Tab and cylindrical battery

Abstract

The utility model discloses a tab and a cylindrical battery, the tab comprises a main body part and a side edge part, and the main body part is used for being welded with a current collector; the number of the side edge parts is two, the two side edge parts are located on the two sides, in the width direction of the tab, of the main body part respectively, and the rigidity of the two side edge parts is smaller than that of the main body part. Therefore, when the tab provided by the embodiment is used for the cylindrical battery, the side edge part is easier to deform along with winding of the pole piece, so that the side edge of the tab is prevented from cutting a current collector, and the performance of the cylindrical battery is further improved.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and particularly relates to an ear tab and a cylindrical battery. Background Art

[0002] Cylindrical batteries are widely used in fields such as solar lamps, lawn lamps, backup power sources, power tools, toy models, and photovoltaic energy. A cylindrical battery usually includes a casing, an electrode core, and an ear tab. Among them, the electrode core is wound and arranged inside the casing. The electrode core includes electrode plates, and the electrode plates include current collectors and active substances. The ear tab is welded to the current collector. However, since the ear tab in the cylindrical battery will bend along with the electrode plate during winding, there is a risk that the edge of the ear tab will cut the current collector in the cylindrical battery, resulting in a reduction in the performance of the cylindrical battery. Content of the Utility Model

[0003] The utility model aims to solve at least one of the technical problems existing in the prior art. For this purpose, the utility model provides an ear tab that can be used in a cylindrical battery to ensure the performance of the cylindrical battery.

[0004] The utility model also provides a cylindrical battery including the above-mentioned ear tab.

[0005] The ear tab according to the first aspect embodiment of the utility model includes a main body portion and side edge portions;

[0006] The main body portion is used for welding with the electrode plate; the ear tab includes two side edge portions, and the two side edge portions are respectively located on both sides of the main body portion along the width direction of the ear tab, and the stiffness of the two side edge portions is less than that of the main body portion.

[0007] The ear tab according to the embodiment of the utility model has at least the following beneficial effects:

[0008] In this embodiment, the stiffness of the side edge portion is less than that of the main body portion. Since the side edge portion is located on both sides of the main body portion along the width direction of the ear tab, when the ear tab of this embodiment is used in a cylindrical battery, the side edge portion is more likely to deform along with the winding of the electrode plate, thereby preventing the side edge of the ear tab from cutting the current collector, and further ensuring the performance of the cylindrical battery.

[0009] According to some embodiments of the utility model, both of the two side edge portions have a plurality of weakening holes.

[0010] According to some embodiments of the utility model, along the direction from the side edge portion to the main body portion, the dimension of each weakening hole along the length direction of the ear tab gradually decreases.

[0011] According to some embodiments of the present utility model, along the thickness direction of the tab, the tab has two large surfaces disposed opposite to each other, the area of each large surface is S1, the total area of the weakening holes is S2, and S2 / S1 is set to be 4% to 11%.

[0012] According to some embodiments of the present utility model, along the thickness direction of the tab, the size of the side edge portion is H1, the size of the main body portion is H2, and H1 < H2.

[0013] According to some embodiments of the present utility model, (H2 - H1) / H2 is set to be 5% to 10%.

[0014] According to some embodiments of the present utility model, the main body includes a first connection portion and a second connection portion connected to each other, the first connection portion is used to connect to the electrode plate, and the second connection portion is used to be electrically connected to the electrode post;

[0015] One side of the first connection portion away from the second connection portion has a penetration hole, and the penetration hole penetrates through the first connection portion along the thickness direction of the tab; and / or,

[0016] One side of the second connection portion away from the first connection portion has a penetration hole, and the penetration hole penetrates through the second connection portion along the thickness direction of the tab.

[0017] According to some embodiments of the present utility model, both of the two side edge portions have a plurality of weakening holes, the weakening holes penetrate through the side edge portions along the thickness direction of the tab, the total area of the weakening holes is S2, the total area of the penetration holes is S3, and (S3 - S2) / S2 is set to be 20% to 50%.

