Preparation method of ternary nitrogen-doped hollow sphere mesoporous carbon, product and application

Abstract

The application provides a preparation method of ternary nitrogen-doped hollow sphere mesoporous carbon, a product and an application thereof. Silica is dispersed in a trimethylamine buffer solution and ultrasonic treatment is performed, hydrochloric acid dopamine is added into the solution and ultrasonic treatment is performed, stirring, centrifugal separation, washing, carbonization, washing in a hydrogen chloride amine solution, nitrogen-doped hollow sphere mesoporous carbon is obtained, the nitrogen-doped hollow sphere mesoporous carbon is dissolved in deionized water, soluble cobalt salt is added, and ultrasonic dispersion is performed; the solution is dispersed in peroxyacetic acid, stirring, centrifugal separation, drying, and cobalt tetraoxide nitrogen-doped hollow sphere mesoporous carbon is obtained; a lithium source, a nickel salt, cobalt tetraoxide nitrogen-doped hollow sphere mesoporous carbon and a manganese salt are uniformly mixed, and then calcination is performed at 750-900 DEG C for 10-15 h, and a final product is obtained. The first discharge specific capacity of the ternary nitrogen-doped hollow sphere mesoporous carbon is 178.6 mAh / g, and after 50 cycles, the discharge specific capacity is 173.2 mAh / g, and the capacity retention rate is 96.7%.

Description

TECHNICAL FIELD

[0001] The application relates to a preparation method of a lithium battery positive electrode material, in particular to a preparation method of ternary nitrogen-doped hollow sphere mesoporous carbon, and a product and application thereof. BACKGROUND

[0002] Lithium ion secondary batteries have been widely applied in the fields of mobile communication, notebook computers, video cameras, cameras, portable instruments and meters, etc. as high specific energy chemical power sources, and have rapidly developed into one of the most important secondary batteries. As the latest generation of green high-energy storage batteries, lithium ion batteries have rapidly developed since the early 1990s. Lithium ion batteries are favored due to their high voltage, high energy density, long cycle life, small environmental pollution and other advantages.

[0003] The ternary material LiNi 1-x-y Co x Mn y O2 (referred to as NCM, wherein 0 < x < 1, 0 < y < 1) has characteristics superior to lithium iron phosphate and lithium cobaltate, and different performance ternary electrode materials can be prepared according to the proportion of nickel, cobalt and manganese. NCM improves the structural stability of the material, improves the charge-discharge cycle stability and high-temperature stability of the material, and maximizes the excellent electrochemical performance thereof.

[0004] The application provides a preparation method of ternary nitrogen-doped hollow sphere mesoporous carbon, and a product and application thereof. The ternary nitrogen-doped hollow sphere mesoporous carbon is prepared by compounding ternary and nitrogen-doped hollow sphere mesoporous carbon. The compounding of the ternary and nitrogen-doped hollow sphere mesoporous carbon increases the electronic conduction channel, improves the electrical conductivity of the material, and has a shielding effect, so that the stability of the battery material is improved. SUMMARY

[0005] The application aims to provide a preparation method of ternary nitrogen-doped hollow sphere mesoporous carbon.

[0006] The application further aims to provide a ternary nitrogen-doped hollow sphere mesoporous carbon product prepared by the above method.

[0007] The application further aims to provide an application of the above product.

[0008] The application aims to achieve the above purposes by the following scheme: a preparation method of ternary nitrogen-doped hollow sphere mesoporous carbon, which is prepared by compounding ternary and nitrogen-doped hollow sphere mesoporous carbon. The compounding of the ternary and nitrogen-doped hollow sphere mesoporous carbon includes the following steps:

[0009] 1) dispersing silica in a trimethylamine buffer solution, ultrasonic for 10~20 min, adding dopamine hydrochloride into the above solution, the mass ratio of silica and dopamine hydrochloride is 5:1, continuing ultrasonic for 5~10 min, stirring at room temperature for 20~30 h, centrifuging the suspension, and washing 3~5 times with deionized water and ethanol, carbonizing under the condition of inert gas argon at 800~850 ℃ for 2~3 h, then washing in 4~6 M hydrogen chloride amine solution for 24~36 h, obtaining nitrogen-doped hollow sphere mesoporous carbon;

[0010] 2) weighing nitrogen-doped hollow sphere mesoporous carbon and dissolving it in deionized water, adding soluble cobalt salt thereto, wherein the molar ratio of nitrogen-doped hollow sphere mesoporous carbon and manganese salt is 1:6, ultrasonic dispersion for 30~60 min;

