CN112142025A - Novel method capable of flexibly improving iron phosphate to phosphorus ratio - Google Patents

Novel method capable of flexibly improving iron phosphate to phosphorus ratio Download PDF

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Publication number
CN112142025A
CN112142025A CN201910559203.7A CN201910559203A CN112142025A CN 112142025 A CN112142025 A CN 112142025A CN 201910559203 A CN201910559203 A CN 201910559203A CN 112142025 A CN112142025 A CN 112142025A
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iron
iron phosphate
phosphorus ratio
phosphate
phosphorus
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李锦�
郭米艳
应皆荣
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Hubei Hongrun High Tech New Materials Co ltd
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Hubei Hongrun High Tech New Materials Co ltd
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    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B25/00—Phosphorus; Compounds thereof
    • C01B25/16—Oxyacids of phosphorus; Salts thereof
    • C01B25/26—Phosphates
    • C01B25/37—Phosphates of heavy metals
    • C01B25/375—Phosphates of heavy metals of iron
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y40/00—Manufacture or treatment of nanostructures
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/30—Particle morphology extending in three dimensions
    • C01P2004/32—Spheres
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/60—Particles characterised by their size
    • C01P2004/62—Submicrometer sized, i.e. from 0.1-1 micrometer
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/60—Particles characterised by their size
    • C01P2004/64—Nanometer sized, i.e. from 1-100 nanometer
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2006/00—Physical properties of inorganic compounds
    • C01P2006/80—Compositional purity

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  • Organic Chemistry (AREA)
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  • Condensed Matter Physics & Semiconductors (AREA)
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Abstract

The invention discloses a novel method capable of flexibly improving iron-phosphorus ratio of iron phosphate, which mainly researches a production process of iron phosphate by a precipitation method by taking ferrous sulfate, phosphoric acid, diammonium hydrogen phosphate and hydrogen peroxide as raw materials and improving the iron-phosphorus ratio of a product through 3 process routes, wherein in the route 1, iron phosphate with different iron-phosphorus ratios is obtained by adjusting the ratio of a first washing filter cake to a second washing filter cake, and the iron phosphate with the iron-phosphorus ratio of 0.96-0.99 can be obtained theoretically; in the route 2, ammonia water is added to adjust the pH value of the aged slurry, so as to obtain iron phosphate with high iron-phosphorus ratio; in the route 3, the iron phosphate with low cost and high iron-phosphorus ratio is obtained by improving the first two routes, and the iron-phosphorus ratio of the product is improved to be more than 0.975. The iron phosphate prepared by the method has the advantages of low impurity element content, high specific surface area, high iron-phosphorus ratio and low cost, and can be used as a precursor raw material for preparing high-capacity lithium iron phosphate.

