Battery pole piece and battery

Abstract

The utility model relates to battery technology field, concretely provides a kind of battery pole piece and battery.The battery pole piece includes current collector and active material layer.Current collector includes tab and main body, and the one side of main body is provided with tab along first direction.Tab includes first part and at least one second part, and first part is connected with main body by second part.Wherein, first part is provided with welding area, and second part includes second area connected with main body, and the thickness of second area is greater than the thickness of first part, and first direction is the width direction of main body.Active material layer is set in main body.The utility model solves the structural instability problems, such as collapse or unexpected bending, that battery pole piece is prone to in production and processing process multiple times over roller, improves structural damage of tab when continuously over roller by local thickening setting and promote structural strength.At the same time, local thickening retains welding area, avoids that tab structure strengthens and leads to virtual welding due to insufficient deformation resilience, improves battery reliability and safety performance.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and in particular to a battery electrode and a battery. Background Technology

[0002] As battery production demands increasingly higher energy density, battery electrodes are becoming thinner, and consequently, the design of battery tabs is also continuously shrinking. During the cell winding process, the battery tabs require multiple guide roller traction, alignment, and pre-bending treatments.

[0003] Thinner battery tabs are susceptible to localized collapse, curling, folding, or even tearing due to friction from the roller surface and tension fluctuations, which in turn affects the quality of the battery cell. Summary of the Invention

[0004] The battery electrode and battery provided by the embodiments of the present invention at least solve the problem that the battery tabs are prone to folding and collapse and structural instability during the production process.

[0005] In a first aspect, embodiments of the present invention provide a battery electrode sheet, which includes...

[0006] A current collector includes an electrode tab and a body. The electrode tab is disposed on one side of the body along a first direction. The electrode tab includes a first part and at least one second part. The first part is connected to the body through the second part. The first part is provided with a welding area. The second part includes a second area connected to the body. The thickness of the second area is greater than the thickness of the first part. The first direction is the width direction of the body.

[0007] An active material layer is disposed on the main body.

[0008] The battery electrode provided in the present invention includes a second part comprising a first region and a second region connected in sequence; the first part is connected to the first region; wherein the thickness of the first region decreases along the direction from the second region to the first region.

[0009] The battery electrode provided in this embodiment of the invention has, along the first direction, a tab with a size of L1, where 10mm≤L1≤60mm; and a second region of the second part with a size of L2.

[0010] Where 3mm≤L2≤30mm, or / and 0.1≤L2 / L1≤0.6.

[0011] The battery electrode provided by the present invention includes at least one third part and a fourth part in its main body;

[0012] The third part and the second part are connected in a one-to-one correspondence; along the first direction, the fourth part and the third part are connected; wherein, the maximum thickness of the third part is greater than the thickness of the fourth part, and the maximum thickness of the third part is less than or equal to the maximum thickness of the second part.

[0013] The battery electrode provided in the embodiment of the present invention includes a third part comprising a third region and a fourth region connected in sequence, wherein the third region and the second part are connected in a one-to-one correspondence, and the fourth region and the fourth part are connected.

[0014] The thickness of the third region is greater than the thickness of the fourth region; the thickness of the fourth region decreases along the direction from the third region to the fourth region.

[0015] The battery electrode provided in the embodiments of the present invention includes a third part comprising a main body base and a main body thickening part connected sequentially along the thickness direction; the main body base and the fourth part are integrally formed, and the main body base and the second part are integrally formed; the main body thickening part and the main body base are integrally formed; or, the main body thickening part is a conductive coating.

[0016] The battery electrode provided in the embodiment of the present invention includes, in the second part, a tab base and a tab thickening portion connected sequentially along the thickness direction;

[0017] The base of the electrode tab and the first part are integrally formed; the base of the electrode tab and the main body are integrally formed; the thickened part of the electrode tab and the base of the electrode tab are integrally formed; or, the thickened part of the electrode tab is a conductive coating.

