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, the pole lug comprises reinforcing ribs which are concave relative to a first surface of the pole lug, and the reinforcing ribs and areas without the reinforcing ribs are alternately arranged on the pole lug; the tab comprises cutting edges, the cutting edges intersect with the reinforcing ribs and the reinforcing-rib-free areas, and on at least one cutting edge, the width of the reinforcing ribs is not equal to the width of the adjacent reinforcing-rib-free areas. The utility model aims to provide the pole piece, the secondary battery and the electronic device, so as to enhance the supporting force on the tab and avoid burrs generated in the tab cutting process.

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, power 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 enhance the support force of tab and avoid burr when cutting tab.

[0005] To achieve the above-mentioned purpose, the utility model provides a kind of pole piece, including: pole piece main body and tab protruding from pole piece main body, tab includes the reinforcing rib recessed compared to the first surface of tab, wherein the reinforcing rib and the non-reinforced rib area are arranged alternately on the tab;Tab includes cutting edge, cutting edge intersects with reinforcing rib and non-reinforced rib area, and on at least one cutting edge, the width of reinforcing rib is not equal to the width of adjacent non-reinforced rib area.

[0006] In some embodiments, on the cutting edge, the width of the reinforcing rib is d1, and the width of the non-reinforced rib area adjacent to the reinforcing rib is d2, d2>d1.

[0007] In some embodiments, the ratio of d1 to d2 is in the range of 0.15-0.5.

[0008] In some embodiments, on the cutting edge, the width of the reinforcing rib is d1, and the width of the non-reinforced rib area adjacent to the reinforcing rib is d2, d2<d1.

[0009] In some embodiments, the tab includes a top edge away from the pole piece main body, and the cutting edge is two opposite side edges connected between the top edge and the pole piece main body.

[0010] In some embodiments, the tab includes: a top edge away from the pole piece main body, and two opposite side edges connected between the top edge and the pole piece main body, and the cutting edge is the two opposite side edges and the top edge.

[0011] In some embodiments, the extension path of the reinforcing ribs is a continuous wavy shape.

[0012] In some embodiments, a plurality of reinforcing ribs are arranged on the first surface of the tab, and the plurality of reinforcing ribs are spaced apart from each other along the protruding direction of the tab to form an array of reinforcing ribs.

[0013] Embodiments of the present application also provide a secondary battery comprising the tab of any one of the above.

[0014] Embodiments of the present application also provide an electronic device comprising the secondary battery of any one of the above.

[0015] The beneficial technical effects of the present application are at least:

[0016] In the present application, the width of the reinforcing rib on at least one cutting edge is not equal to the width of the adjacent non-reinforced area, which can at least avoid burrs in cutting. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the drawings needed in the embodiment or prior art description will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0018] Figure 1 A schematic diagram of an electronic device exemplified by a vehicle is shown.

[0019] Figure 2 A three-dimensional schematic diagram of a secondary battery according to an embodiment of the present application is shown.

[0020] Figure 3 A cross-sectional schematic diagram of a secondary battery according to an embodiment of the present application is shown.

[0021] Figure 4 A three-dimensional schematic diagram of a secondary battery according to another embodiment of the present application is shown, exemplified by a square cell.

[0022] Figure 5 A schematic diagram of a tab before cutting according to an embodiment of the present application is shown.

[0023] Figure 6 And Figure 7 A path of cutting of a tab according to some embodiments of the present application is shown.

[0024] Figure 8 A tab according to an embodiment of the present application is shown.

[0025] Figure 9A schematic view of a tab is shown. Figure 8 A schematic view of a tab is shown.

[0026] Figure 10 A schematic view of laser cutting an uncoated area is shown.

[0027] Figure 11 A schematic view of a laser cutting edge cut by laser cutting path a is shown.

[0028] Figure 12 A schematic view of a laser cutting edge cut by laser cutting path b is shown.

[0029] Figure 13 A schematic view of laser cutting a tab is shown. DETAILED DESCRIPTION

[0030] For better understanding of the spirit of the present application, the following further describes the present application in connection with some preferred embodiments of the present application.

