Battery cell and electric equipment

Abstract

The invention provides a battery cell and electric equipment, the battery cell comprises an electrode assembly with a winding structure, the electrode assembly comprises a positive pole piece and a negative pole piece, the positive pole piece comprises a positive pole main body, and a plurality of first positive pole tabs and a plurality of second positive pole tabs which are connected to the positive pole main body, the negative pole piece comprises a negative pole main body, and a plurality of first negative pole tabs and a plurality of second negative pole tabs which are connected to the negative pole main body, and the plurality of first positive pole tabs and the plurality of first negative pole tabs are positioned at one end of the electrode assembly along the winding axis direction of the electrode assembly; and the plurality of second positive electrode tabs and the plurality of second negative electrode tabs are positioned at the other end of the electrode assembly along the winding axis direction of the electrode assembly. Along the winding axis direction of the electrode assembly, the width of the negative electrode main body is W1 mm, the thickness of the first negative electrode tab is H1 mm, and 0.64 * 107 < = W12 / H1 < = 2.1 * 107. And the battery cell has relatively high rate capability, safety and long high-temperature cycle life.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more specifically, to a battery cell and an electrical device. Background Technology

[0002] Currently, with the rapid development of new energy technologies, battery cells have been widely used in electronic devices, electric vehicles, electric two-wheelers, power tools, and other fields. As the application of battery cells becomes more widespread, higher requirements are being placed on their safety performance. Summary of the Invention

[0003] This application provides a battery cell and an electrical device that can improve the safety, rate performance, and high-temperature cycle life of the battery cell.

[0004] In a first aspect, this application provides a battery cell comprising an electrode assembly with a wound structure. The electrode assembly includes a positive electrode and a negative electrode. The positive electrode includes a positive electrode body and a plurality of first positive electrode tabs and a plurality of second positive electrode tabs connected to the positive electrode body. The negative electrode includes a negative electrode body and a plurality of first negative electrode tabs and a plurality of second negative electrode tabs connected to the negative electrode body. The plurality of first positive electrode tabs and the plurality of first negative electrode tabs are located at one end of the electrode assembly along its winding axis, and the plurality of second positive electrode tabs and the plurality of second negative electrode tabs are located at the other end of the electrode assembly along its winding axis. Along the winding axis of the electrode assembly, the width of the negative electrode body is W1 mm, and the thickness of the first negative electrode tabs is H1 mm, 0.64 × 10⁻⁶ mm. 7 ≤W1 2 / H1≤2.1×10 7 .

[0005] In the above technical solution, by making the positive electrode plate include a positive electrode body and multiple first positive electrode tabs and multiple second positive electrode tabs connected to the positive electrode body, and the negative electrode plate include a negative electrode body and multiple first negative electrode tabs and multiple second negative electrode tabs connected to the negative electrode body, with the multiple first positive electrode tabs and multiple first negative electrode tabs located at one end of the electrode assembly along its winding axis, and the multiple second positive electrode tabs and multiple second negative electrode tabs located at the other end of the electrode assembly along its winding axis, it is possible to increase the number of first positive electrode tabs and second positive electrode tabs leading out from the positive electrode plate, thereby increasing the total current-carrying area of ​​the multiple first positive electrode tabs and multiple second positive electrode tabs. At the same time, it is possible to increase the number of first negative electrode tabs and second negative electrode tabs leading out from the negative electrode plate, thereby increasing the total current-carrying area of ​​the multiple first negative electrode tabs and multiple second negative electrode tabs. This improves the current-carrying capacity of the battery cell, improves the rate performance of the battery cell, and also helps to reduce the temperature rise of the battery cell, reduce the risk of thermal runaway of the battery cell, and improve the safety and high-temperature cycle life of the battery cell.

[0006] When W1 2 / H1 is greater than or equal to 0.64 × 10 7 This ensures that W1 is not too small, preventing the volume of the negative electrode active material layer from becoming too small, which is beneficial for improving the energy density of the battery cell; and / or, this ensures that H1 is not too large, reducing the space occupied by the first negative electrode tab, which is beneficial for improving the energy density of the battery cell; when W1 2 H1 is less than or equal to 2.1 × 10 7 This ensures that W1 is not too large, thus preventing the current flow path along the winding axis of the electrode assembly from becoming too large, thereby improving the rate performance of the battery cell; and / or, this ensures that H1 is not too small, preventing the current flow area of ​​the first negative electrode tab from becoming too small, thereby improving the current flow capability of the battery cell and improving its rate performance; therefore, when 0.64×10 7 ≤W1 2 / H1≤2.1×10 7 The battery cell has high energy density and rate performance. Furthermore, due to W1... 2 / H1 is positively correlated with the heat generated by the battery cell, by making 0.64×10 7 ≤W1 2 / H1≤2.1×10 7 This ensures that the heat generated by the battery cell is not excessive, which helps to reduce the temperature rise of the battery cell, reduce the risk of thermal runaway, and improve the safety and high-temperature cycle life of the battery cell.

[0007] In some embodiments of this application, 1.1 × 10 7 ≤W1 2 / H1≤1.7×10 7 .

[0008] In the above technical solution, when W1 2 / H1 is greater than or equal to 1.1 × 10 7 This further ensures that W1 is not too small, thus preventing the volume of the negative electrode active material layer from becoming too small, which is beneficial for further improving the energy density of the battery cell; and / or, this further ensures that H1 is not too large, reducing the space occupied by the first negative electrode tab, which is beneficial for further improving the energy density of the battery cell; when W1 2 / H1 is less than or equal to 1.7 × 10 7 This further ensures that W1 is not too large, further ensures that the current flow path along the winding axis of the electrode assembly is not too large, and further improves the rate performance of the cell; and / or, ensures that H1 is not too small, further ensures that the current flow area of ​​the first negative electrode tab is not too small, and can further improve the current flow capability of the cell, and further improve the rate performance of the cell; therefore, when 1.1×10 7 ≤W1 2 / H1≤1.7×10 7The battery cell has high energy density and rate performance. Furthermore, due to W1... 2 / H1 is positively correlated with the heat generation of the battery cell, by making 1.1×10 7 ≤W1 2 / H1≤1.7×10 7 This can further prevent the cell from generating excessive heat, which helps to further reduce the temperature rise of the cell, further reduce the risk of thermal runaway, and further improve the safety and high-temperature cycle life of the cell.

[0009] In some embodiments of this application, the number of first negative electrode tabs is N1, 0.8 × 10⁻⁶. 5 ≤W1 2 / (H1×N1)≤2.8×10 5 .

[0010] In the above technical solution, when W1 2 / (H1×N1) is greater than or equal to 0.8×10 5 This ensures that W1 is not too small, preventing the volume of the negative electrode active material layer from becoming too small, which is beneficial for improving the energy density of the battery cell; and / or, this ensures that H1×N1 is not too large, reducing the total space occupied by multiple first negative electrode tabs, which is beneficial for improving the energy density of the battery cell; when W1 2 / (H1×N1) is less than or equal to 2.8×10 5 This ensures that W1 is not too large, thus preventing the current flow path along the winding axis of the electrode assembly from becoming too large, thereby improving the rate performance of the battery cell; and / or, this ensures that H1×N1 is not too small, thus preventing the total current-carrying area of ​​the multiple first negative electrode tabs from becoming too small, thereby improving the current-carrying capacity of the battery cell and improving its rate performance; therefore, when 0.8×10 5 ≤W1 2 / (H1×N1)≤2.8×10 5 The battery cell has high energy density and rate performance. Furthermore, due to W1... 2 / (H1×N1) is positively correlated with the heat generation of the battery cell, by making 0.8×10 5 ≤W1 2 / (H1×N1)≤2.8×10 5 This ensures that the heat generated by the battery cell is not excessive, which helps to reduce the temperature rise of the battery cell, reduce the risk of thermal runaway, and improve the safety and high-temperature cycle life of the battery cell.

[0011] In some embodiments of this application, 1.5 × 10 5 ≤W1 2 / (H1×N1)≤2.3×10 5 .

[0012] In the above technical solution, when W1 2 / (H1×N1) is greater than or equal to 1.5×10 5 This further ensures that W1 is not too small, thus preventing the volume of the negative electrode active material layer from becoming too small, which is beneficial for further improving the energy density of the battery cell; and / or, it ensures that H1×N1 is not too large, thus reducing the total space occupied by multiple first negative electrode tabs, which is beneficial for further improving the energy density of the battery cell; when W1 2 / (H1×N1) is less than or equal to 2.3×10 5 This further ensures that W1 is not too large, further ensures that the current flow path along the winding axis of the electrode assembly is not too large, and thus further improves the rate performance of the cell; and / or, ensures that H1×N1 is not too small, further ensures that the total overcurrent area of ​​the multiple first negative electrode tabs is not too small, which can further improve the overcurrent capability of the cell and further improve the rate performance of the cell; therefore, when 1.5×10 5 ≤W1 2 / (H1×N1)≤2.3×10 5 The battery cell has high energy density and rate performance. Furthermore, due to W1... 2 / (H1×N1) is positively correlated with the heat generation of the battery cell, by making 1.5×10 5 ≤W1 2 / (H1×N1)≤2.3×10 5 This can further prevent the cell from generating excessive heat, which helps to further reduce the temperature rise of the cell, further reduce the risk of thermal runaway, and further improve the safety and high-temperature cycle life of the cell.

[0013] In some embodiments of this application, along the winding axis of the electrode assembly, the width of the positive electrode body is W2mm, and the thickness of the first positive electrode tab is H2mm, 1.7×10 6 ≤W2 2 / H2≤5.9×10 6 .

[0014] In the above technical solution, when W2 2 / H2 is greater than or equal to 1.7 × 10 6 This ensures that W2 is not too small, thus preventing the volume of the positive electrode active material layer from becoming too small, which is beneficial for improving the energy density of the battery cell; and / or, this ensures that H2 is not too large, reducing the space occupied by the first positive electrode tab, which is beneficial for improving the energy density of the battery cell; when W2 2 / H2 is less than or equal to 5.9 × 10 6This ensures that W2 is not too large, thus preventing the current flow path along the winding axis of the electrode assembly from becoming too large, thereby improving the rate performance of the cell; and / or, this ensures that H2 is not too small, preventing the current flow area of ​​the first positive electrode tab from becoming too small, thereby improving the current flow capability of the cell and improving its rate performance; therefore, when 1.7 × 10 6 ≤W2 2 / H2≤5.9×10 6 The battery cells possess high energy density and rate performance. Furthermore, due to W2... 2 H2 is positively correlated with the heat generated by the battery cell, by making 1.7×10 6 ≤W2 2 / H2≤5.9×10 6 This ensures that the heat generated by the battery cell is not excessive, which helps to reduce the temperature rise of the battery cell, reduce the risk of thermal runaway, and improve the safety and high-temperature cycle life of the battery cell.

[0015] In some embodiments of this application, 2.1 × 10 6 ≤W2 2 / H2≤4.2×10 6 .

