Preparation method and application of orientation-adjustable battery grade manganous-manganic oxide

Abstract

The invention provides a preparation method and application of orientation-adjustable battery-grade manganous-manganic oxide, and relates to the technical field of synthesis of manganous-manganic oxide for batteries, the preparation method comprises the following steps: adding a complexing agent into a base solution, adjusting to a set pH value, stirring, and introducing oxidizing gas for reaction; the preparation method comprises the following steps: respectively preparing a manganese salt, a complexing agent, a crystal face regulator and an alkaline solution, adding into a reaction base solution, maintaining the pH value of the system at a set value, carrying out aging reaction to obtain manganous-manganic oxide slurry, filtering, washing, and drying to obtain manganous-manganic oxide particles with different orientations, and adding the crystal face regulator into the reaction solution to regulate the growth speed of the crystal face, thereby obtaining the manganous-manganic oxide particles with different orientations. According to the present invention, the growth of the crystal face is promoted or inhibited by using different crystal face regulators, such that the orientation controllable regulation of the manganous-manganic oxide is achieved, and the crystal structure, the crystal grain and the crystal face of the material are optimized so as to obtain the regular spherical battery grade manganous-manganic oxide product with different framework manganese distortion degrees, less impurity and high purity, and reduce the internal stress generated during the LiMn2O4 preparation.

Description

Technical Field

[0001] The present application belongs to the technical field of energy materials, and relates to the technical field of synthesis of manganese tetraoxide for batteries, and specifically to a method for preparing orientation-adjustable battery-grade manganese tetraoxide and its application. Background Art

[0002] At present, lithium manganese oxide (LiMn2O4) is one of the positive electrode materials of the new generation of lithium batteries. It has gradually entered the public's field of vision with its low raw material cost, high working voltage, environmental friendliness and good safety performance. The production of traditional lithium manganese oxide mainly uses manganese sulfate or electrolytic manganese dioxide as the manganese source, adds lithium carbonate as the lithium source and is prepared by high-temperature roasting with additives. However, LiMn2O4 prepared by this method has problems such as poor cycle performance, low capacity, and poor high-temperature performance. In recent years, studies have found that LiMn2O4 prepared from spinel-structured manganese tetraoxide (Mn3O4) as the manganese source has no drastic changes in its structure during the reaction and has less internal stress, which makes it show better electrochemical performance. It is better than LiMn2O4 prepared from manganese dioxide in terms of both gram capacity and cycle performance. Therefore, Mn3O4 has gradually become one of the most promising precursor raw materials for the production of LiMn2O4.

[0003] The preparation methods of manganese tetraoxide mainly include metal manganese oxidation method, electrolytic oxidation method and manganese salt precipitation method. Manganese salt precipitation method is one of the most widely used methods at present. Its advantages are good dispersibility, easy regulation and modification of the reaction process, easy operation, high product purity, etc., but there is still room for development in the preparation of high-quality manganese tetraoxide. So far, most patents focus on physical indicators such as particle size, tap density, sphericity, and specific surface area as adjustment directions, which have certain limitations. For example, the lithium manganate prepared from the manganese tetraoxide precursor has low capacity and poor circulation, and the adjustment of the crystal structure is physical parameter adjustment. Summary of the invention

[0004] The present application provides a method for preparing battery-grade trimanganese tetraoxide with adjustable orientation and its application, aiming to solve the problem of low capacity and difficult-to-control crystal face structure of lithium manganate prepared from trimanganese tetraoxide precursor to a certain extent. On the basis of not changing the basic parameters, the crystal face orientation is adjusted, the internal structure and exposed crystal face are adjusted, and the crystal face growth rate is adjusted to obtain high-quality battery-grade trimanganese tetraoxide with adjustable orientation, high product purity, uniform size, high sphericity and low cost, providing high-quality trimanganese tetraoxide precursor for high-performance lithium manganate.

