WO2019062495A1

WO2019062495A1 - Carbon material and asphalt-based negative electrode material for sodium-ion battery, and preparation method therefor and applications thereof

Info

Publication number: WO2019062495A1
Application number: PCT/CN2018/104035
Authority: WO
Inventors: 陆雅翔; 容晓晖; 秦东; 唐堃; 胡勇胜; 陈立泉
Original assignee: 中国科学院物理研究所; 北京中科海钠科技有限责任公司
Priority date: 2017-09-29
Filing date: 2018-09-04
Publication date: 2019-04-04
Also published as: CN109148838A; CN109148838B

Abstract

Disclosed in the present invention are a carbon material and asphalt-based negative electrode material for a sodium-ion battery, and a preparation method therefor and applications thereof. The negative electrode material for a sodium-ion battery is a composite carbon material whose surface is coated with an asphalt-based block-shaped or vertical channel-shaped material that is of an ordered carbon structure or whose morphology is irregular. Carbon materials and asphalt are used as precursor materials, the precursor materials are mechanically mixed and experience thermal treatment in the air, so that melted asphalt is coated on the surface of the carbon material, and then, the asphalt and the carbon materials experience carbonization and cracking reactions in an inert atmosphere at the same time, so as to obtain the composite carbon material having a structure whose surface is ordered and whose inside is disordered, the carbon materials comprising wood charcoal materials and bamboo charcoal materials in type, the wood charcoals comprising one or more mixtures obtained by mixing white charcoal, black charcoal, activated charcoal and machine-made charcoal, the bamboo charcoal materials comprising one or more carbonized material mixtures obtained by mixing phyllostachys pubescen, phyllostachys glauca, pleioblastus amarus, phyllostachys praecox and dendrocalamus membranaceus, and the asphalt materials being one or more mixtures obtained by mixing coal tar pitch, petroleum asphalt and natural bitumen.

Description

Sodium ion battery anode material based on carbon material and asphalt, preparation method and application thereof

The present application claims priority to Chinese Patent Application No. 200910904851.2, entitled "Nano-ion battery anode material based on carbon material and asphalt, and its preparation method and application", filed on September 29, 2017.

Technical field

The invention relates to the technical field of materials, in particular to a sodium ion battery anode material based on carbon material and asphalt, and a preparation method and application thereof.

Background technique

With the gradual depletion of fossil fuels and the increasing environmental pollution, the development and utilization of new energy carriers has received more and more attention. Secondary batteries, as the main chemical energy storage devices, play an important role in this field. The replacement of fossil fuels with electricity as the main means of energy supply for vehicles will significantly reduce greenhouse gas emissions. Building and improving renewable energy systems such as wind, solar, and geothermal energy will greatly improve the efficiency of renewable energy use.

Sodium-ion batteries have made up for the limitations of lithium-ion battery resources, such as scarcity, uneven distribution and high cost due to their rich sodium resources, wide distribution and low cost. They have received widespread attention in recent years and have been widely studied. . The development of high performance electrode materials is critical to the commercialization of sodium ion batteries. Up to now, the development of some cathode materials has basically met the requirements of the application, but the anode material still restricts the practical use of sodium ion batteries.

Among the reported negative electrode materials for sodium ion batteries, amorphous carbon materials have become the most promising sodium ion battery anodes due to their relatively low sodium storage potential, high sodium storage capacity and good cycle stability. material. The precursors for preparing amorphous carbon materials can be classified into soft carbon and hard carbon precursors. The former is inexpensive, can be completely graphitized at high temperatures, and has excellent electrical conductivity; the latter is relatively expensive and cannot be completely graphitized at high temperatures, but The carbon material obtained after carbonization has a relatively high storage capacity and first-cycle efficiency. Combining the advantages of the two precursors, the amorphous carbon material obtained by combining the two precursors is expected to further exert its advantages and promote its large-scale application as a negative electrode of sodium ion batteries.

Summary of the invention

Embodiments of the present invention provide a sodium ion battery anode material based on carbon material and asphalt, and a preparation method and application thereof, which are rich in resources, low in price, renewable charcoal and/or bamboo charcoal, and low in cost. Common petroleum industry residue asphalt together as a composite raw material, taking into account high capacity and excellent electrical conductivity, proposed a composite carbon with low cost, simple preparation process, disordered degree, high carbon yield and suitable for large-scale production. The material was applied as a negative electrode material to a sodium ion secondary battery.

