CN110299528B - Fluorinated phosphate ferric sodium pyrophosphate @ C @ RGO composite material, preparation method thereof and application thereof in sodium ion battery - Google Patents
Fluorinated phosphate ferric sodium pyrophosphate @ C @ RGO composite material, preparation method thereof and application thereof in sodium ion battery Download PDFInfo
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- H01M10/00—Secondary cells; Manufacture thereof
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- H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
- H01M4/136—Electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy
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- H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
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- H01M4/00—Electrodes
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- H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
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Abstract
The invention belongs to the field of electrode materials of sodium-ion batteries, and particularly discloses a fluorinated phosphate ferric sodium pyrophosphate @ C @ RGO composite material which comprises reduced graphene oxide and active particles compounded on the surface of the reduced graphene oxide in situ; the active particles are carbon-coated fluorinated phosphate ferric sodium pyrophosphate; the chemical formula of the fluorinated phosphoric acid ferric sodium pyrophosphate is Na4Fe3PO4P2O7F3. The invention also provides a preparation method and application of the material. The material has the characteristics of high theoretical quantity, high voltage, stable circulation and low raw material cost, and has good industrial prospect. The invention finds that the brand new active ingredients are matched with the innovative double-carbon in-situ composite morphology, so that the technical problems of phase transformation, poor stability, poor electrical performance and the like of the conventional iron-based cathode material are effectively solved, and the voltage, the capacity, the multiplying power and the cycling stability of the material are effectively improved.
Description
Technical Field
The invention relates to the field of sodium ion battery materials, in particular to a positive electrode active material of a sodium ion battery.
Background
The lithium ion battery has the advantages of high energy density, high stability, long service life and the like, and has great success in the last two decades, but the lithium resource has low reserve in the earth crust and cannot become the key of large-scale pure energy. Therefore, the research of the sodium ion battery becomes a hot spot, and the sodium ion battery is considered to be an ideal large-scale electricity storage application technology due to abundant sodium resource and environmental friendliness.
The sodium ion battery and the lithium ion battery are only different from each other in intercalation ion on the surface, but belong to different fields, and have quite different requirements on electrode materials. For example, sodium ions are about 55% larger than lithium ions, so that the intercalation and diffusion of sodium ions in the same structural material are often relatively difficult, and the structural change of the intercalated material is larger, so that the specific capacity, the dynamic performance, the cycle performance and the like of the electrode material are correspondingly deteriorated. Compared with the field of lithium ion batteries, the field of sodium ion batteries has a plurality of technical problems to be overcome, and the technical maturity of the sodium ion batteries is seriously lagged behind that of the lithium ion batteries.
During the past decades, researchers have conducted extensive research into positive electrode materials for sodium ion batteries. In the existing positive electrode material system, researchers pursue high capacity, long cycle, high stability, and demand for a wide range of raw material sources.
The iron-based system material is regarded as the sodium-electricity positive electrode material system with the most commercial prospect due to the characteristics of easily available raw materials and wide sources. However, the problem of phase transformation of the iron phosphate based material affects its practical application.
Disclosure of Invention
Aiming at the defect problems of the existing positive electrode material of the sodium-ion battery, the first object of the invention is to provide a fluorinated phosphate ferric pyrophosphate sodium @ C @ RGO composite material (also called Na in the invention) with excellent electrochemical performance4Fe3PO4P2O7F3@ C @ RGO composite material, or composite material and positive electrode active materialMaterial).
The second purpose of the invention is to provide a method for preparing the composite material, which has good repeatability, simple operation, environmental protection and low cost, and has industrial application prospect.
The third purpose of the invention is to provide an application of the composite material, aiming at improving the performances of the sodium ion battery such as voltage, charge-discharge specific capacity, energy density, rate capability, cycling stability and the like.
The fourth purpose of the invention is to provide a positive electrode material of a sodium-ion battery, which comprises the composite material.
The fifth purpose of the invention is to provide a positive electrode of a sodium-ion battery containing the positive electrode material.
A sixth object of the present invention is to provide a sodium ion battery including the positive electrode.
A fluorinated phosphate ferric sodium pyrophosphate @ C @ RGO composite material comprises reduced graphene oxide and active particles compounded on the surface of the reduced graphene oxide in situ; the active particles are carbon-coated fluorinated phosphate ferric sodium pyrophosphate; the chemical formula of the fluorinated phosphoric acid ferric sodium pyrophosphate is Na4Fe3PO4P2O7F3。
The invention provides a new chemical formula of Na4Fe3PO4P2O7F3And found that it can exhibit excellent electrical properties as an active material for sodium ion batteries. Furthermore, the invention also innovatively provides a method for preparing the Na4Fe3PO4P2O7F3And forming active particles through in-situ carbon coating, and further carrying out in-situ loading on the double-carbon in-situ composite morphology on the reduced graphene three-dimensional network. The invention finds that the brand new active ingredients are matched with the innovative double-carbon in-situ composite morphology, so that the technical problems of phase transformation, poor stability, poor electrical performance and the like of the conventional iron-based cathode material are effectively solved, and the voltage, the capacity, the multiplying power and the cycling stability of the material are effectively improved.