[0031] Embodiments of the present application will be described in detail below. Throughout the specification, like drawing reference numerals and characters are generally used to refer to like elements throughout. Embodiments described herein with reference to the drawings are illustrative in nature, diagrammatic in nature, and are used to provide a basic understanding of the present application. Embodiments of the present application should not be construed as limiting the present application.

[0032] As used herein, the terms "approximately," "substantially," "about," and "generally" are used to describe and account for small variations. When utilized in connection with an event or circumstance, such terms can refer to instances in which the event or circumstance is exact, and instances in which the event or circumstance is close to approximating.

[0033] In this specification, relative terms such as "central," "longitudinal," "lateral," "forward," "rearward," "rightward," "leftward," "internal," "external," "lower," "upper," "horizontal," "vertical," "above," "below," "top," "bottom," and derivatives thereof (e.g., "horizontally," "downwardly," "upwardly," etc.) should be construed to refer to the orientation as then described or as shown in the drawing under discussion. These relative terms are for convenience of description only and do not require that the application be practiced with the particular orientation described or shown.

[0034] For ease of description, "first," "second," "third," etc. can be used herein to distinguish between different components of one figure or series of figures. The "first," "second," "third," etc. are not intended to describe corresponding components.

[0035] Figure 1 A schematic diagram of an electronic device is shown, taking vehicle 1000 as an example. Referring to Figure 1 , the following embodiments are described taking vehicle 1000 as an example for convenience of description. It should be understood 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, etc.

[0036] The inside of vehicle 1000 can be provided with a battery pack 1002, which can be arranged at the bottom of vehicle body 1001 (as shown in Figure 1 ), or at the head, or at the tail, or at any other appropriate position. Battery pack 1002 can be used for power supply of vehicle 1000, for example, battery pack 1002 can be used as an operating power supply or a driving power supply of vehicle 1000. Battery pack 1002 can include a plurality of secondary batteries (such as secondary battery 100A described with respect to Figure 2 and Figure 3 , or secondary battery 100B described with respect to Figure 4 , and a box assembly accommodating the plurality of secondary batteries.

[0037] It should be understood that the secondary battery in the present application can be a secondary battery of various shapes, for example, can be in a cylindrical shape, a flat shape, a cuboid shape, or other shapes, etc., and the embodiments of the present application do not limit this. 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, etc., and the embodiments of the present application do not limit this either.

[0038] Figure 2 A perspective view of secondary battery 100A according to an embodiment of the present application is shown. In the embodiment shown in Figure 2 , secondary battery 100A is shown as an example of a cylindrical battery. Figure 3 A cross-sectional view of secondary battery 100A according to an embodiment of the present application is shown. In combination with 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).

[0039] 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.

[0040] 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.

[0041] 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 In some embodiments, 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.

[0042] 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. Regarding the positive and negative electrode tabs, further details will be described in the subsequent drawings.

[0043] In addition, in order to prevent short circuit between the positive electrode tab and the negative electrode tab, an insulating material is usually coated near the edge of the positive electrode active material layer of the positive electrode tab or the negative electrode active material layer of the negative electrode tab to form an insulating layer.

[0044] Figure 5 A schematic diagram of the tab 300 before being cut to form the tab is shown. Similar to the above introduction of the tab, the tab 300 can be the positive electrode tab or the negative electrode tab described above. Before being cut to form the tab, the tab 300 includes a coated area 301 coated with the positive / negative electrode active material and an uncoated area 302 not coated with the positive / negative electrode active material. Generally, after the active material layer is coated and rolled on the tab 300, the uncoated area 302 is cut (for example, in some embodiments, the cutting is laser cutting) to form the tab 320 (not shown, see, for example, Figure 8 ) of the tab 300 and the tab body 310 (not shown, see, for example, Figure 8). After that, the tab 300 with the tab 320 is wound up, which can be referred to as winding. However, during the winding process, the tab 320 of the tab 300 is generally a thin foil, and the material of the tab 320 is soft and easy to bend. During the winding process, the tab 320 can be folded towards the coating area 301 coated with the active material layer and be wound into the tab body 310 being wound, and not exposed relative to the tab body 310. Moreover, in the secondary battery (100A / 100B), since the tab 320 bears the function of transmitting current, the folded tab 320 will subsequently enter the secondary battery (100A / 100B) during the subsequent processing process, and the current cannot flow out from the folded tab 320, resulting in an increase in internal resistance. More seriously, the folded tab 320 inserted into the winding core can be short-circuited by the conductive positive and negative electrodes, affecting the safety performance of the secondary battery (100A / 100B). In this case, before the tab 320 of the tab 300 is formed, a reinforcing rib 323 (not shown, see, for example Figure 6 ) is processed on the surface of the tab 320 to play a role in strengthening the support of the tab 300. The formation of the reinforcing rib 323 involved in the present application can be realized by rolling or stamping and the like, for example, in some embodiments, the tab 320 is rolled by a embossing roller provided with a convex rib on the surface, so that a groove recessed compared to the first surface 321 of the tab 320 is left on the tab 320 to form the reinforcing rib 323, at this time, the reinforcing rib 323 formed can also be referred to as embossing, but is not limited thereto. Further, after the reinforcing rib 323 capable of strengthening the support of the tab 320 is rolled, the uncoated area 302 is laser cut to cut out the tab 320.