In a first aspect, an embodiment of the present invention provides a negative electrode material for a sodium ion battery based on a carbon material and a pitch, wherein the negative electrode material of the sodium ion battery is an irregularly shaped block having a surface-coated asphalt-based ordered carbon structure or Vertical channel-like composite carbon material; carbon material and asphalt as precursor materials, mechanically mixed and then heat treated in air, so that the asphalt is melted and coated on the surface of the carbon material, and then the asphalt and carbon materials are simultaneously in an inert atmosphere. Carbonized and cracked;

The carbon material comprises charcoal and/or bamboo charcoal; the charcoal comprises one or more mixtures of white carbon, black carbon, activated carbon and mechanical charcoal, and the bamboo charcoal includes carbonization of bamboo, light bamboo, bitter bamboo, Leizhu and yellow bamboo. One or more mixtures of materials; the asphalt is one or more mixtures of coal tar pitch, petroleum pitch, and natural asphalt;

The negative electrode material of the sodium ion battery has structural features of surface order and internal disorder;

Wherein, the composite carbon material prepared by the composite of the charcoal and the asphalt is irregular in shape, and the size is between 2-10 microns, the d ₀₀₂ value is between 0.37-0.40 nm, and the Lc value is 1-4 nm. Between the 3-5 nm; the composite carbon material prepared by the composite of the charcoal and the asphalt has a vertical channel shape, the length is 5-30 microns, and the pipe diameter is 2-3 microns, d _The value of ₀₀₂ is between 0.36 and 0.38 nm, the value of Lc is between 1-4 nm, and the value of La is between 3-5 nm. The carbonaceous material with irregular morphology is prepared by the composite of bamboo charcoal and asphalt. Between 2-15 microns, the d ₀₀₂ value is between 0.35 and 0.37 nm, the Lc value is between 1-4 nm, and the La value is between 3-5 nm.

Preferably, the mass ratio of the carbon material to the asphalt is 1: (0.05-0.2).

Preferably, the charcoal is obtained by kiln burning method of iron wood or hard wood, and the bamboo charcoal is obtained by kiln burning, and the asphalt is petroleum asphalt.

A second aspect of the present invention provides a method for preparing a negative electrode material for a sodium ion battery according to the above first aspect, comprising:

Mixing one or more charcoal or bamboo charcoal and asphalt raw materials in a mass ratio of 1: (0.05-0.2) to obtain a coarse powder;

Refine the coarse powder to obtain a fine powder raw material having a particle size within a certain scale;

The fine powder raw material is placed in a muffle furnace and heat-treated at 250-300 ° C for 2-4 hours to melt the asphalt and coat the surface of the carbon material;

The heat-treated raw material is placed in a high-temperature carbonization furnace, heated to a temperature of 1200 ° C to 1600 ° C at a temperature increase rate of 3 ° C / min - 5 ° C / min, and the raw material is heated at a high temperature in an inert atmosphere for a period of 2-4 In an hour, the carbonization and cracking reaction of the raw material occurs;

After cooling to room temperature, a composite carbon material having a surface ordered order, an internal disorder, and an irregular block shape or a vertical channel shape is obtained as the anode material of the sodium ion battery.

Preferably, the pulverization and mixing specifically comprises: mechanical pulverization, ball milling, stirring, sieving, and/or ultrasonic dispersion.

Preferably, before the pulverizing the one or more charcoal or bamboo charcoal and asphalt raw materials in a mass ratio of 1: (0.05-0.2), the method further comprises:

The charcoal and bamboo charcoal are prepared by a kiln firing method.

Preferably, the charcoal comprises iron charcoal or hard charcoal, the bamboo charcoal comprises porphyra charcoal, and the asphalt comprises petroleum asphalt.

In a third aspect, an embodiment of the present invention provides a negative pole piece of a sodium ion battery, including:

A current collector, a binder coated on the current collector, and the sodium ion battery anode material described in the above aspect.

According to a fourth aspect, an embodiment of the present invention provides a sodium ion secondary battery including the negative electrode tab of the above third aspect, wherein the sodium ion secondary battery is used for mobile equipment, a vehicle, and renewable energy generation, Smart grid peaking, distribution power station, backup power supply or energy storage equipment of communication base stations.

