A dispensing device and a method for manufacturing a lithium-ion battery using the dispensing device

Abstract

The present invention belongs to the technical field of lithium-ion batteries, and particularly relates to a dispensing device, which includes a dispensing tank provided with a glue outlet. The dispensing tank is sequentially provided with a glue particle storage chamber, a heat insulation pad and a heating chamber communicating with each other from top to bottom. The glue outlet is communicated with the heating chamber, and the temperature of the heating chamber is controlled at 50-60 °C. In addition, the present invention also provides a production method of a lithium-ion battery using the dispensing device, including the steps: S1, uniformly dot-coating slightly heat-melted glue particles on the aluminum foil on the wide surface of the battery cell body; S2, encapsulating the battery cell body with an aluminum-plastic film; S3, performing hot pressing and forming on the encapsulated battery cell to tightly press and bond the aluminum-plastic film, the glue particles and the aluminum foil together at high temperature; S4, taking out the battery cell and cooling it. Compared with the prior art, the glue particles of the present invention will not flow around on the surface of the bare battery cell, and a glue particle structure with good thickness consistency and uniform distribution can be formed on the surface of the bare battery cell, which is beneficial to reducing the safety risk caused by battery drop.

Description

Technical Field

[0001] The present invention belongs to the technical field of lithium-ion batteries, and particularly relates to a dispensing device and a method for producing a lithium-ion battery using the dispensing device. Background Art

[0002] Lithium-ion batteries are widely used in devices such as mobile phones, laptop computers, and power banks due to their advantages of high energy density, long cycle life, no memory effect, and low pollution. Along with the wide application of lithium-ion batteries, various problem batteries have emerged, and the problem of fire or even explosion caused by dropping is the most prominent. Therefore, how to fix the position of the bare battery cell in the battery assembly is particularly important.

[0003] Currently, most of the processes used are to stick double-sided hot melt adhesive between the aluminum plastic film and the aluminum foil. Although this process is mature and simple, the potential safety risks have emerged, specifically including: 1) The bonding force-receiving surfaces of the bare battery cell and the aluminum plastic film with the hot melt double-sided adhesive are overly concentrated. In an environment where the battery is getting heavier during production, this structure makes the battery prone to uneven stress during dropping, and relative displacement is likely to occur between the bare battery cell and the aluminum plastic film, resulting in tearing of the aluminum foil on the outer layer of the bare battery cell, and further causing problems such as internal short circuit of the battery, diaphragm folding, ear breakage, and damage to the aluminum plastic film; 2) The hot melt double-sided adhesive is usually relatively soft, so it is easy to cause the tape to wrinkle during gluing, affecting the quality and efficiency of gluing; 3) Current winding equipment cannot paste large-area hot melt adhesive, and it can only rely on manual gluing, resulting in an increase in labor costs; 4) The hot melt adhesive will swell and debond under the long-term immersion of the electrolyte, and in severe cases, it will completely lose its viscosity, affecting the use stability of the battery.

[0004] To solve the problems existing in pasting double-sided hot melt adhesive, a spraying process was developed. Glue is sprayed on the surface of the bare battery cell and cooled to form a bonding body, and then processes such as encapsulation and hot pressing are carried out. Although this method solves the problem of pasting hot melt adhesive to a certain extent, the spraying process has the problem of local over-thickness of the colloid at the horizontal and vertical junctions, and the local high temperature of the spraying valve will damage the foil and / or diaphragm in the bare battery cell. Summary of the Invention

[0005] One of the purposes of the present invention is to provide a dispensing device in view of the deficiencies of the prior art. The structure is simple, and the discharged glue particles will not flow around on the surface of the bare battery cell, and a glue particle structure with good thickness consistency and uniform distribution can be formed on the surface of the bare battery cell, which is beneficial to reducing the safety risks caused by battery dropping.

[0006] To achieve the above purpose, the present invention adopts the following technical solutions:

[0007] A dispensing device, comprising a dispensing tank provided with a glue outlet. The dispensing tank is successively provided with a glue particle storage chamber, a heat insulation pad and a heating chamber communicating with each other from top to bottom. The glue outlet communicates with the heating chamber, and the temperature of the heating chamber is controlled at 50-60°C.

[0008] As an improvement of the dispensing device described in the present invention, the diameter of the glue outlet is 1-3 mm.

[0009] As an improvement of the dispensing device described in the present invention, the heat insulation pad is provided with a channel for the glue particles to pass through, and the diameter of the channel is 1.5-2 mm.

[0010] As an improvement of the dispensing device described in the present invention, the channel is arranged vertically or obliquely.

[0011] As an improvement of the dispensing device described in the present invention, the thickness of the heat insulation pad is 5-20 mm.

[0012] As an improvement of the dispensing device described in the present invention, the heating chamber is provided with a heating element, and the heating temperature of the heating element is 50-60°C.

[0013] As an improvement of the dispensing device described in the present invention, the outer wall of the heating chamber is provided with a heat preservation layer.

[0014] As an improvement of the dispensing device described in the present invention, it further includes a clamping member, and the clamping member is connected to the dispensing tank.

