CN117276494B - Heteroatom-doped carbon-coated Na4MxFe3-x (PO 4) 2P2O7 composite material and preparation method and application thereof - Google Patents

Heteroatom-doped carbon-coated Na4MxFe3-x (PO 4) 2P2O7 composite material and preparation method and application thereof Download PDF

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CN117276494B
CN117276494B CN202311142947.1A CN202311142947A CN117276494B CN 117276494 B CN117276494 B CN 117276494B CN 202311142947 A CN202311142947 A CN 202311142947A CN 117276494 B CN117276494 B CN 117276494B
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CN117276494A (en
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张满强
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Guangdong Nayi New Energy Technology Co ltd
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Abstract

The invention discloses a heteroatom doped carbon coated Na 4 M x Fe 3‑x (PO 4 ) 2 P 2 O 7 Composite material, preparation method and application, it is a technical field of battery; the heteroatom doped carbon coated Na provided by the invention 4 M x Fe 3‑x (PO 4 ) 2 P 2 O 7 The composite material has smaller granularity and even distribution, has rich heteroatom sites on the surface, can change the electron structure of the mesoporous carbon surface, enhances the adsorption capacity of the carbon material surface to electrons and sodium ion diffusion kinetics, and further has larger pore diameter and higher discharge specific capacity of 0.2C and 5C when the composite material is used for the preparation of the subsequent positive electrode material; in addition, the heteroatom doped carbon coated Na provided by the invention 4 M x Fe 3‑x (PO 4 ) 2 P 2 O 7 The preparation method of the composite material is simple and environment-friendly, no toxic or harmful gas is discharged, and the used raw materials are simple and easy to obtain and are easy for practical production.

Description

Heteroatom doped carbon coated Na 4 M x Fe 3-x (PO 4 ) 2 P 2 O 7 Composite material, preparation method and application thereof
Technical Field
The invention belongs to the technical field of batteries, and particularly relates to a heteroatom doped carbon coated Na 4 M x Fe 3-x (PO 4 ) 2 P 2 O 7 Composite materials, methods of making and uses thereof.
Background
With the continuous development of human society, the demand for energy has also increased. The use of clean energy sources such as wind energy, solar energy, geothermal energy and the like is limited by factors such as geographical environment, climate conditions, time and the like, has intermittent characteristics, and the use needs to be carried out such as peak clipping and valley filling, firstly, the energy sources are stored, and then the energy sources are stably conveyed through a power grid in the electricity consumption peak period. The lithium ion battery has the characteristics of high system modularization integration level, high conversion efficiency, high energy density and the like, and meets the long-cycle and large-scale requirements of the energy storage system to a certain extent, but the price of the lithium ion battery is fluctuated by the price of raw material lithium carbonate, so that the development of a low-cost secondary energy storage battery technology is urgently needed.
As LiFePO 4 The iron-based phosphate sodium ion battery anode material has wide application prospect and uses Na as a substitute 4 Fe 3 (PO 4 ) 2 P 2 O 7 For example, the theoretical capacity of the positive electrode material is about 129mAh g -1 The average working voltage is about 3.2V, the conductivity of the material is poor, the material needs to be combined with carbon-based materials, a multidimensional sodium ion diffusion path exists in crystals, the structural stability and the long cycle life are good, and the synthesis of the material is also same as LiFePO 4 Similarly. Firstly, sodium sources used for synthesizing materials are generally sodium carbonate, sodium bicarbonate and the like, so that the cost is low and the materials are easy to obtain; secondly, the iron source used for material synthesis can use the existing battery grade ferric phosphate or ferrous oxalate, and no new iron source raw material needs to be developed; furthermore, the production of the material can completely borrow the existing LiFePO 4 The sanding-spraying process route and equipment further shorten the difficulty of mass production.
However, na 4 Fe 3 (PO 4 ) 2 P 2 O 7 The material has inherent low electron conductivity problem, needs to be combined with carbon material, and Na 4 Fe 3 (PO 4 ) 2 P 2 O 7 The sintering temperature of the material is lower than 600 , at which the conductivity of amorphous carbon is poor, the material is difficult to reach the theoretical capacity, and secondly, the material is matched with LiFePO 4 Similarly, sintering temperature and particle size also apply to Na 4 Fe 3 (PO 4 ) 2 P 2 O 7 In addition, the carbon material needs to be subjected to certain improvement process, and two or more modification methods are required to be combined to ensure that the capacity of the material is exerted. Prior ArtDifferent studies have been made to ensure capacity exertion, for example CN112768673A proposes a Na 4 Fe 3-x (PO 4 ) 2 P 2 O 7 The iron defect can be introduced by reducing the consumption of iron source in the raw material of the positive electrode material/C, and NaFePO is inhibited 4 The formation of impurities, but the reduction of iron atom pairs involved in the redox reaction, is at the expense of theoretical capacity to increase product purity. For example, CN114883540a proposes to coat an iron-based phosphate positive electrode material with polyaniline, but polyaniline is a toxic and flammable substance, and sintering can produce nitrogen oxide emissions. Thus, high performance Na was developed 4 Fe 3 (PO 4 ) 2 P 2 O 7 The carbon composite material has very challenging, firstly, the used carbon source needs to protect the main material to a certain extent, the structure of the positive electrode material in the circulating process is ensured not to be damaged, and the surface of the material needs to be uniformly coated; secondly, the raw materials are screened to a certain extent, the safety and environmental protection of actual production are considered, and the emission of nitrogen oxides and sulfur oxides is avoided; furthermore, the amount of carbon source used also affects the coating effect and compaction density of the composite material, further affecting the electrical properties of the composite material.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provide the heteroatom doped carbon coated Na which has the advantages of simple and environment-friendly synthesis method, small and uniform particle size and excellent sodium storage performance 4 M x Fe 3-x (PO 4 ) 2 P 2 O 7 Composite materials, methods of making and uses thereof.
To achieve the above object, in a first aspect of the present invention, there is provided a heteroatom-doped carbon-coated Na 4 M x Fe 3-x (PO 4 ) 2 P 2 O 7 Composite material, the heteroatom doped carbon coating Na 4 M x Fe 3-x (PO 4 ) 2 P 2 O 7 The carbon content in the composite material is 0.2-6%; wherein x is 0.ltoreq.x<3, a step of; m is selected from Mg, mn, zn, cu, al, ti, mo, V, zr, mn, cr, ni, co element and rare earthOne or more of the elemental compounds;
in the heteroatom doped carbon, the heteroatom is boron and phosphorus, and the sum of the mass percentages of the boron and the phosphorus is 0.2-5% based on the heteroatom doped carbon.
