Production process of lithium battery aluminum plastic film

Abstract

The application discloses a production process of a lithium battery aluminum plastic film, which comprises the following steps: treating the surface of an aluminum foil layer; performing thermal compounding of one side of the aluminum foil layer with a heat-sealing layer; and coating an adhesive on the other side of the aluminum foil layer and performing dry compounding of the aluminum foil layer with a nylon layer. The aluminum foil layer is first subjected to thermal compounding with the heat-sealing layer, and then subjected to dry compounding with the nylon layer, so that the influence of high-temperature baking during thermal compounding on the nylon layer is effectively avoided, the performance of the nylon layer is guaranteed, the electrolyte resistance and water resistance of the aluminum plastic film are good, the punching performance of the aluminum plastic film is improved, the product performance of the aluminum plastic film is more excellent, and the applicability is stronger.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lithium battery aluminum-plastic film, more particularly, the present application relates to a production process of lithium battery aluminum-plastic film. BACKGROUND

[0002] The aluminum-plastic film for soft-pack lithium battery is divided into an outer nylon layer, an intermediate aluminum foil layer and an inner polypropylene film layer according to the structure, the nylon layer and the aluminum foil layer are bonded by glue, and the bonding mode between the aluminum foil and the polypropylene film can divide the aluminum-plastic film into dry process and hot process.

[0003] As shown in Figure 1 , the hot process is to make the modified polypropylene layer (heat sealing layer 2) adhere to the aluminum foil layer 1 in a molten state by heating, which is relatively difficult to implement, and has the advantages of good electrolyte resistance and water resistance, but the performance of the nylon layer is affected due to long-time high-temperature baking; as shown in Figure 2 , the dry process is to bond the aluminum foil layer 1 and the polypropylene layer (heat sealing layer 2) together by the adhesive 4, which has the advantage of good punching performance, but the electrolyte resistance and water resistance are relatively poor.

[0004] The traditional hot process flow is to dry-composite the aluminum foil layer 1 and the nylon layer 3, and then hot-composite the polypropylene layer, which will cause long-time high-temperature baking of the nylon layer 3, thereby affecting the performance of the nylon layer 3.

[0005] Therefore, it is necessary to propose a production process of lithium battery aluminum-plastic film to at least partially solve the problems in the prior art. SUMMARY

[0006] A series of simplified concepts are introduced in the summary section, which will be further described in detail in the specific embodiment section. The summary section of the present application does not mean to attempt to limit the key features and necessary technical features of the claimed technical solution, and does not mean to attempt to determine the protection scope of the claimed technical solution.

[0007] To at least partially solve the above problems, the present application provides a production process of lithium battery aluminum-plastic film, comprising:

[0008] S1, treating the surface of the aluminum foil layer;

[0009] S2, hot-compositing one side of the aluminum foil layer with the heat sealing layer;

[0010] S3, coating the adhesive on the other side of the aluminum foil layer and dry-compositing with the nylon layer.

[0011] Preferably, the S2 comprises:

[0012] S210, the aluminum foil layer is conveyed to below the extruding mechanism, and the molten heat-seal layer is extruded between the aluminum foil layer and the first composite roller through the extruding mechanism;

[0013] S220, the aluminum foil layer and the heat-seal layer are compressed and hot-combined through the first composite roller and the first compression roller.

[0014] Preferably, the heat-seal layer comprises an acid-modified polypropylene layer and a multi-layer polypropylene layer.

[0015] The acid-modified polypropylene layer and the multi-layer polypropylene layer are extruded together from the extruding mechanism to the surface of the aluminum foil layer.

[0016] Preferably, the thickness of the aluminum foil layer is 30-50 μm, the thickness of the nylon layer is 15-25 μm, and the thickness of the heat-seal layer is 30-50 μm.

[0017] Preferably, the S3 comprises:

[0018] S310, the adhesive is coated on the other side of the aluminum foil layer and the heat-seal layer after the combination;

[0019] S320, the aluminum foil layer and the nylon layer coated with the adhesive are combined together through the second composite roller and the second compression roller.

