Quick-charge sodium ion battery composite positive electrode material and preparation method thereof

Abstract

The invention discloses a composite positive electrode material for a quick-charge sodium-ion battery and a preparation method of the composite positive electrode material, belongs to the technical field of sodium-ion batteries, and particularly relates to the preparation method of the composite positive electrode material for the quick-charge sodium-ion battery. Then adding sodium carbonate and carrying out high-temperature calcination treatment to obtain an O3-phase layered metal oxide; and mixing with an iron source, a phosphorus source, a sodium source and a carbon source, adding an organic dispersant, and carrying out high-speed stirring dispersion, nanometer sanding, spray drying and calcination treatment to obtain the composite positive electrode material for the fast-charging sodium-ion battery. The sodium-ion battery assembled by the fast-charge sodium-ion battery composite positive electrode material prepared by the invention has large reversible capacity and high capacity retention ratio, and the reversible capacity reaches 127.5 mAh / g or above under the condition of 1C; and the capacity retention ratio after 1000 cycles is 85.4-99.4%.

Description

Technical Field

[0001] The present invention relates to the technical field of sodium-ion batteries, and particularly relates to a fast-charging sodium-ion battery composite cathode material and a preparation method thereof. Background Art

[0002] Due to its rich resources and low cost, sodium-ion batteries have become an important option to replace lithium-ion batteries in the field of small power. As the core component of sodium-ion batteries, the rate performance of the cathode material plays a decisive role in application scenarios that pursue fast charging. Currently, layered oxide cathode materials are favored due to their high specific capacity and moderate working voltage. However, layered oxide cathode materials have obvious deficiencies in rate performance and cycle life. Especially under fast charging conditions, their poor ion / electron conductivity becomes the primary limiting factor. Therefore, there is an urgent need for a fast-charging sodium-ion battery composite cathode material to solve the problems such as poor rate performance, unsatisfactory cycle life, and small reversible capacity of single-layered oxide cathode materials or polyanion-type cathode materials. Summary of the Invention

[0003] The purpose of the present invention is to provide a fast-charging sodium-ion battery composite cathode material and a preparation method thereof, which can effectively improve the conductivity and structural stability of the material, thereby improving the reversible capacity and capacity retention rate of the sodium-ion battery assembled with the fast-charging sodium-ion battery composite cathode material.

[0004] The technical solution adopted by the present invention to achieve the above purpose is as follows: A preparation method of a fast-charging sodium-ion battery composite cathode material includes performing a coprecipitation reaction on a metal salt solution, a sodium carbonate solution, and ammonia water, and then adding sodium carbonate for high-temperature calcination treatment to obtain an O3-phase layered metal oxide; mixing the O3-phase layered metal oxide with an iron source, a phosphorus source, a sodium source, and a carbon source, adding an organic dispersant, and performing high-speed stirring and dispersion, nanosand grinding treatment, spray drying, and calcination treatment to obtain the fast-charging sodium-ion battery composite cathode material; the organic dispersant includes at least N-methylpyrrolidone.

[0005] The present invention composites the O3-phase layered metal oxide with an iron source, a phosphorus source, a sodium source, and a carbon source through a novel synthesis process to construct an O3-phase layered metal oxide / polyanion compound heterostructure, optimize the intrinsic conductivity of the cathode material, and utilize the synergistic effect between the two materials to alleviate the degree of positive electrode volume deformation during the sodiation / desodiation process, and finally improve the structural stability and conductivity of the cathode material to obtain a cathode material suitable for fast-charging sodium-ion batteries.

[0006] Preferably, the metal salt solution is obtained by mixing ferrous sulfate heptahydrate, manganese sulfate monohydrate, nickel sulfate hexahydrate, copper sulfate pentahydrate, and deionized water.

[0007] Preferably, in the high temperature calcination treatment, the calcination temperature is 800-1100° C. and the calcination time is 6-24 h.

[0008] Preferably, the organic dispersant includes at least one of N-methylpyrrolidone and pyridazinyl derivatives. The present invention improves the electron conduction between the O3 phase layered metal oxide and the iron source, phosphorus source, sodium source and carbon source material particles by using N-methylpyrrolidone and pyridazinyl derivatives as organic dispersants, thereby improving the electrochemical performance of the prepared fast-charging sodium ion battery composite positive electrode material, so that the sodium ion battery assembled by the fast-charging sodium ion battery composite positive electrode material has a large reversible capacity and a high capacity retention rate.

[0009] More preferably, in the preparation of the pyridazine derivative, 3-carboxypyridazine is first reacted with ethylenediamine, then treated with a lithium aluminum hydride solution, and then reacted with 8-bromo-1-octene to obtain the pyridazine derivative.

