Lithium ion battery tab, manufacturing method and lithium ion battery

Abstract

The present application discloses a lithium-ion battery pole ear, a manufacturing method and a lithium-ion battery, wherein the pole ear is a long strip of metal strip, and the pole ear includes a first long and wide surface partially welded to a current collector, a second long and wide surface corresponding to the first long and wide surface, and a first long and high surface and a second long and high surface between the first long and wide surface and the second long and wide surface, wherein the first long and high surface is connected to the first long and wide surface and the second long and wide surface respectively by chamfering, and the second long and high surface is connected to the first long and wide surface and the second long and wide surface respectively by chamfering. In a specific embodiment of the present application, the pole ear is in smooth contact with the current collector and other parts of the battery, and the edge of the pole ear is no longer sharp, which reduces the degree of damage of the pole ear to the shear force of the current collector, improves the qualified rate and power characteristics of the lithium-ion battery, and also improves the safety of using the lithium-ion battery and increases the service life of the lithium-ion battery.

Description

Technical Field

[0001] The present application relates to the field of lithium-ion battery manufacturing, and in particular to a lithium-ion battery tab, a manufacturing method and a lithium-ion battery. Background Art

[0002] The positive electrode material of lithium-ion battery tabs is generally made of aluminum, other metals or metal alloys, and the negative electrode material is generally made of nickel, other metals or metal alloys. The tabs of lithium-ion batteries are generally welded to the positive or negative current collector by welding methods such as ultrasonic welding and riveting.

[0003] In the manufacturing process of lithium-ion batteries, the tabs are prone to shear forces on the current collector during welding and protective adhesive application. In addition, during the charging and discharging process, when the lithium-ion battery is charged in a fixed volume space, its negative electrode material expands, which will continuously squeeze the tabs and current collector, and will also generate shear forces on the current collector, and this shear force will continue to appear throughout the life cycle of the battery. At present, these two shear forces are unavoidable, and these shear forces will cause the tabs to damage the current collector of the lithium-ion battery, causing the current collector to deform and crack.

[0004] like Figure 1 The lithium-ion battery pole lug shown is a long strip of metal strip, which includes a first length and width surface a1 welded to the lithium battery current collector portion, a second length and width surface a2 corresponding to the first length and width surface a1, and a first length and height surface a3 and a second length and height surface a4 between the first length and width surface a1 and the second length and width surface a2. This type of lithium battery pole lug is generally cut into metal strips by the positive or negative metal foil according to the width requirements of various types of lithium-ion battery pole lugs, and then rolled into a roll for punching and welding of the pole lugs. The slitting of the metal foil is generally carried out by mechanical processing. The edges of the cut metal strips, that is, the angles between the first length and height surface and the second length and width surface will be 90° or close to 90°, and there will be burrs on the edges, and the edges are sharp. The metal strip is installed on the automatic winding machine in a roll, separated from the metal roll after punching to form a single pole lug, and welded with the current collector of the lithium battery to form a lithium battery pole lug.

[0005] During the manufacturing and use of lithium-ion batteries, the sharp edges of the tabs will aggravate the damage caused by the shear force of the tabs on the current collectors, especially the edges of the tabs that are in direct contact with the current collectors. The damage to the current collectors is more serious, which can easily lead to partial or complete breakage of the current collectors during processing or use of the batteries, thereby causing battery failure and more seriously causing safety risks. Summary of the invention

[0006] The present application provides a lithium-ion battery tab, a manufacturing method and a lithium-ion battery.

[0007] According to the first aspect of the present application, the present application provides a lithium-ion battery pole lug, which is a long strip of metal strip, and the pole lug includes a first long and wide surface partially welded to the current collector, a second long and wide surface corresponding to the first long and wide surface, and a first long and high surface and a second long and high surface between the first long and wide surface and the second long and wide surface, the first long and high surface are respectively connected to the first long and wide surface and the second long and wide surface by chamfering, and the second long and high surface are respectively connected to the first long and wide surface and the second long and wide surface by chamfering.

[0008] In the above-mentioned lithium-ion battery tab, the chamfer comprises an arc chamfer.

[0009] According to a second aspect of the present application, the present application provides a lithium-ion battery, comprising the above-mentioned lithium-ion battery tab.

[0010] According to a third aspect of the present application, the present application provides a method for manufacturing a lithium-ion battery tab, comprising:

[0011] Prepare the corrosive liquid and place it in a container;

[0012] Soaking a coiled metal strip for making a tab in a corrosive solution, so that a first length and height surface of the coiled metal strip is connected to a first length and width surface and a second length and width surface through chamfering, and a second length and height surface is connected to the first length and width surface and the second length and width surface through chamfering;

[0013] taking out the rolled metal strip and washing away the corrosive liquid;

[0014] The rolled metal strip is punched into tabs according to the length of the tabs of the lithium battery.

