Lithium ferric manganese phosphate precursor as well as preparation method and application thereof
The preparation of hollow iron-manganese lithium phosphate material through saponification and foaming combined with co-precipitation process has solved the problem of low conductivity of lithium ferroferro phosphate, achieved higher ion transfer rate and chemical stability, and improved battery performance.
Patent Information
- Application Number
- CN202510477615.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-16
- Publication Date
- 2025-07-15
AI Technical Summary
The existing lithium manganese ferrophosphate materials have low electronic and ion conductivity, which leads to a large gap between their performance and commercial ternary positive electrode materials, limiting their application prospects.
The hollow structure of ferromanganese lithium phosphate precursor material was prepared by saponification foaming and co-precipitation process, and hollow iron manganese lithium phosphate material was synthesized by high-temperature lithiation sintering method, and lithium-based biomass-derived surfactant was used as a dispersant and lithium source to form a uniform iron manganese lithium phosphate structure.
It improves the ion transmission rate and rate performance of lithium iron manganese phosphate, increases the specific surface area and chemical stability, and improves the cycling performance and rate performance of the battery.
Smart Images
Figure CN120308934A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of lithium-ion battery materials, relates to a cathode material for lithium-ion batteries, and specifically relates to a lithium iron manganese phosphate precursor, a preparation method thereof, and an application thereof. Background Art
[0002] Lithium iron phosphate (LiFePO4, abbreviated as LFP) is a lithium-ion battery electrode material with an olivine structure. This structure endows lithium iron phosphate with excellent stability and cycling performance. The energy density of lithium iron phosphate batteries is relatively low, mainly due to its relatively low theoretical specific capacity (about 170 mAh / g). Although the energy density can be improved to a certain extent by optimizing the structure and composition of the cathode material, developing new electrolytes, and improving the utilization rate of the anode material, there is still a certain gap in energy density between lithium iron phosphate batteries and other types of lithium batteries, such as ternary lithium batteries.
[0003] Lithium iron manganese phosphate is a new cathode material formed by doping a certain amount of manganese element on the basis of lithium iron phosphate and is considered to be an upgraded version of lithium iron phosphate. The crystal structure of lithium iron manganese phosphate (LMFP) is similar to that of LFP, and it also has characteristics such as stable chemical properties and excellent safety performance. At the same time, the doped manganese element in LMFP can increase the charging voltage of the material, raising the charging voltage from 3.4 V of LFP to 4.1 V, which increases the theoretical energy density of LMFP batteries by 15 - 20%, further extending the cruising range. The safety performance of LMFP is better than that of NCM, and the energy density is higher than that of LFP. In addition, LMFP has a low dependence on rare metals and can be produced in the same line as LFP, with obvious cost advantages. Lithium iron manganese phosphate has better low-temperature performance than lithium iron phosphate, so lithium iron manganese phosphate has good application scenarios.
[0004] However, in the existing technology, lithium iron manganese phosphate has the problem of low electron and ion conductivity, and there is a large gap in performance with commercial ternary cathode materials, which affects the application prospect of lithium iron manganese phosphate. Summary of the Invention
[0005] In view of the defects and deficiencies existing in the prior art, on the first aspect, the present invention provides a preparation method of lithium iron manganese phosphate; on the second aspect, the present invention provides a lithium iron manganese phosphate; on the third aspect, the present invention provides a battery.
[0006] On the first aspect, the present invention provides a preparation method of lithium iron manganese phosphate, comprising the following steps: Step 1, heating a mixed material of a lithium salt solution, ammonia water, and a biomass material to obtain Material A, and then stirring until a large number of bubbles appear in Material A; Step 2, adjusting the pH value of Material A to 6 - 7, then adding a manganese salt solution and an iron salt solution, and stirring to obtain Material B; Step 3: Add a phosphate solution to Material B, and obtain Material C after reaction; Step 4: Heat Material C until the solvent is completely evaporated to obtain Material D; Step 5: Sinter Material D at a high temperature under an inert atmosphere, and the obtained solid particles are the lithium iron manganese phosphate.
[0007] Preferably, in Step 1, the lithium salt is any one or more of lithium hydroxide, lithium citrate, and lithium chloride.
[0008] Preferably, in Step 1, the biomass material is any one or more of saponins, coconut oil, lard, beef tallow, and mutton tallow.