[0016] In the above technical solution, when W2 2 / H2 is greater than or equal to 2.1 × 10 6 This further ensures that W2 is not too small, thus preventing the volume of the positive electrode active material layer from becoming too small, which is beneficial for further improving the energy density of the cell; and / or, this further ensures that H2 is not too large, reducing the space occupied by the first positive electrode tab, which is beneficial for further improving the energy density of the cell; when W2 2 / H2 is less than or equal to 4.2 × 10 6 This further ensures that W2 is not too large, further ensures that the current flow path along the winding axis of the electrode assembly is not too large, and further improves the rate performance of the cell; and / or, ensures that H2 is not too small, further ensures that the current flow area of ​​the first positive electrode tab is not too small, and can further improve the current flow capability of the cell, and further improve the rate performance of the cell; therefore, when 2.1×10 6 ≤W2 2 / H2≤4.2×10 6 The battery cells possess high energy density and rate performance. Furthermore, due to W2... 2 H2 is positively correlated with the heat generated by the battery cell, by making 2.1×10 6 ≤W2 2 / H2≤4.2×10 6This can further prevent the cell from generating excessive heat, which helps to further reduce the temperature rise of the cell, further reduce the risk of thermal runaway, and further improve the safety and high-temperature cycle life of the cell.

[0017] In some embodiments of this application, the number of first positive electrode tabs is N², 2.3 × 10⁻⁶. 4 ≤W2 2 / (H2×N2)≤8×10 4 .

[0018] In the above technical solution, when W2 2 / (H2×N2) is greater than or equal to 2.3×10 4 This ensures that W2 is not too small, preventing the volume of the positive electrode active material layer from becoming too small, which is beneficial for improving the energy density of the battery cell; and / or, it ensures that H2×N2 is not too large, reducing the total space occupied by multiple first positive electrode tabs, which is beneficial for improving the energy density of the battery cell; when W2 2 / (H2×N2) is less than or equal to 8×10 4 This ensures that W2 is not too large, thus preventing the current flow path along the winding axis of the electrode assembly from becoming too large, thereby improving the rate performance of the cell; and / or, it ensures that H2×N2 is not too small, thus preventing the total current-carrying area of ​​the multiple first positive electrode tabs from becoming too small, thereby improving the current-carrying capacity of the cell and improving its rate performance; therefore, when 2.3×10 4 ≤W2 2 / (H2×N2)≤8×10 4 The battery cells possess high energy density and rate performance. Furthermore, due to W2... 2 / (H2×N2) is positively correlated with the heat generation of the battery cell, by making 2.3×10 4 ≤W2 2 / (H2×N2)≤8×10 4 This ensures that the heat generated by the battery cell is not excessive, which helps to reduce the temperature rise of the battery cell, reduce the risk of thermal runaway, and improve the safety and high-temperature cycle life of the battery cell.

[0019] In some embodiments of this application, 2.8 × 10 4 ≤W2 2 / (H2×N2)≤5.7×10 4 .

[0020] In the above technical solution, when W2 2 / (H2×N2) is greater than or equal to 2.8×10 4This further ensures that W2 is not too small, thus preventing the volume of the positive electrode active material layer from becoming too small, which is beneficial for further improving the energy density of the battery cell; and / or, it ensures that H2×N2 is not too large, thus further reducing the total space occupied by multiple first positive electrode tabs, which is beneficial for further improving the energy density of the battery cell; when W2 2 / (H2×N2) is less than or equal to 2.8×10 4 This further ensures that W2 is not too large, further ensures that the current flow path along the winding axis of the electrode assembly is not too large, and further improves the rate performance of the cell; and / or, ensures that H2×N2 is not too small, further ensures that the total overcurrent area of ​​the multiple first positive electrode tabs is not too small, which can further improve the overcurrent capacity of the cell and further improve the rate performance of the cell; therefore, when 2.8×10 4 ≤W2 2 / (H2×N2)≤5.7×10 4 The battery cells possess high energy density and rate performance. Furthermore, due to W2... 2 / (H2×N2) is positively correlated with the heat generation of the battery cell, by making 2.8×10 4 ≤W2 2 / (H2×N2)≤5.7×10 4 This can further prevent the cell from generating excessive heat, which helps to further reduce the temperature rise of the cell, further reduce the risk of thermal runaway, and further improve the safety and high-temperature cycle life of the cell.

[0021] In some embodiments of this application, the electrode assembly includes a first straight region, a first bent region, a second straight region, and a second bent region connected end-to-end. The first straight region and the second straight region are disposed opposite each other along the thickness direction of the electrode assembly, and the first bent region and the second bent region are disposed opposite each other along the width direction of the electrode assembly. At least a portion of the first positive electrode tab is located in the first bent region, and at least a portion of the first negative electrode tab is located in the second bent region. At least a portion of the second positive electrode tab is located in the second bent region, and at least a portion of the second negative electrode tab is located in the first bent region.

[0022] In the above technical solution, by having at least a portion of the first positive electrode tab located in the first bending region and at least a portion of the first negative electrode tab located in the second bending region, and at least a portion of the second positive electrode tab located in the second bending region and at least a portion of the second negative electrode tab located in the first bending region, the tabs can utilize the space of the bending regions, thereby increasing the width of the first positive electrode tab, the first negative electrode tab, the second positive electrode tab, and the second negative electrode tab. This improves the current-carrying capacity of the first positive electrode tab, the first negative electrode tab, the second positive electrode tab, and the second negative electrode tab, enhances the rate performance of the battery cell, and also helps to reduce the temperature rise of the battery cell, reduce the risk of thermal runaway, and improve the safety and high-temperature cycle life of the battery cell.

[0023] In some embodiments of this application, along the winding direction of the electrode assembly, the first positive electrode tab includes a first portion, a second portion, and a third portion. The first portion is located in a first straight region, the second portion is located in a first bent region, and the third portion is located in a second straight region. The second portion connects the first portion and the third portion. Along the winding direction of the electrode assembly, the first negative electrode tab includes a fourth portion, a fifth portion, and a sixth portion. The fourth portion is located in the first straight region, the fifth portion is located in the second bent region, and the sixth portion is located in the second straight region. The fifth portion connects the fourth portion and the sixth portion.

[0024] In the above technical solution, by making the first positive electrode tab include a first part, a second part, and a third part, with the first part located in a first flat region, the second part located in a first bent region, and the third part located in a second flat region, and the second part connecting the first part and the third part; and the first negative electrode tab includes a fourth part, a fifth part, and a sixth part, with the fourth part located in the first flat region, the fifth part located in the second bent region, and the sixth part located in the second flat region, and the fifth part connecting the fourth part and the sixth part, the width of the first positive electrode tab and the first negative electrode tab can be further increased, thereby improving the current carrying capacity of the first positive electrode tab and the first negative electrode tab and improving the rate performance of the battery cell; and the first part located in the first flat region and the third part located in the second flat region are connected through the second part of the first bent region, and the fourth part located in the first flat region and the sixth part located in the second flat region are connected through the fifth part of the second bent region, the number of the first positive electrode tab and the first negative electrode tab can be reduced, improving the manufacturing efficiency of the battery cell, and having a smaller impact on the energy density of the battery cell.

[0025] In some embodiments of this application, the width of the first portion is equal to the width of the third portion along the width direction of the electrode assembly.

[0026] In the above technical solution, by making the width of the first part and the width of the third part equal, it is easy to retract and connect multiple first positive electrode tabs.

[0027] In some embodiments of this application, the width of the fourth portion and the width of the sixth portion are equal along the width direction of the electrode assembly.

[0028] In the above technical solution, by making the widths of the fourth and sixth parts equal, it is easy to retract and connect multiple first negative electrode tabs.

[0029] In some embodiments of this application, the electrode assembly further includes a separator disposed between the positive electrode and the negative electrode. Each positive electrode layer has a first positive electrode tab. Along the winding direction of the electrode assembly, and among the plurality of first positive electrode tabs, the maximum width of the first positive electrode tab closest to the winding start end of the positive electrode is A1 mm. From the winding center of the electrode assembly outward, the maximum width of the first positive electrode tab of the nth positive electrode layer is An mm. The thickness of the negative electrode is T1 mm, the thickness of the positive electrode is T2 mm, and the thickness of the separator is T3 mm. An = A1 + (n-1) × (T1 + T1 + 2 × T3) × σ1, where n is an integer greater than or equal to 2, and 3 ≤ σ1 ≤ 3.24.

[0030] In the above technical solution, by providing a first positive electrode tab for each positive electrode layer, the total current-carrying area of ​​the first positive electrode tab can be increased, thereby improving the current-carrying capacity of the battery cell, improving the rate performance of the battery cell, and also helping to reduce the temperature rise of the battery cell, reduce the risk of thermal runaway of the battery cell, and improve the safety and high-temperature cycle life of the battery cell.

[0031] By making An = A1 + (n-1) × (T1 + T1 + 2 × T3) × σ1, 3 ≤ σ1 ≤ 3.24, the second part of the first positive electrode tab in the first bending region is approximately semi-circular, that is, the part of each layer of positive electrode sheet in the first bending region is approximately semi-circular, making the transition of each layer of positive electrode sheet in the first bending region smoother. This helps to make the distance between the positive and negative electrode sheets of adjacent layers more uniform, reducing the risk of metal ion precipitation and improving the safety of the battery cell.

[0032] In some embodiments of this application, each negative electrode sheet is provided with a first negative electrode tab. Along the winding direction of the electrode assembly, and among the multiple first negative electrode tabs, the maximum width of the first negative electrode tab closest to the winding start end of the negative electrode sheet is B1 mm. From the winding center of the electrode assembly outward, the maximum width of the first negative electrode tab of the m-th negative electrode sheet is Bm mm, where Bm = B1 + (m-1) × (T1 + T1 + 2 × T3) × σ2, and m is an integer greater than or equal to 2, and 3 ≤ σ2 ≤ 3.24.

[0033] In the above technical solution, by providing a first negative electrode tab for each negative electrode layer, the total current-carrying area of ​​the first negative electrode tab can be increased, thereby improving the current-carrying capacity of the battery cell, improving the rate performance of the battery cell, and also helping to reduce the temperature rise of the battery cell, reduce the risk of thermal runaway of the battery cell, and improve the safety and high-temperature cycle life of the battery cell.

[0034] By making Bm = B1 + (m-1) × (T1 + T1 + 2 × T3) × σ2, 3 ≤ σ2 ≤ 3.24, the fifth part of the first negative electrode tab in the second bending region is approximately semi-circular. That is, the part of each negative electrode sheet in the second bending region is approximately semi-circular, making the transition of each negative electrode sheet in the second bending region smoother. This helps to make the distance between the positive and negative electrode sheets of adjacent layers more uniform, reducing the risk of metal ion precipitation and improving the safety of the battery cell.

[0035] In some embodiments of this application, the distance between any first positive electrode tab and any first negative electrode tab along the width direction of the electrode assembly is S mm, where 0 < S ≤ 20.

