Cathode electrode, anode electrode, battery cell, battery and electrical device

Abstract

This application provides a cathode electrode, an anode electrode, a battery cell, a battery, and an electrical device. The electrode includes a current collector and an active material layer; the current collector includes a main body and a tab. The ratio of the product of the cross-sectional area at the root of a single tab and the current collector, to the length between the central axes of two adjacent tabs, and the product of the width of the active material layer and the mass per unit area of ​​the active material layer, satisfies a design factor of at least 0.1 for the cathode tab and at least 0.02 for the anode tab. This application adjusts the size specifications of a single tab and the spacing between adjacent tabs based on the design parameters of the single tab, thereby improving the volumetric energy density of the battery cell while ensuring that the battery cell has a matching overcurrent capacity and that the local temperature rise of the corresponding battery cell under a fixed charging process does not exceed a threshold.

Description

Technical Field

[0001] This application relates to the field of batteries, specifically to a cathode electrode, an anode electrode, a battery cell, a battery, and an electrical device. Background Technology

[0002] Secondary batteries have advantages such as high operating voltage, wide operating temperature range, and low self-discharge rate, and are widely used in mobile electronic devices, home appliances, electric vehicles, and other fields. With the continuous development of products using them, various fields are placing higher demands on the capacity, energy density, charge / discharge rate, and cycle stability of secondary batteries. Summary of the Invention

[0003] In view of the above problems, this application provides a cathode electrode, an anode electrode, a battery cell, a battery, and an electrical device that can provide a reasonable adjustment range for the size of the tabs and the layout distribution of the tabs in the electrode sheet while improving the volumetric energy density of the battery cell and ensuring that the internal temperature of the battery cell does not exceed the threshold.

[0004] In a first aspect, this application provides a cathode electrode sheet, including a cathode current collector and a cathode active material layer disposed on at least one side of the cathode current collector; the cathode current collector includes a cathode body portion and at least one cathode tab disposed at one end of the cathode body portion;

[0005] Wherein, the width of the root of a single cathode tab along the MD direction is m1 (in mm); the thickness of the root of a single cathode tab is d1 (in mm); the dimension between the central axes of two adjacent cathode tabs along the MD direction is b1 (in mm); the conductivity of the cathode current collector is S1 (in S / m); the width of the cathode active material layer along the TD direction is a1 (in mm); and the unit area mass of the cathode active material layer is CW1 (in g / 1540.25 mm). 2 ;

[0006] The design parameter for a single cathode tab is Fc. The unit is 15.4025 S·mm·g -1 The value of Fc satisfies Fc≧0.1.

[0007] In the technical solution of this application embodiment, the size specifications of a single cathode tab and the spacing between adjacent cathode tabs are adjusted according to the design parameters of a single cathode tab. On the basis of improving the volumetric energy density of the battery cell, the battery cell is guaranteed to have a matching overcurrent capacity, and the local temperature rise of the corresponding battery cell under a fixed charging process does not exceed the threshold.

[0008] In some embodiments, the design parameters of a single cathode tab are such that Fc ≥ 0.4.

[0009] In the technical solution of this application embodiment, by further optimizing the design parameters of a single cathode tab, the design of the cathode tab ensures that the volumetric energy density of the battery cell reaches a certain level, and that the local temperature rise of the battery cell under a fixed charging process does not exceed a threshold.

[0010] In some embodiments, the ratio of the unit area mass of the cathode active material layer to the thickness of the cathode current collector is used as the cathode electrode factor; the value of the cathode electrode factor satisfies the following conditions: This refers to the cathode electrode factor, measured in g / 1540.25mm. 3 .

[0011] In the technical solution of this application embodiment, by limiting the value of the cathode electrode factor, on the one hand, it ensures that the cathode current collector 110 is kept above a certain strength and will not cause problems such as cold pressing breakage or internal brittle fracture of the battery cell. On the other hand, it controls the unit area mass of the cathode active material layer within a certain range and will not cause serious coating cracking, poor weight distribution uniformity, or easy demolding of the electrode, thus ensuring the manufacturing yield and cost advantage of the battery cell.

[0012] 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 .

[0013] In the technical solution of this application embodiment, the value range of various parameters of the cathode tab, the cathode active material layer and the cathode current collector is determined. Within the above value range, the product performance stability of the battery cell is satisfied.

[0014] In some embodiments, the cathode active material layer comprises lithium iron phosphate material.

[0015] In the technical solution of this application embodiment, by designing the cathode tab of 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 under a fixed charging process can be guaranteed not to exceed 60°C.

[0016] Secondly, this application provides an anode electrode sheet, including an anode current collector and an anode active material layer disposed on at least one side of the anode current collector; the anode current collector includes an anode body portion and at least one anode tab disposed at one end of the anode body portion;

[0017] Wherein, the width of the root of a single anode tab along the MD direction is m2 (mm); the thickness of the root of a single anode tab is d2 (mm); the dimension between the central axes of two adjacent anode tabs along the MD direction is b2 (mm); the conductivity of the anode current collector is S2 (S / m); the width of the anode active material layer along the TD direction is a2 (mm); and the unit area mass of the anode active material layer is CW2 (g / 1540.25mm). 2 ;

[0018] The design parameter for a single anode tab is Fa. The unit is 15.4025 S·mm·g -1 The value of Fa satisfies Fa≧0.02.

[0019] In the technical solution of this application embodiment, the size specifications of a single anode tab and the spacing between adjacent anode tabs are adjusted according to the design parameters of a single anode tab. On the basis of improving the volumetric energy density of the battery cell, the battery cell is guaranteed to have a matching overcurrent capacity, and the local temperature rise of the corresponding battery cell under a fixed charging process does not exceed the threshold.

