CN110745799A - Iron phosphide nanocube modified graphene/carbon nanotube composite aerogel material, preparation method thereof and lithium-sulfur battery - Google Patents

Iron phosphide nanocube modified graphene/carbon nanotube composite aerogel material, preparation method thereof and lithium-sulfur battery Download PDF

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CN110745799A
CN110745799A CN201911024743.1A CN201911024743A CN110745799A CN 110745799 A CN110745799 A CN 110745799A CN 201911024743 A CN201911024743 A CN 201911024743A CN 110745799 A CN110745799 A CN 110745799A
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composite aerogel
carbon nanotube
aerogel material
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邓昭
陈宇杰
赵晓辉
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Suzhou University
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Abstract

The invention discloses a preparation method of a graphene/carbon nanotube composite aerogel material modified by iron phosphide nanocubes, which comprises the following steps: dispersing graphene powder, acidified carbon nanotubes and Prussian blue in water to form a dispersion liquid, and quickly freezing and drying by adopting liquid nitrogen; heating sodium hypophosphite to obtain phosphine gas to reduce the composite aerogel, and phosphorizing Prussian blue in the material to obtain the iron phosphide nanocube modified graphene/carbon nanotube composite aerogel material. The invention also provides the composite aerogel material prepared by the method and application of the composite aerogel material in a lithium-sulfur battery. The iron phosphide nanocube modified graphene/carbon nanotube composite aerogel material can fix lithium polysulfide and reduce the shuttle effect of the lithium polysulfide in a lithium-sulfur battery, so that the cycling stability and the utilization rate of active substances of the lithium-sulfur battery are greatly improved; meanwhile, a large amount of lithium polysulfide solution is stored, so that the surface capacity of the lithium-sulfur battery is greatly improved.

Description

Iron phosphide nanocube modified graphene/carbon nanotube composite aerogel material, preparation method thereof and lithium-sulfur battery
Technical Field
The invention relates to the technical field of lithium batteries, in particular to a graphene/carbon nanotube composite aerogel material modified by an iron phosphide nanocube, a preparation method thereof and application thereof in a lithium-sulfur battery.
Background
The development of new energy automobiles has increasingly increased demand for power batteries, and the traditional lithium ion batteries are increasingly unsuitable for the demand of new energy automobiles for the power batteries due to low energy density and high raw material price. The demand for next-generation high-energy batteries is increasing. The lithium-sulfur battery has the characteristics of high energy density, wide source of active substance sulfur, low price, environmental friendliness and the like, and becomes a powerful competitor of the next generation of power batteries. There are several technical problems that limit its practical application.
The first is the insulating problem of elemental sulfur and its electrochemical reaction products. In general, researchers have enhanced their electron transport capabilities by complexing sulfur with conductive carbon materials. This is then the shuttling effect of soluble lithium polysulphides as reaction intermediates, which is characteristic of lithium sulphur batteries. This is the main reason for the continuous capacity decline of lithium sulfur batteries during cycling. Because there is always a concentration difference between the positive and negative electrodes, lithium polysulfide will always shuttle between the positive and negative electrodes driven by the concentration difference. This is also often accompanied by corrosion of the lithium metal negative electrode, causing greater damage to the overall battery. The conductive porous carbon material also has a certain inhibition effect on such shuttle effect. By preparing the sulfur into a nano grade and limiting the sulfur in the conductive porous carbon material, two decisive performances of the lithium-sulfur battery, namely the cycle and the specific capacity, can be effectively improved. However, the physical force between the carbon material and elemental sulfur is not strong, so that the carbon material is far from being satisfied when the surface capacity of the lithium-sulfur battery is required. In this case, it is necessary to introduce a polar substance having a stronger restriction effect on soluble lithium polysulfide, and it is desirable that the introduced substance be capable of catalyzing the conversion reaction of lithium polysulfide and be within a reasonable range in price. Researchers have tested a large number of materials, and found that most of the substances meeting the conditions are transition metal oxides, sulfides and phosphides. Additional binder and metal current collectors are added when assembling the battery. This would undoubtedly reduce the proportion of active material in the overall battery. Moreover, the electrochemical reaction occurs more on the surface of the electrode, and more specific surface area is needed to provide more electrochemical reaction sites. At this time, the self-supporting conductive aerogel material having a three-dimensional structure exhibits its own advantages.