The invention provides a heteroatom doped carbon coated Na 4 M x Fe 3-x (PO 4 ) 2 P 2 O 7 The composite material has smaller granularity and even distribution, wherein D50 is below 12 mu m, and the granularity distribution coefficient P is below 7.28; the surface of the mesoporous carbon material has rich heteroatom sites, the surface electron structure of the mesoporous carbon material can be changed, the adsorption capacity of the surface of the mesoporous carbon material to electrons and the diffusion kinetics of sodium ions are enhanced, and when the mesoporous carbon material is used for the preparation of a subsequent anode material, the pore diameter of the obtained anode material is larger, the discharge specific capacity of 0.2C is high and is more than 25.6nm, the discharge specific capacity of 5C is more than 102.4mAh/g, and the discharge specific capacity of 5C is more than 96.3 mAh/g.
Preferably, M is selected from any one of Mg and Mn.
When M is selected to be any one of Mg and Mn, the preparation method provided by the invention can ensure that the particle size of the obtained product is small and uniform, and the obtained corresponding positive electrode material has higher specific discharge capacity.
In a second aspect of the invention, the invention provides the heteroatom doped carbon coated Na 4 M x Fe 3-x (PO 4 ) 2 P 2 O 7 The preparation method of the composite material comprises the following steps:
preparing a template solution: dissolving a boron source, a phosphine source and a block copolymer in deionized water to obtain a template solution;
preparation of suspension slurry: dissolving porous ferric phosphate in deionized water, stirring and dispersing to obtain suspension slurry;
preparing a precursor solution: mixing a template solution and suspension slurry, and then adding a sodium source, a sodium phosphorus source, a carbon source and an M source to obtain a precursor solution;
preparing a precursor: sanding and drying the precursor solution to obtain a precursor;
preparation of the composite material: sintering the precursor twice, crushing and sieving after each sintering to obtain a composite material;
in the two-time sintering, the temperature rising rate of the first sintering is 1-5 /min, the sintering temperature is 280-400 , the sintering time is 4-8h, the temperature rising rate of the second sintering is 1-5 /min, the sintering temperature is 500-600 , and the sintering time is 8-15h.
The heteroatom doped carbon coated Na provided by the invention 4 M x Fe 3-x (PO 4 ) 2 P 2 O 7 In the preparation method of the composite material, unique porous ferric phosphate is adopted as an inner core, so that the diffusion resistance of a sodium source and a phosphorus source in high-temperature sintering is reduced, and Na with higher purity is more easily diffused into a crystal lattice to form 4 M x Fe 3-x (PO 4 ) 2 P 2 O 7 The composite material is self-assembled through intermolecular hydrogen bonding between a phosphine source and a block copolymer, and in the pyrolysis process, the surface of the porous ferric phosphate generates doped carbon enriched with hetero atoms, so that the obtained hetero atom doped carbon-coated Na 4 M x Fe 3-x (PO 4 ) 2 P 2 O 7 The composite material has excellent sodium storage performance as a positive electrode material of a sodium ion battery.
Specifically, in the first aspect, the self-assembly is realized through the intermolecular hydrogen bonding of the block copolymer, a certain boron source, a phosphine source and a carbon source are added, and the subsequent sintering process of specific temperature raising program, heat preservation temperature and time is matched, so that hetero atom doped mesoporous carbon can be generated in situ in the pyrolysis process, a material is endowed with a larger specific surface area, a uniform pore structure and rich three-dimensional sodium ion diffusion channels, and the stability of the composite material in the circulation process is further ensured. In the second aspect, the porous ferric phosphate is used as the inner core, the diffusion resistance of sodium atoms and phosphorus atoms in a high-temperature environment is reduced by the rich pores of the porous ferric phosphate, the high-temperature sintering energy consumption is reduced, and the unique porous structure is favorable for uniform mixing among atoms, so that the purity of a product is improved. In a third aspect, the present invention employs a sanding process to treat the precursor solution to enableHeteroatom doped carbon coated Na 4 M x Fe 3-x (PO 4 ) 2 P 2 O 7 The composite material has smaller granularity and concentrated distribution, the smaller granularity is favorable for the transmission of sodium ions among the particles, the sodium ion transmission resistance is smaller, no emission of harmful gases such as nitrogen oxides, boron oxides and sulfur oxides is generated in the synthesis process, and the obtained boron-doped carbon-coated Na is obtained 4 M x Fe 3-x (PO 4 ) 2 P 2 O 7 The composite material has higher compaction density and excellent sodium storage performance.
Preferably, in the two-time sintering, the heating rate of the first sintering is 3 /min, the sintering temperature is 400 , the sintering time is 4h, the heating rate of the second sintering is 3 /min, the sintering temperature is 540 , and the sintering time is 10h.
The inventors have found that when the sintering parameters are more preferably the above values, the resulting composite material has more excellent overall properties.
Preferably, the sintering atmosphere is a nitrogen atmosphere.
As a preferred embodiment of the production method of the present invention, the block copolymer is at least one selected from polyoxyethylene fatty acid esters, polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymers, and sorbitan fatty acid ester compounds.
The segmented copolymer can form intermolecular self-assembly, so that the material is endowed with a larger specific surface area, a uniform pore structure and rich three-dimensional sodium ion diffusion channels, and the stability of the composite material in the circulating process is further ensured; the inventors have found that when the block copolymer is selected as the above-mentioned substance, the resultant composite is more excellent in comprehensive properties.
As a preferred embodiment of the preparation method of the invention, the M source is a magnesium source or a manganese source.
As a preferred embodiment of the production method of the present invention, at least one of the following (a) to (g):
(a) The boron source is at least one selected from methyl boric acid, boric acid and boron phosphate;
(b) The phosphine source is at least one of hydroxyethylidene diphosphonic acid, phosphonoglycolic acid and phosphonobutane tricarboxylic acid;
(c) The sodium source is at least one of sodium carbonate, sodium bicarbonate and sodium oxalate;
(d) The sodium-phosphorus source is at least one selected from sodium dihydrogen phosphate, sodium phosphate and sodium hexametaphosphate;
(e) The manganese source is at least one of manganese oxalate and manganese carbonate;
(f) The magnesium source is at least one of magnesium oxide and magnesium citrate;
(g) The carbon source is at least one selected from citric acid and glucose.
The inventors have found that when the selected components are the above-mentioned substances, the resultant composite material is more excellent in comprehensive effect.
As a preferred embodiment of the preparation method of the invention, the mass concentration of the boron source in the template solution is 1-100g/L, the mass concentration of the phosphine source is 1-100g/L, and the mass concentration of the block copolymer is 1-200g/L;
and/or, in the suspension slurry, the mass-volume ratio of the porous ferric phosphate to the deionized water is 100-500g/mL;
and/or the volume ratio of the template solution to the suspension slurry is (0.1-1): 1.
the inventors have found that when the template solution, the mass concentration of the substance in the suspension slurry, and the volume ratio of the two are used in the above ranges, the resultant composite material is more excellent in the comprehensive effect.
