Preparation method of multi-component composite positive electrode of lithium battery

Abstract

The invention belongs to the technical field of chemical power sources, and particularly relates to a lithium battery multi-component composite positive electrode preparation method which comprises the following steps: S1, performing high-speed ball milling and sieving on carbon fluoride, electrolytic manganese dioxide, superconductive carbon black and carbon fibers, baking at the high temperature of 350 DEG C for 12 hours, naturally cooling to 60 DEG C, and keeping the constant temperature for later use; s2, sequentially adding a binder, deionized water, a carbon nanotube and a sulfur-carbon composite material into stirring equipment, and stirring; adding the materials for later use, continuously stirring, and sieving the slurry for later use; s3, uniformly coating two surfaces of a carbon aluminum foil with the positive electrode slurry, carrying out vacuum drying on a coated pole piece at 65 DEG C for 16 hours, and carrying out rolling and punching to prepare a multi-component composite positive electrode; the raw materials are evenly mixed through the stirring paddle, then the evenly mixed raw materials are discharged, in the discharging process, filtering and screening are conducted through the first filter plate and the second filter plate, large particles are filtered through the first filter plate, small particles are filtered through the second filter plate, and finally the fine and smooth raw materials are obtained.

Description

Technical Field

[0001] The present invention belongs to the technical field of chemical power sources, and specifically relates to a method for preparing a lithium battery multi-component composite positive electrode. Background Art

[0002] As a branch of chemical power sources, primary lithium batteries have become important supporting components or systems for various modern electronic information and national defense equipment due to their excellent performance, especially in the fields of portable information equipment such as communication facilities, aircraft, life-saving equipment, and underwater vehicles. These equipments all require batteries with high specific energy, good safety, and long storage life to provide power. Currently, the commercialized batteries have problems such as poor performance uniformity, low specific energy, and safety that cannot meet the usage requirements. Making primary lithium batteries with multi-component composite positive electrodes has advantages such as high specific energy, good safety performance, and long storage life, meeting the requirements for the performance and safety of power sources in various fields.

[0003] A Chinese patent with the publication number CN209438483U discloses a lithium battery positive electrode material preparation device, including: a bottom plate; a first box body fixed on the top of the bottom plate; a second box body fixed on the top of the first box body; a fixing plate fixed on the top of the second box body; a first motor fixed on the front of the fixing plate through a connecting block; a vertical plate fixed on the top of the second box body; storage boxes are fixedly connected to both sides of the top of the bottom plate; this device can quickly and fully clean the raw materials after production, so there is no need for manual cleaning, which reduces the burden on the staff, saves time, improves the efficiency of preparing lithium battery positive electrode materials, and also saves raw materials and reduces the cost of preparing lithium battery positive electrode materials.

[0004] In the prior art, the stirred raw materials are directly stored in the storage box, but neither the second box body nor the storage box has a sieving function, and sieving cannot be carried out during stirring or storage. The raw materials for making the positive electrode sheet include large particle impurities and cannot be sieved. Direct coating will cause impurities on the surface of the positive electrode sheet and poor quality.

[0005] Therefore, the present invention provides a method for preparing a lithium battery multi-component composite positive electrode. Summary of the Invention

[0006] In order to make up for the deficiencies of the prior art and solve at least one of the technical problems proposed in the background art.

[0007] The technical solution adopted by the present invention to solve its technical problems is: A method for preparing a lithium battery multi-component composite positive electrode according to the present invention includes the following steps:

[0008] S1: After high-speed ball milling and sieving carbon fluoride, electrolytic manganese dioxide, superconducting carbon black, and carbon fiber, bake them at a high temperature of 350°C to 420°C for 12h to 16h, and then naturally cool to 60°C for constant temperature use.

[0009] S2: Add the binder, deionized water, carbon nanotubes, and sulfur-carbon composite material to the stirring equipment in sequence and stir; then add the above-mentioned materials for standby, continue to stir, and sieve the slurry for standby.

[0010] S3: Evenly coat both sides of the carbon-coated aluminum foil with the positive electrode slurry, and vacuum dry the coated electrode at 65°C for 16h to 24h, and then roll and punch to produce a multi-component composite positive electrode.

[0011] Preferably, the multi-component composite positive electrode material is composed of the following raw materials in parts by weight:

[0012] Carbon fluoride: 38 - 45;

[0013] Manganese dioxide: 5 - 8;

[0014] Sulfur-carbon composite: 38 - 45;

[0015] Superconducting carbon black: 3 - 5;

[0016] Carbon fiber: 0.5 - 1;

[0017] Binder: 4 - 6;

[0018] Carbon nanotubes: 0.5 - 1.

