Battery monomer, battery and electric device

Abstract

The utility model is applicable to the technical field of batteries, and provides a battery monomer, a battery and a power utilization device, the battery monomer comprises an electrode assembly, and the electrode assembly comprises a pole piece, a diaphragm and a reinforcing piece; the pole piece comprises a current collector, an active substance layer arranged on the current collector and a tab formed on the side edge of the current collector; the diaphragm is arranged between the two pole pieces with opposite polarities; and the reinforcer is respectively connected with the current collector and the tab to reinforce the strength of the tab. The utility model aims to properly enhance the mechanical structural strength of the battery tab and reduce the risk of damage to the tab.

Description

Technical Field

[0001] The present application belongs to the field of battery technology, and in particular relates to a battery cell, a battery, and an electrical device. Background Art

[0002] Batteries are the core components of electrical devices, and the primary functional module of a battery is the electrode assembly. The electrode assembly consists of pole pieces, which are die-cut from the current collector. During die-cutting, tabs are also formed on the sides of the current collector. The tabs themselves are mechanically weaker than the current collector itself, so during subsequent processing, the tabs can bend or even tear when the pole pieces are fed over rollers. Utility Model Content

[0003] In view of the above problems, the present application provides a battery cell, a battery and an electrical device, aiming to enhance the mechanical strength of the battery tabs and reduce the risk of damage to the tabs.

[0004] To solve the above problems, in a first aspect, the present application provides a battery cell, including an electrode assembly, wherein the electrode assembly includes:

[0005] The pole piece includes a current collector, an active material layer provided on the current collector, and a pole ear formed on the side of the current collector;

[0006] a diaphragm disposed between the two pole pieces of opposite polarity; and

[0007] A reinforcement member connects the current collector and the tab to enhance the tab's strength. The reinforcement member strengthens the structural connection between the tab and the current collector, reducing the risk of bending and tearing the tab during subsequent processing, thereby improving the quality of the electrode assembly and battery.

[0008] In one embodiment of the first aspect, the side of the current collector on which the tab is provided extends in a first direction, and the reinforcement is provided at least at both ends of the tab in the first direction. Placing the reinforcement at locations where the tab is most susceptible to bending and tearing, i.e., at both ends in the first direction, achieves the best technical effect.

[0009] In one embodiment of the first aspect, the reinforcement is provided on at least one surface of the tab. The reinforcement can be provided on one surface or both surfaces of the tab as required to appropriately enhance the strength of the tab to meet usage requirements.

[0010] In one embodiment of the first aspect, the reinforcement is attached to the surface of the tab and the current collector by gluing. First, the gluing structure is simpler and more convenient to operate. When installing the reinforcement, simply attaching it is sufficient to achieve adhesion. This is easier to operate than other connection methods and does not cause physical damage to the tab and current collector. Furthermore, the gluing method allows for a larger contact area between the reinforcement, the tab, and the current collector, resulting in better integrity and stability.

[0011] In one embodiment of the first aspect, a direction perpendicular to both the first direction and the thickness direction of the tab is a second direction, the width of the tab in the first direction is N, the coverage area of ​​the reinforcement member on the tab is a first region, the projection length of all first regions on the same side of the tab in the second direction in the first direction is M, and M is less than 1 / 3N. Because the tab needs to be ultrasonically welded to the adapter during later processing, this embodiment provides that the projection length of the first region in the second direction in the first direction is M, and M is less than 1 / 3N. This means that the first region does not excessively occupy the width direction of the tab, thereby avoiding any impact on the later ultrasonic welding of the tab.

[0012] In one embodiment of the first aspect, the tab has a height H1 in the second direction; the projections of all first regions on the same side of the tab in the first direction in the second direction have a height H2, where H2 ≥ 1 / 3 H1. The tab protrudes from the side of the current collector. Due to its protruding structure, it has relatively low mechanical strength and is prone to bending or even tearing. Therefore, sufficient connection strength is required in the protruding direction, i.e., the aforementioned second direction. Therefore, in this embodiment, the projections of the first regions in the first direction in the second direction have a height H2, where H2 ≥ 1 / 3 H1. This ensures sufficient strength for the tab.

[0013] In one embodiment of the first aspect, the reinforcement covers the current collector in a second region, and the active material layer is not provided in the second region. The second region is not covered with the active material layer, thereby avoiding interference with the active material layer and enabling the active material layer to best function.

[0014] In one embodiment of the first aspect, the side of the current collector and the area adjacent to the side edge serve as an insulating region for preventing short circuits, the second region is located within the insulating region, and the reinforcement is an insulating member. The reinforcement is connected to the insulating region, not directly to the active material layer, thereby avoiding interference with the functioning of the active material layer. Furthermore, the provision of the insulating region prevents short circuit accidents and improves safety in use.

