CN116332144A - Sodium-rich ferric sodium phosphate positive electrode material, and preparation method and application thereof - Google Patents

Sodium-rich ferric sodium phosphate positive electrode material, and preparation method and application thereof Download PDF

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CN116332144A
CN116332144A CN202310078393.7A CN202310078393A CN116332144A CN 116332144 A CN116332144 A CN 116332144A CN 202310078393 A CN202310078393 A CN 202310078393A CN 116332144 A CN116332144 A CN 116332144A
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张翔
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Shanghai Puna Energy Technology Co ltd
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Abstract

The invention discloses a sodium-rich ferric sodium phosphate anode material, the chemical general formula of which is Na 4+x Fe 3+x (PO 4 ) 2+x (P 2 O 7 )，0<x is less than or equal to 1. The invention also discloses a preparation method of the sodium iron phosphate anode material, which comprises the following steps: weighing a carbon source, an iron source, a sodium source and a phosphorus source according to a chemical formula, and uniformly dispersing in deionized water to obtain a dispersion liquid, wherein the molar ratio of sodium in the sodium source to iron in the iron source to phosphorus in the phosphorus source satisfies the ratio of Na to Fe: p= (4+x): (3+x): (4+x), 0<x is less than or equal to 1; stirring and dispersing the dispersion liquid, and performing wet sanding at a rotating speed of 300-1000 rpm until the particle size is between 0.2 and 2 mu m to obtain slurry; spraying and granulating the slurry, wherein the particle size is controlled to be 3-15 mu m, and the sprayed powder is obtained; sintering the sprayed powder in inert atmosphere to obtain sodium iron phosphateA polar material. Na of the invention 4+x Fe 3+x (PO 4 ) 2+x (P 2 O 7 ) The positive electrode material can improve Na 4 Fe 3 (PO 4 ) 2 (P 2 O 7 ) Is used for compensating irreversible capacity loss of the anode material. Compared with the prior Na 4 Fe 3 (PO 4 ) 2 (P 2 O 7 ) The positive electrode material can improve the energy density of the full cell.

Description

Sodium-rich ferric sodium phosphate positive electrode material, and preparation method and application thereof
Technical Field
The invention relates to the technical field of sodium batteries, in particular to a sodium-rich ferric sodium phosphate (NFPP) positive electrode material, and a preparation method and application thereof.
Background
In recent years, lithium ion batteries have been rapidly developed and have been widely used in various industries. However, the increasing demands and the impoverishment of lithium resources directly restrict the development of lithium ion batteries. Sodium atoms and lithium atoms have similar atomic structures and chemical properties, the reserves of the global sodium element are extremely rich, and the sodium ion battery also has higher specific energy and low production cost. Sodium ion batteries with similar electrochemical properties are therefore a focus of attention for researchers as lithium ion batteries are limited in their wide range of applications by the impact of lithium resources and production costs.
Na 4 Fe 3 (PO 4 ) 2 (P 2 O 7 ) The positive electrode material has the characteristics of low cost and rich sources, and is very suitable for the original purpose of sodium ion battery development. But Na is 4 Fe 3 (PO 4 ) 2 (P 2 O 7 ) The specific capacity of the positive electrode material is low, particularly the first charge capacity is low, and the energy density of the sodium ion battery is further reduced after the capacity loss of the negative electrode is compensated. In order to compensate for irreversible consumption of sodium on the negative electrode material of the sodium ion battery, researchers usually adopt methods of embedding sodium into the negative electrode material in advance, adding a sodium supplementing agent at the positive electrode material end, and the like. However, the methods have complicated processes and high cost, and are not easy to scale up.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provide a sodium iron phosphate positive electrode material rich in sodium, which is simple in preparation process and high in sodium ion battery charging capacity, and a preparation method and application thereof.
