Positive electrode material precursor and preparation method thereof

Abstract

The invention provides a ternary positive electrode material precursor and a preparation method thereof. The preparation method of the ternary positive electrode material precursor comprises the following steps: (1) coprecipitation reaction and aging: carrying out coprecipitation reaction by adopting a micro-channel reactor, and aging to obtain a reaction solution containing the ternary positive electrode material precursor; (2) washing and filtering: washing and filtering the ternary positive electrode material precursor obtained in the step (1); and (3) flash evaporation dynamic drying and crushing: carrying out flash evaporation dynamic drying and crushing on the ternary positive electrode material precursor treated in the step (2). The method provided by the invention can solve the problem of irregular particle size of the positive electrode material precursor prepared by the microchannel reactor, and the positive electrode material precursor with improved morphology and proper particle size is obtained.

Description

Technical Field

[0001] The invention belongs to the technical field of battery materials and relates to a positive electrode material precursor and a preparation method thereof. Background Art

[0002] The reaction preparation process of ternary cathode material precursors usually uses a reactor for batch (intermittent method) or continuous preparation. The whole process involves the generation of crystal nuclei and the growth reaction of grains at the same time. There are many control parameters and the stabilization time is long. Microchannel reactors can significantly increase the reaction rate, organically separate the nucleation and growth processes, reduce control parameters, and shorten the reaction time. Compared with the traditional cathode material precursor preparation process, when using a microchannel reactor to prepare cathode material precursors, due to the extremely fast micro-reaction rate, the explosive nucleation of primary particles leads to the agglomeration of secondary particles, which tend to be irregular in morphology, and the particle size distribution is wider than that of traditional reactors.

[0003] In the drying and granulation stages, traditional methods such as disc drying cannot meet the requirements of particle size and morphology of cathode material precursor products prepared by microchannel reactors. Existing technologies such as CN202110556082.8 use spray drying to control the morphology and particle size of cathode material precursors prepared by microchannel reactors, but due to the low solid content of cathode material precursor slurry, the operation process is complicated and the drying cost is significantly increased.

[0004] Therefore, there is a need in the art for a method for controlling the particle size and morphology of a cathode material precursor prepared by a microchannel reactor with a simple process, energy saving and environmental protection. Summary of the invention

[0005] In view of the problems existing in the prior art, the present invention provides a method for controlling the particle size and morphology of a cathode material precursor prepared by a microchannel reactor in a drying stage. The present invention uses flash dynamic drying and crushing in the drying stage to complete the particle size control and morphology shaping of the cathode material precursor prepared by a microchannel reactor. The method provided by the present invention can solve the problem of irregular particle size of the cathode material precursor prepared by a microchannel reactor, and obtain a cathode material precursor with a spherical morphology and a suitable particle size.

[0006] Specifically, the present invention provides a method for preparing a ternary cathode material precursor, the preparation method comprising the following steps:

[0007] (1) Coprecipitation reaction and aging: A coprecipitation reaction is carried out in a microchannel reactor, and a reaction solution containing a ternary cathode material precursor is obtained after aging;

[0008] (2) washing and filtering: washing and filtering the ternary cathode material precursor obtained in step (1);

[0009] (3) Flash dynamic drying and crushing: Flash dynamic drying and crushing the ternary positive electrode material precursor after the treatment in step (2).

[0010] In one or more embodiments, the process parameters of the flash dynamic drying and pulverization in step (3) meet one or more of the following characteristics:

[0011] The inlet air temperature is 150-250°C, preferably 180-240°C;

[0012] The feeding frequency is 5-30 Hz, preferably 15-30 Hz;

[0013] The blowing frequency is 20-40Hz;

[0014] The host frequency is 40-50Hz;

[0015] The airflow feeding frequency is 20-50Hz;

[0016] The induced air frequency is 35-50Hz;

[0017] The sum of the feeding frequency and the airflow feeding frequency is 40-80 Hz.

[0018] In one or more embodiments, in step (3), a flash dynamic drying and pulverizing system is used for flash dynamic drying and pulverizing, and the flash dynamic drying and pulverizing system includes an air heater, a feeding device, a mechanical pulverizer, a cyclone separator, an air flow pulverizer, a first collection chamber, a first induced draft fan, a second collection chamber and a second induced draft fan, the air heater and the feeding device are connected to the mechanical pulverizer, a blade is provided at the bottom of the mechanical pulverizer, the mechanical pulverizer is connected to the cyclone separator, the cyclone separator is connected to the air flow pulverizer and the second collection chamber, the air flow pulverizer is connected to the first collection chamber, the first collection chamber is provided with an ejector, the first collection chamber is connected to the first induced draft fan, and the second collection chamber is connected to the second induced draft fan.

[0019] In one or more embodiments, step (3) comprises the following steps:

[0020] (A) Coarse pulverization: air is heated by the air heater and then enters the mechanical pulverizer, while the material is fed to the mechanical pulverizer by the feeding device, and the material is dried and crushed under the action of the high-speed rotating blades and hot air;

[0021] (B) Cyclone separation: under the negative pressure generated by the first induced draft fan and the second induced draft fan, the material enters the cyclone separator from the mechanical pulverizer; in the cyclone separator, unqualified materials with smaller particle sizes rise and enter the second collecting chamber, and materials with larger particle sizes fall from the bottom of the cyclone separator into the air flow pulverizer;

[0022] (C) Airflow pulverization: In the airflow pulverizer, compressed air is passed through an ejector to generate a high-speed jet that contacts the material, causing the material to be pulverized to a target particle size and then enter the first collecting chamber.

[0023] In one or more embodiments, the chemical formula of the ternary cathode material precursor is Ni x Co y M z (OH)2, wherein 0.6≤x≤0.95, 0<y≤0.2, 0<z≤0.3, x+y+z=1, and M is Al or Mn.

[0024] In one or more embodiments, in step (1), the ternary cathode material precursor is generated by co-precipitation reaction of nickel salt, cobalt salt and aluminum salt or nickel salt, cobalt salt and manganese salt in the presence of a precipitant and a complexing agent in a microchannel reactor.

[0025] In one or more embodiments, the microchannel reactor is a valve-type microreactor, which includes a first feed port, a second feed port, a first feed pressure regulating device, a second feed pressure regulating device, a reaction chamber and a discharge port, wherein the first feed port is connected to the reaction chamber through a first flow channel, and the second feed port is connected to the reaction chamber through a second flow channel. The first feed pressure regulating device is arranged on the first flow channel between the first feed port and the reaction chamber, and is used to control the feed pressure of the first feed port. The second feed pressure regulating device is arranged on the second flow channel between the second feed port and the reaction chamber, and is used to control the feed pressure of the second feed port. The discharge port is connected to the reaction chamber, and the nickel salt, cobalt salt and aluminum salt or nickel salt, cobalt salt and manganese salt are fed to the reaction chamber through the first flow channel, and the precipitant and complexing agent are fed to the reaction chamber through the second flow channel.

[0026] In one or more embodiments, the end of the first flow channel and the end of the second flow channel are provided with a plurality of micropores and / or slits distributed in an annular shape, so that the jets ejected from the end of the first flow channel and the end of the second flow channel correspond one to one, and real-time collision and mixing occur.

[0027] In one or more embodiments, step (2) comprises the following steps:

[0028] (a) Dehydration: removing the mother liquor from the aged material;

[0029] (b) washing: using water at 50-80° C., preferably 60-80° C., and in a water:material mass ratio of (5-15):1, preferably (6-12):1, the water and the material are sequentially put into a beating kettle for stirring and beating, the beating time is 30-120 min, preferably 45-90 min, and the stirring speed is 50-200 rpm, preferably 60-150 rpm;

[0030] (c) Filtration: filtering the material after pulping;

[0031] (d) Repeat step (b) washing and step (c) filtering, with the total number of washing times being ≥ 2 times, until the pH value of the washing water is ≤ 9.5.

[0032] The present invention also provides a ternary positive electrode material precursor prepared by the preparation method described in any embodiment of the present invention.

[0033] In one or more embodiments, the Dmin of the ternary cathode material precursor is 0.005 to 0.015 μm.

[0034] In one or more embodiments, the D10 of the ternary cathode material precursor is 0.015 to 0.025 μm.

[0035] In one or more embodiments, the D50 of the ternary cathode material precursor is 0.05 to 0.5 μm.

[0036] In one or more embodiments, the D90 of the ternary cathode material precursor is 1 to 11 μm.

[0037] In one or more embodiments, the Dmax of the ternary cathode material precursor is 16 to 60 μm.

[0038] The present invention also provides a ternary positive electrode material prepared from the ternary positive electrode material precursor described in any embodiment of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 Schematic diagram of a valved microreactor in some embodiments of the present invention. Figure 1 In the figure, 201 is the first feed inlet, 202 is the second feed inlet, 203 is the second feed pressure regulating device, 204 is the first feed pressure regulating device, 205 is the reaction chamber, and 206 is the discharge port.

[0040] Figure 2 Schematic diagram of a system for preparing a cathode material precursor in some embodiments of the present invention. Figure 2In the figure, 101 is a first feeding system, 102 is a second feeding system, 103 is a connecting pipeline, 104 is a valve type microreactor, 105 is a vacuum negative pressure tank, 106 is a vacuum pump, and 107 is an aging device.

[0041] Figure 3 Schematic diagram of a system for preparing a cathode material precursor in some embodiments of the present invention. Figure 3 In the figure, 101 is the first feeding system, 102 is the second feeding system, 104 is the valve type microreactor, 105 is the vacuum negative pressure tank, 106 is the vacuum pump, 107 is the aging device, 108 is the first raw material tank, 109 is the first washing water tank, 301 is the first feeding device, 302 is the first mass flow meter, 303 is the first pressure controller, 304 is the first reversing valve, 110 is the second raw material tank, 111 is the second washing water tank, 401 is the second feeding device, 402 is the second mass flow meter, 403 is the second pressure controller, and 404 is the second reversing valve.

