A hot-pressing device with tab auxiliary heating mechanism

Abstract

The application belongs to the technical field of battery production and manufacture, and particularly relates to a hot-pressing device with a tab auxiliary heating mechanism, which comprises a hot-pressing frame, a first hot-pressing plate and a second hot-pressing plate are arranged in the hot-pressing frame, a connecting rod is arranged at the upper end of the first hot-pressing plate, sliding blocks are arranged at the two ends of the connecting rod, a motor is arranged at the top of the hot-pressing frame, the output end of the motor is connected with the connecting rod, the side of the first hot-pressing plate and the side of the second hot-pressing plate are both provided with the tab auxiliary heating mechanism, the bare battery cell is placed in the pressing and shaping device with the tab auxiliary heating mechanism, the sliding blocks are driven by the propulsion motor to control the first hot-pressing plate and the tab auxiliary heating mechanism to ascend and descend, and the bare battery cell and the surface of the tab are integrally pressurized and heated, the heat transfer efficiency in the battery cell can be improved, the hot-pressing time is shortened, and the production capacity of the hot-pressing process is improved.

Description

Technical Field

[0001] This invention belongs to the technical field of battery manufacturing, specifically relating to a hot pressing device with an auxiliary heating mechanism for electrode tabs. Background Technology

[0002] With the development of the new energy industry and the continuous expansion of lithium-ion battery applications, lithium-ion batteries are widely used in electric vehicles, energy storage, and other fields. Among them, square lithium batteries with wound / stacked structures have become the mainstream lithium batteries due to their superior performance and high manufacturing efficiency. Due to the unique structural advantages of square lithium batteries with wound / stacked structures, the overall energy density of the battery pack can be increased by increasing the capacity of individual cells. The main method is to increase the volume of the lithium battery (i.e., increase the thickness and area of ​​the bare cells). The manufacturing process of square aluminum-cased batteries with wound / stacked structures includes: stirring, coating, rolling, die-cutting, slitting, winding / stacking, hot pressing, core pairing, welding of core and connecting piece, welding of connecting piece and top cover, wrapping with polyester film (mylar), casing, welding of top cover and aluminum shell, baking, primary electrolyte injection, formation, secondary electrolyte injection, etc. The process includes sealing, capacitive bonding, voltage and internal resistance testing, encapsulation, and dimensional measurement. After winding / stacking, the bare cells are in a loose state and the separator is stretched. A hot-pressing shaping process is needed to control the thickness, hardness, and flatness of the bare cells to ensure that the automatic encapsulation and casing processes can proceed smoothly and to reduce the risk of deformation during cycling. The hot-pressing shaping process uses a hot press to heat and pressurize the bare cells, causing them to undergo plastic deformation under high temperature and high pressure to achieve the required thickness, hardness, and flatness. At the same time, it can release the tensile stress of the separator during winding and reduce cell deformation.

[0003] The existing hot pressing process uses a hot pressing plate to heat and pressurize the surface of the bare cell, but does not heat the bare cell tabs with high thermal conductivity. In addition, the traditional hot pressing method has low internal heat transfer efficiency of the bare cell. As the thickness of the bare cell increases, the hot pressing time will also increase, resulting in a decrease in the production capacity of the hot pressing process. Furthermore, if the temperature of the inner electrode sheet of the bare cell is not heated to the process requirements, rapid pressing will cause powder to fall off at the electrode crease or even the electrode sheet to break. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a hot pressing device with an auxiliary heating mechanism for electrode tabs, which can solve the problem of low internal heat transfer efficiency during heating and pressurizing of bare battery cells, which easily leads to electrode wear and breakage.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A hot pressing device with an auxiliary heating mechanism for electrodes includes a hot pressing frame. A first hot pressing plate and a second hot pressing plate are disposed inside the hot pressing frame. A connecting rod is disposed at the upper end of the first hot pressing plate, and slide rails are disposed at both ends of the connecting rod. A motor is disposed at the top of the hot pressing frame, and the output end of the motor is connected to the connecting rod. ， Both the side of the first hot press plate and the side of the second hot press plate are provided with tab auxiliary heating mechanisms.

[0007] Preferably, the bottom of the second hot press plate is provided with a first base.

[0008] Preferably, the electrode auxiliary heating mechanism includes a second base, on which a housing is disposed, inside which a support body is disposed, and a heat-conducting block is disposed.

[0009] Preferably, the electrode auxiliary heating mechanism further includes a heating wire that is wrapped around the support.

[0010] Preferably, the heating wire is a spring heating wire.

[0011] Preferably, the first hot press plate and the second hot press plate have the same thickness.

[0012] Preferably, a telescopic rod is provided on the top of the first hot press plate, one end of the telescopic rod is connected to the motor, and the other end of the telescopic rod is connected to the connecting rod.

[0013] Preferably, the first hot press plate and the second hot press plate are arranged in parallel.

