Ultrahigh-solid-content self-supporting film and processing device thereof

Abstract

The utility model discloses an ultrahigh solid content self-supporting film and a processing device thereof. The extrusion mechanism is used for extruding the ultrahigh-solid-content self-supporting membrane; the rolling and thinning mechanism is arranged at the downstream of the extrusion mechanism and is used for rolling and thinning the ultrahigh-solid-content self-supporting membrane to the process thickness to form the ultrahigh-solid-content self-supporting membrane; the trimming mechanism is arranged at the downstream of the rolling and thinning mechanism; the winding mechanism is arranged at the downstream of the edge cutting mechanism; and the release film unwinding mechanism is used for unwinding a release film, and the release film and the ultrahigh solid content self-supporting film are compounded. The self-supporting film winding device is used for solving the technical problems that when an existing self-supporting film is wound, the surface quality is damaged due to adhesion of film materials, and the follow-up compounding quality of the self-supporting film and a current collector is poor. The utility model further discloses a processing device of the self-supporting film with the ultrahigh solid content.

Description

Technical Field

[0001] This utility model belongs to the field of electrode sheet technology, specifically relating to an ultra-high solids content self-supporting film and a processing device for the aforementioned ultra-high solids content self-supporting film. Background Technology

[0002] In the lithium battery new energy industry, the manufacturing process and equipment for lithium battery positive and negative electrodes are formed by wet slurry coating process, which has high investment costs and high energy consumption. The equipment investment cost of this process accounts for 30% of the total production line equipment cost, and energy consumption accounts for 15%.

[0003] Dry electrode technology is one of the iterative processes in the development of lithium batteries from liquid to solid-state batteries. High-solids-content and dry electrode technology can be used not only in the manufacture of liquid lithium batteries, but also in the manufacture of solid-state lithium battery electrodes. It is one of the methods to improve the performance of solid-state lithium batteries. In the past year, research literature on solid-state lithium batteries has been frequently reported at home and abroad. It is a hot research object in the new energy industry and a future development trend.

[0004] Dry electrode technology can effectively reduce investment and production costs, improve production efficiency, and eliminate solvent evaporation, making it safer and more environmentally friendly. However, due to material characteristics, pure dry electrode negative sheets have been used in mass production of batteries by Tesla in the United States, but pure dry electrode positive sheet manufacturing has not yet been fully realized at home and abroad. Therefore, the ultra-high solids content extrusion "self-supporting film" process has become a new solution for the formation of lithium battery electrode sheets, and is a brand-new process solution for reducing investment costs and saving energy in lithium batteries.

[0005] The dry-process production of self-supporting films for lithium-ion battery cathode sheets has high requirements for equipment and materials. In laboratory-made batteries using this dry-process cathode sheet manufacturing method, the active material easily peels off from the current collector during charge and discharge processes after being wetted and soaked in electrolyte, and the binder fails to form a good bond with the current collector. Currently, there is no solution for the dry-process production of lithium-ion battery cathode sheets in the domestic or international industry, and it remains in the laboratory manufacturing stage without industrial application.

[0006] Ultra-high solids content refers to lithium-ion battery gel electrode mixtures with a solids content ≥85%, which is known in the industry as ultra-high solids content. Ultra-high solids content self-supporting films refer to lithium-ion battery gel electrode mixtures with a solids content ≥85%, which do not require other substrates and can be continuously formed into films and continuously wound into rolls solely based on the adhesive properties of their own material system. Existing "ultra-high solids content self-supporting films" require continuous single-sided composite current collectors during preparation, and ultra-high solids content self-supporting films cannot be wound into rolls, failing to solve the problem of surface adhesion causing damage to the film surface during winding.

[0007] The Chinese invention patent specification, published under publication number CN118077066A and titled "Electrode Manufacturing Apparatus and Electrode Manufacturing Method," describes a process where a continuous composite current collector is extruded, sheared, and not wound up, but only formed on one side. In contrast, battery electrodes have "ultra-high solids content self-supporting films" with active material on both sides. When the second side is laminated, the first side is rolled and sheared again during the shearing process, which cannot meet the process requirements. Utility Model Content

[0008] The first objective of this invention is to provide an ultra-high solids content self-supporting membrane to solve the technical problem that the surface quality of the membrane material is damaged by adhesion during the winding of existing self-supporting membranes, resulting in poor quality of subsequent composite bonding between the self-supporting membrane and the current collector.

