Phosphate-based material of nanoporous structure, and method for preparing and use thereof

Abstract

The application discloses a kind of nano-porous structure phosphate-based materials and its preparation method and purposes. Among them, the chemical general formula of phosphate-based material is Mn 1‑a‑b Fe a M b PO4, 0.01≤a≤0.98, 10 ‑4 ≤b≤10 ‑2 . Wherein M is selected from magnesium, titanium, vanadium, chromium, cobalt, nickel, zinc, gallium, aluminum, zirconium, niobium, molybdenum, tin, antimony, calcium, barium, strontium, boron, ruthenium, silicon, tellurium, copper and lithium in five kinds above, and its particle size is 50nm below, also has porous structure. The material can be used in lithium ion battery high-entropy doped manganese iron lithium phosphate anode material preparation, the specific capacity, rate and cycle performance of the obtained anode material are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to a phosphate-based material with a nanoporous structure and a preparation method and use thereof. BACKGROUND

[0002] In recent decades, nanomaterials and porous materials are functional materials with special structures, which play a unique role and value in many application fields such as photocatalysis, solar cells, electromagnetism, optics, etc., attracting the attention of researchers. Manganese iron phosphate material can be used as phosphating agent to prevent rust and corrosion of steel products; it can also be used as ion exchanger, sensor, adsorbent, magnetic material, etc., and is a very important non-metallic inorganic material. In addition, manganese iron phosphate can also be used as an important precursor material for manganese iron phosphate positive electrode material in lithium ion batteries. Since manganese and iron in manganese iron phosphate material have a uniform mixing degree at the atomic level, when used to prepare manganese iron phosphate positive electrode material, the manganese and iron metal elements in the positive electrode material are also uniformly distributed at the atomic level, which is beneficial to improve the rate performance and cycle stability of manganese iron phosphate lithium ion battery, and to improve the voltage drop and manganese dissolution phenomenon.

[0003] Elemental doping is a common technical means for modifying materials, and usually 1 to 2 elements are selected for doping to improve the performance of the material. High-entropy doping refers to the substitution of manganese elements in the manganese iron phosphate lattice with a small amount of metal or non-metal elements, and the number of types of metal or non-metal elements needs to be 5 or more. Due to the high-entropy effect, high-entropy materials have many advantages, such as: thermodynamic stability, higher electrochemical activity, kinetic hysteresis diffusion effect, and richer material performance.

[0004] Currently, there are few reports on the preparation of manganese iron phosphate, and there are even fewer reports on nanoporous manganese iron phosphate. Chinese patent CN111908442A discloses manganese iron phosphate and a preparation method thereof. The method uses manganese dioxide, ferrous oxalate and phosphoric acid to react in the presence of a reducing agent to obtain (Mn 1-x Fe x ) a PO4·H2O crystals, which are then filtered, washed and sintered at high temperature to obtain amorphous (Mn 1-x Fe x ) a PO4 powder with a particle size of about 2 um. This method requires the introduction of a reducing agent during the preparation process, and heating is required during the reaction process. The manganese iron phosphate material prepared has a large particle size, which is micron level, and the particles have high density and no porous structure. There are almost no reports on nanoporous high-entropy doped manganese iron phosphate materials.

[0005] For the preparation method of manganese phosphate, the literature relates to oxidation-precipitation method, reduction-precipitation method, hydrothermal method and the like. Most of the manganese phosphate particles prepared by these methods are micron grade, and the particle size is too large; and the product solution contains a large amount of metal ions, and the purity is not high. In addition, the manganese phosphate prepared by the preparation method of manganese phosphate may not necessarily obtain pure-phase manganese phosphate iron, and it is very likely to obtain a mixture of manganese phosphate and iron phosphate. SUMMARY

[0006] In view of the defects and deficiencies of the prior art, the present application provides a phosphate-based material with a nanoporous structure, the particle size of the manganese iron phosphate material is small, at the nanometer level, and the particles have a porous structure. When used as a precursor of a high-entropy manganese iron lithium phosphate battery cathode material, the specific capacity of the cathode material can be improved, and the rate and cycle performance of the battery can be improved.

[0007] The present application also provides a preparation method of a phosphate-based material with a nanoporous structure, which does not require the use of a reducing agent and a soluble manganese salt, has mild reaction conditions, and can obtain a high-purity phosphate-based material.

[0008] To achieve the above-mentioned object, the technical scheme adopted by the present application is as follows:

[0009] A phosphate-based material, the chemical general formula of the phosphate-based material is Mn 1-a-b Fe a M b PO4, wherein M is selected from five or more of magnesium, titanium, vanadium, chromium, cobalt, nickel, zinc, gallium, aluminum, zirconium, niobium, molybdenum, tin, antimony, calcium, barium, strontium, boron, ruthenium, silicon, tellurium, copper and lithium, and 0.01≤a≤0.98, 10 -4 ≤b≤10 -2 , the particle size of the phosphate-based material is 50 nm or less, and the phosphate-based material has a porous structure.

[0010] In the present application, the aforementioned phosphate-based material is doped with five or more other metals, which is a doped manganese iron phosphate. The corresponding doped manganese iron lithium phosphate synthesized as a precursor has a high-entropy effect and belongs to a high-entropy doped manganese iron lithium phosphate.

[0011] In some embodiments, the particle size of the phosphate-based material is 40 nm or less, further preferably 5-40 nm, and more further preferably 10-30 nm.

[0012] In some embodiments, the pore size of the phosphate-based material is 2-10 nm; preferably, the pore size of the phosphate-based material is 3-5 nm.

[0013] In some embodiments, the specific surface area of the phosphate-based material is 10-30 m 2 / g; preferably, the specific surface area of the phosphate-based material is 12-18 m 2 / g.

[0014] In some embodiments, 0.2 -3 ≤ b ≤ 10 -2 .

[0015] In some embodiments, the phosphate-based material is monoclinic.

