CN106207144B - silicon nanowire, preparation method thereof and application of silicon nanowire in preparation of carbon-coated silicon nanowire negative electrode material - Google Patents
silicon nanowire, preparation method thereof and application of silicon nanowire in preparation of carbon-coated silicon nanowire negative electrode material Download PDFInfo
- Publication number
- CN106207144B CN106207144B CN201610786002.7A CN201610786002A CN106207144B CN 106207144 B CN106207144 B CN 106207144B CN 201610786002 A CN201610786002 A CN 201610786002A CN 106207144 B CN106207144 B CN 106207144B
- Authority
- CN
- China
- Prior art keywords
- silicon nanowire
- electrolysis
- sodium chloride
- negative electrode
- electrode material
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
- H01M4/386—Silicon or alloys based on silicon
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/362—Composites
- H01M4/366—Composites as layered products
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Abstract
The invention relates to a silicon nanowire, a preparation method thereof and application of the silicon nanowire in preparing a carbon-coated silicon nanowire negative electrode material. The method for preparing the silicon nanowire comprises the following steps: pressing the mixed powder of silicon dioxide and sodium chloride into a cathode sheet; sintering the cathode plate at low temperature; fixing the obtained cathode sheet on an iron-chromium-aluminum wire to be used as a cathode, using high-purity graphite as an anode, and electrolyzing in a molten salt system of CaCl2 under the atmosphere of high-purity argon to obtain a silicon nanowire; ball-milling a proper amount of acetylene black and the silicon nanowire; sintering the powder obtained by ball milling in an inert atmosphere to obtain the carbon-coated silicon nanowire negative electrode material. The silicon nanowire is good in appearance, the carbon-coated silicon nanowire negative electrode material is prepared by taking the silicon nanowire as a precursor and assembled into a battery, and the battery has very good battery cycle performance, stable electrochemical performance and high energy density; the preparation method is simple, low in production cost and high in raw material utilization rate.
Description
Technical Field
The invention belongs to the technical field of lithium ion and sodium ion batteries, relates to a silicon nanowire, a preparation method and application thereof, and particularly relates to a silicon nanowire, a preparation method thereof and application thereof in preparing a carbon-coated silicon nanowire negative electrode material.
Background
compared with the traditional graphite negative electrode material, the silicon has extremely high specific mass capacity of 4200mAh/g, which is more than ten times of that of natural graphite; compared with metal lithium, the bulk density of silicon in the alloy material is similar to that of lithium, so that the silicon also has high volume specific capacity; different from graphite materials, the high specific capacity of silicon is originated from the alloying process of silicon and lithium, so that the silicon negative electrode material cannot be subjected to solvent co-intercalation with the electrolyte, and the application range of the electrolyte is wider; compared with a carbon material, silicon has higher lithium releasing and inserting potential, can effectively avoid the precipitation of lithium in the process of high-rate charge and discharge, and can improve the safety of the battery. Compared with nano silicon particles, the silicon nanowire has the advantages that the transverse volume effect is not obvious in the lithium intercalation and deintercalation process, crushing and electric contact loss cannot occur like nano silicon particles, and accordingly the circulation stability is better.
CN 103427069 adopts nano-silicon, lithium-containing compound and carbon micropowder as raw materials to prepare the negative electrode material of the lithium battery. This patent directly adopts nanometer silicon to increase the cost for the raw materials, and the nanoparticle has kibbling risk, is unfavorable for the industrialization to be applied. CN 103035915 discloses silicon nanowires on spherical carbonaceous matrix materials as negative electrode materials for lithium batteries. The patent also directly adopts silicon nanowires, silicon oxide nanowires or silicon alloy nanowires as raw materials, and does not relate to a specific preparation method for synthesizing the silicon nanowires. CN 104103821 adopts chemical vapor deposition method to prepare silicon nano-wire. The chemical vapor deposition method has low utilization rate of raw materials and high production cost in the process of preparing Si-SiOx. Therefore, a method for stably producing the carbon-coated silicon nanowire negative electrode material at low cost is particularly important.
CN 102154659A discloses a method for preparing silicon nanowires by refining industrial silicon through molten salt electrolysis, which adopts NaF, LiCl3, NaClKCl, KF, NaOHSIF6, K2SiF6 or a mixture thereof as electrolyte, industrial silicon as an anode and cathode molten salt electrolysis to prepare the silicon nanowires. The method specifically comprises the following steps: (1) dehydrating the molten salt into electrolyte by a conventional method, and directionally solidifying and removing impurities from industrial silicon prepared by reducing quartz stone and carbon to prepare an anode; (2) applying a voltage lower than the voltage of the molten salt electrolyte decomposition and higher than the voltage of silicon deposition between the two electrodes in the molten salt electrolyte, wherein the electrode distance is more than or equal to 1cm, and carrying out constant current electrolytic refining; (3) electrolyzing for a certain time, taking out the cathode tungsten rod, and inserting another cathode tungsten rod for continuous refining. And putting the taken tungsten rod into dilute hydrochloric acid for desalting, filtering a product, washing with deionized water, drying at 60 ℃, and packaging. The method has the advantages of simple process flow, simple and convenient equipment, no solid, liquid and gas waste discharge, no secondary pollution and low cost, and realizes the production of the silicon nanowire. The purity of the prepared silicon nanowire is as high as 6-7N, the size of the prepared silicon nanowire is 30-50 nm, and the prepared silicon nanowire is uniformly distributed. However, the electrolysis temperature of the patent is higher than 650-1010 ℃, the energy consumption is large, and the energy-saving production is not facilitated.
Disclosure of Invention
in view of the above problems in the prior art, the present invention is directed to a silicon nanowire, a method for preparing the same, and a use of the silicon nanowire for preparing a carbon-coated silicon nanowire anode material. The method for preparing the silicon nanowire is simple, low in cost and high in raw material utilization rate, the prepared silicon nanowire is good in appearance, the battery prepared from the carbon-coated silicon nanowire negative electrode material prepared by carbon coating of the silicon nanowire has very good electrochemical performance, the charging capacity of the battery is up to 1450mAh/g, and after the battery is circulated for 80 weeks, the capacity retention rate is 92-95%.