[0009] Preferably, in Step 1, the heating temperature is 50-80 °C, and the heating time is 6-16 h.
[0010] Preferably, in Step 1, the stirring speed is 50-100 rpm, and the stirring time is 1-3 h.
[0011] Preferably, in Step 1, the mass ratio of the lithium salt to the biomass material in the mixed material is 1:5-10.
[0012] Preferably, in Step 1, the pH value of the mixed material is 10-11.
[0013] Preferably, in Step 2, when adjusting the pH value of Material A, the pH regulator used is any one or more of citric acid, oxalic acid, and dilute nitric acid.
[0014] Preferably, in Step 2, the manganese salt solution is any one or more of manganese acetate solution, manganese nitrate solution, and manganese sulfate solution.
[0015] Preferably, in Step 2, the iron salt solution is any one or more of ferrous acetate solution, ferrous nitrate solution, and ferrous sulfate solution.
[0016] Preferably, in Step 2, the concentrations of both the manganese salt solution and the iron salt solution are 1-3 mol / L.
[0017] Preferably, in Step 2, the molar ratio of manganese ions to iron ions in Material B is 1:0.5-9; the ratio of the sum of the molar amounts of manganese ions and iron ions to the molar amount of lithium ions in Material B is 1:1.01-1.1.
[0018] Preferably, in Step 3, the phosphate solution is any one or more of diammonium hydrogen phosphate solution, ammonium dihydrogen phosphate solution, and sodium dihydrogen phosphate solution.
[0019] Preferably, in Step 3, the heating temperature is 60-90 °C, and the heating time is 10-24 h.
[0020] Preferably, in step 3, the molar ratio of the sum of the metal ions in material B to the phosphate radical in the phosphate solution added to material B is 2∶1.03 - 1.2.
[0021] Preferably, in step 4, the heating temperature is 85 - 100 °C.
[0022] Preferably, in step 5, the sintering temperature is 800 - 1000 °C, and the sintering time is 10 - 30 h.
[0023] Preferably, in step 5, the gas providing the inert atmosphere is any one or both of nitrogen and argon.
[0024] In a second aspect, the present invention provides a lithium iron manganese phosphate material prepared by the above preparation method.
[0025] In a third aspect, the present invention provides a battery comprising the above lithium iron manganese phosphate material.
[0026] Compared with the prior art, the present invention has the following obvious beneficial effects: By means of saponification foaming combined with the co - precipitation process, the present invention prepares a lithium iron manganese phosphate precursor material with a hollow structure, and then further synthesizes a hollow lithium iron manganese phosphate material through a high - temperature lithiation sintering method. The prepared lithium iron manganese phosphate material inherits the hollow structure of the precursor, can exhibit a higher ion transport rate and excellent rate performance; and the hollow structure synthesized by this preparation method has a larger specific surface area and better chemical stability. Description of the Drawings
[0027] Figure 1 It is a schematic diagram of the foaming state after stirring the mixed solution obtained in step 1 of Example 1; Figure 2 It is an SEM image of the lithium iron manganese phosphate material prepared in Example 1; Figure 3 It is a cyclic performance graph of the battery assembled from the lithium iron manganese phosphate materials prepared in Examples 1 - 3 and Comparative Example 1; Figure 4 It is a rate performance graph of the battery assembled from the lithium iron manganese phosphate materials prepared in Example 1 and Comparative Example 1. Detailed Embodiments
[0028] The present invention provides the following specific technical solutions.
[0029] In a first aspect, the present invention provides a preparation method of lithium iron manganese phosphate, comprising the following steps: Step 1, heating a mixed material of a lithium salt solution, ammonia water and a biomass material to obtain material A, and then stirring until a large number of bubbles appear in material A; Step 2: Adjust the pH value of Material A to 6 - 7, then add manganese salt solution and iron salt solution, and stir to obtain Material B; Step 3: Add phosphate solution to Material B, and react to obtain Material C; Step 4: Heat Material C until the solvent completely evaporates to obtain Material D; Step 5: Sinter Material D at high temperature under an inert atmosphere, and the obtained solid particles are the lithium iron manganese phosphate.
