Battery

Abstract

The utility model provides a battery which comprises a first pole piece and a second pole piece which are opposite in polarity, the first pole piece and the second pole piece are alternately stacked, the first pole piece comprises a first current collector and a first active material layer located on the first current collector, and the second pole piece comprises a second active material layer located on the second current collector. The first pole piece comprises a first current collector and a first active material layer located on the first current collector, the second pole piece comprises a second current collector and a second active material layer located on the second current collector, the second current collector comprises a second empty foil region and a second gap, the first empty foil region corresponds to the second gap, and the first gap corresponds to the second empty foil region; the extension size W1 of the first empty foil area in the first direction and the extension size H1 of the first empty foil area in the second direction meet the condition that W1 is greater than H1; and / or the extension size W2 of the second empty foil area along the first direction and the extension size H2 of the second empty foil area along the second direction meet the condition that W2 is greater than H2. The battery provided by the utility model is relatively high in energy density.

Description

Technical Field

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

[0002] Laminated cells have been widely used in the field of lithium-ion batteries due to their advantages such as high energy density, low internal resistance and long cycle life.

[0003] In related technologies, laminated cells can include electrodes and separators. The positive electrode, separator, and negative electrode are stacked in sequence. The electrode can include a current collector and paste. During the electrode preparation process, metal molds or laser cutting technology are required to form the electrode. This punching method requires a large empty foil area in the current collector to cut out the specific shape of the electrode tab, which in turn affects the energy density of the battery cell. Utility Model Content

[0004] Based on this, the present application provides a battery to solve the problem of low energy density of batteries in related technologies.

[0005] The battery provided in an embodiment of the present application includes a first electrode sheet and a second electrode sheet of opposite polarity, wherein the first electrode sheet and the second electrode sheet are alternately stacked, the first electrode sheet includes a first current collector and a first active material layer located on the first current collector, the first current collector includes a first hollow foil area and a first notch, the second electrode sheet includes a second current collector and a second active material layer located on the second current collector, the second current collector includes a second hollow foil area and a second notch, the first hollow foil area corresponds to the second notch, and the first notch corresponds to the second hollow foil area;

[0006] An extension dimension W1 of the first empty foil area along the first direction and an extension dimension H1 of the first empty foil area along the second direction satisfy: W1>H1;

[0007] And / or, an extension dimension W2 of the second empty foil area along the first direction and an extension dimension H2 of the second empty foil area along the second direction satisfy: W2>H2.

[0008] In a possible implementation, an extension dimension W3 of the first notch along the first direction and an extension dimension H3 of the first notch along the second direction satisfy:

[0009] W3>H3;

[0010] And / or, an extension dimension W4 of the second notch along the first direction and an extension dimension H4 of the second notch along the second direction satisfy: W4>H4.

[0011] In a possible implementation, the first empty foil area and the first gap are respectively located at two corners of the first current collector.

[0012] In a possible implementation, the area S1 of the first empty foil region, the area S2 of the first notch, and the area S3 of the first electrode sheet satisfy:

[0013] (S1+S2) / S3≤10%;

[0014] And / or, the area S4 of the second empty foil region, the area S5 of the second notch, and the area S6 of the second electrode sheet satisfy:

[0015] (S4+S5) / S6≤8%.

[0016] In a possible implementation, the area S1 of the first empty foil region and the area of ​​the first electrode sheet satisfy: S1 / S3≤6%;

[0017] And / or, the area S2 of the first notch and the area S3 of the first pole piece satisfy:

[0018] S2 / S3≤4%;

[0019] And / or, the area S4 of the second empty foil region and the area S6 of the second electrode sheet satisfy:

[0020] S4 / S6≤5%;

[0021] And / or, the area S5 of the second notch and the area S6 of the second pole piece satisfy:

[0022] S5 / S6≤5%.

[0023] In one possible implementation, the first hollow foil area includes a first side extending along the first direction and a second side intersecting the first active material layer, the first side and the second side forming a first angle α, the first notch includes a third side extending along the first direction and a fourth side intersecting the first active material layer, the third side and the fourth side forming a second angle β;

[0024] The first included angle α and the second included angle β satisfy: α>β.

[0025] In one possible implementation, the second hollow foil area includes a fifth side extending along the first direction and a sixth side intersecting the second active material layer, the fifth side and the sixth side forming a third angle γ, and the second notch includes a seventh side extending along the first direction and an eighth side intersecting the second active material layer, the seventh side and the eighth side forming a fourth angle θ;

[0026] The first angle α and the fourth angle θ satisfy: α>θ, and / or the second angle β and the third angle γ satisfy: β>γ 。

[0027] In a possible implementation, the first angle α satisfies: 20°≤α<45°.

[0028] In a possible implementation, an extension dimension W2 of the second empty foil area along the first direction and an extension dimension W4 of the second gap along the first direction satisfy:

[0029] W2≥W4.

[0030] In a possible implementation, an extension dimension H2 of the second empty foil area along the second direction and an extension dimension H4 of the second gap along the second direction satisfy: H2 ≥ H4.

[0031] In a possible implementation, an extension dimension W1 of the first empty foil area along the first direction and an extension dimension W2 of the second empty foil area along the first direction satisfy:

[0032] 0.1mm≤W1-W2≤1.3mm;

[0033] and / or, an extension dimension H1 of the first hollow foil area along the second direction and an extension dimension H2 of the second hollow foil area along the second direction satisfy: 0.1 mm ≤ H1 - H2 ≤ 1.3 mm;

[0034] and / or, an extension dimension W3 of the first notch along the first direction and an extension dimension W4 of the second notch along the first direction satisfy: 0.1 mm ≤ W3 - W4 ≤ 1.3 mm;

[0035] And / or, an extension dimension H3 of the first notch along the second direction and an extension dimension H4 of the second notch along the second direction satisfy: 0.1 mm ≤ H3 − H4 ≤ 1.3 mm.

[0036] In a possible implementation, the first electrode has a first side edge on a side facing away from the first empty foil area, and the first side edge extends along the first direction; the second electrode has a second side edge on a side facing away from the second empty foil area, and the second side edge extends along the first direction;

[0037] An extension dimension L1 of the first side satisfies: W1 + W3 < L1 , and / or an extension dimension L2 of the second side satisfies: W2 + W4 < L2 .

