Pole piece, secondary battery and electronic device

Abstract

The utility model provides a pole piece which comprises a pole piece main body and a pole lug protruding from the pole piece main body along a first direction, the pole lug is provided with a reinforcing rib array, and the reinforcing rib array comprises a plurality of first reinforcing ribs; and in the first direction, every two adjacent first reinforcing ribs are separated from each other. The utility model aims to provide a pole piece, a secondary battery and an electronic device so as to at least enhance the supporting force on a tab.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of pole piece, secondary battery and electronic device. BACKGROUND

[0002] In the field of new energy power battery, the application of secondary battery is more and more widely, such as secondary battery (for example, lithium ion battery) can be applied to car, energy storage, mobile phone, tablet computer, wearable device, mobile power supply, electronic cigarette, digital product, electric tool, power device, energy storage device and other electronic devices. Secondary battery usually includes shell and electrode assembly, electrode assembly includes positive pole piece, first diaphragm, negative pole piece and second diaphragm, which are stacked in sequence to make wound electrode assembly or laminated electrode assembly, and then packaged in shell.

[0003] However, the tab is prone to folding during the production process, especially during the die cutting (or laser cutting) and winding process. SUMMARY

[0004] To solve the problems in the related art, the utility model aims to provide a kind of pole piece, secondary battery and electronic device, to at least enhance the support force of tab.

[0005] To achieve the above-mentioned purpose, the utility model provides a kind of pole piece, including: pole piece main body and tab that protrudes from pole piece main body along first direction, tab is provided with reinforcement rib array, reinforcement rib array includes a plurality of first reinforcement rib;Wherein, along the first direction, every two adjacent first reinforcement rib is spaced apart from each other.

[0006] In some embodiments, the minimum spacing of the two adjacent first reinforcement ribs in the first direction is a, the tab has a height h in the first direction, and the ratio of a to h is in the range of 0.08-0.5.

[0007] In some embodiments, the first reinforcement rib has at least one first bending portion, the inner angle of the first bending portion faces the pole piece main body, and the first bending portions of every two adjacent first reinforcement ribs are aligned in the first direction and spaced apart by a minimum spacing a along the first direction.

[0008] In some embodiments, the ratio of a to h is in the range of 0.15-0.35.

[0009] In some embodiments, the ratio of a to the thickness of the tab is in the range of 200-4000.

[0010] In some embodiments, in the direction perpendicular to the extension path of the first reinforcement rib, the maximum width of a single first reinforcement rib is y, and the ratio of y to a is in the range of 0.05-0.5.

[0011] In some embodiments, each first reinforcing rib has: first bending portions and second bending portions alternately distributed along a second direction, an inner angle of the first bending portion faces the pole piece body, an inner angle of the second bending portion faces away from the pole piece body, and a connecting portion connecting the second bending portion and the first bending portion, the second direction is perpendicular to the first direction; wherein the second bending portion and the first bending portion are circular arc transitions, the maximum width of the circular arc transition in the radius direction is y1, the width of the connecting portion perpendicular to the extension direction of the connecting portion is y2, and the ratio of y1 to y2 is in the range of 1.2-2.5.

[0012] In some embodiments, the distance between the vertexes of the two adjacent first bending portions of a single first reinforcing rib is b, wherein, in the second direction, the tab has a maximum width c1 and a minimum width c2, wherein: the ratio of c1 to b is in the range of 1.5-3, and / or, the ratio of c2 to b is in the range of 1.5-3.

[0013] In some embodiments, the first reinforcing rib is filled with a second reinforcing rib in the area enclosed by the edge of the tab and the first reinforcing rib arranged on both sides or one side edge of the tab along the first direction, the shape and / or size of the second reinforcing rib is different from that of the first reinforcing rib.

[0014] In some embodiments, the first reinforcing rib has a conformal portion with the second reinforcing rib, wherein the conformal portion is the same size as or different from the second reinforcing rib.

[0015] In some embodiments, the minimum distance between the conformal portion of the adjacent first reinforcing rib and the second reinforcing rib in the first direction is a,

[0016] The minimum distance between any two adjacent first reinforcing ribs in the first direction in the reinforcing rib array is a.

[0017] In some embodiments, along the first direction, each first reinforcing rib includes a nearest end close to the pole piece body and a farthest end away from the pole piece body; wherein the distance between the farthest end of the first reinforcing rib close to the pole piece body and the pole piece body in the two adjacent first reinforcing ribs is d1, the distance between the nearest end of the first reinforcing rib away from the pole piece body and the pole piece body is d2, and d1 is greater than d2.

[0018] In some embodiments, there is no intersection between each first reinforcing rib in the reinforcing rib array.

[0019] In some embodiments, the first reinforcing rib is a strip-shaped groove or a plurality of triangular grooves connected together.

[0020] Embodiments of the present application also provide a secondary battery comprising the pole piece of any one of the above.

[0021] The embodiment of the present application also provides an electronic device comprising the secondary battery of any one of the above.

[0022] The embodiment of the present application has at least the following beneficial technical effects:

[0023] The tab of the embodiment of the present application is provided with a rib array, the rib array comprises a plurality of first ribs, and each adjacent two first ribs are spaced apart from each other along a first direction, so that the support force on the tab is strengthened, and the risk of tab folding is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings required to be used in the embodiment or prior art description will be briefly introduced below, and obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0025] Figure 1 A schematic diagram of an electronic device exemplified by a vehicle is shown.

[0026] Figure 2 A three-dimensional schematic diagram of a secondary battery according to an embodiment of the present application is shown.

[0027] Figure 3 A cross-sectional schematic diagram of a secondary battery according to an embodiment of the present application is shown.