The carbon material and asphalt-based sodium ion battery anode material provided by the embodiment of the invention and the preparation method and application thereof are rich in resources, low in price, renewable charcoal and/or bamboo charcoal, and common petroleum with lower cost Industrial residue asphalt together as a composite raw material, taking into account high capacity and excellent electrical conductivity, a composite carbon material with low cost, simple preparation process, adjustable disorder, high carbon yield and suitable for large-scale production is proposed. This was applied as a negative electrode material to a sodium ion secondary battery. The sodium ion secondary battery using the anode material of the invention has high working voltage and energy density, excellent rate performance, stable cycle performance and good safety performance, and can be used not only for power sources of mobile devices and electric vehicles, but also for Energy storage equipment for renewable energy generation, smart grid peak shaving, distribution power stations, backup power sources or communication base stations.

DRAWINGS

1 is a method for preparing a composite carbon material based on carbon material and asphalt according to Embodiment 1 of the present invention;

2 is a schematic view showing the surface-ordered and internal disordered structure of the carbon material coated on the surface of the carbon material according to Embodiment 1 of the present invention;

Figure 3 is a graph showing the thermal weight loss curve of the charcoal raw material provided in Example 2 of the present invention;

4 is an XRD pattern of a composite carbon material provided in Example 3 of the present invention;

5 is a Raman spectrum of a composite carbon material according to Embodiment 3 of the present invention;

6 is an SEM image of a composite carbon material provided in Example 3 of the present invention;

7a is a graph showing a constant current charge and discharge curve of a sodium ion battery according to Embodiment 3 of the present invention;

7b is a cycle diagram of a sodium ion battery according to Embodiment 3 of the present invention;

8 is an XRD pattern of a composite carbon material provided in Example 4 of the present invention;

9 is a Raman spectrum of a composite carbon material according to Embodiment 4 of the present invention;

Figure 10 is an SEM image of a composite carbon material provided in Example 4 of the present invention;

11a is a graph showing a constant current charge and discharge curve of a sodium ion battery according to Embodiment 4 of the present invention;

Figure 11b is a cycle diagram of a sodium ion battery according to Embodiment 4 of the present invention;

12 is an XRD pattern of a composite carbon material provided in Example 5 of the present invention;

Figure 13 is an SEM image of a composite carbon material provided in Example 5 of the present invention;

14a is a graph showing a constant current charge and discharge of a sodium ion battery according to Embodiment 5 of the present invention;

14b is a cycle diagram of a sodium ion battery according to Embodiment 5 of the present invention;

15 is a graph showing a constant current charge and discharge curve of a sodium ion full battery according to Embodiment 16 of the present invention;

16 is a graph showing a constant current charge and discharge curve of a sodium ion full battery according to Embodiment 17 of the present invention.

Detailed ways

The technical solutions of the present invention are further described in detail below through the accompanying drawings and embodiments, but are not intended to limit the scope of the present invention.

Example 1

1 is a method for preparing a sodium ion battery anode material based on carbon material and asphalt according to an embodiment of the present invention, and the steps thereof are as shown in FIG. 1 , including:

Step 110, mixing one or more charcoal and / or bamboo charcoal and asphalt raw materials in a mass ratio of 1: (0.05-0.2) to obtain a coarse powder;

Specifically, the manner of pulverizing and mixing is preferably mechanical mixing, including mechanical pulverization, ball milling, stirring, sieving, and ultrasonic dispersion, and the combination of any of the above several methods. The time of mechanical mixing can be determined by the size of the precursor selected and the size of the desired pulverized particle size.

Wherein, the charcoal comprises one or more mixtures of white carbon, black carbon, activated carbon and mechanical carbon, and the bamboo charcoal comprises one or more mixtures of carbonized materials of bamboo, light bamboo, bitter bamboo, Lei bamboo and yellow bamboo, and the asphalt is coal. One or more mixtures of coke pitch, petroleum pitch, and natural bitumen. In a preferred example, the charcoal is selected from the iron charcoal or the hard charcoal prepared by the kiln firing method, and the bamboo charcoal is prepared by the kiln firing method, and the asphalt is petroleum pitch.

