Pole piece, secondary battery and electronic device

Abstract

The embodiment of the utility model provides a pole piece, a secondary battery and an electronic device, the pole piece comprises a pole piece main body, the pole piece main body comprises a current collector and an active material layer, the current collector has two surfaces opposite to each other along the thickness direction of the current collector, and the active material layer covers the two surfaces; the tab extends out of the pole piece main body along a first direction, the tab comprises an array area, a plurality of first reinforcing ribs are arranged in the array area, the plurality of first reinforcing ribs respectively penetrate through the tab along a second direction perpendicular to the first direction and are mutually spaced in the first direction, the tab further comprises a first edge filling area, and the first edge filling area is arranged between the first edge filling area and the second edge filling area. At least one second reinforcing rib is arranged in the first edge filling area, and the first edge filling area is located on the side, away from the active material layer, of the array area or located on the side, close to the active material layer, of the array area. According to the technical scheme provided by the invention, active substance falling or tab foil wrinkling caused by stress concentration at least can be relieved.

Description

Technical Field

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

[0002] For secondary batteries in the field of new energy power batteries, copper foil and aluminum foil are generally used as current collectors for the electrodes. As the foil material becomes thinner, the bending strength of the foil material itself is extremely low, and the electrode tabs are prone to folding or even tearing, which greatly affects the battery production efficiency and yield.

[0003] Existing technologies improve the bending strength of the tabs by adding reinforcing ribs to the surface of the tabs. Compared with tabs without reinforcing ribs, this increases the strength of the tabs and reduces the possibility of tab bending. However, existing reinforcing rib structures still have shortcomings. For example, forming a reinforcing rib structure in existing technologies can lead to the shedding of the active material layer or wrinkling of the tab foil. Utility Model Content

[0004] In view of the problems existing in the related technologies, the purpose of this application is to provide an electrode, a secondary battery and an electronic device that can at least alleviate the loss of active material or wrinkling of electrode foil caused by stress concentration.

[0005] To achieve the above objectives, embodiments of this application provide an electrode sheet comprising: an electrode sheet body including a current collector and an active material layer, the current collector having two opposing surfaces along the thickness direction of the current collector, the active material layer covering the two surfaces; and an electrode tab extending from the electrode sheet body along a first direction, the electrode tab including an array region, the array region having a plurality of first reinforcing ribs disposed therein, the plurality of first reinforcing ribs being spaced apart from each other in the first direction, the electrode tab also including a first edge filling region, wherein at least one second reinforcing rib is disposed within the first edge filling region, the first edge filling region being located on the side of the array region away from the active material layer, or on the side of the array region closer to the active material layer.

[0006] In some embodiments, a plurality of second reinforcing ribs are provided within the first edge filling region, with the two ends of the second reinforcing ribs located at the first edge of the first edge filling region away from the array region.

[0007] In some embodiments, the first edge filling region is located on the side of the array region closer to the active material layer, wherein at least a portion of a second reinforcing rib is located on the active material layer.

[0008] In some embodiments, the tab further includes a second edge filling region, the first edge filling region is located on the side of the array region closer to the active material layer, and the second edge filling region is located on the side of the array region away from the active material layer; the first edge filling region includes a first edge away from the array region, and the second edge filling region includes a second edge away from the array region, wherein, in a second direction perpendicular to the first direction, the distribution density of multiple second reinforcing ribs in the first edge filling region along the first edge is greater than the distribution density of multiple second reinforcing ribs in the second edge filling region along the second edge, wherein a portion of the second reinforcing ribs in the first edge filling region is located on the active material layer.

[0009] In some embodiments, the tab further includes a second edge filling region, the first edge filling region is located on the side of the array region away from the active material layer, and the second edge filling region is located on the side of the array region close to the active material layer; the first edge filling region includes a first edge away from the array region, and the second edge filling region includes a second edge away from the array region, wherein, in a second direction perpendicular to the first direction, the distribution density of multiple second reinforcing ribs in the first edge filling region along the first edge is greater than the distribution density of multiple second reinforcing ribs in the second edge filling region along the second edge, wherein the foil thickness of the tab is ≤6μm.

[0010] In some embodiments, along a first direction, each adjacent pair of the first reinforcing rib and the second reinforcing rib is spaced apart from each other at equal intervals, the first minimum height of the second reinforcing rib in the first edge filling area in the first direction is h1, and the second minimum height of the second reinforcing rib in the second edge filling area in the first direction is h2, where h1 < h2.