Description

Novel method capable of flexibly improving iron phosphate to phosphorus ratio
Technical Field
The invention belongs to the field of new energy battery materials, and particularly relates to a net-shaped porous nano material with flexible iron-phosphorus ratio iron phosphate and a preparation method thereof.
Background
With the rapid development of social economy, the demand of human beings on energy is increasing day by day, and the pressure of fossil resource shortage and environmental pollution is compelled, and in recent years, new energy technology represented by solar energy, wind energy and hydrogen energy becomes a research hotspot of various countries, and is paid attention and favour by people. Compared with mechanical energy storage, electromagnetic energy storage and phase change energy storage, electrochemical energy storage has the characteristics of high efficiency, low cost, safety, convenience and the like, and develops into the current main energy storage technology. Among them, the lithium ion battery is one of the most important electrochemical energy storage devices, and has the characteristics of high working voltage, high energy density, no memory effect, small self-discharge, long cycle life, environmental friendliness and the like, so that the lithium ion battery is widely applied to a plurality of fields of electronic products, aerospace, military and military industry and the like.
The iron phosphate is an important raw material for producing the lithium iron phosphate, and battery material manufacturers generally adopt the high-temperature solid-phase method of the iron phosphate and lithium salt to produce the lithium iron phosphate. Along with the popularization and application of new energy automobiles and the development of energy storage batteries in China, the demand of lithium iron phosphate will be increased rapidly, the demand of corresponding raw material iron phosphate is also increased explosively, the performance of the lithium iron phosphate depends on iron phosphate products to a great extent, the iron phosphate has high iron-phosphorus ratio and high specific surface, and the low-impurity iron phosphate is favorable for preparing the high-energy-density lithium iron phosphate battery.
The whole industrial chain profit space of lithium iron phosphate is little at present, and iron phosphate raw materials enterprise wants to survive under the market environment that the competition is fierce, must accomplish two points, firstly reduces the raw and auxiliary materials cost, secondly promotes product quality. At present, the iron-phosphorus ratio of most iron phosphate enterprises is 0.96-0.97, most downstream customers require the iron-phosphorus ratio to be more than 0.97 for battery-grade iron phosphate, and therefore, the iron phosphate with low cost and high iron-phosphorus ratio has market competitiveness.
The low iron-phosphorus ratio is always a ubiquitous problem for iron phosphate enterprises. On the premise of keeping lower cost and lower impurity elements, the improvement of the iron-phosphorus ratio and the specific surface of the iron phosphate is a hotspot of research in the iron phosphate industry and a trend of developing a new generation of lithium iron phosphate battery.
Disclosure of Invention
The invention aims to solve the problems, and the iron phosphate material prepared by solvothermal method, washing, aging, drying and sintering has the characteristics of high iron-phosphorus ratio, large specific surface area and low impurity. The method has the characteristics of simplicity, easiness in operation, excellent performance, good reproducibility, no pollution, high product purity and the like, and is very suitable for preparing various metal oxide materials.
The technical scheme of the invention is as follows: ferrous sulfate is used as an iron source, phosphoric acid is used as a phosphorus source, hydrogen peroxide is used as an oxidant, diammonium hydrogen phosphate is used as a buffering agent, simple solvent thermal synthesis is adopted, and the spherical nano material with high iron-phosphorus ratio, large specific surface area and low impurities is obtained by simple washing, pulping, aging and sintering.
Drawings
FIG. 1 is a flow chart of a process for preparing spherical nano-structured ferric phosphate.
FIG. 2 is a scanning electron micrograph of iron phosphate prepared according to examples 1 to 3.
Figure 3 is an XRD pattern of iron phosphate prepared in examples 1-3.
Detailed Description
In order to further understand the summary and features of the present invention, 13 preferred embodiments of the present invention are given below, but the scope of the present invention is not limited thereto.
The experimental procedures in the following examples are conventional unless otherwise specified.
Example 1
The novel method for flexibly improving the iron phosphate iron phosphorus ratio comprises the following process route 1:
(1) respectively weighing a phosphate solution (phosphoric acid solution and diammonium phosphate) and a ferrous sulfate solution according to a molar stoichiometric ratio of 1.02/1, and dropwise adding a phosphorus salt into the ferrous sulfate solution within 30 minutes;