[0010] More preferably, the mass ratio of ethylenediamine to 3-carboxypyridazine is 1:2-10.

[0011] More preferably, the lithium aluminum hydride solution is a mixture of lithium aluminum hydride and tetrahydrofuran, and the dosage ratio of the 3-carboxypyridazine to the lithium aluminum hydride solution is 1 g: 1-3 mL.

[0012] More preferably, the mass ratio of 3-carboxypyridazine to 8-bromo-1-octene is 1:1-5.

[0013] Preferably, a method for preparing a composite positive electrode material for a fast-charging sodium-ion battery comprises: S1. Mix ferrous sulfate heptahydrate, manganese sulfate monohydrate, nickel sulfate hexahydrate and cupric sulfate pentahydrate, and add deionized water to obtain a metal salt solution A.

[0014] S2. Add ammonia water to the sodium carbonate solution and mix well to obtain solution B.

[0015] S3. After nitrogen protective gas is introduced into the reactor, metal salt solution A and solution B are simultaneously added dropwise into the reactor at a feed rate of 10-50 mL / min, stirred at a speed of 100-600 r / min, and a co-precipitation reaction is carried out at 40-80 ° C and pH 9-9.5. After the reaction is completed, it is vacuum dried to obtain a carbonate precursor with a D50 particle size of 1-5 μm.

[0016] S4. After the carbonate precursor is fully mixed with sodium carbonate, the mixture is calcined at 800-1100° C. in an air atmosphere for 6-24 hours to obtain an O3 phase layered metal oxide.

[0017] S5. Mix ferrous oxalate, sodium dihydrogen phosphate, citric acid and O3-phase layered metal oxide, add an organic dispersant, and carry out high-speed stirring and dispersion at 500 - 1500 r / min for 0.5 - 2 h. Then, perform nano-grinding treatment at a grinding linear velocity of 12 - 16.6 m / s for 0.5 - 3 h to obtain a uniformly mixed slurry C. The D50 particle size of the particles in the slurry C is 100 - 500 nm.

[0018] S6. Under the conditions of a feed rate of 200 - 1000 mL / h and an inlet air temperature of 150 - 200 °C, perform spray drying treatment on the slurry C to obtain a dry powder precursor D.

[0019] S7. Under a nitrogen atmosphere, increase the temperature to 400 - 650 °C at a heating rate of 2 - 10 °C / min. Under these conditions, perform calcination treatment on the dry powder precursor D for 6 - 24 h. After the calcination is completed and the material temperature drops to room temperature, a fast-charging sodium-ion battery composite cathode material is obtained.

[0020] More preferably, in step S1, the mass ratio of manganese sulfate monohydrate to ferrous sulfate heptahydrate is 1:1 - 4.

[0021] More preferably, in step S1, the mass ratio of nickel sulfate hexahydrate to ferrous sulfate heptahydrate is 1:1 - 4.

[0022] More preferably, in step S1, the mass ratio of copper sulfate pentahydrate to ferrous sulfate heptahydrate is 1:0.5 - 2.

[0023] More preferably, in step S1, the dosage ratio of anhydrous copper sulfate to deionized water is 1 g:10 - 50 mL.

[0024] More preferably, in step S2, the concentration of the sodium carbonate solution is 0.5 - 5 mol / L, the mass concentration of ammonia water is 1 - 3%, and the volume ratio of ammonia water to the sodium carbonate solution is 1:1 - 5.

[0025] More preferably, in step S3, the volume ratio of metal salt solution A to solution B is 1:1 - 3.

[0026] More preferably, in step S4, the mass ratio of the sodium carbonate salt precursor to sodium carbonate is 1:0.5 - 1.

[0027] More preferably, in step S5, the mass ratio of ferrous oxalate to sodium dihydrogen phosphate is 1:1 - 3.

[0028] More preferably, in step S5, the mass ratio of citric acid to sodium dihydrogen phosphate is 1:3 - 6.

[0029] More preferably, in step S5, the mass ratio of citric acid to O3-phase layered metal oxide is 1:10 - 15.

[0030] More preferably, the organic dispersant in step S5 includes at least one of N-methylpyrrolidone, pyridazinyl derivative, and pyrrolyl derivative. By further using pyrrolyl derivative as the organic dispersant, the present invention helps to further improve the reversible capacity and capacity retention rate of the sodium-ion battery assembled with the fast-charging sodium-ion battery composite cathode material.

[0031] More preferably, the dosage ratio of citric acid to N-methylpyrrolidone in step S5 is 1 g: 20-50 mL.