[0038] In one possible implementation, the battery further includes a first adapter tab and a second adapter tab, the first adapter tab including a first connecting portion, the projection of the first connecting portion in the thickness direction of the first electrode sheet is located within the first empty foil area, and the first connecting portion is connected to the first empty foil area, the second adapter tab includes a second connecting portion, the projection of the second connecting portion in the thickness direction of the second electrode sheet is located within the second empty foil area, and the second connecting portion is connected to the second empty foil area.

[0039] In a possible implementation, an extension dimension W5 of the first connecting portion along the first direction satisfies: 2 mm ≤ W5 ≤ 10 mm;

[0040] And / or, an extension dimension H5 of the first connecting portion along the second direction satisfies:

[0041] 0.3mm≤H5≤5mm;

[0042] And / or, an extension dimension W6 of the second connecting portion along the first direction satisfies:

[0043] 2mm≤W6≤10mm;

[0044] And / or, an extension dimension H6 of the second connecting portion along the second direction satisfies:

[0045] 0.3mm≤H6≤5mm.

[0046] In one possible implementation, the first hollow foil area has a first outer edge, the first outer edge extends along the second direction, and a first distance D1 is formed between a side of the first connecting portion facing the first outer edge and the first outer edge; the second hollow foil area has a second outer edge, the second outer edge extends along the second direction, and a second distance D2 is formed between a side of the second connecting portion facing the second outer edge and the second outer edge;

[0047] The first distance D1 satisfies: D1 ≥ 1.5 mm, and / or the second distance D2 satisfies: D2 ≥ 1.5 mm.

[0048] In one possible implementation, the battery further includes a first weld mark and a second weld mark, the first connection portion is connected to the first empty foil area via the first weld mark, and the second connection portion is connected to the second empty foil area via the second weld mark;

[0049] In the first direction, the first weld mark is centrally arranged on the first connecting portion, and / or, in the first direction, the second weld mark is centrally arranged on the second connecting portion.

[0050] In a possible implementation, the length H7 of the first weld mark and the extension dimension H5 of the first connecting portion along the second direction satisfy: 0.5*H5≤H7≤H5;

[0051] And / or, the length H8 of the second weld mark and the extension dimension H6 of the first connecting portion along the second direction satisfy: 0.5*H6≤H8≤H6.

[0052] In a possible implementation, the length direction of the first weld mark is consistent with the third direction, and the third direction forms a fifth angle with the first direction;

[0053] And / or, the length direction of the second weld mark is consistent with the fourth direction, and the fourth direction has a sixth angle with the first direction.

[0054] The battery provided in the present application includes a first electrode sheet and a second electrode sheet, the first electrode sheet includes a first current collector and a first active material layer, the first current collector includes a first empty foil area and a first notch, the second electrode sheet includes a second current collector and a second active material layer, the second current collector includes a second empty foil area and a second notch. A first empty foil area is provided for providing a contact point for charging and discharging for the first electrode, a second empty foil area is provided for providing a contact point for charging and discharging for the second electrode, a first gap is provided for avoiding the second empty foil area so that multiple second empty foil areas are connected to each other, a second gap is provided for avoiding the first empty foil area so that multiple first empty foil areas are connected to each other, an extension dimension W1 of the first empty foil area along the first direction is made greater than an extension dimension H1 of the first empty foil area along the second direction, so as to reduce the area of ​​the first empty foil area, thereby increasing the active material content of the first electrode, and allowing the first empty foil area to provide sufficient connection area for the first transfer electrode ear, and an extension dimension W2 of the second empty foil area along the first direction is made equal to an extension dimension H2 of the second empty foil area along the second direction, so as to reduce the area of ​​the second empty foil area, thereby increasing the active material content of the second electrode, and allowing the second empty foil area to provide sufficient connection area for the second transfer electrode ear.

[0055] In addition to the technical problems solved by the embodiments of the present application described above, the technical features that constitute the technical solutions, and the beneficial effects brought about by the technical features of these technical solutions, other technical problems that can be solved by the battery provided by the present application, other technical features included in the technical solutions, and the beneficial effects brought about by these technical features will be further described in detail in the specific implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0057] Figure 1 A schematic diagram of the structure of a battery provided in an embodiment of the present application;

[0058] Figure 2 A schematic structural diagram of a first electrode sheet and a first adapter tab in a battery provided in an embodiment of the present application;

[0059] Figure 3 A schematic structural diagram of the second electrode piece and the second adapter tab in the battery provided in an embodiment of the present application;

[0060] Figure 4 A schematic structural diagram of the first electrode in the battery provided in an embodiment of the present application;

[0061] Figure 5 Another structural schematic diagram of the first electrode in the battery provided in an embodiment of the present application;

[0062] Figure 6 A schematic structural diagram of the second electrode in the battery provided in an embodiment of the present application;

[0063] Figure 7 A schematic diagram of the partial structure of the first electrode sheet, the first adapter tab, and the first weld mark in the battery provided in an embodiment of the present application;

[0064] Figure 8 A schematic diagram of the partial structure of the second electrode sheet, the second adapter tab, and the second weld mark in the battery provided in an embodiment of the present application;

[0065] Figure 9 This is another partial structural diagram of the first electrode sheet, the first adapter tab, and the first weld mark in the battery provided in an embodiment of the present application;

[0066] Figure 10 This is another partial structural schematic diagram of the second electrode sheet, second adapter tab, and second weld mark in the battery provided in an embodiment of the present application.

[0067] Description of reference numerals:

[0068] 100-first electrode; 110-first empty foil area; 111-first outer edge; 120-first notch; 130-first side; 200-second electrode; 210-second empty foil area; 211-second outer edge; 220-second notch; 230-second side; 300-first adapter tab; 310-first connecting portion; 400-second adapter tab; 410-second connecting portion; 500-first weld mark; 600-second weld mark. DETAILED DESCRIPTION

[0069] In order to make the purpose, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be described in more detail below in conjunction with the drawings in the preferred embodiments of the present application. In the drawings, the same or similar reference numerals throughout represent the same or similar parts or parts with the same or similar functions. The described embodiments are part of the embodiments of the present application, not all of the embodiments. The embodiments described below with reference to the drawings are exemplary and are intended to be used to explain the present application, and should not be understood as limitations on the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. The embodiments of the present application are described in detail below in conjunction with the drawings.