In order to solve the technical problems, the invention adopts the following technical scheme:
sodium-rich ferric sodium phosphate positive electrode material, wherein the chemical general formula of the ferric sodium phosphate positive electrode material is Na 4+x Fe 3+x (PO 4 ) 2+x (P 2 O 7 )，0<x≤1。
The particle size of the sodium iron phosphate positive electrode material is 2-10 mu m, and the specific surface area is 3-15 m 2 Per gram, the tap density is 0.9-1.5 g/cm 3 。
The invention also provides a preparation method of the sodium iron phosphate anode material, which comprises the following steps of:
s1, weighing a carbon source, an iron source, a sodium source and a phosphorus source according to a chemical formula, and uniformly dispersing in deionized water to obtain a dispersion liquid, wherein the molar ratio of sodium in the sodium source to iron in the iron source to phosphorus in the phosphorus source satisfies the condition that Na and Fe are P= (4+x): (3+x): (4+x), and x is more than 0 and less than or equal to 1;
s2, stirring and dispersing the dispersion liquid, and performing wet sanding at a rotating speed of 300-1000 rpm until the particle size is between 0.2 and 2 mu m to obtain slurry;
s3, carrying out spray granulation on the slurry, and controlling the particle size to be 3-15 mu m to obtain sprayed powder;
and S4, sintering the sprayed powder under an inert atmosphere to obtain the sodium iron phosphate anode material.
As a further improvement to the above technical solution:
in the step S4, the sintering temperature is 400-600 ℃, and the sintering time is 2-10 h.
In the step S4, the sintering atmosphere includes one of argon, nitrogen, an argon-hydrogen mixture and a nitrogen-hydrogen mixture. In the step S1, the sodium source includes one or more of inorganic sodium salt and organic sodium salt;
the inorganic sodium salt comprises at least one of trisodium phosphate, sodium dihydrogen phosphate, disodium hydrogen phosphate, sodium pyrophosphate, trisodium dihydrogen pyrophosphate, disodium dihydrogen pyrophosphate, trisodium dihydrogen pyrophosphate, sodium carbonate and sodium bicarbonate.
The organic sodium salt comprises at least one of sodium acetate, sodium oxalate and sodium citrate.
In the step S1, the phosphorus source includes one or more of phosphoric acid, phosphate and pyrophosphate;
the phosphate comprises at least one of sodium dihydrogen phosphate, disodium hydrogen phosphate, trisodium phosphate, ammonium dihydrogen phosphate and diammonium hydrogen phosphate.
The pyrophosphate comprises at least one of sodium pyrophosphate, trisodium hydrogenpyrophosphate, disodium dihydrogen pyrophosphate and trisodium dihydrogen pyrophosphate.
In the step S1, the carbon source includes one or more of graphite, activated carbon, carbon nanotubes, graphene, glucose, and sucrose.
In the step S1, the dispersion is specifically sanding for 0.5-3 hours.
In the step S1, the iron source is one or more of ferrous oxalate and ferric phosphate, and the particle size of the iron source is 0.5-7 mu m.
In the step S2, the sanding mode includes one of a disc type, a pin type, and a turbine type.
In the step S2, the sanded medium includes one or more of natural sand stone, glass beads, steel balls, zirconia beads, zirconium silicate beads and agate beads.
In the step S2, the sanding time is 0.5-3 h.
As a general inventive concept, the invention also provides an application of the sodium-rich ferric sodium phosphate positive electrode material or the ferric sodium phosphate positive electrode material prepared by the preparation method in sodium ion batteries.
The application comprises the following steps: and the sodium iron phosphate anode material is taken as an anode, and is assembled with a cathode, a diaphragm and electrolyte to form the sodium ion battery.
Compared with the prior art, the invention has the advantages that:
the invention relates to a sodium-rich ferric sodium phosphate anode material, which has a chemical general formula of Na 4+x Fe 3+x (PO 4 ) 2+x (P 2 O 7 ) Satisfy 0 of<x≤1，Na 4+x Fe 3+x (PO 4 ) 2+x (P 2 O 7 ) The positive electrode material can improve Na 4 Fe 3 (PO 4 ) 2 (P 2 O 7 ) Ensures higher first-charge specific capacity, compensates irreversible loss of negative electrode material sodium in the first charge and discharge process of the sodium ion battery, and compared with the prior Na 4 Fe 3 (PO 4 ) 2 (P 2 O 7 ) The positive electrode material can improve the energy density of the full cell. The sodium iron phosphate positive electrode materialThe grain diameter of the material is 2-10 mu m, and the specific surface area is 3-15 m 2 Per gram, the tap density is 0.9-1.5 g/cm 3 。
The preparation method of the sodium-rich ferric sodium phosphate anode material has the advantages of low raw material price and easiness in obtaining, is simple, pollution-free and can be used for large-scale production.