[0028] Figure 4 A three-dimensional schematic diagram of a secondary battery exemplified by a square cell according to another embodiment of the present application is shown.

[0029] Figure 5 A schematic diagram of a tab according to an embodiment of the present application is shown.

[0030] Figure 6A A schematic diagram of a tab according to an embodiment of the present application is shown.

[0031] Figure 6B A schematic diagram of a tab according to another embodiment of the present application is shown.

[0032] Figure 7 A schematic diagram of a single first rib according to an embodiment of the present application is shown.

[0033] Figure 8 A schematic diagram of a tab according to another embodiment of the present application is shown.

[0034] Figures 9A-9C A schematic diagram of a pattern of first ribs according to some embodiments of the present application is shown.

[0035] Figures 10A-10B A schematic diagram showing the pattern of a first reinforcing rib according to some embodiments of this application is provided.

[0036] Figures 11A-12B A schematic diagram showing the pattern of a first reinforcing rib according to some embodiments of this application is provided.

[0037] Figures 13A-13B A schematic diagram showing the pattern of a first reinforcing rib according to some embodiments of this application is provided. Detailed Implementation

[0038] To better understand the spirit of the embodiments of this application, the following description is based on some preferred embodiments of this application.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] Figure 1 A schematic diagram of an electronic device is shown, using vehicle 1000 as an example. See also Figure 1The following embodiments are described with reference to the electronic device being a vehicle 1000 for ease of illustration. It should be appreciated, however, that the electronic device provided by the present application is not limited to a vehicle, and the electronic device can be a vehicle, a mobile phone, a portable device, a notebook computer, a ship, a spacecraft, an electric toy, an electric tool, and the like.

[0044] The vehicle 1000 can be provided with a battery pack 1002, which can be arranged at the bottom of the vehicle body 1001 (as shown in Figure 1 ), or at the head, or at the tail, or at any other appropriate position. The battery pack 1002 can be used for power supply of the vehicle 1000, for example, the battery pack 1002 can be used as an operating power source or a driving power source of the vehicle 1000. The battery pack 1002 can include a plurality of secondary batteries (such as the secondary battery 100A described with reference to Figure 2 and Figure 3 , or the secondary battery 100B described with reference to Figure 4 ) and a box assembly accommodating the plurality of secondary batteries.

[0045] It should be understood that the secondary battery in the present application can be a secondary battery of various shapes, such as a cylindrical shape, a flat shape, a cuboid shape, or other shapes, and the embodiments of the present application do not limit the shape of the secondary battery. On the other hand, the secondary battery in the present application can be a lithium ion battery, a lithium-sulfur battery, a sodium lithium ion battery, a sodium ion battery, and the like, and the embodiments of the present application do not limit the type of the secondary battery.

[0046] Figure 2 A perspective view of a secondary battery 100A according to an embodiment of the present application is shown. In the embodiment shown in Figure 2 , the secondary battery 100A is shown as a cylindrical battery as an example. Figure 3 A cross-sectional view of the secondary battery 100A according to an embodiment of the present application is shown. In the embodiment shown in Figure 2 and Figure 3As shown, the secondary battery 100A can include an electrode assembly 120, an electrolyte, a case 200, and an end cover 202. The case 200 can have an opening 205 at one end in a height direction, and the end cover 202 is arranged at the opening 205 and seals the accommodation cavity. The case 200 and the end cover 202 are components that collectively accommodate the electrode assembly 120 and the electrolyte. The case 200 can be made of any of a variety of available materials, such as copper, iron, aluminum, steel, aluminum alloy, etc. The case 200 can be cylindrical and define an accommodation cavity in which the electrode assembly 120 is arranged. The diameter of the case 200 can be determined according to the specific size of the electrode assembly 120, such as 18 mm, 21 mm, 46 mm, etc. In some embodiments, the secondary battery 100A can be a 4680 cylindrical battery (diameter 46 mm, height 80 mm), the secondary battery 100A can be a 4695 cylindrical battery (diameter 46 mm, height 95 mm), or the secondary battery 100A can be a 46120 cylindrical battery (diameter 46 mm, height 120 mm).

[0047] The case 200 can be connected to the negative electrode of the electrode assembly 120. The secondary battery 100A can also have a pole 208 at one end relative to the end cover 202, which can be connected to the positive electrode of the electrode assembly 120. It should be understood that the pole 208 and the case 200 are in an insulating fit state to avoid short circuiting of the battery.

[0048] In some embodiments, the electrode assembly 120 can include a first electrode sheet, a first separator, a second electrode sheet, and a second separator stacked in sequence. In this embodiment, the stacked first electrode sheet, first separator, second electrode sheet, and second separator can be wound to form a cylindrical electrode assembly 120. The electrode assembly 120 is provided with a first tab and a second tab at both ends in the height direction h of the secondary battery 100. The electrolyte can be located between the first electrode sheet, the first separator, the second electrode sheet, and the second separator. In some embodiments, the first electrode sheet is a positive electrode sheet, and the second electrode sheet is a negative electrode sheet. In some embodiments, the positive electrode tab faces the end wall 111 and is electrically connected to the pole 208 to make the pole 208 positively charged; the negative electrode tab faces the opening 205, and the case 200 is electrically connected to the negative electrode tab to make it negatively charged.

[0049] Figure 4 A perspective view of a secondary battery 100B in the form of a square cell according to another embodiment of the application is shown. In Figure 4 the secondary battery 100B is a square cell. In combination with Figure 2 and Figure 3As shown, the secondary battery 100B can include a housing 400 and a cover plate assembly 402. The housing 400 can have a flat cuboid shape. The housing 400 can have an opening (not shown) at one end in the height direction, and the cover plate assembly 402 is arranged at the opening. The cover plate assembly 402 is provided with a first pole 411, a second pole 412, and an explosion-proof valve 413. In some embodiments, the first pole 411 and the second pole 412 are used as the positive pole and the negative pole, respectively.

