Cathode plate, anode plate, battery cell, battery and electric device

Abstract

The present application provides a cathode plate, an anode plate, a battery cell, a battery, and an electric device. The plate includes a current collector and an active material layer, and the current collector includes a main body and a tab. The ratio of the product of the cross-sectional area of ​​the root of a single tab and the electrical conductivity of the current collector to the product of the length between the central axes of two adjacent tabs and the width of the active material layer and the mass per unit area of ​​the active material layer satisfies the following: the design factor for the cathode tab is at least 0.1, and the design factor for the anode tab is at least 0.02. The present application adjusts the dimensional specifications of a single tab and the pitch of adjacent tabs based on the design parameters of a single tab to improve the volumetric energy density of the battery cell, ensure that the battery cell has a matching current-carrying capacity, and ensure that the local temperature rise during a certain charging process of the corresponding battery cell does not exceed a threshold.

Description

[Technical Field]

[0001] This application relates to the field of batteries, and more particularly to cathode plates, anode plates, battery cells, batteries, and electrical devices. [Background technology]

[0002] Secondary batteries have advantages such as high operating voltage, wide applicable temperature range, and low self-discharge rate, and are widely used in fields such as portable electronic devices, home appliances, electric vehicles, etc. With the continuous development of products using secondary batteries, there are increasing demands on the capacity, energy density, charge / discharge rate, and cycle stability of secondary batteries in each field. Summary of the Invention [Means for solving the problem]

[0003] In view of the above problems, the present application provides a cathode plate, an anode plate, a battery cell, a battery, and an electric device that can provide a reasonable adjustment range for the dimensions of the tab itself and the layout distribution of the tab on the plate, under the premise of improving the volumetric energy density of the battery cell and ensuring that the internal temperature of the battery cell does not exceed a threshold.

[0004] In a first aspect, the present application provides a cathode plate including a cathode current collector and a cathode active material layer provided on at least one side of the cathode current collector, wherein the cathode current collector includes a cathode main body and at least one cathode tab provided on one end of the cathode main body; The width of the base portion of a single cathode tab in the MD direction is m1, measured in mm; the thickness of the base portion of a single cathode tab is d1, measured in mm; the distance between the central axes of two adjacent cathode tabs along the MD direction is b1, measured in mm; the conductivity of the cathode current collector is S1, measured in S / m; the width of the cathode active material layer in the TD direction is a1, measured in mm; and the mass per unit area of ​​the cathode active material layer is CW1, measured in g / 1540.25mm 2 and The design parameters for a single cathode tab are Fc and Fc [ka] and its unit is 15.4025 S mm g -1 and a cathode plate is provided in which the value of Fc satisfies Fc≧0.1.

[0005] In the technical solution of the embodiment of the present application, the dimensional specifications of a single cathode tab and the design of the pitch of adjacent cathode tabs are adjusted based on the design parameters of a single cathode tab, thereby improving the volumetric energy density of the battery cell, ensuring that the battery cell has a matching current passing capacity, and ensuring that the local temperature rise of the corresponding battery cell during a certain charging process does not exceed a threshold.

[0006] In some embodiments, the design parameter values ​​of the single cathode tab satisfy Fc≧0.4.

[0007] In the technical solution of the embodiment of the present application, the design parameters of the single cathode tab are further optimized to ensure that the volumetric energy density of the battery cell reaches a certain level, and that the cathode tab is designed to ensure that the local temperature rise during a certain charging process of the battery cell does not exceed a threshold.

[0008] In some embodiments, the ratio of the mass per unit area of ​​the cathode active material layer to the thickness of the cathode current collector is referred to as the cathode plate factor, and the value of the cathode plate factor satisfies 17≦φc≦50, where φc is the cathode plate factor and is expressed in units of g / 1540.25 mm. 3 is.

[0009] In the technical solution of the embodiment of the present application, the value of the cathode plate factor is limited, thereby ensuring that the cathode current collector 110 maintains a certain strength or above, and that problems such as breakage due to cold pressing or brittle fracture inside the battery cell do not occur. Meanwhile, the mass per unit area of ​​the cathode active material layer is controlled within a certain range, which prevents problems such as serious coating cracks, poor weight distribution uniformity, and easy plate demolding, thereby ensuring the manufacturing yield and cost benefits of the battery cell.

[0010] In some embodiments, m1≧0.02 mm, and / or d1≦0.02 mm, and / or b1≦0.6 mm, and / or S1≧30 S / m, and / or a1≦0.3 mm, and / or 0.35 g / 1540.25 mm 2 ≦CW1≦0.5g / 1540.25mm 2 is.

[0011] In the technical solution of the embodiment of the present application, the value ranges of the parameters of the cathode tab, the cathode active material layer and the cathode current collector are determined, and within the value ranges, the stability of the product performance of the battery cell is satisfied.

[0012] In some embodiments, the cathode active material layer comprises a lithium iron phosphate material.

[0013] In the technical solution of the embodiment of the present application, by designing a cathode tab for a lithium iron phosphate secondary battery, the volumetric energy density of the battery cell can be effectively improved to 300Wh / L, and the local temperature rise of the battery cell during a certain charging process can be guaranteed not to exceed 60°C.

[0014] In a second aspect, the present application provides an anode plate including an anode current collector and an anode active material layer provided on at least one side of the anode current collector, wherein the anode current collector includes an anode main body and at least one anode tab provided on one end of the anode main body; The width of the base portion of a single anode tab in the MD direction is m2, measured in mm; the thickness of the base portion of a single anode tab is d2, measured in mm; the distance between the central axes of two adjacent anode tabs along the MD direction is b2, measured in mm; the conductivity of the anode current collector is S2, measured in S / m; the width of the anode active material layer in the TD direction is a2, measured in mm; and the mass per unit area of ​​the anode active material layer is CW2, measured in g / 1540.25mm 2 and The design parameters for a single anode tab are Fa and Fa [ka] and its unit is 15.4025 S mm g -1 and an anode plate is provided in which the value of Fa satisfies Fa≧0.02.

[0015] In the technical solution of the embodiment of the present application, the dimensional specifications of the single anode tab and the design of the pitch of adjacent anode tabs are adjusted based on the design parameters of the single anode tab, thereby improving the volumetric energy density of the battery cell, ensuring that the battery cell has a matching current passing capacity, and ensuring that the local temperature rise of the corresponding battery cell during a certain charging process does not exceed a threshold.

[0016] In some embodiments, the design parameter values ​​of the single anode tab satisfy Fa≧0.1.