[0020] Preferably, the second composite roller and the second compression roller are used to combine the aluminum foil layer and the nylon layer with a preset compression force.

[0021] The preset compression force is set according to the peel strength of the aluminum-plastic film.

[0022] Preferably, the second compression roller is arranged on the first adjusting mechanism, and the second compression roller can be away from or close to the second composite roller through the first adjusting mechanism to adjust the compression force between the two to meet the preset compression force.

[0023] The first adjusting mechanism is provided with an auxiliary compression roller, which provides an auxiliary support force for the middle part of the second compression roller that can change with the compression force, so that the compression force between the second compression roller and the second composite roller is homogenized in the axial direction.

[0024] Preferably, the first adjusting mechanism comprises:

[0025] Two symmetrically arranged first support side plates, the second compression roller is rotatably connected between the two first support side plates.

[0026] A support cross plate connected between the two first support side plates, which is provided with a second adjusting mechanism for supporting and adjusting the auxiliary compression roller.

[0027] The first telescopic part is arranged at the end of the first supporting side plate away from the second compression roller, and is used to drive the second compression roller and the auxiliary compression roller to move simultaneously.

[0028] The first pressure sensor is arranged between the first telescopic part and the first supporting side plate, and is used to detect the compression force between the second compression roller and the second composite roller.

[0029] Preferably, the second adjusting mechanism comprises:

[0030] The two second supporting side plates are symmetrically arranged, and the auxiliary compression roller is rotatably connected between the two second supporting side plates.

[0031] The second telescopic part is arranged on the supporting horizontal plate and connected with the second supporting side plate, and is used to drive the auxiliary compression roller to move.

[0032] The second pressure sensor is arranged between the second supporting side plate and the second telescopic part, and is used to detect the auxiliary supporting force between the auxiliary compression roller and the second compression roller, so as to compensate the compression force between the second compression roller and the second composite roller.

[0033] Preferably, the relationship between the auxiliary supporting force and the compression force is obtained by the following method:

[0034] Step A1, a compression force is applied between the second compression roller and the second composite roller; wherein the compression force is obtained by the first pressure sensor;

[0035] Step A2, after the compression force is applied, an auxiliary supporting force is applied between the auxiliary compression roller and the second compression roller, and with the change of the auxiliary supporting force, the pressure values at multiple detection points in the axial direction between the second compression roller and the second composite roller are detected;

[0036] Step A3, when the standard deviation of the multiple pressure values reaches a minimum value, the size of the auxiliary supporting force obtained by the second pressure sensor at the current time is recorded;

[0037] Step A4, steps A1-A3 are repeated, different compression forces are applied between the second compression roller and the second composite roller, and the relationship between the auxiliary supporting force and the compression force is obtained.

[0038] Compared with the prior art, the present application at least has the following beneficial effects:

[0039] The production process of the lithium battery aluminum-plastic film disclosed by the application first performs thermal compounding on the aluminum foil layer and the heat-sealing layer, and then performs dry compounding on the aluminum foil layer and the nylon layer, thereby effectively avoiding the influence of high-temperature baking on the nylon layer during thermal compounding, ensuring the performance of the nylon layer, making the electrolyte resistance and water resistance of the aluminum-plastic film good, improving the punching performance of the aluminum-plastic film, and making the product performance of the aluminum-plastic film more excellent and the applicability stronger.

[0040] The production process of the lithium battery aluminum-plastic film described in this invention, as well as other advantages, objectives, and features of this invention, will be partly apparent from the following description and partly understood by those skilled in the art through study and practice of this invention. Attached Figure Description

[0041] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0042] Figure 1 A schematic diagram of the structure of aluminum-plastic film produced by the thermal process;

[0043] Figure 2 A schematic diagram of the structure of aluminum-plastic film produced by dry process;

[0044] Figure 3 This is a flowchart of the production process of the lithium battery aluminum-plastic film described in this invention;

[0045] Figure 4 This is a flowchart of step S2 in the production process of the lithium battery aluminum-plastic film described in this invention.