In order to achieve the purpose, the invention adopts the following technical scheme:
In a first aspect, the present invention provides a method for preparing a silicon nanowire, the method comprising the steps of:
(1) Pressing the mixed powder of silicon dioxide and sodium chloride into a cathode sheet;
(2) sintering the cathode sheet obtained in the step (1);
(3) and (3) fixing the cathode sheet sintered in the step (2) on an iron-chromium-aluminum wire to be used as a cathode, using graphite as an anode, and electrolyzing in a CaCl2 molten salt system to obtain the silicon nanowire.
preferably, in the mixed powder of silicon dioxide and sodium chloride in step (1), the mass percentage of sodium chloride is 3% to 12%, for example, 3%, 4.5%, 6%, 7%, 8%, 10%, 11%, 12%, or the like, based on 100% by mass of the total mixed powder of silicon dioxide and sodium chloride.
preferably, the particle size of the mixed powder of silicon dioxide and sodium chloride in the step (1) is 100-300 meshes.
preferably, the sintering temperature in step (2) is 260-360 deg.C, such as 260 deg.C, 280 deg.C, 300 deg.C, 310 deg.C, 325 deg.C, 335 deg.C, 350 deg.C or 360 deg.C.
preferably, the sintering time in the step (2) is 2 to 10 hours, for example, 2 to 3 hours, 3.5 hours, 4.5 hours, 5 hours, 6 hours, 6.5 hours, 7 hours, 8 hours, 9 hours or 10 hours, and the like, and preferably 2 to 5 hours.
preferably, the sintering of step (2) is carried out in a tube furnace.
Preferably, the voltage for the electrolysis in step (3) is 2V to 3.2V, and may be, for example, 2V, 2.2V, 2.4V, 2.5V, 2.6V, 2.8V, 3.0V, 3.2V, or the like.
preferably, the temperature of the electrolysis in step (3) is 500 to 600 ℃, and may be, for example, 500 ℃, 520 ℃, 530 ℃, 550 ℃, 560 ℃, 580 ℃, 590 ℃, 600 ℃, or the like.
preferably, the time for the electrolysis in step (3) is 4h to 10h, and may be 4h, 5h, 5.5h, 6h, 7h, 8h, 8.5h, 9h or 10h, for example.
Preferably, the electrolysis of step (3) is carried out under an atmosphere of high purity argon.
preferably, the electrolysis in step (3) is direct voltage electrolysis.
Preferably, the graphite in the step (3) is high-purity graphite, and the high-purity graphite refers to that the carbon content of the graphite is more than 99.99%.
As a preferable technical scheme of the preparation method of the silicon nanowire, the method further comprises the step of sieving the mixed powder of the silicon dioxide and the sodium chloride before the cathode sheet is pressed in the step (1), and in the sieving step, 100-300 mesh sieve is used for sieving, and 200 mesh sieve is preferably used for sieving.
preferably, the preparation method of the silicon nanowire further comprises the step (1)': mixing and grinding silica particles and sodium chloride particles to obtain mixed powder of silica and sodium chloride, wherein the mixing and grinding sequence is not limited, the silica particles and the sodium chloride particles can be mixed firstly, and then the mixed particles are ground to obtain mixed powder of silica and sodium chloride; alternatively, the silica particles and the sodium chloride particles may be ground separately to obtain silica powder and sodium chloride powder, respectively, and then the two powders may be mixed to obtain a mixed powder of silica and sodium chloride.
As another preferable technical solution of the method for preparing a silicon nanowire of the present invention, the method further comprises the step of sequentially performing water soaking, washing and drying on the electrolysis product after the electrolysis of step (3).
preferably, the step of water soaking is: the electrolysis product is soaked in water, and the soaking time is preferably 3h to 5h, and can be 3h, 3.3h, 3.5h, 4h, 4.2h, 4.6h or 5h, and the like.
preferably, the step of washing is: and (3) soaking the electrolytic product by adopting hydrofluoric acid and then deionized water washing water.
as a further preferable technical solution of the method for preparing a silicon nanowire of the present invention, the method comprises the steps of:
(1) ' mixing silica particles and sodium chloride particles, and then grinding the resulting mixed particles to obtain a mixed powder of silica and sodium chloride;
(1) sieving the mixed powder of silicon dioxide and sodium chloride by using a 200-mesh sieve, and then pressing into a cathode sheet;
(2) Putting the cathode plate obtained in the step (1) into a tube furnace, and sintering for 2-5 h at 260-360 ℃;
(3) Fixing the cathode sheet sintered in the step (2) on an iron-chromium-aluminum wire to serve as a cathode, using graphite as an anode, electrolyzing for 4-10 hours at 500-600 ℃ in a CaCl2 molten salt system at the direct current voltage of 2-3.2V, soaking an electrolysis product in water for 3-5 hours, then washing with hydrofluoric acid, then washing with deionized water, and finally drying to obtain the silicon nanowire.
In a second aspect, the invention provides the silicon nanowire prepared by the method of the first aspect, wherein the diameter of the cross section of the silicon nanowire is 50-500 nm, and the length of the silicon nanowire is 0.5-10 μm.
In a third aspect, the present invention provides the use of a silicon nanowire as described in the second aspect for the preparation of a carbon-coated silicon nanowire anode material. The raw material components of the carbon-coated silicon nanowire comprise the silicon nanowire as described in the second aspect as a precursor.
The preferred preparation method of the carbon-coated silicon nanowire negative electrode material comprises the following steps:
(A) Mixing the precursor with acetylene black by using the silicon nanowire as a precursor, and then performing ball milling to obtain powder;
(B) and (C) sintering the powder obtained in the step (A) in an inert atmosphere to obtain the carbon-coated silicon nanowire negative electrode material.
preferably, the acetylene black in step (a) is 5 to 15% by mass, for example, 5%, 7%, 8%, 10%, 11%, 13%, 14%, 15% or the like, based on 100% by mass of the precursor in step (a).
preferably, the rotation speed of the ball milling in the step (A) is 40-60 r/min, and the ball milling time is preferably 15-20 h.
preferably, the inert atmosphere in step (B) is any one of a nitrogen atmosphere, a helium atmosphere, a neon atmosphere, an argon atmosphere, a krypton atmosphere, or a xenon atmosphere, or a combination of at least two thereof.
Preferably, the sintering temperature in step (B) is 800-1200 deg.C, such as 800 deg.C, 850 deg.C, 900 deg.C, 920 deg.C, 950 deg.C, 1000 deg.C, 1050 deg.C, 1100 deg.C, 1150 deg.C or 1200 deg.C.
Preferably, the sintering time in step (B) is 2h to 8h, and may be, for example, 2h, 2.5h, 3h, 4h, 4.5h, 5h, 6h, 7h, 8h, or the like.
As a further preferable technical scheme of the preparation method of the carbon-coated silicon nanowire negative electrode material, the method comprises the following steps:
(1) ' mixing silica particles and sodium chloride particles, and then grinding the resulting mixed particles to obtain a mixed powder of silica and sodium chloride;
(1) Sieving the mixed powder of silicon dioxide and sodium chloride by using a 200-mesh sieve, and then pressing into a cathode sheet;
(2) putting the cathode plate obtained in the step (1) into a tube furnace, and sintering for 2-5 h at 260-360 ℃;
(3) Fixing the cathode sheet sintered in the step (2) on an iron-chromium-aluminum wire to serve as a cathode, using graphite as an anode, electrolyzing for 4-10 hours at 500-600 ℃ in a CaCl2 molten salt system at the direct current voltage of 2-3.2V, soaking an electrolysis product in water for 3-5 hours, then washing with hydrofluoric acid, then washing with deionized water, and finally drying to obtain the silicon nanowire.