As a preferred embodiment of the preparation method of the present invention, the mass sum of the sodium source, the sodium phosphorus source, the M source, the carbon source and the porous iron phosphate in the precursor solution is a;
based on the weight of A, the mass of the boron source is 0.1-5% of the weight of A, the mass of the phosphine source is 0.1-5% of the weight of A, the mass of the block copolymer is 0.1-8% of the weight of A, and the mass of the carbon source is 5-8% of the weight of A.
Preferably, the mass of the boron source is 1-3% of A; the mass of the phosphine source is 0.1-3% of that of A, and the mass of the block copolymer is 4-8% of that of A.
As a preferred embodiment of the preparation method of the present invention, in the precursor solution, the molar ratio of porous iron phosphate to sodium element is porous iron phosphate: sodium element= (2.95-3): 4.
the inventors have found that when the mass ratio or the molar ratio of the substances in the precursor solution is within the above range, the resultant composite material is more excellent in the comprehensive effect.
As a preferred embodiment of the preparation method of the present invention, the rotational speed of the sand mill is 1000-3000rpm, and the sand milling time is 0.5-1h.
The sanding treatment can lead the particle size of the composite material to be smaller and concentrated, thereby being beneficial to the transmission of sodium ions among particles and having smaller sodium ion transmission resistance; when the rotational speed and time of the sanding are further selected within the above ranges, good performance can be ensured on the basis of the improved efficiency.
Preferably, the drying is centrifugal spray drying; in the spray drying, the slurry treatment capacity is 9-11L/h, the air inlet temperature is 200-210 , and the outlet temperature is 90-100 .
Preferably, after drying is completed, the moisture content in the precursor is < 3000ppm.
Preferably, the number of the screened screens is 300-400 mesh.
In a third aspect of the present invention, there is provided a sodium ion battery positive electrode material comprising the heteroatom doped carbon coated Na of the present invention 4 M x Fe 3-x (PO 4 ) 2 P 2 O 7 A composite material.
In a fourth aspect of the present invention, the present invention provides a method for preparing the positive electrode material of a sodium ion battery, the method comprising the steps of:
doping heteroatom with carbon-coated Na 4 M x Fe 3-x (PO 4 ) 2 P 2 O 7 The composite material and PVDF binder, carbon black according to 8:1:1 to obtain a positive plate of the sodium ion battery, and assembling sodium ions according to a positive plate-diaphragm-negative plate shell modeThe battery is provided with electrolyte dropwise at the same time, wherein the used diaphragm is glass fiber, the negative plate is sodium plate or hard carbon, and the used electrolyte is 1mol/L NaClO 4 Dissolved in EC: DEC (volume ratio 1:1) with 5% fec additive.
Compared with the prior art, the invention has the beneficial effects that:
the invention provides a heteroatom doped carbon coated Na 4 M x Fe 3-x (PO 4 ) 2 P 2 O 7 The composite material has smaller granularity and even distribution, wherein D50 is below 12.0 mu m, and the granularity distribution coefficient P is below 7.28; the surface of the mesoporous carbon material has rich heteroatom sites, the surface electron structure of the mesoporous carbon material can be changed, the adsorption capacity of the surface of the mesoporous carbon material to electrons and the diffusion kinetics of sodium ions are enhanced, and when the mesoporous carbon material is used for the preparation of a subsequent anode material, the pore diameter of the obtained anode material is larger, the discharge specific capacity of 0.2C is high and is more than 25.6nm, the discharge specific capacity of 5C is more than 102.4mAh/g, and the discharge specific capacity of 5C is more than 96.3 mAh/g. In addition, the heteroatom doped carbon coated Na provided by the invention 4 M x Fe 3-x (PO 4 ) 2 P 2 O 7 The preparation method of the composite material is simple and environment-friendly, no toxic or harmful gas is discharged, and the used raw materials are simple and easy to obtain and are easy for practical production.
Drawings
FIG. 1 shows Na obtained in example 1 4 Fe 3 (PO 4 ) 2 P 2 O 7 XRD pattern of the composite material;
FIG. 2 is a view of Na obtained in example 1 4 Fe 3 (PO 4 ) 2 P 2 O 7 SEM images of the composite material;
FIG. 3 is a view of Na obtained in example 1 4 Fe 3 (PO 4 ) 2 P 2 O 7 A first charge-discharge curve graph of the composite material at 0.2C multiplying power;
FIG. 4 is a view of Na obtained in example 2 4 Mn 0.05 Fe 2.95 (PO 4 ) 2 P 2 O 7 XRD pattern of the composite material;
FIG. 5 is a view of Na obtained in example 2 4 Mn 0.05 Fe 2.95 (PO 4 ) 2 P 2 O 7 SEM images of the composite material;
FIG. 6 is a graph of Na obtained in example 2 4 Mn 0.05 Fe 2.95 (PO 4 ) 2 P 2 O 7 A first charge-discharge curve graph of the composite material at 0.2C multiplying power;
FIG. 7 is a view of Na obtained in example 3 4 Mg 0.05 Fe 2.95 (PO 4 ) 2 P 2 O 7 XRD pattern of the composite material;
FIG. 8 is a view of Na obtained in example 3 4 Mg 0.05 Fe 2.95 (PO 4 ) 2 P 2 O 7 SEM images of the composite material;
FIG. 9 shows Na obtained in example 3 4 Mg 0.05 Fe 2.95 (PO 4 ) 2 P 2 O 7 First charge-discharge curve graph of composite material at 0.2C rate.
Detailed Description
For a better description of the objects, technical solutions and advantages of the present invention, the present invention will be further described with reference to the following specific examples.
Unless otherwise specified, the raw materials used in the present invention are conventional commercially available raw materials, and the raw materials used in the parallel examples or comparative examples in the present invention are identical.
