Ferromanganese phosphate as well as preparation method and device thereof

Abstract

The invention provides ferromanganese phosphate and a preparation method thereof, and relates to the technical field of new energy. According to the preparation method of the ferromanganese phosphate, a first raw material containing amorphous ferric phosphate, a second raw material containing manganous-manganic oxide, a first oxidizing agent and a phosphoric acid solution react to generate homogeneous ferromanganese phosphate, and the characteristic that the manganous-manganic oxide in the second raw material is similar to the amorphous ferric phosphate in the first raw material in solubility and reaction speed is utilized; homogeneous co-precipitation of Mn and Fe is realized, and ferromanganese phosphate with uniformly distributed elements is generated. In addition, according to the preparation method of the ferromanganese phosphate, monodisperse growth of crystals can be achieved without an organic matter dispersing agent.

Description

Technical Field

[0001] The present application relates to the field of new energy technology, and in particular to a manganese ferrophosphate, and a preparation method and device thereof. Background Art

[0002] The power battery field mainly includes two major categories of products: lithium iron phosphate and ternary lithium batteries. Compared with ternary lithium batteries, lithium iron phosphate batteries have better cycle stability and safety, but lower energy density. Lithium manganese phosphate materials (4.1V) have a higher voltage platform (relative to Li+ / Li) than lithium iron phosphate materials (3.4V), and excellent low-temperature performance, but lithium manganese phosphate materials have poor conductivity and more serious manganese ion dissolution in the electrolyte. Therefore, lithium manganese iron phosphate materials and batteries with relatively high energy density, excellent low-temperature performance, and moderate material conductivity and stability came into being.

[0003] Currently, lithium iron manganese phosphate materials are mainly based on high-temperature solid-phase synthesis of iron manganese phosphate precursors. The existing preparation methods of iron manganese phosphate precursors mainly have the problem of uneven distribution of iron and manganese elements. Summary of the invention

[0004] The purpose of this application is to provide a ferromanganese phosphate and a preparation method thereof to solve the above problems.

[0005] To achieve the above objectives, this application adopts the following technical solutions:

[0006] The present application first provides a method for preparing ferromanganese phosphate, comprising:

[0007] A first raw material containing amorphous ferric phosphate and a second raw material containing manganese tetraoxide are mixed to form a slurry, a first oxidant is added, the pH value is adjusted to 0.5-5, and ferromanganese phosphate is obtained by reaction.

[0008] The present application scheme utilizes the characteristics of similar solubility and reaction speed of trimanganese tetraoxide in the second raw material and amorphous ferric phosphate in the first raw material to mix and react. During the reaction process, the two substances are simultaneously dissolved and oxidized in trace amounts, and the oxidized manganese ions are immediately co-precipitated with iron ions. The co-precipitation process consumes iron ions, manganese ions and phosphate ions in the solution, promoting the dissolution process of amorphous ferric phosphate and trimanganese tetraoxide. After the reaction is complete, ferromanganese phosphate with better uniformity of distribution of iron and manganese elements is finally obtained.

[0009] The mixing of the first raw material containing amorphous iron phosphate and the second raw material containing manganese tetraoxide to form a slurry includes first separating the first raw material and the second raw material into solid-liquid state, then forming a slurry, and then mixing, or first separating the first raw material and the second raw material into solid-liquid state or mixing, and then forming a slurry. Optionally, the first raw material and the second raw material are first separated into solid-liquid state or mixed, and then forming a slurry.

[0010] Among them, amorphous iron phosphate has no corresponding crystal form and is in an amorphous state.

[0011] Optionally, the first raw material includes amorphous iron phosphate and water, or the first raw material is amorphous iron phosphate and water;

[0012] The second raw material includes trimanganese tetraoxide and water, or the second raw material is trimanganese tetraoxide and water.

[0013] Optionally, the water content (i.e., moisture content) in the first raw material accounts for more than 0.1wt% of the mass of the first raw material; optionally, the moisture content of the first raw material can be 0.2wt%, 0.5wt%, 1wt%, 3wt%, 5wt%, 8wt%, 10wt%, 12wt%, 16wt%, 20wt%, 25wt%, 30wt% and any moisture content range thereof; excluding water, the content of amorphous iron phosphate in the first raw material is more than 99wt%, i.e., the dry basis purity is relatively high.

