WO2023246724A1 - Anode material precursor, anode material, method for preparing same, and use thereof - Google Patents

Abstract

Disclosed are an anode material precursor, an anode material, a method for preparing same, and use thereof. The method for preparing the anode material precursor comprises the following steps: mixing a salt solution of a transition metal and a precipitant solution under a supergravity condition for a coprecipitation reaction to obtain a precipitate, wherein the transition metal is selected from one or more of nickel, iron, manganese, copper, aluminum, cerium, cobalt, zinc, tin, and titanium. The preparation method of the present invention features low energy consumption, low time consumption, and continuous and controllable reaction and enables large-scale, rapid, and high-quality production of the precursor. The precursor prepared according to the present invention is good in morphology, particle size, and consistency, and the anode material prepared from the precursor has excellent electrochemical performance.

Description

A kind of cathode material precursor, cathode material and preparation method and application thereof Technical field

The invention relates to a positive electrode material precursor, a positive electrode material and a preparation method and application thereof.

Background technique

Batteries are increasingly used in people's daily lives and work, as well as in industrial production, such as daily electronic products, low-speed electric vehicles and electric vehicles for transportation, battery devices for energy storage, etc. The production of battery electrode materials often requires the first production of precursors. Its function is to achieve uniform mixing of metal ions on a microscopic scale, and at the same time form nano- or micron-sized particles that meet the requirements in size and morphology, which facilitates the subsequent firing of the materials and The production of electrodes brings out the intrinsic electrochemical capacity of the material. The ternary lithium battery cathode materials currently widely used in electric vehicles are manufactured using such a production process. Sodium-ion batteries have become a hot research topic in battery technology in recent years due to their high safety, abundant raw materials and low cost.

The cathode material of sodium-ion batteries is one of the key materials for sodium-ion batteries. The layered structure transition metal oxide has a high specific capacity and is comparable to the more mature cathode materials of lithium batteries currently on the market in terms of synthesis and battery manufacturing. It has many similarities and is one of the materials that has the potential to be commercially produced as a cathode material for sodium-ion batteries. The relatively optimized manufacturing process of this layered structure transition metal oxide cathode material for sodium ion batteries also starts from the production of co-precipitated precursors.

The currently mature industrial method for producing co-precipitated precursor materials is carried out in a stirred reactor. The metal ion salt solution that needs to be precipitated is added into the stirring reactor through a metering pump, and a precipitating agent (for example, NaOH, Na ₂ CO ₃ , sodium oxalate Na ₂ C ₂ O ₄ , etc.) is added at the same time. In order to ensure uniform concentration in the reactor, it is necessary to select a suitable stirrer and use a high stirring speed. In addition, the feeding should be as slow as possible and the concentration of the feed liquid should be as low as possible to avoid excessive local reactant concentration and the formation of particles of different sizes and low density. Therefore, the efficiency of the stirred tank co-precipitation method for producing precursors is very low. The co-precipitation equipment required to achieve a certain output is very large, and the consistency of the produced products is difficult to control, which makes production difficult and costly.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the shortcomings of low efficiency and difficult to control consistency of battery cathode material precursor produced by co-precipitation method in the prior art, and to provide a cathode material precursor, cathode material and their preparation method and application. The preparation method of the cathode material precursor of the present invention is highly efficient, and the prepared cathode material precursor has good consistency.

The present invention solves the above technical problems through the following technical solutions:

A method for preparing a cathode material precursor, which includes the following steps:

Mix the transition metal salt solution and the precipitant under hypergravity conditions to perform a co-precipitation reaction to obtain a precipitate; where,

The transition metal is selected from one or more of nickel, iron, manganese, copper, aluminum, cobalt, zinc, cerium, tin and titanium.

Using the method of the present invention, a positive electrode material precursor for sodium-ion batteries can be prepared, such as a nickel-iron-manganese ternary precursor or a Prussian blue material.

When the prepared cathode material precursor is a nickel-iron-manganese ternary precursor, the preparation method includes:

The transition metals are preferably nickel, iron and manganese. Among them, the molar ratio of nickel, iron, and manganese is preferably (0-8): (1-8): (1-5), for example, 1:1:1.

The type of salt in the transition metal salt solution may be a conventional salt in the art, such as sulfate.

The transition metal salt solution includes a mixed solution of nickel sulfate, manganese sulfate and ferrous sulfate.

The concentration of the transition metal salt solution is 0.5-4 mol/L, more preferably 2 mol/L, where the concentration refers to the total concentration of all transition metal ions in the salt solution.

The precipitant in the precipitant solution can be a conventional precipitant in the art, such as sodium hydroxide.

The anions in the precipitant solution can be selected from OH ^- , CO ₃ ^2- , HCO ₃ ^- or oxalate C ₂ O ₄ ^2- . For example, the precipitant solution is a sodium hydroxide solution.

Preferably, the concentration of the precipitant solution is 0.5-8 mol/L, more preferably 2 mol/L.

A complexing agent can also be added to the precipitant solution according to routine practices in this field.

Wherein, the complexing agent can be a conventional complexing agent in this field, such as ammonia water, and the concentration of ammonia water is preferably 0.3-1 mol/L, such as 0.56 mol/L.

The rotation speed under the hypergravity condition is 500-3000rpm, such as 2200rpm, 2500rpm or 2700rpm.

In the present invention, supergravity refers to the force that material experiences in an environment that is much larger than the earth's gravitational acceleration (9.8m/s ² ). Supergravity is generally achieved through high-speed rotation. Different reactants enter the high-speed rotating reaction chamber in proportions, and the interior is filled with fillers of different structures. The fluid entering the cavity is rapidly dispersed and mixed under the action of centrifugal force generated by high-speed rotation, thereby achieving rapid microscopic-scale mixing reactions between fluids.

In the present invention, rapid microscopic mixing of the salt solution and the precipitant (alkali) solution can be achieved through supergravity, so that the concentration during the co-precipitation reaction is consistent, and the size of the formed precipitate particles is more uniform.

In the present invention, the hypergravity condition can be achieved by a hypergravity mixer. The packing of the super gravity mixer can be in columnar or mesh shape. The hypergravity mixer can be selected from conventional commercially available hypergravity mixers, for example, the manufacturer is Beijing Kai Meinuo Technology Co., Ltd., the super gravity mixer equipment model is KMN-BCUT-2021-06.

Wherein, in the hypergravity mixer, the salt solution of the transition metal and the precipitant solution are pumped into the hypergravity mixer at a certain flow rate to perform a rapid reaction.

Preferably, the transition metal salt solution and the precipitant solution are pumped into the hypergravity mixer at a flow rate ratio (L/min:L/min) of (0.8-1.2): (0.8-1.2) middle. The ratio of the flow rates is preferably 1:1 (L/min:L/min).