Step 120, refining the coarse powder to obtain a fine powder raw material having a particle size within a certain scale;

Step 130, the fine powder raw material is placed in a muffle furnace and heat-treated at 250-300 ° C for 2-4 hours, and the asphalt is melted and coated on the surface of the carbon material;

Step 140, the heat-treated raw material is placed in a high-temperature carbonization furnace, and the temperature is raised to 1200 ° C - 1600 ° C at a temperature increase rate of 3 ° C / min - 5 ° C / min, and the raw material is heated at a high temperature in an inert atmosphere for a period of time. 2-4 hours, the carbonization and cracking reaction of the raw material;

Among them, the asphalt coated on the surface of the carbon material during heat treatment gradually forms long-range ordered carbon in the carbonization process, and the inner carbon material forms a carbon layer disorderly stacking carbon with nano-pores, that is, the surface is ordered and the internal disorder is obtained. The structure (shown in Figure 2) improves electrical conductivity and further reduces costs.

The inert gas introduced is preferably argon.

In step 150, cooling to room temperature to obtain a composite carbon material having a structure, an irregular shape or a vertical channel shape is the anode material of the sodium ion battery.

Specifically, the cooling can be carried out by natural cooling, and taken out of the tube furnace after being cooled to room temperature.

The carbon material and the pitch-based pyrolysis composite carbon material provided by the embodiment are simple in preparation process, low in raw material cost, high in production efficiency, and suitable for mass production. By mixing different charcoal and/or bamboo charcoal with asphalt and adjusting the mass ratio thereof, materials of different structures and feature sizes can be obtained. By compounding with asphalt, the conductivity of the carbon material can be improved, and the degree of disorder of the composite carbon material can be adjusted by adjusting the cracking temperature, thereby obtaining a carbon material having the best electrochemical performance according to different requirements, as a sodium ion secondary battery. Anode active material.

The structural characteristics of the prepared negative electrode material for sodium ion batteries will be described below by way of Example 2.

Example 2

This embodiment provides the negative electrode material of the sodium ion battery prepared in the above Example 1.

Depending on the choice of the raw material of the carbon material and the ratio of the composite with the asphalt, the prepared negative electrode material has a surface order, an internal disorder, and an irregular block shape or a vertical channel shape. Irregular bulk carbon material prepared by the combination of charcoal and asphalt, the size is between 2-10 microns, the d ₀₀₂ value is between 0.37-0.40nm, the Lc value is between 1-4nm, and the La value is 3-5nm. The vertical channel-like carbon material prepared by the combination of charcoal and asphalt, the length is between 5-30 microns, the pipe diameter is between 2-3 microns, the d ₀₀₂ value is between 0.36-0.38 nm, and the Lc value is 1 Between -4nm, the La value is between 3-5nm; the irregular bulk carbon material prepared by the combination of bamboo charcoal and asphalt, the size is between 2-15 microns, the d ₀₀₂ value is between 0.35-0.37nm, the Lc value Between 1-4 nm, the La value is between 3-5 nm. Figure 3 shows the thermogravimetric curves of two kinds of morphological anode materials prepared by charcoal cracking at 900 °C, and their carbon yields are 71.69% and 72.49%, respectively.

The sodium ion secondary battery anode active material of the present embodiment is based on a renewable carbon material as a raw material, and is mixed with a certain proportion of low-cost soft carbon precursor asphalt, and is subjected to a preparation process of pulverization, refinement, heat treatment, and carbonization cracking. The unique morphology structure of the carbon material is preserved, the performance of the anode material is improved, and the comprehensive electrochemical performance in the sodium ion battery is improved.

In order to better understand the technical solutions provided by the present invention, specific processes for preparing the carbon material-based and pitch-based anode materials provided by the above examples of the present invention, and sodium ion secondary batteries, are respectively described below by way of a plurality of specific examples. A method in which a negative electrode material is assembled in a sodium ion secondary battery and its battery characteristics.

Example 3

2 g of iron charcoal was weighed, and 0.1 g of petroleum asphalt was mechanically pulverized, uniformly mixed, and loaded into a magnetic boat. First, it was placed in a muffle furnace, heated up to 260 ° C at a rate of 3 ° C / min, and kept for 3 hours to obtain a heat-treated asphalt-coated carbon material. Then, the heat-treated powder is placed in a tube furnace, argon gas is introduced as a shielding gas, and the temperature is raised to 1400 ° C at a rate of 3 ° C / min, and the temperature is kept for 2 hours; then, the material is naturally cooled to room temperature, and the material is taken out to obtain a final composite. The carbon material is a negative electrode material for a sodium ion secondary battery.

