CN116169264A - Carbon-coated sodium-rich ferric sodium pyrophosphate composite positive electrode material, preparation method and application - Google Patents

Carbon-coated sodium-rich ferric sodium pyrophosphate composite positive electrode material, preparation method and application Download PDF

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CN116169264A
CN116169264A CN202310095529.5A CN202310095529A CN116169264A CN 116169264 A CN116169264 A CN 116169264A CN 202310095529 A CN202310095529 A CN 202310095529A CN 116169264 A CN116169264 A CN 116169264A
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sodium
carbon
ferric
rich
anode material
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李喜飞
侯宁静
王晓雪
王慧
徐绍霞
王广进
李默恒
席玉坤
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Xian University of Technology
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Abstract

The invention discloses a carbon-coated sodium-rich ferric sodium pyrophosphate composite anode material, a preparation method and application thereof, and a molecular formula is Na 4+x Fe 3‑y M y (PO 4 ) 2 P 2 O 7 F x C@rGO; in the molecular formula, x is more than 0 and less than or equal to 0.1, y is more than or equal to 0 and less than or equal to 3, and M is Mn, co, ni, ti, mg, alOne or more than two mixtures. According to the carbon-coated sodium-rich sodium ferric pyrophosphate and sodium phosphate composite anode material, the preparation method and the application thereof, disclosed by the invention, after the precursor of the carbon-coated sodium-rich sodium ferric pyrophosphate and sodium phosphate composite anode material is synthesized, the final required carbon-coated sodium-rich sodium ferric pyrophosphate and sodium phosphate composite anode material is obtained through heat treatment, and a thinking is provided for the development of new materials of the anode of the sodium ion battery.

Description

Carbon-coated sodium-rich ferric sodium pyrophosphate composite positive electrode material, preparation method and application
Technical Field
The invention belongs to the technical field of new materials for sodium ion batteries, and particularly relates to a carbon-coated sodium-rich ferric sodium pyrophosphate composite anode material. The invention also relates to a preparation method of the carbon-coated sodium-rich ferric sodium pyrophosphate composite anode material. The invention further relates to a method for preparing the sodium ion battery positive electrode plate by using the carbon-coated sodium-rich ferric sodium pyrophosphate composite positive electrode material.
Background
With the continuous worsening of global environmental problems and the increasing of energy crisis, clean, renewable energy is urgently needed. In recent years, market demands continue to drive the energy storage field toward electrochemical energy storage. Compared with the traditional lithium ion battery anode material, such as lithium cobaltate, lithium manganate, ternary material and the like, the sodium ion battery anode material sodium iron pyrophosphate (Na 4 Fe 3 (PO 4 ) 2 P 2 O 7 And is marked as NFPP) has the advantages of rich reserves, wide distribution, low price, stable structure and the like. This feature is well suited to large-scale energy storage device characteristics, and therefore sodium ion batteries are considered one of the potential candidates for large-scale energy storage systems. For the sodium iron phosphate NFPP, the sodium iron phosphate NFPP has higher theoretical capacity (about 129 mAh/g) and higher working voltage (about 3.1V, na) + Na) and lower volume expansion (-4%) are considered to be the most potential positive materials for sodium ion batteries. BeforeIn the research process, the applicant has found that adding excessive sodium ions into the material and simultaneously introducing double doping of anions and cations can effectively improve the discharge specific capacity of the material and improve the cycling stability of the material. Based on this, researchers further find that the electrochemical performance of the material can be improved more effectively by introducing different coating layers into the material, and the finding provides a thinking for improving the material performance.
Disclosure of Invention
The invention aims to provide a carbon-coated sodium-rich sodium ferric pyrophosphate sodium phosphate composite anode material, which solves the problem that the existing electrochemical energy storage is too dependent on the anode material of a lithium ion battery.
The invention further aims to provide a preparation method of the carbon-coated sodium-rich sodium ferric pyrophosphate sodium composite anode material.
The invention further aims to provide a method for preparing the sodium ion battery positive plate by using the carbon-coated sodium-rich ferric sodium pyrophosphate composite positive electrode material.
