CN115465849B - Phosphate positive electrode material and preparation method and application thereof - Google Patents

Phosphate positive electrode material and preparation method and application thereof Download PDF

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CN115465849B
CN115465849B CN202211180262.1A CN202211180262A CN115465849B CN 115465849 B CN115465849 B CN 115465849B CN 202211180262 A CN202211180262 A CN 202211180262A CN 115465849 B CN115465849 B CN 115465849B
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phosphate
positive electrode
electrode material
source
sintering
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CN115465849A (en
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唐杰
傅正
孔令涌
李亨利
陈振绳
徐荣益
李意能
刘其峰
陈燕玉
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Foshan Dynanonic Technology Co ltd
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    • C01B25/00—Phosphorus; Compounds thereof
    • C01B25/16—Oxyacids of phosphorus; Salts thereof
    • C01B25/26—Phosphates
    • C01B25/45—Phosphates containing plural metal, or metal and ammonium
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
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    • H01M10/00—Secondary cells; Manufacture thereof
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    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
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    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • H01M4/5825—Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines
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    • H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
    • H01M2004/028—Positive electrodes
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Abstract

The invention provides a phosphate positive electrode material, and a preparation method and application thereof, wherein the preparation method comprises the following steps: mixing a metal source, a phosphorus source, a lithium source and a dispersing agent, adding a metal oxide, and mixing with a primary carbon source to obtain a mixed solution, and drying and primary sintering the mixed solution to obtain a semi-finished product; mixing a secondary carbon source with the semi-finished product, and then performing secondary sintering to obtain the phosphate positive electrode material; the preparation method of the phosphate positive electrode material by doping and secondary carbon mixing processes overcomes the defects that the existing phosphate positive electrode material is high in investment and difficult to produce in a large scale in the preparation process, has the advantages of simple flow, low cost, wide raw material sources and high universality, can achieve the mass production of thousands of tons, and the prepared product has small particle size, is of a specific shape, is uniformly coated with a carbon layer and has excellent multiplying power.

Description

Phosphate positive electrode material and preparation method and application thereof
Technical Field
The invention belongs to the technical field of batteries, relates to a preparation method of a positive electrode material, and particularly relates to a phosphate positive electrode material, and a preparation method and application thereof.
Background
The phosphate positive electrode material such as lithium iron phosphate is of an olivine structure, has the advantages of rich raw materials, low cost, high mass specific capacity and the like, and is the first positive electrode material of the power type lithium ion battery at present, but the phosphate positive electrode material is low in conductivity and limits the application of the phosphate positive electrode material in the field of high-power batteries. In the existing preparation method or process of the high-magnification phosphate positive electrode material, modification is mostly carried out by a hydrothermal method with high cost or doping rare noble metals.
As CN 109244458a discloses a three-dimensional network porous graphene/lithium iron phosphate composite positive electrode material and a preparation method, by compounding a three-dimensional network porous structure of a graphene material with flaky lithium iron phosphate, the electrochemical performance of the lithium iron phosphate is improved by utilizing nano flaky structure lithium iron phosphate with a specific surface area larger than that of the traditional lithium iron phosphate, but the adopted synthesis process is complicated and the input cost is high; CN 109192953a discloses a high-magnification spherical lithium iron phosphate carbon composite positive electrode material and a preparation method thereof, by which the spherical lithium iron phosphate positive electrode material with uniformly coated metal-doped carbon is prepared, and the surface and the inside of the positive electrode material particles are uniformly coated with the metal-doped carbon, and although the electrochemical performance of the positive electrode material can be improved, the preparation method of repeated grinding and spray drying is adopted, so that the provided method has high production investment and is not suitable for large-scale production.
And as disclosed in CN 112331846A, the preparation method of the high-rate positive electrode material lithium iron phosphate is characterized in that precursor raw materials are dissolved in a solvent, a powdery precursor is obtained through spray drying, and then a microwave heating method is utilized to prepare the high-power nano lithium iron phosphate material, so that the problems of quick heating reaction, easy bumping and difficult process control when the precursor in a liquid form is subjected to microwave heating by the microwave method are overcome, but the defects of complicated preparation process steps, high input cost and incapability of realizing large-scale production still exist.
Based on the above studies, there is a need to provide a method for preparing a phosphate-based positive electrode material, which can overcome the above-mentioned drawbacks, and which gives a product excellent in properties.
Disclosure of Invention
The invention aims to provide a phosphate positive electrode material and a preparation method and application thereof, in particular to a multiplying power type phosphate positive electrode material and a preparation method and application thereof.
In order to achieve the aim of the invention, the invention adopts the following technical scheme:
in a first aspect, the present invention provides a method for preparing a phosphate-based cathode material, the method comprising the steps of:
(1) Mixing a metal source, a phosphorus source, a lithium source and a dispersing agent, adding a metal oxide, and mixing with a primary carbon source to obtain a mixed solution, and drying and primary sintering the mixed solution to obtain a semi-finished product;
(2) And (3) mixing a secondary carbon source with the semi-finished product obtained in the step (1), and then performing secondary sintering to obtain the phosphate positive electrode material.
The secondary carbon mixing process adopted by the preparation method can realize mass production of the product in kiloton scale, overcomes the defects of high preparation investment and difficult mass production of the existing phosphate positive electrode material, and particularly can realize growth along a specific crystal face by doping metal elements, twice carbon mixing and twice sintering, thereby regulating and controlling the path of lithium ions in a one-dimensional track and improving the rate performance, and on the other hand, the twice carbon mixing can enable the carbon coating to be more compact and complete, so that the conductivity of the material is better, the growth of product particles of the phosphate positive electrode material is effectively controlled, and the electrochemical performance, particularly the rate performance, of the phosphate positive electrode material can be improved.
According to the preparation method, the metal oxide is added in the preparation process, so that the doping element is introduced into the material, and the doping of the metal element can increase the lattice defect of the material, so that the diffusion rate of Li + and the internal conductivity of particles are improved, and the internal mechanism is as follows: ① A proper amount of ion doping expands a one-dimensional diffusion channel of Li + along the b axis; ② Lattice distortion is caused by doping, li-O bond energy is reduced, and lithium ion transmission rate is improved; ③ Doping increases the concentration of Li vacancies, which is beneficial to the deintercalation of Li + in the material; ④ Doping reduces the band gap width of two phases such as LiFePO 4 and FePO 4, and improves the electron conductivity; ⑤ Doping suppresses the formation of inversion defects, reducing the obstruction of defects to Li + diffusion; therefore, the element doping can be matched with secondary carbon mixing, so that lithium ions are deintercalated in a one-dimensional orbit, and the rate capability of the material can be greatly improved.