[0017] In the technical solution of the embodiment of the present application, the design parameters of a single anode tab are further optimized to ensure that the volumetric energy density of the battery cell reaches a certain level, and that the anode tab is designed to ensure that the local temperature rise during a certain charging process of the battery cell does not exceed a threshold.

[0018] In some embodiments, the ratio of the mass per unit area of ​​the anode active material layer to the thickness of the anode current collector is referred to as the anode plate factor, and the value of the anode plate factor satisfies 15≦φa≦85, where φa is the anode plate factor and is expressed in units of g / 1540.25 mm. 3 is.

[0019] In the technical solution of the embodiment of the present application, the value of the anode plate factor is limited, thereby ensuring that the anode current collector maintains a certain strength or above, and that problems such as breakage due to cold pressing or brittle fracture inside the battery cell do not occur. Meanwhile, the mass per unit area of ​​the anode active material layer is controlled within a certain range, which prevents problems such as serious coating cracks, poor weight distribution uniformity, and easy plate demolding, thereby ensuring the manufacturing yield and cost benefits of the battery cell.

[0020] In some embodiments, 0.02 mm≦m2≦0.2 mm, and / or 0.003 mm≦d2≦0.01 mm, and / or 0.1 mm≦b2≦0.6 mm, and / or 50 S / m≦S2≦70 S / m, and / or 0.05 mm≦a2≦0.3 mm, and / or 0.15 g / m≦0.25 mm 2 ≦CW2≦0.25g / 1540.25mm 2 is.

[0021] The inventors of the present application conducted a large number of specific experiments to improve the volumetric energy density of the battery cell and ensure that the local temperature rise during a certain charging process of the battery cell does not exceed a threshold, and then determined the value ranges of the parameters of the anode tab, anode active material layer, and anode current collector, within which the product performance stability of the battery cell can be met.

[0022] In a third aspect, the present application provides a battery cell including the cathode plate and / or the anode plate, A battery cell is provided in which the design parameter value of the single cathode tab satisfies Fc≧0.1 and / or the design parameter value of the single anode tab satisfies Fa≧0.02.

[0023] In the technical solution of the embodiments of the present application, based on the design parameters of the single cathode tab and the single anode tab, the dimensional specifications of the single cathode tab, the dimensional specifications of the single anode tab, and the distribution design of the cathode tab on the cathode plate and the distribution design of the anode tab on the anode plate are adjusted to improve the volumetric energy density of the battery cell and ensure that the local temperature rise during a certain charging process of the battery cell does not exceed a threshold.

[0024] In some embodiments, 0.4≦Fc≦75, 0.1≦Fa≦180, and 17≦φc≦50, 15≦φa≦85, and m1≧0.02 mm, d1≦0.02 mm, b1≦0.6 mm, S1≧30 S / m, a1≦0.3 mm, and / or 0.35 g / m. 2 ≦CW1≦0.5g / 1540.25mm 2 , and 0.02mm≦m2≦0.2mm, 0.003mm≦d2≦0.01mm, 0.1mm≦b2≦0.6mm, 50S / m≦S2≦70S / m, 0.05mm≦a2≦0.3mm, 0.15g / 1540.25mm 2 ≦CW2≦0.25g / 1540.25mm 2 is.

[0025] In the technical solutions of the embodiments of the present application, more preferred value ranges are provided for the parameters of the cathode tab, cathode active material layer and cathode current collector, anode tab, anode active material layer and anode current collector, and within the above value ranges, the stability of the product performance of the battery cell is satisfied.

[0026] In some embodiments, the battery cell is a lithium iron phosphate secondary battery, the volumetric energy density of the battery cell is ≧300 Wh / L, and when the battery cell is charged at a 3C rate for 6 minutes at room temperature, the maximum temperature at the root of the cathode tab and the root of the anode tab of the battery cell is ≦60°C.

[0027] In the technical solution of the embodiment of the present application, by designing the cathode tab and the anode tab for the lithium iron phosphate secondary battery, the volumetric energy density of the battery cell can be effectively improved to 300Wh / L, and the local temperature rise of the battery cell during a certain charging process can be guaranteed not to exceed 60°C.

[0028] According to a fourth technical solution, the present application provides a battery including a housing and a plurality of the above-mentioned battery cells located in the housing.

[0029] According to a fifth technical solution, the present application provides an electric device including the above battery.

[0030] The above description is merely an outline of the technical solution of the present application, and in order to make the technical solution of the present application more clearly understood, and to implement the present invention according to the contents of the specification, and to make the above and other objects, features and advantages of the present application more obvious and understandable, the following provides a description of an embodiment of the present invention. [Brief explanation of the drawings]

[0031] Various other advantages and benefits will become apparent to those skilled in the art after reading the following detailed description of the preferred embodiments. The drawings are for the purpose of illustrating the preferred embodiments only and are not to be construed as limiting the present application. Like reference numerals represent like elements in all drawings. [Figure 1] FIG. 2 is a structural schematic diagram of a cathode plate provided by the present application. [Figure 2] 2 is a schematic cross-sectional view of the cathode plate shown in FIG. 1 taken along line AA. FIG. [Figure 3] 1 is a structural schematic diagram of an anode plate provided by the present application. [Figure 4] 4 is a cross-sectional structural schematic diagram of the anode plate provided in FIG. 3 along line BB. [Figure 5] 1 is a structural schematic diagram of a battery cell provided by the present application; [Figure 6]FIG. 6 is a schematic diagram of the top structure of the battery cell provided in FIG. 5. [Figure 7] 1 is a structural schematic diagram of a battery provided by the present application. [Figure 8] 1 is a structural schematic diagram of an electrical device provided by the present application; DETAILED DESCRIPTION OF THE INVENTION

[0032] Hereinafter, the embodiments of the technical solution of the present application will be described in detail with reference to the drawings. The following embodiments are merely used as examples to more clearly explain the technical solution of the present application, and should not be used to limit the protection scope of the present application.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. The terms used herein are only for describing specific examples and are not intended to limit the present application. The terms "comprises," "has," and any variations thereof in the specification, claims, and description of the drawings of this application are intended to cover the non-exclusive "comprises."

[0034] In the description of the embodiments of the present application, technical terms such as "first," "second," etc. are used only to distinguish different objects, and should not be understood as indicating or implying relative importance, or the number, specific order, or primary-subordinate relationship of the indicated technical features. In the description of the embodiments of the present application, unless otherwise clearly and specifically limited, "plurality" means two or more.

[0035] When referring to an "embodiment" in this specification, it means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present application. Appearances of this phrase in various places in the specification do not necessarily refer to the same embodiment, nor are they mutually exclusive, separate, or alternative embodiments to other embodiments. Those skilled in the art will understand, both explicitly and implicitly, that the embodiments described in this specification can be combined with other embodiments.