[0070] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to a fixed connection, an indirect connection via an intermediate medium, internal communication between two components, or an interaction between two components. Those skilled in the art will understand the specific meanings of these terms in this application based on specific circumstances.

[0071] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are orientations or positional relationships based on the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on this application.

[0072] The terms "first," "second," and "third" (if any) in the specification and claims of this application and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a particular order or sequence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of the application described herein can, for example, be implemented in orders other than those illustrated or described herein.

[0073] In addition, the terms "comprises" and "having" and any variations thereof are intended to cover a non-exclusive inclusion, for example, a process, method, system, product or display that includes a series of steps or elements is not necessarily limited to those steps or elements expressly listed but may include other steps or elements not expressly listed or inherent to such process, method, product or display.

[0074] In related technologies, laminated cells can include electrodes and separators. The positive electrode, separator, and negative electrode are stacked in sequence. The electrode can include a current collector and paste. During the electrode preparation process, metal molds or laser cutting technology are required to form the electrode. This punching method requires a large empty foil area in the current collector to cut out the specific shape of the electrode tab, which in turn affects the energy density of the battery cell.

[0075] In view of the above problems, an embodiment of the present application provides a battery, in which the extension dimension W1 of the first empty foil area along the first direction is greater than the extension dimension H1 of the first empty foil area along the second direction, so as to reduce the area of ​​the first empty foil area, and the extension dimension W2 of the second empty foil area along the first direction is greater than the extension dimension of the second empty foil area along the second direction, so as to reduce the area of ​​the second empty foil area, thereby improving the energy density of the battery.

[0076] The specific implementation of the battery provided in the embodiments of the present application is described in detail below with reference to the accompanying drawings.

[0077] Reference Figures 1 to 6 As shown, the battery provided by the embodiment of the present application includes a first electrode sheet 100 and a second electrode sheet 200 with opposite polarities. For example, the first electrode sheet 100 is a positive electrode and the second electrode sheet 200 is a negative electrode. The first electrode sheet 100 and the second electrode sheet 200 are alternately stacked. The first electrode sheet 100 includes a first current collector and a first active material layer located on the first current collector. The first current collector includes a first empty foil area 110 and a first notch 120. The first empty foil area 110 and the first notch 120 are located at two corners of the first electrode sheet 100. The second electrode sheet 200 includes a second current collector and a second active material layer located on the second current collector. The second current collector includes a second empty foil area 210 and a second notch 220. The first empty foil area 110 corresponds to the second notch 220, and the first notch 120 corresponds to the second empty foil area 210.

[0078] An extension dimension W1 of the first empty foil area 110 along the first direction and an extension dimension H1 of the first empty foil area 110 along the second direction satisfy: W1>H1.

[0079] And / or, an extension dimension W2 of the second empty foil area 210 along the first direction and an extension dimension H2 of the second empty foil area 210 along the second direction satisfy: W2>H2.

[0080] It can be understood that the battery can also include a shell, a first adapter tab 300 and a second adapter tab 400. The first adapter tab 300 and the second adapter tab 400 can be provided with tab glue so that the first adapter tab 300 and the second adapter tab 400 are encapsulated with the shell through the tab glue. The first empty foil area 110 can be used to connect the first adapter tab 300, and then the current of the first electrode 100 is conducted to the outside of the battery through the first empty foil area 110 and the first adapter tab 300. The second empty foil area 210 can be used to connect the second adapter tab 400, and then the current of the second electrode 200 is conducted to the outside through the second empty foil area 210 and the second adapter tab 400.

[0081] Since no active material is coated on the first empty foil area 110, the larger the area of ​​the first empty foil area 110, the lower the active material content of the first electrode sheet 100 will be, and the energy density of the battery will be reduced. Therefore, in the embodiment of the present application, the first empty foil area 110 is arranged at one of the corners of the first electrode sheet 100, and the extension dimension W1 of the first empty foil area 110 along the first direction and the extension dimension H1 of the first empty foil area 110 along the second direction satisfy: W1>H1. In this way, the area of ​​the first empty foil area 110 can be effectively reduced, and the active material content of the first electrode sheet 100 can be increased, thereby improving the energy density of the battery.

[0082] Similarly, since no active material is coated on the second empty foil area 210, the larger the area of ​​the second empty foil area 210, the lower the active material content of the second electrode sheet 200 will be, and the energy density of the battery will be reduced. Therefore, in the embodiment of the present application, the second empty foil area 210 is set at one of the corners of the second electrode sheet 200, and the extension dimension W2 of the second empty foil area 210 along the first direction and the extension dimension H2 of the second empty foil area 210 along the second direction satisfy: W2>H2. In this way, the area of ​​the second empty foil area 210 can be effectively reduced, thereby increasing the active material content of the second electrode sheet 200, thereby improving the energy density of the battery.

[0083] In addition, in order to avoid the second empty foil area 210, a first notch 120 is opened at a position corresponding to the first electrode 100 and the second empty foil area 210. In order to avoid the first empty foil area 110, a second notch 220 is opened at a position corresponding to the second electrode 200 and the first empty foil area 110. This is conducive to the mutual connection of multiple first empty foil areas 110 and multiple second empty foil areas 210.

[0084] It should be noted that, in some embodiments, the first electrode sheet 100 and the second electrode sheet 200 may both be square in shape, the first hollow foil area 110 and the first notch 120 may be located at two adjacent corners of the first electrode sheet 100, and the second hollow foil area 210 and the second notch 220 may be located at two adjacent corners of the second electrode sheet 200. As long as the positions of the first hollow foil area 110 and the second notch 220 correspond to each other, and the positions of the first notch 120 and the second hollow foil area 210 correspond to each other, in the final battery, the first adapter tab 300 and the second adapter tab 400 are located on the same side of the battery, thereby facilitating battery packaging and reducing the dead volume of the battery.