[0046] Figure 5 This is a flowchart of step S3 in the production process of the lithium battery aluminum-plastic film of the present invention.

[0047] Figure 6 This is a schematic diagram of the production equipment in the production process of the lithium battery aluminum-plastic film described in this invention;

[0048] Figure 7 This is a schematic diagram of the auxiliary pressing roller in the production process of the lithium battery aluminum-plastic film described in this invention. Detailed Implementation

[0049] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments, so that those skilled in the art can implement it based on the description.

[0050] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0051] like Figure 1 and Figure 3 As shown, the present invention provides a manufacturing process for aluminum-plastic film for lithium batteries, comprising:

[0052] S1. Treat the surface of aluminum foil layer 1;

[0053] S2. Thermally bond one side of aluminum foil layer 1 to heat-sealing layer 2;

[0054] S3, the other side of the aluminum foil layer 1 is coated with an adhesive 4 and dry compounded with the nylon layer 3.

[0055] In order to improve the bonding ability of the aluminum foil layer 1 with the heat sealing layer 2 and the nylon layer 3, the surface of the aluminum foil layer 1 needs to be treated, then an acid-resistant layer 5 is coated on one side of the aluminum foil layer 1, and the side coated with the acid-resistant layer 5 is hot compounded with the heat sealing layer 2. The hot compounding can adopt one of the following processes: co-extrusion coating process, sandwich coating process or hot pasting process, and the co-extrusion coating process is preferred.

[0056] The co-extrusion coating process is to coat the heat sealing layer 2 (acid-modified polypropylene layer and multi-layer polypropylene layer) with multiple layers on the surface of the aluminum foil layer 1. In this process, the heat sealing layer 2 can fully contact with the surface of the aluminum foil layer 1, the anchoring area is large, strong adhesion is formed, and the production efficiency is high.

[0057] The sandwich coating process is to extrude the acid-modified polypropylene layer through an extruder, and the acid-modified polypropylene layer is combined between the two sides of the aluminum foil layer 1 and the polypropylene roll. The molten acid-modified polypropylene is bonded together with the polypropylene roll through the heat generated during extrusion.

[0058] The hot pasting process is to pre-coat the acid-modified polypropylene and polypropylene into a polypropylene film roll by co-extrusion casting, and then press the polypropylene film roll together with the aluminum foil roll at high temperature.

[0059] After the hot compounding of the aluminum foil layer 1 and the heat sealing layer 2, the other side of the aluminum foil layer 1 is coated with an adhesive 4, and dry compounded with the nylon layer 3, so that the nylon layer 3 is combined with the aluminum foil layer 1, forming an aluminum plastic film.

[0060] Through the above process, the aluminum foil layer 1 is first hot compounded with the heat sealing layer 2, and then the aluminum foil layer 1 is dry compounded with the nylon layer 3, which effectively avoids the influence of high-temperature baking on the nylon layer 3 during hot compounding, ensures the performance of the nylon layer 3, makes the aluminum plastic film have good electrolyte resistance and water resistance, and improves the punching performance of the aluminum plastic film, so that the product performance of the aluminum plastic film is more excellent and the applicability is stronger.

[0061] As shown in Figure 4 and Figure 6 in one embodiment, the S2 includes:

[0062] S210, the aluminum foil layer 1 is conveyed to below the extrusion mechanism 6, and the molten heat sealing layer 2 is extruded between the aluminum foil layer 1 and the first compounding roller 7 through the extrusion mechanism 6;

[0063] S220, the aluminum foil layer 1 is hot compounded with the heat sealing layer 2 by the first compounding roller 7 and the first pressing roller 8.

[0064] Further, the heat sealing layer 2 includes: an acid-modified polypropylene layer and a multi-layer polypropylene layer.

[0065] The acid-modified polypropylene layer and the multilayer polypropylene layer are extruded together from the extrusion mechanism 6 onto the surface of the aluminum foil layer.