In the present invention, preferably, the flow rate of the transition metal salt solution pumped into the super gravity mixer is 0.5-4L/min, such as 1L/min or 2L/min.

In the present invention, preferably, the flow rate of the precipitant solution pumped into the super gravity mixer is 0.5-4L/min, such as 1L/min or 2L/min.

In the present invention, preferably, the temperature of the co-precipitation reaction is 40-60°C, preferably 50°C.

In the present invention, preferably, the co-precipitation reaction time is 0.01-0.1 s. The reaction time is the residence time of the material in the hypergravity mixer, which can be determined based on the diameter, thickness and reactor speed of the reactor filler, and can be calculated based on basic physical equations.

In the present invention, after the co-precipitation reaction and before obtaining the precipitate, solid-liquid separation, washing, and drying can also be performed according to routine procedures in this field, thereby obtaining the precipitate.

The solid-liquid separation operation may be a conventional solid-liquid separation operation in the art, such as suction filtration, centrifugation or press filtration.

The drying operation may be a conventional drying operation in this field. Preferably, the drying temperature is 100-180°C, more preferably 120°C. The drying time is 10-18h. The drying can be performed in an air atmosphere.

In the present invention, preferably, it also includes the following steps: secondary granulation of the precipitate. By combining secondary granulation with supergravity, multi-field reaction processes can be coupled to quickly synthesize cathode material precursors with uniform particle morphology and size and good performance, and the microstructure and crystal structure of the precursor synthesized in a single supergravity field can be improved.

Wherein, the secondary granulation method includes spray drying, hydrothermal method or aging method, preferably spray drying or hydrothermal method, more preferably hydrothermal method.

When the spray drying is used for secondary granulation, the spray drying preferably includes the following steps: after dissolving the precipitate in a solvent, the inlet temperature is 150-200°C and the outlet temperature is 80-150°C. conditions.

Wherein, the inlet temperature is preferably 200°C, and the outlet temperature is preferably 120°C.

Wherein, the solvent can be a conventional solvent in this field, preferably water or ethanol-aqueous solution.

Wherein, the equipment used in the spray drying may be equipment conventionally used for spray drying in the art, such as a spray dryer.

By coupling spray drying, secondary granulation can be performed to form spherical large-diameter secondary particles, which increases the tap density of the cathode material and the stability of the material during charge and discharge.

When the hydrothermal method is used for secondary granulation, it generally includes the following steps: holding the precipitate at a certain temperature for a certain period of time.

Among them, the heating temperature used in the hydrothermal method is preferably 120-180°C, and more preferably 180°C.

Wherein, the heating time in the hydrothermal method is preferably 8-20h, such as 10, 12 or 14h, more preferably 12h. In the present invention, it is found that different hydrothermal times have an impact on product performance (such as cycle stability).

In the present invention, the equipment used in the hydrothermal method may be equipment commonly used in the field for hydrothermal treatment, such as a hydrothermal kettle.

By performing "dissolution-recrystallization" using a coupled hydrothermal method, spherical particles with uniform morphology can be obtained, and single crystal cathode materials can be synthesized, which greatly improves the cycle stability of cathode materials. At the same time, the small particle single crystal material synthesized by the supergravity-hydrothermal method can also help reduce the sintering temperature and time during the subsequent preparation of cathode materials.

When the prepared cathode material precursor is a Prussian blue material, the preparation method includes the following steps:

(1) Dissolve sodium ferrocyanide, inorganic sodium salt, antioxidant and complexing agent in the solvent, recorded as solution A; dissolve transition metal salt, inorganic sodium salt, antioxidant and complexing agent in the solvent, Marked as solution B;

(2) The solution A and solution B in step (1) are reacted and aged in a hypergravity reactor, and the obtained precipitate is separated and dried to finally obtain a highly crystalline Prussian blue material.

The general structural formula of the Prussian blue material prepared is Na _x M[Fe(CN) ₆ ] _y ·zH ₂ O, where M is one or more transition metals, 0＜x≤2, 0＜y ≤1,0<z≤4.

Preferably:

In step (1):

The inorganic sodium salt is selected from any one of sodium chloride and sodium sulfate, preferably sodium chloride.

The transition metal salt is selected from any one of manganese salts, ferrous salts, nickel salts, copper salts, cobalt salts, aluminum salts, zinc salts, etc., and is particularly preferably any one of manganese sulfate and manganese chloride.

The antioxidant is selected from any one of ascorbic acid, ethanolamine, tartaric acid, citric acid, vitamin E, phosphorous acid, and glutamic acid, and is preferably ascorbic acid.

The complexing agent is selected from any one of sodium citrate, sodium oxalate, disodium ethylenediaminetetraacetate, sodium gluconate, trisodium nitrilotriacetate, sodium tartrate and sodium acetate, and is preferably sodium citrate.

The solvent is preferably deionized water.

The concentration of sodium ferrocyanide is 0.01-3mol/L, and the concentration of manganese sulfate is 0.01-3mol/L. Particularly preferably, the concentration of sodium ferrocyanide is 0.2 mol/L, and the concentration of manganese sulfate is 0.2 mol/L.

In step (2):

The hypergravity reactor can be vertical or horizontal, and the support inside the packing of the hypergravity reactor can be columnar, mesh or other types.

In the hypergravity reactor, when solution A and solution B react, the feeding speed of solution A and solution B is 0.01L/min ~ 1000L/min, the support speed inside the filler is 100r/min ~ 10000r/min, and the reaction temperature The temperature is 20-100°C. A protective atmosphere is introduced throughout the reaction and the temperature is kept constant. After the reaction, a mixed solution containing Prussian blue precipitates is obtained, which is recorded as solution C.

further:

The feeding speed of solution A and solution B is 1~100L/min; the support speed inside the filler is 500r/min~6000r/min; the reaction temperature is 40-80°C; the protective atmosphere is nitrogen, Any of helium gas, neon gas, argon gas, etc., preferably nitrogen gas.

go a step further:

Open the hypergravity reactor, and the support speed in the packing is 1500r/min. Pump solutions A and B into the hypergravity reactor at a rate of 2L/min through a peristaltic pump. The reaction temperature is 60°C. The reaction process is protected by nitrogen and the reaction is completed. Finally, mixed solution C was obtained.

The solution C obtained by the reaction is aged in a hypergravity reactor. The aging process is as follows: the feed speed of solution C is 0.01L/min ~ 1000L/min, and the support speed in the filler is 100r/min ~ 10000r/min. Aging The temperature is 20-100℃, the protective atmosphere is introduced throughout, and the temperature is constant.

Preferably, the aging process: Pump solution C into a hypergravity reactor at 1500 r/min at 60° C. at a rate of 2 L/min, and age for 30 minutes. And the entire process is protected by nitrogen.

