Preparation equipment and preparation method of intermittent electrode plate

Abstract

The embodiment of the invention provides preparation equipment and a preparation method of an intermittent electrode plate. The preparation equipment comprises an unwinding device, a diaphragm feeding device, a compounding device and an air knife, wherein the unwinding device is used for conveying a current collector of which the surface is intermittently distributed with a conductive adhesive to the compounding device; the membrane feeding device is used for conveying a continuous membrane to the compounding device; the compounding device is used for receiving the continuous diaphragm and the current collector, and performing hot-pressing compounding on the continuous diaphragm and the area, where the conductive adhesive is distributed, of the current collector to obtain an electrode plate; the air knife is arranged on the discharging side of the compounding device and used for cutting off a membrane area which is not compounded with the current collector in the electrode plate to obtain an intermittent electrode plate, and the intermittent electrode plate comprises the current collector and an intermittent membrane compounded on the surface of at least one side of the current collector. The preparation equipment is used for achieving the effect that the intermittent electrode plate is prepared by adopting a dry method so as to meet the design requirements of various battery structures.

Description

Technical Field

[0001] The present invention relates to the field of batteries, and particularly to a preparation device and a preparation method for an intermittent electrode sheet. Background Art

[0002] The dry process is a solvent-free method for preparing electrode sheets. Its implementation process is to first use a multi-roll transfer method, utilize multiple continuous over-rolls with inconsistent linear speeds, and form a shearing force under the differential speed action to fibrillate the binder and form a film of the material for the material mixed with the binder under the differential speed action of multiple rolls, and then laminate the film sheet attached to the over-roll and the current collector under a large pressure. Since the above method forms a film under differential speed on continuous over-rolls, therefore, the existing dry process can only prepare electrode sheets with continuous film sheets.

[0003] However, in the design requirements of some battery structures, it is often necessary to use an electrode sheet with an intermittent film sheet (i.e., an intermittent electrode sheet) to optimize the battery performance. For example, when the size of the negative electrode is larger than that of the positive electrode, it is necessary to coat a gasket in the film-free area of the intermittent electrode sheet to cope with a series of problems such as the destruction of the negative electrode sheet structure caused by the huge shearing force brought by the edge of the positive electrode sheet to the negative electrode sheet when preparing the battery under pressure.

[0004] Therefore, there is currently a lack of a method for dry-preparing an intermittent electrode sheet. Summary of the Invention

[0005] The present invention provides a preparation device and a preparation method for an intermittent electrode sheet, so as to achieve the effect of dry-preparing an intermittent electrode sheet to meet the design requirements of various battery structures.

[0006] In a first aspect of the present invention, there is provided a preparation device for an intermittent electrode sheet, including: a unwind device, a film sheet feeding device, a lamination device, and an air knife;

[0007] Wherein, the unwind device is used to convey a current collector with intermittently distributed conductive binder on its surface to the lamination device;

[0008] The film sheet feeding device is used to convey a continuous film sheet to the lamination device;

[0009] The lamination device is used to receive the continuous film sheet and the current collector, and thermally laminate the area with conductive binder distributed on the continuous film sheet and the current collector to obtain an electrode sheet;

[0010] The air knife is arranged on the discharge side of the lamination device, and is used to cut off the film sheet area in the electrode sheet that is not laminated with the current collector to obtain an intermittent electrode sheet, and the intermittent electrode sheet includes the current collector and an intermittent film sheet laminated on at least one surface of the current collector.

[0011] According to an embodiment of the present invention, the preparation device further includes: a swing roller for controlling the distance and / or angle between the diaphragm in the electrode sheet and the air knife.

[0012] According to an embodiment of the present invention, the preparation device further includes: a material collecting device for recovering the diaphragm cut by the air knife.

[0013] According to an embodiment of the present invention, the preparation device further includes: a winding device for winding the intermittently prepared electrode sheet.