[0066] The extrusion mechanism 6 is positioned above the first composite roller 7 and the first pressing roller 8, allowing the extruded heat-sealing layer 2 to fall directly into the gap between the aluminum foil layer 1 and the first composite roller 7, thus improving the composite effect. The first composite roller 7 is a cooling roller, which can reduce the temperature of the heat-sealing layer 2 while pressing, thereby improving its composite efficiency with the aluminum foil layer 1. The molten heat-sealing layer 2 is extruded onto the surface of the aluminum foil layer 1. Under the pressing action of the first composite roller 7 and the first pressing roller 8, the heat generated during the extrusion of the heat-sealing layer 2 is used to bond it together with the aluminum foil layer 1, forming a strong bonding force.

[0067] In one embodiment, the thickness of the aluminum foil layer 1 is 30μm to 50μm, the thickness of the nylon layer 3 is 15μm to 25μm, and the thickness of the heat-sealing layer 2 is 30μm to 50μm.

[0068] Choose polypropylene materials with good heat-sealing strength, and preferably aluminum foil and nylon materials with matching performance, so that they can work together to achieve greater performance advantages.

[0069] The performance requirements for nylon layer 3 are good cold formability, pinhole resistance, heat resistance, and tensile strength after being laminated with aluminum foil.

[0070] like Figure 5 and Figure 6 As shown, in one embodiment, S3 includes:

[0071] S310. Apply adhesive 4 to the other side of the aluminum foil layer 1 after it is laminated with the heat-sealing layer 2 using a coating roller 9.

[0072] S320, the aluminum foil layer 1 and nylon layer 3 coated with adhesive 4 are laminated together by the second composite roller 10 and the second pressing roller 11.

[0073] Furthermore, the second composite roller 10 and the second pressing roller 11 use a preset pressing force to composite the aluminum foil layer 1 and the nylon layer 3;

[0074] The preset clamping force is set based on the peel strength of the aluminum-plastic film.

[0075] After the aluminum foil layer 1, which is laminated with the heat-sealing layer 2, is cooled, the other side is coated with adhesive 4 by the coating roller 9. The adhesive 4 is used to enhance the bonding strength between the aluminum foil layer 1 and the nylon layer 3. The two are laminated by the second composite roller 10 and the second pressing roller 11.

[0076] Since the compounding of the aluminum foil layer 1 and the nylon layer 3 is affected by the pressing force, the temperature and the material conveying speed, before production, the three influence parameters need to be optimized, and the basis for optimization is the peeling strength of the aluminum plastic film, that is, the peeling strength between the nylon layer 3 and the aluminum foil layer 1, otherwise, the compounding effect of the nylon layer 3 and the aluminum foil layer 1 is poor, which will cause delamination, affecting the product quality and the punching performance of the aluminum plastic film; during production, the three influence parameters are used to compound the aluminum foil layer 1 and the nylon layer 3.

[0077] Specifically: a relationship model between the pressing force, the temperature, the speed and the peeling strength is established in advance (which can be obtained through multiple experiments);

[0078] The least square method is used to fit and update the relationship model between the peeling strength, the pressing force, the compounding temperature and the conveying speed, and the optimal pressing force, that is, the preset pressing force, can be obtained according to the relationship model while meeting the peeling strength, the conveying speed and the compounding temperature.

[0079] Through the above method, in the production process, the conveying speed and the compounding temperature of the material are monitored in real time under the condition of meeting the peeling strength, if the two change, the optimal pressing force that meets the conveying speed and the compounding temperature at present can be obtained according to the relationship model, that is, the preset pressing force, and then the pressing force between the second compounding roller 10 and the second pressing roller 11 is adjusted to the preset pressing force, which improves the compounding effect of the aluminum foil layer 1 and the nylon layer 3, and improves the peeling strength and the punching performance.