[0045] However, the uncoated area 302 surface of the tab 320 is uneven between the non-reinforcing rib area 322 (not shown, see, for example Figure 6 and 7 ) and the reinforcing rib 323 (not shown, see, for example Figure 6 and 7 ). Burr is prone to occur when cutting the tab 320. The following is described by taking laser cutting as an example.

[0046] In some embodiments, when the uncoated area 302 is cut using a laser, the focal point of the laser will deviate from one of the non-reinforcing rib area 322 and the reinforcing rib 323 compared to the focal point of the laser due to the height difference between the non-reinforcing rib area 322 and the reinforcing rib 323. For further understanding, please refer to, for example Figure 13 Further understanding, Figure 13 a schematic diagram showing the distance relationship between the focal point JD of the laser JG and the surface of the tab 320 when laser cutting is shown. Figure 13A schematic diagram of laser JG cutting tab 320 is shown, where Δf is the defocus amount, representing the distance between the focus point JD of laser JG and the surface of tab 320. It can be understood that the comparison of the size of defocus amount Δf in the present application is a comparison of the absolute value of Δf. In some embodiments, laser JG cutting tab 320 can be formed by focusing a light beam through a lens, but is not limited thereto. It can be further understood that when defocus amount Δf = 0 (it can be understood that at this time the focus point JD of laser JG is located on the surface of tab 320), the minimum beam diameter of laser JG can be obtained on the surface of tab 320, at this time the maximum energy density can be obtained on the surface of tab 320, and the melting range is relatively narrow, and the cutting seam formed by laser cutting is the narrowest; when defocus amount Δf > 0 (it can be understood that at this time the focus point JD of laser JG is located above the surface of tab 320), the irradiation range of laser JG on the surface of tab 320 becomes wider, and the laser JG in the cutting seam formed by laser cutting appears a diffusion angle, which makes the width of the cutting seam expand; when defocus amount Δf > 0 (it can be understood that at this time the focus point JD of laser JG is located below the surface of tab 320), the irradiation range of laser JG on the surface of tab 320 becomes wider, and the melting ability of laser JG becomes stronger as the focus point JD is closer to the thickness direction of tab 320, and when the cutting depth of laser JG exceeds the focus point JD along the thickness direction of tab 320, the melting ability of laser JG gradually becomes weaker, and the upper part of the cutting seam formed by laser cutting becomes wider. Further, it can be understood that, as shown in Figure 8 the first surface 321 of tab 320 and recessed compared to the first surface 321 of tab 320, when the laser cutting path simultaneously exists the reinforcing rib 323 and the non-reinforcing rib area 322 arranged alternately with the reinforcing rib 323 on the tab 320, the surface of laser cutting is uneven, resulting in a certain defocus amount Δf between the surface of reinforcing rib 323 or non-reinforcing rib area 322 and the focus point JD of laser JG (the focus point JD of laser JG is aligned on the surface of the other one of the two). It can be understood in combination with the above description of defocus amount Δf that, since the melting ability of laser JG is the strongest when the focus point JD is located, the greater the defocus amount Δf between the surface of reinforcing rib 323 or non-reinforcing rib area 322 and the focus point JD of laser JG, the lower the melting ability of laser JG, resulting in poor cutting of tab 320, such as the generation of defects such as burrs.