After the aging is complete, the precipitate is separated, washed and dried to obtain Prussian blue material.

The invention also provides a cathode material precursor prepared by the aforementioned preparation method.

The present invention also provides an application of the aforementioned cathode material precursor in preparing a sodium-ion battery. The cathode material of the sodium-ion battery is made of the cathode material precursor.

The invention also provides a method for preparing a positive electrode material, which includes the following steps: sintering a mixture of the positive electrode material precursor nickel iron manganese ternary precursor and a sodium source to obtain the positive electrode material as a nickel iron manganese ternary sodium ion positive electrode material Na[Ni _1/3 Fe _1/3 Mn _1/3] O ₂ .

Preferably:

The sodium source may be a conventional sodium source in the art, such as sodium carbonate.

The molar ratio of the cathode material precursor to the sodium source can be based on a conventional stoichiometric ratio, preferably 2:1.

The sintering can adopt conventional sintering methods in this field.

The sintering may be performed in an air atmosphere.

The sintering includes the following steps: the first program: constant temperature at a temperature of 500-600°C for 4-8 hours; the second program: a constant temperature at a temperature of 870-1000°C for 15-24 hours.

Wherein, the temperature in the first stage program and the second stage program can be raised in a programmed temperature rise manner, and the temperature rise rate is preferably 2-8°C/min, more preferably 5°C/min.

The first procedure includes the following steps: constant temperature at 550°C for 5 hours.

The second program includes the following steps: constant temperature at 900°C for 18 hours.

The sintering includes the following steps: 5°C/min to 550°C and constant temperature for 5 hours, and then 5°C/min to 900°C and constant temperature for 18 hours.

Compared with the prior art, the present invention has the following beneficial effects:

(1) The preparation method of the cathode material precursor provided by the present invention is based on supergravity technology and achieves rapid and uniform mixing of transition metal salt ions and precipitating agents or complexing agents on a microscopic scale through rapid microscopic mixing reactions, thereby strengthening production. efficiency, producing precursor particles with uniform composition. Compared with the existing coprecipitation method, the mixing time and reaction time are greatly shortened (the current mixing + aging time of the existing coprecipitation process is about 20 hours, this method The invention synthesizes the precursor in less than 1 hour). In addition, the preparation method of the present invention has low energy consumption, short time, continuous and controllable reaction, high equipment utilization rate, and simple process. It can meet the needs of large-scale production and realize large-scale, rapid and high-quality production of precursors.

(2) The present invention further provides a method for continuously preparing transition metal precipitates as material precursors based on a multi-field coupling process of supergravity technology and other technologies (spray drying, hydrothermal method), further achieving particle size and shape. The precise control of the appearance improves the consistency of the product particle size, improves the electrochemical performance of the precursor and cathode materials (especially the cycle performance), and eliminates the need for long-term heating and aging processes.

(3) In the preparation process of a cathode material precursor Prussian blue material provided by the present invention, the supergravity reactor can adopt a feed rate of n L/min level, which is higher than the 1 ml used for traditional co-precipitation reported in the literature. /min is several orders of magnitude higher. Therefore, the preparation method of the present invention can greatly improve the production efficiency of Prussian blue; at the same time, the high-speed operation supported in the filler of the hypergravity reactor can provide a hypergravity environment up to a thousand times higher. The ion migration speed increases in a hypergravity environment, so the number of crystal defects in the prepared Prussian blue-based materials is reduced, thereby effectively improving the material's capacity and cycle stability. Using the hypergravity reactor used in the present invention to replace the traditional reaction kettle can greatly reduce the size of the equipment, reduce the floor space, and is easy to control and produce on a large scale. For liquid-liquid two-phase reactions, the supergravity reactor used in the present invention refines the basic units of the liquid-phase reaction into micron-level liquid films, liquid lines, liquid beads, etc., which greatly reduces the amplification process of traditional tank reactors. Mass transfer and heat transfer problems. Therefore, the hypergravity reactor is highly controllable and has almost no amplification effect. The hypergravity reactor used in the present invention is used to replace the traditional reactor for aging. Due to its large feed speed and hypergravity environment, the aging time can be greatly shortened and the production efficiency can be improved.

(4) The morphology, particle size, and consistency of the precursor prepared by the present invention are good, and the cathode material made from the precursor has excellent electrochemical performance, especially the cycle stability is significantly improved.

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

Description of the drawings

Figure 1 is a schematic flow chart of the hypergravity rapid microscale mixing reaction and coupling other technologies of the present invention;

Figure 2 is an SEM image of the Na[Ni _1/3 Fe _1/3 Mn _1/3 ]O ₂ compound synthesized in Example 1;

Figure 3 is a charge and discharge curve of the Na[Ni _1/3 Fe _1/3 Mn _1/3 ]O ₂ compound button battery synthesized in Example 1;

Figure 4 is a graph showing the cycle charge and discharge capacity changes of the Na[Ni _1/3 Fe _1/3 Mn _1/3 ]O ₂ compound button battery synthesized in Example 1;

Figure 5 is the XRD pattern of the Na[Ni _1/3 Fe _1/3 Mn _1/3 ]O ₂ compound synthesized in Example 1;

Figure 6 is a charge and discharge curve of the Na[Ni _1/3 Fe _1/3 Mn _1/3 ]O ₂ compound button battery synthesized in Example 2;

Figure 7 is a graph showing the cycle charge and discharge capacity changes of the Na[Ni _1/3 Fe _1/3 Mn _1/3 ]O ₂ compound button battery synthesized in Example 2;

Figure 8 is an SEM image of the Na[Ni _1/3 Fe _1/3 Mn _1/3 ]O ₂ compound synthesized in Example 3;

Figure 9 is a charge and discharge curve of the Na[Ni _1/3 Fe _1/3 Mn _1/3 ]O ₂ compound button battery synthesized in Example 3;

Figure 10 is a graph showing the cycle charge and discharge capacity changes of the Na[Ni _1/3 Fe _1/3 Mn _1/3 ]O ₂ compound button battery synthesized in Example 3;

Figure 11 is the XRD pattern of the Na[Ni _1/3 Fe _1/3 Mn _1/3 ]O ₂ compound synthesized in Example 3;

Figure 12 is an SEM pattern of the Na[Ni _1/3 Fe _1/3 Mn _1/3 ]O ₂ compound synthesized in Example 4;

Figure 13 is a charge and discharge curve of the Na[Ni _1/3 Fe _1/3 Mn _1/3 ]O ₂ compound button battery synthesized in Example 4;

Figure 14 is a graph showing the cycle charge and discharge capacity changes of the Na[Ni _1/3 Fe _1/3 Mn _1/3 ]O ₂ compound button battery synthesized in Example 4;

Figure 15 is the XRD pattern of the Na[Ni _1/3 Fe _1/3 Mn _1/3 ]O ₂ compound synthesized in Example 4.