The metal oxide and the primary carbon source can be mutually matched, and if the metal oxide and the primary carbon source are added in advance, anions in the raw materials can react with the metal oxide to generate other complexes, so that loss of main content elements is caused, and other impurity phases in the finished product are generated.
Preferably, the temperature of the secondary sintering in the step (2) is 650-800 ℃, such as 650 ℃, 675 ℃, 700 ℃, 725 ℃, 750 ℃, 775 ℃ or 800 ℃, but not limited to the recited values, and other non-recited values in the range of values are equally applicable.
Preferably, the temperature rising rate of the secondary sintering in the step (2) is 5-20 ℃/min, for example, 5 ℃/min, 7 ℃/min, 9 ℃/min, 11 ℃/min, 13 ℃/min, 15 ℃/min, 17 ℃/min or 20 ℃/min, but the temperature rising rate is not limited to the listed values, and other values not listed in the numerical range are equally applicable.
Preferably, the time of the secondary sintering in the step (2) is 10-16h, for example, 10h, 11h, 12h, 13h, 14h, 15h or 16h, but not limited to the recited values, and other non-recited values in the range of values are equally applicable.
According to the invention, by controlling the sintering process of secondary carbon mixing and adopting a specific sintering temperature and sintering heating rate, the secondary carbon source and the metal oxide can be mutually matched, so that a semi-finished product can be uniformly and compactly coated by carbon, and grown into a phosphate positive electrode material with an elliptic rod shape, but not a spherical shape; the elliptic rod has the advantages that the elliptic rod is found by a characterization means to shorten the path of lithium ions on the b axis, and the phosphate positive electrode material in the center of the elliptic rod can also carry out lithium ion deintercalation in the charge and discharge process, and the quantity of the positive electrode material which is short deactivated is less than that of the spherical positive electrode material, so that the elliptic rod has excellent electrochemical performance under high-rate charge and discharge.
Preferably, the secondary sintering of step (2) is performed in a protective gas comprising any one or a combination of at least two of nitrogen, argon, hydrogen, vaporized methane, or ethanol, typically but not limited to a combination of nitrogen and argon, a combination of hydrogen and argon, or a combination of vaporized methane and ethanol.
Preferably, the secondary carbon source of step (2) comprises any one or a combination of at least two of sucrose, starch, citric acid, glucose, maltose, chitosan, PE, PP, PEG, PVA, PPy or PS, typically but not limited to a combination comprising sucrose and starch, a combination of citric acid and glucose, a combination of maltose and chitosan, or a combination of PE and PP, preferably PEG.
The invention can realize the regulation and control of the particle size of the product particles by selecting different secondary carbon sources.
Preferably, the secondary carbon source in step (2) is added in an amount of 1-5wt%, such as 1wt%, 1.5wt%, 2wt%, 3wt%, 4wt%, 4.5wt%, or 5wt%, of the semi-finished product in step (1), but is not limited to the recited values, and other non-recited values within the range of values are equally applicable.
The addition amount of the secondary carbon source can also influence the particle size of the product particles and the uniformity of the surface carbon coating; the secondary carbon source can obtain a uniform coated carbon layer only by adding 1-5wt% of the semi-finished product, and the particle size of the product particles can be controlled within a specific range; the secondary carbon source is too small in amount compared with the semi-finished product, and the uniformity of the coating layer is lowered, on the other hand, the growth of the product particles cannot be inhibited to a large extent, and the uniformity of the carbon layer on the surface of the product particles is also affected when the secondary carbon source is too large in amount compared with the semi-finished product.
Preferably, the average particle size of the secondary carbon source in step (2) is smaller than the average particle size of the semi-finished product in step (1).
Preferably, the average particle size of the secondary carbon source in step (2) is 0.2 to 0.6 times, for example, 0.2 times, 0.3 times, 0.4 times, 0.5 times or 0.6 times, the average particle size of the semi-finished product in step (1), but is not limited to the recited values.
The invention adopts the secondary carbon source with smaller particle size to be mixed with the semi-finished product, can realize that the secondary carbon source of small particles is filled in the particle gaps of the semi-finished product with large particles, and the secondary carbon source of small particles can be adsorbed on the surface of the semi-finished product with large particles, thereby realizing the uniform coating of the carbon layer on the surface of the product particles, avoiding the problem that the surface of the semi-finished product cannot be contacted with the secondary carbon source due to gaps among particles when the semi-finished product particles are piled up.
Preferably, the mixing of step (2) comprises ball milling or inert gas flow mixing, preferably inert gas flow mixing.
Preferably, the step of mixing the inert gas flow comprises:
(i) Vacuumizing the stirring tank, adding a secondary carbon source and the semi-finished product in the step (1), introducing inert gas to ensure that the pressure in the stirring tank is 2-5atm, such as 2atm, 2.5atm, 3atm, 3.5atm, 4atm or 5atm, and then reducing the pressure in the stirring tank to 1-1.5atm, such as 1atm, 1.1atm, 1.2atm, 1.3atm, 1.4atm or 1.5atm, wherein the pressure is not limited to the recited values, and other non-recited values in the numerical range are applicable;
(ii) The step (i) is sequentially carried out, namely, inert gas is introduced and depressurization is carried out, the mixing process is repeatedly carried out for 3-6 times, for example, 3 times, 4 times, 5 times or 6 times, and the inert gas flow mixing is completed.
According to the invention, the secondary carbon source and the semi-finished product in the stirring tank are mixed in a suspending way by using the air disturbance of the inert air flow when the inert air is introduced, and the secondary carbon source and the semi-finished product can be uniformly mixed by combining the stirring effect of the stirring tank; the inert gas is introduced to enable the pressure in the stirring tank to be higher than normal pressure, then the pressure is reduced to be close to the normal pressure, and repeated operation is carried out for a plurality of times, so that on one hand, the secondary carbon source and the semi-finished product can be fully mixed, and on the other hand, the edges and corners of the secondary carbon source and the semi-finished product can be repeatedly polished by air flow, thereby being beneficial to enabling the semi-finished product to form uniform particles, and enabling the secondary carbon source to be uniformly coated.
Preferably, the inert gas comprises any one or a combination of at least two of helium, argon, neon or krypton, typically but not limited to a combination of helium and argon, a combination of neon and krypton, or a combination of argon and helium.