[0011] In some embodiments, along a first direction, each adjacent pair of the first reinforcing rib and the second reinforcing rib is spaced apart from each other at equal intervals, the shape and / or size of the second reinforcing rib is different from that of the first reinforcing rib, and the first reinforcing rib has a conformal portion that is the same as or different from that of the second reinforcing rib.

[0012] In some embodiments, the array region has a recess on the side facing the first edge filling region, wherein a portion of the second reinforcing rib is located in the recess.

[0013] In some embodiments, the second reinforcing rib includes two connecting portions arranged at an angle, which are connected by an arc-shaped bend.

[0014] In some embodiments, the first reinforcing rib is wholly or partially a W-shaped reinforcing rib, wherein the protrusions of each two adjacent first reinforcing ribs that protrude away from the first direction are aligned in the first direction and spaced apart from each other.

[0015] Embodiments of this application also provide a secondary battery, which includes an electrode assembly, comprising a positive electrode, a negative electrode, and a separator located between the positive electrode and the negative electrode, wherein at least one of the positive electrode and the negative electrode is an electrode of any of the above-mentioned types.

[0016] Embodiments of this application also provide an electronic device that includes the aforementioned secondary battery.

[0017] The beneficial technical effects of this application are as follows:

[0018] By providing at least one second reinforcing rib in the first edge filling area of ​​the electrode array region near or away from the active material layer, the active material shedding caused by stress concentration can be alleviated, or the electrode foil material wrinkling caused by stress concentration can be alleviated. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1A This is a planar schematic diagram of the electrode sheet according to an embodiment of this application.

[0021] Figure 1B yes Figure 1A The diagram shows a cross-sectional view of the electrode.

[0022] Figure 2 yes Figure 1A A magnified schematic diagram of a portion of the tab of the electrode shown.

[0023] Figure 3A This is a plan view of an electrode sheet according to another embodiment of this application.

[0024] Figure 3B yes Figure 3A A magnified schematic diagram of a portion of the tab of the electrode shown.

[0025] Figure 4A and Figure 4B These are schematic planar views of electrode sheets according to other embodiments of this application.

[0026] Figure 5 A perspective view of a secondary battery according to an embodiment of this application is shown.

[0027] Figure 6A cross-sectional schematic diagram of a secondary battery according to an embodiment of this application is shown.

[0028] Figure 7 yes Figure 6 A cross-sectional schematic diagram of the electrode assembly of the secondary battery.

[0029] Figure 8 This is a schematic diagram of an electronic device in an embodiment of this application when it is a vehicle. Detailed Implementation

[0030] To better understand the spirit of the embodiments of this application, the following description is based on some preferred embodiments of this application.

[0031] Embodiments of this application will be described in detail below. Throughout this specification, identical or similar components and components having identical or similar functions are indicated by similar reference numerals. The embodiments described herein with reference to the accompanying drawings are illustrative and diagrammatic in nature and are intended to provide a basic understanding of this application. The embodiments of this application should not be construed as limiting this application.

[0032] As used herein, the terms “approximately,” “generally,” “substantially,” and “about” are used to describe and indicate minor variations. When used in conjunction with an event or situation, these terms may refer to examples in which the event or situation occurred precisely or in examples in which the event or situation occurred very approximately.

[0033] In this specification, unless otherwise specified or limited, relative terms such as “central,” “longitudinal,” “lateral,” “front,” “rear,” “right,” “left,” “inner,” “outer,” “lower,” “higher,” “horizontal,” “vertical,” “above,” “below,” “above,” “below,” “top,” “bottom,” and their derivatives (e.g., “horizontally,” “downward,” “upward,” etc.) should be interpreted as referring to the directions described in the discussion or depicted in the accompanying drawings. These relative terms are used for descriptive convenience only and do not require that this application be constructed or operated in a particular orientation.

[0034] For ease of description, "first," "second," "third," etc., can be used in this article to distinguish different components of a figure or a series of figures. "First," "second," "third," etc., are not intended to describe the corresponding components.