[0014] According to an embodiment of the present invention, the preparation device further includes: a plurality of fixed guide rollers arranged between the discharge side of the composite device and the winding device for guiding the electrode sheet to the position where the air knife is located to cut the diaphragm area not compounded with the current collector.

[0015] According to an embodiment of the present invention, the number of the diaphragm feeding devices is one or two, and the number of the diaphragm feeding devices is the same as the number of the air knives.

[0016] According to an embodiment of the present invention, the number of the swing rollers is the same as the number of the air knives.

[0017] In a second aspect of the present invention, there is provided an intermittent electrode sheet preparation method, which is applied to the preparation device provided in the first aspect of the present invention. The method includes:

[0018] Controlling the unwinding device to convey the current collector with intermittently distributed conductive adhesive on its surface to the composite device;

[0019] Controlling the diaphragm feeding device to convey the continuous diaphragm to the composite device;

[0020] Controlling the composite device to thermally press and compound the continuous diaphragm and the area with conductive adhesive on the current collector to obtain an electrode sheet;

[0021] Controlling the air knife to cut the diaphragm area in the electrode sheet that is not compounded with the current collector to obtain an intermittent electrode sheet, where the intermittent electrode sheet includes the current collector and the intermittent diaphragm compounded on at least one surface of the current collector.

[0022] According to an embodiment of the present invention, the preparation method further includes:

[0023] Controlling the swing roller in the preparation device to adjust the distance and / or angle between the diaphragm in the electrode sheet and the air knife so that the air knife can cut the diaphragm area in the electrode sheet that is not compounded with the current collector.

[0024] According to an embodiment of the present invention, the conductive adhesive is composed of a conductive agent and a binder;

[0025] Among them, the conductive agent is at least one of conductive carbon black, conductive carbon fiber, and carbon nanotube, and / or the binder is at least one of polyvinyl alcohol, polyamide, polyester, polyethylene, and polyurethane.

[0026] According to an embodiment of the present invention, the thickness of the conductive binder is ≤2 μm.

[0027] According to an embodiment of the present invention, the temperature of the hot pressing and compounding is ≥60 °C.

[0028] The preparation equipment and method of the intermittent electrode sheet provided by the embodiment of the present invention intermittently coat a conductive binder on a current collector in advance, so that when a continuous film and the current collector are compounded by a compounding device, only the continuous film can be compounded with the area of the current collector where the conductive binder is distributed; then, a wind knife is used to cut off the film in the uncompounded area between the two to obtain an intermittent electrode sheet, achieving the effect of obtaining an intermittent electrode sheet by dry preparation to meet the design requirements of various battery structures. Description of the Drawings

[0029] The drawings here are incorporated into the specification and constitute a part of this specification, showing the embodiments in line with the present invention, and are used together with the specification to explain the principles of the present invention.

[0030] Figure 1 It is a schematic structural diagram of the preparation equipment of the intermittent electrode sheet provided in Embodiment 1 of the present invention;

[0031] Figure 2 It is a schematic structural diagram of a current collector with a conductive binder intermittently distributed on the surface conveyed by a unwind device;

[0032] Figure 3 It is a schematic structural diagram of the electrode sheet obtained by a compounding device;

[0033] Figure 4 It is a schematic structural diagram of the intermittent electrode sheet;

[0034] Figure 5 It is a schematic structural diagram of the preparation equipment of the specific intermittent electrode sheet provided in Embodiment 2 of the present invention;

[0035] Figure 6 It is a schematic flow chart of a preparation method of an intermittent electrode sheet provided in Embodiment 3 of the present invention.

[0036] Description of the Reference Numerals:

[0037] 101 - unwind device; 104 - wind knife; 105 - swing roller; 106 - receiving device; 107 - winding device; 108 - fixed idler roller; 109 - blanking device; 110 - transfer roller

[0038] 201 - Current collector with intermittently distributed conductive binder on the surface; 2011 - Conductive binder; 202 - Electrode sheet; 203 - Intermittent electrode sheet.