[0050] The positive electrode tab in the secondary battery (such as the secondary battery 100A, 100B) can include a positive electrode current collector and a positive electrode active material layer coated on both side surfaces of the positive electrode current collector. The part of the positive electrode current collector that is not coated with the positive electrode active material layer constitutes the positive electrode tab. The negative electrode tab can include a negative electrode current collector and a negative electrode active material layer coated on both side surfaces of the negative electrode current collector. The part of the negative electrode current collector that is not coated with the negative electrode active material layer constitutes the negative electrode tab. Taking a lithium ion battery as an example, the material of the positive electrode current collector can be aluminum, the positive electrode active material layer can include a positive electrode active material, and the positive electrode active material can be lithium cobaltate, lithium iron phosphate, ternary lithium, or lithium manganate, etc. The material of the negative electrode current collector can be copper, the negative electrode active material layer can include a negative electrode active material, and the negative electrode active material can be carbon or silicon, etc. In some embodiments, the material of the first and second separators can be, for example, PP (polypropylene), PE (polyethylene), or the like.

[0051] Figure 5 A schematic diagram of the tab 300 according to an embodiment of the present application is shown. The tab 300 includes a tab body 310, and a tab ear 320 protruding from the tab body 310 in a first direction F, the tab ear 320 being provided with an array of reinforcing ribs 321. In some embodiments, the array of reinforcing ribs 321 is arranged on the surface of the tab ear 320. The array of reinforcing ribs 321 includes a plurality of first reinforcing ribs 322, each adjacent two first reinforcing ribs 322 being spaced apart from each other along the first direction F. It can be understood that the formation of the first reinforcing ribs involved in the present application can be realized by rolling or stamping, etc., for example, the tab ear is rolled by a embossing roller provided with convex ribs on the surface, so that grooves are left on the tab ear to form the first reinforcing ribs, but it is not limited thereto. In some embodiments, the first reinforcing rib 322 is a continuous groove formed on the surface of the tab ear 320, and the texture formed by the extension path of the first reinforcing rib 322 can be a regular pattern, and a single first reinforcing rib 322 does not interrupt in the area of the tab ear 320, and the array formed by a plurality of single first reinforcing ribs 322 according to a certain rule is the array of reinforcing ribs 321. The tab ear 320 can be the positive electrode tab ear or the negative electrode tab ear described above.

[0052] Generally, for the prior art, before forming the tab of the pole piece, the active material layer is coated on part of the front and back of the pole piece to form a coated area, and the uncoated area is generally located in the wide edge area of the pole piece. After the active material layer is coated, the uncoated area is cut or laser cut to form the tab of the pole piece, and then the pole piece with the tab is wound, which can be called winding. However, during the winding process, the tab of the pole piece is generally a thin foil, and the material of the tab is soft and easy to bend. During the winding process, the tab may be folded towards the coated area coated with the active material layer and wound into the main body of the pole piece being wound, and does not protrude relative to the main body of the pole piece. It is likely that the tab will be folded and inserted into the winding core and overlapped with the main body of the pole piece, forming a defect. Moreover, in the secondary battery, since the tab bears the function of transmitting current, the folded tab will enter the secondary battery during the subsequent processing process. The current cannot flow out of the folded tab, resulting in increased internal resistance. More seriously, the folded tab inserted into the winding core may be short-circuited by the positive and negative electrodes, affecting the safety performance of the battery. In this case, before the tab 320 of the pole piece 300 is formed, the first reinforcing ribs 322 are formed on the surface of the tab 320 to strengthen the support of the tab 320. However, generally, the reinforcing ribs rolled on the tab of the prior art are generally single, and there are many blank areas without reinforcing ribs on the tab. According to the pole piece 300 of the present application, by arranging a reinforcing rib array 321 with a plurality of first reinforcing ribs 322 on the tab 320, and spacing the adjacent two first reinforcing ribs 322 from each other along the first direction F, the surface of the tab 320 is covered with as many first reinforcing ribs 322 as possible, and a dense reinforcing rib array 321 is formed to obtain a stronger support effect on the tab 320.

[0053] Figure 6AA schematic view of the tab 320 is shown according to an embodiment of the present application. The extension path of the first reinforcing ribs 322 forms a pattern, which can have various shapes. As a preferred embodiment, the first reinforcing ribs 322 can be W-shaped reinforcing ribs with a W-shaped pattern, and further, every two adjacent first reinforcing ribs 322 in the reinforcing rib array 321 can be W-shaped reinforcing ribs. It can be understood that, in some embodiments, each first reinforcing rib 322 has at least one second bending portion 3221 and at least one first bending portion 3222 alternately distributed along a second direction, and along a first direction F, the inner angle of the second bending portion 3221 faces away from the tab main body 310, and the inner angle of the first bending portion 3222 faces toward the tab main body 310, and the second direction is perpendicular to the first direction. In another embodiment, it can be understood that the first reinforcing rib 322 is V-shaped, and the first reinforcing rib 322 can be a single V-shaped reinforcing rib or a continuous reinforcing rib formed by connecting multiple V-shaped reinforcing ribs. As a preferred embodiment, the inner angle of the V-shaped first reinforcing rib 322 faces toward the tab main body 310, rather than the inner angle of the V-shaped first reinforcing rib 322 facing away from the tab main body, because when the first reinforcing rib 322 in the reinforcing rib array 321 is too loose, the effect of improving the support of the tab 320 by facing the inner angle of the V-shaped first reinforcing rib 322 toward the tab main body 310 is better than facing the inner angle of the V-shaped first reinforcing rib 322 away from the tab main body 310. However, in some embodiments, when the number of first reinforcing ribs 322 in the reinforcing rib array 321 is larger and has a higher density of first reinforcing ribs 322, if the inner angle of the V-shaped first reinforcing rib 322 is arranged to face away from the tab main body 310, the reinforcing effect of the first reinforcing rib 322 on the tab 320 is also sufficient. It can also be understood that, in some embodiments, the first reinforcing rib 322 has a second bending portion 3221 protruding away from the first direction F, and has a first bending portion 3222 adjacent to the second bending portion 3221 and protruding along the first direction F, and a connecting portion 3223 connecting the second bending portion 3221 and the first bending portion 3222. In another embodiment, the first bending portion 3222 and the second bending portion 3221 have a concave side facing the bending direction of the first bending portion 3222 and the second bending portion 3221 itself, and a convex side facing away from the bending direction of the first bending portion 3222 and the second bending portion 3221 itself, and the second bending portion 3221 and the first bending portion 3222 are alternately arranged in the second direction, the concave side of the second bending portion 3221 faces away from the tab main body 310, and the concave side of the first bending portion 3222 faces toward the tab main body 310.