[0019] Preferably, the carbon fluoride uses a high-voltage energy type carbon fluoride with a fluorine content of ≥59%; the sulfur-carbon composite material uses a nano-micro structure with a sulfur content of ≥90%.

[0020] Preferably, the stirring equipment includes a stirring cylinder, and a feeding hopper is fixedly connected to the inner wall of the stirring cylinder; a first rotating rod is arranged above the feeding hopper, and the first rotating rod is rotatably connected to the top of the stirring cylinder through a bearing; a first motor is arranged at the top of the first rotating rod; a plurality of stirring paddles are fixedly connected to the first rotating rod; a first filter plate and a second filter plate are arranged below the feeding hopper, and both the first filter plate and the second filter plate are fixedly connected to the inner wall of the stirring cylinder; a second rotating rod is rotatably connected to the middle of the first filter plate and the second filter plate through a bearing, and three pushing plates are fixedly connected to the outer side of the second rotating rod, and the bottom parts of the pushing plates are respectively in contact with the surfaces of the first filter plate and the second filter plate; the filter holes of the first filter plate are larger than those of the second filter plate; a connecting mechanism is arranged between the first rotating rod and the second rotating rod.

[0021] Preferably, the connecting mechanism includes two connecting rods fixedly connected to the bottom of the first rotating rod, the bottom of the lower hopper is rotatably connected to a connecting pipe, the bottoms of the connecting rods are fixedly connected to the inner wall of the connecting pipe, and a second solenoid valve is installed on the connecting pipe; two mounting brackets are symmetrically fixed to the side walls of the connecting pipe; the mounting brackets are slidably connected to sliding rods; the bottom of the sliding rods is slidably connected to a lifting bracket; a spring is provided on the outer side of the sliding rod, and the two ends of the spring are respectively fixed to the mounting bracket and the lifting bracket; three toggle rods are fixed to the bottom of the lifting bracket, and the toggle rods respectively cooperate with the three push plates above; a downward pressing mechanism is installed on the mounting bracket.

[0022] Preferably, the pressing mechanism includes second motors respectively fixed to the mounting frames, the output shafts of the second motors are respectively fixed to cam blocks, and the bottom ends of the cam blocks are in contact with the top of the lifting frame.

[0023] Preferably, two first scrapers are fixedly connected to the outer wall of the bottom end of the first rotating rod, and the first scrapers are in contact with the inner wall of the mixing drum and the inner wall of the lower hopper; a second scraper is fixedly connected to the bottom of the second rotating rod, and the second scraper is in contact with the inner wall of the bottom end of the mixing drum.

[0024] Preferably, the mixing drum is provided with two discharge ports, and the bottoms of the discharge ports respectively cooperate with the bottoms of the first filter plate and the second filter plate; a discharge drum is fixedly connected to the outer wall of the mixing drum; the discharge ports are all arranged in the discharge drum; the top of the discharge drum is rotatably connected to a reciprocating screw; a connecting plate is threadedly connected to the reciprocating screw, a baffle is fixedly connected to the inner wall of the connecting plate, the baffle is slidably connected to the inside of the mixing drum, a through opening is provided on the baffle, and the through opening cooperates with the discharge port; a top plate is fixedly connected to the outer wall of the mixing drum, a third motor is fixedly connected to the top plate, and the output shaft of the third motor is fixedly connected to the top of the reciprocating screw; two guide rods are fixedly connected between the top plate and the discharge drum, and the connecting plate is slidably connected to the two guide rods.

[0025] Preferably, a heating cylinder is fixedly connected to the outer side of the top end of the mixing cylinder, and a plurality of heating rods are installed between the heating cylinder and the mixing cylinder.

[0026] Preferably, the top of the mixing drum is connected and fixedly connected to a feed hopper, and a control valve is installed on the feed hopper; and the bottom end of the mixing drum is installed with a first solenoid valve.

[0027] The beneficial effects of the present invention are as follows:

[0028] 1. The method for preparing a multi-component composite positive electrode for a lithium battery described in the present invention comprises the following steps: a connecting mechanism is provided, wherein the first rotating rod drives the connecting rod to rotate during the rotation process, and the connecting rod drives the connecting pipe, the sliding rod, the lifting frame and the toggle rod to rotate; the second motor drives the cam block to rotate, and the long semi-axis of the cam block contacts the top of the lifting frame, and the lifting frame slides to the bottom end of the connecting pipe; the toggle rod drives the push plate to rotate, and the push plate drives the raw materials to be filtered on the first filter plate and the second filter plate, thereby improving the filtration efficiency.