[0042] Figure 4 Schematic diagram of a system for preparing a cathode material precursor in some embodiments of the present invention. Figure 4 Among them, 108 is the first raw material tank, 110 is the second raw material tank, 112 is the third raw material tank, 101 is the first feeding system, 102 is the second feeding system, 103 is the third feeding system, 114 is the first inlet module, 115 is the first heating module, 116 is the second inlet module, 117 is the third inlet module, 119 is the mixing module, 120 is the second heating module, 104 is the valve microreactor, 121 is the outlet module, and 107 is the aging device.

[0043] Figure 5 Schematic diagram of a valved microreactor in some embodiments of the present invention. Figure 5 In the figure, 201 is the first feed port, 202 is the second feed port, 203 is the second feed pressure regulating device, 204 is the first feed pressure regulating device, 205 is the reaction chamber, 206 is the discharge port, 501 is the micropore, and 502 is the slit.

[0044] Figure 6 Schematic diagram of the correspondence between slits and micropores in a valve-type microreactor in some embodiments of the present invention. Figure 6 In the figure, 501 is a microhole and 502 is a slit.

[0045] Figure 7 The figure is a schematic diagram of the process of flash dynamic drying and pulverization in some embodiments of the present invention. Figure 7 Among them, 1 is an air heater, 2 is a feeding device, 3 is a mechanical pulverizer, 4 is a cyclone separator, 5 is an air flow pulverizer, 6 is a first collecting chamber, 7 is a second collecting chamber, 8 is a first induced draft fan, and 9 is a second induced draft fan.

[0046] Figure 8 This is a real picture of the ternary positive electrode material precursor product after flash dynamic drying and crushing in Example 5.

[0047] Fig. 9 This is a SEM image of the ternary cathode material precursor product after flash dynamic drying and crushing in Example 5.

[0048] Fig.10 This is a real shot of the ternary positive electrode material precursor product after being dried by static drying in Comparative Example 3.

[0049] Fig.11 This is a SEM image of the ternary positive electrode material precursor product after being dried by static drying and then coarsely broken and crushed in Comparative Example 4.

[0050] Fig.12 This is a real shot of the ternary positive electrode material precursor product prepared in Comparative Example 5. DETAILED DESCRIPTION

[0051] In order to enable those skilled in the art to understand the characteristics and effects of the present invention, the following is a general description and definition of the terms and expressions mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used in the text are the common meanings understood by those skilled in the art for the present invention. In the event of a conflict, the definition in this specification shall prevail.

[0052] The theories or mechanisms described and disclosed herein, whether correct or incorrect, should not limit the scope of the present invention in any way, that is, the present invention can be implemented without being limited by any specific theory or mechanism.

[0053] Herein, “comprising”, “including”, “containing” and similar terms encompass the meanings of “consisting essentially of” and “consisting of”. For example, when “A comprises B and C” is disclosed herein, “A consists essentially of B and C” and “A consists of B and C” should be deemed to be disclosed herein.

[0054] In this article, all features such as values, quantities, contents and concentrations defined in the form of numerical ranges or percentage ranges are only for brevity and convenience. Accordingly, the description of numerical ranges or percentage ranges should be considered to have included and specifically disclosed all possible secondary ranges and individual values ​​within the range (including integers and fractions).

[0055] In this document, unless otherwise specified, percentage refers to mass percentage and ratio refers to mass ratio.

[0056] Herein, when describing embodiments or examples, it should be understood that they are not used to limit the present invention to these embodiments or examples. On the contrary, all substitutes, improvements and equivalents of the methods and materials described in the present invention can be included in the scope limited by the claims.

[0057] In this document, in order to make the description concise, not all possible combinations of various technical features in various embodiments or examples are described. Therefore, as long as there is no contradiction in the combination of these technical features, the various technical features in various embodiments or examples can be combined arbitrarily, and all possible combinations should be considered to be within the scope of this specification.

[0058] In order to solve the problem of irregular particle size and morphology of the ternary cathode material precursor prepared by the microchannel reactor, the present invention adopts flash dynamic drying and crushing to achieve particle size control and morphology shaping during the drying process.

[0059] The method for preparing the ternary cathode material precursor of the present invention comprises the following steps:

[0060] (1) Coprecipitation reaction and aging: A coprecipitation reaction is carried out in a microchannel reactor, and a reaction solution containing a ternary cathode material precursor is obtained after aging;

[0061] (2) washing and filtering: washing and filtering the ternary cathode material precursor obtained in step (1);

[0062] (3) Flash dynamic drying and crushing: Flash dynamic drying and crushing the ternary positive electrode material precursor after the treatment in step (2).

[0063] In the present invention, a microchannel reactor is used to prepare a ternary cathode material precursor.

[0064] In the present invention, the ternary cathode material precursor refers to the hydroxide of nickel, cobalt, manganese or the hydroxide of nickel, cobalt, aluminum, and the chemical formula is Ni x Co y M z (OH)2, M is Mn or Al, 0<x<1, 0<y<1, 0<z<1, and x+y+z=1. The ternary cathode material precursor is in a granular form, also known as ternary cathode material precursor particles.

[0065] Preferably, the chemical formula of the ternary cathode material precursor is Ni x Co y M zIn (OH)2, x is 0.6 to 0.95, for example, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, preferably 0.6 to 0.8, more preferably 0.6 to 0.7; y is 0 to 0.2, for example, 0.01, 0.05, 0.07, 0.1, 0.12, 0.15, preferably 0.05 to 0.15, more preferably 0.07 to 0.12; z is 0 to 0.3, for example, 0.01, 0.05, 0.07, 0.1, 0.15, 0.2, 0.25, 0.26, 0.28, preferably 0.15 to 0.3, more preferably 0.15 to 0.28.

[0066] The ternary cathode material precursor is generated by coprecipitation reaction of nickel salt, cobalt salt and aluminum salt or nickel salt, cobalt salt and manganese salt in the presence of precipitant and complexing agent. The raw materials for preparing the ternary cathode material precursor generally include: a salt solution of nickel cobalt aluminum or nickel cobalt manganese, a precipitant and a complexing agent. Among them, the precipitant and the complexing agent can be mixed and fed, or they can be fed separately. In the present invention, the salt solution of nickel cobalt manganese is a solution containing nickel salt, cobalt salt and manganese salt, and the salt solution of nickel cobalt aluminum is a solution containing nickel salt, cobalt salt and aluminum salt. Nickel salts, cobalt salts, manganese salts and aluminum salts suitable for the present invention can be nickel salts, cobalt salts, manganese salts and aluminum salts known to be used for preparing ternary cathode material precursors, including but not limited to nickel sulfate, cobalt sulfate, manganese sulfate, aluminum sulfate and hydrates thereof. In the salt solution of nickel cobalt aluminum or nickel cobalt manganese, the total concentration of metal ions can be 1.5 to 2.5 mol / L, preferably 1.5 to 2 mol / L.

[0067] The precipitant may be a sodium hydroxide solution. The concentration of the sodium hydroxide solution may be 4 to 10 mol / L, preferably 4 to 8 mol / L. The complexing agent may be an aqueous ammonia solution. The concentration of the aqueous ammonia solution may be 3 to 10 mol / L, preferably 3 to 8 mol / L. In some embodiments, the complexing agent (e.g., aqueous ammonia solution) and the precipitant (e.g., sodium hydroxide solution) are mixed evenly to form a mixed solution, which is then reacted with a salt solution of nickel-cobalt-aluminum or nickel-cobalt-manganese.

[0068] Before the reaction, the reaction raw materials (such as nickel-cobalt-aluminum or nickel-cobalt-manganese salt solution, precipitant, complexing agent, mixed solution of precipitant and complexing agent) are preferably preheated to 30-80°C, preferably 40-70°C.

[0069] The reaction raw materials can be delivered to the microchannel reactor by a feed pump. The feed flow rate of the nickel-cobalt-aluminum or nickel-cobalt-manganese salt solution can be 50 to 400 kg / h, preferably 100 to 300 kg / h. The feed flow rate of the mixed solution of the precipitant and the complexing agent can be 50 to 400 kg / h, preferably 100 to 300 kg / h.

[0070] In some embodiments, a nickel-cobalt-aluminum or nickel-cobalt-manganese salt solution and a mixed solution of a precipitant and a complexing agent are rapidly mixed in a microchannel reactor to undergo a co-precipitation reaction to obtain a ternary cathode material precursor.

[0071] In the present invention, it is preferred to use a valve microreactor to carry out a coprecipitation reaction to prepare a ternary cathode material precursor. In the present invention, the ternary cathode material precursor prepared by using a valve microreactor as a place for the coprecipitation reaction is called an M ternary cathode material precursor. Therefore, in the present invention, the ternary cathode material precursor used for flash dynamic drying and crushing is preferably an M ternary cathode material precursor. The use of a valve microreactor to prepare an M ternary cathode material precursor has the advantages of high reaction efficiency and reduced control parameters.

[0072] In the present invention, microchannel reactor (also called microreactor) refers to a micro reactor with a characteristic size of 10 to 1000 microns, for example, 10 to 300 microns, manufactured by precision machining technology. The "micro" in microreactor means that the channel of the process fluid is at the micron level, rather than that the overall size of the micro reaction device is small or the output of the product is small.

[0073] The cathode material precursor preparation system (referred to as preparation system) of the present invention can be used to prepare M ternary cathode material precursor. The preparation system of the present invention includes at least two feeding systems and a valve microreactor, wherein the feeding system is used to provide reaction raw materials to the valve microreactor, and the valve microreactor is used to carry out a coprecipitation reaction. In some embodiments, the preparation system of the present invention also includes an aging device, which is used to age the product generated in the valve microreactor. Each feeding system and the valve microreactor and the valve microreactor and the aging device can be connected by a pipeline. The preparation system of the present invention can quickly complete the reaction, reduce the scrap rate, increase the production capacity, completely avoid the amplification effect, shorten the time from research and development to production of the cathode material precursor, and can accurately control the reaction conditions, and can produce products with stable quality and good consistency. The preparation system of the present invention has a simple start-stop reaction, is easy to clean, has a high degree of automation, a stable production process, and is extremely efficient.