Hair brushComposite material of the formula, Na4Fe3PO4P2O7F3Through even amorphous carbon coating, the thermal stability and the chemical stability of the fluorinated phosphate ferric sodium pyrophosphate are improved, the problem of phase stability is effectively solved, and the capacity exertion, the rate capability and the cycle performance of the fluorinated phosphate ferric sodium pyrophosphate are favorably improved. Meanwhile, the carbon-coated fluorinated phosphate ferric sodium pyrophosphate particles uniformly grow on the surface of the RGO, so that the uniform dispersion of the active particles is improved, the performance of the active particles is fully exerted, the stability of the composite material is improved, and the circulation stability of the composite material is synergistically improved.
Preferably, the particle size of the fluorinated phosphate ferric sodium pyrophosphate @ C @ RGO composite material is 100-1000 nm; the specific surface area is preferably greater than or equal to 500m2/g。
Preferably, RGO is 5-15 wt.% of fluorinated phosphate ferric sodium pyrophosphate; further preferably 5-10 wt.%; the balance being said active particles.
The other purpose of the invention is to provide a preparation method of the brand new composite material, but in the early development of the technology, the existing conventional solid phase or liquid phase mixing and roasting process is tried to be adopted, and the problems of oxidative coagulation of iron ions, unstable synthesized substance phase and the like are easily found, so that the performance of the prepared material is not ideal; in order to overcome the technical problem, the inventor of the invention finds that a composite material with stable crystalline phase and structure and excellent electrical properties can be unexpectedly obtained by controlling the pH of the preparation system and matching with the heat treatment temperature.
The technical scheme of the application is as follows: the preparation method of the fluorinated phosphate ferric sodium pyrophosphate @ C @ RGO composite material comprises the steps of dispersing a phosphorus source, a sodium source, an iron source, a fluorine source, RGO and a complexing agent in a mixed solution in water, adjusting the pH value of the mixed solution to 3-4, volatilizing and drying to obtain a precursor, placing the precursor in a protective atmosphere, and carrying out heat treatment at the temperature of 500-650 ℃ to obtain the composite material.
According to the preparation method, the composite material with the in-situ double-carbon composite morphology and high purity of the crystal phase of the sodium ferric pyrophosphate fluophosphate can be obtained by innovatively and accurately regulating the pH value of the raw material solution and regulating and controlling the heat treatment temperature. The preparation method is simple, and the prepared composite material has excellent electrical properties.
Preferably, the phosphorus source comprises at least one of diammonium hydrogen phosphate, ammonium dihydrogen phosphate and phosphoric acid.
Preferably, the sodium source comprises at least one of sodium carbonate, sodium bicarbonate, sodium acetate, sodium oxalate, sodium citrate, and sodium fluoride. The sodium source is preferably anhydrous sodium carbonate or sodium acetate, most preferably anhydrous sodium carbonate.
Preferably, the iron source comprises at least one of ferrous acetate, ferric nitrate nonahydrate, ferric oxalate or iron powder. The most preferred iron source is ferric nitrate nonahydrate.
Preferably, the fluorine source includes at least one of sodium fluoride, ammonium fluoride and hydrogen fluoride.
Preferably, the phosphorus source, the sodium source, the iron source, the fluorine source are as follows: iron: phosphorus: the molar ratio of fluorine elements is 3.9-4.1: 2.9-3.1: 2.9-3.1: 2.9-3.1, preferably mixing according to the stoichiometric ratio (sodium: iron: phosphorus: fluorine is 4: 3: 3: 3).
Preferably, the complexing agent comprises at least one of glucose, ascorbic acid, oxalic acid and citric acid.
Preferably, the mol ratio of the complexing agent to iron in the iron source is 1-5: 1. more preferably 2 to 3: 1.
preferably, the addition amount of RGO is 5-15% of theoretically synthesized sodium iron pyrophosphate fluorophosphate; more preferably 5 to 10%.
In the invention, a phosphorus source, a sodium source, an iron source, a fluorine source, RGO and a complexing agent are dispersed in water to form a mixed solution, and the pH of the mixed solution is innovatively and previously regulated to 3-4. Researches find that the method is helpful for matching with subsequent heat treatment to obtain the material with high crystalline phase purity and the double-carbon in-situ composite morphology. Researches show that the pH value is regulated, or the regulated pH value is larger than the upper limit or lower than the lower limit, the performance of the composite material is influenced, and even the target product cannot be successfully prepared.