[0039] Through the above - mentioned drawings, specific embodiments of the present invention have been shown, and more detailed descriptions will be given hereinafter. These drawings and written descriptions are not intended to limit the scope of the inventive concept in any way, but to illustrate the concept of the present invention to those skilled in the art by reference to specific embodiments. Detailed implementation manners

[0040] To enable those skilled in the art to better understand the solution of the present invention, the present invention will be further described in detail below. The following specific implementation manners listed are only for describing the principles and features of the present invention, and the examples given are only used to explain the present invention and do not limit the scope of the present invention. Based on the embodiments of the present invention, all other implementation manners obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0041] According to the research of the inventor, based on the principle of the existing dry - method for preparing electrode sheets, only continuous diaphragms can be prepared. Therefore, the inventor considered pre - coating the current collector intermittently with a conductive binder that has a certain viscosity at high temperatures, so that when the composite device thermally presses and composites the received continuous diaphragm and the current collector, the areas on the current collector where the conductive binder is distributed are viscous and can effectively composite with the continuous diaphragm, while the blank areas on the current collector are non - viscous and cannot composite with the continuous diaphragm; further, by using an air knife, the diaphragm areas in the electrode sheet output by the composite device that are not composite with the current collector are cut off, and thus an intermittent electrode sheet can be successfully obtained by the dry - method preparation, and this intermittent electrode sheet can be used to meet the design requirements of various battery structures.

[0042] Figure 1 The structural schematic diagram of the preparation equipment for the intermittent electrode sheet provided in the first embodiment of the present invention is as Figure 1 shown. The preparation equipment 10 for the intermittent electrode sheet provided in this embodiment includes: a unwind device 101, a diaphragm feeding device 102, a composite device 103, and an air knife 104.

[0043] Among them, the unwinding device 101 is used to convey the current collector with intermittently distributed conductive adhesives on its surface to the compounding device 103; the diaphragm feeding device 102 is used to convey the continuous diaphragm to the compounding device 103; the compounding device 103 is used to receive the continuous diaphragm and the current collector, and thermocompression bond the areas with conductive adhesives on the continuous diaphragm and the current collector to obtain the electrode sheet; the air knife 104 is arranged on the discharging side of the compounding device 103, and is used to cut off the diaphragm area in the electrode sheet that is not compounded with the current collector, so as to obtain the intermittent electrode sheet. The above-mentioned preparation equipment 10 is used to prepare the intermittent electrode sheet, including the above-mentioned current collector and the intermittent diaphragm compounded on at least one surface of the current collector.

[0044] It should be understood that the air knife 104 can generate a shearing force through the high-speed rotating air flow to separate the uncompounded diaphragm area in the electrode sheet from the compounded diaphragm area in the electrode sheet, so as to realize the cutting off of the uncompounded diaphragm area.

[0045] For the convenience of understanding this solution, the following will be combined with Figures 2 - 4 The structure of the preparation product in each preparation stage will be described in detail. Among them, Figure 2 FIG. is a schematic structural diagram of the current collector with intermittently distributed conductive adhesives on its surface conveyed by the unwinding device; Figure 3 FIG. is a schematic structural diagram of the electrode sheet obtained by the compounding device; Figure 4 FIG. is a schematic structural diagram of the intermittent electrode sheet.

[0046] Specifically, in the preparation equipment 10, the structure of the current collector 201 with intermittently distributed conductive adhesives on its surface conveyed by the unwinding device 101 to the compounding device 103 is as Figure 2 shown. The current collector 201 with intermittently distributed conductive adhesives on its surface is intermittently distributed with conductive adhesives 2011; after the diaphragm feeding device 102 conveys the continuous diaphragm to the compounding device 103, the structure of the electrode sheet 202 obtained by the compounding device receiving the continuous diaphragm and the current collector and thermocompression bonding the areas with conductive adhesives on the continuous diaphragm and the current collector is as Figure 3 shown; the structure of the intermittent electrode sheet 203 obtained by the air knife cutting off the diaphragm area in the electrode sheet that is not compounded with the current collector 201 with intermittently distributed conductive adhesives on its surface is as Figure 4 shown.

