Battery cell, battery device and energy storage device

Abstract

The utility model discloses a single battery, a battery device and an energy storage device, and relates to the technical field of batteries, the single battery comprises a laminated battery cell and a plurality of circles of winding belts, at least one end of the laminated battery cell is provided with a tab, the winding belts are wound on the peripheral wall of the laminated battery cell and are arranged at intervals along the length direction of the laminated battery cell, each circle of wrapping tape comprises at least one adhesive tape, and part of the adhesive tape of each circle of wrapping tape is overlapped so that each circle of wrapping tape can form a closed loop. A plurality of circles of winding belts are arranged on the laminated cell, and part of adhesive tape of each circle of winding belt is overlapped, so that each circle of winding belt forms a closed loop wound on the peripheral wall of the laminated cell, the fixing effect of the winding belts on the laminated cell is improved, and the risk that the laminated cell is scattered in the assembly process is reduced; the reliability of the laminated battery cell is improved, so that the production and manufacturing efficiency and the yield of the laminated battery cell are improved, and the production and manufacturing efficiency and the yield of a battery monomer are further improved.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a battery monomer, a battery device and an energy storage device. Background Art

[0002] During the manufacturing process of battery cells, it is usually necessary to fix the laminated cells.

[0003] In the related art, the fixing effect of the laminated battery core is poor, which affects the reliability of the laminated battery core and thus affects the production efficiency and quality rate of the battery cell. Utility Model Content

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a battery cell having a laminated core with good reliability, which is conducive to improving the production efficiency and quality rate of the battery cell.

[0005] The first objective of the present application is to provide a battery cell.

[0006] The second objective of this application is to provide a battery device.

[0007] The third aspect of the present application is to provide an energy storage device.

[0008] In the first aspect, the present application proposes a battery cell. According to the battery cell of the embodiment of the present application, it includes: a laminated battery cell, at least one end of the laminated battery cell is provided with a pole ear; multiple turns of winding tape, the winding tape is wrapped around the outer peripheral wall of the laminated battery cell and is arranged at intervals along the length direction of the laminated battery cell, each turn of the winding tape includes at least one adhesive tape, and part of the adhesive tape of each turn of the winding tape is overlapped to define a tape connection and make each turn of the winding tape form a closed loop; wherein, the length direction is the direction in which the laminated battery cell extends out of the pole ear.

[0009] In the above technical solution, by arranging multiple turns of winding tape on the laminated battery cell, and partially overlapping the tape of each turn of winding tape so that each turn of winding tape forms a closed loop wrapped around the outer peripheral wall of the laminated battery cell, it is beneficial to improve the fixing effect of the winding tape on the laminated battery cell, reduce the risk of the laminated battery cell dispersing during the assembly process, so as to improve the reliability of the laminated battery cell, thereby helping to improve the production and manufacturing efficiency and quality rate of the laminated battery cell, and further helping to improve the production and manufacturing efficiency and quality rate of the battery cell.

[0010] According to some embodiments of the present application, each circle of the wrapping tape includes an adhesive tape, and the head and tail positions of the adhesive tape overlap with each other to define a tape connection.

[0011] In the above technical solution, by making each circle of the winding tape include an adhesive tape, it is beneficial to simplify the structure of the winding tape and improve the winding efficiency of the winding tape. By making the ends of the adhesive tape overlap with each other to define the connection of the adhesive tape, it is beneficial to improve the connection strength of the adhesive tape itself. At the same time, it is beneficial to increase the contact area between the adhesive tape and the laminated battery cell, improve the fixing effect of the adhesive tape on the laminated battery cell, and reduce the risk of the laminated battery cell falling apart.

[0012] According to some embodiments of the present application, the laminated battery cell includes a first side wall and a second side wall, the first side wall is connected to the second side wall, the first side wall is the side wall with the largest area of ​​the laminated battery cell, and the tape connection defined by the overlapping arrangement of part of the tape is located on the first side wall and / or the second side wall.

[0013] In the above technical solution, by locating the tape connection point on the first side wall, it is beneficial to improve the fixing effect of the winding tape on the laminated battery cell and improve the reliability of the laminated battery cell; by locating the tape connection point on the second side wall, it is beneficial to reduce the risk of interface deterioration of the laminated battery cell due to uneven force on the first side wall after the laminated battery cell expands, thereby helping to reduce the risk of safety hazards and performance degradation of the laminated battery cell; by locating the tape connection point on the first side wall and the second side wall respectively, it is beneficial to improve the fixing effect of the winding tape on the laminated battery cell and at the same time help to reduce the risk of interface deterioration of the laminated battery cell.

[0014] According to some embodiments of the present application, the tape connection is located on the first side wall, and in the first direction, the width of the first side wall is W, the overlapping width of the tape connection is d1, and the ratio of the overlapping width d1 to the width W of the first side wall is in the range of five percent to thirty percent, wherein the first direction is perpendicular to the direction in which the laminated battery cell extends out of the pole ear, and the first direction is perpendicular to the thickness direction of the pole piece of the laminated battery cell.

[0015] In the above technical solution, by making the value range of d1 / W be 5%~30%, it is beneficial to improve the fixing effect of the tape on the laminated battery cell, and at the same time it is beneficial to reduce the risk of uneven force on the first side wall, thereby reducing the problem of interface deterioration of the laminated battery cell and improving the performance of the laminated battery cell.

[0016] According to some embodiments of the present application, a ratio of the overlapping width d1 to the width W of the first sidewall ranges from 13 percent to 23 percent.

[0017] In the above technical solution, by further designing the proportional relationship between the overlapping width d1 at the tape connection and the width W of the first side wall, it is beneficial to further improve the fixing effect of the tape on the laminated battery cell, and at the same time it is beneficial to further reduce the risk of uneven force on the first side wall, thereby helping to reduce the problem of interface deterioration in the laminated battery cell and improve the performance of the laminated battery cell.

[0018] According to some embodiments of the present application, the tape connection is located on the second side wall, and in the second direction, the width of the second side wall is T. The ratio of the overlapping width d1 to the width T of the second side wall is greater than or equal to forty percent, and the second direction is parallel to the thickness direction of the electrode of the laminated battery cell.

[0019] In the above technical solution, by making d1 / T ≥ 40%, the area of ​​the tape connection is increased, which is beneficial to improving the connection strength of the tape itself, and is beneficial to increasing the contact area between the tape and the laminated battery cell, so as to improve the fixing effect of the tape on the laminated battery cell. At the same time, by arranging the tape connection on the second side wall, it is beneficial to improve the problem of uneven force on the laminated battery cell when the laminated battery cell expands, thereby helping to reduce the problem of interface deterioration of the laminated battery cell.

[0020] According to some embodiments of the present application, a ratio of the overlapping width d1 to the width T of the second sidewall ranges from 50 percent to 80 percent.

[0021] In the above technical solution, the proportional relationship between the width d1 of the tape connection and the width T of the second side wall is further designed to improve the fixing effect of the tape on the laminated battery cells while reducing the risk of uneven force on the laminated battery cells. It is also beneficial to reduce the material used for the tape and reduce the production cost of the laminated battery cells.

[0022] According to some embodiments of the present application, there are multiple winding belts, and the multiple winding belts are connected end to end.