[0036] In the description of the embodiments of the present application, the term "and / or" merely describes the relationship between related objects and indicates that three relationships may exist. For example, A and / or B can represent three cases: A alone, a combination of A and B, and B alone. In addition, the character " / " in this specification generally indicates that the related objects before and after it are in an "or" relationship.

[0037] In describing the examples of the present application, the term "plurality" refers to two or more (including two); similarly, "groups" refers to two or more (including two groups); and "plurality" refers to two or more (including two).

[0038] In describing the embodiments of the present application, the orientations or positional relationships indicated by technical terms such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" are based on the orientations or positional relationships shown in the drawings and are intended only to make the embodiments of the present application easier to explain and simplify the description. They do not indicate or imply that the indicated devices or elements necessarily have a specific orientation, or are configured and operate in a specific orientation, and therefore should not be understood as limiting the embodiments of the present application.

[0039] In the description of the embodiments of the present application, unless otherwise clearly defined and limited, technical terms such as "attach," "couple," "connect," and "fixed" should be understood in a broad sense, and may refer to, for example, a fixed connection, a detachable connection, or an integral connection, a mechanical connection, an electrical connection, a direct connection, an indirect connection via an intermediate medium, an internal communication between two elements, or an interactive relationship between two elements. Those skilled in the art will be able to understand the specific meanings of the above terms in the embodiments of the present application according to specific circumstances.

[0040] The inventors of the present application have noticed that, for battery cells of the same chemical system, the larger the cathode coating weight (CW) is, while maintaining the same overall length and film width of the electrode plate, the higher the volumetric energy density of the battery cell. Taking a lithium iron phosphate secondary battery as an example, if the cathode coating weight is 0.35g 1540.25mm -2 If the thickness is above 300 Wh / L, it can be considered a thick coating. The volumetric energy density of a battery cell with a thick coating can reach 300 Wh / L or more.

[0041] Compared with battery cells with thin coatings, battery cells with thick coatings have a larger charge / discharge current at the same rate, which places higher demands on the current-carrying capacity of the battery cell. The current-carrying capacity of a battery cell refers to the ability to pass current inside the battery cell. If the current-carrying capacity of the battery cell does not match the increase in cathode coating weight, the internal temperature of the battery cell is likely to rise. Once the temperature exceeds a certain threshold, a large amount of heat will be generated inside the battery cell, which will cause the internal temperature of the battery cell to continuously rise and be transferred to each other, causing a chain reaction among multiple battery cells in the entire battery, resulting in a serious safety hazard.

[0042] Specifically, it is preferable that the threshold internal temperature of the battery cell does not exceed 60°C. This is because if the internal temperature of the battery cell exceeds 60°C, the solid electrolyte interface (SEI) of the cathode active material layer begins to decompose, causing a rapid deterioration in the performance of the battery cell. Therefore, it is necessary to control the internal temperature of the battery cell to 60°C or less.

[0043] Furthermore, the inventors of the present application discovered that the design of the electrode tabs directly affects the current carrying capacity of a battery cell. If a thick-coated battery cell is used without changing the tab design, the current carrying capacity of the thick-coated battery cell will be relatively reduced under the same charging and discharging process. This will increase Joule heat at the tabs, and if the local temperature at the base of the tabs exceeds a threshold temperature, the battery performance will rapidly decline. In this case, the temperature rise can be suppressed by lowering the charging ratio, but the battery's fast charging performance will also be correspondingly reduced.

[0044] Based on the above considerations, in order to solve the problem of improving the volumetric energy density of a battery cell, improving the current passing capacity of the battery cell, and ensuring the safety and stability of the battery cell performance, the inventors of the present application have conducted in-depth research and proposed a tab design method, in which the width and thickness of the tab base and the pitch of adjacent tabs are designed to adjust the current passing capacity corresponding to a single tab, and the tab design is adapted to the coating thickness of the active material, thereby effectively controlling the internal temperature of the battery cell without sacrificing the fast charging performance of the battery cell.

[0045] The technical solutions described in the embodiments of this application are applicable to cathode plates, anode plates, battery cells, batteries, and electric devices. The battery cells disclosed in this application may be used in lithium-ion secondary batteries or other energy storage batteries, and are not limited thereto.

[0046] The present invention will be described in detail below with reference to the drawings and examples.

[0047] 1 and 2, FIG. 1 is a structural schematic diagram of a cathode plate provided by the present application, and FIG. 2 is a cross-sectional structural schematic diagram of the cathode plate provided by FIG. 1 taken along line AA.

[0048] 1 and 2, the present application provides a cathode plate 100 including a cathode current collector 110 and a cathode active material layer 120 provided on at least one side of the cathode current collector 110. The cathode current collector 110 includes a cathode main body 111 and at least one cathode tab 112 provided on one end of the cathode main body 111.

[0049] The width of the base portion of a single cathode tab 112 in the MD direction is m1, measured in mm. The thickness of the base portion of a single cathode tab 112 is d1, measured in mm. The distance between the central axes M of two adjacent cathode tabs along the MD direction is b1, measured in mm. The conductivity of the cathode current collector 110 is S1, measured in S / m. The width of the cathode active material layer 120 in the TD direction is a1, measured in mm. The mass per unit area of ​​the cathode active material layer 120 is CW1, measured in g / 1540.25mm 2 is.

[0050] The design parameter of a single cathode tab 112 is Fc, and Fc [ka] and its unit is 15.4025 S mm g -1 and the value of Fc satisfies Fc≧0.1.

[0051] In the present application, the cathode plate 100 comprises a cathode current collector 110 and a cathode active material layer 120. The cathode current collector 110 is typically made of a metal material. For example, in a lithium-ion battery, the cathode current collector 110 may be aluminum foil. The cathode active material layer 120 is coated on at least one side of the cathode current collector 110. For example, in a lithium-ion battery, the cathode active material layer 120 may be made of lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide. The cathode active material layer 120 may be formed on only one side of the cathode current collector 110, or on both sides of the cathode current collector 110.

[0052] The cathode main body 111 is the portion of the cathode current collector 110 on which the cathode active material layer 120 is applied. The cathode tab 112 is the portion of the cathode current collector 110 that protrudes from the cathode main body 111. The cathode tab 112 may be provided at only one end of the cathode main body 111, or at both ends of the cathode main body 111. Only one cathode tab 112 may be provided at one end of the cathode main body 111, or multiple cathode tabs 112 may be provided in a stack. It will be understood that the number of cathode tabs 112 in the present application can be adjusted as needed. The central axis M of the cathode tab represents the connecting line of the centroids of the cross sections of all of the cathode tabs 112. In one or more embodiments of the present application, the distance b1 between the central axes M of two cathode tabs adjacent along the MD direction is obtained by first employing a precision measurement tool to determine the central axes M of the two target cathode tabs, and then employing the precision measurement tool to measure the distance b1 between the central axes M of the two target cathode tabs. In one or more embodiments of the present application, a laser distance measuring device is employed as the precision measurement tool.