Example 1
The embodiment of the invention provides a heteroatom doped carbon coated Na 4 M x Fe 3-x (PO 4 ) 2 P 2 O 7 A composite material, wherein x=0, is a heteroatom doped carbon coated Na 4 Fe 3 (PO 4 ) 2 P 2 O 7 A composite material, the method of making the composite material comprising the steps of:
(1) Preparing a template solution: dissolving a boron source (methyl boric acid, 20 g), a phosphine source (hydroxyethylidene diphosphonic acid, 20 g) and a block copolymer (polyoxyethylene fatty acid ester, 40 g) in 0.5L deionized water, mixing and stirring to obtain a template solution;
(2) Preparation of suspension slurry: dissolving porous ferric phosphate (3 mol,452.448 g) in 1L deionized water, and stirring and dispersing to obtain suspension slurry;
(3) Preparing a precursor solution: mixing 0.5L of template solution and 1L of suspension slurry, and adding a sodium source (sodium carbonate, 1.5mol,158.985 g), a sodium phosphorus source (sodium hexametaphosphate, 0.167mol,102.166 g) and a carbon source (a mixture of citric acid and glucose in a mass ratio of 1:1, 53.712 g) to obtain a precursor solution;
(4) Preparing a precursor: sanding the precursor solution for 1h at a rotating speed of 2000rpm, and spray drying the sanded precursor solution under a slurry treatment capacity of 10L/h, wherein the inlet air temperature is kept at 210 , and the outlet air temperature is kept at 95 to obtain a precursor;
(5) Preparation of the composite material: placing the precursor in a nitrogen environment for two times of sintering, wherein the heating rate of the first sintering is 3 /min, the sintering temperature is 400 , and the sintering time is 4 hours; cooling to room temperature after the first sintering, sieving with a 350-mesh sieve for the first time, crushing powder by airflow, sieving with a 350-mesh sieve, and sintering the sieved powder for the second time at a temperature rising rate of 3 /min and a sintering temperature of 540 for 10 hours; cooling to room temperature after sintering, sieving with 350 mesh sieve for the first time, crushing powder by air flow, and sieving with 350 mesh sieve to obtain composite material;
wherein, in the precursor solution, the sum of the mass of a sodium source, a sodium phosphorus source, a carbon source and porous ferric phosphate is A, A is 767.311g, the mass of a boron source is 2.6% of A, the mass of a phosphine source is 2.6% of A, the mass of a block copolymer is 5.2% of A, and the mass of a carbon source is 7% of A; the total amount of doping of the boron source and the phosphorus source in the carbon was 3.3%.
In the precursor solution, the molar ratio of porous ferric phosphate to sodium element is 3:4.
example 2
The embodiment of the invention provides a heteroatom doped carbon coated Na 4 M x Fe 3-x (PO 4 ) 2 P 2 O 7 A composite material, wherein x=0.05, M is Mn, i.e. a heteroatom doped carbon coated Na is provided 4 Mn 0.05 Fe 2.95 (PO 4 ) 2 P 2 O 7 A composite material, the method of making the composite material comprising the steps of:
(1) Preparing a template solution: dissolving a boron source (methyl boric acid, 20 g), a phosphine source (hydroxyethylidene diphosphonic acid, 20 g) and a block copolymer (polyoxyethylene fatty acid ester, 40 g) in 0.5L deionized water, mixing and stirring to obtain a template solution;
(2) Preparation of suspension slurry: porous ferric phosphate (2.95 mol, 444.227 g) is dissolved in 1L deionized water and stirred for dispersion to obtain suspension slurry;
(3) Preparing a precursor solution: mixing 0.5L of template solution and 1L of suspension slurry, and adding a sodium source (sodium carbonate, 1.5mol,158.985 g), a sodium phosphorus source (sodium hexametaphosphate, 0.167mol,102.166 g), an M source (manganese carbonate, 0.05mol,5.748 g) and a carbon source (a mixture of citric acid and glucose in a mass ratio of 1:1, 53.577 g) to obtain a precursor solution;
(4) Preparing a precursor: sanding the precursor solution for 1h at a rotating speed of 2000rpm, and spray drying the sanded precursor solution under a slurry treatment capacity of 10L/h, wherein the inlet air temperature is kept at 210 , and the outlet air temperature is kept at 95 to obtain a precursor;
(5) Preparation of the composite material: placing the precursor in a nitrogen environment for two times of sintering, wherein the heating rate of the first sintering is 3 /min, the sintering temperature is 400 , and the sintering time is 4 hours; cooling to room temperature after the first sintering, sieving with a 350-mesh sieve for the first time, crushing powder by airflow, sieving with a 350-mesh sieve, and sintering the sieved powder for the second time at a temperature rising rate of 3 /min and a sintering temperature of 540 for 10 hours; cooling to room temperature after sintering, sieving with 350 mesh sieve for the first time, crushing powder by air flow, and sieving with 350 mesh sieve to obtain composite material;
wherein, in the precursor solution, the sum of the mass of a sodium source, a sodium phosphorus source, a carbon source, an M source and porous ferric phosphate is A, A is 765.377g, the mass of a boron source is 2.6% of A, the mass of a phosphine source is 2.6% of A, the mass of a block copolymer is 5.2% of A, and the mass of a carbon source is 7% of A; the total amount of doping of the boron source and the phosphorus source in the carbon was 3.3%.
In the precursor solution, the molar ratio of porous ferric phosphate to sodium element is 2.95:4.
example 3
The embodiment of the invention provides a heteroatom doped carbon coated Na 4 M x Fe 3-x (PO 4 ) 2 P 2 O 7 Composite material, wherein x=0.05, M is Mg, i.e. to provide a heteroatom doped carbon coated Na 4 Mg 0.05 Fe 2.95 (PO 4 ) 2 P 2 O 7 A composite material, the method of making the composite material comprising the steps of:
(1) Preparing a template solution: dissolving a boron source (methyl boric acid, 20 g), a phosphine source (hydroxyethylidene diphosphonic acid, 20 g) and a block copolymer (polyoxyethylene fatty acid ester, 40 g) in 0.5L deionized water, mixing and stirring to obtain a template solution;
(2) Preparation of suspension slurry: porous ferric phosphate (2.95 mol, 444.227 g) is dissolved in 1L deionized water and stirred for dispersion to obtain suspension slurry;
(3) Preparing a precursor solution: mixing 0.5L of template solution and 1L of suspension slurry, and adding a sodium source (sodium carbonate, 1.5mol,158.985 g), a sodium phosphorus source (sodium hexametaphosphate, 0.167mol,102.166 g), an M source (magnesium oxide, 0.05mol,2.015 g) and a carbon source (a mixture of citric acid and glucose in a mass ratio of 1:1, 53.577 g) to obtain a precursor solution;
(4) Preparing a precursor: sanding the precursor solution for 1h at a rotating speed of 2000rpm, and spray drying the sanded precursor solution under a slurry treatment capacity of 10L/h, wherein the inlet air temperature is kept at 210 , and the outlet air temperature is kept at 95 to obtain a precursor;
(5) Preparation of the composite material: placing the precursor in a nitrogen environment for two times of sintering, wherein the heating rate of the first sintering is 3 /min, the sintering temperature is 400 , and the sintering time is 4 hours; cooling to room temperature after the first sintering, sieving with a 350-mesh sieve for the first time, crushing powder by airflow, sieving with a 350-mesh sieve, and sintering the sieved powder for the second time at a temperature rising rate of 3 /min and a sintering temperature of 540 for 10 hours; cooling to room temperature after sintering, sieving with 350 mesh sieve for the first time, crushing powder by air flow, and sieving with 350 mesh sieve to obtain composite material;
wherein, in the precursor solution, the sum of the mass of a sodium source, a sodium phosphorus source, a carbon source, an M source and porous ferric phosphate is A, A is 761.65g, the mass of a boron source is 2.6% of A, the mass of a phosphine source is 2.6% of A, the mass of a block copolymer is 5.2% of A, and the mass of a carbon source is 7% of A; the doping amount of the boron source and the phosphorus source in carbon was 3.3%.
