Electrode sheets, electrochemical apparatus, and electrical equipment

Abstract

This application provides electrode sheets, electrochemical apparatus, and electrical equipment. [Solution] The electrode sheet comprises a base portion and a tab, the base portion including a first side connected to the tab in the longitudinal direction of the electrode sheet, and the tab comprising an extension portion and a connecting portion. The extension portion includes a first side and a second side arranged opposite each other in the longitudinal direction of the electrode sheet, and a first side and a second side arranged opposite each other in the longitudinal direction of the electrode sheet. A first intersection is formed between the extension of the first side and the first side, the first intersection is located between a third connecting point and a fourth connecting point, and if α1 is the angle between the half-line from the first intersection to the first connecting point and the half-line from the first intersection to the fourth connecting point, then α1 < 90° is satisfied. A continuous line from the first connecting point to the third connecting point is defined as the first reference line, the connecting portion includes a first reinforcing region, the first reinforcing region is formed enclosed by the third side and the first reference line. The present invention can improve the bending and tearing of the tab.

Description

Technical Field

[0001] This application relates to the field of energy storage technologies, and particularly to electrode sheets, electrochemical devices, and electrical equipment.

Background Art

[0002] Batteries with a multi-tab structure can extract current through multiple tabs, significantly shortening the electron conduction path in the electrode sheet, and thus can meet the usage requirements of high-rate electrical equipment such as smartphones, laptops, drones, power tools, electric vehicles, and electric scooters, so they are widely used.

Summary of the Invention

[0003] However, according to the research of the inventors of this application, in the existing electrode sheets with a multi-tab structure, short-circuit phenomena are likely to occur due to tab bending and internal insertion during the winding process, which has been found to significantly reduce the production yield. In addition, batteries with a multi-tab structure also have an increased risk of tab tearing during the process of being subjected to impacts such as dropping, which affects the normal use of electrical equipment.

[0004] In view of the above problems, this application aims to provide an electrode sheet, an electrochemical device, and an electrical equipment that can improve the short-circuit phenomenon caused by tab bending and internal insertion in the production process, improve the production yield of the electrochemical device, reduce the risk of the tab root being torn during the process of being subjected to impacts such as dropping, and ultimately improve the reliability of use of the electrochemical device.

[0005] A first aspect of the present application provides an electrode sheet comprising a base portion and a tab. The base portion includes a first side connected to the tab in the longitudinal direction of the electrode sheet. The tab comprises an extension portion and a connector portion. The extension portion includes a first side and a second side arranged opposite each other in the longitudinal direction of the electrode sheet. The connector portion is located between the base portion and the extension portion. The connector portion includes a third side and a fourth side arranged opposite each other in the longitudinal direction of the electrode sheet. The third side is connected to the first side and the first side. The fourth side is connected to the first side and the second side. A first connection point is formed between the third side and the first side. A second connection point is formed between the fourth side and the second side. A third connection point is formed between the third side and the first side. A fourth connection point is formed between the fourth side and the first side. When viewed from the thickness direction of the tab, a first intersection point is formed between the extension of the first side and the first side, and this first intersection point is located between the third connection point and the fourth connection point. If α1 is the angle between the half-line from the first intersection point to the first connection point and the half-line from the first intersection point to the fourth connection point, then α1 < 90° is satisfied. When viewed from the thickness direction of the tab, the continuous line from the first connection point to the third connection point is defined as the first reference line, and the connection portion includes a first reinforcement region, which is formed by being enclosed by the third side and the first reference line.

[0006] In the above embodiment, by positioning the first side of the tab diagonally so as to satisfy α1 < 90°, and by providing a first reinforcing region between the third side and the first reference line, the bending rigidity and torsional rigidity of the first side of the tab can be improved. Furthermore, this suppresses bending of the tab during the winding process and short-circuit phenomena due to insertion into the interior, improving the production yield of the electrochemical apparatus, and reduces the risk of the base of the tab tearing during processes such as dropping, thereby improving the reliability of the electrochemical apparatus.

[0007] In some embodiments, the third side includes a fifth side and a sixth side, the fifth side being connected to the first side, and the sixth side being connected to the first side, and the angle between the fifth side and the sixth side being δ1 satisfies 90° < δ1 < 180°. In this way, the first reinforcement region has an obtuse angle structure, which improves the bending and torsional rigidity of the tab, further suppresses bending of the tab during the winding process and short-circuit phenomena due to insertion into the interior, improves the production yield of the electrochemical apparatus, and further reduces the risk of the base of the tab tearing when subjected to impacts such as dropping, thereby improving the reliability of the electrochemical apparatus in use.

[0008] In some embodiments, the condition 180°-α1<δ1 is satisfied. In this way, increasing the obtuse angle of the outer contour of the first reinforcement region further improves the bending and torsional rigidity of the tab.