[0053] The root portion of a single cathode tab 112 refers to the portion of the cathode tab 112 that is connected to the cathode main body 111. In one or more embodiments of the present application, the length of the root portion of a single cathode tab 112 in the TD direction is 50% or less of the length of the single cathode tab 112 in the TD direction. Specifically, the length of the root portion of a single cathode tab 112 in the TD direction is 40% or less, 30% or less, 20% or less, or 10% or less of the length of the single cathode tab 112 in the TD direction, and is set reasonably as needed. The TD direction (Transverse Direction) refers to the width direction of the electrode plate. The length direction of the electrode plate is perpendicular to the TD direction and is the MD (Machine Direction). Corresponding to the thick-coated cathode plate 100 with certain determined parameters, the design parameters of the single cathode tab 112 can be adjusted within a reasonable range, such as the cross-sectional area of ​​the root part of the single cathode tab 112 and the coating weight of the cathode active material corresponding to the single cathode tab 112, to ensure that the local temperature rise of the battery cell during a certain charging process does not exceed a threshold.

[0054] In the formula for calculating the design parameter Fc of a single cathode tab 112, [ka] represents the cross-sectional area of ​​the root of the cathode tab 112, [ka] represents the current carrying capacity of a single cathode tab 112, and in the denominator: [ka] represents the current-passing capacity that must be borne by a single cathode tab 112. The lower limit of Fc corresponds to the critical point where the current-passing ability of a single cathode tab 112 is weakest but the current-passing capacity it must bear is greatest, and setting the lower limit of Fc ensures that the temperature rise at the base of the cathode tab 112 does not exceed 60°C.

[0055] In the embodiment of the present application, the dimensional specifications of the single cathode tab 112 and the design of the pitch of the adjacent cathode tabs are adjusted based on the design parameters of the single cathode tab 112 to improve the volumetric energy density of the battery cell, ensure that the battery cell has a matching current passing capacity, and ensure that the local temperature rise of the corresponding battery cell during a certain charging process does not exceed a threshold.

[0056] In some embodiments, the design parameter values ​​of the single cathode tab 112 satisfy Fc≧0.4.

[0057] In this embodiment, the lower limit of the design parameter value of the single cathode tab 112 indicates that the current passing capacity of the single cathode tab 112 has a certain threshold. If the design parameter value of the single cathode tab 112 exceeds the lower limit, the current passing capacity of the single cathode tab 112 will be too large and the current passing capacity of the single cathode tab 112 will be too small, resulting in increased Joule heat at the base of the cathode tab 112, causing the temperature at the base of the cathode tab 112 to exceed the threshold temperature, and rapidly deteriorating the performance of the battery cell. The upper limit of the design parameter value of the single cathode tab 112 corresponds to the critical point where the current passing capacity is strongest but the current passing capacity is smallest, and is primarily intended to ensure that the design of the single cathode tab 112 can meet the fast charging capability of the battery cell.

[0058] In this embodiment, the design parameters of the single cathode tab 112 are further optimized to ensure that the volumetric energy density of the battery cell reaches a certain level and that the design of the cathode tab 112 ensures that the local temperature rise during a certain charging process of the battery cell does not exceed a threshold.

[0059] In some embodiments, the ratio of the mass per unit area of ​​the cathode active material layer 120 to the thickness of the cathode current collector 110 is referred to as the cathode plate factor, and the value of the cathode plate factor satisfies 17≦φc≦50, where φc is the cathode plate factor and is expressed in units of g / 1540.25 mm. 3 is.

[0060] In this application, the cathode plate factor represents a variable in the design parameters of a single cathode tab 112. The cathode plate factor represents a correlation between the mass per unit area of ​​the cathode active material layer 120 and the thickness of the cathode current collector 110, but the two are not two independent variables and cannot each take an arbitrary value.

[0061] In this embodiment, the lower limit of the cathode plate factor corresponds to the critical point where the mass per unit area of ​​the cathode active material layer 120 is smallest and the thickness of the cathode current collector 110 is largest, and is primarily intended to ensure that the volumetric energy density of the battery cell reaches a certain value. The upper limit of the cathode plate factor corresponds to the critical point where the mass per unit area of ​​the cathode active material layer 120 is large and the thickness of the cathode current collector 110 is smallest.

[0062] In this embodiment, by limiting the value of the cathode plate factor, the cathode current collector 110 maintains a certain strength and ensures that problems such as breakage due to cold pressing or brittle fracture inside the battery cell do not occur, while the mass per unit area of ​​the cathode active material layer 120 is controlled within a certain value range, preventing problems such as severe coating cracking, poor weight distribution uniformity, and easy plate demolding, thereby ensuring battery cell manufacturing yield and cost benefits. It can be seen that the larger the cathode plate factor within the value range, the thicker the battery cell coating and the higher the volumetric energy density.

[0063] In some embodiments, m1≧0.02 mm, and / or d1≦0.02 mm, and / or b1≦0.6 mm, and / or S1≧30 S / m, and / or a1≦0.3 mm, and / or 0.35 g / 1540.25 mm 2 ≦CW1≦0.5g / 1540.25mm 2 is.

[0064] The inventors of the present application have conducted a large number of specific experiments to improve the volumetric energy density of the battery cell (e.g., 300 Wh / L) and ensure that the local temperature rise during a certain charging process of the battery cell does not exceed a threshold value (e.g., 60°C). After that, they have determined the ranges of values ​​for each parameter of the cathode tab 112, the cathode active material layer 120, and the cathode current collector 110, within which the product performance stability of the battery cell can be met.

[0065] In some embodiments, the cathode active material layer 120 includes a lithium iron phosphate material. According to the above technical solution, this embodiment designs the cathode tab 112 for a lithium iron phosphate secondary battery, which can effectively improve the volumetric energy density of the battery cell to 300 Wh / L and ensure that the local temperature rise of the battery cell during a certain charging process does not exceed 60°C.

[0066] 3 and 4, FIG. 3 is a structural schematic diagram of an anode plate provided by the present application, and FIG. 4 is a cross-sectional structural schematic diagram of the anode plate provided by FIG. 3 taken along line BB.