[0074] In the present invention, as a reaction device for coprecipitation reaction, the valve-type microreactor can control the pressure of two or more feed liquids, achieve stable feeding and mixing reactions under large flow and high flow rate, ensure that high-concentration reaction products can be quickly removed, and realize continuous reaction without blockage.

[0075] like Figure 1As shown, in the present invention, the valve type microreactor includes a first feed port 201, a second feed port 202, a first feed pressure regulating device 204, a second feed pressure regulating device 203, a reaction chamber 205 and a discharge port 206. The first feed port 202 is connected to the reaction chamber 205 through a flow channel. The second feed port 202 is connected to the reaction chamber 205 through a flow channel. The first feed pressure regulating device 204 is arranged on the flow channel between the first feed port 201 and the reaction chamber 205. The second feed pressure regulating device 203 is arranged on the flow channel between the second feed port 202 and the reaction chamber 205. The discharge port 206 is connected to the reaction chamber 205.

[0076] Jet-type collision occurs between the various liquids entering the reaction chamber through each feed port of the valve microreactor. The end of the flow channel between the feed port and the reaction chamber (for example, the end of the flow channel between the first feed port 201 and the reaction chamber 205, the end of the flow channel between the second feed port 202 and the reaction chamber 205) is provided with a plurality of micropores and / or slits distributed in an annular manner. Herein, the end refers to the end along the flow direction of the feed liquid. Multiple refers to two or more. Annular distribution means that the micropores and / or slits can be regarded as distributed on a ring. Preferably, the micropores and / or slits are arranged so that the jets ejected from the ends of each flow channel correspond one to one, and collide and mix in real time. In some embodiments, the end of the flow channel between the first feed port 201 and the reaction chamber 205 is provided with a micropore, and the end of the flow channel between the second feed port 202 and the reaction chamber 205 is provided with a slit; preferably, the design of the micropores and slits makes the jets ejected from the ends of the two flow channels correspond one to one, and collide and mix in real time. Preferably, the end of the flow channel between the first feed port 201 and the reaction chamber 205 and the end of the flow channel between the second feed port 202 and the reaction chamber 205 are arranged so that materials ejected from the two flow channel ends collide tangentially in the reaction chamber 205 .

[0077] In the present invention, the first feed pressure regulating device 204 and the second feed pressure regulating device 203 are respectively used to control the feed pressure of the first feed port 210 and the second feed port 202, so that the materials of the two feed ports can be sprayed into the reaction chamber 205 according to the expected pressure, flow rate and flow rate. In a preferred embodiment, the materials of the two feed ports are sprayed into the reaction chamber 205 through the micropores and / or slits distributed in an annular shape according to the expected pressure, flow rate and flow rate, and the spray trajectories of the two materials in the reaction chamber 205 after passing through the micropores and / or slits correspond to each other, and a real-time tangential collision occurs to achieve uniform mixing and reaction, and then the product after the reaction flows out quickly through the discharge port 206 under the pressure and the rear negative pressure that preferably exists. In some embodiments, the first feed pressure regulating device or the second feed pressure regulating device includes a pressure valve, and the pressure valve automatically connects the flow channel between the feed port and the reaction chamber when the feed pressure reaches a certain value. In other embodiments, the first feed pressure regulating device or the second feed pressure regulating device includes a pressure gauge and a valve, and the pressure gauge monitors the feed pressure. When the feed pressure reaches a certain value, the pressure gauge directly controls the valve, or controls the valve through other devices such as a numerical control system to connect the flow channel between the feed port and the reaction chamber. In other embodiments, the first feed pressure regulating device or the second feed pressure regulating device also includes a booster pump. When the feed pressure does not reach the set value, the booster pump pressurizes the feed liquid so that the feed pressure reaches the required value. The flow rate and flow velocity of the feed liquid can be adjusted by regulating the pressure of the feed liquid.

[0078] In the present invention, Figure 1 As shown, the reaction chamber 205 is preferably semi-ellipsoidal, and the discharge port 206 is preferably bell-bottomed. The bell-bottomed discharge port 206 is connected to the opening of the semi-ellipsoidal reaction chamber 205, so that high-concentration reaction products can be quickly discharged, and continuous reaction can be achieved without blockage.

[0079] The valve-type microreactor in the present invention realizes stable feeding and mixing reaction under large flow and high flow rate by setting the first feeding pressure regulating device 204 and the second feeding pressure regulating device 203; by setting a plurality of micropores and / or slits, the jet flow collision route is reasonable, the micropore jet flow corresponds to the slit jet flow one by one, and the collision and mixing are carried out in real time, so that a very high mixing and reaction effect can be achieved in the reaction chamber 205; the reaction chamber 205 is designed to be semi-ellipsoidal, and the discharge port 206 is in a bell-bottomed release state. The reasonable design can ensure that the high-concentration reaction products can be quickly discharged, and continuous reaction can be achieved without blockage.

[0080] The valve type microreactor in the present invention may include a T-type microchannel reactor or a cluster microchannel reactor.

[0081] In the present invention, the feeding system includes a feeding device that can accurately, evenly and stably realize solution filtration, metering, pressure regulation, and liquid delivery according to the pipeline and valve direction. In some embodiments, the feeding system includes a feeding device, a mass flow meter, a pressure controller and a valve, the valve includes an inlet and a first outlet, and the feeding system also includes an inlet pipeline connected to the inlet of the valve and a first outlet pipeline connected to the first outlet of the valve, the feeding device, the mass flow meter and the pressure controller are arranged on the inlet pipeline, and the valve communicates with the inlet pipeline and the first outlet pipeline when the flow detected by the mass flow meter and the pressure detected by the pressure controller meet the set value. The feeding device may include a gear feeding device or a delivery pump. The delivery pump may be a gear pump, a diaphragm pump or a peristaltic pump. Each feeding system may be the same or different. The first outlet pipeline of the feeding system may be directly connected to the valve microreactor, or may be connected to other devices, systems or modules (such as heating modules, mixing modules) arranged between the feeding system and the valve microreactor. The inlet pipeline of the feeding system may be connected to a raw material tank or a washing water tank. The valve may be a reversing valve, including two or more outlets. Each outlet of the valve may be connected to an outlet pipe. The second outlet pipe connected to the second outlet of the valve may be connected to a raw material tank or a washing water tank, so that the material flow or pressure does not meet the set requirements and returns to the raw material tank or the washing water tank.

[0082] In the present invention, the aging device is a place where the reaction product of the valve-type microreactor is further aged. The aging device applicable to the present invention can be an aging device commonly used in the art, such as an aging kettle.

[0083] The preparation system of the present invention preferably includes a negative pressure system arranged between the valve type microreactor and the aging device. The negative pressure system is used to form a negative pressure at the outlet end of the valve type microreactor. All devices or device combinations that can ensure that the reaction products of the mixed reaction of the reactants in the microchannel reactor and the outlet end can be timely removed under the action of the feed pressure and the rear end negative pressure, and ensure that the microchannel reactor can run smoothly without clogging under the reaction condition line of large flow and high pressure can be used as the negative pressure system. In some embodiments, the negative pressure system includes a vacuum pump and a vacuum negative pressure tank.

[0084] In some embodiments, such as Figure 2As shown, the preparation system of the present invention includes a first feeding system 101, a second feeding system 102, a valve microreactor 104, a negative pressure system and an aging device 107. The negative pressure system includes a vacuum negative pressure tank 105 and a vacuum pump 106. The vacuum negative pressure tank 105 is arranged between the valve microreactor 104 and the aging device 107, and is connected to the valve microreactor 104 and the aging device 107 through a pipeline. The first feeding system 101 and the second feeding system 102 are respectively connected to the valve microreactor 104 through a pipeline. The vacuum pump 106 is connected to the vacuum negative pressure tank 105 through a pipeline. The vacuum pump 106 and the vacuum negative pressure tank 105 are used in combination to ensure that a certain negative pressure or normal pressure can always be stably maintained in the vacuum negative pressure tank 105. The negative pressure value in the vacuum negative pressure tank 105 can be adjusted according to the flow rate, concentration of the reactants in the front-end valve type microreactor 104 and the flow rate and concentration, viscosity and solid content of the reaction product, so as to ensure that the reaction product in the valve type microreactor 104 can be removed in time under the action of the feed pressure and the rear-end negative pressure, and ensure that the valve type microreactor 104 can run smoothly without clogging under the reaction conditions of large flow and high pressure. The negative pressure system can be adjusted accordingly depending on the specific reaction situation. The aging device 107 is an aging kettle. The aging kettle is used to age the product under conditions such as stirring at a certain speed and heat preservation.

[0085] In some embodiments, the feed system includes a feeder, a mass flowmeter, a pressure controller and a reversing valve. The reversing valve includes an inlet and at least two outlets. The feed system includes an inlet pipeline connected to the inlet of the reversing valve, a first outlet pipeline connected to the first outlet of the reversing valve, and a second outlet pipeline connected to the second outlet of the reversing valve, the feeder, the mass flowmeter and the pressure controller are arranged on the inlet pipeline, and the reversing valve communicates the inlet pipeline and the first outlet pipeline when the flow detected by the mass flowmeter and the pressure detected by the pressure controller meet the set value. The feeder can be a delivery pump, such as a gear pump, a diaphragm pump or a peristaltic pump. The first outlet pipeline can be connected to the valve microreactor. The second outlet pipeline can be connected to a raw material tank or a washing water tank.

