CN113072073A - Silica powder - Google Patents
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- CN113072073A CN113072073A CN202110389395.9A CN202110389395A CN113072073A CN 113072073 A CN113072073 A CN 113072073A CN 202110389395 A CN202110389395 A CN 202110389395A CN 113072073 A CN113072073 A CN 113072073A
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B33/00—Silicon; Compounds thereof
- C01B33/02—Silicon
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
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- 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
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- 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
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- 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
- H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
- H01M2004/027—Negative electrodes
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- 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 application provides silicon powder, wherein the particle size distribution D50 of the silicon powder is less than or equal to 1.10 mu m; and the silicon powder particles are flaky; the average flake size of the silicon powder particles is 0.40-1.20 mu m; the average thickness of the silicon powder particles is 30-100 nm; the ratio of the flaky size to the thickness of the silicon powder particles is 4-40. The silicon powder related by the application has small granularity, special appearance, high purity and high capacitance, and is suitable for production and use of silicon-carbon cathode materials.
Description
Technical Field
The invention relates to the technical field of silicon materials, in particular to silicon powder capable of being used as a lithium ion battery cathode material.
Background
Along with the rapid development of economy, the energy crisis and environmental problems are increasingly aggravated, and the lithium ion battery has been widely applied to the fields of portable consumer electronics, electric tools, medical electronics and the like due to the advantages of high energy density, high power density, long cycle life, no memory effect, low self-discharge rate, wide working temperature range, safety, reliability, environmental friendliness and the like; meanwhile, the method has good application prospect in the fields of pure electric vehicles, hybrid electric vehicles, energy storage and the like.
However, in recent years, the demand for energy density of batteries has been rapidly increasing in various fields, and development of lithium ion batteries with higher energy density has been strongly demanded. At present, the commercial lithium ion battery mainly uses graphite as a negative electrode material, the theoretical specific capacity of the graphite is 372mAh/g, and the high-end graphite material on the market can reach 360-365 mAh/g, so that the promotion space of the energy density of the corresponding lithium ion battery is quite limited.
Under the background, the silicon-based negative electrode material is considered to be the next generation high energy density lithium ion battery negative electrode material with great potential due to the advantages of higher theoretical specific capacity (4200 mAh/g at high temperature, 3580mAh/g at room temperature), low lithium removal potential (< 0.5V), environmental friendliness, abundant storage capacity, lower cost and the like. However, the silicon material has 300% volume expansion in the process of lithium extraction, and repeated expansion and contraction can cause the negative electrode material to be pulverized and fall off, and finally cause the negative electrode material to lose electric contact, so that the battery completely fails. The nano-crystallization of the silicon material can effectively solve the problems.
However, most of the silicon powder particles of the current silicon-based negative electrode material are spherical, and the charge-discharge specific capacity and the first coulombic efficiency of the prepared battery are low.
Disclosure of Invention
In order to solve the problems, the invention provides silicon powder which is flaky and can simultaneously improve the charge-discharge specific capacity and the first coulombic efficiency. The specific technical scheme comprises the following steps:
1. silicon powder, wherein the particle size distribution D50 of the silicon powder is less than or equal to 1.10 mu m; and is
The silicon powder particles are flaky;
the average sheet size of the silicon powder particles is 0.40-1.20 μm, specifically 0.50 μm, 0.60 μm, 0.70 μm, 0.80 μm, 0.90 μm, 1.00 μm, 1.10 μm, preferably 0.60 μm-1.00 μm;
the average thickness of the silicon powder particles is 30 nm-100 nm, specifically 40nm, 50nm, 60nm, 70nm, 80nm and 90nm, preferably 50 nm-70 nm;
the ratio of the average sheet size to the average thickness of the silicon powder particles is 4-40.
2. The silicon powder according to item 1, having a particle size distribution of: d10 is 0.15-0.40 μm, specifically 0.20 μm, 0.25 μm, 0.30 μm, and 0.35 μm; d50 is 0.65-1.10 μm, specifically 0.70 μm, 0.75 μm, 0.80 μm, 0.85 μm, 0.90 μm, 0.95 μm, 1.00 μm, and 1.05 μm; d90 has a value in the range of 1.95 to 2.75. mu.m, and specifically may have a value in the range of 1.95 to 2.00. mu.m, 2.10 to 2.20. mu.m, 2.30 to 2.40. mu.m, 2.50 to 2.60. mu.m, or 2.70. mu.m.
