Negative electrode material for potassium-ion battery, preparation method thereof and negative electrode sheet

Abstract

The invention discloses a negative electrode material for a potassium-ion battery, a preparation method thereof and a negative electrode sheet. The negative electrode material is a hierarchical porouscarbon microsphere material and has a hierarchical porous structure. The hierarchical porous carbon microsphere material is constituted by winding nitrogen-doped porous carbon nanofibers. The preparation method of the negative electrode material for the potassium-ion battery is friendly to environment, simple in process, safe, low in cost and capable of achieving mass preparation. The negative electrode sheet comprises a negative electrode material for a potassium-ion battery. The negative electrode material of the invention has high level of nitrogen doping and hierarchical porous structureat the same time, which not only ensures rapid electron and ion transport, but also provides a large number of interface potassium storage active sites. In addition, the negative electrode material enhances the adsorption capacity of potassium-ion, and greatly improves the specific capacity and rate capacity of potassium storage, thus providing the negative electrode material for the potassium-ionbattery and the negative electrode sheet with high energy density and high power density.

Description

technical field

[0001] The invention belongs to the field of electrochemistry and battery technology, and more specifically relates to a negative electrode material for a potassium ion battery, a preparation method thereof, and a negative electrode sheet. Background technique

[0002] Energy and environment are two eternal themes involved in the sustainable development of human society. In the face of energy and environmental issues, new clean energy technologies, especially energy storage technologies, are considered to be one of the effective ways. Compared with traditional Ni-MH batteries and lead-acid batteries, alkali metal ions (Li + / Na + / K + ) batteries have higher energy density and environmental friendliness, and have broad application prospects in the field of clean energy storage. Among them, lithium-ion batteries are widely used in communication equipment, electronic equipment, electric vehicles and other fields due to their environmental friendliness, safe...

Examples

preparation example Construction

[0040] According to a second aspect of the present invention, a kind of preparation method of negative electrode material for potassium ion battery is provided, comprising the following steps:

[0041] (1) Disperse chitin powder in a mixed solution of NaOH, urea and water, wherein NaOH accounts for 6wt%-14wt% of the mixed solution, urea accounts for 2wt%-6wt% of the mixed solution, and the freezing temperature is -20°C to - Keep at 45°C for 2 hours to 6 hours, and perform several freeze-thaw cycles until a transparent first solution is obtained;

[0042] (2) Add the first solution to the mixed solution of isooctane and Span 85, wherein the mass ratio of the first solution, isooctane and Span 85 is 16:40:1, stir at -10°C-0°C 0.5 hour-2 hours, obtain the second solution;

[0043] (3) Centrifuge the second solution to obtain the carbon microsphere precursor, wash the carbon microsphere precursor several times with ethanol and water to obtain the third solution, and freeze the th...

Embodiment 1

[0054] A preparation method for a negative electrode material for a potassium ion battery, comprising the following steps:

[0055] (1) Disperse the chitin powder in a mixed solution of NaOH, urea and water, wherein NaOH accounts for 10wt% of the mixed solution, urea accounts for 4wt% of the mixed solution, the freezing temperature is -30°C, keep for 4 hours, and freeze- Thaw several cycles until a clear first solution is obtained;

[0056] (2) Add the first solution to the mixed solution of excess isooctane and a small amount of Span 85 and mix well, wherein the mass ratio of the first solution, isooctane and Span 85 is 16:40:1. Stir for 0.5 hour to obtain the second solution;

[0057] (3) Centrifuge the second solution to obtain the carbon microsphere precursor, wash the carbon microsphere precursor several times with ethanol and water to obtain the third solution, freeze-dry the third solution at -30°C for 4 hours to obtain Nitrogen-doped porous carbon nanofibers;

[005...