[0030] The inventors found through research that the lithium-based biomass-derived surfactant generated after the reaction of biomass material and lithium salt can not only be used as a dispersant but also as a lithium source. After foaming, lithium ions are on the periphery of the micelles, and the organic groups are distributed inside the micelles as a support. Phosphate and manganese-iron precipitates are dispersed around the lithium ions. The heating and drying process can stabilize the hollow structure of the solid particles, which is beneficial to obtaining a lithium iron manganese phosphate cathode material with a hollow structure after high-temperature sintering. Roasting is carried out under an inert atmosphere. During the roasting process, the micelles are first roasted until exhausted. The interaction forces between lithium ions, phosphate, and manganese-iron precipitates enable the relative positions of the materials to be maintained even after the micelles disappear, thus maintaining the hollow structure. The properties of the lithium-based biomass-derived surfactant itself enable lithium ions to better contact and react with the surrounding phosphate, iron, and manganese precipitates in subsequent reactions. As a connection center, lithium ions attract negatively charged phosphate ions and the precipitates of iron and manganese ions, making these components orderly distributed around lithium ions. This distribution method is beneficial to forming a uniform lithium iron manganese phosphate structure in subsequent reactions, laying a foundation for obtaining a high-quality cathode material finally.
[0031] The hollow lithium iron manganese phosphate material can exhibit a higher ion transport rate, thus showing excellent rate performance, and the hollow structure synthesized by this preparation method has a larger specific surface area and better chemical stability.
[0032] Preferably, in Step 1, the lithium salt is any one or more of lithium hydroxide, lithium citrate, and lithium chloride.
[0033] In practical applications, other common lithium salts can also be used as the lithium source of the present invention.
[0034] Preferably, in Step 1, the biomass material is any one or more of saponin, coconut oil, lard, beef tallow, and mutton tallow.
[0035] The inventor has found through research that when the biomass material is saponin, it has certain surface activity, can reduce the surface tension of the solution, and after reacting with lithium salts, the hydrophilic and lipophilic groups in its structure can interact with lithium salts, further optimizing the performance of the surfactant and endowing it with good emulsifying, dispersing, foaming and other properties. The lithium-based surfactants prepared from fats such as coconut oil, lard, beef tallow, and mutton tallow usually have good emulsifying properties and can form stable emulsions of oil and water. The lithium-based biomass-derived surfactant formed by the reaction of saponin, fats and lithium salts is beneficial to subsequent foaming and reduces the possibility of defoaming in subsequent processes.
[0036] In practical applications, in addition to the above several types, the biomass material can also be other commonly used fats that can undergo saponification reaction with lithium salts to form lithium higher fatty acids.
[0037] Preferably, in step 1, the heating temperature is 50~80 °C and the heating time is 6~16 h.
[0038] The inventor has found through research that heating can reduce the viscosity of the biomass material, making it easier to disperse in the aqueous solution, increasing the contact area between the biomass material and lithium salts, and facilitating the formation of lithium-based biomass-derived surfactants.
[0039] Preferably, in step 1, the stirring speed is 50~100 rpm and the stirring time is 1~3 h.
[0040] The purpose of the inventor to provide the above preferred stirring rate and stirring time is to provide the preferred foaming degree of material A, avoid weak foaming degree, large foam and easy defoaming; too long foaming time will increase the cost.
[0041] Preferably, in step 1, the mass ratio of lithium salt to biomass material in the mixed material is 1∶5~10.
[0042] Preferably, in step 1, the pH value of the mixed material is 10~11.
[0043] Preferably, in step 2, when adjusting the pH value of the material A, the pH regulator used is any one or more of citric acid, oxalic acid, and dilute nitric acid.
[0044] Common pH regulators are used to adjust the reaction system to neutral or weakly acidic, which is beneficial to the formation of manganese and iron precipitates.
[0045] Preferably, in step 2, the manganese salt solution is any one or more of manganese acetate solution, manganese nitrate solution, and manganese sulfate solution.
[0046] Preferably, in step 2, the iron salt solution is any one or more of ferrous acetate solution, ferrous nitrate solution, and ferrous sulfate solution.
[0047] Preferably, in step 2, the concentrations of both the manganese salt solution and the iron salt solution are 1 - 3 mol / L.
[0048] Preferably, in step 2, the molar ratio of manganese ions to iron ions in material B is 1∶0.5 - 9; the molar ratio of the sum of the molar amounts of manganese ions and iron ions in material B to lithium ions is 1∶1.01 - 1.1.