[0016] In some embodiments, the chemical formula of the phosphate-based material is Mn 1-a- b Fe a Mg b1 V b2 Ti b3 Cr b4 Co b5 PO4, Mn 1-a-b Fe a Zn b1 Cu b2 Mg b3 Co b4 Ti b5 PO4, Mn 1-a- b Fe a Zn b1 Cu b2 Mg b3 Mo b4 Ti b5 PO4, Mn 1-a-b Fe a Mg b1 V b2 Ti b3 Cr b4 Mo b5 PO4, Mn 1-a-b Fe a Nb b1 B b2 Co b3 V b4 Al b5 PO4, Mn 1-a-b Fe a Co b1 V b2 Ni b3 B b4 Nb b5 PO4, Mn 1-a-b Fe a Co b1 Ga b2 B b3 Al b4 Sr b5PO4or Mn 1-a- b Fe a Mo b1 Co b2 Ni b3 V b4 Ca b5 PO4, where b1+b2+b3+b4+b5=b, the ranges of b1~b5 are respectively: 10 -4 ≤b1≤10 -2 , 10 -4 ≤b2≤10 -2 , 10 -4 ≤b3≤10 -2 , 10 -4 ≤b4≤10 -2 , 10 -4 ≤b5≤10 -2 ;

[0017] In some embodiments, the chemical formula of the phosphate-based material is Mn 0.7 Fe 0.293 Mg 0.015 V 0.001 Ti 0.0005 Cr 0.001 Co 0.003 PO4, Mn 0.6 Fe 0.395 Zn 0.001 Cu 0.0005 Mg 0.001 Co 0.002 Ti 0.0005 PO4, Mn 0.6 Fe 0.39 Zn 0.001 Cu 0.0005 Mg 0.005 Mo 0.003 Ti 0.0005 PO4, Mn 0.7 Fe 0.293 Mg 0.0015 V 0.001 Ti 0.0005 Cr 0.001 Mo 0.003 PO4, Mn 0.7 Fe 0.29 Nb 0.00 3B 0.003 Co 0.001 V 0.002 Al 0.001 PO4, Mn 0.8 Fe 0.19 Co 0.005 V 0.001 Ni 0.0005 B0.003 Nb 0.0005 PO4, Mn 0.5 Fe 0.49 Co 0.002 5Ga 0.0005 B 0.003 Al 0.002 Sr 0.002 PO4 or Mn 0.65 Fe 0.34 Mo 0.003 Co 0.003 Ni 0.002 V 0.0015 Ca 0.0005 PO4.

[0018] The present application also provides a preparation method of the aforementioned phosphate-based material, which comprises the following steps: 1) mixing manganese iron oxide and a compound of element M with phosphoric acid to obtain a reaction mixture; 2) grinding the reaction mixture to make the reaction mixture react to generate phosphate, thereby obtaining a slurry containing phosphate, wherein the particle size of the phosphate in the slurry is below 100 nm; 3) separating the slurry to obtain phosphate particles; and 4) drying and sintering the phosphate particles to obtain the phosphate-based material.

[0019] In some embodiments, the particle size of the manganese iron oxide is 1-20 microns, preferably, the particle size of the manganese iron oxide is 2-7 microns.

[0020] In some embodiments, the molecular formula of the manganese iron oxide is (Mn x Fe y )3O4, wherein 0.51≤x≤0.81, 0.19≤y≤0.49.

[0021] In some embodiments, the molecular formula of the manganese iron oxide is (Mn 0.61 Fe 0.39 )3O4, (Mn 0.70 Fe 0.30 )3O4, (Mn 0.71 Fe 0.29 )3O4, (Mn 0.81 Fe 0.19 )3O4, (Mn 0.51 Fe 0.49 )3O4 or (Mn 0.66 Fe 0.34 )3O4.

[0022] In some embodiments, the phosphoric acid is in the form of an aqueous solution of phosphoric acid, and the mass concentration of the aqueous solution of phosphoric acid is 10%-70%, preferably 20%-40%.

[0023] In some embodiments, in step 1), the mixing is performed under mechanical stirring at a temperature of 20-40°C.

[0024] In some embodiments, in step 1), the mixing is performed for 1-12 hours.

[0025] In some embodiments, in step 2), the grinding is performed in a sand mill, and the temperature of the grinding is 20-40°C.

[0026] In some embodiments, in step 2), the grinding is performed for 0.5-3 hours.

[0027] In some embodiments, in step 4), the drying is performed at a temperature of 100-120°C.

[0028] In some embodiments, in step 4), the drying is performed for 10 hours.

[0029] In some embodiments, in step 4), the sintering is performed at a temperature of 300-400°C.

[0030] In some embodiments, in step 4), the sintering is performed for 1-4 hours.

[0031] In some embodiments, step 3) comprises filtering and washing the phosphate slurry.

[0032] In some embodiments, step 4) comprises drying the phosphate particles to obtain doped manganese iron phosphate monohydrate crystals with a particle size of less than 100 nm, and sintering the doped manganese iron phosphate monohydrate crystals to obtain the phosphate-based material.

[0033] In some embodiments, the ratio of the amount of substance of the manganese iron oxide and the compound of the M element to the amount of substance of the phosphoric acid is 1:1-2.

[0034] In some embodiments, the preparation method further comprises, before step 1), a step of pre-dispersing the manganese iron oxide in an aqueous dispersant solution.

[0035] In some embodiments, the dispersant is selected from the group consisting of one or more of polyvinylpyrrolidone, polyethylene glycol, and TC130 dispersant.

[0036] In some embodiments, the aqueous dispersant solution has a mass concentration of 0.01%-5%.

[0037] In some embodiments, the preparation method further comprises a step of preparing the phosphoric acid by reacting phosphorus pentoxide with water before the step 1). That is, the present application can use phosphoric acid or phosphorus pentoxide as the phosphorus source for preparing the phosphate-based material.

[0038] In some embodiments, the compound of the M element is selected from a combination of five or more of a compound of magnesium, a compound of titanium, a compound of vanadium, a compound of cobalt, a compound of nickel, a compound of zinc, a compound of gallium, a compound of aluminum, a compound of zirconium, a compound of niobium, a compound of molybdenum, a compound of tin, a compound of antimony, a compound of calcium, a compound of barium, a compound of strontium, a compound of boron, a compound of ruthenium, a compound of silicon, a compound of tellurium, a compound of copper, and a compound of lithium.

[0039] In some embodiments, the compound of the M element is selected from a combination of one or more of an oxide, a carbonate, an oxalate, a nitrate, a sulfate, a chloride, and an organic acid salt of the M element.

[0040] In some embodiments, the organic acid salt of the M element is selected from a combination of one or more of an organic phosphate, an acetate, an organic sulfonate, an alkyl salt, an ester salt of the M element.

[0041] Preferably, the compound of the M element is an oxide, or an acetate, or a carbonate.

[0042] In some embodiments, the compound of the M element is a combination of magnesium acetate, ammonium metavanadate, titanium oxide, cadmium oxide, cobalt sulfate, or a combination of zinc sulfate, copper oxalate, cobalt acetate, magnesium nitrate, cobalt oxide, n-butyl titanate, or a combination of zinc oxide, copper oxide, magnesium oxide, molybdenum oxide, titanium dioxide, or a combination of magnesium oxide, ammonium metavanadate, titanium dioxide, chromium sesquioxide, molybdenum oxide, or a combination of niobium oxalate, diboron trioxide, cobalt acetate, ammonium metavanadate, aluminum oxide, or a combination of cobalt acetate, ammonium metavanadate, nickel acetate, boric acid, niobium oxalate, or a combination of cobalt chloride, gallium chloride, boric acid, aluminum sesquioxide, strontium chloride, or a combination of molybdenum oxide, cobalt chloride, nickel chloride, vanadium oxalate, calcium oxide.