[0085] In addition, the shapes of the first empty foil area 110 and the second notch 220 correspond to each other, and the shapes of the first notch 120 and the second empty foil area 210 correspond to each other, which is conducive to the negative electrode covering the positive electrode, thereby ensuring the safety of the battery.

[0086] For example, the first empty foil area 110 and the second gap 220 may both be triangular or trapezoidal, and the first gap 120 and the second empty foil area 210 may also both be triangular or trapezoidal.

[0087] In this way, when the extension dimension W1 of the first empty foil area 110 along the first direction is greater than the extension dimension H1 of the first empty foil area 110 along the second direction, the area of ​​the first empty foil area 110 can be effectively reduced, and the first empty foil area 110 can also provide sufficient space for connection with the first adapter tab 300, thereby avoiding interference between the tab glue on the first adapter tab 300 and the side seal of the shell. When the extension dimension W2 of the second empty foil area 210 along the first direction is greater than the extension dimension H2 of the second empty foil area 210 along the second direction, the area of ​​the second empty foil area 210 can be effectively reduced, and the second empty foil area 210 can also provide sufficient space for connection with the second adapter tab 400, thereby avoiding interference between the tab glue on the second adapter tab 400 and the side seal of the shell.

[0088] Among them, the first direction can be the width direction of the first adapter tab 300 or the second adapter tab 400, and the first direction can refer to the X direction in the accompanying drawings; the second direction can be the length direction of the first adapter tab 300 or the second adapter tab 400, and the second direction can refer to the Y direction in the accompanying drawings.

[0089] The battery provided by the embodiment of the present application includes a first electrode 100 and a second electrode 200. The first electrode 100 includes a first empty foil area 110 and a first notch 120, and the second electrode 200 includes a second empty foil area 210 and a second notch 220. The first empty foil area 110 is provided to provide a contact point for charging and discharging for the first electrode 100, the second empty foil area 210 is provided to provide a contact point for charging and discharging for the second electrode 200, the first notch 120 is provided to avoid the second empty foil area 210 so that a plurality of second empty foil areas 210 are connected to each other, the second notch 220 is provided to avoid the first empty foil area 110 so that a plurality of first empty foil areas 110 are connected to each other, and the extension size W1 of the first empty foil area 110 along the first direction is larger than the extension size W1 of the first empty foil area 110 along the second direction. The extension dimension H1 in the first direction is used to reduce the area of ​​the first empty foil area 110, thereby increasing the active material content of the first electrode 100, and allowing the first empty foil area 110 to provide a sufficient connection area for the first transfer tab 300. The extension dimension W2 of the second empty foil area 210 along the first direction is connected to the extension dimension H2 of the second empty foil area 210 along the second direction, so as to reduce the area of ​​the second empty foil area 210, thereby increasing the active material content of the second electrode 200, and allowing the second empty foil area 210 to provide a sufficient connection area for the second transfer tab 400.

[0090] Reference Figures 3 to 6 As shown, in a possible implementation, an extension dimension W3 of the first notch 120 along the first direction and an extension dimension H3 of the first notch 120 along the second direction satisfy: W3>H3.

[0091] And / or, an extension dimension W4 of the second notch 220 along the first direction and an extension dimension H4 of the second notch 220 along the second direction satisfy: W4>H4.

[0092] It is worth noting that when the first pole piece 100 and the second pole piece 200 are both square, a corner of the first pole piece 100 can be cut off by punching to form the first notch 120 , and a part of the structure on the second pole piece 200 can be cut off to form the second notch 220 .

[0093] For example, when the second empty foil area 210 is a triangle or a trapezoid, a triangle or a trapezoid is cut off at a corner of the first electrode 100 corresponding to the second empty foil area 210 to form the first notch 120; when the first empty foil area 110 is a triangle or a trapezoid, a triangle or a trapezoid is cut off at a corner of the second electrode 200 corresponding to the first empty foil area 110 to form the second notch 220.

[0094] By completing the first electrode 100 into a complete square, the extension dimension W3 of the first notch 120 along the first direction and the extension dimension H3 of the first notch 120 along the second direction can be measured, and W3>H3. In this way, the area of ​​the first notch 120 can be reduced, thereby reducing the content of active materials removed, and increasing the content of active materials remaining on the first electrode 100, thereby improving the energy density of the battery.

[0095] Similarly, by completing the second electrode 200 into a complete square, the extension dimension W4 of the second notch 220 along the first direction and the extension dimension H4 of the second notch 220 along the second direction can be measured, and W4>H4. In this way, the area of ​​the second notch 220 can be reduced, thereby increasing the active material content of the second electrode 200, thereby increasing the energy density of the battery.

[0096] In some embodiments, the area S1 of the first empty foil region 110 , the area S2 of the first notch 120 , and the area S3 of the first electrode 100 satisfy: ( S1 + S2 ) / S3 ≤ 10%.

[0097] And / or, the area S4 of the second empty foil region 210 , the area S5 of the second notch 220 , and the area S6 of the second electrode 200 satisfy: (S4+S5) / S6≤8%.

[0098] In this way, no matter what the shapes of the first empty foil area 110, the second empty foil area 210, the first notch 120 and the second notch 220 are, the areas of the first empty foil area 110 and the first notch 120 can be effectively reduced, thereby increasing the active material content of the first electrode 100, and the areas of the second empty foil area 210 and the second notch 220 can be effectively reduced, thereby increasing the active material content of the second electrode 200, thereby increasing the energy density of the battery.

[0099] It should be understood that in order to ensure that the negative electrode covers the positive electrode and thus ensure the safety of the battery, in a specific implementation, the area ratio of the second empty foil area 210 and the second gap 220 on the second electrode 200 can be set to be higher, that is, (S4+S5) / S6≤8%, and the area ratio of the first empty foil area 110 and the first gap 120 on the first electrode 100 can be set to be lower, that is, (S1+S2) / S3≤10%.

[0100] The area S3 of the first electrode 100 includes the area S1 of the first empty foil region 110 and the area S2 of the first notch 120 , and the area S6 of the second electrode 200 includes the area S4 of the second empty foil region 210 and the area S5 of the second notch 220 .

