Lithium battery vacuum final sealing machine

Abstract

The utility model discloses a lithium battery vacuum final sealing machine which comprises a vacuumizing device, a sealing device and a fixing device, the vacuumizing device comprises a secondary vacuum upper cavity and a secondary vacuum lower cavity which are arranged in a primary vacuum cavity in an up-and-down alignment mode, and a plurality of bayonets are arranged in the secondary vacuum upper cavity. The fixing device comprises a pressing mechanism, the pressing mechanism comprises a pressing plate, an arc-shaped air bag pressing plate is arranged at the front end of the pressing plate, an air bag supporting cushion block of an arch structure is arranged under the air bag pressing plate, an upper cavity notch is formed in the secondary vacuum upper cavity, and the bayonet is in a triangular prism shape. The soft package lithium battery has the advantages that the lithium battery and the battery air bag can be conveniently fixed, meanwhile, gas in the soft package lithium battery can be completely exhausted, the vacuum degree in the soft package lithium battery and the loss of electrolyte are ensured to be within a controllable range, and the capacity of the battery is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium battery manufacturing equipment, in particular to a lithium battery vacuum final sealing machine. Technical Background

[0002] When lithium batteries are being formed, they will produce gases, which will affect the performance and life of the battery, causing the battery to swell. The battery fluid will be discharged when sealing, reducing the battery capacity. The gas will affect the activity of the battery fluid and affect the service life of the battery. Therefore, lithium batteries should be vacuumed before sealing.

[0003] At present, in the sealing process of lithium battery production, many manufacturers still use manual sealing technology, which is labor-intensive and has poor sealing effect. Although some manufacturers have adopted the vacuum final sealing machine currently available on the market, the traditional vacuum final sealing machine cannot completely remove the gas in the battery after vacuuming or over-vacuuming, and will also extract part of the electrolyte, the vacuuming is unstable, and the time is long. When the battery is charged and discharged for the first time to form the SEI film, more gas will be generated due to the decomposition of the electrolyte, which will not only affect the internal space of the battery and cause the battery cell to shake, but also affect the shaping of the battery. At the same time, in the prior art, the fixing structure for the lithium battery can only fix the lithium battery individually, and the fixing effect on the lithium battery is not strong enough. The lithium battery may shake and cause dislocation, affecting the sealing effect.

[0004] Chinese patent CN200920137506.1 discloses a lithium battery vacuum sealer, including a controller, a vacuum device and a sealing device, wherein the vacuum device includes a vacuum pressing cylinder, an upper vacuum pressing strip, a lower vacuum pressing strip, a vacuum pump, a head cylinder, a heat sealing head, and a leveling silicone strip. When processing the battery, the battery cell seal is placed between the head and the vacuum pressing strip from the side, and the vacuum is first evacuated and then sealed. The device puts a vacuum hose into the battery cell seal, and the gas extraction direction corresponds to the battery air bag opening. The gas is directly extracted from the battery air bag opening, so that part of the electrolyte is easily extracted at the same time, resulting in waste and loss of electrolyte, affecting the injection accuracy, thereby affecting the preparation quality of the lithium battery, and also polluting the vacuum pipeline. During the vacuuming process, this structure is prone to surface unevenness such as battery cell wrinkles. For the battery air bag, there is no air bag pressure plate and air bag pad, which is prone to jamming and material stagnation. It cannot adapt to the high-efficiency production mode and is difficult to meet the high-quality requirements of the product. Utility Model Content

[0005] The utility model aims to propose a lithium battery vacuum final sealing machine, which has the advantages of being easy to fix lithium batteries and battery air bags, etc., and solves the problem that the existing final sealing machine lacks a fixing device, which affects the production efficiency and production quality of lithium batteries. At the same time, it can exhaust the gas inside the soft-pack lithium battery, ensure that the vacuum degree inside the soft-pack lithium battery and the loss of electrolyte are within a controllable range, quickly and evenly evacuate the vacuum, improve the softness of the evacuation, and ensure the consistency and capacity of the battery.

[0006] The purpose of the utility model is achieved through the following technical scheme: a lithium battery vacuum final sealing machine, including a vacuum pumping device, a sealing device and a fixing device, the vacuum pumping device includes a secondary vacuum upper chamber and a secondary vacuum lower chamber which are respectively arranged vertically and horizontally at the top and bottom of the inner cavity of a primary vacuum chamber, a plurality of bayonets are arranged inside the secondary vacuum upper chamber, the fixing device includes a clamping mechanism, the clamping mechanism includes a pressing plate, an arc-shaped air bag pressing plate is arranged at the front end of the pressing plate, a supporting air bag cushion block with an arched structure is arranged directly below the air bag pressing plate, an upper chamber notch is arranged on the secondary vacuum upper chamber, and the bayonet is triangular in shape.

[0007] The vacuum pumping device comprises a primary vacuum joint arranged on the primary vacuum cavity and a secondary vacuum joint arranged below the secondary vacuum lower cavity and passing through the outside of the primary vacuum cavity.

[0008] The sealing device comprises a pre-sealing upper head arranged at the top of the inner cavity of the primary vacuum chamber and a pre-sealing lower head arranged at the bottom of the inner cavity of the primary vacuum chamber, and the upper and lower pre-sealing heads are aligned in vertical positions.

[0009] An upper chamber pressure spring is arranged at the top of the secondary vacuum upper chamber.

[0010] The tray of the fixing mechanism is located on a conveying mechanism, and the conveying mechanism includes supporting rollers.

[0011] The height dimension of the notch of the upper cavity is greater than the thickness dimension of the aluminum-plastic film.

[0012] The pressing mechanism and the vacuum device are arranged on both sides of the sealing device.

[0013] The working height of the secondary vacuum chamber is adjusted to be 5 mm higher than the battery air bag.

[0014] The beneficial effects of the utility model are as follows: the arc-shaped air bag pressure plate and the arched air bag support cushion block structure are used to avoid the phenomenon that the battery air bag is too high and the air bag is folded when the secondary vacuum upper cavity is pressed down, so as to better position the battery air bag and improve production efficiency; by setting an upper cavity notch on the secondary vacuum upper cavity, a channel is provided for secondary vacuum extraction, and the softness and uniformity of the extraction are improved; the bayonet adopts a triangular shape, and the small surface of the notch faces the battery cell body, which indirectly fine-tunes the vacuum extraction and improves the vacuum extraction effect; through the pressure plate of the clamping mechanism The setting ensures the stability of the lithium battery; the primary vacuum joint and the secondary vacuum joint are used as gas exhaust channels, and gas is extracted through the vacuum upper cavity and the vacuum lower cavity structure. The battery air bag and the battery body are vertically placed on the fixing device, and the battery air bag enters the secondary vacuum lower cavity. The air bag is first punctured by the bayonet and vacuumed at the same time, so that the gas in the air bag will be extracted, and then the second sealing head is packaged through the sealing device to ensure the airtightness of the battery cell, which can effectively avoid liquid leakage and ensure the quality of the soft-pack lithium battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the structure of the utility model;

[0016] Explanation of numbers in the figure: 1-primary vacuum chamber, 2-battery air bag, 3-bayonet, 4-upper chamber pressure spring, 5-secondary vacuum upper chamber, 6-upper chamber notch, 7-pre-sealed upper head, 8-air bag pressure plate, 9-pressure plate, 10-tray, 11-battery body, 12-support roller, 13-support air bag cushion block, 14-pre-sealed lower head, 15-secondary vacuum joint, 16-secondary vacuum lower chamber, 17-primary vacuum joint. DETAILED DESCRIPTION

[0017] The utility model is further described below in conjunction with the figures.

[0018] See also Figure 1 As shown, the utility model provides a lithium battery vacuum final sealing machine, including a vacuum device, a sealing device, a fixing device and a conveying mechanism. The vacuum device includes a primary vacuum cavity 1, a secondary vacuum upper cavity 5, a secondary vacuum lower cavity 16, a bayonet 3, a primary vacuum joint 17, a secondary vacuum joint 15, and a pressure spring 4; the sealing device includes a pre-sealed upper head 7 and a pre-sealed lower head 14; the fixing device includes a tray 10 and a clamping mechanism, and the clamping mechanism includes a pressing plate 9, an air bag pressing plate 8 and a supporting air bag cushion block 13.

[0019] The secondary vacuum upper chamber 5 and the secondary vacuum lower chamber 16 are respectively aligned with each other at the top and bottom of the primary vacuum chamber 1, and a plurality of bayonets 3 are arranged inside the secondary vacuum upper chamber 5, and the bayonets 3 are in a triangular shape; an upper chamber notch 6 is arranged on the secondary vacuum upper chamber 5.

[0020] An arc-shaped airbag pressing plate 8 is arranged at the front end of the pressing plate 9, and an arched airbag supporting cushion block 13 is arranged directly below the airbag pressing plate 8. The height and position range of the battery airbag 2 are limited to avoid folding and ensure smooth entry into the secondary vacuum chamber 16.

[0021] A vacuum gas exhaust channel is provided, and a primary vacuum joint 17 is provided on the primary vacuum chamber 1 ; a secondary vacuum joint 15 is provided below the secondary vacuum lower chamber 16 and passes through to the outside of the primary vacuum chamber 1 .

[0022] The upper pre-sealing head 7 is connected to the top of the inner cavity of the primary vacuum chamber 1, and the lower pre-sealing head 14 is connected to the bottom of the inner cavity of the primary vacuum chamber 1. The upper pre-sealing head 7 and the lower pre-sealing head 14 are aligned in the upper and lower positions. After vacuuming, the battery air bag 2 is heat-sealed by the upper pre-sealing head 7 and the lower pre-sealing head 14.

[0023] An upper chamber pressure spring 4 is provided at the top of the secondary vacuum upper chamber 5 to facilitate vacuum exhaust.

[0024] The tray 10 of the fixing mechanism is located on the conveying mechanism, and the conveying mechanism includes supporting rollers 12. The soft-pack lithium batteries are transported in and out by the conveying mechanism.

[0025] The height dimension of the notch of the upper cavity 6 is greater than the thickness dimension of the aluminum-plastic film.

[0026] The pressing mechanism and the vacuum pumping device are arranged on both sides of the sealing device.

[0027] The working height of the secondary vacuum chamber 16 can be adjusted, and is generally adjusted to be 5 mm higher than the battery air bag 2 .

[0028] The width of the aluminum-plastic film battery air bag 2 is similar to that of the battery body.

[0029] After the soft-pack lithium battery is filled, it is sealed immediately. The battery air bag is placed vertically and is divided into two parts. The battery is below and the empty air bag part above is used to contain the gas generated by the formation process. Formation is the first charging of the battery, but it will not be charged to the highest voltage used, and the charging current is also very small. The purpose of formation is to form a stable SEI film on the electrode surface, which is equivalent to the process of activating the battery cell. In this process, a certain amount of gas will be generated, so an air bag is reserved for the aluminum-plastic film. When entering the second sealing process, the air bag part of the soft-pack lithium battery enters the fixing device vertically upward, and the reserved air bag part enters the secondary vacuum cavity. The part of the battery air bag 2 equipped with the battery body 11 is outside the secondary vacuum cavity and is pressed and fixed by the pressing plate 9. The bayonet 3 moves downward to pierce the air bag part of the battery air bag 2 that contains gas, and then evacuates. Because the working height of the secondary vacuum lower chamber 16 is the height of the battery air bag 2, the electrolyte itself will not be lost. When evacuating, the gas in the air bag and a small amount of electrolyte are extracted, and the electrolyte loss is within the controllable range required by the process, ensuring the battery capacity.

[0030] The specific implementation process of this practical structure is as follows: when the tray 10 carries the battery body 11 of the battery air bag 2 after formation into the primary vacuum chamber 1, the air bag cushion block 13 lifts the battery air bag 2, and the pressure plate 9 presses down to ensure that the surface of the battery body 11 remains flat when vacuuming. At the same time, the air bag pressure plate 8 in front of the pressure plate 9 ensures that the battery air bag 2 does not lift too high. If the battery air bag 2 lifts too high, it will cause the battery air bag 2 to be folded when the secondary vacuum upper chamber 5 is pressed down. The secondary vacuum lower chamber 16 is lifted by the cylinder and is 5 mm higher than the battery air bag 2. The secondary vacuum upper chamber 5 runs downward and is pressed against the secondary vacuum lower chamber 16. The height of the upper chamber notch 6 is greater than the thickness of the aluminum-plastic film, which can effectively allow the gas inside the battery to be extracted without generating blocking pressure. There is a fixed bayonet 3 in the secondary vacuum upper chamber 5, and the upper chamber pressure spring 4 drives the secondary vacuum upper chamber 5 to press the aluminum-plastic film. The upper chamber pressure spring 4 rebounds, and the bayonet 3 pierces the aluminum-plastic film downward with the secondary vacuum upper chamber 5, and then the secondary vacuum is evacuated. Since the bayonet 3 is in a triangular shape, the small surface of the rupture faces the battery body, which indirectly fine-tunes the vacuum evacuation. After the battery is evacuated, the pre-sealed lower sealing head 14 moves upward, and the pre-sealed upper sealing head 7 moves downward for pre-sealing. After the second sealing, it is cut off and the primary vacuum chamber 1 is taken out by the tray 10. In short, the steps of the application of the utility model structure are: first transfer the soft-pack lithium battery to be evacuated to the closed vacuum chamber, pierce the battery air bag of the soft-pack lithium battery to be evacuated, evacuate the soft-pack lithium battery to be evacuated, heat-seal the battery air bag of the evacuated soft-pack lithium battery, and then cut it off.

[0031] The ultimate effect goal of the utility model is to achieve battery softening and air bag inflation during the lithium battery production process by designing a final sealing vacuum pumping device, shorten the battery vacuum pumping time, and improve the softness of the vacuum pumping, thereby ensuring the consistency and capacity of the battery and reducing the production cycle.

Claims

1. A lithium battery vacuum final sealing machine, comprising a vacuum pumping device, a sealing device and a fixing device, wherein the vacuum pumping device comprises a secondary vacuum upper chamber (5) and a secondary vacuum lower chamber (16) which are arranged vertically and horizontally at the top and bottom of the inner cavity of a primary vacuum cavity (1), respectively, and a plurality of bayonets (3) are arranged inside the secondary vacuum upper chamber (5); the fixing device comprises a clamping mechanism, and the clamping mechanism comprises a pressing plate (9). Features: An arc-shaped air bag pressing plate (8) is arranged at the front end of the pressing plate (9), and an arch-shaped air bag supporting cushion block (13) is arranged directly below the air bag pressing plate (8). An upper cavity notch (6) is arranged on the secondary vacuum upper cavity (5), and the bayonet (3) is in a triangular shape.

2. A lithium battery vacuum sealing machine according to claim 1, Features: The vacuum pumping device comprises a primary vacuum joint (17) arranged on the primary vacuum chamber (1) and a secondary vacuum joint (15) arranged below the secondary vacuum lower chamber (16) and extending to the outside of the primary vacuum chamber (1).

3. A lithium battery vacuum sealing machine according to claim 1 or 2, Features: The sealing device comprises a pre-sealing upper sealing head (7) arranged at the top of the inner cavity of the primary vacuum cavity (1) and a pre-sealing lower sealing head (14) arranged at the bottom of the inner cavity of the primary vacuum cavity (1), and the upper and lower positions of the pre-sealing upper sealing head (7) and the pre-sealing lower sealing head (14) are aligned.

4. A lithium battery vacuum sealing machine according to claim 3, Features: An upper chamber pressure spring (4) is provided at the top of the secondary vacuum upper chamber (5).

5. A lithium battery vacuum sealing machine according to claim 1, Features: The tray (10) of the fixing device is located on a conveying mechanism, and the conveying mechanism comprises supporting rollers (12).

6. A lithium battery vacuum sealing machine according to claim 4, Features: The height dimension of the notch of the upper cavity (6) is greater than the thickness dimension of the aluminum-plastic film.

7. A lithium battery vacuum sealing machine according to any one of claims 1, 2, 4 and 6, Features: The pressing mechanism and the vacuum device are arranged on both sides of the sealing device.

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