplary and should not be construed as limiting the scope of protection of the present invention.

[0035] In the description of the present utility model, it should be noted that if the terms "upper", "lower", "inside", "outside", "vertical" and the like appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, or is the orientation or position relationship in which the utility model product is usually placed when used, rather than indicating or implying that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model.

[0036] At the same time, it should be noted that the terms "first", "second", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0037] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified or limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, an integral connection, or a detachable connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or the internal communication of two components, etc. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] Figure 1 Schematic diagram of the internal structure of the Z-type laminated battery cell 100 provided in this embodiment, Figure 2 This is a schematic diagram of the structure after the core 110 and the external reinforcement structure 120 provided in this embodiment are assembled. Figure 1 and Figure 2This embodiment provides a Z-type laminated battery cell 100 , and also provides a secondary battery (not shown), the secondary battery including the Z-type laminated battery cell 100 .

[0039] The Z-type stacked battery cell 100 includes a core body 110, an external reinforcement structure 120 and a shell 130. The external reinforcement structure 120 includes a fixed skeleton 121 and a packaging film 129. The fixed skeleton 121 has a receiving space 128 and a top opening 125 connected to the receiving space 128. The core body 110 is received in the receiving space 128. The packaging film 129 is used to close the top opening 125, thereby encapsulating the core body 110 in the receiving space 128. The external reinforcement structure 120 and the core 110 located in the accommodating space 128 are accommodated in the outer shell 130, and the external reinforcement structure 120 is made of insulating material. Therefore, on the one hand, the core 110 can be reinforced by the external reinforcement structure 120, and the external reinforcement structure 120 flows with the core 110 to be assembled in the outer shell 130, thereby ensuring its normal flow in the assembly section; on the other hand, the external reinforcement structure 120 is made of insulating material. When the external reinforcement structure 120 is installed in the outer shell 130 with the core 110, the external reinforcement structure 120 can replace the insulating sheet (i.e., mylar sheet) in the battery cell in the prior art to play the role of insulating the core 110. The external reinforcement structure 120 arranged in this way will not cause additional impact on the battery cell assembly and has strong adaptability.

[0040] The Z-type laminated battery cell 100 provided in this embodiment is further described below:

[0041] Figure 3 The schematic diagram of the structure of the core 110 in the Z-type laminated battery cell 100 provided in this embodiment is shown. Figure 1-Figure 3 In this embodiment, the core 110 includes a separator 113, a plurality of positive electrode sheets 111, and a plurality of negative electrode sheets 112. The separator 113 is folded in a Z shape to form a plurality of folding portions 116 connected in sequence, and a positive electrode sheet 111 or a negative electrode sheet 112 is sandwiched between two adjacent folding portions 116, so that both sides of the positive electrode sheet 111 or the negative electrode sheet 112 are isolated by the folding portions 116 to prevent the positive electrode sheet 111 and the negative electrode sheet 112 from directly contacting and conducting electricity. The plurality of positive electrode sheets 111 and the plurality of negative electrode sheets 112 are staggered in sequence, so that along the thickness direction of the core 110, the folding portions 116, the positive electrode sheet 111, the folding sheets, and the negative electrode sheets 112 are repeatedly arranged in a cycle.

[0042] Optionally, the diaphragm 113 is a PP diaphragm. It is understandable that in some other embodiments, the PE+CCS+PCS diaphragm commonly used in the industry can also be used. Compared with the use of traditional PE diaphragms (PE+CCS+PCS), the use of PP diaphragms can further achieve the comprehensive cost reduction of battery cell materials without affecting the overall electrochemical performance and safety performance of the laminated battery cell. At the same time, when the core 110 formed by the Z-type stack of PP diaphragms is reinforced by an external reinforcement structure 120, the film requirements of the PP diaphragm battery cell can be effectively met. At the same time, the PP diaphragm will not wrinkle during subsequent infiltration, thereby increasing the cross-section of the battery pole piece and effectively promoting the application of PP diaphragms in the mass production of long laminated battery cells.

[0043] Figure 4 The structural diagram of the fixed frame 121 provided in this embodiment is shown. Figure 1-Figure 4 In this embodiment, the fixed frame 121 includes a first reinforcing plate 122, a second reinforcing plate 123 and a third reinforcing plate 124. The first reinforcing plate 122 and the third reinforcing plate 124 are arranged relatively spaced apart, so that the first reinforcing plate 122, the second reinforcing plate 123 and the third reinforcing plate 124 enclose an accommodation space 128, and the top opening 125 is an opening located between the first reinforcing plate 122 and the third reinforcing plate 124 and directly facing the second reinforcing plate 123.