(A) taking the silicon nanowire obtained in the step (3) as a precursor, mixing the precursor with acetylene black accounting for 5-15% of the mass of the precursor, and then carrying out ball milling to obtain powder;
(B) And (C) putting the powder obtained in the step (A) into a tube furnace, vacuumizing, sintering for 2-8 h at 800-1200 ℃ in an inert atmosphere, and cooling after sintering to obtain the carbon-coated silicon nanowire negative electrode material.
In a fourth aspect, the invention also provides a battery, which comprises the carbon-coated silicon nanowire negative electrode material in the third aspect.
preferably, the battery is a lithium ion battery or a sodium ion battery or the like.
Compared with the prior art, the invention has the following beneficial effects:
(1) According to the invention, silicon dioxide and sodium chloride are adopted, the content proportion relation of the silicon dioxide and the sodium chloride is adjusted to prepare the cathode plate, the sintering temperature of the cathode plate is 260-360 ℃ due to the addition of CaCl2 components and the cooperation of the CaCl2 components and the silicon dioxide, the sintering temperature of the cathode plate is far lower than 1000 ℃ in the prior art, the cathode plate is fixed on an iron-chromium-aluminum wire to serve as a cathode, graphite serves as an anode, and molten salt electrolysis is carried out under a CaCl2 molten salt system to prepare the silicon nanowire, wherein the obtained silicon nanowire has good appearance and uniform distribution, the diameter of the nanowire is 50-500 nm, and the length of the.
(2) The carbon-coated silicon nanowire negative electrode material is prepared by using the prepared silicon nanowire as a precursor, the addition amount of acetylene black, ball milling parameters, sintering parameters and the like in the preparation process of the carbon-coated silicon nanowire are adjusted, the carbon coating of the silicon nanowire is realized, the volume effect of silicon is greatly reduced, the carbon-coated silicon nanowire negative electrode material with good conductivity is obtained, and a lithium ion battery and a sodium ion battery containing the carbon-coated silicon nanowire negative electrode material have very good electrochemical performance, high energy density and good cycle performance, the charge capacity of the battery is up to 1450mAh/g, and the capacity retention rate is 92-95% after 80 weeks of cycle.
(3) The method for preparing the silicon nanowire and the method for preparing the carbon-coated silicon nanowire negative electrode material have the advantages of simple process, high raw material utilization rate, low production cost, environmental friendliness and the like, and the electrolysis temperature is lower than 500-600 ℃, so that the energy consumption is low, and the industrial production is facilitated.
drawings
Fig. 1 is an SEM image of the electrolytic product silicon nanowire prepared in example 1.
fig. 2 is an XRD pattern of the electrolytic product silicon nanowire prepared in example 1.
Fig. 3 is a graph of the result of electrochemical cycle performance test performed on a battery assembled by the carbon-coated silicon nanowire negative electrode material prepared in example 1 as the negative electrode material of the battery.
Detailed Description
the technical scheme of the invention is further explained by the specific implementation mode in combination with the attached drawings.
The carbon-coated silicon nanowire negative electrode materials of examples 1 to 15 were used as negative electrode materials to prepare batteries under the same conditions and to test electrochemical properties thereof, and the specific preparation method of the batteries was as follows:
(1) mixing materials: and uniformly mixing the negative electrode material and the PVDF in a mass ratio of 9:1 under magnetic stirring for 3-5 hours.
(2) Blade coating: and (3) taking the copper foil as a current collector, and uniformly coating the slurry on the copper foil by adopting a scraper die.
(3) and (3) vacuum drying: vacuum drying at 120 deg.C for 12 hr in vacuum drying oven.
(4) cutting: all pole pieces were cut into circular pieces with a diameter of 10 mm.
(5) Assembling the battery: the battery is assembled in a glove box by adopting a CR2032 battery case, the positive electrode is a lithium sheet, the electrolyte is 1M LiPF6in EC, DMC is 1:1, the diaphragm is Celgard2400, and the negative electrode is a lithium sheet.
The prepared battery was subjected to a charge and discharge test using constant current charge and discharge at a current density of 0.1C (about 420mA/g), and the test results are shown in table 1.
Example 1
preparing a silicon nanowire:
(1) Weighing 95g of silicon dioxide particles and 5g of sodium chloride particles, grinding the silicon dioxide particles and the sodium chloride particles into powder, sieving the powder by using a 200-mesh sieve, and pressing a cathode sheet;
(2) placing the cathode plate into a tube furnace for low-temperature sintering at 320 ℃ for 2 h;
(3) Fixing the obtained cathode sheet on an iron-chromium-aluminum wire as a cathode, using high-purity graphite as an anode, and carrying out direct-current voltage electrolysis in a molten salt system of CaCl2 under the atmosphere of high-purity argon, wherein the electrolysis voltage is 2.8V, the electrolysis temperature is 500 ℃, and the electrolysis time is 4.5 h;
(4) and soaking the obtained cathode plate in water for 5h, then taking out, washing with hydrofluoric acid, washing with deionized water, and finally drying to obtain the silicon nanowire.
preparing a carbon-coated silicon nanowire negative electrode material:
(A) weighing 15g of acetylene black by taking the silicon nanowire obtained in the step (4) as a precursor, and carrying out ball milling on the acetylene black and the silicon nanowire obtained in the step (4), wherein the ball milling rotation speed is 60r/min, and the ball milling time is 15h to obtain powder;
(B) And putting the obtained powder into a tubular furnace, vacuumizing, sintering in the tubular furnace under an inert atmosphere at the sintering temperature of 1000 ℃ for 2h, and cooling to obtain the carbon-coated silicon nanowire negative electrode material (also called a silicon-based negative electrode material).
And (3) performance detection:
the carbon-coated silicon nanowire negative electrode material prepared in the embodiment is used as a negative electrode material of a battery to be assembled into the battery, and electrochemical performance tests are carried out, and the results are shown in table 1.
FIG. 1 is an SEM image of the electrolytic product silicon nanowires prepared in the embodiment 1, and it can be seen that the silicon nanowires are uniformly distributed, the diameter of the nanowires is 50-500 nm, and the length of the nanowires is 0.5-10 μm.
Fig. 2 is an XRD pattern of the electrolytic product silicon nanowire prepared in this example 1, and it can be seen that the width of the peak is narrow, indicating that the product silicon grain is well developed.
Fig. 3 is a graph showing the result of electrochemical cycle performance test performed on a battery assembled by using the carbon-coated silicon nanowire negative electrode material prepared in this example 1 as a negative electrode material of the battery, and it can be seen from fig. 3 that the specific charge capacity of the first turn is 1423 mAh/g. The capacity reached a maximum at the eighth turn of 1450 mAh/g. Thereafter, the capacity was slightly attenuated, and after 80 weeks of circulation, the capacity was 1342mAh/g, and the capacity retention was 94.3%.
