Tab rubberizing structure and sodium ion battery

Abstract

The utility model discloses a tab rubberizing structure and a sodium ion battery, and relates to the technical field of batteries. The tab rubberizing structure comprises gummed paper, the gummed paper covers an empty foil area of the foil material through adhesion, and a tab is welded to the empty foil area; the adhesive tape comprises a transparent or semitransparent base material, two opposite ends of the base material are coating areas, the middle part of the base material is a reserved area, the coating areas are coated with adhesive layers, and the width of the reserved area is not smaller than that of the tab; the sodium ion battery comprises a positive plate, a negative plate and a diaphragm, wherein the positive plate and the negative plate adopt the tab rubberizing structure in the embodiment. The adhesive paper can be adhered to and cover the empty foil area welded with the tab through the adhesive layer, and meanwhile, the transparent or semitransparent reserved area can cover the welding point of the tab, so that burrs at the welding point can be prevented from puncturing the diaphragm, and a quality inspector can judge whether the welding position of the tab has the problem of pseudo soldering or welding penetration or not during secondary retest.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a tab adhesive structure and a sodium ion battery. Background Art

[0002] Currently, tabs are typically attached to battery electrodes using welding. However, the welds formed during welding often have burrs, which can pierce the separator, causing contact between the positive and negative electrodes and leading to an internal short circuit. Therefore, after welding, the tab welds must be taped to prevent burrs from piercing the separator.

[0003] After welding is complete, technicians first inspect the welds for cold joints or weld penetrations. If these pass inspection, they proceed to the adhesive application process. Existing adhesive application techniques typically utilize fully adhesive-coated high-temperature tape. However, the adhesive applied by this tape typically appears blue or brown, making it difficult for quality inspectors to determine whether the tab welds are cold joints or weld penetrations during secondary retesting. Utility Model Content

[0004] In order to solve the above technical problems, the purpose of the present utility model is to provide a tab adhesive structure and a sodium ion battery using the tab adhesive structure.

[0005] The technical solutions provided by this utility model are as follows:

[0006] A tab adhesive structure includes adhesive tape, which is bonded to cover a hollow foil area of ​​a foil material, where a tab is welded;

[0007] The adhesive tape includes a transparent or translucent substrate, the opposite ends of the substrate are coating areas, and the middle is a reserved area. The coating areas are coated with an adhesive layer, and the width of the reserved area is not less than the width of the tab.

[0008] Furthermore, the substrate is a polyimide substrate, and the adhesive layer is a silicone pressure-sensitive adhesive layer.

[0009] Furthermore, the width of the adhesive layer is in the range of 2-10 mm.

[0010] Furthermore, when the empty foil area is located in the middle of the foil, the adhesive layers at the opposite ends are respectively bonded to the pole sheet area of ​​the foil, the overlapping width of the adhesive layer and the pole sheet area is 2-4 mm, and the width of the reserved area is equal to the width of the empty foil area.

[0011] Furthermore, when the empty foil area is located at the end position of the foil, the adhesive layer close to the pole sheet area of ​​the foil is bonded to the pole sheet area, and the overlapping width of the adhesive layer and the pole sheet area is 2-4 mm. The adhesive layer away from the pole sheet area is bonded to the empty foil area, and the width of the reserved area is equal to the width of the pole ear.

[0012] Furthermore, it also includes full-adhesive paper, which is covered on the electrode tab by bonding and is located above the welding position between the electrode tab and the empty foil area.

[0013] Furthermore, the coverage length of the full adhesive paper on the tab is in the range of 3-4 mm.

[0014] On the other hand, the present invention also provides a sodium ion battery, comprising:

[0015] A positive electrode sheet using the tab adhesive structure described in any one of the above embodiments;

[0016] A negative electrode sheet using the tab adhesive structure described in any one of the above embodiments;

[0017] A separator is provided between the positive electrode sheet and the negative electrode sheet.

[0018] Furthermore, the sodium ion battery also includes an outer shell, a battery roll core placed in the outer shell, a cap arranged on the top of the outer shell, and a rubber ring arranged between the cap and the outer shell. The battery roll core is formed by winding the positive electrode sheet, the diaphragm and the negative electrode sheet. The negative electrode tab corresponding to the negative electrode sheet is welded to the bottom of the outer shell, and the positive electrode tab corresponding to the positive electrode sheet is welded to the cap.

[0019] Furthermore, the positive electrode sheet is provided with a positive electrode tab located in the middle of the foil, and the empty foil area for welding the positive electrode tab is located in the middle of the foil;

[0020] And / or, the negative electrode sheet is provided with two negative electrode tabs respectively located at the front end and the rear end of the foil, and the empty foil areas for welding the two negative electrode tabs are respectively located at the front end and the rear end of the foil.