Drawings
FIG. 1 is a positive electrode material Na prepared in example 1 5 Fe 4 (PO 4 ) 3 (P 2 O 7 ) Is a scanning electron microscope image of (c).
FIG. 2 is a positive electrode material Na prepared in example 1 5 Fe 4 (PO 4 ) 3 (P 2 O 7 ) Is a XRD pattern of (C).
FIG. 3 is a positive electrode material Na prepared in example 1 5 Fe 4 (PO 4 ) 3 (P 2 O 7 ) Is a 0.2C charge-discharge curve.
FIG. 4 is a positive electrode material Na prepared in comparative example 1 4 Fe 3 (PO 4 ) 2 (P 2 O 7 ) Is a 0.2C charge-discharge curve.
Detailed Description
The present invention will be described in further detail below. The instruments or materials used in the present invention are commercially available unless otherwise specified.
Example 1
The sodium-rich ferric sodium phosphate positive electrode material of the embodiment has a chemical formula of Na 5 Fe 4 (PO 4 ) 3 (P 2 O 7 ). The particle size of the sodium iron phosphate positive electrode material is 6.7 mu m, and the specific surface area is 11.5m 2 Per gram, tap density of 1.2g/cm 3 。
The preparation method of the positive electrode active material of the embodiment specifically comprises the following steps:
s1, respectively weighing 4mol of iron phosphate (FePO) as raw materials according to stoichiometric ratio 4 Iron source and phosphorus source), 4mol sodium acetate (CH 3 COONa, sodium source and carbon source), 1mol of sodium dihydrogen phosphate (NaH 2PO4, sodium source and phosphorus source), 0.5mol of sucrose (carbon source), wherein Na: fe: p molar ratio=5:4:5, uniformly dispersing in deionized water; the FePO 4 The particle size distribution range of (2) is 0.5-7 mu m;
s2, dispersing the dispersion liquid in a vertical mixer for 1h, then transferring the dispersion liquid into a sand mill, and performing wet sand milling at 800rpm for 2h, wherein the particle size distribution range is controlled between 0.2 and 2 mu m;
s3, spraying and granulating the sanded slurry, wherein the particle size distribution range is controlled to be 3-15 mu m;
s4, sintering the sprayed powder in an inert atmosphere at 500 ℃ for 5 hours to obtain Na rich in sodium 5 Fe 4 (PO 4 ) 3 (P 2 O 7 ) And (3) powder.
FIG. 1 shows a positive electrode active material Na prepared in this example 5 Fe 4 (PO 4 ) 3 (P 2 O 7 ) The scanning electron microscope image of the powder can be seen to be in a quasi-spherical shape, and the particle size of the product is controllable.
FIG. 2 shows a positive electrode active material Na prepared in this example 5 Fe 4 (PO 4 ) 3 (P 2 O 7 ) An additional diffraction peak appears at the x-tag position, indicating an excess of NaFePO 4 Has been successfully incorporated into the final product.
And the sodium-rich ferric sodium phosphate positive electrode material is taken as a positive electrode, and is assembled with a negative electrode, a diaphragm and electrolyte to form the sodium ion battery. As can be seen from fig. 3, the first charge capacity of the button half cell assembled by using the material prepared in this example as the positive electrode material is 118mAh/g, and the discharge capacity reaches 102mAh/g.