[0014] Optionally, the water content (i.e., moisture content) in the second raw material is more than 0.1wt% of the mass of the second raw material; optionally, the moisture content of the first raw material can be 0.2wt%, 0.5wt%, 1wt%, 3wt%, 5wt%, 8wt%, 10wt%, 12wt%, 16wt%, 20wt%, 25wt%, 30wt% and any moisture content range thereof; excluding water, the content of manganese tetraoxide in the second raw material is more than 99wt%, i.e., the dry basis purity is relatively high.

[0015] In the present application, the first raw material containing amorphous ferric phosphate and the second raw material containing manganese tetraoxide form a slurry in an aqueous phase for reaction, so when the first raw material and the second raw material contain water, it will not have an adverse effect on the reaction.

[0016] In some embodiments, the preparation of amorphous ferric phosphate is also carried out in an aqueous solution, and the amorphous ferric phosphate can be directly used as the first raw material without drying and dehydration after solid-liquid separation. Similarly, in some embodiments, the preparation of manganese tetraoxide is also carried out in an aqueous solution, and the manganese tetraoxide can be directly used as the second raw material without drying and dehydration after solid-liquid separation.

[0017] After solid-liquid separation, no drying and dehydration is performed, and undehydrated amorphous ferric phosphate and manganese tetraoxide are used as the first raw material and the second raw material, respectively. This can save energy consumption in the dehydration process and is more conducive to pulping the first raw material and the second raw material.

[0018] Optionally, the pH value is adjusted using a phosphoric acid solution, and the pH value is 0.5-1.5, 1.5-3.5 or 3.5-5. Optionally, the pH value is 1.5-3.5; the phosphoric acid solution is a phosphoric acid solution formed by diluting high-concentration phosphoric acid into a low-concentration phosphoric acid solution or a phosphoric acid solution formed by phosphate and a strong acid.

[0019] Optionally, the first oxidant includes any one or more of sodium ferrate, sodium permanganate, potassium permanganate, and ozone.

[0020] Optionally, the reaction temperature is 80°C to 100°C; and the reaction time is 2 to 5 hours.

[0021] Optionally, the method for preparing the first raw material containing amorphous ferric phosphate comprises:

[0022] The iron salt solution, the phosphorus source solution and the second oxidant are mixed and reacted to obtain a first raw material containing amorphous iron phosphate.

[0023] Optionally, the iron salt includes any one or more of ferrous sulfate, ferrous chloride, ferrous nitrate, ferric sulfate, ferric chloride, and ferric nitrate;

[0024] Optionally, the phosphorus source includes phosphoric acid or a phosphorus salt, and the phosphorus salt includes any one or more of monoammonium phosphate, diammonium phosphate, triammonium phosphate, sodium dihydrogen phosphate, disodium hydrogen phosphate, and trisodium phosphate.

[0025] Optionally, the method for preparing the second raw material containing trimanganese tetraoxide comprises:

[0026] The manganous salt solution, the second oxidant and the alkaline solution are mixed and reacted to obtain the second raw material containing trimanganese tetraoxide.

[0027] Optionally, the manganous salt includes any one or more of manganous sulfate, manganous chloride, and manganous nitrate;

[0028] Optionally, the second oxidant includes any one or more of hydrogen peroxide, ozone, sodium persulfate, perchloric acid, hypochlorous acid, sodium hypochlorite, ammonium persulfate, sodium ferrate, sodium permanganate, and potassium permanganate;

[0029] Optionally, the alkaline solution includes any one or more of aqueous ammonia, liquid alkali, aqueous potassium hydroxide solution, sodium carbonate solution, and potassium carbonate solution.

[0030] As the same inventive concept, the present application provides a ferromanganese phosphate, which is prepared by the above-mentioned preparation method of ferromanganese phosphate, and the chemical formula of ferromanganese phosphate is Mn x Fe (1-x) PO 4 ·yH 2 O, 0<x<1, 0<y<2;

[0031] Optionally, the primary particle size of the ferromanganese phosphate is 10-20 nm, and the secondary particle D50 is 50-1000 nm.

[0032] As the same inventive concept, the present application provides a positive electrode material, the raw materials of which include the above-mentioned ferromanganese phosphate.