[0021] Compared with the prior art, the tab adhesive structure provided by the embodiment of the present invention has at least the following technical effects:

[0022] The tab glue structure includes adhesive tape, which includes a transparent or translucent base material. The opposite ends of the adhesive tape are coating areas, and the middle is a reserved area. The coating area is coated with an adhesive layer, and the width of the reserved area is not less than the width of the tab, so that the adhesive tape can be bonded and covered on the empty foil area welded with the tab through the adhesive layer. At the same time, the transparent or translucent reserved area can cover the welding point of the tab, which can prevent the burrs at the welding point from piercing the diaphragm, and is also helpful for quality inspectors to judge whether there are cold welds or weld-through problems at the tab welding point during the second retest.

[0023] The sodium ion battery uses the tab adhesive structure in the above embodiment, and therefore has the technical effects possessed by the tab adhesive structure in the above embodiment, which will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 This is a schematic structural diagram of the adhesive tape of the tab adhesive structure in one embodiment of the present invention;

[0026] Figure 2 This is a schematic top view of the structure in which the tab is welded to the foil in one embodiment of the present invention;

[0027] Figure 3 This is a schematic top view of the structure in which the tab is welded to the foil in another embodiment of the present invention;

[0028] Figure 4 Schematic diagram of the structure of a sodium ion battery in one embodiment of the present invention.

[0029] Reference numerals:

[0030] 10. Adhesive paper; 101. Base material; 102. Coating area; 1021. Adhesive layer; 103. Reserved area; 20. Foil; 201. Empty foil area; 202. Pole material area; 30. Tab; 40. Full adhesive paper; 21. Positive tab; 31. Negative tab; 4. Casing; 5. Battery core; 6. Cap; 7. Rubber ring. DETAILED DESCRIPTION

[0031] In order to help those skilled in the art better understand the technical solutions of the present invention, the technical solutions in the embodiments of the present invention are clearly and completely described below. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0032] It should be noted that when an element is referred to as being “fixed on” or “set on” another element, it can be directly on the other element or indirectly set on the other element; when an element is referred to as being “connected to” another element, it can be directly connected to the other element or indirectly connected to the other element.

[0033] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0034] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features being referred to. Thus, features defined as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of this utility model, "plurality" or "several" means two or more, unless otherwise specifically defined.

[0035] It should be noted that the structures, proportions, sizes, etc. depicted in the drawings of this specification are only used to match the contents disclosed in the specification so that people familiar with this technology can understand and read them. They are not used to limit the conditions under which the present invention can be implemented. Therefore, they have no substantive technical significance. Any structural modifications, changes in proportional relationships, or adjustments in size should still fall within the scope of the technical contents disclosed in this utility model without affecting the effects and purposes that can be achieved by the present utility model.

[0036] To prevent burrs at the welding points of the tabs from piercing the diaphragm when the tabs are welded to the electrode sheets, causing contact between the positive and negative electrodes and an internal short circuit, the tab welding points must be glued. Specifically, after the tabs are welded, technicians will inspect the welds for cold joints and weld penetrations before applying glue. To ensure battery safety, quality inspectors are generally required to retest the welds after gluing is complete.

[0037] The prior art glue treatment usually uses a high-temperature tape with a fully glued structure. However, the glue coated on this tape is generally blue or brown, which is not conducive to the quality inspector to judge whether there is a cold weld or weld-through problem at the tab welding point during the second retest. In addition, the use of a high-temperature tape with a fully glued structure will increase costs and reduce the energy density of the battery. It should be further explained that the thickness of the high-temperature tape is usually 12um. For a two-tab battery, the thickness of the battery tab is about 24um thicker than that of other positions. When the distance between the positive and negative tabs is close, the high-temperature tape overlaps, resulting in an increase of 48um in thickness at the thickest part of the battery cell, thereby reducing the energy density of the battery. Based on the above technical problems, the present invention provides a new type of tab glue structure, and the following are specific embodiments.

[0038] Please refer to the attached Figure 1 To the attached Figure 2 As shown, an embodiment of the present invention provides a tab adhesive structure, including adhesive tape 10, which is covered on the empty foil area 201 of the foil material 20 by bonding, and the empty foil area 201 is welded with a tab 30; the adhesive tape 10 includes a transparent or translucent substrate 101, whose opposite ends are coating areas 102, and the middle is a reserved area 103, the coating area 102 is coated with an adhesive to form an adhesive layer 1021, the reserved area 103 maintains the original structure of the substrate 101, and the width of the reserved area 103 is not less than the width of the tab 30.