[0020] In some embodiments, the design parameters of a single anode tab are such that Fa ≥ 0.1.

[0021] In the technical solution of this application embodiment, by further optimizing the design parameters of a single anode tab, the design of the anode tab ensures that the volumetric energy density of the battery cell reaches a certain level, and that the local temperature rise of the battery cell under a fixed charging process does not exceed a threshold.

[0022] In some embodiments, the ratio of the unit area mass of the anode active material layer to the thickness of the anode current collector is used as the anode electrode factor; the value of the anode electrode factor satisfies the following conditions: This refers to the anode electrode factor, measured in g / 1540.25mm. 3 .

[0023] In the technical solution of this application embodiment, by limiting the value of the anode electrode factor, on the one hand, it ensures that the anode current collector is kept above a certain strength, and problems such as cold pressing breakage and internal brittle fracture of the battery cell will not occur. On the other hand, it controls the unit area mass of the anode active material layer within a certain range, and problems such as serious coating cracking, poor weight distribution uniformity, and easy demolding of the electrode sheet will not occur, thus ensuring the manufacturing efficiency and cost advantage of the battery cell.

[0024] In some embodiments, 0.02mm ≤ m² ≤ 0.2mm; and / or 0.003mm ≤ d² ≤ 0.01mm; and / or 0.1mm ≤ b² ≤ 0.6mm; and / or 50S / m ≤ S² ≤ 70S / m; and / or 0.05mm ≤ a² ≤ 0.3mm; and / or 0.15g / 1540.25mm 2 ≦CW2≦0.25g / 1540.25mm 2 .

[0025] Through numerous specific experiments, the inventors of this application have determined the value range of various parameters for the anode tab, anode active material layer, and anode current collector, based on improving the volumetric energy density of the battery cell and ensuring that the local temperature rise of the battery cell does not exceed the threshold under a fixed charging process. Within the above value range, the stability of the product performance of the battery cell is satisfied.

[0026] Thirdly, this application provides a battery cell, including the above-mentioned cathode electrode and / or the above-mentioned anode electrode;

[0027] The design parameters for a single cathode tab must satisfy Fc ≥ 0.1, and / or the design parameters for a single anode tab must satisfy Fa ≥ 0.02.

[0028] In the technical solution of this application embodiment, the size specifications of a single cathode tab and a single anode tab are adjusted according to the design parameters of a single cathode tab and a single anode tab, as well as the distribution design of the cathode tab on the cathode plate and the anode tab on the anode plate. This ensures that the local temperature rise of the battery cell does not exceed the threshold under a fixed charging process while improving the volumetric energy density of the battery cell.

[0029] In some embodiments, 0.4 ≤ Fc ≤ 75, 0.1 ≤ Fa ≤ 180; and And m1≧0.02mm; d1≦0.02mm; b1≦0.6mm; S1≧30S / m; a1≦0.3mm; and / or 0.35g / 1540.25mm 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 .

[0030] The technical solution of this application provides further preferred value ranges for various parameters of the cathode tab, cathode active material layer and cathode current collector, anode tab, anode active material layer and anode current collector, within the above value range, to ensure the stability of the product performance of the battery cell.

[0031] In some embodiments, the battery cell is a lithium iron phosphate secondary battery; the volumetric energy density of the battery cell is ≥300Wh / L; the battery cell is charged at 3C rate for 6 minutes at room temperature, and the maximum temperature at the root of the cathode tab and the root of the anode tab of the battery cell is ≤60℃.

[0032] In the technical solution of this application embodiment, by designing cathode tabs and anode tabs for lithium iron phosphate secondary batteries, the volumetric energy density of the battery cells can be effectively increased to 300Wh / L, and the local temperature rise of the battery cells under a fixed charging process can be guaranteed not to exceed 60°C.

[0033] Fourthly, this application provides a battery, including a housing and a plurality of the aforementioned battery cells located within the housing.

[0034] Fifthly, this application provides an electrical device including the aforementioned battery.

[0035] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0036] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Throughout the drawings, the same reference numerals denote the same parts. In the drawings:

[0037] Figure 1 This is a schematic diagram of the structure of the cathode electrode provided in this application;

[0038] Figure 2 yes Figure 1 A schematic diagram of the cross-sectional structure of the cathode electrode along line AA is provided.

[0039] Figure 3 This is a schematic diagram of the structure of the anode electrode provided in this application;

[0040] Figure 4 yes Figure 3 A schematic diagram of the cross-sectional structure of the anode electrode along line BB;

[0041] Figure 5 This is a schematic diagram of the structure of the battery cell provided in this application;

[0042] Figure 6 yes Figure 5 A top view of the provided battery cell structure;

[0043] Figure 7 This is a schematic diagram of the battery structure provided in this application;

[0044] Figure 8 This is a schematic diagram of the electrical device provided in this application.

[0045] Explanation of reference numerals: Cathode electrode, 110-Cathode current collector, 120-Cathode active material layer, 111-Cathode body, 112-Cathode tab, M-Central axis of cathode tab, 200-Anode electrode, 210-Anode current collector, 220-Anode active material layer, 211-Anode body, 212-Anode tab, N-Central axis of anode tab, 300-Battery cell, 400-Casing, 500-Battery, 600-Electric vehicle, 601-Controller, 602-Motor. Detailed Implementation

[0046] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0047] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0048] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0049] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0050] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0051] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0052] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0053] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0054] The inventors of this application have noted that, within battery cells with the same chemical system, keeping the total electrode length and film width constant, a higher cathode coating weight (CW) results in a higher volumetric energy density of the battery cell. Taking a lithium iron phosphate secondary battery as an example, a cathode coating weight of 0.35 g × 1540.25 mm... -2The above can be considered a thick coating. The volumetric energy density of a single battery cell with a thick coating can reach over 300Wh / L.