Disclosure of Invention
The invention aims to provide a preparation method of a graphene/carbon nanotube composite aerogel material modified by an iron phosphide nanocube, when the composite aerogel material prepared by the method is used as an electrode material of a lithium-sulfur battery, lithium polysulfide can be fixed, and the shuttle effect of the lithium polysulfide in the lithium-sulfur battery is reduced, so that the cycle stability of the lithium-sulfur battery and the utilization rate of active substances are greatly improved; meanwhile, the catalyst has a certain catalytic effect on the conversion reaction of lithium polysulfide, so that the reaction kinetics of the lithium-sulfur battery is greatly improved.
In order to solve the technical problem, the invention provides a preparation method of a graphene/carbon nanotube composite aerogel material modified by iron phosphide nanocubes, which comprises the following steps:
(1) dispersing graphene powder, acidified carbon nanotubes and prussian blue in water to form a dispersion liquid, and freeze-drying the dispersion liquid by adopting liquid nitrogen to obtain a porous prussian blue/graphene/carbon nanotube composite aerogel material; the mass ratio of the graphene powder to the acidified carbon nano tubes is 1: 1-9: 1, and the mass of the Prussian blue is 5-20 wt% of the total mass of the graphene powder and the acidified carbon nano tubes;
(2) and (3) reducing the Prussian blue in the composite aerogel material by adopting phosphine gas to obtain the iron phosphide nanocube modified graphene/carbon nanotube composite aerogel material.
According to the invention, graphene/carbon nanotubes can form uniform dispersion liquid in water, Prussian blue can form a metal organic framework material in water, and then the graphene/carbon nanotube composite aerogel material modified by the organic metal framework material is obtained by utilizing a liquid nitrogen quick freezing method and freeze drying. Among them, carbon nanotubes are used to improve the electrical conductivity and elasticity of aerogels, and the rapid freezing process by introducing liquid nitrogen helps to form small ice crystals inside the solution and leaves almost the same size of pores after freeze-drying.
During phosphorization, the metal organic framework material is converted into iron phosphide with strong chemical adsorption effect on lithium polysulfide, and the porous iron phosphide nanocubes are uniformly decorated on the three-dimensional aerogel as a lithium polysulfide fixing agent. Meanwhile, the graphene aerogel is reduced by phosphine gas generated during phosphorization, so that the conductivity of the three-dimensional aerogel is enhanced. The method is environment-friendly, all raw materials are effectively utilized, no solid waste is generated, and the method can be used for large-scale production.
Further, in the step (1), the thickness of the graphene powder is 3-5 nm, and the sheet diameter is 0.5-5 um; the carbon nano tube before acidification has the outer diameter of 10-20 nm, the length of 10-30 um and the purity of more than 98%.
Further, in the step (1), the mass ratio of the graphene powder to the acidified carbon nanotubes is 7: 3.
Further, in the step (1), the mass of the prussian blue is 10 wt% of the total mass of the graphene powder and the acidified carbon nanotube.
Further, in the step (1), the freeze-drying time is not less than 24 hours, so as to completely remove the moisture in the aerogel.
Further, in the step (2), the reduction process specifically comprises:
placing the composite aerogel material obtained in the step (1) in hydrogen phosphide gas flow for 2-5 ℃ min-1Heating to 350-450 ℃ at the speed of (1-2) h. More preferably, the heating rate is 2 ℃ min-1The heating temperature is 400 ℃, and the heat preservation time is 2 hours.