[0032] More preferably, the mass ratio of citric acid to pyridazinyl derivative in step S5 is 1: 0.05-0.1.

[0033] More preferably, the mass ratio of citric acid to pyrrolyl derivative in step S5 is 1: 0.02-0.05.

[0034] More preferably, the preparation of the pyridazinyl derivative is specifically as follows: Weigh 3-carboxypyridazine, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and 4-dimethylaminopyridine, add methane and stir until dissolved, stir at 0-5 °C for 0.5-1 h, add ethylenediamine and stir to react for 6-12 h, dropwise add lithium aluminum hydride solution, reflux and react at 60-80 °C for 24-48 h, add deionized water, filter to remove solid particles, add 8-bromo-1-octene, anhydrous potassium carbonate, and potassium iodide, react at 70-90 °C for 24-48 h, and obtain the pyridazinyl derivative after column chromatography purification.

[0035] Even more preferably, the mass ratio of 3-carboxypyridazine to 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride is 1: 1-3.

[0036] Even more preferably, the mass ratio of 4-dimethylaminopyridine to 3-carboxypyridazine is 1: 50-150.

[0037] Even more preferably, the dosage ratio of 3-carboxypyridazine to methane is 1 g: 5-20 mL.

[0038] Even more preferably, the mass ratio of ethylenediamine to 3-carboxypyridazine is 1: 2-10.

[0039] Even more preferably, in the preparation of the lithium aluminum hydride solution, lithium aluminum hydride and tetrahydrofuran are mixed to a final concentration of 2-4 mol / L.

[0040] Even more preferably, the dosage ratio of 3-carboxypyridazine to the lithium aluminum hydride solution is 1 g: 1-3 mL.

[0041] Even more preferably, the dosage ratio of 3-carboxypyridazine to deionized water is 1 g: 2-10 mL.

[0042] Further preferably, the mass ratio of 3-carboxypyridazine to 8-bromo-1-octene is 1:1-5.

[0043] Further preferably, the mass ratio of potassium carbonate anhydrous to 3-carboxypyridazine is 1:1-5.

[0044] Further preferably, the mass ratio of 3-carboxypyridazine to potassium iodide is 1:1-2.

[0045] The present invention also discloses a fast-charging sodium-ion battery composite cathode material prepared by the above preparation method.

[0046] The present invention also discloses the application of the fast-charging sodium-ion battery composite cathode material in the preparation of a battery.

[0047] Since the present invention uses N-methylpyrrolidone, pyridazinyl derivatives and pyrrolyl derivatives as organic dispersants to participate in the composite of O3-phase layered metal oxide with iron source, phosphorus source, sodium source and carbon source to construct a fast-charging sodium-ion battery composite cathode material with an O3-phase layered metal oxide / polyanion compound heterostructure, the following beneficial effects are obtained: The sodium-ion battery assembled with the fast-charging sodium-ion battery composite cathode material prepared by the present invention has a large reversible capacity and a high capacity retention rate. Under the condition of 1C, the reversible capacity is 127.5-153.8 mAh / g; the capacity retention rate after 1000 cycles is 85.4-99.4%. Therefore, the present invention is a fast-charging sodium-ion battery composite cathode material and its preparation method capable of improving the reversible capacity and capacity retention rate of the assembled sodium-ion battery. Description of the Drawings

[0048] Figure 1 It is the reversible capacity of the button-type sodium-ion battery prepared by the present invention. Detailed Embodiments

[0049] The present invention will be further described in detail below in conjunction with the specific embodiments. The examples given are only for clarifying the present invention, rather than limiting the scope of the present invention. The following examples can be used as a guide for those of ordinary skill in the art to make further improvements, and do not limit the present invention in any way.

[0050] The experimental methods in the following examples are all conventional methods unless otherwise specified. The materials, reagents, etc. used in the following examples can all be obtained from commercial sources unless otherwise specified.

[0051] Example 1: Preparation of the fast-charging sodium-ion battery composite cathode material, including, S1. Mix ferrous sulfate heptahydrate, manganese sulfate monohydrate, nickel sulfate hexahydrate and copper sulfate pentahydrate, and add deionized water to obtain metal salt solution A. The mass ratio of manganese sulfate monohydrate to ferrous sulfate heptahydrate is 1:1.6; the mass ratio of nickel sulfate hexahydrate to ferrous sulfate heptahydrate is 1:1; the mass ratio of copper sulfate pentahydrate to ferrous sulfate heptahydrate is 1:3.3; the dosage ratio of anhydrous copper sulfate to deionized water is 1g:20mL.

[0052] S2. Add ammonia water to the sodium carbonate solution and mix well to obtain solution B. The concentration of the sodium carbonate solution is 2 mol / L, the mass concentration of the ammonia water is 2.28%, and the volume ratio of the ammonia water to the sodium carbonate solution is 1:2.