[0039] In this embodiment, the tab adhesive structure includes a tape 10, which includes a transparent or translucent substrate 101. The opposite ends of the tape 10 are coated areas 102, and the middle is a reserved area 103. The coated area 102 is coated with an adhesive layer 1021. The width of the reserved area 103 is not less than the width of the tab 30. The tape 10 can be bonded and covered on the empty foil area 201 welded with the tab 30 through the adhesive layer 1021. At the same time, the transparent or translucent reserved area 103 can cover the welding point of the tab 30. This can prevent the burrs at the welding point from piercing the diaphragm and facilitate the quality inspector to determine whether there is a cold weld or a weld-through problem at the tab 30 welding point during the second retest. In addition, the tape 10 reduces the cost of the battery and improves the energy density of the battery.

[0040] In some optional embodiments, the substrate 101 is a polyimide substrate, and the adhesive layer 1021 is a silicone pressure-sensitive adhesive layer. The polyimide substrate is a transparent material.

[0041] In some optional embodiments, the width of the adhesive layer 1021 ranges from 2 mm to 10 mm.

[0042] Please refer again to the attached Figure 2 As shown, in some optional embodiments, when the empty foil area 201 is located in the middle of the foil 20, the adhesive layers 1021 at opposite ends are respectively adhered to the electrode material area 202 of the foil 20. The overlapping width of the adhesive layer 1021 and the electrode material area 202 is 2-4 mm, and the width of the reserved area 103 is equal to the width of the empty foil area 201. It can be explained that the electrode material area 202 refers to the area used for coating the positive electrode material or the negative electrode material. In this embodiment, the adhesive tape 10 completely covers the tab 30 and the empty foil area 201. The length of the adhesive tape = 2 × the width of the adhesive layer + the length of the empty foil area (this length includes the width of the tab).

[0043] Please see the attached Figure 3 As shown, in some optional embodiments, when the empty foil area 201 is located at the end of the foil 20, the adhesive layer 1021 near the electrode material area 202 of the foil 20 is bonded to the electrode material area 202, and the overlapping width of the adhesive layer 1021 and the electrode material area 202 is 2-4 mm. The adhesive layer 1021 away from the electrode material area 202 is bonded to the empty foil area 201, and the width of the reserved area 103 is equal to the width of the tab 30. In this embodiment, the length of the adhesive tape = 2 × the width of the adhesive layer + the width of the tab. This length is reasonably designed and effectively avoids the problem of excessive adhesive tape causing an increase in battery volume and thus reducing battery energy density.

[0044] During the production process of the battery, in order to further improve the safety of the battery, in certain optional embodiments, the tab adhesive structure includes, in addition to the adhesive tape 10 of any of the above embodiments, a full adhesive tape 40. The full adhesive tape 40 is covered on the tab 30 by bonding and is located above the welding position between the tab 30 and the empty foil area 201. When the tab 30 is used as the positive tab, this structure can effectively prevent the risk of direct short circuit between the positive and negative electrodes of the battery due to contact with the battery steel shell when bent. The reason is that the negative tab is usually welded to the bottom of the battery steel shell, that is, the steel shell and the bottom are both connected to the negative tab. If the positive tab contacts the steel shell when bent, it will cause a direct short circuit between the positive and negative electrodes of the battery. It can be explained that the full-adhesive paper 40 is a fully adhesive-coated structure, and its surface is evenly coated with a high-temperature resistant silicone pressure-sensitive adhesive. The bonding position of the full-adhesive paper 40 is above the welding position between the tab 30 and the empty foil area 201, which can ensure the safety and reliability of the tab 30 and will not affect the secondary retest of the welding quality by the quality inspector.

[0045] In some optional embodiments, the full-adhesive paper 40 covers the tab 30 to a length ranging from 3 to 4 mm.

[0046] On the other hand, one embodiment of the present invention provides a sodium-ion battery, comprising a positive electrode sheet, a negative electrode sheet, and a separator. The positive electrode sheet utilizes the tab adhesive structure of any of the aforementioned embodiments; the negative electrode sheet also utilizes the tab adhesive structure of any of the aforementioned embodiments; and the separator is disposed between the positive and negative electrode sheets. The sodium-ion battery provided in this embodiment utilizes the tab adhesive structure of any of the aforementioned embodiments, and thus possesses the technical effects of the tab adhesive structures of the aforementioned embodiments, which will not be further elaborated here.

[0047] Please see the attached Figure 4 As shown, in some optional embodiments, the sodium ion battery further includes an outer shell 4, a battery core 5 placed in the outer shell 4, a cap 6 arranged on the top of the outer shell 4, and a rubber ring 7 arranged between the cap 6 and the outer shell 4. The battery core 5 is wound by a positive electrode sheet, a diaphragm and a negative electrode sheet. The negative electrode tab 31 corresponding to the negative electrode sheet is welded to the bottom of the outer shell 4, and the positive electrode tab 21 corresponding to the positive electrode sheet is welded to the cap 6. Among them, the outer shell 4 is a steel shell. After the positive electrode sheet, the diaphragm and the negative electrode sheet are wound to form a battery core 5 and placed in the steel shell, the positive electrode tab 21 is folded, which can be a "Z" shape. The rubber ring 7 set between the cap 6 and the outer shell 4 can prevent direct short circuit between the positive and negative electrodes of the battery.