3. The silicon powder according to any one of items 1 to 2, wherein the particle size distribution diagram includes at least three peaks, and the peaks of the first three in height are respectively located at 0.10 to 0.20 μm, 0.40 to 0.60 μm, and 1.40 to 1.70 μm.
4. The silicon powder according to any one of items 1 to 3, wherein the proportion of silicon powder with a particle size of 0.50 μm or less is 31.0 to 33.0% by volume; the proportion of the silicon powder with the granularity of more than 0.50 mu m and less than or equal to 1.50 mu m is 45.0-47.0%; the proportion of the silicon powder with the granularity of more than 1.50 mu m is 21.0-23.0%.
5. The silicon powder according to any one of items 1 to 4, wherein the surface of the silicon powder particles is oxidized, and the thickness of the oxide layer is 2 to 10nm, specifically 3nm, 4nm, 5nm, 6nm, 7nm, 8nm, and 9nm, and preferably 2 to 5 nm.
6. The silicon powder according to any one of items 1 to 5, wherein the silicon content in the silicon powder is greater than 90.0% by mass.
7. The silicon powder according to any one of items 1 to 6, wherein the total content of metal ion impurities in the silicon powder is 500ppm or less by mass.
8. The silicon powder according to any one of items 1 to 7, wherein the oxygen content in the silicon powder is 2.0% to 6.0%, specifically 3.0%, 4.0%, and 5.0% by mass.
9. The silicon powder according to any one of items 1 to 8, wherein the carbon content in the silicon powder is 1.0 to 4.0% by mass, specifically 2.0% and 3.0% by mass.
10. The silicon powder according to any one of items 1 to 9, having a tap density of 0.05 to 0.25g/cm3Specifically, it may be 0.10g/cm3、0.15g/cm3、0.20g/cm3Preferably 0.08 to 0.15g/cm3。
11. The silicon powder according to any one of items 1 to 10, having a specific surface area of 10.00 to 25.00m2A specific value of 15.00 m/g2/g、20.00m2Preferably 14.00 to 19.00 m/g2/g。
The silicon powder is flaky nano silicon powder, the thickness of the silicon powder is less than 100nm, the granularity D50 is less than or equal to 1.10 microns, the particle size is small, the morphology is special, the purity is high, the capacitance is high, the first coulombic efficiency is high, and the silicon-carbon negative electrode material is suitable for production and use.
Noun interpretation
Particle size distribution and particle size distribution diagram:
in the present invention, the particle size distribution of the silicon powder refers to the particle size volume distribution of the silicon powder detected by a laser particle size distribution meter. The graph output by the laser particle size distribution instrument for detecting the particle size volume distribution of the silicon powder is a particle size distribution graph. The volume ratio of the silicon powder in different particle size range distributions can be calculated through the integral area of the peaks in different particle size distribution.
FIG. 1 is a graph showing the particle size distribution of the silicon powder of example 1 measured by a betersize 2600 laser particle size distributor manufactured by Dandong Baite instruments Co.
Diamond wire cutting waste liquid:
when a diamond wire cutting method is used for producing silicon wafers, a surfactant and cooling water are used as cooling and lubricating media, a high-speed running steel wire with electroplated diamond particles is used for cutting crystalline silicon, and the surfactant and the cooling water bring out cut silicon powder to form diamond wire cutting waste liquid. Because the crystalline silicon has anisotropy, the crystalline silicon can be cut from a specific cleavage plane in the cutting process, so that particles with a specific shape are formed.
Silicon sludge:
in the production process, because the mortar cannot be directly discharged and can meet the discharge requirement only through sewage treatment, the mortar is subjected to the procedures of centrifugation, filtration, filter pressing and the like to reduce water content, and a semi-solid paste is produced, namely the silicon mud in the application.
Mortar:
the diamond wire cutting waste liquid can be directly used as mortar, or silicon mud is added into the diamond wire cutting waste liquid to form high-solid-content mortar for subsequent treatment.
The flake size of the silicon powder particles:
the sheet size of the silicon powder particles refers to the maximum value of any two line segments passing through the geometric center of the sheet surface of the silicon powder particles detected by using a scanning electron microscope.