[0009] In some embodiments, the third side includes the fifth and sixth sides, a fifth connection point is formed between the fifth and sixth sides, the fifth side is connected to the first side, and the sixth side is connected to the first side. If β1 is the angle between the half-line from the third connection point to the fifth connection point and the half-line from the third connection point to the fourth connection point, then β1 ≤ α1 < 90° and / or 60° ≤ β1 ≤ 90° are satisfied. In this way, the rigidity of the tab connection is improved, and bending and twisting of the tab are better suppressed, thereby improving the production yield of the electrochemical apparatus, reducing the risk of the base of the tab tearing during impacts such as drops, and improving the reliability of the electrochemical apparatus in use.

[0010] In some embodiments, if the height of the tab is H and the height of the connection portion is h in the short direction of the electrode sheet, then h / H ≥ 1 / 5 is satisfied.

[0011] In some embodiments, when viewed from the thickness direction of the tab, a second intersection occurs between the extension of the second side and the first side, the second intersection is located between the third and fourth connection points, and if α2 is the angle between the half-line from the second intersection to the second connection point and the half-line from the second intersection to the third connection point, then α2 < 90°. When viewed from the thickness direction of the tab, the continuous line from the second connection point to the fourth connection point is the second reference line, the connection portion includes a main body region and a second reinforcement region, the main body region is located between the first and second reference lines, and the second reinforcement region is formed by being enclosed by the fourth side and the second reference line.

[0012] In the above embodiment, the second side of the tab is positioned diagonally so as to satisfy α2 < 90°, and a second reinforcing region is provided between the fourth side and the second reference line, thereby improving the bending and torsional rigidity of the second side of the tab, further suppressing bending of the tab during the winding process and short-circuit phenomena due to insertion into the interior, improving the production yield of the electrochemical apparatus, and reducing the risk of the base of the tab tearing during processes such as dropping, thereby further improving the reliability of the electrochemical apparatus.

[0013] In some embodiments, the fourth side includes the seventh and eighth sides, with a sixth connection point between the seventh and eighth sides, the seventh side being connected to the second side, and the eighth side being connected to the first side, and the angle between the seventh and eighth sides being δ2, satisfying 90° < δ2 < 180°. Thus, the second reinforcement region has an obtuse angle structure, improving the bending and torsional rigidity of the second side of the tab, further suppressing bending of the tab during the winding process and short-circuit phenomena due to internal insertion, thereby improving the production yield of the electrochemical apparatus, and further reducing the risk of the base of the tab tearing during processes such as dropping, thereby improving the reliability of the electrochemical apparatus in use.

[0014] In some embodiments, if β2 is the angle between the half-line from the fourth connection point to the sixth connection point and the half-line from the fourth connection point to the third connection point, then β2 ≤ α2 < 90° and / or 60° ≤ β2 ≤ 90° are satisfied. In this way, the rigidity of the tab connection is improved, and bending and twisting of the tab are better suppressed, thereby improving the production yield of the electrochemical apparatus, reducing the risk of the base of the tab tearing during processes such as dropping, and improving the reliability of the electrochemical apparatus in use.

[0015] In some embodiments, if L is the distance between the first and second intersections, and L1 is the distance from the third connection point to the fourth connection point, then L1 ≥ 1.1 × L is satisfied. By improving the bending and torsional rigidity of the tab in this way, the production yield of the electrochemical apparatus is improved, the risk of the base of the tab tearing during impacts such as dropping is reduced, and the reliability of the electrochemical apparatus in operation is improved.

[0016] In some embodiments, the condition 180°-α2<δ2 is satisfied. In this way, increasing the obtuse angle of the outer contour of the second reinforcement region further improves the bending and torsional stiffness of the tab.

[0017] In some embodiments, the third side includes at least one of a polyline or an arc.

[0018] In some embodiments, the fourth side includes at least one of a broken line or an arc.

[0019] In some embodiments, the base portion includes a current collector and a first active material layer, the first active material layer being provided on the surface of the current collector.

[0020] In some embodiments, the electrode sheet is a negative electrode sheet, and the negative electrode sheet further includes a second active material layer, the second active material layer being provided on the surface of the connection portion. In this way, the rigidity of the tab connection portion is further improved, thereby further suppressing bending and tearing of the tab.

[0021] In some embodiments, the electrode sheet is a positive electrode sheet, and the positive electrode sheet further includes a first insulating layer provided on the surface of the connection portion. Thus, by further improving the rigidity of the connection portion of the tab, the bending and tearing of the tab are further suppressed.

[0022] The second aspect of the present application provides an electrochemical device including a wound electrode assembly, and the electrode assembly includes the electrode sheet according to any of the above aspects. By improving the bending rigidity and torsional rigidity of the tab in the electrode sheet, the risk of tearing at the root of the tab during the process of receiving impacts such as dropping is reduced, and thus the reliability of use of the electrochemical device is improved.

[0023] The third aspect of the present application provides an electrical device including the electrochemical device according to the above embodiment.