[0015] In one embodiment of the first aspect, the reinforcement members are symmetrically disposed on both sides of the tab, and the area of ​​the reinforcement member not covering the tab and the current collector is a third area. The third areas of the corresponding reinforcement members located on the two side surfaces are connected by glue. The provision of the third area on the reinforcement member connects the reinforcement members on both sides to form a monolithic structure, further enhancing the strength of the entire tab.

[0016] In one embodiment of the first aspect, the reinforcement member is disposed on a side surface of the tab, and an area of ​​the reinforcement member that does not cover the tab and the current collector is a third area, which is a non-adhesive area. The reinforcement member can be positioned as needed, allowing for the presence of a third area that does not cover the tab and the current collector. This provides greater flexibility in the placement of the reinforcement member, thereby achieving optimal reinforcement of the tab.

[0017] In one embodiment of the first aspect, the reinforcement covers at least both ends of the tab root in the first direction. The tab root, where the tab connects to the current collector, is most susceptible to bending or even tearing, especially at both ends. Therefore, this embodiment provides reinforcement covering both ends of the tab root to enhance strength there, achieving excellent results.

[0018] In one embodiment of the first aspect, the sum of the thickness of the tab and the thickness of the reinforcement is less than the sum of the thickness of the current collector and the thickness of the active material layer. This is to reduce the space occupied by the reinforcement, save as much space as possible, and also to avoid affecting subsequent processing of the electrode, such as the winding process of the electrode.

[0019] In one embodiment of the first aspect, the electrode assembly includes multiple layers of tabs stacked together, and the reinforcement is in contact with the side surfaces of the first and last tabs; or, the reinforcement is in contact with the side surfaces of the first and last tabs and the side ends of the multiple layers of tabs in the first direction. The multiple layers of tabs are adaptively reinforced as needed.

[0020] In one embodiment of the first aspect, the reinforcement is an organic material film layer or an inorganic carbon-based material film layer. These two materials have the characteristics of high strength and good toughness, and are light weight and stable performance, making them good material choices for the reinforcement.

[0021] In a second aspect, the present application further provides a battery comprising any of the battery cells described above. When the battery provided by the present application comprises the battery cell, the quality of the battery is also guaranteed.

[0022] In a third aspect, the present application further provides an electrical device, comprising the battery provided in the embodiment, which increases the reliability and safety of the electrical device.

[0023] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the embodiments below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present application. The same reference numerals are used throughout the accompanying drawings to represent the same components.

[0025] In the attached figure:

[0026] Figure 1 A schematic structural diagram of a vehicle according to some embodiments of the present application;

[0027] Figure 2 A schematic diagram of the structure of a battery in some embodiments of the present application;

[0028] Figure 3 Schematic diagram of the structure of the electrode piece and reinforcement of the electrode assembly in the battery cell of some embodiments of the present application;

[0029] Figure 4 for Figure 3 Schematic diagram of the enlarged structure at A in the middle;

[0030] Figure 5 Schematic diagram of the structure of the electrode piece and reinforcement of the electrode assembly in the battery cell of some embodiments of the present application;

[0031] Figure 6 Schematic diagram of the structure of the electrode piece and reinforcement of the electrode assembly in the battery cell of some embodiments of the present application;

[0032] Figure 7 for Figure 6 Schematic diagram of the enlarged structure at B in the middle;

[0033] Figure 8 for Figure 6 A side structural diagram of

[0034] Figure 9 A schematic diagram of a structure in which a reinforcement member is provided when multiple pole pieces are stacked in some embodiments of the present application;

[0035] Figure 10 A schematic diagram of a structure in which a reinforcement member is provided when multiple pole pieces are stacked in some embodiments of the present application;

[0036] Figure 11Schematic diagram of the structure of providing reinforcement members when multiple pole pieces are arranged in a stacked form in some embodiments of the present application.

[0037] The accompanying drawings in the specific implementation manner are as follows:

[0038] 1000. Vehicle;

[0039] 100, battery; 200, controller; 300, motor;

[0040] 1. Pole piece; 11. Current collector; 12. Active material layer; 13. Tab; 2. Reinforcement member; 21. First region; 22. Second region; 23. Third region; 111. Insulating region. DETAILED DESCRIPTION

[0041] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments 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 figure descriptions are intended to cover non-exclusive inclusions.

[0043] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0044] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present 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. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0045] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0046] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0047] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0048] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0049] Currently, market developments indicate that batteries are increasingly being used. They are not only used in energy storage systems such as hydropower, thermal, wind, and solar power plants, but are also widely used in electric vehicles like electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. As battery applications continue to expand, market demand is also growing.