[0014] Preferably, a gap is provided between the first hot press plate and the second hot press plate and the electrode tab auxiliary heating mechanism.

[0015] Preferably, the connecting rod is provided with sliders at both ends, and the sliders are slidably connected to the slide rail.

[0016] The beneficial effects of the present invention are that by placing the battery cell in a pressing and shaping device containing an auxiliary heating mechanism for the tabs, and using a propulsion motor to drive a slider to control the lifting and lowering of the first hot pressing plate and the auxiliary heating mechanism for the tabs, the bare battery cell and the surface of the tabs are pressurized and heated as a whole, which can improve the internal heat transfer efficiency of the battery cell, shorten the hot pressing time, and increase the production capacity of the hot pressing process. Attached Figure Description

[0017] The features, advantages, and technical effects of exemplary embodiments of the present invention will now be described with reference to the accompanying drawings.

[0018] Figure 1 This is a schematic diagram of a pressing and shaping device with a tab-assisted heating mechanism in one embodiment of the present invention.

[0019] Figure 2 This is a schematic diagram of the electrode auxiliary heating mechanism in another embodiment of the present invention.

[0020] The reference numerals in the attached figures are explained as follows:

[0021] 1-Motor; 2-Slider; 3-First hot press plate; 4-Second hot press plate; 5-Electric tab auxiliary heating mechanism; 6-First base; 7-Heat-conducting block; 8-House; 9-Support body; 10-Heating wire; 11-Second base. Detailed Implementation

[0022] If certain terms are used in the specification and claims to refer to specific components, those skilled in the art will understand that hardware manufacturers may use different names to refer to the same component. This specification and claims do not distinguish components based on differences in name, but rather on differences in function. The term "comprising" as used throughout the specification and claims is an open-ended term and should be interpreted as "comprising but not limited to." "Approximately" means that within an acceptable margin of error, those skilled in the art can solve the technical problem and substantially achieve the technical effect within a certain margin of error.

[0023] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be interpreted as indicating or implying relative importance.

[0024] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0025] The following is in conjunction with the appendix Figure 1-2 The present invention will be described in further detail, but this is not intended to limit the invention.

[0026] Implementation Method 1

[0027] The following is in conjunction with the appendix Figure 1 Description of Implementation Method 1

[0028] A hot pressing device with an auxiliary heating mechanism for electrode tabs includes a hot pressing frame. Inside the hot pressing frame are a first hot pressing plate 3 and a second hot pressing plate 4. During the hot pressing and shaping of the bare battery cell, the first hot pressing plate 3 acts on the surface of the bare battery cell, heating and pressurizing it. A connecting rod is provided at the upper end of the first hot pressing plate 3, and sliders 2 are provided at both ends of the connecting rod. The sliders 2 are connected to a slide rail and fixed on the hot pressing frame. A motor 1 is provided at the top of the hot pressing frame. The motor 1 pushes the first hot pressing plate 3 to move up and down on the slide rail surface and provides pressure for the hot pressing of the bare battery cell. The output end of the motor 1 is connected to the connecting rod. ， Both the side of the first hot press plate 3 and the side of the second hot press plate 4 are provided with tab auxiliary heating mechanism 5. The bare battery cell after winding or stacking is placed on this device so that the bare battery cell tab is aligned with the tab auxiliary heating mechanism 5, ensuring that the auxiliary heating mechanism can press the tab tightly during the hot pressing process.

[0029] Preferably, the bottom of the second hot press plate 4 is provided with a first base 6 to provide stable support for the hot pressing shaping equipment. When the hot pressing device is started, the temperature of the hot press plate and the auxiliary heating mechanism reaches the process set temperature. The first hot press plate 3 presses the surface of the bare battery cell, and at the same time, the auxiliary heating mechanism 5 presses the bare battery cell tabs. After the hot pressing reaches the process time, the hot pressing process is completed. The hot pressing time is determined according to the thickness and material of the bare battery cell, and is generally between 10 and 2000s, for example, it can be 10s, 500s, 1000s, 1500s, or 2000s.

[0030] Implementation Method 2

[0031] Unlike Embodiment 1, the tab auxiliary heating mechanism 5 in this embodiment includes a second base 11, which provides stable support for the tab auxiliary heating mechanism 5. A housing 8 is provided on the second base 11, and a support body 9 is provided inside the housing 8. The support body 9 is used to install and fix the heating wire 10. The housing 8 serves to protect the heating wire 10. A heat-conducting block 7 is provided on the housing 8, which is used to press the tab and transfer the heat of the heating wire 10 to the surface of the tab.

[0032] Preferably, the electrode auxiliary heating mechanism 5 also includes a heating wire 10, which is wrapped around the support body 9 to provide heat and pressure.

[0033] Preferably, the heating wire 10 is a spring heating wire, which is wound and fixed on the support body 9, and the electrode tab can fully receive the pressure and heat source provided by the heating wire 10.

[0034] The other structures are the same as in Implementation Method 1, and will not be described again here.

