CN116443862A - A kind of high-performance sodium-ion battery negative electrode material and preparation method thereof - Google Patents

Abstract

The invention discloses a high-performance sodium ion battery anode material and a preparation method thereof, wherein in a specific autoclave, a phosphorus simple substance is used as a raw material, an organic solvent is used as a carbon source, sodium metal is used as a reducing agent, ferrocene is used as a pore-forming agent, under inert atmosphere, the raw material is heated to generate chemical reaction in a closed container and generate pressure to carry out molecule or atom recombination, in the process, the organic solvent and the ferrocene react to generate graphene and simultaneously realize doping and pore-forming, and simultaneously, the recombination process from bottom to top can realize uniform recombination of nano black phosphorus and doped perforated graphene, so that the high-performance doped perforated graphene/black phosphorus nano composite material is prepared in one step. The perforated graphene in the composite material provides high electronic conductivity, holes reduce the problems of large sheets and low ion transmission rate caused by stacking, the nano black phosphorus provides high sodium storage capacity, and doping can modulate the electrode potential of the black phosphorus-based nanocomposite material by changing the intermediate phase of the black phosphorus-based nanocomposite material in the electrochemical reaction process, and meanwhile, an ion transmission channel is constructed, so that the electrochemical reaction path is changed, and the voltage hysteresis phenomenon is reduced. The invention develops a mild one-step solvothermal method, realizes the efficient preparation of the doped perforated graphene/black phosphorus nanocomposite, and simultaneously lays a foundation for the rapid development of sodium ion batteries, wherein the high-performance sodium ion battery anode material has high specific capacity, good cycle performance, excellent multiplying power performance and small voltage hysteresis.

Description

A kind of high-performance sodium-ion battery negative electrode material and preparation method thereof

technical field

The invention belongs to the field of battery materials and the technical field of nanometer materials, and relates to a high-performance sodium-ion battery negative electrode material and a solvothermal preparation method thereof.

Background technique

Due to its high theoretical specific capacity and fast ion transport rate, black phosphorus can greatly improve the energy density and power density of sodium-ion batteries, and is a promising negative electrode material. However, the large volume expansion of single black phosphorus during sodium storage leads to poor cycle stability. By nanosizing it and combining it with other highly conductive materials such as graphene, its volume expansion can be alleviated, so that it has both high specific capacity and excellent cycle performance. However, the currently reported black phosphorus-based nanocomposites still have the problems of high electrode potential and large voltage hysteresis. The higher electrode potential of the negative electrode material will lead to lower battery energy density. At present, some researchers have found that doping with different elements can change the intermediate phase in the reaction process of black phosphorus-based materials, and then adjust its electrode potential. Secondly, a large voltage hysteresis will lead to low energy storage efficiency of the battery. The voltage hysteresis is mainly affected by reaction kinetics and reaction thermodynamics. It is expected to reduce the voltage hysteresis by constructing ion transport channels or changing the electrochemical reaction path. The combination of highly conductive perforated graphene and black phosphorus can improve the reaction kinetics to a certain extent, but more sodium phosphide produced during the reaction will still hinder the transmission of some ions. Surprisingly, tin phosphide in metal phosphides has almost no voltage hysteresis, so metal doping of black phosphorus-based nanocomposites is expected to construct ion transport channels and change the reaction path to reduce voltage hysteresis. Based on this, the development of a doped perforated graphene/black phosphorus nanocomposite material for the anode material of sodium ion batteries is expected to reduce the electrode potential and voltage hysteresis at the same time.

At present, the preparation methods of black phosphorus-based nanocomposites mainly include ball milling method, high pressure method, chemical vapor deposition method and solvothermal method. Among them, the ball milling method will destroy the structure of the black phosphorus-based material; the high-pressure method requires harsh conditions and poor controllability; the black phosphorus-based material prepared by the chemical vapor deposition method has a large size. In contrast, the solvent method has the characteristics of simple operation and strong controllability, and is expected to achieve efficient preparation of high-performance sodium-ion battery anode materials. However, the traditional solvothermal method can only prepare nano-black phosphorus/graphene composites and the temperature used is relatively high, or prepare perforated graphene, and there is no one-step preparation of doped perforated graphene/black phosphorus nanocomposites. precedent. Therefore, the development of a mild one-step solvothermal method to achieve efficient preparation and uniform compounding of doped perforated graphene/black phosphorus nanocomposites is of great significance for promoting the application of black phosphorus-based nanocomposites in the field of energy storage.