[0053] S3. After nitrogen protective gas was introduced into the reactor, metal salt solution A and solution B were simultaneously added dropwise to the reactor at a feed rate of 20 mL / min, stirred at a speed of 200 r / min, and coprecipitated at 60°C and pH 9. After the reaction, the mixture was vacuum dried to obtain a carbonate precursor with a D50 particle size of 3 μm. The volume ratio of metal salt solution A to solution B was 1:1.7.

[0054] S4, after the carbonate precursor and sodium carbonate are fully mixed, the mixture is calcined at 950°C in an air atmosphere for 12 hours to obtain an O3-phase layered metal oxide of O3-NaFe 0.3 Mn 0.3 Ni 0.3 Cu 0.1 O 2 The mass ratio of the sodium carbonate salt precursor to sodium carbonate is 1:0.7.

[0055] S5, ferrous oxalate, sodium dihydrogen phosphate, citric acid and O3-NaFe 0.3 Mn 0.3 Ni 0.3 Cu 0.1 O 2 After mixing, N-methylpyrrolidone was added, and the mixture was dispersed at a high speed of 800 r / min for 1 h, and then nano-sand milling was performed at a sand milling line speed of 14 m / s for 1.5 h to obtain a uniformly mixed slurry C, in which the particle D50 size was 250 nm. The mass ratio of ferrous oxalate to sodium dihydrogen phosphate was 1:1.2; the mass ratio of citric acid to sodium dihydrogen phosphate was 1:5.4; the mass ratio of citric acid to O3-NaFe 0.3 Mn 0.3 Ni 0.3 Cu 0.1 O 2 The mass ratio of citric acid and N-methylpyrrolidone is 1g:38mL.

[0056] S6. Under the conditions of a feed rate of 300 mL / h and an inlet air temperature of 150 °C, slurry C is subjected to spray drying treatment to obtain a dry powder precursor D.

[0057] S7. Under a nitrogen atmosphere, the temperature is raised to 500 °C at a heating rate of 5 °C / min. Under these conditions, the dry powder precursor D is calcined for 12 h. After the calcination is completed and the material temperature drops to room temperature, a fast-charging sodium-ion battery composite cathode material is obtained.

[0058] Example 2: The preparation of the pyridazinyl derivative includes: Weigh 3-carboxypyridazine, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and 4-dimethylaminopyridine, add methane and stir until dissolved. Stir at 4 °C for 0.5 h, add ethylenediamine and stir to react for 8 h. Dropwise add lithium aluminum hydride solution, reflux at 70 °C for 48 h, add deionized water, filter to remove solid particles, add 8-bromo-1-octene, anhydrous potassium carbonate, and potassium iodide, react at 80 °C for 48 h, and obtain the pyridazinyl derivative after column chromatography purification. The mass ratio of 3-carboxypyridazine to 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride is 1:1.5; the mass ratio of 4-dimethylaminopyridine to 3-carboxypyridazine is 1:100; the dosage ratio of 3-carboxypyridazine to methane is 1 g:10 mL; the mass ratio of ethylenediamine to 3-carboxypyridazine is 1:4.5; in the preparation of the lithium aluminum hydride solution, lithium aluminum hydride and tetrahydrofuran are mixed to a final concentration of 2.5 mol / L; the dosage ratio of 3-carboxypyridazine to the lithium aluminum hydride solution is 1 g:1.5 mL; the dosage ratio of 3-carboxypyridazine to deionized water is 1 g:5 mL; the mass ratio of 3-carboxypyridazine to 8-bromo-1-octene is 1:1.5; the mass ratio of anhydrous potassium carbonate to 3-carboxypyridazine is 1:3; the mass ratio of 3-carboxypyridazine to potassium iodide is 1:1.

[0059] The preparation of the fast-charging sodium-ion battery composite cathode material includes: S1. Mix ferrous sulfate heptahydrate, manganese sulfate monohydrate, nickel sulfate hexahydrate, and copper sulfate pentahydrate, and add deionized water to obtain a metal salt solution A. The mass ratio of manganese sulfate monohydrate to ferrous sulfate heptahydrate is 1:1.6; the mass ratio of nickel sulfate hexahydrate to ferrous sulfate heptahydrate is 1:1; the mass ratio of copper sulfate pentahydrate to ferrous sulfate heptahydrate is 1:3.3; the dosage ratio of anhydrous copper sulfate to deionized water is 1 g:20 mL.