[0011] 3) dispersing the solution in step 2) in 10%~15% peroxoacetic acid, magnetic stirring for 3~5 h, then centrifuging and drying at 60~80 ℃ for 0.5~2 h, obtaining cobalt tetroxide@nitrogen-doped hollow sphere mesoporous carbon;

[0012] 4) mixing lithium source, nickel salt, cobalt tetroxide@nitrogen-doped hollow sphere mesoporous carbon and manganese salt uniformly, wherein the molar ratio of lithium salt, nickel salt, cobalt tetroxide@nitrogen-doped hollow sphere mesoporous carbon and manganese salt is 1:1-x-y:x:y (0

[0013] The cobalt salt is one or a combination of cobalt chloride, cobalt acetate or cobalt nitrate.

[0014] The lithium source is one or a combination of lithium hydroxide, lithium acetate or lithium carbonate.

[0015] The nickel salt is one or a combination of nickel chloride, nickel acetate or nickel nitrate.

[0016] The manganese salt is one or a combination of manganese chloride, manganese acetate or manganese nitrate.

[0017] The application provides a ternary@nitrogen-doped hollow sphere mesoporous carbon prepared according to any of the above-mentioned methods.

[0018] The application provides application of the ternary@nitrogen-doped hollow sphere mesoporous carbon in lithium battery positive electrode materials.

[0019] Advantages:

[0020] The application provides a preparation method, product and application of ternary nitrogen-doped hollow sphere mesoporous carbon. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 Figure is a cycle life diagram of the ternary nitrogen-doped hollow sphere mesoporous carbon in Example 1. DETAILED DESCRIPTION

[0022] The application is described in detail through the following specific examples, but the protection scope of the application is not limited to the examples.

[0023] Example 1

[0024] A ternary nitrogen-doped hollow sphere mesoporous carbon is prepared through the following steps:

[0025] 1) dispersing silica in a trimethylamine buffer solution, ultrasonicating for 10 min, adding dopamine hydrochloride into the above solution, the mass ratio of silica and dopamine hydrochloride being 5:1, continuing to ultrasonicate for 5-10 min, stirring at room temperature for 20 h, centrifuging the suspension, and washing with deionized water and ethanol for 3 times, carbonizing at 800 DEG C under the condition of inert gas argon for 3 h, then washing in a 4 M hydrogen chloride amine solution for 24-36 h, to obtain nitrogen-doped hollow sphere mesoporous carbon;

[0026] 2) weighing the nitrogen-doped hollow sphere mesoporous carbon, dissolving it in deionized water, and adding soluble cobalt acetate into it, wherein the molar ratio of the nitrogen-doped hollow sphere mesoporous carbon and the cobalt acetate is 1:6, and ultrasonicating for 3 min;

[0027] 3) dispersing the solution in step 2) in 10% peroxoacetic acid, magnetically stirring for 5 h, then centrifuging and drying at 60 DEG C for 2 h, to obtain cobalt tetraoxide@nitrogen-doped hollow sphere mesoporous carbon;

[0028] 4) mixing lithium source, nickel salt, cobalt tetraoxide@nitrogen-doped hollow sphere mesoporous carbon and manganese acetate uniformly, wherein the molar ratio of lithium acetate, nickel acetate, cobalt tetraoxide@nitrogen-doped hollow sphere mesoporous carbon and manganese acetate is 1:0.333:0.333:0.333, then calcining at 750 DEG C for 15 h, to obtain the final product.

[0029] Figure 1 Figure is a cycle life diagram of the ternary nitrogen-doped hollow sphere mesoporous carbon in Example 1, the first discharge specific capacity of which is 178.6 mAh / g, and the discharge specific capacity after 50 cycles is 173.2 mAh / g, and the capacity retention rate is 96.7%.

[0030] Example 2

[0031] A ternary nitrogen-doped hollow sphere mesoporous carbon is prepared by the following steps:

[0032] 1) The silica is dispersed in a trimethylamine buffer solution, and ultrasonic is applied for 15 min. Dopamine hydrochloride is added to the above solution, and the mass ratio of silica to dopamine hydrochloride is 5:1. Ultrasonic is applied for another 10 min. Stirring is applied at room temperature for 30 h. The suspension is centrifuged, and washed with deionized water and ethanol for 5 times. Carbonization is applied at 850 ℃ under the condition of inert gas argon for 2 h. Then, washing is applied in 5 M hydrogen chloride amine solution for 30 h, to obtain the nitrogen-doped hollow sphere mesoporous carbon.

