Lithium battery film pressing and extending mechanism

Abstract

The utility model provides a kind of lithium battery film press bonding extension mechanism, including machine cover, two corresponding press bonding rollers are rotatably installed in the inside middle of machine cover, and two press bonding rollers are fixed with the fixed mounting press bonding motor output end of machine cover outside, and extension wheel and two groups of parallel conveying rollers are rotatably installed in the region of both ends of machine cover, and the output end fixedly installed of two groups of conveying rollers is fixed with the corresponding conveying gearbox outside machine cover;Air extraction cover and air supply cover are fixedly installed in the inside of machine cover respectively, air extraction cover and air supply cover are respectively installed with airflow fan in the inside, wherein air supply cover is installed with heating assembly in the inside, and air outlet corresponding with air extraction cover and air supply cover is provided on machine cover;The utility model air extraction cover and air supply cover form hot layer flow preheating pole piece, cooperate press bonding roller heating to increase pressure density;Extension spiral of extension wheel reduces loss by reducing the contraction rate of pole piece;Air flow can also remove impurities to prevent leakage, ensure safety and improve the qualified rate of pole piece.

Description

Technical Field

[0001] This utility model belongs to the field of battery film technology, and in particular relates to a lithium battery film pressing and stretching mechanism. Background Technology

[0002] As a core energy storage component in the new energy industry, lithium batteries' energy density, cycle life, and safety are highly dependent on the lamination and stretching process of the electrode sheets (battery films). This process uses mechanical pressure to cause plastic deformation of the coated electrode sheets (containing active materials, binders, and current collectors), reducing porosity and enhancing the bonding force between the active materials and the current collectors. It is a key step that determines the core performance of the battery.

[0003] In existing technologies, lithium battery film pressing and stretching mechanisms mostly adopt the basic structure of "single-stage double-roller pressing + passive conveying", which has three major defects: First, the preheating method is unreasonable. Traditional contact heating rollers are prone to local overheating and degradation of the electrode. Second, there is a lack of lateral stretching control. After pressing, the electrode is prone to lateral shrinkage of 3%-5% due to stress release, resulting in a width consistency deviation of more than ±5mm, which increases the loss rate of subsequent slitting processes.

[0004] Therefore, it is essential to invent a lithium battery film pressing and stretching mechanism. Utility Model Content

[0005] To solve the above-mentioned technical problems, this utility model provides a lithium battery film pressing and stretching mechanism, including a machine cover, pressing rollers, lifting rollers, conveying rollers, extending rollers, pressing motors, conveying gearboxes, exhaust hoods, air supply hoods, airflow fans, heating components, and airflow ports. Two corresponding pressing rollers are rotatably installed inside the machine cover, and the two pressing rollers are fixed to the output end of the pressing motor fixedly installed outside the machine cover. Lifting rollers and extending rollers are rotatably installed at both ends of the machine cover, as well as two sets of parallel conveying rollers. The two sets of conveying rollers are fixedly installed to the output ends of corresponding conveying gearboxes fixedly installed outside the machine cover. The exhaust hood and air supply hood are fixedly installed inside the machine cover, and the airflow fans are installed inside the exhaust hood and air supply hood, respectively. The air supply hood contains a heating component, and the machine cover has airflow ports corresponding to the exhaust hood and air supply hood.

[0006] Preferably, the upper and lower pressing rollers are respectively provided with heating coils inside, and the upper and lower pressing rollers are located between the lifting roller and the conveying roller. The upper and lower pressing rollers are used to press and extend the battery film.

[0007] Preferably, the lifting roller is located below the exhaust hood and the air supply hood, the exhaust hood and the air supply hood have the same structure and are arranged correspondingly, and their openings are in a relative relationship.

[0008] Preferably, the airflow fans installed inside the exhaust hood and the air supply hood are respectively an exhaust fan and an air supply fan, and the heating component installed inside the air supply hood is located below the airflow fan. The exhaust hood and the air supply hood can guide the hot airflow to form laminar flow above the lifting roller.

[0009] Preferably, the upper and lower sets of conveying rollers rotate in opposite directions and are driven by the corresponding conveying gearboxes. The conveying gearboxes are equipped with driving components, and the extension wheels are located between the conveying rollers. The upper and lower distributed extension wheels can roll into contact with the edge of the battery film.

[0010] Preferably, the outer surface of the expanding wheel is provided with an expanding spiral, and the expanding spirals provided on the outer surfaces of the upper and lower expanding wheels correspond to each other.