[0035] Implementation Method 3

[0036] Unlike the first embodiment, the first hot pressing plate 3 and the second hot pressing plate 4 in this embodiment have the same thickness. When the first hot pressing plate 3 and the second hot pressing plate 4 press the battery cell, the heat-conducting blocks 7 of the two electrode auxiliary heating mechanisms 5 respectively provided on the sides of the two heating blocks are in close contact with the electrode tabs for heating. The bare battery cell and the electrode tabs are simultaneously pressurized and heated, which is efficient and the hot pressing time is effectively shortened.

[0037] Preferably, a telescopic rod is provided at the top of the first hot press plate 3. The telescopic rod is a telescopic hollow cylindrical rod made of metal strip or plastic sheet. Because the metal strip or plastic sheet is pre-shaped into an elastic coiled layer with memory function that is smaller than the outer diameter of the rod, it has a self-tightening function, so that the coiled layer always has elastic potential energy to apply pressure to the telescopic rod. 。 One end of the telescopic rod is connected to the motor 1, and the other end of the telescopic rod is connected to the connecting rod. When the power is turned on, the motor 1 drives the telescopic rod to make the slider 2 on the connecting piece slide freely along the slide rail. The position of the slider 2 is adjusted according to the thickness of the battery cell to accurately control the pressure applied to the battery cell.

[0038] Preferably, the first hot-pressing plate 3 and the second hot-pressing plate 4 are arranged in parallel to apply uniform pressure to the bare battery cell, so as to avoid battery cell cracking and wear caused by uneven force on the battery cell and reduce losses.

[0039] Preferably, a gap is provided between the first hot pressing plate 3 and the second hot pressing plate 4 and the electrode tab auxiliary heating mechanism 5. The positive electrode tab is made of aluminum metal and the negative electrode tab is made of copper metal, which has a significantly better thermal conductivity than the diaphragm and electrode sheet. Heating the electrode tab can significantly shorten the time for the inner electrode sheet to reach the process requirements, thereby shortening the hot pressing time and increasing the hot pressing process capacity. The electrode tab and the bare battery cell have different heat distribution to the heat-conducting block 7. The gap is provided to avoid the problem of the battery cell being deformed and damaged due to excessive heating.

[0040] Preferably, the slider 2 and the slide rail are slidably connected. The slider 2 slides and rubs against the slide rail to perform vertical lifting and lowering movements. The slide rail provides support for the up and down movement of the surface hot press plate, saving time and effort and improving hot pressing efficiency.

[0041] The other structures are the same as in Implementation Method 1, and will not be described again here.

[0042] Based on the disclosure and teachings of the foregoing specification, those skilled in the art can make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments described above, and any obvious improvements, substitutions, or modifications made by those skilled in the art based on the present invention are within the scope of protection of the present invention. Furthermore, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation on the present invention.

Claims

1. A hot pressing device with a tab-assisted heating mechanism, characterized in that: The device includes a hot press frame, inside which are a first hot press plate and a second hot press plate. A connecting rod is provided at the upper end of the first hot press plate, and slide rails are provided at both ends of the connecting rod. A motor is provided at the top of the hot press frame, and the output end of the motor is connected to the connecting rod. Both the sides of the first hot press plate and the sides of the second hot press plate are provided with tab auxiliary heating mechanisms. The electrode auxiliary heating mechanism includes a second base, on which a housing is disposed, a support body is disposed inside the housing, and a heat-conducting block is disposed in the housing; The electrode auxiliary heating mechanism also includes a heating wire, which is wrapped around the support body; The heating wire is a spring heating wire; When the first hot pressing plate and the second hot pressing plate press the battery cell, the heat-conducting blocks of the two auxiliary heating mechanisms of the electrode tabs respectively provided on the sides of the first hot pressing plate and the second hot pressing plate are in close contact with the electrode tabs for heating. The bare battery cell and the electrode tabs are pressurized at the same time, resulting in high heating efficiency. A gap is provided between the first hot press plate and the second hot press plate and the electrode tab auxiliary heating mechanism.

2. The hot pressing device with a tab auxiliary heating mechanism as described in claim 1, characterized in that: The second hot press plate has a first base at its bottom.

3. The hot pressing device with a tab auxiliary heating mechanism as described in claim 1, characterized in that: The thickness of the first hot press plate is the same as the thickness of the second hot press plate.

4. A hot pressing device with a tab-assisted heating mechanism as described in claim 1, characterized in that: A telescopic rod is provided on the top of the first hot press plate. One end of the telescopic rod is connected to the motor, and the other end of the telescopic rod is connected to the connecting rod.

5. A hot pressing device with a tab-assisted heating mechanism as described in claim 1, characterized in that: The first hot press plate and the second hot press plate are arranged in parallel.

6. A hot pressing device with a tab-assisted heating mechanism as described in claim 1, characterized in that: The connecting rod is provided with sliders at both ends, and the sliders are slidably connected to the slide rail.

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