Double-tab battery cell structure

Abstract

The utility model relates to the technical field of lithium ion batteries, and discloses a double-tab battery cell structure, which comprises a positive plate, a negative plate and a diaphragm, the battery cell structure comprises the diaphragm, the negative plate, the diaphragm and the positive plate which are sequentially stacked from bottom to top, the positive plate further comprises two positive tabs, and the two positive tabs are arranged in parallel. The positive plate comprises two positive tabs and two negative tabs, the two positive tabs are respectively positioned at 1 / 3 and 2 / 3 positions of the positive plate, the negative plate also comprises two negative tabs, and the two negative tabs are arranged at the two ends of the negative plate, the positive plate and the negative plate both adopt double tabs, the two positive tabs are respectively positioned at 1 / 3 and 2 / 3 positions of the positive plate, and the two positive tabs are respectively positioned at 1 / 3 and 2 / 3 positions of the negative plate. The cylindrical lithium ion battery has the advantages that the structure is simple, the fast charging and fast discharging performance of the cylindrical lithium ion battery at high rate can be improved, the heating value of a battery cell in the charging and discharging process is reduced, and the excellent cycle performance is guaranteed.

Description

TECHNICAL FIELD

[0001] The utility model relates to lithium ion battery technical field, concretely is a kind of bipolar tab electric core structure. BACKGROUND

[0002] Lithium ion battery is more and more paid attention to and adopted by electric tool, electric motorcycle etc. manufacturer due to high energy density, long life, light weight etc. With the rapid development of lithium ion battery technology, higher demand is put forward to lithium ion battery's rate charging, rate discharging and temperature rise.

[0003] In prior art, CN219476721U discloses a kind of high rate bipolar tab lithium battery electric core, positive sheet contains two tabs, two tabs are arranged adjacent in positive sheet 1 / 3-2 / 3 position, interval is greater than or equal to 0.2mm,;Negative sheet contains two tabs, two tabs are arranged adjacent in negative sheet 1 / 3-2 / 3 position, interval is greater than or equal to 0.2mm.Setting double tab can effectively reduce internal resistance, reduce the heat generation of electric core in the process of charging and discharging, improve the charge-discharge rate performance of electric core.

[0004] But above-mentioned technical scheme has big limitation in actual production, mainly because the thickness of positive and negative current collector is thin, due to the long foil area in the middle of current collector, it will be wrinkled due to uneven extension when rolling.The tab of the positive sheet is wrinkled, which increases the welding defect, thereby increasing the internal resistance of the battery, so that the cycle life attenuation of lithium ion battery increases in the process of charging and discharging. UTILITY MODEL CONTENTS

[0005] The utility model aims at providing a kind of bipolar tab electric core structure to solve the problems raised in the above background.

[0006] To achieve the above object, the utility model provides the following technical scheme: a kind of bipolar tab electric core structure, including positive sheet, negative sheet and diaphragm, electric core structure is sequentially stacked from bottom to top as follows: diaphragm, negative sheet, diaphragm, positive sheet, the positive sheet further includes positive tab, the positive tab has two, two the positive tab is located at 1 / 3, 2 / 3 position of positive sheet respectively, the negative sheet further includes negative tab, the negative tab has two, two the negative tab is set at both ends of negative sheet.

[0007] Further, the positive tab is aluminum strip, the width of the positive tab is 4-6mm, and the thickness is 0.10-0.20mm.

[0008] Further, the negative tab is copper-nickel composite strip, the width of the negative tab is 3-5mm, and the thickness is 0.07-0.09mm.

[0009] Further, the positive tab is provided with a positive tab high-temperature adhesive tape above.

[0010] Further, the negative tab is provided with a negative tab high-temperature adhesive tape above.

[0011] Further, the positive tab is coated with a positive slurry layer on the outside, the negative tab is coated with a negative slurry layer on the outside, the positive tab is provided with a positive empty foil area at the positive tab mounting position, and the negative tab is provided with a negative empty foil area at the negative tab mounting position.