In addition, the average flake size in the present invention refers to the arithmetic mean of the flake sizes of any number of silicon powder particles. In the examples and comparative examples, 5 regions were randomly selected to photograph silicon powder using a U.S. FEI cold field emission scanning electron microscope Quanta SEM scanning electron microscope at a magnification of 50000 times, and the average flake size was obtained by counting the flake sizes of all silicon powder particles in the photographing field and taking the arithmetic mean.
Thickness of the silicon powder particles:
the thickness of the silicon powder particles refers to the smallest dimension of the silicon powder particles in a direction perpendicular to the sheet-shaped surface through the geometric center of the silicon powder particles detected by a scanning electron microscope.
In addition, the average thickness in the present invention refers to the arithmetic mean of the thicknesses of any number of silicon powder particles. In the examples and comparative examples, the invention uses a U.S. FEI cold field emission scanning electron microscope Quanta SEM scanning electron microscope to randomly select 5 regions to shoot silicon powder under the condition of a magnification of 50000 times, and counts the thicknesses of all silicon powder particles in the shooting field and takes the arithmetic mean value to obtain the average thickness.
The above description is only an overview of the technical solutions of the present invention, and in order to make the technical means of the present invention more clearly apparent, and to make the implementation of the content of the description possible for those skilled in the art, and to make the above and other objects, features and advantages of the present invention more obvious, the following description is given by way of example of the specific embodiments of the present invention.
Drawings
FIG. 1: the particle size distribution detection result of the silicon powder obtained in example 1;
FIG. 2: a scanning electron microscope picture of the silicon powder obtained in example 1 is taken;
FIG. 3: the nitrogen isothermal adsorption and desorption curve of the silicon powder obtained in example 1;
FIG. 4: FIG. 4-1: peak separation diagram of oxygen element excitation peak in 524-540 electron volt interval; FIG. 4-2: an X-ray photoelectron spectroscopy (XPS) total spectrum of the silicon powder obtained in example 1; FIGS. 4-3: a peak separation chart of silicon element excitation peaks in a 95-107 electron volt interval;
FIG. 5: a transmission electron microscope picture of the silicon powder obtained in example 1 is taken;
FIG. 6: the X-ray diffraction pattern (XRD) of the silicon powder obtained in example 1;
FIG. 7: a first charge-discharge curve of the button cell prepared from the silicon powder obtained in example 1;
FIG. 8: the results of particle size distribution measurement of silica powder particles in the mortar raw material of example 1.
Detailed Description
The following embodiments of the present invention are merely illustrative of specific embodiments for carrying out the present invention and should not be construed as limiting the present invention. Other changes, modifications, substitutions, combinations, and simplifications which may be made without departing from the spirit and principles of the invention are intended to be equivalents thereof and to fall within the scope of the invention.
The invention provides silicon powder, wherein the particle size distribution D50 of the silicon powder is less than or equal to 1.10 mu m, and the silicon powder particles are flaky;
the average sheet size of the silicon powder particles is 0.40-1.20 μm, preferably 0.60-1.00 μm;
the average thickness of the silicon powder particles is 30 nm-100 nm, preferably 50 nm-70 nm;
the ratio of the average sheet size to the average thickness of the silicon powder particles is 4-40.
The silicon powder has small granularity, flaky microscopic appearance, thin thickness and large specific surface area, and can be directly coated with a carbon source to prepare the silicon-carbon cathode material without special treatment; through detection, the button cell prepared from the material has high charge-discharge specific capacity and high first coulombic efficiency.
In a specific embodiment, the particle size distribution of the silicon powder is as follows: d10 is 0.15-0.40 μm; d50 has a value range of 0.65-1.10 μm; d90 has a value range of 1.95-2.75 μm.
In a specific embodiment, the particle size distribution diagram of the silicon powder comprises at least three peaks, and the peaks with the first three heights are respectively located at 0.10 μm to 0.20 μm, 0.40 μm to 0.60 μm, and 1.40 μm to 1.70 μm.
In a specific embodiment, the proportion of the silicon powder with the particle size of 0.50 μm or less is 31.0-33.0% by volume; the proportion of the silicon powder with the granularity of more than 0.50 mu m and less than or equal to 1.50 mu m is 45.0-47.0%; the proportion of the silicon powder with the granularity of more than 1.50 mu m is 21.0-23.0%.