[0047] According to some embodiments of the present invention, in the preparation equipment 10 for the intermittent electrode sheet provided by the present invention, the number of the diaphragm feeding devices 102 can be one or two, and the number of the diaphragm feeding devices 10 is the same as the number of the air knives 10.

[0048] In these embodiments, if the preparation device 10 is only a preparation device capable of preparing an intermittent electrode sheet with an intermittent diaphragm compounded only on one surface of the current collector, correspondingly, in this preparation device 10, the number of diaphragm feeding devices 102 and the number of air knives 10 are both one; if the preparation device 10 is a preparation device capable of preparing an intermittent electrode sheet with intermittent diaphragms compounded on both surfaces of the current collector, correspondingly, in this preparation device 10, the number of diaphragm feeding devices 102 and the number of air knives 10 are both two. Such a setting can meet the design requirements of various types of intermittent electrode sheets.

[0049] According to some embodiments of the present invention, the preparation device 10 for the intermittent electrode sheet provided by the present invention further includes: a swing roller for controlling the distance and / or angle between the diaphragm in the electrode sheet 202 and the air knife 104.

[0050] It should be understood that if the distance between the diaphragm and the air knife is too close, it may cause excessive gas pressure and damage the diaphragm; if the distance between the diaphragm and the air knife is too far, the expected cutting effect may not be achieved. In addition, if the angle between the diaphragm and the air knife is inappropriate, it may affect the flatness of the cutting of the diaphragm by the air knife. Therefore, by providing a swing roller in the preparation device, the distance and / or angle between the diaphragm in the electrode sheet and the air knife can be adjusted by adjusting the position of the swing roller, so as to ensure that the gas blown by the air knife can act on the diaphragm with appropriate force and angle, thereby effectively removing the uncompounded diaphragm area in the electrode sheet.

[0051] Further, according to some embodiments of the present invention, in the preparation device 10 for the intermittent electrode sheet provided by the present invention, the number of swing rollers is the same as the number of air knives 104. It should be understood that the function of the swing roller is realized by cooperating with the air knife. Therefore, the number of swing rollers is the same as the number of air knives.

[0052] According to some embodiments of the present invention, the preparation device 10 for the intermittent electrode sheet provided by the present invention further includes a material collecting device for recovering the diaphragm cut by the air knife 104. It should be understood that by providing a material collecting device in the preparation device, not only can the reuse of the diaphragm material be realized, which helps to reduce the production cost, but also the cleanliness of the working environment of the preparation device can be ensured.

[0053] Further, according to some embodiments of the present invention, in the preparation device 10 for the intermittent electrode sheet provided by the present invention, the number of material collecting devices is the same as the number of air knives 104. It should be understood that the function of the material collecting device is realized by cooperating with the air knife. Therefore, the number of swing rollers is the same as the number of air knives.

[0054] According to some embodiments of the present invention, in the preparation device 10 of the intermittent electrode sheet provided by the present invention, a winding device is further included for winding the prepared intermittent electrode sheet 203. It should be understood that through the cooperative rolling between the unwinding device and the winding device, the current collector with intermittently distributed conductive adhesives on its surface can be continuously input into the composite device, and the obtained intermittent electrode sheet can be continuously wound.

[0055] According to some embodiments of the present invention, in the preparation device 10 of the intermittent electrode sheet provided by the present invention, it further includes: a plurality of fixed guide rollers arranged between the discharging side of the composite device 103 and the winding device for guiding the electrode sheet 202 to the position where the air knife 104 is located to cut off the film area not composite with the current collector.

[0056] It should be understood that the purpose of setting the fixed guide rollers is to guide the electrode sheet to the position where the air knife is located. Therefore, the number of fixed guide rollers can be designed according to specific application situations, such as 3, 4, 5, etc. As long as the number meets the requirement of guiding the electrode sheet to the position where the air knife is located, the specific value of the fixed guide rollers is not limited in this application.