Example 2
The sodium-rich ferric sodium phosphate positive electrode material of the embodiment has a chemical formula of Na 4.5 Fe 3.5 (PO 4 ) 2.5 (P 2 O 7 ). The particle size of the sodium iron phosphate positive electrode material is 2.1 mu m, and the specific surface area is 14.9m 2 Per gram, tap density of 0.95g/cm 3 。
The preparation method of the positive electrode active material of the embodiment specifically comprises the following steps:
s1, respectively weighing 3.5mol of ferrous oxalate (FeC 2O4, iron source), 1.5mol of sodium dihydrogen phosphate (NaH 2PO4, sodium source and phosphorus source), 3mol of ammonium dihydrogen phosphate (NH 4H2PO4, phosphorus source), 1mol of sodium citrate (C6H 5Na3O7, sodium source and carbon source) and 0.5mol of glucose (carbon source) according to stoichiometric ratios, wherein Na: fe: p molar ratio = 4.5:3.5:4.5, uniformly dispersing in deionized water; the particle size distribution range of the ferrous oxalate is 0.5-7 mu m;
s2, dispersing the dispersion liquid in a vertical mixer for 1h, then transferring the dispersion liquid into a sand mill, and performing wet sand milling at 300rpm for 3h, wherein the particle size distribution range is controlled between 0.2 and 2 mu m;
s3, spraying and granulating the sanded slurry, wherein the particle size distribution range is controlled to be 3-15 mu m;
s4, sintering the sprayed powder in an inert atmosphere at 600 ℃ for 2 hours to obtain the Na rich in sodium 4.5 Fe 3.5 (PO 4 ) 2.5 (P 2 O 7 ) And (3) powder.
The first charge capacity of the button half battery assembled by taking the material prepared in the embodiment as the positive electrode material at 0.2C is 111mAh/g, and the discharge capacity reaches 99mAh/g.
Example 3
The sodium-rich ferric sodium phosphate positive electrode material of the embodiment has a chemical formula of Na 4.1 Fe 3.1 (PO 4 ) 2.1 (P 2 O 7 ). The particle size of the sodium iron phosphate positive electrode material is 9.8 mu m, and the specific surface area is 3.5m 2 Per gram, tap density of 1.48g/cm 3 。
The preparation method of the positive electrode active material of the embodiment specifically comprises the following steps:
s1, respectively weighing 3.1mol FePO according to stoichiometric ratio 4 (iron source and phosphorus source), 1.05mol of sodium oxalate (Na 2C2O4, sodium source and carbon source), 1mol of disodium hydrogen phosphate (Na 2HPO4, sodium source and phosphorus source), 0.5mol of glucose (carbon source), wherein Na: fe: p molar ratio = 4.1:3.1:4.1, uniformly dispersing in deionized water; the FePO 4 The particle size distribution range of (2) is 0.5-7 mu m;
s2, dispersing the dispersion liquid in a vertical mixer for 1h, then transferring the dispersion liquid into a sand mill, and performing wet sand milling at 500rpm for 2h, wherein the particle size distribution range is controlled between 0.2 and 2 mu m;
s3, spraying and granulating the sanded slurry, wherein the particle size distribution range is controlled to be 3-15 mu m;
s4, sintering the sprayed powder in an inert atmosphere at 550 ℃ for 5 hours to obtain the Na rich in sodium 4.1 Fe 3.1 (PO 4 ) 2.1 (P 2 O 7 ) And (3) powder.
The first charge capacity of the button half battery assembled by taking the material prepared in the embodiment as the positive electrode material at 0.2C is 105mAh/g, and the discharge capacity reaches 100mAh/g.
Example 4
The sodium-rich ferric sodium phosphate positive electrode material of the embodiment has a chemical formula of Na 4.5 Fe 3.5 (PO 4 ) 2.5 (P 2 O 7 ). The particle size of the sodium iron phosphate positive electrode material is 5.9 mu m, and the specific surface area is 10.5m 2 Per gram, tap density of 1.1g/cm 3 。
The preparation method of the positive electrode active material of the embodiment specifically comprises the following steps:
s1, respectively weighing 3.5mol FePO according to stoichiometric ratio 4 (iron source and phosphorus source), 2.5mol sodium acetate (CH) 3 COONa, sodium source and carbon source), 1mol of disodium hydrogen phosphate (Na 2HPO4, sodium source and phosphorus source), 0.5mol of glucose (carbon source), wherein Na: fe: p molar ratio = 4.5:3.5:4.5, uniformly dispersing in deionized water; the FePO 4 The particle size distribution range of (2) is 0.5-7 mu m;
s2, dispersing the dispersion liquid in a vertical mixer for 1h, then transferring the dispersion liquid into a sand mill, and performing wet sand milling at 1000rpm for 0.5h, wherein the particle size distribution range is controlled between 0.2 and 2 mu m;
s3, spraying and granulating the sanded slurry, wherein the particle size distribution range is controlled to be 3-15 mu m;
s4, sintering the sprayed powder in an inert atmosphere at 400 ℃ for 10 hours to obtain the Na rich in sodium 4.5 Fe 3.5 (PO 4 ) 2.5 (P 2 O 7 ) And (3) powder.