[0009] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: an ultra-high solids content self-supporting membrane, characterized in that a release film is provided on the ultra-high solids content self-supporting membrane.

[0010] This invention adds a release film to an ultra-high solids content self-supporting film, effectively solving the technical problem of the contradiction between the film material sticking and damaging the surface quality during winding and the need for the film surface to be tacky for the next lamination process.

[0011] To solve the technical problem of the release film placement position, the present invention adopts the following technical solution: the release film is placed above and / or below the ultra-high solids content self-supporting film.

[0012] To solve the technical problem of the thickness of ultra-high solids content self-supporting membranes, the present invention adopts the following technical solution, wherein the thickness of the ultra-high solids content self-supporting membrane is 0.1-2.5mm.

[0013] The second objective of this invention is to provide a processing apparatus for ultra-high solids content self-supporting films, comprising:

[0014] Extrusion mechanism for extruding ultra-high solids content self-supporting membranes;

[0015] A roll shearing mechanism is located downstream of the extrusion mechanism and is used to roll shear the ultra-high solids content self-supporting film to the process thickness to form an ultra-high solids content self-supporting film.

[0016] The edge trimming mechanism is located downstream of the roll forming and shearing mechanism;

[0017] The winding mechanism is located downstream of the trimming mechanism;

[0018] A release film unwinding mechanism is used to unwind the release film, which is composited with an ultra-high solids content self-supporting film, and then wound up by the winding mechanism.

[0019] This utility model relates to a high-solids-content self-supporting film processing equipment. It innovatively incorporates a release film unwinding mechanism to prepare "high-solids-content self-supporting films," thus resolving the contradiction between the film material sticking and damaging the surface quality during winding and the need for film surface adhesion in the next lamination process.

[0020] To solve the technical problem of how to set up the release film unwinding mechanism, the present invention adopts the following technical solution: the roller pressing and shearing mechanism includes 1-N roller pressing and shearing mechanisms connected in series along the self-supporting film conveying direction, where N is a natural number.

[0021] To solve the technical problem of how to set the release film unwinding mechanism, the present invention adopts the following technical solution: the release film unwinding mechanism is set above and / or below the feed end of the Nth roller pressing and shearing mechanism.

[0022] To solve the technical problem of how to set up the release film unwinding mechanism, the present invention adopts the following technical solution: the release film unwinding mechanism is set above and / or below the discharge end of the cutting mechanism.

[0023] To solve the technical problem of how to set up the release film unwinding mechanism, the present invention adopts the following technical solution: the release film unwinding mechanism is set above and / or below the feed end of the winding mechanism.

[0024] To solve the technical problem of how to set up the release film unwinding mechanism, the present invention adopts the following technical solution: a correction mechanism is set between the edge cutting mechanism and the winding mechanism;

[0025] The release film unwinding mechanism is located above and / or below the feed end of the web guiding mechanism.

[0026] To solve the technical problem of how the extrusion mechanism is implemented, the present invention adopts the following technical solution, wherein the extrusion mechanism is a twin-screw extruder.

[0027] To solve the technical problem of self-supporting membrane conveying and guiding, this utility model adopts the following technical solution, wherein the extrusion mechanism is a twin-screw extruder;

[0028] A first guide conveyor roller group mechanism is provided between the extrusion mechanism and the roll pressing and shearing mechanism;

[0029] A second guide conveyor roller group mechanism is provided between the roll pressing and shearing mechanisms;

[0030] A third guide conveyor roller group mechanism is provided between the Nth roller pressing and shearing mechanism and the edge trimming mechanism;

[0031] A fourth guide conveyor roller group mechanism is provided between the edge trimming mechanism and the correction mechanism;

[0032] A fifth guide conveyor roller group mechanism is provided between the correction mechanism and the winding mechanism. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the winding structure of an existing ultra-high solids content self-supporting membrane;