Preferably, the metal oxide in step (1) comprises any one or a combination of at least two of magnesium oxide, titanium oxide, vanadium oxide, niobium oxide, zirconium oxide or potassium oxide, typically but not limited to a combination of magnesium oxide and titanium oxide, a combination of vanadium oxide and niobium oxide, or a combination of zirconium oxide or potassium oxide, with the purpose that the metal oxide may be dissolved in the dispersant and no other anionic impurities may be attached during the introduction, thereby ensuring the purity of the product.
Preferably, the metal oxide in the step (1) is added in an amount of 0.3 to 2wt% based on the theoretical mass of the phosphate-based cathode material, for example, 0.3wt%, 0.5wt%, 0.7wt%, 0.9wt%, 1.1wt%, 1.3wt%, 1.5wt%, 1.7wt% or 2wt%, but not limited to the recited values, and other non-recited values in the numerical range are equally applicable.
The addition amount of the metal oxide is in a reasonable range, so that the metal oxide can be matched with a matched sintering process and a matched carbon mixing process, if the addition amount is too small, the lattice defect concentration of the anode material becomes small, and the metal oxide cannot be matched with twice carbon mixing and twice sintering, so that the diffusion rate of lithium ions is not obviously changed; if the amount of the additive is too large, it reacts with other raw materials to generate an impurity phase, which affects the electrochemical performance of the positive electrode material itself.
Preferably, the primary carbon source of step (1) comprises any one or a combination of at least two of sucrose, glucose, citric acid or PEG, typically but not limited to a combination of sucrose and glucose, or a combination of citric acid and PEG.
Preferably, the primary carbon source in the step (1) is added in an amount of 4 to 12wt% based on the theoretical mass of the phosphate-based cathode material, for example, 4wt%, 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, 10wt%, 11wt% or 12wt%, but not limited to the recited values, and other non-recited values in the numerical range are equally applicable.
Preferably, the temperature of the primary sintering in the step (1) is 300-650 ℃, for example, 300 ℃, 400 ℃, 450 ℃, 500 ℃, 550 ℃, 600 ℃ or 650 ℃, but is not limited to the recited values, and other non-recited values in the numerical range are equally applicable.
Preferably, the time of the primary sintering in the step (1) is 3-8h, for example, 3h, 4h, 5h, 6h, 7h or 8h, but not limited to the recited values, and other non-recited values in the range of values are equally applicable.
The temperature of the secondary sintering is not lower than that of the primary sintering, the sintering time is longer than that of the primary sintering, the primary sintering is carried out at a relatively low temperature to carry out primary carbon mixing to obtain a semi-finished product, then the semi-finished product is mixed with a secondary carbon source, and secondary sintering is carried out at a relatively high temperature to enable the semi-finished product obtained through primary carbon mixing and the secondary carbon source to be matched with each other, so that the growth of product particles is inhibited, the product grows into an elliptic rod shape, the carbon coating layer is complete and uniform in structure, and the particle size is small.
Preferably, the temperature rising rate of the primary sintering in the step (1) is 5-20 ℃ per minute, for example, 5 ℃/min, 7 ℃/min, 9 ℃/min, 11 ℃/min, 13 ℃/min, 15 ℃/min, 17 ℃/min or 20 ℃/min, but the method is not limited to the listed values, and other values not listed in the numerical range are applicable.
Preferably, the primary sintering of step (1) is performed in a protective gas comprising any one or a combination of at least two of nitrogen, argon, hydrogen, vaporized methane, or ethanol, typically but not limited to a combination of nitrogen and argon, a combination of hydrogen and argon, or a combination of vaporized methane and ethanol.
Preferably, the crushing is also performed before and after the primary sintering in step (1).
Preferably, the primary sintering in step (1) and the secondary sintering in step (2) are both performed in a sintering furnace, which comprises any one of a tube furnace, a roller kiln or a rotary kiln.
Preferably, the dispersant in the step (1) is added in an amount of 10 to 30wt% based on the theoretical mass of the phosphate-based cathode material, for example, 10wt%, 15wt%, 20wt%, 25wt% or 30wt%, but not limited to the values listed, and other values not listed in the numerical range are equally applicable.
Preferably, the dispersant in step (1) comprises water, or a mixture of water and ethanol.
Preferably, the molar ratio of the metal source, the phosphorus source and the lithium source in the step (1) is (0.93-0.98): (0.98-1.00): (1.02-1.06), and may be, for example, 0.93:1:1.02, 0.95:1:1.06 or 0.93:0.98:1.02, but is not limited to the recited values, and other non-recited values in the range of values are equally applicable.
Preferably, the metal source of step (1) comprises any one or a combination of at least two of an iron source, a manganese source, a nickel source, a cobalt source or an aluminum source, typically but not limited to a combination of an iron source and a manganese source, or a combination of a nickel source and a cobalt source, preferably an iron source.
Preferably, the iron source comprises any one or a combination of at least two of ferric nitrate, ferrous sulfate, ferrous oxalate, ferric oxide or ferrous phosphate, typically but not limited to a combination of ferric nitrate and ferrous sulfate, or a combination of ferrous oxalate and ferric oxide.
The preparation method disclosed by the invention has universality, is suitable for preparing various positive electrode materials, adopts different metal salts, and can obtain different positive electrode materials, for example, when an iron source is adopted as the metal source, the obtained phosphate positive electrode material is lithium iron phosphate, and when the iron source and the manganese source are adopted as the metal source, the obtained phosphate positive electrode material is lithium manganese iron phosphate.
Preferably, the lithium source of step (1) comprises any one or a combination of at least two of lithium oxide, lithium carbonate, lithium acetate, lithium hydroxide, lithium acetate or lithium phosphate, typically but not limited to a combination of lithium oxide and lithium carbonate, a combination of lithium acetate and lithium hydroxide, or a combination of lithium acetate and lithium phosphate.
Preferably, the phosphorus source of step (1) comprises any one or a combination of at least two of phosphoric acid, monoammonium phosphate or diammonium phosphate, typically but not limited to a combination of phosphoric acid and monoammonium phosphate, or a combination of phosphoric acid and diammonium phosphate.