[0067] 3 and 4, the present application provides an anode plate 200 including an anode current collector 210 and an anode active material layer 220 provided on at least one side of the anode current collector 210. The anode current collector 210 includes an anode main body 211 and at least one anode tab 212 provided on one end of the anode main body 211.

[0068] The width of the base portion of a single anode tab 212 in the MD direction is m2, measured in mm. The thickness of the base portion of a single anode tab 212 is d2, measured in mm. The distance between the central axes N of two adjacent anode tabs along the MD direction is b2, measured in mm. The conductivity of the anode current collector 210 is S2, measured in S / m. The width of the anode active material layer 220 in the TD direction is a2, measured in mm. The mass per unit area of ​​the anode active material layer 220 is CW2, measured in g / 1540.25mm 2 is.

[0069] The design parameters of the single anode tab 212 are Fa and Fa [ka] and its unit is 15.4025 S mm g -1 The value of Fa satisfies Fa≧0.02.

[0070] In the present application, the anode plate 200 comprises an anode current collector 210 and an anode active material layer 220. The anode current collector 210 is typically made of a metal material, and in the case of a lithium-ion battery, the anode current collector 210 may be made of copper foil. The anode active material layer 220 is coated on at least one side of the anode current collector 210, and in the case of a lithium-ion battery, the material of the anode active material layer 220 may be carbon or silicon. The anode active material layer 220 may be formed on only one side of the anode current collector 210, or on both sides of the anode current collector 210.

[0071] The anode main body 211 is the portion of the anode current collector 210 on which the anode active material layer 220 is applied. The anode tab 212 is the portion of the anode current collector 210 that protrudes from the anode main body 211. The anode tab 212 may be provided at only one end of the anode main body 211, or at both ends of the anode main body 211. Only one anode tab 212 may be provided at one end of the anode main body 211, or multiple anode tabs 212 may be provided in a stack. It will be understood that the number of anode tabs 212 in the present application can be adjusted as needed. The central axis N of the anode tab represents the connecting line between the centroids of the cross sections of all the anode tabs 212. In one or more embodiments of the present application, the distance b2 between the central axes N of two anode tabs adjacent along the MD direction is obtained by first employing a precision measuring tool to determine the central axes N of the two target anode tabs, and then employing the precision measuring tool to measure the distance b2 between the central axes N of the two target anode tabs. In one or more embodiments of the present application, a laser distance measuring device is employed as the precision measuring tool.

[0072] The root portion of the single anode tab 212 refers to the portion of the anode tab 212 that is connected to the anode main body 211. In one or more embodiments of the present application, the length of the root portion of the single anode tab 212 in the TD direction is 50% or less of the length of the single anode tab 212 in the TD direction. Specifically, the length of the root portion of the single anode tab 212 in the TD direction is 40% or less, 30% or less, 20% or less, or 10% or less of the length of the single anode tab 212 in the TD direction, and may be reasonably set as needed. For a thick-coated anode plate 200 with certain determined parameters, the design parameters of the single anode tab 212 can be adjusted within reasonable ranges, such as the cross-sectional area of ​​the root portion of the anode tab 212 and the coating weight of the anode active material corresponding to the single anode tab 212, to ensure that the local temperature rise of the battery cell during a certain charging process does not exceed a threshold.

[0073] In the calculation formula for the design parameter Fa of a single anode tab 212, [ka] represents the cross-sectional area of ​​the root of the anode tab 212, [ka] represents the current carrying capacity of a single anode tab 212, and in the denominator: [ka] represents the current-passing capacity that must be borne by a single anode tab 212. The lower limit of Fa corresponds to the critical point where the current-passing ability of a single anode tab 212 is the weakest but the current-passing capacity borne by a single anode tab 212 is the greatest, and mainly ensures that the temperature rise at the base of the anode tab 212 does not exceed 60°C.

[0074] In the embodiment of the present application, the dimensional specifications of the single anode tab 212 and the design of the pitch of adjacent anode tabs 212 are adjusted based on the design parameters of the single anode tab 212 to improve the volumetric energy density of the battery cell, ensure that the battery cell has a matching current passing capacity, and ensure that the local temperature rise of the corresponding battery cell during a certain charging process does not exceed a threshold.

[0075] In some embodiments, the design parameter values ​​of the single anode tab 212 satisfy Fa≧0.1.

[0076] In this embodiment, the lower limit of the design parameter value of the single anode tab 212 indicates that the current passing capacity of the single anode tab 212 has a certain threshold. If the design parameter value of the single anode tab 212 exceeds the lower limit, the current passing capacity of the single anode tab 212 will be too large and the current passing capacity of the single anode tab 212 will be too small, resulting in increased Joule heat at the base of the anode tab 212, causing the temperature at the base of the anode tab 212 to exceed the threshold temperature, and rapidly deteriorating the performance of the battery cell. The upper limit of the design parameter value of the single anode tab 212 corresponds to the critical point where the current passing capacity is strongest but the current passing capacity is smallest, and primarily ensures that the design of the single anode tab 212 can meet the fast charging capability of the battery cell.

[0077] In this embodiment, the design parameters of the single anode tab 212 are further optimized to ensure that the volumetric energy density of the battery cell reaches a certain level, and that the design of the anode tab 212 ensures that the local temperature rise during a certain charging process of the battery cell does not exceed a threshold.

[0078] In some embodiments, the ratio of the mass per unit area of ​​the anode active material layer 220 to the thickness of the anode current collector 210 is referred to as the anode plate factor, where the value of the anode plate factor satisfies 15≦φa≦85, where φa is the anode plate factor and is expressed in units of g / 1540.25 mm. 3 is.

[0079] In this application, the anode plate factor represents a variable in the design parameters of a single anode tab 212. The anode plate factor represents a correlation between the mass per unit area of ​​the anode active material layer 220 and the thickness of the anode current collector 210, but the two are not two independent variables and cannot each take an arbitrary value.

[0080] In this embodiment, the lower limit of the anode plate factor corresponds to the critical point where the mass per unit area of ​​the anode active material layer 220 is smallest and the thickness of the anode current collector 210 is largest, and mainly ensures that the volumetric energy density of the battery cell reaches a certain value. The upper limit of the anode plate factor corresponds to the critical point where the mass per unit area of ​​the anode active material layer 220 is large and the thickness of the anode current collector 210 is smallest.

[0081] In this embodiment, by limiting the value of the anode plate factor, the anode current collector 210 maintains a certain strength and ensures that problems such as breakage due to cold pressing or brittle fracture inside the battery cell do not occur, while the mass per unit area of ​​the anode active material layer 220 is controlled within a certain value range, preventing problems such as serious coating cracks, poor weight distribution uniformity, and easy plate demolding, thereby ensuring battery cell manufacturing yield and cost benefits. It can be seen that the larger the anode plate factor within the value range, the thicker the battery cell coating and the higher the volumetric energy density.