The first technical scheme adopted by the invention is as follows: carbon-coated sodium-rich ferric sodium pyrophosphate composite positive electrode material with molecular formula of Na 4+x Fe 3-y M y (PO 4 ) 2 P 2 O 7 F x C@rGO; in the molecular formula, x is more than 0 and less than or equal to 0.1, y is more than or equal to 0 and less than or equal to 3, and M is one or a mixture of more than two of Mn, co, ni, ti, mg, al.
The first technical solution of the invention is also characterized in that,
the composite positive electrode material is a particle having an average particle diameter of 50nm to 10. Mu.m, preferably 3 to 5. Mu.m.
The second technical scheme adopted by the invention is as follows: the preparation method of the carbon-coated sodium-rich ferric sodium pyrophosphate composite anode material comprises the following steps:
step 1, performing ultrasonic treatment on rGO dispersion liquid;
step 2, respectively dissolving phosphate, ferric salt, sodium salt, fluoride, M salt and a carbon source in the dispersion liquid obtained in the step 1;
step 3, drying the solution obtained in the step 2 to obtain a powdery mixed precursor;
and step 4, performing heat treatment on the precursor obtained in the step 3 in an inert reducing atmosphere to obtain the catalyst.
The second technical proposal of the invention is also characterized in that,
the rGO dispersion in step 1 is sonicated for 0.5 to 2 hours, preferably 0.5 to 1 hour.
In the step 2, the phosphate is one or more than two of sodium dihydrogen phosphate, diammonium hydrogen phosphate and monoammonium phosphate, preferably sodium dihydrogen phosphate; the ferric salt is one or more than two of ferrous acetate, ferric nitrate, ferrous oxalate and ferrous sulfate, preferably ferric nitrate; the sodium salt is one or more of sodium dihydrogen phosphate, sodium carbonate, sodium bicarbonate, sodium acetate, sodium oxalate and sodium citrate, preferably sodium dihydrogen phosphate; the fluoride is one or two of sodium fluoride and ammonium fluoride; the M salt is one or more of M acetate, M sulfate, M chloride, M nitrate and M dihydrogen phosphate, preferably M acetate, and M is one or more of Mn, co, ni, ti, mg, al; the carbon source is one or more than two of starch, citric acid, sucrose and glucose, preferably citric acid; the carbon source is 1 to 10wt.%, preferably 5wt.% of the material dissolved in the dispersion in step 2.
In the step 2, the mixing ratio of the phosphate, the ferric salt, the sodium salt, the fluoride and the M salt is 4:0-3:4-4.1:0-0.1:0-3, preferably 4:2.99:4.01:0.01:0.01.
The rGO in the dispersion of step 2 is present in an amount of 0.5 to 15wt.%, preferably 1 to 5wt.%, based on the total weight of the dispersion-soluble material.
The drying mode in the step 3 is a spray drying method or a freeze drying method, preferably a spray drying method.
In the step 4, the inert reducing atmosphere is one or a mixture of more than two of nitrogen, argon and hydrogen, preferably argon and hydrogen mixed gas, and the hydrogen volume percentage is 5%; the heat treatment comprises two steps of presintering and high-temperature calcination: presintering technology: the heating rate is 1-5 ℃/min, preferably 2 ℃/min; the temperature is 250-350 ℃, preferably 300 ℃; the heat preservation time is 3-10 h, preferably 6h; cooling is carried out along with furnace cooling; and (3) a high-temperature calcination process: the heating rate is 1-5 ℃/min, preferably 2 ℃/min; the temperature is 450-550 ℃, preferably 500 ℃; the heat preservation time is 5-15 h, preferably 10h; cooling is carried out along with furnace cooling.
The third technical scheme adopted by the invention is as follows: the method for preparing the sodium ion battery positive electrode plate by using the carbon-coated sodium-rich ferric sodium pyrophosphate composite positive electrode material comprises the following steps of:
step 1, weighing the following components in parts by weight: 80 parts of the carbon-coated sodium-rich ferric sodium pyrophosphate composite anode material, 10 parts of acetylene black and 10 parts of a binder;
and 2, dissolving the carbon-coated sodium-rich sodium ferric pyrophosphate sodium phosphate composite anode material weighed in the step 1, acetylene black and a binder in N-methylpyrrolidone, coating the mixture on the treated aluminum foil, and drying the mixture to obtain the composite anode material.