Further, the speed of the carrier gas flow is 50-200 sccm.min-1Preferably 100 sccm/min-1。
Further, the phosphine gas flow is obtained by heating and decomposing sodium hypophosphite or other substances which generate phosphine by heating.
In the present invention, the acidified carbon nanotube is used for the purpose of improving its dispersibility in water because the surface thereof is grafted with an oxygen-containing group after acidification. Further, in the step (1), the preparation method of the acidified carbon nanotube comprises:
heating the carbon nano tube to remove impurities, dispersing the carbon nano tube in a nitric acid/sulfuric acid mixed solution with a volume ratio of 1:3, performing ultrasonic treatment, and refluxing for 4 hours at 80 ℃; and cooling, washing with distilled water until the pH value of the solution reaches 7, filtering and collecting the carbon nano tube, and drying to obtain the acidified carbon nano tube.
Further, in the step (1), the preparation method of the prussian blue comprises the following steps:
mixing polyvinylpyrrolidone and K4Fe(CN)6·3H2Dissolving O in HCl solution, and drying at 80 ℃ for 24 h; and centrifuging to obtain a blue precipitate, washing with distilled water and ethanol, and vacuum drying to obtain the Prussian blue powder.
The invention also provides the iron phosphide nanocube modified graphene/carbon nanotube composite aerogel material prepared by the method. The iron phosphide nanocube modified graphene/carbon nanotube composite aerogel material has the characteristics of ultralow density, large specific surface area and high electrolyte absorption capacity, and the characteristics make the iron phosphide nanocube modified graphene/carbon nanotube composite aerogel material an ideal cathode material of a polysulfide battery.
The invention also provides a preparation method of the lithium-sulfur battery, and the cathode of the lithium-sulfur battery is prepared by pouring lithium polysulfide into the iron phosphide nanocube modified graphene/carbon nanotube composite aerogel material.
The invention has the beneficial effects that:
1. the chemical action of the iron phosphide on the lithium polysulfide is utilized, the lithium polysulfide is fixed, and the shuttle effect of the lithium polysulfide in the lithium sulfur battery is reduced, so that the cycle stability of the lithium sulfur battery is greatly improved; meanwhile, the iron phosphide also has a certain catalytic effect on the conversion reaction of lithium polysulfide, so that the capacity of the lithium-sulfur battery is greatly improved.
2. The invention introduces the three-dimensional graphene/carbon nano tube composite aerogel electrode, reduces the proportion of inactive substances in a battery device, and improves the surface capacity of the lithium-sulfur battery.
3. According to the invention, a lithium polysulfide perfusion mode is used, and active substances are uniformly dispersed in the three-dimensional electrode, so that the sulfur is utilized by 100% in a loading process, and the energy loss in a sulfur charging process is reduced.
4. All solid raw materials used in the invention are in the final product, and no solid waste is generated in all processes, so that the method is environment-friendly.
Drawings
FIG. 1 is a scanning electron micrograph (a), a cross-sectional view (b), an enlarged view (c), and a transmission electron micrograph (d) of the composite aerogel material prepared in example 2;
fig. 2 is a scanning electron microscope picture of prussian blue nanoparticles;
FIG. 3 shows the composite aerogel materials prepared in example 2 and comparative example in 5mM Li2S6Absorbing the ultraviolet absorption spectrum for 3 hours in the solution;
FIG. 4 is a CV plot of composite aerogel materials prepared in example 2 and comparative examples;
FIG. 5 is a charge and discharge curve at 0.2C for composite aerogel materials prepared in examples 1-3 and comparative examples;
FIG. 6 is a graph of the cycling stability at 0.2C for composite aerogel materials prepared in example 1(b), example 2(C), example 3(d), and comparative example (a);
FIG. 7 is a surface capacity curve at high load for the composite aerogel prepared in example 2;
the composite aerogel comprises a composite aerogel body, a composite aerogel body and a composite aerogel body, wherein HA refers to the composite aerogel body when the Prussian blue feeding ratio is 0, HA/FeP5 refers to the composite aerogel body when the Prussian blue feeding ratio is 5%, HA/FeP5 refers to the composite aerogel body when the Prussian blue feeding ratio is 10%, and HA/FeP5 refers to the composite aerogel body when the Prussian blue feeding ratio is 20%.