[0023] In the above technical solution, by setting up multiple winding tapes, it is beneficial to increase the contact area between the winding tape and the laminated battery core, so as to further improve the fixing effect of the winding tape on the laminated battery core, thereby helping to improve the strength of the laminated battery core. By connecting multiple winding tapes end to end, it is beneficial to make the winding tape evenly distributed on the laminated battery core, thereby helping to disperse the pressure of the winding tape on the laminated battery core and reduce the risk of damage to the laminated battery core due to uneven force.

[0024] According to some embodiments of the present application, the tape is provided with notches, and the notches are spaced apart from the connection point of the tape.

[0025] In the above technical solution, by setting notches on the tape and spacing the notches and the connection between the tape and the laminated battery cell, the tape can be broken, so that the laminated battery cell can be released from its restraint on the laminated battery cell after the laminated battery cell expands to a certain extent, thereby helping to reduce the risk of uneven stress distribution in the laminated battery cell due to the tape restraining the laminated battery cell too tightly, thereby helping to reduce the risk of interface deterioration in the laminated battery cell, and further helping to improve the performance of the laminated battery cell.

[0026] According to some embodiments of the present application, the Young's modulus E of the area of ​​the tape where the notch is not provided satisfies: 0.1 MPa≤E≤800 MPa.

[0027] In the above technical solution, the Young's modulus of the tape is designed to facilitate deformation of the tape, which is beneficial to improving the force uniformity of the laminated battery cell, thereby improving the performance of the laminated battery cell, and at the same time improving the fixing effect of the tape on the laminated battery cell.

[0028] According to some embodiments of the present application, 1 MPa≤E≤100 MPa.

[0029] In the above technical solution, by further designing the Young's modulus of the tape, it is beneficial to further improve the convenience of the tape deformation, thereby helping to further improve the force uniformity of the laminated battery cell, and thus helping to improve the performance of the laminated battery cell. At the same time, it is beneficial to further improve the fixing effect of the tape on the laminated battery cell, thereby improving the reliability of the laminated battery cell.

[0030] According to some embodiments of the present application, the laminated battery cell includes a positive electrode sheet, a negative electrode sheet and an isolation membrane, the isolation membrane is located between the positive electrode sheet and the negative electrode sheet, the thickness of the current collector of the positive electrode sheet is in the range of 12μm~20μm; and / or the thickness of the current collector of the negative electrode sheet is in the range of 6μm~12μm.

[0031] In the above technical solution, by making the thickness of the current collector of the positive electrode sheet range from 12μm to 20μm, it is beneficial to improve the structural strength and support effect of the positive electrode sheet, and thus it is beneficial to improve the structural strength of the laminated battery cell; by making the thickness of the current collector of the negative electrode sheet range from 6μm to 12μm, it is beneficial to improve the structural strength and support effect of the negative electrode sheet, and thus it is beneficial to improve the structural strength of the laminated battery cell.

[0032] According to some embodiments of the present application, at least one side of the isolation membrane is provided with an oil-based polyvinylidene fluoride coating.

[0033] In the above technical solution, by providing an oil-based polyvinylidene fluoride coating on at least one side of the isolation membrane, it is beneficial to improve the bonding force between the isolation membrane and the positive electrode sheet and / or the negative electrode sheet, thereby helping to improve the connection strength between the isolation membrane and the positive electrode sheet and / or the negative electrode sheet, and further helping to improve the strength of the laminated battery cell and improve the manufacturability of the laminated battery cell.

[0034] According to some embodiments of the present application, the battery cell further includes a packaging bag, the laminated battery cell is arranged in the packaging bag, the electrode lead-out piece connected to the tab extends out of the packaging bag, and the dimensions of the laminated battery cell in length L, width W, and thickness T are in the range of: 550mm≤L≤650mm, 100mm≤W≤140mm, 12mm≤T≤40mm.

[0035] In the above technical solution, by designing the length L, width W and thickness T of the laminated battery cell, it is beneficial to ensure that the laminated battery cell meets the energy density requirements while making the laminated battery cell have lower internal resistance and better electrical performance.

[0036] The second object of the present application is to provide a battery device. According to an embodiment of the present application, the battery device includes a box and the above-mentioned battery cell, and the battery cell is arranged in the box.

[0037] The advantages of the battery device are the same as those of the aforementioned battery cell, which will not be described in detail here.

[0038] The third object of the present application is to provide an energy storage device. The energy storage device according to an embodiment of the present application includes the above-mentioned battery cell or the above-mentioned battery device, and the battery cell or the battery device is used to store or provide electrical energy.

[0039] The energy storage device has the same advantages as the above-mentioned battery cell or battery device, which will not be described in detail here.

[0040] Additional aspects and advantages of the present invention will be given in part in the following description and will become apparent from the following description or learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0042] Figure 1 A simplified structural diagram of the energy storage device described in an embodiment of the present application;

[0043] Figure 2 An exploded view of a battery device according to an embodiment of the present application;

[0044] Figure 3This is a schematic diagram of the structure of the battery cell described in the embodiment of this application. Figure 1 ;

[0045] Figure 4 This is a schematic diagram of the structure of the battery cell described in the embodiment of this application. Figure 2 ;

[0046] Figure 5 This is a schematic diagram of the structure of the battery cell described in the embodiment of this application. Figure 3 .

[0047] Reference numerals:

[0048] Battery cell 100,

[0049] Laminated battery core 110, first side wall 111, second side wall 112,

[0050] Tab 120,

[0051] Wrapping tape 130, tape 131, tape joint 132, notch 133,

[0052] Battery device 200, housing 210, first housing 211, second housing 212,

[0053] Energy storage device 1000 and control unit 300. DETAILED DESCRIPTION

[0054] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0055] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0056] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments.

[0057] In the description of this application, it should be noted that, unless otherwise specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood broadly. For example, they can refer to direct connection or indirect connection through an intermediary. Those skilled in the art will understand the specific meanings of these terms in this application based on specific circumstances.

[0058] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0059] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and should not constitute any limitation on this application.

[0060] The term "plurality" used in this application refers to two or more (including two).

[0061] In this application, battery cells may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, and the embodiments of this application are not limited thereto. Battery cells may be cylindrical, flat, rectangular, or in other shapes, and the embodiments of this application are not limited thereto.

[0062] For example, a battery cell typically includes a packaging bag, a laminated battery cell, and an electrolyte. The packaging bag is used to hold the laminated battery cell, and at least one tab extends from the packaging bag. The laminated battery cell includes one or more electrode assemblies, which are formed by a positive electrode sheet, a negative electrode sheet, and a separator. The battery cell primarily operates by the movement of metal ions between the positive and negative electrode sheets.

[0063] The positive electrode sheet generally includes a current collector and a positive electrode active material layer. The positive electrode active material layer is directly or indirectly coated on the positive electrode current collector. The current collector not coated with the positive electrode active material layer protrudes from the current collector coated with the positive electrode active material layer, and the current collector not coated with the positive electrode active material layer serves as the positive electrode tab. Taking lithium-ion batteries as an example, the positive electrode current collector can be made of aluminum, and the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc.