[0054] It can be understood that the connecting portion 3223 is a smooth section connecting the second bending portion 3221 and the first bending portion 3222. In some embodiments, the connecting portion 3223 can be a straight section connecting the second bending portion 3221 and the first bending portion 3222, or can be an arc section with a certain arc. Preferably, by forming such a W-shaped reinforcing rib, a plurality of compact triangular support structures are formed on the tab 320, further strengthening the support of the tab 320.

[0055] In some embodiments, in order to control the compactness of the reinforcing rib array 321, the minimum spacing a of two adjacent first reinforcing ribs 322 in the first direction F is a, the tab 320 has a height h in the first direction F, and the ratio of a to the height h of the tab 320 in the first direction F is within the range of 0.08-0.5. If the ratio is too high, higher than 0.5, the reinforcing rib array 321 is loose, and the reinforcing effect is reduced; if the ratio is too small, smaller than 0.08, the reinforcing rib array 321 is too compact, and the stress is too large to press the tab 320 when rolling to form the first reinforcing rib 322. As preferred, the ratio is within the range of 0.15-0.35, which can better balance the reinforcing effect of the tab 320 and the stress reduction when rolling. In some embodiments, the minimum spacing a of the second bending portion 3221 of every two adjacent first reinforcing ribs 322 in the first direction F is a, that is, the minimum spacing a of two adjacent first reinforcing ribs 322 in the first direction F is the minimum spacing a of the second bending portion 3221 of two adjacent first reinforcing ribs 322. In some embodiments, the second bending portion 3221 and / or the first bending portion 3222 of every two adjacent first reinforcing ribs 322 are not aligned in the first direction F, at this time, the minimum spacing a between two adjacent first reinforcing ribs 322 in the first direction F is a. In some embodiments, along the first direction F, the distance between each point on a single first reinforcing rib 322 and the nearest point on another first reinforcing rib 322 adjacent to the first reinforcing rib 322 is equal, at this time, the distance is defined as a. In other embodiments, similarly, the minimum spacing a of the first bending portion 3222 of every two adjacent first reinforcing ribs 322 in the first direction F is a.

[0056] In some embodiments, the ratio of a to the thickness of the tab 320 is in the range of 200-4000. It can be appreciated that in some embodiments, the active material layers on the front and back surfaces of the tab body 310 can extend onto the surfaces of the tab 320, however the thickness of the tab 320 in this case does not include the thickness of the active material layers that can extend onto the front and back surfaces of the tab 320, but only includes the thickness of the foil material of the tab 320. It can be appreciated that for a tab 320 of a certain thickness, a relatively dense array of the reinforcing ribs 321, while providing a better reinforcing effect, is prone to crushing the tab 320 and causing the tab 320 to crack. For example, when the ratio of a to the thickness of the tab 320 is less than 200, it indicates that the minimum spacing a is set to be too small and the thickness of the tab 320 is set to be too large, and the dense first reinforcing ribs are prone to crushing the tab 320 and causing the tab 320 to crack. For another example, when the ratio of a to the thickness of the tab 320 is greater than 4000, it indicates that the minimum spacing a is set to be too large and the thickness of the tab 320 is set to be too small, and the sparse first reinforcing ribs provide a limited reinforcing effect on the tab 320 and are insufficient to alleviate or solve the problem of the tab 320 being folded over.

[0057] In some embodiments, the first reinforcing rib 322 is a W-shaped reinforcing rib as a whole or in part. The first reinforcing rib 322 that is a W-shaped reinforcing rib in part can be a wavy first reinforcing rib 322 formed by one or more W-shaped reinforcing ribs connected together.

[0058] Further, each two adjacent first reinforcing ribs 322 can be W-shaped reinforcing ribs of the same shape and size, or W-shaped reinforcing ribs of different shapes and sizes. In some embodiments, when each two adjacent first reinforcing ribs 322 in the array of reinforcing ribs 321 are W-shaped reinforcing ribs of the same shape and size, the maximum width y of a single first reinforcing rib 322 in a direction perpendicular to the extension path of the first reinforcing rib 322 is in the range of 0.05-0.5 times a. For example Figure 6A The maximum width y of a single first reinforcing rib 322 is shown in FIG. 15A as the width of the second bending portion 3221 perpendicular to the extension path thereof. Accordingly, in some embodiments, the maximum width y of a single first reinforcing rib 322 can be the width of the first bending portion 3222 perpendicular to the extension path thereof.