[0012] Compared with the prior art, the utility model has the beneficial effects that:

[0013] The utility model discloses a positive tab, a negative tab and a diaphragm are set up, and are stacked according to the order of diaphragm-negative tab-diaphragm-positive tab, and are made into a winding core through the winding mode, wherein the positive tab and the negative tab are both double-pole tabs, two positive tabs are located at 1 / 3 and 2 / 3 positions of the positive tab respectively, and two negative tabs are located at both ends of the negative tab, which has the simple structure and can improve the fast charging and discharging performance of the cylindrical lithium ion battery under high rate, reduce the heat generation of the electric core in the charging and discharging process and guarantee excellent cycle performance. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 It is a positive tab structure schematic view of the utility model discloses a double-pole tab electric core structure.

[0015] Figure 2 It is a negative tab structure schematic view of the utility model discloses a double-pole tab electric core structure.

[0016] Figure 3 It is a positive tab and negative tab stacked state schematic view of the utility model discloses a double-pole tab electric core structure.

[0017] Figure 4 It is a 2C / 3C 100 percent DOD cycle performance side view of the utility model discloses a double-pole tab electric core structure.

[0018] In the drawing: 1, positive tab;2, positive tab;3, positive tab high-temperature adhesive tape;4, negative tab;5, negative tab;6, negative tab high-temperature adhesive tape;7, diaphragm. DETAILED DESCRIPTION

[0019] The technical scheme in the embodiments of the utility model will be apparently and completely described in combination with the drawings in the embodiments of the utility model, and apparently, the described embodiments are only a part of the embodiments of the utility model, not all the embodiments.

[0020] Please refer to Figure 1-Figure 3The utility model provides a technical scheme: a bipolar ear electric core structure, including positive sheet 1, negative sheet 4 and diaphragm 7, and the electric core structure is sequentially stacked from below to above: diaphragm 7, negative sheet 4, diaphragm 7, positive sheet 1's order, the positive sheet 1 still includes positive pole lug 2, the positive pole lug 2 has two, and two positive pole lug 2 is located at 1 / 3, 2 / 3 position of positive sheet 1 respectively, the negative sheet 4 still includes negative pole lug 5, and the negative pole lug 5 has two, and two negative pole lug 5 is arranged at both ends of negative sheet 4. By setting two pole lug at the different position of positive sheet, can make the distribution of electric current in the battery interior more uniform. This helps to reduce the local overheating and current concentration, thereby improving the performance of the battery under high rate charge and discharge conditions. Uniform current distribution can also reduce the heat generation of the battery during charging and discharging. This is because the transmission path of the current in the current collector is shortened, reducing the heat generated by the resistance, thereby reducing the overall temperature rise, which is beneficial to maintaining the stability of the battery and prolonging its service life. The structure design optimizes the flow and distribution of the current in the battery, reduces the internal resistance and heat generation, not only improves the fast charging and discharging performance, but also helps to maintain the long-term stability and safety of the battery.

[0021] The positive pole lug 2 is an aluminum strip, and the width of the positive pole lug 2 is 4-6mm and the thickness is 0.10-0.20mm. This size can provide sufficient conductive area to ensure that electrons can be efficiently transmitted from the positive current collector to the external circuit of the battery. At the same time, this width range is also to maintain the mechanical strength of the pole lug to avoid breaking during battery assembly or use.

[0022] The thickness of the positive pole lug 2 is between 0.10-0.20mm. Thinner pole lug can reduce the internal resistance of the battery and improve the charging and discharging efficiency of the battery. At the same time, the appropriate thickness can ensure that the pole lug has enough material basis to withstand the processing process such as welding and the mechanical stress in long-term use.

[0023] The negative pole lug 4 is a copper-nickel composite strip, and the width of the negative pole lug 4 is 3-5mm and the thickness is 0.07-0.09mm. The width of the negative pole lug 4 is between 3-5mm. This size can provide sufficient conductive area to ensure that electrons can be efficiently transmitted from the negative current collector to the external circuit of the battery. At the same time, this width range is also to maintain the mechanical strength of the pole lug to avoid breaking during battery assembly or use.