[0055] Compared to cells with thin coatings, cells with thick coatings require larger charge / discharge currents at the same rate, placing higher demands on their current-carrying capacity. The current-carrying capacity of a cell indicates its ability to conduct current. If the current-carrying capacity of a cell cannot keep up with the increased weight of the cathode coating, the internal temperature of the cell will easily rise. Once a certain temperature threshold is exceeded, a large amount of heat will be generated inside the cell. This heat will cause the internal temperature of the cell to continue to rise and transfer to other cells, leading to a chain reaction among multiple cells within the battery and potentially causing a serious safety accident.

[0056] Specifically, the internal temperature threshold of a single battery cell should not exceed 60°C. This is because when the internal temperature of a single battery cell exceeds 60°C, the solid electrolyte interphase (SEI) of its cathode active material layer begins to decompose, leading to a sharp deterioration in the performance of the battery cell. Therefore, the internal temperature of a single battery cell needs to be controlled below 60°C.

[0057] Furthermore, the inventors of this application discovered that the design of the electrode tabs directly affects the current-carrying capacity of a single battery cell. If a thick coating is used in the battery cell, but the tab design remains unchanged, the current-carrying capacity of the thick-coated battery cell is relatively reduced under the same charge / discharge process, leading to increased Joule heating at the tabs. When the local temperature at the base of the tabs exceeds the threshold temperature, battery performance will degrade more rapidly. In this case, the temperature rise can be reduced by lowering the charging rate, but the battery's fast-charging performance will also be correspondingly compromised.

[0058] Based on the above considerations, in order to solve the problem of improving the current carrying capacity of battery cells while increasing the volumetric energy density of battery cells, and ensuring the safety and stability of battery cell performance, the inventors of this application have conducted in-depth research and proposed a tab design method. By designing the width and thickness of the tab root and the spacing between adjacent tabs, the current carrying capacity of a single tab is controlled, so that the tab design matches the coating thickness of the active material, effectively controlling the internal temperature of the battery cell without sacrificing the fast charging performance of the battery cell.

[0059] The technical solutions described in the embodiments of this application are applicable to cathode electrodes, anode electrodes, battery cells, batteries, and electrical devices. The battery cells disclosed in this application can be used in lithium-ion secondary batteries, and can also be used in other energy storage batteries; this application does not impose any limitations.

[0060] The present application will now be described in detail with reference to the accompanying drawings and embodiments.

[0061] Please see Figures 1-2 , Figure 1This is a schematic diagram of the structure of the cathode electrode provided in this application. Figure 2 yes Figure 1 A schematic diagram of the cross-sectional structure of the provided cathode electrode along line AA.

[0062] See Figures 1-2 This application provides a cathode electrode 100, including a cathode current collector 110 and a cathode active material layer 120 disposed on at least one side of the cathode current collector 110. The cathode current collector 110 includes a cathode body portion 111 and at least one cathode tab 112 disposed at one end of the cathode body portion 111.

[0063] The width of the root of a single cathode tab 112 along the MD direction is m1 (mm). The thickness of the root of a single cathode tab 112 is d1 (mm). The dimension between the central axes M of two adjacent cathode tabs along the MD direction is b1 (mm). The conductivity of the cathode current collector 110 is S1 (S / m). The width of the cathode active material layer 120 along the TD direction is a1 (mm). The mass per unit area of ​​the cathode active material layer 120 is CW1 (g / 1540.25mm²). 2 .

[0064] The design parameter for a single cathode tab 112 is Fc. The unit is 15.4025 S·mm·g -1 The value of Fc satisfies Fc≧0.1.

[0065] In this application, the cathode electrode 100 is composed of a cathode current collector 110 and a cathode active material layer 120. The cathode current collector 110 is typically made of a metallic material; for example, in a lithium-ion battery, the cathode current collector 110 can 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 material of the cathode active material layer 120 can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The cathode active material layer 120 can be disposed on only one side of the cathode current collector 110, or it can be disposed on both sides of the cathode current collector 110.

[0066] The cathode body 111 is the portion of the cathode current collector 110 coated with the cathode active material layer 120. The cathode tab 112 is the portion of the cathode current collector 110 that protrudes from the cathode body 111. The cathode tab 112 may be located at only one end of the cathode body 111, or at both ends. One end of the cathode body 111 may have only one cathode tab 112, or multiple cathode tabs 112 may be stacked. It is understood that the number of cathode tabs 112 in this application can be adjusted according to requirements. The central axis M of the cathode tabs represents the line connecting the centroids of the cross-sections of all the cathode tabs 112. In one or more embodiments of this application, the dimension b1 between the central axes M of two adjacent cathode tabs along the MD direction is measured by the following method: first, the central axes M of two target cathode tabs are determined using a precision measuring tool; then, the dimension b1 between the central axes M of the two target cathode tabs is measured using the same precision measuring tool. In one or more embodiments of this application, the precision measuring tool is a laser rangefinder.