Figure 16 is a charge and discharge curve of the Na[Ni _1/3 Fe _1/3 Mn _1/3 ]O ₂ compound button battery synthesized in Example 5;

Figure 17 is a graph showing the cycle charge and discharge capacity changes of the Na[Ni _1/3 Fe _1/3 Mn _1/3 ]O ₂ compound button battery synthesized in Example 5;

Figure 18 is the rate performance curve of the sodium-ion battery made of Prussian blue materials in Example 6 and Comparative Example 1;

Figure 19 is the cycle performance curve of the sodium-ion battery made of Prussian blue materials in Example 6 and Comparative Example 1 at a rate of 1C;

Figure 20 is a structural principle diagram of the hypergravity reactor used in the present invention.

The reference numbers in Figure 1 are as follows: 1. Raw material kettle containing transition metal salt solution; 2. Raw material kettle containing precipitant solution; 3. Flow meter; 4. Hypergravity reactor; 5. Spray dryer; 6. Water heating kettle.

The reference signs in Figure 20 are as follows: A is the inlet of solution A, B is the inlet of solution B, C is the outlet of the precipitated product, and D is the inner support of the packing.

Detailed ways

Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present invention and cannot be understood as limiting the present invention.

Taking the ternary precursor of nickel-iron-manganese (molar ratio 1:1:1) as an example, the flow chart of the experimental device for synthesizing the precursor through rapid mixing is shown in Figure 1: raw material kettle 1 filled with transition metal salt solution and The raw materials in the precipitant solution raw material kettle 2 pass through the flow meter 3 and enter the hypergravity reactor 4 for mixing reaction, and then can pass through the spray dryer 5 or the hydrothermal kettle 6 Carry out the secondary granulation process. In the following examples, the volume of the hypergravity mixer used is 0.8L.

Example 1: Preparation of nickel-iron-manganese ternary sodium ion cathode material Na[Ni _1/3 Fe _1/3 Mn _1/3 ]O ₂

1. Preparation of cathode material precursor:

(1) Weigh 175.2g of nickel sulfate hexahydrate, 112.7g of hydrated manganous sulfate, and 185.3g of ferrous sulfate heptahydrate according to the molar ratio Ni:Fe:Mn=1:1:1, and add 791.3g of deionized water to the salt solution Stir in the tank until dissolved. The concentration of the salt solution is 2mol/L; where the concentration of the salt solution refers to the total concentration of all transition metal ions in the salt solution;

(2) Prepare 2 mol/L NaOH solution in the alkali tank, add a certain proportion of ammonia water as a complexing agent in the alkali tank, and the ammonia concentration in the alkali tank is 0.56 mol/L;

(3) Start the super gravity mixer and adjust the speed to 2500rpm;

(4) Adjust the flow rate of the metering pumps of the salt solution and the alkali solution to 1L/min, and turn on the two metering pumps at the same time; the salt solution and the alkali solution undergo a co-precipitation reaction in the supergravity mixer, and the salt solution and the alkali solution are mixed. The pH of the solution is controlled at 9-11; the reaction temperature is controlled at 50°C. The reaction time is reflected by the rotation speed of the supergravity filler, which is generally 0.01-0.1s (the discharge rate is consistent with the feed rate, and the reaction time is when the material is in the reactor The residence time is related to the reactor volume and the rotation speed of the super gravity filler);

(5) Collect the discharge material from the hypergravity reactor, vacuum filter and wash it. Place the filter cake in a blast oven and bake at 120°C for 10 hours to remove water. The dried solid powder is the nickel iron manganese ternary precursor.

2. Preparation of cathode materials:

Using the nickel-iron-manganese ternary precursor prepared above, evenly mix in the required sodium source (Na ₂ CO ₃ ). The molar ratio of the sodium source to the precursor is 1:2. Through the sintering process (sintering in air atmosphere, 5°C /min to 550°C and constant temperature for 5 hours, and then 5°C/min to 900°C and constant temperature for 18 hours) to prepare the nickel-iron-manganese ternary sodium ion cathode material Na[Ni _1/3 Fe _1/3 Mn _1/3 ]O ₂ .

Example 2: Preparation of nickel-iron-manganese ternary sodium ion cathode material Na[Ni _1/3 Fe _1/3 Mn _1/3 ]O ₂

The preparation method is the same as Example 1, except that in the preparation of the cathode material precursor: the rotation speed of the supergravity mixer in step (3) is 1800 rpm.

Example 3: Preparation of nickel-iron-manganese ternary sodium ion cathode material Na[Ni _1/3 Fe _1/3 Mn _1/3 ]O ₂

A method for preparing a cathode material precursor, which uses a rapid microscale mixing reaction coupled with a spray drying process to prepare a transition metal precipitate as a precursor, which specifically includes the following steps:

(1) Weigh 175.2g of nickel sulfate hexahydrate, 112.7g of hydrated manganous sulfate, and 185.3g of ferrous sulfate heptahydrate according to the molar ratio Ni:Fe:Mn=1:1:1, and add 791.3g of deionized water to the salt solution Stir in the tank until dissolved; the concentration of the salt solution is 2mol/L;

(2) Prepare 2 mol/L NaOH solution in the alkali tank, add a certain proportion of ammonia water as a complexing agent in the alkali tank, and the ammonia concentration in the alkali tank is 0.56 mol/L;

(3) Start the super gravity mixer and adjust the speed to 2500rpm;

(4) Adjust the flow rate of the metering pumps of the salt solution and the alkali solution to 1L/min, and turn on the two metering pumps at the same time; the salt solution and the alkali solution undergo a co-precipitation reaction in the supergravity mixer, and the salt solution and the alkali solution are mixed. The pH of the solution is controlled at 9-11; the reaction temperature is controlled at 50°C, and the speed of the super gravity filler is reflected, generally 0.01-0.1s;

(5) Collect the discharge material from the hypergravity reactor, vacuum filter and wash it. Dissolve the obtained solid in deionized water and perform secondary granulation through spray drying (inlet temperature is 200°C, outlet temperature is 120°C, and the equipment is a spray dryer). The obtained powder is spray-dried nickel iron. Manganese ternary precursor.

Preparation of cathode materials:

Utilize the nickel-iron-manganese ternary precursor prepared in the above step (5), and evenly mix in the required sodium source ((Na ₂ CO ₃ ). The molar ratio of the sodium source to the precursor is 1:2. Through the sintering process (air atmosphere Sintering at 5°C/min, rising to 550°C at a constant temperature for 5 hours, then rising to a constant temperature of 900°C at 5°C/min for 18h), the nickel-iron-manganese ternary sodium ion cathode material Na[Ni _1/3 Fe _1/3 Mn _{1 /3} ]O ₂ .