[0018] According to the embodiments of the second aspect of the present utility model, a cylindrical battery includes a battery cell, a housing, and the tab according to the embodiments of the first aspect.

[0019] The battery cell includes wound electrode plates, the electrode plates include current collectors, the tab is connected to the current collector, the housing has a receiving cavity, and the battery cell is disposed in the receiving cavity.

[0020] The tab according to the embodiments of the present utility model has at least the following beneficial effects:

[0021] By using the tab of the first aspect embodiments, the stiffness of the side edge portion of the tab is less than that of the main body portion. Since the side edge portions are located on both sides of the main body portion along the width direction of the tab, the side edge portions are more likely to deform as the electrode plate is wound, thereby preventing the side edges of the tab from scratching the current collector, and further ensuring the performance of the cylindrical battery of the present embodiment.

[0022] According to some embodiments of the present utility model, an edge of the side edge portion facing away from the main body portion and towards the pole piece is a first edge, and the cylindrical battery further includes a protective member, and the protective member is clamped between the first edge and the current collector.

[0023] Additional aspects and advantages of the present utility model will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present utility model. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present utility model will be further described below in conjunction with the drawings and embodiments, where:

[0025] Figure 1 is a schematic structural diagram of the first type of tab in the first aspect embodiment of the present utility model;

[0026] Figure 2 is a schematic structural diagram of the second type of tab in the first aspect embodiment of the present utility model;

[0027] Figure 3 is Figure 2 another perspective schematic diagram;

[0028] Figure 4 is a schematic structural diagram of the third type of tab in the first aspect embodiment of the present utility model;

[0029] Figure 5 is a schematic structural diagram of the fourth type of tab in the first aspect embodiment of the present utility model;

[0030] Figure 6 is a schematic structural diagram of the fifth type of tab in the first aspect embodiment of the present utility model;

[0031] Figure 7 is a schematic structural diagram of the tab and the current collector in the first type of cylindrical battery in the second aspect embodiment of the present utility model;

[0032] Figure 8 is a schematic structural diagram of the tab and the current collector in the second type of cylindrical battery in the second aspect embodiment of the present utility model.

[0033] Reference numerals:

[0034] Main body portion 100;

[0035] Side edge portion 200, weakening hole 210, first edge 220;

[0036] First connecting portion 300, second connecting portion 400, permeation hole 500, current collector 600, protective member 700. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0037] Embodiments of the present utility model will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present utility model, and should not be construed as a limitation of the present utility model.

[0038] In the description of the present utility model, it should be understood that with respect to the orientation description, such as the orientation or positional relationship indicated by up, down, front, back, left, right, etc., is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present utility model.

[0039] In the description of the present utility model, the meaning of several is more than one, the meaning of multiple is more than two, and understandings such as greater than, less than, exceeding, etc. do not include the present number, and understandings such as above, below, within, etc. include the present number. If there is a description of first and second, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features.

[0040] In the description of the present utility model, unless otherwise clearly defined, words such as setting, installing, connecting, etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above words in the present utility model in combination with the specific content of the technical solution.

[0041] Cylindrical batteries are widely used in fields such as solar lamps, lawn lamps, backup power sources, power tools, toy models, photovoltaic energy, etc. A cylindrical battery usually includes a housing, an electrode core, and an electrode tab. Among them, the electrode core is wound and arranged in the housing. The electrode core includes electrode plates, and the electrode plates include current collectors and active substances. The electrode tabs are welded to the current collectors. However, since the electrode tabs in the cylindrical battery will bend along with the electrode plates during winding, there is a risk that the edge of the electrode tab will cut the current collector in the cylindrical battery, resulting in a reduction in the performance of the cylindrical battery. For example, the internal resistance of the battery increases, the battery capacity decreases, and lithium deposition occurs.