[0067] The root of a single cathode tab 112 represents the portion of the cathode tab 112 that connects to the cathode body 111. In one or more embodiments of this application, the length of the root of a single cathode tab 112 along the TD direction is less than 50% of the length of the single cathode tab 112 along the TD direction. Specifically, the length of the root of a single cathode tab 112 along the TD direction is less than 40%, 30%, 20%, or 10% of the length of the single cathode tab 112 along the TD direction, and can be reasonably set as needed. The TD direction (Transverse Direction) represents the width direction of the electrode sheet. The length direction of the electrode sheet is perpendicular to the TD direction, which is the MD direction (Machine Direction). For a thick-coated cathode electrode sheet 100 with certain parameters, the cross-sectional area of ​​the root of the single cathode tab 112 and the coating weight of the cathode active material corresponding to the single cathode tab 112 can be adjusted to a reasonable range through the design parameters of the single cathode tab 112, ensuring that the local temperature rise of the battery cell does not exceed the threshold under a fixed charging process.

[0068] In the calculation formula for the design parameter Fc of a single cathode tab 112, m1×d1 in the numerator represents the cross-sectional area of ​​the root of the cathode tab 112, and m1×d1×S1 represents the current-carrying capacity of a single cathode tab 112; in the denominator, CW1×a1×b1 represents the current-carrying capacity that a single cathode tab 112 needs to bear. The lower limit of Fc corresponds to the critical point where the current-carrying capacity of a single cathode tab 112 is the weakest, while its current-carrying capacity is the largest. The setting of the lower limit of Fc ensures that the temperature rise at the root of the cathode tab 112 does not exceed 60℃.

[0069] In this embodiment, the size and spacing of a single cathode tab 112 are adjusted according to the design parameters of the single cathode tab 112. This improves the volumetric energy density of the battery cell while ensuring that the battery cell has a matching overcurrent capability and that the local temperature rise of the corresponding battery cell under a fixed charging process does not exceed the threshold.

[0070] In some embodiments, the design parameters of a single cathode tab 112 are such that Fc ≥ 0.4.

[0071] In this embodiment, the lower limit of the design parameters for a single cathode tab 112 indicates that the overcurrent capacity borne by a single cathode tab 112 has a certain threshold. If the design parameters of a single cathode tab 112 exceed the lower limit, the overcurrent capacity borne by the single cathode tab 112 is too large, the overcurrent capacity of the single cathode tab 112 is too small, the Joule heat at the root of the cathode tab 112 increases, and the temperature at the root of the cathode tab 112 exceeds the threshold temperature, resulting in a rapid degradation of the battery cell's performance. The upper limit of the design parameters for a single cathode tab 112 corresponds to the critical point where the overcurrent capacity is strongest and the overcurrent capacity is smallest, mainly ensuring that the design of the single cathode tab 112 can meet the fast charging capability of the battery cell.

[0072] This embodiment further optimizes the design parameters of a single cathode tab 112 to ensure that the design of the cathode tab 112 ensures that the volumetric energy density of the battery cell reaches a certain level, and that the local temperature rise of the battery cell under a fixed charging process does not exceed the threshold.

[0073] In some embodiments, the ratio of the unit area mass of the cathode active material layer 120 to the thickness of the cathode current collector 110 is used as the cathode electrode factor; the value of the cathode electrode factor satisfies the following conditions: This refers to the cathode electrode factor, measured in g / 1540.25mm. 3 .

[0074] In this application, the cathode electrode factor represents a variable in the design parameters of a single cathode tab 112. The cathode electrode factor indicates that the unit area mass of the cathode active material layer 120 is related to the thickness of the cathode current collector 110; the two are not two independent variables, and neither can take arbitrary values.

[0075] In this embodiment, the lower limit of the cathode electrode factor corresponds to the critical point where the unit area mass of the cathode active material layer 120 is the minimum and the thickness of the cathode current collector 110 is the maximum, mainly to ensure that the volumetric energy density of the battery cell reaches a certain value. The upper limit of the cathode electrode factor corresponds to the critical point where the unit area mass of the cathode active material layer 120 is the maximum and the thickness of the cathode current collector 110 is the minimum.

[0076] This embodiment, by limiting the value of the cathode electrode factor, ensures that the cathode current collector 110 maintains a certain strength, preventing problems such as cold-pressing breakage and internal brittle fracture of the battery cell. Simultaneously, it controls the unit area mass of the cathode active material layer 120 within a certain range, avoiding serious coating cracking, poor weight distribution uniformity, and easy electrode demolding, thus ensuring the manufacturing yield and cost advantage of the battery cell. It can be understood that the larger the cathode electrode factor within its range, the thicker the coating and the higher the volumetric energy density of the battery cell.

[0077] 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 .

[0078] Through numerous specific experiments, the inventors of this application determined the value range of various parameters of the cathode tab 112, the cathode active material layer 120, and the cathode current collector 110, based on improving the volumetric energy density of the battery cell (e.g., 300Wh / L) and ensuring that the local temperature rise of the battery cell does not exceed the threshold (e.g., 60℃) under a fixed charging process. Within the above value range, the stability of the product performance of the battery cell is satisfied.

[0079] In some embodiments, the cathode active material layer 120 includes lithium iron phosphate material. Under the above scheme, this embodiment, by designing the cathode tab 112 of the lithium iron phosphate secondary battery, can effectively improve the volumetric energy density of the battery cell to 300Wh / L and ensure that the local temperature rise of the battery cell does not exceed 60°C under a fixed charging process.

[0080] Please see Figures 3-4 , Figure 3 This is a schematic diagram of the anode electrode provided in this application. Figure 4 yes Figure 3 A schematic diagram of the cross-sectional structure of the anode electrode along line BB is provided.

[0081] See Figures 3-4 This application provides an anode electrode 200, including an anode current collector 210 and an anode active material layer 220 disposed on at least one side of the anode current collector 210. The anode current collector 210 includes an anode body portion 211 and at least one anode tab 212 disposed at one end of the anode body portion 211.