Example 4: Preparation of nickel-iron-manganese ternary sodium ion cathode material Na[Ni _1/3 Fe _1/3 Mn _1/3 ]O ₂

A method for preparing a cathode material precursor, which uses a rapid microscale mixing reaction coupled with a hydrothermal process to prepare a transition metal precipitate as a precursor, which specifically includes the following steps:

(1) Weigh 175.2g of nickel sulfate hexahydrate, 112.7g of hydrated manganous sulfate, and 185.3g of ferrous sulfate heptahydrate according to the molar ratio Ni:Fe:Mn=1:1:1, and add 791.3g of deionized water to the salt solution Stir in the tank until dissolved. The concentration of the salt solution is 2mol/L;

(2) Prepare a 2 mol/L NaOH solution and add a certain proportion of ammonia in the alkali tank as a complexing agent. The ammonia concentration in the alkali solution is 0.56 mol/L;

(3) Start the super gravity mixer and adjust the speed to 2500rpm;

(4) Adjust the flow rate of the metering pumps of the salt solution and the alkali solution to 1L/min, and turn on the two metering pumps at the same time; the salt solution and the alkali solution undergo a co-precipitation reaction in the supergravity mixer, and the salt solution and the alkali solution are mixed. The pH of the solution is controlled at 9-11; the reaction temperature is controlled at 50°C, and the reaction time is reflected by the rotation speed of the supergravity filler, which is generally 0.01-0.1s;

(5) Collect the discharged material from the hypergravity reactor and place it directly into a hydrothermal kettle, keeping the temperature constant at 180°C for 12 hours. Vacuum filter and wash the hydrothermal material. Place the filter cake in a blast oven and dry it at 120°C for 10 hours. water. The obtained powder is the nickel-iron-manganese ternary precursor after hydrothermal treatment.

Preparation of cathode materials:

Utilize the nickel-iron-manganese ternary precursor prepared in the above step (5), and evenly mix in the required sodium source (Na ₂ CO ₃ ). The molar ratio of the sodium source to the precursor is 1:2. Through the sintering process (under air atmosphere Sintering, 5℃/min to 550℃ and constant temperature for 5h, then 5℃/min to 900℃ and constant temperature for 18h) to prepare nickel iron manganese ternary sodium ion cathode material Na[Ni _1/3 Fe _1/3 Mn _{1/ 3} ]O ₂ .

Example 5: Preparation of nickel-iron-manganese ternary sodium ion cathode material Na[Ni _1/3 Fe _1/3 Mn _1/3 ]O ₂

A method for preparing a cathode material precursor, which uses a rapid microscale mixing reaction coupled with a hydrothermal process to prepare a transition metal precipitate as a precursor, which specifically includes the following steps:

(1) Weigh 175.2g of nickel sulfate hexahydrate, 112.7g of hydrated manganous sulfate, and 185.3g of ferrous sulfate heptahydrate according to the molar ratio Ni:Fe:Mn=1:1:1, and add 791.3g of deionized water to the salt solution Stir in the tank until dissolved. The concentration of the salt solution is 2mol/L;

(2) Prepare 2mol/L NaOH solution in the alkali tank;

(3) Start the super gravity mixer and adjust the speed to 2500rpm;

(4) Adjust the flow rate of the metering pumps of the salt solution and the alkali solution to 2L/min, and turn on the two metering pumps at the same time; the salt solution and the alkali solution undergo a co-precipitation reaction in the supergravity mixer, and the salt solution and the alkali solution are mixed. The pH of the solution is controlled at 9-11; the reaction temperature is controlled at 50°C, and the reaction time is reflected by the rotation speed of the supergravity filler, which is generally 0.01-0.1s;

(5) Collect the discharged material from the supergravity reactor and place it directly into a hydrothermal kettle at a constant temperature of 180°C for 14 hours. Vacuum filter and wash the hydrothermal material. Place the filter cake in a blast oven and dry it at 120°C for 10 hours. water. The obtained powder is the nickel-iron-manganese ternary precursor after hydrothermal treatment.

Preparation of cathode materials:

Utilize the nickel-iron-manganese ternary precursor prepared in the above step (5), and evenly mix in the required sodium source (Na ₂ CO ₃ ). The molar ratio of the sodium source to the precursor is 2:1. Through the sintering process (under air atmosphere Sintering, 5℃/min to 550℃ and constant temperature for 5h, then 5℃/min to 900℃ and constant temperature for 18h) to prepare nickel iron manganese ternary sodium ion cathode material Na[Ni _1/3 Fe _1/3 Mn _{1/ 3} ]O ₂ .

Effect Example

1. Material characterization

The nickel-iron-manganese ternary sodium ion cathode materials prepared in Examples 1, 3, and 4 were characterized by SEM and SEM images of ion cathode materials. Figures 5, 11, and 15 are XRD patterns of the nickel-iron-manganese ternary sodium ion cathode materials obtained in Examples 1, 3, and 4 respectively.

It can be seen from the XRD pattern that the ternary sodium ion battery cathode material with good crystal form was synthesized using the synthesis process of the present invention.

2.Electrochemical performance test

Production of button batteries for electrochemical performance testing: Mix the nickel-iron-manganese ternary sodium ion cathode material prepared in Examples 1-5, conductive agent and binder evenly at a mass ratio of 8:1:1, and apply them on on aluminum foil, and then dried in a vacuum oven for 12 hours to make pole pieces. The pole pieces are taken out and cut into discs with a diameter of 12mm. Make a button battery in the glove box, take the positive electrode case, place the electrode piece on the positive electrode case, drip in a certain amount of electrolyte, and put in the separator for later use. Metal sodium is cut, rolled and punched to obtain round sodium flakes. Place the nickel mesh on the sodium sheet, then put the sodium sheet into the positive electrode case, add electrolyte and cover the negative electrode case, and finally press and seal to obtain a button battery. (Note: The above button cells are half cells. Half cells are generally used for laboratory testing. Their performance is generally lower than that of full cells, which is normal.)

Electrochemical performance test: The button cells (half cells) prepared above were tested under the conditions of 0.2C, 25℃, and 2-4V, and the charge and discharge curves were obtained, as shown in Figures 3, 6, 9, 13, and 16. Test under the conditions of 1C, 25℃, 2-4V, and obtain the cycle charge and discharge capacity change diagram, as shown in Figures 4, 7, 10, 14, and 17.