Brief Description of the Drawings

[0024] [Figure 1] It is a schematic diagram of an electrical device according to an embodiment of the present application. [Figure 2] It is a schematic diagram of an electrode assembly according to an embodiment of the present application. [Figure 3] It is a front view of the unfolded state of an electrode sheet according to an embodiment of the present application. [Figure 4] It is a side view of the unfolded state of an electrode sheet according to an embodiment of the present application. [Figure 5] It is a schematic diagram of a base portion and a tab according to an embodiment of the present application. [Figure 6] It is a partial view showing a first reinforcing region in a connection portion according to an embodiment of the present application. [Figure 7] It is a partial view showing a second reinforcing region in a connection portion according to an embodiment of the present application. [Figure 8] It is a schematic diagram of a base portion and a trapezoidal tab according to related art. [Figure 9] It is a schematic diagram of a base portion and a tab according to another embodiment of the present application. [Figure 10] It is a schematic diagram of a base portion and a tab according to still another embodiment of the present application. [Figure 11] This is a schematic diagram of the base and tab according to another embodiment of the present application. [Figure 12] This is a schematic diagram of a base portion and a tab according to another embodiment of the present application. [Modes for carrying out the invention]

[0025] The technical proposal in the embodiments of this application will be described below with reference to the attached drawings. Clearly, the embodiments described are only some of the embodiments of this application, not all of them.

[0026] Furthermore, when one component is considered to be "connected" to another component, it may be directly connected to the other component, or there may be an intermediate component between them. When one component is considered to be "provided" to another component, it may be directly installed to the other component, or there may be an intermediate component between them. The terms and similar expressions used herein, such as "top," "bottom," "up," "down," "left," "right," "front," and "back," are for illustrative purposes only.

[0027] Terms such as "first," "second," etc., are used solely to distinguish between different subjects and should not be understood as indicating or implying relative importance, nor do they implicitly include the quantity, specific order, or priority of the technical features presented.

[0028] The term "parallel" describes an ideal state between two components. In actual manufacturing or use, a near-parallel state can exist between two components. Two components described as "parallel" do not have to be an absolute straight line or plane; they may be approximately straight or plane, and macroscopically, if the overall direction of extension of the components is straight or plane, they can be considered "straight" or "plane."

[0029] The dimensions and thicknesses of each component shown in the attached drawings are for better understanding and easier explanation, and this application is not limited to the dimensions and thicknesses shown in the attached drawings.

[0030] All technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which this application belongs, unless otherwise defined. Terms used in this specification are for the purpose of describing specific embodiments and are not intended to limit this application.

[0031] Some embodiments of this application will be described below with reference to the attached drawings. To the extent that they do not contradict each other, the following embodiments and features of the embodiments can be combined with each other.

[0032] As shown in Figure 1, some embodiments of the present invention provide an electrical device 1000, which comprises an electrochemical apparatus 100.

[0033] In some embodiments, as shown in Figure 1, the electrical equipment 1000 further comprises an equipment body 200, and the electrochemical apparatus 100 is attached to the equipment body 200.

[0034] In some embodiments, the electrical device 1000 may be a smartphone, laptop computer, tablet, drone, power tool, electric toy, game console, video recorder, portable recorder, radio, smartwatch, electric vehicle, or electric motorcycle, etc., which are not listed here.

[0035] In some embodiments, as shown in Figure 2, the electrochemical apparatus 100 comprises an electrode assembly 101, the electrode assembly 101 comprises an electrode sheet 10, and the electrode sheet 10 includes a positive electrode sheet and a negative electrode sheet.

[0036] In some embodiments, the electrode assembly 101 further includes a separator (not shown) which is provided between the positive electrode sheet and the negative electrode sheet to separate the positive electrode sheet from the negative electrode sheet.

[0037] In some embodiments, the separator may be made of a material such as polyethylene (PE) or polypropylene (PP).

[0038] The electrode assembly 101 may have a wound structure or a laminated structure. If the electrode assembly 101 has a wound structure, the positive electrode sheet may include a plurality of positive electrode tabs 1201, and the negative electrode sheet may include a plurality of negative electrode tabs 1202. After winding, when viewed from the thickness direction of the electrode assembly 101, the plurality of positive electrode tabs 1201 may overlap each other, and the plurality of negative electrode tabs 1202 may overlap each other. If the electrode assembly 101 has a laminated structure, the electrode assembly 101 includes a plurality of positive electrode sheets and a plurality of negative electrode sheets, each positive electrode sheet includes at least one positive electrode tab 1201, and each negative electrode sheet includes at least one negative electrode tab 1202. When viewed from the thickness direction of the electrode assembly 101, the positive electrode tabs 1201 of the plurality of positive electrode sheets may overlap each other, and the negative electrode tabs 1202 of the plurality of negative electrode sheets may overlap each other.