Detailed Description
The present invention is further described below in conjunction with the following figures and specific examples so that those skilled in the art may better understand the present invention and practice it, but the examples are not intended to limit the present invention.
1. Prussian blue synthesis
19g of polyvinylpyrrolidone (PVP, K30, M)W40000) and 0.55g K4Fe(CN)6·3H2O was dissolved in 250ml of 0.1M HCl solution and the clear solution was transferred to an oven at 80 ℃ for 24 hours. The blue precipitate was centrifuged and washed several times with distilled water and ethanol, and then dried in a vacuum oven for 12 hours to obtain prussian blue powder.
2. Acidification of carbon nanotubes
After heating the carbon nanotubes in a furnace at 450 ℃ for 2 hours to remove impurities, the carbon nanotubes were sonicated in 80ml of nitric acid and sulfuric acid (1: 3 by volume) for 1 hour, and then refluxed at 80 ℃ for 4 hours. After cooling, the carbon nanotubes were washed with distilled water until the pH of the solution reached 7. The carbon nanotubes were then collected by filtration and dried for further use.
3. Preparation of iron phosphide nanocube modified graphene/carbon nanotube composite aerogel
Example 1
Mixing 140mg of graphene powder, 60mg of acidified carbon nanotubes and 10mg of Prussian blue in 50ml of distilled water, and after 1 hour of ultrasonic treatment, subjecting the solution to vigorous sonicationStir overnight. The prepared solution was then dispensed into plastic caps every 2ml, and freeze-dried by immersion in liquid nitrogen for over 24 hours to completely remove the water from the aerogel. The aerogel obtained was placed in a tube furnace, upstream of which was placed 5 times the mass of NaH2PO2The gas flow rate is 100 sccm.min-1. Placing the tube furnace at 2 deg.C for min-1Is heated to 400 c and held for 2 hours. After cooling to room temperature, the iron phosphide nanocube modified graphene/carbon nanotube composite aerogel is compressed and cut into rectangular plates for future use.
Example 2
140mg of graphene powder, 60mg of acidified carbon nanotubes and 20mg of prussian blue were mixed in 50ml of distilled water, and after sonication for 1 hour, the solution was vigorously stirred overnight. The prepared solution was then dispensed into plastic caps every 2ml, and freeze-dried by immersion in liquid nitrogen for over 24 hours to completely remove the water from the aerogel. The aerogel obtained was placed in a tube furnace, upstream of which was placed 5 times the mass of NaH2PO2The gas flow rate is 100 sccm.min-1. Placing the tube furnace at 2 deg.C for min-1Is heated to 400 c and held for 2 hours. After cooling to room temperature, the iron phosphide nanocube modified graphene/carbon nanotube composite aerogel is compressed and cut into rectangular plates for future use.
Example 3
140mg of graphene powder, 60mg of acidified carbon nanotubes and 40mg of prussian blue were mixed in 50ml of distilled water, and after sonication for 1 hour, the solution was vigorously stirred overnight. The prepared solution was then dispensed into plastic caps every 2ml, and freeze-dried by immersion in liquid nitrogen for over 24 hours to completely remove the water from the aerogel. The aerogel obtained was placed in a tube furnace, upstream of which was placed 5 times the mass of NaH2PO2The gas flow rate is 100 sccm.min-1. Placing the tube furnace at 2 deg.C for min-1Is heated to 400 c and held for 2 hours. Cooling to room temperature, compressing and cutting the iron phosphide nanocube modified graphene/carbon nanotube composite aerogel into rectangular platesFor future use.