In the method, the pH can be regulated by adopting the existing method, and preferably, the pH is regulated by using sulfurous acid. Researches find that the sulfurous acid is adopted for pH regulation and control, which is helpful for further improving the electrical property of the prepared composite material.
In the invention, the solution with the regulated and controlled pH value is volatilized, and then is dried to obtain the precursor. The drying can be carried out by adopting the conventional method, for example, vacuum drying is adopted, and the vacuum drying temperature is 80-120 ℃, and most preferably 80-100 ℃.
According to the invention, under the innovative pH regulation and control, the heat treatment temperature is further controlled, so that the composite material with excellent electrical properties can be prepared.
Researches find that the temperature of the heat treatment needs to be controlled between 500 and 650 ℃, and the temperature is higher than the upper limit or lower than the lower limit, which is not beneficial to obtaining the composite material with high crystalline phase purity, stability and excellent electrical properties.
Preferably, the temperature of the heat treatment is 500 to 650 ℃, and more preferably 500 to 550 ℃.
Preferably, the heat treatment process is performed under a protective gas, such as nitrogen or an inert gas.
Preferably, the heat treatment time is 8-16 h.
The method is preferably Na4Fe3PO4P2O7F3The preparation method of the @ C @ RGO composite material comprises the following steps:
step (1): weighing ferric nitrate nonahydrate, ammonium dihydrogen phosphate, anhydrous sodium carbonate, ammonium fluoride, ascorbic acid and RGO according to a stoichiometric ratio, dissolving the weighed materials in deionized water, adjusting the pH value to 3-4 by using sulfurous acid, stirring and then drying in vacuum;
step (2): taking out the obtained powder, sintering the powder for 8 to 12 hours in a tube furnace at the temperature of 500 to 650 ℃ under inert atmosphere, and finally carrying out Na4Fe3PO4P2O7F3@ C @ RGO composite.
The invention also provides Na4Fe3PO4P2O7F3The application of the @ C @ RGO composite material is used as a positive active material of a sodium-ion battery.
Preferably, said Na is4Fe3PO4P2O7F3And mixing the @ C @ RGO composite material, a binder and a conductive agent to prepare slurry, coating the slurry on a current collector, and curing to obtain the sodium-ion battery anode.
In a further preferred application, the positive electrode is assembled into a sodium ion battery.
The invention also provides a sodium-ion battery positive electrode material which comprises the fluorinated zirconium manganese phosphate sodium/carbon composite material (sodium-ion battery positive electrode active material).
Preferably, the positive electrode material further comprises a binder and a conductive agent. The binder may be any material having a binding effect available to those skilled in the art of sodium batteries, such as PVDF. The conductive agent can be any material having enhanced conductive function available to those skilled in the art of sodium electricity, such as conductive carbon black.
In the positive electrode material, the positive electrode active material, the binder and the conductive agent can be adjusted based on the use requirement in the field of sodium electricity.
The invention also provides a positive electrode of the sodium-ion battery, which comprises a current collector and the positive electrode material of the sodium-ion battery compounded on the surface of the current collector.
The current collector may be any positive electrode carrier material known in the sodium electricity industry, such as aluminum foil.
The invention also includes adding Na4Fe3PO4P2O7F3The @ C @ RGO composite material is used for preparing the positive electrode of the sodium-ion battery, and the electrochemical performance of the positive electrode is tested.
For example, mixing the Na4Fe3PO4P2O7F3The @ C @ RGO composite material is mixed with a conductive agent and a binder, and then coated on an aluminum foil to prepare the positive electrode of the sodium-ion battery. The conductive agent and the binder can adopt the technical fieldMaterials well known to those skilled in the art. The method for assembling and preparing the positive electrode material of the sodium-ion battery can also refer to the existing method.
For example, Na produced by the present invention4Fe3PO4P2O7F3The @ C @ RGO composite material is prepared by grinding conductive carbon black and PVDF binder according to the mass ratio of 8:1:1, fully mixing, adding NMP to form uniform slurry, coating the slurry on an aluminum foil to serve as a test electrode, taking metal sodium as a counter electrode, and taking 1M NaClO 4/100% PC as electrolyte.
The invention also provides a sodium ion battery, and the positive electrode of the sodium ion battery is used as the positive electrode.
The structure of the sodium ion battery can be referred to the structure known in the industry, and the main difference is that the positive electrode containing the innovative positive active material of the invention is adopted.