The beneficial effects of the invention are as follows: according to the carbon-coated sodium-rich sodium ferric pyrophosphate and sodium phosphate composite anode material, the preparation method and the application thereof, disclosed by the invention, after the precursor of the carbon-coated sodium-rich sodium ferric pyrophosphate and sodium phosphate composite anode material is synthesized, the final required carbon-coated sodium-rich sodium ferric pyrophosphate and sodium phosphate composite anode material is obtained through heat treatment, and a thinking is provided for the development of new materials of the anode of the sodium ion battery.
Drawings
FIG. 1 is an electron microscopic view of a carbon-coated sodium-rich ferric sodium pyrophosphate composite anode material of the present invention;
FIG. 2 is an XRD pattern of the carbon-coated sodium-rich ferric sodium pyrophosphate composite anode material prepared in example 2 of the present invention;
FIG. 3 is a graph showing the charge and discharge of the button cell of example 4 of the present invention at a 0.1C rate;
fig. 4 is a cycle chart of the button cell of example 4 of the present invention at a 1C rate.
Detailed Description
The invention will be described in detail with reference to the accompanying drawings and detailed description.
The invention provides a carbon-coated sodium-rich ferric pyrophosphateAs shown in FIG. 1, the molecular formula of the sodium composite positive electrode material is Na 4+x Fe 3-y M y (PO 4 ) 2 P 2 O 7 F x C@rGO (one or more of x is more than 0 and less than or equal to 0.1, y is more than or equal to 0 and less than 3, and M= Mn, co, ni, ti, mg, al). The positive electrode material is in the form of particles of 50nm to 10. Mu.m, preferably 3 to 5. Mu.m.
The invention also provides a preparation method of the carbon-coated sodium-rich ferric sodium pyrophosphate composite anode material, which comprises the following steps:
and step 1, performing ultrasonic treatment on the rGO dispersion liquid for 0.5-2 h, preferably 0.5-1 h.
Step 2, respectively dissolving phosphate, ferric salt, sodium salt, fluoride, M salt and a carbon source in the dispersion liquid obtained in the step 1; the phosphate is one or more of sodium dihydrogen phosphate, diammonium hydrogen phosphate and monoammonium dihydrogen phosphate, preferably sodium dihydrogen phosphate; the ferric salt is one or more of ferrous acetate, ferric nitrate, ferrous oxalate and ferrous sulfate, preferably ferric nitrate; the sodium salt is one or more of sodium dihydrogen phosphate, sodium carbonate, sodium bicarbonate, sodium acetate, sodium oxalate and sodium citrate, preferably sodium dihydrogen phosphate; the fluoride is one or two of sodium fluoride and ammonium fluoride; the M salt is one or more of M acetate, M sulfate, M chloride, M nitrate and M dihydrogen phosphate, preferably M acetate; the carbon source is one or more of starch, citric acid, sucrose and glucose, preferably citric acid; the carbon source accounts for 1 to 10wt.%, preferably 5wt.% of the material; the mixing ratio of the phosphate, the ferric salt, the sodium salt, the fluoride and the M salt is 4:0-3:4-4.1:0-0.1:0-3, and the preferable ratio is 4:2.99:4.01:0.01:0.01; the total salt amount and the rGO mixing ratio in the step 2 are in mass ratio, wherein the rGO accounts for 0.5-15%, preferably 1-5%.
Step 3, drying the solution obtained in the step 2 to obtain a powdery mixed precursor; the drying method is a spray drying method or a freeze drying method, and is preferably a spray drying method.