As a preferred technical method of the preparation method of the invention, the preparation method comprises the following steps:
(1) Mixing and dispersing a metal source, a phosphorus source and a lithium source with the molar ratio of (0.93-0.98) (0.98-1.00) (1.02-1.06) in a dispersing agent, adding metal oxide, stirring, mixing with a primary carbon source to obtain a mixed solution, drying and crushing the mixed solution, and sintering the mixed solution in protective gas at the temperature rising rate of 5-20 ℃/min to 300-650 ℃ for 3-8 hours to obtain a semi-finished product;
The addition amount of the primary carbon source is 4-12wt% of the theoretical mass of the phosphate positive electrode material, the addition amount of the metal oxide is 0.3-2wt% of the theoretical mass of the phosphate positive electrode material, and the addition amount of the dispersing agent is 10-30wt% of the theoretical mass of the phosphate positive electrode material;
(2) Mixing an inert gas flow with the secondary carbon source and the semi-finished product obtained in the step (1), and then performing secondary sintering for 10-16 hours in protective gas at a heating rate of 5-20 ℃/min to 650-800 ℃ to obtain the phosphate anode material;
the addition amount of the secondary carbon source is 1-5wt% of the semi-finished product in the step (1), and the average particle size of the secondary carbon source is 0.2-0.6 times of the average particle size of the semi-finished product in the step (1);
The step of mixing the inert gas stream comprises: (i) Vacuumizing the stirring tank, adding a secondary carbon source and the semi-finished product obtained in the step (1), introducing inert gas to ensure that the pressure in the stirring tank is 2-5atm, and then reducing the pressure to ensure that the pressure in the stirring tank is 1-1.5atm; (ii) And (3) introducing inert gas and reducing pressure in the step (i) sequentially to form a primary mixing process, and repeating the primary mixing process for 3-6 times to finish mixing.
In a second aspect, the present invention provides a phosphate-based positive electrode material, which is prepared by the preparation method according to the first aspect;
the cell parameters a, b and c of the phosphate positive electrode material satisfy the following conditions: 1.278.ltoreq.b/c.ltoreq. 1.283,0.581.ltoreq.b/a.ltoreq.0.583, where the unit cell parameter b is
According to the preparation method, the specific relation among the cell parameters a, b and c is met, meanwhile, the cell parameter b is smaller and the range is narrower, firstly, the smaller cell parameter b can shorten the transmission distance of lithium ions and improve the transmission rate of the lithium ions, so that the rate performance is improved, secondly, the distribution range of the cell parameter b is narrow, and the preparation method is proved to be high in uniformity of the obtained product.
The 1.278.ltoreq.b/c.ltoreq.1.283 may be 1.278, 1.279, 1.280, 1.281, 1.282 or 1.283,0.581.ltoreq.b/a.ltoreq.0.583, for example 0.581, 0.5815, 0.582, 0.5825 or 0.583, where the unit cell parameter b isFor example, it may be/> Or/>But are not limited to the values recited, other non-recited values within the range of values are equally applicable, preferably/>
The lattice defect concentration of the phosphate-based positive electrode material is preferably 0.05 to 0.2%, and may be, for example, 0.05%, 0.07%, 0.09%, 0.11%, 0.13%, 0.15%, 0.17%, 0.19%, or 0.2%, but is not limited to the values recited, and other values not recited in the numerical range are equally applicable, and preferably 0.05 to 0.15%.
The concentration of the lattice defects is in a specific range, so that the transmission rate of lithium ions can be further improved, the rate capability is improved, and meanwhile, the generation of impurity phases can be avoided.
Preferably, the morphology of the phosphate-based positive electrode material is in the shape of an oval rod.
The size of the particle diameter of the phosphate-based positive electrode material in the long axis direction is preferably in the range of 150 to 500nm, and the minimum value of the particle diameter in the long axis direction is 150nm or more, for example, 150nm, 160nm, 170nm, 180nm, 190nm or 200nm, and the maximum value is 500nm or less, for example, 500nm, 490nm, 480nm, 470nm, 460nm or 450nm, but the present invention is not limited to the above-mentioned values, and other values not mentioned in the numerical range are applicable.
The particle size of the phosphate positive electrode material is smaller, so that the tap density of the material is improved, and the performance of the phosphate positive electrode material can be further improved.
Preferably, the phosphate-based positive electrode material is any one or a combination of at least two of lithium iron phosphate, lithium manganese iron phosphate, lithium vanadium iron phosphate, lithium titanium iron phosphate or lithium nickel iron phosphate, and typical but non-limiting combinations include combinations of lithium iron phosphate and lithium manganese iron phosphate, or combinations of lithium vanadium iron phosphate and lithium titanium iron phosphate.
In a third aspect, the present invention provides a lithium ion battery comprising the phosphate-based cathode material according to the second aspect.
Compared with the prior art, the invention has the following beneficial effects:
(1) According to the invention, the phosphate positive electrode material is prepared by adopting a secondary carbon mixing process, and the doped metal oxide and the sintering process are matched, so that the product is doped and coated along a specific crystal face, the growth of the product is effectively controlled, oval rod-shaped product particles are obtained, the unit cell parameter b of the product is smaller, the one-dimensional diffusion path of lithium ions is shortened, the rapid extraction and intercalation of lithium ions on a one-dimensional track are realized, meanwhile, the unit cell parameters a, b and c meet a specific relation, the extraction and intercalation of lithium ions outside the one-dimensional track can be avoided, the lattice stability is improved, the extraction and intercalation rate of lithium ions is ensured, and therefore, the rate capability of the material is improved.
(2) The preparation method of the invention only comprises the processes of mixing, drying, crushing and sintering, and does not involve the re-granulation process, so that the elliptic rod-shaped anode material with complete and compact coating layer, doping elements and smaller particle size of phosphate series anode material can be obtained; therefore, the preparation method is simple, can be applied to large-scale production, realizes mass production of kiloton scale, and overcomes the defects that the preparation process in the prior art involves a large number of processes and is not suitable for large-scale mass production;
(3) In the preparation method, the average grain diameter of the secondary carbon source is smaller than that of the semi-finished product, and the secondary carbon source and the semi-finished product are mixed by inert gas flow, namely, the secondary carbon source is uniformly adsorbed on the surface of the precursor through the cooperation of the grain diameter and a specific mixing mode, so that the secondary carbon source can inhibit the growth of product grains to the greatest extent, and the carbon coating on the surface of the product is complete and uniform.
Drawings
FIG. 1 is a flow chart of the preparation method of example 1 of the present invention;
FIG. 2 is an SEM image of a phosphate-based positive electrode material according to example 1 of the present invention;
FIG. 3 is a graph showing the particle size distribution of a phosphate-based positive electrode material according to example 1 of the present invention;
Fig. 4 is a charge-discharge graph of a lithium ion battery using the phosphate-based cathode material according to example 2 of the present invention;
Fig. 5 is a refined XRD pattern of the phosphate-based cathode material according to example 1 of the present invention.
Detailed Description
The technical scheme of the invention is further described by the following specific embodiments. It will be apparent to those skilled in the art that the examples are merely to aid in understanding the invention and are not to be construed as a specific limitation thereof.