[0080] As shown in Figure 6 and Figure 7 , in one embodiment, the second pressing roller 11 is arranged on the first adjusting mechanism, and the second pressing roller 11 can be away from or close to the second compounding roller 10 through the first adjusting mechanism to adjust the pressing force between the two to meet the preset pressing force;

[0081] The first adjusting mechanism is provided with an auxiliary pressing roller 12, which provides an auxiliary supporting force for the middle part of the second pressing roller 11 that can change with the pressing force, so that the pressing force between the second pressing roller 11 and the second compounding roller 10 is uniform in the axial direction.

[0082] In the production process, in order to facilitate the adjustment of the pressing force between the second pressing roller 11 and the second compounding roller 10, the second pressing roller 11 is arranged on the first adjusting mechanism, so that it can move relative to the second compounding roller 10, which facilitates the adjustment of the pressing force between the two;

[0083] Since the length of the second compression roller 11 is relatively long, the force is usually applied to the two ends of the second compression roller 11, so that the middle part of the second compression roller 11 cannot reach the preset compression force with the middle part of the second composite roller 10, that is, the compression force distribution of the two in the axial direction is uneven, which will lead to that when the aluminum foil layer 1 and the nylon layer 3 are compounded, the compression force on both sides can meet the preset compression force, but the compression force in the middle may be less than the preset compression force, so that the quality of the obtained product is uneven, affecting the performance of the aluminum plastic film, and easily causing the phenomenon of delamination between the nylon layer 3 and the aluminum foil layer 1.

[0084] Therefore, an auxiliary compression roller 12 is additionally provided to provide auxiliary support force for the second compression roller 11, so that the compression force between the second compression roller 11 and the second composite roller 10 is more uniform in the axial direction, so that the compression force consistency in the width direction of the combination of the aluminum foil layer 1 and the nylon layer 3 is better, thereby obtaining a product with higher quality.

[0085] As shown in Figure 7 Further, the first adjusting mechanism comprises:

[0086] Two symmetrically arranged first support side plates 13, and the second compression roller 11 is rotationally connected between the two first support side plates 13;

[0087] A support cross plate 14 connected between the two first support side plates 13, and a second adjusting mechanism for supporting and adjusting the auxiliary compression roller 12 is arranged on the support cross plate 14;

[0088] A first telescopic part 15 arranged at the end of the first support side plate 13 away from the second compression roller 11, for driving the second compression roller 11 and the auxiliary compression roller 12 to move simultaneously;

[0089] A first pressure sensor arranged between the first telescopic part 15 and the first support side plate 13, for detecting the compression force between the second compression roller 11 and the second composite roller 10.

[0090] Further, the second adjusting mechanism comprises:

[0091] Two symmetrically arranged second support side plates 16, and the auxiliary compression roller 12 is rotationally connected between the two second support side plates 16;

[0092] A second telescopic part 17 connected with the second support side plate 16 and arranged on the support cross plate 14, for driving the auxiliary compression roller 12 to move;

[0093] A second pressure sensor arranged between the second support side plate 16 and the second telescopic part 17, for detecting the auxiliary support force between the auxiliary compression roller 12 and the second compression roller 11, so as to compensate the compression force between the second compression roller 11 and the second composite roller 10.

[0094] The first support side plate 13 and the support horizontal plate 14 are slidingly arranged on the production equipment body, and the movement of the first support side plate 13 and the support horizontal plate 14 is driven by the first telescopic part 15, which can simultaneously drive the second compression roller 11 and the auxiliary compression roller 12 to move;

[0095] The first pressure sensor is used to detect the force between the first telescopic part 15 and the first support side plate 13 in real time, that is, the compression force between the second compression roller 11 and the second composite roller 10. When it is detected that the compression force needs to be adjusted (for example, when the detected compression force is less than or greater than the preset compression force under other conditions unchanged; or when the composite temperature or the conveying speed changes, the compression force needs to be adjusted to the optimal compression force), the first telescopic part 15 is elongated or shortened to change the force applied to the second compression roller 11 until the compression force is adjusted to the preset compression force, and at the same time, the second telescopic part 17 is elongated or shortened to change the auxiliary support force applied to the auxiliary compression roller 12, so that the auxiliary support force changes with the compression force, and the compression force between the second compression roller 11 and the second composite roller 10 is uniformized in the axial direction.