In a specific embodiment, the surface of the silicon powder particles is oxidized, and the thickness of the oxide layer is 2 to 10nm, preferably 2 to 5 nm.
In a specific embodiment, the silicon powder contains more than 90.0% by mass of silicon.
The silicon powder of the invention has high silicon content, and the prepared button cell has high charge and discharge capacity.
In a specific embodiment, the total content of metal ion impurities in the silicon powder is less than or equal to 500ppm by mass.
The silicon powder has high purity, and the prepared silicon-carbon cathode material and the battery have excellent comprehensive performance.
In a specific embodiment, the silicon powder contains 2.0 to 6.0 mass% of oxygen.
In a specific embodiment, the silicon powder contains 1.0-4.0% of carbon by mass.
The silicon powder of the invention has low carbon content, and the prepared button cell has high electric charge and discharge capacity.
In a specific embodiment, the tap density of the silicon powder is 0.05-0.25 g/cm3Preferably 0.08 to 0.15g/cm3。
In a specific embodiment, the specific surface area of the silicon powder is 10.00-25.00 m2Preferably 14.00 to 19.00 m/g2/g。
The silicon powder provided by the application is of a sheet structure, the thickness of the silicon powder is less than or equal to 100nm, and compared with the prior art, the silicon powder can simultaneously improve the charging and discharging specific capacity and the first coulombic efficiency of a battery, and is suitable for production and use of a silicon-carbon negative electrode material.
Examples
The experimental methods used in the following examples are all conventional methods, unless otherwise specified.
Materials, reagents and the like used in the following examples are commercially available unless otherwise specified.
The source of the mortar is as follows:
the mortar used in the following examples is waste diamond wire cutting liquid generated when the applicant cuts crystalline silicon by diamond wire in the production process of silicon wafers and silicon mud mixed in the waste diamond wire cutting liquid. The solid content of the silicon powder in the diamond wire cutting waste liquid is 3.5 to 6.5 percent. Unless otherwise specified in the following procedures, the mortars used were all from the mortars produced by the applicant. Because the current processes for cutting silicon wafers by diamond wires are similar, the compositions of the generated diamond wire cutting waste liquid and the characteristics of silicon powder particles in the diamond wire cutting waste liquid are also similar, so that the technical personnel in the field know that the diamond wire cutting waste liquid produced by other companies is used as the mortar in the embodiment of the application.
In addition, the mortar may be stirred in order to prevent agglomeration of the silica powder in the mortar before the silica powder is prepared.
And (3) detecting the solid content of the mortar:
in the following examples and comparative examples, the solid content of the mortar was measured by centrifugation and drying, specifically, a quantitative mortar was taken and centrifuged at high speed until the supernatant was transparent (the centrifuge was a Thermo Fisher Scientific brand Sorvall MTX 150 desk-top micro ultracentrifuge); and discharging the supernatant, drying the solid slag in vacuum to constant weight, and calculating the solid content of the mortar according to the weight of the solid slag.
Spray drying:
in the following examples and comparative examples, 8LPG-50 type spray dryer, Gannan forest drying engineering Co., Ltd. of Changzhou city, was used for spray drying.
Airflow crushing:
in the following examples and comparative examples, jet milling was carried out using a JSDL-Q jet mill, a Sichuan ultra-fast kinetic ultrafine powder manufacturing facility Co.
Example 1
(1) Detecting mortar:
the mortar used in this example was diamond wire cutting waste liquid.
Taking the mortar, and measuring the solid content of the mortar to be 4.2%;
(2) carrying out spray drying on the mortar:
the air inlet temperature of spray drying is 210 ℃, and the air outlet temperature is 85 ℃;
(3) then, carrying out jet milling:
the air flow pressure: 0.3MPa, and the rotating speed of the grading wheel is 4500 rpm.
Thereby producing silicon powder.
Examples 2 to 7 differ from example 1 in the solids content of the mortar and in the parameters of spray drying and jet milling. In addition, in example 7, a silicon sludge was added to the diamond wire cutting waste liquid to form a mortar.
Comparative examples 1 to 7 differ from example 1 in the parameters of spray drying and jet milling.
The mortar treatment parameters of examples 1 to 7 and comparative examples 1 to 6 are detailed in Table 1.