Example 2
Preparing a silicon nanowire:
(1) weighing 92g of silicon dioxide particles and 8g of sodium chloride particles, grinding the silicon dioxide particles and the sodium chloride particles into powder, sieving the powder by using a 200-mesh sieve, and pressing a cathode sheet;
(2) placing the cathode plate into a tube furnace for low-temperature sintering at 300 ℃ for 3 h;
(3) Fixing the obtained cathode sheet on an iron-chromium-aluminum wire as a cathode, using high-purity graphite as an anode, and carrying out direct-current voltage electrolysis in a molten salt system of CaCl2 under the atmosphere of high-purity argon, wherein the electrolysis voltage is 2.5V, the electrolysis temperature is 530 ℃, and the electrolysis time is 6 h;
(4) Soaking the obtained cathode plate in water for 4h, taking out, washing with hydrofluoric acid, washing with deionized water, and drying to obtain silicon nanowires;
preparing a carbon-coated silicon nanowire negative electrode material:
(A) weighing 12g of acetylene black by taking the silicon nanowire obtained in the step (4) as a precursor, and carrying out ball milling on the acetylene black and the silicon nanowire obtained in the step (4), wherein the ball milling rotation speed is 50r/min, and the ball milling time is 18h to obtain powder;
(B) and putting the obtained powder into a tubular furnace, vacuumizing, sintering in the tubular furnace under an inert atmosphere at the sintering temperature of 900 ℃ for 6 hours, and cooling to obtain the carbon-coated silicon nanowire negative electrode material.
And (3) performance detection:
The carbon-coated silicon nanowire negative electrode material prepared in the embodiment is used as a negative electrode material of a battery to be assembled into the battery, and electrochemical performance tests are carried out, and the results are shown in table 1.
Example 3
preparing a silicon nanowire:
(1) 89g of silicon dioxide particles and 11g of sodium chloride particles are weighed and ground into powder, and the powder is sieved by a 200-mesh sieve and then pressed into a cathode piece;
(2) placing the cathode plate into a tube furnace for low-temperature sintering at 280 ℃ for 5 h;
(3) fixing the obtained cathode sheet on an iron-chromium-aluminum wire as a cathode, using high-purity graphite as an anode, and carrying out direct-current voltage electrolysis in a molten salt system of CaCl2 under the atmosphere of high-purity argon, wherein the electrolysis voltage is 2.0V, the electrolysis temperature is 560 ℃, and the electrolysis time is 10 h;
(4) soaking the obtained cathode plate in water for 3h, then taking out, washing with hydrofluoric acid, washing with deionized water, and finally drying to obtain the silicon nanowire;
Preparing a carbon-coated silicon nanowire negative electrode material:
(A) Taking the silicon nanowire obtained in the step (4) as a precursor, weighing 8g of acetylene black, and carrying out ball milling on the acetylene black and the silicon nanowire obtained in the step (4), wherein the ball milling rotation speed is 40r/min, and the ball milling time is 20h to obtain powder;
(B) and putting the obtained powder into a tubular furnace, vacuumizing, sintering in the tubular furnace under an inert atmosphere at the sintering temperature of 800 ℃ for 8h, and cooling to obtain the carbon-coated silicon nanowire negative electrode material.
And (3) performance detection:
The carbon-coated silicon nanowire negative electrode material prepared in the embodiment is used as a negative electrode material of a battery to be assembled into the battery, and electrochemical performance tests are carried out, and the results are shown in table 1.
Example 4
preparing a silicon nanowire:
(1) Weighing 88g of silicon dioxide particles and 12g of sodium chloride particles, grinding the silicon dioxide particles and the sodium chloride particles into powder, sieving the powder by using a 200-mesh sieve, and pressing a cathode sheet;
(2) Placing the cathode plate into a tube furnace for low-temperature sintering, wherein the sintering temperature is 260 ℃, and the sintering time is 5 hours;
(3) fixing the obtained cathode sheet on an iron-chromium-aluminum wire as a cathode, using high-purity graphite as an anode, and carrying out direct-current voltage electrolysis in a molten salt system of CaCl2 under the atmosphere of high-purity argon, wherein the electrolysis voltage is 2.2V, the electrolysis temperature is 590 ℃, and the electrolysis time is 9 h;
(4) soaking the obtained cathode plate in water for 3.5h, then taking out, washing with hydrofluoric acid, washing with deionized water, and finally drying to obtain the silicon nanowire;
preparing a carbon-coated silicon nanowire negative electrode material:
(A) weighing 9g of acetylene black by taking the silicon nanowire obtained in the step (4) as a precursor, and carrying out ball milling on the acetylene black and the silicon nanowire obtained in the step (4), wherein the ball milling rotation speed is 60r/min, and the ball milling time is 15h to obtain powder;
(B) And putting the obtained powder into a tubular furnace, vacuumizing, sintering in the tubular furnace under an inert atmosphere at the sintering temperature of 850 ℃ for 7h, and cooling to obtain the carbon-coated silicon nanowire negative electrode material.
and (3) performance detection:
the carbon-coated silicon nanowire negative electrode material prepared in the embodiment is used as a negative electrode material of a battery to be assembled into the battery, and electrochemical performance tests are carried out, and the results are shown in table 1.
example 5
Preparing a silicon nanowire:
(1) Weighing 97g of silicon dioxide particles and 3g of sodium chloride particles, grinding the silicon dioxide particles and the sodium chloride particles into powder, sieving the powder by using a 200-mesh sieve, and pressing a cathode sheet;
(2) Placing the cathode plate into a tube furnace for low-temperature sintering, wherein the sintering temperature is 360 ℃, and the sintering time is 2 hours;
(3) Fixing the obtained cathode sheet on an iron-chromium-aluminum wire as a cathode, using high-purity graphite as an anode, and carrying out direct-current voltage electrolysis in a molten salt system of CaCl2 under the atmosphere of high-purity argon, wherein the electrolysis voltage is 2.3V, the electrolysis temperature is 600 ℃, and the electrolysis time is 9.5 h;
(4) soaking the obtained cathode plate in water for 4.5h, then taking out, washing with hydrofluoric acid, washing with deionized water, and finally drying to obtain the silicon nanowire;
Preparing a carbon-coated silicon nanowire negative electrode material:
(A) taking the silicon nanowire obtained in the step (4) as a precursor, weighing 10g of acetylene black, and carrying out ball milling on the acetylene black and the silicon nanowire obtained in the step (4), wherein the ball milling rotation speed is 50r/min, and the ball milling time is 18h to obtain powder;
(B) And putting the obtained powder into a tubular furnace, vacuumizing, sintering in the tubular furnace under an inert atmosphere at the sintering temperature of 950 ℃ for 7.5h, and cooling to obtain the carbon-coated silicon nanowire negative electrode material.
and (3) performance detection:
the carbon-coated silicon nanowire negative electrode material prepared in the embodiment is used as a negative electrode material of a battery to be assembled into the battery, and electrochemical performance tests are carried out, and the results are shown in table 1.