[0005] In a first aspect, the present application provides a method for preparing battery-grade manganese tetraoxide with adjustable orientation, comprising the following steps:

[0006] S1. Add a complexing agent to the bottom liquid, adjust it to the set pH, stir and introduce an oxidation gas for reaction to obtain a reaction bottom liquid;

[0007] S2. Prepare manganese salt, complexing agent, crystal plane regulator, and alkaline solution respectively, add them to the reaction bottom liquid, maintain the pH of the system at the set value, and after aging reaction, obtain manganese tetraoxide slurry;

[0008] S3. Collect the manganese tetraoxide slurry, filter, wash, and dry it to obtain manganese tetraoxide particles with different orientations.

[0009] In some embodiments, the bottom liquid in step S1 is water, the addition amount of the water is 5 - 20 L, and the set pH is 8 - 12; the complexing agent is an ammonium-containing solution, and the ammonium-containing solution is one or a combination of more than one of ammonium hydroxide, ammonium sulfate, ammonium chloride, ammonium carbonate, and ammonium nitrate; the addition amount of the complexing agent is 0.1% - 2% of the mass fraction of the bottom liquid.

[0010] In some embodiments, the manganese salt in step S2 is one or a combination of more than one of manganese chloride, manganese acetate, manganese nitrate, manganese oxalate, and manganese sulfate; the complexing agent is an ammonium-containing solution, and the ammonium-containing solution is one or a combination of more than one of ammonium hydroxide solution, ammonium sulfate solution, ammonium chloride solution, ammonium carbonate solution, and ammonium nitrate solution; the alkaline solution is one or a combination of more than one of ammonia water, sodium hydroxide solution, and potassium hydroxide solution.

[0011] In some embodiments, the crystal plane regulator in step S2 is divided into a promoter and an inhibitor; the crystal plane regulation promoter is alkylamine, including one or a combination of more than one of methylamine, ethylamine, propylamine, butylamine, pentylamine, ethylenediamine, and diethylamine; the crystal plane regulation inhibitor is alkyl carboxylic acid, including one or a combination of more than one of formic acid, sodium formate, acetic acid, sodium acetate, sodium propionate, sodium butyrate, sodium hexanoate, benzene-1,3,5-tricarboxylic acid, sodium benzoate, oxalic acid, malonic acid, and sodium oxalate; the organic matter of the crystal plane regulation promoter alkylamine has a concentration of 12 - 20 g / L; the crystal plane regulation inhibitor is carboxylic acid organic matter, and its concentration is 10 - 16 g / L. Due to the presence of the crystal plane regulator, organic molecules are adsorbed on the crystal surface during the crystal growth stage, affecting the growth rate of each crystal plane of the crystal, resulting in the promotion or inhibition of the growth of a certain crystal plane of the crystal, thereby affecting the exposed crystal plane situation of the precursor, and ultimately affecting the performance of the LiMn2O4 cathode material.

[0012] In some embodiments, the ratio of the addition amount of the soluble manganese salt to water in step S2 is 100-200 g / L, where the contents of various impurity elements Ca, Mg, and Na in the manganese salt are less than 100 ppm; the ratio of the addition amount of the complexing agent to water is 10-30 g / L; the ratio of the addition amount of the crystal plane regulator to water is 5-25 g / L; the concentration of the alkaline solution is 1-4 M.

[0013] In some embodiments, the pH value in step S2 is 8-11, the aging reaction time is 1-10 h, the reaction temperature is 30-80 °C, and the stirring speed for aging is 300-600 rpm.

[0014] In some embodiments, steps S1 and S2 are carried out in an oxidation gas atmosphere throughout, the oxidation gas is oxygen or air, and the volume of the oxidation gas is 1.5-4 m 3 / h. Oxygen is introduced in advance to promote the conversion of manganese hydroxide to manganese tetraoxide.

[0015] In some embodiments, the manganese tetraoxide slurry in step S3 is centrifuged and washed 2-5 times and dried in a vacuum drying oven at 60-120 °C.

[0016] In some embodiments, the peak intensity of the manganese tetraoxide shows different orientations according to different crystal plane regulators.

[0017] Based on the overall inventive concept, the present invention also provides an application of the battery-grade manganese tetraoxide with adjustable orientation in the battery cathode material.

