Soft package lithium ion battery integrated tab and battery structure

Abstract

The utility model relates to a new energy battery technology, in particular to a soft package lithium ion battery integrated tab and a battery structure, and a positive tab and a negative tab of the battery are of an integrated structure. In the prior art, the distance between tabs cannot be accurately controlled in the welding process, the conditions of top sealing and pressing of the tabs, poor edge sealing thickness, seal wrinkles and the like can be possibly found in the film coating process, and the risks of liquid leakage, corrosion and even fire catching can be caused when abnormal battery cells flow into a client side. According to the utility model, the positive and negative tabs are arranged into an integrated structure, so that during mass production, the distance between the positive and negative tabs is designed in advance according to the specifications of the applied batteries, the distance between the positive and negative tabs is strictly specified, the reject ratio of the batteries is avoided, the use safety of subsequent batteries and modules is ensured, and the production and use requirements are met.

Description

Technical Field

[0001] The utility model relates to new energy battery technology, in particular to a soft-pack lithium-ion battery connected pole ear and a battery structure. Background Art

[0002] Nowadays, with the rapid development of electronic technology, the importance of electronic information products in daily life is becoming more and more prominent. Lithium-ion batteries have become a hot chemical power source due to their high energy density, long cycle life, high operating voltage, and low self-discharge rate. Compared with aluminum-shell lithium-ion batteries, soft-pack lithium-ion batteries are favored by consumers due to their light weight, small size, good safety performance, and flexible shape.

[0003] Lithium-ion battery is a rechargeable battery. Its basic principle is to use lithium ions to migrate back and forth between the positive and negative electrodes of the battery to achieve the storage and release of electrical energy. It is mainly composed of a positive electrode, a negative electrode, an electrolyte and a separator. In a lithium-ion battery, the positive electrode is usually composed of a lithium compound (such as lithium manganese oxide, lithium cobalt oxide or lithium iron phosphate), and the negative electrode is usually composed of a carbon material (such as graphite). The two are separated by an electrolyte (usually an organic solution) and a separator to prevent direct contact between the positive and negative electrodes. When charging, an external power source passes current through the lithium-ion battery, causing the lithium ions in the electrolyte to dissociate from the positive electrode and move to the negative electrode, while electrons flow through the external circuit to complete the battery charging process. When discharging, lithium ions are released from the negative electrode, pass through the electrolyte and the separator, and move to the positive electrode. At the same time, electrons flow back to the negative electrode through the external circuit again to achieve the release of electrical energy.

[0004] The tab is a metal conductor that connects the positive and negative electrodes of a lithium-ion battery. It is composed of a metal layer and a tab glue layer. The positive tab metal layer is usually made of aluminum, and the negative tab metal layer is usually made of nickel or copper-plated nickel. The tab glue layer is the insulating part of the tab, which plays a role in hot-melt bonding with the aluminum-plastic film PP layer to achieve soft-pack lithium-ion battery packaging.

[0005] At present, soft-pack lithium-ion batteries connect the positive and negative tabs with the current collector through a welding process to achieve electronic connectivity. In order to avoid short circuits and poor packaging caused by direct contact between the tab metal layer and the aluminum layer in the aluminum-plastic film during the subsequent packaging process, the tab spacing must be strictly controlled. However, in actual production, due to fluctuations in process equipment, defective products with poor tab spacing will be produced, which will lead to top-sealed tabs, poor edge thickness, and seal wrinkles in the coating process. The above abnormal cells will flow into the client and there will be a risk of leakage, corrosion, and even fire. Therefore, it is particularly important to propose a new tab structure to accurately control the tab spacing. Summary of the invention

[0006] The main purpose of the utility model is to provide a soft-pack lithium-ion battery integrated pole ear and battery structure, which can effectively overcome the process defect that the distance between the pole ears cannot be accurately controlled.

[0007] To achieve the above-mentioned purpose, the utility model proposes a one-piece pole ear and battery structure for a soft-pack lithium-ion battery, by setting the positive and negative pole ears as an integrated structure, designing the positive and negative pole ear spacing in advance according to the applied battery specifications, strictly controlling the positive and negative pole ear spacing, reducing battery packaging defects, ensuring the safety of subsequent batteries and modules, and meeting the requirements of production use.

[0008] Furthermore, the positive electrode tab and the negative electrode tab are parallel to each other.

[0009] Furthermore, the positive electrode tab and the negative electrode tab respectively include a connection end connected to the battery electrode sheet and an exposed end of the tab opposite to the connection end.

[0010] Furthermore, the battery also includes a shell, and the exposed ends of the positive and negative tabs extend from the shell and are sealed to the shell by PP glue, and in the top sealing stage of the encapsulation process, they should be sealed on the PP glue and keep a part of the PP glue exposed.

[0011] In the utility model, PP glue is selected and a physical hot pressing process (mainly contact heating) is adopted when in use, that is, a heating tube heats the heater, the heater is pressed onto the metal belt, and heating is performed multiple times to heat the metal belt to a certain temperature to dissolve the glue.

[0012] Furthermore, the length of the PP glue is the same as the width of the battery cell membrane shell.

[0013] In batteries of the same specifications, compared with the prior art, the PP glue of the utility model is longer. The extended version of the PP glue can ensure the sealing thickness, reduce the side voltage and side resistance defects, and the top seal head does not need to open the pole ear groove to ensure the sealing thickness, which increases the types of available heads and can reduce the poor appearance of the top seal edge.

[0014] Furthermore, the positive electrode ear and the negative electrode ear are perpendicular to the PP glue.

[0015] Furthermore, the PP glue is divided into PP glue for the negative electrode lug area, PP glue for the positive electrode lug area, and PP glue for the non-lug area.

[0016] Furthermore, the thickness of the PP glue in the negative electrode lug area plus the lug thickness is equal to the thickness of the PP glue in the non-lug area, and the thickness of the PP glue in the positive electrode lug area plus the lug thickness.

[0017] This structure can eliminate the slotting in the tab area of ​​the top seal head, thus improving the universality of the top seal head. The thickness of the top seal edge is also easier to control, which is of great benefit to improving the packaging yield.

[0018] Furthermore, the positive electrode ear is made of a special surface-treated aluminum conductor.

[0019] Furthermore, the negative electrode ear material is one of special surface treated nickel, nickel alloy, and copper-plated nickel.

[0020] The utility model has the following beneficial effects:

[0021] (1) The utility model effectively controls the size of the distance between the tabs, and there is no need to open tab grooves on the top seal head, thereby improving the yield and consistency of the coating process;

[0022] (2) The utility model reduces the problems of battery short circuit and leakage caused by pressing the tabs during film coating due to large differences in the spacing between the tabs. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 : The utility model is a schematic diagram of a soft-pack lithium-ion battery body-type pole ear and a battery structure.

[0024] Figure 2 : A schematic diagram of a one-piece pole ear of a soft-pack lithium-ion battery of the present invention.

[0025] Among them: 1 positive ear, 2 negative ear, 3 connection end, 4 ear exposed end, 5 shell, 6 PP rubber strip, 7 PP glue in the negative ear area, 8 PP glue in the positive ear area, 9 PP glue in the non-ear area, 10 battery cell membrane shell. DETAILED DESCRIPTION

[0026] The utility model is further described below in conjunction with the drawings and specific embodiments of the specification. A person of ordinary skill in the art will be able to implement the utility model based on these descriptions. In addition, the embodiments of the utility model involved in the following description are usually only embodiments of a part of the utility model, rather than all of the embodiments. Therefore, based on the embodiments in the utility model, all other embodiments obtained by a person of ordinary skill in the art without making creative work should fall within the scope of protection of the utility model.

[0027] like Figure 1 As shown, a soft-pack lithium-ion battery integrated pole ear and battery structure, wherein the positive pole ear 1 and the negative pole ear 2 of the battery are an integrated structure. In this embodiment, by setting the positive pole ear 1 and the negative pole ear 2 as an integrated structure, in mass production, according to the battery specifications used, the spacing between the positive pole ear 1 and the negative pole ear 2 is set in advance, and the spacing between the positive pole ear 1 and the negative pole ear 2 is strictly specified, thereby avoiding the defective rate of the battery, ensuring the safety of the subsequent use of the battery and the module, and meeting the requirements of production and use.

[0028] In this embodiment, the distance between the positive electrode tab 1 and the negative electrode tab 2 is controlled to be 20 mm±1 mm according to the process requirements.

[0029] In another embodiment, the distance between the positive electrode tab 1 and the negative electrode tab 2 is controlled to be 30 mm ± 1 mm according to process requirements.

[0030] like Figure 2 As shown, in this embodiment, the positive electrode ear 1 and the negative electrode ear 2 are parallel to each other, the positive electrode ear 1 and the negative electrode ear 2 are perpendicular to the PP glue 6, and the positive electrode ear 1 and the negative electrode ear 2 respectively include a connection end 3 connected to the battery electrode sheet and an exposed end 4 of the electrode ear opposite to the connection end 3. Figure 1 As shown, the battery further includes a shell 5, and the exposed ends 4 of the positive tab 1 and the negative tab 2 extend from the shell 5 and are sealed to the shell 5 by PP glue 6. In this embodiment, PP glue 6 is selected, and a heating tube is used to heat the heater during use, and the heater is pressed onto the metal strip, and the metal strip is heated multiple times to be heated to a certain temperature to melt the glue.

[0031] In this embodiment, if Figure 1 As shown, the length of the PP glue 6 is the same as the width of the cell membrane shell 10. In batteries of the same specifications, compared with the prior art, the length of the PP glue 6 of this device is longer. The extended version of the PP glue 6 can ensure the consistency of the seal thickness, reduce the side voltage and side resistance, and the top seal head does not need to open the pole ear groove to ensure the seal thickness. The top seal head can be designed to be universal, and there is no need to design a separate top seal head for each product, and the poor appearance of the top seal edge can be reduced.

[0032] In this embodiment, the length of the PP glue 6 is 144-146 mm.

[0033] In this embodiment, the positive electrode tab 1 and the negative electrode tab 2 are perpendicular to the PP glue 6 .

[0034] In this embodiment, the thickness of the PP glue 7 in the negative electrode ear area plus the negative electrode ear 2 is equal to the thickness of the PP glue 9 in the non-electrode ear area, and equal to the thickness of the PP glue 8 in the positive electrode ear area plus the positive electrode ear 1. This structure can eliminate the slotting in the ear area of ​​the top seal head, improve the universality of the top seal head, and the thickness of the top seal edge is easier to control, which can improve the yield of the packaging process.

[0035] In this embodiment, the positive electrode tab 1 is an aluminum conductor with a special surface treatment.

[0036] In this embodiment, the negative electrode tab 2 is a nickel conductor with a special surface treatment.

[0037] In another embodiment, the negative electrode tab 2 is a specially surface treated aluminum conductor.

Claims

1. A one-piece tab for a soft-pack lithium-ion battery, characterized in that: The positive electrode ear (1) and the negative electrode ear (2) of the battery are an integrated structure; The positive electrode lug (1) and the negative electrode lug (2) respectively comprise a connection end (3) connected to the battery electrode sheet and an exposed end (4) of the lug opposite to the connection end (3); The battery further comprises a shell (5), the exposed ends (4) of the positive electrode lug (1) and the negative electrode lug (2) extending from the shell (5) and sealed to the shell (5) via PP glue (6), and in the top sealing stage of the encapsulation process, sealed on the PP glue (6) and leaving a portion of the PP glue (6) exposed.

2. The one-piece tab of a soft-pack lithium-ion battery according to claim 1, characterized in that: The positive electrode tab (1) and the negative electrode tab (2) are parallel to each other.

3. The one-piece tab of a soft-pack lithium-ion battery according to claim 1, characterized in that: The length of the PP glue (6) is the same as the width of the battery cell membrane shell (10).

4. The one-piece tab of a soft-pack lithium-ion battery according to claim 1, characterized in that: The positive electrode ear (1) and the negative electrode ear (2) are perpendicular to the PP glue (6).

5. The one-piece tab of a soft-pack lithium-ion battery according to claim 1, characterized in that: The PP glue (6) is divided into a negative electrode lug region PP glue (7), a positive electrode lug region PP glue (8), and a non-lug region PP glue (9).

6. The one-piece tab of a soft-pack lithium-ion battery according to claim 5, characterized in that: The thickness of the PP glue (7) in the negative electrode ear area plus the negative electrode ear (2) is equal to the thickness of the PP glue (9) in the non-electrode ear area, and equal to the thickness of the PP glue (8) in the positive electrode ear area plus the positive electrode ear (1).

7. A battery structure, characterized in that: It comprises the one-piece pole ear of the soft-pack lithium-ion battery as described in any one of claims 1 to 6.

Images