[0047] Figure 6 and Figure 7 A cutting path of tab 300 according to some embodiments of the present application is shown. As shown in Figure 6 and Figure 7 The non-reinforcing rib area 322 and the reinforcing rib 323 are formed on the uncoated area 302 of tab 300. Figure 6 and 7The dotted line shows the cutting path of the tab 320, which is cut by laser cutting in some embodiments. Two laser cutting paths are shown here according to some embodiments of the present application. In some embodiments, the laser cutting path does not cut the top edge 325 of the tab 320 away from the tab body 310, but only cuts a pair of opposite side edges 326 of the tab 320 connecting the tab body 310 to the top edge 325. In some embodiments, the laser cutting path cuts the top edge 325 of the tab 320 away from the tab body 310, and cuts a pair of opposite side edges 326 of the tab 320 connecting the tab body 310 to the top edge 325. (The top edge 325 and the side edge 326 are not shown, see, for example Figure 8 )

[0048] Figure 8 The tab 320 according to some embodiments of the present application is shown. Referring to Figure 8 , the laser-cut tab 320 corresponding to Figure 6 is shown. The tab 320 includes a tab body 310, and a tab 320 protruding from the tab body, a first surface 321 of the tab is provided with a rib-free area 322 and a rib 323 recessed compared to the rib-free area 322; the ribs 323 are arranged alternately with the rib-free areas 322, and the tab 320 further includes a cutting edge, which can be a laser cutting edge 324 formed by laser cutting, and the laser cutting edge 324 intersects with the adjacent rib 323 and rib-free area 322. In some embodiments, the tab 320 and the tab body 310 are an integral piece.

[0049] Figure 9 The schematic diagram of the tab 320 in Figure 8 is shown. Referring to Figure 6 , 8 and 9, the laser cutting edge 324 formed by laser cutting is shown, and the laser cutting edge 324 is formed as a pair of opposite side edges 326 of the tab 320. It can be understood that in some embodiments, referring to Figure 7 shown, the laser cutting edge 324 can also be formed as a top edge 325 away from the tab body 310, and two opposite side edges 326 connecting the top edge 325 and the tab body 310. Referring back to Figure 9The projection of the ribs 323 on the first surface 321 of the tab 300 is a continuous wave shape. It can be appreciated that the width of the ribs 323 is not equal to the width of the adjacent rib-free areas 322 on at least one of the laser-cut edges 324. And referring to the above description of the defocusing amount Af, it can be appreciated that the surface of the ribs 323, when laser-cut, is at a different defocusing amount Af from the focal point JD of the laser JG than the surface of the rib-free areas 322 (in some embodiments, it can be appreciated that the first surface 321) of the lug 320, when laser-cut, is at a different defocusing amount Af from the focal point JD of the laser JG. This results in the melting ability of the laser JG on the surface of the ribs 323 being different from the melting ability of the laser JG on the surface of the rib-free areas 322 of the lug 320 when laser-cut. It can be appreciated that due to the different melting abilities of the laser on the two surfaces, there is a certain heat transition zone between the rib-free areas 322 and the adjacent ribs 323 in the laser-cut path, and the one of the rib-free areas 322 and the adjacent ribs 323 that has a stronger melting ability when laser-cut can transfer the residual heat generated when laser-cut to the other through thermal influence, thereby improving the cutting quality of the laser-cut edge. However, when the width of the rib-free areas 322 of the lug 320 is equal to the width of the adjacent ribs 323, the effect of improving the cutting quality by residual heat at the edge is small. The width of the rib-free areas 322 and the adjacent ribs 323 on the laser-cut edge 324 formed can be controlled to be unequal, that is, the width of the rib-free areas 322 and the adjacent ribs 323 passed in the laser-cut path can be controlled to be unequal. In order to use the residual heat of the wider of the rib-free areas 322 and the ribs 323 on the laser-cut edge 324 when laser-cut to heat the narrower of the rib-free areas 322 and the ribs 323 in the laser-cut path to at least improve the quality of the laser-cut and avoid burrs in the laser-cut. The rib-free areas 322 and the ribs 323 on the laser-cut edge 324 are arranged adjacent to and alternately with each other. Further, it can be appreciated that the width d2 of a single rib-free area 322 on the laser-cut edge 324 on the first surface 321 can be not equal to the width dl of the adjacent single rib 323.