[0015] As an improvement of the dispensing device described in the present invention, it further includes a PLC controller, and the PLC controller is connected to the clamping member and the heating element, and is used to control the moving path of the clamping member and the heating temperature of the heating element.

[0016] The second object of the present invention is to provide a method for producing a lithium-ion battery using the described dispensing device, comprising the following steps:

[0017] S1, Dispensing, evenly dotting slightly hot-melted glue particles on the aluminum foil on the wide surface of the cell body.

[0018] S2, Encapsulation, encapsulating the cell body in step S1 with an aluminum-plastic film.

[0019] S3, Thermal pressing and forming, thermally pressing and forming the cell encapsulated in step S2, and tightly pressing and bonding the aluminum-plastic film, the glue particles and the aluminum foil together at high temperature.

[0020] S4, Cooling, taking out the cell in step S3 and cooling it.

[0021] Compared with the prior art, the present invention has at least the following beneficial effects:

[0022] 1) In the dispensing device of the present invention, the dispensing tank is provided with a glue particle storage chamber, a heat insulation pad, and a heating chamber in sequence from top to bottom. That is, a heat insulation pad is arranged in a traditional storage tank, and a heating element is arranged in the lower half, with a simple structure.

[0023] 2) The dispensing device of the present invention controls the temperature of the heating chamber at 50 - 60 °C, so that the glue particles entering the heating chamber from the glue particle storage chamber via the heat insulation pad change from a state without initial adhesion to a weak hot melt state. When it is dot-coated on the surface of the bare battery cell, it has a certain adhesiveness and will not cause the problem of glue flowing around. Moreover, there will be no problem of damaging the separator and foil due to excessive temperature. It can form a glue particle structure with good thickness uniformity and uniform distribution on the surface of the bare battery cell, which is beneficial to reducing the safety risk caused by battery drop.

[0024] 3) Using the dispensing device of the present invention for dispensing can avoid the problems of wrinkling easily caused during traditional hot melt adhesive pasting and the labor cost problem due to pasting a large area of hot melt adhesive. Description of the Drawings

[0025] Figure 1 is a schematic structural diagram of the dispensing device in the present invention.

[0026] Figure 2 is a schematic structural diagram of the lithium-ion battery obtained by the present invention.

[0027] Among them: 100 - dispensing tank, 200 - clamping member, 300 - PLC controller, 400 - battery cell body, 500 - aluminum plastic film, 600 - glue particles, 1 - glue particle storage chamber, 2 - heat insulation pad, 3 - heating chamber, 4 - glue outlet, 21 - channel, 31 - heating element, 32 - heat preservation layer. Detailed Embodiments

[0028] The following further describes the present invention in detail in combination with the detailed embodiments and the drawings of the specification, but the embodiments of the present invention are not limited thereto.

[0029] Example 1

[0030] As Figure 1 shown, a dispensing device for lithium-ion battery production includes a dispensing tank 100 provided with a glue outlet 4. The dispensing tank 100 is provided with a mutually connected glue particle storage chamber 1, a heat insulation pad 2, and a heating chamber 3 in sequence from top to bottom. The glue outlet 4 is communicated with the heating chamber 3, and the temperature of the heating chamber 3 is controlled at 50 - 60 °C.

[0031] Preferably, the diameter of the glue outlet 4 is 1 - 3 mm. More preferably, the diameter of the glue outlet 4 is 1.5 - 2 mm. The diameter of the glue outlet 4 is determined according to the size of the glue particles, generally slightly larger than the diameter of the glue particles.

[0032] Preferably, the heat insulation pad 2 is provided with a channel 21 through which the rubber particles can pass. The diameter of the channel 21 is 1.5 - 2 mm. The rubber particles enter the heating chamber 3 from the rubber particle storage chamber through the channel 21. The diameter of the channel 21 is slightly larger than the diameter of the rubber particles. Since the rubber particles are small, the setting of the channel 21 does not affect the heat insulation performance of the heat insulation pad 2.

[0033] Preferably, the channel 21 is arranged vertically or obliquely.

[0034] Preferably, the thickness of the heat insulation pad 2 is 5 - 20 mm. The heat insulation pad 2 is mainly used to isolate the heat transfer from the heating chamber 3 to the rubber particle storage chamber 1, avoiding the melting of the rubber particles in the rubber particle storage chamber 1. If the thickness of the heat insulation pad 2 is too small, the heat insulation effect is poor, while if the thickness of the heat insulation pad 2 is too large, it will waste materials.

[0035] Preferably, the heating chamber 3 is provided with a heating element 31, and the heating temperature of the heating element 31 is 50 - 60 °C. Heating to this temperature causes the rubber particles to only slightly melt, thus solving the problem that they stick to the surface of the bare battery cell and flow around.

[0036] Preferably, the outer wall of the heating chamber 3 is provided with a heat insulation layer 32. The heat insulation layer 32 can ensure that the temperature of the heating chamber 3 is maintained in a stable range, does not cool down too quickly, and can reduce energy consumption.

[0037] Preferably, the dispensing device for lithium-ion battery production further includes a clamping member 200 and a PLC controller 300. The clamping member 200 is connected to the dispensing tank 100. The PLC controller 300 is connected to the clamping member 200 and the heating element 31, and is used to control the moving path of the clamping member 200 and the heating temperature of the heating element 31.