[0034] Figure 2 This is a schematic diagram of the winding structure of the ultra-high solids content self-supporting film of this utility model. Figure 1 ;

[0035] Figure 3 This is a schematic diagram of the winding structure of the ultra-high solids content self-supporting film of this utility model. Figure 2 ;

[0036] Figure 4 This is a schematic diagram of the structure of an existing ultra-high solids content self-supporting membrane processing device;

[0037] Figure 5 This is a schematic diagram of the structure of the ultra-high solids content self-supporting membrane processing device of this utility model. Figure 1 ;

[0038] Figure 6 This is a schematic diagram of the structure of the ultra-high solids content self-supporting membrane processing device of this utility model. Figure 2 ;

[0039] Figure 7 This is a schematic diagram of the structure of the ultra-high solids content self-supporting membrane processing device of this utility model. Figure 3 ;

[0040] Figure 8 This is a schematic diagram of the structure of the ultra-high solids content self-supporting membrane processing device of this utility model. Figure 4 ;

[0041] Figure 9 This is a schematic diagram of the structure of the ultra-high solids content self-supporting membrane processing device of this utility model. Figure 5 ;

[0042] Figure 10 This is a schematic diagram of the structure of the ultra-high solids content self-supporting membrane processing device of this utility model. Figure 6 . Detailed Implementation

[0043] Compare with Example 1

[0044] like Figure 1 As shown, the ultra-high solids content self-supporting film requires a surface with adhesive properties for its processing. The existing self-supporting film after winding is 701'. The surface adhesiveness of the ultra-high solids content self-supporting film causes adhesion between the layers in the roll, resulting in defects on the electrode surface during subsequent unwinding and lamination processes. These defects are then addressed during winding. Figure 1 As shown, it does not meet the process requirements.

[0045] Example 1

[0046] like Figure 2 , Figure 3 As shown, in this embodiment, during the manufacturing and winding process of the ultra-high solids content self-supporting film 701, a release film 702 is added so that the wound ultra-high solids content self-supporting films 701 are separated by the release film 702, preventing them from sticking together. In one embodiment, as... Figure 2 As shown, the release membrane 702 is disposed below the ultra-high solids content self-supporting membrane 701.

[0047] In one embodiment, the release film 702 is disposed above the ultra-high solids content self-supporting film 701.

[0048] In one embodiment, such as Figure 3 The release membrane 702 shown is disposed above and below the ultra-high solids content self-supporting membrane 701.

[0049] In one embodiment, the thickness of the ultra-high solids self-supporting film 701 is 0.1-2.5 mm. Lithium-ion battery wet slurry, with a solids content ≥85%, becomes a soft film in a rubbery state with strong surface adhesion. It cannot be coated using a traditional wet coating machine; instead, it is extruded using a screw extruder to form continuous strips (self-supporting films). The width and thickness of the self-supporting film are determined according to the process, controlled within a certain range of 0.1-2.5 mm.

[0050] Compare with Example 2

[0051] The extrusion and shearing process for preparing "ultra-high solids self-supporting membranes" without the addition of release film, such as... Figure 4 As shown, the existing self-supporting film processing device 10' includes an extrusion mechanism 100', a roll forming and shearing mechanism 200', an edge trimming mechanism 300', a winding mechanism 400', and a web guiding mechanism 600'.

[0052] A first guide conveyor roller assembly 810' is provided between the extrusion mechanism 100' and the roll forming and shearing mechanism 200'. A second guide conveyor roller assembly 820' is provided between the roll forming and shearing mechanisms 200'. A third guide conveyor roller assembly 820' is provided between the Nth roll forming and shearing mechanism 200' and the edge trimming mechanism 300. A fourth guide conveyor roller assembly 840' is provided between the edge trimming mechanism 300' and the web guiding mechanism 600'. A third guide conveyor roller assembly 850' is provided between the web guiding mechanism 600' and the winding mechanism 400'.