[0060] S2. Add ammonia water to the sodium carbonate solution, and mix evenly to obtain solution B. The concentration of the sodium carbonate solution is 2 mol / L, the mass concentration of the ammonia water is 2.28%, and the volume ratio of the ammonia water to the sodium carbonate solution is 1:2.

[0061] S3. After introducing nitrogen protective gas into the reaction kettle, while maintaining a feeding rate of 20 mL / min, metal salt solution A and solution B are simultaneously and dropwise added to the reaction kettle, stirred at a speed of 200 r / min, and a coprecipitation reaction is carried out under the conditions of 60 °C and a pH of 9. After the reaction is completed, it is dried under vacuum to obtain a carbonate precursor with a D50 particle size of 3 μm. The volume ratio of metal salt solution A to solution B is 1:1.7.

[0062] S4. After thoroughly mixing the carbonate precursor with sodium carbonate, it is calcined at 950 °C for 12 h under an air atmosphere to obtain an O3-phase layered metal oxide, which is O3-NaFe 0.3 Mn 0.3 Ni 0.3 Cu 0.1 O 2 . The mass ratio of the carbonate precursor to sodium carbonate is 1:0.7.

[0063] S5. Mix ferrous oxalate, sodium dihydrogen phosphate, citric acid and O3-NaFe 0.3 Mn 0.3 Ni 0.3 Cu 0.1 O 2 . Add N-methylpyrrolidone and pyridazinyl derivative, and carry out high-speed stirring and dispersion at 800 r / min for 1 h, then carry out nano-grinding treatment at a grinding linear speed of 14 m / s for 1.5 h to obtain a uniformly mixed slurry C. The D50 particle size of the particles in slurry C is 250 nm. The mass ratio of ferrous oxalate to sodium dihydrogen phosphate is 1:1.2; the mass ratio of citric acid to sodium dihydrogen phosphate is 1:5.4; the mass ratio of citric acid to O3-NaFe 0.3 Mn 0.3 Ni 0.3 Cu 0.1 O 2 is 1:14; the dosage ratio of citric acid to N-methylpyrrolidone is 1 g:38 mL; the mass ratio of citric acid to pyridazinyl derivative is 1:0.1.

[0064] S6. Under the conditions of a feeding rate of 300 mL / h and an inlet air temperature of 150 °C, slurry C is spray-dried to obtain a dry powder precursor D.

[0065] S7. Under a nitrogen atmosphere, the temperature is raised to 500 °C at a heating rate of 5 °C / min, and the dry powder precursor D is calcined under these conditions for 12 h. After the calcination is completed and the material temperature is reduced to room temperature, a fast-charging sodium-ion battery composite cathode material is obtained.

[0066] Example 3: The preparation of the pyridazinyl derivative is the same as that in Example 2.

[0067] Preparation of the composite cathode material for fast-charging sodium-ion battery. Compared with Example 2, except that the mass ratio of citric acid to pyridazinyl derivative in step S5 is changed to 1:0.05, other conditions are the same as those in Example 2.

[0068] Example 4: The preparation of the pyridazinyl derivative is the same as that in Example 2.

[0069] The preparation of the pyrrolyl derivative includes: Weigh polyethylene glycol and triethylamine, add them to dichloromethane and stir to dissolve. After introducing nitrogen for 30 min, stir at 0 °C for 1 h, add p-toluenesulfonyl chloride and react for 24 h. Then add 3-pyrrolidin-2-yl-propan-1-ol and anhydrous potassium carbonate, and stir and react at 100 °C for 24 h. After the reaction is completed, it is subjected to rotary evaporation, filtration, and column chromatography purification to obtain the pyrrolyl derivative. The mass ratio of triethylamine to polyethylene glycol is 1:20; the dosage ratio of triethylamine to dichloromethane is 1 g:4.5 mL; the mass ratio of p-toluenesulfonyl chloride to polyethylene glycol is 1:10; the mass ratio of p-toluenesulfonyl chloride to 3-pyrrolidin-2-yl-propan-1-ol is 1:1; the mass ratio of 3-pyrrolidin-2-yl-propan-1-ol to anhydrous potassium carbonate is 1:3.

[0070] The preparation of the composite cathode material for fast-charging sodium-ion battery includes: S1. Mix ferrous sulfate heptahydrate, manganese sulfate monohydrate, nickel sulfate hexahydrate and copper sulfate pentahydrate, and add deionized water to obtain metal salt solution A. The mass ratio of manganese sulfate monohydrate to ferrous sulfate heptahydrate is 1:1.6; the mass ratio of nickel sulfate hexahydrate to ferrous sulfate heptahydrate is 1:1; the mass ratio of copper sulfate pentahydrate to ferrous sulfate heptahydrate is 1:3.3; the dosage ratio of anhydrous copper sulfate to deionized water is 1 g:20 mL.