[0039] In some embodiments, as shown in Figures 3 and 4, the electrode sheet 10 includes a base portion 11. The base portion 11 includes a current collector 10a and a first active material layer 10b, the first active material layer 10b being provided on the surface of the current collector 10a. The electrode sheet 10 may be a positive electrode sheet or a negative electrode sheet. The positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer. The positive electrode current collector may be a metal layer containing at least one of aluminum, nickel, tantalum, titanium, etc., for example, aluminum foil. The positive electrode active material layer includes a positive electrode active material, which may include at least one of lithium cobalt oxide, nickel cobalt manganese oxide lithium, nickel cobalt aluminate lithium, lithium iron phosphate, manganese iron phosphate lithium, or lithium manganese oxide. The negative electrode sheet 10 includes a negative electrode current collector and a negative electrode active material layer. The negative electrode current collector may be a metal layer containing at least one of copper, nickel, tantalum, titanium, etc., for example, copper foil. The negative electrode active material layer contains a negative electrode active material, which may contain at least one of the following: graphite, hard carbon, soft carbon, silicon, silicon oxide material, or silicon carbon material.

[0040] In some embodiments, as shown in Figures 3 to 5, the electrode sheet 10 includes a base portion 11 and a tab 12 that connect to each other. The tab 12 includes an extension portion 121 and a connecting portion 122, the connecting portion 122 being located between the extension portion 121 and the base portion 11, and the connecting portion 122 connecting the extension portion 121 and the base portion 11.

[0041] The connection portion 122 is connected to the current collector 10a in the base portion 11. The tab 12 can be formed by cutting it integrally with the current collector 10a. In the short direction Y of the electrode sheet 10, the tab 12 is located on the base portion 11 side.

[0042] In some embodiments, as shown in Figures 5 to 7, the base portion 11 includes a first side 111 connected to the tab 12 in the longitudinal direction X of the electrode sheet 10. The extension portion 121 includes a first side 1211 and a second side 1212 positioned opposite the longitudinal direction X of the electrode sheet 10, and the connecting portion 122 includes a third side 1221 and a fourth side 1222 positioned opposite the longitudinal direction X of the electrode sheet 10. The third side 1221 is connected to the first side 111 and the first side 1211, and the fourth side 1222 is connected to the first side 111 and the second side 1212. A first connection point 12a is formed between the third side 1221 and the first side 1211, a second connection point 12b is formed between the fourth side 1222 and the second side 1212, a third connection point 12c is formed between the third side 1221 and the first side 111, and a fourth connection point 12d is formed between the fourth side 1222 and the first side 111.

[0043] When viewed from the thickness direction Z of tab 12, a first intersection point 111a is formed between the extension of the first side 1211 and the first side 111, and the first intersection point 111a is located between the third connection point 12c and the fourth connection point 12d. If α1 is the angle between the half-line from the first intersection point 111a to the first connection point 12a and the half-line from the first intersection point 111a to the fourth connection point 12d, then α1 < 90° is satisfied. When viewed from the thickness direction Z of tab 12, the continuous line from the first connection point 12a to the third connection point 12c is defined as the first reference line 121a, and the connection portion 122 includes a first reinforcement region 122a, which is formed by being enclosed by the third side 1221 and the first reference line 121a.

[0044] According to the inventors' research, the tabs 12 are prone to being bent or twisted when subjected to force during production processes such as the cutting process and the winding process of the electrode sheets 10. When bent or twisted, the tabs 12 are prone to bending or short circuits (caused by contact with electrode sheets 10 of different polarities) due to insertion, significantly reducing the production yield. At the same time, in electrochemical apparatus 100 having a multi-tab 12 structure, the risk of the tabs 12 tearing increases when subjected to impacts such as dropping, affecting the normal use of the electrical equipment 1000. This invention improves the bending and torsional rigidity of the first side of the tab 12 by arranging the first side 1211 of the tab 12 diagonally so as to satisfy α1 < 90°, and by providing a first reinforcing region 122a between the third side 1221 and the first reference line 121a, thereby suppressing bending of the tab 12 and short-circuit phenomena due to insertion into the interior during the winding process, improving the production yield of the electrochemical apparatus 100, and reducing the risk of the base of the tab 12 tearing when the electrochemical apparatus 100 is subjected to impacts such as dropping, thereby improving the reliability of the electrochemical apparatus 100 in use.

[0045] The first intersection point 111a between the extension of the first side 1211 and the first side 111 can be understood as the intersection point between the extension of the first side 1211 and the line on which the first side 111 is located. The first side is the side of the tab 12 on which the first side 1211 is provided. In some embodiments, α1 ≤ 85° is satisfied. For example, α1 may be within the range of 85°, 80°, 70°, 60°, 50°, 45°, or any two angles selected from these angles.

[0046] In some embodiments, as shown in Figures 5 to 7, the projection of the extension portion 121 is located within the projection of the connecting portion 122 in the short direction Y of the electrode sheet 10. This makes the dimension of the connecting portion 122 in the longitudinal direction X of the electrode sheet 10 larger than the dimension of the extension portion 121 in the longitudinal direction X of the electrode sheet 10, thereby improving the rigidity of the tab 12 and reducing the possibility of the tab 12 bending or tearing.