[0057] In the preparation device 10 of the intermittent electrode sheet provided by the present invention, the composite device 103 can perform hot pressing and composite on the area where the conductive adhesive 2011 is distributed on the continuous film sheet and the current collector 201 with intermittently distributed conductive adhesives on its surface to obtain the electrode sheet 202; the air knife 104 can cut off the film area of the electrode sheet 202 not composite with the current collector to obtain the intermittent electrode sheet 203, so that the preparation device 10 can successfully obtain the intermittent electrode sheet by the dry method preparation method to meet the design requirements of various battery structures.

[0058] Figure 5 It is a schematic structural diagram of the specific preparation device of the intermittent electrode sheet provided in the second embodiment of the present invention. In this embodiment, a preparation device including two film feeding devices and two air knives is taken as an example to schematically show the specific structure of the preparation device 10.

[0059] As Figure 5 shown, the preparation device 10 of the intermittent electrode sheet provided in this embodiment specifically includes: an unwinding device 101, an air knife 104, a swing roller 105, a receiving device 106, a winding device 107, a fixed guide roller 108, a blanking device 109, and a transfer roller 110. Among them, through the guiding of the fixed guide roller 108 and the swing roller 105, the current collector 201 with intermittently distributed conductive adhesives on its surface is located between the unwinding device 101 and the transfer roller 110; the electrode sheet 202 is located between the transfer roller 110 and the first air knife 104; the intermittent electrode sheet 203 is located between the second air knife 104 and the winding device 107.

[0060] Specifically, in the above-mentioned preparation device 10, the transfer roller 110 includes two composite sub-rollers and multiple transfer sub-rollers. Among them, the two composite sub-rollers are arranged on both sides of the current collector 201 with intermittently distributed conductive binder on its surface and are in close contact with the current collector 201 with intermittently distributed conductive binder on its surface, serving as the composite device in the preparation device 10; the multiple transfer sub-rollers are arranged on both sides of the two composite sub-rollers in the transmission direction of the continuous diaphragm. Two blanking devices 109 are respectively arranged between the two outermost transfer sub-rollers at both ends of the transfer roller 110. The blanking device 109 on one side of the current collector 201 with intermittently distributed conductive binder on its surface and the multiple transfer sub-rollers on this side serve as a diaphragm feeding device in the preparation device 10. In this embodiment, the preparation device 10 includes two diaphragm feeding devices.

[0061] Furthermore, the unwinding device 101 is used to convey the current collector 201 with intermittently distributed conductive binder on its surface between the two composite sub-rollers; the blanking device 109 is used to make the raw material of the diaphragm enter between the two outermost transfer sub-rollers at both ends of the transfer roller 110; the multiple transfer sub-rollers are used to gradually roll and press the raw material into a continuous diaphragm by the differential speed action between the multiple transfer sub-rollers and convey the continuous diaphragm between the composite sub-roller and the current collector 201 with intermittently distributed conductive binder on its surface; the composite sub-roller is used to receive the continuous diaphragm and the current collector 201 with intermittently distributed conductive binder on its surface, and thermally press and composite the area with conductive binder 2011 distributed on the continuous diaphragm and the current collector 201 with intermittently distributed conductive binder on its surface to obtain the electrode sheet 202; the air knife 104 is used to cut off the diaphragm area in the electrode sheet 202 that is not composite with the current collector 201 with intermittently distributed conductive binder on its surface to obtain the intermittent electrode sheet 203.

[0062] In practical applications, an intermittent electrode sheet with an intermittent diaphragm composite only on one side surface of the current collector can be prepared by adding the raw material of the diaphragm only in the blanking device 109 on one side, and correspondingly, by coating the conductive binder only on the corresponding side of the current collector; an intermittent electrode sheet with intermittent diaphragms composite on both side surfaces of the current collector can also be prepared by adding the raw material of the diaphragm in both blanking devices 109 at the same time and coating the conductive binder on both sides of the current collector.