Contents of the invention

Aiming at the problem that the current black phosphorus-based nanocomposites are difficult to have high specific capacity, excellent cycle performance, low electrode potential and small voltage hysteresis, and lack of a mild, efficient and uniform preparation method, the present invention designs a high Performance sodium ion battery negative electrode material and preparation method thereof. On the one hand, rapid ion transport is realized by punching graphene, and at the same time, doping black phosphorus-based nanocomposites changes the chemical composition, and adjusts the reaction path to reduce its electrode potential and voltage hysteresis. On the other hand, through a gentle step Efficient and uniform preparation of high performance doped perforated graphene/black phosphorus nanocomposites by solvothermal method. This is of great significance for promoting the application of black phosphorus-based nanocomposites in the field of energy storage.

A high-performance sodium-ion battery negative electrode material and a preparation method thereof, the specific steps are as follows:

(1) In a specific autoclave, use phosphorus as a raw material, an organic solvent as a carbon source and a dopant, sodium metal as a reducing agent, and ferrocene as a pore-forming agent. Under an inert atmosphere, the autoclave is carried out heating;

(2) After reacting for a period of time, the raw materials generate pressure in the airtight container to carry out molecular or atomic recombination. While doping and forming holes in graphene, the uniform compounding of nano black phosphorus and doped perforated graphene is realized, resulting in high Performance doped perforated graphene/black phosphorus nanocomposites.

In the step (1), the phosphorus element form includes a kind of white phosphorus and red phosphorus;

In the step (1), the organic solvent includes one of all easily carbonized organic solvents such as ethanol, methanol, ethylenediamine, N-methylpyrrolidone, acetonitrile, and dimethylformamide;

In the step (1), the reducing agent includes sodium, magnesium, aluminum, zinc, iron, copper and other metals with strong reducing properties;

In the step (1), the pore-forming agent includes one of ferrocene, cobaltous acetylacetonate, and nickel;

Inert atmosphere is argon and/or nitrogen in the described step (1);

The heating temperature in the step (1) is ≥100°C;

The reaction time in the step (2) is ≥ 12h;

In the step (2), the appropriate mass ratio of nanometer black phosphorus to doped perforated graphene is 3:1˜1:7.

The perforated graphene doped in the step (2) includes one of porous graphene doped with various metal and non-metal atoms, porous carbon and carbon nanotubes.

Advantages and beneficial effects of the present invention:

1. The present invention designs a doped perforated graphene/black phosphorus nanocomposite material as the negative electrode material of sodium ion battery, which has both high specific capacity, good cycle performance, excellent rate performance and small voltage hysteresis. Laid the foundation for the rapid development of sodium-ion batteries;

2. The present invention develops a mild one-step solvothermal method, which realizes the efficient preparation and uniform compounding of doped black phosphorus-based nanocomposites, and the method is universal and applicable to the preparation of most nanocomposites.

Detailed ways

The present invention will be further described in detail through specific examples below, but the protection scope of the present invention is not limited to the content described.

Embodiment 1: a kind of high-performance sodium-ion battery negative electrode material and preparation method thereof, concrete steps are as follows:

(1) In a specific autoclave, red phosphorus is used as a raw material, ethanol is used as a carbon source, sodium metal is used as a reducing agent, and ferrocene is used as a pore-forming agent, and the autoclave is heated to 120° C. under an inert atmosphere;

(2) After reacting for 12 hours, the raw materials generate pressure in the airtight container to carry out molecular or atomic recombination. While doping and forming holes in graphene, the uniform compounding of nano black phosphorus and doped perforated graphene is realized, resulting in high performance Doped perforated graphene/black phosphorus nanocomposites.

Embodiment 2: a kind of high-performance sodium-ion battery negative electrode material and preparation method thereof, concrete steps are as follows:

(1) In a specific autoclave, red phosphorus is used as a raw material, ethanol is used as a carbon source, sodium metal is used as a reducing agent, and ferrocene is used as a pore-forming agent, and the autoclave is heated to 200° C. under an inert atmosphere;

(2) After reacting for 36 hours, the raw materials generate pressure in the airtight container to carry out molecular or atomic recombination. While doping and forming holes in graphene, the uniform compounding of nano black phosphorus and doped perforated graphene is realized, resulting in high performance Doped perforated graphene/black phosphorus nanocomposites.