[0086] In some embodiments, such as Figure 3As shown, the preparation system of the present invention includes a first feeding system 101, a second feeding system 102, a valve microreactor 104, a vacuum negative pressure tank 105, a vacuum pump 106, an aging device 107, a first raw material tank 108, a first washing water tank 109, a second raw material tank 110 and a second washing water tank 111. Wherein, the first feeding system 101 includes a first feeding device 301, a first mass flowmeter 302, a first pressure controller 303 and a first reversing valve 304, and the second feeding system 102 includes a second feeding device 401, a second mass flowmeter 402, a second pressure controller 403 and a second reversing valve 404. The reversing valve has a feed port, a discharge port, a raw material reflow port and a washing water reflow port. The feed port of the reversing valve is connected to a feed pipe. The raw material tank and the washing water tank are connected to the feed pipe. The feeding device, the mass flowmeter and the pressure controller are arranged on the feed pipe. The discharge port of the reversing valve is connected to the valve microreactor 104 through a pipeline. The raw material reflux port of the reversing valve is connected to the raw material tank through a pipeline. The washing water reflux port of the reversing valve is connected to the washing water tank through a pipeline. The feeding device is a gear pump. The main function of the gear pump is to deliver liquid raw materials of a specific flow rate and pressure according to the set flow rate. The mass flow meter measures the flow rate in real time and feeds back the flow rate information in time. The pressure control device monitors the liquid pressure in real time and sets the required liquid pressure. When the feeding system is started, before the flow rate and pressure reach the set flow rate and pressure, the reversing valve can be set (for example, controlled by a control system) to allow the raw materials to enter from the feed port and return to the raw material tank from the raw material reflux port to form a cycle to prevent the waste of raw materials. When the flow rate and pressure meet the process requirements, the reversing valve can be set to allow the reaction raw materials to enter the valve microreactor 104 from the discharge port, fully mix and react quickly, and quickly enter the vacuum negative pressure tank 105. After a certain amount is stored, it enters the aging device 107 for a certain period of aging. After the reaction is completed, the washing water in the washing water tank is passed into the feeding system and the valve type microreactor 104 to achieve rapid washing of the feeding system and the valve type microreactor 104. A reversing valve can be arranged between the raw material tank and the washing water tank and the feeding pipeline, and the reversing valve can have a raw material inlet, a washing water inlet and an outlet. The raw material inlet of the reversing valve is connected to the raw material tank through a pipeline, the washing water inlet of the reversing valve is connected to the washing water tank through a pipeline, and the outlet of the reversing valve is connected to the feeding pipeline.

[0087] In some embodiments, the preparation system of the present invention further includes a control system, such as a numerical control system. The control system is used to receive process parameters such as flow rate and pressure measured by detection devices such as flow meters and pressure gauges, and control the operation of working devices such as valves (such as reversing valves), pumps (such as booster pumps, vacuum pumps), and feeding devices according to the received process parameters. The control system can be connected to other systems, devices, equipment, modules, components, etc. in the preparation system of the present invention, such as a feeding system and a valve-type microreactor in a wired or wireless manner.

[0088] The preparation system of the present invention may also include a heating module arranged between one or more feed systems and the valve microreactor. The heating module is used to preheat the material entering the valve microreactor. The heating module can be combined with the valve microreactor, for example, the heating module is arranged before the feed port of the valve microreactor, and the reaction raw materials are heated to the temperature required by the process before entering the valve microreactor. In some embodiments, the preparation system of the present invention includes at least three feed systems and a mixing module arranged between at least two feed systems and the valve microreactor, and the mixing module is used to mix the reaction raw materials from the at least two feed systems and provide the mixed reaction raw materials to the valve microreactor. The mixing module may include a stacked mixer, a valve mixer, a T-type microchannel reactor or a clustered microchannel reactor.

[0089] In some embodiments, such as Figure 4 As shown, the preparation system of the present invention includes a first raw material tank 108, a second raw material tank 110, a third raw material tank 112, a first feeding system 101, a second feeding system 102, a third feeding system 103, a first inlet module 114, a first heating module 115, a second inlet module 116, a third inlet module 117, a mixing module 119, a second heating module 120, a valve microreactor 104, an outlet module 121, an aging device 107 and a negative pressure system ( Figure 6 107 is an aging kettle, and the mixing module 119 is a stacked mixer. The negative pressure system includes a vacuum negative pressure tank and a negative pressure pump, the vacuum negative pressure tank is arranged between the outlet module 121 and the aging device 107, and the negative pressure pump is connected to the vacuum negative pressure tank. In the present invention, the inlet module and the outlet module can be simple inlet and outlet connection modules.

[0090] In some embodiments, such as Figure 5As shown, the valve type microreactor used in the present invention includes a first feed port 201, a second feed port 202, a first feed pressure regulating device 204, a second feed pressure regulating device 203, a reaction chamber 205, a discharge port 206, a micropore 501 and a slit 502. The first feed pressure regulating device 204 is arranged on the flow channel between the first feed port 201 and the reaction chamber 205. The second feed pressure regulating device 203 is arranged on the flow channel between the second feed port 202 and the reaction chamber 205. The reaction chamber 205 is semi-ellipsoidal. The discharge port 206 is flared. The discharge port 206 of the flared trousers is connected to the opening of the semi-ellipsoidal reaction chamber 205, so that the high-concentration reaction product can be quickly discharged, and continuous reaction can be achieved without blockage. Looking at the reaction chamber 205 from the discharge port 206, the cross section of the reaction chamber 205 is elliptical, indicating that the reaction chamber 205 is semi-ellipsoidal. The micropore 501 is disposed at the end of the flow channel between the first feed port 201 and the reaction chamber 205 . The slit 502 is disposed at the end of the flow channel between the second feed port 202 and the reaction chamber 205 .

[0091] A jet-like collision occurs between the various liquids entering the reaction chamber through the various feed ports of the valve-type microreactor. The end of the flow channel between the feed port and the reaction chamber (for example, the end of the flow channel between the first feed port 201 and the reaction chamber 205, the end of the flow channel between the second feed port 202 and the reaction chamber 205) is provided with a plurality of micropores and / or slits distributed in an annular shape. Preferably, the micropores and / or slits are arranged so that the jets ejected from the two flow channel ends correspond to each other one by one, and collide and mix in real time. In some embodiments, such as Figure 5 and Figure 6 As shown, a micropore 501 is provided at the end of the flow channel between the first feed inlet 201 and the reaction chamber 205, and a slit 502 is provided at the end of the flow channel between the second feed inlet 202 and the reaction chamber 205. Preferably, as Figure 6 As shown, the design of micropores 501 and slits 502 allows the jets ejected from the two flow channel ends to correspond to each other and collide and mix in real time. Figure 6 As shown, each micropore 501 is evenly distributed in an annular shape, and each slit 502 is also evenly distributed in an annular shape and corresponds to each micropore 501 one by one, so that the jets sprayed into the reaction chamber 205 from the two flow channel ends can correspond to each other one by one and collide and mix in real time. Preferably, the end of the flow channel between the first feed port 201 and the reaction chamber 205 and the end of the flow channel between the second feed port 202 and the reaction chamber 205 are arranged so that the materials sprayed from the two flow channel ends collide tangentially in the reaction chamber 205.

[0092] In some embodiments, such as Figure 5 and Figure 6As shown, the diameter of the micropore 501 is 10-100 μm, such as 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, and the gap of the slit 502 is 100-200 μm, such as 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, 160 μm, 170 μm, 180 μm, 190 μm. The above-mentioned size design of the micropore and the slit is conducive to the high-speed injection of the material flow, realizing real-time collision mixing and quickly completing the reaction. In this article, the gap of the slit refers to the gap width of the slit.

[0093] In the present invention, Figure 5 As shown, the reaction chamber 205 is preferably semi-ellipsoidal, and the discharge port 206 is preferably bell-bottomed. The bell-bottomed discharge port 206 is connected to the opening of the semi-ellipsoidal reaction chamber 205, so that high-concentration reaction products can be quickly discharged, and continuous reaction can be achieved without blockage.

[0094] The preparation system of the present invention may optionally further include one or more or all of the following equipment or devices: a centrifugal device, a washing device, a filtering device, a drying device, a mixing device, a screening device, a demagnetizing device, and a packaging device. The centrifugal device is used to centrifugally dry the aged positive electrode material precursor slurry. The centrifugal device can be a centrifuge. The washing device is used to perform alkali washing, water washing and other washing operations on the positive electrode material precursor after centrifugal drying. After washing, the filter device is used for filtering. The filter cake is dried into powder particles by a drying device. The drying device can be a dynamic drying device. The dried powder particles enter the mixing device in batches for uniform mixing. The mixing device can be a mixer. The mixed powder is passed through a screening device, such as a screen, to remove large particles that are bonded, and then the magnetic substances in the powder particles are removed by a demagnetizing device, such as a demagnetizer, and finally packaged and packaged into a positive electrode material precursor product by a packaging device, such as a vacuum packaging machine.

[0095] The M ternary positive electrode material precursor of the present invention can be prepared using the preparation system of the present invention. The preparation method can completely avoid the amplification effect, shorten the time from research and development to production of the positive electrode material precursor, and can achieve precise control, and can produce products with stable quality and good consistency. The preparation method of the present invention has a simple start-stop reaction, and the production process greatly reduces the generation of waste and energy consumption compared to traditional production processes.

[0096] In some embodiments, the method for preparing M ternary cathode material precursor includes: providing at least two reaction raw materials to a valve microreactor through a feeding system, allowing each reaction raw material to undergo a co-precipitation reaction in the valve microreactor after passing through a feeding pressure regulating device.