See Figure 4 for its XRD pattern. From the XRD pattern, d ₀₀₂ = 0.392 nm and L _c = 2.15 nm of the carbon material were obtained. Its Raman spectrum is shown in Fig. 5. From the Raman spectrum, L _a = 3.18 nm of the carbon material can be obtained. FIG. 6 is an SEM image of the carbon material prepared in the present embodiment. As can be seen from the figure, the carbon material prepared in this embodiment has an irregular shape and a size of between 2 and 10 microns.

The carbon material prepared above was used as an active material of a battery negative electrode material for the preparation of a sodium ion battery.

The powder of the prepared carbon material and the sodium alginate binder are mixed at a mass ratio of 95:5, and an appropriate amount of water is added to grind to form a slurry, and then the uniformly ground slurry is uniformly coated on the current collector aluminum foil, and dried. , cut into pieces (8 × 8) mm ² pole pieces. The pole pieces were dried under vacuum at 100 ° C for 10 hours and then transferred to a glove box for use.

The assembly of the simulated battery was carried out in a glove box of an Ar atmosphere, using sodium metal as a counter electrode, and dissolving 1 mol of NaPF ₆ in 1 L of a mixture of ethylene carbonate and diethyl carbonate in a volume ratio of 1:1 as an electrolyte. Into the CR2032 button battery. The charge and discharge test was performed at a C/10 current density using a constant current charge and discharge mode. Under the conditions of discharge cut-off voltage of 0V and charge cut-off voltage of 2.5V, the test results are shown in Figure 7a and Figure 7b. The reversible specific capacity is 304.9mAh/g, the first week Coulomb efficiency is 90.79%, and the cycle performance is stable.

Example 4

2 g of hard charcoal was weighed, and 0.1 g of petroleum asphalt was mechanically pulverized, uniformly mixed, and loaded into a magnetic boat. First, it was placed in a muffle furnace, heated up to 270 ° C at a rate of 3 ° C / min, and kept for 3 hours to obtain a heat-treated asphalt-coated carbon material. Then, the heat-treated powder is placed in a tube furnace, argon gas is introduced as a shielding gas, and the temperature is raised to 1400 ° C at a rate of 3 ° C / min, and the temperature is maintained for 2 hours; then naturally cooled to room temperature, and the material is taken out to obtain a final composite. The carbon material is a negative electrode material for a sodium ion secondary battery.

See Figure 8 for its XRD pattern. From the XRD pattern, d ₀₀₂ =0.378 nm and L _c = 2.55 nm of the carbon material were obtained. Its Raman spectrum is shown in Fig. 9. From the Raman spectrum, L _a = 4.00 nm of the carbon material can be obtained. 10 is an SEM image of the carbon material prepared in the present embodiment. It can be seen from the figure that the carbon material prepared in this embodiment has a vertical channel shape, a length of 5-30 micrometers, and a pipe aperture of 2- 3 microns.

The carbon material prepared above was used as an active material of a battery negative electrode material for the preparation of a sodium ion battery, and subjected to an electrochemical charge and discharge test. The preparation process and test method are the same as those in Example 3. The test voltage range is 0V-2.5V. The test results are shown in Figure 11a and Figure 11b. The reversible specific capacity is 261.8mAh/g, and the first week Coulomb efficiency is 89.20%. The cycle performance is stable.

Example 5

2 g of bamboo charcoal was weighed and 0.1 g of petroleum asphalt was mechanically pulverized and uniformly mixed and placed in a magnetic boat. First, it was placed in a muffle furnace, heated up to 280 ° C at a rate of 3 ° C/min, and kept for 3 hours to obtain a heat-treated asphalt-coated carbon material. Then, the heat-treated powder is placed in a tube furnace, argon gas is introduced as a shielding gas, and the temperature is raised to 1400 ° C at a rate of 3 ° C / min, and the temperature is maintained for 2 hours; then naturally cooled to room temperature, and the material is taken out to obtain a final composite. The carbon material is a negative electrode material for a sodium ion secondary battery.

See Figure 12 for its XRD pattern. From the XRD pattern, d ₀₀₂ = 0.374 nm, L _c = 2.53 nm, and La = 3.91 of the carbon material were obtained. FIG. 13 is an SEM image of the carbon material prepared in the present embodiment. As can be seen from the figure, the carbon material prepared in this embodiment has an irregular block shape and a size of 2-15 micrometers.