[0029] 2. The method for preparing a multi-component composite positive electrode for a lithium battery described in the present invention sets a baffle, turns on a third motor to rotate the reciprocating screw, drives the connecting plate to move upward through the reciprocating screw, and drives the baffle to move upward through the connecting plate until the through port is aligned with the upper discharge port, stops moving, and then drives the push plate to drive the impurities on the first filter plate and the second filter plate to centrifugal movement, and finally the impurities are cleaned through the discharge port and the discharge barrel, thereby realizing the cleaning function of the particulate impurities.

[0030] 3. The method for preparing a multi-component composite positive electrode for a lithium battery described in the present invention optimizes and determines the material ratio and process parameters by borrowing testing methods such as XRD method, electron microscope scanning, and polarization curve, and adopts a water-based coating process to prepare a thin multi-component composite electrode, thereby increasing the electrode reaction area, reducing the polarization internal resistance and ohmic internal resistance, improving the material utilization rate and rate characteristics, and being capable of large-scale continuous production with high efficiency and good consistency. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present invention will be further described below with reference to the accompanying drawings.

[0032] Figure 1 is a flow chart of the method of the present invention;

[0033] Figure 2 It is a perspective view of the present invention;

[0034] Figure 3 It is a cross-sectional view of the present invention;

[0035] Figure 4 This is a schematic structural diagram of the first rotating rod and the second rotating rod in the present invention;

[0036] Figure 5 It is a structural schematic diagram of the cam block in the present invention;

[0037] Figure 6 It is a structural schematic diagram of the lifting frame of the present invention;

[0038] Figure 7 It is a structural schematic diagram of the baffle in the present invention;

[0039] In the figure: 1, mixing drum; 2, heating drum; 21, heating rod; 3, feeding hopper; 31, control valve; 4, first motor; 41, first rotating rod; 42, mixing paddle; 43, first scraper; 44, discharging hopper; 45, connecting pipe; 451, lifting frame; 452, toggling rod; 453, mounting frame; 454, connecting rod; 455, sliding rod; 456, spring; 457, cam block; 458, second motor; 46, second rotating rod; 461, pushing plate; 462, first filter plate; 463, second filter plate; 464, second scraper; 47, first solenoid valve; 48, second solenoid valve; 5, discharging cylinder; 51, connecting plate; 52, top plate; 53, third motor; 54, reciprocating lead screw; 55, baffle; 56, through port; 57, discharging port; 58, guide rod. Detailed implementation manners

[0040] In order to make the technical means, creative features, achieved purposes and functions of the present invention easy to understand, the present invention will be further described below in conjunction with specific implementation manners.

[0041] Embodiment 1:

[0042] As Figure 1 shown, a method for preparing a lithium battery multi-component composite positive electrode according to an embodiment of the present invention includes the following steps:

[0043] S1: After high-speed ball milling and sieving carbon fluoride, electrolytic manganese dioxide, superconducting carbon black, and carbon fiber, bake at 350 °C for 12 h, and naturally cool to 60 °C for constant temperature use;

[0044] S2: Add the binder, deionized water, carbon nanotubes, and sulfur-carbon composite material to the mixing equipment in sequence and stir; then add the above-mentioned materials for standby, continue to stir, and sieve the slurry for standby;

[0045] S3: Coat both sides of the positive electrode slurry evenly on the carbon-coated aluminum foil, and vacuum dry the coated electrode sheet at 65 °C for 16 h, and roll and punch to produce a multi-component composite positive electrode.

[0046] The multi-component composite positive electrode material is composed of the following raw materials in parts by weight:

[0047] Carbon fluoride: 38;

[0048] Manganese dioxide: 5;

[0049] Sulfur-carbon composite: 38;

[0050] Superconducting carbon black: 3;

[0051] Carbon fiber: 0.5;

[0052] Binder: 4;

[0053] Carbon nanotubes: 0.5.

[0054] Example 2:

[0055] As Figure 1 shown, a method for preparing a lithium battery multi-component composite cathode according to an embodiment of the present invention includes the following steps:

[0056] S1: After high-speed ball milling and sieving carbon fluoride, electrolytic manganese dioxide, superconducting carbon black, and carbon fiber, bake at 385 °C for 14 h, cool naturally to 60 °C, and keep at a constant temperature for use;

[0057] S2: Add the binder, deionized water, carbon nanotubes, and sulfur-carbon composite material to the stirring equipment in sequence and stir; then add the above-mentioned materials for use, continue to stir, and sieve the slurry for use;

[0058] S3: Coat both sides of the carbon-coated aluminum foil evenly with the positive electrode slurry, vacuum dry the coated electrode sheet at 65 °C for 20 h, and roll and punch to produce a multi-component composite cathode.

[0059] The multi-component composite cathode material is composed of the following raw materials in parts by weight:

[0060] Carbon fluoride: 41.5;

[0061] Manganese dioxide: 6.5;

[0062] Sulfur-carbon composite: 41.5;

[0063] Superconducting carbon black: 4;

[0064] Carbon fiber: 0.75;

[0065] Binder: 5;

[0066] Carbon nanotubes: 0.75.