[0043] The present application also provides a use of the aforementioned phosphate-based material for preparing a battery cathode material.

[0044] The present application also provides a high-entropy manganese iron lithium phosphate cathode material prepared by high-temperature sintering reaction of raw materials comprising the aforementioned phosphate-based material, a lithium source compound, and optionally an organic carbon source.

[0045] Further, the lithium source compound is selected from a combination of one or more of lithium carbonate, lithium hydroxide, lithium chloride, lithium sulfate, lithium nitrate, lithium dihydrogen phosphate, lithium hydrogen phosphate, and lithium acetate.

[0046] Further, the organic carbon source is selected from the group consisting of glucose, sucrose, fructose, citric acid, polyethylene glycol, polyvinylpyrrolidone, ethylenediaminetetraacetic acid and ascorbic acid, in combination of one or more.

[0047] The application also provides a lithium ion battery comprising the aforementioned high-entropy manganese iron lithium phosphate cathode material.

[0048] Further, the lithium ion battery has a discharge specific capacity of 150 mAh / g or more at 0.1C, a discharge specific capacity of 140 mAh / g or more at 1C, and a capacity retention rate of 95% or more after 200 cycles of charging and discharging at 1C rate. It can be seen that the lithium ion battery has excellent cycle performance.

[0049] Compared with the prior art, the application has the following advantages:

[0050] The particle size of the phosphate material of the application is nanoscale, small in size, and has a porous structure. The phosphate material is a variety of metal-doped manganese iron phosphate, which is used as a precursor of a high-entropy doped manganese iron lithium phosphate cathode material. When the high-entropy doped manganese iron lithium phosphate cathode material is used in a lithium ion battery, the specific capacity, rate and cycle performance of the battery can be significantly improved. BRIEF DESCRIPTION OF DRAWINGS

[0051] Figure 1 XRD pattern of the manganese iron oxide raw material used in Example 1;

[0052] Figures 2-3 SEM pattern of the manganese iron oxide raw material used in Example 1, the scales are different;

[0053] Figure 4 XRD pattern of the doped manganese iron phosphate monohydrate in Example 1;

[0054] Figures 5-6 SEM pattern of the doped manganese iron phosphate monohydrate in Example 1, the scales are 1 micron and 2 micron respectively;

[0055] Figure 7 XRD pattern of the doped manganese iron phosphate prepared in Example 1;

[0056] Figure 8 SEM pattern of the doped manganese iron phosphate prepared in Example 1;

[0057] Figure 9 XRD pattern of the product of step 2) in Comparative Example 1;

[0058] Figures 10-11 SEM pattern of the product of step 2) in Comparative Example 1, the scales are different;

[0059] Figure 12 XRD pattern of the final product in Comparative Example 1;

[0060] Figure 13 SEM pattern of the final product in Comparative Example 1.

[0061] Figure 14 Adsorption-desorption curve of the doped manganese iron phosphate prepared in Example 1;

[0062] Figure 15 Pore size distribution of the doped manganese iron phosphate prepared in Example 1;

[0063] Figure 16 Rate test results of the doped manganese iron phosphate prepared in Example 1 for button cell;

[0064] Figure 17 Cycle test results of the doped manganese iron phosphate prepared in Example 1 for button cell. DETAILED DESCRIPTION

[0065] The present application provides an improved doped manganese iron phosphate, the main innovation of which is that the particle size is controlled to be less than 50 nm, and the product has a porous structure. Although the prior art discloses doped manganese iron phosphate, the particle size is in the micron level, the particle size is large, and the doped manganese iron phosphate in the prior art has high density and is usually non-porous.

[0066] The specific capacity, charge-discharge rate and cycle performance of a lithium ion battery including the high-entropy doped manganese iron lithium phosphate cathode material can be significantly improved. The manganese iron active element in the structure of the cathode material is partially occupied by more than five doped metal elements, and the cathode material has a high-entropy effect, which is specifically as follows: 1) the thermodynamics of the material is more stable, because the high-entropy material with multiple elements forms a single-phase solid solution, rather than a mixture of multiple solid solutions; 2) the electrochemical activity of the material is higher, because the atoms in the high-entropy material are randomly distributed in the crystal lattice, and the different metal atom radii, chemical bonds, and environments around each atom are different, which makes the lattice have more distortion and defects than traditional one or two element phosphate materials, and the material has higher activity; 3) the kinetic diffusion effect is slow, that is, the internal diffusion and phase transition speed of the high-entropy material is very slow; 4) the performance of the material is more abundant, because the basic characteristics of different components and their interactions make the high-entropy material have more complex characteristics. Therefore, under the influence of the high-entropy effect, the performance of the high-entropy doped manganese iron lithium phosphate cathode material is much better than that of the corresponding performance of the binary metal element, such as the manganese iron phosphate cathode material. The high-entropy doped manganese iron phosphate cathode material not only has a more stable crystal structure, but also makes it more difficult for manganese and other metal ions to dissolve, thereby improving the cycle performance of the material; and in the presence of multiple active metals and the synergistic effect between the multiple active metals, the electrochemical platform of the cathode material is more, and the connection between the platforms is more gentle, eliminating the phenomenon of steep decline at the end of the discharge platform. In addition, the electronic and ionic conduction speed of the high-entropy doped manganese iron lithium phosphate cathode material can be higher, and the rate performance of the lithium ion battery is better.

[0067] Another innovation of the present application is the preparation process of the doped manganese iron phosphate material. In the present application, manganese iron oxide, at least five other doped metal element compounds are directly mixed with phosphoric acid, and then grinding is performed to accelerate the reaction rate between them, so that the reaction between them generates a nano-sized phosphate slurry, and at the same time, multiple doped ions are incorporated into the phosphate material. After the particles are separated from the slurry, the particles are dried to obtain a nano-sized doped manganese iron phosphate monohydrate crystal, and finally sintering is performed to obtain the nano-porous doped manganese iron phosphate of the present application. Compared with the prior art, the present application does not require a reducing agent or a soluble ferrous salt as a reaction raw material, but directly reacts manganese iron oxide, which is a compound of manganese iron elements uniformly mixed at an atomic level, with phosphoric acid to obtain high-purity manganese iron phosphate, and the process is simple. More than five doped ion compounds will also react with phosphoric acid, and at the same time, the manganese iron phosphate material is gradually generated, and the ions are doped into the manganese iron phosphate material in the form of ions, and finally the doped manganese iron phosphate material is obtained. The aforementioned grinding can accelerate the reaction rate. If grinding is not performed, the reaction between manganese iron oxide, doped ion compounds and phosphoric acid is very slow, the reaction period is very long and it is difficult to react completely, and the ion doping is very uneven.