[0011] Compared with the prior art, the present invention has the following beneficial effects: This invention utilizes a directional airflow channel formed by a relatively positioned exhaust hood and an air supply hood. Combined with a heating component and airflow fan within the air supply hood, a stable thermal laminar flow field is constructed above the lifting roller. Compared to traditional contact heating rollers, non-contact thermal laminar flow improves the uniformity of electrode preheating temperature, effectively preventing binder degradation caused by localized overheating. Simultaneously, the preheated electrode binder exhibits enhanced fluidity, reducing the breakage rate of active materials during pressing. This, combined with the heating coil built into the pressing roller, forms a synergistic "preheating-hot pressing" dual heating system, increasing compaction density and significantly optimizing battery energy density.

[0012] This invention features vertically distributed extending wheels between the conveying rollers. The corresponding extending spirals on their outer surfaces apply a directional extending force to the edge of the electrode sheet through rolling friction. This design reduces the lateral shrinkage rate of the electrode sheet from the traditional 3%-5% to below 1%, controls the width consistency deviation within ±1μm, and reduces the material loss rate of subsequent slitting processes by 8%-10%, significantly improving production economy.

[0013] The hot airflow from the air supply hood of this invention can blow away dust and impurities adhering to the surface of the electrode sheets, while the exhaust hood promptly removes volatiles and suspended particles before pressing, keeping the dust concentration in the working area below 0.5 mg / m³. Simultaneously, the enclosed hood structure and dedicated airflow port design prevent volatile leakage, ensuring a safe production environment and reducing the impact of impurities on the pressing interface, thus increasing the electrode sheet qualification rate to over 98%. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0015] Figure 2 This is a partial cross-sectional structural diagram of the present invention.

[0016] Figure 3 This is a utility model Figure 2 A schematic diagram of the main structure.

[0017] Figure 4 This is a utility model Figure 2 A magnified schematic diagram of the structure at point A.

[0018] In the picture: 1. Machine cover, 2. Pressing roller, 3. Lifting roller, 4. Conveying roller, 5. Extending wheel, 6. Pressing motor, 7. Conveying gearbox, 8. Exhaust hood, 9. Air supply hood, 10. Airflow fan, 11. Heating component, 12. Airflow port, 13. Extending spiral. Detailed Implementation

[0019] To enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0020] In the description of the embodiments, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the present invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In the description of the utility model, it should be noted that unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in the present utility model based on the specific circumstances.

[0021] As attached Figure 1 To be continued Figure 4 As shown: This utility model provides a lithium battery film pressing and stretching mechanism, including a housing 1, pressing rollers 2, lifting rollers 3, conveying rollers 4, extending wheels 5, pressing motors 6, conveying gearboxes 7, exhaust hoods 8, air supply hoods 9, airflow fans 10, heating components 11, and airflow ports 12. Two corresponding pressing rollers 2 are rotatably mounted inside the housing 1, and the two pressing rollers 2 are fixed to the output end of the pressing motor 6 fixedly mounted outside the housing 1. Lifting rollers 3 and extending wheels 5 are rotatably mounted at both ends of the housing 1, as well as two sets of parallel conveying rollers 4. The two sets of conveying rollers 4 are fixed to the output ends of the corresponding conveying gearboxes 7 fixedly mounted outside the housing 1. The exhaust hood 8 and air supply hood 9 are fixedly mounted inside the housing 1, and the airflow fans 10 are installed inside the exhaust hood 8 and air supply hood 9, respectively. The heating component 11 is installed inside the air supply hood 9, and airflow ports 12 corresponding to the exhaust hood 8 and air supply hood 9 are provided on the housing 1.

[0022] Furthermore, both the upper and lower pressing rollers 2 are made of high-strength alloy rollers, with a wear-resistant ceramic coating sprayed on the roller surface to improve resistance to slurry corrosion and surface smoothness. An annular cavity is formed axially inside the pressing roller 2, and a heating coil is fixed inside the cavity via a high-temperature resistant insulating bracket. The heating coil is made of nickel-chromium alloy, with a rated power of 2-3kW, and can achieve temperature adjustment from 50-150℃, with a roller surface temperature uniformity error ≤±1℃. The upper and lower pressing rollers 2 are rotatably mounted on bearing seats on the inner wall of the machine cover 1 via rolling bearings. A servo-driven gap adjustment mechanism is connected to the outside of the bearing seats, allowing real-time adjustment of the roller gap according to the battery film thickness requirements. One end of the roller shaft of the pressing roller 2 is fixedly connected to the output end of the pressing motor 6 via a flexible coupling. The pressing motor 6 is a variable frequency servo motor, which can be matched with different battery film conveying speeds. In this structure, the preheated battery film conveyed by the lifting roller 3 directly enters between the upper and lower pressing rollers 2. Under the combined action of mechanical pressure and roller heating, it completes compaction and extension. The pressed battery film is then conveyed to the area of ​​the conveying roller 4.