[0071] S2. Add ammonia water to the sodium carbonate solution, and mix evenly to obtain solution B. The concentration of the sodium carbonate solution is 2 mol / L, the mass concentration of ammonia water is 2.28%, and the volume ratio of ammonia water to sodium carbonate solution is 1:2.

[0072] S3. After introducing nitrogen protective gas into the reaction kettle, at a feeding speed of 20 mL / min, synchronously dropwise add metal salt solution A and solution B into the reaction kettle, stir at a speed of 200 r / min, and carry out a coprecipitation reaction at 60 °C and pH of 9. After the reaction is completed, it is vacuum dried to obtain a carbonate precursor with a D50 particle size of 3 μm. The volume ratio of metal salt solution A to solution B is 1:1.7.

[0073] S4. After fully mixing the carbonate precursor with sodium carbonate, perform high-temperature calcination treatment at 950 °C in an air atmosphere for 12 h to obtain the O3-phase layered metal oxide as O3-NaFe0.3 Mn 0.3 Ni 0.3 Cu 0.1 O 2 。The mass ratio of the sodium carbonate salt precursor to sodium carbonate is 1:0.7.

[0074] S5. Mix ferrous oxalate, sodium dihydrogen phosphate, citric acid and O3-NaFe 0.3 Mn 0.3 Ni 0.3 Cu 0.1 O 2 together, add N-methylpyrrolidone, pyridazinyl derivative and pyrrolyl derivative, carry out high-speed stirring and dispersion at 800 r / min for 1 h, then carry out nano sanding treatment at a sanding linear speed of 14 m / s for 1.5 h to obtain a uniformly mixed slurry C, and the D50 particle size of the particles in the slurry C is 250 nm. The mass ratio of ferrous oxalate to sodium dihydrogen phosphate is 1:1.2; the mass ratio of citric acid to sodium dihydrogen phosphate is 1:5.4; the mass ratio of citric acid to O3-NaFe 0.3 Mn 0.3 Ni 0.3 Cu 0.1 O 2 is 1:14; the dosage ratio of citric acid to N-methylpyrrolidone is 1 g:38 mL; the mass ratio of citric acid to pyridazinyl derivative is 1:0.1; the mass ratio of citric acid to pyrrolyl derivative is 1:0.05.

[0075] S6. Under the conditions of a feeding rate of 300 mL / h and an inlet air temperature of 150 °C, carry out spray drying treatment on the slurry C to obtain a dry powder precursor D.

[0076] S7. Under a nitrogen atmosphere, raise the temperature to 500 °C at a heating rate of 5 °C / min, and carry out calcination treatment on the dry powder precursor D for 12 h under this condition. After the calcination is completed and the material temperature drops to room temperature, a fast-charging sodium-ion battery composite cathode material is obtained.

[0077] Example 5: The preparation of the pyridazinyl derivative is the same as that in Example 2.

[0078] The preparation of the pyrrolyl derivative is the same as that in Example 4.

[0079] The preparation of the fast-charging sodium-ion battery composite cathode material is the same as that in Example 4 except that the mass ratio of citric acid to pyrrolyl derivative in step S5 is changed to 1:0.02.

[0080] Comparative Example 1: The preparation of the pyrrolyl derivative is the same as that in Example 4.

[0081] Preparation of the composite cathode material for the fast-charging sodium-ion battery, compared with Example 4, except that the pyridazinyl derivative is not added in step S5, other conditions are the same as those in Example 4.

[0082] Experimental Example: Button-type sodium-ion batteries were assembled using the composite cathode materials for the fast-charging sodium-ion battery prepared in Examples 1-5 of the present invention and Comparative Example 1, and electrochemical performance tests were carried out. The specific steps are as follows: Preparation of the sodium-ion battery positive electrode sheet: The composite cathode material for the fast-charging sodium-ion battery was mixed with acetylene black and an N-methylpyrrolidone / polyvinylidene fluoride mixed solution. 15 zirconia beads with a diameter of 3 mm were added, and a mixed slurry was obtained using a micro vibration ball mill. It was coated on aluminum foil and placed in a vacuum drying oven at 100 °C for vacuum drying for 6 h. After the solvent was completely evaporated, it was cut into pieces to obtain the sodium-ion battery positive electrode sheet. The N-methylpyrrolidone / polyvinylidene fluoride mixed solution includes N-methylpyrrolidone and polyvinylidene fluoride, and the volume ratio of polyvinylidene fluoride to N-methylpyrrolidone is 1 g: 20 mL; the mass ratio of acetylene black to the high-compactness sodium iron pyrophosphate positive electrode material is 1:31; the dosage ratio of acetylene black to the N-methylpyrrolidone / polyvinylidene fluoride mixed solution is 1 g: 1 mL.