[0047] In some embodiments, as shown in Figures 5 to 7, when viewed from the thickness direction Z of the tab 12, a second intersection 111b occurs between the extension of the second side 1212 and the first side 111, and the second intersection 111b is located between the third connection point 12c and the fourth connection point 12d. If α2 is the angle between the half-line from the second intersection 111b to the second connection point 12b and the half-line from the second intersection 111b to the third connection point 12c, then α2 < 90° is satisfied. When viewed from the thickness direction Z of the tab 12, the continuous line from the second connection point 12b to the fourth connection point 12d is defined as the second reference line 121b. The connecting portion 122 further includes a main body region and a second reinforcement region 122b. The main body region is located between the first reference line 121a and the second reference line 121b, and the second reinforcement region 122b is formed by being surrounded by the fourth side 1222 and the second reference line 121b. By positioning the second side 1212 of the tab 12 diagonally so as to satisfy α2 < 90°, and by providing the second reinforcement region 122b between the fourth side 1222 and the second reference line 121b, the bending rigidity and torsional rigidity of the second side of the tab 12 are improved, further suppressing bending of the tab 12 during the winding process and short-circuit phenomena due to insertion into the interior, thereby improving the production yield of the electrochemical apparatus 100, and reducing the risk of the base of the tab 12 tearing when the electrochemical apparatus 100 is subjected to impacts such as dropping, thereby further improving the reliability of the electrochemical apparatus 100.

[0048] The second intersection point 111b between the extension of the second side 1212 and the first side 111 can be understood as the intersection point between the extension of the second side 1212 and the line on which the first side 111 is located. The second side is the side of the tab 12 on which the second side 1212 is provided. In some embodiments, α2 ≤ 85° is satisfied. For example, α2 may be within the range of 85°, 80°, 70°, 60°, 50°, 45°, or any two angles selected from these angles.

[0049] In some embodiments, the first side 1211 and the second side 1212 may be straight or curved. If the first side 1211 and the second side 1212 are straight, their extensions are straight lines. If the first side 1211 and the second side 1212 are curved, their extensions are the tangent lines at the first intersection 111a of the first side 1211 and the tangent line at the second intersection 111b of the second side 1212.

[0050] In some embodiments, as shown in Figures 5 to 7, the third side 1221 includes a fifth side 1223 and a sixth side 1224 connected to each other, the fifth side 1223 being connected to the first side 1211, and the sixth side 1224 being connected to the first side 111. If the angle between the fifth side 1223 and the sixth side 1224 is δ1, then the condition 90° < δ1 < 180° is satisfied. When this condition is met, the outer contour of the first reinforcement region 122a has an obtuse angle structure, thereby improving the bending and torsional rigidity of the tab 12, further suppressing bending of the tab 12 during the winding process and short-circuit phenomena due to insertion into the interior, thereby improving the production yield of the electrochemical apparatus 100, and further reducing the risk of the base of the tab 12 tearing when the electrochemical apparatus 100 is subjected to impacts such as dropping, thereby improving the reliability of the electrochemical apparatus 100.

[0051] For example, δ1 may be within the range of 100°, 110°, 120°, 130°, 140°, 150°, or any two angles selected from these angles.

[0052] In some embodiments, the condition 180°-α1<δ1 is satisfied, as shown in Figures 5 to 7. When this condition is met, increasing the obtuse angle of the outer contour of the first reinforcement region 122a further improves the bending and torsional rigidity of the tab 12, thereby suppressing bending and tearing of the tab 12.

[0053] In some embodiments, as shown in Figures 5 to 7, the third side 1221 includes a fifth side 1223 and a sixth side 1224 connected to each other, with a fifth connection point 12e between the fifth side 1223 and the sixth side 1224, the fifth side 1223 being connected to the first side 1211, and the sixth side 1224 being connected to the first side 111. If β1 is the angle between the half-line from the third connection point 12c to the fifth connection point 12e and the half-line from the third connection point 12c to the fourth connection point 12d, then β1 ≤ α1 < 90° and / or 60° ≤ β1 ≤ 90° are satisfied. When these conditions are met, improving the rigidity of the connection portion 122 of the tab 12 better suppresses bending and twisting of the tab 12, thereby improving the production yield of the electrochemical apparatus 100, and reducing the risk of the base of the tab 12 tearing when the electrochemical apparatus 100 is subjected to impacts such as dropping, thereby improving the reliability of the electrochemical apparatus 100.

[0054] For example, β1 may be within the range of 60°, 70°, 80°, 85°, 90°, or any two angles selected from these angles.