[0018] The battery electrode provided in the embodiment of the present invention has a plurality of second parts; the plurality of second parts are spaced apart along a second direction; the second direction is the length direction of the current collector.

[0019] The battery electrode provided in this embodiment of the invention has a first portion with a thickness of D1 and a second portion with a maximum thickness of D2.

[0020] When the battery electrode is a positive electrode, 8μm≤D1≤15μm, 10μm≤D2≤30μm, or / and, 1.1≤D2 / D1≤3;

[0021] When the battery electrode is a negative electrode, 3μm≤D1≤10μm, 4μm≤D2≤15μm, or / and 1.1≤D2 / D1≤5.

[0022] Secondly, embodiments of the present invention also provide a battery comprising the battery electrode sheets described in any of the above embodiments.

[0023] The battery electrode and battery provided by this invention solve the structural instability problem of battery electrode sheets easily collapsing or unexpectedly bending during repeated rolling in the production process. By locally thickening the electrode, the structural strength is improved, reducing structural damage to the electrode tabs during continuous rolling. While locally thickening, the welding area is preserved to avoid insufficient deformation springback leading to poor welding caused by the reinforcement of the electrode tab structure, thus improving battery reliability and safety performance. Attached Figure Description

[0024] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0025] Figure 1 This is a schematic diagram of the structure of the battery electrode sheet according to Embodiment 1 of the present invention.

[0026] Figure 2 This is a cross-sectional view of the battery electrode along the A-A' direction in one embodiment of the present invention.

[0027] Figure 3 This is a cross-sectional view of the battery electrode along the A-A' direction in another embodiment of the present invention.

[0028] Figure 4 This is a schematic diagram of the first structure at the connection between the third and fourth parts of Embodiment 1 of the present invention.

[0029] Figure 5 This is a schematic diagram of the second structure at the connection between the third and fourth parts of Embodiment 1 of the present invention.

[0030] Figure 6 This is a schematic diagram of the third structure at the connection between the third and fourth parts of Embodiment 1 of the present invention.

[0031] Figure 7 This is a schematic diagram of a structure in Embodiment 1 of the present invention when multiple second and third parts are provided.

[0032] Figure 8 This is another structural diagram of the second and third parts in Embodiment 1 of the present invention when multiple parts are provided.

[0033] The above figures include the following reference numerals:

[0034] 1. Current collector; 2. Tab; 21. First part; 210. Welding area; 22. Second part; 221. First zone; 222. Second zone; 223. Tab base; 224. Tab thickened part; 2240. Protruding ridge; 2241. Gap; 3. Main body; 31. Third part; 311. Third zone; 312. Fourth zone; 3101. Main body base; 3102. Main body thickened part; 32. Fourth part; 4. Active material layer. Detailed Implementation

[0035] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0036] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0037] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this application. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0038] In high-power applications such as electric vehicles, battery applications involve three levels: individual battery cells, battery modules, and battery packs. Battery modules are formed by electrically connecting a certain number of individual battery cells and placing them in a frame to protect them from external shocks, heat, and vibration. Battery packs represent the final state of the battery system installed in an electric vehicle. Currently, most battery packs are made by assembling a battery management system (BMS), thermal management components, and various control and protection systems onto one or more battery modules. With technological advancements, the battery module level can be omitted, meaning that battery packs can be formed directly from individual battery cells. This improvement increases the gravimetric and volumetric energy density of the battery system while significantly reducing the number of components. The batteries mentioned in this application include battery modules or battery packs.

[0039] The battery mentioned in the embodiments of this application refers to a single physical module that provides higher voltage and capacity. For example, the battery mentioned in this application can be a single battery cell, a battery module including multiple battery cells, or a battery pack including multiple battery cells.