[0036] In the above technical solution, when S is greater than 0, the spacing between any first positive electrode tab and any first negative electrode tab will not be too small, which can reduce the risk of thermal runaway of the battery cell caused by short circuit between the first positive electrode tab and the first negative electrode tab, and improve the safety of the battery cell. When S is less than or equal to 20, the battery cell can have more space for setting the first positive electrode tab and / or the first negative electrode tab, so that the width of the first positive electrode tab and / or the first negative electrode tab along the winding direction of the electrode assembly will not be too small, which is beneficial to increasing the current-carrying area of ​​the first positive electrode tab and / or the first negative electrode tab, improving the current-carrying capacity of the battery cell, and improving the rate capability of the battery cell. Yes, it also helps to reduce the temperature rise of the battery cell, reduce the risk of thermal runaway, and improve the safety of the battery cell. Therefore, when 0 < S ≤ 20, it can not only reduce the risk of thermal runaway caused by short circuit between the first positive electrode and the first negative electrode, thus improving the safety of the battery cell, but also ensure that the width of the first positive electrode and / or the first negative electrode is not too small along the winding direction of the electrode assembly. This helps to increase the current-carrying area of ​​the first positive electrode and / or the first negative electrode, improve the current-carrying capacity of the battery cell, improve the rate performance of the battery cell, and also help to reduce the temperature rise of the battery cell, reduce the risk of thermal runaway, and improve the safety and high-temperature cycle life of the battery cell.

[0037] In some embodiments of this application, 5 ≤ S ≤ 10.

[0038] In the above technical solution, when S is greater than or equal to 5, the spacing between any first positive electrode tab and any first negative electrode tab will not be too small, further reducing the risk of thermal runaway of the battery cell caused by short circuit between the first positive electrode tab and the first negative electrode tab, and further improving the safety of the battery cell; when S is less than or equal to 10, the battery cell will have more space for setting the first positive electrode tab and / or the first negative electrode tab, ensuring that the width of the first positive electrode tab and / or the first negative electrode tab is not too small along the winding direction of the electrode assembly, which is beneficial to further increase the current-carrying area of ​​the first positive electrode tab and / or the first negative electrode tab, further improving the current-carrying capacity of the battery cell and increasing the battery cell's efficiency. In addition to improving rate performance, it also helps reduce the temperature rise of the battery cell, reduce the risk of thermal runaway, and further improve the safety of the battery cell. Therefore, when 5≤S≤10, it can further reduce the risk of thermal runaway caused by short circuit between the first positive electrode and the first negative electrode, further improving the safety of the battery cell. It can also ensure that the width of the first positive electrode and / or the first negative electrode is not too small along the winding direction of the electrode assembly, which is conducive to increasing the current-carrying area of ​​the first positive electrode and / or the first negative electrode, improving the current-carrying capacity of the battery cell, further improving the rate performance of the battery cell, and also helps reduce the temperature rise of the battery cell, reduce the risk of thermal runaway, and further improve the safety and high-temperature cycle life of the battery cell.

[0039] In some embodiments of this application, the battery cell further includes a first electrical connector, and a plurality of first negative electrode tabs converge along the thickness direction of the electrode assembly and connect to the first electrical connector. The thickness of the first electrical connector is C1 mm, and 60 ≤ C1 / H1 ≤ 150.

[0040] In the above technical solution, when C1 / H1 is greater than or equal to 60, the thickness of the first electrical connector is not too small, resulting in a strong current-carrying capacity of the first electrical connector, which improves the rate performance of the battery cell and helps reduce the temperature rise of the battery cell, reducing the risk of thermal runaway and improving the safety of the battery cell; and / or, the thickness of the first negative electrode tab is not too large, which reduces the space occupied by the first negative electrode tab and helps improve the energy density of the battery cell; when C1 / H1 is less than or equal to 150, the thickness of the first electrical connector is not too large, facilitating the bending of the first electrical connector and its connection with other components; and / or, the thickness of the first negative electrode tab is not too small, resulting in a strong current-carrying capacity of the first negative electrode tab, which improves the rate performance of the battery cell and helps reduce the temperature rise of the battery cell, reducing the risk of thermal runaway and improving the safety of the battery cell; therefore, when 60≤C1 / H1≤150, the battery cell has high safety and energy density. In some embodiments of this application, 70 ≤ C1 / H1 ≤ 120.

[0041] In the above technical solution, when C1 / H1 is greater than or equal to 70, the thickness of the first electrical connector is not too small, resulting in a stronger current-carrying capacity of the first electrical connector, which further improves the rate performance of the battery cell and helps reduce the temperature rise of the battery cell, reducing the risk of thermal runaway and further improving the safety of the battery cell; and / or, the thickness of the first negative electrode tab is not too large, reducing the space occupied by the first negative electrode tab and helping to further improve the energy density of the battery cell; when C1 / H1 is less than or equal to 120, the thickness of the first electrical connector is not too large, facilitating the bending of the first electrical connector and its connection with other components; and / or, the thickness of the first negative electrode tab is not too small, resulting in a stronger current-carrying capacity of the first negative electrode tab, improving the rate performance of the battery cell, reducing the temperature rise of the battery cell, reducing the risk of thermal runaway and further improving the safety of the battery cell; therefore, when 70≤C1 / H1≤120, the battery cell has high safety and energy density. In some embodiments of this application, the battery cell further includes a second electrical connector, and a plurality of first positive electrode tabs converge along the thickness direction of the electrode assembly and are connected to the second electrical connector; the thickness of the first positive electrode tabs is H2 mm, the thickness of the second electrical connector is C2 mm, and 30≤C2 / H2≤80.

[0042] In the above technical solution, when C2 / H2 is greater than or equal to 30, the thickness of the second electrical connector is not too small, resulting in a strong current-carrying capacity of the second electrical connector, which improves the rate performance of the battery cell and helps reduce the temperature rise of the battery cell, reducing the risk of thermal runaway and improving the safety of the battery cell; and / or, the thickness of the first positive electrode tab is not too large, which reduces the space occupied by the first positive electrode tab and helps improve the energy density of the battery cell; when C2 / H2 is less than or equal to 80, the thickness of the second electrical connector is not too large, facilitating the bending of the second electrical connector and its connection with other components; and / or, the thickness of the first positive electrode tab is not too small, resulting in a strong current-carrying capacity of the first positive electrode tab, which improves the rate performance of the battery cell and helps reduce the temperature rise of the battery cell, reducing the risk of thermal runaway and improving the safety of the battery cell; therefore, when 30≤C2 / H2≤80, the battery cell has high safety and energy density. In some embodiments of this application, 40 ≤ C2 / H2 ≤ 62.

[0043] In the above technical solution, when C2 / H2 is greater than or equal to 40, the thickness of the second electrical connector is not too small, resulting in a stronger current-carrying capacity of the second electrical connector, which further improves the rate performance of the battery cell and helps reduce the temperature rise of the battery cell, reducing the risk of thermal runaway and further improving the safety of the battery cell; and / or, the thickness of the first positive electrode tab is not too large, reducing the space occupied by the first positive electrode tab and further improving the energy density of the battery cell; when C2 / H2 is less than or equal to 62, the thickness of the second electrical connector is not too large, facilitating the bending of the second electrical connector and its connection with other components; and / or, the thickness of the first positive electrode tab is not too small, resulting in a stronger current-carrying capacity of the first positive electrode tab, improving the rate performance of the battery cell, reducing the temperature rise of the battery cell, reducing the risk of thermal runaway and further improving the safety of the battery cell; therefore, when 40≤C2 / H2≤62, the battery cell has high safety and energy density.

[0044] In some embodiments of this application, the width of the electrode assembly is W0 mm, the maximum width of the first positive electrode tab is A mm, and 1 < W0 / A ≤ 5.

[0045] In the above technical solution, when W0 / A is greater than 1, W0 will not be too small, which allows for a larger capacity of the battery cell, thus improving its range; and / or, A will not be too large, which reduces the wind direction that could cause a short circuit between the first positive electrode and the first negative electrode, thus improving the safety of the battery cell; when W0 / A is less than or equal to 5, W0 will not be too large, which prevents the current path along the winding axis of the electrode assembly from becoming too large, thus improving the rate performance of the battery cell; and / or, A will not be too small, which prevents the current-carrying area of ​​the first positive electrode from becoming too small, thus improving the current-carrying capacity and rate performance of the battery cell; therefore, when 1 < W0 / A ≤ 5, the battery cell has good range, high safety, and high rate performance.

[0046] In some embodiments of this application, 1 < W0 / A ≤ 2.

[0047] In the above technical solution, when W0 / A is greater than 1, W0 will not be too small, which allows for a larger capacity of the battery cell and improves its range; and / or, A will not be too large, which reduces the wind direction that could cause a short circuit between the first positive electrode and the first negative electrode, thus improving the safety of the battery cell; when W0 / A is less than or equal to 2, W0 will not be too large, further ensuring that the current path along the winding axis of the electrode assembly is not too large, thus further improving the rate performance of the battery cell; and / or, A will not be too small, ensuring that the current-carrying area of ​​the first positive electrode is not too small, thus further improving the current-carrying capacity of the battery cell and further improving its rate performance; therefore, when 1 < W0 / A ≤ 2, the battery cell has good range, high safety, and high rate performance.

[0048] In some embodiments of this application, the maximum width of the first negative electrode tab is B mm, and 1 < W0 / B ≤ 5.

[0049] In the above technical solution, when W0 / B is greater than 1, W0 will not be too small, which allows for a larger capacity of the battery cell and improves its range; and / or, B will not be too large, which reduces the wind direction that could cause a short circuit between the first positive electrode and the first negative electrode, thus improving the safety of the battery cell; when W0 / B is less than or equal to 5, W0 will not be too large, which prevents the current path along the winding axis of the electrode assembly from becoming too large, thus improving the rate performance of the battery cell; and / or, B will not be too small, which prevents the current-carrying area of ​​the first negative electrode from becoming too small, thus improving the current-carrying capacity and rate performance of the battery cell; therefore, when 1 < W0 / B ≤ 5, the battery cell has good range, high safety, and high rate performance.

[0050] In some embodiments of this application, 1 < W0 / B ≤ 4.

[0051] In the above technical solution, when W0 / B is greater than 1, W0 will not be too small, which allows for a larger capacity of the battery cell and improves its range; and / or, B will not be too large, which reduces the wind direction that could cause a short circuit between the first positive electrode and the first negative electrode, thus improving the safety of the battery cell; when W0 / B is less than or equal to 4, W0 will not be too large, further ensuring that the current path along the winding axis of the electrode assembly is not too large, thus further improving the rate performance of the battery cell; and / or, B will not be too small, ensuring that the current-carrying area of ​​the first negative electrode is not too small, thus further improving the current-carrying capacity of the battery cell and further improving its rate performance; therefore, when 1 < W0 / B ≤ 4, the battery cell has good range, high safety, and high rate performance.

[0052] Secondly, this application provides an electrical device including a battery cell as described above, the battery cell being used to provide electrical energy. Attached Figure Description

[0053] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings.