[0050] Batteries 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 are not limited to these in the present application. Batteries may be cylindrical, flat, rectangular, or in other shapes, and are not limited to these in the present application. Batteries are generally categorized into three types based on packaging: cylindrical batteries, prismatic batteries, and pouch batteries.

[0051] To meet different power requirements, a battery can include multiple battery cells, where the multiple battery cells can be connected in series, parallel, or in a hybrid connection. Hybrid connection refers to a mixture of series and parallel connections. Optionally, multiple battery cells can first be connected in series, parallel, or in a hybrid connection to form a battery module, and multiple battery modules can then be connected in series, parallel, or in a hybrid connection to form a battery. In other words, multiple battery cells can be directly combined into a battery, or they can first be combined into battery modules, and then the battery modules can be combined into a battery. The battery is further installed in an electrical device to provide power to the device.

[0052] The battery cell may be a secondary battery or a primary battery, wherein a secondary battery refers to a battery cell that can be recharged to activate the active material after the battery cell is discharged and can continue to be used, and a primary battery refers to a battery cell that cannot be recharged to activate the active material after the battery cell's power is exhausted and can continue to be used. The battery cell may also be a lithium-ion battery, a sodium-ion battery, a sodium-lithium-ion battery, a lithium metal battery, a sodium metal battery, a lithium-sulfur battery, a magnesium-ion battery, a nickel-hydrogen battery, a nickel-cadmium battery, a lead-acid battery, etc., but is not limited thereto. The battery cell may be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell, or a battery cell of other shapes. Prismatic battery cells include square-shell battery cells, blade-shaped battery cells, and polygonal prismatic batteries. Polygonal prismatic batteries are, for example, hexagonal prismatic batteries, etc. This application has no particular limitations.

[0053] A battery cell is the smallest unit for storing and outputting electrical energy. A battery cell typically contains at least one electrode assembly. The electrode assembly is the component within the battery cell where electrochemical reactions occur. The electrode assembly includes a positive electrode sheet, a negative electrode sheet, and a separator separating the positive and negative electrode sheets. The positive electrode sheet, separator, and negative electrode sheet can be wound to form a rolled electrode assembly, such that the electrode assembly has a main body region and a bending region disposed at the end of the main body region. When the battery cell is charged, the positive electrode sheet generates active ions. The active ions provided by the positive electrode sheet can penetrate the pores of the separator and move to the negative electrode sheet and embed into the negative active material of the negative electrode sheet. Conversely, when the battery cell is discharged, the active ions embedded in the negative active material of the negative electrode sheet are released. The active ions released from the negative electrode sheet can penetrate the pores of the separator and move to the positive electrode sheet and embed into the positive active material of the positive electrode sheet. The structure of the electrode assembly includes, but is not limited to, a wound structure or a stacked structure.

[0054] During the electrode assembly production process, the active material is first prepared and stirred. The active material is then applied to the current collector to form an active material layer. However, the active material is not completely coated on the current collector, leaving uncoated areas on the sides. These uncoated areas can be used to die-cut into tabs. Once the active material coating is complete, the current collector is cold-pressed, followed by slitting, including die-cutting the tabs, and winding.

[0055] During the cold pressing of the current collector, a double cold pressing roller is used. Due to the presence of active material, the thickness of the current collector in the active material area is greater than that in the area without active material. The pressure applied to the two areas is different during the cold pressing process, resulting in different ductility. After the tabs are formed, the mechanical strength of the tabs is relatively low. Moreover, since the tabs are separate protruding structures, they are prone to bending or even tearing during subsequent processing, such as when the tape passes over the rollers, especially at the base of the tabs. Furthermore, the tabs may be misaligned during winding, affecting the battery processing quality.

[0056] Based on this, this embodiment provides a battery cell having an electrode assembly having a reinforcement member 2. The reinforcement member 2 connects the current collector 11 and the tab 13, respectively, thereby increasing the strength of the tab 13. This reduces the risk of bending and tearing of the tab 13 and improves the processing quality of the battery cell.

[0057] The present application also provides a battery 100, such as Figure 2 The battery 100 is provided with the above-mentioned battery monomer, thereby improving the quality of the battery 100.

[0058] The present application also provides an electrical device, and the battery 100 provided in the present application can be applied to the electrical device, that is, an electrical device using the battery 100 as a power source or various energy storage systems using the battery 100 as an energy storage element. Among them, the electrical device can be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, etc. Among them, the electric toy can include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, etc., and the spacecraft can include an airplane, a rocket, a space shuttle, and a spacecraft, etc.

[0059] The battery 100 disclosed in the embodiment of the present application can be used in, but is not limited to, electrical devices such as vehicles 1000, ships, or aircraft. Electrical devices can use a power supply system equipped with the battery 100 disclosed in this application, which helps improve the reliability of the electrical devices.