[0023] Furthermore, the lifting roller 3 is made of 304 stainless steel with a mirror-polished surface. It is rotatably mounted on a bracket inside the machine housing 1 via deep groove ball bearings at both ends. The height of the bracket can be finely adjusted using adjusting bolts to ensure that the upper surface of the lifting roller 3 is flush with the center line of the roller gap of the pressing roller 2. The exhaust hood 8 and the air supply hood 9 are both hollow shells formed by sheet metal welding, made of cold-rolled steel plate and powder-coated for rust prevention. Their lengths are matched to the length of the lifting roller 3, and the opening width is 50-80mm. The exhaust hood 8 and the air supply hood 9 are symmetrically fixed to the crossbeam on the inner wall of the machine housing 1 with bolts, and the center of the opening is in the same vertical plane as the upper surface of the lifting roller 3, forming an airflow channel across the top of the lifting roller 3. This ensures that the battery film is completely covered by the airflow of the two hoods during the support and conveying process of the lifting roller 3.

[0024] Furthermore, both the exhaust fan and the supply fan are centrifugal fans, fixed to the top mounting ports of the exhaust hood 8 and the supply hood 9 respectively via flanges. The fan outlets are sealed to the airflow inlets 12 on the hood 1 via flexible hoses. The heating element 11 inside the supply hood 9 is a finned electric heater, fixed directly below the supply fan by a high-temperature resistant bracket. A heat insulation pad (made of ceramic fiber) is placed between the bracket and the heating element 11 to prevent heat conduction to the hood. A honeycomb guide plate is installed below the heating element 11 to distribute the airflow into a uniform flow. During operation, the supply fan draws outside air into the supply hood 9 through the airflow inlet 12, heats it to 60-120°C by the heating element 11, and then forms a stable airflow that is delivered downwards through the guide plate. Simultaneously, the exhaust fan draws air through the exhaust hood 8, forming a directional laminar flow with a velocity of 3-5 m / s above the lifting roller 3. The hot airflow flows in the opposite direction of the openings of the two hoods, achieving non-contact uniform preheating of the battery membrane.

[0025] Furthermore, the conveyor rollers 4 are divided into upper and lower groups, each group containing 2-3 roller bodies. The roller bodies are made of nitrile rubber, and the roller surface is decorated with fine anti-slip textures. The upper and lower conveyor rollers 4 are connected by synchronous shaft transmission and are rotatably mounted on the upper and lower brackets inside the machine cover 1, respectively. The conveyor gearbox 7 is a gear-type gearbox, fixedly mounted on the outside of the machine cover 1. Its input end is connected to the drive component (variable frequency servo motor, power 1.5-2.2kW) via a pulley, and its output end is fixed to the roller shaft of the conveyor rollers 4 via a universal coupling. The linear speed of the conveyor rollers 4 can be synchronized with that of the pressing rollers 2 by adjusting the gearbox. The extension wheel 5 is mounted on an adjustable slider via rolling bearings. The slider is slidably connected to the slide rail of the machine cover 1, and the position of the extension wheel 5 can be adjusted according to the width of the battery film.

[0026] Furthermore, the outer surface of the expansion wheel 5 is provided with an expansion spiral 13, and the expansion spirals 13 on the outer surfaces of the upper and lower expansion wheels 5 correspond to each other. The wheel core of the expansion wheel 5 is made of aluminum alloy, and the outer surface is integrally injection molded with the expansion spiral 13. The expansion spiral 13 is made of polyurethane elastomer material, which has good wear resistance and elasticity, and can avoid scratching the edge of the battery film. The pitch of the expansion spiral 13 is 15-25mm, and the spiral angle is 20-30°. The expansion spirals 13 on the upper and lower expansion wheels 5 have opposite directions of rotation and meshing teeth, forming a symmetrical spiral propulsion structure. When the expansion wheel 5 rotates with the battery film, the expansion spiral 13 applies a uniform radial expansion force to both sides of the battery film through friction with the edge of the battery film, and the spiral structure can convert the axial conveying force into a lateral expansion force, ensuring a smooth and impact-free expansion process. The surface of the expansion spiral 13 is sandblasted to increase the coefficient of friction with the battery film and improve the stability of the expansion effect.