[0063] In addition, in the above-mentioned preparation device 10, the number of air knives 104 is two, which are respectively used to cut off the diaphragm areas that are not composite with the current collector on both sides of the electrode sheet; the number of swing rollers 105 is two, which are respectively used to control the distance and / or angle between the diaphragm in the electrode sheet and the two air knives 104; the number of winding devices 106 is two, which are respectively used to recycle the diaphragms cut off by the two air knives 104.

[0064] In the above-mentioned preparation device 10, the winding device 107 is used to wind the intermittently prepared electrode sheet 203; a plurality of fixed guide rollers 108 are arranged between the discharge side of the lamination device 103 and the winding device, and are used to guide the electrode sheet 202 to the position where the air knife 104 is located to cut off the diaphragm area that is not laminated with the current collector 202. The number of fixed guide rollers in this embodiment is 6.

[0065] In the specific intermittent electrode sheet preparation device 10 provided by the present invention, a plurality of transfer sub-rollers in the blanking device 109 and the transfer roller 110 are used as the diaphragm feeding device of the preparation device 10, and two composite sub-rollers in the transfer roller 110 are used as the lamination device of the preparation device 10, so that the plurality of transfer sub-rollers can convey the continuous diaphragm to between the composite sub-roller and the current collector 201 with intermittently distributed conductive adhesive on its surface, so as to realize the thermal pressing and lamination of the continuous diaphragm and the area with conductive adhesive 2011 distributed on the current collector 201 with intermittently distributed conductive adhesive on its surface; then, the air knife 104 can cut off the diaphragm area of the electrode sheet 202 that is not laminated with the current collector, and obtain the intermittent electrode sheet 203, so that the preparation device 10 can successfully obtain the intermittent electrode sheet by the dry method preparation method, so as to meet the design requirements of various battery structures.

[0066] Figure 6 It is a schematic flow chart of a method for preparing an intermittent electrode sheet provided in Embodiment 3 of the present invention, which is applied to the above-mentioned preparation device 10 to prepare an intermittent electrode sheet, as Figure 6 shown. The method for preparing an intermittent electrode sheet provided in this embodiment includes:

[0067] S301. Control the unwinding device to convey the current collector with intermittently distributed conductive adhesive on its surface to the lamination device.

[0068] It should be understood that the conductive adhesive is a material with both conductive performance and adhesive performance. Among them, the conductivity of the conductive adhesive can effectively guarantee the conductivity of the prepared intermittent electrode sheet; the adhesiveness of the conductive adhesive effectively ensures that the continuous diaphragm can be laminated with the area of the current collector with conductive adhesive distributed thereon.

[0069] Specifically, whether the conductive adhesive is intermittently distributed on a single surface of the current collector or on both surfaces of the current collector is determined according to the preparation requirements of the intermittent diaphragm.

[0070] According to some embodiments of the present invention, the conductive adhesive is composed of a conductive agent and an adhesive. Among them, the conductive agent is at least one of conductive carbon black (SP), conductive carbon fiber (VGCF), and carbon nanotube (CNT), and / or the adhesive is at least one of polyvinyl alcohol, polyamide, polyester, polyethylene, and polyurethane.

[0071] According to some embodiments of the present invention, the thickness of the conductive binder intermittently distributed on the current collector is ≤2 μm. It should be understood that if the thickness of the conductive binder is too thick, it will affect the conductivity of the obtained intermittent electrode sheet. By setting the thickness of the conductive binder to ≤2 μm, while ensuring that the area of the conductive binder intermittently distributed on the current collector is effectively compounded, the conductivity of the obtained intermittent electrode sheet can be guaranteed. Specifically, the thickness of the conductive binder is, for example, ≤0.1 μm, 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1 μm, 1.1 μm, 1.2 μm, 1.3 μm, 1.4 μm, 1.5 μm, 1.6 μm, 1.7 μm, 1.8 μm, 1.9 μm, 2 μm, or a new range is formed by selecting any two of the foregoing values, and the values taken within the new range.