[0018] Compared with the prior art, the beneficial effects of the present application are as follows:

[0019] 1. For the preparation method of the battery-grade manganese tetraoxide with adjustable orientation described in the present invention, a crystal plane regulator is added to the reaction solution to adjust the growth rate of the crystal plane, and different crystal plane regulators are used to promote or inhibit the growth of the crystal plane, so as to realize the controllable adjustment of the orientation of manganese tetraoxide, optimize the crystal structure, crystal grains and crystal planes of the material, and thus obtain a battery-grade manganese tetraoxide product with different degrees of distortion of the framework manganese, less impurities, high purity and regular spherical shape, reduce the internal stress generated during the preparation of LiMn2O4, and provide a high-quality manganese tetraoxide precursor for the synthesis of high-performance LiMn2O4.

[0020] 2. The present invention has a manganese tetraoxide with adjustable orientation, which adsorbs on the crystal surface from the solution at the initial stage of nucleation, promotes the relative increase or decrease of the growth rate of a certain crystal plane, induces its growth in a certain orientation, and prepares manganese tetraoxide with different orientations through a simple crystal plane regulator, so as to achieve the effect of different growth rates of the crystal plane. The preparation method is simple and easy to implement, the regulation method is simple and convenient, and it can be mass-produced, having good industrial application prospects.

[0021] Brief Description of Drawings

[0022] To more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0023] Figure 1 It is the SEM image of manganese tetraoxide prepared in Example 1 of the present invention;

[0024] Figure 2 It is the XRD pattern of manganese tetraoxide prepared in Example 1 of the present invention;

[0025] Figure 3 It is the SEM image of manganese tetraoxide prepared in Example 2 of the present invention;

[0026] Figure 4 It is the XRD pattern of manganese tetraoxide prepared in Example 2 of the present invention;

[0027] Figure 5 It is the SEM image of manganese tetraoxide prepared in Comparative Example 1;

[0028] Figure 6 It is the XRD pattern of manganese tetraoxide prepared in Comparative Example 1. Detailed Embodiments

[0029] In order to make the technical problems to be solved, technical solutions and beneficial effects of the present application clearer and more understandable, the following further details the present application in combination with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0030] In the present application, the term "and / or" describes the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. Wherein A and B can be singular or plural. The character " / " generally represents an "or" relationship between the front and back associated objects.

[0031] In this application, "at least one" means one or more, and "a plurality" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can both represent: a, b, c, a~b (i.e., a and b), a~c, b~c, or a~b~c, where a, b, and c can each be single or multiple.

[0032] The terms "first" and "second" are used only for descriptive purposes to distinguish objects such as substances from each other, and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. For example, without departing from the scope of the embodiments of this application, the first XX can also be referred to as the second XX, and similarly, the second XX can also be referred to as the first XX. Thus, the features defined with "first" and "second" can explicitly or implicitly include one or more of such features.

[0033] The terms used in the embodiments of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The singular forms "a", "the", and "said" used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0034] It should be understood that in various embodiments of this application, the magnitude of the serial numbers of the various processes does not mean the order of execution. Some or all of the steps can be executed in parallel or sequentially. The order of execution of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of this application.

[0035] The weights of the relevant components mentioned in the specification of the embodiments of this application can not only refer to the specific contents of each component, but also represent the proportional relationship of the weights between the components. Therefore, as long as the contents of the relevant components in the specification of the embodiments of this application are scaled up or down proportionally, they are within the scope disclosed in the specification of the embodiments of this application. Specifically, the mass described in the specification of the embodiments of this application can be mass units well-known in the chemical field such as μg, mg, g, kg, etc.

[0036] Unless otherwise defined, all professional terms used hereinafter have the same meaning as commonly understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the protection scope of the present invention.

[0037] Unless otherwise specifically stated, all kinds of raw materials, reagents, instruments, equipment, etc. used in this application can be obtained through the market or can be prepared by existing methods.

[0038] The technical solutions of the present application will be described below through specific examples and comparative examples.

[0039] To enable those skilled in the art to clearly understand the above implementation details and operations of the present application, and to significantly reflect the improved performance of the embodiments of the present application, the above technical solutions will be illustrated by multiple examples below.