[0096] In an embodiment, the relationship between the auxiliary support force and the compression force is obtained by the following method:

[0097] Step A1, apply a compression force between the second compression roller 11 and the second composite roller 10; wherein the compression force is obtained by the first pressure sensor;

[0098] Step A2, after applying the compression force, apply an auxiliary support force between the auxiliary compression roller 12 and the second compression roller 11, and detect the pressure values at multiple detection points in the axial direction between the second compression roller 11 and the second composite roller 10 as the auxiliary support force changes;

[0099] Step A3, when the standard deviation of the multiple pressure values reaches a minimum value, record the size of the auxiliary support force obtained by the second pressure sensor at the current time;

[0100] Step A4, repeat steps A1-A3, apply different compression forces multiple times between the second compression roller 11 and the second composite roller 10, and obtain the relationship between the auxiliary support force and the compression force.

[0101] In order to ensure the accuracy of the auxiliary supporting force changing with the compression force adjusting, the relationship between the two is obtained in advance, a plurality of detection points are arranged on the surface of the second compression roller 11 in advance, the plurality of detection points are arranged in the axial direction, different compression forces are applied multiple times through the first telescopic part 15, the compression forces can be obtained by the first pressure sensor, then after each time the compression force is applied, the auxiliary supporting force is slowly applied between the auxiliary compression roller 12 and the second compression roller 11 through the second telescopic part 17, and the plurality of pressure values at the plurality of detection points are detected in the process, when the standard deviation of the plurality of pressure values reaches the minimum value, the size of the auxiliary supporting force obtained by the second pressure sensor is recorded; wherein the standard deviation can reflect the difference between the plurality of pressure values, the smaller the standard deviation, the smaller the difference between the plurality of pressure values, when the standard deviation of the plurality of pressure values reaches the minimum value, it indicates that the auxiliary supporting force applied at this moment can make the uniformity of the compression force between the second compression roller 11 and the second composite roller 10 in the axial direction optimal, improve the uniformity when the nylon layer 3 is compounded with the aluminum foil layer 1, and improve the compounding quality.

[0102] The plurality of compression forces and the auxiliary supporting force are obtained in the above manner, and the change relationship between the two can be obtained, and then the auxiliary supporting force is adaptively adjusted according to the change relationship, so that the uniformity of the compression force between the second compression roller 11 and the second composite roller 10 is better.

[0103] In the description of the present application, it should be understood that the orientations or positional relationships indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0104] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood broadly, for example, can be fixed connection, or can be detachable connection, or can be integrated; can be mechanical connection, or can be electrical connection or communication with each other; can be directly connected, or indirectly connected through an intermediate medium; can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0105] While embodiments of the application have been disclosed in connection with the above specification and drawings this description is not intended to limit the scope of the application and many modifications, enhancements, alternatives, and variations will become apparent to those skilled in the art from this disclosure. Accordingly, it is intended that the application not be limited to the described embodiments, but that it include all variations falling within the scope of the claims, and their equivalents.

Claims

1. A manufacturing process for an aluminum-plastic film for lithium batteries, characterized in that, include: S1. Treat the surface of the aluminum foil layer (1); S2. Heat-bond one side of the aluminum foil layer (1) with the heat-sealing layer (2); S3. Apply adhesive (4) to the other side of the aluminum foil layer (1) and dry-laminate it with the nylon layer (3); S3 includes: S310. Apply adhesive (4) to the other side of the aluminum foil layer (1) after it is laminated with the heat-sealing layer (2) using a coating roller (9); S320, the aluminum foil layer (1) and nylon layer (3) coated with adhesive (4) are laminated together by passing through the second composite roller (10) and the second pressing roller (11); The second composite roller (10) and the second pressing roller (11) use a preset pressing force to composite the aluminum foil layer (1) and the nylon layer (3); The preset clamping force is set based on the peel strength of the aluminum-plastic film; The second pressing roller (11) is mounted on the first adjustment mechanism. The second pressing roller (11) can move away from or closer to the second composite roller (10) through the first adjustment mechanism to adjust the pressing force between the two to meet the preset pressing force. The first adjustment mechanism is provided with an auxiliary pressing roller (12), which provides an auxiliary support force to the middle part of the second pressing roller (11) that can vary with the pressing force, so that the pressing force between the second pressing roller (11) and the second composite roller (10) is uniform in the axial direction.