Example 6
preparing a silicon nanowire:
(1) Weighing 94g of silicon dioxide particles and 6g of sodium chloride particles, grinding the silicon dioxide particles and the sodium chloride particles into powder, sieving the powder by using a 200-mesh sieve, and pressing a cathode sheet;
(2) Placing the cathode plate into a tube furnace for low-temperature sintering at 320 ℃ for 4 h;
(3) fixing the obtained cathode sheet on an iron-chromium-aluminum wire as a cathode, using high-purity graphite as an anode, and carrying out direct-current voltage electrolysis in a molten salt system of CaCl2 under the atmosphere of high-purity argon, wherein the electrolysis voltage is 2.4V, the electrolysis temperature is 500 ℃, and the electrolysis time is 8 h;
(4) soaking the obtained cathode plate in water for 4h, taking out, washing with hydrofluoric acid, washing with deionized water, and drying to obtain silicon nanowires;
preparing a carbon-coated silicon nanowire negative electrode material:
(A) weighing 17.65g of acetylene black by taking the silicon nanowire obtained in the step (4) as a precursor, and carrying out ball milling on the acetylene black and the silicon nanowire in the step (4), wherein the ball milling rotation speed is 40r/min, and the ball milling time is 20h to obtain powder;
(B) And putting the obtained powder into a tubular furnace, vacuumizing, sintering in the tubular furnace under an inert atmosphere at the sintering temperature of 1100 ℃ for 4h, and cooling to obtain the carbon-coated silicon nanowire negative electrode material.
And (3) performance detection:
the carbon-coated silicon nanowire negative electrode material prepared in the embodiment is used as a negative electrode material of a battery to be assembled into the battery, and electrochemical performance tests are carried out, and the results are shown in table 1.
Example 7
Preparing a silicon nanowire:
(1) Weighing 91g of silicon dioxide particles and 9g of sodium chloride particles, grinding the silicon dioxide particles and the sodium chloride particles into powder, sieving the powder by using a 200-mesh sieve, and pressing a cathode sheet;
(2) Placing the cathode plate into a tube furnace for low-temperature sintering at 280 ℃ for 3 h;
(3) Fixing the obtained cathode sheet on an iron-chromium-aluminum wire as a cathode, using high-purity graphite as an anode, and carrying out direct-current voltage electrolysis in a molten salt system of CaCl2 under the atmosphere of high-purity argon, wherein the electrolysis voltage is 2.6V, the electrolysis temperature is 530 ℃, and the electrolysis time is 6 h;
(4) and soaking the obtained cathode plate in water for 5h, then taking out, washing with hydrofluoric acid, washing with deionized water, and finally drying to obtain the silicon nanowire.
preparing a carbon-coated silicon nanowire negative electrode material:
(A) taking the silicon nanowire obtained in the step (4) as a precursor, weighing 5.26g of acetylene black, and carrying out ball milling on the acetylene black and the silicon nanowire obtained in the step (4), wherein the ball milling rotation speed is 60r/min, and the ball milling time is 15h to obtain powder;
(B) And putting the obtained powder into a tubular furnace, vacuumizing, sintering in the tubular furnace under an inert atmosphere at the sintering temperature of 850 ℃ for 5h, and cooling to obtain the carbon-coated silicon nanowire negative electrode material.
and (3) performance detection:
the carbon-coated silicon nanowire negative electrode material prepared in the embodiment is used as a negative electrode material of a battery to be assembled into the battery, and electrochemical performance tests are carried out, and the results are shown in table 1.
example 8
Preparing a silicon nanowire:
(1) weighing 94g of silicon dioxide particles and 6g of sodium chloride particles, grinding the silicon dioxide particles and the sodium chloride particles into powder, sieving the powder by using a 200-mesh sieve, and pressing a cathode sheet;
(2) placing the cathode plate into a tube furnace for low-temperature sintering at 300 ℃ for 4 h;
(3) Fixing the obtained cathode sheet on an iron-chromium-aluminum wire as a cathode, using high-purity graphite as an anode, and carrying out direct-current voltage electrolysis in a molten salt system of CaCl2 under the atmosphere of high-purity argon, wherein the electrolysis voltage is 2.8V, the electrolysis temperature is 560 ℃, and the electrolysis time is 9.5 h;
(4) and soaking the obtained cathode plate in water for 4.5h, then taking out, washing with hydrofluoric acid, washing with deionized water, and finally drying to obtain the silicon nanowire.
preparing a carbon-coated silicon nanowire negative electrode material:
(A) Taking the silicon nanowire obtained in the step (4) as a precursor, weighing 10g of acetylene black, and carrying out ball milling on the acetylene black and the silicon nanowire obtained in the step (4), wherein the ball milling rotation speed is 50r/min, and the ball milling time is 18h to obtain powder;
(B) and putting the obtained powder into a tubular furnace, vacuumizing, sintering in the tubular furnace under an inert atmosphere at the sintering temperature of 950 ℃ for 7.5h, and cooling to obtain the carbon-coated silicon nanowire negative electrode material.
and (3) performance detection:
the carbon-coated silicon nanowire negative electrode material prepared in the embodiment is used as a negative electrode material of a battery to be assembled into the battery, and electrochemical performance tests are carried out, and the results are shown in table 1.
Example 9
Preparing a silicon nanowire:
(1) Weighing 97g of silicon dioxide particles and 3g of sodium chloride particles, grinding the silicon dioxide particles and the sodium chloride particles into powder, sieving the powder by using a 200-mesh sieve, and pressing a cathode sheet;
(2) Placing the cathode plate into a tube furnace for low-temperature sintering, wherein the sintering temperature is 260 ℃, and the sintering time is 5 hours;
(3) fixing the obtained cathode sheet on an iron-chromium-aluminum wire as a cathode, using high-purity graphite as an anode, and carrying out direct-current voltage electrolysis in a molten salt system of CaCl2 under the atmosphere of high-purity argon, wherein the electrolysis voltage is 3.0V, the electrolysis temperature is 590 ℃, and the electrolysis time is 5 h;
(4) And soaking the obtained cathode plate in water for 3h, then taking out, washing with hydrofluoric acid, washing with deionized water, and finally drying to obtain the silicon nanowire.