[0035] A rechargeable battery is a battery that can be recharged after discharge to reactivate its active materials and continue to be used. Types of rechargeable batteries include nickel-metal hydride batteries, nickel-cadmium batteries, lead-acid batteries, lithium-ion batteries, and polymer lithium-ion batteries. The electrode assembly of a rechargeable battery mainly consists of a positive electrode and a negative electrode, separated by a separator. The positive and negative electrodes are formed into an electrode assembly by winding or stacking, and then the electrode assembly is sealed in a casing to form the rechargeable battery.

[0036] The positive electrode may include a positive current collector and a positive active material layer, the positive active material layer being coated on a portion of the surface of the positive current collector. The negative electrode may include a negative current collector and a negative active material layer, the negative active material layer being coated on a portion of the surface of the negative current collector. In some embodiments, such as in a lithium-ion battery, the material of the positive current collector may be aluminum. The positive active material layer may include a positive active material, such as lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide. For high-nickel ternary lithium batteries, the positive active material may be a ternary material composed of nickel, cobalt, and manganese (or aluminum). The material of the negative current collector may be copper. The negative active material layer may include a negative active material, such as carbon or silicon. The separator material may be, for example, PP (polypropylene) or PE (polyethylene).

[0037] Figure 1A This is a planar schematic diagram of the electrode sheet according to an embodiment of this application. Figure 1B yes Figure 1A A schematic cross-sectional view of the electrode is shown. See also... Figure 1A and Figure 1B As shown, the electrode 100 includes an electrode body 160 and tabs 150 extending from the electrode body along a first direction D1 (parallel to the width direction of the electrode). The electrode body 160 includes a current collector 110 and an active material layer 130, the active material layer 130 in the electrode body 160 covering two opposing surfaces of the current collector 110 along its thickness direction. In this embodiment, the tabs 150 are formed from the portion of the current collector 110 not covered by the active material layer 130. The tabs 150 include a first edge 150a and a second edge 150b opposing each other in the first direction, the first edge 150a being the edge of the tab 150 adjacent to the active material layer 130, and the second edge 150b being the edge of the tab 150 away from the active material layer 130. In some embodiments, the size of the first edge 150a is larger than the size of the second edge 150b along a second direction D2 (parallel to the length direction of the electrode) perpendicular to the first direction D1. In some embodiments, the size of the first edge 150a may be equal to the size of the second edge 150b.

[0038] In some embodiments where electrode 100 is a negative electrode, current collector 110 is a negative current collector, and active material layer 130 is a negative active material layer. In some embodiments, the material of the negative current collector may be, for example, copper. In some embodiments where electrode 100 is a positive electrode, current collector 110 is a positive current collector, and active material layer 130 is a positive active material layer. In some embodiments, the material of the positive current collector may be aluminum.

[0039] Generally, before cutting the tabs, an active material layer 130 can be coated on the opposite surface of the current collector 110 along its thickness direction. After coating the active material layer, the uncoated area is cut or laser-cut to form the tabs 150 of the electrode sheet and the electrode body 160 coated with the active material layer. Then, the electrode sheet with the tabs formed is wound up; this process can be called winding. However, during winding, since the tabs are generally thin foils, the material of the tabs is soft and easily bent. During winding, the tabs may fold towards the coated area of ​​the active material layer and be wound into the wound electrode body. Typically, a single reinforcing rib can be formed on the tabs of the electrode sheet by roll forming to strengthen and support the tabs.

[0040] Figure 2 yes Figure 1A A magnified view of a portion of the tab of the electrode shown. See also... Figure 2 As shown, the electrode 150 may include an array region 152. Array region 152 ( Figure 2 The boundary of the array region 152 is shown by a dashed line in the middle. Multiple first reinforcing ribs 190 are provided within the region. Figure 2The diagram shows three first reinforcing ribs 190 as an example, but in other embodiments, the array region 152 may have more or fewer first reinforcing ribs 190. Multiple first reinforcing ribs 190 are spaced apart from each other along a first direction D1. For example, multiple first reinforcing ribs 190 may be equally spaced. It is understood that the first reinforcing ribs 190 may be a continuous, regular pattern or texture formed on the surface of the tab 150, with no interruption in the area of ​​the tab 150, and multiple first reinforcing ribs 190 within the array region 152 may be an array arranged according to a certain pattern. In this embodiment, each first reinforcing rib 190 is wholly or partially W-shaped. Every two adjacent first reinforcing ribs 190 may be W-shaped reinforcing ribs of the same shape and size; in other embodiments, every two adjacent first reinforcing ribs 190 may be W-shaped reinforcing ribs of different shapes or sizes. The first reinforcing rib 190 has a first protrusion 191 protruding away from the first direction D1, and a second protrusion 192 adjacent to the first protrusion 191 and protruding along the first direction D1, and a connecting portion 193 connecting the first protrusion 191 and the second protrusion 192. The connecting portion 193 may be an arc-shaped connecting portion. In some embodiments, the connecting portion 193 may be a straight portion having two parallel straight lines connecting the first protrusion 191 and the second protrusion 192, or it may be an arc portion with a certain curvature. By forming such a W-shaped reinforcing rib, it is equivalent to forming multiple dense triangular support structures on the electrode tab 150, further strengthening the support for the electrode tab.