After the above electrochemical performance test, the measured electrochemical performance results are as follows in Table 1:

Table 1. Electrochemical performance test results of Examples 1-5 nickel iron manganese ternary sodium ion cathode materials

It can be seen from the electrochemical performance test results that the cathode material prepared by the direct supergravity method has a high initial capacity, but the cycle performance is average; after the secondary granulation in the coupled spray drying process, the initial capacity decreases slightly, but the cycle performance is greatly improved; coupled water After the thermal process, the precursor undergoes a "dissolution-recrystallization" process, which greatly improves the material morphology, although the initial capacity is slightly decreased, but greatly improved cycle stability.

Example 6: Preparation of Prussian blue material Na _1.8 Mn[Fe(CN) ₆ ] _0.95 ·0.1H ₂ O

(1) Take a beaker and add 2g ascorbic acid, 0.2mol sodium ferrocyanide, 3mol sodium chloride and 0.2mol sodium tartrate in 1000mL deionized water at 60°C to obtain solution A;

(2) Take a beaker and add 2g ascorbic acid, 0.2mol manganese sulfate, 2mol sodium chloride and 0.1mol sodium acetate in 1000mL deionized water at 60°C to obtain solution B;

(3) Turn on the hypergravity reactor, set the support speed in the packing to 1500r/min, and pump solutions A and B into the hypergravity reactor at a rate of 2L/min through a peristaltic pump. The reaction temperature is 60°C. The reaction process is protected by nitrogen. , after the reaction is completed, precipitation mixture C is obtained;

(4) Under nitrogen protection, re-pump the C solution into the 1500r/min hypergravity reactor at 60°C at a rate of 2L/min for aging for 30min.

(5) After the aging is completed, separate the precipitate from the precipitated mixture through a centrifuge, wash it three times with deionized water and once with ethanol, dry it in a blast oven at 80°C for 2 hours, and then dry it in a vacuum oven at 120°C. After 12 hours, the solid powder obtained was Prussian blue material Na _1.8 Mn[Fe(CN) ₆ ] _0.95 ·0.1H ₂ O.

Examples 6-1～6-4: Preparation of Prussian blue material Na _1.8 Mn[Fe(CN) ₆ ] _0.95 ·0.1H ₂ O

The preparation method is the same as in Example 6, except that the reaction speed of step (3) and the feed rates of solutions A and B are adjusted as shown in Table 2, and their influence on the particle size of the prepared Prussian blue material is tested.

Table 2. Effect of different reaction speeds on the reaction

Analysis: As shown in Table 2, the reaction speed has a great influence on the particle size of the prepared Prussian blue material. As the reaction speed increases, the particle size of the prepared Prussian blue material also increases accordingly.

Examples 6-5～6-13: Preparation of Prussian blue material Na _1.8 Mn[Fe(CN) ₆ ] _0.95 ·0.1H ₂ O

The preparation method is the same as in Example 6, except that the complexing agent, reaction solution concentration, reaction temperature, aging method, antioxidant, protective atmosphere, M salt selection, inorganic sodium salt, aging time, etc. are adjusted respectively, as shown in the table 3, and test its effect on the particle size of the prepared Prussian blue material.

Example 6-5: Effect of changing complexing agent on reaction

In this example, the complexing agents in steps (1) and (2) were replaced with sodium oxalate, and the remaining experimental conditions were the same as in Example 6.

Example 6-6: Effect of adjusting the concentration of the reaction solution on the reaction

In this example, the concentration of sodium ferrocyanide was adjusted to 0.02 mol/L, and the concentration of manganese sulfate was adjusted to 0.02 mol/L. The remaining experimental conditions were the same as in Example 6.

Example 6-7: Effect of adjusting reaction temperature on reaction

In this example, the reaction temperature and aging temperature were both adjusted to 75°C, and the remaining experimental conditions were the same as in Example 6.

Example 6-8: Effect of adjusting aging method on reaction

In this embodiment, the aging method was adjusted to use conventional stirring for aging, and the remaining experimental conditions were the same as in Example 6.

Example 6-9: Adjusting the impact of antioxidants on the reaction

In this example, the antioxidant in steps (1) and (2) was adjusted to glutamic acid, and the remaining experimental conditions were the same as in Example 6.

Example 6-10: Effect of adjusting the protective atmosphere on the reaction

In this embodiment, the protective atmosphere in step (3) was adjusted to argon, and the other experimental conditions were the same as in Example 6.

Example 6-11: Effect of replacing M salt on the reaction

In this example, the M salt was replaced with manganese chloride, and the remaining experimental conditions were the same as in Example 6.

Example 6-12: Effect of replacing inorganic sodium salt on the reaction

In this example, all inorganic sodium salts were replaced with sodium sulfate, and the remaining experimental conditions were the same as in Example 6.

Example 6-13: Effect of adjusting aging time on reaction

In this embodiment, the aging time is adjusted to 5 minutes, and the other experimental conditions are the same as in Example 6.

Table 3. Influence of other factors on response

Example 7: Preparation of Prussian blue material Na _1.85 Mn _0.5 Ni _0.5 [Fe(CN) ₆ ] _0.94 ·0.2H ₂ O

(1) Take a beaker and add 2g ascorbic acid, 0.2mol sodium ferrocyanide, 8mol sodium chloride and 0.4mol sodium oxalate in 1000mL deionized water at 80°C to obtain solution A;

(2) Take a beaker and add 2g ascorbic acid, 0.1mol manganese sulfate, 0.1mol nickel sulfate, 8mol sodium chloride and 1mol sodium citrate in 1000mL deionized water at 80°C to obtain solution B;

(3) Turn on the hypergravity reactor, set the support speed in the packing to 1500r/min, and pump solutions A and B into the hypergravity reactor at a rate of 1L/min through a peristaltic pump. The reaction temperature is 80°C. The reaction process is protected by nitrogen. , after the reaction is completed, precipitation mixture C is obtained;

(4) Under nitrogen protection, re-pump the C solution into a 1500r/min hypergravity reactor at 80°C at a rate of 1L/min for aging for 30min.

(5) After the aging is completed, separate the precipitate from the precipitated mixture through a centrifuge, wash it three times with deionized water and once with ethanol, dry it in a blast oven at 80°C for 2 hours, and then dry it in a vacuum oven at 120°C. After 12h, Prussian blue material Na _1.85 Mn _0.5 Ni _0.5 [Fe(CN) ₆ ] _0.94 ·0.2H ₂ O was obtained.

Examples 7-1 to 7-4: Preparation of Prussian blue materials Na _1.85 Mn _0.5 Ni _0.5 [Fe(CN) ₆ ] _0.94 ·0.2H ₂ O

The preparation method is the same as Example 7, except that the feeding speeds of A and B in step (3) are adjusted (the feeding speeds of A and B are the same) as shown in Table 4, and their effect on the particle size of the prepared Prussian blue material is tested. Impact.