[0060] For the convenience of description, the following embodiments are described by taking the electric device provided in the embodiments of the present application as a vehicle 1000 as an example.

[0061] Please refer to Figure 1 , Figure 1A schematic structural diagram of a vehicle 1000 provided for some embodiments of the present application. The vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100 is provided inside the vehicle 1000. The battery 100 may be provided at the bottom, head or tail of the vehicle 1000. The battery 100 may be used to power the vehicle 1000. For example, the battery 100 may serve as an operating power source for the vehicle 1000. The vehicle 1000 may further include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to power the motor 300, for example, to meet the power requirements for starting, navigating and driving the vehicle 1000.

[0062] In some embodiments of the present application, the battery 100 can serve not only as an operating power source for the vehicle 1000, but also as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0063] As a specific example of the battery cell provided in this application, please refer to Figure 3-Figure 8 A battery cell includes an electrode assembly, which includes a pole piece 1, a diaphragm, and a reinforcement 2.

[0064] The electrode 1 includes a current collector 11, an active material layer 12 disposed on the current collector 11, and a tab 13 formed on the side of the current collector 11. The separator is disposed between two electrode sheets 1 with opposite polarities; the reinforcement 2 connects the current collector 11 and the tab 13 to strengthen the tab 13.

[0065] The current collector 11 is a substrate for making the electrode 1, and copper foil, aluminum foil, etc. can be used. An active material layer 12 is provided on the current collector 11 and a pole ear 13 is formed at the side of the current collector 11, thereby forming a pole piece 1. The pole piece 1 includes at least two pole pieces with opposite polarities, and when in use, there is an electrolyte between the two pole pieces, thereby generating a flow of current. The diaphragm is provided between the two pole pieces 1 with opposite polarities. The diaphragm can use a PE-based isolation film, and both sides can be coated with a CCS coating and a PCS coating respectively. Optionally, both sides are coated with a 2μm CCS coating and a 1.5mg PCS coating respectively.

[0066] The current collector 11 is coated with an active material layer 12, which refers to an active material coated on the front and back surfaces of the current collector 11 to form a layered structure. The active materials coated on the pole pieces 1 with opposite polarities are different.

[0067] The tab 13 is formed at the side of the current collector 11 , which means that the tab 13 is formed at the side of the current collector 11 and protrudes from the side.

[0068] The reinforcement 2 is connected to the current collector 11 and the tab 13 respectively, which means that one end of the reinforcement 2 is connected to the current collector 11 and the other end is connected to the tab 13, thereby strengthening the connection strength between the tab 13 and the current collector 11 and strengthening the integrity of the protruding tab 13 and the current collector 11.

[0069] The effect of this embodiment is that, due to the provision of the reinforcement 2, the strength of the connection structure between the tab 13 and the current collector 11 is enhanced, reducing the risk of bending and tearing of the tab 13 during subsequent processing, thereby improving the quality of the electrode assembly and the battery 100.

[0070] In some embodiments, the electrode sheet 1 includes a positive electrode sheet and a negative electrode sheet; the positive electrode sheet includes a first current collector and a first active material layer provided on the first current collector; the negative electrode sheet includes a second current collector and a second active material layer provided on the second current collector; and the separator is provided between the positive electrode sheet and the negative electrode sheet.

[0071] Specifically, the electrode sheets 1 with opposite polarities may be a positive electrode sheet and a negative electrode sheet, and the two correspond to a first current collector, a first active material, and a second current collector and a second active material layer, respectively.

[0072] The first active material layer of the positive electrode sheet can be made of a positive electrode slurry obtained by uniformly mixing LiFePO4 (LFP), a binder polyvinylidene fluoride (PVDF) and a conductive carbon black (Super P) in a mass ratio of LPF:PVDF:Super P=95:3:2, and dispersing the mixed slurry using 1-methyl-2-pyrrolidone (NMP) solvent.

[0073] The second active material layer of the negative electrode sheet can be made of graphite, graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, etc.

[0074] In some embodiments, see Figure 3-Figure 7 The extending direction of the side of the current collector 11 where the tab 13 is provided is the first direction, and the reinforcement 2 is provided at least at both ends of the tab 13 in the first direction.

[0075] Among them, the tab 13 is a thin sheet structure with a certain thickness, width and height, wherein the width direction can be understood as the first direction mentioned above, and the height direction and thickness direction are both perpendicular to the first direction. Figure 3 、 Figure 5 and Figure 6 In the X direction, the two ends of the tab 13 in the first direction can be understood as the smaller end faces composed of the edges in the height direction and the edges in the thickness direction on both sides of the tab 13 in the first direction and / or the local area of ​​the large face adjacent to the smaller end face, and the large face refers to the face composed of the edges in the height direction and the edges in the width direction.