[0101] In a possible implementation, the area S3 of the first pole piece 100 and the area S6 of the second pole piece 200 satisfy: S3 ≤ S6.

[0102] With such an arrangement, after the first electrode sheet 100 and the second electrode sheet 200 are stacked, the second electrode sheet 200 can cover the first electrode sheet 100 , thereby preventing lithium deposition in the battery and improving battery safety.

[0103] In one possible implementation, the area S1 of the first hollow foil region 110 and the area S3 of the first electrode 100 satisfy the following relationship: S1 / S3 ≤ 6%. Furthermore, the area S2 of the first notch 120 and the area S3 of the first electrode 100 satisfy the following relationship: S2 / S3 ≤ 4%. Furthermore, the area S4 of the second hollow foil region 210 and the area S6 of the second electrode 200 satisfy the following relationship: S4 / S6 ≤ 5%. Furthermore, the area S5 of the second notch 220 and the area S6 of the second electrode 200 satisfy the following relationship: S5 / S6 ≤ 5%.

[0104] With such a configuration, the area of ​​the first empty foil area 110 can be larger than the area of ​​the first notch 120, thereby controlling the areas of the first empty foil area 110 and the first notch 120 within a preset range, thereby increasing the active material content of the first electrode 100, and allowing the first empty foil area 110 to have sufficient area to connect with the first transfer tab 300, and the area of ​​the second empty foil area 210 can be larger than the area of ​​the second notch 220, thereby controlling the areas of the second empty foil area 210 and the second notch 220 within a preset range, thereby increasing the active material content of the first electrode 100, and allowing the second empty foil area 210 to have sufficient area to connect with the second transfer tab 400.

[0105] Reference Figure 4 and Figure 6 As shown, in a possible implementation, the first empty foil area 110 includes a first side extending along the first direction and a second side bordering the first active material layer. A first angle α is formed between the first side and the second side. The first angle α satisfies: The first notch 120 includes a third side extending along the first direction and a fourth side bordering the first active material layer. A second angle β is formed between the third side and the fourth side. The second angle β satisfies:

[0106] The first included angle α and the second included angle β satisfy: α>β.

[0107] For example, when the first empty foil area 110 and the first notch 120 are both triangular, the first empty foil area 110 and the first notch 120 both have two acute angles, wherein the first empty foil area 110 and the first notch 120 have a first angle α and a second angle β on the side close to each other, respectively, and α>β. In this way, while ensuring the connection strength between the first adapter tab 300 and the first empty foil area 110, the second electrode 200 can cover the first electrode 100 in the first direction, thereby avoiding lithium deposition in the battery.

[0108] Reference Figure 4 and Figure 6 As shown, in a possible implementation, the second empty foil area 210 includes a fifth side extending along the first direction and a sixth side bordering the second active material layer. A third angle γ is formed between the fifth side and the sixth side. The third angle γ satisfies: The second notch 220 includes a seventh side extending along the first direction and an eighth side bordering the second active material layer. A fourth angle θ is formed between the seventh side and the eighth side. The fourth angle θ satisfies:

[0109] The first angle α and the fourth angle θ satisfy: α>θ, and / or the second angle β and the third angle γ satisfy: β>γ 。

[0110] Exemplarily, when the first empty foil area 110 and the first notch 120 are both triangles, correspondingly, the second empty foil area 210 and the second notch 220 are also triangles, and the second empty foil area 210 and the second notch 220 both have two acute angles, wherein the sides of the second empty foil area 210 and the second notch 220 close to each other have a third angle γ and a fourth angle θ, respectively, wherein α>θ, and / or β>γ. In this way, while ensuring the connection strength between the second transfer tab 400 and the second empty foil area 210, the second electrode 200 can cover the first electrode 100 in the first direction, thereby avoiding lithium deposition in the battery.

[0111] In some embodiments, the first angle α satisfies: 20°≤α<45°. In this way, the connection performance of the first empty foil area 110 can be guaranteed, and the area of ​​the first empty foil area 110 can be effectively reduced, thereby improving the energy density of the battery.

[0112] Reference Figure 6 As shown, in a possible implementation, an extension dimension W2 of the second empty foil area 210 along the first direction and an extension dimension W4 of the second gap 220 along the first direction satisfy: W2 ≥ W4.

[0113] That is to say, the extension dimension W2 of the second empty foil area 210 along the first direction is larger, and the extension dimension W4 of the second gap 220 along the first direction is smaller, so that the area of ​​the second empty foil area 210 can be larger than the area of ​​the second gap 220, thereby ensuring the connection strength between the second transfer tab 400 and the second empty foil area 210.

[0114] Reference Figure 6 As shown, in some embodiments, the extension dimension H2 of the second hollow foil area 210 along the second direction and the extension dimension H4 of the second notch 220 along the second direction satisfy: H2 ≥ H4. This configuration can make the area of ​​the second hollow foil area 210 larger than the area of ​​the second notch 220, thereby ensuring the connection strength between the second transition tab 400 and the second hollow foil area 210.

[0115] In one possible implementation, the extension dimension W1 of the first empty foil area 110 along the first direction and the extension dimension W2 of the second empty foil area 210 along the first direction satisfy: 0.1mm≤W1-W2≤1.3mm. In this way, the extension dimension W1 of the first empty foil area 110 along the first direction can be greater than or equal to the extension dimension W2 of the second empty foil area 210 along the first direction, and the difference between the two can be controlled within the required range, thereby meeting the positive and negative electrode ratio requirements and allowing the second electrode sheet 200 to cover the first electrode sheet 100.

[0116] And / or, the extension dimension H1 of the first empty foil area 110 along the second direction and the extension dimension H2 of the second empty foil area 210 along the second direction satisfy: 0.1mm≤H1-H2≤1.3mm. In this way, the extension dimension H1 of the first empty foil area 110 along the second direction is greater than or equal to the extension dimension H2 of the second empty foil area 210 along the second direction, and the difference between the two is controlled within the required range, thereby meeting the positive and negative electrode ratio requirements and allowing the second electrode sheet 200 to cover the first electrode sheet 100.