The carbon material prepared above was used as an active material of a battery negative electrode material for the preparation of a sodium ion battery, and subjected to an electrochemical charge and discharge test. The preparation process and test method are the same as those in Example 3. The test voltage range is 0V-2.5V. The test results are shown in Figure 14a and Figure 14b. The reversible specific capacity is 259.7mAh/g, and the first week Coulomb efficiency is 89.33%. The cycle performance is stable.

Example 6

2 g of iron charcoal was weighed, and 0.16 g of petroleum asphalt was mechanically pulverized, uniformly mixed, and loaded into a magnetic boat. First, it was placed in a muffle furnace, heated up to 270 ° C at a rate of 3 ° C/min, and kept for 3 hours to obtain a heat-treated asphalt-coated carbon material. Then, the heat-treated powder is placed in a tube furnace, argon gas is introduced as a shielding gas, and the temperature is raised to 1200 ° C at a rate of 3 ° C / min, and the temperature is maintained for 2 hours; then, the mixture is naturally cooled to room temperature, and the material is taken out to obtain a final composite. Carbon material.

The carbon material prepared above was used as an active material of a battery negative electrode material for the preparation of a sodium ion battery, and subjected to an electrochemical charge and discharge test. The preparation process and test method are the same as those in Example 3. The test voltage range is 0V-2.5V, and the results are shown in Table 1 below.

Example 7

2 g of hard charcoal was weighed, 0.2 g of petroleum asphalt was mechanically pulverized, uniformly mixed, and loaded into a magnetic boat. First, it was placed in a muffle furnace, heated up to 280 ° C at a rate of 3 ° C/min, and kept for 3 hours to obtain a heat-treated asphalt-coated carbon material. Then, the heat-treated powder is placed in a tube furnace, argon gas is introduced as a shielding gas, and the temperature is raised to 1400 ° C at a rate of 3 ° C / min, and the temperature is maintained for 2 hours; then naturally cooled to room temperature, and the material is taken out to obtain a final composite. Carbon material.

Example 8

2 g of bamboo charcoal was weighed, and 0.12 g of petroleum asphalt was mechanically pulverized, uniformly mixed, and loaded into a magnetic boat. First, it was placed in a muffle furnace, heated to 290 ° C at a rate of 3 ° C / min, and kept for 3 hours to obtain a heat-treated asphalt-coated carbon material. Then, the heat-treated powder is placed in a tube furnace and argon gas is introduced as a shielding gas, and the temperature is raised to 1400 ° C at a rate of 4 ° C / min, and the temperature is kept for 2 hours; then, the mixture is naturally cooled to room temperature, and the material is taken out to obtain a final composite. Carbon material.

Example 9

2 g of iron charcoal was weighed, and 0.24 g of petroleum asphalt was mechanically pulverized, uniformly mixed, and loaded into a magnetic boat. First, it was placed in a muffle furnace, heated up to 280 ° C at a rate of 3 ° C/min, and kept for 3 hours to obtain a heat-treated asphalt-coated carbon material. Then, the heat-treated powder is placed in a tube furnace and argon gas is introduced as a shielding gas, and the temperature is raised to 1600 ° C at a rate of 4 ° C / min, and the temperature is kept for 2 hours; then, the mixture is naturally cooled to room temperature, and the material is taken out to obtain a final composite. Carbon material.

Example 10

2 g of hard charcoal was weighed, 0.3 g of petroleum asphalt was mechanically pulverized, uniformly mixed, and loaded into a magnetic boat. First, it was placed in a muffle furnace, heated to 290 ° C at a rate of 3 ° C / min, and kept for 3 hours to obtain a heat-treated asphalt-coated carbon material. Then, the heat-treated powder is placed in a tube furnace and argon gas is introduced as a shielding gas, and the temperature is raised to 1600 ° C at a rate of 4 ° C / min, and the temperature is kept for 2 hours; then, the mixture is naturally cooled to room temperature, and the material is taken out to obtain a final composite. Carbon material.

Example 11

2 g of bamboo charcoal was weighed, and 0.24 g of petroleum asphalt was mechanically pulverized, uniformly mixed, and loaded into a magnetic boat. First, it was placed in a muffle furnace, heated up to 300 ° C at a rate of 3 ° C / min, and kept for 3 hours to obtain a heat-treated asphalt-coated carbon material. Then, the heat-treated powder is placed in a tube furnace, argon gas is introduced as a shielding gas, and the temperature is raised to 1400 ° C at a rate of 4 ° C / min, and the temperature is kept for 2 hours; then, the material is naturally cooled to room temperature, and the material is taken out to obtain a final composite. Carbon material.