[0059] In one example of a W-shaped reinforcing rib, each two adjacent connecting portions 3223 in the first reinforcing rib 322 are connected by a transition portion, wherein the width of the transition portion in a direction perpendicular to the extension path thereof is the maximum width of a single first reinforcing rib 322 and is wider than the width of the connecting portion 3223, so as to avoid the problem of wrinkles easily occurring in the area between the upper and lower adjacent first reinforcing ribs 322.

[0060] It is obvious to understand that, in terms of shape, the transition is the second bending portion 3221 and the first bending portion 3222 of the first reinforcing rib 322. In addition, the transition is a circular arc transition, which will be further described in Figure 7 It is understood that if the ratio is too small, it means that the maximum width y of the single first reinforcing rib 322 is set too small relative to the minimum spacing a, less than 0.05, and the reinforcing strength is not enough; if the ratio is too large, it means that the maximum width y of the single first reinforcing rib 322 is set too large relative to the minimum spacing a, greater than 0.5, and the tab 320 is easily crushed.

[0061] Figure 6B A schematic diagram of a tab 320 according to another embodiment of the present application is shown. In some embodiments, the spacing between the two adjacent first bending portions 3222 of a single first reinforcing rib 322 along the first direction away from the vertex of the tab body 310 is b, and in the width direction of the tab 320 perpendicular to the first direction F (i.e. the second direction as described above), the tab 320 has a maximum width c1 and a minimum width c2, the ratio of c1 to b is in the range of 1.5-3, and the ratio of c2 to b is in the range of 1.5-3. When the ratio is greater than 1.5, it can ensure that the reinforcing rib array 321 with at least one W-shaped first reinforcing rib 322 is formed on the tab 320 after rolling to ensure the reinforcing effect; but if the ratio is too large, for example, greater than 3, the reinforcing rib array 321 formed at this time is too dense, and the tab 320 is easily crushed.

[0062] Figure 7A schematic view of a single first reinforcing rib 322 according to an embodiment of the application is shown. In some embodiments, the second bending portion 3221 and the first bending portion 3222 are circular arc transitions, and the maximum width of the circular arc transitions in the radius direction is y1 (at this time y1 is the maximum width y of the single first reinforcing rib 322), the width of the connecting portion 3223 perpendicular to the extension direction of the connecting portion 3223 is y2, and the ratio of y1 to y2 is in the range of 1.2-2.5. It can also be understood that, in some embodiments, when the second bending portion 3221 and the first bending portion 3222 are circular arc transitions, the internal angle of the second bending portion 3221 and the first bending portion 3222 at this time can be the included angle of the tangent lines of the two end points of the circular arc segment. In some embodiments, the second bending portion 3221 and the first bending portion 3222 have a circular arc segment and two straight line segments respectively connecting the two end portions of the circular arc segment, and at this time the internal angle of the second bending portion 3221 and the first bending portion 3222 can be the included angle of the two straight line segments. It can also be understood that, if the ratio of y1 to y2 is lower than the lower limit value 1.2, it is difficult to form a smooth fillet of the circular arc transition, and in the formation of the first reinforcing rib 322, for example, in the rolling process to form the first reinforcing rib 322, the tab 320 is easily damaged, and if the ratio is higher than the upper limit value 2.5, wrinkles are easily generated in the area between adjacent first reinforcing ribs 322 during the rolling process, for example, Figure 7 The plurality of semi-enclosed triangular regions formed by the first reinforcing ribs 322 shown are prone to wrinkles, which is not conducive to the subsequent welding of the tab 320.