Preparing a carbon-coated silicon nanowire negative electrode material:
(A) weighing 13g of acetylene black by taking the silicon nanowire obtained in the step (4) as a precursor, and carrying out ball milling on the acetylene black and the silicon nanowire obtained in the step (4), wherein the ball milling rotation speed is 40r/min, and the ball milling time is 20h to obtain powder;
(B) And putting the obtained powder into a tubular furnace, vacuumizing, sintering in the tubular furnace under an inert atmosphere at the sintering temperature of 1200 ℃ for 2h, and cooling to obtain the carbon-coated silicon nanowire negative electrode material.
and (3) performance detection:
The carbon-coated silicon nanowire negative electrode material prepared in the embodiment is used as a negative electrode material of a battery to be assembled into the battery, and electrochemical performance tests are carried out, and the results are shown in table 1.
example 10
Preparing a silicon nanowire:
(1) Weighing 92g of silicon dioxide particles and 8g of sodium chloride particles, grinding the silicon dioxide particles and the sodium chloride particles into powder, sieving the powder by using a 200-mesh sieve, and pressing a cathode sheet;
(2) Placing the cathode plate into a tube furnace for low-temperature sintering at 280 ℃ for 3 h;
(3) fixing the obtained cathode sheet on an iron-chromium-aluminum wire as a cathode, using high-purity graphite as an anode, and carrying out direct-current voltage electrolysis in a molten salt system of CaCl2 under the atmosphere of high-purity argon, wherein the electrolysis voltage is 3.2V, the electrolysis temperature is 600 ℃, and the electrolysis time is 10 h;
(4) Soaking the obtained cathode plate in water for 5h, then taking out, washing with hydrofluoric acid, washing with deionized water, and finally drying to obtain the silicon nanowire;
Preparing a carbon-coated silicon nanowire negative electrode material:
(A) Weighing 15g of acetylene black by taking the silicon nanowire obtained in the step (4) as a precursor, and carrying out ball milling on the acetylene black and the silicon nanowire obtained in the step (4), wherein the ball milling rotation speed is 60r/min, and the ball milling time is 15h to obtain powder;
(B) and putting the obtained powder into a tubular furnace, vacuumizing, sintering in the tubular furnace under an inert atmosphere at the sintering temperature of 800 ℃ for 8h, and cooling to obtain the carbon-coated silicon nanowire negative electrode material.
And (3) performance detection:
The carbon-coated silicon nanowire negative electrode material prepared in the embodiment is used as a negative electrode material of a battery to be assembled into the battery, and electrochemical performance tests are carried out, and the results are shown in table 1.
example 11
Preparing a silicon nanowire:
(1) Weighing 96g of silicon dioxide particles and 4g of sodium chloride particles, grinding the silicon dioxide particles and the sodium chloride particles into powder, sieving the powder by using a 200-mesh sieve, and pressing a cathode sheet;
(2) placing the cathode plate into a tube furnace for low-temperature sintering at 300 ℃ for 3 h;
(3) fixing the obtained cathode sheet on an iron-chromium-aluminum wire as a cathode, using high-purity graphite as an anode, and carrying out direct-current voltage electrolysis in a molten salt system of CaCl2 under the atmosphere of high-purity argon, wherein the electrolysis voltage is 2V, the electrolysis temperature is 500 ℃, and the electrolysis time is 4 h;
(4) And soaking the obtained cathode plate in water for 3h, then taking out, washing with hydrofluoric acid, washing with deionized water, and finally drying to obtain the silicon nanowire.
preparing a carbon-coated silicon nanowire negative electrode material:
(A) Taking the silicon nanowire obtained in the step (4) as a precursor, weighing 10g of acetylene black, and carrying out ball milling on the acetylene black and the silicon nanowire obtained in the step (4), wherein the ball milling rotation speed is 50r/min, and the ball milling time is 18h to obtain powder;
(B) and putting the obtained powder into a tubular furnace, vacuumizing, sintering in the tubular furnace under an inert atmosphere at the sintering temperature of 900 ℃ for 7h, and cooling to obtain the carbon-coated silicon nanowire negative electrode material.
and (3) performance detection:
the carbon-coated silicon nanowire negative electrode material prepared in the embodiment is used as a negative electrode material of a battery to be assembled into the battery, and electrochemical performance tests are carried out, and the results are shown in table 1.
Example 12
Preparing a silicon nanowire:
(1) Weighing 94g of silicon dioxide particles and 6g of sodium chloride particles, grinding the silicon dioxide particles and the sodium chloride particles into powder, sieving the powder by using a 200-mesh sieve, and pressing a cathode sheet;
(2) Placing the cathode plate into a tube furnace for low-temperature sintering at 320 ℃ for 2 h;
(3) fixing the obtained cathode sheet on an iron-chromium-aluminum wire as a cathode, using high-purity graphite as an anode, and carrying out direct-current voltage electrolysis in a molten salt system of CaCl2 under the atmosphere of high-purity argon, wherein the electrolysis voltage is 2.2V, the electrolysis temperature is 530 ℃, and the electrolysis time is 10 h;
(4) and soaking the obtained cathode plate in water for 5h, then taking out, washing with hydrofluoric acid, washing with deionized water, and finally drying to obtain the silicon nanowire.
preparing a carbon-coated silicon nanowire negative electrode material:
(A) taking the silicon nanowire obtained in the step (4) as a precursor, weighing 10g of acetylene black, and carrying out ball milling on the acetylene black and the silicon nanowire obtained in the step (4), wherein the ball milling rotation speed is 40r/min, and the ball milling time is 20h to obtain powder;
(B) and putting the obtained powder into a tubular furnace, vacuumizing, sintering in the tubular furnace under an inert atmosphere at the sintering temperature of 1000 ℃ for 4h, and cooling to obtain the carbon-coated silicon nanowire negative electrode material.
And (3) performance detection:
the carbon-coated silicon nanowire negative electrode material prepared in the embodiment is used as a negative electrode material of a battery to be assembled into the battery, and electrochemical performance tests are carried out, and the results are shown in table 1.
Example 13
preparing a silicon nanowire:
(1) weighing 95g of silicon dioxide particles and 5g of sodium chloride particles, grinding the silicon dioxide particles and the sodium chloride particles into powder, sieving the powder by using a 200-mesh sieve, and pressing a cathode sheet;
(2) Placing the cathode plate into a tube furnace for low-temperature sintering, wherein the sintering temperature is 360 ℃, and the sintering time is 2 hours;
(3) fixing the obtained cathode sheet on an iron-chromium-aluminum wire as a cathode, using high-purity graphite as an anode, and carrying out direct-current voltage electrolysis in a molten salt system of CaCl2 under the atmosphere of high-purity argon, wherein the electrolysis voltage is 2.4V, the electrolysis temperature is 560 ℃, and the electrolysis time is 5 h;
(4) And soaking the obtained cathode plate in water for 4h, then taking out, washing with hydrofluoric acid, washing with deionized water, and finally drying to obtain the silicon nanowire.
preparing a carbon-coated silicon nanowire negative electrode material:
(A) Weighing 12g of acetylene black by taking the silicon nanowire obtained in the step (4) as a precursor, and carrying out ball milling on the acetylene black and the silicon nanowire obtained in the step (4), wherein the ball milling rotation speed is 60r/min, and the ball milling time is 15h to obtain powder;
(B) and putting the obtained powder into a tubular furnace, vacuumizing, sintering in the tubular furnace under an inert atmosphere at the sintering temperature of 900 ℃ for 7h, and cooling to obtain the carbon-coated silicon nanowire negative electrode material.
and (3) performance detection:
The carbon-coated silicon nanowire negative electrode material prepared in the embodiment is used as a negative electrode material of a battery to be assembled into the battery, and electrochemical performance tests are carried out, and the results are shown in table 1.