[0067] Example 3:

[0068] As Figure 1 shown, a method for preparing a lithium battery multi-component composite cathode according to an embodiment of the present invention includes the following steps:

[0069] S1: After high-speed ball milling and sieving carbon fluoride, electrolytic manganese dioxide, superconducting carbon black, and carbon fiber, bake at 420 °C for 16 h, cool naturally to 60 °C, and keep at a constant temperature for use;

[0070] S2: Add the binder, deionized water, carbon nanotubes, and sulfur-carbon composite material to the stirring equipment in sequence and stir; then add the above-mentioned materials for use, continue to stir, and sieve the slurry for use;

[0071] S3: Coat both sides of the carbon-coated aluminum foil evenly with the positive electrode slurry, vacuum dry the coated electrode sheet at 65 °C for 24 h, and roll and punch to produce a multi-component composite cathode.

[0072] The multi-component composite cathode material is composed of the following raw materials in parts by weight:

[0073] Carbon fluoride: 45;

[0074] Manganese dioxide: 8;

[0075] Sulfur-carbon composite: 45;

[0076] Superconducting carbon black: 5;

[0077] Carbon fiber: 1;

[0078] Binder: 6;

[0079] Carbon nanotubes: 1.

[0080] For the batteries prepared according to the above three embodiments, constant current discharge at 1.6 A is carried out until 1.5 V, and the battery capacity is calculated.

[0081] Battery capacity (Ah) Example 1 7 Example 2 9 Example 3 8

[0082] Taking carbon fluoride: electrolytic manganese dioxide: sulfur-carbon composite material: superconducting carbon black: carbon fiber: binder: carbon nanotubes = 50:8:30:4:0.75:5.5:0.75 as an example for preparation:

[0083] Put carbon fluoride, electrolytic manganese dioxide, superconducting carbon black, and carbon fiber into a ball milling tank in a certain proportion, carry out high-speed ball milling for 5 h, screen, bake at a constant temperature of 390 °C for 12 h, and then naturally cool to 60 °C for standby;

[0084] According to the proportion, stir the water-based binder LA139 and deionized water at a low speed for 10 min to 15 min; sequentially add carbon nanotubes and stir at a medium speed for 45 min to 60 min, add sulfur-carbon composite material and stir at a medium speed for 45 min to 60 min, add the heat-treated materials to be used and stir at a high speed for 6 h to 8 h; stir at a low speed of 300 - 1000 rpm, at a medium speed of 1000 - 2500 rpm, and at a high speed of 2500 - 4000 rpm; stir the slurry evenly, scan with an electron microscope, screen through 150 meshes, and then carry out processes such as coating, drying, rolling, and punching; rolling thickness: 0.32 - 0.35 mm, surface density: 35 - 40 (mg / cm 2 ), and the size of the punched pole piece: 78×50 mm.

[0085] By borrowing testing methods such as XRD method, electron microscope scanning, and polarization curve, optimize and determine the material ratio and process parameters, adopt the water-based coating process to prepare a thin multi-component composite electrode, increase the electrode reaction area, reduce the polarization internal resistance and ohmic internal resistance, improve the material utilization rate and rate performance, and can be continuously produced on a large scale with high efficiency and good consistency.

[0086] As Figure 1 shown, the carbon fluoride used is a high-voltage energy type carbon fluoride, where the fluorine content is ≥59%; the sulfur-carbon composite material adopts a nano-micro structure, where the sulfur content is ≥90%.

[0087] In the present invention, the carbon fluoride used is a high-voltage energy type carbon fluoride, which improves the specific capacity of the positive electrode material through its high-voltage characteristics. At the same time, the high fluorine content ensures the cycle stability and reduces side reactions, where the fluorine content is ≥59%, ensuring a high degree of fluorination of the material, thereby improving the capacity and stability;

[0088] The sulfur-carbon composite material adopts a nano-micro structure, that is, a nano or micro-level composite structure. While ensuring a high sulfur loading, it uses the carbon skeleton to suppress the defects of sulfur and improve the overall performance of the composite positive electrode; where the sulfur content is ≥90%, indicating that sulfur is the active main body, and the carbon skeleton mainly plays a role in conduction and buffering.