Example 1
The embodiment provides a preparation method of a phosphate positive electrode material, wherein a flow chart of the preparation method is shown in fig. 1, and the preparation method comprises the following steps:
(1) Mixing and dispersing ferric nitrate, ammonium dihydrogen phosphate and lithium hydroxide in ethanol at a molar ratio of 0.95:1:1.04, adding magnesium oxide, stirring, mixing with a primary carbon source to obtain a mixed solution, drying, crushing, and sintering in a nitrogen atmosphere at a heating rate of 10 ℃/min to 550 ℃ for 5 hours to obtain a semi-finished product;
The primary carbon source is glucose, the addition amount of the primary carbon source is 8wt% of the theoretical mass of the phosphate positive electrode material, the addition amount of the magnesium oxide is 0.5wt% of the theoretical mass of the phosphate positive electrode material, and the addition amount of the ethanol is 12wt% of the theoretical mass of the phosphate positive electrode material;
(2) Mixing a secondary carbon source with the semi-finished product obtained in the step (1) by inert gas flow, and then performing secondary sintering for 12 hours in a nitrogen atmosphere at a heating rate of 15 ℃/min to 730 ℃ to obtain the phosphate-based anode material;
The secondary carbon source is glucose, the addition amount is 2wt% of the mass of the semi-finished product in the step (1), and the average particle size is 0.4 times of the average particle size of the semi-finished product in the step (1);
the step of mixing the inert gas stream comprises: (i) Vacuumizing a stirring tank, adding a secondary carbon source and the semi-finished product obtained in the step (1), introducing argon to ensure that the pressure in the stirring tank is 3atm, and then reducing the pressure to ensure that the pressure in the stirring tank is 1.2atm; (ii) Introducing inert gas and reducing pressure sequentially in the step (i) to form a primary mixing process, and repeating the primary mixing process for 4 times to finish mixing;
The phosphate positive electrode material prepared in the embodiment is lithium iron phosphate;
the SEM image of the phosphate-based cathode material of this example is shown in fig. 2, the particle size distribution diagram is shown in fig. 3, the finishing XRD image is shown in fig. 5, and the unit cell parameters and unit cell volume of this example are obtained by the finishing XRD image, as shown in the following diagram;
example 2
The embodiment provides a preparation method of a phosphate positive electrode material, which comprises the following steps:
(1) Mixing and dispersing ferrous sulfate, phosphoric acid and lithium carbonate in water in a molar ratio of 0.93:1:1.06, adding magnesium oxide, stirring, mixing with a primary carbon source to obtain a mixed solution, drying, crushing, and sintering in an argon atmosphere for 8 hours at a temperature rising rate of 5 ℃/min to 300 ℃ to obtain a semi-finished product;
the primary carbon source is glucose, the addition amount of the primary carbon source is 4wt% of the theoretical mass of the phosphate positive electrode material, the addition amount of the magnesium oxide is 0.5wt% of the theoretical mass of the phosphate positive electrode material, and the addition amount of the water is 30wt% of the theoretical mass of the phosphate positive electrode material;
(2) Mixing a secondary carbon source with the semi-finished product obtained in the step (1) by inert gas flow, and performing secondary sintering for 16 hours in a nitrogen atmosphere at a heating rate of 5 ℃/min to 650 ℃ to obtain the phosphate-based anode material;
the secondary carbon source is sucrose, the addition amount is 1 weight percent of the mass of the semi-finished product in the step (1), and the average grain diameter is 0.2 times of the average grain diameter of the semi-finished product in the step (1);
the step of mixing the inert gas stream comprises: (i) Vacuumizing the stirring tank, adding a secondary carbon source and the semi-finished product obtained in the step (1), introducing inert gas to ensure that the pressure in the stirring tank is 2atm, and then reducing the pressure to ensure that the pressure in the stirring tank is 1.5atm; (ii) Introducing inert gas and reducing pressure sequentially in the step (i) to form a primary mixing process, and repeating the primary mixing process for 3 times to finish mixing;
the lithium iron phosphate as the phosphate-based positive electrode material prepared in this example provides a charge-discharge curve of a lithium ion battery prepared from the phosphate-based positive electrode material as shown in fig. 4.
Example 3
The embodiment provides a preparation method of a phosphate positive electrode material, which comprises the following steps:
(1) Mixing and dispersing a metal source, diammonium hydrogen phosphate and lithium hydroxide in water according to the molar ratio of 0.98:0.98:1.02, adding vanadium oxide, stirring, mixing with a primary carbon source to obtain a mixed solution, drying, crushing, and sintering in a nitrogen atmosphere at a heating rate of 20 ℃/min to 650 ℃ for 3 hours to obtain a semi-finished product;
The metal source comprises ferric nitrate and manganese nitrate with a molar ratio of 1:1, the primary carbon source is glucose, the addition amount of the primary carbon source is 12wt% of the theoretical mass of the phosphate positive electrode material, the addition amount of the vanadium oxide is 1wt% of the theoretical mass of the phosphate positive electrode material, and the addition amount of the water is 10wt% of the theoretical mass of the phosphate positive electrode material;
(2) Mixing a secondary carbon source with the semi-finished product obtained in the step (1) by inert gas flow, and then performing secondary sintering for 12 hours in an argon atmosphere at a heating rate of 10 ℃/min to 730 ℃ to obtain the phosphate-based anode material;
the secondary carbon source is PEG2000, the addition amount is 5wt% of the semi-finished product in the step (1), and the average particle size is 0.6 times of the average particle size of the semi-finished product in the step (1);
The step of mixing the inert gas stream comprises: (i) Vacuumizing the stirring tank, adding a secondary carbon source and the semi-finished product obtained in the step (1), introducing inert gas to ensure that the pressure in the stirring tank is 5atm, and then reducing the pressure to ensure that the pressure in the stirring tank is 1atm; (ii) Introducing inert gas and reducing pressure sequentially in the step (i) to form a primary mixing process, and repeating the primary mixing process for 6 times to finish mixing;
The phosphate positive electrode material prepared in this example is lithium iron manganese phosphate.