[0082] In some embodiments, 0.02 mm≦m2≦0.2 mm, and / or 0.003 mm≦d2≦0.01 mm, and / or 0.1 mm≦b2≦0.6 mm, and / or 50 S / m≦S2≦70 S / m, and / or 0.05 mm≦a2≦0.3 mm, and / or 0.15 g / m≦0.25 mm 2 ≦CW2≦0.25g / 1540.25mm 2 is.

[0083] The inventors of the present application have conducted a large number of specific experiments to improve the volumetric energy density of the battery cell (e.g., 300 Wh / L) and ensure that the local temperature rise during a certain charging process of the battery cell does not exceed a threshold value (e.g., 60°C). After that, they have determined the value ranges of the parameters of the anode tab 212, the anode active material layer 220, and the anode current collector 210, within which the product performance stability of the battery cell can be met.

[0084] 5 and 6, FIG. 5 is a structural schematic diagram of a battery cell provided by the present application, and FIG. 6 is a top structural schematic diagram of the battery cell provided by FIG.

[0085] 5 and 6, the present application provides a battery cell 300 including a cathode plate 100 and / or an anode plate 200. Referring to FIGS. 1 and 2, the cathode plate 100 includes a cathode current collector 110 and a cathode active material layer 120 provided on at least one side of the cathode current collector 110. The cathode current collector 110 includes a cathode main body 111 and at least one cathode tab 112 provided on one end of the cathode main body 111. Referring to FIGS. 3 and 4, the anode plate 200 includes an anode current collector 210 and an anode active material layer 220 provided on at least one side of the anode current collector 210. The anode current collector 210 includes an anode main body 211 and at least one anode tab 212 provided on one end of the anode main body 211. As shown in FIG. 6, this embodiment provides a wound-type battery cell 300. It is understood that the battery cell 300 may be a stacked type, and may be configured as needed, and is not limited in this application.

[0086] 1 to 4, the width in the MD direction of the base portion of a single cathode tab 112 is m1, and the width in the MD direction of the base portion of a single anode tab 212 is m2, both measured in mm. The thickness of the base portion of a single cathode tab 112 is d1, and the thickness of the base portion of a single anode tab 212 is d2, both measured in mm. Along the MD direction, the distance between the central axes M of two adjacent cathode tabs is b1, and the distance between the central axes N of two adjacent anode tabs is b2, both measured in mm. The conductivity of the cathode current collector 110 is S1, and the conductivity of the anode current collector 210 is S2, both measured in S / m. The width in the TD direction of the cathode active material layer 120 is a1, and the width in the TD direction of the anode active material layer 220 is a2, both measured in mm. The mass per unit area of ​​the cathode active material layer 120 is CW1, and the mass per unit area of ​​the anode active material layer 220 is CW2, and the unit is g / 1540.25 mm 2 is.

[0087] The design parameter of a single cathode tab 112 is Fc, and Fc [ka] and the design parameters of the single anode tab 212 are Fa and Fa [ka] and its unit is 15.4025 S mm g -1 and the value of Fc satisfies Fc≧0.1, and / or the value of Fa satisfies Fa≧0.02.

[0088] In the embodiment of the present application, based on the design parameters of the single cathode tab 112 and the single anode tab 212, the dimensional specifications of the single cathode tab 112, the dimensional specifications of the single anode tab 212, the distribution design of the cathode tab 112 on the cathode plate 100, and the distribution design of the anode tab 212 on the anode plate 200 are adjusted to improve the volumetric energy density of the battery cell 300 and ensure that the local temperature rise during a certain charging process of the battery cell 300 does not exceed a threshold.

[0089] In some embodiments, m1≧0.02 mm, d1≦0.02 mm, b1≦0.6 mm, S1≧30 S / m, a1≦0.3 mm, and 0.35 g / 1540.25 mm 2 ≦CW1≦0.5g / 1540.25mm 2 , 0.02mm≦m2≦0.2mm, 0.003mm≦d2≦0.01mm, 0.1mm≦b2≦0.6mm, and 50S / m≦S2≦70S / m, 0.05mm≦a2≦0.3mm, 0.15g / 1540.25mm 2 ≦CW2≦0.25g / 1540.25mm 2 is.

[0090] The inventors of the present application have conducted a large number of specific experiments to improve the energy density (e.g., 300 Wh / L) of the battery cell 300 and ensure that the local temperature rise during a certain charging process of the battery cell 300 does not exceed a threshold value (e.g., 60°C). After this, they have determined more preferable value ranges for each parameter of the cathode tab 112, the cathode active material layer 120 and the cathode current collector 110, the anode tab 212, the anode active material layer 220, and the anode current collector 210. Within these value ranges, the product performance stability of the battery cell 300 can be ensured.

[0091] In some embodiments, the battery cell 300 is a lithium iron phosphate secondary battery. The volumetric energy density of the battery cell 300 is 300 Wh / L or more. When the battery cell 300 is charged at a 3C rate for 6 minutes at room temperature, the maximum temperature at the base of the cathode tab 112 and the anode tab 212 of the battery cell 300 is 60°C or less.

[0092] In this embodiment, by designing the cathode tab 112 and the anode tab 212 for the lithium iron phosphate secondary battery, the volumetric energy density of the battery cell can be effectively improved to 300 Wh / L, and the local temperature rise of the battery cell during a certain charging process can be ensured not to exceed 60°C.

[0093] Please refer to FIG. 7, which is a structural schematic diagram of the battery provided by the present application.

[0094] Referring to FIG. 7 , the present application provides a battery 500 including a housing 400 and a plurality of battery cells 300 positioned within the housing 400. The battery 500 may further include a housing 400 for providing storage space for the battery cells 300, and the housing 400 may have various shapes. In the battery 500, the plurality of battery cells 300 may be connected in series, parallel, or series-parallel, and a series-parallel connection means that the plurality of battery cells 300 may be connected in both series and parallel. The plurality of battery cells 300 may be directly connected in series, parallel, or series-parallel, and then the entire battery cell set may be housed within the housing 400. Of course, the battery 500 may be formed by first connecting the plurality of battery cells 300 in series, parallel, or series-parallel to form a battery module, and then further connecting the plurality of battery modules in series, parallel, or series-parallel to form a single whole and housed within the housing 400. The battery 500 may further include other structures, for example, the battery 500 may further include busbar members for realizing electrical connection between the multiple battery cells 300. Each battery cell 300 may be a secondary battery or a primary battery, and may be, but is not limited to, a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery. The battery cell 300 may have, but is not limited to, a cylindrical body, a flat body, a rectangular parallelepiped, or other shape.