Has the advantages that:
1) the invention provides a new chemical formula of Na4Fe3PO4P2O7F3The novel compound has excellent electrical properties in sodium electrolysis.
2) The invention also innovatively provides the Na4Fe3PO4P2O7F3And forming active particles through in-situ carbon coating, and further carrying out in-situ loading on the double-carbon in-situ composite morphology on the reduced graphene three-dimensional network. Through discovery, the composite material with the double-carbon in-situ composite morphology has good stability of crystalline phase, heat and the like, and has excellent electrical properties.
3) The composite material with the brand-new active ingredient and the brand-new double-carbon in-situ composite morphology has good conductivity, thermal stability and chemical stability, and has excellent capacity, rate capability and cycle performance.
4) The invention also discovers that the pH value of the system is innovatively controlled to be 3-4, and the research shows that the composite material with high crystalline phase purity and the double-carbon in-situ composite morphology can be prepared by matching the heat treatment temperature, and the material with excellent electrical property can be prepared.
5) Na produced by the present invention4Fe3PO4P2O7F3The @ C @ RGO composite material has excellent performance, simple and easy synthesis method, easy industrialization, environmental protection, rich raw material resources, low cost and wide industrial application prospect.
Drawings
FIG. 1 shows Na obtained in example 14Fe3PO4P2O7F3XRD pattern of @ C @ RGO;
FIG. 2 shows Na obtained in example 14Fe3PO4P2O7F3SEM picture of @ C @ RGO.
Detailed Description
The following examples are intended to illustrate the invention in further detail; and the scope of the claims of the present invention is not limited by the examples.
Example 1
Firstly, 0.015mol of ferric nitrate nonahydrate, 0.015mol of ammonium dihydrogen phosphate, 0.02mol of anhydrous sodium carbonate, 0.015mol of ammonium fluoride and 0.03mol (mol ratio to iron is 2: 1) of ascorbic acid are weighed, 0.15g of RGO (equivalent to 5% of theoretical active substance) is dissolved in deionized water, and the pH is adjusted to 3-4 by utilizing sulfurous acid. Evaporating water at 80 deg.C, vacuum drying at 100 deg.C for 4 hr to obtain powder, placing into a porcelain boat, and sintering at 550 deg.C for 12 hr under argon atmosphere. To obtain Na4Fe3PO4P2O7F3@ C @ RGO. The XRD pattern is shown in figure 1, and the material with high crystalline phase purity is obtained. SEM is shown in figure 2.
The sodium ion battery composite positive electrode material prepared by the embodiment and a sodium sheet are assembled into a button battery, and the voltage of the material can reach 3.6V; under the multiplying power of 1C, the discharge specific capacity of 100 cycles reaches 95mAh/g, and the capacity retention rate reaches over 90 percent.
Example 2
Firstly, 0.015mol of ferric nitrate nonahydrate, 0.015mol of ammonium dihydrogen phosphate, 0.02mol of anhydrous sodium carbonate, 0.015mol of ammonium fluoride and 0.045mol (mol ratio to iron is 3: 1) ofAscorbic acid, 0.15g RGO is weighed and dissolved in deionized water, and the pH is adjusted to 3-4 by using sulfurous acid. Evaporating water at 80 deg.C, vacuum drying at 100 deg.C for 4 hr to obtain powder, placing into a porcelain boat, and sintering at 550 deg.C for 12 hr under argon atmosphere. To obtain Na4Fe3PO4P2O7F3@C@RGO。
The sodium ion battery composite positive electrode material prepared by the embodiment and a sodium sheet are assembled into a button battery, the discharge specific capacity of 100 cycles reaches 92mAh/g under the 1C multiplying power, and the capacity retention rate reaches over 90 percent.
Example 3
Firstly, 0.015mol of ferric nitrate nonahydrate, 0.015mol of ammonium dihydrogen phosphate, 0.02mol of anhydrous sodium carbonate, 0.015mol of ammonium fluoride and 0.03mol (mol ratio to iron is 2: 1) of ascorbic acid are taken, then 0.15g of RGO is weighed and dissolved in deionized water, and the pH value is adjusted to 3-4 by utilizing sulfurous acid. Evaporating water at 80 deg.C, vacuum drying at 100 deg.C for 4 hr to obtain powder, placing into a porcelain boat, and sintering at 650 deg.C for 16 hr under argon atmosphere. To obtain Na4Fe3PO4P2O7F3@C@RGO。
The sodium ion battery composite positive electrode material prepared by the embodiment and a sodium sheet are assembled into a button battery, the discharge specific capacity of 100 cycles reaches 87mAh/g under the 1C multiplying power, and the capacity retention rate reaches over 90 percent.