Example 14
Preparing a silicon nanowire:
(1) weighing 97g of silicon dioxide particles and 3g of sodium chloride particles, grinding the silicon dioxide particles and the sodium chloride particles into powder, sieving the powder by using a 200-mesh sieve, and pressing a cathode sheet;
(2) placing the cathode plate into a tube furnace for low-temperature sintering, wherein the sintering temperature is 260 ℃, and the sintering time is 5 hours;
(3) Fixing the obtained cathode sheet on an iron-chromium-aluminum wire as a cathode, using high-purity graphite as an anode, and carrying out direct-current voltage electrolysis in a molten salt system of CaCl2 under the atmosphere of high-purity argon, wherein the electrolysis voltage is 2V, the electrolysis temperature is 500 ℃, and the electrolysis time is 4 h;
(4) And soaking the obtained cathode plate in water for 3h, then taking out, washing with hydrofluoric acid, washing with deionized water, and finally drying to obtain the silicon nanowire.
Preparing a carbon-coated silicon nanowire negative electrode material:
(A) Taking the silicon nanowire obtained in the step (4) as a precursor, weighing 5.26g of acetylene black, and carrying out ball milling on the acetylene black and the silicon nanowire obtained in the step (4), wherein the ball milling rotation speed is 50r/min, and the ball milling time is 18h to obtain powder;
(B) And putting the obtained powder into a tubular furnace, vacuumizing, sintering in the tubular furnace under an inert atmosphere at the sintering temperature of 800 ℃ for 2h, and cooling to obtain the carbon-coated silicon nanowire negative electrode material.
and (3) performance detection:
The carbon-coated silicon nanowire negative electrode material prepared in the embodiment is used as a negative electrode material of a battery to be assembled into the battery, and electrochemical performance tests are carried out, and the results are shown in table 1.
example 15
preparing a silicon nanowire:
(1) weighing 88g of silicon dioxide particles and 12g of sodium chloride particles, grinding the silicon dioxide particles and the sodium chloride particles into powder, sieving the powder by using a 200-mesh sieve, and pressing a cathode sheet;
(2) placing the cathode plate into a tube furnace for low-temperature sintering, wherein the sintering temperature is 360 ℃, and the sintering time is 2 hours;
(3) Fixing the obtained cathode sheet on an iron-chromium-aluminum wire as a cathode, using high-purity graphite as an anode, and carrying out direct-current voltage electrolysis in a molten salt system of CaCl2 under the atmosphere of high-purity argon, wherein the electrolysis voltage is 3.2V, the electrolysis temperature is 600 ℃, and the electrolysis time is 10 h;
(4) and soaking the obtained cathode plate in water for 5h, then taking out, washing with hydrofluoric acid, washing with deionized water, and finally drying to obtain the silicon nanowire.
preparing a carbon-coated silicon nanowire negative electrode material:
(A) Weighing 17.65g of acetylene black by taking the silicon nanowire obtained in the step (4) as a precursor, and carrying out ball milling on the acetylene black and the silicon nanowire in the step (4), wherein the ball milling rotation speed is 40r/min, and the ball milling time is 20h to obtain powder;
(B) and putting the obtained powder into a tubular furnace, vacuumizing, sintering in the tubular furnace under an inert atmosphere at the sintering temperature of 1200 ℃ for 8h, and cooling to obtain the carbon-coated silicon nanowire negative electrode material.
and (3) performance detection:
the carbon-coated silicon nanowire negative electrode material prepared in the embodiment is used as a negative electrode material of a battery to be assembled into the battery, and electrochemical performance tests are carried out, and the results are shown in table 1.
TABLE 1
the applicant states that the present invention is illustrated in detail by the above examples, but the present invention is not limited to the above detailed methods, i.e. it is not meant that the present invention must rely on the above detailed methods for its implementation. It should be understood by those skilled in the art that any modification of the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.
Claims (19)
1. a method for preparing silicon nanowires, characterized in that the method comprises the following steps:
(1) Pressing the mixed powder of silicon dioxide and sodium chloride into a cathode sheet, wherein the sodium chloride accounts for 3-12% of the total mass of the mixed powder of silicon dioxide and sodium chloride as 100%;
(2) Sintering the cathode sheet obtained in the step (1), wherein the sintering temperature is 260-360 ℃;
(3) And (3) fixing the cathode sheet sintered in the step (2) on an iron-chromium-aluminum wire to serve as a cathode, using graphite as an anode, and electrolyzing in a CaCl2 molten salt system at the temperature of 500-600 ℃ to obtain the silicon nanowire.
2. the method for preparing silicon nanowires according to claim 1, wherein the particle size of the mixed powder of silicon dioxide and sodium chloride in step (1) is 100 to 300 mesh.
3. The method for preparing silicon nanowires according to claim 1, wherein the sintering time in the step (2) is 2-10 h.
4. The method for preparing silicon nanowires according to claim 3, wherein the sintering time in the step (2) is 2-5 h.
5. the method for preparing silicon nanowires according to claim 1, wherein the sintering of step (2) is performed in a tube furnace.
6. The method for preparing silicon nanowires according to claim 1, wherein the voltage for electrolysis in step (3) is 2-3.2V.
7. the method for preparing silicon nanowires according to claim 1, wherein the time for electrolysis in step (3) is 4-10 h.
8. The method for preparing silicon nanowires according to claim 1, wherein the electrolysis in the step (3) is performed in an atmosphere of high purity argon.
9. The method for preparing silicon nanowires according to claim 1, wherein the electrolysis in the step (3) is direct-current voltage electrolysis.
10. The method for preparing silicon nanowires according to claim 1, wherein the graphite in the step (3) is high-purity graphite.
11. The method for preparing silicon nanowires of claim 1, further comprising a step of sieving the mixed powder of silicon dioxide and sodium chloride before pressing the cathode sheet in step (1).
12. The method as claimed in claim 11, wherein the sieving step is performed using a 100-300 mesh sieve.
13. the method for producing silicon nanowires according to claim 12, wherein in the step of sieving, sieving is performed using a 200-mesh sieve.
14. The method for preparing silicon nanowires according to claim 1, further comprising performing step (1)' before step (1): the silica particles and the sodium chloride particles are mixed and ground to obtain a mixed powder of silica and sodium chloride.
15. The method for preparing silicon nanowires of claim 1, further comprising the step of sequentially performing water soaking, washing and drying on the electrolysis product after the electrolysis of step (3).
16. the method for preparing silicon nanowires of claim 15, wherein the step of soaking in water is: the electrolysis product is soaked in water.
17. the method of claim 16, wherein the soaking time is 3 to 5 hours.