[0038] During use, the PLC controller 300 controls the clamping member 200 to move to a specified position. The rubber particles in the rubber particle storage chamber 1 enter the heating chamber 3 through a pipeline, are heated to 50 - 60 °C under the action of the heating element 31, and then are dot-coated on the wide surface of the battery cell body through the glue outlet 4 at regular intervals. Finally, rubber particles with uniform thickness and uniform distribution are formed on the wide surface of the battery cell body.

[0039] Embodiment 2

[0040] A method for producing a lithium-ion battery using the dispensing device of Embodiment 1 includes the following steps:

[0041] S1, Dispensing, uniformly dot-coating slightly melted rubber particles 600 on the aluminum foil on the wide surface of the battery cell body 400;

[0042] S2, Encapsulation, encapsulating the battery cell body in step S1 with an aluminum-plastic film 500;

[0043] S3. Hot pressing and forming: subject the battery cell encapsulated in step S2 to hot pressing and forming, and tightly press and bond the aluminum plastic film 500, the rubber particles and the aluminum foil together at high temperature;

[0044] S4. Cooling: take out the battery cell in step S3 and cool it.

[0045] The obtained lithium-ion battery is as Figure 2 shown.

[0046] Performance test

[0047] To demonstrate the advancement of the present invention, Comparative Example 1 and Comparative Example 2 are now set up to conduct a drop test comparison with the battery obtained in Example 2, and observe whether the foil and diaphragm of each battery cell are damaged. Among them, Comparative Example 1 is a battery obtained by using the traditional method of sticking hot melt adhesive, and Comparative Example 2 is a battery obtained by using the traditional method of spraying adhesive. The length and width of the battery cells of several batteries are 87 mm and 63 mm respectively, the length and width of the hot melt adhesive are 50 mm and 20 mm respectively; the spacing between each bonding body obtained by spraying adhesive is 2 mm, and the diameter of the bonding body is 1.5 mm; the spacing between the rubber particles of the present invention is 2 mm, and the diameter of the rubber particles is 1.5 mm. The drop test conditions are: the drop height is 1.2 m. During actual measurement, battery cells of different weights are obtained by controlling the different thicknesses of the battery cells. The test results are shown in Table 1.

[0048] Table 1 Test results

[0049]

[0050]

[0051] As can be seen from Table 1, the battery obtained by using the dispensing device of the present invention has good drop resistance performance, and there will be no damage to the foil and diaphragm, nor will there be a phenomenon of glue flowing around.

[0052] According to the disclosure and teaching of the above specification, those skilled in the art to which the present invention pertains can also make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the above specific embodiments, and any obvious improvements, substitutions or variations made by those skilled in the art on the basis of the present invention all fall within the protection scope of the present invention. In addition, although some specific terms are used in this specification, these terms are only for convenience of description and do not constitute any limitation to the present invention.

Claims

1. A dispensing device, characterized in that: It includes a dispensing tank provided with a glue outlet. The dispensing tank is successively provided with a glue particle storage chamber, a heat insulation pad and a heating chamber communicating with each other from top to bottom. The glue outlet communicates with the heating chamber. The temperature of the heating chamber is controlled at 50-60 °C to cause the glue particles to undergo slight heat melting. The glue outlet is used to dot the slightly heat-melted glue particles on the wide surface of the battery cell body.

2. The dispensing device according to claim 1, characterized in that: The diameter of the glue outlet is 1-3 mm.

3. The dispensing device according to claim 1, characterized in that: The heat insulation pad is provided with a passage for the glue particles to pass through, and the diameter of the passage is 1.5-2 mm.

4. The dispensing device according to claim 3, characterized in that: The passage is arranged vertically or obliquely.

5. The dispensing device according to claim 1, characterized in that: The thickness of the heat insulation pad is 5-20 mm.

6. The dispensing device according to claim 1, characterized in that: The heating chamber is provided with a heating element, and the heating temperature of the heating element is 50-60 °C.

7. The dispensing device according to claim 1, wherein: The outer wall of the heating chamber is provided with a heat preservation layer.

8. The dispensing device according to claim 6, wherein: It further includes a clamping member, and the clamping member is connected to the dispensing tank.

9. The dispensing device according to claim 8, wherein: It further includes a PLC controller. The PLC controller is connected to the clamping member and the heating element, and is used to control the moving path of the clamping member and the heating temperature of the heating element.

10. A method for producing a lithium-ion battery using the dispensing device according to any one of claims 1 to 9, characterized in that, It includes the following steps: S1, Dispensing, uniformly dotting the slightly heat-melted glue particles on the aluminum foil on the wide surface of the battery cell body. S2, Encapsulation, encapsulating the battery cell body in step S1 with an aluminum-plastic film. S3, Hot pressing and forming, performing hot pressing and forming on the battery cell encapsulated in step S2, and tightly pressing and bonding the aluminum-plastic film, the glue particles and the aluminum foil together at high temperature. S4, Cooling, taking out the battery cell in step S3 and performing cooling.

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