2. The production process of the lithium battery aluminum-plastic film according to claim 1, characterized in that, S2 includes: S210, the aluminum foil layer (1) is conveyed to the extrusion mechanism (6) below, and the molten heat-sealing layer (2) is extruded between the aluminum foil layer (1) and the first composite roller (7) through the extrusion mechanism (6); S220. The aluminum foil layer (1) and the heat-sealing layer (2) are pressed and heat-bonded by the first composite roller (7) and the first pressing roller (8).

3. The production process of the lithium battery aluminum-plastic film according to claim 2, characterized in that, The heat-sealing layer (2) includes: an acid-modified polypropylene layer and a multilayer polypropylene layer; The acid-modified polypropylene layer and the multilayer polypropylene layer are extruded together from the extrusion mechanism (6) onto the surface of the aluminum foil layer (1).

4. The production process of the lithium battery aluminum-plastic film according to claim 1, characterized in that, The thickness of the aluminum foil layer (1) is 30μm to 50μm, the thickness of the nylon layer (3) is 15μm to 25μm, and the thickness of the heat-sealing layer (2) is 30μm to 50μm.

5. The production process of the lithium battery aluminum-plastic film according to claim 1, characterized in that, The first adjustment mechanism includes: Two symmetrically arranged first support side plates (13) are connected to the second pressing roller (11) rotatably between the two first support side plates (13); A support cross plate (14) is connected between two first support side plates (13), and a second adjustment mechanism is provided thereon for supporting and adjusting the auxiliary pressing roller (12); The first telescopic part (15) is provided at the end of the first support side plate (13) away from the second pressing roller (11) and is used to drive the second pressing roller (11) and the auxiliary pressing roller (12) to move simultaneously. A first pressure sensor is installed between the first telescopic part (15) and the first support side plate (13) to detect the clamping force between the second pressing roller (11) and the second composite roller (10).

6. The production process of the lithium battery aluminum-plastic film according to claim 5, characterized in that, The second adjustment mechanism includes: Two symmetrically arranged second support side plates (16), with the auxiliary pressing roller (12) rotatably connected between the two second support side plates (16); The second telescopic part (17), which is connected to the second support side plate (16), is provided on the support cross plate (14) and is used to drive the auxiliary pressing roller (12) to move. The second pressure sensor, located between the second support side plate (16) and the second telescopic part (17), is used to detect the auxiliary support force between the auxiliary pressing roller (12) and the second pressing roller (11) to compensate for the pressing force between the second pressing roller (11) and the second composite roller (10).

7. The production process of the lithium battery aluminum-plastic film according to claim 6, characterized in that, The relationship between the auxiliary support force and the clamping force is obtained in the following way: Step A1: Apply a clamping force between the second clamping roller (11) and the second composite roller (10); wherein the clamping force is obtained by a first pressure sensor; Step A2: After applying the clamping force, apply an auxiliary support force between the auxiliary clamping roller (12) and the second clamping roller (11). As the auxiliary support force changes, detect the pressure values ​​at multiple detection points in the axial direction between the second clamping roller (11) and the second composite roller (10). Step A3: When the standard deviation of multiple pressure values ​​reaches the minimum value, record the magnitude of the auxiliary support force acquired by the second pressure sensor at the current moment; Step A4: Repeat steps A1-A3 to apply different clamping forces multiple times between the second clamping roller (11) and the second composite roller (10) to obtain the relationship between the auxiliary support force and the clamping force.

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