Example 12

2 g of iron charcoal was weighed, and 0.32 g of petroleum asphalt was mechanically pulverized, uniformly mixed, and loaded into a magnetic boat. First, it was placed in a muffle furnace, heated to 290 ° C at a rate of 3 ° C / min, and kept for 3 hours to obtain a heat-treated asphalt-coated carbon material. Then, the heat-treated powder is placed in a tube furnace, argon gas is introduced as a shielding gas, and the temperature is raised to 1400 ° C at a rate of 3 ° C / min, and the temperature is maintained for 2 hours; then naturally cooled to room temperature, and the material is taken out to obtain a final composite. Carbon material.

Example 13

Weigh 2g of hard charcoal, 0.4g of petroleum asphalt is powdered, uniformly mixed and loaded into the magnetic boat. First, it was placed in a muffle furnace, heated up to 280 ° C at a rate of 3 ° C/min, and kept for 3 hours to obtain a heat-treated asphalt-coated carbon material. Then, the heat-treated powder is placed in a tube furnace, argon gas is introduced as a shielding gas, and the temperature is raised to 1200 ° C at a rate of 2 ° C / min, and the temperature is kept for 2 hours; then naturally cooled to room temperature, and the material is taken out to obtain a final composite. Carbon material.

Example 14

2 g of bamboo charcoal was weighed, and 0.36 g of petroleum asphalt was mechanically pulverized and uniformly mixed and charged into a magnetic boat. First, it was placed in a muffle furnace, heated up to 270 ° C at a rate of 3 ° C / min, and kept for 3 hours to obtain a heat-treated asphalt-coated carbon material. Then, the heat-treated powder is placed in a tube furnace and argon gas is introduced as a shielding gas, and the temperature is raised to 1400 ° C at a rate of 4 ° C / min, and the temperature is kept for 2 hours; then, the mixture is naturally cooled to room temperature, and the material is taken out to obtain a final composite. Carbon material.

Example 15

2 g of iron charcoal was weighed, 0.4 g of petroleum asphalt was mechanically pulverized, uniformly mixed, and loaded into a magnetic boat. First, it was placed in a muffle furnace, heated up to 300 ° C at a rate of 3 ° C / min, and kept for 3 hours to obtain a heat-treated asphalt-coated carbon material. Then, the heat-treated powder is placed in a tube furnace, argon gas is introduced as a shielding gas, and the temperature is raised to 1400 ° C at a rate of 3 ° C / min, and the temperature is maintained for 2 hours; then naturally cooled to room temperature, and the material is taken out to obtain a final composite. Carbon material.

Example 16

The carbon material provided in Example 3 is used as an active material of a negative electrode material for a sodium ion secondary battery, and O3-NaCu _1/9 Ni _2/9 Fe _1/3 Mn _1/3 O _{2 is} used as a positive electrode active material for sodium ion. The preparation of the whole battery, the preparation process and the test method were the same as in Example 3, and the electrochemical charge and discharge test was performed. The test voltage range is 1.5-4.0V, and the charge and discharge test results are shown in Figure 15.

Example 17

The carbon material provided in Example 4 is used as an active material of a negative electrode material for a sodium ion secondary battery, and O3-NaCu _1/9 Ni _2/9 Fe _1/3 Mn _1/3 O _{2 is} used as a positive electrode active material for sodium ions. The preparation of the whole battery, the preparation process and the test method were the same as in Example 3, and the electrochemical charge and discharge test was performed. The test voltage range is 1.5-4.0V, and the charge and discharge test results are shown in Figure 16.

Table 1 Related structural parameters and specific capacity of anode materials prepared in different examples

The negative electrode material for sodium ion secondary battery provided in the above embodiments of the present invention is rich in raw material resources, low in cost, simple in preparation process, high in production efficiency, and suitable for mass production. The composite carbon material obtained by the preparation method provided by the embodiment of the invention is used as the negative electrode active material of the sodium ion battery, and the measured sodium ion battery has high working voltage and energy density, excellent rate performance, stable cycle performance and good safety performance. It can be used not only for power supplies of mobile devices and electric vehicles, but also for energy storage devices such as renewable energy generation, smart grid peak shaving, distributed power stations, backup power supplies or communication base stations.