[0064] A negative electrode sheet generally includes a current collector and a negative active material layer. The negative active material layer is directly or indirectly coated on the current collector. The current collector uncoated with the negative active material layer protrudes from the current collector coated with the negative active material layer. The current collector uncoated with the negative active material layer serves as the negative electrode tab. The negative electrode current collector can be made of copper, and the negative active material can be carbon, silicon, or other materials. To ensure that high currents can pass without melting, multiple positive electrode tabs are stacked together, and multiple negative electrode tabs are stacked together.

[0065] The material of the isolation film is not limited, and can be, for example, polypropylene or polyethylene.

[0066] The battery cells mentioned in this application may also be provided with a pressure relief structure. When the internal pressure of the battery cell is excessive (e.g., due to overcharging), the pressure relief structure is used to release the gas inside the battery cell to reduce the internal pressure of the battery cell and prevent the battery cell from exploding due to excessive internal pressure. For example, the pressure relief structure may be an explosion-proof valve, explosion-proof disk, etc.

[0067] In recent years, new energy batteries have been used more and more widely in life and industry. For example, new energy vehicles equipped with batteries have been widely used. In addition, batteries are also increasingly used in energy storage fields.

[0068] In the related art, in the process of manufacturing battery cells, short tapes are often used to fix the two side walls of the laminated battery cells in the length direction. This fixing method has poor fixing effect and there is a risk of the tape falling off, which leads to the risk of the pole pieces spreading out or folding during the assembly of the laminated battery cells, affecting the reliability of the laminated battery cells and causing a reduction in the production efficiency and quality rate of the laminated battery cells.

[0069] Based on the above considerations, in order to improve the reliability of laminated battery cells, a battery cell is proposed, which includes: a laminated battery cell and multiple turns of winding tape, at least one end of the laminated battery cell is provided with a pole ear, the winding tape is wrapped around the outer peripheral wall of the laminated battery cell and is arranged at intervals along the length direction of the laminated battery cell, each turn of the winding tape includes at least one adhesive tape, and part of the adhesive tape of each turn of the winding tape is overlapped so that each turn of the winding tape forms a closed loop; wherein the length direction is the direction in which the laminated battery cell extends out of the pole ear.

[0070] In the above technical solution, by arranging multiple turns of winding tape on the laminated battery cell, and partially overlapping the tape of each turn of winding tape so that each turn of winding tape forms a closed loop wrapped around the outer peripheral wall of the laminated battery cell, it is beneficial to improve the fixing effect of the winding tape on the laminated battery cell, reduce the risk of the laminated battery cell dispersing during the assembly process, so as to improve the reliability of the laminated battery cell, thereby helping to improve the production and manufacturing efficiency and quality rate of the laminated battery cell, and further helping to improve the production and manufacturing efficiency and quality rate of the battery cell.

[0071] The embodiments of the present application provide a battery device including the battery cells disclosed herein. The battery device referred to in the embodiments of the present application refers to a single physical module that includes multiple battery cells to provide higher voltage and capacity. For example, the battery device referred to in the present application may be a battery module or a battery pack. A battery module generally includes multiple battery cells. The battery device generally includes a casing for encapsulating multiple battery cells or multiple battery modules. The casing can prevent liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0072] An embodiment of the present application provides an energy storage device for storing electrical energy and capable of providing electrical energy using the above-mentioned battery device. The energy storage device may include but is not limited to an energy storage container, an energy storage cabinet, etc.

[0073] For the convenience of description, the following embodiments are described by taking the energy storage device 1000 of some embodiments of the present application as an example.

[0074] Please refer to Figure 1 , Figure 1 This is a simplified structural diagram of the energy storage device 1000 provided in some embodiments of the present application. The energy storage device 1000 may be an energy storage container or an energy storage cabinet. Figure 1 As shown, the energy storage device 1000 may include a battery device 200 and a control unit 300. The control unit 300 is used to control the charging and discharging of the battery device 200 to ensure the normal operation of the battery device 200. For example, the control unit 300 can be used to detect ambient temperature, humidity parameters, etc.

[0075] Please refer to Figure 2 , Figure 2 This is an exploded view of a battery device 200 provided in an embodiment of the present application. The battery device 200 includes a housing 210 and a battery cell 100. The battery cell 100 is disposed within the housing 210, which provides assembly space for the battery cell 100. In some embodiments, the housing 210 may include a first housing 211 and a second housing 212. The first housing 211 may be snap-fitted with the second housing 212 and fixedly connected via a threaded connector. The first housing 211 and the second housing 212 may together define a housing cavity for accommodating the battery cell 100.

[0076] For example: Refer to Figure 2 The first box body 211 and the second box body 212 can also be formed as a hollow structure with one side open, and the open side of the first box body 211 covers the open side of the second box body 212 to form the box body 210 with a storage space. For another example, the second box body 212 can be a hollow structure with one end open, and the first box body 211 can be a plate-shaped structure, and the first box body 211 covers the open side of the second box body 212, so that the first box body 211 and the second box body 212 jointly define a storage cavity. Of course, it is understandable that the box body 210 can be formed in various shapes, such as a cylinder or a rectangular parallelepiped.

[0077] In the battery device 200, multiple battery cells 100 can be connected in series, in parallel, or in a hybrid connection. A hybrid connection refers to a combination of series and parallel connections among the multiple battery cells 100. Multiple battery cells 100 can be directly connected in series, in parallel, or in a hybrid connection, and then the entire battery unit formed by the multiple battery cells 100 can be housed within the housing 210. Alternatively, the battery device 200 can be formed by first connecting multiple battery cells 100 in series, in parallel, or in a hybrid connection to form a battery module. The multiple battery modules are then connected in series, in parallel, or in a hybrid connection to form an entire battery unit, which is then housed within the housing 210. The battery device 200 can also include other structures. For example, the battery device 200 can also include a busbar for electrically connecting the multiple battery cells 100.

[0078] Please refer to Figure 3 and Figure 4 , Figure 3 Schematic diagram of the structure of the battery cell 100 provided in some embodiments of the present application Figure 1 ; Figure 4 The structure of the battery cell 100 provided in some embodiments of the present application is schematically shown. Figure 2 In an embodiment of the present application, a battery cell 100 includes a laminated cell 110 and multiple wraps of tape 130 . A tab 120 is provided at at least one end of the laminated cell 110 . The tape 130 wraps around the outer circumferential wall of the laminated cell 110 and is spaced apart along the length of the laminated cell 110 . Each wrap 130 includes at least one adhesive tape 131 . Portions of the adhesive tape 131 of each wrap 130 overlap to form a closed loop. The length direction is the direction in which the laminated cell 110 extends out of the tab.

[0079] In the above technical solution, by arranging multiple circles of winding tape 130 on the laminated battery core 110, and partially overlapping the tape 131 of each circle of winding tape 130 so that each circle of winding tape 130 forms a closed loop wound around the outer peripheral wall of the laminated battery core 110, it is beneficial to improve the fixing effect of the winding tape 130 on the laminated battery core 110, reduce the risk of the laminated battery core 110 dispersing during the assembly process, thereby helping to improve the reliability of the laminated battery core 110, and further helping to improve the production efficiency and quality rate of the laminated battery core 110.