[0076] Specifically, the side of the current collector 11 has a certain extension direction. The side of the current collector 11 is a straight side. The tab 13 is formed at the side, that is, it protrudes from the side. The length of the side extends in a first direction. The reinforcement member 2 is provided at least at both ends of the tab 13 in the first direction. This means that the tab 13 is provided with a reinforcement member 2 at least at both ends in the first direction. On this basis, the reinforcement member 2 can also be provided at other locations. The reinforcement member 2 is provided at least at both ends in the first direction because these are the weak points connecting the tab 13 and the current collector 11, which are prone to bending and tearing.

[0077] In this embodiment, the reinforcement members 2 are arranged at the positions where the tabs 13 are most susceptible to bending and tearing, namely, at both ends in the first direction, which achieves the best technical effect.

[0078] In some embodiments, continue to refer to Figure 3-Figure 8 The reinforcement 2 is provided on at least one side surface of the tab 13 .

[0079] Specifically, both the tab 13 and the current collector 11 have two surfaces, and active material is coated on both surfaces of the current collector 11. The tab 13 is formed at the side of the current collector 11 and also has two surfaces. The reinforcement 2 is provided on at least one surface of the tab 13. That is, the reinforcement 2 can be provided on one surface of the tab 13, or on both surfaces of the tab 13.

[0080] The effect of this embodiment is that the reinforcement 2 can be selectively provided on one side surface or both sides of the tab 13 as required, so as to appropriately enhance the strength of the tab 13 to meet the use requirements.

[0081] In some embodiments, the reinforcement 2 is bonded to the surface of the tab 13 and the current collector 11 by gluing.

[0082] Specifically, the purpose of the reinforcement 2 is to strengthen the connection between the pole tab 13 and the current collector 11. When the two are connected, the overall effect is better to enhance the mechanical strength of the pole tab 13. This embodiment provides a connection method in the form of gluing, that is, a part of the reinforcement 2 is adhered to the pole tab 13 by gluing, and the other part is adhered to the current collector 11 by gluing.

[0083] The advantages of this embodiment are that, firstly, the adhesive bonding structure is simpler and the operation is more convenient. When setting the reinforcement 2, it only needs to be attached to achieve bonding, which is easier to operate than other connection methods and does not cause hard damage to the tab 13 and the current collector 11. Furthermore, the adhesive bonding method allows the reinforcement 2 to have a larger contact area with the tab 13 and the current collector 11, and improves the integrity and stability.

[0084] In some embodiments, see Figure 3-Figure 7 , a direction perpendicular to both the first direction and the thickness direction of the tab 13 is the second direction, the width of the tab 13 in the first direction is N, the coverage area of ​​the reinforcement 2 on the tab 13 is the first area 21, and the length of the projection in the first direction of all the first areas 21 located on the same side of the tab 13 in the second direction is M, then M<1 / 3N.

[0085] Specifically, the second direction is a direction perpendicular to the first direction, such as Figure 3 、 Figure 5 and Figure 6 The Y direction is perpendicular to the side of the current collector 11. Figure 3 、 Figure 4 as well as Figure 6 、 Figure 7 For example, the first direction is the length direction of the side of the current collector 11 where the tab 13 is located. The tab 13 itself has a width N in the first direction. The reinforcement member 2 can be pasted onto the tab 13. A single reinforcement member 2 has a certain coverage area on the surface of the tab 13, which is called the first area 21. The reinforcement members 2 pasted on the same side of the tab 13 all have the first area 21. The projection of the first area 21 in the second direction has a length M in the first direction. The so-called projection in the second direction can be understood as the projection of the first area 21 in the first direction when a parallel light beam is projected along the second direction. This projection has a certain length in the first direction, which is called M, so M < 1 / 3N.

[0086] like Figure 4 and Figure 7 Since there may be more than one first region 21 on the side of the tab 13, and each first region 21 can form a projection in the second direction, M is equal to the sum of the lengths of the multiple projections in the first direction. Figure 4 and Figure 7 In the figure, d1 and d2 are respectively the projected length of one of the first regions 21 and the projected length of the other first region 21 , and the sum of their widths is M=d1+d2, where M is less than 1 / 3N, that is, less than one third of the width of the tab 13 .

[0087] It should be noted that when the projections of a plurality of first regions 21 in the second direction overlap, the length of the overlapping projections in the first direction is selected.