[0040] In the mass production of power batteries, the processing stability of the tabs, as the core carrier connecting the internal electrochemical reaction of the cell to the external load, directly determines the battery yield and safety performance. The demand for high energy density drives the continuous thinning of battery tabs. After traction, correction, and pre-bending during the production process, dynamic structural instability is easily generated. Repeated bending deteriorates the grain orientation of the tabs, significantly concentrates stress in the crease area, and exacerbates cumulative damage. Related technologies use reinforcing ribs to strengthen the bending stiffness of the tabs, but this leads to a loss of flexibility, making them prone to secondary deformation under winding tension. Therefore, this utility model provides a battery electrode sheet that balances structural strength and dynamic flexibility, solving the problem of structural instability and damage of thinned battery tabs during multi-roll processing.

[0041] Specifically, refer to Figures 1 to 8 As shown, the battery electrode includes a current collector 1 and an active material layer 4. The current collector 1 includes a tab 2 and a body 3; the tab 2 is disposed on one side of the body 3 along a first direction, which is the width direction of the body 3. The tab 2 is used to electrically connect with the terminal post to realize the transmission of current. Preferably, multiple tabs 2 are provided, and the multiple tabs 2 are spaced apart along the length direction of the body 3. The active material layer 4 is disposed on the body 3.

[0042] It should be noted that an active material layer 4 is provided on at least one side of the thickness direction of the main body 3. Preferably, an active material layer 4 is provided on both sides of the thickness direction of the main body 3.

[0043] Next, the electrode 2 includes a first part 21 and at least one second part 22. The first part 21 of the electrode 2 is connected to the main body 3 through the second part 22 of the electrode 2. The first part 21 of the electrode 2 is provided with a welding area 210. The second part 22 includes a second area 222 connected to the main body 3. The thickness of the second area 222 is greater than the thickness of the first part 21.

[0044] It should be noted that when there is one second part 22 in the same electrode 2, it can be understood as, see Figure 1 As shown, all parts of the tab 2 except for the first part 21 have been thickened; when multiple second parts 22 are provided in the same tab 2, it can be understood that, see Figures 7-8 As shown, the part of the tab 2 other than the first part 21 has been locally thickened.

[0045] In this embodiment, considering that multiple tabs of the same polarity in the electrode assembly are stacked together and connected by ultrasonic welding, excessively thick tabs can lead to weak ultrasonic welding. Furthermore, considering that thin tabs are prone to folding during electrode assembly production, especially at the connection between the tab and the main body, the tab may fold into the electrode assembly. Therefore, the welding area 210 is used as the basis for dividing the tab into a first part 21 and a second part 22. The thickness of the first part 21, which requires ultrasonic welding, is designed to be less than the thickness of the second part 22. On the one hand, thickening the second part 22 of the tab 2 achieves localized thickening of the battery electrode, structurally strengthening the tab 2 and improving its resistance to deformation. This prevents the tab 2 from breaking or bending under stress during battery production, assembly, and use, ensuring the stability of the current conduction path. On the other hand, this invention avoids the first part 21, which requires welding, by thickening the area of ​​the tab 2. The thickening does not affect the flexibility of the first part 21 or the normal welding operation of the welding area 210. Retaining a thinner first part 21 allows energy to penetrate the welding zone 210 more concentratedly during welding, ensuring full fusion of the welded parts, improving welding strength and reliability, reducing defects such as incomplete welding and missing welding, and overcoming problems of contact resistance and uneven current distribution caused by material accumulation.

[0046] In some embodiments, if the thickness of the second part 22 is too large, it will cause processing difficulties and material waste. If the thickness of the second part 22 is too small, it will not be able to strengthen the tab 2 and reduce the risk of the tab 2 folding. Therefore, the thickness of the first part 21 is set to D1; the maximum thickness of the second part 22 is set to D2; when the battery electrode is a positive electrode, 8μm≤D1≤15μm, 10μm≤D2≤30μm, or / and, 1.1≤D2 / D1≤3, preferably 8μm≤D1≤15μm, 10μm≤D2≤30μm, and 1.1≤D2 / D1≤3; when the battery electrode is a negative electrode, 3μm≤D1≤10μm, 4μm≤D2≤15μm, or / and 1.1≤D2 / D1≤5, preferably 3μm≤D1≤10μm, 4μm≤D2≤15μm, and 1.1≤D2 / D1≤5.