Example 4
Firstly, 0.015mol of ferric nitrate nonahydrate, 0.015mol of ammonium dihydrogen phosphate, 0.02mol of anhydrous sodium carbonate, 0.015mol of ammonium fluoride and 0.03mol (mol ratio to iron is 2: 1) of ascorbic acid are taken, then a certain amount of 0.15g of RGO is weighed and dissolved in deionized water, and the pH value is adjusted to 3-4 by utilizing sulfurous acid. Evaporating water at 80 deg.C, vacuum drying at 100 deg.C for 4 hr to obtain powder, placing into a porcelain boat, and sintering at 500 deg.C for 10 hr under argon atmosphere. To obtain Na4Fe3PO4P2O7F3@C@RGO。
The sodium ion battery composite positive electrode material prepared by the embodiment and a sodium sheet are assembled into a button battery, the discharge specific capacity of 100 cycles reaches 90mAh/g under the 1C multiplying power, and the capacity retention rate reaches over 90 percent.
Example 5
Firstly, 0.015mol of ferric nitrate nonahydrate, 0.015mol of ammonium dihydrogen phosphate, 0.02mol of anhydrous sodium carbonate, 0.015mol of hydrogen fluoride and 0.03mol (mol ratio to iron is 2: 1) of ascorbic acid are taken, then 0.15g of RGO is weighed and dissolved in deionized water, and the pH value is adjusted to 3-4 by utilizing sulfurous acid. Evaporating water at 80 deg.C, vacuum drying at 100 deg.C for 4 hr to obtain powder, placing into a porcelain boat, and sintering at 550 deg.C for 12 hr under argon atmosphere. To obtain Na4Fe3PO4P2O7F3@C@RGO。
The sodium ion battery composite positive electrode material prepared by the embodiment and a sodium sheet are assembled into a button battery, the discharge specific capacity of 100 cycles reaches 90mAh/g under the 1C multiplying power, and the capacity retention rate reaches over 90 percent.
Example 6
Firstly, 0.015mol of ferric nitrate nonahydrate, 0.015mol of ammonium dihydrogen phosphate, 0.02mol of anhydrous sodium carbonate, 0.015mol of ammonium fluoride and 0.03mol (mol ratio to iron is 2: 1) of ascorbic acid are taken, then 0.15g of RGO is weighed and dissolved in deionized water, and the pH value is adjusted to 3-4 by utilizing sulfurous acid. Evaporating water at 80 ℃, vacuum drying at 120 ℃ for 4h to obtain powder, putting the powder into a porcelain boat, and sintering at 550 ℃ for 12h in the atmosphere of argon. To obtain Na4Fe3PO4P2O7F3@C@RGO。
The sodium ion battery composite positive electrode material prepared by the embodiment and a sodium sheet are assembled into a button battery, the discharge specific capacity of 100 cycles reaches 87mAh/g under the 1C multiplying power, and the capacity retention rate reaches over 90 percent.
Example 7
Firstly, 0.015mol of ferric nitrate nonahydrate, 0.015mol of ammonium dihydrogen phosphate, 0.02mol of anhydrous sodium carbonate, 0.015mol of ammonium fluoride and 0.03mol (mol ratio to iron is 2: 1) of ascorbic acid are taken, then 0.3g of gRGO is weighed and dissolved in deionized water, and the pH value is adjusted to 3-4 by utilizing sulfurous acid. Evaporating water at 80 ℃, vacuum-drying at 80 ℃ for 3h to obtain powder, putting the powder into a porcelain boat, and sintering at 550 ℃ for 12h in the atmosphere of argon. To obtain Na4Fe3PO4P2O7F3@C@RGO。
The sodium ion battery composite positive electrode material prepared by the embodiment and a sodium sheet are assembled into a button battery, the discharge specific capacity of 100 cycles reaches 91mAh/g under the 1C multiplying power, and the capacity retention rate reaches over 90 percent.
Example 8
Firstly, 0.015mol of ferric nitrate nonahydrate, 0.015mol of ammonium dihydrogen phosphate, 0.02mol of anhydrous sodium carbonate, 0.015mol of ammonium fluoride and 0.075mol (mol ratio to iron is 5: 1) of ascorbic acid are weighed and then 0.15g of RGO is weighed, dissolved in deionized water, and the pH value is adjusted to 3-4 by utilizing sulfurous acid. Evaporating water at 80 deg.C, vacuum drying at 100 deg.C for 4 hr to obtain powder, placing into a porcelain boat, and sintering at 550 deg.C for 12 hr under argon atmosphere. To obtain Na4Fe3PO4P2O7F3@C@RGO。
The sodium ion battery composite positive electrode material prepared by the embodiment and a sodium sheet are assembled into a button battery, the discharge specific capacity of 100 cycles reaches 89.3mAh/g under the 1C multiplying power, and the capacity retention rate reaches over 90 percent. Indicating that too much complexing agent does not work as well.