[0068] Another innovation of the present application is that the dissolution rate of manganese iron oxide and the nucleation rate of manganese iron phosphate can be adjusted by changing the concentration of phosphoric acid, and then the crystal particle size of manganese iron phosphate is regulated. The phosphoric acid can also be prepared by reacting phosphorus pentoxide with water, that is, the phosphorus source for preparing manganese iron phosphate in the present application can be phosphoric acid or phosphorus pentoxide.

[0069] The present application will be further described below in conjunction with examples. However, the present application is not limited to the following examples. The implementation conditions used in the examples can be further adjusted according to different requirements of specific use, and the implementation conditions not specified are conventional conditions in the industry. The technical features involved in each embodiment of the present application can be combined with each other as long as there is no conflict between them.

[0070] Example 1

[0071] The present embodiment provides a nano-porous doped manganese iron phosphate with a chemical formula of Mn 0.6 Fe 0.39 Zn 0.00 1Cu 0.0005 Mg 0.005 Mo 0.003 Ti 0.0005 PO4, and the preparation process is as follows:

[0072] 1) In a glass beaker, add concentrated phosphoric acid solution and deionized water in turn, and after stirring evenly, prepare a 25% mass concentration phosphoric acid aqueous solution; according to the molar ratio of Mn and Fe to P element of 1:1.5, pour 114.93 g of micron-sized manganese iron oxide (molecular formula (MnFe2O4), purchased from Sichuan Qingyuan New Material Co., Ltd., average particle size 7 microns) into 882 mL of the above phosphoric acid aqueous solution, 0.081 g of zinc oxide, 0.040 g of copper oxide, 0.20 g of magnesium oxide, 0.432 g of molybdenum oxide, 0.040 g of titanium dioxide, and mechanically stir for 12 hours to obtain a reaction mixture; 0.61 Fe 0.39 )3O4, purchased from Sichuan Qingyuan New Material Co., Ltd., average particle size 7 microns), 0.081 g of zinc oxide, 0.040 g of copper oxide, 0.20 g of magnesium oxide, 0.432 g of molybdenum oxide, 0.040 g of titanium dioxide, and mechanically stir for 12 hours to obtain a reaction mixture;

[0073] 2) Pour the reaction mixture into a sand mill and sand mill for 1 hour to obtain a greenish slurry; filter and wash the slurry to obtain particles, and then dry the particles at 100°C to obtain a greenish powder (doped manganese iron phosphate monohydrate);

[0074] 3) Sinter the aforementioned doped manganese iron phosphate monohydrate in a muffle furnace at 400°C for 2 hours to obtain a red-brown powder.

[0075] The XRD pattern and SEM image of the manganese iron oxide are shown in Figs. Figure 1 、 2 -3, and it can be seen that the manganese iron oxide has a crystal structure. The XRD pattern and SEM image of the doped manganese iron phosphate monohydrate obtained in step 2) are shown in Figs. Figure 4 、 5 -6, and it can be seen that the crystal phase is a monoclinic crystal structure of MnPO4·H2O. The particle size of the doped manganese iron phosphate monohydrate is 25 nm, as measured by scanning electron microscopy (SEM). The XRD pattern and SEM image of the doped manganese iron phosphate obtained in step 3) are shown in Figs. Figure 7 、 8 , and it can be seen that the doped manganese iron phosphate has a certain degree of crystallinity, and a large number of porous structures are distributed between the particles. The crystal phase remains a monoclinic crystal structure, as determined by XRD testing. The particle size of the doped manganese iron phosphate is 35 nm, as measured by scanning electron microscopy (SEM). The adsorption-desorption test and analysis of the doped manganese iron phosphate using a specific surface area and pore size tester are shown in Figs. Figure 14 、 15 , and it can be seen that the doped manganese iron phosphate material has a mesoporous structure, with a pore size mainly distributed around 4-6 nm, and a specific surface area of about 15.1 m 2 / g.

[0076] Example 2

[0077] This example provides a doped manganese iron phosphate with a nanoporous structure, with a chemical formula of Mn 0.7 Fe0.293 Mg 0.0015 V 0.001 Ti 0.0005 Cr 0.001 Mo 0.003 PO4, prepared as follows:

[0078] 1) A 25% phosphoric acid solution was prepared by adding a concentrated phosphoric acid solution and deionized water into a glass beaker in sequence, and stirring until uniform; 882 mL of the above phosphoric acid solution was poured into 114.81 g of micron-sized manganese-iron oxide (molecular formula (MnFe)304, purchased from Sichuan Qingyuan New Material Co., Ltd., average particle size 7 microns), 0.060 g of magnesium oxide, 0.117 g of ammonium metavanadate, 0.399 g of titanium dioxide, 0.152 g of chromium sesquioxide, and 0.432 g of molybdenum oxide, according to a molar ratio of Mn and Fe to P of 1:1.5, and mechanically stirring for 12 hours to obtain a reaction mixture; 0.70 Fe 0.30 )3O4, purchased from Sichuan Qingyuan New Material Co., Ltd., average particle size 7 microns), 0.060 g of magnesium oxide, 0.117 g of ammonium metavanadate, 0.399 g of titanium dioxide, 0.152 g of chromium sesquioxide, and 0.432 g of molybdenum oxide, according to a molar ratio of Mn and Fe to P of 1:1.5, and mechanically stirring for 12 hours to obtain a reaction mixture;

[0079] 2) The reaction mixture was poured into a sand mill and sand milled for 1 hour to obtain a greenish slurry; the slurry was filtered and washed to obtain particles, and the particles were dried at 100°C to obtain a greenish powder (doped manganese-iron phosphate monohydrate);

[0080] 3) The above doped manganese-iron phosphate monohydrate was sintered in a muffle furnace at 400°C for 2 hours to obtain a red-brown powder.