18. the method of claim 15, wherein the washing step comprises: and (3) soaking the electrolytic product by adopting hydrofluoric acid and then deionized water washing water.
19. the method for preparing silicon nanowires of claim 1, wherein the method comprises the steps of:
(1) ' mixing silica particles and sodium chloride particles, and then grinding the resulting mixed particles to obtain a mixed powder of silica and sodium chloride;
(1) Sieving the mixed powder of silicon dioxide and sodium chloride by using a 200-mesh sieve, and then pressing into a cathode sheet;
(2) putting the cathode plate obtained in the step (1) into a tube furnace, and sintering for 2-5 h at 260-360 ℃;
(3) fixing the cathode sheet sintered in the step (2) on an iron-chromium-aluminum wire to serve as a cathode, using graphite as an anode, electrolyzing for 4-10 hours at 500-600 ℃ in a CaCl2 molten salt system at the direct current voltage of 2-3.2V, soaking an electrolysis product in water for 3-5 hours, then washing with hydrofluoric acid, then washing with deionized water, and finally drying to obtain the silicon nanowire.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610786002.7A CN106207144B (en) | 2016-08-31 | 2016-08-31 | silicon nanowire, preparation method thereof and application of silicon nanowire in preparation of carbon-coated silicon nanowire negative electrode material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610786002.7A CN106207144B (en) | 2016-08-31 | 2016-08-31 | silicon nanowire, preparation method thereof and application of silicon nanowire in preparation of carbon-coated silicon nanowire negative electrode material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN106207144A CN106207144A (en) | 2016-12-07 |
| CN106207144B true CN106207144B (en) | 2019-12-06 |
Family
ID=58085172
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610786002.7A Active CN106207144B (en) | 2016-08-31 | 2016-08-31 | silicon nanowire, preparation method thereof and application of silicon nanowire in preparation of carbon-coated silicon nanowire negative electrode material |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN106207144B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106784680A (en) * | 2016-12-20 | 2017-05-31 | 山东精工电子科技有限公司 | One-dimensional silicon-carbon cathode material and preparation method thereof |
| CN110629241B (en) * | 2019-09-16 | 2021-06-22 | 上海大学 | Silicon material manufacturing method |
| CN110649238B (en) * | 2019-09-27 | 2020-10-27 | 东北大学 | Silicon-based Si-C cathode material and electrochemical synthesis method and application thereof |
| CN113991099A (en) * | 2021-10-27 | 2022-01-28 | 昆明理工大学 | Method for preparing nano silicon-based negative electrode material from silicon cutting waste |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TW201331121A (en) * | 2012-01-17 | 2013-08-01 | Nat Univ Kaohsiung | Manufacturing method for porous silicon nanowire and porous silicon nanowire manufactured therewith |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101736354B (en) * | 2008-11-06 | 2011-11-16 | 北京有色金属研究总院 | Method for preparing one or more of silicon nano power, silicon nanowires and silicon nanotubes by electrochemical method |
| CN101871116B (en) * | 2010-05-28 | 2012-01-04 | 南阳理工学院 | Preparation method for ordered silicon nano-wires |
| US20130081679A1 (en) * | 2011-09-30 | 2013-04-04 | Ut-Battelle, Llc | Multijunction hybrid solar cell incorporating vertically-aligned silicon nanowires with thin films |
| CN105018956B (en) * | 2014-04-30 | 2017-11-03 | 北京有色金属研究总院 | A kind of crystalline silica/carbon is composite porous and preparation method thereof |
| CN104577045B (en) * | 2014-12-20 | 2018-07-10 | 江西正拓新能源科技股份有限公司 | A kind of lithium ion battery silicon-carbon composite and preparation method thereof |
-
2016
- 2016-08-31 CN CN201610786002.7A patent/CN106207144B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TW201331121A (en) * | 2012-01-17 | 2013-08-01 | Nat Univ Kaohsiung | Manufacturing method for porous silicon nanowire and porous silicon nanowire manufactured therewith |
Also Published As
| Publication number | Publication date |
|---|---|
| CN106207144A (en) | 2016-12-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108461723B (en) | Silicon-based composite material for lithium ion battery and preparation method thereof | |
| CN102983313B (en) | Si-C composite material and preparation method thereof, lithium ion battery | |
| Bi et al. | Recent advances in LiFePO 4 nanoparticles with different morphology for high-performance lithium-ion batteries | |
| CN100379059C (en) | Composite cathode material of silicon/carbon/graphite in lithium ion batteries, and preparation method | |
| CN109755482B (en) | Silicon/carbon composite material and preparation method thereof | |
| CN105633374A (en) | Preparation method of silicon-carbon-graphite composite anode material | |
| CN106207144B (en) | silicon nanowire, preparation method thereof and application of silicon nanowire in preparation of carbon-coated silicon nanowire negative electrode material | |
| CN111009647B (en) | Lithium borosilicate alloy cathode active material of lithium secondary battery, cathode, preparation and application thereof | |
| CN110429277B (en) | Preparation method of high-compaction high-rate lithium iron phosphate cathode material | |
| CN111769272A (en) | Bi @ C hollow nanosphere composite material and preparation method and application thereof | |
| WO2020151094A1 (en) | Silicon oxide composite negative electrode material for lithium ion secondary battery and preparation method therefor | |
| CN109473665A (en) | A kind of nano silica-base material and its preparation method and application | |
| CN108767203B (en) | Titanium dioxide nanotube-graphene-sulfur composite material and preparation method and application thereof | |
| CN108899499B (en) | Sb/Sn phosphate-based negative electrode material, preparation method thereof and application thereof in sodium ion battery | |
| CN112803021A (en) | Nano FeF3/C composite positive electrode material, preparation method thereof and lithium ion battery | |
| CN107482206A (en) | A kind of preparation method of lithium ion battery good stability composite negative pole material | |
| CN109494399A (en) | A kind of silicon/solid electrolyte nanocomposite and its preparation method and application | |
| CN108933243B (en) | High-specific-capacity sodium ion battery positive electrode material, preparation method thereof and sodium ion battery | |
| CN107742710B (en) | Preparation method of chromium-based lithium ion battery composite negative electrode material | |
| CN112736233B (en) | Lithium ion battery electrode active material, preparation method thereof, electrode and battery | |
| CN107681141B (en) | Carbon-coated nickel borate nanorod negative electrode material of sodium ion battery | |
| CN107516734B (en) | Preparation method of carbon-coated nickel-tin alloy nanospheres and application of nanospheres in lithium battery | |
| CN110600710B (en) | Iron sulfide-carbon composite material and preparation method thereof, lithium ion battery negative electrode material, lithium ion battery negative electrode piece and lithium ion battery | |
| Liu et al. | Integrated structure design and synthesis of a pitaya-like SnO 2/N-doped carbon composite for high-rate lithium storage capability | |
| CN107195897B (en) | Nano FeNbO4Graphene composite material and preparation and application thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |