Y-shaped battery tab and preparation method thereof

Abstract

The Y-shaped battery tab comprises a tab metal belt and a tab adhesive tape, and the tab adhesive tape is hot-pressed on the tab metal belt and is used for being compositely sealed with a battery packaging film; the tab metal belt comprises an outer tab belt located outside the battery and at least two inner tab belts located inside the battery, one inner tab belt is a main metal belt integrated with the outer tab belt, the other inner tab belt is an auxiliary metal belt, the head end of the auxiliary metal belt is welded with the main metal belt in parallel, and the outer tab belt and the auxiliary metal belt are welded in parallel. The tail end of the auxiliary metal belt is branched from the main metal belt and is respectively welded with the positive electrode or the negative electrode of a battery current collector so as to lead out current; and the two symmetrically arranged tab rubber strips are compounded at the welding seam in a hot pressing manner. And the tab lead welding process is reduced, and the energy density is improved. And the related production cost of the battery cell and the tab can be greatly reduced. And the traditional welding mode of the positive and negative current collectors of the laminated battery is changed. The purpose of higher charging speed is achieved, and the welding difficulty of the positive and negative current collectors and the tabs is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium battery preparation, in particular to a Y-shaped battery pole ear and a preparation method thereof. Background Art

[0002] The positive current collector of traditional lithium battery cores is a single-layer aluminum foil with a certain thickness and high purity, and the negative current collector is a single-layer copper foil with a certain thickness and high purity. When a lithium battery is accidentally punctured by an external object, it causes a short circuit, which poses a risk of combustion and explosion. Studies have found that replacing the original single-layer aluminum foil and single-layer copper foil with composite aluminum foil and composite copper foil can greatly reduce the huge safety risks of lithium batteries causing short circuits, combustion and explosions when the battery core is accidentally punctured by an external object (also known as a lithium battery puncture test). The composite aluminum foil and composite copper foil here refer to a highly insulating polypropylene film with a certain thickness in the middle, and a certain thickness of high-purity aluminum or high-purity copper is symmetrically attached to both sides of the film. Since the two sides of the original positive current collector and negative current collector are directly connected to the current, charging or discharging can be completed by welding the pole ear on any side, while the two sides of the current collector and negative current collector are insulated, and charging and discharging must be led out from both sides at the same time, while the traditional pole ear can only be led out from one side and cannot complete this function. The traditional method is to first align and symmetrically weld two tab leads on the positive electrode collector or the negative electrode collector, and then weld the two leads of each to the main tab metal strip to complete the charge and discharge connection. Summary of the invention

[0003] The technical problem to be solved by the present invention is to solve the shortcomings of the prior art and propose a battery Y-shaped pole ear that reduces the pole ear lead welding process and improves the energy density. The present invention also proposes a preparation method of the battery Y-shaped pole ear.

[0004] The technical problem to be solved by the present invention is achieved through the following technical solution, a battery Y-shaped pole ear, which is characterized by: It includes a tab metal belt and a tab rubber strip, wherein the tab rubber strip is hot pressed on the tab metal belt for composite sealing with the battery packaging film; The tab metal strip includes an outer tab strip located outside the battery and an inner tab strip located inside the battery, and at least two inner tab strips are provided, one of which is a main metal strip integrated with the outer tab strip, and the rest are auxiliary metal strips, the head end of the auxiliary metal strip is welded parallel to the main metal strip, and the tail end of the auxiliary metal strip is forked from the main metal strip and respectively welded to the positive electrode or negative electrode of the battery current collector to draw out current; Two symmetrically arranged tab rubber strips are hot pressed and laminated at the above-mentioned weld.

[0005] The technical problem to be solved by the present invention can also be further achieved by the following technical solution: the main metal strip and the auxiliary metal strip form a Y-shaped structure inside the battery.

[0006] The technical problem to be solved by the present invention can be further achieved by the following technical solution: the thickness of the auxiliary metal strip is 0.3 to 1.0 times the thickness of the main metal strip.

[0007] The technical problem to be solved by the present invention can be further achieved by the following technical solution: the two tab rubber strips are aligned vertically.

[0008] The technical problem to be solved by the present invention can be further achieved by the following technical solution: the lower edge of the tab rubber strip is spaced 0.1 to 0.3 mm from the above-mentioned weld.

[0009] A method for preparing the above-mentioned Y-shaped battery tab is characterized by: The welding surface of the main metal belt is treated with anti-corrosion, and the main metal belt is rolled into a ring belt; The welding surface of the main metal strip is intermittently conveyed to the welding station with the welding surface facing upwards. The auxiliary metal strip is cut into a specified length and conveyed to the welding station by a machine. After being aligned with the welding surface of the main metal strip, the head end of the auxiliary metal strip is parallelly welded to the above-mentioned main metal strip. After welding, it is transported to the hot pressing station; the upper and lower ear rubber strips are aligned and laminated on the main metal strip, and pressed and welded at the same time, and the upper and lower hot pressing heads perform an overall preheating and pressing composite; Transport to the shaping station; use the upper and lower hot pressing heads to perform the second hot pressing compound on the tab rubber strip part except the weld; It is transported to the cutting station and the main metal strip after hot pressing composite forming is cut into specified lengths to form Y-shaped tabs for batteries.