[0095] Please refer to FIG. 8, which is a structural schematic diagram of an electric device provided by the present application.

[0096] Referring to FIG. 8 , the present application provides an electric device including the battery 500. The electric device may be a mobile phone, a personal computer, an electric motorcycle, an electric vehicle 600, etc. In this embodiment, the electric vehicle 600 is taken as an example. The battery 500 is provided inside the electric vehicle 600, and may be provided at the bottom, front, or rear of the electric vehicle 600. The battery 500 can be used to power the electric vehicle 600, for example, as an operating power source for the electric vehicle 600. The electric vehicle 600 may further include a controller 601 and a motor 602, and the controller 601 is used to control the battery 500 to power the motor 602, for example, to meet the operating power needs of the electric vehicle 600 during starting, navigation, and driving. In some embodiments of the present application, the battery 500 can be used not only as an operating power source for the electric vehicle 600, but also as a driving power source for the electric vehicle 600, providing driving power to the electric vehicle 600.

[0097] In this application, the provided cathode plate 100, anode plate 200, and separator are formed into a battery cell 300 by a conventional forming method (e.g., winding or folding). Temperature sensing wires are placed at the bases of the cathode tab 112 and anode tab 212 of the battery cell 300. The assembled battery cell 300 is placed in a room temperature environment and charged at 3 C for 6 minutes, and the temperatures at the bases of the cathode tab 112 and anode tab 212 of the battery cell 300 are immediately monitored during the charging process.

[0098] By varying the design parameters of the cathode tab 112 and the anode tab 212, Examples 1 to 30 and Comparative Examples 1 to 6 were formed. The parameter settings and test results for each Example and Comparative Example are shown in Table 1.

[0099] [Table 1-1] [Table 1-2] [Table 1-3]

[0100] The test data in Table 1 is analyzed.

[0101] (1) As can be seen from the test data of Comparative Example 1, when the cathode tab design parameter Fc, the cathode plate factor φc, the anode tab design parameter Fa, and the anode plate factor φa are all smaller than the minimum values ​​of each parameter, the volumetric energy density of the battery cell is lower than 300 Wh / L, and the maximum temperatures at the base of the cathode tab and the base of the anode tab both exceed 60°C.

[0102] (2) As can be seen from the test data of Comparative Example 2, when the cathode plate factor φc and the anode plate factor φa are within the ranges of values ​​provided by the present application, and the cathode tab design parameter Fc and the anode tab design parameter Fa are both lower than their respective minimum values, the volumetric energy density of the battery cell exceeds 300 Wh / L, but the maximum temperatures at the root of the cathode tab and the maximum temperatures at the root of the anode tab both exceed 60°C.

[0103] (3) As can be seen from the test data of Comparative Example 3, when the cathode tab design parameter Fc and the anode tab design parameter Fa are within the ranges of values ​​provided by the present application, and the cathode plate factor φc and the anode plate factor φa are both greater than their respective maximum values, the volumetric energy density of the battery cell is 500 Wh / L, but the maximum temperatures at the base of the cathode tab and the maximum temperatures at the base of the anode tab both exceed 60°C.

[0104] (4) As can be seen from the test data of Comparative Examples 4 and 5, when the cathode tab design parameter Fc and the anode tab design parameter Fa are within the value ranges provided by the present application, and one of the cathode plate factor φc and the anode plate factor φa is within that value range and the other is smaller than the minimum value, the volumetric energy density of the battery cell is less than 300 Wh / L, but the maximum temperature at the base of the cathode tab and the maximum temperature at the base of the anode tab are both lower than 60°C.

[0105] (5) As can be seen from the test data of Comparative Example 6, when the cathode tab design parameter Fc and the anode tab design parameter Fa are within the value ranges provided by the present application, the cathode plate factor φc is outside that value range, and the anode plate factor φa is within that value range, the volumetric energy density of the battery cell is higher than 300 Wh / L, the maximum temperature at the base of the anode tab is lower than 60°C, but the maximum temperature at the base of the cathode tab is higher than 60°C.

[0106] (6) As can be seen from the test data of Examples 1 to 8, when the cathode plate factor φc and the anode plate factor φa are within the value ranges provided by the present application, the cathode tab design parameter Fc is within the value ranges, and the anode tab design parameter Fa is smaller than the minimum value, the volumetric energy density of the battery cell exceeds 300 Wh / L, and the maximum temperatures at the base of the cathode tab are all lower than 60°C, but the maximum temperatures at the base of the anode tab are all higher than 60°C.

[0107] (7) As can be seen from the test data of Examples 9 to 14, when the cathode plate factor φc and the anode plate factor φa are within the ranges of values ​​provided by the present application, the cathode tab design parameter Fc is not within the ranges of values, and the anode tab design parameter Fa is within the ranges of values, the volumetric energy density of the battery cell exceeds 300 Wh / L, the maximum temperatures at the base of the cathode tab are all above 60°C, but the maximum temperatures at the base of the anode tab are not above 60°C.

[0108] (8) As can be seen from the test data of Examples 9 to 14, when the cathode plate factor φc and the anode plate factor φa are within the value ranges provided by the present application, the cathode tab design parameter Fc is not within the value ranges, and the anode tab design parameter Fa is within the value ranges, the volumetric energy density of the battery cell exceeds 300 Wh / L, the maximum temperatures at the base of the cathode tab are all above 60°C, but the maximum temperatures at the base of the anode tab are not above 60°C.

[0109] (9) As can be seen from the test data of Examples 15 to 30, when the cathode tab design parameter Fc, the cathode plate factor φc, the anode tab design parameter Fa, and the anode plate factor φa are within the value ranges provided by the present application, the volumetric energy density of the battery cell exceeds 300 Wh / L, and the maximum temperature at the base of the cathode tab and the maximum temperature at the base of the anode tab do not exceed 60°C. As can be seen from the test data of Examples 15 to 20, the cathode plate factor φc remains unchanged, the anode plate factor φa gradually increases, and the volumetric energy density of the battery cell gradually decreases. As can be seen from the test data of Examples 21 to 25, the anode plate factor φa remains unchanged, the cathode plate factor φc gradually increases, and the volumetric energy density of the battery cell gradually increases. As can be seen from the test data of Examples 26 to 30, the anode plate factor φa and the cathode plate factor φc are both at their maximum values, and the volumetric energy density of the battery cell remains unchanged. As the values ​​of the cathode tab design parameter Fc and the anode tab design parameter Fa gradually increase, the maximum temperature at the root of the cathode tab and the maximum temperature at the root of the anode tab both gradually decrease.