[0083] Preparation of the button-type sodium-ion battery: Using the prepared sodium-ion battery positive electrode sheet as the battery positive electrode, a glass fiber membrane as the separator, and a sodium sheet as the battery negative electrode. The electrolyte includes sodium perchlorate, fluoroethylene carbonate, and propylene carbonate. The dosage ratio of sodium perchlorate to propylene carbonate is 1 mol: 1 L, and the dosage ratio of fluoroethylene carbonate to propylene carbonate is 1 g: 20 mL, and the button-type sodium-ion battery was prepared.

[0084] The constant current charge and discharge test and cycle life test of the button-type sodium-ion battery were carried out using the newwei CT4000 power cell tester.

[0085] 1. Reversible capacity test Under the condition of 1C, the reversible capacity test results of the button-type sodium-ion batteries assembled with the composite cathode materials for the fast-charging sodium-ion battery prepared in Examples 1-5 and Comparative Example 1 are as Figure 1 shown.

[0086] Figure 1The reversible capacity of the button-type sodium-ion battery prepared according to the present invention, S1 is the reversible capacity of the button-type sodium-ion battery assembled with the fast-charging sodium-ion battery composite cathode material prepared in Example 1, S2 is the reversible capacity of the button-type sodium-ion battery assembled with the fast-charging sodium-ion battery composite cathode material prepared in Example 2, S3 is the reversible capacity of the button-type sodium-ion battery assembled with the fast-charging sodium-ion battery composite cathode material prepared in Example 3, S4 is the reversible capacity of the button-type sodium-ion battery assembled with the fast-charging sodium-ion battery composite cathode material prepared in Example 4, S5 is the reversible capacity of the button-type sodium-ion battery assembled with the fast-charging sodium-ion battery composite cathode material prepared in Example 5, and S6 is the reversible capacity of the button-type sodium-ion battery assembled with the fast-charging sodium-ion battery composite cathode material prepared in Comparative Example 1.

[0087] It can be seen from Figure 1 that the reversible capacity of the button-type sodium-ion battery assembled with the fast-charging sodium-ion battery composite cathode material prepared in Examples 2-3 of the present invention is greater than that in Example 1. This is because in the preparation of the fast-charging sodium-ion battery composite cathode material, pyridazine-based derivatives were additionally used as organic dispersants in Examples 2-3, while pyridazine-based derivatives were not used in Example 1; the reversible capacity of the button-type sodium-ion battery assembled with the fast-charging sodium-ion battery composite cathode material prepared in Example 2 of the present invention is greater than that in Example 3 because the usage amount of pyridazine-based derivatives is different in the preparation of the fast-charging sodium-ion battery composite cathode material. This shows that the fast-charging sodium-ion battery composite cathode material prepared by additionally using pyridazine-based derivatives in the present invention can improve the reversible capacity of the button-type sodium-ion battery assembled therewith. The reversible capacity of the button-type sodium-ion battery assembled with the fast-charging sodium-ion battery composite cathode material prepared in Examples 4-5 of the present invention is greater than that in Example 2 and Comparative Example 1 because in the preparation of the fast-charging sodium-ion battery composite cathode material, pyridazine-based derivatives and pyrrolyl-based derivatives were additionally used synergistically in Examples 4-5, while only pyridazine-based derivatives were used in Example 2 and only pyrrolyl-based derivatives were used in Comparative Example 1; the reversible capacity of the button-type sodium-ion battery assembled with the fast-charging sodium-ion battery composite cathode material prepared in Example 4 of the present invention is greater than that in Example 5 because the usage amount of pyrrolyl-based derivatives is different in the preparation of the fast-charging sodium-ion battery composite cathode material. This shows that the fast-charging sodium-ion battery composite cathode material prepared by additionally using pyridazine-based derivatives and pyrrolyl-based derivatives in the present invention can further improve the reversible capacity of the button-type sodium-ion battery assembled therewith.

[0088] 2. Cycle life test After the button-type sodium-ion batteries assembled with the fast-charging sodium-ion battery composite cathode materials prepared in Examples 1-5 and Comparative Example 1 were cycled 1000 times, the test results of their capacity retention rates are shown in Table 1.