The specific embodiments of the present invention have been described in detail with reference to the preferred embodiments of the present invention. All modifications, equivalent substitutions, improvements, etc., made within the spirit and scope of the invention are intended to be included within the scope of the invention.

Claims

A sodium ion battery anode material based on carbon material and asphalt, characterized in that the anode material of the sodium ion battery is a composite of a surface-coated asphalt-based ordered carbon structure in an irregular block shape or a vertical channel shape. Carbon material; carbon material and asphalt as precursor materials, mechanically mixed and then heat treated in air, the asphalt is melted and coated on the surface of the carbon material, and then the asphalt and carbon materials are simultaneously carbonized and cracked under an inert atmosphere. to make;

The carbon material comprises charcoal and/or bamboo charcoal; the charcoal comprises one or more mixtures of white carbon, black carbon, activated carbon and mechanical charcoal, and the bamboo charcoal includes carbonization of bamboo, light bamboo, bitter bamboo, Leizhu and yellow bamboo. One or more mixtures of materials; the asphalt is one or more mixtures of coal tar pitch, petroleum pitch, and natural asphalt;

The negative electrode material of the sodium ion battery has structural features of surface order and internal disorder;

Wherein, the composite carbon material prepared by the composite of the charcoal and the asphalt is irregular in shape, and the size is between 2-10 microns, the d 002 value is between 0.37-0.40 nm, and the Lc value is 1-4 nm. Between the 3-5 nm; the composite carbon material prepared by the composite of the charcoal and the asphalt has a vertical channel shape, the length is 5-30 microns, and the pipe diameter is 2-3 microns, d The value of 002 is between 0.36 and 0.38 nm, the value of Lc is between 1-4 nm, and the value of La is between 3-5 nm. The carbonaceous material with irregular morphology is prepared by the composite of bamboo charcoal and asphalt. Between 2-15 microns, the d 002 value is between 0.35 and 0.37 nm, the Lc value is between 1-4 nm, and the La value is between 3-5 nm.
The negative electrode material for a sodium ion battery according to claim 1, wherein a mass ratio of the carbon material to the pitch is 1: (0.05 - 0.2).
The negative electrode material for a sodium ion battery according to claim 1, wherein the charcoal is obtained by kiln firing of iron wood or hard wood, and the bamboo charcoal is obtained by kiln firing.
The method for preparing a negative electrode material for a sodium ion battery according to any one of claims 1 to 3, wherein the method comprises:

Mixing one or more carbon materials and asphalt raw materials in a mass ratio of 1: (0.05-0.2) to obtain a coarse powder;

Refine the coarse powder to obtain a fine powder raw material having a particle size within a certain scale;

The fine powder raw material is placed in a muffle furnace and heat-treated at 250-300 ° C for 2-4 hours to melt the asphalt and coat the surface of the carbon material;

The heat-treated raw material is placed in a high-temperature carbonization furnace, heated to a temperature of 1200 ° C to 1600 ° C at a temperature increase rate of 3 ° C / min - 5 ° C / min, and the raw material is heated at a high temperature in an inert atmosphere for a period of 2-4 In an hour, the carbonization and cracking reaction of the raw material occurs;

After cooling to room temperature, a composite carbon material having a surface ordered order, an internal disorder, and an irregular block shape or a vertical channel shape is obtained as the anode material of the sodium ion battery.
The preparation method according to claim 4, wherein the method further comprises: before the one or more carbon materials and the pitch raw material are pulverized in a mass ratio of 1: (0.05 - 0.2), the method further comprises :

The charcoal and bamboo charcoal are prepared by a kiln firing method.
The method according to claim 4, wherein the charcoal comprises iron charcoal or hard charcoal, and the charcoal comprises cinnamaria charcoal.
The preparation method according to claim 4, wherein the carbon material and the asphalt are heat-treated at a low temperature in the air, and the asphalt is melted and coated on the surface of the carbon material, and is externally ordered after being carbonized at a high temperature in an inert atmosphere. Internally disordered composite carbon material.
A negative pole piece of a sodium ion battery, characterized in that the negative electrode piece comprises:

A current collector, an adhesive coated on the current collector, and the sodium ion battery negative electrode material according to any one of claims 1 to 3.
A sodium ion secondary battery comprising the negative electrode tab of claim 8, wherein the sodium ion secondary battery is used for mobile equipment, vehicles, and renewable energy power generation, smart grid peak shaving, Large-scale energy storage equipment for distributed power stations, backup power sources, or communication base stations.