[0044] Specifically, the first reinforcing plate 122, the second reinforcing plate 123 and the third reinforcing plate 124 are all rectangular plate-shaped members, and the first reinforcing plate 122 and the third reinforcing plate 124 are respectively located on both sides of the width direction of the second reinforcing plate 123, and the first reinforcing plate 122 and the second reinforcing plate 123 are relatively parallel to each other, so that the accommodation space 128 defined by the first reinforcing plate 122, the second reinforcing plate 123 and the third reinforcing plate 124 is in the shape of a rectangular parallelepiped. The top opening 125 is an opening in the circumferential direction of the rectangular parallelepiped.

[0045] Furthermore, at both ends of the second reinforcing plate 123, the first reinforcing plate 122, the second reinforcing plate 123 and the third reinforcing plate 124 form a first end opening 126 and a second end opening 127. The core 110 has a first pole ear 114 and a second pole ear 115 at both ends, the first pole ear 114 extends out of the accommodation space 128 from the first end opening 126, and the second pole ear 115 extends out of the accommodation space 128 from the second end opening 127.

[0046] Specifically, at both ends of the length direction of the second reinforcing plate 123, the first reinforcing plate 122, the second reinforcing plate 123 and the third reinforcing plate 124 enclose a first end opening 126 and a second end opening 127, and the first end opening 126 and the second end opening 127 are located at both ends of the length direction of the accommodating space 128. The core 110 has a first pole ear 114 and a second pole ear 115 at both ends, one of which is a positive pole ear formed by the pole ear on the positive electrode sheet 111, and the other of which is a negative pole ear formed by the pole ear on the negative electrode sheet 112. The first pole ear 114 extends out of the accommodation space 128 from the first end opening 126 , and the second pole ear 115 extends out of the accommodation space 128 from the second end opening 127 , so that after the packaging film 129 encapsulates the core 110 in the accommodation space 128 , the first pole ear 114 and the second pole ear 115 are located outside the accommodation space 128 to be conductive with the outside.

[0047] Figure 5 FIG. 1 shows a process diagram of packaging the core body 110 in the accommodation space 128 in the Z-type laminated battery core 100 provided in this embodiment. Figure 5 In this embodiment, the core 110 is first formed by stacking sheets, and then the core 110 is placed in the receiving space 128 of the fixed frame 121 after hot pressing, and then the packaging film 129 is attached to the upper side of the core 110, and the packaging film 129 is fixed to the fixed frame 121 by hot melting. Specifically, the fixed frame 121 is made of a hard material to play a supporting role, and the packaging film 129 is a soft film. The fixed frame 121 and the packaging film 129 play an insulating role in the core 110, and the insulating sheet (mylar sheet) is omitted in the structure, and the step of wrapping the insulating sheet is omitted in the process.

[0048] Since the fixed frame 121 and the packaging film 129 need to replace the insulating sheet to achieve the insulation of the core 110, the first end opening 126 and the second end opening 127 can also be closed by the packaging film 129 during packaging, ensuring that only the first pole ear 114 and the second pole ear 115 are not packaged.

[0049] Furthermore, at least one core 110 can be stacked in the accommodation space 128, that is, in the actual production process, one core 110 or two or more cores 110 can be placed in the accommodation space 128 according to needs. Figure 5 As shown, in this embodiment, two cores 110 are placed in the accommodating space 128. Therefore, when placing the cores 110 into the accommodating space 128 of the fixed frame 121, one of the cores 110 can be loaded first, and then the other core 110 can be stacked on top of the first core 110. After completing the core assembling step, packaging is performed.

[0050] Please refer again Figure 4 In this embodiment, the first reinforcing plate 122, the second reinforcing plate 123 and the third reinforcing plate 124 are an integrally formed structure. Specifically, the fixed frame 121 having the first reinforcing plate 122, the second reinforcing plate 123 and the third reinforcing plate 124 can be integrally formed by injection molding. The integrally formed structure makes the overall strength of the core 110 better after being installed.

[0051] Optionally, the material of the fixed skeleton 121 can be PP or PE material, which reduces the cost without affecting the overall electrochemical performance of the battery cell. Optional materials include plastics such as polycarbonate (PC), acrylonitrile-butadiene-styrene (ABS), polyimide (PI) or polymethyl methacrylate (PMMA).

[0052] Optionally, the packaging film 129 is made of polypropylene (PP).

[0053] In this embodiment, the thickness of the fixed skeleton 121 and the thickness of the packaging film 129 are equivalent to or slightly thicker than the thickness of the insulating sheet in the traditional battery cell, ensuring that the subsequent assembly will not be affected after the insulating sheet is replaced by the fixed skeleton 121 and the packaging film 129, thereby avoiding the problem of excessive width. Optionally, the thickness of the fixed skeleton 121 can be set to 0.1mm~0.3mm. Specifically, the thickness of the fixed skeleton 121 can be set to 0.1mm, 0.2mm or 0.3mm. Optionally, the thickness of the packaging film 129 can be set to 0.1mm~0.3mm. Specifically, the thickness of the packaging film 129 can be set to 0.1mm, 0.2mm or 0.3mm.