In the precursor solution, the molar ratio of the porous ferric phosphate to the sodium element is 2.95:4.
Example 4
The embodiment of the invention provides a heteroatom doped carbon coated Na 4 Fe 3 (PO 4 ) 2 P 2 O 7 The only difference between the composite material and example 1 is that the mass of the boron source during the preparation is 0.1% of A.
Example 5
The embodiment of the invention provides a heteroatom doped carbon coated Na 4 Fe 3 (PO 4 ) 2 P 2 O 7 The only difference between the composite material and example 1 is that the mass of the boron source during the preparation is 1% of a.
Example 6
The embodiment of the invention provides a heteroatom doped carbon coated Na 4 Fe 3 (PO 4 ) 2 P 2 O 7 The only difference between the composite material and example 1 is that the mass of the boron source during the preparation is 5% of a.
Example 7
The embodiment of the invention provides a heteroatom doped carbon coated Na 4 Fe 3 (PO 4 ) 2 P 2 O 7 The only difference between the composite material and example 1 is that the mass of the phosphine source during the preparation is 0.1% of A.
Example 8
The embodiment of the invention provides a heteroatom doped carbon coated Na 4 Fe 3 (PO 4 ) 2 P 2 O 7 Composite material, andthe only difference in example 1 is that the mass of the phosphine source during the preparation is 3% of A.
Example 9
The embodiment of the invention provides a heteroatom doped carbon coated Na 4 Fe 3 (PO 4 ) 2 P 2 O 7 The only difference between the composite material and example 1 is that the mass of the phosphine source during the preparation is 5% of A.
Example 10
The embodiment of the invention provides a heteroatom doped carbon coated Na 4 Fe 3 (PO 4 ) 2 P 2 O 7 The only difference from example 1 is that the mass of the block copolymer during the preparation is 0.1% of A.
Example 11
The embodiment of the invention provides a heteroatom doped carbon coated Na 4 Fe 3 (PO 4 ) 2 P 2 O 7 The only difference from example 1 is that the mass of the block copolymer during the preparation is 2% of A.
Example 12
The embodiment of the invention provides a heteroatom doped carbon coated Na 4 Fe 3 (PO 4 ) 2 P 2 O 7 The only difference from example 1 is that the mass of the block copolymer during the preparation is 4% of A.
Example 13
The embodiment of the invention provides a heteroatom doped carbon coated Na 4 Fe 3 (PO 4 ) 2 P 2 O 7 The only difference from example 1 is that the mass of the block copolymer during the preparation is 8% of A.
Example 14
The embodiment of the invention provides a heteroatom doped carbon coated Na 4 Fe 3 (PO 4 ) 2 P 2 O 7 The only difference between the composite material and example 1 is that the phosphine source is phosphonoglycolic acid.
Example 15
The embodiment of the invention provides a heteroatom doped carbon coated Na 4 Fe 3 (PO 4 ) 2 P 2 O 7 The only difference between the composite material and example 1 is that the phosphine source is a mixture of hydroxyethylidene diphosphonic acid, phosphonoglycolic acid, phosphonobutane tricarboxylic acid formed in a mass ratio of 1:1:1.
Example 16
The embodiment of the invention provides a heteroatom doped carbon coated Na 4 Fe 3 (PO 4 ) 2 P 2 O 7 The only difference with example 1 is that the phosphine source is phosphoric acid.
Example 17
The embodiment of the invention provides a heteroatom doped carbon coated Na 4 Fe 3 (PO 4 ) 2 P 2 O 7 The only difference from example 1 is that the block copolymer is a polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer.
Example 18
The embodiment of the invention provides a heteroatom doped carbon coated Na 4 Fe 3 (PO 4 ) 2 P 2 O 7 The only difference from example 1 is that the block copolymer is a sorbitan fatty acid ester compound.
Example 19
The embodiment of the invention provides a heteroatom doped carbon coated Na 4 Fe 3 (PO 4 ) 2 P 2 O 7 The only difference from example 1 is that the block copolymer is a styrene-isoprene-styrene triblock copolymer.
Example 20
The embodiment of the invention provides a heteroatom doped carbon coated Na 4 Fe 3 (PO 4 ) 2 P 2 O 7 The only difference from example 1 is that the boron source is a mixture of methyl boric acid, boric acid and boron phosphate in a mass ratio of 1:1:1.
Example 21
The embodiment of the invention provides a heteroatom doped carbon coated Na 4 Fe 3 (PO 4 ) 2 P 2 O 7 The only difference from example 1 is that the mass concentration of the boron source is 60g/L, the mass concentration of the phosphine source is 60g/L, and the mass concentration of the block copolymer is 100g/L; in the suspension slurry, the mass volume ratio of the porous ferric phosphate to the deionized water is 226.224g/L; the volume ratio of template solution to suspension slurry was 0.375:1.
example 22
The embodiment of the invention provides a heteroatom doped carbon coated Na 4 Fe 3 (PO 4 ) 2 P 2 O 7 The only difference from example 1 is that the first sintering has a temperature rise rate of 5 /min, a sintering temperature of 280 , a sintering time of 8 hours, and the second sintering has a temperature rise rate of 1 /min, a sintering temperature of 600 and a sintering time of 8 hours.
Comparative example 1
The comparative example of the present invention provides a heteroatom doped carbon coated Na 4 Fe 3 (PO 4 ) 2 P 2 O 7 The only difference from example 1 is that no block copolymer is added in step (1).
Comparative example 2
The comparative example of the present invention provides a heteroatom doped carbon coated Na 4 Fe 3 (PO 4 ) 2 P 2 O 7 The only difference between the composite material and example 1 is that there is no sanding in step (4).
Comparative example 3
The comparative example of the present invention provides a heteroatom doped carbon coated Na 4 Fe 3 (PO 4 ) 2 P 2 O 7 The only difference from example 1 is that in step (5), the temperature rise rate of the first sintering is 10 /min, the sintering temperature is 400 , and the sintering time is 4 hours.