[0080] Combine Figure 3 and Figure 4 For example, the laminated battery cell 110 is provided with a tab 120 at at least one end in the length direction. For example, the laminated battery cell 110 is provided with a tab 120 at one end in the length direction, or the laminated battery cell 110 is provided with tabs 120 at both ends in the length direction. The extension direction of the tab 120 can be the same as the length direction of the laminated battery cell 110.

[0081] The wrapping tape 130 is spaced apart from the tab 120, that is, the wrapping tape 130 can be wound around the outer peripheral wall of the laminated battery core 110 along the width direction and thickness direction of the laminated battery core 110, and the wrapping tape 130 is spaced apart from the tab 120, so as to improve the fixing effect of the wrapping tape 130 on the laminated battery core 110 while reducing the risk of the wrapping tape 130 blocking the tab 120. Multiple turns of the wrapping tape 130 are spaced apart along the length direction of the laminated battery core 110 to further improve the fixing effect of the wrapping tape 130 on the laminated battery core 110, which is conducive to further improving the reliability of the laminated battery core 110.

[0082] In some examples, each turn of the winding tape 130 may include a tape 131, and a tape 131 may be wound on the outer peripheral wall of the laminated battery cell 110 along the width direction and the thickness direction of the laminated battery cell 110, and the head end and the tail end of the tape 131 may be overlapped so that each turn of the winding tape 130 forms a closed loop.

[0083] It should be noted that the “starting end of the tape 131 ” can be understood as the end where the tape 131 is initially fixed on the laminated battery cell 110 , and the “tailing end of the tape 131 ” can be understood as the ending portion where the tape 131 is wound to form a closed loop.

[0084] In other examples, each circle of the wrapping tape 130 may include two tapes 131, the ends of the two tapes 131 may be overlapped to define a tape connection 132, and each circle of the wrapping tape 130 may be formed into a closed loop to be wrapped around the outer peripheral wall of the laminated battery cell 110 to fix the laminated battery cell 110.

[0085] Therefore, by overlapping part of the tape 131 of each circle of the wrapping tape 130 so that each circle of the wrapping tape 130 forms a closed loop, it is beneficial to increase the contact area between the wrapping tape 130 and the laminated battery cell 110, thereby helping to improve the adhesion of the wrapping tape 130 to the laminated battery cell 110, and further helping to improve the fixing effect of the wrapping tape 130 on the laminated battery cell 110, reducing the risk of the laminated battery cell 110 falling apart, and improving the reliability of the laminated battery cell 110.

[0086] Please combine Figure 3 and Figure 4 In some embodiments of the present application, each winding tape 130 includes a tape 131 , and the beginning and end positions of the tape 131 overlap with each other to define a tape connection 132 .

[0087] In the above technical solution, by making each circle of the winding tape 130 include a tape 131, it is beneficial to simplify the structure of the winding tape 130 and improve the winding efficiency of the winding tape 130. By making the ends of the tape 131 overlap with each other to define the tape connection 132, it is beneficial to improve the connection strength of the tape 131 itself, and at the same time it is beneficial to increase the contact area between the tape 131 and the laminated battery cell 110, improve the fixing effect of the tape 131 on the laminated battery cell 110, and reduce the risk of the laminated battery cell 110 falling apart.

[0088] Exemplarily, the head end of the tape 131 can first be adhered to one side wall of the laminated battery cell 110, and then the tape 131 can be wrapped around the outer peripheral wall of the laminated battery cell 110 in a direction perpendicular to the tab 120, and the tail end of the tape 131 and the head end of the tape 131 are located on the same side wall of the laminated battery cell 110, and the head end and tail end of the tape 131 are overlapped with each other to define a tape connection 132, which is beneficial to improving the connection strength of the tape 131 itself, and at the same time, the tape 131 can be formed into a closed loop, increasing the connection area between the tape 131 and the laminated battery cell 110, thereby improving the fixing effect of the tape 131 on the laminated battery cell 110.

[0089] like Figure 3 As shown, in some embodiments of the present application, the laminated battery cell 110 includes a first side wall 111 and a second side wall 112, the first side wall 111 is connected to the second side wall 112, the first side wall 111 is the side wall with the largest area of ​​the laminated battery cell 110, and the tape connection 132 defined by the overlapping arrangement of part of the tape 131 is located on the first side wall 111 and / or the second side wall 112.

[0090] In the above technical solution, by locating the tape connection 132 at the first side wall 111, it is beneficial to improve the fixing effect of the winding tape 130 on the laminated battery cell 110, and improve the reliability of the laminated battery cell 110; by locating the tape connection 132 at the second side wall 112, it is beneficial to reduce the risk of interface deterioration of the laminated battery cell 110 due to uneven force at the first side wall 111 after the laminated battery cell 110 expands, thereby helping to reduce the risk of safety hazards and performance degradation of the laminated battery cell 110; by locating the tape connection 132 at the first side wall 111 and the second side wall 112 respectively, it is beneficial to improve the fixing effect of the winding tape 130 on the laminated battery cell 110, and at the same time help to reduce the risk of interface deterioration of the laminated battery cell 110.

[0091] Exemplarily, the tab 120 is arranged on the end face of the laminated battery cell 110 in the length direction, the first side wall 111 and the second side wall 112 are perpendicular to each other and connected, and the first side wall 111 and the second side wall 112 are respectively perpendicular to the end face where the tab 120 is provided, and the winding tape 130 is wound around the first side wall 111 and the second side wall 112.

[0092] Please refer to Figure 3 In some examples, each winding tape 130 may include a tape 131, the leading end of the tape 131 may be disposed on the first side wall 111, and similarly, the trailing end of the tape 131 may be disposed on the same first side wall 111 as the leading end of the tape 131, and the leading end and the trailing end of the tape 131 overlap with each other to define a tape connection 132, and the tape connection 132 is located on the first side wall 111. Since the first side wall 111 is the largest area of ​​the laminated battery cell 110, That is, the area on the first side wall 111 that can be used to arrange the tape connection 132 is larger. Therefore, arranging the tape connection 132 on the first side wall 111 is beneficial to increasing the area of ​​the tape connection 132, thereby helping to improve the connection strength of the tape 131 itself, and helping to further increase the contact area between the tape 131 and the laminated battery cell 110, thereby improving the fixing effect of the tape 131 on the laminated battery cell 110, and thus improving the reliability of the laminated battery cell 110.

[0093] In other embodiments, each winding tape 130 may include an adhesive tape 131, and the head end of the adhesive tape 131 may be disposed on the second side wall 112. Similarly, the tail end of the adhesive tape 131 may be disposed on the same second side wall 112 as the head end of the adhesive tape 131, and the head end and the tail end of the adhesive tape 131 overlap with each other to define an adhesive tape connection 132, and the adhesive tape connection 132 is located on the second side wall 112. Considering that when the laminated battery core 110 expands, the large surface of the laminated battery core 110 (that is, The amount of expansion caused by uneven force on the first side wall 111 (such as the first side wall 111) may be greater than the amount of expansion caused by uneven force on the small surface of the laminated battery cell 110 (such as the second side wall 112). Therefore, by arranging the tape connection 132 on the second side wall 112, it is beneficial to improve the force uniformity of the first side wall 111 of the laminated battery cell 110, thereby helping to improve the problem of interface deterioration of the laminated battery cell 110 due to uneven force on the first side wall 111 after the laminated battery cell 110 expands.