[0024] The thickness of the negative pole lug 4 is usually between 0.07-0.09mm. Thinner pole lug can reduce the internal resistance of the battery and improve the charging and discharging efficiency of the battery. At the same time, the appropriate thickness can ensure that the pole lug has enough material basis to withstand the processing process such as welding and the mechanical stress in long-term use.

[0025] The positive tab 2 is provided with a positive tab high-temperature adhesive tape 3 above it. The negative tab 5 is provided with a negative tab high-temperature adhesive tape 6 above it. The tab is the part that connects the positive and negative electrodes of the battery to the external circuit. Since the tab is usually connected to the battery cover or battery connector through welding or the like, the high-temperature adhesive tape provided above the tab can provide the necessary insulation protection to prevent the tab from short-circuiting with the battery shell or other metal parts.

[0026] During the charging and discharging process of the battery, especially during high-rate charging and discharging, the tab area may generate high temperature. The high-temperature adhesive tape can withstand these high temperatures and maintain its insulation performance unaffected. The high-temperature adhesive tape also helps to enhance the mechanical strength of the tab and reduce damage to the tab caused by improper operation or mechanical stress. During the manufacturing process of the battery, the high-temperature adhesive tape can protect the tab from being contaminated by dust, electrolyte or other substances that may affect the performance of the battery. If an abnormality occurs inside the battery, such as overheating or short circuit, the high-temperature adhesive tape can serve as an additional layer of protection to reduce the safety risk.

[0027] The positive plate 1 is coated with a positive slurry layer on the outside, and the negative plate 4 is coated with a negative slurry layer on the outside. The positive plate 1 is provided with a positive empty foil area at the installation position of the positive tab 2, and the negative plate 4 is provided with a negative empty foil area at the installation position of the negative tab 5. The positive empty foil area and the negative empty foil area are not coated with a positive slurry layer or a negative slurry layer to keep the current collector exposed. In this empty foil area, it is helpful for the welding operation during the assembly process of the battery, and it ensures the uniform distribution of current and the transmission efficiency.

[0028] The cylindrical lithium ion battery with the double-tab cell structure of the present application was tested for 2C / 3C 100% DOD cycle performance at room temperature 25℃, and the test results are shown in the following table. Figure 4 As can be seen from the figure, the battery still has a capacity retention rate of 87% after 1700 cycles, indicating that the double-tab cell structure prepared in the present application has excellent cycle performance under the condition of ensuring fast charging and discharging capability.

[0029] Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present application.

Claims

1. A bipolar tab cell structure comprising a positive electrode tab (1), a negative electrode tab (4) and a separator (7), characterized in that: The cell structure is sequentially stacked from bottom to top as follows: diaphragm (7), negative plate (4), diaphragm (7), positive plate (1), the positive plate (1) further comprises positive tab (2), the positive tab (2) has two, the two positive tabs (2) are respectively located at 1 / 3 and 2 / 3 positions of the positive plate (1), the negative plate (4) further comprises negative tab (5), the negative tab (5) has two, the two negative tabs (5) are arranged at both ends of the negative plate (4).

2. The bipolar tab cell structure of claim 1, wherein: The positive tab (2) is an aluminum strip, the width of the positive tab (2) is 4-6mm, and the thickness is 0.10-0.20mm.

3. The bipolar tab cell structure of claim 2, wherein: The negative tab (5) is a copper-nickel composite strip, the width of the negative tab (5) is 3-5mm, and the thickness is 0.07-0.09mm.

4. The bipolar tab cell structure of claim 1, wherein: The positive tab (2) is provided with a positive tab high-temperature adhesive tape (3) above.

5. The bipolar tab cell structure of claim 1, wherein: The negative tab (5) is provided with a negative tab high-temperature adhesive tape (6) above.

6. The bipolar tab cell structure of claim 1, wherein: The positive plate (1) is coated with a positive slurry layer on the outside, the negative plate (4) is coated with a negative slurry layer on the outside, the positive plate (1) is provided with a positive empty foil area at the mounting position of the positive tab (2), and the negative plate (4) is provided with a negative empty foil area at the mounting position of the negative tab (5).

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