[0049] In practical applications, the lithium ions in material B are slightly in excess to prevent lithium loss caused by high - temperature sintering.
[0050] Preferably, in step 3, the phosphate solution is any one or more of diammonium hydrogen phosphate solution, ammonium dihydrogen phosphate solution, and sodium dihydrogen phosphate solution.
[0051] Preferably, in step 3, the reaction duration is 8 - 12 h.
[0052] Preferably, in step 3, the molar ratio of the sum of the molar amounts of metal ions in material B to the phosphate groups in the phosphate solution added to material B is 2∶1.03 - 1.2.
[0053] Preferably, in step 4, the heating temperature is 85 - 100 °C.
[0054] Preferably, in step 5, the sintering temperature is 800 - 1000 °C, and the sintering time is 10 - 30 h.
[0055] In practical applications, the sintering temperature and sintering time are easily affected by the ambient temperature and equipment, and can be adjusted according to the actual situation. In the specific embodiments of the present invention, the sintering temperature can be 800 °C, 850 °C, 900 °C, 950 °C, 1000 °C, and the sintering time can be 10 h, 15 h, 20 h, 25 h, 30 h.
[0056] Preferably, the gas providing the inert atmosphere is any one or both of nitrogen and argon.
[0057] Second, the present invention provides a lithium iron manganese phosphate material prepared by the above - mentioned preparation method.
[0058] Third, the present invention provides a battery including the above - mentioned lithium iron manganese phosphate material.
[0059] To make the technical problems, technical solutions, and technical advantages to be solved by the present invention clearer, the following will be described in detail with specific examples, but the protection scope of the present invention is not limited to the following specific embodiments.
[0060] Unless otherwise defined, all technical terms used hereinafter have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing specific embodiments only and are not intended to limit the scope of the present invention.
[0061] Unless otherwise specifically stated, various raw materials, reagents, instruments, equipment, etc. used in the present invention can be obtained through market purchase or can be prepared by existing methods.
[0062] Example 1: A preparation method of lithium iron manganese phosphate, comprising the following steps: Step 1: Disperse 2.855 g (0.0136 mol) of lithium citrate in 200 ml of deionized water, then add 22.84 g of beef tallow and ammonia water with a mass fraction of 23% to obtain a mixed solution. The pH value of the mixed solution is 11. Heat it to 60 °C and react for 10 h to obtain Material A. Stir it at 80 rpm for 2 h until a large number of bubbles appear in Material A.
[0063] Step 2: After adjusting the pH of Material A to 6 - 7 with 1 mol / L citric acid solution, take 0.02 mol of manganese acetate and 0.02 mol of ferrous acetate and disperse them in 40 ml of deionized water to form a uniform metal salt solution. Add it to the above Material A and stir evenly to obtain Material B.
[0064] Step 3: Take 0.045 mol of (NH4)2HPO4 and dissolve it in 50 ml of deionized water to form a phosphate solution. Add the phosphate solution to Material B and stir continuously for 10 h to obtain Material C.
[0065] Step 4: Heat Material C to 90 °C, and then keep it warm until the solvent evaporates completely to obtain solid particles as Material D.
[0066] Step 5: Place Material D in a nitrogen atmosphere and sinter it at 900 °C for 22 h to obtain the lithium iron manganese phosphate material.
[0067] Figure 1 It is a schematic diagram of the foaming state after stirring of the mixed solution obtained in Step 1 of Example 1. As Figure 1 can be seen, the foaming state of the mixed solution is good, the foaming is uniform, and it can be reasonably speculated that it lays a solid foundation for the hollow structure of the subsequent lithium iron manganese phosphate material.
[0068] Figure 2 It is an SEM image of the lithium iron manganese phosphate material prepared in Example 1. As Figure 1 can be seen, the lithium iron manganese phosphate material has a hollow structure, a large specific surface area, and the particles are uniform and have good consistency.
[0069] Comparative Example 1: A preparation method of lithium iron manganese phosphate material, comprising the following steps: Step 1: Dissolve 0.2 mol of manganese acetate, 0.2 mol of ferrous acetate, and 0.408 mol of lithium acetate in deionized water to form a metal salt solution. Dissolve 0.45 mol of (NH4)2HPO4 in 200 ml of deionized water to form a phosphate solution. Add the phosphate solution to the metal salt solution and stir continuously. At the same time, heat at 70 °C and react fully for 16 h. After filtration, washing, and drying, a lithium iron manganese phosphate precursor is obtained.