[0033] 2) The nitrogen-doped hollow sphere mesoporous carbon is weighed and dissolved in deionized water. Soluble cobalt chloride is added thereto, and the molar ratio of the nitrogen-doped hollow sphere mesoporous carbon to the cobalt chloride is 1:6. Ultrasonic dispersion is applied for 40 min.

[0034] 3) The above solution is dispersed in 15% peroxoacetic acid by mass fraction, and magnetic stirring is applied for 3 h. Then, centrifugation is applied and drying is applied at 80 ℃ for 2 h, to obtain the ternary cobalt oxide@nitrogen-doped hollow sphere mesoporous carbon.

[0035] 4) Lithium hydroxide, nickel chloride, ternary cobalt oxide@nitrogen-doped hollow sphere mesoporous carbon, and manganese chloride are uniformly mixed, and the molar ratio of the lithium hydroxide, the nickel chloride, the ternary cobalt oxide@nitrogen-doped hollow sphere mesoporous carbon, and the manganese chloride is 1:0.5:0.3:0.2. Then, calcination is applied at 800 ℃ for 12 h, to obtain the final product.

[0036] Example 3

[0037] A ternary nitrogen-doped hollow sphere mesoporous carbon is prepared by the following steps:

[0038] 1) The silica is dispersed in a trimethylamine buffer solution, and ultrasonic is applied for 20 min. Dopamine hydrochloride is added to the above solution, and the mass ratio of silica to dopamine hydrochloride is 5:1. Ultrasonic is applied for another 10 min. Stirring is applied at room temperature for 30 h. The suspension is centrifuged, and washed with deionized water and ethanol for 5 times. Carbonization is applied at 850 ℃ under the condition of inert gas argon for 2 h. Then, washing is applied in 6 M hydrogen chloride amine solution for 36 h, to obtain the nitrogen-doped hollow sphere mesoporous carbon.

[0039] 2) The nitrogen-doped hollow sphere mesoporous carbon is weighed and dissolved in deionized water. Soluble cobalt nitrate is added thereto, and the molar ratio of the nitrogen-doped hollow sphere mesoporous carbon to the cobalt nitrate is 1:6. Ultrasonic dispersion is applied for 60 min.

[0040] 3) dispersing the above solution in 15% peracetic acid by mass fraction, magnetically stirring for 5 h, then centrifuging and drying at 80 ℃ for 1 h to obtain cobalt tetraoxide@nitrogen-doped hollow sphere mesoporous carbon;

[0041] Lithium carbonate, nickel nitrate, cobalt tetraoxide@nitrogen-doped hollow sphere mesoporous carbon, and manganese nitrate are uniformly mixed, wherein the molar ratio of lithium carbonate, nickel nitrate, cobalt tetraoxide@nitrogen-doped hollow sphere mesoporous carbon, and manganese nitrate is 1:0.8:0.1:0.1, then calcined at 900 ℃ for 10 h to obtain the final product.

Claims

1. A method for preparing ternary nitrogen-doped hollow spherical mesoporous carbon, characterized in that, It includes the following steps: 1) Disperse silica in a tris buffer solution, and ultrasonicate for 10 - 20 min. Add dopamine hydrochloride to the above solution. The mass ratio of silica to dopamine hydrochloride is 5:

1. Continue ultrasonicating for 5 - 10 min, stir at room temperature for 20 - 30 h, centrifuge the suspension, and wash it 3 - 5 times with deionized water and ethanol. Carbonize it at 800 - 850 °C for 2 - 3 h under the condition of inert gas argon, and then wash it in 4 - 6 M ammonium chloride solution for 24 - 36 h to obtain nitrogen-doped hollow spherical mesoporous carbon; 2) Weigh the nitrogen-doped hollow spherical mesoporous carbon and dissolve it in deionized water. Add a soluble cobalt salt to it and ultrasonic disperse for 30 - 60 min; 3) Disperse the solution in step 2) in peracetic acid with a mass fraction of 10% - 15%, magnetically stir for 3 - 5 h, then centrifuge and dry at 60 - 80 °C for 0.5 - 2 h to obtain cobalt tetroxide@nitrogen-doped hollow spherical mesoporous carbon; 4) Mix the lithium source, nickel salt, cobalt tetroxide@nitrogen-doped hollow spherical mesoporous carbon, and manganese salt evenly. The molar ratio of the lithium source, nickel salt, cobalt tetroxide@nitrogen-doped hollow spherical mesoporous carbon, and manganese salt is 1:1 - x - y:x:y, where 0 < x < 1 and 0 < y < 1. Then calcine at 750 - 900 °C for 10 - 15 h to obtain the final product.