Example 4
The embodiment provides a preparation method of a phosphate positive electrode material, which comprises the following steps:
(1) Mixing and dispersing ferrous oxalate, ammonium dihydrogen phosphate and lithium hydroxide in ethanol at a molar ratio of 0.96:1:1.04, adding vanadium oxide, stirring, mixing with a primary carbon source to obtain a mixed solution, drying, crushing, and sintering in a nitrogen atmosphere at a heating rate of 10 ℃/min to 550 ℃ for 8 hours to obtain a semi-finished product;
the primary carbon source is glucose, the addition amount of the primary carbon source is 8wt% of the theoretical mass of the phosphate positive electrode material, the addition amount of the vanadium oxide is 1wt% of the theoretical mass of the phosphate positive electrode material, and the addition amount of the ethanol is 15wt% of the theoretical mass of the phosphate positive electrode material;
(2) Mixing a secondary carbon source with the semi-finished product obtained in the step (1) by inert gas flow, and then performing secondary sintering for 10 hours in a nitrogen atmosphere at a heating rate of 20 ℃/min to 800 ℃ to obtain the phosphate anode material;
the secondary carbon source is PVA, the addition amount is 2wt% of the semi-finished product in the step (1), and the average grain diameter is 0.4 times of the average grain diameter of the semi-finished product in the step (1);
the step of mixing the inert gas stream comprises: (i) Vacuumizing a stirring tank, adding a secondary carbon source and the semi-finished product obtained in the step (1), introducing argon to ensure that the pressure in the stirring tank is 3atm, and then reducing the pressure to ensure that the pressure in the stirring tank is 1.2atm; (ii) Introducing inert gas and reducing pressure sequentially in the step (i) to form a primary mixing process, and repeating the primary mixing process for 4 times to finish mixing;
The phosphate positive electrode material prepared in this example was lithium iron phosphate.
Example 5
This example provides a method for producing a phosphate-based positive electrode material, which differs from example 1 only in that the magnesium oxide in step (1) is replaced with vanadium oxide in equal amounts, and the remainder is the same as example 1.
Example 6
This example provides a method for producing a phosphate-based positive electrode material, which differs from example 1 only in that the magnesium oxide in step (1) is replaced with titanium oxide in equal amounts, and the remainder is the same as in example 1.
Example 7
This example provides a method for producing a phosphate-based positive electrode material, which differs from example 1 only in that the magnesium oxide in step (1) is replaced with niobium oxide in equal amounts, and the remainder is the same as example 1.
Example 8
The present example provides a method for preparing a phosphate-based cathode material, which is different from example 1 only in that the magnesium oxide is added in the amount of 0.15wt% of the theoretical mass of the phosphate-based cathode material in step (1), and the rest is the same as example 1.
Example 9
The present example provides a method for preparing a phosphate-based cathode material, which is different from example 1 only in that the magnesium oxide is added in the amount of 2wt% of the theoretical mass of the phosphate-based cathode material in step (1), and the rest is the same as example 1.
Example 10
The present example provides a method for preparing a phosphate-based cathode material, which is different from example 1 only in that the magnesium oxide is added in the amount of 2.5wt% of the theoretical mass of the phosphate-based cathode material in step (1), and the rest is the same as example 1.
Example 11
This example provides a method for producing a phosphate-based positive electrode material, which differs from example 1 only in that the secondary sintering in step (2) is performed at 600 ℃ and the remainder is the same as in example 1.
Example 12
This example provides a method for producing a phosphate-based positive electrode material, which differs from example 1 only in that the secondary sintering in step (2) is performed at a temperature of 850 ℃ and the remainder is the same as example 1.
Example 13
This example provides a method for producing a phosphate-based positive electrode material, which differs from example 1 only in that the rate of temperature rise in the secondary sintering in step (2) is 3 ℃/min, and the remainder is the same as example 1.
Example 14
This example provides a method for producing a phosphate-based positive electrode material, which differs from example 1 only in that the rate of temperature rise in the secondary sintering in step (2) is 23 ℃/min, and the remainder is the same as example 1.
Comparative example 1
This comparative example provides a method for producing a phosphate-based positive electrode material, which differs from example 1 only in that magnesium oxide is not added in step (1), and the rest is the same as example 1.
Comparative example 2
This comparative example provides a method for producing a phosphate-based positive electrode material, which differs from example 1 only in that step (2) is the same as example 1 except that a secondary carbon source is not added.
Comparative example 3
This comparative example provides a method for producing a phosphate-based positive electrode material, which differs from example 1 only in that no magnesium oxide is added in step (1), and no secondary carbon source is added in step (2), and the remainder is the same as example 1.
The particle size ranges, the unit cell parameters b/C, b/a, and the lattice defect concentrations of the phosphate-based cathode materials provided in the above examples and comparative examples in the long axis direction are shown in table 1, and the phosphate-based cathode materials were assembled into button half cells, and charge and discharge tests were performed at room temperature of 25 ℃ at different current densities, wherein the 1C discharge capacity and the 5C discharge capacity are shown in table 1.
TABLE 1
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From table 1, the following points can be seen:
(1) As is clear from the above examples, the present invention has the advantages that the metal oxide is doped, the secondary carbon mixing process and the sintering process are combined, the particle size of the obtained phosphate positive electrode material is small, the electrochemical performance is excellent, compared with comparative examples 1-3, no metal oxide is added, comparative example 2 does not add a secondary carbon source, neither the metal oxide source nor the secondary carbon source is added, the obtained material performance is not only large in particle size, the unit cell parameter b is large, the one-dimensional channel is long, and the rate performance is reduced, so that the metal oxide and the secondary carbon source are combined, and the two are indispensable, so that the provided product has excellent rate performance, and is the high-rate phosphate positive electrode material.
(2) As can be seen from examples 1 and 5-7, the purpose of adding the metal oxide is to: the metal oxide can be dissolved in the dispersing agent, and in the introducing process, other anionic impurities are not attached, so that the product can be doped with atoms, the purity of the product is not damaged, and the influence of the type of the metal oxide on the performance is little as compared with the obtained performance; as can be seen from examples 1 and 8-10, the defect concentration of the positive electrode material becomes smaller and the cell parameter b becomes larger, so that the effect of mixing the metal element, twice mixing and twice sintering cannot be exerted, and the diffusion rate of lithium ions does not significantly change, and when the addition amount is properly increased, the effect of mixing can be exerted, as shown in example 9, compared with the performance of example 8, but when the addition amount of the metal oxide is too large as shown in example 10, the metal oxide reacts with other raw materials to generate an impurity phase, and the cell parameter b likewise becomes larger, thereby affecting the electrochemical performance of the positive electrode material itself.
(3) As can be seen from examples 1 and 11-14, by controlling the sintering process of secondary carbon mixing and adopting a specific sintering temperature and sintering heating rate, the secondary carbon source and the metal oxide can be mutually matched, so that the semi-finished product can be uniformly and compactly coated by carbon, and the semi-finished product grows into a phosphate positive electrode material with an elliptic rod shape, but not into a spherical shape.