[0042] Based on the above problems, the first aspect embodiment of the present utility model proposes an electrode tab that can be used in a cylindrical battery to reduce the risk of the current collector 600 in the cylindrical battery being cut. Refer to Figures 1 to 4 , Figure 1 is a schematic structural diagram of the first type of electrode tab according to the first aspect embodiment of the present utility model. Figure 2 is a schematic structural diagram of the second type of electrode tab according to the first aspect embodiment of the present utility model. Figure 3 is Figure 2 Another perspective schematic diagram of Figure 41 is a schematic diagram of the structure of the third type of electrode tab according to the first aspect of the present utility model. The electrode tab of this embodiment includes a main body portion 100 and a side edge portion 200.

[0043] The main body 100 is used for welding with the current collector 600, and the pole ear includes two side edge portions 200. The pole ear has a set width. The two side edge portions 200 are respectively located on both sides of the main body 100 along the width direction of the pole ear, that is, the two sides of the pole ear that are lifted up during the winding process of the pole piece. The rigidity of the two side edge portions 200 is less than the rigidity of the main body 100. The side edge portion 200 and the main body 100 are an integrated structure, including but not limited to being made of the same material, as long as the rigidity of the side edge portion 200 is less than the rigidity of the main body 100, so that the side edge portion 200 is more easily deformed. For example, in some embodiments, the side edge portion 200 is provided with a weakening hole 210 (such as Figure 1 As shown in FIG. 2 ), the weakened hole 210 may be a through hole or a blind hole. The weakened hole 210 is not limited to a circular hole, and may also be a hole of any shape such as a triangular hole, a square hole or a trapezoidal hole. The provision of the weakened hole 210 can reduce the rigidity of the side edge portion 200, thereby making the side edge portion 200 more likely to deform. Or, for example, in some embodiments, the thickness of the side edge portion 200 is less than the thickness of the main body portion 100 (such as Figure 2 and Figure 3 ), so that the rigidity of the side edge portion 200 is less than that of the main body 100, thereby making the side edge portion 200 more easily deformable than the main body 100. Further, in some embodiments, the thickness of the side edge portion 200 is less than that of the main body 100 and the side edge portion 200 also has a weakened hole 210 (such as Figure 4 shown).

[0044] Specifically, in this embodiment, the stiffness of the side edge portion 200 is less than the stiffness of the main body 100. Therefore, when the tab of this embodiment is used for a cylindrical battery, the side edge portion 200 is more likely to deform as the pole piece is wound, thereby preventing the side edge of the tab from cutting the current collector 600, thereby improving the performance of the cylindrical battery.

[0045] It should be noted that the reason why the stiffness of the side edge portion 200 is less than that of the main body 100, and the stiffness of the entire tab is not directly reduced, is to ensure that the tab as a whole has a certain strength, thereby preventing the tab from breaking during installation or use, thereby ensuring the yield rate of cylindrical battery assembly and performance during use.

[0046] In addition, it can be understood that during the liquid injection process of the cylindrical battery, it is usually left standing for a period of time to ensure that the electrolyte fully penetrates into the positive and negative plates, thereby ensuring the performance and lifespan of the battery. When the weakening holes 210 provided on the side edge portion 200 are through holes, and the tab of this embodiment is used for the cylindrical battery, during the liquid injection process of the cylindrical battery, the electrolyte can flow in the weakening holes 210, which is conducive to the absorption of electrolyte seepage, so as to improve the liquid injection efficiency of the battery.

[0047] Referring to Figure 1 , in some embodiments, the tab has two large surfaces disposed opposite to each other in the thickness direction, and four small surfaces located between the two side surfaces. The adjacent two small surfaces are transitioned by rounded corners or chamfers, so as to avoid the formation of sharp corners on the tab, and further avoid the sharp corners formed on the tab from piercing the current collector 600, further reducing the risk of the current collector 600 being pierced, and thus further ensuring the performance of the battery. In some embodiments, the adjacent side surfaces of the electrode tab are all transitioned by rounded corners or chamfers, thereby eliminating the sharp edges formed on the electrode tab.