[0082] The width of the root of a single anode tab 212 along the MD direction is m2 (mm). The thickness of the root of a single anode tab 212 is d2 (mm). The dimension between the central axes N of two adjacent anode tabs along the MD direction is b2 (mm). The conductivity of the anode current collector 210 is S2 (S / m). The width of the anode active material layer 220 along the TD direction is a2 (mm). The unit area mass of the anode active material layer 220 is CW2 (g / 1540.25mm²). 2 .

[0083] The design parameters for a single anode tab 212 are Fa, The unit is 15.4025 S·mm·g -1 The value of Fa satisfies Fa≧0.02.

[0084] In this application, the anode electrode 200 is composed of an anode current collector 210 and an anode active material layer 220. The anode current collector 210 is typically made of a metallic material; for example, in a lithium-ion battery, the anode current collector 210 can be copper foil. The anode active material layer 220 is coated on at least one side of the anode current collector 210; for example, in a lithium-ion battery, the material of the anode active material layer 220 can be carbon or silicon, etc. The anode active material layer 220 can be disposed on only one side of the anode current collector 210, or it can be disposed on both sides of the anode current collector 210.

[0085] The anode body 211 is the portion of the anode current collector 210 coated with the anode active material layer 220. The anode tab 212 is the portion of the anode current collector 210 that protrudes from the anode body 211. The anode tab 212 may be located at only one end of the anode body 211, or at both ends. One end of the anode body 211 may have only one anode tab 212, or multiple anode tabs 212 stacked together. It is understood that the number of anode tabs 212 in this application can be adjusted according to requirements. The central axis N of the anode tabs represents the line connecting the centroids of the cross-sections of all anode tabs 212. In one or more embodiments of this application, the dimension b2 between the central axes N of two adjacent anode tabs along the MD direction is measured by the following method: first, the central axes N of two target anode tabs are determined using a precision measuring tool; then, the dimension b1 between the central axes N of the two target anode tabs is measured using the same precision measuring tool. In one or more embodiments of this application, the precision measuring tool is a laser rangefinder.

[0086] The root of a single anode tab 212 represents the portion where the anode tab 212 connects to the anode body 211. In one or more embodiments of this application, the length of the root of a single anode tab 212 along the TD direction is less than 50% of the total length of the single anode tab 212 along the TD direction. Specifically, the length of the root of a single anode tab 212 along the TD direction is less than 40%, 30%, 20%, or 10% of the total length of the single anode tab 212 along the TD direction, and can be reasonably set as needed. For a thickly coated anode electrode 200 with a certain set of parameters, the cross-sectional area of ​​the root of the anode tab 212 and the coating weight of the anode active material corresponding to the single anode tab 212 can be adjusted to a reasonable range through the design parameters of the single anode tab 212, ensuring that the local temperature rise of the battery cell does not exceed the threshold under a fixed charging process.

[0087] In the calculation formula for the design parameter Fa of a single anode tab 212, m2×d2 in the numerator represents the cross-sectional area of ​​the root of the anode tab 212, and m2×d2×S2 represents the current carrying capacity of a single anode tab 212; in the denominator, CW2×a2×b2 represents the current carrying capacity that a single anode tab 212 needs to bear. The lower limit of Fa corresponds to the critical point where the current carrying capacity of a single anode tab 212 is weakest, while the current carrying capacity of a single anode tab 212 is largest, mainly ensuring that the temperature rise at the root of the anode tab 212 does not exceed 60℃.

[0088] In this embodiment, the size and spacing of a single anode tab 212 are adjusted according to the design parameters of the single anode tab 212. This improves the volumetric energy density of the battery cell while ensuring that the battery cell has a matching overcurrent capacity and that the local temperature rise of the corresponding battery cell under a fixed charging process does not exceed the threshold.

[0089] In some embodiments, the design parameters of a single anode tab 212 are such that Fa ≥ 0.1.

[0090] In this embodiment, the lower limit of the design parameters for a single anode tab 212 indicates that the overcurrent capacity borne by a single anode tab 212 has a certain threshold. If the design parameters of a single anode tab 212 exceed the lower limit, the overcurrent capacity borne by the single anode tab 212 is too large, the overcurrent capacity of the single anode tab 212 is too small, the Joule heat at the root of the anode tab 212 increases, and the temperature at the root of the anode tab 212 exceeds the threshold temperature, leading to a rapid deterioration of the battery cell's performance. The upper limit of the design parameters for a single anode tab 212 corresponds to the critical point where the overcurrent capacity is strongest and the overcurrent capacity is smallest, mainly ensuring that the design of the single anode tab 212 can meet the fast charging capability of the battery cell.

[0091] This embodiment further optimizes the design parameters of a single anode tab 212 to ensure that the design of the anode tab 212 ensures that the volumetric energy density of the battery cell reaches a certain level, and that the local temperature rise of the battery cell under a fixed charging process does not exceed the threshold.

[0092] In some embodiments, the ratio of the unit area mass of the anode active material layer 220 to the thickness of the anode current collector 210 is used as the anode electrode factor; the value of the anode electrode factor satisfies the following conditions: This refers to the anode electrode factor, measured in g / 1540.25mm. 3 .

[0093] In this application, the anode electrode factor represents a variable in the design parameters of a single anode tab 212. The anode electrode factor indicates that the unit area mass of the anode active material layer 220 is related to the thickness of the anode current collector 210; the two are not two independent variables, and neither can take arbitrary values.