[0054] Figure 1 A three-dimensional structural schematic diagram of a battery cell provided in some embodiments of this application; Figure 2 This is a schematic diagram of the electrode assembly of a battery cell provided in some embodiments of this application; Figure 3 This is a schematic diagram of a partial structure of a battery cell provided in some embodiments of this application; Figure 4 A schematic diagram of the unfolded structure of the positive electrode sheet of a battery cell provided in some embodiments of this application; Figure 5 A schematic diagram of the unfolded negative electrode sheet of a battery cell provided in some embodiments of this application; Figure 6 This is a schematic diagram of a partial structure of a battery cell provided in some embodiments of this application.

[0055] Icons: 10-Battery cell; 100-Electrode assembly; 101-First straight region; 102-First bending region; 103-Second straight region; 104-Second bending region; 110-Positive electrode sheet; 111-Positive electrode body; 112-First positive electrode tab; 1121-First part; 1122-Second part; 1123-Third part; 113-Second positive electrode tab; 120-Negative electrode sheet; 121-Negative electrode body; 1 22-First negative electrode tab; 1221-Fourth part; 1222-Fifth part; 1223-Sixth part; 123-Second negative electrode tab; 130-Separating membrane; 200-Outer shell; 310-First electrical connector; 320-Second electrical connector; 330-Third electrical connector; 340-Fourth electrical connector; X-Wound axis direction of the electrode assembly; Y-Thickness direction of the electrode assembly; Z-Width direction of the electrode assembly. Detailed Implementation

[0056] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0057] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the specification of this application 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.

[0058] The terms "first," "second," etc., in the specification, claims, or the accompanying drawings of this application are used to distinguish different objects, rather than to describe a specific order or primary / secondary relationship.

[0059] In this application, the reference to "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 in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0060] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0061] With the development of the new energy industry, batteries are gradually moving towards higher energy density and higher power density, and the requirements for battery safety are becoming increasingly stringent. In a battery cell, the positive and negative electrodes are typically led out through positive and negative tabs to achieve electrical connection between the cell and the load. Currently, the positive and negative tabs are only led out on one side of the cell, resulting in a limited number of tabs and a smaller total current-carrying area. This affects the cell's current-carrying capacity, and consequently, its rate performance and high-temperature cycle life.

[0062] To improve the safety of the battery cell, this application provides a battery cell including an electrode assembly with a wound structure. The electrode assembly includes a positive electrode plate and a negative electrode plate. The positive electrode plate includes a positive electrode body and a plurality of first positive electrode tabs and a plurality of second positive electrode tabs connected to the positive electrode body. The negative electrode plate includes a negative electrode body and a plurality of first negative electrode tabs and a plurality of second negative electrode tabs connected to the negative electrode body. The plurality of first positive electrode tabs and the plurality of first negative electrode tabs are located at one end of the electrode assembly along its winding axis, and the plurality of second positive electrode tabs and the plurality of second negative electrode tabs are located at the other end of the electrode assembly along its winding axis. Along the winding axis of the electrode assembly, the width of the negative electrode body is W1 mm, and the thickness of the first negative electrode tabs is H1 mm, 0.64 × 10⁻⁶ mm. 7≤W1 2 / H1≤2.1×10 7 .

[0063] In this type of battery cell structure, by having the positive electrode plate include a positive electrode body and multiple first positive electrode tabs and multiple second positive electrode tabs connected to the positive electrode body, and the negative electrode plate include a negative electrode body and multiple first negative electrode tabs and multiple second negative electrode tabs connected to the negative electrode body, the multiple first positive electrode tabs and multiple first negative electrode tabs are located at one end of the electrode assembly along its winding axis, and the multiple second positive electrode tabs and multiple second negative electrode tabs are located at the other end of the electrode assembly along its winding axis, it is possible to increase the number of first positive electrode tabs and second positive electrode tabs leading out from the positive electrode plate, thereby increasing the total current-carrying area of ​​the multiple first positive electrode tabs and multiple second positive electrode tabs, and also to increase the number of first negative electrode tabs and multiple second negative electrode tabs leading out from the negative electrode plate, thereby increasing the total current-carrying area of ​​the multiple first negative electrode tabs and multiple second negative electrode tabs, thus improving the current-carrying capacity of the battery cell, improving the rate performance of the battery cell, and also helping to reduce the temperature rise of the battery cell, reduce the risk of thermal runaway of the battery cell, and improve the safety and high-temperature cycle life of the battery cell.

[0064] When W1 2 / H1 is greater than or equal to 0.64 × 10 7 This ensures that W1 is not too small, preventing the volume of the negative electrode active material layer from becoming too small, which is beneficial for improving the energy density of the battery cell; and / or, this ensures that H1 is not too large, reducing the space occupied by the first negative electrode tab, which is beneficial for improving the energy density of the battery cell; when W1 2 H1 is less than or equal to 2.1 × 10 7 This ensures that W1 is not too large, thus preventing the current flow path along the winding axis of the electrode assembly from becoming too large, thereby improving the rate performance of the battery cell; and / or, this ensures that H1 is not too small, preventing the current flow area of ​​the first negative electrode tab from becoming too small, thereby improving the current flow capability of the battery cell and improving its rate performance; therefore, when 0.64×10 7 ≤W1 2 / H1≤2.1×10 7 The battery cell has high energy density and rate performance. Furthermore, due to W1... 2 / H1 is positively correlated with the heat generated by the battery cell, by making 0.64×10 7 ≤W1 2 / H1≤2.1×10 7 This ensures that the heat generated by the battery cell is not excessive, which helps to reduce the temperature rise of the battery cell, reduce the risk of thermal runaway, and improve the safety and high-temperature cycle life of the battery cell.

[0065] The battery cell provided in this application embodiment can be a secondary battery, such as a lithium-ion battery, sodium-ion battery, or magnesium-ion battery, etc., and this application embodiment is not limited in this respect. The battery cell can be cylindrical, flat, cuboid, or other shapes, etc., and this application embodiment is not limited in this respect either.

[0066] This application provides an electrical device that uses battery cells as a power source. The electrical device can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc.

[0067] See Figure 1 and Figure 2 , Figure 1 A three-dimensional structural schematic diagram of a battery cell provided in some embodiments of this application; Figure 2 This is a schematic diagram of the electrode assembly of a battery cell provided in some embodiments of this application.

[0068] This application provides a battery cell 10, which includes an electrode assembly 100, a housing 200, and an electrolyte. The electrode assembly 100 and the electrolyte are housed within the housing 200. The electrode assembly 100 includes a positive electrode 110, a negative electrode 120, and a separator 130. The battery cell 10 primarily operates by the movement of metal ions between the positive electrode 110 and the negative electrode 120. The positive electrode 110 includes a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive current collector, and the portion of the positive current collector not coated with the positive active material layer serves as a positive electrode tab, through which electrical energy is input or output to the positive electrode 110. Taking a lithium-ion battery as an example, the material of the positive current collector can be aluminum, and the positive active material can be lithium cobalt oxide, lithium iron phosphate, ternary materials (such as lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, etc.), or lithium manganese oxide, etc. The negative electrode 120 includes a negative current collector and a negative active material layer. The negative active material layer is coated on the surface of the negative current collector, and the portion of the negative current collector not coated with the negative active material layer serves as a negative electrode tab, through which electrical energy is input or output from the negative electrode 120. The material of the negative current collector can be copper, and the negative active material can be carbon or silicon, etc. The separator 130 can be made of polypropylene (PP) or polyethylene (PE), etc. The electrolyte can include organic solvents, lithium salts, etc.

[0069] In some embodiments, the housing 200 can be made of a high-strength rigid material, such as metal materials like steel or aluminum alloy, or non-metallic materials like carbon fiber or rigid plastic.

[0070] In other embodiments, the outer shell 200 may also be a packaging bag made of flexible materials, such as aluminum-plastic film, steel-plastic film, etc.

[0071] See also Figures 3 to 5, Figure 3 This is a schematic diagram of a partial structure of a battery cell provided in some embodiments of this application; Figure 4 A schematic diagram of the unfolded structure of the positive electrode sheet of a battery cell provided in some embodiments of this application; Figure 5 This is a schematic diagram of the unfolded structure of the negative electrode sheet of a battery cell provided in some embodiments of this application.

[0072] In some embodiments, the battery cell 10 includes an electrode assembly 100 with a wound structure. The electrode assembly 100 includes a positive electrode 110 and a negative electrode 120. The positive electrode 110 includes a positive electrode body 111 and a plurality of first positive electrode tabs 112 and a plurality of second positive electrode tabs 113 connected to the positive electrode body 111. The negative electrode 120 includes a negative electrode body 121 and a plurality of first negative electrode tabs 122 and a plurality of second negative electrode tabs 123 connected to the negative electrode body 121. The plurality of first positive electrode tabs 112 and the plurality of first negative electrode tabs 122 are located at one end of the electrode assembly 100 along its winding axis direction X, and the plurality of second positive electrode tabs 113 and the plurality of second negative electrode tabs 123 are located at the other end of the electrode assembly 100 along its winding axis direction X.

[0073] By making the positive electrode 110 include a positive electrode body 111 and a plurality of first positive electrode tabs 112 and a plurality of second positive electrode tabs 113 connected to the positive electrode body 111, and the negative electrode 120 includes a negative electrode body 121 and a plurality of first negative electrode tabs 122 and a plurality of second negative electrode tabs 123 connected to the negative electrode body 121, with the plurality of first positive electrode tabs 112 and the plurality of first negative electrode tabs 122 located at one end of the electrode assembly 100 along its winding axis direction X, and the plurality of second positive electrode tabs 113 and the plurality of second negative electrode tabs 123 located at the other end of the electrode assembly 100 along its winding axis direction X, it is possible to make the positive electrode... The electrode 110 has a large number of first positive electrode tabs 112 and second positive electrode tabs 113, which increases the total current-carrying area of ​​the multiple first positive electrode tabs 112 and multiple second positive electrode tabs 113. This results in a large number of first negative electrode tabs 122 and second negative electrode tabs 123 drawn from the negative electrode 120, which also increases the total current-carrying area of ​​the multiple first negative electrode tabs 122 and multiple second negative electrode tabs 123. This improves the current-carrying capacity of the cell 10, improves the rate performance of the cell 10, and also helps to reduce the temperature rise of the cell 10, reduce the risk of thermal runaway of the cell 10, and improve the safety and high-temperature cycle life of the cell 10.

[0074] See Figure 5 In some embodiments, along the winding axis X of the electrode assembly, the width of the negative electrode body 121 is W1 mm, and the thickness of the first negative electrode tab 122 is H1 mm, 0.64 × 10⁻⁶ mm. 7 ≤W1 2 / H1≤2.1×10 7 For example, W12 / H1 can be 0.64×10 7 0.65×10 7 0.7×10 7 0.9×10 7 1×10 7 1.2×10 7 1.5×10 7 1.8×10 7 2×10 7 Or 2.1×10 7 etc., or a range consisting of any two of these values.