Comparative example 4
The comparative example of the present invention provides a heteroatom doped carbon packageCoating with Na 4 Fe 3 (PO 4 ) 2 P 2 O 7 The only difference from example 1 is that in step (5), the temperature rise rate of the first sintering is 3 /min, the sintering temperature is 230 , and the sintering time is 4h.
Comparative example 5
The comparative example of the present invention provides a heteroatom doped carbon coated Na 4 Fe 3 (PO 4 ) 2 P 2 O 7 The only difference from example 1 is that in step (5), the second sintering is performed at a temperature increase rate of 0.5 /min, a sintering temperature of 540 and a sintering time of 10 hours.
Comparative example 6
The comparative example of the present invention provides a heteroatom doped carbon coated Na 4 Fe 3 (PO 4 ) 2 P 2 O 7 The only difference from example 1 is that in step (5), the second sintering is performed at a temperature rise rate of 3 /min, a sintering temperature of 650 and a sintering time of 10 hours.
Comparative example 7
The comparative example of the present invention provides a heteroatom doped carbon coated Na 4 Fe 3 (PO 4 ) 2 P 2 O 7 The only difference from example 1 is that in step (5) only one sintering is performed, in particular at a temperature rise rate of 3 /min, a sintering temperature of 400 and a sintering time of 14h.
Comparative example 8
The comparative example of the present invention provides a heteroatom doped carbon coated Na 4 Fe 3 (PO 4 ) 2 P 2 O 7 The only difference from example 1 is that in step (5) only one sintering is performed, in particular the temperature rise rate is 3 /min, the sintering temperature is 540 , and the sintering time is 14h.
Comparative example 9
The comparative example of the present invention provides a heteroatom doped carbon coated Na 4 Fe 3 (PO 4 ) 2 P 2 O 7 The only difference between the composite material and example 1 is that, during the preparation,the mass of the boron source is 10% of that of A.
Comparative example 10
The comparative example of the present invention provides a heteroatom doped carbon coated Na 4 Fe 3 (PO 4 ) 2 P 2 O 7 The only difference between the composite material and example 1 is that the phosphine source has a mass of 10% of A during the preparation.
Comparative example 11
The comparative example of the present invention provides a heteroatom doped carbon coated Na 4 Fe 3 (PO 4 ) 2 P 2 O 7 The only difference from example 1 is that the mass of the block copolymer during the preparation is 15% of A.
Comparative example 12
The comparative example of the present invention provides a heteroatom doped carbon coated Na 4 Fe 3 (PO 4 ) 2 P 2 O 7 The only difference between the composite material and example 1 is that no boron source is added during the preparation.
Comparative example 13
The comparative example of the present invention provides a heteroatom doped carbon coated Na 4 Fe 3 (PO 4 ) 2 P 2 O 7 The only difference between the composite material and example 1 is that no phosphine source was added during the preparation.
Effect example
The method has the advantages that the prepared heteroatom doped carbon is coated with Na 4 M x Fe 3-x (PO 4 ) 2 P 2 O 7 Performing effect verification on the composite material;
at the same time coating the prepared heteroatom doped carbon with Na 4 M x Fe 3-x (PO 4 ) 2 P 2 O 7 The composite material is further prepared into a positive electrode material for verification, and the preparation method of the positive electrode material comprises the following steps: the heteroatom-doped carbon coated Na prepared in examples 1-22 and comparative examples 1-13, respectively 4 M x Fe 3-x (PO 4 ) 2 P 2 O 7 Composite material and PVDF binder, carbon black according to 8:1:1 to obtain a positive plate of the sodium ion battery, assembling the sodium ion battery according to a positive plate-diaphragm-negative plate shell mode, simultaneously dropwise adding electrolyte, wherein the diaphragm is glass fiber, the negative plate is sodium plate or hard carbon, and the electrolyte is 1mol/L NaClO4 dissolved in EC: DEC (volume ratio 1:1) contains 5% of FEC additive to obtain sodium ion anode material;
specifically, the present invention relates to a method for manufacturing a semiconductor device;
1. measurement of particle size and average particle size distribution coefficient: mastersizer 3000;
firstly, opening a preset SOP file, weighing about 10mL of slurry, pouring the slurry into a water tank containing deionized water, performing ultrasonic dispersion for 1min, and performing click test to obtain the particle size data of the sample, wherein the average particle size distribution coefficient is (D90-D10)/D10 calculation result.
2. Carbon content testing: HCS-800B;
weighing 0.2g of powder sample, placing the powder sample in a combustion furnace at 1600 , collecting and separating tail gas generated after combustion, and calculating the carbon content in the sample through the absorption of the separated tail gas to infrared spectrum.
3. Testing of powder compaction density: FT-100F;
firstly, preheating a powder compaction density measuring instrument for 10min, weighing 1 g+/-0.05 g of sample, pouring the sample into a compaction die, and recording the compaction density of the sample powder under 250 Mpa.
4. Pore size testing: NOVA 3000e;
weighing 0.5g of sample to be measured, placing the sample into a glass tube filled with the sample, degassing the sample, installing a liquid nitrogen bottle, fitting a nitrogen isothermal adsorption and desorption curve of the sample according to a Brunauer-Emmett-Teller method, fitting a pore size distribution curve of the sample according to the curve, and calculating the average pore size of the sample.
5. Test of specific discharge capacity at 0.2C or 5C: newware BTS4000;
clamping a CR2032 button battery by using plastic tweezers, placing the button battery in a constant temperature box at 25+/-0.5 , opening the software for testing the BTS4000 of the new technology, clicking a corresponding channel, selecting the "start" by a right button, and calculating the living timeCalculating the current of 0.2C multiplying power or 5C multiplying power according to the mass of the sexual substance, setting the working steps, wherein the working step sequence is 1 s-constant current charging-1 s-constant current discharging-circulation, the selected voltage interval is 2-4V, and 1C=126 mAh g -1 Specific discharge capacity data of 0.2C or 5C was obtained.
6. Heteroatom testing: perkinElmer Optima 8300 the amount of heteroatom (boron, phosphorus) doping tested was based on heteroatom-doped carbon.
0.5g of the sample is weighed and placed in a beaker containing 24mL of aqua regia, the aqua regia is prepared from 18mL of hydrochloric acid and 6mL of nitric acid, and the solution is heated and dissolved for 2h on a constant temperature heating plate at 200 . The sample in the polytetrafluoroethylene cup was allowed to cool to room temperature, the sample was filtered, the filtrate was fixed to volume to 50mL with ultrapure water after filtration, and finally the sample was tested with PerkinElmer Optima 8300.