[0094] In some other examples, each circle of winding tape 130 may include two tapes 131, and the leading end of one tape 131 and the tail end of the other tape 131 may be set on the first side wall 111 and overlap with each other to define a tape connection 132, and the tape connection 132 is located at the first side wall 111, and the tail ends of the two tapes 131 may be set on the second side wall 112 and overlap with each other to define another tape connection 132, and the tape connection 132 is located at the second side wall 112, thereby achieving the tape connection 132 being located at the first side wall 111 and the second side wall 112 respectively.

[0095] In some other examples, each circle of the wrapping tape 130 may include two tapes 131, and the leading end of one tape 131 and the trailing end of the other tape 131 may be set on one of the two first side walls 111 and overlap with each other to define a tape connection 132, and the trailing end of one tape 131 and the leading end of the other tape 131 may be set on the other of the two first side walls 111 and overlap with each other to define another tape connection 132, thereby achieving that the tape connection 132 is respectively located on the two opposite first side walls 111.

[0096] In other examples, each circle of the wrapping tape 130 may include two tapes 131, and the leading end of one tape 131 and the trailing end of the other tape 131 may be set on one of the two second side walls 112 and overlap with each other to define a tape connection 132, and the trailing end of one tape 131 and the leading end of the other tape 131 may be set on the other of the two second side walls 112 and overlap with each other to define another tape connection 132, thereby achieving that the tape connection 132 is respectively located on the two opposite second side walls 112.

[0097] It is understandable that the specific location of the tape connection 132 can be determined according to actual production requirements and is not specifically limited here.

[0098] Please refer to Figure 3 and Figure 4 In some embodiments of the present application, the tape connection 132 is located on the first side wall 111, and in the first direction, the width of the first side wall 111 is W, the overlapping width of the tape connection 132 is d1, and the ratio of the overlapping width d1 to the width W of the first side wall 111 ranges from five percent to thirty percent, wherein the first direction is perpendicular to the direction in which the laminated battery cell 110 extends out of the tab 120, and the first direction is perpendicular to the thickness direction of the electrode of the laminated battery cell 110.

[0099] It should be noted that the specific direction of the “first direction” can be referred to Figure 3 shown.

[0100] In the above technical solution, by making the value range of d1 / W be 5%~30%, it is beneficial to improve the fixing effect of the tape 131 on the laminated battery core 110, and at the same time it is beneficial to improve the force uniformity of the first side wall 111, thereby helping to reduce the problem of interface deterioration of the laminated battery core 110 and improve the performance of the laminated battery core 110.

[0101] Exemplarily, within the same horizontal plane, the dimension of the first side wall 111 in the extension direction perpendicular to the tab 120 is the width W of the first side wall 111, and the dimension of the tape connection 132 in the width direction parallel to the first side wall 111 is the overlapping width d1 of the tape connection 132, and d1 / W satisfies the relationship: 5%≤d1 / W≤30%. For example, d1 / W can be 5%, 10%, 12%, 30%, etc., so as to reasonably distribute the area of ​​the first side wall 111 where the tape connection 132 is arranged, so as to increase the area of ​​the tape connection 132, improve the fixing effect of the tape 131 on the laminated battery cell 110, and at the same time help reduce the risk of affecting the force uniformity of the first side wall 111 due to the excessive area of ​​the tape connection 132.

[0102] When d1 / W is less than 5%, the area of ​​the tape connection 132 is too small compared to the area of ​​the first side wall 111, the connection strength of the tape 131 itself is poor, and the contact area between the tape 131 and the laminated battery cell 110 is small, resulting in poor fixing effect of the tape 131 on the laminated battery cell 110; when d1 / W is greater than 30%, the area of ​​the tape connection 132 is too large, so that the connection strength of the tape 131 itself is high. When the laminated battery cell 110 expands, the force at the position where the tape connection 132 is arranged on the laminated battery cell 110 is greater than the force at the position where the tape connection 132 is not arranged on the laminated battery cell 110. Therefore, when the area of ​​the tape connection 132 is too large, the force uniformity of the laminated battery cell 110 will be reduced, thereby causing the laminated battery cell 110 to have an interface deterioration problem, thereby affecting the performance of the laminated battery cell 110.

[0103] Of course, it is understandable that the specific value of d1 / W can be determined according to actual production requirements and is not specifically limited here.

[0104] In some embodiments of the present application, a ratio of the overlapping width d1 to the width W of the first sidewall 111 ranges from 13 percent to 23 percent.

[0105] In the above technical solution, by further designing the proportional relationship between the overlapping width d1 of the tape connection 132 and the width W of the first side wall 111, it is beneficial to further improve the fixing effect of the tape 131 on the laminated battery cell 110, and at the same time it is beneficial to further reduce the risk of uneven force on the first side wall 111, thereby helping to reduce the problem of interface deterioration of the laminated battery cell 110 and improve the performance of the laminated battery cell 110.

[0106] For example, the value of d1 / W can be 13%, 15%, 18%, 20%, 23%, etc. When d1 / W is less than 13%, the area of ​​the tape connection 132 is smaller than the area of ​​the first side wall 111, the connection strength of the tape 131 itself is poor, and the contact area between the tape 131 and the laminated battery core 110 is small, resulting in poor fixing effect of the tape 131 on the laminated battery core 110; when d1 / W is greater than 2 ... is smaller than the area of ​​the first side wall 111, the connection strength of the tape 131 is poor, and the contact area between the tape 131 and the laminated battery core 110 is small, The large area makes the connection strength of the tape 131 itself high. When the laminated battery cell 110 expands, the force at the position where the tape connection 132 is arranged on the laminated battery cell 110 is greater than the force at the position where the tape connection 132 is not arranged on the laminated battery cell 110. Therefore, the large area of ​​the tape connection 132 will reduce the force uniformity of the laminated battery cell 110, thereby causing the interface deterioration problem of the laminated battery cell 110, and further affecting the performance of the laminated battery cell 110.

[0107] Of course, it is understandable that the specific value of d1 / W can be determined according to actual production requirements and is not specifically limited here.

[0108] Please refer to Figure 4 and Figure 5 ,in, Figure 5 Schematic diagram of the structure of the battery cell 100 provided in some embodiments of the present application Figure 3 In some embodiments of the present application, the tape connection 132 is located on the second side wall 112 . In the second direction, the width of the second side wall 112 is T, the overlapping width of the tape connection 132 is d1, and the ratio of the overlapping width d1 to the width T of the second side wall 112 is greater than or equal to 40%. The second direction is parallel to the thickness direction of the electrode of the laminated battery cell 110 .

[0109] It should be noted that the second direction is perpendicular to the first direction, and the second direction is perpendicular to the direction in which the laminated battery core 110 extends out of the tab 120. For specific directions, please refer to Figure 4 shown.

[0110] In the above technical solution, by making d1 / T ≥ 40%, the area of ​​the tape connection 132 is increased, which is beneficial to improving the connection strength of the tape 131 itself, and is beneficial to increasing the contact area between the tape 131 and the laminated battery cell 110, so as to improve the fixing effect of the tape 131 on the laminated battery cell 110. At the same time, by arranging the tape connection 132 on the second side wall 112, it is beneficial to improve the problem of uneven force on the laminated battery cell 110 when the laminated battery cell 110 expands, thereby helping to reduce the problem of interface deterioration of the laminated battery cell 110.