[0075] When W1 2 / H1 is greater than or equal to 0.64 × 10 7 This ensures that W1 is not too small, thus preventing the volume of the negative electrode active material layer from becoming too small, which is beneficial for improving the energy density of the cell 10; and / or, this ensures that H1 is not too large, reducing the space occupied by the first negative electrode tab 122, which is beneficial for improving the energy density of the cell 10; when W1 2 H1 is less than or equal to 2.1 × 10 7 This ensures that W1 is not too large, thus preventing the current path along the winding axis X of the electrode assembly from becoming too large, thereby improving the rate performance of the cell 10; and / or, this ensures that H1 is not too small, preventing the current-carrying area of ​​the first negative electrode tab 122 from becoming too small, thereby improving the current-carrying capacity of the cell 10 and improving its rate performance; therefore, when 0.64 × 10 7 ≤W1 2 / H1≤2.1×10 7 Cell 10 has high energy density and rate performance. Furthermore, due to W1... 2 / H1 is positively correlated with the heat generation of cell 10, by making 0.64×10 7 ≤W1 2 / H1≤2.1×10 7 This ensures that the heat generated by the battery cell 10 is not excessive, which helps to reduce the temperature rise of the battery cell 10, reduce the risk of thermal runaway of the battery cell 10, and improve the safety and high-temperature cycle life of the battery cell 10.

[0076] In some embodiments, 1.1 × 10 7 ≤W1 2 / H1≤1.7×10 7 For example, W1 2 / H1 can be 1.1 × 10 7 1.15×10 7 1.2×10 7 1.25×10 71.3×10 7 1.35×10 7 1.4×10 7 1.45×10 7 1.5×10 7 1.55×10 7 1.6×10 7 1.65×10 7 Or 1.7×10 7 etc., or a range consisting of any two of these values.

[0077] When W1 2 / H1 is greater than or equal to 1.1 × 10 7 This further ensures that W1 is not too small, thus preventing the volume of the negative electrode active material layer from becoming too small, which is beneficial for further improving the energy density of the cell 10; and / or, this further ensures that H1 is not too large, reducing the space occupied by the first negative electrode tab 122, which is beneficial for further improving the energy density of the cell 10; when W1 2 / H1 is less than or equal to 1.7 × 10 7 This further ensures that W1 is not too large, further ensures that the current flow path along the winding axis X of the electrode assembly is not too large, and further improves the rate performance of the cell 10; and / or, ensures that H1 is not too small, further ensures that the current flow area of ​​the first negative electrode tab 122 is not too small, and further improves the current flow capability of the cell 10, and further improves the rate performance of the cell 10; therefore, when 1.1×10 7 ≤W1 2 / H1≤1.7×10 7 Cell 10 has high energy density and rate performance. Furthermore, due to W1... 2 / H1 is positively correlated with the heat generation of cell 10, by making 1.1×10 7 ≤W1 2 / H1≤1.7×10 7 This will further prevent the heat generated by the battery cell 10 from becoming excessive, which will help to further reduce the temperature rise of the battery cell 10, further reduce the risk of thermal runaway of the battery cell 10, and further improve the safety and high-temperature cycle life of the battery cell 10.

[0078] In some embodiments, the number of first negative electrode tabs 122 is N1, 0.8 × 10⁻⁶. 5 ≤W1 2 / (H1×N1)≤2.8×10 5 For example, W1 2 / (H1×N1) can be 0.8×10 5 1×10 5 1.2×105 1.5×10 5 1.8×10 5 2×10 5 2.2×10 5 2.5×10 5 Or 2.8×10 5 etc., or a range consisting of any two of these values.

[0079] When W1 2 / (H1×N1) is greater than or equal to 0.8×10 5 This ensures that W1 is not too small, preventing the volume of the negative electrode active material layer from becoming too small, which is beneficial for improving the energy density of the cell 10; and / or, this ensures that H1×N1 is not too large, reducing the total space occupied by the multiple first negative electrode tabs 122, which is beneficial for improving the energy density of the cell 10; when W1 2 / (H1×N1) is less than or equal to 2.8×10 5 This ensures that W1 is not too large, thus preventing the current flow path along the winding axis X of the electrode assembly from becoming too large, thereby improving the rate performance of the cell 10; and / or, this ensures that H1×N1 is not too small, thus preventing the total current flow area of ​​the multiple first negative electrode tabs 122 from becoming too small, thereby improving the current flow capability of the cell 10 and improving its rate performance; therefore, when 0.8×10 5 ≤W1 2 / (H1×N1)≤2.8×10 5 Cell 10 has high energy density and rate performance. Furthermore, due to W1... 2 / (H1×N1) is positively correlated with the heat generation of cell 10, by making 0.8×10 5 ≤W1 2 / (H1×N1)≤2.8×10 5 This ensures that the heat generated by the battery cell 10 is not excessive, which helps to reduce the temperature rise of the battery cell 10, reduce the risk of thermal runaway of the battery cell 10, and improve the safety and high-temperature cycle life of the battery cell 10.

[0080] In some embodiments, 1.5 × 10 5 ≤W1 2 / (H1×N1)≤2.3×10 5 For example, W1 2 / (H1×N1) can be 1.5×10 5 1.6×10 5 1.7×10 5 1.8×10 5 1.9×10 5 2×10 5 2.1×105 2.2×10 5 Or 2.3×10 5 etc., or a range consisting of any two of these values.

[0081] When W1 2 / (H1×N1) is greater than or equal to 1.5×10 5 This further ensures that W1 is not too small, thus preventing the volume of the negative electrode active material layer from becoming too small, which is beneficial for further improving the energy density of the cell 10; and / or, it ensures that H1×N1 is not too large, thus further reducing the total space occupied by the multiple first negative electrode tabs 122, which is beneficial for further improving the energy density of the cell 10; when W1 2 / (H1×N1) is less than or equal to 2.3×10 5 This further ensures that W1 is not too large, further ensures that the current flow path along the winding axis X of the electrode assembly is not too large, and further improves the rate performance of the cell 10; and / or, ensures that H1×N1 is not too small, further ensures that the total overcurrent area of ​​the multiple first negative electrode tabs 122 is not too small, and can further improve the overcurrent capability of the cell 10, and further improve the rate performance of the cell 10; therefore, when 1.5×10 5 ≤W1 2 / (H1×N1)≤2.3×10 5 Cell 10 has high energy density and rate performance. Furthermore, due to W1... 2 / (H1×N1) is positively correlated with the heat generation of cell 10, by making 1.5×10 5 ≤W1 2 / (H1×N1)≤2.3×10 5 This will further prevent the heat generated by the battery cell 10 from becoming excessive, which will help to further reduce the temperature rise of the battery cell 10, further reduce the risk of thermal runaway of the battery cell 10, and further improve the safety and high-temperature cycle life of the battery cell 10.

[0082] See Figure 4 In some embodiments, along the winding axis X of the electrode assembly, the width of the positive electrode body 111 is W2 mm, and the thickness of the first positive electrode tab 112 is H2 mm, 1.7 × 10⁻⁶ mm. 6 ≤W2 2 / H2≤5.9×10 6 For example, W2 2 / H2 can be 1.7 × 10 6 2×10 6 2.5×10 6 3×10 6 3.5×10 6 4×106 4.5×10 6 5×10 6 5.5×10 6 Or 5.9×10 6 etc., or a range consisting of any two of these values.

[0083] When W2 2 / H2 is greater than or equal to 1.7 × 10 6 This ensures that W2 is not too small, thus preventing the volume of the positive electrode active material layer from becoming too small, which is beneficial for improving the energy density of the cell 10; and / or, this ensures that H2 is not too large, reducing the space occupied by the first positive electrode tab 112, which is beneficial for improving the energy density of the cell 10; when W2 2 / H2 is less than or equal to 5.9 × 10 6 This ensures that W2 is not too large, thus preventing the current flow path along the winding axis X of the electrode assembly from becoming too large, thereby improving the rate performance of the cell 10; and / or, this ensures that H2 is not too small, preventing the current flow area of ​​the first positive electrode tab 112 from becoming too small, thereby improving the current flow capability of the cell 10 and improving its rate performance; therefore, when 1.7 × 10 6 ≤W2 2 / H2≤5.9×10 6 Cell 10 has high energy density and rate performance. Furthermore, due to W2... 2 H2 is positively correlated with the heat generation of cell 10, by making 1.7×10 6 ≤W2 2 / H2≤5.9×10 6 This ensures that the heat generated by the battery cell 10 is not excessive, which helps to reduce the temperature rise of the battery cell 10, reduce the risk of thermal runaway of the battery cell 10, and improve the safety and high-temperature cycle life of the battery cell 10.

[0084] In some embodiments, 2.1 × 10 6 ≤W2 2 / H2≤4.2×10 6 For example, W2 2 / H2 can be 2.1 × 10 6 2.3×10 6 2.5×10 6 2.7×10 6 2.9×10 6 3×10 6 3.2×10 6 3.5×10 6 3.8×10 6 4×10 6 Or 4.2×10 6etc., or a range consisting of any two of these values.

[0085] When W2 2 / H2 is greater than or equal to 2.1 × 10 6 This further ensures that W2 is not too small, thus ensuring that the volume of the positive electrode active material layer is not too small, which is beneficial to further improving the energy density of the cell 10; and / or, this further ensures that H2 is not too large, thus reducing the space occupied by the first positive electrode tab 112, which is beneficial to further improving the energy density of the cell 10; when W2 2 / H2 is less than or equal to 4.2 × 10 6 This further ensures that W2 is not too large, further ensures that the current flow path along the winding axis X of the electrode assembly is not too large, and further improves the rate performance of the cell 10; and / or, ensures that H2 is not too small, further ensures that the current flow area of ​​the first positive electrode tab 112 is not too small, and further improves the current flow capability of the cell 10, and further improves the rate performance of the cell 10; therefore, when 2.1 × 10 6 ≤W2 2 / H2≤4.2×10 6 Cell 10 has high energy density and rate performance. Furthermore, due to W2... 2 H2 is positively correlated with the heat generation of cell 10, by making 2.1×10 6 ≤W2 2 / H2≤4.2×10 6 This will further prevent the heat generated by the battery cell 10 from becoming excessive, which will help to further reduce the temperature rise of the battery cell 10, further reduce the risk of thermal runaway of the battery cell 10, and further improve the safety and high-temperature cycle life of the battery cell 10.

[0086] In some embodiments, the number of first positive electrode tabs 112 is N², 2.3 × 10⁻⁶. 4 ≤W2 2 / (H2×N2)≤8×10 4 For example, W2 2 / (H2×N2) can be 2.3×10 4 2.5×10 4 3×10 4 3.5×10 4 4×10 4 4.5×10 4 5×10 4 5.5×10 4 6×10 4 6.5×10 4 7×10 4 7.5×10 4 Or 8×104 etc., or a range consisting of any two of these values.