Comparative example 1
Compared with example 1, the only difference is that no RGO is added, specifically:
firstly, 0.015mol of ferric nitrate nonahydrate, 0.015mol of ammonium dihydrogen phosphate, 0.02mol of anhydrous sodium carbonate, 0.015mol of ammonium fluoride and 0.03mol (mol ratio to iron is 2: 1) of ascorbic acid are taken, RGO is not added, the mixture is dissolved in deionized water, and the pH value is adjusted to 3-4 by utilizing sulfurous acid. Evaporating water at 80 deg.C, vacuum drying at 100 deg.C for 4 hr to obtain powder, placing into a porcelain boat, and sintering at 550 deg.C for 12 hr under argon atmosphere. To obtain Na4Fe3PO4P2O7F3@ C. The existence of impure phase is determined, the sodium ion battery composite positive electrode material prepared by the embodiment and a sodium sheet are assembled into a button cell, and the discharge specific capacity of 100 cycles reaches 75mAh/g under the 1C multiplying power. The cycle performance of the material is obviously reduced.
Comparative example 2
Compared with example 1, the difference is only that the pH is not regulated, specifically:
firstly, 0.015mol of ferric nitrate nonahydrate, 0.015mol of ammonium dihydrogen phosphate, 0.02mol of anhydrous sodium carbonate, 0.015mol of ammonium fluoride and 0.03mol (mol ratio to iron is 2: 1) of ascorbic acid are taken, then a certain amount of RGO is weighed and dissolved in deionized water, and the substantial pH value of the system is 6-7. Evaporating water at 80 deg.C, vacuum drying at 100 deg.C for 4 hr to obtain powder, placing into a porcelain boat, and sintering at 550 deg.C for 12 hr under argon atmosphere. The product was determined to have a large amount of heterogeneous phase. The sodium ion battery composite positive electrode material prepared by the embodiment and a sodium sheet are assembled into a button battery, the discharge specific capacity of 100 cycles reaches 45mAh/g under the 1C multiplying power, and the capacity retention rate reaches over 90 percent. The cycle performance is significantly reduced.
Comparative example 3
Compared with the example 1, the only difference is that no complexing agent is added, specifically as follows:
firstly, 0.015mol of ferric nitrate nonahydrate, 0.015mol of ammonium dihydrogen phosphate, 0.02mol of anhydrous sodium carbonate, 0.015mol of ammonium fluoride and 0mol (mol ratio of the ammonium fluoride to the iron is 2: 1) of ascorbic acid are taken, then a certain amount of RGO is weighed and dissolved in deionized water, and the pH value is adjusted to 3-4 by utilizing sulfurous acid. The precursor could not be obtained by evaporating water at 80 ℃.
Comparative example 4
The only difference compared with example 1 is that the calcination temperature is outside the scope of the invention, which is specified as follows:
firstly, 0.015mol of ferric nitrate nonahydrate, 0.015mol of ammonium dihydrogen phosphate, 0.02mol of anhydrous sodium carbonate, 0.015mol of ammonium fluoride and 0.03mol (mol ratio to iron is 2: 1) of ascorbic acid are taken, then a certain amount of RGO is weighed and dissolved in deionized water, and the pH value is adjusted to 3-4 by utilizing sulfurous acid. Evaporating water at 80 deg.C, vacuum drying at 100 deg.C for 4 hr to obtain powder, placing into a porcelain boat, and sintering at 850 deg.C for 12 hr under argon atmosphere. No corresponding material was obtained.
Comparative example 5
The active ingredients are not obtained, and the specific details are as follows:
firstly, 0.015mol of ferric nitrate nonahydrate, 0.015mol of ammonium dihydrogen phosphate, 0.02mol of anhydrous sodium carbonate, 0.015mol of ammonium fluoride and 0.03mol (mol ratio to iron is 2: 1) of ascorbic acid are taken, 0.15g of RGO is weighed and dissolved in deionized water, and the pH value is adjusted to 3-4 by utilizing sulfurous acid. Evaporating water at 80 deg.C, vacuum drying at 100 deg.C for 4 hr to obtain powder, placing into a porcelain boat, and calcining at 550 deg.C under argon atmosphereAnd (5) forming a knot 12 h. To obtain Na4Fe3PO4(P2O7)2@C@RGO。
The sodium ion battery composite positive electrode material prepared by the embodiment and the sodium sheet are assembled into the button cell, and the voltage is relatively low, namely 3.2V. Under the multiplying power of 1C, the discharge specific capacity of 100 cycles reaches 71.3 mAh/g.