And 4, performing heat treatment on the precursor obtained in the step 3 in an inert reducing atmosphere, wherein the inert reducing atmosphere is one or a mixture of two or more of nitrogen, argon and hydrogen, preferably argon-hydrogen mixed gas, and the hydrogen volume percentage is 5%. The heat treatment comprises two steps of presintering and high-temperature calcination: presintering technology: the heating rate is 1-5 ℃/min, preferably 2 ℃/min; the temperature is 250-350 ℃, preferably 300 ℃; the heat preservation time is 3-10 hours, preferably 6 hours; cooling is carried out along with furnace cooling. And (3) a high-temperature calcination process: the heating rate is 1-5 ℃/min, preferably 2 ℃/min; the temperature is 450-550 ℃, preferably 500 ℃; the heat preservation time is 5-15 h, preferably 10h; cooling is carried out along with furnace cooling.
The invention also provides a method for preparing the sodium ion battery positive electrode plate by using the carbon-coated sodium-rich ferric sodium pyrophosphate composite positive electrode material, which comprises the following steps:
step 1, weighing the following components in parts by weight: 80 parts of carbon-coated sodium-rich ferric sodium pyrophosphate composite anode material, 10 parts of acetylene black and 10 parts of binder;
and 2, dissolving the carbon-coated sodium-rich sodium ferric pyrophosphate sodium phosphate composite anode material weighed in the step 1, acetylene black and a binder in N-methylpyrrolidone, coating the mixture on the treated aluminum foil, and drying the mixture to obtain the carbon-coated sodium-rich sodium ferric pyrophosphate sodium phosphate composite anode sheet.
And then assembling the cell and the sodium sheet into a button cell in a glove box, and carrying out subsequent electrochemical performance tests. The obtained carbon-coated sodium-rich ferric sodium pyrophosphate composite positive electrode material is positive, the sodium sheet is opposite to the negative electrode, and the electrolyte is 1mol L - 1 NaClO 4 The sodium salt of (2) is dissolved in a 1:1 volume ratio of Ethylene Carbonate (EC) to Propylene Carbonate (PC) solution, and 5% fluoroethylene carbonate (FEC) additive is additionally added into the electrolyte. In the electrochemical performance test process, the current 1C is 129mA/g, and the charge-discharge temperature is room temperature.
Example 1
The rGO dispersion was sonicated for 0.5h, and 2mmol of sodium dihydrogen phosphate, 1mmol of ferric nitrate nonahydrate, 0.25mmol of nickel acetate tetrahydrate, 0.25mmol of magnesium acetate tetrahydrate, 2mmol of citric acid, and 0.05mmol of sodium fluoride were dissolved in the dispersion. Wherein the mass ratio of rGO in the composite material is 0.5wt.%. After spray drying, a precursor powder is obtained. Heating precursor powder to 250 ℃ in a tubular vacuum furnace, preserving heat for 10 hours, then heating to 450 ℃ and preserving heat for 15 hours, protecting the whole argon-hydrogen mixed gas, heating at a speed of 1 ℃/min, and cooling along with the furnace to obtain the required Na 4.1 Fe 2 Ni 0.5 Mg 0.5 (PO 4 ) 2 P 2 O 7 F 0.1 And (3) a C@rGO positive electrode composite material.
Example 2
The rGO dispersion was sonicated for 1h, and 1.495mmol of ferric nitrate nonahydrate, 1.002mol of citric acid, 2mmol of anhydrous sodium dihydrogen phosphate, 0.005mmol of manganese acetate, and 0.005mmol of sodium fluoride were dissolved in the dispersion. Wherein the mass ratio of rGO in the composite is 2.5wt.%. After spray drying, a precursor powder is obtained. Heating the mixture to 300 ℃ in a tubular vacuum furnace, preserving heat for 6 hours, then heating to 500 ℃ and preserving heat for 10 hours, protecting the whole argon-hydrogen mixed gas, heating at a speed of 2 ℃/min, and cooling along with the furnace to obtain the required Na 4.01 Fe 2.99 Mn 0.01 (PO 4 ) 2 P 2 O 7 F 0.01 And (3) a C@rGO positive electrode composite material.