[0087] When W2 2 / (H2×N2) is greater than or equal to 2.3×10 4 This ensures that W2 is not too small, preventing the volume of the positive electrode active material layer from becoming too small, which is beneficial for improving the energy density of the cell 10; and / or, this ensures that H2×N2 is not too large, reducing the total space occupied by the multiple first positive electrode tabs 112, which is beneficial for improving the energy density of the cell 10; when W2 2 / (H2×N2) is less than or equal to 8×10 4 This ensures that W2 is not too large, thus preventing the current flow path along the winding axis X of the electrode assembly from becoming too large, thereby improving the rate performance of the cell 10; and / or, this ensures that H2×N2 is not too small, thus preventing the total current flow area of ​​the multiple first positive electrode tabs 112 from becoming too small, thereby improving the current flow capability of the cell 10 and improving its rate performance; therefore, when 2.3×10 4 ≤W2 2 / (H2×N2)≤8×10 4 Cell 10 has high energy density and rate performance. Furthermore, due to W2... 2 / (H2×N2) is positively correlated with the heat generation of cell 10, by making 2.3×10 4 ≤W2 2 / (H2×N2)≤8×10 4 This ensures that the heat generated by the battery cell 10 is not excessive, which helps to reduce the temperature rise of the battery cell 10, reduce the risk of thermal runaway of the battery cell 10, and improve the safety and high-temperature cycle life of the battery cell 10.

[0088] In some embodiments, 2.8 × 10 4 ≤W2 2 / (H2×N2)≤5.7×10 4 For example, W2 2 / (H2×N2) can be 2.8×10 4 3×10 4 3.2×10 4 3.5×10 4 3.7×10 4 4×10 4 4.2×10 4 4.5×10 4 4.8×10 4 5×10 4 5.3×10 4 5.5×10 4 Or 5.7×10 4etc., or a range consisting of any two of these values.

[0089] When W2 2 / (H2×N2) is greater than or equal to 2.8×10 4 This further ensures that W2 is not too small, thus preventing the volume of the positive electrode active material layer from becoming too small, which is beneficial for further improving the energy density of the cell 10; and / or, it ensures that H2×N2 is not too large, thus further reducing the total space occupied by the multiple first positive electrode tabs 112, which is beneficial for further improving the energy density of the cell 10; when W2 2 / (H2×N2) is less than or equal to 2.8×10 4 This further ensures that W2 is not too large, further ensures that the current flow path along the winding axis X of the electrode assembly is not too large, and further improves the rate performance of the cell 10; and / or, ensures that H2×N2 is not too small, further ensures that the total current flow area of ​​the multiple first positive electrode tabs 112 is not too small, and can further improve the current flow capability of the cell 10, and further improve the rate performance of the cell 10; therefore, when 2.8×10 4 ≤W2 2 / (H2×N2)≤5.7×10 4 Cell 10 has high energy density and rate performance. Furthermore, due to W2... 2 / (H2×N2) is positively correlated with the heat generation of cell 10, by making 2.8×10 4 ≤W2 2 / (H2×N2)≤5.7×10 4 This will further prevent the heat generated by the battery cell 10 from becoming excessive, which will help to further reduce the temperature rise of the battery cell 10, further reduce the risk of thermal runaway of the battery cell 10, and further improve the safety and high-temperature cycle life of the battery cell 10.

[0090] In some embodiments, the electrode assembly 100 includes a first straight region 101, a first bent region 102, a second straight region 103, and a second bent region 104 connected end-to-end. The first straight region 101 and the second straight region 103 are disposed opposite each other along the thickness direction Y of the electrode assembly, and the first bent region 102 and the second bent region 104 are disposed opposite each other along the width direction Z of the electrode assembly. At least a portion of the first positive electrode tab 112 is located in the first bent region 102, and at least a portion of the first negative electrode tab 122 is located in the second bent region 104. At least a portion of the second positive electrode tab 113 is located in the second bent region 104, and at least a portion of the second negative electrode tab 123 is located in the first bent region 102.

[0091] By positioning at least a portion of the first positive electrode tab 112 in the first bending region 102 and at least a portion of the first negative electrode tab 122 in the second bending region 104, and at least a portion of the second positive electrode tab 113 in the second bending region 104 and at least a portion of the second negative electrode tab 123 in the first bending region 102, the tabs can utilize the space of the bending regions, thereby increasing the width of the first positive electrode tab 112, the first negative electrode tab 122, the second positive electrode tab 113, and the second negative electrode tab 123. This improves the current-carrying capacity of the first positive electrode tab 112, the first negative electrode tab 122, the second positive electrode tab 113, and the second negative electrode tab 123, enhances the rate performance of the battery cell 10, reduces the temperature rise of the battery cell 10, reduces the risk of thermal runaway of the battery cell 10, and improves the safety and high-temperature cycle life of the battery cell 10.

[0092] See Figure 2 In some embodiments, along the winding direction of the electrode assembly 100, the first positive electrode tab 112 includes a first portion 1121, a second portion 1122, and a third portion 1123. The first portion 1121 is located in a first straight region 101, the second portion 1122 is located in a first bending region 102, and the third portion 1123 is located in a second straight region 103. The second portion 1122 connects the first portion 1121 and the third portion 1123. Along the winding direction of the electrode assembly 100, the first negative electrode tab 122 includes a fourth portion 1221, a fifth portion 1222, and a sixth portion 1223. The fourth portion 1221 is located in the first straight region 101, the fifth portion 1222 is located in the second bending region 104, and the sixth portion 1223 is located in the second straight region 103. The fifth portion 1222 connects the fourth portion 1221 and the sixth portion 1223.

[0093] By making the first positive electrode tab 112 include a first portion 1121, a second portion 1122, and a third portion 1123, with the first portion 1121 located in a first straight region 101, the second portion 1122 located in a first bending region 102, and the third portion 1123 located in a second straight region 103, and the second portion 1122 connecting the first portion 1121 and the third portion 1123; and the first negative electrode tab 122 includes a fourth portion 1221, a fifth portion 1222, and a sixth portion 1223, with the fourth portion 1221 located in the first straight region 101, the fifth portion 1222 located in the second bending region 104, and the sixth portion 1223 located in the second straight region 103, and the fifth portion 1222 connecting the fourth portion 1221 and the sixth portion 1223, it is possible to Furthermore, the widths of the first positive electrode tab 112 and the first negative electrode tab 122 are made larger, thereby improving the current carrying capacity of the first positive electrode tab 112 and the first negative electrode tab 122 and improving the rate performance of the battery cell 10; and the first part 1121 located in the first flat region 101 and the third part 1123 located in the second flat region 103 are connected through the second part 1122 of the first bending region 102, and the fourth part 1221 located in the first flat region 101 and the sixth part 1223 located in the second flat region 103 are connected through the fifth part 1222 of the second bending region 104, which can reduce the number of the first positive electrode tab 112 and the first negative electrode tab 122, improve the manufacturing efficiency of the battery cell 10, and have a smaller impact on the energy density of the battery cell 10.

[0094] In some embodiments, along the width direction Z of the electrode assembly, the width of the first portion 1121 is equal to the width of the third portion 1123.

[0095] By making the width of the first part 1121 and the width of the third part 1123 equal, it is easy to retract and connect multiple first positive electrode tabs 112.

[0096] In other embodiments, the difference between the width of the first portion 1121 and the width of the third portion 1123 can be less than a threshold value. For example, the threshold value can be 0.2 mm, 0.5 mm, or 1 mm, etc. This facilitates the retraction and connection of multiple first positive electrode tabs 112.

[0097] In some embodiments, along the width direction Z of the electrode assembly, the width of the fourth portion 1221 and the width of the sixth portion 1223 are equal.

[0098] By making the widths of the fourth part 1221 and the sixth part 1223 equal, it is easy to retract and connect multiple first negative electrode tabs 122.

[0099] In other embodiments, the difference in width between the fourth portion 1221 and the sixth portion 1223 may be less than a threshold value. For example, the threshold value may be 0.2 mm, 0.5 mm, or 1 mm, etc. This facilitates the retraction and connection of multiple first negative electrode tabs 122.

[0100] In some embodiments, each positive electrode 110 is provided with a first positive electrode tab 112.

[0101] By providing a first positive electrode tab 112 for each positive electrode layer 110, the total current-carrying area of ​​the first positive electrode tab 112 can be increased, thereby improving the current-carrying capacity of the cell 10, improving the rate performance of the cell 10, and also helping to reduce the temperature rise of the cell 10, reduce the risk of thermal runaway of the cell 10, and improve the safety and high-temperature cycle life of the cell 10.

[0102] See Figure 2 and Figure 4 In some embodiments, the electrode assembly 100 further includes a separator 130 disposed between the positive electrode 110 and the negative electrode 120. Along the winding direction of the electrode assembly 100, and among the plurality of first positive electrode tabs 112, the maximum width of the first positive electrode tab 112 closest to the winding start end of the positive electrode 110 is A1 mm. From the winding center of the electrode assembly 100 outwards, the maximum width of the first positive electrode tab 112 of the nth layer of positive electrode 110 is An mm. The thickness of the negative electrode 120 is T1 mm, the thickness of the positive electrode 110 is T2 mm, and the thickness of the separator 130 is T3 mm. An = A1 + (n-1) × (T1 + T1 + 2 × T3) × σ1, where n is an integer greater than or equal to 2, and 3 ≤ σ1 ≤ 3.24. For example, σ1 can be 3, 3.02, 3.05, 3.08, 3.1, 3.2, 3.15, 3.18, 3.2, 3.22 or 3.24, or a range of any two of these values.

[0103] A1 is the maximum width of the first positive electrode tab 112 along the length direction P after the positive electrode sheet is unfolded. An is the maximum width of the first positive electrode tab 112 of the nth layer positive electrode sheet 110 along the length direction P after the positive electrode sheet is unfolded.

[0104] By making An = A1 + (n-1) × (T1 + T1 + 2 × T3) × σ1, 3 ≤ σ1 ≤ 3.24, the second part 1122 of the first positive electrode tab 112 located in the first bending region 102 is approximately semi-circular, that is, the part of each layer of positive electrode sheet 110 located in the first bending region 102 is approximately semi-circular, making the transition of each layer of positive electrode sheet 110 located in the first bending region 102 smoother. This is beneficial to make the distance between the positive electrode sheet 110 and the negative electrode sheet 120 of adjacent layers more uniform, reducing the risk of metal ion precipitation and improving the safety of the cell 10.

[0105] In some embodiments, each negative electrode sheet 120 is provided with a first negative electrode tab 122.

[0106] By providing a first negative electrode tab 122 for each negative electrode sheet 120, the total current-carrying area of ​​the first negative electrode tab 122 can be increased, thereby improving the current-carrying capacity of the battery cell 10, improving the rate performance of the battery cell 10, and also helping to reduce the temperature rise of the battery cell 10, reduce the risk of thermal runaway of the battery cell 10, and improve the safety and high-temperature cycle life of the battery cell 10.

[0107] See Figure 2 and Figure 5 In some embodiments, along the winding direction of the electrode assembly 100, and among the plurality of first negative electrode tabs 122, the maximum width of the first negative electrode tab 122 closest to the winding start end of the negative electrode sheet 120 is B1 mm. From the winding center of the electrode assembly 100 outwards, the maximum width of the first negative electrode tab 122 of the m-th negative electrode sheet 120 is Bm mm, where Bm = B1 + (m-1) × (T1 + T1 + 2 × T3) × σ2, and m is an integer greater than or equal to 2, and 3 ≤ σ2 ≤ 3.24. For example, σ2 can be 3, 3.02, 3.05, 3.08, 3.1, 3.2, 3.15, 3.18, 3.2, 3.22, or 3.24, or a range consisting of any two of these values.

[0108] B1 is the maximum width of the first negative electrode tab 122 along the length direction P' after the negative electrode sheet is unfolded. Bm is the maximum width of the first negative electrode tab 122 of the m-th negative electrode sheet 120 along the length direction P' after the negative electrode sheet is unfolded.

[0109] By making Bm = B1 + (m-1) × (T1 + T1 + 2 × T3) × σ2, 3 ≤ σ2 ≤ 3.24, the fifth part 1222 of the first negative electrode tab 122 in the second bending region 104 is approximately semi-circular, that is, the part of each negative electrode sheet 120 in the second bending region 104 is approximately semi-circular, making the transition of each negative electrode sheet 120 in the second bending region 104 smoother. This is beneficial to make the distance between the positive electrode sheet 110 and the negative electrode sheet 120 of adjacent layers more uniform, reducing the risk of metal ion precipitation and improving the safety of the cell 10.

[0110] See Figure 2 In some embodiments, the distance between any first positive electrode tab 112 and any first negative electrode tab 122 along the width direction Z of the electrode assembly is S mm, where 0 < S ≤ 20. For example, S can be 0.1, 0.5, 0.8, 1, 3, 5, 7, 10, 12, 15, 17, 19 or 20, or a range of any two of these values.

[0111] When S is greater than 0, the spacing between any first positive electrode tab 112 and any first negative electrode tab 122 is not too small, which reduces the risk of thermal runaway of the cell 10 caused by short circuit between the first positive electrode tab 112 and the first negative electrode tab 122, thus improving the safety of the cell 10. When S is less than or equal to 20, the cell 10 has more space for setting the first positive electrode tab 112 and / or the first negative electrode tab 122, ensuring that the width of the first positive electrode tab 112 and / or the first negative electrode tab 122 along the winding direction of the electrode assembly 100 is not too small. This helps to increase the current-carrying area of ​​the first positive electrode tab 112 and / or the first negative electrode tab 122, improving the current-carrying capacity of the cell 10 and improving the rate performance of the cell 10. This is beneficial for reducing the temperature rise of the battery cell 10, reducing the risk of thermal runaway of the battery cell 10, and improving the safety of the battery cell 10. Therefore, when 0 < S ≤ 20, it can not only reduce the risk of thermal runaway of the battery cell 10 caused by short circuit between the first positive electrode tab 112 and the first negative electrode tab 122, thus improving the safety of the battery cell 10, but also ensure that the width of the first positive electrode tab 112 and / or the first negative electrode tab 122 along the winding direction of the electrode assembly 100 is not too small, which is beneficial for increasing the current-carrying area of ​​the first positive electrode tab 112 and / or the first negative electrode tab 122, improving the current-carrying capacity of the battery cell 10, improving the rate performance of the battery cell 10, and also beneficial for reducing the temperature rise of the battery cell 10, reducing the risk of thermal runaway of the battery cell 10, and improving the safety and high-temperature cycle life of the battery cell 10.

[0112] In some embodiments, 5 ≤ S ≤ 10. For example, S can be 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5 or 10, or a range of any two of these values.

[0113] When S is greater than or equal to 5, the spacing between any first positive electrode tab 112 and any first negative electrode tab 122 is not too small, further reducing the risk of thermal runaway of the cell 10 caused by short circuit between the first positive electrode tab 112 and the first negative electrode tab 122, thus further improving the safety of the cell 10. When S is less than or equal to 10, the cell 10 has more space for setting the first positive electrode tab 112 and / or the first negative electrode tab 122, ensuring that the width of the first positive electrode tab 112 and / or the first negative electrode tab 122 along the winding direction of the electrode assembly 100 is not too small, which helps to further increase the current-carrying area of ​​the first positive electrode tab 112 and / or the first negative electrode tab 122, further improving the current-carrying capacity of the cell 10 and improving the rate performance of the cell 10. This also helps to reduce the temperature rise of the battery cell 10, reduce the risk of thermal runaway of the battery cell 10, and further improve the safety of the battery cell 10. Therefore, when 5≤S≤10, it can further reduce the risk of thermal runaway of the battery cell 10 caused by short circuit between the first positive electrode tab 112 and the first negative electrode tab 122, further improving the safety of the battery cell 10. It can also further ensure that the width of the first positive electrode tab 112 and / or the first negative electrode tab 122 along the winding direction of the electrode assembly 100 is not too small, which helps to increase the current-carrying area of ​​the first positive electrode tab 112 and / or the first negative electrode tab 122, improve the current-carrying capacity of the battery cell 10, further improve the rate performance of the battery cell 10, and also helps to reduce the temperature rise of the battery cell 10, reduce the risk of thermal runaway of the battery cell 10, and further improve the safety and high-temperature cycle life of the battery cell 10.

[0114] See Figure 1 and Figure 6 , Figure 6 This is a schematic diagram of a partial structure of a battery cell provided in some embodiments of this application.

[0115] In some embodiments, the battery cell 10 further includes a first electrical connector 310, wherein a plurality of first negative electrode tabs 122 converge along the thickness direction Y of the electrode assembly and are connected to the first electrical connector 310. The thickness of the first electrical connector 310 is C1 mm, and 60 ≤ C1 / H1 ≤ 150. For example, C1 / H1 can be 60, 70, 80, 90, 100, 110, 120, 130, 140 or 150, or a range consisting of any two of these values.

[0116] When C1 / H1 is greater than or equal to 60, the thickness of the first electrical connector 310 is not too small, resulting in a stronger current-carrying capacity of the first electrical connector 310, which improves the rate performance of the battery cell 10 and helps reduce the temperature rise of the battery cell 10, reducing the risk of thermal runaway and improving the safety of the battery cell 10; and / or, the thickness of the first negative electrode tab 122 is not too large, reducing the space occupied by the first negative electrode tab 122 and helping to improve the energy density of the battery cell 10; when C1 / When H1 is less than or equal to 150, the thickness of the first electrical connector 310 is not too large, facilitating its bending and connection with other components; and / or, the thickness of the first negative electrode tab 122 is not too small, resulting in a stronger current carrying capacity, which improves the rate performance of the battery cell 10, reduces the temperature rise of the battery cell 10, reduces the risk of thermal runaway, and improves the safety of the battery cell 10. Therefore, when 60≤C1 / H1≤150, the battery cell 10 has high safety and energy density. In some embodiments, 70 ≤ C1 / H1 ≤ 120. For example, C1 / H1 can be 70, 75, 80, 85, 90, 95, 100, 105, 110, 115 or 120, or a range consisting of any two of these values.

[0117] When C1 / H1 is greater than or equal to 70, the thickness of the first electrical connector 310 is not too small, resulting in a stronger current-carrying capacity of the first electrical connector 310, which further improves the rate performance of the battery cell 10 and helps reduce the temperature rise of the battery cell 10, reducing the risk of thermal runaway and further improving the safety of the battery cell 10; and / or, it further ensures that the thickness of the first negative electrode tab 122 is not too large, reducing the space occupied by the first negative electrode tab 122 and further improving the energy density of the battery cell 10; when C1 / H1 is less than or equal to 120, which further ensures that the thickness of the first electrical connector 310 is not too large, making it easier to bend the first electrical connector 310 and connect it with other components; and / or, further ensures that the thickness of the first negative electrode tab 122 is not too small, making the first negative electrode tab 122 have a stronger current carrying capacity, which can improve the rate performance of the battery cell 10, and is conducive to reducing the temperature rise of the battery cell 10, reducing the risk of thermal runaway of the battery cell 10, and further improving the safety of the battery cell 10; therefore, when 70≤C1 / H1≤120, the battery cell 10 has high safety and energy density. In some embodiments, the battery cell 10 further includes a second electrical connector 320, wherein a plurality of first positive electrode tabs 112 converge along the thickness direction Y of the electrode assembly and are connected to the second electrical connector 320; the thickness of the first positive electrode tabs 112 is H2 mm, the thickness of the second electrical connector 320 is C2 mm, and 30 ≤ C2 / H2 ≤ 80. For example, C2 / H2 can be 30, 35, 40, 45, 50, 55, 60, 65, 70, 75 or 80, or a range consisting of any two of these values.

[0118] When C2 / H2 is greater than or equal to 30, the thickness of the second electrical connector 320 is not too small, resulting in a stronger current-carrying capacity of the second electrical connector 320, which improves the rate performance of the battery cell 10 and helps reduce the temperature rise of the battery cell 10, reducing the risk of thermal runaway and improving the safety of the battery cell 10; and / or, the thickness of the first positive electrode tab 112 is not too large, reducing the space occupied by the first positive electrode tab 112 and helping to improve the energy density of the battery cell 10; when C2 / When H2 is less than or equal to 80, the thickness of the second electrical connector 320 is not too large, facilitating its bending and connection with other components; and / or, the thickness of the first positive electrode tab 112 is not too small, resulting in a stronger current carrying capacity, which improves the rate performance of the battery cell 10, reduces the temperature rise of the battery cell 10, reduces the risk of thermal runaway, and improves the safety of the battery cell 10. Therefore, when 30≤C2 / H2≤80, the battery cell 10 has high safety and energy density. In some embodiments, 40 ≤ C2 / H2 ≤ 62. For example, C2 / H2 can be 40, 42, 45, 47, 50, 52, 55, 57, 60 or 62, or a range consisting of any two of these values.

[0119] When C2 / H2 is greater than or equal to 40, the thickness of the second electrical connector 320 is not too small, resulting in a stronger current-carrying capacity of the second electrical connector 320, which further improves the rate performance of the battery cell 10 and helps reduce the temperature rise of the battery cell 10, reducing the risk of thermal runaway and further improving the safety of the battery cell 10; and / or, it further ensures that the thickness of the first positive electrode tab 112 is not too large, reducing the space occupied by the first positive electrode tab 112 and further improving the energy density of the battery cell 10; when C2 / When H2 is less than or equal to 62, the thickness of the second electrical connector 320 is not too large, facilitating its bending and connection with other components; and / or, the thickness of the first positive electrode tab 112 is not too small, resulting in a stronger current carrying capacity, which improves the rate performance of the cell 10 and helps reduce the temperature rise of the cell 10, thereby reducing the risk of thermal runaway and further enhancing the safety of the cell 10. Therefore, when 40 ≤ C2 / H2 ≤ 62, the cell 10 has high safety and energy density.

[0120] In some embodiments, the width of the electrode assembly 100 is W0 mm, the maximum width of the first positive electrode tab 112 is A mm, and 1 < W0 / A ≤ 5. For example, W0 / A can be 1.1, 1.2, 1.5, 1.8, 2, 2.5, 3, 3.5, 4, 4.5 or 5, or a range consisting of any two of these values.