Table 1:
the following tests were carried out on the silicon powders obtained in examples 1 to 7 and comparative examples 1 to 6. The method and results of testing the silicon powder obtained in example 1 are given as an example, and the methods of testing other examples and comparative examples are the same as example 1. The results of the measurement are shown in Table 2 (tables 2-1 and 2-2):
(1) measurement of particle size distribution of silicon powder
The particle size distribution was measured using a betersize 2600 manufactured by dandongbott instruments ltd.
As shown in fig. 1, the particle size volume distribution detection result of the silicon powder obtained in example 1 includes 3 peaks, which are sequentially from small to large according to the peak position order: 0.13 μm (first peak position), 0.52 μm (second peak position), 1.55 μm (third peak position); the particle size is D10:0.242 μm, D50:0.745 μm, D90:2.049 μm. The volume ratio of the silicon powder in different particle size range distributions can be calculated through the integral area of the peaks in different particle size distribution.
(2) Determination of sample state of silicon powder particles
Silicon powder is shot by using a Quanta SEM scanning electron microscope of an FEI cold field emission scanning electron microscope.
FIG. 2 (FIG. 2-1, FIG. 2-2) shows a scanning electron micrograph of the silicon powder of example 1, wherein the silicon powder particles have a lamellar nanostructure and an average thickness of 60 nm; the average platelet size was: 0.792 μm, so its average platelet size to average thickness ratio is 13.2.
The average flake size and average thickness are obtained by randomly selecting 5 regions to shoot the silicon powder under the condition of magnification of 50000 times by using a scanning electron microscope, counting the flake sizes and thicknesses of all silicon powder particles in a shooting field, and taking an arithmetic mean value, namely the average flake size and average thickness of the embodiment 1. The average plate-like size and average thickness were obtained in the same manner in the following examples and comparative examples.
(3) Determination of tap density of silicon powder
According to GB/T-2433, the test was carried out using an HY-100 tap density tester from Haoyu technologies, Inc., Dandong.
Wherein, the detection result of the embodiment 1 is 0.1123g/cm3。
(4) Determination of specific surface area of silicon powder
According to GB/T-19587, the measurements were carried out using a Tristar model 3020 specific surface area and porosity analyzer, manufactured by Micromeritics, USA.
As shown in FIG. 3, the nitrogen isothermal adsorption and desorption curves of the silicon powder of example 1 are shown. According to the calculation of a BET equation, the specific surface area of the silicon powder is as follows: 15.95m2/g。
(5) Surface chemical bond detection
Detection was carried out using X-ray photoelectron spectroscopy (XPS) model K-Alpha from Thermo Fisher Scientific, USA.
In examples 1 to 7 and comparative examples 1 to 6, the surface of the nano silicon mainly contains three elements, i.e., silicon, oxygen, and carbon. According to the peak separation result, the silicon surface is completely oxidized, and no other impurities except carbon exist; meanwhile, the presence of silicon-silicon bonds indicates that the thickness of the silicon oxide layer is less than 10nm (XPS ray detection depth), which is not shown in table 2.
The detection diagram of the embodiment 1 is shown in the attached figure 4 (figures 4-1-4-3) in detail.
Wherein: FIG. 4-1 is a peak-separation diagram of the oxygen excitation peak in the range of 524 to 540 electron volts;
FIG. 4-2 is a total X-ray photoelectron spectroscopy (XPS) spectrum of silicon powder;
FIG. 4-3 is a peak separation diagram of the silicon excitation peak in the interval of 95 to 107 electron volts.
(6) Thickness of surface oxide layer
Detecting with Theris type TEM transmission electron microscope of Thermo Fisher Scientific, USA, and analyzing the surface state of the material by high power transmission electron microscope;
FIG. 5(5-1, 5-2) is a transmission electron microscope photograph of the silicon powder of example 1.
The high-power transmission electron microscope photo shows that the material matrix is in a crystalline state, and an amorphous state of 2-5 nm exists on the surface; the thickness of the oxide layer on the surface of the silicon powder is about 2-5 nm, and the oxidation degree is smaller.
(7) Crystal form detection
And (3) crystal form detection: and performing product crystal form detection by using a BRUKER (Bruker) D8 ADVANCE type X-ray polycrystalline diffractometer.