[0111] Exemplarily, the dimension of the second side wall 112 in the extension direction perpendicular to the first side wall 111 and the tab 120 is defined as the width T of the second side wall 112, and the dimension of the tape connection 132 in the width direction parallel to the second side wall 112 is defined as the overlapping width d1 of the tape connection 132, d1 / T ≥ 40%, for example: d1 / T can be 40%, 45%, 50% or 65%, etc. Since the area of ​​the second side wall 112 is smaller than that of the first side wall 111, by making d1 / T ≥ 40%, the area of ​​the tape connection 132 can be maximized within the limited space on the second side wall 112, thereby helping to improve the connection strength of the tape 131 itself, and helping to increase the contact area between the tape 131 and the laminated battery cell 110, thereby helping to improve the fixing effect of the tape 131 on the laminated battery cell 110.

[0112] It is understandable that the specific value of d1 / T can be determined according to actual production requirements and is not specifically limited here.

[0113] In some embodiments of the present application, a ratio of the overlapping width d1 to the width T of the second sidewall 112 ranges from 50% to 80%.

[0114] In the above technical solution, by further designing the proportional relationship between the width d1 of the tape connection 132 and the width T of the second side wall 112, the fixing effect of the tape 131 on the laminated battery cell 110 can be improved while reducing the risk of uneven force on the laminated battery cell 110, and it is beneficial to reduce the material used for the tape 131 and reduce the production cost of the laminated battery cell 110.

[0115] Exemplarily, the value of d1 / T can be 50%, 51%, 55%, 60%, 70% or 80%, etc. When d1 / T is less than 50%, the area of ​​the tape connection 132 is small, resulting in poor connection strength of the tape 131 itself, and causing the tape 131 to have poor fixing effect on the laminated battery cell 110; when d1 / T is greater than 80%, the area of ​​the tape connection 132 is large, so that the connection strength of the tape 131 itself is high. When the laminated battery cell 110 expands, the force at the position where the tape connection 132 is arranged on the second side wall 112 is greater than the force at the position where the tape connection 132 is not arranged on the second side wall 112. Therefore, the large area of ​​the tape connection 132 will reduce the force uniformity of the second side wall 112, thereby reducing the force uniformity of the laminated battery cell 110, and further causing the laminated battery cell 110 to have interface deterioration problems, affecting the performance of the laminated battery cell 110.

[0116] Please combine Figures 3 to 5 In some embodiments of the present application, there are multiple wrapping belts 130, and the multiple wrapping belts 130 are connected end to end.

[0117] In the above technical solution, by providing multiple winding tapes 130, it is beneficial to increase the contact area between the winding tape 130 and the laminated battery core 110, so as to further improve the fixing effect of the winding tape 130 on the laminated battery core 110, thereby helping to improve the strength of the laminated battery core 110. By connecting multiple winding tapes 130 end to end, it is beneficial to make the winding tape 130 evenly distributed on the laminated battery core 110, thereby helping to disperse the pressure of the winding tape 130 on the laminated battery core 110, and reducing the risk of damage to the laminated battery core 110 due to uneven force.

[0118] For the sake of convenience, three winding tapes 130 are provided on the laminated battery core 110 for illustration, and the three winding tapes 130 are connected end to end on the laminated battery core 110, that is, the tail end of the first winding tape 130 can be overlapped and connected with the head end of the second winding tape 130, and the tail end of the second winding tape 130 can be overlapped and connected with the head end of the third winding tape 130. It can also be understood that multiple winding tapes 130 are serpentine-wound on the laminated battery core 110, so as to improve the fixing effect of the winding tape 130 on the laminated battery core 110, while facilitating dispersing the pressure of the winding tape 130 on the laminated battery core 110.

[0119] Please combine Figure 3 and Figure 5 In some embodiments of the present application, the tape 131 is provided with a notch 133 , and the notch 133 is spaced apart from the tape connection 132 .

[0120] In the above technical solution, by setting a notch 133 on the tape 131 and spacing the notch 133 and the tape connection 132, the tape 131 can be broken, so that after the laminated battery cell 110 expands to a certain extent, the tape 131 can release the restraint on the laminated battery cell 110, thereby helping to reduce the risk of uneven stress distribution in the laminated battery cell 110 due to the tape 131 restraining the laminated battery cell 110 too tightly, thereby helping to reduce the risk of interface deterioration in the laminated battery cell 110, and further helping to improve the performance of the laminated battery cell 110.

[0121] Combine Figure 3 and Figure 5 For example, the tape connection 132 can be located on the second side wall 112, and the notch 133 can be located on the first side wall 111, so that the notch 133 and the tape connection 132 can be spaced apart. When the laminated battery cell 110 expands, the laminated battery cell 110 will exert a force on the tape 131. Since the connection strength of the tape 131 at the position where the notch 133 is provided is low, when the laminated battery cell 110 expands to a certain extent, the tape 131 can break at the notch 133 to release the restraint on the laminated battery cell 110, thereby reducing the risk of uneven force on the laminated battery cell 110, thereby improving the performance of the laminated battery cell 110.

[0122] In some embodiments, the tape 131 can be made of a PET (polyethylene terephthalate) substrate. By providing notches on the PET substrate to reduce the tensile strength of the PET substrate, the tensile strength of the tape 131 can be reduced, so that the tape 131 breaks after the laminated battery cell 110 expands.

[0123] It is understandable that the adhesive tape 131 may also be made of other materials. The specific material of the adhesive tape 131 may be determined according to actual production requirements and is not specifically limited here.

[0124] In some embodiments of the present application, the Young's modulus E of the area of ​​the tape 131 where no notches 133 are provided satisfies the following relationship: 0.1 MPa≤E≤800 MPa.

[0125] In the above technical solution, the Young's modulus of the tape 131 is designed to facilitate deformation of the tape 131, which is beneficial to improving the force uniformity of the laminated battery cell 110, and further beneficial to improving the performance of the laminated battery cell 110, and at the same time, it is beneficial to improve the fixing effect of the tape 131 on the laminated battery cell 110.

[0126] Exemplarily, the tape 131 can be made of an elastic substrate, for example, the substrate made of the tape 131 can be one of an acrylic substrate, a polyurethane substrate or a rubber substrate. When the laminated battery cell 110 expands, the laminated battery cell 110 will exert a force on the tape 131 so that the tape 131 elastically deforms to adapt to the expansion of the laminated battery cell 110, thereby reducing the risk of uneven stress distribution in the laminated battery cell 110 due to the tape 131 being too tight on the laminated battery cell 110, thereby helping to reduce the risk of interface deterioration in the laminated battery cell 110, and further helping to improve the performance of the laminated battery cell 110.

[0127] When the Young's modulus E of the tape 131 is less than 0.1 MPa, the ability of the tape 131 to resist elastic deformation caused by external force is too poor, resulting in poor fixing effect of the tape 131 on the laminated battery core 110, thereby reducing the reliability of the laminated battery core 110; when the Young's modulus E of the tape 131 is greater than 800 MPa, the ability of the tape 131 to resist elastic deformation caused by external force is too strong, and it is not easy for the tape 131 to elastically deform when the laminated battery core 110 expands, which easily leads to uneven force on the laminated battery core 110.