[0081] After testing and analysis, the obtained doped manganese-iron phosphate monohydrate was MnPO4·H2O with a monoclinic crystal structure, and the particle size was 25 nm; the doped manganese-iron phosphate after heat treatment had a certain degree of crystallinity, and the crystal phase still maintained a monoclinic crystal structure; a large number of porous structures were distributed between the particles, and the particle size was 35 nm; the doped manganese-iron phosphate material had a mesoporous structure, and the pore size mainly distributed around 4-6 nm, and the specific surface area was about 14.8 m2 / g. 2

[0082] Example 3

[0083] The present example provides a doped manganese-iron phosphate with a nanoporous structure, with a chemical formula of Mn 0.7 Fe 0.29 Nb 0.00 3B 0.003 Co 0.001 V 0.002 Al 0.001 PO4, prepared as follows:

[0084] ​1) In a glass beaker, add concentrated phosphoric acid solution and deionized water in turn, and after stirring evenly, prepare a 30% mass concentration phosphoric acid aqueous solution; according to the molar ratio of Mn and Fe to P element is 1:1.5, pour 114.80g micron-sized manganese iron oxide (molecular formula is (Mn 0.71 Fe 0.29 )3O4, purchased from Sichuan Qingyuan New Material Co., Ltd., with an average particle size of 7 microns) into 735mL of the above phosphoric acid aqueous solution, 1.614g niobium oxalate, 0.104g boron trioxide, 0.177g cobalt acetate, 0.234g ammonium metavanadate, 0.051g aluminum oxide, and mechanically stir for 12 hours to obtain a reaction mixture;

[0085] 2) Pour the reaction mixture into a sand mill and sand mill for 1 hour to obtain a greenish slurry; filter and wash the slurry to obtain particles, and then dry the particles at 100°C to obtain a greenish powder (doped manganese iron phosphate monohydrate);

[0086] 3) Sinter the aforementioned doped manganese iron phosphate monohydrate in a muffle furnace at 400°C for 2 hours to obtain a red-brown powder.

[0087] After testing and analysis, the obtained doped manganese iron phosphate monohydrate is MnPO4·H2O with a monoclinic crystal structure, with a particle size of 20nm; the doped manganese iron phosphate after heat treatment has a certain degree of crystallinity, and the crystal phase still maintains a monoclinic crystal structure; a large number of porous structures are distributed between the particles, and the particle size is 30nm; the doped manganese iron phosphate material has a mesoporous structure, with a pore size mainly distributed around 3-5nm, and a specific surface area of about 16.5m 2 / g.

[0088] Example 4

[0089] This example provides a nano-porous high-entropy doped manganese iron phosphate with a chemical formula of Mn 0.8 Fe 0.19 Co 0.005 V 0.001 Ni 0.0005 B 0.003 Nb 0.0005 PO4, and the preparation process is as follows:

[0090] 1) In a glass beaker, add concentrated phosphoric acid solution and deionized water in turn, and after stirring evenly, prepare a 30% mass concentration phosphoric acid aqueous solution; according to the molar ratio of Mn and Fe to P element is 1:1.5, pour 114.80g micron-sized manganese iron oxide (molecular formula is (Mn 0.81 Fe 0.19)304, purchased from Sichuan Qingyuan New Material Co., Ltd., average particle size of 7 microns), 0.885 g of cobalt acetate, 0.117 g of ammonium metavanadate, 0.088 g of nickel acetate, 0.186 g of boric acid, 0.269 g of niobium oxalate, mechanical stirring for 12 hours to obtain a reaction mixture;

[0091] 2) Pour the reaction mixture into a sand mill and sand mill for 1 hour to obtain a green slurry; filter and wash the slurry to obtain particles, and then dry the particles at 100°C to obtain a green powder (doped manganese iron phosphate monohydrate);

[0092] 3) Sinter the aforementioned doped manganese iron phosphate monohydrate in a muffle furnace at 400°C for 2 hours to obtain a red-brown powder.

[0093] After testing and analysis, the obtained doped manganese iron phosphate monohydrate is MnPO4·H2O with a monoclinic crystal structure, and the particle size is 20 nm; the doped manganese iron phosphate after heat treatment has a certain crystallinity, and the crystal phase still maintains a monoclinic crystal structure; a large number of porous structures are distributed between the particles, and the particle size is 30 nm; the doped manganese iron phosphate material has a mesoporous structure, and the pore size mainly distributes around 4-5 nm, and the specific surface area is about 16.8 m 2 / g.

[0094] Example 5

[0095] This example provides a doped manganese iron phosphate with a nanoporous structure, which has a chemical formula of Mn 0.5 Fe 0.49 Co 0.0025 Ga 0.0005 B 0.003 Al 0.002 Sr 0.002 PO4, and the preparation process is as follows:

[0096] 1) In a glass beaker, add concentrated phosphoric acid solution and deionized water in sequence, and after stirring uniformly, prepare a phosphoric acid aqueous solution with a mass concentration of 25%; according to the molar ratio of Mn and Fe to P element of 1:1.5, pour 115.07 g of micron-sized manganese iron oxide (molecular formula (Mn 0.51 Fe 0.49 )304, purchased from Sichuan Qingyuan New Material Co., Ltd., average particle size of 7 microns) into 882 mL of the above-mentioned phosphoric acid aqueous solution, 0.325 g of cobalt chloride, 0.088 g of gallium chloride, 0.186 g of boric acid, 0.102 g of aluminum oxide, 0.317 g of strontium chloride, and mechanically stir for 12 hours to obtain a reaction mixture;

[0097] 2) Pour the reaction mixture into a sand mill and sand mill for 1 hour to obtain a dark green slurry; filter and wash the slurry to obtain particles, and then dry the particles at 100°C to obtain a dark green powder (doped manganese iron phosphate monohydrate);

[0098] 3) Sinter the aforementioned doped manganese iron phosphate monohydrate in a muffle furnace at 400°C for 2 hours to obtain a red-brown powder.

[0099] After testing and analysis, the obtained doped manganese iron phosphate monohydrate is MnPO4·H2O with a monoclinic crystal structure, and the particle size is 25 nm; the doped manganese iron phosphate after heat treatment has a certain crystallinity, and the crystal phase still maintains a monoclinic crystal structure; a large number of porous structures are distributed between the particles, and the particle size is 35 nm; the doped manganese iron phosphate material has a mesoporous structure, and the pore size mainly distributes around 4-6 nm, and the specific surface area is about 14.5 m 2 / g.