[0048] Referring to Figure 5 , Figure 5 FIG. is a schematic structural diagram of the fourth tab according to the first aspect embodiment of the present invention. In some embodiments, along the direction from the side edge portion 200 to the main body portion 100, the dimensions of each weakening hole 210 in the length direction of the tab gradually decrease. For example, the weakening hole 210 is provided as a trapezoidal hole or a triangular hole. Taking the trapezoidal hole as an example, the long side of the trapezoidal hole faces away from the main body portion 100, and the short side is close to the main body portion 100, so as to ensure that the stiffness at the edge of the tab is small, and the strength of the middle region of the tab is high, thereby making the edge of the tab easier to deform and having less impact on the overall strength of the tab.

[0049] In some embodiments, along the thickness direction of the tab, the tab has two major surfaces disposed opposite to each other, and the area of each major surface is S1. The total area of the weakening holes 210 is S2, and S2 / S1 is set to be 4% to 11%. Specifically, it can be known that the weakening holes 210 can not only reduce the stiffness of the side edge portion 200, but also reduce the overall strength of the tab. Therefore, if the proportion of the weakening holes 210 is too small, the stiffness of the side edge portion 200 will be relatively large, which is not conducive to the deformation of the side edge portion 200. If the proportion of the weakening holes 210 is too large, the overall strength of the tab will be too low, resulting in the tab being prone to fracture. In addition, it can be known that if the weakening holes 210 are too large, the strength of the side edge portion 200 will be relatively low. During the winding process of the tab with the electrode sheet, there may be a situation where the side edge portion 200 breaks and falls off. The falling off of the side edge portion 200 will not only cause the cross-sectional area of the tab to decrease and increase the internal resistance of the tab, but in severe cases, the falling off side edge portion 200 may also cut the separator between the positive and negative electrode sheets, resulting in a short circuit between the positive and negative electrodes of the cylindrical battery and causing the cylindrical battery to catch fire. Based on this, in order to ensure the practical performance of the cylindrical battery while improving the safety during the use of the cylindrical battery. In this embodiment, the size of the weakening holes 210 is set within a suitable range, that is, the ratio of the total area of the weakening holes 210 to the major surface of the electrode sheet is 4% to 11%. Thus, on the premise of ensuring that the electrode sheet and the side edge portion 200 have sufficient strength, the side edge portion 200 is more likely to deform.

[0050] As can be seen from the above embodiments, the stiffness of the side edge portion 200 can be achieved by reducing the thickness, that is, the thickness of the side edge portion 200 is less than the thickness of the main body portion 100. Specifically, along the thickness direction of the tab, the size of the side edge portion 200 is H1, and the size of the main body portion 100 is H2, where H1 < H2. As described above, in order to make the side edge portion 200 more likely to deform on the premise of ensuring that the electrode sheet and the side edge portion 200 have sufficient strength, in this embodiment, (H2 - H1) / H2 is set to be 5% to 10%, that is, the side edge portion 200 is thinned by 5% to 10% relative to the main body portion 100. Similarly, along the width direction of the tab, the size of the side edge portion 200 is 1 mm to 2 mm.