2. The method for preparing ternary@nitrogen-doped hollow spherical mesoporous carbon according to claim 1, characterized in that... The cobalt salt is one or a combination of cobalt chloride, cobalt acetate, or cobalt nitrate.

3. The method for preparing ternary@nitrogen-doped hollow spherical mesoporous carbon according to claim 1, characterized in that... The lithium source is one or a combination of lithium hydroxide, lithium acetate, or lithium carbonate.

4. The method for preparing ternary@nitrogen-doped hollow spherical mesoporous carbon according to claim 1, characterized in that... The nickel salt is one or a combination of nickel chloride, nickel acetate, or nickel nitrate.

5. A method for preparing a ternary nitrogen-doped hollow spherical mesoporous carbon according to any one of claims 1 to 4, characterized in that, It is prepared according to the following steps: 1) Disperse silica in a tris buffer solution, ultrasonicate for 15 min. Add dopamine hydrochloride to the above solution. The mass ratio of silica to dopamine hydrochloride is 5:

1. Continue ultrasonicating for 10 min, stir at room temperature for 30 h, centrifuge the suspension, and wash it 5 times with deionized water and ethanol. Carbonize it at 850 °C for 2 h under the condition of inert gas argon, and then wash it in 5 M ammonium chloride solution for 30 h to obtain nitrogen-doped hollow spherical mesoporous carbon; 2) Weigh the nitrogen-doped hollow spherical mesoporous carbon and dissolve it in deionized water. Add soluble cobalt chloride to it. The molar ratio of nitrogen-doped hollow spherical mesoporous carbon to cobalt chloride is 1:

6. Ultrasonic disperse for 40 min; 3) Disperse the above solution in peracetic acid with a mass fraction of 15%, magnetically stir for 3 h, then centrifuge and dry at 80 °C for 2 h to obtain cobalt tetroxide@nitrogen-doped hollow spherical mesoporous carbon; 4) Mix lithium hydroxide, nickel chloride, cobalt tetroxide@nitrogen-doped hollow spherical mesoporous carbon, and manganese chloride evenly. The molar ratio of lithium hydroxide, nickel chloride, cobalt tetroxide@nitrogen-doped hollow spherical mesoporous carbon, and manganese chloride is 1:0.5:0.3:0.

2. Then calcine at 800 °C for 12 h to obtain the final product.

6. A method for preparing ternary nitrogen-doped hollow spherical mesoporous carbon according to any one of claims 1 to 4, characterized in that, It is prepared according to the following steps: 1) Disperse silica in tris(hydroxymethyl)amine buffer solution and sonicate for 20 min. Add dopamine hydrochloride to the above solution with a mass ratio of silica to dopamine hydrochloride of 5:

1. Continue sonicating for 10 min and stirring at room temperature for 30 h. Centrifuge the suspension and wash it 5 times with deionized water and ethanol. Carbonize it at 850 °C for 2 h under inert argon gas and then wash it in 6 M ammonium chloride solution for 36 h to obtain nitrogen-doped hollow spherical mesoporous carbon. 2) Weigh nitrogen-doped hollow sphere mesoporous carbon and dissolve it in deionized water. Add soluble cobalt nitrate to the solution, wherein the molar ratio of nitrogen-doped hollow sphere mesoporous carbon to cobalt nitrate is 1:

6. Disperse the solution by ultrasonication for 60 min. 3) The above solution was dispersed in 15% peracetic acid by mass, magnetically stirred for 5 h, then centrifuged and dried at 80 °C for 1 h to obtain cobalt tetroxide@nitrogen-doped hollow spherical mesoporous carbon. 4) Lithium carbonate, nickel nitrate, cobalt tetroxide@nitrogen-doped hollow spherical mesoporous carbon, and manganese nitrate were mixed evenly, wherein the molar ratio of lithium carbonate, nickel nitrate, cobalt tetroxide@nitrogen-doped hollow spherical mesoporous carbon, and manganese nitrate was 1:0.8:0.1:0.

1. Then, the mixture was calcined at 900 °C for 10 h to obtain the final product.

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