[0033] As the same inventive concept, the present application also provides a lithium-ion battery, the raw materials of which include the above-mentioned positive electrode material.

[0034] As the same inventive concept, the present application provides a device for ferromanganese phosphate, corresponding to the above-mentioned method for preparing ferromanganese phosphate, including a reactor, a first container for storing a first raw material, and a second container for storing a second raw material, the reactor being connected to the first container and the second container respectively, and an agitator being installed in the reactor; the reactor is also connected to a third container for storing a first oxidant and a fourth container for storing a pH adjusting agent.

[0035] Optionally, the present application provides a device for producing ferromanganese phosphate, further comprising a heating device for heating the reactor.

[0036] The beneficial effects of this application include:

[0037] First, the present application provides a method for preparing ferromanganese phosphate, which utilizes the similar solubility and reaction rate of manganese tetraoxide in the second raw material and amorphous ferrophosphate in the first raw material to generate ferromanganese phosphate with uniform element distribution. In addition, the method for preparing ferromanganese phosphate does not add an organic dispersant, and can achieve monodisperse crystal growth.

[0038] Second, the residual Mn and iron in the waste liquid after the reaction is within 10 ppm, achieving low impurities and high yield, with the yield as high as 99.5%.

[0039] Third, the entire process uses common raw materials and does not require harsh oxidants (concentrated sulfuric acid, perchloric acid, nitric acid, etc.). The wastewater is a sulfate solution, which is easy to handle and pollution-free. The preparation process is safe, green and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope of the present application.

[0041] Figure 1 This is a low-magnification surface SEM image of the ferromanganese phosphate product of Example 1;

[0042] Figure 2 This is a high-magnification surface SEM image of the ferromanganese phosphate product of Example 1;

[0043] Figure 3 This is a cross-sectional SEM image of the ferromanganese phosphate product of Example 1;

[0044] Figure 4 This is the EDS (P element distribution) diagram of the ferromanganese phosphate product of Example 1;

[0045] Figure 5 This is the EDS (Mn element distribution) diagram of the ferromanganese phosphate product of Example 1;

[0046] Figure 6 This is the EDS (Fe element distribution) diagram of the ferromanganese phosphate product of Example 1;

[0047] Figure 7 This is the XRD diagram of the ferromanganese phosphate product of Example 1;

[0048] Figure 8 This is the XRD pattern of the product obtained in Comparative Example 1. DETAILED DESCRIPTION

[0049] “And / or” is used to indicate that one or both of the stated situations may occur, for example, A and / or B includes (A and B) and (A or B).

[0050] The embodiments of the present application will be described in detail below in conjunction with specific examples, but it will be appreciated by those skilled in the art that the following examples are only used to illustrate the present application and should not be considered as limiting the scope of the present application. If specific conditions are not specified in the examples, they are carried out according to normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0051] Example 1

[0052] 2.6 mol of manganous sulfate, 4.2 mol of sodium hydroxide, and 1.3 mol of hydrogen peroxide are added to a reactor and stirred to obtain a second raw material containing manganese tetraoxide; 2.0 mol of ferrous sulfate, 1.0 mol of monoammonium phosphate, and 0.6 mol of hydrogen peroxide are added to a reactor and stirred to obtain a first raw material containing amorphous iron phosphate; the second raw material containing manganese tetraoxide and the first raw material containing amorphous iron phosphate are mixed evenly, filtered and washed to obtain a mixed solid of the second raw material containing manganese tetraoxide and the first raw material containing amorphous iron phosphate. Water and sodium permanganate are added to the mixed solid to stir into a slurry, phosphoric acid is added, the pH value is adjusted to 2, the temperature is raised to 90°C and the reaction is carried out for 3 hours, and then the slurry is filtered, separated, washed, and dried to obtain Mn. 0.6 Fe 0.4 PO 4 1.4H 2 O.

[0053] The low-magnification surface SEM image of the ferromanganese phosphate product prepared in Example 1 is as follows: Figure 1 As shown, the high magnification surface SEM image is as follows Figure 2 As shown in the figure, it can be seen that the manganese iron phosphate particles grow in a monodisperse manner. The particle size of the primary particles is 10-20nm, and the particle size of the secondary particles is 50-1000nm.