[0040] Example 1:

[0041] A preparation method of battery-grade manganese tetraoxide with adjustable orientation:

[0042] Add 10 L of water as the bottom liquid into the reactor, and at the same time add ammonia water with a mass fraction of 1% as the complexing agent. Turn on the stirrer and accelerate to 400 rpm, and continuously introduce 2 m 3 / h of air at the bottom of the reactor, and turn on the reactor heater until the temperature rises to 60 °C.

[0043] Prepare a manganese sulfate solution with a concentration of 140 g / L, an ammonia water solution with a concentration of 15 g / L, a formate crystal plane regulator with a concentration of 12 g / L, and the concentration of sodium hydroxide is 2 M. Respectively, pump the four reaction solutions into the reactor simultaneously in a continuous feeding manner through peristaltic pumps. During this process, adjust the feeding speed and ratio of the manganese sulfate and sodium hydroxide solutions to maintain the pH value of the system at about 8. Use the added formate as the crystal plane regulator to adjust the crystal orientation and inhibit the growth of crystal planes to achieve the purpose of adjusting the orientation;

[0044] Keep the reaction continuing and maintain the pH value at about 9, and at the same time the stirring speed is 450 rpm, and age for 4 h until the reaction ends.

[0045] Collect the manganese tetraoxide slurry after the reaction ends, wash it by centrifugation twice, and place it in a vacuum drying oven to dry at 100 °C to obtain manganese tetraoxide with inhibited orientation.

[0046] Figure 1 is the SEM image of the manganese tetraoxide prepared in Example 1; it can be seen from the figure that the manganese tetraoxide is spherical-like, the grains grow agglomerated with each other, and there are relatively large gaps between the grains, indicating that the crystal growth is affected by the regulator.

[0047] Figure 2 is the XRD pattern of the manganese tetraoxide prepared in Example 1. It can be seen from the figure that there are typical diffraction peaks of manganese tetraoxide, but the peak intensities of the crystal planes are different. It can be observed that the crystal plane ratio of (211 / 103) is inhibited by the crystal plane regulator.

[0048] Example 2:

[0049] A preparation method of battery-grade manganese tetraoxide with adjustable orientation:

[0050] Add 15 L of water to the reactor as the bottom liquid, and at the same time add ammonia water with a mass fraction of 1.2% as the complexing agent. Turn on the stirrer and accelerate it to 400 rpm. Continuously introduce air at 3 m 3 / h at the bottom of the reactor, and turn on the reactor heater until the temperature rises to 70 °C.

[0051] Prepare a manganese sulfate solution with a concentration of 160 g / L, an ammonia water solution with a concentration of 12 g / L, a sodium acetate crystal plane regulator with a concentration of 10 g / L, and the concentration of sodium hydroxide is 2 M. Respectively, pump the four reaction liquids into the reactor in a continuous feeding manner through peristaltic pumps. During this process, adjust the feeding speed and ratio of the manganese sulfate and sodium hydroxide solutions to maintain the pH value of the system at about 8.5. Adjust the crystal orientation by adding sodium acetate as the crystal plane regulator to inhibit the growth of crystal planes to achieve the purpose of adjusting the orientation;

[0052] Keep the reaction continuing and maintain the pH value at about 9. At the same time, the stirring speed is 450 rpm, and age for 4 h until the reaction ends.

[0053] Collect the manganese tetraoxide slurry after the reaction ends, wash it by centrifugation 4 times, and place it in a vacuum drying oven to dry at 100 °C to obtain manganese tetraoxide with inhibited orientation.

[0054] Figure 3 It is the SEM image of the manganese tetraoxide prepared in Example 2; it can be seen from the figure that the manganese tetraoxide is spherical, and several large grains grow agglomerated with each other, and the growth between the grains is relatively tight, indicating that the crystal growth is affected by the regulator.

[0055] Figure 4 It is the XRD pattern of the manganese tetraoxide prepared in Example 2. Typical diffraction peaks of manganese tetraoxide can be seen from the figure, but the peak intensities of the crystal planes are different, and it can be observed that the crystal plane ratio of (211 / 103) is promoted by the crystal plane regulator.