[0054] In completing Figure 5 After the packaging work shown, the structure formed by the packaging, that is, the structure formed by the external reinforcement structure 120 and the core 110 packaged in the external reinforcement structure 120, can be placed in the shell 130 to form a battery cell. The shell 130 can adopt the structure of the existing battery cell, generally, it includes a shell 131 with an opening and a top cover 132 that closes the opening, and a closed chamber is formed by the shell 131 and the top cover 132 to accommodate the structure formed by the external reinforcement structure 120 and the core 110 packaged in the external reinforcement structure 120.

[0055] The Z-type laminated cell 100 and the secondary battery provided by the embodiment of the utility model are prepared by first laminating the core 110, and then sequentially loading the two cores 110 into the accommodating space 128 of the fixed frame 121 for core assembling, and the packaging film 129 is pressed against the core 110 after the core assembling, and the hot melting step is performed. The core 110 can be hot pressed before being loaded into the accommodating space 128, or after being loaded into the accommodating space 128. At this time, the structural rigidity can be improved by fixing the frame 121, thereby avoiding problems such as insufficient hot pressing after the hot pressing process, and further avoiding the problem of poor adhesion between the pole piece and the diaphragm 113 leading to defects in the cell.

[0056] After the packaging film 129 is hot-melt packaged, subsequent assembly operations can be carried out, including welding the adapter, inserting the shell 131, and welding the top cover 132. When performing the above-mentioned assembly operations, the structure formed by the external reinforcement structure 120 and the core 110 encapsulated in the external reinforcement structure 120 can complete normal circulation, and the reinforcement structure does not affect the welding of the adapter and the welding of the top cover 132. The reinforcement structure can also play an insulating role for the bare battery cell (i.e., the core 110), eliminating the mylar sheet and mylar wrapping process, further simplifying the process flow. The battery cell continues to circulate in the assembly section and the inspection section, and there is no subsequent risk. And the rigid fixed skeleton 121 can play a shaping role to a certain extent, preventing the PP diaphragm from wrinkling during infiltration and causing the pole piece to wrinkle. The Z-type laminated battery cell 100 is particularly suitable for long laminated batteries with PP diaphragms.

[0057] The above is only a specific implementation of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technology in this field within the technical scope disclosed by the present invention should be included in the protection scope of the present invention.

Claims

1. A Z-type laminated battery cell, characterized in that: The Z-type laminated battery cell comprises: Core; an external reinforcement structure, the external reinforcement structure having a fixed frame and a packaging film, the fixed frame having a receiving space and a top opening communicated with the receiving space, the receiving space being used to receive the core, and the packaging film being used to close the top opening; and A shell, wherein the external reinforcement structure and the core located in the accommodating space are accommodated in the shell; Wherein, the external reinforcement structure is made of insulating material to play the role of insulating the core.

2. The Z-type laminated battery cell according to claim 1, characterized in that: The fixed frame includes a first reinforcing plate, a second reinforcing plate and a third reinforcing plate connected in sequence, the first reinforcing plate and the third reinforcing plate are arranged relatively spaced apart to form the accommodating space between the first reinforcing plate, the second reinforcing plate and the third reinforcing plate, and the top opening is opposite to the second reinforcing plate.

3. The Z-type laminated battery cell according to claim 2, characterized in that: The first reinforcing plate, the second reinforcing plate and the third reinforcing plate are an integrally formed structure.

4. The Z-type laminated battery cell according to claim 2, characterized in that: At both ends of the second reinforcing plate, the first reinforcing plate, the second reinforcing plate and the third reinforcing plate form a first end opening and a second end opening; the two ends of the core body are respectively provided with a first pole ear and a second pole ear, the first pole ear extends out of the accommodation space from the first end opening, and the second pole ear extends out of the accommodation space from the second end opening.

5. The Z-type laminated battery cell according to claim 1, characterized in that: The material of the fixed frame includes polycarbonate, acrylonitrile-butadiene-styrene, polyimide or polymethyl methacrylate.

6. The Z-type laminated battery cell according to claim 1, characterized in that: The packaging film is made of polypropylene.

7. The Z-type laminated battery cell according to claim 1, characterized in that: The thickness of the fixed frame is 0.1 mm to 0.3 mm; and / or, The packaging film has a thickness of 0.1 mm to 0.3 mm.

8. The Z-type laminated battery cell according to claim 1, characterized in that: At least one core is stacked in the accommodation space.

9. The Z-type laminated battery cell according to claim 1, characterized in that: The core body includes a PP separator, a plurality of positive electrode sheets and a plurality of negative electrode sheets, wherein the plurality of positive electrode sheets and the plurality of negative electrode sheets are alternately distributed in sequence, and the PP separator is folded in a Z shape to form a plurality of folded parts connected in sequence, and the positive electrode sheet or the negative electrode sheet is arranged between two adjacent folded parts.

10. A secondary battery, characterized in that: The secondary battery comprises the Z-type stacked battery cell as described in any one of claims 1 to 9.

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