[0015] In the above method, the corrosive solution comprises an acidic solution.

[0016] In the above method, the acidic solution includes HCL, H 2 SO4 or HNO 3 .

[0017] In the above method, the chamfering includes arc chamfering.

[0018] In the above method, the rolled metal strip is fixed in the container via a supporting shaft.

[0019] The above method, wherein the coiled metal strip for making the tab is immersed in a corrosive solution, specifically comprises:

[0020] Passing the support shaft through the central cylinder of the coiled metal strip so that the coiled metal strip is vertically arranged in the etching liquid;

[0021] The etching solution is caused to flow around the coiled metal strip.

[0022] The above method, the step of taking out the rolled metal strip and washing away the corrosive liquid, specifically comprises:

[0023] The rolled metal strip is taken out, first rinsed with water, and then soaked in alcohol.

[0024] Due to the adoption of the above technical solution, the beneficial effects of this application are:

[0025] In a specific embodiment of the present application, since the first length and height surface of the pole ear is respectively connected to the first length and width surface and the second length and width surface by chamfering, and the second length and height surface is respectively connected to the first length and width surface and the second length and width surface by chamfering, the pole ear is in smooth contact with the current collector and other components of the battery, and the edge of the pole ear is no longer sharp, which reduces the degree of damage to the shear force of the pole ear on the current collector, improves the qualified rate and power characteristics of the lithium-ion battery, and also improves the safety of using lithium-ion batteries and increases the service life of lithium-ion batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the three-dimensional structure of the existing lithium-ion battery tab;

[0027] Figure 2 This is a schematic diagram of the three-dimensional structure of a lithium-ion battery tab in one embodiment of the present application;

[0028] Figure 3 This is a left view of a lithium-ion battery tab in one embodiment of the present application. DETAILED DESCRIPTION

[0029] The present invention will be further described in detail below through specific implementation modes in conjunction with the accompanying drawings.

[0030] Embodiment 1:

[0031] like Figure 2 , Figure 3 As shown, the lithium-ion battery pole ear of the present application is made of metal. One embodiment thereof is a long strip of metal strip. The pole ear is a very thin rectangular parallelepiped, including a first long and wide surface 10, a second long and wide surface 20, a first long and high surface 30 and a second long and high surface 40. The first long and wide surface 10 is partially welded to the current collector, and the second long and wide surface 20 corresponds to the first long and wide surface 10, that is, the second long and wide surface 20 is arranged opposite to the first long and wide surface 10, the first long and high surface 30 is arranged between the first long and wide surface 10 and the second long and wide surface 20, and the second long and high surface 40 is also arranged between the first long and wide surface 10 and the second long and wide surface 20, and the first long and high surface 30 and the second long and high surface 40 are arranged opposite to each other, the first long and high surface 30 is connected to the first long and wide surface 10 and the second long and wide surface 20 respectively by chamfering, and the second long and high surface 40 is connected to the first long and wide surface 10 and the second long and wide surface 20 respectively by chamfering.

[0032] The lithium-ion battery pole ear of the present application is welded on the current collector and serves as a connector between the current collector and the outside of the lithium-ion battery. The first length and width surface 10 of the pole ear is in direct contact with the current collector, and the first length and height surface 30 thereof is connected to the first length and width surface 10 and the second length and width surface 20 respectively through chamfering, and the second length and height surface 40 is also connected to the first length and width surface 10 and the second length and width surface 20 respectively through chamfering 40. Although the pole ear inevitably exerts shear force on the current collector during the manufacturing and charging and discharging process, the smooth transition on the pole ear makes it difficult for the pole ear to produce concentrated stress on the current collector, and the damage to the current collector will be reduced, thereby improving the qualified rate of lithium-ion batteries, improving the power characteristics of lithium-ion batteries, and enhancing the service life and safety of lithium-ion batteries. Especially for cylindrical lithium batteries, since the thickness of the current collector tab welding point is inconsistent with the thickness on the current collector, and the ductility of the tab itself is inconsistent with the ductility of the current collector, and the current collector surface of the cylindrical lithium battery is arc-shaped, it is more likely to cause uneven stress on the current collector under the action of the tab, and the chamfer 50 can reduce the damage of the tab to the current collector. In one embodiment, the chamfer 50 includes an arc chamfer. Such a tab with an arc chamfer can prevent the tab from piercing the diaphragm, scratching the current collector, and damaging the current collector, causing cracks and ruptures in the current collector.

[0033] Embodiment 2:

[0034] The lithium-ion battery of the present application is a lithium-ion battery including the tab in the first embodiment, and the tab is welded on the current collector of the lithium-ion battery.