[0047] Specifically, when the battery electrode is a positive electrode, the value of D1 is 8μm, 10μm, 12μm, 13μm, or 15μm, and the value of D2 is 10μm, 14μm, 18μm, 23μm, 27μm, or 30μm. The ratio of D2 to D1 is 1.1, 1.3, 1.5, 1.7, 1.8, 2.3, 2.6, 2.8, or 3. When the battery electrode is a negative electrode, the value of D1 is 3μm, 4μm, 5μm, 7μm, 9μm, or 10μm, and the value of D2 is 4μm, 5μm, 6μm, 7μm, 9μm, 11μm, 13μm, or 15μm. The ratio of D2 to D1 is 1.1, 1.2, 1.4, 2.3, 2.6, 3.7, 4.2, 4.7, or 5.

[0048] In some implementations, refer to Figures 2 to 6 As shown, in order to avoid stress concentration at the connection between the second part 22 and the first part 21 due to the difference in thickness, the second part 22 includes a first region 221 and a second region 222 connected in sequence.

[0049] Along the width direction of the battery electrode, the first part 21 is connected to the first region 221, and the second region 222 is connected to the main body 3. The thickness of the first region 221 decreases from the second region 222 to the first region 221; the thickness of the second region 222 is greater than the thickness of the first part 21. Preferably, the thickness of the first region 221 decreases from the second region 222 to the first part 21 along a first direction.

[0050] The thickness of the first region 221 can be set to decrease uniformly, with a trapezoidal cross-section along the thickness direction and planar surfaces on both sides of the thickness direction. Alternatively, the thickness of the first region 221 can decrease non-uniformly, with curved or other irregular surfaces on both sides of the thickness direction. This invention features a gradually thickened first region 221 in the second part 22, which allows for a smooth transition in thickness between the first part 21 and the second region 222 of the second part 22, avoiding stress concentration and preventing mechanical weaknesses caused by abrupt thickness changes. Simultaneously, the gradual thickness change makes current conduction from the electrode to the main body 3 more uniform, preventing heat accumulation due to excessive local current density and improving reliability and safety.

[0051] In some embodiments, see Figure 2 As shown, when the tab 2 is too long along the first direction, it not only makes it easy to fold during the winding of the electrode sheet, but also occupies more internal space of the battery, which is not conducive to energy density. On the other hand, when the tab 2 is too short along the first direction, it is not conducive to the welding of the tab 2 and the adapter piece. Therefore, the size of the tab 2 along the first direction is set to L1, 10mm≤L1≤60mm. Specifically, the value of L1 can be 10mm or 12mm or 15mm or 20mm or 25mm or 28mm or 36mm or 39mm or 43mm or 47mm or 55mm or 60mm. When the dimension of the second region 222 along the first direction is too short, it cannot be ensured that the first part 21 of the electrode tab 2 will not contact the main body 3 after being folded. When the dimension of the second region 222 along the first direction is too long, it will cause material waste. Therefore, the dimension of the second region 222 of the second part 22 is set to L2, with 3mm≤L2≤30mm. Specifically, the value of L2 can be 3mm or 6mm or 9mm or 13mm or 18mm or 23mm or 27mm or 30mm. And / or, in order to ensure that the first part 21 of the electrode tab 2 will not contact the main body 3 after being folded, and to ensure the welding of the electrode tab 2 and the adapter piece, the relationship between L1 and L2 satisfies: 0.1≤L2 / L1≤0.6. Specifically, the ratio of L2 / L1 can be 0.1 or 0.2 or 0.3 or 0.4 or 0.5 or 0.6. Preferably, 10mm≤L1≤60mm, 3mm≤L2≤30mm, and 0.1≤L2 / L1≤0.6.