Comparative example
140mg of graphene powder and 60mg of acidified carbon nanotubes in 50ml of distilled water were mixed, and after 1 hour of sonication, the solution was vigorously stirred overnight. The prepared solution was then dispensed into plastic caps every 2ml, and freeze-dried by immersion in liquid nitrogen for over 24 hours to completely remove the water from the aerogel. The aerogel obtained was placed in a tube furnace, upstream of which was placed 5 times the mass of NaH2PO2The gas flow rate is 100 sccm.min-1. Placing the tube furnace at 2 deg.C for min-1Is heated to 400 c and held for 2 hours. After cooling to room temperature, the graphene/carbon nanotube composite aerogel is compressed and cut into rectangular plates for future use.
Physical and chemical property test
As shown in fig. 1, the iron phosphide nanocube modified graphene carbon nanotube composite aerogel shows a fluffy and porous structure at a scale of 200um, and a side view thereof shows a layer-by-layer stacked structure. This is caused when an external force is applied. Such a porous, fluffy structure facilitates the infusion and storage of lithium polysulphides. From a scanning electron microscope with the size of 5um, the fact that iron phosphide nanocubes are uniformly dispersed in the composite aerogel is easily found, and due to the fact that the iron phosphide nanocubes have strong chemical adsorption energy on lithium polysulfide, the iron phosphide nanocubes greatly help uniform dispersion of a lithium polysulfide solution. From a transmission electron microscope image, it can be easily found that the carbon nanotubes are uniformly dispersed on the surface of the graphene thin layer, which enhances the conductivity and mechanical properties of the composite aerogel. The iron phosphide nano-cube is coated by graphene, and a plurality of carbon nano-tubes are distributed around the iron phosphide nano-cube, so that electrons can be better transferred to the iron phosphide nano-cube, and the electrochemical reaction is facilitated.
FIG. 2 is a scanning electron microscope image of Prussian blue nanoparticles, from which it can be seen that the Prussian blue nanoparticles are uniform in size, and the average particle size is about 600-800 nm.
10mg of each sample was placed in 5mM Li2S6Adsorbing the solution for 3h, and then testing the ultraviolet absorption spectrum of the adsorbed solution to obtain the ultraviolet absorption spectrum of the solution shown in figure 3. FromAs can be seen in the figure, the ultraviolet absorption curve of the graphene carbon nanotube composite aerogel is almost equal to that of 5mM Li2S6The solutions are consistent, but the absorption peaks of the iron phosphide nanocubes modified graphene carbon nanotube composite aerogel are greatly reduced, which shows the super-strong lithium polysulfide adsorption capacity of the composite aerogel.
Then, the composite aerogel materials prepared in the examples and the comparative examples are prepared into electrodes and assembled into batteries, and the electrochemical performance of the batteries is tested by the following specific processes:
before the battery is assembled, the synthesized iron phosphide nanocube modified graphene/carbon nanotube composite aerogel material is dried in a vacuum oven at 80 ℃ for 12 hours to completely remove moisture. The 2025 type button cell was directly assembled in an argon-filled glove box using a compressed iron phosphide nanocube modified graphene/carbon nanotube composite aerogel material electrode (O2<0.1ppm，H2O<0.1ppm) without using any binder. The graphene/carbon nanotube composite aerogel material modified with the cut iron phosphide nanocubes was used as a cathode, while lithium metal was used as a counter electrode and a reference electrode,
Figure BDA0002248313340000081
the 2400 film was used as the separator. According to the weight of the iron phosphide nanocube modified graphene/carbon nanotube composite aerogel material, the sulfur content is fixed to be 60%. The battery was first charged to 2.8V and then cycled over a voltage range of 1.7-2.8V using the bond battery test system (CT2001A, wuhan bond electronics limited, china). At 0.1mV s between 1.7V and 2.8V on an electrochemical workstation (Sazana, Germany)-1Scan rate test Cyclic Voltammetry (CV) measurements. Electrochemical Impedance Spectroscopy (EIS) measurements were performed at a frequency range of 100mHz to 100kHz with an amplitude of 5 mV. For the high-sulfur-load battery, a plastic ring is additionally used inside the button battery to prevent the cathode electrolyte from overflowing.