[0053] The "ultra-high solids self-supporting film" after being thinned to the process thickness contains a small amount of solvent and has a certain degree of adhesion on its surface. "Adhesion" is a necessary characteristic of the "ultra-high solids self-supporting film" and is a material property that the subsequent composite current collector must possess. Battery electrodes have active materials on both sides. The patent CN118077066A for electrode manufacturing device and electrode manufacturing method describes the extrusion and thinning of the continuous composite current collector without winding, which is only a single-sided forming of the composite current collector. However, battery electrodes have active materials ("ultra-high solids self-supporting film") on both sides. When the second side is composited, the first side will be rolled and sheared again during the thinning process, which cannot meet the process requirements.

[0054] Example 2

[0055] like Figure 5 As shown, the ultra-high solids content self-supporting film processing device 10 in this embodiment includes an extrusion mechanism 100, a roll pressing and shearing mechanism 200, an edge trimming mechanism 300, a winding mechanism 400, and a release film unwinding mechanism 500.

[0056] The extrusion mechanism 100 is used to extrude ultra-high solids content self-supporting films. Preferably, the extrusion mechanism 100 is a twin-screw extruder. Powder materials such as lithium battery active materials, conductive agents, and binders, according to the formula requirements, are continuously fed in precise control using a loss-in-weight weigher. The feeding amount is precisely controlled according to the battery formula. The solvent is added in precise control according to the formula requirements via a precision screw pump. Strong shearing is achieved through the internal spiral elements of the twin screw, resulting in homogenization. Different widths and thicknesses are set according to the process settings to extrude continuous ultra-high solids content self-supporting films. This section of equipment is collectively referred to as the "twin-screw extruder." The sheet-like self-supporting film enters the shearing roll mill through a tension control mechanism. The tension control mechanism is used to control the matching of the film-forming linear speed of the "twin-screw extruder" with the linear speed of the roll mill. The control logic is that the linear speed of the entire line is based on the film-forming linear speed V1 of the "twin-screw extruder," and other linear speeds are matched to it through the control of the tension control mechanism.

[0057] A roll forming and shearing mechanism 200 is disposed downstream of the extrusion mechanism 100 and is used to roll form and shear the ultra-high solids content self-supporting film to the process thickness. In one embodiment, the roll forming and shearing mechanism includes 1-N roll forming and shearing mechanisms arranged in series along the self-supporting film conveying direction, where N is a natural number.

[0058] If the thickness of the self-supporting film formed by screw extrusion does not meet the thickness required for lithium battery processes, it needs to be rolled and sheared to the required thickness using a rolling mill once or "multiple times". The "multiple times" described here is not limited to 2 times, but also includes 3 times, 4 times, and N times.

[0059] The number of shearing passes depends on the process requirements, with the control standard being the achieved process thickness and quality. The illustration shows two shearing passes, but there may be three, four, or even more passes as needed, all within the scope of this patent. After achieving the process thickness, the edges are then trimmed to the process width. To address the adhesion of the self-supporting surface between rolls, which causes product quality defects, the patented solution cleverly incorporates a release film into the extrusion shearing process of the "ultra-high solids self-supporting film" to separate the rolls. The addition of the release film during the extrusion shearing process of the "ultra-high solids self-supporting film" is key to the successful implementation of this process equipment and is also a major point of patent protection. The locations where the release film is added include, but are not limited to, […]. Figure 2 , 3 The structural positions shown in 4, 5, 6, and 7 are numerous. There are many structural positions in which the release film is added during the extrusion and shearing process of the "ultra-high solids content self-supporting film". This patent will not describe them one by one, but they are all included in the scope of this patent.

[0060] The trimming mechanism 300 is located downstream of the roll forming and shearing mechanism 200. The winding mechanism 400 is located downstream of the trimming mechanism 300. A first guide conveyor roller group mechanism 810 is provided between the extrusion mechanism 100 and the roll forming and shearing mechanism 200. A second guide conveyor roller group mechanism 820 is provided between the roll forming and shearing mechanisms 200. A third guide conveyor roller group mechanism 820 is provided between the Nth roll forming and shearing mechanism 200 and the trimming mechanism 300.

[0061] In one embodiment, a correction mechanism 600 is provided between the trimming mechanism 300 and the winding mechanism 400. A fourth guide conveyor roller group mechanism 840 is provided between the trimming mechanism 300 and the correction mechanism 600. A third guide conveyor roller group mechanism 850 is provided between the correction mechanism 600 and the winding mechanism 400.