[0110] It is understood that the disclosed systems, devices, and methods in some embodiments provided by the present application may be realized in other forms. For example, the device embodiments described above are merely exemplary, and the division of units is merely a division of logical functions. In actual implementation, other division forms may be used, for example, multiple units or components may be combined or integrated into another system, or some features may be omitted or not implemented.

[0111] Furthermore, each functional unit in each embodiment of the present application may be integrated into one processing unit, each unit may exist physically alone, or two or more units may be integrated into one unit. The integrated units may be realized in the form of hardware or in the form of a software functional unit.

[0112] Finally, it should be noted that the above embodiments are used only to explain the technical solutions of the present application, and are not intended to limit the same. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art can still modify the technical solutions described in the above embodiments, or make equivalent substitutions for some or all of the technical features thereof. These modifications and substitutions do not deviate from the substance of the corresponding technical solutions within the scope of the technical solutions of the embodiments of the present application, and all such modifications and substitutions should be included in the scope of the claims and the description of the present application. In particular, as long as there is no structural contradiction, all technical features mentioned in the embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed in the description, but includes all technical solutions within the scope of the claims. [Explanation of symbols]

[0113] 100 cathode plate 110 Cathode current collector 120 Cathode active material layer 111 cathode main body 112 Cathode tab M Central axis of cathode tab 200 anode plate 210 Anode current collector 220 Anode active material layer 211 Anode main body 212 Anode tab N Central axis of the anode tab 300 battery cells 400 cabinets 500 batteries 600 electric vehicles 601 Controller 602 Motor

Claims

1. A cathode plate including a cathode current collector and a cathode active material layer provided on at least one side of the cathode current collector, the cathode current collector including a cathode main body and at least one cathode tab provided on one end of the cathode main body; The width of the base portion of the single cathode tab in the MD direction is m1, measured in mm; the thickness of the base portion of the single cathode tab is d1, measured in mm; the distance between the central axes of two adjacent cathode tabs along the MD direction is b1, measured in mm; the conductivity of the cathode current collector is S1, measured in S / m; the width of the cathode active material layer in the TD direction is a1, measured in mm; and the mass per unit area of ​​the cathode active material layer is CW1, measured in g / 1540.25 mm ２ and The design parameter of a single cathode tab is Fc, and Fc [Equation 1] and the unit is 15.4025 S mm g －１ and the value of Fc satisfies Fc≧0.

1.

2. The cathode plate according to claim 1 , wherein the design parameter value of the single cathode tab satisfies Fc≧0.

4.

3. The ratio of the mass per unit area of ​​the cathode active material layer to the thickness of the cathode current collector is defined as a cathode plate factor φc, and the value of the cathode plate factor satisfies 17≦φc≦50, where φc is the cathode plate factor and its unit is g / 1540.25 mm. ３ The cathode plate according to claim 1 , wherein

4. m1≧0.02 mm, and / or d1≦0.02 mm, and / or b1≦0.6 mm, and / or S1≧30 S / m, and / or a1≦0.3 mm, and / or 0.35 g / 1540.25 mm ２ ≦CW1≦0.5g / 1540.25mm ２ The cathode plate according to claim 1 , wherein

5. 10. The cathode plate of claim 1, wherein the cathode active material layer comprises a lithium iron phosphate material.

6. An anode plate including an anode current collector and an anode active material layer provided on at least one side of the anode current collector, the anode current collector including an anode main body and at least one anode tab provided on one end of the anode main body, The width of the base portion of the single anode tab in the MD direction is m2, measured in mm; the thickness of the base portion of the single anode tab is d2, measured in mm; the distance between the central axes of two adjacent anode tabs along the MD direction is b2, measured in mm; the conductivity of the anode current collector is S2, measured in S / m; the width of the anode active material layer in the TD direction is a2, measured in mm; and the mass per unit area of ​​the anode active material layer is CW2, measured in g / 1540.25 mm ２ and The design parameter of the single anode tab is Fa, and Fa [Equation 2] and the unit is 15.4025 S mm g －１ and the value of Fa satisfies Fa≧0.

02.

7. The anode plate according to claim 6, wherein the design parameter value of the single anode tab satisfies Fa≧0.

1.

8. The ratio of the mass per unit area of ​​the anode active material layer to the thickness of the anode current collector is defined as the anode plate factor φa, and the value of the anode plate factor satisfies 15≦φa≦85, where φa is the anode plate factor and its unit is g / 1540.25 mm. ３ The anode plate according to claim 6, wherein

9. 0.02 mm≦m2≦0.2 mm, and / or 0.003 mm≦d2≦0.01 mm, and / or 0.1 mm≦b2≦0.6 mm, and / or 50 S / m≦S2≦70 S / m, and / or 0.05 mm≦a2≦0.3 mm, and / or 0.15 g / 1540.25 mm ２ ≦CW2≦0.25g / 1540.25mm ２ The anode plate according to claim 6, wherein

10. A battery cell comprising the cathode plate according to any one of claims 1 to 5 and / or the anode plate according to any one of claims 6 to 9, A battery cell, wherein a design parameter value of the single cathode tab satisfies Fc≧0.1, and / or a design parameter value of the single anode tab satisfies Fa≧0.

02.

11. 0.4≦Fc≦75, 0.1≦Fa≦180, and 17≦φc≦50, 15≦φa≦85, and m1≧0.02 mm, d1≦0.02 mm, b1≦0.6 mm, S1≧30 S / m, a1≦0.3 mm, 0.35 g / 1540.25 mm ２ ≦CW1≦0.5g / 1540.25mm ２ , and 0.02 mm≦m2≦0.2 mm, 0.003 mm≦d2≦0.01 mm, 0.1 mm≦b2≦0.6 mm, 50 S / m≦S2≦70 S / m, 0.05 mm≦a2≦0.3 mm, 0.15 g / 1540.25 mm ２ ≦CW2≦0.25g / 1540.25mm ２ The battery cell according to claim 10 ,

12. 11. The battery cell of claim 10, wherein the battery cell is a lithium iron phosphate secondary battery, the volumetric energy density of the battery cell is ≥ 300 Wh / L, and the maximum temperature of the root portion of the cathode tab and the root portion of the anode tab of the battery cell is ≤ 60°C when the battery cell is charged at a 3C rate for 6 minutes at room temperature.

13. A battery comprising a housing and a plurality of the battery cells of claim 10 positioned within the housing.

14. An electrical device comprising the battery of claim 13.

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