The results obtained from the test are shown in table 1;
TABLE 1
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The XRD patterns, SEM patterns and first charge-discharge curves of the composite materials obtained in examples 1-3 at 0.2C magnification are shown in FIGS. 1-9, respectively;
FIG. 1 shows that the sample is pure Na 4 Fe 3( PO 4 ) 2 P 2 O 7 Materials, and no distinct hetero-phase peaks were observed; FIG. 2 shows that the precursor solution is spray dried to show secondary spheres with higher sphericity, primary particles are substantially smaller than 100nm, and the distribution is more concentrated; FIG. 3 shows that the composite material shows typical Na 4 Fe 3 (PO 4 ) 2 P 2 O 7 A charge-discharge curve; FIG. 4 shows that XRD of the composite material is not greatly changed compared with an undoped sample after the sample is doped with a certain amount of manganese element, and no obvious impurity peak exists; FIG. 5 showsThe precursor solution is subjected to spray drying treatment, and shows higher sphericity; FIG. 6 shows the charge-discharge curve and Na of Mn-doped composite material ratio 4 Fe 3 (PO 4 ) 2 P 2 O 7 The difference is not great; FIG. 7 shows that the sample was pure doped MgNa 4 Fe 3 (PO 4 ) 2 P 2 O 7 Materials, and no distinct hetero-phase peaks were observed; FIG. 8 shows that the precursor solution is spray dried to show secondary spheres with higher sphericity, primary particles substantially smaller than 100nm, and more concentrated distribution, with less impact of magnesium doping on primary particle size; FIG. 9 shows charge-discharge curves and Na of Mg-doped composite ratios 4 Fe 3 (PO 4 ) 2 P 2 O 7 The comparison is not very different.
As can be seen from table 1, when the technical scheme of the invention is adopted, the obtained product has excellent comprehensive performance, wherein D50 is below 12.0 m and P is below 7.28, and the obtained composite material has smaller particle size and uniform distribution; the carbon content is between 1.35 and 1.82, which accords with the requirement of mesoporous materials; the compaction density of the powder is between 1.90 and 2.14, which indicates that more composite materials can be filled in the unit volume of the pole piece, and the specific energy of the battery cell is further improved; the pore size is above 25.6nm, which indicates that the composite material has a large amount of mesopores, so that the material has a larger specific surface area, and the abundant pore structure is helpful for the contact of the electrode and the electrolyte and promotes the capacity release; the specific discharge capacity of 0.2C is more than 102.4mAh/g, and the specific discharge capacity of 5C is more than 96.3mAh/g, which shows that the problem of low electron conductivity of the polyanion cathode material is improved, the carbon coating effect based on the self-assembly between supermolecules is better, and the high capacity is still maintained during charge and discharge under high multiplying power;
as can be seen from examples 1, 4 to 6 and comparative example 9, the addition amount of the boron source has an influence on the performance of the product, and when the addition amount of the boron source is increased within a certain range, the discharge specific capacity of the obtained product at 0.2C and 5C is increased, and the pore diameter is also increased; however, when the added amount of the boron source is further increased, the specific discharge capacity of the obtained product at 0.2C and 5C is obviously reduced, the aperture is also reduced, and the D50 is increased; when the addition amount of the boron source in comparative example 9 was too high, the 0.2C discharge specific capacity and the 5C discharge specific capacity were decreased by 10.79% and 5.52% respectively, as compared with example 1;
as can be seen from examples 1, 7 to 9 and comparative example 10, the addition amount of the phosphine source has an influence on the performance of the product, and when the addition amount of the phosphine source is increased within a certain range, the discharge specific capacity of the obtained product at 0.2C and 5C shows an upward trend, and the pore diameter also shows an upward trend; however, when the addition amount of the phosphine source is further increased, the obtained product still shows a trend of increasing pore diameter, but the specific discharge capacity of the product at 0.2C and 5C is obviously reduced; when the addition amount of the phosphine source in comparative example 10 was too high, the specific discharge capacity at 0.2C and the specific discharge capacity at 5C were decreased by 9.53% and 11.14%, respectively, as compared with example 1;
as can be seen from examples 1, 10-13 and comparative example 11, the addition amount of the block copolymer has an influence on the properties of the product, and when the addition amount of the block copolymer is increased within a certain range, the discharge specific capacity of the obtained product at 0.2C and 5C is increased, and the pore diameter is also increased; however, when the addition amount of the block copolymer is further increased, the obtained product shows a trend of increasing pore diameter, but the discharge capacity of the product at 0.2C and the discharge specific capacity at 5C are significantly reduced; when the addition amount of the block copolymer in comparative example 11 was too high, the specific discharge capacity at 0.2C and the specific discharge capacity at 5C were decreased by 10.70% and 20.48% respectively, as compared with example 1;
it can be seen from examples 1 and examples 14 to 16, examples 1 and 17 to 19, and examples 1 and 20 that the kinds of boron source, phosphine source and block copolymer also have an influence on the properties of the products, and the combination effect obtained is more excellent when the types of components in the present invention are further selected;
as can be seen from example 1 and comparative example 1, when the block copolymer was not added, the D50 of the obtained product was significantly increased, the particle size distribution coefficient was significantly increased, D50 was increased by 371.43%, the particle size distribution coefficient was increased by 350.41%, the pore size was also significantly reduced by 25.84%, the specific discharge capacities of 0.2C and 5C were also significantly reduced by 9.35% and 16.95%, respectively;
as can be seen from examples 1 and comparative example 2, when there is no sanding step, the overall properties of the obtained product are also significantly deteriorated, the D50 of the obtained product is significantly increased, the particle size distribution coefficient is significantly increased, D50 is increased by 666.67%, the increase amplitude of the particle size distribution coefficient is 356.20%, the pore size is also significantly reduced, the decrease amplitude is 34.76%, the specific discharge capacities of 0.2C and 5C are also significantly reduced, in particular, the specific discharge capacity of 5C is reduced by 17.81% compared with example 1;
it can be seen from example 1 and comparative examples 3 to 8 that the parameters of the sintering process of the present invention are also very critical, when the parameters of the sintering process are outside the scope of the present invention; the specific discharge capacities of 0.2C and 5C of the obtained products were significantly reduced, and the reduction in specific discharge capacities of 0.2C and 5C in comparative examples 3 to 8 was between 10.25 and 63.85% and between 9.62 and 85.43%, respectively, as compared with example 1.
Finally, it should be noted that the above-mentioned embodiments illustrate rather than limit the scope of the invention, and that those skilled in the art will understand that changes can be made to the technical solutions of the invention or equivalents thereof without departing from the spirit and scope of the technical solutions of the invention.