In summary, the invention provides a phosphate positive electrode material, and a preparation method and application thereof, wherein the preparation method adopts a secondary carbon mixing process with low cost, wide raw material sources and simple flow, realizes mass production of the positive electrode material in kiloton scale, and the phosphate positive electrode material is in an elliptic rod shape, has a particle size reaching 100-300nm, and has excellent multiplying power.
The foregoing is merely illustrative of the present invention, and the present invention is not limited thereto, and it should be apparent to those skilled in the art that any changes or substitutions that fall within the technical scope of the present invention disclosed herein are within the scope of the present invention.

Claims (31)

1. The preparation method of the phosphate positive electrode material is characterized by comprising the following steps of:
(1) Mixing and dissolving a metal source, a phosphorus source, a lithium source and a dispersing agent, adding a metal oxide, and mixing with a primary carbon source to obtain a mixed solution, and drying and primary sintering the mixed solution to obtain a semi-finished product;
(2) Mixing the secondary carbon source with the semi-finished product obtained in the step (1), and then performing secondary sintering to obtain the phosphate-based positive electrode material, wherein the unit cell parameter b of the phosphate-based positive electrode material is
Wherein the addition amount of the metal oxide in the step (1) is 0.3-2wt% of the theoretical mass of the phosphate positive electrode material;
The temperature of the primary sintering in the step (1) is 300-550 ℃;
The secondary carbon source in the step (2) comprises any one or a combination of at least two of sucrose, starch, citric acid, glucose, maltose, chitosan, PE, PP, PEG, PVA, PPy or PS;
and (3) the temperature of the secondary sintering in the step (2) is 650-800 ℃.
2. The method of claim 1, wherein the rate of rise of temperature of the secondary sintering in step (2) is 5-20 ℃/min.
3. The method of claim 1, wherein the secondary sintering in step (2) is performed for a period of 10 to 16 hours.
4. The method of claim 1, wherein the secondary sintering of step (2) is performed in a protective gas comprising any one or a combination of at least two of nitrogen, argon, hydrogen, vaporized methane, or ethanol.
5. The method of claim 1, wherein the secondary carbon source in step (2) is PEG.
6. The method according to claim 1, wherein the secondary carbon source is added in the amount of 1 to 5wt% based on the mass of the semi-finished product in the step (1).
7. The method according to claim 1, wherein the secondary carbon source in step (2) has an average particle diameter smaller than that of the semi-finished product in step (1).
8. The method according to claim 1, wherein the average particle diameter of the secondary carbon source in step (2) is 0.2 to 0.6 times the average particle diameter of the semi-finished product in step (1).
9. The method of claim 1, wherein the mixing of step (2) comprises ball milling or inert gas flow mixing.
10. The method of claim 9, wherein the mixing in step (2) is inert gas flow mixing.
11. The method of claim 9, wherein the step of mixing the inert gas stream comprises:
(i) Vacuumizing the stirring tank, adding a secondary carbon source and the semi-finished product obtained in the step (1), introducing inert gas to ensure that the pressure in the stirring tank is 2-5atm, and then reducing the pressure to ensure that the pressure in the stirring tank is 1-1.5atm;
(ii) And (3) introducing inert gas and reducing pressure in the step (i) sequentially to form a primary mixing process, and repeating the primary mixing process for 3-6 times to finish inert gas flow mixing.
12. The method according to claim 1, wherein the metal oxide in the step (1) comprises any one or a combination of at least two of magnesium oxide, titanium oxide, vanadium oxide, niobium oxide, zirconium oxide, and potassium oxide.
13. The method of claim 1, wherein the primary carbon source of step (1) comprises any one or a combination of at least two of sucrose, glucose, citric acid, or PEG.
14. The method according to claim 1, wherein the primary carbon source in the step (1) is added in an amount of 4 to 12wt% based on the theoretical mass of the phosphate-based positive electrode material.
15. The method of claim 1, wherein the time for the one sintering in step (1) is 3 to 8 hours.
16. The method according to claim 1, wherein the temperature rise rate of the primary sintering in the step (1) is 5 to 20 ℃/min.
17. The method of claim 1, wherein the primary sintering of step (1) is performed in a protective gas comprising any one or a combination of at least two of nitrogen, argon, hydrogen, vaporized methane, or ethanol.
18. The method of claim 1, wherein the step (1) is further performed with crushing before and after the primary sintering.
19. The method according to claim 1, wherein the step (1) is performed after the completion of the one-time sintering.
20. The method of claim 1, wherein the primary sintering in step (1) and the secondary sintering in step (2) are performed in a sintering furnace, the sintering furnace comprising any one of a tube furnace, a roller kiln, or a rotary kiln.
21. The method according to claim 1, wherein the dispersant in the step (1) is added in an amount of 10 to 30wt% based on the theoretical mass of the phosphate-based positive electrode material.
22. The method of claim 1, wherein the dispersant of step (1) comprises water or a mixture of water and ethanol.
23. The method of claim 1, wherein the molar ratio of the metal source, the phosphorus source and the lithium source in step (1) is (0.93-0.98): 0.98-1.00): 1.02-1.06.
24. The method of claim 1, wherein the metal source of step (1) comprises any one or a combination of at least two of an iron source, a manganese source, a nickel source, a cobalt source, or an aluminum source.
25. A phosphate-based positive electrode material, characterized in that the phosphate-based positive electrode material is produced by the production method according to any one of claims 1 to 24;
the cell parameters a, b and c of the phosphate positive electrode material satisfy the following conditions: 1.278.ltoreq.b/c.ltoreq. 1.283,0.581.ltoreq.b/a.ltoreq.0.583, where the unit cell parameter b is
26. The phosphate-based positive electrode material according to claim 25, wherein the lattice defect concentration of the phosphate-based positive electrode material is 0.05 to 0.2%.
27. The phosphate-based positive electrode material according to claim 26, wherein the lattice defect concentration of the phosphate-based positive electrode material is 0.05 to 0.15%.
28. The phosphate-based positive electrode material according to claim 25, wherein the morphology of the phosphate-based positive electrode material is elliptical rod-like.
29. The phosphate-based positive electrode material according to claim 25, wherein the size of the particle diameter of the phosphate-based positive electrode material in the long axis direction is in the range of 150 to 500 nm.
30. The phosphate-based positive electrode material according to claim 25, wherein the phosphate-based positive electrode material is any one or a combination of at least two of lithium iron phosphate, lithium manganese iron phosphate, lithium vanadium iron phosphate, lithium ferrotitanium phosphate, or lithium nickel iron phosphate.