[0100] Example 6

[0101] The present embodiment provides a doped manganese iron phosphate with a nanoporous structure, which has a chemical formula of Mn 0.65 Fe 0.34 Mo 0.003 Co 0.003 Ni 0.002 V 0.0015 Ca 0.0005 PO4, and the preparation process is as follows:

[0102] 1) In a glass beaker, add a concentrated phosphoric acid solution and deionized water in sequence, and after stirring uniformly, prepare a phosphoric acid aqueous solution with a mass concentration of 25%; according to the molar ratio of Mn and Fe to P element of 1:1.5, pour 114.87 g of micron-sized manganese iron oxide (molecular formula (Mn 0.66 Fe 0.34 )3O4, purchased from Sichuan Qingyuan New Material Co., Ltd., with an average particle size of 7 microns), 0.432 g of molybdenum oxide, 0.389 g of cobalt chloride, 0.259 g of nickel chloride, 0.4 g of vanadium oxalate, and 0.028 g of calcium oxide into 882 mL of the aforementioned phosphoric acid aqueous solution, and mechanically stir for 12 hours to obtain a reaction mixture;

[0103] 2) Pour the reaction mixture into a sand mill and sand mill for 1 hour to obtain a dark green slurry; filter and wash the slurry to obtain particles, and then dry the particles at 100°C to obtain a dark green powder (doped manganese iron phosphate monohydrate);

[0104] 3) Sinter the aforementioned doped manganese iron phosphate monohydrate in a muffle furnace at 400°C for 2 hours to obtain a red-brown powder.

[0105] The doped manganese iron phosphate monohydrate obtained through test analysis is MnPO4H2O with monoclinic crystal structure, and the particle size is 25 nm; the doped manganese iron phosphate after heat treatment has certain crystallinity, and the crystal phase still maintains monoclinic crystal structure; a large number of porous structures are distributed between the particles, and the particle size is 35 nm; the doped manganese iron phosphate material has mesoporous structure, and the pore size mainly distributes at about 4-6 nm, and the specific surface area is about 14.7 m2 / g. 2 / g.

[0106] Comparative Example 1

[0107] The present comparative example provides a comparative phosphate material, and the preparation process is basically the same as that of Example 1, and the specific process is as follows:

[0108] 1) A concentrated phosphoric acid solution and deionized water are sequentially added into a glass beaker, and a phosphoric acid aqueous solution with a mass concentration of 25% is prepared after stirring; according to the molar ratio of Mn and Fe to P element of 1:1.5, 48.15 g of manganese sesquioxide, 31.14 g of iron sesquioxide (the particle sizes of manganese oxide and iron oxide are both 7 microns), 0.081 g of zinc oxide, 0.040 g of copper oxide, 0.20 g of magnesium oxide, 0.432 g of molybdenum oxide, and 0.040 g of titanium dioxide are poured into 882 mL of the above phosphoric acid aqueous solution, and mechanical stirring is performed for 12 hours to obtain a reaction mixture;

[0109] 2) The reaction mixture is poured into a sand mill and sand-milled for 1 hour to obtain a dark brown slurry; the slurry is filtered and washed to obtain particles, and the particles are dried at 100°C to obtain a dark brown product;

[0110] 3) The product of step 2) is sintered in a muffle furnace at 400°C for 2 hours to obtain a dark brown final product.

[0111] The XRD pattern and SEM image of the product obtained in step 2) are shown in FIGS. Figure 9 、 10 -11, and it can be seen that the product is a mixture of zinc copper magnesium molybdenum titanium doped manganese phosphate (Mn 0.9839 Zn 0.0016 Cu 0.0008 Mg 0.0081 Mo 0.0048 Ti 0.0008 )PO4H2O and iron oxide, and the particle size distribution of the product is not uniform, and is between 50-2000 nm. The small particles with a particle size of about 50 nm are zinc copper magnesium molybdenum titanium doped manganese phosphate monohydrate, and the large particles with a particle size of about 2000 nm are iron oxide. The XRD pattern and SEM image of the final product obtained in step 3) are shown in FIGS. Figure 12 、 13 , and it can be seen that the final product is zinc copper magnesium molybdenum titanium doped manganese phosphate (Mn0.9839 Zn 0.0016 Cu 0.0008 Mg 0.0081 Mo 0.0048 Ti 0.0008 )PO4 with iron oxide, and the particle size distribution of the final product is also uneven, mainly distributed between 50-2000 nm, and the pore structure between small particles is more, but the large particles are more dense.

[0112] Comparative Example 2

[0113] This comparative example provides a comparative phosphate material, which is prepared basically the same as Example 1, the difference is only that no compound of doping elements is added in step 1), and the preparation process is as follows:

[0114] 1) In a glass beaker, add concentrated phosphoric acid solution and deionized water in turn, and prepare a 25% mass concentration phosphoric acid aqueous solution after stirring uniformly; according to the molar ratio of Mn and Fe to P element of 1:1.5, pour 114.93g micron-sized manganese-iron oxide (molecular formula is (Mn 0.61 Fe 0.39 )3O4, purchased from Sichuan Qingyuan New Material Co., Ltd., with an average particle size of 7 microns) into 882mL of the above phosphoric acid aqueous solution, mechanically stir for 12 hours to obtain a reaction mixture;

[0115] 2) Pour the reaction mixture into a sand mill and sand mill for 1 hour to obtain a dark green slurry; filter and wash the slurry to obtain particles, and then dry the particles at 100°C to obtain a dark green powder of manganese-iron phosphate monohydrate;

[0116] 3) Sinter the manganese-iron phosphate monohydrate in a muffle furnace at 400°C for 2 hours to obtain a red-brown powder.

[0117] Among them, the dark green powder obtained in step 2) is tested and analyzed by XRD and SEM, and the crystal phase of the material is MnPO4·H2O with monoclinic crystal structure, and the particle size is 25nm.

[0118] The red-brown powder obtained in step 3) is tested and analyzed by XRD and SEM, and the crystal phase of the material still remains monoclinic crystal structure, and the particle size is 35nm. The manganese-iron phosphate material has a mesoporous structure, and the pore size mainly distributes around 4-6nm, and the specific surface area is about 15.1m 2 / g.

[0119] Comparative Example 3

[0120] This comparative example provides a comparative phosphate material, which is prepared basically the same as Example 1, the difference is only that only 4 compounds of doping elements are added in step 1), and the preparation process is as follows:

[0121] 1) In a glass beaker, add concentrated phosphoric acid solution and deionized water in turn, and after stirring evenly, prepare a 25% mass concentration phosphoric acid aqueous solution; according to the molar ratio of Mn and Fe to P element of 1:1.5, pour 114.93g micron-sized manganese iron oxide (molecular formula (Mn 0.61 Fe 0.39 )3O4, purchased from Sichuan Qingyuan New Material Co., Ltd., with an average particle size of 7 microns) into 882mL of the above phosphoric acid aqueous solution, 0.081g zinc oxide, 0.040 copper oxide, 0.20g magnesium oxide, 0.040g titanium dioxide, and mechanically stir for 12 hours to obtain a reaction mixture;

[0122] 2) Pour the reaction mixture into a sand mill and sand mill for 1 hour to obtain a greenish slurry; filter and wash the slurry to obtain particles, and then dry the particles at 100°C to obtain a greenish powder (doped manganese iron phosphate monohydrate);

[0123] 3) Sinter the aforementioned doped manganese iron phosphate monohydrate in a muffle furnace at 400°C for 2 hours to obtain a red-brown powder.