[0048] In some optional embodiments, the positive electrode sheet is provided with a positive electrode tab 21 located in the middle of the foil, and the empty foil area for welding the positive electrode tab 21 is located in the middle of the foil. Specifically, an empty foil area is provided in the middle of the foil corresponding to the positive electrode sheet, and the positive electrode tab 21 is welded to the empty foil area. The adhesive layers 1021 at both ends of the adhesive paper 10 are respectively bonded to the electrode sheet material area of ​​the foil, and the width of the reserved area 103 of the adhesive paper 10 is equal to the width of the empty foil area. Furthermore, in order to avoid direct short circuit between the positive and negative electrodes of the battery, full adhesive paper is bonded on the positive electrode tab 21 and above the welding position of the positive electrode tab 21 and the empty foil area. The coverage length of the full adhesive paper on the positive electrode tab 21 ranges from 3 to 4 mm.

[0049] In some optional embodiments, the negative electrode sheet is provided with two negative electrode tabs 31, respectively located at the front and rear ends of the foil, and the empty foil areas for welding the two negative electrode tabs 31 are respectively located at the front and rear ends of the foil. Specifically, for the negative electrode sheet, an empty foil area is provided at the front and rear ends of the corresponding foil, and the two negative electrode tabs 31 are welded to their respective empty foil areas. The adhesive layer of the adhesive tape near the electrode sheet area is bonded to the electrode sheet area, while the adhesive layer away from the electrode sheet area is bonded to the empty foil area.

[0050] The above description of the disclosed embodiments will enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A tab adhesive structure, characterized in that: The adhesive tape is covered on the empty foil area of ​​the foil material by bonding, and the empty foil area is welded with a tab; The adhesive tape includes a transparent or translucent substrate, the opposite ends of the substrate are coating areas, and the middle is a reserved area. The coating areas are coated with an adhesive layer, and the width of the reserved area is not less than the width of the tab.

2. The tab adhesive structure according to claim 1, characterized in that: The substrate is a polyimide substrate, and the adhesive layer is an organic silicone pressure-sensitive adhesive layer.

3. The tab adhesive structure according to claim 1, characterized in that: The width of the adhesive layer is in the range of 2-10 mm.

4. The tab adhesive structure according to claim 1, characterized in that: When the empty foil area is located in the middle of the foil, the adhesive layers at the opposite ends are respectively bonded to the pole sheet area of ​​the foil, the overlapping width of the adhesive layer and the pole sheet area is 2-4 mm, and the width of the reserved area is equal to the width of the empty foil area.

5. The tab adhesive structure according to claim 1, characterized in that: When the empty foil area is located at the end position of the foil, the adhesive layer close to the pole sheet material area of ​​the foil is bonded to the pole sheet material area, and the overlapping width of the adhesive layer and the pole sheet material area is 2-4mm. The adhesive layer away from the pole sheet material area is bonded to the empty foil area, and the width of the reserved area is equal to the width of the pole ear.

6. The tab adhesive structure according to claim 1, characterized in that: It also includes full-adhesive paper, which is covered on the electrode tab by bonding and is located above the welding position between the electrode tab and the empty foil area.

7. The tab adhesive structure according to claim 6, characterized in that: The full adhesive paper covers the tab in a length range of 3-4 mm.

8. A sodium ion battery, characterized in that: include: A positive electrode sheet using the tab adhesive structure according to any one of claims 1 to 7; A negative electrode sheet using the tab adhesive structure according to any one of claims 1 to 7; A separator is provided between the positive electrode sheet and the negative electrode sheet.

9. The sodium ion battery according to claim 8, characterized in that It also includes an outer shell, a battery roll core placed in the outer shell, a cap arranged on the top of the outer shell, and a rubber ring arranged between the cap and the outer shell. The battery roll core is formed by winding the positive electrode sheet, the diaphragm and the negative electrode sheet. The negative electrode tab corresponding to the negative electrode sheet is welded to the bottom of the outer shell, and the positive electrode tab corresponding to the positive electrode sheet is welded to the cap.

10. The sodium ion battery according to claim 9, characterized in that The positive electrode sheet is provided with a positive electrode tab located in the middle of the foil, and the empty foil area for welding the positive electrode tab is located in the middle of the foil; And / or, the negative electrode sheet is provided with two negative electrode tabs respectively located at the front end and the rear end of the foil, and the empty foil areas for welding the two negative electrode tabs are respectively located at the front end and the rear end of the foil.

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