[0010] Compared with the prior art, the positive and negative pole tabs of the present invention break the traditional single-layer metal strip of the pole tab inside the battery cell and become a multi-layer metal strip, and the multi-layer metal strip is welded to the two surfaces of the positive electrode collector or the negative electrode collector respectively. The advantage of this is that the pole tab lead welding process is reduced, and the difficulty of aligning the upper and lower pieces of the pole tab lead is much higher than the difficulty of aligning the two layers of metal of the main pole tab. One metal sheet is reduced, the weight and volume are reduced, and the energy density is greatly improved. The use of the Y-type pole tab process can greatly reduce the production costs related to the battery cell and the pole tab. The Y-type pole tab can divide the number of layers of the positive and negative current collectors of the traditional laminated battery into three and weld them to the positive and negative pole tabs. The advantage of this is that the charging speed is faster and the difficulty of welding the positive and negative current collectors to the pole tabs is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic diagram of the Y-type pole ear structure of the present invention. DETAILED DESCRIPTION

[0012] The specific technical solutions of the present invention are further described below. To make the purpose, technical solutions and advantages of the embodiments of the present invention clearer and to facilitate those skilled in the art to further understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of them, and do not constitute a limitation on the rights thereof. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention.

[0013] A battery Y-shaped tab, comprising a tab metal strip and a tab rubber strip, wherein the tab rubber strip is hot pressed on the tab metal strip for composite sealing with a battery packaging film; The tab metal strip includes an outer tab strip located outside the battery and an inner tab strip located inside the battery, and at least two inner tab strips are provided, one of which is a main metal strip integrated with the outer tab strip, and the rest are auxiliary metal strips, the head end of the auxiliary metal strip is welded parallel to the main metal strip, and the tail end of the auxiliary metal strip is forked from the main metal strip and respectively welded to the positive electrode or negative electrode of the battery current collector to draw out current; Two symmetrically arranged tab rubber strips are hot pressed and laminated at the above-mentioned weld.

[0014] Furthermore, the main metal strip and the auxiliary metal strip form a Y-shaped structure inside the battery.

[0015] Furthermore, the thickness of the auxiliary metal strip is 0.3 to 1.0 times the thickness of the main metal strip.

[0016] Furthermore, the two tab rubber strips are aligned vertically.

[0017] Furthermore, the lower edge of the tab rubber strip is spaced 0.1 to 0.3 mm from the above-mentioned weld.

[0018] A method for preparing the above-mentioned Y-shaped battery tab, The welding surface of the main metal belt is treated with anti-corrosion, and the main metal belt is rolled into a ring belt; The welding surface of the main metal strip is intermittently conveyed to the welding station with the welding surface facing upwards. The auxiliary metal strip is cut into a specified length and conveyed to the welding station by a machine. After being aligned with the welding surface of the main metal strip, the head end of the auxiliary metal strip is parallelly welded to the above-mentioned main metal strip. After welding, it is transported to the hot pressing station; the upper and lower ear rubber strips are aligned and laminated on the main metal strip, and pressed and welded at the same time, and the upper and lower hot pressing heads perform an overall preheating and pressing composite; Transport to the shaping station; use the upper and lower hot pressing heads to perform the second hot pressing compound on the tab rubber strip part except the weld; It is transported to the cutting station and the main metal strip after hot pressing composite forming is cut into specified lengths to form Y-shaped tabs for batteries.

[0019] The unwinding part of the ear tab is designed as a double-row coil. After the auxiliary metal strip is unwound, a fixed-length cutting mechanism is installed to accurately convey the cut auxiliary metal strip to the main metal strip of the ear tab. Through precise positioning, welding is carried out, and then two symmetrical ear tab rubber strips are hot-pressed and laminated on the front and back sides of the main metal strip of the ear tab at a distance of 0.1~0.3mm from the weld.

Claims

1. A battery Y-shaped tab, characterized in that: It includes a tab metal belt and a tab rubber strip, wherein the tab rubber strip is hot pressed on the tab metal belt for composite sealing with the battery packaging film; The tab metal strip includes an outer tab strip located outside the battery and an inner tab strip located inside the battery, and at least two inner tab strips are provided, one of which is a main metal strip integrated with the outer tab strip, and the rest are auxiliary metal strips, the head end of the auxiliary metal strip is welded parallel to the main metal strip, and the tail end of the auxiliary metal strip is forked from the main metal strip and respectively welded to the positive electrode or negative electrode of the battery current collector to draw out current; Two symmetrically arranged tab rubber strips are hot pressed and laminated at the above-mentioned weld.

2. The battery Y-shaped tab according to claim 1, characterized in that: The primary metal strip and the secondary metal strip form a Y-shaped structure inside the battery.

3. The Y-shaped battery tab according to claim 1, characterized in that: The thickness of the auxiliary metal strip is 0.3~1.0 times the thickness of the main metal strip.

4. The battery Y-shaped tab according to claim 1, characterized in that: The two tab rubber strips are aligned vertically.

5. The battery Y-shaped tab according to claim 1 or 4, characterized in that: The lower edge of the tab rubber strip is spaced 0.1 to 0.3 mm from the above-mentioned weld.

6. A method for preparing the Y-shaped battery tab according to claim 1, characterized in that: The welding surface of the main metal belt is treated with anti-corrosion, and the main metal belt is rolled into a ring belt; The welding surface of the main metal strip is intermittently conveyed to the welding station with the welding surface facing upwards. The auxiliary metal strip is cut into a specified length and conveyed to the welding station by a machine. After being aligned with the welding surface of the main metal strip, the head end of the auxiliary metal strip is parallelly welded to the above-mentioned main metal strip. After welding, it is transported to the hot pressing station; the upper and lower ear rubber strips are aligned and laminated on the main metal strip, and pressed and welded at the same time, and the upper and lower hot pressing heads perform an overall preheating and pressing composite; Transport to the shaping station; use the upper and lower hot pressing heads to perform the second hot pressing compound on the tab rubber strip part except the weld; It is transported to the cutting station and the main metal strip after hot pressing composite forming is cut into specified lengths to form Y-shaped tabs for batteries.

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