Comparative example 6
The only difference compared with example 1 is that the calcination temperature is outside the scope of the invention, which is specified as follows:
firstly, 0.015mol of ferric nitrate nonahydrate, 0.015mol of ammonium dihydrogen phosphate, 0.02mol of anhydrous sodium carbonate, 0.015mol of ammonium fluoride and 0.03mol (mol ratio to iron is 2: 1) of ascorbic acid are taken, 0.15g of RGO is weighed and dissolved in deionized water, and the pH value is adjusted to 3-4 by utilizing sulfurous acid. Evaporating water at 80 deg.C, vacuum drying at 100 deg.C for 4 hr to obtain powder, placing into a porcelain boat, and sintering at 400 deg.C for 12 hr under argon atmosphere. The material could not be obtained.
Claims (16)
1. A fluorinated phosphate ferric sodium pyrophosphate @ C @ RGO composite material is characterized in that: the graphene oxide/graphene oxide composite material comprises reduced graphene oxide and active particles compounded on the surface of the reduced graphene oxide in situ; the active particles are carbon-coated fluorinated phosphate ferric sodium pyrophosphate; the chemical formula of the fluorinated phosphoric acid ferric sodium pyrophosphate is Na4Fe3PO4P2O7F3。
2. The fluorinated phosphate ferric pyrophosphate sodium @ C @ RGO composite material of claim 1 wherein: the particle size of the fluorinated phosphate ferric sodium pyrophosphate @ C @ RGO composite material is 100-1000 nm; specific surface area of 500m or more2/g。
3. The fluorinated phosphate pyrophosphate iron sodium @ C @ RGO composite material according to claim 1 or 2, wherein: RGO is 5-15 wt.% of fluorinated phosphate ferric sodium pyrophosphate, and the balance is the active particles.
4. A preparation method of the fluorinated phosphate pyrophosphate iron sodium @ C @ RGO composite material as claimed in any one of claims 1 to 3, characterized by comprising the following steps: dispersing a phosphorus source, a sodium source, an iron source, a fluorine source, RGO and a complexing agent in a mixed solution of water, adjusting the pH of the mixed solution to 3-4 by sulfurous acid, volatilizing and drying to obtain a precursor, and placing the precursor in a protective atmosphere and carrying out heat treatment at the temperature of 500-650 ℃ to obtain the composite material.
5. The method of claim 4, wherein: the phosphorus source comprises at least one of diammonium hydrogen phosphate, ammonium dihydrogen phosphate and phosphoric acid;
the sodium source comprises at least one of sodium carbonate, sodium bicarbonate, sodium acetate, sodium oxalate and sodium citrate;
the iron source comprises at least one of ferrous acetate, ferric nitrate, ferric oxalate and iron powder;
the fluorine source is at least one of sodium fluoride, ammonium fluoride and hydrogen fluoride;
phosphorus source, sodium source, iron source, fluorine source according to sodium: iron: phosphorus: the molar ratio of fluorine elements is 3.9-4.1: 2.9-3.1: 2.9-3.1: 2.9-3.1 mixing.
6. The method of claim 5, wherein: and mixing a phosphorus source, a sodium source, an iron source and a fluorine source according to the stoichiometric ratio.
7. The method of claim 5, wherein: the complexing agent comprises at least one of glucose, ascorbic acid, oxalic acid and citric acid.
8. The method of claim 7, wherein: the mol ratio of the complexing agent to iron in the iron source is 1-5: 1.
9. the method of claim 4, wherein: the addition amount of RGO is 5-15% of the theoretical weight of the synthesized fluorinated phosphate ferric sodium pyrophosphate.
10. The application of the fluorinated phosphate ferric sodium pyrophosphate @ C @ RGO composite material as described in any one of claims 1 to 3 or the fluorinated phosphate ferric sodium pyrophosphate @ C @ RGO composite material prepared by the preparation method as described in any one of claims 4 to 9 is characterized in that the fluorinated phosphate ferric sodium pyrophosphate @ C @ RGO composite material is used as a positive electrode active material of a sodium ion battery.
11. The application of claim 10, wherein the fluorinated phosphate ferric sodium pyrophosphate @ C @ RGO composite material is mixed with a binder and a conductive agent to form slurry, the slurry is coated on a current collector, and the slurry is cured to obtain the sodium-ion battery positive electrode.
12. The use of claim 10, wherein the positive electrode is assembled into a sodium ion battery.
13. A positive electrode material for a sodium ion battery, characterized by comprising the fluorinated phosphate pyrophosphate iron sodium @ C @ RGO composite material according to any one of claims 1 to 3.