(2) putting the solution obtained in the step (1) into a first washing filter press, washing the solution to 500us/cm with the conductivity, and wet mixing the two filter cakes washed in the normal process according to a feeding batch proportion 1/1 (0.2/1-20/1);
(3) washing to a normal secondary washing level, drying and sintering to obtain spherical nano iron phosphate with low impurity iron-phosphorus ratio of 0.9884, wherein the performance of the lithium iron is verified by customers, the charging and discharging specific capacity of 0.1C is 163 mAh/g and 159mAh/g, and the first effect is 97.6%.
Electron microscopy and XRD analysis of the obtained iron phosphate2 (a-c), the ferric phosphate is in a spherical nano structure with the diameter of 10-150nm, and the XRD pattern of the sample in figure 3 shows that the obtained product is FePO4(JCPDS card No. 29-0715).
The iron-phosphorus ratio of the directly-washed filter cake is 1.02 and is more than 1, the iron-phosphorus ratio of the directly-washed filter cake is 0.969, and the XRD (X-ray diffraction) of two materials sintered at the same temperature has no obvious difference, so that the iron phosphate with the iron-phosphorus ratio of any ratio between 0.969 and 1.02 can be obtained by mixing the first-washed filter cake and the second-washed filter cake according to different ratios theoretically.
The process route is equivalent to reducing the pulping and aging procedure after the first washing, saving 2 procedures, reducing the use amount of water and phosphoric acid, reducing the cost, keeping all impurity elements within 3ppm, and improving the iron-phosphorus ratio.
Table one impurity element content (ppm)
Al Co Ni Cr Ca Cu K Mg Na Pb Zn Mn Cd Ti S
6.63 0.62 2.61 5.91 9.79 0 6.75 19.85 4.68 2.61 23.56 25.70 0.45 19.17 23.6
Example 2
The novel method for flexibly improving the iron phosphate iron phosphorus ratio, provided by the invention, has the following process route 2:
(1) respectively weighing a phosphate solution (phosphoric acid solution and diammonium phosphate) and a ferrous sulfate solution according to a molar stoichiometric ratio of 1.02/1, and dropwise adding a phosphorus salt into the ferrous sulfate solution within 30 minutes;
(2) pumping the solution obtained in the step (1) into a first-washing filter press, washing the solution to 1.3ms/cm at the first-washing conductivity, and adding ammonia water to adjust the pH value to 5 (5-7) after the aging is completed normally;
(3) and washing to a normal secondary washing level, drying and sintering to obtain the spherical nano iron phosphate with the iron-phosphorus ratio of 0.9899.
The obtained ferric phosphate is analyzed by electron microscopy and XRD, the ferric phosphate is in a spherical nano structure with the diameter of 10-150nm as shown in figure 2 (d-f), and the XRD of the sample in figure 3 shows that the obtained product is FePO4(JCPDS card No. 29-0715).
Example 3
The novel method for flexibly improving the iron phosphate iron phosphorus ratio has the following process route 3:
(1) the process route 1 is that after wet mixing is carried out according to the proportion of 0.5/1 of first-washing filter cakes and second-washing filter cakes, ammonia water is used for adjusting the pH value to 5;
(2) and washing to a normal secondary washing level, drying and sintering to obtain the spherical nano iron phosphate with the iron-phosphorus ratio of 0.9901.
The obtained ferric phosphate is analyzed by electron microscopy and XRD, the ferric phosphate is in a spherical nano structure with the diameter of 10-150nm as shown in figure 2 (g-i), and the XRD pattern of the sample in figure 3 shows that the obtained product is FePO4(JCPDS card No. 29-0715).
Example 4
The same as example 1 except that the ratio of the first filter cake to the second filter cake was different (ratio 1.5/1) from example 1.
Example 5
The same as example 1 except that the proportions of the first and second filter cake washes were different (the proportion was 20/1) compared to example 1.
Example 6
The same as example 2 was repeated, except that the pH after aging was changed (pH was 5.5) to example 2.
Example 7
The same as example 2 except that the pH after aging was changed (pH was 6) as compared with example 2.
Example 8
The same as example 2 except that the pH after aging was changed (pH was 7) as compared with example 2.
Example 9
The same as example 3 except that the ratio of the first filter cake to the second filter cake was different (ratio: 0.8/1) from example 3.
Example 10
The same as example 3 except that the ratio of the first filter cake to the second filter cake was different (ratio: 0.2/1) from example 3.
Example 11
The same as example 3 was repeated, except that the pH after aging was changed (pH was 5.5) as compared with example 3.
Example 12
The same as example 3 was repeated, except that the pH after aging was changed (pH was 6.0) as compared with example 3.
Example 13
The same as example 3 was repeated, except that the pH after aging was changed (pH was 7.0) as compared with example 3.