[0124] After testing and analysis, the obtained doped manganese iron phosphate monohydrate is MnPO4·H2O with a monoclinic crystal structure, and the particle size is 25nm; the doped manganese iron phosphate after heat treatment has a certain degree of crystallinity, and the crystal phase still maintains a monoclinic crystal structure; a large number of porous structures are distributed between the particles, and the particle size is 35nm; the doped manganese iron phosphate material has a mesoporous structure, and the pore size mainly distributes around 4-6nm, and the specific surface area is about 15m 2 / g.

[0125] Application Example 1

[0126] The phosphate-based materials prepared in Examples 1-6 and Comparative Examples 1-3 are used to prepare lithium manganese iron phosphate respectively, and the specific operation is as follows:

[0127] 1) According to the element molar ratio of Li:(Mn+Fe):P of 1.02:1:1, weigh 113g of lithium carbonate, 450.9g of the phosphate-based material, and 68.3g of glucose respectively;

[0128] 2) Pour 2.5Kg of water and the weighed glucose into the sand mill, and mechanically stir for 10min until the glucose is completely dissolved;

[0129] 3) Pour the weighed phosphate-based material and lithium carbonate into the sand mill, and sand mill for 2h;

[0130] 4) Spray dry the slurry obtained by sand mill dispersion to obtain the precursor powder of lithium manganese iron phosphate (LMFP) / C;

[0131] 5) The LMFP / C precursor powder is pre-fired at 350°C for 2h under an inert atmosphere, and then sintered at 600°C for 10h, to obtain the LMFP / C cathode material.

[0132] The above LMFP / C cathode material is mixed with the conductive agent carbon nanotube, the conductive agent carbon black, the binder polyvinylidene fluoride, and the solvent N-methyl pyrrolidone to form a cathode slurry, wherein the mass ratio of the LMFP / C cathode material, the conductive agent carbon nanotube, the conductive agent carbon black, and the binder polyvinylidene fluoride is 91.5:1.5:1.0:6; the cathode slurry is coated on an aluminum foil, vacuum baked, punched, and finally formed into a LMFP / C cathode sheet. A button cell is assembled using the LMFP / C as the cathode, a lithium sheet as the anode, and a 1 mol / L LiPF6 EC / DMC / EMC solution as the electrolyte, and the cell is subjected to charge-discharge test (charge-discharge window is 2.5V-4.3V), to obtain the electrical performance of the lithium manganese iron phosphate. The results are shown in Table 1 below.

[0133] Table 1 Electrical performance of lithium manganese iron phosphate

[0134]

[0135] The above examples are only for illustrating the technical concept and characteristics of the present application, and the purpose is to enable those skilled in the art to understand the content of the present application and implement it, and cannot limit the protection scope of the present application. Any equivalent changes or modifications made according to the spirit and essence of the present application should be covered within the protection scope of the present application.

[0136] The endpoints of the ranges and any values claimed herein are not limited to the precise values. The ranges and values should be construed as being approximate. The endpoints of the ranges and values are provided as example of the boundaries of the ranges and are not to be designed to limit the range or value. The range values are intended to be approximate values. The endpoints of the ranges of values and single values can be combined with one another to form new ranges or values, which are to be considered as being within the scope of the present disclosure.

Claims

1. A phosphate-based material, characterized by: The chemical general formula of the phosphate-based material is Mn 1-a-b Fe a M b PO4, wherein M is selected from five or more of magnesium, titanium, vanadium, chromium, cobalt, nickel, zinc, gallium, aluminum, zirconium, niobium, molybdenum, tin, antimony, calcium, barium, strontium, boron, ruthenium, silicon, tellurium, copper, and lithium, and 0.01≤a≤0.98, 10 -4 ≤b≤10 -2 The particle size of the phosphate-based material is 50 nm or less, and the phosphate-based material has a porous structure; the specific surface area of the phosphate-based material is 10-30 m 2 / g, and the pore size is 2-10 nm. The phosphate-based material is prepared by a preparation method comprising the following steps: 1) mixing manganese iron oxide and a compound of element M with phosphoric acid to obtain a reaction mixture; 2) grinding the reaction mixture to make the reaction mixture react to generate phosphate, thereby obtaining a slurry containing phosphate, wherein the particle size of the phosphate in the slurry is less than 100 nm; 3) separating the slurry to obtain phosphate particles; and 4) drying and sintering the phosphate particles to obtain the phosphate-based material.

2. The phosphate-based material according to claim 1, characterized by The particle size of the phosphate-based material is less than 40 nm.

3. The phosphate-based material according to claim 1, characterized by, The particle size of the phosphate-based material is 5-40 nm.

4. The phosphate-based material according to claim 1, characterized by, 0.2 < a < 0.5, 10 -3 < b < 10 -2 .

5. The phosphate-based material according to claim 1, characterized by The phosphate-based material is monoclinic.

6. The phosphate-based material according to claim 1, characterized by The chemical formula of the phosphate-based material is Mn 1-a-b Fe a Mg b1 V b2 Ti b3 Cr b4 Co b5 PO4, Mn 1-a-b Fe a Zn b1 Cu b2 Mg b3 Co b4 Ti b5 PO4, Mn 1-a- b Fe a Zn b1 Cu b2 Mg b3 Mo b4 Ti b5 PO4, Mn 1-a-b Fe a Mg b1 V b2 Ti b3 Cr b4 Mo b5 PO4, Mn 1-a-b Fe a Nb b1 B b2 Co b3 V b4 Al b5 PO4, Mn 1-a-b Fe a Co b1 V b2 Ni b3 B b4 Nb b5 PO4, Mn 1-a-b Fe a Co b1 Ga b2 B b3 Al b4 Sr b5 PO4, or Mn 1-a- b Fe a Mo b1 Co b2 Ni b3 V b4 Ca b5 PO4, wherein b1+b2+b3+b4+b5=b, the ranges of b1~b5 are respectively: 10 -4 ≤b1≤10 -2 , 10 -4 ≤b2≤10 -2 , 10 -4 ≤ b3≤ 10 -2 , 10 -4 ≤ b4≤ 10 -2 , 10 -4 ≤ b5≤ 10 -2 .