The cyclic voltammetry of fig. 4 is used for illustrating the electrochemical performance of the iron phosphide nanocube modified graphene carbon nanotube composite aerogel. The two cathodic peaks at 2.33V and 1.99V represent the reduction of sulfur to long-chain lithium polysulfides and their subsequent conversion to short-chain lithium polysulfides, respectively. The peaks of the graphene carbon nanotube composite aerogel are located at 2.17V and 1.79V, and obviously, the reduction peak of the graphene carbon nanotube composite aerogel modified by the iron phosphide nanoparticles is more obvious. The same result can be seen in the anode scan with the oxidation peak shifted about 1V relative to the negative. From the results, the reaction kinetics of the lithium-sulfur battery can be obviously improved through the catalytic action by introducing the FeP nanocubes.
Since iron phosphide is not a reactive substance, its introduction causes a decrease in the specific capacity of the entire electrode, and therefore, an optimization experiment was conducted with respect to its introduction amount, and the sulfur mass ratio in all electrodes was 60%, and the results are shown in fig. 5 to 6.
In the graphene carbon nanotube composite aerogel (comparative example), the specific discharge capacity after it was stabilized at 0.2C is shown in the figure as 937.5mAh g-1The capacity is kept to 724.7mAh g after one hundred cycles-1And the coulombic efficiency is kept above 99%.
In the iron phosphide nanoparticle-modified graphene carbon nanotube composite aerogel (example 1) synthesized at a mass charge ratio of 5% of prussian blue, the discharge specific capacity after stabilization at 0.2C is shown as 1139.2mAh g in the figure-1The capacity is kept to 1024.8mAh g after one hundred cycles-1And the coulombic efficiency is kept above 99%.
In the iron phosphide nanoparticle-modified graphene carbon nanotube composite aerogel (example 2) synthesized at the mass charge ratio of 10% of prussian blue, the discharge specific capacity after being stabilized at 0.2C is shown as 1312.3mAh g in the figure-1The capacity is kept 1217mAh g after one hundred cycles-1And the coulombic efficiency is kept above 99%.
In the iron phosphide nanoparticle-modified graphene carbon nanotube composite aerogel (example 3) synthesized at the mass charge ratio of 20% of prussian blue, the discharge specific capacity after being stabilized at 0.2C is shown as 995.3mAh g in the figure-1The capacity is kept to 943.3mAh g after one hundred cycles-1And the coulombic efficiency is kept above 99 percent。
From the above results, 10% was the optimum charge ratio. We then performed the high load test on the sample of example 2, and the results are shown in fig. 7. The surface capacity of the rice noodle reaches 9mAh cm -250 circles of lower cycle, which is much higher than 4mAh cm of commercial lithium ion battery-2。
Based on the test results, the iron phosphide nanocube modified graphene/carbon nanotube composite aerogel material can be used as an electrode material, and can fix lithium polysulfide and reduce the shuttle effect of the lithium polysulfide in a lithium-sulfur battery, so that the cycle stability and the active substance utilization rate of the lithium-sulfur battery are greatly improved, and meanwhile, a large amount of lithium polysulfide solution is stored, so that the surface capacity of the lithium-sulfur battery is also greatly improved; secondly, by using a lithium polysulfide perfusion mode, active substances are uniformly dispersed in the three-dimensional electrode, so that the sulfur is utilized by 100% in the loading process, and the energy loss in the sulfur charging process is reduced; in addition, all solid raw materials are in the final product, and no solid waste is generated in all processes, so that the method is environment-friendly. Therefore, the iron phosphide nanocube modified graphene/carbon nanotube composite aerogel material has a wide application prospect in the field of lithium batteries.
The above-mentioned embodiments are merely preferred embodiments for fully illustrating the present invention, and the scope of the present invention is not limited thereto. The equivalent substitution or change made by the technical personnel in the technical field on the basis of the invention is all within the protection scope of the invention. The protection scope of the invention is subject to the claims.