[0117] And / or, the extension dimension W3 of the first notch 120 along the first direction and the extension dimension W4 of the second notch 220 along the first direction satisfy: 0.1 mm ≤ W3 - W4 ≤ 1.3 mm. In this way, the extension dimension W3 of the first notch 120 along the first direction is greater than or equal to the extension dimension W4 of the second notch 220 along the first direction, and the difference between the two is controlled within the required range, thereby meeting the positive and negative electrode ratio requirements and ensuring that the second electrode sheet 200 covers the first electrode sheet 100.

[0118] And / or, the extension dimension H3 of the first notch 120 along the second direction and the extension dimension H4 of the second notch 220 along the second direction satisfy: 0.1 mm ≤ H3 - H4 ≤ 1.3 mm. In this way, the extension dimension H3 of the first notch 120 along the second direction and the extension dimension H4 of the second notch 220 along the second direction are controlled within the required range, thereby meeting the positive and negative electrode ratio requirements and ensuring that the second electrode sheet 200 covers the first electrode sheet 100.

[0119] For example, the difference (W1-W2) between the extension dimension W1 of the first hollow foil area 110 along the first direction and the extension dimension W2 of the second hollow foil area 210 along the first direction can be any one of 0.1 mm, 0.2 mm, 0.5 mm, 1 mm, and 1.3 mm, or within any two numerical ranges. Furthermore, the difference (H1-H2) between the extension dimension H1 of the first hollow foil area 110 along the second direction and the extension dimension H2 of the second hollow foil area 210 along the second direction can be any one of 0.1 mm, 0.3 mm, 0.6 mm, 1 mm, and 1.3 mm, or within any two numerical ranges. Furthermore, the difference (W3-W4) between the extension dimension W3 of the first notch 120 along the first direction and the extension dimension W4 of the second notch 220 along the first direction can be any one of 0.15 mm, 0.4 mm, 0.8 mm, 1.1 mm, and 1.3 mm, or within any two numerical ranges. And / or, the difference H3-H4 between the extension dimension H3 of the first notch 120 along the second direction and the extension dimension H4 of the second notch 220 along the second direction can be any one of 0.1mm, 0.2mm, 0.25mm, 0.09mm, 1.3mm or within any two value ranges.

[0120] Reference Figure 4 and Figure 6 As shown, in a possible implementation, the first electrode 100 has a first side 130 on a side facing away from the first empty foil area 110, and the first side 130 extends along the first direction, and the second electrode 200 has a second side 230 on a side facing away from the second empty foil area 210, and the second side 230 extends along the first direction.

[0121] The extension dimension L1 of the first side 130 satisfies: W1 + W3 < L1, and / or the extension dimension L2 of the second side 230 satisfies: W2 + W4 < L2.

[0122] That is to say, the sum of the extension dimension W1 of the first empty foil area 110 along the second direction and the extension dimension W3 of the first notch 120 along the second direction is smaller than the extension dimension L1 of the first electrode 100 along the second direction, and the sum of the extension dimension W2 of the second empty foil area 210 along the second direction and the extension dimension W4 of the first notch 120 along the second direction is smaller than the extension dimension L2 of the second electrode 200 along the second direction. Such an arrangement can ensure that the first transfer tab 300 and the second transfer tab 400 are well connected, and can reduce the area of ​​the first empty foil area 110 and the area of ​​the second empty foil area 210, and ensure that the second electrode 200 covers the first electrode 100.

[0123] Reference Figures 1 to 3 、 Figures 7 to 10 As shown, in a possible implementation, the battery further includes a first adapter tab 300 and a second adapter tab 400, the first adapter tab 300 includes a first connecting portion 310, the projection of the first connecting portion 310 in the thickness direction of the first electrode 100 is located in the first empty foil area 110, and the first connecting portion 310 is connected to the first empty foil area 110, the second adapter tab 400 includes a second connecting portion 410, the projection of the second connecting portion 410 in the thickness direction of the second electrode 200 is located in the second empty foil area 210, and the second connecting portion 410 is connected to the second empty foil area 210.

[0124] In this way, the first transfer tab 300 can be connected to the first empty foil area 110 through the first connecting portion 310 , and the second transfer tab 400 can be connected to the second empty foil area 210 through the second connecting portion 410 .

[0125] Reference Figure 7 and Figure 8As shown, in one possible implementation, the extension dimension W5 of the first connection portion 310 along the first direction satisfies the following conditions: 2 mm ≤ W5 ≤ 10 mm. Furthermore, the extension dimension H5 of the first connection portion 310 along the second direction satisfies the following conditions: 0.3 mm ≤ H5 ≤ 5 mm. Furthermore, the extension dimension W6 of the second connection portion 410 along the first direction satisfies the following conditions: 2 mm ≤ W6 ≤ 10 mm. Furthermore, the extension dimension H6 of the second connection portion 410 along the second direction satisfies the following conditions: 0.3 mm ≤ H6 ≤ 5 mm.

[0126] For example, the extension dimension W5 of the first connecting portion 310 along the first direction may be any one of 2 mm, 3 mm, 4 mm, 5 mm, and 10 mm, or be within any two numerical ranges. Furthermore, the extension dimension H5 of the first connecting portion 310 along the second direction may be any one of 0.3 mm, 0.4 mm, 1 mm, 3 mm, and 5 mm, or be within any two numerical ranges. Furthermore, the extension dimension W6 of the second connecting portion 410 along the first direction may be any one of 2 mm, 3 mm, 5 mm, 6 mm, and 10 mm, or be within any two numerical ranges. Furthermore, the extension dimension H6 of the second connecting portion 410 along the second direction may be any one of 0.3 mm, 0.5 mm, 1 mm, 2 mm, and 5 mm, or be within any two numerical ranges.

[0127] In this way, the first connecting portion 310 can have a sufficient length and width, so that the first transfer tab 300 and the first empty foil area 110 can be reliably connected, and the second connecting portion 410 can have a sufficient length and width, so that the second transfer tab 400 and the second empty foil area 210 can be reliably connected, thereby ensuring the connection strength between the first transfer tab 300 and the first empty foil area 110, and ensuring the connection strength between the second transfer tab 400 and the second empty foil area 210.