[0128] It is understandable that E can be 0.1 MPa, 0.7 MPa, 10 MPa, 500 MPa or 800 MPa, etc. The specific value of E can be determined according to actual production requirements and is not specifically limited here.

[0129] In some embodiments of the present application, 1 MPa≤E≤100 MPa.

[0130] In the above technical solution, by further designing the Young's modulus of the tape 131, it is beneficial to further improve the convenience of deformation of the tape 131, thereby helping to further improve the force uniformity of the laminated battery cell 110, and further helping to improve the performance of the laminated battery cell 110, and at the same time helping to further improve the fixing effect of the tape 131 on the laminated battery cell 110, thereby improving the reliability of the laminated battery cell 110.

[0131] Specifically, when the Young's modulus E of the tape 131 is less than 1 MPa, the tape 131 has poor ability to resist elastic deformation caused by external force, resulting in poor fixing effect of the tape 131 on the laminated battery core 110, thereby reducing the reliability of the laminated battery core 110; when the Young's modulus E of the tape 131 is greater than 100 MPa, the tape 131 has strong ability to resist elastic deformation caused by external force, resulting in the laminated battery core 110 not being easy to elastically deform the tape 131 when it expands, which easily leads to uneven force on the laminated battery core 110.

[0132] It is understandable that E can be 1 MPa, 9 MPa, 75 MPa or 100 MPa, etc. The specific value of E can be determined according to actual production requirements and is not specifically limited here.

[0133] In some embodiments of the present application, the laminated battery cell 110 includes a positive electrode sheet, a negative electrode sheet and an isolation membrane, the isolation membrane is located between the positive electrode sheet and the negative electrode sheet, the thickness of the current collector of the positive electrode sheet ranges from 12μm to 20μm; and / or the thickness of the current collector of the negative electrode sheet ranges from 6μm to 12μm.

[0134] In the above technical solution, by making the thickness of the current collector of the positive electrode sheet range from 12μm to 20μm, it is beneficial to improve the structural strength and support effect of the positive electrode sheet, and thus it is beneficial to improve the structural strength of the laminated battery cell 110; by making the thickness of the current collector of the negative electrode sheet range from 6μm to 12μm, it is beneficial to improve the structural strength and support effect of the negative electrode sheet, and thus it is beneficial to improve the structural strength of the laminated battery cell 110.

[0135] In some examples, the thickness of the current collector of the positive electrode sheet of the laminated battery cell 110 ranges from 12 μm to 20 μm, for example, the thickness of the current collector of the positive electrode sheet can be 12 μm, 15 μm, 18 μm or 20 μm, etc., to improve the structural strength and support effect of the positive electrode sheet; in other examples, the thickness of the current collector of the negative electrode sheet ranges from 6 μm to 12 μm, for example, the thickness of the current collector of the negative electrode sheet can be 6 μm, 9 μm or 12 μm, etc., to improve the structural strength and support effect of the negative electrode sheet.

[0136] In other examples, the thickness of the current collector of the positive electrode sheet is in the range of 12μm~20μm, and the thickness of the current collector of the negative electrode sheet is in the range of 6μm~12μm, so as to further improve the structural strength of the laminated battery cell 110, wherein the current collector of the positive electrode sheet can be made of aluminum foil, and the current collector of the negative electrode sheet can be made of copper foil. At the same thickness, the structural strength of copper foil is greater than that of aluminum foil. Therefore, the thickness of the current collector of the negative electrode sheet is smaller than the thickness of the current collector of the positive electrode sheet, which can also make the negative electrode sheet have good structural strength. Therefore, the thickness of the current collector of the positive electrode sheet is in the range of 12μm~20μm, and the thickness of the current collector of the negative electrode sheet is in the range of 6μm~12μm, which can effectively improve the structural strength of the laminated battery cell 110, and is beneficial to reducing the material cost of the laminated battery cell 110, thereby helping to reduce the production cost of the laminated battery cell 110.

[0137] In some specific examples, the current collector of the positive electrode sheet is formed as aluminum foil, and the current collector of the negative electrode sheet is formed as copper foil, which is beneficial to improving the charge and discharge performance and energy output of the battery cell 100.

[0138] In some embodiments of the present application, at least one side of the isolation membrane is provided with an oil-based polyvinylidene fluoride coating.

[0139] It should be noted that "polyvinylidene fluoride is abbreviated as PVDF. For the sake of convenience, "PVDF" will be used to represent polyvinylidene fluoride below. "Oil-based PVDF" can be understood as a slurry formed by dissolving PVDF powder in an oily solvent (such as NMP, NMP refers to N-methylpyrrolidone). "Oil-based PVDF coating" can be understood as a continuous polymer film formed after the slurry dries.

[0140] In the above technical solution, by providing an oil-based PVDF coating on at least one side of the isolation membrane, it is beneficial to improve the bonding force between the isolation membrane and the positive electrode sheet and / or the negative electrode sheet, thereby helping to improve the connection strength between the isolation membrane and the positive electrode sheet and / or the negative electrode sheet, and further helping to improve the strength of the laminated battery cell 110 and improve the manufacturability of the laminated battery cell 110.

[0141] In some examples, a slurry formed by dissolving PVDF powder in an oily solvent can be coated on the surface of the side of the isolation membrane facing the positive electrode sheet. After the slurry dries, an oil-based PVDF coating is formed on the side of the isolation membrane facing the positive electrode sheet; in other examples, a slurry formed by dissolving PVDF powder in an oily solvent can be coated on the surface of the side of the isolation membrane facing the negative electrode sheet. After the slurry dries, an oil-based PVDF coating is formed on the side of the isolation membrane facing the negative electrode sheet; in still other examples, a slurry formed by dissolving PVDF powder in an oily solvent can be respectively coated on the surface of the side of the isolation membrane facing the positive electrode sheet and the negative electrode sheet. After the slurry dries, oil-based PVDF coatings are formed on both sides of the isolation membrane in the stacking direction of the laminated battery cell 110.

[0142] It is understandable that the specific location of the oil-based PVDF coating on the isolation membrane can be determined according to actual production requirements and is not specifically limited here.

[0143] Compared with the point-like polymers formed on the surface of the isolation membrane by the water-based PVDF coating, the oil-based PVDF coating can form a continuous polymer film on the surface of the isolation membrane, which is beneficial to improve the adhesion between the isolation membrane and the positive electrode sheet or the negative electrode sheet, thereby helping to improve the connection strength between the isolation membrane and the positive electrode sheet or the negative electrode sheet, and further helping to improve the manufacturability of the laminated battery cell 110.

[0144] In some embodiments of the present application, a ceramic coating is provided on at least one surface of the isolation membrane.

[0145] In the above technical solution, by setting a ceramic coating on at least one side of the isolation membrane, it is beneficial to improve the structural strength of the isolation membrane, improve the isolation membrane's ability to resist deformation, and help reduce the risk of damage to the isolation membrane. In addition, the ceramic coating can also play a role in supporting the oil-based PVDF coating, so as to facilitate the setting of the oil-based PVDF coating on the isolation membrane.