Example 3
The rGO dispersion was sonicated for 2h, and 0.1mmol ferric nitrate nonahydrate, 2mmol sodium phosphate monobasic, 0.4mmol cobalt acetate, 0.25mmol titanium sulfate, 0.5mmol aluminum chloride, 1.002mol citric acid, and 0.005mmol sodium fluoride were dissolved in the dispersion. Wherein the mass ratio of rGO in the composite material is 15wt.%. After spray drying, a precursor powder is obtained. Heating the mixture to 350 ℃ in a tubular vacuum furnace, preserving heat for 3 hours, then heating to 550 ℃ and preserving heat for 5 hours, protecting the whole argon-hydrogen mixed gas, heating at a speed of 5 ℃/min, and cooling along with the furnace to obtain the required Na 4.01 Fe 0.2 Co 0.8 Ti 0.5 Al(PO 4 ) 2 P 2 O 7 F 0.01 And (3) a C@rGO positive electrode composite material.
Example 4
0.4g of Na obtained in example 2 was taken 4.01 Fe 2.99 Mn 0.01 (PO 4 ) 2 P 2 O 7 F 0.01 The desired positive electrode slurry was obtained by mixing the composite material of positive electrode/C@rGO, 0.05g of a conductive agent (acetylene black), 0.05g of a binder (polyvinylidene fluoride (PVDF)), and 0.5. 0.5g N-methylpyrrolidone (NMP). And then, coating the slurry on the treated aluminum foil, and drying the aluminum foil in a vacuum drying oven at 90 ℃ for 10 hours to obtain the positive electrode plate. And assembling the pole piece and the sodium piece into the button cell in a glove box. Wherein the electrolyte is 1mol L - 1 NaClO 4 The sodium salt of (2) is dissolved in a 1:1 volume ratio of Ethylene Carbonate (EC) and Ethylene Methyl Carbonate (EMC) solution, and 5% fluoroethylene carbonate (FEC) additive is additionally added into the electrolyte. Subsequent electrochemical performance testing will be based on button cells.
Test example 1
Na prepared in example 2 4.01 Fe 2.99 Mn 0.01 (PO 4 ) 2 P 2 O 7 F 0.01 the/C@rGO positive electrode composite material was subjected to X-ray diffraction (SHIMADZU XRD-7000) test. The experimental conditions were as follows: copper target (λ= 0.1518 nm), 2 θ angle range from 5 to 70 °. The XRD pattern is shown in FIG. 2.
As can be seen from the XRD pattern in FIG. 2, na 4.01 Fe 2.99 Mn 0.01 (PO 4 ) 2 P 2 O 7 F 0.01 the/C@rGO positive electrode composite material has Pn2 with high crystallinity 1 a space group pure phase crystal structure (PDF standard card number: PDF#89-0579). No obvious diffraction peak of impurities is observed, which indicates that adding a small amount of sodium ions, doping partial manganese elements, fluorine elements, coating a certain carbon layer and graphene does not affect the crystal structure of the material. The result shows that the carbon-coated sodium-rich sodium ferric pyrophosphate sodium composite anode material with pure phase and high crystallinity can be prepared by the experimental method.
Test example 2
Na prepared in example 2 4.01 Fe 2.99 Mn 0.01 (PO 4 ) 2 P 2 O 7 F 0.01 The composite material of the positive electrode of the @ C@rGO was subjected to scanning electron microscope observation (FESEM, JSM-6700F). A specific image is shown in fig. 1.
As shown in FIG. 1, na 4.01 Fe 2.99 Mn 0.01 (PO 4 ) 2 P 2 O 7 F 0.01 The composite material of the positive electrode of the/C@rGO is integrally expressed as spherical particles, and the particle size is between 3 and 5 mu m. Wherein, the surface is graphene, and the matrix material is uniformly coated. The preparation method is capable of synthesizing the carbon-coated sodium-rich ferric sodium pyrophosphate composite anode material with smaller size and concentrated distribution.
Test example 3
The button cell prepared in example 4 was subjected to charge and discharge test. The current 1C was 129mA/g, and the charge-discharge temperature was room temperature.