Table 4. Effect of feed rate on reaction

Example 8: Preparation of Prussian blue material Na _1.92 Mn[Fe(CN) ₆ ] _0.96 ·0.08H ₂ O

(1) Take a beaker and add 2g ascorbic acid, 0.1mol sodium ferrocyanide, 5mol sodium chloride and 0.4mol sodium gluconate in 1000mL deionized water at 40°C to obtain solution A;

(2) Take a beaker and add 2g ascorbic acid, 0.1mol manganese sulfate, 8mol sodium chloride and 0.2mol disodium ethylenediaminetetraacetate into 1000mL deionized water at 40°C to obtain solution B;

(3) Turn on the hypergravity reactor, set the support speed in the filler to 4000r/min, and pump solutions A and B into the hypergravity reactor at a rate of 1L/min through a peristaltic pump. The reaction temperature is 40°C, and the reaction process is protected by nitrogen. , after the reaction is completed, precipitation mixture C is obtained;

(4) Pump the C solution back into the 4000r/min hypergravity reactor at 40°C at a rate of 1L/min for aging for 30min.

(5) After the aging is completed, separate the precipitate from the precipitated mixture through a centrifuge, and wash it three times with deionized water. After washing once with ethanol, it was dried in a blast oven at 80°C for 2 hours, and then dried in a vacuum oven at 120°C for 12 hours to obtain Prussian blue material Na _1.92 Mn[Fe(CN) ₆ ] _0.96 ·0.08H ₂ O.

Examples 8-1 to 8-4: Preparation of Prussian blue material Na _1.92 Mn[Fe(CN) ₆ ] _0.96 ·0.08H ₂ O

The preparation method is the same as in Example 8, except that the feed speed and reaction speed of A and B in step (3) are adjusted, as shown in Table 5, and their impact on the particle size of the prepared Prussian blue material is tested.

Table 5. Effect of synergy between feed speed and rotation speed on reaction

Example 9: Preparation of Prussian blue material Na _1.81 Mn[Fe(CN) ₆ ] _0.93 ·0.15H ₂ O

(1) Take a beaker and add 1g ascorbic acid, 0.1mol sodium ferrocyanide, 4mol sodium chloride and 0.2mol sodium tartrate in 1000mL deionized water at 60°C to obtain solution A;

(2) Take a beaker and add 1g ascorbic acid, 0.3mol manganese sulfate, 4mol sodium chloride and 0.2mol sodium citrate in 1000mL deionized water at 60°C to obtain solution B;

(3) Turn on the hypergravity reactor, set the support speed in the packing to 600r/min, and pump solutions A and B into the hypergravity reactor at a rate of 2L/min through a peristaltic pump. The reaction temperature is 60°C, and the reaction process is protected by nitrogen. , after the reaction is completed, precipitation mixture C is obtained;

(4) Pump the C solution back into the hypergravity reactor at 600r/min at 60°C at a rate of 2L/min for aging for 30min.

(5) After the aging is completed, separate the precipitate from the precipitated mixture through a centrifuge, wash it three times with deionized water and once with ethanol, dry it in a blast oven at 80°C for 2 hours, and then dry it in a vacuum oven at 120°C. After 12h, Prussian blue material Na _1.81 Mn[Fe(CN) ₆ ] _0.93 ·0.15H ₂ O was obtained.

Examples 9-1 to 9-4: Preparation of Prussian blue material Na _1.81 Mn[Fe(CN) ₆ ] _0.93 ·0.15H ₂ O

The preparation method is the same as Example 9, except that the reaction speed of step (3), the C feed speed and aging speed of step (4) are adjusted, as shown in Table 6, and their effect on the prepared Prussian blue material is tested. Effect of particle size.

Table 6. The synergistic effect of reaction speed and aging speed on the reaction

Comparative Example 1: Preparation of Na _1.4 Mn[Fe(CN) ₆ ] _0.75 ·2.2H ₂ O by co-precipitation method

Add 1000 mL deionized water, 0.1 mol sodium ferrocyanide, 2 g ascorbic acid, 8 mol sodium chloride and 0.4 mol sodium tartrate to the flask, stir to fully dissolve, place in a 60°C water bath and pass in nitrogen to obtain solution A;

Take a beaker and add 2g ascorbic acid, 0.1mol manganese sulfate, 8mol sodium chloride and 0.4mol sodium acetate in 1000mL deionized water at 60°C to obtain solution B;

Pump solution B into solution A through a peristaltic pump at a rate of 1 mL/min, and the reaction process is protected by nitrogen;

After the reaction is completed, the precipitate mixture is obtained by aging at 60°C for 12 hours. The precipitate mixture is separated by a centrifuge, washed three times with deionized water and once with ethanol, and then dried in a blast oven at 80°C for 2 hours. Then it was dried in a vacuum oven at 120°C for 12 hours to obtain the co-precipitated Prussian blue material Na _1.4 Mn[Fe(CN) ₆ ] _0.75 ·2.2H ₂ O.

Performance comparison:

The Prussian blue material prepared by supergravity prepared in Example 6 and the Prussian blue material prepared by co-precipitation in Comparative Example 1 were respectively prepared into positive electrode sheets and assembled into a CR2016 button battery, in which the negative electrode used sodium sheets and the electrolyte sodium The salt is sodium hexafluorophosphate, and rate and cycle performance tests were conducted at a voltage of 2-4V. The results are shown in Figures 18 and 19.

From Figure 18, it can be seen that the doped cathode material in Example 6 is better than Comparative Example 1 in rate performance. At the same time, it can be seen from Figure 19 that the cycle performance of Example 6 is significantly better than Comparative Example 1, which illustrates that super gravity The reactor synthesis method effectively improves the rate performance and cycle performance of Prussian blue cathode materials.

Claims (17)