The first charge capacity of the button half battery assembled by taking the material prepared in the embodiment as the positive electrode material at 0.2C is 112mAh/g, and the discharge capacity reaches 98.8mAh/g.
Example 5
The sodium-rich ferric sodium phosphate positive electrode material of the embodiment has a chemical formula of Na 4.3 Fe 3.3 (PO 4 ) 2.3 (P 2 O 7 ). The particle size of the sodium iron phosphate positive electrode material is 7.8 mu m, and the specific surface area is 8.5m 2 Per gram, tap density of 1.25g/cm 3 。
The preparation method of the positive electrode active material of the embodiment specifically comprises the following steps: :
s1, respectively weighing 3.3mol of ferrous oxalate (FeC 2O4, iron source) and 1mol of sodium acetate (CH 3 COONa, sodium source and carbon source), 1.1mol sodium phosphate (Na 3PO4, sodium source and phosphorus source), 3.2mol ammonium dihydrogen phosphate (NH 4H2PO4, phosphorus source), 0.5mol sucrose (carbon source), 1wt% carbon nanotubes (carbon source, here carbon nanotubes, mass fraction of all raw materials), wherein Na: fe: p molar ratio = 4.3:3.3:4.3, uniformly dispersing in deionized water;
s2, the particle size distribution range of the ferrous oxalate is 0.5-7 mu m; dispersing the dispersion in a vertical mixer for 1h, transferring to a sand mill, and performing wet sand milling at 500rpm for 1h, wherein the particle size distribution range is controlled between 0.2 and 2 mu m
S3, spraying and granulating the sanded slurry, wherein the particle size distribution range is controlled to be 3-15 mu m;
s4, sintering the sprayed powder in an inert atmosphere at 500 ℃ for 6 hours to obtain the Na rich in sodium 4.3 Fe 3.3 (PO 4 ) 2.3 (P 2 O 7 ) And (3) powder.
The first charge capacity of the button half battery assembled by taking the material prepared in the embodiment as the positive electrode material at 0.2C is 108.7mAh/g, and the discharge capacity reaches 99.5mAh/g.
Comparative example 1
The positive electrode active material of this comparative example was substantially the same as in example 4, except that: the chemical formula is Na 4 Fe 3 (PO 4 ) 2 (P 2 O 7 )。
The preparation method of the comparative example positive electrode active material is substantially the same as that of example 4, and specifically comprises the following steps:
s1, respectively weighing 3mol FePO according to stoichiometric ratio 4 (iron source and phosphorus source), 2mol sodium acetate (CH) 3 COONa, sodium source and carbon source), 1mol of disodium hydrogen phosphate (Na 2HPO4, sodium source and phosphorus source), 0.5mol of glucose (carbon source), wherein Na: fe: p molar ratio = 4:3:4, uniformly dispersing in deionized water; the FePO 4 The particle size distribution range of (2) is 0.5-7 mu m;
s2, dispersing the dispersion liquid in a vertical mixer for 1h, then transferring the dispersion liquid into a sand mill, and performing wet sand milling at 500rpm for 1h, wherein the particle size distribution range is controlled between 0.2 and 2 mu m;
s3, spraying and granulating the sanded slurry, wherein the particle size distribution range is controlled to be 3-15 mu m;
s4, sintering the sprayed powder in an inert atmosphere at 500 ℃ for 6 hours to obtain Na 4 Fe 3 (PO 4 ) 2 (P 2 O 7 ) And (3) powder. The first charge capacity of the button half cell assembled by taking the material prepared in the comparative example as the positive electrode material is 101mAh/g, the discharge capacity reaches 99mAh/g, as shown in FIG. 4, the first charge capacity of the comparative example is lower than that of the material prepared in the example 4, which shows that the conventional sodium iron phosphate positive electrode material Na is adopted 4 Fe 3 (PO 4 ) 2 (P 2 O 7 ) The first charge capacity of (a) is less than that of sodium-rich sodium iron phosphate positive electrode material.