[0088] The effect of this embodiment is that, since the tab 13 needs to be ultrasonically welded with the adapter during later processing, this embodiment provides that the projection of the first area 21 in the second direction has a length M in the first direction, then M < 1 / 3N, which is equivalent to the first area 21 not occupying too much space in the width direction of the tab 13, thus avoiding the impact on the later ultrasonic welding of the tab 13.

[0089] In some embodiments, continue to refer to Figure 3-Figure 7 , the height of the tab 13 in the second direction is H1; the height of the projections of all the first regions 21 on the same side of the tab 13 in the first direction in the second direction is H2, and H2 ≥ 1 / 3 H1.

[0090] Specifically, see Figure 4 and Figure 7 , the tab 13 has a certain height in the second direction, that is, the distance from one end of the tab 13 away from the side of the current collector 11 to the side. The height of the tab 13 in the second direction is H1. Since a first area 21 covered by the reinforcement 2 is provided on the side of the tab 13, the first area 21 also has a certain height in the second direction. Therefore, the projection of the first area 21 in the first direction has a height in the second direction of H2. The so-called projection in the first direction can be understood as a parallel light beam projected along the first direction, and the projection of the first area 21 under this light beam is formed. This projection has a certain height in the second direction, which is called H2, and H2 ≥ 1 / 3H1.

[0091] Similarly, when there are multiple first regions 21, the multiple first regions 21 will generate multiple projections, and H2 is the sum of the heights of the multiple projections in the second direction. When the projections of the multiple first regions 21 overlap, H2 is the height of the overlapping projections in the second direction.

[0092] The effect of this embodiment is that the tab 13 is a structure that protrudes from the side of the current collector 11. Due to the protruding structure, the mechanical strength is relatively low and it is easy to bend or even tear. Therefore, sufficient connection strength is required in the protruding direction, that is, the second direction mentioned above. Therefore, this embodiment provides that the height of the projection of the first region 21 in the first direction in the second direction is H2, and H2 ≥ 1 / 3 H1. This ensures that the tab 13 has sufficient strength.

[0093] In some embodiments, as Figure 3-Figure 7 The covering area of ​​the reinforcement 2 on the current collector 11 is the second area 22 , and the active material layer 12 is not provided in the second area 22 .

[0094] Specifically, one end of the reinforcement 2 is connected and attached to the electrode tab 13, and the other end is connected and attached to the current collector 11. The coverage area of ​​the reinforcement 2 on the current collector 11 is defined as the second area 22, but the second area 22 is not the area where the active material is set, that is, the active material layer 12 is not set.

[0095] Specifically, the active material layer 12 does not cover the entire current collector 11 . An area without active material is reserved at the edge of the current collector 11 . The tab 13 is formed in this area, and the second area 22 covered by the reinforcement 2 is also provided in this area.

[0096] The effect of this embodiment is that the second region 22 does not cover the active material layer 12 , thus avoiding interference with the active material layer 12 and allowing the active material layer 12 to best play its role.

[0097] In some embodiments, as Figure 3-Figure 7 The side of the current collector 11 and the area adjacent to the side edge are insulating areas 111 for preventing short circuits. The second area 22 is located in the insulating area 111, and the reinforcement 2 is an insulating member.

[0098] Specifically, the active material layer 12 does not completely cover the current collector 11. An area not covered with active material is provided on the side of the current collector 11. A pole ear 13 is formed on the side of the area. At the same time, the area is an insulating area 111. The two ends of the reinforcement 2 are respectively connected to the pole ear 13 and the insulating area 111. The insulating area 111 is an area where an insulating material is provided on the current collector 11. The insulating material can be an insulating oxide.

[0099] First, the reinforcement 2 is connected to the insulating region 111 and is not directly connected to the active material layer 12, thereby avoiding interference with the functioning of the active material layer 12. Furthermore, the provision of the insulating region 111 can prevent short circuit accidents and improve safety in use.

[0100] In some embodiments, see Figure 6-Figure 8 The reinforcement 2 is symmetrically arranged on the two side surfaces of the pole ear 13. The area where the reinforcement 2 does not cover the pole ear 13 and the current collector 11 is the third area 23. The third areas 23 of the reinforcement 2 located on the two side surfaces and correspondingly arranged are bonded by glue.

[0101] Specifically, this embodiment provides that reinforcements 2 are provided on both side surfaces of the tab 13, and the reinforcements 2 respectively located on the two side surfaces are provided in a one-to-one correspondence. Optionally, the corresponding reinforcements 2 are symmetrical about the tab 13. In some cases, the reinforcement 2 includes not only the first region 21 and the second region 22, but also the middle portion that is neither fitted with the current collector 11 nor the tab 13, which can be referred to as a suspended region. In this embodiment, the suspended region is referred to as the third region 23. The purpose of providing the third region 23 is to enable the reinforcements 2 on both sides to be combined and connected together to enhance the integrity and stability. When the third region 23 is provided, the third regions 23 of the reinforcements 2 symmetrically provided on both sides are relatively provided with a certain gap between the two, and glue is provided in this gap, so that the reinforcements 2 on both sides can be connected together to form a stable overall structure, thereby enhancing the strength of the tab 13.