Fig. 3 shows charge and discharge curves of the assembled button cell of example 4. The charge-discharge current is 0.1C, and the charge-discharge voltage range is 1.8-4.2V. In the figure, a curve 1 is a charging curve, and a curve 2 is a discharging curve. As can be seen from the graph, in the whole charge and discharge process, the charge and discharge curve is smooth and complete, which indicates that the battery can be charged and discharged well; the specific charge capacity is 135mAh/g, the specific discharge capacity is 125mAh/g, and the first-circle coulomb efficiency is 92.5%. The data show that the carbon-coated sodium-rich ferric sodium pyrophosphate composite anode material has higher specific discharge capacity.
Test example 4
The button cell prepared in example 4 was subjected to charge and discharge test. The current 1C was 129mA/g, and the charge-discharge temperature was room temperature.
Fig. 4 shows a 1C cycle curve of the assembled button cell of example 4. The charge-discharge voltage range is 1.8-4.2V, and 3 circles of activation are performed by using 0.2C small current before 1C formal circulation. As can be seen from the graph, the initial discharge specific capacity of the cycle was 99.6mAh/g, the discharge specific capacity after 200 cycles was 95.8mAh/g, and the capacity retention was 95.5%. The data show that the carbon-coated sodium-rich ferric sodium pyrophosphate composite anode material has higher cycle stability.
Through the mode, the carbon-coated sodium-rich sodium ferric pyrophosphate sodium phosphate composite anode material is prepared by mixing and dissolving phosphate, ferric salt, sodium salt, fluoride, doping salt and graphene oxide in stoichiometric ratio, preparing a precursor by a spray drying method, and performing heat treatment on the obtained precursor in a reducing atmosphere to finally obtain the carbon-coated sodium-rich sodium ferric pyrophosphate sodium phosphate composite anode material. The obtained nano material has better electrochemical behavior and is used for the positive electrode of the rechargeable sodium ion battery. According to the method, excessive sodium ions are added in the preparation process of the material, and a certain amount of graphene is added while the double doping of anions and cations is introduced.

Claims (10)

1. The carbon-coated sodium-rich ferric sodium pyrophosphate composite anode material is characterized in that the molecular formula is Na 4+x Fe 3-y M y (PO 4 ) 2 P 2 O 7 F x C@rGO; in the molecular formula, x is more than 0 and less than or equal to 0.1, y is more than or equal to 0 and less than or equal to 3, and M is one or a mixture of more than two of Mn, co, ni, ti, mg, al.
2. The carbon-coated sodium-rich ferric sodium pyrophosphate composite cathode material according to claim 1, wherein said composite cathode material is a particle having an average particle diameter of 50nm to 10 μm, preferably 3 to 5 μm.
3. The preparation method of the carbon-coated sodium-rich ferric sodium pyrophosphate composite anode material is characterized by comprising the following steps of:
step 1, performing ultrasonic treatment on rGO dispersion liquid;
step 2, respectively dissolving phosphate, ferric salt, sodium salt, fluoride, M salt and a carbon source in the dispersion liquid obtained in the step 1;
step 3, drying the solution obtained in the step 2 to obtain a powdery mixed precursor;
and step 4, performing heat treatment on the precursor obtained in the step 3 in an inert reducing atmosphere to obtain the catalyst.
4. The method for preparing a carbon-coated sodium-rich ferric sodium pyrophosphate composite anode material according to claim 3, wherein the rGO dispersion liquid in the step 1 is subjected to ultrasonic treatment for 0.5-2 h, preferably 0.5-1 h.
5. The method for preparing a carbon-coated sodium-rich ferric sodium pyrophosphate composite anode material according to claim 3, wherein the phosphate in the step 2 is one or more than two of sodium dihydrogen phosphate, diammonium hydrogen phosphate and ammonium dihydrogen phosphate, preferably sodium dihydrogen phosphate; the ferric salt is one or more than two of ferrous acetate, ferric nitrate, ferrous oxalate and ferrous sulfate, preferably ferric nitrate; the sodium salt is one or more of sodium dihydrogen phosphate, sodium carbonate, sodium bicarbonate, sodium acetate, sodium oxalate and sodium citrate, preferably sodium dihydrogen phosphate; the fluoride is one or two of sodium fluoride and ammonium fluoride; the M salt is one or more of M acetate, M sulfate, M chloride, M nitrate and M dihydrogen phosphate, preferably M acetate, and M is one or more of Mn, co, ni, ti, mg, al; the carbon source is one or more than two of starch, citric acid, sucrose and glucose, preferably citric acid; the carbon source is 1 to 10wt.%, preferably 5wt.% of the material dissolved in the dispersion in step 2.