[0056] Example 3:

[0057] A preparation method of battery-grade manganese tetraoxide with adjustable orientation:

[0058] Add 12 L of water to the reactor as the bottom liquid, and at the same time add ammonium sulfate with a mass fraction of 1.2% as the complexing agent. Turn on the stirrer and accelerate it to 500 rpm. Continuously introduce air at 2.5 m 3 / h at the bottom of the reactor, and turn on the reactor heater until the temperature rises to 65 °C.

[0059] Prepare a manganese sulfate solution with a concentration of 150 g / L, an ammonium sulfate solution with a concentration of 18 g / L, an ethylenediamine crystal plane regulator with a concentration of 14 g / L, and a sodium hydroxide solution with a concentration of 3 M. Then, simultaneously pump the four reaction solutions into the reactor in a continuous feeding manner through peristaltic pumps. During this process, adjust the feeding rates and ratios of the manganese sulfate and sodium hydroxide solutions to maintain the pH value of the system at around 8.5. Use the added ethylenediamine as a crystal plane regulator to adjust the crystal orientation and promote the growth of crystal planes to achieve the purpose of orientation adjustment;

[0060] Keep the reaction continuing and maintain the pH value at around 10, while the stirring speed is 500 rpm, and age for 3 h until the reaction ends.

[0061] Collect the manganese tetroxide slurry after the reaction ends, centrifuge and wash it 3 times, and place it in a vacuum drying oven to dry at 90 °C to obtain manganese tetroxide with promoted orientation.

[0062] Example 4:

[0063] A preparation method of battery-grade manganese tetroxide with adjustable orientation:

[0064] Add 12 L of water as the bottom liquid to the reactor, and at the same time add ammonium sulfate with a mass fraction of 1.2% as a complexing agent. Turn on the stirring and accelerate to 500 rpm, continuously introduce air at 3 m3 / h at the bottom of the reactor, and turn on the reactor heater until the temperature rises to 65 °C.

[0065] Prepare a manganese sulfate solution with a concentration of 150 g / L, an ammonium sulfate solution with a concentration of 20 g / L, an ethylamine and propylamine crystal plane regulator with a concentration of 15 g / L, and a sodium hydroxide solution with a concentration of 4 M. Then, simultaneously pump the four reaction solutions into the reactor in a continuous feeding manner through peristaltic pumps. During this process, adjust the feeding rates and ratios of the manganese sulfate and sodium hydroxide solutions to maintain the pH value of the system at around 9. Use the added ethylamine and propylamine as crystal plane regulators to adjust the crystal orientation and promote the growth of crystal planes to achieve the purpose of orientation adjustment;

[0066] Keep the reaction continuing and maintain the pH value at around 10, while the stirring speed is 500 rpm, and age for 5 h until the reaction ends.

[0067] Collect the manganese tetroxide slurry after the reaction ends, centrifuge and wash it 3 times, and place it in a vacuum drying oven to dry at 90 °C to obtain manganese tetroxide with promoted orientation.

[0068] Comparative Example 1:

[0069] A preparation method of battery-grade manganese tetroxide with adjustable orientation:

[0070] Add 10 L of water to the reactor as the bottom liquid, and simultaneously add ammonia water with a mass fraction of 1% as the complexing agent. Turn on the stirrer and accelerate it to 400 rpm. Continuously introduce air at a rate of 2 m3 / h at the bottom of the reactor, and turn on the reactor heater until the temperature rises to 60 °C.

[0071] Prepare a manganese sulfate solution with a concentration of 140 g / L, an ammonia water solution with a concentration of 15 g / L, and a sodium hydroxide solution with a concentration of 2 M. Respectively, pump the four reaction liquids into the reactor in a continuous feeding manner through a peristaltic pump. During this process, adjust the feeding speed and ratio of the manganese sulfate and sodium hydroxide solutions to maintain the pH value of the system at about 8. Do not add a crystal plane regulator to compare the natural growth of the crystal plane with that of adding a regulator.

[0072] Keep the reaction continuing and maintain the pH value at about 9. At the same time, the stirring speed is 450 rpm, and age for 4 h until the reaction ends.

[0073] Collect the manganese tetraoxide slurry after the reaction ends, wash it by centrifugation 4 times, and place it in a vacuum drying oven to dry at 100 °C to obtain manganese tetraoxide under natural growth.