A preparation method of a cathode material precursor, characterized in that it includes the following steps: mixing a salt solution of a transition metal and a precipitant solution under hypergravity conditions, performing a co-precipitation reaction, and obtaining a precipitate, wherein: the transition metal The metal is selected from one or more of nickel, iron, manganese, copper, aluminum, cerium, cobalt, zinc, tin and titanium. The preparation method of a positive electrode material precursor according to claim 1, characterized in that: the positive electrode material precursor is a positive electrode material precursor for sodium ion batteries, and the positive electrode material precursor is nickel iron manganese trioxide. Precursor or Prussian Blue type materials. The preparation method of a positive electrode material precursor according to claim 1, characterized in that: the positive electrode material precursor is a nickel iron manganese ternary precursor; And/or, the transition metal is nickel, iron and manganese; wherein the molar ratio of nickel, iron and manganese is (0-8): (1-8): (1-5); And/or, the type of salt in the transition metal salt solution is sulfate; And/or, the transition metal salt solution includes a mixed solution of nickel sulfate, manganese sulfate and ferrous sulfate; And/or, the concentration of the salt solution of the transition metal is 0.5-4mol/L, wherein the concentration refers to the total concentration of all transition metal ions in the salt solution; And/or, the anions in the precipitant solution are selected from OH ^- , CO ₃ ^2- , HCO ₃ ^- or oxalate C ₂ O ₄ ^2- ; And/or, the concentration of the precipitant solution is 0.5-8mol/L; And/or, the precipitant solution further includes a complexing agent, the complexing agent may be ammonia water, and the concentration of the ammonia water is 0.3-1 mol/L. The preparation method of a positive electrode material precursor according to claim 1, characterized in that: the positive electrode material precursor is a nickel iron manganese ternary precursor; The rotation speed under the hypergravity condition is 500-3000rpm; And/or, the hypergravity condition is achieved by a hypergravity mixer; wherein, The salt solution of the transition metal and the precipitant solution are pumped into the hypergravity mixer at a flow rate ratio of (0.8-1.2): (0.8-1.2); The flow rate of the transition metal salt solution pumped into the super gravity mixer is 0.5-4L/min; The flow rate of the precipitant solution pumped into the super gravity mixer is 0.5-4L/min; And/or, the temperature of the co-precipitation reaction is 40-60°C; And/or, the co-precipitation reaction time is 0.01-0.1s; And/or, after the co-precipitation reaction and before obtaining the precipitate, solid-liquid separation, washing, and drying are also performed to obtain the precipitate; wherein, The solid-liquid separation operation may be suction filtration, centrifugation or press filtration; The drying temperature can be 100-180°C, and the drying time can be 10-18 hours; the drying can be performed in an air atmosphere. The preparation method of a cathode material precursor according to claim 3, characterized in that: the preparation method further includes the following steps: secondary granulation of the precipitate, and the secondary granulation method includes Spray drying, hydrothermal method or aging method, wherein, When the spray drying is used for secondary granulation, the spray drying includes the following steps: after dissolving the precipitate in a solvent, the inlet temperature is 150-200°C and the outlet temperature is 80-150°C. squirt; The solvent is water or ethanol-water solution; When the hydrothermal method is used for secondary granulation, the heating temperature used in the hydrothermal method is 120-180°C; Wherein, the heating time in the hydrothermal method is 8-20h. A method for preparing a positive electrode material precursor according to claim 1, characterized in that: the positive electrode material precursor is a Prussian blue material, and the preparation of the Prussian blue material includes the following steps: (1) Dissolve sodium ferrocyanide, inorganic sodium salt, antioxidant and complexing agent in the solvent, recorded as solution A; dissolve transition metal salt, inorganic sodium salt, antioxidant and complexing agent in the solvent, Marked as solution B; (2) The solution A and solution B in step (1) are reacted and aged in a hypergravity reactor, and the obtained precipitate is separated and dried to obtain a Prussian blue material. The preparation method of a cathode material precursor according to claim 6, characterized in that: in step (1): the inorganic sodium salt is selected from any one of sodium chloride and sodium sulfate; the transition metal salt Any one selected from manganese salts, ferrous salts, nickel salts, copper salts, cobalt salts, aluminum salts, and zinc salts; the antioxidant is selected from ascorbic acid, ethanolamine, tartaric acid, citric acid, vitamin E, phosphorous acid, glutathione, Any one of amino acids; the complexing agent is selected from any one of sodium citrate, sodium oxalate, disodium edetate, sodium gluconate, trisodium nitrilotriacetate, sodium tartrate and sodium acetate. The preparation method of a cathode material precursor according to claim 6, characterized in that: in step (1): the solvent is deionized water, the concentration of sodium ferrocyanide is 0.01~3mol/L, and the sulfuric acid The manganese concentration is 0.01~3mol/L. The method for preparing a cathode material precursor according to claim 6, characterized in that: in step (2): when solution A and solution B react in the hypergravity reactor, the flow of solution A and solution B is The material speed is 0.01L/min~1000L/min, the support speed inside the filler is 100r/min~10000r/min, the reaction temperature is 20-100℃, and the reaction is complete The process was introduced into a protective atmosphere and kept at a constant temperature. After the reaction, a mixed solution containing Prussian blue precipitates was obtained, which was recorded as solution C. The method for preparing a cathode material precursor according to claim 6, characterized in that: in step (2): the feeding speed of the solution A and solution B is 1 to 100/min; the filler is supported within the The rotation speed is 500r/min～6000r/min; the reaction temperature is 40-80°C; the protective atmosphere is any one of nitrogen, helium, neon and argon. A method for preparing a cathode material precursor according to claim 6, characterized in that: in step (2): the hypergravity reactor is opened, the support speed in the filler is 1500r/min, and the peristaltic pump is used at a rate of 2L/min. Pump solutions A and B into the hypergravity reactor respectively. The reaction temperature is 60°C. The reaction process is protected by nitrogen. After the reaction is completed, the mixed solution is recorded as solution C. The preparation method of a cathode material precursor according to claim 9, characterized in that: in step (2): the solution C obtained by the reaction is aged in a hypergravity reactor, and the aging process is as follows: the solution C is The material speed is 0.01L/min ~ 1000L/min, the support speed inside the filler is 100r/min ~ 10000r/min, the aging temperature is 20-100°C, and the protective atmosphere is introduced throughout the process and the temperature is constant. The preparation method of a cathode material precursor according to claim 12, characterized in that: the aging process: at a constant temperature of 60°C, under nitrogen protection, solution C is pumped into 1500r/min at a rate of 2L/min. Aging in a hypergravity reactor for 30 minutes. A cathode material precursor prepared by the method for preparing a cathode material precursor according to claim 2. A method for preparing a positive electrode material, characterized in that it includes the following steps: sintering a mixture of the positive electrode material precursor nickel iron manganese ternary precursor prepared in claim 3 and a sodium source to obtain a positive electrode material of nickel iron Manganese ternary sodium ion cathode material Na[Ni _1/3 Fe _1/3 Mn _1/3 ]O ₂ . The preparation method of a positive electrode material according to claim 15, characterized in that: the sodium source is sodium carbonate; And/or, the molar ratio of the cathode material precursor to the sodium source is 2:1; And/or, the sintering is performed in an air atmosphere; And/or, the sintering includes the following steps: the first program: constant temperature at a temperature of 500-600°C for 4-8h, the second program: a constant temperature at a temperature of 870-1000°C for 15-24h; Wherein, the temperature in the first stage program and the second stage program is raised in a programmed temperature rise manner, and the temperature rise rate is preferably 2-8°C/min. An application of the cathode material precursor in a sodium-ion battery as claimed in claim 14, characterized in that: the cathode material of the sodium-ion battery is made of the cathode material precursor.