Embodiment 3: a kind of high-performance sodium-ion battery negative electrode material and preparation method thereof, concrete steps are as follows:

(1) In a specific autoclave, red phosphorus is used as a raw material, ethanol is used as a carbon source, sodium metal is used as a reducing agent, and ferrocene is used as a pore-forming agent. Under an inert atmosphere, the autoclave is heated to 280°C;

(2) After reacting for 72 hours, the raw materials generate pressure in the airtight container to carry out molecular or atomic recombination. While doping and forming holes in graphene, the uniform compounding of nano black phosphorus and doped perforated graphene is realized, resulting in high performance Doped perforated graphene/black phosphorus nanocomposites.

Embodiment 4: a kind of high-performance sodium-ion battery negative electrode material and preparation method thereof, concrete steps are as follows:

(1) In a specific autoclave, use red phosphorus as a raw material, ethanol as a carbon source, metallic sodium as a reducing agent, and ferrocene as a pore-forming agent, and heat the autoclave to 360°C under an inert atmosphere;

(2) After reacting for 72 hours, the raw materials generate pressure in the airtight container to carry out molecular or atomic recombination. While doping and forming holes in graphene, the uniform compounding of nano black phosphorus and doped perforated graphene is realized, resulting in high performance Doped perforated graphene/black phosphorus nanocomposites.

Claims (10)

1. a high-performance sodium ion battery negative electrode material and preparation method thereof, is characterized in that, concrete steps are as follows: (1) In a specific autoclave, using phosphorus as a raw material, an organic solvent as a carbon source, sodium metal as a reducing agent, and ferrocene as a pore-forming agent, the autoclave is heated under an inert atmosphere; (2) After reacting for a period of time, the raw materials undergo a chemical reaction in the airtight container and generate pressure to carry out molecular or atomic recombination, and realize the uniform compounding of nano black phosphorus and doped perforated graphene while doping and forming holes in graphene , to generate high-performance doped perforated graphene/black phosphorus nanocomposites. 2. A high-performance sodium-ion battery negative electrode material and a preparation method thereof according to claim 1, characterized in that: the phosphorus element in the step (1) is white phosphorus or red phosphorus. 3. a kind of high-performance sodium-ion battery negative electrode material and preparation method thereof according to claim 1, is characterized in that: in step (1), organic solvent comprises ethanol, methyl alcohol, ethylenediamine, N-methylpyrrolidone, four One of all easily carbonized organic solvents such as carbon chloride, acetonitrile, and dimethylformamide. 4. a kind of high-performance sodium ion battery negative electrode material and preparation method thereof according to claim 1, is characterized in that: in step (1), reducing agent comprises sodium, magnesium, aluminium, zinc, iron, copper etc. have stronger reducing metals. 5. a kind of high-performance sodium-ion battery negative electrode material and preparation method thereof according to claim 1, is characterized in that: in step (1), pore-forming agent comprises ferrocene, cobaltous acetylacetonate, nickelocene A sort of. 6. A high-performance sodium-ion battery negative electrode material and a preparation method thereof according to claim 1, wherein the inert atmosphere in step (1) is argon and/or nitrogen. 7. A high-performance sodium-ion battery negative electrode material and its preparation method according to claim 1, characterized in that: the heating temperature in step (1) is ≥ 100°C. 8. A high-performance sodium ion battery negative electrode material and preparation method thereof according to claim 1, characterized in that: the reaction time in step (2) is ≥ 12h. 9. A kind of high-performance sodium ion battery negative electrode material and preparation method thereof according to claim 1, is characterized in that: in the step (2), the appropriate mass ratio of nano black phosphorus and doped perforated graphene is 3:1 ~1:7. 10. A kind of high-performance sodium-ion battery negative electrode material and preparation method thereof according to claim 1, is characterized in that: in step (2), doping perforated graphene comprises doping various metal and non-metal atom's porous One of graphene, porous carbon and carbon nanotubes.