[0052] It should be noted that the dimensions of the first region 221 along the first direction can also be designed. For example, along the first direction, the dimension of the first region 221 of the second part 22 is set to L3, with 3mm≤L3≤30mm, or / and 0.1≤L3 / L1≤0.6. Preferably, 3mm≤L3≤30mm and 0.1≤L3 / L1≤0.6. Along the first direction, the dimension of the first part 21 is set to L4, then L1=L2+L3+L4.

[0053] In some embodiments, refer to Figure 2 and Figure 3 As shown, the main body 3 includes a fourth part 32 and at least one third part 31, with the third part 31 and the second part 22 connected in a one-to-one correspondence; the fourth part 32 and the third part 31 are connected along the first direction; wherein, the maximum thickness of the third part 31 is greater than the thickness of the fourth part 32, and the maximum thickness of the third part 31 is less than or equal to the maximum thickness of the second part 22.

[0054] Understandably, the number of third parts 31 can be one or more. That is, when there is only one, the third part 31 extends along the length of the main body, meaning its dimensions along the length of the main body are the same as the dimensions of the fourth part 32 along the length of the main body. When there are multiple third parts 31, they are spaced apart along the length of the main body, meaning their dimensions along the length of the main body are smaller than the dimensions of the fourth part 32 along the length of the main body. When there is only one third part 31, the second part 22 of each tab 2 is connected to the third part 31. When there are multiple third parts 31, the number of third parts 31 is the same as the number of second parts 22, the positions of the third parts 31 and the second parts 22 correspond one-to-one, and the third parts 31 and the second parts 22 are connected.

[0055] See first. Figure 1 , Figure 7 and Figure 8 As shown, in order to save materials and to enable the thickening process of the third part 31 and the second part 22 to be carried out simultaneously, the third part 31 is designed to be multiple, and the third part 31 and the second part 22 are connected in a one-to-one correspondence.

[0056] In this embodiment, the thickness of the third part 31 connecting the second part 22 on the main body 3 is increased. On the one hand, this can strengthen the connection between the tab 2 and the main body 3 and further reduce the risk of the tab 2 flipping. On the other hand, it can avoid the thinning of the electrode edge and thus avoid the problem of lithium plating at the edge of the electrode assembly.

[0057] See Figure 2 As shown, if the size of the third part 31 along the first direction is too large, it will reduce the coating amount of the active material slurry, thereby affecting the energy density. If the size of the third part 31 along the first direction is too small, it will not be able to solve the problem of thinning the electrode edge. Therefore, along the first direction, the size of the third part 31 is set to L5, and the size of the main body 3 is set to L6, 10mm≤L6≤200mm. The third part 31 is set to 2mm≤L5≤10mm, or / and 0.02≤L5 / L6≤0.6. Preferably, 10mm≤L6≤200mm, 2mm≤L5≤10mm, and 0.02≤L5 / L6≤0.6.

[0058] Specifically, the value of L6 can be 10mm, 30mm, 60mm, 80mm, 100mm, 120mm, 140mm, 150mm, 180mm, or 200mm; the value of L5 can be 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, or 10mm; the ratio of L5 to L6 can be 0.02, 0.08, 0.12, 0.15, 0.18, 0.22, 0.27, 0.34, 0.38, 0.42, 0.46, 0.49, 0.55, or 0.6.

[0059] In some embodiments, refer to Figures 3 to 6 As shown, to avoid stress concentration at the connection between the third part 31 and the fourth part 32 due to their different thicknesses, the third part 31 includes a third region 311 and a fourth region 312 connected sequentially. The third region 311 is connected to the second part 22 in a one-to-one correspondence, and the fourth region 312 is connected to the fourth part 32. The thickness of the third region 311 is greater than the thickness of the fourth part 32; the thickness of the fourth region 312 decreases along the direction from the third region 311 to the fourth region 312. By designing the fourth region 312, a smooth transition connection between the third region 311 and the fourth part 32 is achieved, avoiding stress concentration and structural instability caused by abrupt changes in thickness.