[0072] According to some embodiments of the present invention, if the obtained intermittent electrode sheet is a positive electrode sheet, the material of the current collector can be at least one of aluminum foil and nickel foil; if the obtained intermittent electrode sheet is a negative electrode sheet, the material of the current collector can be at least one of copper foil, nickel foam, and copper foam.

[0073] According to some embodiments of the present invention, the thickness of the current collector is 4 - 20 μm. Specifically, the thickness of the current collector is, for example, 4 μm, 6 μm, 8 μm, 10 μm, 12 μm, 14 μm, 16 μm, 18 μm, 20 μm, or a new range is formed by selecting any two of the foregoing values, and the values taken within the new range.

[0074] S302. Control the diaphragm feeding device to convey the continuous diaphragm to the composite device.

[0075] In this step, it is necessary to control the diaphragm feeding device to gradually roll the raw material of the diaphragm into a continuous diaphragm and convey the continuous diaphragm into the composite device.

[0076] Among them, the raw material of the diaphragm is a substance obtained by mixing the electrode main material, solid electrolyte, binder, and conductive agent. It should be understood that the present invention does not strictly limit the electrode main material, solid electrolyte, binder, and conductive agent in the raw material of the diaphragm, and they can be the commonly used materials for the electrode main material, solid electrolyte, binder, and conductive agent in the art.

[0077] According to some embodiments of the present invention, the solid electrolyte can be at least one of sulfide electrolytes, halide electrolytes, etc.

[0078] According to some embodiments of the present invention, the binder can be at least one of polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), etc.

[0079] According to some embodiments of the present invention, the conductive agent may be at least one of conductive carbon black (SP), Ketjen black (ECP), conductive carbon fiber (VGCF), carbon nanotube (CNT), etc.

[0080] According to some embodiments of the present invention, if the obtained intermittent electrode sheet is a positive electrode sheet, the main electrode material is at least one of lithium nickel cobalt manganese oxide, lithium-rich material, lithium iron phosphate, etc.

[0081] According to some embodiments of the present invention, if the obtained intermittent electrode sheet is a negative electrode sheet, the main electrode material is at least one of graphite, hard carbon, soft carbon, mesophase carbon microspheres, silicon-based negative electrode materials (mainly including silicon monoxide and silicon-carbon negative electrodes), tin-based negative electrode materials (mainly including tin and tin alloys), etc.

[0082] S303. Control the composite device to perform hot pressing and composite the area on the continuous diaphragm and the current collector where the conductive binder is distributed to obtain an electrode sheet.

[0083] In this step, since at a certain high temperature, the area on the current collector where the conductive binder is distributed has high viscosity, while the blank area on the current collector has no viscosity. Therefore, the composite device can only composite the continuous diaphragm and the area on the current collector where the conductive binder is distributed by hot pressing the continuous diaphragm and the current collector to obtain an electrode sheet.

[0084] According to some embodiments of the present invention, the temperature of the hot pressing and composite is ≥60°C. It should be understood that a temperature of ≥60°C for the hot pressing and composite can ensure effective composite between the continuous diaphragm and the area on the current collector where the conductive binder is distributed, thereby ensuring the stability of the obtained intermittent diaphragm. Specifically, the temperature of the hot pressing and composite is, for example, a value greater than or equal to 60°C such as 60°C, 65°C, 70°C, 75°C, 80°C, 100°C, 120°C, 150°C, 180°C, 220°C, 300°C, etc., not limited to the listed values, and other unlisted values within the given range are equally applicable.

[0085] S304. Control the air knife to cut off the diaphragm area in the electrode sheet that is not composite with the current collector to obtain an intermittent electrode sheet, and this intermittent electrode sheet includes a current collector and an intermittent diaphragm composite on at least one side surface of the current collector.

[0086] In this step, in order to obtain an intermittent diaphragm, it is necessary to control the air knife so that the air knife generates a shearing force through a high-speed rotating air flow to separate the uncomposite diaphragm area in the electrode sheet from the composite diaphragm area in the electrode sheet, thereby realizing the cutting off of the uncomposite diaphragm area and obtaining an intermittent electrode sheet including a current collector and an intermittent diaphragm composite on at least one side surface of the current collector.