[0063] Figure 8 A schematic view of a tab 320 according to another embodiment of the application is shown. In some embodiments, the area enclosed by the first reinforcing ribs 322 arranged on the edges of both sides or one side of the tab 320 along the first direction F is filled with second reinforcing ribs 350, and the shape and / or size of the second reinforcing ribs 350 are different from those of the first reinforcing ribs 322. As an example, in some embodiments, along the first direction F, the edges on both sides of the tab include a lower edge 326 connected to the tab body 310 and an upper edge 327. The area enclosed by the first reinforcing ribs 322 (which can also be understood as one of the first reinforcing ribs 322 closest to the lower edge 326 in the reinforcing rib array 321 and one of the first reinforcing ribs 322 closest to the upper edge 327 in the reinforcing rib array 321) arranged on the edges (the lower edge 326 and / or the upper edge 327) of both sides or one side of the tab 320 along the first direction F has second reinforcing ribs 350 filled in the area (for the convenience of understanding, the second reinforcing ribs 350 are shown in the area enclosed by the first reinforcing ribs 322 in the figure). Figure 8The second reinforcing ribs 350 are shown in lighter color. The second reinforcing ribs 350 are formed between the enclosed areas between the two first reinforcing ribs 322 closest to the lower edge 326 and the upper edge 327 of the reinforcing rib array 321 and the edges of the tab 320 (e.g. the upper edge 326 and the lower edge 327, however, in some embodiments, the enclosed areas between the two first reinforcing ribs 322 of the reinforcing rib array 321 closest to the lower edge 326 and the upper edge 327 of the reinforcing rib array 321 and the two side edges of the tab 320 along a second direction perpendicular to the first direction F can also be provided with the second reinforcing ribs 350.) The second reinforcing ribs 350 are further formed to fill the areas of the tab 320 not covered by the first reinforcing ribs 322, to avoid stress junctions on the areas not formed with the first reinforcing ribs 322, and to further strengthen the support of the tab 320 to reduce the possibility of bending of the tab 320. It can be appreciated that in some embodiments, the second reinforcing ribs 350 filling the enclosed areas between one of the first reinforcing ribs 322 closest to the lower edge 326 and the lower edge 326 have better strengthening effect on the tab 320 than the second reinforcing ribs 350 filling the enclosed areas between one of the first reinforcing ribs 322 closest to the upper edge 327 and the upper edge 327, and are comparatively more capable of strengthening the strength of the root area of the tab 320 connecting with the tab body 310, and have stronger effect on the additional support of the tab 320. It can be appreciated that in some embodiments, the second reinforcing ribs 350 have the same shape and / or size as a portion of the first reinforcing ribs 322, and / or the second reinforcing ribs 350 have different shape and / or size than the first reinforcing ribs 322. It can also be appreciated from another perspective that in some embodiments, the second reinforcing ribs 350 are portions of the first reinforcing ribs 322 truncated along the lateral direction by the lower edge 326 and the upper edge 327 of the tab 320 and have the same shape and / or size as the first reinforcing ribs 322. In some embodiments, the second reinforcing ribs 350 have the same shape as the first reinforcing ribs 322 but have different size, for example, the second reinforcing ribs 350 can be a complete single w-shaped reinforcing rib, a complete continuous reinforcing rib composed of multiple w-shaped reinforcing ribs and have smaller size than the first reinforcing ribs 322. In some embodiments, the second reinforcing ribs 350 have the same shape as a portion of the first reinforcing ribs 322 but have larger or smaller size than the portion of the first reinforcing ribs 322. As mentioned above, the second reinforcing ribs 350 have the same shape as a portion of the first reinforcing ribs 322, which can be understood as the second reinforcing ribs 350 are conformal to the portion of the first reinforcing ribs 322, and generally speaking, the shape profile of the second reinforcing ribs 350 can be scaled or not scaled to coincide with the shape profile of the portion of the first reinforcing ribs 322, and the shape profile being the same but not limited to the size is called "conformal".In specific implementations, for example, when the first reinforcing rib 322 and the second reinforcing rib 350 are rolled on the tab 320 using an embossing roller with raised ribs, the pattern on the embossing roller corresponding to the second reinforcing rib 350 can, in terms of shape, be any segment cut from the pattern corresponding to the first reinforcing rib 322. For example, if the pattern corresponding to the first reinforcing rib 322 is a continuous W-shaped pattern, the pattern corresponding to the second reinforcing rib 350 can be any segment cut from this continuous W-shaped pattern, such as a V-shape or an inverted V-shape. In other embodiments, the embossing roller may have only a single continuous raised rib, corresponding to the shape of a single first reinforcing rib 322; for example, the embossing roller is formed on the tab 320. Figure 8 The first reinforcing rib at the bottom, 322; along Figure 8 The first direction F is shifted upwards, and then formed Figure 8 The second reinforcing rib 322 from bottom to top is formed; this step is repeated, and since the ribs on the embossing roller extend beyond the upper edge 327 of the tab 320, a second reinforcing rib 350 is formed by being cut off by the upper edge. In some other embodiments, the pattern formed by the extension path of the second reinforcing rib 350 can be a reasonable shape such as a W-shape, a ring shape, a dot shape, a semi-circular arc, a circle, a triangle, etc.

[0064] In some embodiments, the texture formed by the extension path of the second reinforcing rib 350 is the same as a portion of the first reinforcing rib 322 in the reinforcing rib array 321. The minimum spacing between the second reinforcing rib 350 and the first reinforcing rib 322 in the first direction F is a, and the minimum spacing between two adjacent first reinforcing ribs 322 in the first direction F is a, that is, the minimum spacing between the two is equal and both are a. It can also be understood that, as mentioned above, the first reinforcing rib 322 has a portion conforming to the second reinforcing rib 350 and has the same size. The minimum spacing between the conforming portion of the first reinforcing rib 322 adjacent to the second reinforcing rib 350 and the second reinforcing rib 350 in the first direction F is a, and the minimum spacing between any two adjacent first reinforcing ribs 322 in the first direction in the reinforcing rib array in the first direction is also a. It can be understood that if there are multiple second reinforcing ribs 350 in the area enclosed by the edge first reinforcing rib and the two sides or one side edge of the tab 320, the minimum spacing between the second reinforcing ribs 350 in the first direction F can also be a. By ensuring that the minimum spacing between the second reinforcing rib 350 and the first reinforcing rib 322 in the first direction is the same and is a, and the texture formed by the extension path of the second reinforcing rib 350 is the same as a part of the first reinforcing rib 322 in the reinforcing rib array 321, the stress on all the first reinforcing ribs on the tab 320 is relatively uniform during the forming process, thus avoiding the tab cracking caused by the stress difference between the second reinforcing rib 350 and the first reinforcing rib 322 during the forming process.