[0094] In this embodiment, the lower limit of the anode electrode factor corresponds to the critical point where the unit area mass of the anode active material layer 220 is the minimum and the thickness of the anode current collector 210 is the maximum, mainly to ensure that the volumetric energy density of the battery cell reaches a certain value. The upper limit of the anode electrode factor corresponds to the critical point where the unit area mass of the anode active material layer 220 is the maximum and the thickness of the anode current collector 210 is the minimum.

[0095] This embodiment, by limiting the value of the anode electrode factor, ensures that the anode current collector 210 maintains a certain strength, preventing problems such as cold-pressing breakage and internal brittle fracture of the battery cell. Simultaneously, it controls the unit area mass of the anode active material layer 220 within a certain range, avoiding serious coating cracking, poor weight distribution uniformity, and easy electrode demolding, thus ensuring the manufacturing yield and cost advantage of the battery cell. It can be understood that the larger the cathode electrode factor within its range, the thicker the coating and the higher the volumetric energy density of the battery cell.

[0096] In some embodiments, 0.02mm ≤ m² ≤ 0.2mm; and / or 0.003mm ≤ d² ≤ 0.01mm; and / or 0.1mm ≤ b² ≤ 0.6mm; and / or 50S / m ≤ S² ≤ 70S / m; and / or 0.05mm ≤ a² ≤ 0.3mm; and / or 0.15g / 1540.25mm 2 ≦CW2≦0.25g / 1540.25mm 2 .

[0097] Through numerous specific experiments, the inventors of this application determined the value range of various parameters for the anode tab 212, the anode active material layer 220, and the anode current collector 210, based on improving the volumetric energy density of the battery cell (e.g., 300Wh / L) and ensuring that the local temperature rise of the battery cell does not exceed a threshold (e.g., 60℃) under a fixed charging process. Within the above value range, the stability of the product performance of the battery cell is satisfied.

[0098] Please see Figures 5-6 , Figure 5 This is a schematic diagram of the structure of the battery cell provided in this application. Figure 6 yes Figure 5 A top view diagram of the provided battery cell structure.

[0099] See Figures 5-6 This application provides a battery cell 300, including a cathode electrode 100 and / or an anode electrode 200. (Combined with...) Figure 1 and Figure 2 The cathode electrode 100 includes a cathode current collector 110 and a cathode active material layer 120 disposed on at least one side of the cathode current collector 110. The cathode current collector 110 includes a cathode body portion 111 and at least one cathode tab 112 disposed at one end of the cathode body portion 111. Figure 3 and Figure 4 The anode electrode 200 includes an anode current collector 210 and an anode active material layer 220 disposed on at least one side of the anode current collector 210. The anode current collector 210 includes an anode body portion 211 and at least one anode tab 212 disposed at one end of the anode body portion 211. In this embodiment, as shown... Figure 6 As shown, a wound battery cell 300 is provided. It is understood that the battery cell 300 can also be stacked, which can be set as needed, and this application does not limit it.

[0100] Among them, combined Figures 1-4 The width of the root of a single cathode tab 112 along the MD direction is m1, and the width of the root of a single anode tab 212 along the MD direction is m2, both in mm. The thickness of the root of a single cathode tab 112 is d1, and the thickness of the root of a single anode tab 212 is d2, both in mm. Along the MD direction, the dimension between the central axes M of two adjacent cathode tabs is b1, and the dimension between the central axes N of two adjacent anode tabs is b2, both in mm. The conductivity of the cathode current collector 110 is S1, and the conductivity of the anode current collector 210 is S2, both in S / m. The width of the cathode active material layer 120 along the TD direction is a1, and the width of the anode active material layer 220 along the TD direction is a2, both in mm. The unit area mass of the cathode active material layer 120 is CW1, and the unit area mass of the anode active material layer 220 is CW2, both in g / 1540.25mm.2 .

[0101] The design parameter for a single cathode tab 112 is Fc. The design parameters for a single anode tab 212 are Fa, The unit is 15.4025 S·mm·g -1 The value of Fc satisfies Fc≧0.1, and / or the value of Fa satisfies Fa≧0.02.

[0102] According to the design parameters of a single cathode tab 112 and a single anode tab 212, this application embodiment adjusts the size specifications of a single cathode tab 112 and a single anode tab 212, as well as the distribution design of the cathode tab 112 on the cathode electrode 100 and the anode tab 212 on the anode electrode 200, so as to improve the volumetric energy density of the battery cell 300 and ensure that the local temperature rise of the battery cell 300 does not exceed the threshold under a fixed charging process.

[0103] In some embodiments, 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 ; 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 .

[0104] Through numerous specific experiments, the inventors of this application have determined further preferred value ranges for various parameters of the cathode tab 112, cathode active material layer 120 and cathode current collector 110, and anode tab 212, anode active material layer 220 and anode current collector 210, based on improving the volumetric energy density of the battery cell 300 (e.g., 300Wh / L) and ensuring that the local temperature rise of the battery cell 300 does not exceed a threshold (e.g., 60°C) under a fixed charging process. Within the above value range, the stability of the product performance of the battery cell 300 is satisfied.

[0105] In some embodiments, the battery cell 300 is a lithium iron phosphate secondary battery. The volumetric energy density of the battery cell 300 is ≥300Wh / L. When the battery cell 300 is charged at a 3C rate for 6 minutes at room temperature, the maximum temperature at the root of the cathode tab 112 and anode tab 212 of the battery cell 300 is ≤60°C.

[0106] This embodiment, by designing cathode tab 112 and anode tab 212 for the lithium iron phosphate secondary battery, can effectively improve the volumetric energy density of the battery cell to 300Wh / L and ensure that the local temperature rise of the battery cell does not exceed 60°C under a fixed charging process.