[0074] Figure 5 This is the SEM image of the manganese tetraoxide prepared in Comparative Example 1; it can be seen from the figure that the manganese tetraoxide is spherical, with one or two grains growing agglomerated with each other, the gaps between the grains are small, and the particle morphology is complete.

[0075] Figure 6 This is the XRD pattern of the manganese tetraoxide prepared in Comparative Example 1. From the figure, the typical diffraction peaks of manganese tetraoxide can be seen, and it can be observed that the crystal plane ratio of (211 / 103) is the ratio when no regulator is added.

[0076] Comparative Example 2:

[0077] A preparation method of battery-grade manganese tetraoxide with adjustable orientation:

[0078] Add 12 L of water to the reactor as the bottom liquid, and simultaneously add ammonium sulfate with a mass fraction of 1.2% as the complexing agent. Turn on the stirrer and accelerate it to 500 rpm. Continuously introduce air at a rate of 2.5 m3 / h at the bottom of the reactor, and turn on the reactor heater until the temperature rises to 65 °C.

[0079] Prepare a manganese sulfate solution with a concentration of 150 g / L, an ammonia water solution with a concentration of 18 g / L, and a sodium hydroxide solution with a concentration of 3 M. Respectively, pump the three reaction liquids into the reactor in a continuous feeding manner through a peristaltic pump. During this process, adjust the feeding speed and ratio of the manganese sulfate and sodium hydroxide solutions to maintain the pH value of the system at about 8.5. Do not add a crystal plane regulator to compare the natural growth of the crystal plane with that of adding a regulator.

[0080] Keep the reaction going and maintain the pH value at around 10, while the stirring speed is 500 rpm, and age for 6 h until the reaction ends.

[0081] Collect the manganese tetroxide slurry after the reaction ends, centrifuge and wash it 3 times, and place it in a vacuum drying oven to dry at 90 °C to obtain manganese tetroxide grown naturally.

[0082] Test examples:

[0083] The manganese tetroxide obtained from the examples and comparative examples of the present invention was tested as follows:

[0084] X-ray Powder Diffraction (XRD) was used to analyze the crystal structure and purity of the synthesized samples. The instrument model used was Smart Lab 9kW from Japan. Place the sample powder in a glass cell, flatten the surface with a glass slide, and place it horizontally in the machine. The instrument and specific test parameters are as follows: Cu Kα target, voltage and current 240 kV / 50 mA, scanning step 0.02°, scanning speed 10° / min, test angle 10 - 80°. Import the obtained results into Jade software for peak intensity analysis and calculate the corresponding ratio.

[0085] The results obtained are shown in Table 1

[0086] Table 1: Crystal plane ratios of each sample

[0087] Orientation ratio Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 (211) / (103) 1.2124 1.3281 1.8470 2.4689 1.5585 1.5362

[0088] According to Table 1, the preparation process of battery-grade manganese tetroxide described in the present invention can produce samples with different orientations. It can be seen from Example 1 that adding a crystal plane regulator is crucial in this process, which has a decisive effect on the orientation of the final product. As shown in Example 1 and Example 3, after introducing the crystal plane inhibitor and crystal plane promoter, the ratio of the (211) crystal plane to the (103) crystal plane shows a weakening or strengthening phenomenon respectively, thus successfully obtaining manganese tetroxide materials with the expected different orientation characteristics.

[0089] The battery-grade manganese tetroxide prepared by the technical solution of the present invention, when used for synthesizing LiMn2O4, can specifically change the crystal plane orientation of the precursor to eliminate the internal stress of LiMn2O4, making the phase structure change less. It not only improves the specific capacity of the material but also enhances its cycling performance, showing extremely high application potential and promotion value.

[0090] The above content elaborates on the basic principles, main features, and advantages of the present invention. It should be emphasized that those skilled in the art should understand that the present invention is not limited to the above specific embodiments. These examples are only used to illustrate the principles of the present invention. Without departing from the core idea and scope of the present invention, various forms of changes or improvements can be made to the invention, and all such variants should be considered to fall within the protection scope of the present invention. Ultimately, the specific protection scope of the present invention shall be subject to the appended claims and their equivalents.