[0065] Figures 9A-9CA schematic view of a pattern of the grooves formed by the extending direction of the first reinforcing ribs 322 is shown. Referring to FIG. 3B, the first reinforcing ribs 322 are arranged in a pattern of parallel lines. Figures 9A-9C In some embodiments, the first reinforcing ribs 322 are continuous grooves formed on the surface of the tab 320. Referring to FIG. 3B, the first reinforcing ribs 322 are continuous grooves formed on the surface of the tab 320. Figure 9A and Figure 6B In some embodiments, along the first direction F, each of the first reinforcing ribs 322 includes a nearest end close to the tab body 310 and a farthest end away from the tab body 310; wherein the distance between the farthest end of the first reinforcing rib 322 close to the tab body 310 and the tab body 310 is d1, and the distance between the nearest end of the first reinforcing rib 322 away from the tab body 310 and the tab body 310 is d2, d1 is greater than d2. As shown in FIG. 3B, along the first direction F, the lowest point of each of the first reinforcing ribs 322 is lower than the vertex of the adjacent first reinforcing rib 322 below. Figure 9A As shown in FIG. 3B, along the first direction F, the lowest point of each of the first reinforcing ribs 322 is lower than the vertex of the adjacent first reinforcing rib 322 below. Figure 9B As shown in FIG. 3B, along the first direction F, the lowest point of each of the first reinforcing ribs 322 is lower than the vertex of the adjacent first reinforcing rib 322 below. Figure 9C As shown in FIG. 3B, along the first direction F, the lowest point of each of the first reinforcing ribs 322 is lower than the vertex of the adjacent first reinforcing rib 322 below. Figure 9B and Figure 9C The case shown in FIG. 3B is often undesirable, which will be further described later. Figures 10A-10B A schematic view of a pattern of the first reinforcing ribs 322 is shown. Referring to FIG. 3B, the first reinforcing ribs 322 are arranged in a pattern of parallel lines. Figures 10A-10BThe dashed lines in the figure show the baselines between the farthest ends of the two adjacent first reinforcing ribs 322 away from the electrode body 310 and the nearest ends of the two adjacent first reinforcing ribs 322. It is often undesirable when, along the first direction F, the nearest ends of each first reinforcing rib 322 near the electrode body 310 are at the same height or higher than the farthest ends of the adjacent first reinforcing ribs below it. This is because there are cases where the height baselines of the farthest ends of the two adjacent first reinforcing ribs 322 away from the electrode body 310 coincide, or, in some cases, the farthest ends of the two adjacent first reinforcing ribs 322 away from the electrode body 310 and the nearest ends of the two adjacent first reinforcing ribs 322 are aligned and coincident, and similarly, there are cases where the farthest ends of the two adjacent first reinforcing ribs 322 away from the electrode body 310 and the nearest ends of the two adjacent first reinforcing ribs 322 are aligned and the nearest end is higher than the farthest end. This can also be understood as the aforementioned case where d1 is less than or equal to d2. "Alignment" can be understood as the farthest ends of the two adjacent first reinforcing ribs 322, furthest from the electrode body 310, and the closest ends, closest to the electrode body 310, lying on the same straight line extending along the first direction F. On one hand, this alignment and overlap of the nearest and farthest ends can lead to, for example, in... Figure 10A The intersection of the first reinforcing rib 322 on the dashed line shown constitutes a stress concentration line. (See figure.) Figure 10A As shown, when the pattern in which the farthest point of the two adjacent first reinforcing ribs 322 away from the electrode body 310 is aligned with and overlaps with the nearest point of the electrode body 310 is rolled onto the tab 320, it causes the tab 320 to move along... Figure 10A The dotted line shown here bends downwards, which is often undesirable. Generally, in another undesirable situation, such as... Figure 10B As illustrated, along the first direction F, when the farthest ends of two adjacent first reinforcing ribs 322 away from the electrode body 310 are aligned with the nearest ends close to the electrode body 310, the nearest end of each first reinforcing rib 322 close to the electrode body 310 is higher than the farthest end of the adjacent first reinforcing rib 322 below that is away from the electrode body 310. Compared to Figure 10A In the case of the example, Figure 10BThe illustrated case can avoid the situation that the intersection forms a stress concentration line and causes the tab 320 to bend, but because the nearest end of each first reinforcing rib 322 close to the tab body 310 is higher than the farthest end of the adjacent first reinforcing rib 322 away from the tab body 310, there are some blank areas (which can be understood as areas where the first reinforcing rib 322 is absent) between the two adjacent first reinforcing ribs 322 in the up-and-down direction, which causes the reinforcing effect of the first reinforcing rib 322 to be weakened in these blank areas. Furthermore, in order to avoid the situation that the tab 320 bends as described above, in some embodiments, there is no intersection between the first reinforcing ribs 322 in the reinforcing rib array 321.

[0066] It should be noted that the above is an example in which the first reinforcing rib 322 is a W-shaped reinforcing rib. In actual implementation, the pattern formed by the extension path of the first reinforcing rib 322 can also be any other possible continuous regular pattern, for example, a continuous strip-shaped first reinforcing rib 322 on the surface of the tab 320.

[0067] Specifically: Figures 11A-12B A schematic diagram of the pattern of the first reinforcing rib 322 according to an embodiment of the present application is shown. As shown in the diagram, the first reinforcing rib 322 is a W-shaped reinforcing rib formed on the surface of the tab 320. Figures 11A-12B As illustrated, in some embodiments, the first reinforcing rib 322 is a plurality of triangular grooves formed on the surface of the tab 320 and connected together. Preferably, the connection position between the triangular grooves can be provided with a transition portion, and the shape of the transition portion can be, for example, an arc-shaped groove, a rectangular groove, or any other shaped groove. The provision of the transition portion can be referred to, for example, the description of the transition portion in the first reinforcing rib 322 of the first reinforcing rib array 321. Figure 7 The illustrated circular arc transition connects the two adjacent corners of two adjacent triangular grooves. As can be seen from the diagram Figures 11A-12B A pattern of the first reinforcing rib 322 in the form of a plurality of triangular area-shaped reinforcing ribs connected together is shown. Similar to the description of the first reinforcing rib 322 of the first reinforcing rib array 321, Figure 10A and 10B the dashed line shown along the first direction F is the reference line of the farthest end away from the tab body 310 and the nearest end close to the tab body 310 of the two adjacent first reinforcing ribs 322 in the up-and-down direction. Now refer to Figures 12A-12B When the nearest end close to the tab body 310 of each first reinforcing rib 322 is at the same height or higher than the farthest end away from the tab body 310 of the adjacent first reinforcing rib 322 in the up-and-down direction, this is often undesirable. Because there is a case where the height reference line of the farthest end away from the tab body 310 and the nearest end close to the tab body 310 coincides between the two adjacent first reinforcing ribs 322 in the up-and-down direction, or it can also be understood that the farthest end away from the tab body 310 and the nearest end close to the tab body 310 of the two adjacent first reinforcing ribs 322 in the up-and-down direction coincide with each other, for example Figure 12A the illustrated case. This can cause, for example, in Figure 10Aa stress concentration point on the dotted line, when this pattern of first reinforcing ribs 322 is rolled onto the tab 320, will cause the tab 320 to fold down along this dotted line. Similarly Figure 10B as described above, as exemplified in Figure 12B along the first direction F, when the farthest end of two adjacent first reinforcing ribs 322 above and below away from the tab main body 310 is aligned with the closest end of the two adjacent first reinforcing ribs 322 above and below close to the tab main body 310, the closest end of each first reinforcing rib 322 close to the tab main body 310 is higher than the farthest end of the adjacent first reinforcing rib 322 below away from the tab main body 310, which is also often undesirable due to the larger blank area between the two adjacent first reinforcing ribs 322 above and below.