[0107] Please see Figure 7 , Figure 7 This is a schematic diagram of the battery structure provided in this application.

[0108] See Figure 7 This application provides a battery 500, including a housing 400 and a plurality of battery cells 300 located within the housing 400. The battery 500 may further include the housing 400 for providing housing space for the battery cells 300, and the housing 400 may have various shapes. In the battery 500, the plurality of battery cells 300 can be connected in series, parallel, or in a mixed configuration. A mixed configuration means that the plurality of battery cells 300 are connected in both series and parallel connections. The plurality of battery cells 300 can be directly connected in series, parallel, or in a mixed configuration, and then the entire assembly of the plurality of battery cells 300 is housed within the housing 400. Alternatively, the battery 500 may consist of multiple battery cells 300 first connected in series, parallel, or in a mixed configuration to form a battery module, and then multiple battery modules are connected in series, parallel, or in a mixed configuration to form a whole, which is then housed within the housing 400. The battery 500 may also include other structures; for example, the battery 500 may also include a busbar component for realizing electrical connections between the plurality of battery cells 300. Each battery cell 300 can be a secondary battery or a primary battery, and can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited to these. The battery cell 300 can be cylindrical, flat, cuboid, or other shapes, but is not limited to these.

[0109] Please see Figure 8 , Figure 8 This is a schematic diagram of the electrical device provided in this application.

[0110] See Figure 8This application provides an electrical device including the aforementioned battery 500. The electrical device can be a mobile phone, computer, electric motorcycle, electric car 600, etc. This embodiment uses an electric car 600 as an example for description. The electric car 600 has a battery 500 internally disposed therein, and the battery 500 can be located at the bottom, head, or tail of the electric car 600. The battery 500 can be used to power the electric car 600; for example, the battery 500 can serve as the operating power source for the electric car 600. The electric car 600 may also include a controller 601 and a motor 602. The controller 601 controls the battery 500 to supply power to the motor 602, for example, to meet the power needs of the electric car 600 during startup, navigation, and driving. In some embodiments of this application, the battery 500 can not only serve as the operating power source for the electric car 600 but also as the driving power source for the electric car 600, providing driving power to the electric car 600.

[0111] This application provides a cathode electrode 100, an anode electrode 200, and a separator, which are then formed into a battery cell 300 using conventional forming methods (such as winding or folding). Temperature sensing wires are arranged at the base of the cathode tab 112 and anode tab 212 in the battery cell 300. The assembled battery cell 300 is placed in a room temperature environment and charged at 3C for 6 minutes, with the temperature at the base of the cathode tab 112 and anode tab 212 in the battery cell 300 monitored in real time during the charging process.

[0112] Based on the different 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 of each example and comparative example are shown in Table 1.

[0113] Table 1. Setting parameters and test results of battery cells in various embodiments of this application.

[0114]

[0115]

[0116] Analyze the test data in Table 1:

[0117] (1) According to the test data of Comparative Example 1, the design parameters Fc of the cathode tab and the cathode electrode factor are: Design parameters Fa of anode tab, anode factor If all values ​​are below the minimum values ​​of each parameter, then the volumetric energy density of the battery cell is less than 300Wh / L, and the maximum temperature at the root of the cathode tab and the maximum temperature at the root of the anode tab both exceed 60℃.

[0118] (2) According to the test data in Comparison Document 2, the cathode electrode factor is: and anode electrode factor If the design parameters Fc of the cathode tab and Fa of the anode tab are both below their respective minimum values ​​within the range provided in this application, the volumetric energy density of the battery cell exceeds 300Wh / L, but the maximum temperature at the root of both the cathode tab and the anode tab exceeds 60°C.

[0119] (3) According to the test data in prior art document 3, the design parameters Fc of the cathode tab and Fa of the anode tab are within the range provided in this application, and the cathode electrode factor is within the range provided in this application. and anode electrode factor If both are higher than their respective maximum values, then the volumetric energy density of the battery cell is 500Wh / L, but the maximum temperature at the root of the cathode tab and the maximum temperature at the root of the anode tab both exceed 60℃.

[0120] (4) According to the test data in prior art documents 4-5, the design parameters Fc of the cathode tab and Fa of the anode tab are within the range provided in this application, and the cathode electrode factor... and anode electrode factor If one value is within the range and the other is below the minimum value, then the volumetric energy density of the battery cell is less than 300Wh / L, but the maximum temperature at the root of both the cathode tab and the anode tab is less than 60℃.

[0121] (5) According to the test data in prior art document 6, the design parameters Fc of the cathode tab and Fa of the anode tab are within the range provided in this application, and the cathode electrode factor... Anode electrode factor exceeding the range If the values ​​are within the specified range, the volumetric energy density of the battery cell is higher than 300Wh / L, the maximum temperature at the root of the anode tab is lower than 60℃, but the maximum temperature at the root of the cathode tab exceeds 60℃.

[0122] (6) According to the test data of Examples 1-8, the cathode electrode factor is: and anode electrode factor If the design parameter Fc of the cathode tab is within the range provided in this application, and the design parameter Fa of the anode tab is lower than the minimum value, then the volumetric energy density of the battery cell exceeds 300Wh / L, the maximum temperature at the root of the cathode tab is lower than 60℃, but the maximum temperature at the root of the anode tab exceeds 60℃.