[0146] In some examples, a ceramic coating is provided on the side of the isolation membrane facing the positive electrode sheet; in other examples, a ceramic coating is provided on the side of the isolation membrane facing the negative electrode sheet; in still other examples, a ceramic coating is provided on both sides of the isolation membrane in the stacking direction of the laminated battery cell 110.

[0147] It is understandable that the specific arrangement position of the ceramic coating on the isolation membrane can be determined according to actual production requirements and is not specifically limited here.

[0148] Please combine Figure 4 and Figure 5In some embodiments of the present application, the battery cell 100 further includes a packaging bag, the laminated battery cell 110 is arranged in the packaging bag, the electrode lead-out sheet connected to the tab 120 extends out of the packaging bag, and the dimensions of the laminated battery cell 110, including length L, width W, and thickness T, are in the range of 550 mm ≤ L ≤ 650 mm, 100 mm ≤ W ≤ 140 mm, and 12 mm ≤ T ≤ 40 mm.

[0149] In the above technical solution, by designing the length L, width W and thickness T of the laminated battery core 110, it is beneficial to ensure that the laminated battery core has lower internal resistance and better electrical performance while ensuring that the laminated battery core meets the energy density requirements.

[0150] Exemplarily, the battery cell 100 can be constructed as a soft-pack battery, the laminated battery cell 110 is arranged in a packaging bag, the electrode lead-out tabs of the laminated battery cell 110 extend from the packaging bag and are connected to the tabs 120, wherein the length L of the laminated battery cell 110 can be 550mm, 560mm, 580mm or 650mm, etc., the width W of the laminated battery cell 110 can be 100mm, 110mm, 115mm, 120mm, 130mm or 140mm, etc., and the thickness T of the laminated battery cell 110 can be 12mm, 17mm, 18mm, 18.5mm, 20mm, 25mm, 30mm, 35mm or 40mm, etc.

[0151] It is understandable that the length L, width W and thickness T of the laminated battery core 110 can be determined according to actual production requirements and are not specifically limited here, as long as the size of the laminated battery core 110 can meet actual production requirements.

[0152] In some examples, the packaging bag can be formed of an aluminum-plastic film to reduce the risk of moisture or oxygen entering the packaging bag, thereby improving the performance and service life of the battery cell 100. It is understood that the specific material of the packaging bag can be determined according to actual production requirements and is not specifically limited here.

[0153] In some examples, the laminated battery cell 110 may be a lithium iron phosphate system energy storage laminated battery cell 110 .

[0154] According to some embodiments of the present application, the present application further provides a battery device 200 , which includes a box body 210 and the above-mentioned battery cell 100 , wherein the battery cell 100 is disposed in the box body 210 .

[0155] In the above technical solution, since the battery device 200 is provided with the above-mentioned battery cell 100 and the production efficiency and quality rate of the battery cell 100 are high, the production efficiency and quality rate of the battery device 200 are advantageously improved.

[0156] According to some embodiments of the present application, the present application further provides an energy storage device 1000 , which includes the battery cell 100 of the above embodiment or the above battery device 200 , and the battery cell 100 or the battery device 200 is used to store or provide electrical energy.

[0157] In the above technical solution, since the energy storage device 1000 is provided with the above battery cell 100 or the above battery device 200 and the production efficiency and quality rate of the battery cell 100 or the battery device 200 are high, it is beneficial to improve the production efficiency and quality rate of the energy storage device 1000.

[0158] It should be noted that, unless there is any conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0159] The above are merely preferred embodiments of the present application and are not intended to limit the present application. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A battery cell, characterized in that: include: A laminated battery core, wherein at least one end of the laminated battery core is provided with a tab; a plurality of wrapping tapes, the wrapping tapes being wrapped around the outer peripheral wall of the laminated core and spaced apart along the length of the laminated core, each wrapping tape comprising at least one adhesive tape, with portions of the adhesive tapes of each wrapping tape overlapping so that each wrapping tape forms a closed loop; The length direction is the direction in which the laminated battery core extends out of the tab.

2. The battery cell according to claim 1, wherein: Each circle of the wrapping tape includes an adhesive tape, and the head and tail positions of the adhesive tape overlap each other to define an adhesive tape connection.

3. The battery cell according to claim 1, wherein: The laminated battery core includes a first side wall and a second side wall, the first side wall is connected to the second side wall, the first side wall is the side wall with the largest area of ​​the laminated battery core, and the tape connection defined by the overlapping arrangement of part of the tape is located on the first side wall and / or the second side wall.

4. The battery cell according to claim 3, characterized in that The tape connection is located on the first side wall. In the first direction, the width of the first side wall is W, the overlapping width of the tape connection is d1, and the ratio of the overlapping width d1 to the width W of the first side wall is in the range of 5% to 30%, wherein the first direction is perpendicular to the direction in which the laminated battery cell extends out of the electrode ear, and the first direction is perpendicular to the thickness direction of the electrode sheet of the laminated battery cell.

5. The battery cell according to claim 4, characterized in that The ratio of the overlap width d1 to the width W of the first sidewall ranges from 13 percent to 23 percent.

6. The battery cell according to claim 3, characterized in that The tape connection is located on the second side wall. In the second direction, the width of the second side wall is T, the overlapping width of the tape connection is d1, and the ratio of the overlapping width d1 to the width T of the second side wall is greater than or equal to forty percent. The second direction is parallel to the thickness direction of the electrode of the laminated battery cell.

7. The battery cell according to claim 6, characterized in that The ratio of the overlapping width d1 to the width T of the second side wall ranges from 50% to 80%.

8. The battery cell according to claim 1, wherein: There are multiple winding belts, and the multiple winding belts are connected end to end.

9. The battery cell according to claim 1, characterized in that The adhesive tape is provided with notches, and the notches are spaced apart from the connection point of the adhesive tape.

10. The battery cell according to claim 9, characterized in that The Young's modulus E of the area of ​​the adhesive tape where the notches are not provided satisfies the following condition: 0.1 MPa≤E≤800 MPa.

11. The battery cell according to claim 10, characterized in that 1Mpa≤E≤100Mpa.

12. The battery cell according to claim 1, wherein The laminated battery cell includes a positive electrode sheet, a negative electrode sheet and a separator, the separator is located between the positive electrode sheet and the negative electrode sheet, the thickness of the current collector of the positive electrode sheet ranges from 12μm to 20μm; and / or the thickness of the current collector of the negative electrode sheet ranges from 6μm to 12μm.

13. The battery cell according to claim 12, characterized in that At least one side of the isolation membrane is provided with an oil-based polyvinylidene fluoride coating.

14. The battery cell according to any one of claims 1 to 13, characterized in that: The battery cell also includes a packaging bag, the laminated battery cell is arranged in the packaging bag, and the electrode lead-out piece connected to the tab extends out of the packaging bag. The dimensions of the laminated battery cell, length L, width W, and thickness T, are in the range of: 550mm≤L≤650mm, 100mm≤W≤140mm, and 12mm≤T≤40mm.

15. A battery device, characterized in that: The invention comprises a box body and a battery cell according to any one of claims 1 to 14, wherein the battery cell is arranged in the box body.

16. An energy storage device, characterized in that: The battery cell according to any one of claims 1 to 14 or the battery device according to claim 15 is used for storing or providing electrical energy.

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