[0060] It should be noted that the two sides of the fourth zone 312 in the thickness direction can be set as inclined surfaces, concave arc surfaces, convex arc surfaces or multi-step surfaces.

[0061] In some embodiments, see Figure 3 As shown, the second part 22 includes a tab base 223 and a tab thickening part 224 connected sequentially along the thickness direction. The third part 31 includes a main body base 3101 and a main body thickening part 3102 connected sequentially along the thickness direction.

[0062] Understandably, the thickness of the main body base 3101 is the same as the thickness of the fourth part 32. On the same side of the main body thickness direction, the portion of the third part 31 that protrudes from the fourth part 32 is the main body thickening part 3102. The thickness of the tab base 223 is the same as the thickness of the first part 21. On the same side of the tab thickness direction, the portion of the second part 22 that protrudes from the first part 21 is the tab thickening part 224.

[0063] In this embodiment, the tab thickening portion 224 is disposed on one or both surfaces of the tab base 223 in the thickness direction. The main body thickening portion 3102 is disposed on one or both surfaces of the main body base 3101 in the thickness direction. When both the tab thickening portion 224 and the main body thickening portion 3102 are disposed on only one surface of the base, they can be disposed on the same side or opposite sides of the electrode sheet in the thickness direction. When both the tab thickening portion 224 and the main body thickening portion are disposed on both sides of the base, the thickening portions on both sides can be disposed symmetrically or asymmetrically; the thickening portions on both sides can be machined as a whole or machined separately.

[0064] Preferably, the thickened tab portion 224 is symmetrically arranged on both sides of the tab base 223, and the thickened body portion 3102 is symmetrically arranged on both sides of the body base 3101. The connection between the third part 31 and the second part 22 is smooth. The symmetrical thickening on both sides allows the tab 2 and the body 3 to be subjected to more balanced forces, avoiding structural skewing or stress concentration caused by unilateral thickening, enhancing the bending and fracture resistance of the battery electrode, and optimizing mechanical strength. The path is more symmetrical during current conduction, avoiding excessive local current density and reducing the risk of heat accumulation. In addition, the uniform thickening on both sides also makes the connection interface between the tab 2 and the body 3 more regular and the structural stability better.

[0065] It should be noted that when there is one second part 22 in the same tab 2, it can be understood that the tab thickening part 224 is provided on the surface of the tab base 223 and covers the entire area. However, when there are multiple second parts 22 in the same tab 2, it can be understood that the tab thickening part 224 is provided on a part of the surface of the tab base 223.

[0066] It should also be noted that when one part is provided in the third part 31 and extends along the length of the main body, it can be understood that the main body thickening part 3102 is provided on the surface of the main body base 3101 and covers the entire area. When multiple parts are provided in the third part 31 and correspond one-to-one with the second part 22, it can be understood that the main body thickening part 3102 is provided in a part of the surface of the main body base 3101, and the main body thickening part 3102 and the tab thickening part 224 correspond one-to-one.

[0067] As an example, in the same tab 2, multiple second parts 22 are provided; the multiple second parts 22 are spaced apart along a second direction; the second direction is the length direction of the current collector 1.

[0068] Understandably, in the same tab 2, there are multiple tab thickening portions 224, and the multiple tab thickening portions 224 are spaced apart along the second direction.

[0069] Priority, refer to Figure 7 and Figure 8As shown, in order to facilitate the processing of the tab thickening portion 224 and the main body thickening portion 3102, the tab thickening portion 224 and the main body thickening portion 3102 are designed to be processed as a whole, that is, the tab thickening portion 224 and the main body thickening portion 3102 are in a one-to-one correspondence. The tab thickening portion 224 extends along the first direction to the main body base 3101 to form the main body thickening portion 3102. The tab thickening portion 224 and the main body thickening portion 3102 constitute an integral convex ridge 2240.