31. A lithium ion battery comprising the phosphate-based positive electrode material according to claims 25-30.
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Citations (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6319632B1 (en) * 1999-11-24 2001-11-20 Japan Storage Battery Co., Ltd. Active material for lithium batteries
CN101315981A (en) * 2008-06-16 2008-12-03 合肥工业大学 Lithium iron phosphate anode material for lithium ion battery and modification method
CN101428781A (en) * 2008-12-08 2009-05-13 广州丰江电池新技术有限公司 Conglobation type nanostructured lithium iron phosphate anode material and method for producing the same
CN101980956A (en) * 2008-03-31 2011-02-23 户田工业株式会社 Lithium iron phosphate powder manufacturing method, olivine structured lithium iron phosphate powder, cathode sheet using said lithium iron phosphate powder, and non-aqueous solvent secondary battery
CN102569794A (en) * 2011-03-23 2012-07-11 江苏菲思特新能源有限公司 Carbon-coating method for lithium iron phosphate anode material
CN102790216A (en) * 2012-08-24 2012-11-21 广州市香港科大***研究院 Supercritical solvent thermal preparation method of cathode material lithium iron phosphate of lithium ion battery
DE102011056816A1 (en) * 2011-12-21 2013-08-01 Chemische Fabrik Budenheim Kg Manganese-containing metal phosphates and process for their preparation
CN103427079A (en) * 2013-08-09 2013-12-04 中物院成都科学技术发展中心 Preparation method of lithium ion phosphate/carbon composite material for high-rate-capability lithium ion battery
CN103515601A (en) * 2013-10-28 2014-01-15 金瑞新材料科技股份有限公司 Positive pole material LiFePO4 for lithium ion battery and preparation method thereof
CN104183827A (en) * 2014-08-21 2014-12-03 浙江大学 Lithium iron phosphate nanorods and preparation method thereof
CN109192936A (en) * 2018-07-25 2019-01-11 深圳市德方纳米科技股份有限公司 A kind of preparation method of LiFePO4
CN109860572A (en) * 2019-03-01 2019-06-07 沈阳国科金能科技有限公司 The preparation method of the compound carbon-coated nano-scale lithium iron phosphate of three-dimensional net structure
CN112599768A (en) * 2020-12-18 2021-04-02 湖北融通高科先进材料有限公司 Preparation method of lithium iron phosphate material
CN112897491A (en) * 2021-01-21 2021-06-04 广东邦普循环科技有限公司 Preparation method and application of lithium iron phosphate anode material
CN113764637A (en) * 2021-08-31 2021-12-07 远景动力技术(江苏)有限公司 Positive plate of high-energy-density lithium ion battery and preparation method thereof
CN114824163A (en) * 2022-04-29 2022-07-29 佛山市德方纳米科技有限公司 Positive electrode material and preparation method and application thereof
CN114956031A (en) * 2022-05-13 2022-08-30 浙江格派钴业新材料有限公司 Preparation method of fertilskite type sodium iron phosphate composite material

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102012000914B4 (en) * 2012-01-18 2012-11-15 Süd-Chemie AG Producing fine mixed lithium transition metal phosphate or a lithium titanate, useful e.g. in electrode, comprises converting starting compounds to a precursor mixture and/or suspension, and recovering e.g. lithium titanate compounds
US10270099B2 (en) * 2015-03-04 2019-04-23 Kabushiki Kaisha Toyota Jidoshokki Positive electrode for lithium-ion secondary battery, production process for the same, and lithium-ion secondary battery

Patent Citations (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6319632B1 (en) * 1999-11-24 2001-11-20 Japan Storage Battery Co., Ltd. Active material for lithium batteries
CN101980956A (en) * 2008-03-31 2011-02-23 户田工业株式会社 Lithium iron phosphate powder manufacturing method, olivine structured lithium iron phosphate powder, cathode sheet using said lithium iron phosphate powder, and non-aqueous solvent secondary battery
CN101315981A (en) * 2008-06-16 2008-12-03 合肥工业大学 Lithium iron phosphate anode material for lithium ion battery and modification method
CN101428781A (en) * 2008-12-08 2009-05-13 广州丰江电池新技术有限公司 Conglobation type nanostructured lithium iron phosphate anode material and method for producing the same
CN102569794A (en) * 2011-03-23 2012-07-11 江苏菲思特新能源有限公司 Carbon-coating method for lithium iron phosphate anode material
DE102011056816A1 (en) * 2011-12-21 2013-08-01 Chemische Fabrik Budenheim Kg Manganese-containing metal phosphates and process for their preparation
CN102790216A (en) * 2012-08-24 2012-11-21 广州市香港科大***研究院 Supercritical solvent thermal preparation method of cathode material lithium iron phosphate of lithium ion battery
CN103427079A (en) * 2013-08-09 2013-12-04 中物院成都科学技术发展中心 Preparation method of lithium ion phosphate/carbon composite material for high-rate-capability lithium ion battery
CN103515601A (en) * 2013-10-28 2014-01-15 金瑞新材料科技股份有限公司 Positive pole material LiFePO4 for lithium ion battery and preparation method thereof
CN104183827A (en) * 2014-08-21 2014-12-03 浙江大学 Lithium iron phosphate nanorods and preparation method thereof
CN109192936A (en) * 2018-07-25 2019-01-11 深圳市德方纳米科技股份有限公司 A kind of preparation method of LiFePO4
CN109860572A (en) * 2019-03-01 2019-06-07 沈阳国科金能科技有限公司 The preparation method of the compound carbon-coated nano-scale lithium iron phosphate of three-dimensional net structure
CN112599768A (en) * 2020-12-18 2021-04-02 湖北融通高科先进材料有限公司 Preparation method of lithium iron phosphate material
CN112897491A (en) * 2021-01-21 2021-06-04 广东邦普循环科技有限公司 Preparation method and application of lithium iron phosphate anode material
CN113764637A (en) * 2021-08-31 2021-12-07 远景动力技术(江苏)有限公司 Positive plate of high-energy-density lithium ion battery and preparation method thereof
CN114824163A (en) * 2022-04-29 2022-07-29 佛山市德方纳米科技有限公司 Positive electrode material and preparation method and application thereof
CN114956031A (en) * 2022-05-13 2022-08-30 浙江格派钴业新材料有限公司 Preparation method of fertilskite type sodium iron phosphate composite material

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
杨佳星.中国优秀硕士学位论文全文数据库.(07),全文. *

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