Claims (8)

1. A novel method capable of flexibly improving the iron phosphate iron phosphorus ratio is characterized in that the material is of a spherical nano structure, and the diameter range is 10-150 nm.
2. A novel method capable of flexibly improving iron-phosphorus ratio of iron phosphate is characterized in that the iron-phosphorus ratio can be flexibly adjusted through three different process routes.
3. A novel method capable of flexibly improving iron phosphate to phosphorus ratio is characterized by comprising the following steps:
(1) synthesizing: taking ferrous sulfate as an iron source, phosphoric acid as a phosphorus source, hydrogen peroxide as an oxidant, ammonium dihydrogen phosphate as a buffering agent, and adopting a simple solvent to carry out thermal synthesis to prepare iron phosphate slurry, wherein the ratio of phosphorus salt to iron salt is 1.5/1-0.98/1;
(2) first washing: washing the iron phosphate slurry with deionized water of a filter press, and washing with electric conductivity to 500us/cm to obtain a first-washing filter cake;
(3) pulping: adding deionized water into a filter cake for pulping, and stirring for 30 min;
(4) aging: aging the slurry, adding phosphoric acid, adding 1/3 slurry, keeping the temperature for 45min at 95 ℃ after the temperature changes, adding the rest 2/3 slurry, and keeping the temperature for 45min at 95 ℃;
(5) and (2) secondary washing: washing (secondary washing) the aged slurry, and washing the slurry to below 120us/cm in conductivity to obtain a secondary washing filter cake;
(6) drying and sintering: and drying and sintering the second washing filter cake to obtain the spherical nano iron phosphate.
4. The novel method capable of flexibly increasing the iron phosphate iron phosphorus ratio according to claim 2 is characterized in that a process route 1 is to perform wet mixing on a first filter cake and a second filter cake in different ratios (0.2-20: 1), so that iron phosphate with any iron phosphorus ratio can be obtained theoretically.
5. The novel method for flexibly increasing the iron phosphate iron phosphorus ratio according to claim 2, wherein the process route 2 is to add alkali to the aged slurry to adjust the pH value, wherein the pH value is within the range of: 5-7.
6. The novel method for flexibly increasing the iron phosphate iron phosphorus ratio according to claim 2 is characterized in that the process route 3 combines advantages and disadvantages of the process route 1 and the process route 2, and the iron phosphate iron phosphorus ratio is increased.
7. The novel method for flexibly increasing the iron-to-phosphorus ratio of iron phosphate according to claim 3, wherein the pH value of iron salt is 3-4, and the pH value of phosphorus salt is 7.05-7.25.
8. The novel method for flexibly increasing the iron phosphate iron phosphorus ratio according to claim 3 is characterized in that sintering is carried out in a rotary kiln, and the sintering temperature is set as follows: 300 ℃/450 ℃/500-.
CN201910559203.7A 2019-06-26 2019-06-26 Novel method capable of flexibly improving iron phosphate to phosphorus ratio Pending CN112142025A (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113666350A (en) * 2021-08-19 2021-11-19 湖北虹润高科新材料有限公司 Dihydrate ferric phosphate capable of flexibly adjusting crystal structure and preparation method thereof
CN114314680A (en) * 2022-03-02 2022-04-12 湖北虹润高科新材料有限公司 Method for preparing low-impurity iron phosphate by using monocalcium phosphate and application

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101462704A (en) * 2008-12-29 2009-06-24 刘世琦 Production method of ultrafine cell level ferric orthophosphate
CN101481104A (en) * 2009-02-11 2009-07-15 刘世琦 Method for producing high purity battery level ferric pyrophosphate from pickle liquor
CN107522188A (en) * 2017-08-11 2017-12-29 高延敏 The preparation method of nanometer spherical iron phosphate and nano ferric phosphate, LiFePO4 and the lithium battery prepared by this method
CN108455547A (en) * 2018-02-11 2018-08-28 衢州华友钴新材料有限公司 A kind of low impurity high ferro phosphorus is than greatly than the preparation method of table battery-grade iron phosphate
CN109205584A (en) * 2018-10-09 2019-01-15 湖南雅城新材料有限公司 A kind of preparation method of high-speed rail phosphorus than ferric phosphate

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101462704A (en) * 2008-12-29 2009-06-24 刘世琦 Production method of ultrafine cell level ferric orthophosphate
CN101481104A (en) * 2009-02-11 2009-07-15 刘世琦 Method for producing high purity battery level ferric pyrophosphate from pickle liquor
CN107522188A (en) * 2017-08-11 2017-12-29 高延敏 The preparation method of nanometer spherical iron phosphate and nano ferric phosphate, LiFePO4 and the lithium battery prepared by this method
CN108455547A (en) * 2018-02-11 2018-08-28 衢州华友钴新材料有限公司 A kind of low impurity high ferro phosphorus is than greatly than the preparation method of table battery-grade iron phosphate
CN109205584A (en) * 2018-10-09 2019-01-15 湖南雅城新材料有限公司 A kind of preparation method of high-speed rail phosphorus than ferric phosphate

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
彭爱国等: "电池级超微细磷酸铁的制备", 《武汉工程大学学报》 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113666350A (en) * 2021-08-19 2021-11-19 湖北虹润高科新材料有限公司 Dihydrate ferric phosphate capable of flexibly adjusting crystal structure and preparation method thereof
CN114314680A (en) * 2022-03-02 2022-04-12 湖北虹润高科新材料有限公司 Method for preparing low-impurity iron phosphate by using monocalcium phosphate and application

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Application publication date: 20201229