[0054] The cross-sectional SEM image of the ferromanganese phosphate product prepared in Example 1 is as follows: Figure 3 As shown, Figures 4 to 6 The P element distribution diagram, Mn element distribution diagram and Fe element distribution diagram of the ferromanganese phosphate product of Example 1 are respectively Figures 4 to 6 It can be seen that the Mn, Fe and P elements of the ferromanganese phosphate product prepared in Example 1 are uniformly distributed. The XRD results of the ferromanganese phosphate product prepared in Example 1 are as follows: Figure 7 As shown, the XRD results show that the ferromanganese phosphate of Example 1 is a pure phase. The pure phase and monodispersed growth of ferromanganese phosphate can prove that the manganese and iron elements in the ferromanganese phosphate are uniformly distributed.

[0055] Example 2

[0056] 2.6 mol of manganous sulfate, 4.2 mol of sodium hydroxide, and 1.3 mol of hydrogen peroxide are added to a reactor and stirred to obtain a second raw material containing manganese tetraoxide; 2.0 mol of ferrous sulfate, 1.0 mol of monoammonium phosphate, and 0.6 mol of hydrogen peroxide are added to a reactor and stirred to obtain a first raw material containing amorphous iron phosphate; the second raw material containing manganese tetraoxide and the first raw material containing amorphous iron phosphate are mixed evenly, filtered and washed to obtain a mixed solid of the second raw material containing manganese tetraoxide and the first raw material containing amorphous iron phosphate. Water and sodium permanganate are added to the mixed solid to stir into a slurry, phosphoric acid is added, the pH value is adjusted to 3, the temperature is raised to 90°C and reacted for 3 hours, and then the slurry is filtered, separated, washed, and dried to obtain Mn. 0.6 Fe 0.4 PO 4 1.4H 2 O.

[0057] Example 3

[0058] 3.6 mol of manganous sulfate, 6.0 mol of sodium hydroxide, and 1.8 mol of hydrogen peroxide are added to a reactor and stirred to obtain a second raw material containing manganese tetraoxide; 0.4 mol of ferrous sulfate, 0.4 mol of monoammonium phosphate, and 0.03 mol of hydrogen peroxide are added to a reactor and stirred to obtain a first raw material containing amorphous iron phosphate; the second raw material containing manganese tetraoxide and the first raw material containing amorphous iron phosphate are mixed evenly, filtered and washed to obtain a mixed solid of the second raw material containing manganese tetraoxide and the first raw material containing amorphous iron phosphate. Water and sodium permanganate are added to the mixed solid to stir into a slurry, phosphoric acid is added, the pH value is adjusted to 0.5, the temperature is raised to 90°C and reacted for 3 hours, and then the slurry is filtered, separated, washed, and dried to obtain Mn. 0.9 Fe 0.1 PO 4 1.1H 2 O.

[0059] Example 4

[0060] 0.4 mol of manganous sulfate, 0.8 mol of sodium hydroxide, and 0.24 mol of hydrogen peroxide are added to a reactor and stirred to obtain a second raw material containing manganese tetraoxide; 3.56 mol of ferrous sulfate, 3.56 mol of monoammonium phosphate, and 2.2 mol of hydrogen peroxide are added to a reactor and stirred to obtain a first raw material containing amorphous iron phosphate; the second raw material containing manganese tetraoxide and the first raw material containing amorphous iron phosphate are mixed evenly, filtered and washed to obtain a mixed solid of the second raw material containing manganese tetraoxide and the first raw material containing amorphous iron phosphate. Water and sodium permanganate are added to the mixed solid to stir into a slurry, phosphoric acid is added, the pH value is adjusted to 5, the temperature is raised to 90°C and the reaction is carried out for 3 hours, and then the slurry is filtered, separated, washed, and dried to obtain Mn. 0.1 Fe 0.9 PO 4 1.9H 2 O.