[0055] In some embodiments, as shown in Figures 5 to 7, the fourth side 1222 includes the seventh side 1225 and the eighth side 1226, with a sixth connection point 12f between the seventh side 1225 and the eighth side 1226, where the seventh side 1225 is connected to the second side 1212 and the eighth side 1226 is connected to the first side 111. If the angle between the seventh side 1225 and the eighth side 1226 is δ2, then the condition 90° < δ2 < 180° is satisfied. When these conditions are met, the outer contour of the second reinforcement region 122b has an obtuse angle structure, which improves the bending and torsional rigidity of the tab 12, further suppresses bending of the tab 12 during the winding process and short-circuit phenomena due to insertion into the interior, thereby improving the production yield of the electrochemical apparatus 100, and further reduces the risk of the base of the tab 12 tearing when the electrochemical apparatus 100 is subjected to impacts such as dropping, thereby improving the reliability of the electrochemical apparatus 100 in use.

[0056] For example, δ2 may be within the range of 100°, 110°, 120°, 130°, 140°, 150°, or any two angles selected from these angles. It may also be within the range thus formed.

[0057] In some embodiments, as shown in Figures 5 to 7, if β2 is the angle between the half-line from the fourth connection point 12d to the sixth connection point 12f and the half-line from the fourth connection point 12d to the third connection point 12c, then β2 ≤ α2 < 90° and / or 60° ≤ β2 ≤ 90° are satisfied. When these conditions are met, the rigidity of the connection portion 122 of the tab 12 is improved, thereby better suppressing bending and twisting of the tab 12, and consequently improving the production yield of the electrochemical apparatus 100. At the same time, the risk of the base of the tab 12 tearing during impacts such as dropping the electrochemical apparatus 100 is reduced, thereby improving the reliability of the electrochemical apparatus 100.

[0058] For example, β2 may be within the range of 60°, 70°, 80°, 85°, 90°, or any two angles selected from these angles.

[0059] In some embodiments, the condition 180°-α2<δ2 is satisfied, as shown in Figures 5 to 7. When this condition is met, increasing the obtuse angle of the outer contour of the second reinforcement region 122b further improves the bending and torsional rigidity of the tab 12, thereby suppressing bending and tearing of the tab 12.

[0060] In some embodiments, as shown in Figures 5 to 7, if L is the distance between the first intersection 111a and the second intersection 111b, and L1 is the distance from the third connection point 12c to the fourth connection point 12d, then L1 ≥ 1.1 × L is satisfied. When this condition is met, the rigidity of the connection portion 122 of the tab 12 can be improved, bending and twisting of the tab can be suppressed, and in turn, the production yield of the electrochemical apparatus 100 can be improved, the risk of the base of the tab 12 tearing during the process of the electrochemical apparatus 100 being subjected to impacts such as dropping can be reduced, and the reliability of the electrochemical apparatus 100 can be improved.

[0061] For example, L1 may be within the range of 1.1L, 1.2L, 1.3L, 1.4L, 1.5L, or any two distances selected from these distances.

[0062] In some embodiments, as shown in Figures 5 and 9, the third side 1221 includes a bend, and the bend may be a double or triple bend. For example, the third side 1221 includes a fifth side 1223 and a sixth side 1224 connected to each other, the fifth side 1223 being connected to the first side 1211, and the sixth side 1224 being connected to the first side 111. An angle δ1 is formed between the fifth side 1223 and the sixth side 1224, thereby forming a double bend structure between the fifth side 1223 and the sixth side 1224. The triple bend structure of the third side 1221 will not be described in detail here, but both the double and triple bend structures of the third side 1221 improve the bending and torsional rigidity of the tab 12 and further suppress bending and tearing of the tab 12.

[0063] In some embodiments, as shown in Figure 10, the third side 1221 includes an arc, i.e., the outer contour of the third side 1221 is arc-shaped, and the arc structure improves the bending and torsional rigidity of the tab 12 and further suppresses bending and tearing of the tab 12.

[0064] In some embodiments, as shown in Figures 5 and 9, the fourth side 1222 includes a polyline, which may be a double or triple polyline. For example, the fourth side 1222 includes the seventh side 1225 and the eighth side 1226, with a sixth connection point 12f between the seventh side 1225 and the eighth side 1226, where the seventh side 1225 is connected to the second side 1212 and the eighth side 1226 is connected to the first side 111, and an angle δ2 is formed between the seventh side 1225 and the eighth side 1226, thereby forming a double polyline structure between the seventh side 1225 and the eighth side 1226. Although the triple-folded structure of the fourth side 1222 will not be described in detail here, both the double-folded and triple-folded structures of the fourth side 1222 improve the bending and torsional rigidity of the tab 12, and further suppress bending and tearing of the tab 12.

[0065] In some embodiments, as shown in Figure 10, the fourth side 1222 includes an arc, i.e., the outer contour of the fourth side 1222 is arc-shaped, and the arc structure improves the bending and torsional rigidity of the tab 12 and further suppresses bending and tearing of the tab 12.