[0102] It can also be understood that the reinforcements 2 on the two side surfaces are relatively attached to the tabs 13 and the current collector 11, respectively, and the third regions 23 of the two are not attached to the tabs 13 and the current collector 11, so the third regions 23 of the two are relatively spaced apart, so glue is set between the two to strengthen the connection.

[0103] The effect of this embodiment is that the third region 23 is provided on the reinforcement member 2 , which can connect the reinforcement members 2 on both sides to form an integral structure, thereby further enhancing the strength of the entire tab 13 .

[0104] In some embodiments, as Figure 5 The reinforcement 2 is provided on one side surface of the tab 13 , and the area where the reinforcement 2 does not cover the tab 13 and the current collector 11 is the third area 23 , and the third area 23 is a glue-free area.

[0105] Specifically, the reinforcement 2 provided in this embodiment is arranged on the surface of the pole tab 13 on one side. The reinforcement 2 is not limited to only the first area 21 and the second area 22. In some cases, it may also have a third area 23, that is, an area that does not cover the pole tab 13 and the current collector 11. Since the reinforcement 2 is arranged on the surface of one side of the pole tab 13, this area can be a glue-free area, that is, no glue is provided, and it just exists in the air.

[0106] The effect of this embodiment is that the reinforcement 2 can be arranged according to the needs of the position, allowing the existence of a third area 23 that does not cover the tab 13 and the current collector 11. In this way, the arrangement of the reinforcement 2 is more flexible, so that the tab 13 can form the best reinforcement effect.

[0107] In some embodiments, as Figure 3 and Figure 5 The reinforcement 2 at least covers both ends of the root of the tab 13 in the first direction.

[0108] Specifically, the root of the tab 13, i.e., the location where the tab 13 is connected to the current collector 11, is most prone to bending or even tearing, especially at both ends of this location. Therefore, this embodiment provides a reinforcement 2 covering both ends of the root of the tab 13 to enhance the strength here, which has a very good effect.

[0109] In some embodiments, as Figure 8 The sum of the thickness of the tab 13 and the thickness of the reinforcement 2 is smaller than the sum of the thickness of the current collector 11 and the thickness of the active material layer 12 .

[0110] Specifically, the thickness direction is a direction perpendicular to both the first and second directions described above. In this direction, the tab 13, the current collector 11, the reinforcement 2, and the active material layer 12 all have thicknesses. In this embodiment, the sum of the thicknesses of the tab 13 and the reinforcement 2 is set to be smaller than the sum of the thicknesses of the current collector 11 and the active material layer 12. This is to reduce the space occupied by the reinforcement 2 and save as much space as possible. It is also to avoid any impact on the subsequent processing of the pole piece 1, such as the winding process of the pole piece 1.

[0111] In some embodiments, see Figure 10 and Figure 11 The electrode assembly includes a plurality of stacked tabs 13, such as Figure 10 , the reinforcement 2 is fitted with the sides of the first and last tabs 13; or, Figure 11 The reinforcement 2 is in contact with the side surfaces of the first and last tabs 13 and the side ends of the multi-layer tabs 13 in the first direction. Figure 9 A reinforcement 2 is provided on one side of each of the multi-layered pole tabs 13 .

[0112] Specifically, the multi-layer pole tab 13 can be formed by stacking the pole tabs 13 of multiple pole sheets 1 after multiple pole sheets 1 are stacked; or, the multi-layer pole tab 13 can also be formed by stacking multiple pole tabs 13 located at different positions of the pole sheet 1 after the pole sheet 1 is wound.

[0113] When multiple positive or negative electrode sheets are stacked, the multiple tabs 13 thereon are also stacked. Alternatively, after the same positive or negative electrode sheet is wound, the tabs 13 at different positions on the positive or negative electrode sheet will form an aligned stacked form.

[0114] Therefore, for the case of multi-layer tabs 13, this embodiment provides that the reinforcement 2 can be attached to the side surfaces of the first and last tabs 13. Alternatively, the reinforcement 2 can be attached to the side surfaces of the first and last tabs 13 and the side ends of the multi-layer tabs 13 in the first direction.

[0115] Therefore, the adaptability of the multi-layer tab 13 can be enhanced as needed.

[0116] In some embodiments, the cross-sectional shape of the reinforcement 2 is one or more of a rectangle, a parallelogram, a triangle, a circle, an ellipse, and a trapezoid.