Embodiment 2

[0079] A preparation method for a negative electrode material for a potassium ion battery, comprising the following steps:

[0080] (1) Disperse the chitin powder in the mixed solution of NaOH, urea and water, wherein NaOH accounts for 6wt% of the mixed solution, urea accounts for 6wt% of the mixed solution, the freezing temperature is -20°C, keep for 6 hours, and freeze- Thaw several cycles until a clear first solution is obtained;

[0081] (2) Add the first solution to the mixed solution of excess isooctane and a small amount of Span 85, mix well, and stir at -5°C for 1 hour to obtain the second solution;

[0082] (3) Centrifuge the second solution to obtain the carbon microsphere precursor, wash the carbon microsphere precursor several times with ethanol and water to obtain the third solution, freeze-dry the third solution at -20°C for 6 hours to obtain Nitrogen-doped porous carbon nanofibers;

[0083](4) The nitrogen-doped porous carbon nanofibers were heat-treated for 4...

technical field

[0001] The invention belongs to the field of electrochemistry and battery technology, and more specifically relates to a negative electrode material for a potassium ion battery, a preparation method thereof, and a negative electrode sheet. Background technique

[0002] Energy and environment are two eternal themes involved in the sustainable development of human society. In the face of energy and environmental issues, new clean energy technologies, especially energy storage technologies, are considered to be one of the effective ways. Compared with traditional Ni-MH batteries and lead-acid batteries, alkali metal ions (Li + / Na + / K + ) batteries have higher energy density and environmental friendliness, and have broad application prospects in the field of clean energy storage. Among them, lithium-ion batteries are widely used in communication equipment, electronic equipment, electric vehicles and other fields due to their environmental friendliness, safe...

Examples

preparation example Construction

[0040] According to a second aspect of the present invention, a kind of preparation method of negative electrode material for potassium ion battery is provided, comprising the following steps:

[0041] (1) Disperse chitin powder in a mixed solution of NaOH, urea and water, wherein NaOH accounts for 6wt%-14wt% of the mixed solution, urea accounts for 2wt%-6wt% of the mixed solution, and the freezing temperature is -20°C to - Keep at 45°C for 2 hours to 6 hours, and perform several freeze-thaw cycles until a transparent first solution is obtained;

[0042] (2) Add the first solution to the mixed solution of isooctane and Span 85, wherein the mass ratio of the first solution, isooctane and Span 85 is 16:40:1, stir at -10°C-0°C 0.5 hour-2 hours, obtain the second solution;

[0043] (3) Centrifuge the second solution to obtain the carbon microsphere precursor, wash the carbon microsphere precursor several times with ethanol and water to obtain the third solution, and freeze the th...

Embodiment 1

[0054] A preparation method for a negative electrode material for a potassium ion battery, comprising the following steps:

[0055] (1) Disperse the chitin powder in a mixed solution of NaOH, urea and water, wherein NaOH accounts for 10wt% of the mixed solution, urea accounts for 4wt% of the mixed solution, the freezing temperature is -30°C, keep for 4 hours, and freeze- Thaw several cycles until a clear first solution is obtained;

[0056] (2) Add the first solution to the mixed solution of excess isooctane and a small amount of Span 85 and mix well, wherein the mass ratio of the first solution, isooctane and Span 85 is 16:40:1. Stir for 0.5 hour to obtain the second solution;

[0057] (3) Centrifuge the second solution to obtain the carbon microsphere precursor, wash the carbon microsphere precursor several times with ethanol and water to obtain the third solution, freeze-dry the third solution at -30°C for 4 hours to obtain Nitrogen-doped porous carbon nanofibers;

[005...

Embodiment 2

[0079] A preparation method for a negative electrode material for a potassium ion battery, comprising the following steps:

[0080] (1) Disperse the chitin powder in the mixed solution of NaOH, urea and water, wherein NaOH accounts for 6wt% of the mixed solution, urea accounts for 6wt% of the mixed solution, the freezing temperature is -20°C, keep for 6 hours, and freeze- Thaw several cycles until a clear first solution is obtained;

[0081] (2) Add the first solution to the mixed solution of excess isooctane and a small amount of Span 85, mix well, and stir at -5°C for 1 hour to obtain the second solution;

[0082] (3) Centrifuge the second solution to obtain the carbon microsphere precursor, wash the carbon microsphere precursor several times with ethanol and water to obtain the third solution, freeze-dry the third solution at -20°C for 6 hours to obtain Nitrogen-doped porous carbon nanofibers;

[0083](4) The nitrogen-doped porous carbon nanofibers were heat-treated for 4...

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