[0070] Step 2: Ball-mill and crush the lithium iron manganese phosphate precursor, and then place it under a nitrogen atmosphere and sinter at 900 °C for 22 h to prepare the lithium iron manganese phosphate cathode material.
[0071] Example 2: A preparation method of lithium iron manganese phosphate material, comprising the following steps: Step 1: Dissolve 9.676 g (0.404 mol) of lithium hydroxide in 200 ml of deionized water, then add 48.38 g of coconut oil and ammonia water with a mass fraction of 22% to obtain a mixed solution. The pH value of the mixed solution is 11. Heat to 50 °C and react for 16 h to obtain material A. Stir at 50 rpm for 3 h until a large number of bubbles appear in material A.
[0072] Step 2: After adjusting the pH of material A to 6 - 7 with 0.5 mol / L nitric acid solution, dissolve 0.27 mol of manganese nitrate and 0.13 mol of ferrous nitrate in 400 ml of deionized water to form a uniform metal salt solution, and add it to the above-mentioned material A. Stir evenly to obtain material B.
[0073] Step 3: Dissolve 0.414 mol of (NH4)2HPO4 in 50 ml of deionized water to form a phosphate solution. Add the phosphate solution to material B and stir continuously for 8 h to obtain material C.
[0074] Step 4: Heat material C to 85 °C, and then keep it warm until the solvent evaporates completely to obtain solid particles as material D.
[0075] Step 6: Place material D under a nitrogen atmosphere and sinter at 800 °C for 30 h to obtain the lithium iron manganese phosphate material.
[0076] Example 3: A preparation method of lithium iron manganese phosphate material, comprising the following steps: Step 1: Disperse 2.242 g (0.022 mol) of lithium chloride in 200 ml of deionized water, then add 22.42 g of saponin and 25% ammonia water by mass to obtain a mixed solution with a pH value of 10. Heat the solution to 80 °C and react for 6 h to obtain Material A. Stir at 100 rpm for 1 h until a large number of bubbles appear in Material A.
[0077] Step 2: After adjusting the pH of Material A to 6 - 7 with 0.5 mol / L nitric acid solution, disperse 0.004 mol of manganese acetate and 0.036 mol of ferrous acetate in 40 ml of deionized water to form a uniform metal salt solution, and add it to the above Material A. Stir evenly to obtain Material B.
[0078] Step 3: Dissolve 0.0504 mol of (NH4)2HPO4 in 50 ml of deionized water to form a phosphate solution, add the phosphate solution to Material B, and stir continuously for 12 h to obtain Material C.
[0079] Step 4: Heat Material C to 100 °C, then keep it warm until the solvent evaporates completely to obtain solid particles as Material D.
[0080] Step 5: Place Material D in a high-temperature sintering furnace under a nitrogen atmosphere at 1000 °C for 10 h to obtain the lithium iron manganese phosphate material.
[0081] Take the lithium iron manganese phosphate materials prepared in Examples 1 - 3 and Comparative Example 1 as the positive electrode active material, mix them with the conductive agent acetylene black (AB) and the binder polyvinylidene fluoride (PVDF) in a mass ratio of 8:1:1, use N-methylpyrrolidone (NMP) as the solvent, place them in a small beaker and stir the mixture at a speed of 800 r / min for 2 h to obtain a slurry. Use an automatic coater to coat the slurry on the current collector aluminum foil, place it flat on the tempered glass and transfer it to a vacuum drying oven at 85 °C for drying for 4 h. After punching into a pole piece with a diameter of 12 mm, dry it in a vacuum drying oven at 105 °C for 4 h, place it in a glove box with a water content and oxygen content both lower than 0.1 ppm and filled with argon atmosphere for 4 h to reduce the moisture adsorbed by the pole piece during the transfer process, and then assemble it into a CR2032 type button battery in the glove box. Use a pure metal lithium sheet with a diameter of 16 mm and a thickness of 0.5 mm as the negative electrode, and a porous polyethylene film with a diameter of 18 mm and a model of Celgard2300 as the separator.