Comparative example 2
The positive electrode active material of comparative example has the chemical formula Na 4.5 Fe 3.5 (PO 4 ) 2.5 (P 2 O 7 )。
The preparation method of the comparative example positive electrode active material is substantially the same as that of example 4, and specifically comprises the following steps:
s1, respectively weighing 3.5mol FePO according to stoichiometric ratio 4 1.25mol sodium carbonate (Na 2 CO 3 ) 1mol of phosphorusDisodium hydrogen (Na 2HPO 4), 0.5mol glucose, wherein Na: fe: p molar ratio = 4.5:3.5:4.5, uniformly dispersing in deionized water; the FePO 4 The particle size distribution range of (2) is 0.5-7 mu m;
s2, dispersing the dispersion liquid in a vertical mixer for 1h, then transferring the dispersion liquid into a sand mill, and performing wet sand milling at 500rpm for 1h, wherein the particle size distribution range is controlled between 0.2 and 2 mu m;
s3, spraying and granulating the sanded slurry, wherein the particle size distribution range is controlled to be 3-15 mu m;
s4, sintering the sprayed powder in an inert atmosphere at a sintering temperature of 650 ℃ for 5 hours to obtain Na 4.5 Fe 3.5 (PO 4 ) 2.5 (P 2 O 7 ) And (3) powder.
The first charge capacity of the button half battery assembled by taking the material prepared in the comparative example as the positive electrode material at 0.2C is 90.3mAh/g, and the discharge capacity reaches 88mAh/g. The comparative example uses the same mole ratio of sodium to iron as in example 4, but when sintering, high temperature sintering at 650 ℃ is adopted, the obtained material is assembled into a battery, and higher charge capacity cannot be obtained, the performance of the assembled battery is obviously lower than that of example 4, which means that excessive sodium is not successfully doped into sodium iron phosphate powder at the sintering temperature, when the mole ratio of sodium to iron exceeds the numerical range defined in the application, that is, x is more than 1, the excessive sodium cannot be successfully doped into sodium iron phosphate by adopting the preparation method of the invention, that is, the sodium-rich sodium phosphate positive electrode material is not obtained by directly increasing the sodium content in the raw material during preparation, and the technical problem that sodium cannot be successfully doped into sodium phosphate is also faced when the sodium content is increased.
Comparative example 3
The positive electrode active material of comparative example has the chemical formula Na 4 Fe 3 (PO 4 ) 2 (P 2 O 7 )。
The preparation method of the positive electrode active material of the comparative example is substantially the same as that of comparative example 1, and specifically comprises the following steps:
s1, respectively weighing 3mol FePO according to stoichiometric ratio 4 1mol sodium carbonate (Na) 2 CO 3 ) 1mol of disodium hydrogen phosphate (Na 2HPO 4), 0.5mol of glucose, wherein Na: fe: p molar ratio = 4:3:4, uniformly dispersing in deionized water; the FePO 4 The particle size distribution range of (2) is 0.5-7 mu m;
s2, spraying and granulating slurry obtained by dispersing the dispersion liquid in a vertical mixer for 1h, wherein the particle size distribution range is controlled to be 3-15 mu m;
s3, sintering the sprayed powder in an inert atmosphere at 500 ℃ for 5 hours to obtain Na 4 Fe 3 (PO 4 ) 2 (P 2 O 7 ) And (3) powder.
The first charge capacity of the button half battery assembled by taking the material prepared in the comparative example as the positive electrode material at 0.2C is 95mAh/g, and the discharge capacity reaches 86mAh/g. Compared with the preparation method of the raw materials with the same molar ratio of sodium to iron, the comparative example only adopts stirring and dispersing before spray drying, and wet sanding is not carried out, and the first charge capacity of the final product is inferior to that of comparative example 1, which shows that the wet ball milling can improve the first charge capacity.
While the invention has been described in terms of preferred embodiments, it is not intended to be limiting. Many possible variations and modifications of the disclosed technology can be made by anyone skilled in the art, or equivalent embodiments with equivalent variations can be made, without departing from the scope of the invention. Therefore, any simple modification, equivalent variation and modification of the above embodiments according to the technical substance of the present invention shall fall within the scope of the technical solution of the present invention.