Claims (10)

1. Heteroatom doped carbon coated Na 4 M x Fe 3-x (PO 4 ) 2 P 2 O 7 The preparation method of the composite material is characterized by comprising the following steps:
preparing a template solution: dissolving a boron source, a phosphorus source and a block copolymer in deionized water to obtain a template solution;
preparation of suspension slurry: dissolving porous ferric phosphate in deionized water, stirring and dispersing to obtain suspension slurry;
preparing a precursor solution: mixing a template solution and suspension slurry, and then adding a sodium source, a sodium phosphorus source, a carbon source and an M source to obtain a precursor solution;
preparing a precursor: sanding and drying the precursor solution to obtain a precursor;
preparation of the composite material: sintering the precursor twice, crushing and sieving after each sintering to obtain a composite material;
in the two-time sintering, the temperature rising rate of the first sintering is 1-5 /min, the sintering temperature is 280-400 , the sintering time is 4-8h, the temperature rising rate of the second sintering is 1-5 /min, the sintering temperature is 500-600 , and the sintering time is 8-15h;
in the precursor solution, the sum of the mass of a sodium source, a sodium phosphorus source, an M source, a carbon source and porous ferric phosphate is A; the mass of the boron source is 0.1-5% of the mass of A, the mass of the phosphorus source is 0.1-5% of the mass of A, and the mass of the block copolymer is 0.1-8% of the mass of A.
2. The method according to claim 1, wherein the block copolymer is at least one selected from the group consisting of polyoxyethylene fatty acid esters, polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymers, and sorbitan fatty acid ester compounds.
3. The method of claim 1, wherein the M source is a magnesium source or a manganese source.
4. A method of preparing according to claim 3, wherein at least one of the following (a) - (g):
(a) The boron source is at least one selected from methyl boric acid, boric acid and boron phosphate;
(b) The phosphorus source is at least one selected from hydroxyethylidene diphosphate, phosphoryl glycolic acid and phosphoryl butane tricarboxylic acid;
(c) The sodium source is at least one of sodium carbonate, sodium bicarbonate and sodium oxalate;
(d) The sodium-phosphorus source is at least one selected from sodium dihydrogen phosphate, sodium phosphate and sodium hexametaphosphate;
(e) The manganese source is at least one of manganese oxalate and manganese carbonate;
(f) The magnesium source is at least one of magnesium oxide and magnesium citrate;
(g) The carbon source is at least one selected from citric acid and glucose.
5. The method according to claim 1, wherein the mass concentration of the boron source in the template solution is 1 to 100g/L, the mass concentration of the phosphorus source is 1 to 100g/L, and the mass concentration of the block copolymer is 1 to 200g/L;
and/or, in the suspension slurry, the mass-volume ratio of the porous ferric phosphate to the deionized water is 100-500g/L;
and/or the volume ratio of the template solution to the suspension slurry is (0.1-1): 1.
6. the method according to claim 1, wherein the mass sum of the sodium source, the sodium phosphorus source, the M source, the carbon source and the porous iron phosphate in the precursor solution is a;
the mass of the carbon source is 5-8% of the mass of A.
7. The method of claim 1, wherein the molar ratio of porous iron phosphate to elemental sodium in the precursor solution is porous iron phosphate: sodium element= (2.95-3): 4.
8. the method according to claim 1, wherein the rotational speed of the sand mill is 1000-3000rpm and the sand milling time is 0.5-1h.
9. Heteroatom doped carbon coated Na 4 M x Fe 3-x (PO 4 ) 2 P 2 O 7 A composite material characterized in that the heteroatom doped carbon is coated with Na 4 M x Fe 3-x (PO 4 ) 2 P 2 O 7 The composite material is prepared by the preparation method according to any one of claims 1 to 8;
the hetero atom is doped withImpurity carbon coated Na 4 M x Fe 3-x (PO 4 ) 2 P 2 O 7 The carbon content in the composite material is 0.2-6%;
wherein x is 0.ltoreq.x <3; m is selected from one or more of Mg, mn, zn, cu, al, ti, mo, V, zr, mn, cr, ni, co element and rare earth element compound;
in the heteroatom doped carbon, the heteroatom is boron and phosphorus, and the sum of the mass percentages of the boron and the phosphorus is 0.2-5% based on the heteroatom doped carbon.
10. A positive electrode material for a sodium ion battery, comprising the heteroatom doped carbon coated Na of claim 9 4 M x Fe 3-x (PO 4 ) 2 P 2 O 7 A composite material.
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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105355879A (en) * 2015-11-11 2016-02-24 兰州理工大学 Composite carbon coated metal oxide and preparation method thereof
CN110061233A (en) * 2019-05-22 2019-07-26 中南大学 A kind of carbon-coated phosphoric acid ferric sodium pyrophosphate@mesoporous carbon composite material of fluorine doped and its preparation and the application in sodium-ion battery
CN115411252A (en) * 2022-09-26 2022-11-29 中南大学 Carbon quantum dot and phosphate magnesium iron pyrophosphate sodium composite material coated by derivative of carbon quantum dot, and preparation method and application of composite material
CN115888785A (en) * 2022-10-25 2023-04-04 中国科学院合肥物质科学研究院 Heteroatom doped carbon-coated metal catalyst and preparation method thereof
CN115974033A (en) * 2022-12-21 2023-04-18 华南理工大学 Nitrogen-doped mesoporous carbon-coated iron sodium phosphate pyrophosphate composite material and preparation method thereof
CN116154129A (en) * 2023-02-07 2023-05-23 深圳市德方创域新能源科技有限公司 Negative electrode material, preparation method thereof, negative electrode plate and secondary battery

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105355879A (en) * 2015-11-11 2016-02-24 兰州理工大学 Composite carbon coated metal oxide and preparation method thereof
CN110061233A (en) * 2019-05-22 2019-07-26 中南大学 A kind of carbon-coated phosphoric acid ferric sodium pyrophosphate@mesoporous carbon composite material of fluorine doped and its preparation and the application in sodium-ion battery
CN115411252A (en) * 2022-09-26 2022-11-29 中南大学 Carbon quantum dot and phosphate magnesium iron pyrophosphate sodium composite material coated by derivative of carbon quantum dot, and preparation method and application of composite material
CN115888785A (en) * 2022-10-25 2023-04-04 中国科学院合肥物质科学研究院 Heteroatom doped carbon-coated metal catalyst and preparation method thereof
CN115974033A (en) * 2022-12-21 2023-04-18 华南理工大学 Nitrogen-doped mesoporous carbon-coated iron sodium phosphate pyrophosphate composite material and preparation method thereof
CN116154129A (en) * 2023-02-07 2023-05-23 深圳市德方创域新能源科技有限公司 Negative electrode material, preparation method thereof, negative electrode plate and secondary battery

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Boron and Phosphorus Dual-Doped Carbon Coating Improves Electrochemical Performances of LiFe0.8Mn0.2PO4 Cathode Materials;Kuanyou Tuo;《ACS Applied Energy Materials》;20210805;第8003-8015页 *

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