[0089] As Figures 2 to 4 shown, the stirring device includes a stirring cylinder 1, and a feeding hopper 44 is fixedly connected to the inner wall of the stirring cylinder 1; a first rotating rod 41 is arranged above the feeding hopper 44, and the first rotating rod 41 is rotatably connected to the top of the stirring cylinder 1 through a bearing; a first motor 4 is arranged at the top of the first rotating rod 41; a plurality of stirring paddles 42 are fixedly connected to the first rotating rod 41; a first filter plate 462 and a second filter plate 463 are arranged below the feeding hopper 44, and both the first filter plate 462 and the second filter plate 463 are fixedly connected to the inner wall of the stirring cylinder 1; a second rotating rod 46 is rotatably connected to the middle of the first filter plate 462 and the second filter plate 463 through a bearing, and three pushing plates 461 are fixedly connected to the outer side of the second rotating rod 46, and the bottoms of the pushing plates 461 are respectively in contact with the surfaces of the first filter plate 462 and the second filter plate 463; the filter holes of the first filter plate 462 are larger than those of the second filter plate 463; a connecting mechanism is arranged between the first rotating rod 41 and the second rotating rod 46.

[0090] When the stirring equipment provided by the present invention is in use, first, carbon fluoride, manganese dioxide, superconducting carbon black, and carbon fiber are ball-milled and mixed in proportion for 4h - 6h, sieved, baked at 350°C - 420°C for 12h - 16h, and then naturally cooled to 60°C for standby; then, a binder, deionized water, carbon nanotubes, and a sulfur-carbon composite material are added in proportion in sequence, stirred to form a sulfur-carbon slurry, and then the above-mentioned heat-treated materials to be used are added in proportion and stirred. During the stirring process, by starting the first motor 4, the first motor 4 drives the first rotating rod 41 to rotate through the output shaft, the first rotating rod 41 drives the stirring paddle 42 to rotate, and the raw materials are evenly mixed by the stirring paddle 42. Then, the evenly mixed raw materials are fed. During the feeding process, filtering and screening are carried out through the first filter plate 462 and the second filter plate 463. Larger particles are filtered through the first filter plate 462, and smaller particles are filtered through the second filter plate 463, and finally, delicate raw materials are obtained; wherein the first rotating rod 41 drives the push plate 461 to rotate through the connecting mechanism, and the raw materials are driven by the push plate 461 to be filtered on the first filter plate 462 and the second filter plate 463, improving the filtering efficiency and preventing the first filter plate 462 and the second filter plate 463 from being blocked by particulate impurities.

[0091] As Figures 4 to 6 shown, the connecting mechanism includes two connecting rods 454 fixedly connected to the bottom of the first rotating rod 41. The bottom of the feeding hopper 44 is rotatably connected with a communicating pipe 45. The bottoms of the connecting rods 454 are fixedly connected to the inner wall of the communicating pipe 45. A second solenoid valve 48 is installed on the communicating pipe 45; two mounting brackets 453 are symmetrically and fixedly connected to the side wall of the communicating pipe 45; a sliding rod 455 is slidably connected to each of the mounting brackets 453; the bottom of the sliding rod 455 is slidably connected to a lifting frame 451; a spring 456 is sleeved on the outer side of the sliding rod 455, and the two ends of the spring 456 are fixedly connected to the mounting bracket 453 and the lifting frame 451 respectively; three toggle rods 452 are fixedly connected to the bottom of the lifting frame 451, and the toggle rods 452 cooperate with the three push plates 461 above respectively; a pressing mechanism is installed on the mounting bracket 453.

[0092] When the first rotating rod 451 is in operation, the first rotating rod 454 drives the connecting rod 454 to rotate, and the connecting rod 454 drives the connecting pipe 45 to rotate, and the connecting pipe 45 drives the sliding rod 455 to rotate, and the sliding rod 455 drives the lifting frame 451 and the toggle rod 452 to rotate.

[0093] like Figure 5 and Figure 6 As shown, the pressing mechanism includes second motors 458 respectively fixed on the mounting brackets 453 , and the output shafts of the second motors 458 are fixed with cam blocks 457 , and the bottom ends of the cam blocks 457 are in contact with the top of the lifting bracket 451 .

[0094] When the cam block 457 provided by the present invention is in use and the lifting frame 451 needs to be moved, the second motor 458 is turned on, and the output shaft of the second motor 458 drives the cam block 457 to rotate, and the long semi-axis of the cam block 457 contacts the top of the lifting frame 451, and the lifting frame 451 slides to the bottom end of the connecting pipe 45; when the short semi-axis of the cam block 457 contacts the top of the lifting frame 451, under the action of the spring 456, the lifting frame 451 slides away from the bottom end of the connecting pipe 45, thereby realizing the function of quickly adjusting the height of the lifting frame 451.

[0095] like Figure 4 As shown, two first scrapers 43 are fixedly connected to the outer wall of the bottom end of the first rotating rod 41, and the first scrapers 43 are in contact with the inner wall of the mixing drum 1 and the inner wall of the lower hopper 44; a second scraper 464 is fixedly connected to the bottom of the second rotating rod 46, and the second scraper 464 is in contact with the inner wall of the bottom end of the mixing drum 1.