[0061] Example 5

[0062] Take 2.6 mol of manganous sulfate, 4.2 mol of sodium hydroxide, and 1.3 mol of hydrogen peroxide and add them to the reactor, stir to obtain the second raw material containing manganese tetraoxide, filter, wash, and dry at 120°C for 4 hours to obtain the dehydrated second material containing manganese tetraoxide. Take 2.0 mol of ferrous sulfate, 1.0 mol of monoammonium phosphate, and 0.6 mol of hydrogen peroxide and add them to the reactor and stir to obtain the first raw material containing amorphous iron phosphate, and filter and wash to obtain the first raw material containing amorphous iron phosphate. Add water to the dehydrated second material containing manganese tetraoxide, the first raw material containing amorphous iron phosphate, and sodium permanganate, mix and stir to form a slurry, add phosphoric acid, adjust the pH value to 2, heat to 90°C and react for 3 hours, then filter, separate, wash, and dry the slurry to obtain the manganese iron phosphate product Mn. 0.6 Fe 0.4 PO 4 1.4H 2 O.

[0063] Example 6

[0064] Take 2.6 mol of manganous sulfate, 4.2 mol of sodium hydroxide, and 1.3 mol of hydrogen peroxide and add them to the reactor, stir to obtain the second raw material containing trimanganese tetraoxide, filter and wash. Take 2.0 mol of ferrous sulfate, 1.0 mol of monoammonium phosphate, and 0.6 mol of hydrogen peroxide and add them to the reactor and stir to obtain the first raw material containing amorphous iron phosphate, filter and wash, and dry at 120°C for 4 hours to obtain the dehydrated first raw material containing amorphous iron phosphate. Add water to the second raw material containing trimanganese tetraoxide, the dehydrated first raw material containing amorphous iron phosphate, and sodium permanganate, mix and stir to form a slurry, add phosphoric acid, adjust the pH value to 2, heat to 90°C and react for 3 hours, then filter, separate, wash, and dry the slurry to obtain the manganese iron phosphate product Mn. 0.6 Fe 0.4 PO 4 1.4H 2 O.

[0065] Comparative Example 1

[0066] The difference between Comparative Example 1 and Example 1 is that the first oxidant sodium permanganate is not used.

[0067] The specific steps of this comparative example are as follows: 2.6 mol of manganous sulfate, 4.2 mol of sodium hydroxide, and 1.3 mol of hydrogen peroxide are added to a reactor and stirred to obtain a second raw material containing manganese tetraoxide; 2.0 mol of ferrous sulfate, 1.0 mol of monoammonium phosphate, and 0.6 mol of hydrogen peroxide are added to a reactor and stirred to obtain a first raw material containing amorphous iron phosphate; the first raw material containing amorphous iron phosphate and the second raw material containing manganese tetraoxide are mixed evenly and filtered and washed to obtain a mixed solid of the first raw material containing amorphous iron phosphate and the second raw material containing manganese tetraoxide. The mixed solid is stirred into slurry by adding water, phosphoric acid is added, the pH value is adjusted to 2, the temperature is raised to 90°C and reacted for 3 hours, and then the slurry is filtered, separated, washed, and dried to obtain a manganese iron phosphate product.

[0068] The XRD results of the product obtained in Comparative Example 1 are as follows: Figure 8 As shown, the XRD results show that the product obtained in Comparative Example 1 is a non-pure phase of ferromanganese phosphate, which contains about 4% of dihydrate ferrophosphate impurity phase. This is mainly because without the addition of sodium permanganate, manganous ions cannot be oxidized, and the precipitation rates of manganous phosphate, manganese phosphate and ferric phosphate are inconsistent.

[0069] Comparative Example 2

[0070] Compared with Example 1, Comparative Example 2 is different in that ferric phosphate dihydrate and the second raw material containing trimanganese tetraoxide are mixed into a slurry and acid is added to transform the crystals.

[0071] The specific steps of comparative example 2 are as follows: 2.6 mol of manganous sulfate, 4.2 mol of sodium hydroxide, and 1.3 mol of hydrogen peroxide are added to a reactor and stirred to obtain a second raw material containing manganese tetraoxide. 2.0 mol of ferrous sulfate, 1.0 mol of monoammonium phosphate, and 0.6 mol of hydrogen peroxide are added to a reactor and stirred to obtain a first raw material containing amorphous iron phosphate, and the first raw material containing amorphous iron phosphate is slurried and aged to obtain dihydrated iron phosphate. The second raw material containing manganese tetraoxide and dihydrated iron phosphate are mixed evenly and filtered and washed to obtain a mixed solid material, and the mixed solid material is mixed with water and sodium permanganate to form a slurry, phosphoric acid is added, the pH value is adjusted to 2, the temperature is raised to 90°C and reacted for 3 hours, and then the slurry is filtered, separated, washed, and dried to obtain a mixture of dihydrated iron phosphate and manganese phosphate. This is because dihydrated iron phosphate is a crystalline product and does not dissolve during slurry acidification. In this reaction, only a trace amount of manganese tetraoxide is dissolved, oxidized, and precipitated.