[0066] In some embodiments, as shown in Figures 3 and 11, the electrode sheet 10 further includes a second active material layer 10c, the second active material layer 10c being provided on the surface of the connection portion 122. By providing the second active material layer 10c on the surface of the connection portion 122, the second active material layer 10c can share the stress transmitted to the tab 12, improving the rigidity of the connection portion 122 of the tab 12 and further suppressing bending and tearing of the tab 12.

[0067] Although not particularly limited here, the second active material layer 10c may be provided on a part of the surface of the connecting portion 122, for example, on the surface of the first region adjacent to the base portion 11 in the connecting portion 122, or it may be provided on the entire surface of the connecting portion 122.

[0068] In some embodiments, the electrode sheet 10 is a negative electrode sheet, in which case both the first active material layer 10b and the second active material layer 10c are negative electrode active material layers, and their specific composition is the same as that of the negative electrode active material layer described above, so a detailed explanation is omitted.

[0069] In some embodiments, as shown in Figure 12, the electrode sheet 10 further includes a first insulating layer 10d, the first insulating layer 10d being provided on the surface of the connection portion 122. By providing the first insulating layer 10d on the surface of the connection portion 122, the first insulating layer 10d can share the stress transmitted to the tab 12, improving the rigidity of the connection portion 122 of the tab 12, and further suppressing bending and tearing of the tab 12. Although not particularly limited here, the first insulating layer 10d is on the surface of the connection portion 122 It may be provided in part, for example, on the surface of the second region adjacent to the base portion 11 in the connecting portion 122, or it may be provided on the entire surface of the connecting portion 122.

[0070] In some embodiments, the electrode sheet 10 is a positive electrode sheet, and the side of the current collector 10a adjacent to the tab 12 includes a third region, and the electrode sheet 10 further includes a second insulating layer 10e, the second insulating layer 10e is provided on the surface of the third region. The second insulating layer 10e may be connected to the first insulating layer 10d.

[0071] In some embodiments, the first insulating layer 10d and the second insulating layer 10e may contain inorganic particles and a binder, and their compositions may be the same or different, and are not particularly limited herein.

[0072] Furthermore, the intersections and connection points of the outer contour of the electrode sheet 10 of this application may be chamfered or rounded, and are not particularly limited thereto.

[0073] To verify the improvement effect of the structure of the electrode sheet 10 of this application on preventing tab bending of the tabs 12, the improvement effect on production yield was compared with an example of a large soft pack battery having multiple tabs 12. Data from each group was obtained from 400 electrode assemblies 101, each electrode assembly 101 having 98 cut tabs 12, and the number of electrode assemblies 101 in which the tabs 12 were bent during the winding molding process was statistically recorded. The electrode sheet of the comparative example has a trapezoidal tab 12' with a base width L=45mm, hypotenuse angle α=80°, and height H=24mm, as shown in Figure 8. In addition to the comparative example, the tab 12 of the embodiment of this application has a reinforced area, and in the tab 12, α1=α2=α=80°, and the base width L1, angle δ1 / δ2, angle β1 / β2, and height h of the connection part 122 of the tab 12 were adjusted. The test results are shown in Table 1 below.

[0074] [Table 1]

[0075] As can be seen from the comparison between the examples and comparative examples in Table 1, by adopting the electrode sheet 10 structure of the present invention, the bending rate of the tabs 12 of the electrode assembly 101 can be significantly reduced, thereby improving the production yield of the electrochemical apparatus 100. At the same time, by improving the bending and torsional rigidity of the tabs 12, the risk of the base of the tabs 12 tearing during impacts such as dropping the electrochemical apparatus 100 can be reduced, thereby improving the reliability of the electrochemical apparatus 100.

[0076] As can be seen from the comparison between Example 1-2 and Examples 2-1 to 2-3, when the conditions β1 ≤ α1 < 90° / β2 ≤ α2 < 90° are further satisfied, the rigidity of the connection portion 122 of the tab 12 is further improved, thereby better suppressing bending and twisting of the tab 12, and consequently improving the production yield of the electrochemical apparatus 100, as well as reducing the risk of the base of the tab 12 tearing when the electrochemical apparatus 100 is subjected to impacts such as dropping, thereby improving the reliability of the electrochemical apparatus 100.

[0077] Furthermore, those skilled in the art should understand that the above embodiments are for illustrative purposes only and do not limit the present application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present application are all included within the scope of protection. [Explanation of symbols]

[0078] 10 electrode sheets 10a current collector 10b First active material layer 10c 2nd active material layer 10d First insulating layer 10e Second insulating layer 11 Base section 111 First side 111a 1st intersection 111b 2nd intersection 12 tabs 121 Extension 1211 1st side 1212 Second side 121a 1st reference line 121b 2nd reference line 122 Connection part 1221 Third side 1222 4th side 1223 5th side 1224 6th side 1225 7th side 1226 8th side 122a 1st reinforcement area 122b 2nd reinforcement area 12a First connection point 12b Second connection point 12c Third connection point 12d Fourth connection point 12e Fifth connection point 12f Sixth connection point 1201 Positive Tab 1202 Negative Electrode Tab 101 Electrode assembly 100 Electrochemical apparatus 200 Main unit 1000 Electrical equipment 12' trapezoidal tab Longitudinal direction of the X electrode sheet Y electrode sheet, short side Z tab thickness direction