Claims (10)

1. A sodium-rich ferric sodium phosphate positive electrode material is characterized in that: the chemical general formula of the sodium iron phosphate anode material is Na 4+x Fe 3+x (PO 4 ) 2+x (P 2 O 7 )，0<x≤1。
2. The sodium iron phosphate positive electrode material according to claim 1, characterized in thatThe method comprises the following steps: the particle size of the sodium iron phosphate positive electrode material is 2-10 mu m, and the specific surface area is 3-15 m 2 Per gram, the tap density is 0.9-1.5 g/cm 3 。
3. A method for preparing the sodium iron phosphate positive electrode material according to claim 1 or 2, characterized in that: the method comprises the following steps:
s1, weighing a carbon source, an iron source, a sodium source and a phosphorus source according to a chemical formula, and uniformly dispersing in deionized water to obtain a dispersion liquid, wherein the molar ratio of sodium in the sodium source to iron in the iron source to phosphorus in the phosphorus source satisfies the condition that Na and Fe are P= (4+x): (3+x): (4+x), and x is more than 0 and less than or equal to 1;
s2, stirring and dispersing the dispersion liquid, and performing wet sanding at a rotating speed of 300-1000 rpm until the particle size is between 0.2 and 2 mu m to obtain slurry;
s3, carrying out spray granulation on the slurry, and controlling the particle size to be 3-15 mu m to obtain sprayed powder;
and S4, sintering the sprayed powder under an inert atmosphere to obtain the sodium iron phosphate anode material.
4. A method of preparation according to claim 3, characterized in that: in the step S4, the sintering temperature is 400-600 ℃, and the sintering time is 2-10 h.
5. A method of preparation according to claim 3, characterized in that: in the step S4, the sintering atmosphere includes one of argon, nitrogen, an argon-hydrogen mixture and a nitrogen-hydrogen mixture.
6. A method of preparation according to claim 3, characterized in that: in the step S1, the sodium source includes one or more of inorganic sodium salt and organic sodium salt;
the inorganic sodium salt comprises at least one of trisodium phosphate, sodium dihydrogen phosphate, disodium hydrogen phosphate, sodium pyrophosphate, trisodium dihydrogen pyrophosphate, disodium dihydrogen pyrophosphate, trisodium dihydrogen pyrophosphate, sodium carbonate and sodium bicarbonate; the organic sodium salt comprises at least one of sodium acetate, sodium oxalate and sodium citrate.
7. A method of preparation according to claim 3, characterized in that: in the step S1, the phosphorus source includes one or more of phosphoric acid, phosphate and pyrophosphate;
the phosphate comprises at least one of sodium dihydrogen phosphate, disodium hydrogen phosphate, trisodium phosphate, ammonium dihydrogen phosphate and diammonium hydrogen phosphate; the pyrophosphate comprises at least one of sodium pyrophosphate, trisodium hydrogenpyrophosphate, disodium dihydrogen pyrophosphate and trisodium dihydrogen pyrophosphate.
8. A method of preparation according to claim 3, characterized in that: in the step S1, the carbon source includes one or more of graphite, activated carbon, carbon nanotubes, graphene, glucose, and sucrose.
9. Use of the sodium-enriched iron sodium phosphate positive electrode material according to claim 1 or 2 or the iron sodium phosphate positive electrode material prepared by the preparation method according to any one of claims 3 to 8 in sodium ion batteries.
10. The use according to claim 9, characterized in that: and the sodium iron phosphate anode material is taken as an anode, and is assembled with a cathode, a diaphragm and electrolyte to form the sodium ion battery.
CN202310078393.7A 2023-01-16 2023-01-16 Sodium-rich ferric sodium phosphate positive electrode material, and preparation method and application thereof Pending CN116332144A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116741988A (en) * 2023-08-11 2023-09-12 深圳海辰储能控制技术有限公司 Positive electrode plate, preparation method thereof, energy storage device and power utilization device

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116741988A (en) * 2023-08-11 2023-09-12 深圳海辰储能控制技术有限公司 Positive electrode plate, preparation method thereof, energy storage device and power utilization device

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