[0050] As a priority, the width d2 of the single non-ribbed portion 322 on the laser cutting edge 324 can be greater than the width d1 of the adjacent single ribbed portion 323. For example, the defocusing amount Δf of the single non-ribbed portion 322 can be 0, and the width d2 of the single non-ribbed portion 322 can be greater than the width d1 of the adjacent single ribbed portion 323. However, conversely, for example, the defocusing amount Δf of the single ribbed portion 323 can be 0, and the width d2 of the single non-ribbed portion 322 on the laser cutting edge 324 can be less than the width d1 of the adjacent single ribbed portion 323. When the consistency of the depth of the single ribbed portion 323 on the laser cutting edge 324 relative to the surface of the tab 320 is good, the defocusing amount Δf of the single ribbed portion 323 can be 0, and d2 is less than d1. When the consistency of the depth of the single ribbed portion 323 on the laser cutting edge 324 relative to the surface of the tab 320 is poor, as a priority, the width d2 of the single non-ribbed portion 322 on the laser cutting edge 324 can be greater than the width d1 of the adjacent single ribbed portion 323.

[0051] Figure 10 A schematic diagram of laser cutting of the uncoated area 302 is shown. Without being limited to Figure 10 The ribbed portion 323 shown in FIG. 1A can present a variety of shapes, for example Figure 10 The sawtooth shape shown in FIG. 1B. In some embodiments, a plurality of ribbed portions 323 are provided on the first surface 321 of the tab 320, and spaced apart from each other along the direction of the tab 320 protruding from the tab body 310 to form a ribbed portion array. Figure 11 Two laser cutting paths a and b are shown in FIG. 1C, both of which pass through the non-ribbed area 322 and the ribbed portion 323. Figure 12 A cross-sectional schematic diagram of the laser cutting edge 324 cut by the laser cutting path a is shown. Figure 9 A cross-sectional schematic diagram of the laser cutting edge 324 cut by the laser cutting path b is shown. Referring to Figure 11 The laser cutting edge 324 can be formed as only a single side edge and a top edge, or only a single side edge, or only a single top edge, all of which are possible. As a priority, on the laser cutting edge 324, the width of the ribbed portion 323 is d1, and the width of the non-ribbed area 322 adjacent to the ribbed portion 323 is d2, d2>d1. Referring to Figure 12 and Figure 11 Corresponding to Figure 12 The laser cutting edge 324 only intersects with a single ribbed portion 323 and intersects with two non-ribbed areas 322, at this time, d1 on the laser cutting path a, that is, d1 on the laser cutting edge 324 is d1a, d2 is d21a and d22a. Corresponding to Figure 11, the laser cutting path b intersects the plurality of reinforcing ribs 323 and the plurality of non-reinforcing rib areas 322, at this time, d1 on the laser cutting edge 324 on the laser cutting path b, i.e. d1 on the laser cutting edge 324, are d11b, d12b, d13b, d14b and d15b respectively, and d2 are d21b, d22b, d23b, d24b, d25b and d26b respectively. As preferred, the ratio of a single d1 to an adjacent single d2, d1 / d2, is within the range of 0.15-0.5, when the ratio is greater than 0.5, the cutting is poor, the probability of burr occurrence is greatly increased, when the ratio is less than 0.15, the width of the reinforcing rib 323 formed is narrower, the reinforcing effect on the tab 320 is lower.