[0082] After the battery assembly is completed, age it for 12 h, then at a voltage of 2 - 4.4 V, activate it for 3 cycles at a current density of 0.1 C, and then cycle it 100 times at a current density of 2 C.
[0083] Figure 3 It is the cycle performance diagram of the batteries assembled with the lithium iron manganese phosphate materials prepared in Examples 1 - 3 and Comparative Example 1. Figure 2It can be seen that the cycle performance of the lithium iron manganese phosphate material prepared by the preparation method provided by the present invention has been greatly improved, which can prove from the side that the lithium iron manganese phosphate material prepared by the preparation method provided by the present invention can exhibit a higher ion transport rate.
[0084] Figure 4 Fig. is the rate performance diagram of the battery assembled from the lithium iron manganese phosphate materials prepared in Example 1 and Comparative Example 1. It can be seen from Figure 3 that the lithium iron manganese phosphate material prepared in Example 1 can improve the rate performance of the battery, which indicates that the lithium iron manganese phosphate material prepared by the preparation method provided by the present invention can exhibit a higher ion transport rate.
[0085] The above embodiments are only preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope of the present invention, according to the technical solution and its concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.
Claims
1. A preparation method of lithium iron manganese phosphate, characterized in that, It includes the following steps: Step 1: Heat the mixed material of lithium salt solution, ammonia water and biomass material to obtain Material A, and then stir until a large number of bubbles appear in Material A; Step 2: After adjusting the pH value of Material A to 6 - 7, add manganese salt solution and iron salt solution, and stir to obtain Material B; Step 3: Add phosphate solution to Material B, and obtain Material C after reaction; Step 4: Heat Material C until the solvent completely evaporates to obtain Material D; Step 5: Sinter Material D at high temperature under an inert atmosphere, and the obtained solid particles are the lithium iron manganese phosphate.
2. The preparation method of lithium iron manganese phosphate according to claim 1, characterized in that In Step 1, the stirring speed is 50 - 100 rpm, and the stirring time is 1 - 3 h; the mass ratio of lithium salt to biomass material in the mixed material is 1∶5 - 10; the pH value of the mixed material is 10 - 11; the heating temperature is 50 - 80 °C, and the heating time is 6 - 16 h.
3. The preparation method of lithium iron manganese phosphate according to claim 1 or 2, characterized in that, The lithium salt is any one or more of lithium hydroxide, lithium citrate, and lithium chloride; the biomass material is any one or more of saponin, coconut oil, lard, beef tallow, and mutton tallow.
4. The preparation method of lithium iron manganese phosphate according to claim 1, wherein, In Step 2, the pH regulator used to adjust the pH value of Material A is any one or more of citric acid, oxalic acid, and dilute nitric acid; the manganese salt solution is any one or more of manganese acetate solution, manganese nitrate solution, and manganese sulfate solution; the iron salt solution is any one or more of ferrous acetate solution, ferrous nitrate solution, and ferrous sulfate solution.
5. The preparation method of lithium iron manganese phosphate according to claim 1 or 4, characterized in that, In Step 2, the molar ratio of manganese ions to iron ions in Material B is 1∶0.5 - 9; the ratio of the sum of the molar amounts of manganese ions and iron ions in Material B to the molar amount of lithium ions is 1∶1.01 - 1.
1.
6. The preparation method of lithium iron manganese phosphate according to claim 1, characterized in that, In Step 3, the phosphate solution is any one or more of diammonium hydrogen phosphate solution, ammonium dihydrogen phosphate solution, and sodium dihydrogen phosphate solution; the ratio of the sum of the molar amounts of metal ions in Material B to the molar amount of phosphate radicals in the phosphate solution added to Material B is 2∶1.03 - 1.2; the heating temperature is 60 - 90 °C, and the heating time is 10 - 24 h.
7. The preparation method of lithium iron manganese phosphate according to claim 1, characterized in that, The sintering temperature is 800 - 1000 °C, and the sintering time is 10 - 30 h.
8. The preparation method of lithium iron manganese phosphate according to claim 1, characterized in that, The gas providing the inert atmosphere is any one or both of nitrogen and argon.
9. A lithium iron manganese phosphate, characterized in that, Prepared by the preparation method according to any one of claims 1 - 8 above.
10. A battery, characterized in that, It includes the lithium iron manganese phosphate material according to claim 9.