7. The phosphate-based material according to claim 1, characterized by, The chemical formula of the phosphate-based material is Mn 0.7 Fe 0.293 Mg 0.015 V 0.001 Ti 0.0005 Cr 0.001 Co 0.003 PO4, Mn 0.6 Fe 0.395 Zn 0.001 Cu 0.0005 Mg 0.001 Co 0.002 Ti 0.000 5PO4, Mn 0.6 Fe 0.39 Zn 0.001 Cu 0.0005 Mg 0.005 Mo 0.003 Ti 0.0005 PO4, Mn 0.7 Fe 0.293 Mg 0.0015 V 0.001 Ti 0.0005 Cr 0.001 Mo 0.003 PO4, Mn 0.7 Fe 0.29 Nb 0.003 B 0.003 Co 0.001 V 0.002 Al 0.001 PO4, Mn 0.8 Fe 0.19 Co 0.005 V 0.001 Ni 0.0005 B 0.003 Nb 0.0005 PO4, Mn 0.5 Fe 0.49 Co 0.0025 Ga 0.0005 B 0.003 Al 0.002 Sr 0.002 PO4, or Mn 0.65 Fe 0.34 Mo 0.003 Co 0.003 Ni 0.00 2V 0.0015 Ca 0.0005 PO4.

8. A method for producing the phosphate-based material according to any one of claims 1 to 7, characterized by, The preparation method comprises the following steps: 1) mixing manganese iron oxide and a compound of element M with phosphoric acid to obtain a reaction mixture; 2) grinding the reaction mixture to make the reaction mixture react to generate phosphate, thereby obtaining a slurry containing phosphate, wherein the particle size of the phosphate in the slurry is less than 100 nm; 3) separating the slurry to obtain phosphate particles; and 4) drying and sintering the phosphate particles to obtain the phosphate-based material.

9. The method for producing a phosphate-based material according to claim 8, characterized by: The particle size of the manganese iron oxide is 1-20 microns; and / or, the phosphoric acid is in the form of a phosphoric acid aqueous solution, and the mass concentration of the phosphoric acid aqueous solution is 10%-70%.

10. The method for producing a phosphate-based material according to claim 8, characterized by: In step 1), the mixing is performed under mechanical stirring at a temperature of 20-40°C; and / or, in step 2), the grinding is performed in a sand mill, and the temperature of the grinding is 20-40°C; and / or, in step 4), the drying is performed at a temperature of 100-120°C; and / or, in step 4), the sintering is performed at a temperature of 300-400°C; and / or, the step 3) comprises filtering and washing the phosphate slurry.

11. The method for producing a phosphate-based material according to claim 8, characterized by: The step 4) comprises drying the phosphate particles to obtain doped manganese iron phosphate monohydrate crystals with a particle size of less than 100 nm, and sintering the doped manganese iron phosphate monohydrate crystals to obtain the phosphate-based material.

12. The method for producing a phosphate-based material according to claim 8, characterized by: The ratio of the amount of substance of the manganese iron oxide and the compound of element M to the amount of substance of the phosphoric acid is 1:1-2.

13. The method for producing a phosphate-based material according to claim 8, characterized by: The preparation method further comprises, before the step 1), a step of dispersing the manganese iron oxide in a dispersant aqueous solution; and / or, the preparation method further comprises, before the step 1), a step of preparing the phosphoric acid by reacting phosphorus pentoxide with water.

14. The method for producing a phosphate-based material according to claim 13, characterized by: The dispersant is selected from the group consisting of one or more of polyvinylpyrrolidone, polyethylene glycol, and TC130 dispersant; and / or, the mass concentration of the dispersant aqueous solution is 0.01%-5%.

15. The method for producing a phosphate-based material according to any one of claims 8 to 14, characterized in that: The compound of the M element is selected from a combination of five or more of a compound of magnesium, a compound of titanium, a compound of vanadium, a compound of cobalt, a compound of nickel, a compound of zinc, a compound of gallium, a compound of aluminum, a compound of zirconium, a compound of niobium, a compound of molybdenum, a compound of tin, a compound of antimony, a compound of calcium, a compound of barium, a compound of strontium, a compound of boron, a compound of ruthenium, a compound of silicon, a compound of tellurium, a compound of copper, and a compound of lithium.

16. The method for producing a phosphate-based material according to any one of claims 8 to 14, characterized by: The compound of the M element is selected from a combination of one or more of an oxide, a carbonate, an oxalate, a nitrate, a sulfate, a chloride, and an organic acid salt of the M element.

17. The method for producing a phosphate-based material according to any one of claims 8 to 14, characterized by: The compound of the M element is a combination of magnesium acetate, ammonium metavanadate, titanium oxide, cadmium oxide, cobalt sulfate, or a combination of zinc sulfate, copper oxalate, cobalt acetate, magnesium nitrate, cobalt oxide, n-butyl titanate, or a combination of zinc oxide, copper oxide, magnesium oxide, molybdenum oxide, titanium dioxide, or a combination of magnesium oxide, ammonium metavanadate, titanium dioxide, chromium sesquioxide, molybdenum oxide, or a combination of niobium oxalate, diboron trioxide, cobalt acetate, ammonium metavanadate, aluminum oxide, or a combination of cobalt acetate, ammonium metavanadate, nickel acetate, boric acid, niobium oxalate, or a combination of cobalt chloride, gallium chloride, boric acid, aluminum sesquioxide, strontium chloride, or a combination of molybdenum oxide, cobalt chloride, nickel chloride, vanadium oxalate, calcium oxide.

18. Use of the phosphate-based material of any one of claims 1-7 for preparing a cathode material for a lithium ion battery.

19. A high-entropy lithium manganese iron phosphate cathode material, characterized in that: The high-entropy lithium manganese iron phosphate cathode material is prepared by a high-temperature sintering reaction of raw materials including the phosphate-based material of any one of claims 1-7, a lithium source compound, and optionally an organic carbon source.

20. The high-entropy lithium manganese iron phosphate cathode material of claim 19, wherein: The lithium source compound is selected from a combination of one or more of lithium carbonate, lithium hydroxide, lithium chloride, lithium sulfate, lithium nitrate, lithium dihydrogen phosphate, lithium hydrogen phosphate, and lithium acetate; and / or, the organic carbon source is selected from a combination of one or more of glucose, sucrose, fructose, citric acid, polyethylene glycol, polyvinylpyrrolidone, ethylenediaminetetraacetic acid, and ascorbic acid.

21. A lithium-ion battery comprising a cathode material, characterized in that: The cathode material includes the high-entropy lithium manganese iron phosphate cathode material of claim 19 or 20.

22. The lithium-ion battery of claim 21, wherein: The lithium ion battery has a discharge specific capacity of 150 mAh / g or more at 0.1C, a discharge specific capacity of 140 mAh / g or more at 1C, and a capacity retention rate of 95% or more after 200 cycles of charge and discharge at 1C rate.

Images