[0052] Further referring to Figure 12 and Figure 12 , for the width of a single reinforcing rib 323 on the laser cutting edge 324, for example d11b to d15b in Figure 12 , can be less than the width of a single non-reinforcing rib area 322 on the adjacent laser cutting edge 324. In some embodiments, it is further understood that when the laser cutting paths a and b are the total path of a single laser cutting, at this time the laser cutting edge 324 formed should be the total path of the laser cutting paths a and b cutting the uncoated area 302. At this time d1 is still not equal to d2, and has a ratio within the range of 0.15-0.5, when the ratio is greater than 0.5, the cutting is poor, the probability of burr occurrence is greatly increased, when the ratio is less than 0.15, the width of the reinforcing rib 323 formed is narrower, the reinforcing effect on the tab 320 is lower. But it can also be understood that in some embodiments, on the laser cutting edge 324, the width of the reinforcing rib 323 is d1, and the width of the adjacent non-reinforcing rib area 322 is d2, d2

[0053] Continuing to refer to ​In some embodiments, the laser JG cuts from a second surface 333 of the tab 320 opposite the first surface 321. The reinforcing rib 323 has a protrusion 350 protruding relative to the second surface 333. It can be understood that, accordingly, along the laser cutting path of the laser cutting edge 324, the width of the protrusion 350 is d3, and the width of the non-reinforcing rib area 322 adjacent to the protrusion 350 at the second surface 333 is d4. Similar to the description of d1 and d2 above, when the laser JG cuts from the second surface 333, d3 and d4 can not be equal, d3 can be greater than d4, or d3 can be less than d4. Further, preferably, when d3>d4, the ratio of d4 to d3 is in the range of 0.15-0.5, and when the ratio is greater than 0.5, poor cutting is formed, and the probability of burr occurrence is greatly increased. Also, preferably, when d4>d3, the ratio of d3 to d4 is in the range of 0.15-0.5, and when the ratio is greater than 0.5, poor cutting is formed, and the probability of burr occurrence is greatly increased, and when the ratio is less than 0.15, the width of the protrusion 350 of the reinforcing rib 323 formed is narrow, and the reinforcing effect on the tab 320 is low.

[0054] It should be noted that the present application sets the defocus amount Δf to 0 to cut the reinforcing rib 323 and the non-reinforcing rib area 322 with a wider width as an example. In actual implementation, there are also cases where the defocus amount Δf>0, for example, the lower limit value of the power adjustable range of the on-site laser equipment is high, and the energy is too large when Δf=0, which causes the material of the tab 320 to splash during cutting. Similarly, there are also cases where the defocus amount Δf<0, for example, the thickness of the tab 320 itself is relatively thick.

[0055] Embodiments of the present application also provide a secondary battery 100A / B including 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.

[0056] Embodiments of the present application also provide an electronic device 1000 including 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.

[0057] 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, characterized in that, Comprising: a tab body, and a tab ear protruding from the tab body, the tab ear comprising a reinforcing rib recessed compared to a first surface of the tab ear, wherein the reinforcing rib and a non-reinforcing rib region are alternately arranged on the tab ear; the tab ear comprises a cutting edge, the cutting edge intersects the reinforcing rib and the non-reinforcing rib region, on at least one of the cutting edges, a width of the reinforcing rib is not equal to a width of the adjacent non-reinforcing rib region.

2. The pole piece of claim 1, wherein on the cutting edge, the width of the reinforcing rib is d1, the width of the non-reinforcing rib region adjacent to the reinforcing rib is d2, d2>d1.

3. The pole piece of claim 2, wherein a ratio of the d1 to the d2 is in a range of 0.15-0.

5.

4. The pole piece of claim 1, wherein on the cutting edge, the width of the reinforcing rib is d1, the width of the non-reinforcing rib region adjacent to the reinforcing rib is d2, d2<d1.

5. The pole piece of claim 1, wherein the tab ear comprises a top edge away from the tab body, and the cutting edge is two opposite side edges connected between the top edge and the tab body.

6. The pole piece of claim 1, wherein the tab ear comprises a top edge away from the tab body, and two opposite side edges connected between the top edge and the tab body, and the cutting edge is the two opposite side edges and the top edge.

7. The pole piece of claim 1, wherein an extension path of the reinforcing rib is a continuous wave shape.

8. The pole piece of claim 1, wherein a plurality of the reinforcing ribs are arranged on the first surface of the tab ear, and the plurality of the reinforcing ribs are spaced apart from each other to form a reinforcing rib array along a protruding direction of the tab ear.

9. A secondary battery characterized by comprising: A battery comprising the tab of any one of claims 1-8.

10. An electronic device, comprising: A secondary battery comprising the tab of claim 9.

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