A continuous pipeline mixing method and apparatus for preparing lithium battery cathode materials

Abstract

This invention discloses a continuous pipeline mixing method and apparatus for preparing lithium-ion battery cathode materials, comprising the following steps: S1 Batching: Using a precision batching device, various cathode material raw material powders stored in a silo are batched according to a certain ratio. After batching, the cathode material raw materials enter a buffer silo for later use; S2 Feeding: The mass flow rate of the cathode material raw materials unloaded from the buffer silo is precisely controlled by a precision feeding device to ensure uniform and stable feeding; S3 Pneumatic circulation conveying and mixing: Using a blower to generate pneumatic force, under positive pressure conveying or negative pressure suction conveying, the material in the buffer silo enters the mixing pipeline, and the material flows into a multi-stage collision mixing device, undergoing multiple collision mixing until the mixing is completed; S4 Unloading: After the multi-stage mixing is completed, the cathode material raw materials are unloaded by positive pressure conveying or negative pressure suction conveying through the pipeline. Compared with the prior art, this invention can achieve efficient mixing of powders.

Description

Technical Field

[0001] This invention relates to a method for mixing powders, and particularly to a continuous pipeline mixing method and apparatus for preparing lithium battery cathode materials. Background Technology

[0002] Ternary cathode materials are a component of lithium batteries, and their quality directly affects the performance and safety of lithium battery products. Mixing is a crucial step in the production of ternary cathode materials; the mixing efficiency and performance determine the quality of the cathode material.

[0003] Currently, most ternary cathode material mixing processes employ mechanical dry mixing, relying on high-speed moving mechanical parts to shear and mix the cathode material powder. This often results in poor uniformity of the mixed ternary cathode material powder, powder agglomeration, and magnetic impurity contamination. Furthermore, mechanical mixing is mostly batch mixing, unable to perform continuous operations, and cannot achieve precise control over material concentration and speed, thus failing to meet the mixing requirements of ternary cathode materials under complex conditions.

[0004] Existing pipeline mixers have complex internal structures, are difficult to manufacture, and have high manufacturing costs. Furthermore, when used for mixing powder materials, the wear and tear of particles on the pipeline mixer must be considered, resulting in low mixing efficiency.

[0005] In view of this, a continuous pipeline mixing method and apparatus for preparing lithium battery cathode materials is proposed. Summary of the Invention

[0006] The purpose of this invention is to provide a pipeline continuous mixing method and apparatus for preparing lithium battery cathode materials, which can achieve efficient mixing of powders.

[0007] The above-mentioned technical objective of the present invention is achieved through the following technical solution:

[0008] A continuous pipeline mixing method for preparing lithium-ion battery cathode materials includes the following steps:

[0009] S1 Batching: Through a precision batching device, various cathode material raw material powders stored in the silo are batched according to a certain ratio. After the batching is completed, the cathode material raw materials enter the buffer silo for later use.

[0010] S2 feeding: The mass flow rate of the cathode material unloaded from the buffer chamber is precisely controlled by a precision feeding device to ensure uniform and stable feeding;

[0011] S3 Pneumatic Circulation Conveying and Mixing: Using a blower to generate pneumatic force, under the action of positive pressure conveying or negative pressure suction conveying, the material in the buffer bin enters the mixing pipe, and the material flows into the multi-stage collision mixing equipment, where it undergoes multiple collisions and mixing until the mixing is completed.

[0012] S4 Unloading: After multi-stage mixing, the cathode material raw material is unloaded by positive pressure conveying or negative pressure suction conveying through pipeline;

[0013] The multi-stage collision mixing device includes at least two feed pipes, a first-stage mixing chamber, a first-stage mixing pipe, a second-stage mixing chamber, at least two second-stage mixing pipes, a third-stage mixing chamber, and a discharge pipe. One end of the feed pipe is connected to the first-stage mixing chamber via a corrugated hose. One end of the first-stage mixing pipe is connected to the first-stage mixing chamber via a corrugated hose, and the other end is connected to the second-stage mixing chamber via a corrugated hose. One end of the second-stage mixing pipe is connected to the second-stage mixing chamber via a corrugated hose, and the other end is connected to the third-stage mixing chamber via a corrugated hose. The discharge pipe is connected to the third-stage mixing chamber. Alternatively, one end of the feed pipe is connected to the first-stage mixing chamber via a ball joint. One end of the first-stage mixing pipe is connected to the first-stage mixing chamber via a ball joint, and the other end is connected to the second-stage mixing chamber via a ball joint. The second-stage mixing pipe is connected to the second-stage mixing chamber via a ball joint, and the other end is connected to the third-stage mixing chamber via a ball joint. The discharge pipe is connected to the third-stage mixing chamber.

[0014] In a preferred embodiment, the cathode material raw materials include ternary materials and lithium iron phosphate materials.

[0015] In a preferred embodiment, in step S1, the D50 of the cathode material raw material powder is set to 0.5-50 μm, and the cathode material raw material powder includes ternary materials and lithium iron phosphate materials.

[0016] In a preferred embodiment, the ternary material precursor is NCM or NCA.

[0017] In a preferred embodiment, the lithium iron phosphate material is prepared from one or more of lithium carbonate, lithium acetate, lithium phosphate, lithium dihydrogen phosphate, and lithium hydroxide.

[0018] In a preferred embodiment, in step S2, the pneumatic force is generated by the flow of air, nitrogen, argon, or nitrogen.

[0019] In a preferred embodiment, during step 3, the solid-to-gas ratio in the unloading pipe ranges from 10 to 25.

[0020] A continuous pipeline mixing device for preparing lithium-ion battery cathode materials, applied to the above-mentioned continuous pipeline mixing method for preparing lithium-ion battery cathode materials, includes a multi-stage collision mixing device. The multi-stage collision mixing device includes at least two feed pipes, a first-stage mixing chamber, a first-stage mixing pipe, a second-stage mixing chamber, at least two second-stage mixing pipes, a third-stage mixing chamber, and a discharge pipe. One end of the feed pipe is connected to the first-stage mixing chamber via a corrugated flexible hose, and one end of the first-stage mixing pipe is connected to the first-stage mixing chamber via a corrugated flexible hose, while the other end is connected to the second-stage mixing chamber via a corrugated flexible hose. One end of the second-stage mixing pipe is connected to the second-stage mixing chamber via a corrugated hose, and the other end is connected to the third-stage mixing chamber via a corrugated hose; the discharge pipe is connected to the third-stage mixing chamber; and / or, one end of the feed pipe is connected to the first-stage mixing chamber via a ball joint, one end of the first-stage mixing pipe is connected to the first-stage mixing chamber via a ball joint, and the other end is connected to the second-stage mixing chamber via a ball joint; the second-stage mixing pipe is connected to the second-stage mixing chamber via a ball joint, and the other end is connected to the third-stage mixing chamber via a ball joint; the discharge pipe is connected to the third-stage mixing chamber.

[0021] In a preferred embodiment, a vibration mixing device is provided between the bottom of the first-stage mixing chamber and the top of the second-stage mixing chamber.

[0022] In a preferred embodiment, the vibration mixing device includes a pneumatic motor, a first mounting plate, a second mounting plate, an upper top plate, a lower top plate, a cam, a spring, a bearing, and a fixed cover. The first mounting plate and the second mounting plate are installed in parallel. A sliding groove is provided on the opposite surfaces of the first mounting plate and the second mounting plate. The upper top plate and the lower top plate are mounted on the sliding groove. A spring is installed between the upper top plate and the lower top plate. The cam is also installed between the first mounting plate and the second mounting plate. The cam is also connected to the shaft of the pneumatic motor. A bearing is installed between the shaft of the pneumatic motor and the first mounting plate. The end of the shaft of the pneumatic motor is bolted to the fixed cover.

[0023] Compared with existing technologies, this invention provides a continuous pipeline mixing method and apparatus for preparing lithium-ion battery cathode materials. It utilizes gas to drive the cathode material raw materials through collision mixing within the pipeline, increasing the collision intensity and mixing efficiency between raw material particles. The mixing process offers high precision in material preparation, with adjustable material quantity and gas-solid flow velocity to meet the mixing requirements of various materials. Multi-stage collision mixing is employed, allowing for appropriate collision speeds and stages based on different materials, reducing system energy consumption while meeting mixing uniformity requirements. Key components are made of non-metallic materials, preventing contamination of the ternary material raw materials by metallic impurities during intense collisions. Dense-phase conveying is used during unloading to prevent segregation of the mixed material during unloading, which could reduce mixing uniformity. A vibratory mixing device is used to induce stronger reciprocating collisions between particles and the wall surface, increasing the number of collisions between the two cathode materials and improving mixing efficiency. The designed hinged structure can adapt to different spatial scenarios and facilitates installation. Attached Figure Description

[0024] Figure 1 This invention relates to a process flow diagram of a continuous pipeline mixing method for preparing lithium battery cathode materials.

[0025] Figure 2 This is a schematic diagram of the collision mixing device of Scheme 1, which is used in a continuous pipeline mixing method for preparing lithium battery cathode materials according to the present invention.

[0026] Figure 3 This is a front view of the collision mixing device used in a continuous pipeline mixing method for preparing lithium battery cathode materials, which is a structural front view of the present invention.

[0027] Figure 4 This invention relates to a structural schematic diagram of a vibration mixing device in a pipeline continuous mixing method for preparing lithium battery cathode materials, specifically a collision mixing apparatus.

[0028] Figure 5 This is a front cross-sectional view of a vibration mixing device in a pipeline continuous mixing method for preparing lithium battery cathode materials, which is an application of the present invention.

[0029] Figure 6 This is a side cross-sectional view of a vibration mixing device in a pipeline continuous mixing method for preparing lithium battery cathode materials, which is an application of the present invention.

[0030] Figure 7 This is a cross-sectional view of the first-stage mixing chamber of a collision mixing device used in a continuous pipeline mixing method for preparing lithium battery cathode materials, which is an invention of the present invention.

[0031] Figure 8This is a schematic diagram of the first-stage mixing chamber of a collision mixing device used in a continuous pipeline mixing method for preparing lithium battery cathode materials, which is an application of the present invention.

[0032] Figure 9 This is a front view of the structure of the articulated collision mixing device used in a continuous pipeline mixing method for preparing lithium battery cathode materials, which is a schematic diagram of the present invention.

[0033] Figure 10 This is a side view of the structure of the articulated collision mixing device used in a continuous pipeline mixing method for preparing lithium battery cathode materials, which is an application of the present invention.

[0034] Figure 11 This invention relates to a cross-sectional view of the first-stage mixing chamber of an articulated collision mixing device used in a continuous pipeline mixing method for preparing lithium battery cathode materials.

[0035] In the picture

[0036] 1. Feed pipe; 2. First-stage mixing chamber; 201. Guide boss; 202. Mixing chamber connector; 2.1. First-stage mixing chamber; 3. First-stage mixing pipe; 3.1. First-stage mixing pipe; 3.2. Ball joint mounting seat; 3.3. Sealing ring; 4. Second-stage mixing chamber 1; 4.1. Second-stage mixing chamber; 5. Second-stage mixing pipe; 5.1. Second-stage mixing pipe; 6. Third-stage mixing chamber; 6.1. Third-stage mixing chamber; 7. Discharge pipe; 8. Vibrating mixing device; 801. Pneumatic motor; 802. First mounting plate; 803. Second mounting plate; 804. Upper top plate; 805. Lower top plate; 806. Cam; 807. Spring; 808. Bearing; 809. Sleeve; 810. Fixing cover; 811. Shaft end retaining ring 1; 812. Shaft end retaining ring 2; 9. Corrugated hose; 10. Clamp. Detailed Implementation

[0037] The present invention will be further described in detail below with reference to the accompanying drawings.

[0038] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

[0039] like Figure 1 As shown, a continuous mixing method using a pipeline for preparing lithium-ion battery cathode materials includes the following steps:

[0040] S1 Batching: Through a precision batching device, various cathode material raw material powders stored in the silo are batched according to a certain ratio. After the batching is completed, the cathode material raw materials enter the buffer silo for later use.

[0041] S2 feeding: The mass flow rate of the cathode material unloaded from the buffer chamber is precisely controlled by a precision feeding device to ensure uniform and stable feeding;

[0042] S3 Pneumatic Circulation Conveying and Mixing: Using a blower to generate pneumatic force, under the action of positive pressure conveying or negative pressure suction conveying, the material in the buffer bin enters the mixing pipe, and the material flows into the multi-stage collision mixing equipment, where it undergoes multiple collisions and mixing until the mixing is completed.

[0043] S4 Unloading: After multi-stage mixing, the cathode material raw material is unloaded by positive pressure conveying or negative pressure suction conveying through pipeline.

[0044] This embodiment presents a continuous pipeline mixing method for preparing lithium-ion battery cathode materials. It employs gas-driven collision mixing of cathode material raw materials within a pipeline, increasing the collision intensity and mixing efficiency between raw material particles. The mixing process boasts high precision in material preparation, with adjustable material quantity and gas-solid flow velocity to meet the mixing requirements of various materials. Multi-stage collision mixing is used, with appropriate collision speeds and stages set according to different materials, reducing system energy consumption while meeting mixing uniformity requirements. Key components are made of non-metallic materials, preventing contamination of the ternary material raw materials by metallic impurities during violent collisions. Dense-phase conveying is used during unloading to prevent segregation of the mixed material during unloading, which could lead to a decrease in mixing uniformity.

[0045] Furthermore, in step S1, the feeding speed of the feeding device is 3-6 kg / min, the feeding accuracy is 5‰, the D50 of the cathode material raw material powder is set to 0.5-50 μm, and the cathode material raw material powder includes ternary materials, lithium iron phosphate, and other materials.

[0046] Furthermore, the cathode material precursor is NCM, NCA, or iron phosphate, and the lithium source includes one or more of lithium carbonate, lithium acetate, lithium phosphate, lithium dihydrogen phosphate, and lithium hydroxide.

[0047] Furthermore, in step S2, the feeding speed of the precision feeding device ranges from 3.5 kg / min to 7 kg / min, and the feeding error is less than 0.5%.

[0048] Furthermore, in step S3, the gas flow is generated by the flow of air, nitrogen, argon, or nitrogen. In practical applications, it is usually generated by the flow of air. When the precursor or lithium source is not suitable for contact with air, such as when the air is prone to deterioration, a protective gas can be used. The protective gas includes, but is not limited to, helium, argon, or nitrogen.

[0049] Furthermore, the gas in the system is recycled. The system is a closed pneumatic system that uses positive pressure conveying or negative pressure suction conveying. During the pneumatic circulation conveying process, the material quantity and gas-solid conveying speed in the system can be adjusted by adjusting the fan or other devices. The material quantity range is 200-400 kg / h, and the gas-solid conveying speed is 12-22 m / s.

[0050] Furthermore, in step S4, during unloading, the solid-to-gas ratio in the unloading pipe is in the range of 10-25, which is a dense phase transport.

[0051] Furthermore, during the mixing process, the part that comes into direct contact with the cathode material is made of non-metallic material to prevent metallic impurities from contaminating the raw material during mixing.

[0052] Furthermore, such as Figures 2 to 3 As shown, the multi-stage collision mixing device includes at least two feed pipes 1, a first-stage mixing chamber 2, a first-stage mixing pipe 3, a second-stage mixing chamber 4, at least two second-stage mixing pipes 5, a third-stage mixing chamber 6, and a discharge pipe 7. One end of the feed pipe 1 is connected to the first-stage mixing chamber 2 via a corrugated hose 9. One end of the first-stage mixing pipe 3 is connected to the first-stage mixing chamber 2 via a corrugated hose 9, and the other end is connected to the second-stage mixing chamber 4 via a corrugated hose 9. One end of the second-stage mixing pipe 5 is connected to the second-stage mixing chamber 4 via a corrugated hose 9, and the other end is connected to the third-stage mixing chamber 6 via a corrugated hose 9. The discharge pipe 7 is connected to the third-stage mixing chamber 6. All the corrugated hoses 9 between the mixing chambers and the pipes are installed and secured using clamps 10; and / or, as shown Figures 9 to 11 As shown, one end of the feed pipe 1 is ball-jointed to the first-stage mixing chamber 2.1; one end of the first-stage mixing pipe 3.1 is ball-jointed to the first-stage mixing chamber 2.1, and the other end is ball-jointed to the second-stage mixing chamber 4.1; the second-stage mixing pipe 5.1 is ball-jointed to the second-stage mixing chamber 4.1, and the other end is ball-jointed to the third-stage mixing chamber 6.1; the discharge pipe 7 is connected to the third-stage mixing chamber 6.1. All the pipes are mounted on the ball-joint mounting base 3.2 in the form of ball joints. A sealing ring 3.3 is installed between the inner wall of the ball-joint mounting base 3.2 and each pipe. The ball-joint mounting base 3.2 is also connected to the flange of each mixing chamber. A sealing ring 3.3 is installed between the flange and the ball-joint mounting base 3.2.

[0053] Furthermore, such as Figure 8As shown, guide bosses 201 are machined around the sides of the first-stage mixing chamber 2 and the second-stage mixing chamber 4. Grooves are opened in the feed pipe 1, the first-stage mixing pipe 3 and the second-stage mixing pipe 5, and are connected to the feed pipe 1, the first-stage mixing pipe 3 and the second-stage mixing pipe 5 in sequence to ensure that the first-stage mixing chamber 2 and the second-stage mixing chamber 4 can slide up and down.

[0054] Furthermore, such as Figures 4 to 8 As shown, the first mounting plate 802 and the second mounting plate 803 are installed in parallel. An upper top plate 804 and a lower top plate 805 are mounted on a groove between the first mounting plate 802 and the second mounting plate 803. A spring 807 is installed between the upper top plate 804 and the lower top plate 805. A cam 806 is also installed between the first mounting plate 802 and the second mounting plate 803. The cam 806 is also connected to the shaft of the pneumatic motor 801. A shaft end retaining ring 2812 is installed at the front end of the pneumatic motor 801 shaft to prevent axial displacement of the cam 806. A bearing 808 is installed between the shaft of the pneumatic motor 801 and the first mounting plate 802. The bearing 808 is axially fixed by a sleeve 809. The end of the pneumatic motor 801 shaft is bolted to a fixing cover 810. A shaft end retaining ring 1811 is installed between the fixing cover 810 and the first mounting plate 802. The mixing chamber connector 202 at the bottom of the first-stage mixing chamber 2 is connected to the upper top plate 804 of the vibrating mixing device 8, and the mixing chamber connector 202 at the top of the second-stage mixing chamber 4 is connected to the lower top plate 805 of the vibrating mixing device 8.

[0055] The material is fed into the feed pipe 1 under positive or negative pressure, and then enters the first-stage mixing chamber 2 / first-stage mixing chamber 2.1, where it is mixed by collision. Then, it enters the first-stage mixing pipe 3 / first-stage mixing pipe 3.1 through the first-stage mixing chamber 2 / first-stage mixing chamber 2.1, and then reaches the second-stage mixing chamber 4 / second-stage mixing chamber 4.1, where it undergoes a second collision mixing. After that, it enters the third-stage mixing chamber 6 / third-stage mixing chamber 6.1 through the second-stage mixing pipe 5 / second-stage mixing pipe 5.1 for a third collision mixing. After mixing is completed, it is discharged from the discharge pipe 7, achieving a highly efficient mixing process.

[0056] To effectively improve mixing efficiency, a vibrating mixing device 8 is installed between the first-stage mixing chamber 2 and the second-stage mixing chamber 4. The vibrating mixing device 8 is driven by a pneumatic motor 801 to rotate a cam 806. Since the first mounting plate 802 and the second mounting plate 803 are fixedly installed, the long-diameter end of the cam 806 can overcome the clamping force of the spring 807, thereby pushing the upper top plate 804 and the lower top plate 805 to slide outward between the grooves of the first mounting plate 802 and the second mounting plate 803, causing the first mixing chamber 2 and the second mixing chamber 4 to displace outward. Since the feed pipe 1, the first-stage mixing pipe 3, and the second-stage mixing pipe 5 are all fixedly installed, the displacement of the first-stage mixing chamber 2 and the second-stage mixing chamber 4 will pull the corrugated hose 9 to deform in the same displacement direction. When the pneumatic motor 801 drives the cam 806 to continue rotating, the contact position between the cam 806 and the upper and lower top plates 804 and 805 gradually transitions from the long-diameter end to the short-diameter end. Under the action of the spring 807, the cam is tightened inward, and the upper and lower top plates 804 and 805 also shift inward, thereby driving the first-stage mixing chamber 2 and the second-stage mixing chamber 4 to move inward as well, completing one cycle of up-and-down reciprocating vibration. During the gas-solid collision mixing process, the vibrating mixing device 8 performs high-speed periodic vibration, allowing the two positive electrode materials in the first-stage mixing chamber 2 and the second-stage mixing chamber 4 to undergo more intense reciprocating collisions with the upper and lower walls of the first-stage mixing chamber 2 and the second-stage mixing chamber 4 under pneumatic force. This increases the number of collisions between the two positive electrode materials and improves the mixing efficiency.

[0057] Further, such as Figures 9 to 11 As shown, the articulated multi-stage collision mixing device can also adopt a ball joint connection method. By utilizing the omnidirectional rotation characteristics of the ball joint, the feed pipe 1, the first-stage mixing pipe 3, and the second-stage mixing pipe 5 can achieve rotation around the axis and angular swing within a certain range, which can adapt to different spatial scenarios and facilitate installation.

[0058] To further illustrate this case in detail, the following two specific embodiments are provided:

[0059] Example 1:

[0060] S1 Feeding: Select appropriate amounts of LiCO3 and (Ni0.5Co0.2Mn0.3)(OH)2 for feeding. The D50 of the two materials are 8μm and 10μm, respectively, and the weight ratio is 1:2.3. The feeding speeds are 1.06kg / s and 2.44kg / s, respectively, and the feeding accuracy is 5‰. After feeding, the LiCO3 and (Ni0.5Co0.2Mn0.3)(OH)2 enter the buffer chamber.

[0061] S2 Feeding: The positive electrode material LiCO3 and (Ni0.5Co0.2Mn0.3)(OH)2 raw materials unloaded from the buffer chamber are precisely controlled by a precision feeding device. The feeding speed is 3.5Kg / min and the feeding error is less than 0.5%, ensuring uniform and stable feeding.

[0062] S3 Pneumatic Circulation Mixing: LiCO3 and (Ni0.5Co0.2Mn0.3)(OH)2, after being batched in the buffer chamber, enter the feed pipe 1. Nitrogen gas is introduced as a protective gas into the multi-stage pipeline collision mixing device. The blower starts working, and the two ternary cathode material raw materials begin to flow in the multi-stage collision mixing device. During this process, the material flow rate is 210 kg / h, the average gas-solid flow velocity is 15 m / s, and there is no obvious material accumulation at the bottom of the pipe during pneumatic conveying. The gas after mixing returns to the mixing device through the pipeline and circulating blower, realizing the recycling of nitrogen gas. LiCO3 and (Ni0.5Co0.2Mn0.3)(OH)2 undergo collision mixing in the mixing chamber and mixing pipe. The particle velocity before collision is 14-16 m / s. The mixing process is as described above, and the number of mixing stages is set to three. Equipment is installed in the first mixing chamber 2 and the second mixing chamber 4. Figure 4 The vibratory mixing device 8 shown is used. After three-stage mixing, the uniformity of the ternary cathode material meets the requirements of subsequent production. During the gas-solid collision mixing process, the vibratory mixing device 8 performs high-speed periodic vibration, which allows the two cathode materials in the first-stage mixing chamber 2 and the second-stage mixing chamber 4 under the action of air force to have more intense reciprocating collisions with the upper and lower walls of the first-stage mixing chamber 2 and the second-stage mixing chamber 4. This increases the number of collisions and reduces the agglomeration behavior between materials, achieving enhanced mixing of the ternary cathode material. After three-stage mixing, the uniformity of the ternary cathode material meets the requirements of subsequent production, and the mixing energy consumption is less than 3KW / 100Kg.

[0063] S4 Dense Phase Conveying and Unloading: After multi-stage collision mixing, LiCO3 and (Ni0.5Co0.2Mn0.3)(OH)2 enter the unloading pipe 7 together to start unloading. During the unloading process, the gas-solid ratio is greater than 10 to ensure the stability of the mixture of the two materials.

[0064] Example 2:

[0065] S1 Batching: Select appropriate amounts of LiOH·H2O and (Ni0.8Co0.15Al0.05)(OH)2 for batching. The D50 values ​​of the two materials are 10μm and 15μm, respectively, with a weight ratio of 1:2.5. The batching speeds are 1.71kg / s and 4.29kg / s, respectively, with a batching accuracy of 5‰. After batching, the LiOH·H2O and (Ni0.8Co0.15Al0.05)(OH)2 enter the buffer chamber.

[0066] S2 Feeding: The positive electrode material LiOH·H2O and (Ni0.8Co0.15Al0.05)(OH)2 raw materials unloaded from the buffer chamber are precisely controlled by a precision feeding device. The feeding speed is 6Kg / min and the feeding error is less than 0.5%, ensuring uniform and stable feeding.

[0067] S3 Pneumatic Circulation Mixing: The LiOH·H2O and (Ni0.8Co0.15Al0.05)(OH)2, after being batched in the buffer chamber, enter feed pipe 1. Nitrogen gas is introduced as a protective gas into the multi-stage pipe collision mixing device. The blower starts working, and the two ternary cathode material raw materials begin to flow in the multi-stage collision mixing device. During this process, the material flow rate is 360 kg / h, the average gas-solid flow velocity is 18 m / s, and there is no obvious material accumulation at the bottom of the pipe during pneumatic conveying. After mixing, the gas returns to the mixing device through the pipe and circulating blower, realizing the recycling of nitrogen gas. LiOH·H2O and (Ni0.8Co0.15Al0.05)(OH)2 undergo collision mixing in the mixing chamber and mixing pipe. Before collision, the particle velocity is 16-20 m / s. The mixing process is as described above for the ball-and-joint type mixing device, with the number of mixing stages set to three or two. After three-stage or two-stage mixing, the uniformity of the ternary cathode material mixing meets the requirements of subsequent production, and the mixing energy consumption is less than 5KW / 100Kg.

[0068] S4 Dense Phase Conveying and Unloading: After multi-stage collision mixing, LiOH·H2O and (Ni0.8Co0.15Al0.05)(OH)2 enter the unloading pipe 7 together to start unloading. During the unloading process, the solid-to-gas ratio is greater than 10 to ensure the stability of the mixture of the two materials.

[0069] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Unless otherwise specified, an element defined by the phrase "comprising..." or "including..." does not exclude the presence of additional elements in the process, method, article, or terminal device that includes said element. Additionally, in this document, "greater than," "less than," "exceeding," etc., are understood to exclude the stated number; "above," "below," "within," etc., are understood to include the stated number.

[0070] The above description of the embodiments is provided to facilitate understanding and use of the present invention by those skilled in the art. It is obvious to those skilled in the art that various modifications can be easily made to the embodiments, and the general principles described herein can be applied to other embodiments without creative effort. Therefore, the present invention is not limited to the above embodiments. Improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the protection scope of the present invention.

Claims

1. A continuous pipeline mixing method for preparing lithium battery cathode materials, characterized in that, Includes the following steps: S1 Batching: Through a precision batching device, various cathode material raw material powders stored in the silo are batched according to a certain ratio. After the batching is completed, the cathode material raw materials enter the buffer silo for later use. S2 feeding: The mass flow rate of the cathode material unloaded from the buffer chamber is precisely controlled by a precision feeding device to ensure uniform and stable feeding; S3 Pneumatic Circulation Conveying and Mixing: Using a blower to generate pneumatic force, under the action of positive pressure conveying or negative pressure suction conveying, the material in the buffer bin enters the mixing pipe, and the material flows into the multi-stage collision mixing equipment, where it undergoes multiple collisions and mixing until the mixing is completed. S4 Unloading: After multi-stage mixing, the cathode material raw material is unloaded by positive pressure conveying or negative pressure suction conveying through pipeline; The multi-stage collision mixing device includes at least two feed pipes, a first-stage mixing chamber, a first-stage mixing pipe, a second-stage mixing chamber, at least two second-stage mixing pipes, a third-stage mixing chamber, and a discharge pipe. One end of the feed pipe is connected to the first-stage mixing chamber via a corrugated hose. One end of the first-stage mixing pipe is connected to the first-stage mixing chamber via a corrugated hose, and the other end is connected to the second-stage mixing chamber via a corrugated hose. One end of the second-stage mixing pipe is connected to the second-stage mixing chamber via a corrugated hose, and the other end is connected to the third-stage mixing chamber via a corrugated hose. The discharge pipe is connected to the third-stage mixing chamber. Alternatively, one end of the feed pipe is connected to the first-stage mixing chamber via a ball joint. One end of the first-stage mixing pipe is connected to the first-stage mixing chamber via a ball joint, and the other end is connected to the second-stage mixing chamber via a ball joint. The second-stage mixing pipe is connected to the second-stage mixing chamber via a ball joint, and the other end is connected to the third-stage mixing chamber via a ball joint. The discharge pipe is connected to the third-stage mixing chamber.

2. The continuous mixing method in a pipeline for preparing lithium battery cathode materials according to claim 1, characterized in that, The cathode material raw materials include ternary materials and lithium iron phosphate materials.

3. The continuous mixing method in a pipeline for preparing lithium-ion battery cathode materials according to claim 1, characterized in that, In step S1, the D50 of the cathode material raw material powder is set to 0.5-50μm, and the cathode material raw material powder includes ternary materials and lithium iron phosphate materials.

4. The continuous mixing method in a pipeline for preparing lithium battery cathode materials according to claim 3, characterized in that, The ternary material precursor is NCM or NCA.

5. The continuous mixing method in a pipeline for preparing lithium-ion battery cathode materials according to claim 3, characterized in that, The lithium iron phosphate material is prepared from one or more of lithium carbonate, lithium acetate, lithium phosphate, lithium dihydrogen phosphate, and lithium hydroxide.

6. The continuous mixing method in a pipeline for preparing lithium-ion battery cathode materials according to claim 1, characterized in that, In step S2, the pneumatic force is generated by the flow of air, nitrogen, argon, or nitrogen.

7. The continuous mixing method in a pipeline for preparing lithium-ion battery cathode materials according to claim 1, characterized in that, In step 3, during unloading, the solid-to-gas ratio in the unloading pipe is in the range of 10-25.

8. A continuous pipeline mixing apparatus for preparing lithium-ion battery cathode materials, applied in the continuous pipeline mixing method for preparing lithium-ion battery cathode materials according to any one of claims 1 to 7, characterized in that, The device includes a multi-stage collision mixing apparatus, comprising at least two feed pipes, a first-stage mixing chamber, a first-stage mixing pipe, a second-stage mixing chamber, at least two second-stage mixing pipes, a third-stage mixing chamber, and a discharge pipe. One end of each feed pipe is connected to the first-stage mixing chamber via a corrugated flexible hose; one end of each first-stage mixing pipe is connected to the first-stage mixing chamber via a corrugated flexible hose, and the other end is connected to the second-stage mixing chamber via a corrugated flexible hose; one end of each second-stage mixing pipe is connected to the second-stage mixing chamber via a corrugated flexible hose, and the other end is connected to the third-stage mixing chamber via a corrugated flexible hose; the discharge pipe is connected to the third-stage mixing chamber. Alternatively, one end of each feed pipe is connected to the first-stage mixing chamber via a ball joint; one end of each first-stage mixing pipe is connected to the first-stage mixing chamber via a ball joint, and the other end is connected to the second-stage mixing chamber via a ball joint; one end of each second-stage mixing pipe is connected to the second-stage mixing chamber via a ball joint, and the other end is connected to the third-stage mixing chamber via a ball joint; the discharge pipe is connected to the third-stage mixing chamber.

9. The continuous pipeline mixing device for preparing lithium battery cathode materials according to claim 8, characterized in that, A vibration mixing device is provided between the bottom of the first-stage mixing chamber and the top of the second-stage mixing chamber.

10. The continuous pipeline mixing apparatus for preparing lithium battery cathode materials according to claim 9, characterized in that, The vibration mixing device includes a pneumatic motor, a first mounting plate, a second mounting plate, an upper top plate, a lower top plate, a cam, a spring, a bearing, and a fixed cover. The first mounting plate and the second mounting plate are installed in parallel. Slide grooves are provided on the opposite sides of the first mounting plate and the second mounting plate. The upper top plate and the lower top plate are mounted on the slide grooves. A spring is installed between the upper top plate and the lower top plate. The cam is also installed between the first mounting plate and the second mounting plate. The cam is also connected to the shaft of the pneumatic motor. A bearing is installed between the shaft of the pneumatic motor and the first mounting plate. The end of the shaft of the pneumatic motor is bolted to the fixed cover.

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