[0097] In some embodiments, the present invention uses Figure 3The preparation system shown prepares M ternary positive electrode material precursor. The salt solution of nickel-cobalt-aluminum or nickel-cobalt-manganese-aluminum is configured according to the process requirements, stored in the first raw material tank 108 and kept warm, and the precipitant (such as sodium hydroxide) and the complexing agent (such as ammonia water) are stirred and mixed uniformly in the second raw material tank 110 according to the proportion and concentration required by the process, and stored warm. Then the feeding devices 301 and 401 are started. Before the flow rate and pressure reach the set flow rate and pressure, valves 304 and 404 can be set to allow the raw materials to enter the feed port of the valve and return to the first raw material tank 108 and the second raw material tank 110 from the reflux port to form a cycle, and the waste of raw materials is eliminated. When the flow rate and pressure meet the process requirements, the reaction raw materials can be switched according to the process. Pipeline 104, fully mixed and quickly reacted to generate M ternary positive electrode material precursor, and then quickly enter the vacuum negative pressure tank 105, after a certain amount of storage, it is placed in the aging device 107 for a certain period of aging. After the reaction is completed, the washing water in the first washing water tank 109 and the second washing water tank 111 is quickly introduced into the first feeding system 101, the second feeding system 102 and the valve microreactor 104 to achieve rapid washing. In the present invention, the flow rate setting value of the feed liquid can be 6-720L / h, such as 10L / h, 20L / h, 50L / h, 100L / h, 200L / h, 500L / h, and the pressure setting value can be 3-30bar, such as 5±0.5bar, 8±0.5bar, 10±0.5bar, 15±0.5bar, 20±0.5bar, 25±0.5bar.

[0098] In some embodiments, the present invention uses Figure 4The preparation system shown prepares M ternary positive electrode material precursor. First, nickel salt, cobalt salt and aluminum salt, or nickel salt, cobalt salt and manganese salt are dissolved into a mixed salt solution of a certain concentration and molar ratio according to the process requirements, and stored in the first raw material tank 108, wherein the total concentration of metal elements can be 0.5-2.2mol / L, for example, 0.8mol / L, 1mol / L, 1.2mol / L, 1.5mol / L, 1.8mol / L, 2mol / L, and the higher the concentration, the greater the production capacity in the corresponding time. In the present invention, when the salt solution contains multiple metal elements, the concentration of metal elements in the salt solution refers to the total concentration of all metal elements. For example, for a mixed salt solution of nickel salt, cobalt salt and manganese salt, the concentration of metal elements refers to the total concentration of nickel, cobalt and manganese. The precipitant and the complexing agent are stored in the second raw material tank 110 and the third raw material tank 112, respectively. The concentration of the precipitant (such as sodium hydroxide solution) can be configured to 2-10mol / L according to the specific process requirements, such as 3mol / L, 4mol / L, 5mol / L, 6mol / L, 7mol / L, 8mol / L, 9mol / L. The concentration of the complexing agent (such as ammonia water) can be 2-10mol / L, such as 3mol / L, 4mol / L, 5mol / L, 6mol / L, 7mol / L, 8mol / L, 9mol / L. The higher the concentration, the greater the product capacity at the corresponding time, and the higher the solid content. The precipitant (such as sodium hydroxide solution) and the complexing agent (such as ammonia water) can be stored in the same raw material tank, but it is more conducive to adjusting the pH of the reaction system to store and feed the precipitant and the complexing agent separately. Then, the first feeding system 101 injects the salt solution into the first heating module 115 through the first inlet module 114 according to the process setting flow rate (the production flow rate can be 6-720L / h), and heats it to a certain temperature, generally 30-65°C, through the heating module. The second feeding system 102 and the third feeding system 103 respectively inject the precipitant and the complexing agent into the mixing module 119 (for example, a stacked mixer) according to the process required flow rate (the production flow rate can be 6-720L / h) through the second inlet module 116 and the third inlet module 117 to fully mix the multiple strands of materials, and quickly heat the raw material liquid in the channel to the temperature required by the process, generally 30-65°C, through the second heating module 120, and then directly pass into the valve microreactor 104. The feed pressure can be 3-30bar, for example, 5±0.5bar, 8±0.5bar, 10±0.5bar, 15±0.5bar, 20±0.5bar, 25±0.5bar. Each heating module is combined with the valve microreactor 104, and the heating module is arranged before the feed port of the valve microreactor to heat the corresponding reaction raw materials to the temperature required by the process before entering the valve microreactor. The salt solution is introduced into the valve microreactor 104 to be fully mixed and reacted with the remaining reaction raw materials entering the valve microreactor 104 from another feed port to generate M ternary positive electrode material precursor.In the real-time reaction process of preparing the M ternary cathode material precursor, the molar ratio of ammonia to metal elements in the reaction system in any instantaneous mixed reaction stage is a fixed value, which is between 0-1. For different series of products, the optimal value interval of the ratio of ammonia to metal elements is different; the molar ratio of sodium hydroxide to metal elements is between 2.2:1 and 1.8:1, ensuring that the pH value is stable during instantaneous reaction, and for different series of products, the optimal value is different, and the optimal value range is between 10-12.5. The preparation method of the present invention makes full use of the efficient mass transfer, heat transfer and mixing performance of the valve microreactor, and quickly mixes the materials evenly in a short time to make it react quickly. The final product flows out to the subsequent aging device 107 (such as aging kettle) via the outlet module 121. After a period of aging, the slurry is pumped into a centrifuge for centrifugal drying, alkali washing, water washing and other washing operations to reduce the content of impurities such as ammonia nitrogen, sodium, and sulfate in the product. The filter cake is then dried continuously and regularly at a fixed process temperature by a dynamic drying device into loose powder particles, which are then fed into a mixer in batches for uniform mixing, and then passed through a screen to remove large particles that are bonded, and then passed through a demagnetizer to remove magnetic substances from the powder particles, and finally packaged and packaged into a qualified positive electrode material precursor by a vacuum packaging machine. In some embodiments, a negative pressure system is provided before aging, and the product first enters a vacuum negative pressure tank and then enters an aging device.

[0099] The M ternary positive electrode material precursor has the advantages of stable quality and good consistency. The M ternary positive electrode material precursor is a secondary particle composed of primary particles of nanometer scale (≤100nm). The particle size of the primary particles of the M ternary positive electrode material precursor is between 10nm-100nm, for example, 20nm, 25nm, 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, 90nm, and the preferred particle size is between 30nm-100nm. In the present invention, the particle size of the primary particles of the M ternary positive electrode material precursor is nanometer scale (≤100nm), while the particle size of the primary particles of the conventional ternary positive electrode material precursor is subnanometer scale to micrometer scale (hundreds of nanometers to several microns). Before flash dynamic drying and pulverization, the particle size D50 of the secondary particles of the M ternary positive electrode material precursor can be between 2μm and 20μm, such as 3μm, 5μm, 7μm, 10μm, 12μm, 15μm, 18μm, and preferably the particle size D50 is between 2μm and 8μm. Before flash dynamic drying and pulverization, the specific surface area of ​​the M ternary positive electrode material precursor is 35-150m 2 / g, preferably 50-110m 2 / g, for example 60m 2 / g, 70m 2 / g, 80m 2 / g, 90m 2 / g、100m 2 / g, which is 7-10 times that of conventional ternary cathode material precursors (the specific surface area of ​​conventional ternary cathode material precursors is generally 5-15m 2 / g). Before flash dynamic drying and pulverization, the shape of the secondary particles of the M ternary cathode material precursor is an irregular shape formed by loosely overlapping primary particles. Herein, the irregular shape includes but is not limited to rod-shaped, disc-shaped, bow-shaped, star-shaped, elliptical, polygonal or any other irregular shape and a mixture of these shapes.

[0100] In the present invention, after the reaction liquid containing the ternary cathode material precursor is prepared using a microchannel reactor, the reaction liquid is sent to an aging device for aging. The aging device can be an aging kettle. The main purpose of aging is to promote the growth of crystal nuclei and improve the uniformity of primary particle agglomerates. Aging is to allow the reaction liquid to continue to react for a period of time. The aging time can be 2-12h, for example, 3h, 4h, 5h, 6h, 7h, 8h, 9h, 10h, 11h. During aging, the temperature of the reaction liquid is preferably controlled to be 25-80°C, preferably 30-65°C, for example 55-65°C, 60±2°C, 60±1°C, 60±0.5°C. The reaction liquid can be stirred during aging, and the stirring speed can be 50-150rpm, preferably 80-100rpm.

[0101] After aging, a slurry containing the precursor of the ternary positive electrode material is obtained, and the aged slurry is then washed and filtered. The washing and filtering preferably make the pH of the washing water ≤ 9.5.

[0102] In some embodiments, washing and filtering comprises the following steps:

[0103] (a) Dehydration: removing the mother liquor from the aged slurry;

[0104] (b) washing: using water at 50-80°C, preferably 60-80°C, for example 70°C, and in a water:material mass ratio of (5-15):1, preferably (6-12):1, for example 8:1, 10:1, the water and the material are sequentially put into a beating kettle for stirring and beating, the beating time is 30-120min, preferably 45-90min, for example 60min, 70min, 80min, the stirring speed is 50-200rpm, preferably 60-150rpm, for example 80rpm, 100rpm, 120rpm, 140rpm;

[0105] (c) Filtration: filtering the slurry after beating;

[0106] (d) Repeat step (b) washing and step (c) filtering, with the total number of washing times being ≥ 2 times, until the pH value of the washing water is ≤ 9.5.

[0107] In step (a), dehydration can be performed by a centrifuge or a filter press. In step (c), filtering can be performed by a centrifuge or a filter press. In step (c), the ternary cathode material precursor slurry after beating can be pumped into a centrifuge or a filter press by a pneumatic diaphragm pump for filtering.

[0108] In the present invention, the positive electrode material precursor is dried and crushed by flash dynamic drying and crushing in the drying and crushing steps. In the present invention, a flash dynamic drying and crushing system is used for flash dynamic drying and crushing. In the present invention, an existing flash dynamic drying and crushing system can be used, such as the flash drying equipment in CN115978952A, CN219199907U, CN218955360U, CN218884551U, CN218955314U, CN218864688U, and CN219199905U.

[0109] In some embodiments, such as Figure 7 As shown, the flash dynamic drying pulverizing system used in the present invention includes an air heater 1, a feeding device 2, a mechanical pulverizer 3, a cyclone separator 4, an air flow pulverizer 5, a first collecting chamber 6, a second collecting chamber 7, a first induced draft fan 8 and a second induced draft fan 9. The air heater 1 and the feeding device 2 are connected to the mechanical pulverizer 3. A blade is provided at the bottom of the mechanical pulverizer 3. The mechanical pulverizer 3 is connected to the cyclone separator 4. The cyclone separator 4 is connected to the air flow pulverizer 5 and the second collecting chamber 7. The air flow pulverizer 5 is connected to the first collecting chamber 6. The first collecting chamber 6 is provided with an ejector. A discharge port is provided at the bottom of the first collecting chamber 6. A ash collecting port is provided at the bottom of the second collecting chamber 7. The first collecting chamber 6 is connected to the first induced draft fan 8, and the second collecting chamber 7 is connected to the second induced draft fan 9.

[0110] In some embodiments, the present invention uses Figure 7 The flash dynamic drying and pulverizing system shown uses the following steps to dry and pulverize the washed and filtered ternary cathode material precursor:

[0111] (A) Coarse pulverization: air is heated by an air heater 1 and then enters a mechanical pulverizer 3. At the same time, the precursor of the ternary cathode material (hereinafter referred to as material) is fed to the mechanical pulverizer 3 by a feeding device 2. A blade is provided at the bottom of the mechanical pulverizer 3. The material is dried and crushed under the action of the high-speed rotating blade and hot air.

[0112] (B) Cyclone separation: Under the negative pressure generated by the first induced draft fan 8 and the second induced draft fan 9, the material enters the cyclone separator 4 from the mechanical pulverizer 3; in the cyclone separator 4, unqualified materials with smaller particle sizes rise to the second collection chamber 7, and materials with larger particle sizes fall from the bottom of the cyclone separator 4 into the air flow pulverizer 5;

[0113] (C) Airflow pulverization: In the airflow pulverizer 5 , compressed air is passed through an ejector to generate a high-speed jet that contacts the material, causing the material to be pulverized to a target particle size and then enter the first collection chamber 6 .

[0114] In the present invention, in the air heater 1, air can be blown into the electric heater by a blower, and the air is heated to a desired temperature by a heating rod. The blower air inlet is preferably designed as a scroll type, which has the advantage of small wind resistance, reducing system resistance and reducing fan power to achieve energy saving effect.

[0115] In the present invention, the feeding device 2 may be provided with a blade arch breaker to prevent the material from bridging in the hopper.

[0116] In the present invention, the feeding device 3 may include a feeding screw, and the material enters the mechanical crusher 3 through the feeding screw of the feeding device 3. The bottom of the mechanical crusher 3 has a high-speed rotating blade, and the material is broken up and crushed under the action of centrifugal force and rotating rising hot air.

[0117] In the present invention, under the action of the vacuum negative pressure generated by the first induced draft fan 8 and the second induced draft fan 9, the material carrying the particles enters the cyclone separator 4, and the unqualified materials with smaller particle sizes rise and enter the second collection chamber 7 (for example, a bag dust collector). The cyclone separator 4 can have a conical barrel wall, and the materials with larger particle sizes slide along the conical barrel wall to the entrance of the air flow pulverizer 5 under the action of gravity and centrifugal force.

[0118] In the present invention, the material enters the air flow mill 5 under the action of the first induced draft fan 8. In the air flow mill 5, the compressed air generates a high-speed jet through the ejector to contact the material. Driven by the high-speed jet, the precursor particles perform high-speed rotation in the air flow milling chamber 5 and generate a strong rotating airflow. Not only will the material particles collide with each other, but the high-speed jet will also have an impact and shearing effect on the material. At the same time, the material and the air flow milling chamber 5 will also have an impact, friction, and shearing effect. Finally, the material that is crushed to the target particle size enters the first collection chamber 6, and the qualified material is collected from the discharge port.

[0119] In the present invention, the first collection chamber 6 and the second collection chamber 7 can be bag dust collectors. The bag dust collector preferably adopts a horizontal flow air intake. The principle is to add an air intake chamber in the length direction of the bag dust collector to increase the air inlet area of ​​the bag dust collector. In this way, the air inlet is enlarged under the condition of unchanged air intake volume, and the wind speed entering the bag dust collector is reduced. The changed wind speed is one fifth of the original wind speed. If it is not changed, the gas carrying dust enters the bag dust collector at a high speed and blows directly on the bag. The dust can easily wear out the bag, causing unintentional powder leakage.

[0120] like Figure 7As shown, in the coarse crushing step, the positive electrode material precursor filter cake after washing and filtering is fed into the mechanical crusher 3 by the feeding device 2. The feeding device 2 may include a screw feeder, and the material enters the mechanical crusher via the screw feeder. The material is mechanically crushed under the action of the mechanical crusher 3, and hot air enters the mechanical crusher 3 from the bottom of the mechanical crusher 3, so that the material is blown and rotated, generating a strong shear force, and the material is micronized due to the effects of centrifugation, shearing, collision, and friction.

[0121] like Figure 7 As shown, in the air flow pulverizing step, the coarsely pulverized material enters the air flow pulverizer 5 under the action of the first induced draft fan 8, and the compressed air generates a high-speed jet through the ejector, which contacts the precursor material in the air flow pulverizer 5. Driven by the high-speed jet, the precursor particles make a high-speed rotation motion in the air flow pulverizer 5 and generate a strong rotating airflow. Not only do the material particles collide with each other, but the high-speed jet also produces an impact and shearing effect on the material. At the same time, the material and the air flow pulverizer 5 also undergo impact, friction, and shearing effects. The qualified pulverized material is sent to the first collection chamber 6 by the air flow and collected through the discharge port of the first collection chamber.

[0122] The present invention accurately controls the moisture, particle size and material processing volume of the positive electrode material precursor product by changing the parameters such as the air inlet temperature, feeding frequency, blast frequency, host frequency, air flow feeding frequency and induced draft frequency of the flash dynamic drying and pulverization, thereby meeting the product specification requirements. Figure 7In the flash dynamic drying pulverizing system shown, the inlet air temperature refers to the temperature of the air after being heated by the air heater 1, the feeding frequency refers to the feeding frequency of the feeding device 2, the blast frequency refers to the air supply frequency of the air heater 1, the host frequency refers to the blade rotation frequency of the mechanical pulverizer 3, the airflow feeding frequency refers to the air supply frequency of the ejector in the airflow pulverizer 5, and the induced draft frequency refers to the induced draft frequency of the first induced draft fan 8. In the present invention, the inlet air temperature can be controlled to 150-250°C, preferably 180-240°C, such as 200°C, 220°C. The feeding frequency can be controlled to 5-30Hz, such as 10Hz, 15Hz, 20Hz, 25Hz. The blast frequency can be controlled to 20-40Hz, such as 25Hz, 30Hz, 32Hz, 35Hz. The host frequency can be controlled to 40-50Hz, such as 42Hz, 44Hz, 46Hz, 48Hz. The airflow feeding frequency can be controlled to be 20-50Hz, such as 25Hz, 30Hz, 35Hz, 40Hz, and 45Hz. The induced draft frequency can be controlled to be 35-50Hz, such as 40Hz and 45Hz. In some embodiments, the feeding frequency is 15-30Hz, and the sum of the feeding frequency and the airflow feeding frequency is 40-80Hz, which helps to control the particle size D90 of the ternary positive electrode material precursor to 1-11μm and the particle size Dmax to 16-60μm. If Dmax is too large, the particles cannot be burned to form an ideal single crystal morphology during the sintering process of the ternary positive electrode material precursor, which will affect the capacity and cycle performance of the subsequent positive electrode material. The larger the particles, the greater the driving force required to form a single crystal. In order to make large particles form a single crystal morphology, small particles will be overburned, which will also reduce the capacity and cycle performance.

[0123] In the present invention, the main control parameters of flash dynamic drying and pulverization are: the inlet air temperature mainly affects the inlet air temperature. Increasing the inlet air temperature can improve the heat exchange efficiency and reduce the moisture content of the outlet material, while too high a temperature will cause the precursor to oxidize and affect the final product quality; reducing the feeding frequency can slow down the feeding rate, thereby increasing the pulverization strength of the unit mass of particles, while too low a frequency will significantly reduce the material processing capacity and affect the equipment capacity; increasing the blast frequency (increasing the air volume in the system) can reduce the particle size to a certain extent, but when the blast frequency is increased to a certain value, the inlet air temperature is unstable and fluctuates greatly, affecting the consistency of the material; reducing the airflow feeding frequency can also improve the pulverization strength and improve the uniformity of the material within a certain range.

[0124] In the present invention, the ternary cathode material precursor after flash dynamic drying and crushing has a spherical morphology. In the present invention, the ternary cathode material precursor after flash dynamic drying and crushing may have one or more or all of the following particle size distribution characteristics:

[0125] Dmin is 0.005~0.015μm, such as 0.007μm, 0.008μm, 0.009μm, 0.01μm, 0.011μm, 0.012μm, 0.013μm;

[0126] D10 is 0.015 to 0.025 μm, for example, 0.017 μm, 0.018 μm, 0.019 μm, 0.02 μm, 0.021 μm, 0.022 μm, 0.023 μm;

[0127] D50 is 0.05 to 0.5 μm, for example, 0.06 μm, 0.07 μm, 0.08 μm, 0.09 μm, 0.1 μm, 0.11 μm, 0.12 μm, 0.15 μm, 0.2 μm, 0.3 μm, 0.4 μm;

[0128] D90 is 1 to 11 μm, for example, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm;

[0129] Dmax is 16 to 60 μm, for example, 20 μm, 30 μm, 40 μm, or 50 μm.

[0130] The ternary positive electrode material can be prepared by sintering the ternary positive electrode material precursor of the present invention.