Claims

1. An electrode sheet comprising a base portion and a tab, The base portion includes a first side connected to the tab in the longitudinal direction of the electrode sheet, The aforementioned tab is An extension portion including a first side and a second side arranged opposite to each other in the longitudinal direction of the electrode sheet, A connecting portion located between the base portion and the extension portion, and including a third side and a fourth side arranged opposite each other in the longitudinal direction of the electrode sheet, wherein the third side is connected to the first side and the first side, and the fourth side is connected to the first side and the second side, and a first connection point is formed between the third side and the first side, a second connection point is formed between the fourth side and the second side, a third connection point is formed between the third side and the first side, and a fourth connection point is formed between the fourth side and the first side, Equipped with, When viewed from the thickness direction of the tab, a first intersection point is formed between the extension of the first side and the first side, the first intersection point is located between the third connection point and the fourth connection point, and the angle between the half-line from the first intersection point to the first connection point and the half-line from the first intersection point to the fourth connection point is α １ Therefore, α １ <Satisfying 90°, When viewed from the thickness direction of the tab, the continuous line from the first connection point to the third connection point is defined as the first reference line, the connection portion includes a first reinforcement region, and the first reinforcement region is formed by being surrounded by the third side and the first reference line. An electrode sheet characterized by the following features.

2. The third side includes the fifth side and the sixth side, The fifth side is connected to the first side, The sixth side is connected to the first side, The angle between the fifth side and the sixth side is δ １ Therefore, 90° < δ １ <Satisfying 180° The electrode sheet according to feature 1.

3. 180°-α １ <δ １ Satisfying The electrode sheet according to feature 2.

4. The following conditions, i.e., (1) The third side includes a fifth side and a sixth side, a fifth connection point occurs between the fifth side and the sixth side, the fifth side is connected to the first side, the sixth side is connected to the first side, and an angle β is formed between the half-line from the third connection point to the fifth connection point and the half-line from the third connection point to the fourth connection point. １ Then, β １ ≤α １ <90° and / or 60° ≤ β １ satisfies ≤ 90°. (2) In the short direction of the electrode sheet, if the height of the tab is H and the height of the connection portion is h, then h / H ≥ 1 / 5 is satisfied. Satisfying at least one of the following conditions: The electrode sheet according to feature 1.

5. When viewed from the thickness direction of the tab, a second intersection point is formed between the extension of the second side and the first side, the second intersection point is located between the third connection point and the fourth connection point, and the angle between the half-line from the second intersection point to the second connection point and the half-line from the second intersection point to the third connection point is α ２ Therefore, α ２ <Satisfying 90°, When viewed from the thickness direction of the tab, the continuous line from the second connection point to the fourth connection point is defined as the second reference line, the connection portion includes a main body region and a second reinforcement region, the main body region is located between the first reference line and the second reference line, and the second reinforcement region is formed by being surrounded by the fourth side and the second reference line. The electrode sheet according to feature 1.

6. The fourth side includes the seventh side and the eighth side, A sixth connection point is formed between the seventh side and the eighth side. The seventh side is connected to the second side, The eighth side is connected to the first side, and the following conditions apply: (1) The angle between the seventh side and the eighth side is δ ２ Therefore, 90° < δ ２ <Satisfying 180° (2) The angle between the half-line from the fourth connection point to the sixth connection point and the half-line from the fourth connection point to the third connection point is β ２ Therefore, β ２ ≤α ２ <90° and / or 60° ≤ β ２ Satisfying ≤ 90°, (3) Let L be the distance between the first intersection and the second intersection. The distance from the third connection point to the fourth connection point is L. １ Therefore, L １ Satisfying ≥ 1.1 × L, Satisfying at least one of the following conditions: The electrode sheet according to feature 5.

7. 180°-α ２ <δ ２ Satisfying The electrode sheet according to feature 6.

8. The following conditions, i.e., (1) The third side includes at least one of a broken line or an arc, (2) The fourth side includes at least one of a broken line or an arc. (3) The base portion includes a current collector and a first active material layer, the first active material layer is provided on the surface of the current collector, (4) The electrode sheet is a negative electrode sheet, and the negative electrode sheet further includes a second active material layer, the second active material layer is provided on the surface of the connection portion, or the electrode sheet is a positive electrode sheet, and the positive electrode sheet further includes a first insulating layer, the first insulating layer is provided on the surface of the connection portion. Satisfying at least one of the following conditions: The electrode sheet according to feature 1.

9. Equipped with a wound electrode assembly, The electrode assembly includes the electrode sheet described in any one of claims 1 to 8. An electrochemical apparatus characterized by the following features.

10. The electrochemical apparatus is provided as described in claim 9. An electrical device characterized by the following features.

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