14. The positive electrode material for sodium-ion batteries according to claim 13, further comprising a binder and a conductive agent.
15. A positive electrode of a sodium-ion battery, comprising a current collector and the positive electrode material of the sodium-ion battery according to claim 13 or 14 compounded on the surface of the current collector.
16. A sodium ion battery, characterized in that the positive electrode of the sodium ion battery according to claim 15 is a positive electrode.
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| CN111162256A (en) * | 2019-12-28 | 2020-05-15 | 上海电力大学 | Mixed polyanion type sodium ion battery positive electrode material and preparation thereof |
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| CN114057175B (en) * | 2021-11-11 | 2023-12-15 | 上海电力大学 | Fluorine ion doped modified ferric sodium pyrophosphate for sodium ion battery anode material, preparation method and application thereof |
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| CN114068938B (en) * | 2022-01-17 | 2022-04-15 | 中南大学 | Sodium vanadium fluorophosphate coated sodium iron pyrophosphate phosphate composite material and preparation method and application thereof |
| CN114883547B (en) * | 2022-05-20 | 2024-03-26 | 湖南钠邦新能源有限公司 | Na (Na) 2 Fe x M y PO 4 F@MF z @C composite material, preparation method thereof and application thereof in sodium ion battery |
| CN114975927B (en) * | 2022-05-26 | 2024-02-20 | 南京邮电大学 | Graphene oxide-sodium iron phosphate composite positive electrode material and preparation method thereof |
| CN116053470B (en) * | 2023-04-03 | 2023-06-20 | 中南大学 | Iron-based composite positive electrode active material, and preparation method and application thereof |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1948137A (en) * | 2006-10-23 | 2007-04-18 | 南京航空航天大学 | Sol-gel method of ferresodium flurophosphate for sodium ion battery |
| CN103765640A (en) * | 2011-08-29 | 2014-04-30 | 丰田自动车株式会社 | Positive electrode active material for sodium batteries and method for producing same |
| WO2016147853A1 (en) * | 2015-03-18 | 2016-09-22 | 日本電気硝子株式会社 | Positive electrode active material powder for sodium ion secondary cells |
| CN107697898A (en) * | 2017-09-11 | 2018-02-16 | 华中科技大学 | A kind of NASICON structures water system sodium-ion battery positive electrode and its synthetic method |
| CN108046231A (en) * | 2017-11-13 | 2018-05-18 | 中南大学 | A kind of sodium-ion battery positive material and preparation method thereof |
| CN108963294A (en) * | 2018-07-20 | 2018-12-07 | 大连交通大学 | A kind of proton exchange membrane fuel cell metal graphite composite bipolar plate preparation method |
| CN109734069A (en) * | 2019-01-08 | 2019-05-10 | 广西卡耐新能源有限公司 | A kind of sodium ion secondary battery high-voltage anode material, preparation method, electrode and sodium ion secondary battery |
-
2019
- 2019-07-02 CN CN201910590817.1A patent/CN110299528B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1948137A (en) * | 2006-10-23 | 2007-04-18 | 南京航空航天大学 | Sol-gel method of ferresodium flurophosphate for sodium ion battery |
| CN103765640A (en) * | 2011-08-29 | 2014-04-30 | 丰田自动车株式会社 | Positive electrode active material for sodium batteries and method for producing same |
| WO2016147853A1 (en) * | 2015-03-18 | 2016-09-22 | 日本電気硝子株式会社 | Positive electrode active material powder for sodium ion secondary cells |
| CN107697898A (en) * | 2017-09-11 | 2018-02-16 | 华中科技大学 | A kind of NASICON structures water system sodium-ion battery positive electrode and its synthetic method |
| CN108046231A (en) * | 2017-11-13 | 2018-05-18 | 中南大学 | A kind of sodium-ion battery positive material and preparation method thereof |
| CN108963294A (en) * | 2018-07-20 | 2018-12-07 | 大连交通大学 | A kind of proton exchange membrane fuel cell metal graphite composite bipolar plate preparation method |
| CN109734069A (en) * | 2019-01-08 | 2019-05-10 | 广西卡耐新能源有限公司 | A kind of sodium ion secondary battery high-voltage anode material, preparation method, electrode and sodium ion secondary battery |
Non-Patent Citations (1)
| Title |
|---|
| "Rational Design of Na4Fe3(PO4)2(P2O7) Nanoparticles Embedded in Graphene: Toward Fast Sodium Storage Through the Pseudocapacitive Effect";Ma Xudong et al.;《ACS APPLIED ENERGY MATERIALS》;20181009;第1卷(第11期);第6268-6278页 * |
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