[0027] The working principle is as follows: First, the battery film enters the machine cover 1 and is supported and conveyed forward by the lifting roller 3. During this process, the air supply fan 10 (air supply fan) in the air supply cover 9 draws in outside air through the air outlet 12. The air is heated by the heating component 11 to form a hot airflow. At the same time, the air supply fan 10 (exhaust fan) in the exhaust cover 8 simultaneously draws in air, forming a directional thermal laminar flow above the lifting roller 3, which performs non-contact uniform preheating of the battery film.

[0028] Next, the preheated battery film is conveyed between the upper and lower pressing rollers 2. The pressing motor 6 drives the pressing rollers 2 to rotate. The upper and lower pressing rollers 2 press the battery film under mechanical pressure. At the same time, the heating coil inside the pressing rollers 2 heats the roller body. Through the synergistic effect of pressing and heating, the battery film undergoes plastic deformation, achieving compaction and extension.

[0029] Then, the pressed and stretched battery film is conveyed between two sets of conveying rollers 4. The conveying gearbox 7 drives the conveying rollers 4 to rotate, and the upper and lower conveying rollers 4 continue to convey the battery film forward by rotating in opposite directions. During this process, the upper and lower expansion wheels 5 located between the conveying rollers 4 roll in contact with the edge of the battery film. The expansion spiral 13 on the outer surface of the expansion wheel 5 converts the axial conveying force into the lateral expansion force through friction, and applies a uniform radial force to both sides of the battery film, so that the battery film can be laterally expanded and the width consistency can be optimized.

[0030] Any technical solution that achieves the above-mentioned technical effects by utilizing the technical solution described in this utility model, or by designing a similar technical solution inspired by the technical solution described in this utility model, falls within the protection scope of this utility model.

Claims

1. A lithium battery film pressing and stretching mechanism, characterized in that, The machine includes a housing (1), pressing rollers (2), lifting rollers (3), conveying rollers (4), extending wheels (5), pressing motors (6), conveying gearboxes (7), exhaust hoods (8), air supply hoods (9), airflow fans (10), heating components (11), and airflow inlets (12). Two corresponding pressing rollers (2) are rotatably mounted inside the housing (1), and the two pressing rollers (2) are fixed to the output end of the pressing motor (6) fixedly mounted outside the housing (1). Lifting rollers (3) and extending wheels (5) are rotatably mounted at both ends of the housing (1). 5), and two sets of parallel conveying rollers (4), the two sets of conveying rollers (4) are respectively fixed to the output end of the conveying gearbox (7) corresponding to the outside of the machine cover (1); the exhaust hood (8) and the air supply hood (9) are respectively fixedly installed inside the machine cover (1), the airflow fan (10) is respectively installed inside the exhaust hood (8) and the air supply hood (9), the heating component (11) is installed inside the air supply hood (9), and the machine cover (1) is provided with airflow ports (12) corresponding to the exhaust hood (8) and the air supply hood (9).

2. The lithium battery film pressing and stretching mechanism as described in claim 1, characterized in that: Heating coils are respectively provided inside the upper and lower pressing rollers (2). The upper and lower pressing rollers (2) are located between the lifting roller (3) and the conveying roller (4). The upper and lower pressing rollers (2) are used to press and extend the battery film.

3. The lithium battery film pressing and stretching mechanism as described in claim 2, characterized in that: The lifting roller (3) is located below the exhaust hood (8) and the air supply hood (9). The exhaust hood (8) and the air supply hood (9) have the same structure and are set in a corresponding manner, and their openings are in a relative relationship.

4. The lithium battery film pressing and stretching mechanism as described in claim 3, characterized in that: The airflow fans (10) installed inside the exhaust hood (8) and the air supply hood (9) are respectively the exhaust fan and the air supply fan. The heating component (11) installed inside the air supply hood (9) is located below the airflow fan (10). The exhaust hood (8) and the air supply hood (9) can guide the hot airflow to form laminar flow above the lifting roller (3).

5. The lithium battery film pressing and stretching mechanism as described in claim 1, characterized in that: The upper and lower sets of conveying rollers (4) rotate in opposite directions and are driven by the corresponding conveying gearbox (7). The conveying gearbox (7) is equipped with a driving component. The extension wheel (5) is located between the conveying rollers (4). The upper and lower distributed extension wheels (5) can roll and contact the edge of the battery film.

6. The lithium battery film pressing and stretching mechanism as described in claim 5, characterized in that: The outer surface of the expansion wheel (5) is provided with an expansion spiral (13), and the expansion spirals (13) provided on the outer surfaces of the upper and lower expansion wheels (5) correspond to each other.

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