[0091] In the above embodiments, the descriptions of each embodiment have their own focuses. For parts not detailed or recorded in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0092] The above-described embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit them. Although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments or perform equivalent replacements for some of the technical features. These modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present application and should all be included in the protection scope of the present application.

Claims

1. A method for preparing battery-grade trimanganese tetraoxide with adjustable orientation, characterized in that: The following steps are involved: S1, adding a complexing agent to the base liquid, adjusting to a set pH, stirring and introducing an oxidizing gas to react, to obtain a reaction base liquid; S2, respectively preparing a manganese salt, a complexing agent, a crystal surface regulator, and an alkaline solution, adding them to the reaction base solution, maintaining the pH of the system at a set value, and obtaining manganese tetraoxide slurry after aging reaction; S3, collecting the trimanganese tetraoxide slurry, filtering, washing, and drying to obtain trimanganese tetraoxide particles with different orientations.

2. The preparation method according to claim 1, characterized in that: In step S1, the base liquid is water, the amount of water added is 5 to 20 L, and the set pH is 8 to 12; the complexing agent is an ammonium-containing solution, and the ammonium-containing solution is a combination of one or more of ammonium hydroxide, ammonium sulfate, ammonium chloride, ammonium carbonate, and ammonium nitrate; the amount of the complexing agent added is 0.1% to 2% of the mass fraction of the base liquid.

3. The preparation method according to claim 1, characterized in that: In step S2, the manganese salt is a combination of one or more of manganese chloride, manganese acetate, manganese nitrate, manganese oxalate and manganese sulfate; the complexing agent is an ammonium-containing solution, and the ammonium-containing solution is a combination of one or more of ammonium hydroxide solution, ammonium sulfate solution, ammonium chloride solution, ammonium carbonate solution and ammonium nitrate solution; The alkaline solution is a combination of one or more of ammonia water, sodium hydroxide solution and potassium hydroxide solution.

4. The preparation method according to claim 1, characterized in that: The crystal plane regulator in step S2 is divided into a promoter and an inhibitor; the crystal plane regulation promoter is an alkylamine, including a combination of one or more of methylamine, ethylamine, propylamine, butylamine, pentylamine, ethylenediamine, and diethylamine; the crystal plane regulation inhibitor is an alkyl carboxylic acid, including a combination of one or more of formic acid, sodium formate, acetic acid, sodium acetate, sodium propionate, sodium butyrate, sodium hexanoate, trimesic acid, sodium benzoate, oxalic acid, malonic acid, and sodium oxalate; the crystal plane regulation promoter alkylamine organic matter has a concentration of 12 to 20 g / L; the crystal plane regulation inhibitor is a carboxylic acid organic matter, and its concentration is 10 to 16 g / L.

5. The preparation method according to claim 2, characterized in that: The ratio of the amount of the soluble manganese salt added in step S2 to water is 100-200 g / L, wherein the various impurity elements Ca, Mg, and Na contained in the manganese salt are less than 100 ppm; the ratio of the amount of the complexing agent added to water is 10-30 g / L; the ratio of the amount of the crystal surface regulator added to water is 5-25 g / L; and the concentration of the alkaline solution is 1-4 M.

6. The preparation method according to claim 1, characterized in that: The pH value in step S2 is 8-11, the aging reaction time is 1-10 hours, the reaction temperature is 30-80° C., and the stirring speed of the aging is 300-600 rpm.

7. The preparation method according to claim 1, characterized in that: Steps S1 and S2 are all carried out in an oxidizing gas atmosphere, wherein the oxidizing gas is oxygen or air, and the volume of the oxidizing gas is 1.5 to 4 m 3 / h.

8. The preparation method according to claim 1, characterized in that: The manganese tetraoxide slurry in step S3 is centrifugally washed 2 to 5 times and dried in a vacuum drying oven at 60 to 120°C.

9. The preparation method according to claim 1, characterized in that: The peak intensity of the trimanganese tetraoxide presents different orientations according to the different crystal plane modifiers.

10. Use of the orientation-adjustable battery-grade manganese tetraoxide as claimed in any one of claims 1 to 9 in a positive electrode material for a battery.

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