[0035] Embodiment three:

[0036] A method for manufacturing a lithium-ion battery of the present application, in one embodiment, comprises the following steps:

[0037] Step 102: Prepare a corrosive solution and place it in a container. The corrosive solution of the present application includes an acidic solution or other solution that can corrode metals. Acidic solutions include HCL, H 2 SO4 or HNO 3 The concentration can be any concentration suitable for corroding metals. In this embodiment, HCL is used to corrode the tabs. The HCL solution is easily volatile and inexpensive, which can save production costs.

[0038] Step 104: Soak the coiled metal strip for making the pole ear in the etching solution, so that the first length and height surface of the coiled metal strip is connected to the first length and width surface and the second length and width surface respectively through chamfering, and the second length and height surface is connected to the first length and width surface and the second length and width surface respectively through chamfering. In one embodiment, the chamfer includes an arc chamfer. The coiled metal strip can be fixed in the container through a support shaft. The coiled metal strip is soaked in the etching solution to avoid unnecessary corrosion of the welding surface of the pole ear and the current collector (i.e., the first length and width surface and the second length and width surface of the pole ear) by the solution.

[0039] The pole ear of the present application is made of metal. For example, the positive pole ear is made of aluminum, and the negative pole ear can be made of nickel. The whole rolled metal strip is immersed in the soaking, so that the corrosion on the surface of the pole ear (i.e., the first long and wide surface and the second long and wide surface) is slight, and the corrosion on the edge of the pole ear is greater. Before the rolled metal strip is placed in the corrosive liquid for corrosion, the pole ear can be pretreated first, that is, the pole ear can be cleaned, and specifically, alcohol can be used for cleaning to ensure that the surface of the pole ear is clean and free of oil stains and debris.

[0040] In one embodiment, the coiled metal strip for making the tab is immersed in a corrosive solution, which may specifically include:

[0041] Step 1042: Pass the support shaft through the central cylinder of the rolled metal strip so that the rolled metal strip is vertically placed in the etching solution.

[0042] Step 1044: Allow the etching solution to flow around the rolled metal strip.

[0043] Controlling the acid solution to form a circular flow in the corrosion tank can, on the one hand, wash away the corrosion products, and on the other hand, the flow will cause serious corrosion to the first contact position, so that the side with more serious corrosion will contact the foil, reducing the damage of the tab to the foil. At the same time, the corrosion rate can also be adjusted by adjusting the flow rate.

[0044] Step 106: Take out the rolled metal strip and wash away the corrosive liquid.

[0045] After the rolled metal strip is taken out, it can be rinsed with water, which is economical, convenient and safe. The post-processing speed should be fast, and the acid solution on the tab should be washed off quickly, otherwise the corrosion will be serious.

[0046] In one embodiment, the rolled metal strip after washing with water can be soaked in alcohol for a period of time, taken out, and allowed to evaporate naturally. This ensures that the corrosive liquid on the surface of the tab is cleaned, avoiding affecting the tab welding, that is, affecting the manufacturing of the lithium battery, and avoiding the corrosive liquid and water affecting the performance of the lithium battery, and even forming a potential safety hazard, reducing the safety of the lithium battery. Baking can also be used, which saves the manufacturing time of the tab.

[0047] Step 108: Punch the rolled metal strip into tabs according to the length of the tabs of the lithium battery.

[0048] The above contents are further detailed descriptions of the present invention in combination with specific implementation methods, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention.

Claims

1. A method for manufacturing a lithium-ion battery tab, characterized in that include: Prepare the corrosive liquid and place it in a container; Soaking a coiled metal strip for making a tab in a corrosive solution, so that a first length and height surface of the coiled metal strip is connected to a first length and width surface and a second length and width surface through chamfering, and a second length and height surface is connected to the first length and width surface and the second length and width surface through chamfering; taking out the rolled metal strip and washing away the corrosive liquid; Punching the rolled metal strip into tabs according to the length of the tabs of the lithium battery; The step of placing the coiled metal strip for making the tab into a corrosive solution and soaking it comprises: Passing a support shaft through the central cylinder of the coiled metal strip so that the coiled metal strip is vertically arranged in the etching liquid; The etching solution is caused to flow around the coiled metal strip.

2. The method for manufacturing a tab according to claim 1, wherein: The corrosive solution includes an acidic solution.

3. The method for manufacturing a tab according to claim 2, wherein: The acidic solution includes HCL, H2SO4 or HNO3.

4. The method for manufacturing a tab according to claim 1, wherein: The chamfer includes an arc chamfer.

5. The method for manufacturing a tab according to claim 1, wherein: The coiled metal strip is fixed in the container via a support shaft.

6. The method for manufacturing a tab according to claim 1, wherein: The step of taking out the rolled metal strip and washing away the corrosive liquid specifically comprises: The rolled metal strip is taken out, first rinsed with water, and then soaked in alcohol.

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