[0087] The intermittent electrode sheet preparation method provided by the present invention obtains an electrode sheet by thermocompression bonding the areas with conductive adhesives distributed on a continuous diaphragm and a current collector through a composite device; then, an air knife is used to cut off the diaphragm area of the electrode sheet that is not bonded to the current collector, and the intermittent electrode sheet is obtained by means of a dry method preparation, achieving the effect of meeting the design requirements of various battery structures.

[0088] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An intermittent electrode sheet preparation device, characterized in that, Comprising: A unwind device, a diaphragm feeding device, a laminating device and an air knife; Wherein, the unwind device is used to convey the current collector with intermittently distributed conductive adhesive on its surface to the laminating device; The diaphragm feeding device is used to convey the continuous diaphragm to the laminating device; The laminating device is used to receive the continuous diaphragm and the current collector, and thermally press and laminate the areas with conductive adhesive on the continuous diaphragm and the current collector to obtain an electrode sheet; The air knife is arranged on the discharging side of the laminating device, and is used to cut off the diaphragm area in the electrode sheet that is not laminated with the current collector to obtain an intermittent electrode sheet, and the intermittent electrode sheet includes the current collector and the intermittent diaphragm laminated on at least one side surface of the current collector.

2. The preparation device according to claim 1, characterized in that, The preparation equipment further includes: a swing roller, which is used to control the distance and / or angle between the diaphragm in the electrode sheet and the air knife.

3. The production equipment according to claim 1 or 2, characterized in that The preparation equipment further includes: a collecting device, which is used to recycle the diaphragm cut off by the air knife.

4. The preparation device according to claim 1 or 2, characterized in that The preparation equipment further includes: a winding device, which is used to wind the prepared intermittent electrode sheet.

5. The preparation device according to claim 4, characterized in that, The preparation equipment further includes: a plurality of fixed guide rollers, which are arranged between the discharging side of the laminating device and the winding device, and are used to guide the electrode sheet to the position where the air knife is located to cut off the diaphragm area that is not laminated with the current collector.

6. The production equipment according to claim 1, characterized in that, The number of the diaphragm feeding devices is one or two, and the number of the diaphragm feeding devices is the same as the number of the air knives.

7. The production equipment according to claim 2, characterized in that, The number of the swing rollers is the same as the number of the air knives.

8. A preparation method of an intermittent electrode sheet, applied to the preparation equipment described in any one of claims 1-7, characterized in that, The method includes: Controlling the unwind device to convey the current collector with intermittently distributed conductive adhesive on its surface to the laminating device; Controlling the diaphragm feeding device to convey the continuous diaphragm to the laminating device; Controlling the laminating device to thermally press and laminate the areas with conductive adhesive on the continuous diaphragm and the current collector to obtain an electrode sheet; Controlling the air knife to cut off the diaphragm area in the electrode sheet that is not laminated with the current collector to obtain an intermittent electrode sheet, and the intermittent electrode sheet includes the current collector and the intermittent diaphragm laminated on at least one side surface of the current collector.

9. The preparation method according to claim 8, characterized in that, The preparation method further includes: Controlling the swing roller in the preparation equipment to adjust the distance and / or angle between the diaphragm in the electrode sheet and the air knife, so that the air knife can cut off the diaphragm area in the electrode sheet that is not laminated with the current collector.

10. The preparation method according to claim 8 or 9, characterized in that, The conductive adhesive is composed of a conductive agent and a binder; Wherein, the conductive agent is at least one of conductive carbon black, conductive carbon fiber, carbon nanotube, and / or the binder is at least one of polyvinyl alcohol, polyamide, polyester, polyethylene and polyurethane.

11. The preparation method according to claim 8 or 9, characterized in that, The thickness of the conductive adhesive is ≤2μm.

12. The preparation method according to claim 8 or 9, characterized in that, The temperature of the thermal press lamination is ≥60°C.

Images