[0121] When W0 / A is greater than 1, W0 will not be too small, allowing the cell 10 to have a larger capacity, which is beneficial to improving the battery life of the cell 10; and / or, A will not be too large, reducing the wind direction that could cause a short circuit between the first positive electrode tab 112 and the first negative electrode tab 122, which is beneficial to improving the safety of the cell 10; when W0 / A is less than or equal to 5, W0 will not be too large, ensuring that the current path along the winding axis X of the electrode assembly is not too large, thus improving the rate performance of the cell 10; and / or, A will not be too small, ensuring that the current-carrying area of ​​the first positive electrode tab 112 is not too small, thus improving the current-carrying capacity of the cell 10 and improving the rate performance of the cell 10; therefore, when 1 < W0 / A ≤ 5, the cell 10 has good battery life, high safety, and high rate performance.

[0122] In some embodiments, 1 < W0 / A ≤ 2. For example, W0 / A can be 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9 or 2, or a range consisting of any two of these values.

[0123] When W0 / A is greater than 1, W0 will not be too small, allowing the cell 10 to have a larger capacity, which is beneficial to improving the battery life of the cell 10; and / or, A will not be too large, which can reduce the wind direction of the short circuit between the first positive electrode tab 112 and the first negative electrode tab 122, which is beneficial to improving the safety of the cell 10; when W0 / A is less than or equal to 2, W0 will not be too large, which will further ensure that the current flow path along the winding axis X of the electrode assembly will not be too large, further improving the rate performance of the cell 10; and / or, A will not be too small, ensuring that the current flow area of ​​the first positive electrode tab 112 will not be too small, which can further improve the current flow capacity of the cell 10, further improving the rate performance of the cell 10; therefore, when 1 < W0 / A ≤ 2, the cell 10 has good battery life, high safety and rate performance.

[0124] In some embodiments, the maximum width of the first negative electrode tab 122 is B mm, where 1 < W0 / B ≤ 5. For example, W0 / B can be 1.1, 1.2, 1.5, 1.8, 2, 2.5, 3, 3.5, 4, 4.5 or 5, or a range consisting of any two of these values.

[0125] When W0 / B is greater than 1, W0 will not be too small, allowing the cell 10 to have a larger capacity, which is beneficial to improving the battery life of the cell 10; and / or, B will not be too large, reducing the wind direction that could cause a short circuit between the first positive electrode tab 112 and the first negative electrode tab 122, which is beneficial to improving the safety of the cell 10; when W0 / B is less than or equal to 5, W0 will not be too large, ensuring that the current path along the winding axis X of the electrode assembly is not too large, thus improving the rate performance of the cell 10; and / or, B will not be too small, ensuring that the current-carrying area of ​​the first negative electrode tab 122 is not too small, thus improving the current-carrying capacity of the cell 10 and improving the rate performance of the cell 10; therefore, when 1 < W0 / B ≤ 5, the cell 10 has good battery life, high safety, and high rate performance.

[0126] In some embodiments, 1 < W0 / B ≤ 4. For example, W0 / B can be 1.1, 1.5, 2, 2.2, 2.5, 2.8, 3, 3.2, 3.5, 3.8, 4, 4.2, 4.5, 4.8 or 5, or a range consisting of any two of these values.

[0127] When W0 / B is greater than 1, W0 will not be too small, allowing the cell 10 to have a larger capacity, which is beneficial to improving the battery life of the cell 10; and / or, B will not be too large, which can reduce the wind direction of the short circuit between the first positive electrode tab 112 and the first negative electrode tab 122, which is beneficial to improving the safety of the cell 10; when W0 / B is less than or equal to 4, W0 will not be too large, which will further ensure that the current flow path along the winding axis X of the electrode assembly will not be too large, further improving the rate performance of the cell 10; and / or, B will not be too small, which will ensure that the current flow area of ​​the first negative electrode tab 122 will not be too small, which will further improve the current flow capacity of the cell 10, further improving the rate performance of the cell 10; therefore, when 1 < W0 / B ≤ 4, the cell 10 has good battery life, high safety and rate performance.

[0128] In some embodiments, the battery cell 10 further includes a third electrical connector 330, wherein a plurality of second positive electrode tabs 113 converge along the thickness direction Y of the electrode assembly and are connected to the third electrical connector 330.

[0129] In some embodiments, the battery cell 10 further includes a fourth electrical connector 340, wherein a plurality of second negative electrode tabs 123 converge along the thickness direction Y of the electrode assembly and are connected to the fourth electrical connector 340.

[0130] This application provides an electrical device, including a battery cell 10 as described above, the battery cell 10 being used to provide electrical energy.

[0131] The electrical equipment can be any of the aforementioned devices or systems using battery cell 10.

[0132] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0133] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A battery cell, characterized in that, The battery cell includes an electrode assembly with a wound structure. The electrode assembly includes a positive electrode sheet and a negative electrode sheet. The positive electrode sheet includes a positive electrode body and a plurality of first positive electrode tabs and a plurality of second positive electrode tabs connected to the positive electrode body. The negative electrode sheet includes a negative electrode body and a plurality of first negative electrode tabs and a plurality of second negative electrode tabs connected to the negative electrode body. The plurality of first positive electrode tabs and the plurality of first negative electrode tabs are located at one end of the electrode assembly along its winding axis, and the plurality of second positive electrode tabs and the plurality of second negative electrode tabs are located at the other end of the electrode assembly along its winding axis. Along the winding axis of the electrode assembly, the width of the negative electrode body is W1 mm; the thickness of the first negative electrode tab is H1 mm, 0.64 × 10⁻⁶ mm. 7 ≤W1 2 / H1≤2.1×10 7 Preferred, 1.1×10 7 ≤W1 2 / H1≤1.7×10 7 .

2. The battery cell according to claim 1, characterized in that, The number of the first negative electrode tabs is N1, 0.8 × 10⁻⁶. 5 ≤W1 2 / (H1×N1)≤2.8×10 5 Preferred, 1.5×10 5 ≤W1 2 / (H1×N1)≤2.3×10 5 .

3. The battery cell according to claim 1, characterized in that, Along the winding axis of the electrode assembly, the width of the positive electrode body is W2 mm; the thickness of the first positive electrode tab is H2 mm, 1.7 × 10⁻⁶ mm. 6 ≤W2 2 / H2≤5.9×10 6 Preferred, 2.1×10 6 ≤W2 2 / H2≤4.2×10 6 .

4. The battery cell according to claim 3, characterized in that, The number of the first positive electrode tabs is N², 2.3 × 10⁻⁶. 4 ≤W2 2 / (H2×N2)≤8×10 4 Preferred, 2.8×10 4 ≤W2 2 / (H2×N2)≤5.7×10 4 .

5. The battery cell according to any one of claims 1 to 4, characterized in that, The electrode assembly includes a first straight region, a first bent region, a second straight region, and a second bent region connected end to end. The first straight region and the second straight region are arranged opposite each other along the thickness direction of the electrode assembly, and the first bent region and the second bent region are arranged opposite each other along the width direction of the electrode assembly. At least a portion of the first positive electrode tab is located in the first bending region, and at least a portion of the first negative electrode tab is located in the second bending region; At least a portion of the second positive electrode tab is located in the second bending region, and at least a portion of the second negative electrode tab is located in the first bending region.

6. The battery cell according to claim 5, characterized in that, Along the winding direction of the electrode assembly, the first positive electrode tab includes a first part, a second part, and a third part. The first part is located in the first straight region, the second part is located in the first bent region, and the third part is located in the second straight region. The second part connects the first part and the third part. Along the winding direction of the electrode assembly, the first negative electrode tab includes a fourth part, a fifth part, and a sixth part. The fourth part is located in the first straight region, the fifth part is located in the second bending region, and the sixth part is located in the second straight region. The fifth part connects the fourth part and the sixth part.

7. The battery cell according to claim 6, characterized in that, Along the width direction of the electrode assembly, the width of the first portion is equal to the width of the third portion; and / or, Along the width direction of the electrode assembly, the width of the fourth portion is equal to the width of the sixth portion.

8. The battery cell according to any one of claims 1 to 7, characterized in that, The electrode assembly further includes an isolation membrane disposed between the positive electrode and the negative electrode; Each layer of the positive electrode sheet is provided with a first positive electrode tab, and each layer of the negative electrode sheet is provided with a first negative electrode tab; Along the winding direction of the electrode assembly, and among the plurality of first positive electrode tabs, the maximum width of the first positive electrode tab closest to the winding start end of the positive electrode sheet is A1 mm. From the winding center of the electrode assembly outwards, the maximum width of the first positive electrode tab of the nth layer of the positive electrode sheet is An mm. The thickness of the negative electrode sheet is T1 mm, the thickness of the positive electrode sheet is T2 mm, and the thickness of the separator is T3 mm. An = A1 + (n-1) × (T1 + T1 + 2 × T3) × σ1, where n is an integer greater than or equal to 2, 3 ≤ σ1 ≤ 3.24; and / or, Along the winding direction of the electrode assembly, and among the plurality of first negative electrode tabs, the maximum width of the first negative electrode tab closest to the winding start end of the negative electrode sheet is B1 mm. From the winding center of the electrode assembly outward, the maximum width of the first negative electrode tab of the m-th layer of the negative electrode sheet is Bm mm, Bm = B1 + (m-1) × (T1 + T1 + 2 × T3) × σ2, where m is an integer greater than or equal to 2, and 3 ≤ σ2 ≤ 3.

24.

9. The battery cell according to any one of claims 1 to 8, characterized in that, Along the width direction of the electrode assembly, the distance between any first positive electrode tab and any first negative electrode tab is S mm, where 0 < S ≤ 20; preferably, 5 ≤ S ≤ 10.

10. The battery cell according to any one of claims 1 to 9, characterized in that, The battery cell further includes a first electrical connector, wherein a plurality of first negative electrode tabs converge along the thickness direction of the electrode assembly and are connected to the first electrical connector; the thickness of the first electrical connector is C1 mm, 60≤C1 / H1≤150; preferably, 70≤C1 / H1≤120; and / or, The battery cell further includes a second electrical connector, wherein a plurality of first positive electrode tabs converge along the thickness direction of the electrode assembly and are connected to the second electrical connector; the thickness of the first positive electrode tabs is H2 mm, the thickness of the second electrical connector is C2 mm, and 30≤C2 / H2≤80; preferably, 40≤C2 / H2≤62.

11. The battery cell according to any one of claims 1 to 10, characterized in that, The width of the electrode assembly is W0 mm, the maximum width of the first positive electrode tab is A mm, 1 < W0 / A ≤ 5; preferably, 1 < W0 / A ≤ 2; and / or, The maximum width of the first negative electrode tab is B mm, where 1 < W0 / B ≤ 5; preferably, 1 < W0 / B ≤ 4.

12. An electrical appliance, characterized in that, Includes a battery cell as described in any one of claims 1 to 11, the battery cell being used to provide electrical energy.

Images