[0070] It should be noted that, referring to Figure 7 and Figure 8 As shown, the protruding ridge 2240 can extend along straight lines, curves, broken lines, or other irregular lines. The protruding ridges 2240 can be arranged in a certain direction or in other irregular arrangements. (Refer to...) Figure 7 and Figure 8 As shown, the protrusions 2240 are preferably arranged at equal intervals along the length direction of the battery electrode, with a gap 2241 between adjacent protrusions 2240. The length direction is perpendicular to the width direction and the thickness direction of the battery electrode. The equidistant arrangement of the protrusions 2240 allows the tab 2 to be subjected to more uniform force, avoiding stress concentration caused by the dense or sparse protrusions 2240, and enhancing its mechanical stability against bending and fracture.

[0071] See next. Figure 7 As shown, when the protruding rib 2240 is a straight line extending along the first direction, the dimension D3 of the protruding rib 2240 along the second direction is 1mm to 30mm. Specifically, the value of D3 is 1mm, 5mm, 8mm, 12mm, 17mm, 23mm, 27mm, or 30mm. Along the second direction, the dimension D4 of the gap 2241 between adjacent protruding ribs 2240 is 1mm to 10mm. Specifically, the value of D4 is 1mm, 3mm, 5mm, 7mm, or 10mm.

[0072] Regarding the structure of the tab 2, in some embodiments, the tab base 223 and the tab thickening portion are made of the same material, the tab base 223 and the tab thickening portion are set as an integral molding structure, the tab base 223 and the first portion 21 are set as an integral molding structure, and the tab base 223 and the main body 3 are integrally molded. The integrally molded tab 2 can be obtained by pressing the foil material during production.

[0073] In another embodiment, when the tab thickening portion 224 is a conductive coating, the tab base 223 and the first portion 21 are configured as an integrally formed structure. The tab base 223 and the first portion 21 are foils of the same thickness, and the tab 2 is obtained by applying a conductive material to the foil as the tab thickening portion 224. The conductive coating can be a metal layer such as aluminum, iron, or copper, or a conductive material such as conductive carbon or graphite. The conductive material can be sprayed onto the foil surface by magnetron sputtering or other processes. Furthermore, in other embodiments, the tab thickening portion 224 may also include a conductive coating and tab adhesive sequentially along a first direction. In this case, the tab adhesive is located between the conductive coating and the main body 3, and the tab base 223 and the first portion 21 are made of the same material and are configured as an integrally formed structure.

[0074] Regarding the structure of the main body 3, in some embodiments, when the main body thickening portion 3102 and the main body base portion 3101 are made of the same material, the main body base portion 3101, the main body thickening portion 3102 and the fourth portion 32 are made of the same material and integrally formed.

[0075] In another embodiment, when the thickened portion 3102 of the main body is a conductive coating, the base portion 3101 of the main body and the fourth portion 32 are made of the same material and are configured as an integrally formed structure. The conductive coating can be a metal layer such as aluminum, iron, or copper, or a conductive material such as conductive carbon or graphite. The conductive material can be thickened by spraying using magnetron sputtering or other processes.

[0076] Regarding the connection structure between the tab 2 and the main body 3, preferably, the main body base 3101 and the tab base 223 are integrally formed.

[0077] In some embodiments, to enhance the strength of the tab 2, when the tab thickening portion 224 and / or the main body thickening portion 3102 are made of metal or alloy, the hardness can be increased by quenching treatment. The quenching temperature is 500℃~550℃, and the quenching time is 2h~6h.

[0078] The battery electrode sheet provided in Embodiment 1 of this utility model, through localized thickening, can improve the situation where the tab 2 collapses or unexpectedly folds due to roller friction and tension fluctuations during continuous rolling, especially when rolling more than 5 times. It also solves the interface bonding problem of the battery electrode sheet, avoiding lithium plating caused by insufficient edge bonding. While locally thickening, the welding area 210 is retained to prevent incomplete soldering caused by insufficient deformation springback in subsequent winding processes.