[0062] Release film unwinding mechanism 500 is used to unwind release film, which is then combined with ultra-high solids content self-supporting film.

[0063] like Figure 5 As shown, this utility model adds a release film to the surface of the roll material during the manufacturing and winding process of the "ultra-high solids content self-supporting film" to solve the problem of mutual adhesion of the roll material. The roll material prepared by adding the release film.

[0064] This invention incorporates release film preparation and winding into the extrusion and shearing process of "ultra-high solids self-supporting film". The "ultra-high solids self-supporting film" is sheared and wound separately, then transferred to a laminating machine for unwinding. The first and second sides are simultaneously laminated with the current collector using specialized laminating equipment. This invention solves the problem of surface adhesion of the "ultra-high solids self-supporting film" sticking together in the roll during the shearing and winding process, which causes defects on the electrode surface in subsequent unwinding and laminating processes and fails to meet process requirements.

[0065] Example 3

[0066] Unlike Embodiment 2, in this embodiment, the release film unwinding mechanism 500 is positioned above the feed end of the Nth roll shearing mechanism 200.

[0067] In one embodiment, the release film unwinding mechanism 500 is located below the feed end of the Nth roll shearing mechanism 200.

[0068] In one embodiment, such as Figure 5 As shown, the release film unwinding mechanism 500 is positioned above and below the feed end of the Nth roll shearing mechanism 200.

[0069] Before the final shearing stage (as described in the previous n-stage shearing process) in the extrusion shearing preparation of the "ultra-high solids self-supporting film," release film is added at the top and bottom positions before entering the rollers. The release film and the "ultra-high solids self-supporting film" enter the rollers simultaneously. The surface of the "ultra-high solids self-supporting film" is sheared and shaped, then the edges are trimmed sequentially, and finally, it is wound up. The finished roll is as follows: Figure 3 As shown, both the upper and lower surfaces of the membrane are protected by release films, which improves the surface quality of the unwinding process of the "ultra-high solids content self-supporting membrane" composite process.

[0070] Example 4

[0071] Unlike Embodiment 2, in this embodiment, the release film unwinding mechanism 500 is positioned above the discharge end of the edge trimming mechanism 300.

[0072] In one embodiment, such as Figure 7 As shown, the release film unwinding mechanism 500 is located below the discharge end of the edge trimming mechanism 300.

[0073] In one embodiment, such as Figure 6 As shown, the release film unwinding mechanism 500 is positioned above and below the discharge end of the trimming mechanism 300. After the final trimming stage (as described above, N trimming stages) in the extrusion and shearing process of the "ultra-high solids self-supporting film," release film is added to the upper and lower positions after exiting the roll, and then the film is wound up. The finished roll is as shown... Figure 3 As shown, both the upper and lower surfaces of the membrane are protected by release films, which improves the surface quality of the unwinding process of the "ultra-high solids content self-supporting membrane" composite process.

[0074] Example 5

[0075] Unlike Embodiment 2, in this embodiment, the release film unwinding mechanism 500 is positioned above and below the feed end of the winding mechanism 400.

[0076] In one embodiment, such as Figure 10 As shown, the release film unwinding mechanism 500 is positioned above the feed end of the winding mechanism 400.

[0077] In one embodiment, such as Figure 9 As shown, the release film unwinding mechanism 500 is located below the feed end of the winding mechanism 400.

[0078] In the extrusion and shearing process of "ultra-high solids self-supporting film", after the final shearing (as described above with n shearings), a release film is added at the top position after exiting the roll, and then the film is wound up. The finished roll is as follows: Figure 2 As shown, the upper and lower surfaces of the membrane are separated by release films, which serve to protect the membrane during winding and unwinding.

[0079] Example 6

[0080] Unlike Embodiment 2, in this embodiment, the release film unwinding mechanism 500 is positioned above and below the feed end of the web guiding mechanism 600.

[0081] In one embodiment, such as Figure 8 As shown, the release film unwinding mechanism 500 is positioned above the feed end of the web guiding mechanism 600.

[0082] In one embodiment, the release film unwinding mechanism 500 is located below the feed end of the web guiding mechanism 600.