[0131] In the present invention, the ternary cathode material precursor prepared by the microchannel reactor has a high moisture content (30wt%-70wt%) after washing and filtering due to its large specific surface area and small primary particle size, which cannot meet the traditional disc drying feed moisture requirements; when the static drying method is adopted, although the moisture can meet the product requirements, the material agglomeration phenomenon is serious, and multiple additional crushing processes are required, which significantly increases the complexity of the process; although the spray drying method can solve the problem of uneven material particle size distribution and improve the sphericity at the same time, the operation process is complicated, and the solid content of the slurry needs to be maintained at a low level to improve the fluidity of the material, resulting in a significant increase in cost, which seriously limits the application of the equipment in the production of cathode material precursors.

[0132] Compared with spray drying, the flash dynamic drying and crushing adopted in the present invention has the following significant advantages: a. It has a lower requirement on the moisture content of the feed material, is energy-saving and environmentally friendly, and significantly reduces production energy consumption; b. It has a high degree of automation and saves labor costs; c. It has a simple process, convenient operation, large processing capacity, and short processing cycle; d. The equipment is easy to disassemble and clean, wear-resistant, and simple to maintain.

[0133] The cathode material precursor of the present invention is prepared by microchannel reactor reaction, aging, washing, filtering, flash dynamic drying and crushing, and its remarkable features are high reaction efficiency and reduced control parameters. Therefore, compared with the precursor prepared by the traditional reactor, the cathode material precursor particles of the present invention have small primary particle size, high specific surface area, significantly enhanced reaction activity, and are more conducive to the sintering of the cathode material.

[0134] The present invention uses flash dynamic drying and crushing to achieve particle size control and morphology shaping during the drying and crushing process. The present invention prepares a ternary cathode material precursor through a microchannel reactor, and obtains a ternary cathode material precursor with regular particle size and uniform morphology after aging-washing-filtration-flash dynamic drying and crushing. Compared with the precursor prepared by a traditional microchannel reactor, the particle size and morphology of the product of the present invention are significantly improved. The present invention optimizes the process and improves the equipment for the drying process. Compared with other technologies such as spray drying, the energy consumption is significantly reduced, and the production efficiency and process automation are significantly improved.

[0135] The present invention will be described below in the form of specific examples. It should be understood that these examples are merely illustrative and are not intended to limit the scope of the present invention. The methods, reagents and materials used in the examples are, unless otherwise stated, conventional methods, reagents and materials in the art. The raw material compounds in the examples can all be purchased through commercial routes.

[0136] In the present invention, the testing method of particle size parameters such as Dmin, D10, D50, D90, Dmax, etc. is as follows: the material to be tested is added to the dispersant, and the particle size distribution curve of the material is detected by a Bruker laser particle size analyzer under the condition of an ultrasonic intensity of 20-80%, and the instrument automatically generates corresponding parameters.

[0137] Examples 1-7 and Comparative Examples 1-2

[0138] The following steps are used to prepare the ternary cathode material precursor in Example 1-7 and Comparative Example 1-2, except that the parameters of flash dynamic drying and pulverization are set differently:

[0139] (1) Coprecipitation reaction and aging

[0140] use Figure 4 The preparation system shown in FIG. 1 is used to prepare the M ternary cathode material precursor, wherein the valve microreactor is constructed as shown in FIG. Figure 1 , Figure 5 and Figure 6 As shown, the diameter of the micropore 501 is 50 μm, the gap of the slit 502 is 150 μm, and the structure of the feeding system is as follows Figure 3 As shown, the preparation system includes Figure 4The negative pressure system shown in the figure includes a vacuum negative pressure tank and a negative pressure pump. The vacuum negative pressure tank is arranged between the outlet module 121 and the aging device 107. The negative pressure pump is connected to the vacuum negative pressure tank. The aging device 107 is an aging kettle.

[0141] A mixed solution of multiple salts of certain concentrations and molar ratios prepared by dissolving NiSO4·6H2O, CoSO4·7H2O and MnSO4·H2O is stored in a salt storage tank (first raw material tank 108), wherein the total concentration of metal elements is 2 mol / L, and the molar ratio of nickel, cobalt and manganese metal elements is 65:9:26.

[0142] Sodium hydroxide and ammonia water are prepared into sodium hydroxide solution and ammonia water solution of a certain concentration, which are stored in an alkali storage tank (the second raw material tank 110) and an ammonia storage tank (the third raw material tank 112), respectively. The sodium hydroxide concentration c (NaOH) is 8 mol / L, and the ammonia water concentration c (NH3·H2O) is 5 mol / L.

[0143] The second feeding system 102 and the third feeding system 103 feed the ammonia solution and the sodium hydroxide solution at flow rates of 33.6 L / h and 98.4 L / h respectively according to the process requirements and a feed pressure of 8 bar, and then enter the mixing module 119 (stacked mixer) through the second inlet module 116 and the third inlet module 117 to fully mix the two streams of materials. The raw material liquid in the channel is quickly heated to the process required 45°C through the second heating module 120, and then introduced into the valve microreactor 104.

[0144] The first feeding system 101 feeds a metal salt solution with a total concentration of 2 mol / L and a molar ratio of nickel, cobalt, and manganese metal elements of 65:9:26 into the first heating module 115 through the first inlet module 114 according to the process setting flow rate of 168 L / h and a feed pressure of 8 bar. After being heated to 45° C. by the heating module, it is introduced into the valve microreactor 104 and fully mixed with the mixed solution of ammonia solution and sodium hydroxide solution entering the valve microreactor 104 from the other side to generate the ternary positive electrode material precursor Ni 0.65 Co 0.09 Mn 0.26 (OH)2.

[0145] Finally, the product flows out through the outlet module 121 and is sucked into the subsequent aging device 107 (aging kettle) by the negative pressure system for aging at 60° C. and a stirring rate of 90 rpm for 2 hours.

[0146] (2) Washing and filtration

[0147] Dehydration: The mother liquor of the precursor reaction liquid of the ternary positive electrode material obtained in step (1) is removed by a centrifuge; Washing: Using 80°C hot pure water, according to a water: material ratio of 10:1, the water and the material are sequentially put into a pulping kettle for stirring and pulping, the pulping time is 60 minutes, and the stirring speed is 100 rpm; Filtration: After the pulping, the precursor slurry is pumped into a centrifuge for filtration using a pneumatic diaphragm pump; the filtered material is washed and filtered repeatedly for a total of 3 times, and the pH of the last washing water is ≤9.5.

[0148] (3) Flash dynamic drying and crushing

[0149] use Figure 7 The flash dynamic drying and pulverizing system shown performs flash dynamic drying and pulverizing on the washed and filtered ternary positive electrode material precursor (hereinafter referred to as material). The flash dynamic drying and pulverizing system comprises an air heater 1, a feeding device 2, a mechanical pulverizer 3, a cyclone separator 4, an air flow pulverizer 5, a first collection chamber 6 and a second collection chamber 7. The air heater 1 and the feeding device 2 are connected to the mechanical pulverizer 3, a blade is provided at the bottom of the mechanical pulverizer 3, the mechanical pulverizer 3 is connected to the cyclone separator 4, the cyclone separator 4 is connected to the air flow pulverizer 5 and the second collection chamber 7, the air flow pulverizer 5 is connected to the first collection chamber 6, the first collection chamber 6 is provided with an ejector, the first collection chamber 6 is provided with a discharge port at the bottom, the second collection chamber 7 is provided with an ash collection port at the bottom, the first collection chamber 6 is connected to the first induced draft fan 8, and the second collection chamber 7 is connected to the second induced draft fan 9.

[0150] The steps of flash dynamic drying and crushing are as follows:

[0151] (A) Coarse crushing: air is heated by air heater 1 and then enters mechanical crusher 3. At the same time, the material is fed to mechanical crusher 3 by feeding device 2. A blade is provided at the bottom of mechanical crusher 3. The material is dried and crushed by the high-speed rotating blade and hot air.

[0152] (B) Cyclone separation: Under the negative pressure generated by the first induced draft fan 8 and the second induced draft fan 9, the material enters the cyclone separator 4 from the mechanical pulverizer 3; in the cyclone separator 4, unqualified materials with smaller particle sizes rise to the second collection chamber 7, and materials with larger particle sizes fall from the bottom of the cyclone separator 4 into the air flow pulverizer 5;

[0153] (C) Airflow pulverization: In the airflow pulverizer 5, compressed air is passed through an ejector to generate a high-speed jet that contacts the material, causing the material to be pulverized to a target particle size, and then enters the first collecting chamber 6 to obtain a ternary cathode material precursor product.

[0154] In the air heater 1, air is blown into the electric heater by a blower, and the air is heated to the required temperature by a heating rod. The air inlet of the blower is designed to be a scroll type. The feeding device 2 is provided with a blade arch breaker. The feeding device 3 includes a feeding screw, and the material enters the mechanical pulverizer through the feeding screw of the feeding device 3. There are high-speed rotating blades at the bottom of the mechanical pulverizer, and the material is broken up and crushed under the action of centrifugal force and rotating rising hot air. Under the vacuum negative pressure generated by the first induced draft fan 8 and the second induced draft fan 9, the material carrying particles enters the cyclone separator 4, and the unqualified materials with smaller particle sizes rise and enter the second collection chamber 7. The cyclone separator 4 has a conical barrel wall, and the materials with larger particle sizes slide down the conical barrel wall to the inlet of the airflow pulverizer 5 under the action of gravity and centrifugal force. Under the action of the first induced draft fan 8, the material enters the airflow pulverizer 5. In the air flow mill 5, compressed air is passed through the ejector to generate a high-speed jet to contact the material. Driven by the high-speed jet, the precursor particles perform high-speed rotation in the air flow milling chamber 5 and generate a strong rotating airflow. Not only do the material particles collide with each other, but the high-speed jet also produces an impact shearing effect on the material. At the same time, the material and the air flow milling chamber 5 also have impact, friction, and shearing effects. Finally, the material that is crushed to the target particle size enters the first collection chamber 6, and the qualified material is collected from the discharge port. The first collection chamber 6 and the second collection chamber 7 are bag dust collectors. The bag dust collector adopts a horizontal flow air intake, and an air intake chamber is added in the length direction of the bag dust collector to increase the air inlet area of ​​the bag dust collector. In this way, the air inlet is enlarged while the air intake volume remains unchanged, and the wind speed entering the bag dust collector is reduced. The changed wind speed is one fifth of the original wind speed. According to Table 1, the air inlet temperature, feeding frequency, blowing frequency, main engine frequency, air flow feeding frequency and induced draft frequency in the flash dynamic drying and pulverization are set, and the washed and filtered materials are flashed and dynamically dried to obtain a ternary cathode material precursor product.