6. The method for preparing a carbon-coated sodium-enriched ferric sodium pyrophosphate composite anode material according to claim 3, wherein the mixing ratio of the phosphate, the ferric salt, the sodium salt, the fluoride and the M salt in the step 2 is 4:0-3:4-4.1:0-0.1:0-3, preferably 4:2.99:4.01:0.01:0.01.
7. A method for preparing a carbon-coated sodium-rich ferric sodium pyrophosphate composite anode material according to claim 3, wherein the rGO in the dispersion of step 2 is 0.5-15 wt.%, preferably 1-5 wt.%, based on the total weight of the carbon-coated sodium-rich ferric sodium pyrophosphate composite anode material and the material dissolved in the dispersion.
8. The method for preparing a carbon-coated sodium-enriched ferric sodium pyrophosphate composite anode material according to claim 3, wherein the drying mode in the step 3 is a spray drying method or a freeze drying method, preferably a spray drying method.
9. The method for preparing the carbon-coated sodium-enriched sodium ferric pyrophosphate composite anode material according to claim 3, wherein the inert reducing atmosphere in the step 4 is one or a mixture of more than two of nitrogen, argon and hydrogen, preferably a mixed gas of argon and hydrogen, and the hydrogen is 5% by volume; the heat treatment comprises two steps of presintering and high-temperature calcination: presintering technology: the heating rate is 1-5 ℃/min, preferably 2 ℃/min; the temperature is 250-350 ℃, preferably 300 ℃; the heat preservation time is 3-10 h, preferably 6h; cooling is carried out along with furnace cooling; and (3) a high-temperature calcination process: the heating rate is 1-5 ℃/min, preferably 2 ℃/min; the temperature is 450-550 ℃, preferably 500 ℃; the heat preservation time is 5-15 h, preferably 10h; cooling is carried out along with furnace cooling.
10. The method for preparing the sodium ion battery positive electrode plate by using the carbon-coated sodium-rich ferric sodium pyrophosphate composite positive electrode material is characterized by comprising the following steps of:
step 1, weighing the following components in parts by weight: the carbon-coated sodium-rich ferric sodium pyrophosphate composite anode material according to claim 1, wherein the carbon-coated sodium-rich ferric sodium pyrophosphate composite anode material comprises 80 parts of acetylene black 10 parts and a binder 10 parts;
and 2, dissolving the carbon-coated sodium-rich sodium ferric pyrophosphate sodium phosphate composite anode material weighed in the step 1, acetylene black and a binder in N-methylpyrrolidone, coating the mixture on the treated aluminum foil, and drying the mixture to obtain the composite anode material.
CN202310095529.5A 2023-02-10 2023-02-10 Carbon-coated sodium-rich ferric sodium pyrophosphate composite positive electrode material, preparation method and application Pending CN116169264A (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116750741A (en) * 2023-05-29 2023-09-15 浙江鑫钠新材料科技有限公司 Preparation method and application of titanium-doped carbon-coated sodium ferric pyrophosphate material
CN117012956A (en) * 2023-09-26 2023-11-07 深圳华钠新材有限责任公司 Iron-manganese-cobalt-based sodium-rich anion doped positive electrode material and preparation method thereof

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116750741A (en) * 2023-05-29 2023-09-15 浙江鑫钠新材料科技有限公司 Preparation method and application of titanium-doped carbon-coated sodium ferric pyrophosphate material
CN117012956A (en) * 2023-09-26 2023-11-07 深圳华钠新材有限责任公司 Iron-manganese-cobalt-based sodium-rich anion doped positive electrode material and preparation method thereof

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