[0051] As can be seen from the above, during the liquid injection process of the cylindrical battery, it is usually left standing for a period of time to ensure that the electrolyte fully penetrates into the positive and negative electrode plates, thereby ensuring the performance and life of the battery. In order to further improve the penetration speed of the electrolyte, based on this, referring to Figure 6 , Figure 6This is a schematic structural diagram of the fifth tab in the first aspect of the present utility model. In some embodiments, the main body includes a first connecting portion 300 and a second connecting portion 400 that are connected to each other. The first connecting portion 300 is used to connect to the current collector 600, and the second connecting portion 400 is used for electrical connection with the terminal. On the side of the first connecting portion 300 facing away from the second connecting portion 400, there is a penetration hole 500, that is, the penetration hole 500 is located on one side in the length direction of the tab. The penetration hole 500 penetrates through the first connecting portion 300 along the thickness direction of the tab. Therefore, when using the tab of this embodiment in a cylindrical battery, during the process of injecting electrolyte into the cylindrical battery, the electrolyte can flow in the penetration hole 500, which is beneficial to the subsequent absorption of the injected electrolyte, so as to improve the battery electrolyte injection efficiency. Similarly, in some embodiments, there is a penetration hole 500 on the side of the second connecting portion 400 facing away from the first connecting portion 300, and the penetration hole 500 penetrates through the second connecting portion 400 along the thickness direction of the tab, which will not be elaborated here.

[0052] It should be noted that the penetration hole 500 is located on the side where the first connecting portion 300 and the second connecting portion 400 are far away from each other, that is, the penetration hole 500 is located on both sides of the tab along the length direction, so as to reduce the impact on the strength of the tab.

[0053] Based on the above embodiments, both side edge portions 200 have a plurality of weakening holes 210. The weakening holes 210 penetrate through the side edge portions 200 along the thickness direction of the tab, that is, the weakening holes 210 are through holes. The total area of the weakening holes 210 is S2, and the total area of the penetration holes 500 is S3. (S3 - S2) / S2 is set to 20% to 50%, that is, the area of the penetration holes 500 is 20% to 50% larger than that of the weakening holes 210. Specifically, as can be seen from the above, the weakening holes 210 are located on both sides of the tab in the width direction. If the area of the weakening holes 210 is too large, the tab is likely to break, while the penetration holes 500 are located on both sides of the tab in the length direction, and their impact on the overall strength of the tab is relatively small. Of course, if the area of the penetration holes 500 is too large, it will still have a greater impact on the strength of the tab. Therefore, in order to improve the penetration speed of the electrolyte and ensure the strength of the tab, in this embodiment, the total area of the penetration holes 500 is 20% to 50% larger than the total area of the weakening holes 210.

[0054] According to the second aspect of the present invention, the cylindrical battery comprises a battery cell, a shell and a pole ear of the first aspect, the battery cell comprises a pole piece arranged in a winding manner, the pole piece comprises a current collector 600, the pole ear is connected to the current collector, the shell has a receiving cavity, and the battery cell is arranged in the receiving cavity. Since the cylindrical battery of this embodiment adopts the pole ear of the first aspect, the rigidity of the side edge portion 200 of the pole ear is less than the rigidity of the main body 100, and since the side edge portion 200 is located on both sides of the main body 100 along the width direction of the pole ear, the side edge portion 200 is more likely to deform with the winding of the pole piece, thereby preventing the side edge of the pole ear from cutting the current collector 600, thereby improving the performance of the cylindrical battery of this embodiment.

[0055] It should be noted that, since the cylindrical battery of this embodiment adopts all the technical features of the electrode ear of the first aspect embodiment, this embodiment has all the beneficial effects brought by the first aspect embodiment, which will not be repeated here.