[0096] The first scraper 43 and the second scraper 464 provided by the present invention are used to clean the inner wall of the mixing drum 1 when in use. The first scraper 43 is driven to rotate by the first rotating rod 41, and the first scraper 43 is in contact with the inner walls of the mixing drum 1 and the lower hopper 44, which is convenient for cleaning the mixing drum 1 and the lower hopper 44; the second scraper 464 is driven to rotate by the second rotating rod 46, and the second scraper 464 is in contact with the inner wall of the mixing drum 1, which is convenient for cleaning the mixing drum 1 and preventing the slurry from adhering to the inner wall of the mixing drum 1, causing waste of slurry.

[0097] likeFigure 1 , Figure 3 and Figure 7 As shown in Figure 7 , two discharge ports 57 are provided on the mixing drum 1, and the bottoms of the discharge ports 57 are respectively matched with the bottoms of the first filter plate 462 and the second filter plate 463; a discharge cylinder 5 is fixedly connected to the outer wall of the mixing drum 1; the discharge ports 57 are both arranged in the discharge cylinder 5; a reciprocating lead screw 54 is rotatably connected to the top of the discharge cylinder 5; a connecting plate 51 is threadedly connected to the reciprocating lead screw 54, a baffle 55 is fixedly connected to the inner wall of the connecting plate 51, the baffle 55 is slidably connected inside the mixing drum 1, a through port 56 is provided on the baffle 55, and the through port 56 is matched with the discharge port 57; a top plate 52 is fixedly connected to the outer wall of the mixing drum 1, a third motor 53 is fixedly connected to the top plate 52, and the output shaft of the third motor 53 is fixedly connected to the top of the reciprocating lead screw 54; two guide rods 58 are fixedly connected between the top plate 52 and the discharge cylinder 5, and the connecting plate 51 is slidably connected to the two guide rods 58.

[0098] The reciprocating lead screw 54 provided by the present invention is used to lift the baffle 55 during use. During sieving, the baffle 55 blocks the discharge port 57 to prevent raw materials from splashing; when it is necessary to clean the particulate impurities on the first filter plate 462 and the second filter plate 463, by turning on the third motor 53, the output shaft of the third motor 53 drives the reciprocating lead screw 54 to rotate, the connecting plate 51 is driven by the reciprocating lead screw 54 to move upward, the baffle 55 is driven by the connecting plate 51 to move upward, until the through port 56 is aligned with the upper discharge port 57, stop the movement, and then drive the push plate 461 to rotate, the impurities on the first filter plate 462 and the second filter plate 463 are driven to move centrifugally by the push plate 461, and finally the impurities are cleaned through the discharge port 57 and the discharge cylinder 5, realizing the cleaning function of the particulate impurities.

[0099] As Figure 3 shown in Figure 3 , a heating cylinder 2 is fixedly connected to the outer side of the top end of the mixing drum 1, and a plurality of heating rods 21 are installed between the heating cylinder 2 and the mixing drum 1.

[0100] By providing the heating cylinder 2 and the heating rods 21 for heating the mixing drum 1, the temperature is rapidly increased through heat conduction, and the crystallinity, particle size distribution and interfacial bonding performance of the material are affected through temperature control.

[0101] As Figure 3 shown in Figure 3 , a feed hopper 3 is fixedly connected and communicated with the top of the mixing drum 1, and a control valve 31 is installed on the feed hopper 3; a first solenoid valve 47 is installed at the bottom end of the mixing drum 1.

[0102] Raw materials enter through the feed hopper 3. When the raw materials enter, it is necessary to turn on the control valve 31 and then carry out stirring; after the stirring and filtering are completed, when it is necessary to discharge the materials, by turning on the first solenoid valve 47, the filtered raw materials can be discharged.

[0103] Working principle: During the preparation, first put carbon fluoride, electrolytic manganese dioxide, superconducting carbon black and carbon fiber into a ball mill according to a certain proportion, mill them at high speed for 5 hours, sieve them, bake them at a constant temperature of 390℃ for 12 hours, cool them naturally to 60℃ and set them aside; then add water-based adhesive LA139 and deionized water in proportion, stir them at low speed for 10min~15min; add carbon nanotubes in turn, stir them at medium speed for 45min~60min, add sulfur-carbon composite materials, stir them at medium speed for 45min~60min min, add the heat-treated materials to be used and stir at medium-high speed for 6-8 hours; stir at low speed of 300-1000 rpm, medium speed of 1000-2500 rpm, and high speed of 2500-4000 rpm; the slurry is stirred evenly, scanned by electron microscopy, and sieved through a 150-mesh screen before coating, drying, rolling, and punching. The rolling thickness is 0.32-0.35mm, the surface density is 35-40 (mg / cm²), and the electrode punching size is 78×50mm. By using XRD, electron microscopy, polarization curve testing methods, and other testing methods, the material ratio and process parameters are optimized. A water-based coating process is used to prepare thin multi-component composite electrodes, which increase the electrode reaction area, reduce the polarization internal resistance and ohmic internal resistance, improve material utilization and rate characteristics, and can be produced on a large scale and continuously with high efficiency and good consistency.