[0089] Table 1 Capacity retention rate (%)

[0090] As can be seen from Table 1, the capacity retention rate of the button-type sodium-ion battery assembled with the fast-charging sodium-ion battery composite cathode material prepared in Examples 2-3 of the present invention is higher than that in Example 1. This is because in the preparation of the fast-charging sodium-ion battery composite cathode material, pyridazinyl derivatives were additionally used in Examples 2-3, while pyridazinyl derivatives were not used in Example 1; the capacity retention rate of the button-type sodium-ion battery assembled with the fast-charging sodium-ion battery composite cathode material prepared in Example 2 of the present invention is higher than that in Example 3, because in the preparation of the fast-charging sodium-ion battery composite cathode material, the usage amount of pyridazinyl derivatives is different. This shows that the fast-charging sodium-ion battery composite cathode material prepared by additionally using pyridazinyl derivatives in the present invention can improve the capacity retention rate of the button-type sodium-ion battery assembled therewith. The capacity retention rate of the button-type sodium-ion battery assembled with the fast-charging sodium-ion battery composite cathode material prepared in Examples 4-5 of the present invention is higher than that in Example 2 and Comparative Example 1. This is because in the preparation of the fast-charging sodium-ion battery composite cathode material, pyridazinyl derivatives and pyrrolyl derivatives were additionally used synergistically in Examples 4-5, while only pyridazinyl derivatives were used in Example 2 and only pyrrolyl derivatives were used in Comparative Example 1; the capacity retention rate of the button-type sodium-ion battery assembled with the fast-charging sodium-ion battery composite cathode material prepared in Example 4 of the present invention is higher than that in Example 5, because in the preparation of the fast-charging sodium-ion battery composite cathode material, the usage amount of pyrrolyl derivatives is different. This shows that the fast-charging sodium-ion battery composite cathode material prepared by additionally using pyridazinyl derivatives and pyrrolyl derivatives in the present invention can further improve the capacity retention rate of the button-type sodium-ion battery assembled therewith.

[0091] The conventional operations in the operation steps of the present invention are well known to those skilled in the art and will not be elaborated herein.

[0092] The above-described embodiments have elaborated on the technical solutions of the present invention. It should be understood that the above are only specific embodiments of the present invention and do not limit the present invention. Any modifications, supplements, or substitutions in a similar manner within the principle scope of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a composite positive electrode material for a fast-charging sodium ion battery, comprising: A metal salt solution, a sodium carbonate solution and an ammonia solution are subjected to a coprecipitation reaction, and then sodium carbonate is added for high-temperature calcination to obtain an O3 phase layered metal oxide; the O3 phase layered metal oxide is mixed with an iron source, a phosphorus source, a sodium source and a carbon source, an organic dispersant is added, and high-speed stirring and dispersion, nano-sand milling, spray drying and calcination are performed to obtain a fast-charging sodium ion battery composite positive electrode material; the organic dispersant at least includes N-methylpyrrolidone.

2. The method for preparing a fast-charging sodium-ion battery composite positive electrode material according to claim 1, characterized in that: The metal salt solution is obtained by mixing ferrous sulfate heptahydrate, manganese sulfate monohydrate, nickel sulfate hexahydrate, copper sulfate pentahydrate and deionized water.

3. The method for preparing a fast-charging sodium-ion battery composite positive electrode material according to claim 1, characterized in that: In the high temperature calcination treatment, the calcination temperature is 800-1100° C. and the calcination time is 6-24 hours.

4. The method for preparing a fast-charging sodium-ion battery composite positive electrode material according to claim 1, characterized in that: The organic dispersant includes at least one of N-methylpyrrolidone and a pyridazine derivative.

5. The method for preparing a composite positive electrode material for a fast-charging sodium ion battery according to claim 4, characterized in that: In the preparation of the pyridazine derivative, 3-carboxypyridazine is first reacted with ethylenediamine, then treated with a lithium aluminum hydride solution, and then reacted with 8-bromo-1-octene to obtain the pyridazine derivative.

6. The method for preparing a composite positive electrode material for a fast-charging sodium ion battery according to claim 5, characterized in that: The mass ratio of the ethylenediamine to the 3-carboxypyridazine is 1:2-10.

7. The method for preparing a composite positive electrode material for a fast-charging sodium ion battery according to claim 5, characterized in that: The lithium aluminum hydride solution is a mixture of lithium aluminum hydride and tetrahydrofuran, and the dosage ratio of the 3-carboxypyridazine to the lithium aluminum hydride solution is 1 g: 1-3 mL.

8. The method for preparing a composite positive electrode material for a fast-charging sodium ion battery according to claim 5, characterized in that: The mass ratio of the mono-carboxypyridazine to 8-bromo-1-octene is 1:1-5.

9. A fast-charging sodium-ion battery composite positive electrode material prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the fast-charging sodium-ion battery composite positive electrode material according to claim 9 in preparing a battery.

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