[0128] Reference Figure 7 and Figure 8 As shown, in a possible implementation, the first empty foil area 110 has a first outer edge 111, the first outer edge 111 extends along the second direction, and a first distance D1 is formed between the first connecting portion 310 and the first outer edge 111 on a side facing the first outer edge 111; the second empty foil area 210 has a second outer edge 211, the second outer edge 211 extends along the second direction, and a second distance D2 is formed between the second connecting portion 410 and the second outer edge 211 on a side facing the second outer edge 211.

[0129] The first distance D1 satisfies: D1 ≥ 1.5 mm, and / or the second distance D2 satisfies: D2 ≥ 1.5 mm.

[0130] In this way, when the shell is used to encapsulate the first pole piece 100 and the second pole piece 200, the projection of the pole piece glue on the first adapter pole piece 300 in the direction of the thickness of the battery cell is located within the side seal of the shell, and the projection of the pole piece glue on the second adapter pole piece 400 in the direction of the thickness of the battery cell is located between the two side seals of the shell. The side seals are located on both sides of the shell along the first direction, and the side seals extend along the second direction. This can effectively prevent the pole piece glue on the first adapter pole piece 300 and the pole piece glue on the second adapter pole piece 400 from affecting the packaging of the shell.

[0131] Reference Figures 8 to 10 As shown, in a possible implementation, the battery further includes a first weld mark 500 and a second weld mark 600 , the first connection portion 310 is connected to the first empty foil area 110 via the first weld mark 500 , and the second connection portion 410 is connected to the second empty foil area 210 via the second weld mark 600 .

[0132] In the first direction, the first weld mark 500 is centrally disposed on the first connecting portion 310, and / or, in the first direction, the second weld mark 600 is centrally disposed on the second connecting portion 410. This arrangement allows the first weld mark 500 and the second weld mark 600 to be subjected to balanced forces in the first direction, thereby improving the connection strength between the first empty foil area 110 and the first adapter tab 300, and improving the connection strength between the second empty foil area 210 and the second adapter tab 400.

[0133] Reference Figure 7 and Figure 8 As shown, in a possible implementation, the length H7 of the first weld mark 500 and the extension dimension H5 of the first connecting portion 310 along the second direction satisfy: 0.5*H5≤H7≤H5.

[0134] And / or, the length H8 of the second weld mark 600 and the extension dimension H6 of the first connecting portion 310 along the second direction satisfy: 0.5*H6≤H8≤H6.

[0135] Since the first connecting portion 310 is the overlapping area of ​​the first adapter tab 300 and the first empty foil area 110, the first connecting portion 310 is used to weld the first adapter tab 300 and the first empty foil area 110. Therefore, the area ratio of the first weld mark 500 on the first connecting portion 310 has a greater influence on the welding strength of the first adapter tab 300 and the first empty foil area 110. Therefore, the length H7 of the first weld mark 500 and the extension dimension H5 of the first connecting portion 310 along the second direction satisfy: 0.5*H5≤H7≤H5, thereby ensuring the welding strength between the first adapter tab 300 and the first empty foil area 110.

[0136] Similarly, the second connecting portion 410 is the area where the second adapter tab 400 and the second empty foil area 210 overlap. The second connecting portion 410 is used to weld the second adapter tab 400 and the second empty foil area 210. Therefore, the area ratio of the second weld mark 600 on the second connecting portion 410 has a greater influence on the welding strength between the second adapter tab 400 and the second empty foil area 210. Therefore, the length H8 of the second weld mark 600 and the extension dimension H6 of the first connecting portion 310 along the second direction satisfy: 0.5*H6≤H8≤H6, thereby ensuring the welding strength between the second adapter tab 400 and the second empty foil area 210.

[0137] For example, the ratio of the length H7 of the first weld mark 500 to the extension H5 of the first connecting portion 310 along the second direction may be any one of 0.5, 0.6, 0.7, 0.8, and 1, or within any two numerical ranges. And / or, the ratio of the length H8 of the second weld mark 600 to the extension H6 of the first connecting portion 310 along the second direction may be any one of 0.5, 0.55, 0.6, 0.9, and 1, or within any two numerical ranges.

[0138] Reference Figures 7 to 10 As shown, in one possible implementation, the length direction of the first weld mark 500 is consistent with the third direction, and the third direction has a fifth angle with the first direction. And / or, the length direction of the second weld mark 600 is consistent with the fourth direction, and the fourth direction has a sixth angle with the first direction.

[0139] That is to say, the length direction of the first weld mark 500 can be consistent with the third direction, or the length direction of the second weld mark 600 can be consistent with the fourth direction, or the length direction of the first weld mark 500 can be consistent with the third direction and the length direction of the second weld mark 600 can be consistent with the fourth direction.

[0140] The third direction has a fifth angle with the first direction, for example, the third direction and the first direction may have an angle of 0°, 30°, 45°, etc. The fourth direction has a sixth angle with the first direction, for example, the fourth direction and the first direction may have an angle of 0°, 25°, 30°, etc.

[0141] In this way, it is convenient to weld the first transfer tab 300 and the first empty foil area 110 , and the second transfer tab 400 and the second empty foil area 210 according to different requirements without being limited to a single welding process, thereby improving processing flexibility.

[0142] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery, characterized in that: The invention comprises a first electrode sheet and a second electrode sheet with opposite polarities, wherein the first electrode sheet and the second electrode sheet are alternately stacked, the first electrode sheet comprises a first current collector and a first active material layer located on the first current collector; the first current collector comprises a first empty foil area and a first notch, The second pole piece includes a second current collector and a second active material layer located on the second current collector; the second current collector includes a second empty foil area and a second notch, the first empty foil area corresponds to the second notch, and the first notch corresponds to the second empty foil area; An extension dimension W1 of the first empty foil area along the first direction and an extension dimension H1 of the first empty foil area along the second direction satisfy: W1>H1; And / or, an extension dimension W2 of the second empty foil area along the first direction and an extension dimension H2 of the second empty foil area along the second direction satisfy: W2>H2.

2. The battery according to claim 1, characterized in that An extension dimension W3 of the first notch along the first direction and an extension dimension H3 of the first notch along the second direction satisfy: W3>H3; And / or, an extension dimension W4 of the second notch along the first direction and an extension dimension H4 of the second notch along the second direction satisfy: W4>H4.