[0068] Figures 13A-13B A schematic diagram showing the pattern of the first reinforcing ribs 322 is shown. Referring to Figure 13A and Figure 13B the pattern of the first reinforcing ribs 322 can have a wavy shape, or can be formed as an elliptical pattern, and each first reinforcing rib 322 has a different size, and from inside to outside, the size of the first reinforcing ribs 322 gradually increases to accommodate the smaller adjacent first reinforcing ribs. It can be understood that the pattern of the first reinforcing ribs 322 formed by the extension path can also have other shapes: for example, straight line pattern, curved line pattern, circular pattern, rectangular pattern, irregular pattern, etc. The first reinforcing ribs 322 can be, for example, a structure connected together by a plurality of concave filling areas, which can be, for example, the triangular concave areas described above.

[0069] Embodiments of the present application also provide a secondary battery 100A / B comprising the tab 300 of any one of the above, and the secondary battery 100A / B can have the beneficial effects described above with respect to the tab 300.

[0070] Embodiments of the present application also provide an electronic device 1000 comprising the secondary battery 100A / B of any one of the above, and the electronic device 1000 can have the beneficial effects described above with respect to the secondary battery 100A / B.

[0071] The above only describes preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A pole piece, comprising: a pole piece body, and a tab protruding from the pole piece body along a first direction, the tab being provided with an array of ribs, the array of ribs comprising a plurality of first ribs; wherein, along the first direction, every two adjacent first ribs are spaced apart from each other.

2. The pole piece of claim 1, wherein a minimum spacing of the two adjacent first ribs in the first direction is a, the tab has a height h along the first direction, and a ratio of the a to the h is within a range from 0.08 to 0.

5.

3. The pole piece of claim 1, wherein the first rib has at least one first bend, an inner angle of the first bend is toward the pole piece body, and first bends of every two adjacent first ribs in the first direction are aligned in the first direction and spaced apart by the minimum spacing a.

4. The pole piece of claim 2, wherein the ratio of the a to the h is within a range from 0.15 to 0.

35.

5. The pole piece of claim 2, wherein a ratio of the a to a thickness of the tab is within a range from 200 to 4000.

6. The pole piece of claim 2, wherein wherein, in a direction perpendicular to an extension path of the first rib, a maximum width of a single first rib is y, and a ratio of the y to the a is within a range from 0.05 to 0.

5.

7. The pole piece of claim 1, wherein each first rib has: first bends and second bends alternately distributed along a second direction, an inner angle of the first bend is toward the pole piece body, an inner angle of the second bend is away from the pole piece body, and a connecting portion connecting the second bend and the first bend, the second direction being perpendicular to the first direction; wherein, the second bend and the first bend are circular arc transitions, a maximum width of the circular arc transition in a radius direction is y1, a width of the connecting portion perpendicular to an extension direction of the connecting portion is y2, and a ratio of the y1 to the y2 is within a range from 1.2 to 2.

5.

8. The pole piece of claim 7, wherein a spacing between two adjacent first bends of a single first rib is b, wherein, in the second direction, the tab has a maximum width c1 and a minimum width c2, and a ratio of the c1 to the b is within a range from 1.5 to 3 and / or a ratio of the c2 to the b is within a range from 1.5 to 3.

9. The pole piece of claim 1, wherein first ribs of the plurality of first ribs arranged at two or one side edges of the tab in the first direction are filled with second ribs in an area enclosed by edges of the tab, the second ribs being different from the first ribs in shape and / or size.

10. The pole piece of claim 9, wherein, the first rib has a conformal portion with the second rib, and the conformal portion is the same as or different from the second rib in size.

11. The pole piece of claim 10, wherein a minimum spacing of the conformal portion of the first rib adjacent to the second rib and the second rib in the first direction is a, the minimum spacing of every two adjacent first ribs in the array of ribs in the first direction in the first direction is the a.

12. The pole piece of claim 1, wherein Each of the first reinforcing ribs comprises a nearest end close to the pole piece body and a farthest end away from the pole piece body along the first direction; wherein the distance between the farthest end of the first reinforcing rib close to the pole piece body and the pole piece body is d1, and the distance between the nearest end of the first reinforcing rib away from the pole piece body and the pole piece body is d2, d1 is greater than d2.

13. The pole piece of claim 1, wherein There is no intersection between each of the first reinforcing ribs in the array of reinforcing ribs.

14. The pole piece of claim 1, wherein The first reinforcing ribs are strip-shaped grooves or multiple triangular grooves connected together.

15. A secondary battery characterized by comprising: The pole piece comprises any one of claims 1-14.

16. An electronic device, comprising: The secondary battery comprises claim 15.

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