[0117] Specifically, this embodiment provides a cross-sectional shape of the reinforcement member 2, which can be selected from a variety of shapes. Specifically, the shape can be selected to match the shape of the tab 13 and the side shape of the current collector 11. Therefore, the various optional shapes provided in this embodiment can adapt to the shapes of the tab 13 and the current collector 11, and effectively enhance the strength of the tab 13.

[0118] In some embodiments, the reinforcement member 2 is an organic material film layer or an inorganic carbon-based material film layer. These two materials have the characteristics of high strength and good toughness, and are light in weight and stable in performance, and are therefore good choices for the reinforcement member 2.

[0119] Specifically, the material of the reinforcement 2 can be one or more of PET, PP, PI, PA, PTFE, carbon fiber, and flexible carbon cloth.

[0120] In some embodiments, an insulating oxide coating is provided on the insulating region 111. The insulating oxide is a material with stable performance and good insulation effect. It is provided on the insulating region 111 to achieve insulation and has a good technical effect.

[0121] The present application also provides a specific embodiment of a battery 100 , comprising a battery cell provided by any of the above embodiments.

[0122] Since the tabs 13 of the electrode assembly of the battery cell provided in the present application have high strength, bending or tearing will not occur during the processing, so that the production quality of the battery cell is guaranteed. At the same time, when the battery 100 provided in the present application includes the battery cell, the quality of the battery 100 is also guaranteed.

[0123] The present application also provides an electrical device, comprising the battery 100 provided in the above embodiment. Since the quality of the battery 100 is guaranteed, the reliability and safety of the electrical device are also increased.

[0124] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery cell, characterized in that: An electrode assembly is included, the electrode assembly comprising: The pole piece includes a current collector, an active material layer provided on the current collector, and a pole ear formed on the side of the current collector; a diaphragm disposed between the two pole pieces of opposite polarity; and A reinforcement member connects the current collector and the tab to enhance the strength of the tab.

2. The battery cell according to claim 1, wherein The extending direction of the side of the current collector where the tab is provided is a first direction, and the reinforcement is provided at least at two ends of the tab in the first direction.

3. The battery cell according to claim 1, wherein The reinforcement is at least provided on one side surface of the tab.

4. The battery cell according to claim 1, wherein: The reinforcement is bonded to the surface of the tab and the current collector by gluing.

5. The battery cell according to claim 2, wherein: The direction perpendicular to both the first direction and the thickness direction of the tab is the second direction, the width of the tab in the first direction is N, the coverage area of ​​the reinforcement on the tab is the first area, and the length of the projection of all first areas on the same side of the tab in the second direction in the first direction is M, then M<1 / 3N.

6. The battery cell according to claim 5, wherein: The height of the tab in the second direction is H1; the height of the projections of all first regions on the same side of the tab in the first direction in the second direction is H2, and H2 ≥ 1 / 3 H1.

7. The battery cell according to any one of claims 1 to 6, characterized in that: The area covered by the reinforcement on the current collector is a second area, and the active material layer is not provided in the second area.

8. The battery cell according to claim 7, wherein: The side of the current collector and the area adjacent to the side edge are insulating areas for preventing short circuits. The second area is located in the insulating area, and the reinforcement is an insulating member.

9. The battery cell according to claim 3, wherein: The reinforcement is symmetrically arranged on both side surfaces of the electrode tab, and the area of ​​the reinforcement not covering the electrode tab and the current collector is the third area. The third areas of the reinforcements located on the two side surfaces and correspondingly arranged are connected by glue.

10. The battery cell according to claim 3, wherein The reinforcement is provided on one side surface of the electrode tab, and the area where the reinforcement does not cover the electrode tab and the current collector is a third area, and the third area is a glue-free area.

11. The battery cell according to any one of claims 2, 5 and 6, wherein: The reinforcement member at least covers two ends of the tab root in the first direction.

12. The battery cell according to any one of claims 1 to 6, 9 and 10, characterized in that: The sum of the thickness of the tab and the thickness of the reinforcement is smaller than the sum of the thickness of the current collector and the thickness of the active material layer.

13. The battery cell according to claim 2, wherein: The electrode assembly includes multiple layers of tabs stacked together, and the reinforcement is in contact with the side surfaces of the first and last tabs; or, the reinforcement is in contact with the side surfaces of the first and last tabs and the side ends of the multiple layers of tabs in the first direction.

14. The battery cell according to any one of claims 1 to 6, 9, 10 and 13, characterized in that: The reinforcing member is an organic material film layer or an inorganic carbon-based material film layer.

15. A battery, characterized in that: The battery cell comprises the battery cell according to any one of claims 1 to 14.

16. An electrical device, characterized in that: Including the battery according to claim 15.

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