Claims (10)

1. A preparation method of a graphene/carbon nanotube composite aerogel material modified by iron phosphide nanocubes is characterized by comprising the following steps:
(1) dispersing graphene powder, acidified carbon nanotubes and prussian blue in water to form a dispersion liquid, and freeze-drying the dispersion liquid by adopting liquid nitrogen to obtain a porous prussian blue/graphene/carbon nanotube composite aerogel material; the mass ratio of the graphene powder to the acidified carbon nano tubes is 1: 1-9: 1, and the mass of the Prussian blue is 5-20 wt% of the total mass of the graphene powder and the acidified carbon nano tubes;
(2) and (3) reducing the Prussian blue in the composite aerogel material by adopting phosphine gas to obtain the iron phosphide nanocube modified graphene/carbon nanotube composite aerogel material.
2. The preparation method of the iron phosphide nanocube-modified graphene/carbon nanotube composite aerogel material according to claim 1, wherein in the step (1), the thickness of the graphene powder is 3-5 nm, and the sheet diameter is 0.5-5 um; the carbon nano tube before acidification has the outer diameter of 10-20 nm, the length of 10-30 um and the purity of more than 98%.
3. The method for preparing the iron phosphide nanocube-modified graphene/carbon nanotube composite aerogel material according to claim 1, wherein in the step (1), the mass ratio of the graphene powder to the acidified carbon nanotubes is 7: 3.
4. The method for preparing the iron phosphide nanocube-modified graphene/carbon nanotube composite aerogel material according to claim 1, wherein in the step (1), the mass of the prussian blue is 10 wt% of the total mass of the graphene powder and the acidified carbon nanotubes.
5. The method for preparing the iron phosphide nanocube-modified graphene/carbon nanotube composite aerogel material as claimed in claim 1, wherein in the step (1), the freeze-drying time is not less than 24 h.
6. The method for preparing the iron phosphide nanocube-modified graphene/carbon nanotube composite aerogel material according to claim 1, wherein in the step (2), the reduction process specifically comprises:
placing the composite aerogel material obtained in the step (1) in hydrogen phosphide gas flow for 2-5 ℃ min-1Heating to 350-450 ℃ at the speed of (1-2) h.
7. The method for preparing the iron phosphide nanocube modified graphene/carbon nanotube composite aerogel material according to claim 6, wherein the speed of the carrier gas flow is 50-200 sccm-min-1。
8. The method for preparing the iron phosphide nanocube-modified graphene/carbon nanotube composite aerogel material according to claim 6, wherein the hydrogen phosphide gas stream is obtained by heating and decomposing sodium hypophosphite.
9. The iron phosphide nanocube modified graphene/carbon nanotube composite aerogel material prepared according to the method of any one of claims 1 to 8.
10. A lithium-sulfur battery, wherein the negative electrode of the lithium-sulfur battery is prepared by infusing lithium polysulfide into the iron phosphide nanocube modified graphene/carbon nanotube composite aerogel material of claim 9.
CN201911024743.1A 2019-10-25 2019-10-25 Iron phosphide nanocube modified graphene/carbon nanotube composite aerogel material, preparation method thereof and lithium-sulfur battery Pending CN110745799A (en)

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CN113066964A (en) * 2021-03-15 2021-07-02 南昌大学 Double-metal phosphide-inlaid carbon hollow nano cage and preparation method and application thereof
CN113907753A (en) * 2021-09-07 2022-01-11 东南大学 Noninvasive blood glucose detection electrode patch, manufacturing method thereof and anti-iontophoresis in-vitro experimental device

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CN113066964A (en) * 2021-03-15 2021-07-02 南昌大学 Double-metal phosphide-inlaid carbon hollow nano cage and preparation method and application thereof
CN113066964B (en) * 2021-03-15 2022-04-19 南昌大学 Double-metal phosphide-inlaid carbon hollow nano cage and preparation method and application thereof
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