FIG. 6 is a detection spectrum of the silicon powder particles of example 1.
Wherein an X-ray diffraction pattern (XRD) indicates that: the diffraction peak intensity of the silicon powder is high, the background noise is low, all peak positions can be well matched with a crystalline silicon standard map (JCPDS card No.01-0787), and no obvious impurity peak exists; indicating that the silicon powder is a crystalline silicon material.
The results of the tests in examples 1 to 7 and comparative examples 1 to 6 are similar to those in the above examples, and the test results are not shown in Table 2.
(8) Oxygen and carbon content detection
Detecting the carbon content of the silicon powder by using a CS320 high-frequency infrared carbon-sulfur instrument of Chongqing research instrument Co;
the oxygen content of the silicon powder was measured using an ONH-330 model oxygen nitrogen hydrogen tester from Chongqing research instruments, Inc.
Wherein the detection result of the embodiment 1 is as follows:
carbon content: 3.13 percent;
oxygen content: 4.76 percent.
(9) Metal ion impurity detection
Detection was performed using ICPMS model NexiON 2000 from Perkin Elmer PE.
Example 1 the test results are: the total content of total metal ion impurities in the silicon powder is 132 ppm.
Table 2-1:
tables 2 to 2:
in addition, the silicon powder in the prior art is used as comparative examples 7 to 8.
Of these, comparative example 7, which was a silicon powder having a particle size D50 of 0.811 μm obtained by milling from Ishikaki technologies, Inc. of Beijing Deke, was close to the particle size D50 of the silicon powder of example 1, and it was found that the particles of the silicon powder of comparative example 7 were spherical.
Comparative example 8, which was a silicon powder having a particle size D50 of 0.765 μm obtained by milling from Shanghai Chaowei nanotechnology Co., Ltd, was close to the particle size D50 of the silicon powder of example 1, and it was found that the silicon powder of comparative example 8 had a spherical particle shape.
Experimental example:
in the art, the product is usually made into a CR2016 button cell to simulate the full cell reaction, and the specific capacity and coulombic efficiency of the product are detected.
The silicon powders prepared in examples 1-7 and comparative examples 1-8 are respectively prepared into 8 CR2016 button cells, and the preparation method of the cell comprises the following steps:
(1) weighing and mixing silicon powder, conductive carbon black and lithiated polyacrylic acid according to the mass ratio of 7:2:1, and uniformly stirring in a water system to prepare electrode slurry;
(2) coating the electrode slurry on copper foil for a lithium battery negative electrode, wherein the coating thickness is 150 micrometers, and then drying the coated copper foil in a vacuum oven to constant weight to obtain a battery pole piece;
(3) cutting the pole piece into small round pieces by using a cutting machine with the diameter of 12mm, then placing the small round pieces in a glove box, and assembling the button cell under the environment that the water oxygen value is less than 0.1 ppm;
(4) and (3) selecting a CR2016 button cell case, assembling by adopting the sequence of a positive electrode case, a pole piece, a diaphragm, a metal lithium piece, a gasket and a negative electrode case, and then injecting electrolyte for packaging to obtain the assembled button cell.
The average number of the detected specific discharge capacity, the detected charge capacity and the detected first coulombic efficiency of the corresponding batteries prepared in the examples and the comparative examples is recorded in table 3.
Table 3:
the specific measurement method comprises the following steps:
according to GB/T38823-.
Wherein fig. 7 shows the first charge-discharge curve of the battery prepared from the silicon powder of example 1.
Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to the above-described embodiments and application fields, and the above-described embodiments are illustrative, instructive, and not restrictive. Those skilled in the art, having the benefit of this disclosure, may effect numerous modifications thereto without departing from the scope of the invention as defined by the appended claims.
Claims (10)
1. A silicon powder is characterized in that,
the particle size distribution D50 of the silicon powder is less than or equal to 1.10 mu m; and is
The silicon powder particles are flaky;
the average flake size of the silicon powder particles is 0.40-1.20 mu m, and preferably 0.60-1.00 mu m;
the average thickness of the silicon powder particles is 30-100 nm, preferably 50-70 nm;
the ratio of the average sheet size to the average thickness of the silicon powder particles is 4-40.