[0041] The tab 150 may further include a first edge-filling region 154. The first edge-filling region 154 is located in the array region 152 near the active material layer 130 (see...). Figure 1A The first edge filling region 154 is located between the array region 152 and the first edge 150a of the tab 150. The first edge filling region 154 is the area between the array region 152 and the first edge 150a where a first reinforcing rib 190 cannot be provided. If such a first edge filling region 154 is not provided with any reinforcing rib, during the process of forming the reinforcing rib in the tab, the part of the continuous reinforcing rib near the first edge 150a is provided with the end of the reinforcing rib or the transition part of the reinforcing rib. During the formation of the reinforcing rib, stress concentration usually occurs, and the active material layer 130 adjacent to it will fall off due to stress concentration.

[0042] According to an embodiment of this application, a second reinforcing rib is provided within the first edge filling region 154. Figure 2In the illustrated embodiment, two second reinforcing ribs 195A and 195B are shown. The shape and / or size of each second reinforcing rib 195A and 195B differs from that of each first reinforcing rib 190. The second reinforcing ribs 195A and 195B are not continuous within the area of ​​the tab 150, but are interrupted at the first edge 150a. By providing second reinforcing ribs within the first edge filling area 154 to fill the first edge filling area 154, the shedding of active material due to stress concentration can be mitigated.

[0043] In some embodiments, each of the second reinforcing ribs 195A and 195B is not continuous, but is interrupted at the edge of the first edge filling region 154 away from the array region 152 (in this embodiment, the first edge 150a). Thus, both ends of each of the second reinforcing ribs 195A and 195B are located at the edge of the first edge filling region 154 away from the array region 152. In some embodiments, a portion of each of the second reinforcing ribs 195A and 195B is located on the active material layer 130.

[0044] In some embodiments, within the first edge filling region 154, the second reinforcing rib 195A includes two straight portions 1951 and 1952 arranged at an angle, connected by an arcuate bend 1953, thus giving the second reinforcing rib 195A an inverted V-shaped structure. The second reinforcing rib 195B includes two straight portions 1957 and 1958 arranged at an angle, connected by an arcuate bend 1959, thus giving the second reinforcing rib 195B an inverted V-shaped structure. The lengths of the straight portions 1957 and 1958 of the second reinforcing rib 195B are less than those of the straight portions 1957 and 1958 of the second reinforcing rib 195A. In other embodiments, the second reinforcing rib 195B may include only the arcuate bend 1959 or a portion thereof. Therefore, the height of the second reinforcing rib 195B in the direction toward the array region 152 is the first minimum height h1 in the first edge filling region 154, which refers to the height of the second reinforcing rib with the smallest height in the first edge filling region 154. h1 is the farthest distance of the arc bend portion 1959 of the second reinforcing rib 195B from the first edge 150a in the first direction D1.

[0045] The array region 152 has a recess 152r on the side facing the first edge filling region 154. A portion of the second reinforcing ribs 195A and 195B may be located in the recess 152r. The recess 152r may be formed by the first reinforcing rib 190 extending in a wavy shape. Such a structure is more conducive to strengthening and supporting the tabs.

[0046] Along the first direction D1, each pair of adjacent first reinforcing ribs 190 and second reinforcing ribs 195A, 195B is spaced apart from each other at equal intervals. The arcuate bends 1953 and 1959 of the second reinforcing ribs 195A and 190, and the connecting portion 193 of the first reinforcing ribs 190 may be aligned and spaced apart from each other in the first direction D1. The shape and / or size of each second reinforcing rib 195A, 195B may be the same as a portion of a single first reinforcing rib 190. In some embodiments, the shape and / or size of each second reinforcing rib 195A, 195B may differ from a portion of a single first reinforcing rib 190. As described above, in some embodiments, each second reinforcing rib 195A, 195B is interrupted at a first edge 150a, and each second reinforcing rib 195A, 195B has a portion of the first reinforcing rib 190 with the same shape and / or size as the single first reinforcing rib 190. In some embodiments, the second reinforcing ribs 195A and 195B have the same shape as the single first reinforcing rib 190 but different dimensions. For example, each second reinforcing rib 195A and 195B may be a single, complete W-shaped reinforcing rib, or a continuous reinforcing rib composed of a complete set of multiple W-shaped ribs, and have a smaller size than the single first reinforcing rib 190. In some embodiments, each second reinforcing rib 195A and 195B has the same shape as a portion of the single first reinforcing rib 190, but the size of each second reinforcing rib 195A and 195B is larger or smaller than the size of that portion of the single first reinforcing rib 190. As mentioned above, each of the second reinforcing ribs 195A and 195B has the same shape as a portion of the single first reinforcing rib 190. This can be understood as each of the second reinforcing ribs 195A and 195B being conformal to a portion of the single first reinforcing rib 190, and the conformal portion having the same or different dimensions as the second reinforcing ribs 195A and 195B. In general, the shape contour of each of the second reinforcing ribs 195A and 195B can be scaled or not scaled to coincide with a portion of the shape contour of the single first reinforcing rib 190. In some other embodiments, the pattern formed by the extension path of each of the second reinforcing ribs 195A and 195B can be a W-shape, a ring shape, a dot shape, a semi-circular arc, a circle, a triangle, or other reasonable shapes.

[0047] Furthermore, the tab 150 may also include a second edge filling region 156, which is located on the side of the array region 152 away from the active material layer 130. The second edge filling region 156 is located between the array region 152 and the second edge 150b of the tab 150. The second edge filling region 156 is the area between the array region 152 and the second edge 150b where a first reinforcing rib 190 is insufficient to be provided. In this embodiment, the second edge 150b of the tab 150 is the edge of the second edge filling region 156 away from the array region 152. A second reinforcing rib is provided within the second edge filling region 156. Figure 2 In the illustrated embodiment, two second reinforcing ribs 196A and 196B are shown. The second edge filling region 156 and the second reinforcing ribs 196A and 196B can be similar to the descriptions above regarding the first edge filling region 154 and the second reinforcing ribs 195A and 195B, respectively. Along the first direction D1, each pair of adjacent first reinforcing ribs 190 and second reinforcing ribs 195A, 195B, 196A, and 196B is spaced apart from each other at equal intervals.

[0048] In this embodiment, a portion of the second reinforcing ribs 195A and 195B in the first edge filling region 152 is located on the active material layer 130. Furthermore, in this embodiment, in the second direction D2, the distribution density of the multiple second reinforcing ribs 195A and 195B along the first edge 150a in the first edge filling region 154 is greater than the distribution density of the multiple second reinforcing ribs 196A and 196B along the second edge 150b in the second edge filling region 156. This can be understood as the distribution density of each end of the second reinforcing ribs 195A and 195B at the first edge 150a being greater than the distribution density of each end of the second reinforcing ribs 196A and 196B at the second edge filling region 156. Because the second reinforcing ribs 195A and 195B are more densely distributed near the active material layer 130, when the second reinforcing ribs 195A and 195B press against the active material layer 130, they can distribute more pressure, thereby helping to prevent the active material from detaching due to stress concentration.

[0049] Furthermore, similar to the first edge filling region 154, the second minimum height of the second reinforcing ribs 196A and 196B in the second edge filling region 156 along the first direction D1 is h2. h1 is less than h2. Since the spacing between the first reinforcing rib 190 and the second reinforcing ribs 195A, 195B, 196A, and 196B is the same, it can be considered that the second reinforcing ribs in the first edge filling region 154 are more densely packed than those in the second edge filling region 156. When the second reinforcing ribs 195A and 195B press against the active material layer 130, they can distribute more pressure, thereby helping to avoid the active material from falling off due to stress concentration.

[0050] Figure 3A This is a plan view of an electrode sheet according to another embodiment of this application. Figure 3B yes Figure 3A A magnified schematic diagram of a portion of the tab of the electrode shown. Figure 3A and Figure 3B Several aspects of the embodiments shown can be compared with those mentioned above. Figures 1A to 2 Similar to the descriptions below, the main focus is on... Figure 3A and Figure 3B The differences between the embodiments shown.

[0051] See Figure 3A and Figure 3B As shown, the first edge filling region 154 is located on the side of the array region 152 away from the active material layer 130, that is, between the array region 152 and the second edge 150b of the tab 150 away from the active material layer 130. If the first edge filling region 154 on the side of the array region 152 away from the active material layer 130 is not filled, the tab foil will easily wrinkle at this edge filling region due to stress concentration during the processing of the tab to form reinforcing ribs. By providing second reinforcing ribs 195A and 195B in the first edge filling region 154 on the side away from the active material layer 130 to fill the first edge filling region 154, the wrinkling of the tab foil caused by stress concentration can be alleviated.

[0052] In some embodiments, the foil thickness of the tab 150 is ≤6μm. Furthermore, in this embodiment, as described above, the distribution density of the second reinforcing ribs 195A and 195B along the edge of the first edge filling region 154 away from the array region 152 (in this embodiment, the second edge 150b of the tab 150) is greater than the distribution density of the second reinforcing ribs 196A and 196B along the edge of the second edge filling region 156 away from the array region 152 (in this embodiment, the first edge 150a of the tab 150). The first edge filling region 154 has a denser distribution of the second reinforcing ribs than the second edge filling region 156. When a thinner foil is used, wrinkles easily appear at the second edge 150b of the tab. By placing the denser first edge filling region 154 of the tab at the second edge 150b on the side of the tab away from the electrode body 160, wrinkles on that side of the tab can be avoided as much as possible.

[0053] Figure 4A and Figure 4B These are schematic planar views of electrode sheets according to other embodiments of this application. Figure 4A and Figure 4B Several aspects of the embodiments shown can be compared with those mentioned above. Figures 1A to 2 Similar to the descriptions below, the main focus is on... Figure 4Aand Figure 4B The differences between the embodiments shown.

[0054] See Figure 4A As shown, in this embodiment, the first edge filling region 154 is located on the side of the array region 152 near the electrode body 160. A portion of at least one second reinforcing rib within the first edge filling region 154 is located on the active material layer 130. In this embodiment, a portion of each of the two second reinforcing ribs 195A and 195B extends onto the active material layer 130, and the remaining portions of the second reinforcing ribs 195A and 195B are located in the empty foil area of ​​the electrode tab 150.

[0055] With the reinforcing ribs extending onto the active material layer 130, the height of the second reinforcing ribs 195A and 195B in the first direction D1 is limited, meaning the same pressure could subject the active material to higher pressure. Therefore, for a single reinforcing rib in the second reinforcing ribs 195A and 195B, a portion of the pressure can be shared by the empty foil portion of the tab 150 in the first direction D1, thereby reducing the pressure on the active material region and mitigating the risk of overpressure in the active material region.

[0056] As referenced above Figure 2 As described, the second reinforcing ribs in the first edge filling region 154 are more densely packed than those in the second edge filling region 156. When the denser reinforcing ribs in the first edge filling region 154 press against the active material layer 130, they can distribute more pressure, reducing the risk of overpressure on the active material region.

[0057] See Figure 4B As shown, in this embodiment, a portion of the active material layer 130 extends into the tab 150, and the active material layer 130 and the empty foil area of ​​the tab 150 are connected at the edge 130a of the active material layer 130. A portion of the two second reinforcing ribs 195A and 195B in the first edge filling region 154 can extend to the portion of the active material layer 130 coated on the tab 150, but not to the electrode body 160; the remaining portions of the second reinforcing ribs 195A and 195B are located in the empty foil area of ​​the tab 150. As described above, when the denser reinforcing ribs in the first edge filling region 154 press against the active material layer 130, more pressure can be distributed, reducing the risk of overpressure in the active material area.

[0058] In one example, the second reinforcing ribs 195A and 195B extend from the empty foil area of ​​the tab 150 to the active material layer 130, while the first reinforcing rib 190 in the array region 152 avoids the active material layer 130 (i.e. does not extend to the active material layer 130).

[0059] Figure 5A perspective view of a secondary battery according to an embodiment of this application is shown. Figure 6 A cross-sectional schematic diagram of a secondary battery according to an embodiment of this application is shown. Figure 7 yes Figure 6 A cross-sectional schematic diagram of the electrode assembly of the secondary battery.

[0060] Combination Figures 5 to 6 As shown, the secondary battery 500 may include a housing 200, which includes a peripheral sidewall 109 and an end wall 111 connected to one end of the peripheral sidewall 109. An opening 205 is provided at the other end of the peripheral sidewall 109 opposite to the end wall 111. A top cover assembly 220 covers the opening 205 of the housing 200 to define a receiving cavity together with the housing 200, in which the electrode assembly 120 is located.

[0061] The direction from end wall 111 to top cover assembly 220 is the height direction Z of secondary battery 500. Height direction Z can correspond to the direction D1 mentioned above. In this embodiment, two electrode assemblies 120 are stacked in housing 200 along the thickness direction of electrode assembly 120. In other embodiments, more than two electrode assemblies 120 can be provided in housing 200.

[0062] In some embodiments, see Figure 7 As shown, the electrode assembly 120 is a wound body formed by winding a first electrode 201, a second electrode 202, and a separator 204 located between the first electrode 201 and the second electrode 202. In other embodiments, the electrode assembly 120 may also be a stacked body formed by sequentially stacking the first electrode 201, the second electrode 202, and the separator 204 located between the first electrode 201 and the second electrode 202. The electrode assembly 120 may be flat. Correspondingly, the housing 200 may be flat and have a cuboid shape. The plurality of first tabs 121 of the first electrode 201 and the plurality of second tabs 122 of the second electrode 202 may be stacked in the thickness direction of the electrode assembly 120.

[0063] Combination Figures 5 to 7As shown, the top cover assembly 220 includes a top cover body 221 and a first electrode terminal 223 and a second electrode terminal 224 disposed on the top cover body 221. The first electrode terminal 223 and the second electrode terminal 224 can pass through the top cover body 221 and are insulated from the top cover body 221. One of the first electrode terminal 223 and the second electrode terminal 224 is a positive terminal and the other is a negative terminal. The electrode assembly 120 has a tab at one end facing the top cover assembly 220. In this embodiment, the first tab 121 and the second tab 122 at one end of the electrode assembly 120 are respectively connected to the corresponding first electrode terminal 223 and the second electrode terminal 224. In some embodiments, the first tab 121 and the first electrode terminal 223, and the second tab 122 and the second electrode terminal 224 can be connected by corresponding adapter pieces 226. The first tab 121 and the second tab 122 can be bent and welded to the adapter piece 226.

[0064] In some embodiments, one of the first electrode 201 and the second electrode 202 is a positive electrode, and the other is a negative electrode. In some embodiments, at least one of the positive and negative electrodes of the electrode assembly 120 is the aforementioned electrode 100. Correspondingly, one of the first tab 121 and the second tab 122 is a positive tab, and the other is a negative tab. At least one of the positive and negative tabs of the electrode assembly 120 is the tab 150 of the aforementioned electrode 100. In some embodiments, the negative electrode of the electrode assembly 120 is the aforementioned electrode 100, and the negative tab is the aforementioned tab 150.

[0065] It should be understood that Figures 5 to 7 The example given is a prismatic secondary battery. The electrode 100 described above can also be used to form any other suitable type of secondary battery, such as a pouch cell or a cylindrical cell.

[0066] Figure 8 A schematic diagram is shown when the electronic device according to an embodiment of this application is a vehicle. See also Figure 8This application also provides an electronic device 1000. For ease of explanation, the following embodiments use a vehicle as an example. A battery pack 1002 is installed inside the vehicle. The battery pack 1002 can be located at the bottom, front, or rear of the vehicle body 1001. The battery pack 1002 can be used to power the vehicle; for example, it can serve as the vehicle's operating power source. The working part of the electronic device 1000 is electrically connected to the battery pack 1002 to obtain electrical power. The vehicle can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, but are not limited thereto. The working part is the vehicle body, and the battery pack 1002 is located at the bottom of the vehicle body, providing electrical power for the vehicle's movement or the operation of its internal electrical components. However, in other embodiments, the electronic device 1000 can also be a mobile phone, portable device, laptop computer, ship, spacecraft, electric toy, power tool, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc.; the working unit can obtain electrical energy from the battery pack 1002 and perform corresponding work, such as the fan blade rotation unit of a fan, the vacuuming unit of a vacuum cleaner, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc.; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. This application embodiment does not impose any special limitations on the above-described electronic device 1000. The battery pack 1002 may include multiple secondary batteries, such as the secondary battery 500 described above.

[0067] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An electrode sheet, characterized in that, include: The electrode body includes a current collector and an active material layer, wherein the current collector has two opposing surfaces along the thickness direction of the current collector, and the active material layer covers the two surfaces; as well as An electrode tab extends from the electrode body along a first direction. The electrode tab includes an array region, within which multiple first reinforcing ribs are disposed. The multiple first reinforcing ribs are spaced apart from each other along the first direction. The electrode tab also includes a first edge filling region, wherein at least one second reinforcing rib is provided in the first edge filling region. The first edge-filled region is located on the side of the array region away from the active material layer, or on the side of the array region closer to the active material layer.

2. The electrode sheet according to claim 1, characterized in that, Multiple second reinforcing ribs are provided within the first edge filling region, with the two ends of the second reinforcing ribs located at the first edge of the first edge filling region away from the array region.

3. The electrode sheet according to claim 1, characterized in that, The first edge-filled region is located on the side of the array region closest to the active material layer. At least one of the second reinforcing ribs extends onto the active material layer.

4. The electrode sheet according to claim 1, characterized in that, The electrode also includes a second edge filling region, wherein the first edge filling region is located on the side of the array region closer to the active material layer, and the second edge filling region is located on the side of the array region away from the active material layer; The first edge filling region includes a first edge remote from the array region, and the second edge filling region includes a second edge remote from the array region. In a second direction perpendicular to the first direction, the distribution density of the plurality of second reinforcing ribs along the first edge within the first edge filling region is greater than the distribution density of the plurality of second reinforcing ribs along the second edge within the second edge filling region. A portion of the second reinforcing rib within the first edge filling area is located on the active material layer.

5. The electrode sheet according to claim 1, characterized in that, The electrode also includes a second edge filling region, wherein the first edge filling region is located on the side of the array region away from the active material layer, and the second edge filling region is located on the side of the array region closer to the active material layer; The first edge filling region includes a first edge remote from the array region, and the second edge filling region includes a second edge remote from the array region. In a second direction perpendicular to the first direction, the distribution density of the plurality of second reinforcing ribs along the first edge within the first edge filling region is greater than the distribution density of the plurality of second reinforcing ribs along the second edge within the second edge filling region. The foil thickness of the electrode tab is ≤6μm.

6. The electrode sheet according to claim 4 or 5, characterized in that, Along the first direction, each adjacent pair of the first and second reinforcing ribs is spaced apart from each other at equal intervals. The first minimum height of the second reinforcing rib in the first edge filling area in the first direction is h1, and the second minimum height of the second reinforcing rib in the second edge filling area in the first direction is h2, where h1 < h2.

7. The electrode sheet according to claim 1, characterized in that, Along the first direction, each adjacent pair of the first and second reinforcing ribs is spaced apart from each other at equal intervals. The shape and / or size of the second reinforcing rib is different from that of the first reinforcing rib, and the first reinforcing rib has a conformal portion that is the same as or different from that of the second reinforcing rib.

8. The electrode sheet according to claim 1, characterized in that, The array region has a recess on one side facing the first edge filling region, wherein a portion of the second reinforcing rib is located in the recess.

9. The electrode sheet according to claim 1, characterized in that, The second reinforcing rib includes two connecting parts arranged at an angle, which are connected by an arc-shaped bend.

10. The electrode sheet according to claim 1, characterized in that, The first reinforcing rib is wholly or partially W-shaped, wherein the protrusions of each two adjacent first reinforcing ribs that protrude away from the first direction are aligned in the first direction and spaced apart from each other.

11. A secondary battery, characterized in that, include: A positive electrode, a negative electrode, and a separator located between the positive electrode and the negative electrode, wherein at least one of the positive electrode and the negative electrode is an electrode as described in any one of claims 1-10.

12. An electronic device, characterized in that, Includes the secondary battery as described in claim 11.

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