[0079] Embodiment 2 of this utility model also provides a battery. The battery includes a casing, a separator, an electrolyte, and the battery electrodes provided in Embodiment 1 above. The battery electrodes include a positive electrode and a negative electrode. Therefore, this battery includes all the technical effects of the aforementioned battery electrodes. Since the technical effects of the battery electrodes have been described in detail above, they will not be repeated here.

[0080] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0081] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be construed as limiting the scope of protection of this application.

[0082] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A battery electrode, characterized in that, include, A current collector (1) includes an electrode tab (2) and a body (3). The electrode tab (2) is provided on one side of the body (3) along a first direction. The electrode tab (2) includes a first part (21) and at least one second part (22). The first part (21) is connected to the body (3) through the second part (22). The first part (21) is provided with a welding area (210). The second part (22) includes a second area (222) connected to the body (3). The thickness of the second area (222) is greater than the thickness of the first part (21). The first direction is the width direction of the body (3). An active material layer (4) is disposed on the main body (3).

2. The battery electrode according to claim 1, characterized in that, The second part (22) includes a first region (221) and a second region (222) connected in sequence; the first part (21) is connected to the first region (221); wherein the thickness of the first region (221) decreases along the direction from the second region (222) to the first region (221).

3. The battery electrode according to claim 2, characterized in that, Along the first direction, the size of the electrode tab (2) is set to L1, 10mm≤L1≤60mm; the size of the second region (222) of the second part (22) is set to L2; Where 3mm≤L2≤30mm, or / and 0.1≤L2 / L1≤0.

6.

4. The battery electrode according to claim 1, characterized in that, The main body (3) includes at least one third part (31) and a fourth part (32). The third part (31) and the second part (22) are connected in a one-to-one correspondence; along the first direction, the fourth part (32) and the third part (31) are connected; wherein, the maximum thickness of the third part (31) is greater than the thickness of the fourth part (32), and the maximum thickness of the third part (31) is less than or equal to the maximum thickness of the second part (22).

5. The battery electrode according to claim 4, characterized in that, The third part (31) includes a third zone (311) and a fourth zone (312) connected in sequence. The third zone (311) and the second part (22) are connected in a one-to-one correspondence, and the fourth zone (312) and the fourth part (32) are connected. The thickness of the third region (311) is greater than the thickness of the fourth part (32); the thickness of the fourth region (312) decreases along the direction from the third region (311) to the fourth region (312).

6. The battery electrode according to claim 4, characterized in that, The third part (31) includes a main body base (3101) and a main body thickening part (3102) connected sequentially along the thickness direction; the main body base (3101) and the fourth part (32) are integrally formed, and the main body base (3101) and the second part (22) are integrally formed; the main body thickening part (3102) and the main body base (3101) are integrally formed; or, the main body thickening part (3102) is a conductive coating.

7. The battery electrode according to claim 6, characterized in that, The second part (22) includes a base part (223) and a thickened part (224) of the electrode connected sequentially along the thickness direction; The base of the electrode (223) and the first part (21) are integrally formed; the base of the electrode (223) and the main body (3) are integrally formed; the thickened part of the electrode (224) and the base of the electrode (223) are integrally formed; or, the thickened part of the electrode (224) is a conductive coating.

8. The battery electrode according to any one of claims 1 to 7, characterized in that, The second part (22) is provided in multiple ways; the multiple second parts (22) are spaced apart along a second direction; the second direction is the length direction of the current collector (1).

9. The battery electrode according to any one of claims 1 to 7, characterized in that, The thickness of the first part (21) is set to D1; the maximum thickness of the second part (22) is set to D2; When the battery electrode is a positive electrode, 8μm≤D1≤15μm, 10μm≤D2≤30μm, or / and, 1.1≤D2 / D1≤3; When the battery electrode is a negative electrode, 3μm≤D1≤10μm, 4μm≤D2≤15μm, or / and 1.1≤D2 / D1≤5.

10. A battery, characterized in that, The battery comprises battery electrodes as described in any one of claims 1 to 9.

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