2. The silicon powder according to claim 1,
the particle size distribution of the silicon powder is as follows:
d10 is 0.15-0.40 μm;
d50 is 0.65-1.10 μm;
d90 has a value range of 1.95-2.75 μm.
3. The silicon powder according to any one of claims 1 to 2, characterized in that,
the particle size distribution diagram comprises at least three peaks; wherein, the peaks of the first three are respectively positioned at 0.10-0.20 μm, 0.40-0.60 μm and 1.40-1.70 μm.
4. The silicon powder according to any one of claims 1 to 3, characterized in that,
according to the volume ratio of the components,
the proportion of the silicon powder with the granularity of less than or equal to 0.50 mu m is 31.0-33.0%;
the proportion of the silicon powder with the granularity of more than 0.50 mu m and less than or equal to 1.50 mu m is 45.0-47.0%;
the proportion of the silicon powder with the granularity of more than 1.50 mu m is 21.0-23.0%.
5. The silicon powder according to any one of claims 1 to 4, characterized in that,
the surface of the silicon powder particles is oxidized, and the thickness of the oxide layer is 2-10 nm, preferably 2-5 nm.
6. The silicon powder according to any one of claims 1 to 5, characterized in that,
according to the mass ratio, the silicon content in the silicon powder is more than 90.0%.
7. The silicon powder according to any one of claims 1 to 6, characterized in that,
and the total content of metal ion impurities in the silicon powder is less than or equal to 500ppm by mass ratio.
8. The silicon powder according to any one of claims 1 to 7, characterized in that,
the oxygen content in the silicon powder is 2.0-6.0% by mass ratio.
9. The silicon powder according to any one of claims 1 to 8, characterized in that,
the carbon content of the silicon powder is 1.0-4.0% by mass ratio.
10. The silicon powder according to any one of claims 1 to 9, characterized in that,
the tap density of the silicon powderThe degree of the reaction is 0.05 to 0.25g/cm3Preferably 0.08 to 0.15g/cm3(ii) a And/or the presence of a gas in the gas,
the specific surface area of the silicon powder is 10.00-25.00 m2Preferably 14.00 to 19.00 m/g2/g。
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107416839A (en) * | 2017-09-11 | 2017-12-01 | 商永辉 | A kind of method for preparing lithium ion battery negative material using the discarded silica flour slurry of Buddha's warrior attendant wire cutting |
| CN110474032A (en) * | 2019-08-21 | 2019-11-19 | 郑州中科新兴产业技术研究院 | It is a kind of to be given up the silicon-carbon cathode material and preparation method thereof of silicon based on photovoltaic |
| CN111298950A (en) * | 2019-08-07 | 2020-06-19 | 西安隆基锂电新材料有限公司 | Aqueous silicon powder grinding method and silicon powder |
| CN111326723A (en) * | 2020-02-26 | 2020-06-23 | 宁夏博尔特科技有限公司 | Silicon-carbon composite negative electrode material for lithium ion battery and preparation method thereof |
| US20210036315A1 (en) * | 2018-02-07 | 2021-02-04 | Umicore | Silicon-based powder, electrode and battery comprising such a powder |
-
2021
- 2021-04-12 CN CN202110389395.9A patent/CN113072073A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107416839A (en) * | 2017-09-11 | 2017-12-01 | 商永辉 | A kind of method for preparing lithium ion battery negative material using the discarded silica flour slurry of Buddha's warrior attendant wire cutting |
| US20210036315A1 (en) * | 2018-02-07 | 2021-02-04 | Umicore | Silicon-based powder, electrode and battery comprising such a powder |
| CN111298950A (en) * | 2019-08-07 | 2020-06-19 | 西安隆基锂电新材料有限公司 | Aqueous silicon powder grinding method and silicon powder |
| CN110474032A (en) * | 2019-08-21 | 2019-11-19 | 郑州中科新兴产业技术研究院 | It is a kind of to be given up the silicon-carbon cathode material and preparation method thereof of silicon based on photovoltaic |
| CN111326723A (en) * | 2020-02-26 | 2020-06-23 | 宁夏博尔特科技有限公司 | Silicon-carbon composite negative electrode material for lithium ion battery and preparation method thereof |
Non-Patent Citations (1)
| Title |
|---|
| 俞建峰等: "超细粉体制备技术", 中国轻工业出版社 * |
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