[0056] Reference Figure 7 and Figure 8 , Figure 7 This is a schematic diagram of the structure of the tab and the current collector in the first cylindrical battery of the second embodiment of the utility model, Figure 8 This is a schematic diagram of the structure of the pole ear and the current collector in the second cylindrical battery of the second embodiment of the utility model. In some embodiments, the edge of the side edge portion 200 that is away from the main body 100 and faces the current collector 600 is the first edge 220. The cylindrical battery also includes a protective member 700, which is located between the first edge 220 and the pole piece to separate the first edge 220 and the current collector 600. The protective member 700 can be, for example, a prefabricated clamping member. Before the pole ear is welded to the current collector 600, the protective member 700 is clamped to the side edge portion 200, thereby separating the first edge 220 of the pole ear from the current collector 600, thereby reducing the risk of the side edge portion 200 of the pole ear cutting the current collector 600. Alternatively, the protective member 700 is a coating, glue or adhesive tape. Before the tab is welded to the current collector 600, the protective member 700 is arranged at the position of the current collector 600 corresponding to the tab edge. After the tab is welded to the current collector 600, the protective glue is clamped between the side edge portion 200 and the current collector 600. Specifically, when the thickness of the side edge portion 200 is equal to the thickness of the main body 100, the thickness of the protective member 700 is less than or equal to 10 μm. Therefore, when the protective member 700 is arranged between the first edge 220 and the current collector 600, the side edge portion 200 will only be slightly deformed (such as Figure 7 When the thickness of the side edge portion 200 is less than the thickness of the main body 100, the thickness of the protective member 700 is less than or equal to the difference between the thickness of the side edge portion 200 and the thickness of the main body 100, so that the protective member 700 can be arranged between the side edge portion 200 and the current collector 600 without causing the battery cell to bulge (as shown in FIG.Figure 8 as shown, thereby improving the performance of the cylindrical battery.

[0057] It should be noted that the dashed lines in the drawings cannot be construed as the actual contour lines of the tabs, but are only for more clearly showing the positions of the side edge portion 200, the first connecting portion 300, and the second connecting portion 400.

[0058] The embodiments of the present invention have been described in detail above with reference to the drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those of ordinary skill in the relevant art, various changes can be made without departing from the gist of the present invention. In addition, in the description of the present invention, the description with reference to terms such as "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

Claims

1. Tab, characterized in that Comprising: A main body portion for welding with a current collector; Side edge portions, the tab includes two of the side edge portions, the two side edge portions are respectively located on both sides of the main body portion along the width direction of the tab, and the stiffness of the two side edge portions is less than that of the main body portion.

2. The tab according to claim 1, wherein, Both of the two side edge portions have a plurality of weakening holes.

3. The tab according to claim 2, wherein Along the direction from the side edge portion to the main body portion, the dimension of each weakening hole along the length direction of the tab gradually decreases.

4. The tab according to claim 2, wherein Along the thickness direction of the tab, the tab has two large surfaces arranged opposite to each other, the area of each large surface is S1, the total area of the weakening holes is S2, and S2 / S1 is set to 4% to 11%.

5. The tab according to any one of claims 1 to 3, characterized in that Along the thickness direction of the tab, the dimension of the side edge portion is H1, the dimension of the main body portion is H2, and H1 < H2.

6. The tab according to claim 5, wherein (H2 - H1) / H2 is set to 5% to 10%.

7. The tab according to claim 1, wherein The main body includes a first connecting portion and a second connecting portion connected to each other, the first connecting portion is used for connecting with a pole piece, and the second connecting portion is used for electrically connecting with a pole column; One side of the first connecting portion away from the second connecting portion has a penetration hole, and the penetration hole penetrates through the first connecting portion along the thickness direction of the tab; and / or, One side of the second connecting portion away from the first connecting portion has a penetration hole, and the penetration hole penetrates through the second connecting portion along the thickness direction of the tab.

8. The tab according to claim 7, characterized in that, Both of the two side edge portions have a plurality of weakening holes, the weakening holes penetrate through the side edge portions along the thickness direction of the tab, the total area of the weakening holes is S2, the total area of the penetration holes is S3, and (S3 - S2) / S2 is set to 20% to 50%.

9. Cylindrical battery, characterized in that, Comprising: A battery cell including wound pole pieces, and the pole pieces include current collectors; The tab according to any one of claims 1 to 8, the tab is connected to the current collector; A housing having an accommodation cavity, and the battery cell is disposed in the accommodation cavity.

10. The cylindrical battery according to claim 9, characterized in that, The edge of the side edge portion facing away from the main body portion and towards the current collector is a first edge, and the cylindrical battery further includes a protective member, and the protective member is located between the first edge and the current collector.

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