[0083] After the final shearing stage in the extrusion shearing process of the "ultra-high solids self-supporting film" (as mentioned above after n shearing stages), a release film is added at the lower position after exiting the roll, and then the roll is wound up. The finished roll is as follows: Figure 2 As shown, the upper and lower surfaces of the membrane are separated by release films, which serve as protection during winding and unwinding, and improve the surface quality of the unwinding process of the "ultra-high solids content self-supporting membrane" composite process.

[0084] This invention enables the mass production of ultra-high solids content self-supporting film electrodes. Compared with the wet preparation process, the equipment investment cost for each GWh of homogenization and coating process is reduced by about 50%.

[0085] This invention reduces energy consumption by 70% and solvent emissions and recovery by 25-35%, demonstrating significant energy-saving and emission-reduction effects. The electrode manufacturing process time is also reduced by 50%.

[0086] Compared with wet-process electrode sheets, this invention can also achieve the forming of thick electrode sheets with a thickness of 0.3-2.0 mm or even thicker, making it a preferred solution for the preparation of thick electrode sheets for solid-state batteries.

[0087] This invention incorporates a release film to prepare an "ultra-high solids content self-supporting film," solving the adhesion problem during winding. This is a key technical point for successfully implementing the subsequent double-sided composite of the current collector and the "ultra-high solids content self-supporting film." Without the addition of a release film to prepare the "ultra-high solids content self-supporting film," the "ultra-high solids content self-supporting film" cannot be used in the next process after winding, namely the unwinding and composite process.

[0088] The "ultra-high solids content self-supporting film" process of this utility model is the preferred preparation scheme for the mass production of positive electrode sheets for secondary solid-state lithium batteries, and solid-state lithium batteries are the perfect solution for secondary lithium batteries.

[0089] The implementation of this patented solution, such as Figures 5-10 The implementation schemes described are only six examples. This description cannot fully express all the locations where a release film is added to prepare an "ultra-high solids content self-supporting film". However, the addition of a release film during the manufacturing and winding of the "ultra-high solids content self-supporting film" for lithium batteries is within the scope of this patent.

Claims

1. A processing apparatus for ultra-high solids content self-supporting membranes, characterized in that it includes: Extrusion mechanism for extruding ultra-high solids content self-supporting membranes; A roll shearing mechanism is located downstream of the extrusion mechanism and is used to roll shear the ultra-high solids content self-supporting film to the process thickness to form an ultra-high solids content self-supporting film. The edge trimming mechanism is located downstream of the roll forming and shearing mechanism; The winding mechanism is located downstream of the trimming mechanism; Release film unwinding mechanism, used to unwind release film, which is composited with ultra-high solids content self-supporting film.

2. The processing apparatus according to claim 1, characterized in that, The roller pressing and shearing mechanism includes 1-N roller pressing and shearing mechanisms connected in series along the self-supporting diaphragm conveying direction, where N is a natural number.

3. The processing apparatus according to claim 2, characterized in that, The release film unwinding mechanism is located above and / or below the feed end of the Nth roll shearing mechanism.

4. The processing apparatus according to claim 1, characterized in that, The release film unwinding mechanism is located above and / or below the discharge end of the trimming mechanism.

5. The processing apparatus according to claim 1, characterized in that, The release film unwinding mechanism is located above and / or below the feed end of the winding mechanism.

6. The processing apparatus according to claim 1, characterized in that, A correction mechanism is provided between the edge trimming mechanism and the winding mechanism; The release film unwinding mechanism is located above and / or below the feed end of the web guiding mechanism.

7. The processing apparatus according to claim 6, characterized in that, The extrusion mechanism is a twin-screw extruder; A first guide conveyor roller group mechanism is provided between the extrusion mechanism and the roll pressing and shearing mechanism; A second guide conveyor roller group mechanism is provided between the roll pressing and shearing mechanisms; A third guide conveyor roller group mechanism is provided between the Nth roller pressing and shearing mechanism and the edge trimming mechanism; A fourth guide conveyor roller group mechanism is provided between the edge trimming mechanism and the correction mechanism; A fifth guide conveyor roller group mechanism is provided between the correction mechanism and the winding mechanism.

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