3. The battery according to claim 1 or 2, characterized in that The first empty foil area and the first gap are respectively located at two corners of the first current collector.

4. The battery according to claim 1 or 2, characterized in that The area S1 of the first empty foil region, the area S2 of the first notch, and the area S3 of the first electrode sheet satisfy: (S1+S2) / S3≤10%; And / or, the area S4 of the second empty foil region, the area S5 of the second notch, and the area S6 of the second electrode sheet satisfy: (S4+S5) / S6≤8%.

5. The battery according to claim 3, characterized in that The area S1 of the first empty foil region and the area of ​​the first electrode sheet satisfy: S1 / S3≤6%; And / or, the area S2 of the first notch and the area S3 of the first pole piece satisfy: S2 / S3≤4%; And / or, the area S4 of the second empty foil region and the area S6 of the second electrode sheet satisfy: S4 / S6≤5%; And / or, the area S5 of the second notch and the area S6 of the second pole piece satisfy: S5 / S6≤5%.

6. The battery according to claim 2, characterized in that The first empty foil area includes a first side extending along a first direction and a second side bordering the first active material layer, the first side and the second side forming a first angle α. The first notch includes a third side extending along the first direction and a fourth side bordering the first active material layer, wherein the third side and the fourth side form a second angle β. The first angle α and the second angle β satisfy: α>β.

7. The battery according to claim 6, characterized in that The second hollow foil area includes a fifth side extending along the first direction and a sixth side intersecting the second active material layer, the fifth side and the sixth side forming a third angle γ, the second notch includes a seventh side extending along the first direction and an eighth side intersecting the second active material layer, the seventh side and the eighth side forming a fourth angle θ, and the fourth angle θ satisfies: The first angle α and the fourth angle θ satisfy: α>θ, and / or the second angle β and the third angle γ satisfy: β>γ 。 8. The battery according to claim 6 or 7, characterized in that The first angle α satisfies: 20°≤α<45°.

9. The battery according to claim 2, characterized in that The extension dimension W2 of the second empty foil area along the first direction and the extension dimension W4 of the second gap along the first direction satisfy: W2≥W4.

10. The battery according to claim 2, characterized in that An extension dimension H2 of the second empty foil area along the second direction and an extension dimension H4 of the second notch along the second direction satisfy: H2 ≥ H4.

11. The battery according to claim 2, characterized in that The extension size W1 of the first empty foil area along the first direction and the extension size W2 of the second empty foil area along the first direction satisfy: 0.1mm≤W1-W2≤1.3mm; and / or, an extension dimension H1 of the first empty foil area along the second direction and an extension dimension H2 of the second empty foil area along the second direction satisfy: 0.1 mm ≤ H1 - H2 ≤ 1.3 mm; and / or, an extension dimension W3 of the first notch along the first direction and an extension dimension W4 of the second notch along the first direction satisfy: 0.1 mm ≤ W3 - W4 ≤ 1.3 mm; And / or, an extension dimension H3 of the first notch along the second direction and an extension dimension H4 of the second notch along the second direction satisfy: 0.1 mm ≤ H3 - H4 ≤ 1.3 mm.

12. The battery according to claim 2, characterized in that The first electrode has a first side edge on a side facing away from the first empty foil area. The first side edge extends along the first direction. An extension dimension L1 of the first side edge satisfies: W1+W3<L1; And / or, the second pole piece has a second side edge on a side facing away from the second empty foil area, the second side edge extends along the first direction, and an extension dimension L2 of the second side edge satisfies: W2+W4<L2.

13. The battery according to claim 2, characterized in that The first transfer tab further comprises a first transfer tab and a second transfer tab, wherein the first transfer tab comprises a first connecting portion, a projection of the first connecting portion in the thickness direction of the first electrode sheet is located within the first empty foil area, and the first connecting portion is connected to the first empty foil area; The second transfer tab includes a second connecting portion, a projection of the second connecting portion in the thickness direction of the second electrode sheet is located within the second hollow foil area, and the second connecting portion is connected to the second hollow foil area.

14. The battery according to claim 13, characterized in that An extension dimension W5 of the first connecting portion along the first direction satisfies: 2 mm ≤ W5 ≤ 10 mm; And / or, an extension dimension H5 of the first connecting portion along the second direction satisfies: 0.3mm≤H5≤5mm; And / or, an extension dimension W6 of the second connecting portion along the first direction satisfies: 2mm≤W6≤10mm; And / or, an extension dimension H6 of the second connecting portion along the second direction satisfies: 0.3mm≤H6≤5mm.

15. The battery according to claim 13, characterized in that The first hollow foil area has a first outer edge, the first outer edge extends along the second direction, and a first distance D1 is formed between the first outer edge and a side of the first connecting portion facing the first outer edge; the second hollow foil area has a second outer edge, the second outer edge extends along the second direction, and a second distance D2 is formed between the second outer edge and a side of the second connecting portion facing the second outer edge; The first distance D1 satisfies: D1 ≥ 1.5 mm, and / or the second distance D2 satisfies: D2 ≥ 1.5 mm.

16. The battery according to claim 13, characterized in that The invention also includes a first welding mark and a second welding mark, wherein the first connecting portion is connected to the first empty foil area via the first welding mark, and the second connecting portion is connected to the second empty foil area via the second welding mark; In the first direction, the first weld mark is centrally arranged on the first connecting portion, and / or, in the first direction, the second weld mark is centrally arranged on the second connecting portion.

17. The battery according to claim 16, characterized in that The length H7 of the first weld mark and the extension dimension H5 of the first connecting portion along the second direction satisfy: 0.5*H5≤H7≤H5; And / or, the length H8 of the second weld mark and the extension dimension H6 of the first connecting portion along the second direction satisfy: 0.5*H6≤H8≤H6.

18. The battery according to claim 16 or 17, characterized in that The length direction of the first weld mark is consistent with a third direction, and the third direction forms a fifth angle with the first direction; And / or, the length direction of the second weld mark is consistent with a fourth direction, and the fourth direction has a sixth angle with the first direction.

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