[0104] During the stirring process, by turning on the first motor 4, the first motor 4 drives the first rotating rod 41 to rotate through the output shaft, and drives the stirring paddle 42 to rotate through the first rotating rod 41, and the raw materials are mixed evenly through the stirring paddle 42, and then the evenly mixed raw materials are discharged. During the discharge process, filtering and screening are performed through the first filter plate 462 and the second filter plate 463, and larger particles are filtered through the first filter plate 462, and small particles are filtered through the second filter plate 463, so that fine raw materials are finally obtained; the first rotating rod 41 drives the connecting rod 454 to rotate during the rotation process, and drives the connecting pipe 45 to rotate through the connecting rod 454, drives the sliding rod 455 to rotate through the connecting pipe 45, and drives the lifting frame 451 and the toggle rod 452 to rotate through the sliding rod 455. By turning on the second motor 458, the output shaft of the second motor 458 drives the cam block 457 to rotate, and the long semi-axis of the cam block 457 contacts the top of the lifting frame 451, and the lifting frame 451 slides to the bottom end of the connecting pipe 45; the push plate 461 is driven to rotate by the toggle rod 452, and the raw materials are driven to be filtered on the first filter plate 462 and the second filter plate 463 through the push plate 461, thereby improving the filtration efficiency and preventing the first filter plate 462 and the second filter plate 463 from being blocked by particulate impurities; when the short semi-axis of the cam block 457 contacts the top of the lifting frame 451, under the action of the spring 456, the lifting frame 451 slides away from the bottom end of the connecting pipe 45, thereby reducing the friction between the push plate 461 and the first filter plate 462 and the second filter plate 463;

[0105] During sieving, the baffle 55 blocks the discharge port 57 to prevent the raw materials from splashing out; when it is necessary to clean the particulate impurities on the first filter plate 462 and the second filter plate 463, the third motor 53 is turned on, the output shaft of the third motor 53 drives the reciprocating lead screw 54 to rotate, the reciprocating lead screw 54 drives the connecting plate 51 to move upward, the connecting plate 51 drives the baffle 55 to move upward until the through port 56 is aligned with the upper discharge port 57, then the movement stops, and then the push plate 461 is driven to rotate. The impurities on the first filter plate 462 and the second filter plate 463 are centrifugally moved by the push plate 461, and finally the impurities are cleaned through the discharge port 57 and the discharge cylinder 5, realizing the cleaning function of the particulate impurities.

[0106] The foregoing has shown and described the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments, and what is described in the above embodiments and the specification is only to illustrate the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A preparation method for a lithium battery multi-component composite cathode, characterized in that: It includes the following steps: S1: After high-speed ball milling and sieving carbon fluoride, electrolytic manganese dioxide, superconducting carbon black, and carbon fiber, bake them at a high temperature of 350°C to 420°C for 12h to 16h, and naturally cool to 60°C for constant temperature use; S2: Add the binder, deionized water, carbon nanotubes, and sulfur-carbon composite material to the stirring equipment in sequence and stir; then add the above-mentioned materials for standby, continue to stir, and sieve the slurry for standby; S3: Uniformly coat the two sides of the carbon-coated aluminum foil with the positive electrode slurry, and vacuum dry the coated electrode sheet at 65°C for 16h to 24h, and roll and punch to produce a multi-component composite positive electrode.

2. The preparation method of a lithium battery multi-component composite cathode according to claim 1, characterized in that: The multi-component composite positive electrode material is composed of the following raw materials in parts by weight: Carbon fluoride: 38 - 45; Manganese dioxide: 5 - 8; Sulfur-carbon composite: 38 - 45; Superconducting carbon black: 3 - 5; Carbon fiber: 0.5 - 1; Binder: 4 - 6; Carbon nanotubes: 0.5 - 1.

3. A method for preparing a lithium battery multi-component composite cathode according to claim 2, characterized in that: The carbon fluoride uses high-voltage energy-type carbon fluoride, in which the fluorine content is ≥59%; the sulfur-carbon composite material uses a nano-micro structure, in which the sulfur content is ≥90%.

4. A method for preparing a lithium battery multi-component composite cathode according to claim 3, characterized in that: The stirring equipment includes a stirring cylinder (1), and a feeding hopper (44) is fixedly connected to the inner wall of the stirring cylinder (1); a first rotating rod (41) is arranged above the feeding hopper (44), and the first rotating rod (41) is rotatably connected to the top of the stirring cylinder (1) through a bearing; a first motor (4) is arranged at the top of the first rotating rod (41); a plurality of stirring paddles (42) are fixedly connected to the first rotating rod (41); a first filter plate (462) and a second filter plate (463) are arranged below the feeding hopper (44), and both the first filter plate (462) and the second filter plate (463) are fixedly connected to the inner wall of the stirring cylinder (1); a second rotating rod (46) is rotatably connected to the middle of the first filter plate (462) and the second filter plate (463) through a bearing, and three pushing plates (461) are fixedly connected to the outer side of the second rotating rod (46), and the bottom parts of the pushing plates (461) are respectively in contact with the surfaces of the first filter plate (462) and the second filter plate (463); the filter holes of the first filter plate (462) are larger than those of the second filter plate (463); a connecting mechanism is arranged between the first rotating rod (41) and the second rotating rod (46).

5. A method for preparing a lithium battery multi-component composite cathode according to claim 4, characterized in that: The connecting mechanism includes two connecting rods (454) fixedly connected to the bottom of the first rotating rod (41). The bottom of the feeding hopper (44) is rotatably connected to a communicating pipe (45). The bottoms of the connecting rods (454) are fixedly connected to the inner wall of the communicating pipe (45). A second solenoid valve (48) is installed on the communicating pipe (45). Symmetrically, two mounting brackets (453) are fixedly connected to the side wall of the communicating pipe (45). A sliding rod (455) is slidably connected to each of the mounting brackets (453). The bottom of the sliding rod (455) is slidably connected to a lifting bracket (451). A spring (456) is sleeved on the outer side of the sliding rod (455). The two ends of the spring (456) are fixedly connected to the mounting bracket (453) and the lifting bracket (451) respectively. Three toggling rods (452) are fixedly connected to the bottom of the lifting bracket (451), and the toggling rods (452) cooperate with the three upper push plates (461) respectively. A pressing mechanism is installed on the mounting bracket (453).

6. The preparation method of a lithium battery multi-component composite cathode according to claim 5, characterized in that: The pressing mechanism includes a second motor (458) fixedly connected to the mounting bracket (453). The output shafts of the second motors (458) are fixedly connected with cam blocks (457), and the bottom ends of the cam blocks (457) are in contact with the top of the lifting bracket (451).

7. A method for preparing a lithium battery multi-component composite cathode according to claim 6, characterized in that: Two first scraping plates (43) are fixedly connected to the outer wall of the bottom end of the first rotating rod (41). The first scraping plates (43) are in contact with the inner wall of the mixing barrel (1) and the inner wall of the feeding hopper (44). A second scraping plate (464) is fixedly connected to the bottom of the second rotating rod (46). The second scraping plate (464) is in contact with the bottom inner wall of the mixing barrel (1).

8. A method for preparing a lithium battery multi-component composite cathode according to claim 7, characterized in that: Two discharge ports (57) are formed in the mixing barrel (1). The bottoms of the discharge ports (57) are respectively in cooperation with the bottoms of the first filter plate (462) and the second filter plate (463). A discharge barrel (5) is fixedly connected to the outer wall of the mixing barrel (1). The discharge ports (57) are both arranged in the discharge barrel (5). A reciprocating lead screw (54) is rotatably connected to the top of the discharge barrel (5). A connecting plate (51) is threadedly connected to the reciprocating lead screw (54). A baffle (55) is fixedly connected to the inner wall of the connecting plate (51). The baffle (55) is slidably connected inside the mixing barrel (1). A through port (56) is formed in the baffle (55), and the through port (56) cooperates with the discharge port (57). A top plate (52) is fixedly connected to the outer wall of the mixing barrel (1). A third motor (53) is fixedly connected to the top plate (52). The output shaft of the third motor (53) is fixedly connected to the top of the reciprocating lead screw (54). Two guide rods (58) are fixedly connected between the top plate (52) and the discharge barrel (5). The connecting plate (51) is slidably connected to the two guide rods (58).

9. A method for preparing a lithium battery multi-component composite cathode according to claim 8, characterized in that: A heating barrel (2) is fixedly connected to the outer side of the top end of the mixing barrel (1). A plurality of heating rods (21) are installed between the heating barrel (2) and the mixing barrel (1).

10. A method for preparing a lithium battery multi-component composite cathode according to claim 9, characterized in that: The top of the mixing drum (1) is connected and fixedly attached with a feeding hopper (3), and a control valve (31) is installed on the feeding hopper (3); a first electromagnetic valve (47) is installed at the bottom end of the mixing drum (1).

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