[0155] Table 1: Process parameters of flash dynamic drying and pulverization in Examples 1-7 and Comparative Examples 1-2

[0156]

[0157] The particle size distribution of the ternary positive electrode material precursor products of Examples 1-7 and Comparative Examples 1-2 is shown in Table 2.

[0158] Table 2: Particle size distribution of the ternary cathode material precursor products of Examples 1-7 and Comparative Examples 1-2

[0159]

[0160] It can be seen from Table 2 that the ternary positive electrode material precursors of Examples 1-7 have a relatively ideal particle size distribution, and the particle size distribution satisfies: Dmin is 0.005-0.015μm, D10 is 0.015-0.025μm, D50 is 0.05-0.5μm, D90 is 1-11μm, and Dmax is 16-60μm. The particle size Dmax of the ternary positive electrode material precursor of Comparative Example 1 is too large. The particle sizes D90 and Dmax of the ternary positive electrode material precursor of Comparative Example 2 are too large. It can be seen that the process parameters of flash dynamic drying and pulverization will affect the particle size distribution of the ternary positive electrode material precursor. The present invention preferably controls the feeding frequency to 15-30Hz, and the sum of the feeding frequency and the airflow feeding frequency is 40-80Hz.

[0161] Comparative Example 3

[0162] Comparative Example 3 prepares a ternary positive electrode material precursor according to the steps and process parameters of Example 5. The difference from Example 5 is that step (3) of Comparative Example 3 adopts static drying method for drying, and no crushing is performed.

[0163] Comparative Example 4

[0164] Comparative Example 4 prepares a ternary positive electrode material precursor according to the steps and process parameters of Example 5. The difference from Example 5 is that in step (3) of Comparative Example 4, static drying is used for drying, spiral mill is used for coarse crushing, and finally air flow mill is used for crushing.

[0165] Comparative Example 5

[0166] Comparative Example 5: A ternary cathode material precursor is prepared according to the steps and process parameters of Example 5. The difference from Example 5 is that in step (3) of Comparative Example 5, only coarse grinding and cyclone separation are performed, and air flow grinding is not performed.

[0167] The particle size distributions of the ternary cathode material precursor products of Comparative Examples 3-5 are shown in Table 3. The ternary cathode material precursor product of Comparative Example 1 was severely agglomerated and the particle size distribution could not be measured.

[0168] Table 3: Particle size distribution of ternary cathode material precursor products of Comparative Examples 3-5

[0169]

[0170] Figure 8 This is a real picture of the ternary positive electrode material precursor product after flash dynamic drying and crushing in Example 5. Fig. 9 This is a SEM image of the ternary cathode material precursor product after flash dynamic drying and crushing in Example 5.

[0171] Fig.10This is a real picture of the ternary cathode material precursor product after being dried by static drying in Comparative Example 3. Fig.10 It can be seen that the ternary cathode material precursor product of Comparative Example 3 has serious agglomeration phenomenon and needs to be subsequently coarsely broken + pulverized.

[0172] Fig.11 This is a SEM image of the ternary positive electrode material precursor product after being dried by static drying and then coarsely broken and crushed in Comparative Example 4.

[0173] From Table 2, Table 3, Fig. 9 and Fig.11 It can be seen that compared with the ternary cathode material precursor prepared by static drying + coarse crushing + pulverizing, the ternary cathode material precursor prepared by flash dynamic drying and pulverizing of the present invention has very small Dmin, D10, D50 and D90, and the particle size is very regular.

[0174] Fig.12 This is a real shot of the ternary cathode material precursor product prepared in Comparative Example 5. As can be seen from Table 3, without airflow pulverization, the particle size of the ternary cathode material precursor is very large.

Claims

1. A method for preparing a ternary cathode material precursor, characterized in that: The preparation method comprises the following steps: (1) Coprecipitation reaction and aging: A coprecipitation reaction is carried out in a microchannel reactor, and a reaction solution containing a ternary cathode material precursor is obtained after aging; (2) washing and filtering: washing and filtering the ternary cathode material precursor obtained in step (1); (3) Flash dynamic drying and crushing: Flash dynamic drying and crushing the ternary positive electrode material precursor after the treatment in step (2).

2. The preparation method according to claim 1, characterized in that The process parameters of the flash dynamic drying and pulverization in step (3) meet one or more of the following characteristics: The inlet air temperature is 150-250°C, preferably 180-240°C; The feeding frequency is 5-30 Hz, preferably 15-30 Hz; The blowing frequency is 20-40Hz; The host frequency is 40-50Hz; The frequency of airflow feeding is 20-50Hz; The induced air frequency is 35-50Hz; The sum of the feeding frequency and the airflow feeding frequency is 40-80 Hz.

3. The preparation method according to claim 1, characterized in that: In step (3), a flash dynamic drying and pulverizing system is used for flash dynamic drying and pulverizing, wherein the flash dynamic drying and pulverizing system comprises an air heater, a feeding device, a mechanical pulverizer, a cyclone separator, an air flow pulverizer, a first collection chamber, a first induced draft fan, a second collection chamber and a second induced draft fan, wherein the air heater and the feeding device are in communication with the mechanical pulverizer, a blade is provided at the bottom of the mechanical pulverizer, the mechanical pulverizer is in communication with the cyclone separator, the cyclone separator is in communication with the air flow pulverizer and the second collection chamber, the air flow pulverizer is in communication with the first collection chamber, the first collection chamber is provided with an ejector, the first collection chamber is in communication with the first induced draft fan, and the second collection chamber is in communication with the second induced draft fan; Step (3) comprises the following steps: (A) Coarse pulverization: air is heated by the air heater and then enters the mechanical pulverizer, while the material is fed to the mechanical pulverizer by the feeding device, and the material is dried and crushed under the action of the high-speed rotating blades and hot air; (B) Cyclone separation: under the negative pressure generated by the first induced draft fan and the second induced draft fan, the material enters the cyclone separator from the mechanical pulverizer; in the cyclone separator, unqualified materials with smaller particle sizes rise and enter the second collecting chamber, and materials with larger particle sizes fall from the bottom of the cyclone separator into the air flow pulverizer; (C) Airflow pulverization: In the airflow pulverizer, compressed air is passed through an ejector to generate a high-speed jet that contacts the material, causing the material to be pulverized to a target particle size and then enter the first collecting chamber.

4. The preparation method according to claim 1, characterized in that: The chemical formula of the ternary cathode material precursor is Ni x Co y M z (OH)2, wherein 0.6≤x≤0.95, 0<y≤0.2, 0<z≤0.3, x+y+z=1, and M is Al or Mn.

5. The preparation method according to claim 1, characterized in that: In step (1), the ternary cathode material precursor is generated by coprecipitation reaction of nickel salt, cobalt salt and aluminum salt or nickel salt, cobalt salt and manganese salt in the presence of a precipitant and a complexing agent in a microchannel reactor.

6. The preparation method according to claim 5, characterized in that: The microchannel reactor is a valve-type microreactor, which includes a first feed port, a second feed port, a first feed pressure regulating device, a second feed pressure regulating device, a reaction chamber and a discharge port, wherein the first feed port is connected to the reaction chamber via a first flow channel, the second feed port is connected to the reaction chamber via a second flow channel, the first feed pressure regulating device is arranged on the first flow channel between the first feed port and the reaction chamber, and is used to control the feed pressure of the first feed port, the second feed pressure regulating device is arranged on the second flow channel between the second feed port and the reaction chamber, and is used to control the feed pressure of the second feed port, the discharge port is connected to the reaction chamber, the nickel salt, cobalt salt and aluminum salt or the nickel salt, cobalt salt and manganese salt are fed to the reaction chamber via the first flow channel, and the precipitant and complexing agent are fed to the reaction chamber via the second flow channel; Preferably, the ends of the first flow channel and the second flow channel are provided with a plurality of micropores and / or slits distributed in an annular shape, so that the jets ejected from the ends of the first flow channel and the second flow channel correspond one to one, and real-time collision and mixing occur.

7. The preparation method according to claim 1, characterized in that: Step (2) comprises the following steps: (a) Dehydration: removing the mother liquor from the aged material; (b) washing: using water at 50-80° C., preferably 60-80° C., and in a water:material mass ratio of (5-15):1, preferably (6-12):1, the water and the material are sequentially put into a beating kettle for stirring and beating, the beating time is 30-120 min, preferably 45-90 min, and the stirring speed is 50-200 rpm, preferably 60-150 rpm; (c) Filtration: filtering the material after pulping; (d) Repeat step (b) washing and step (c) filtering, with the total number of washing times being ≥ 2 times, until the pH value of the washing water is ≤ 9.

5.

8. A ternary positive electrode material precursor prepared by the preparation method according to any one of claims 1 to 7.

9. The ternary cathode material according to claim 8, wherein the ternary cathode material precursor has one or more of the following characteristics: The Dmin of the ternary cathode material precursor is 0.005 to 0.015 μm; The D10 of the ternary cathode material precursor is 0.015 to 0.025 μm; The D50 of the ternary cathode material precursor is 0.05 to 0.5 μm; The D90 of the ternary cathode material precursor is 1 to 11 μm; The Dmax of the ternary cathode material precursor is 16 to 60 μm.

10. A ternary positive electrode material prepared from the ternary positive electrode material precursor according to claim 8 or 9.

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