[0123] (7) According to the test data of Examples 9-14, the cathode electrode factor is: and anode electrode factor If the design parameter Fc of the cathode tab does not fall within the range provided in this application, but the design parameter Fa of the anode tab does fall within the range, then the volumetric energy density of the battery cell exceeds 300Wh / L, the maximum temperature at the root of the cathode tab exceeds 60℃, but the maximum temperature at the root of the anode tab does not exceed 60℃.

[0124] (8) According to the test data of Examples 9-14, the cathode electrode factor is: and anode electrode factor If the design parameter Fc of the cathode tab does not fall within the range provided in this application, but the design parameter Fa of the anode tab does fall within the range, then the volumetric energy density of the battery cell exceeds 300Wh / L, the maximum temperature at the root of the cathode tab exceeds 60℃, but the maximum temperature at the root of the anode tab does not exceed 60℃.

[0125] (9) According to the test data of Examples 15-30, the design parameters Fc of the cathode tab and the cathode electrode factor are: Design parameters Fa of anode tab, anode factor If the values ​​fall within the range provided in this application, the volumetric energy density of the battery cells exceeds 300Wh / L, and the maximum temperature at the root of both the cathode tab and the anode tab does not exceed 60°C. Furthermore, according to the test data from Examples 15-20, the cathode electrode factor... Unchanged, anode electrode factor As the concentration of energy increases, the volumetric energy density of the battery cell gradually decreases; according to the test data of Examples 21-25, the anode electrode factor... Unchanged, cathode electrode factor As the number of cells gradually increases, the volumetric energy density of the battery cell gradually increases; according to the test data of Examples 26-30, the anode electrode factor... and cathode electrode factor Both are at their maximum values, and the volumetric energy density of the battery cell remains constant. As the design parameters Fc and Fa of the cathode tab and anode tab gradually increase, the maximum temperature at the root of both the cathode tab and anode tab gradually decreases.

[0126] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed.

[0127] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0128] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A cathode electrode, characterized in that, It includes a cathode current collector and a cathode active material layer disposed on at least one side of the cathode current collector; the cathode current collector includes a cathode body and at least one cathode tab disposed at one end of the cathode body; Wherein, the width of the root of a single cathode tab along the MD direction is m1 (mm); the thickness of the root of a single cathode tab is d1 (mm); the dimension between the central axes of two adjacent cathode tabs along the MD direction is b1 (mm); the conductivity of the cathode current collector is S1 (S / m); the width of the cathode active material layer along the TD direction is a1 (mm); and the unit area mass of the cathode active material layer is CW1 (g / 1540.25mm). 2 ; The design parameter for a single cathode tab is Fc. The unit is 15.4025 S·mm·g -1 The value of Fc satisfies Fc≧0.

1.

2. The cathode electrode according to claim 1, characterized in that, The design parameters of a single cathode tab shall satisfy Fc ≥ 0.

4.

3. The cathode electrode according to claim 1, characterized in that, The ratio of the unit area mass of the cathode active material layer to the thickness of the cathode current collector is used as the cathode electrode factor. The values ​​of the cathode electrode factor satisfy the following: This refers to the cathode electrode factor, measured in g / 1540.25mm. 3 .

4. The cathode electrode according to claim 1, characterized in that, 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 .

5. The cathode electrode according to claim 1, characterized in that, The cathode active material layer includes lithium iron phosphate material.

6. An anode electrode, characterized in that, It includes an anode current collector and an anode active material layer disposed on at least one side of the anode current collector; the anode current collector includes an anode body and at least one anode tab disposed at one end of the anode body; Wherein, the width of the root of a single anode tab along the MD direction is m2 (mm); the thickness of the root of a single anode tab is d2 (mm); the dimension between the central axes of two adjacent anode tabs along the MD direction is b2 (mm); the conductivity of the anode current collector is S2 (S / m); the width of the anode active material layer along the TD direction is a2 (mm); and the unit area mass of the anode active material layer is CW2 (g / 1540.25mm). 2 ; The design parameter for a single anode tab is Fa. The unit is 15.4025 S·mm·g -1 The value of Fa satisfies Fa≧0.

02.

7. The anode plate according to claim 6, characterized in that, The design parameters for a single anode tab shall satisfy: Fa ≥ 0.

1.

8. The anode plate according to claim 6, characterized in that, The ratio of the unit area mass of the anolyte active material layer to the thickness of the anolyte current collector is used as the anolyte electrode factor. The value of the anode electrode factor satisfies This refers to the anode electrode factor, measured in g / 1540.25mm. 3 .

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

10. A single battery cell, characterized in that, Includes the cathode electrode sheet according to any one of claims 1 to 5 and / or the anode electrode sheet according to any one of claims 6 to 9; Wherein, the design parameter value of a single cathode tab satisfies Fc≧0.1, and / or the design parameter value of a single anode tab satisfies Fa≧0.

02.

11. The battery cell according to claim 10, characterized in that, 0.4≦Fc≦75, 0.1≦Fa≦180; and And m1≥0.02mm; d1≦0.02mm, b1≦0.6mm, S1≥30S / m; a1≦0.3mm, 0.35g / 1540.25mm 2 ≦CW1≦0.5g / 1540.25mm 2 Furthermore, 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 .

12. The battery cell according to claim 10, characterized in that, The battery cell is a lithium iron phosphate secondary battery; the volumetric energy density of the battery cell is ≥300Wh / L; the battery cell is charged at 3C rate for 6 minutes at room temperature, and the maximum temperature at the root of the cathode tab and the root of the anode tab of the battery cell is ≤60℃.

13. A battery, characterized in that, It includes a housing and a plurality of battery cells as described in claim 10 located within the housing.

14. An electrical appliance, characterized in that, Includes the battery as described in claim 13.

Images