[0072] In Examples 1 to 6, pure phase ferromanganese phosphate can be obtained by adopting the scheme of the present application. The changes in raw materials and products are shown in the following table. In the scheme of Comparative Example 1, the first oxidant is not used in the process of slurrying and acid-transforming, and the obtained ferromanganese phosphate contains part of the impurity phase of dihydrate ferric phosphate; in the scheme of Comparative Example 2, amorphous ferric phosphate is slurried and aged to obtain dihydrate ferric phosphate, and the dihydrate ferric phosphate is mixed with the second raw material containing trimanganese tetroxide, slurried and acid-transformed, and ferromanganese phosphate cannot be obtained.

[0073] Table 1 Raw materials, products, and uniformity of iron and manganese distribution in the examples and comparative examples

[0074]

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

[0076] In addition, those skilled in the art will appreciate that, although some embodiments herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present application and form different embodiments. For example, in the above claims, any one of the claimed embodiments may be used in any combination. The information disclosed in this background technology section is intended only to deepen the understanding of the overall background technology of the present application and should not be regarded as an admission or in any form of implication that the information constitutes prior art known to those skilled in the art.

Claims

1. A method for preparing ferromanganese phosphate, characterized in that: include: A first raw material containing amorphous ferric phosphate and a second raw material containing manganese tetraoxide are mixed to form a slurry, a first oxidant is added, the pH value is adjusted to 0.5-5, and ferromanganese phosphate is obtained by reaction.

2. The method for preparing ferromanganese phosphate according to claim 1, characterized in that: One or more of the following conditions are met: (1) The first raw material includes amorphous iron phosphate and water, or the first raw material is amorphous iron phosphate and water; (2) The second raw material includes trimanganese tetraoxide and water, or the second raw material is trimanganese tetraoxide and water; (3) The first oxidant includes any one or more of sodium ferrate, sodium permanganate, potassium permanganate, and ozone; (4) The reaction temperature is 80°C to 100°C; (5) The reaction time is 2 to 5 hours.

3. The method for preparing ferromanganese phosphate according to claim 1 or 2, characterized in that: The pH value is adjusted using a phosphoric acid solution; preferably, the pH value is 1.5-3.

5.

4. The method for preparing ferromanganese phosphate according to claim 1 or 2, characterized in that: The method for preparing the first raw material containing amorphous ferric phosphate comprises: The iron salt solution, the phosphorus source solution and the second oxidant are mixed and reacted to obtain the first raw material containing amorphous iron phosphate.

5. The method for preparing ferromanganese phosphate according to claim 1 or 2, characterized in that: The method for preparing the second raw material containing trimanganese tetraoxide comprises: The manganous salt solution, the second oxidant and the alkaline solution are mixed and reacted to obtain the second raw material containing trimanganese tetraoxide.

6. A ferromanganese phosphate, characterized in that: The ferromanganese phosphate is prepared by the preparation method of any one of claims 1 to 5, wherein the chemical formula of the ferromanganese phosphate is Mn x Fe (1-x) PO4·yH2O, 0<x<1, 0<y<2.

7. The ferromanganese phosphate according to claim 6, characterized in that The primary particle size of the ferromanganese phosphate is 10-20 nm, and the secondary particle D50 is 50-1000 nm.

8. A positive electrode material, characterized in that The raw material comprises the ferromanganese phosphate as claimed in claim 6 or 7.

9. A lithium ion battery, characterized in that: The raw materials include the positive electrode material as claimed in claim 8.

10. A device for implementing the preparation method according to any one of claims 1 to 5, characterized in that: include: A reactor, a first container for storing a first raw material, and a second container for storing a second raw material. The reactor is connected to the first container and the second container respectively, and an agitator is installed in the reactor; the reactor is also connected to a third container for storing a first oxidant and a fourth container for storing a pH adjusting agent.

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