WO2022007401A1 - 一种锂离子电池用硅碳负极材料及其制备方法 - Google Patents

一种锂离子电池用硅碳负极材料及其制备方法 Download PDF

Info

Publication number
WO2022007401A1
WO2022007401A1 PCT/CN2021/075668 CN2021075668W WO2022007401A1 WO 2022007401 A1 WO2022007401 A1 WO 2022007401A1 CN 2021075668 W CN2021075668 W CN 2021075668W WO 2022007401 A1 WO2022007401 A1 WO 2022007401A1
Authority
WO
WIPO (PCT)
Prior art keywords
silicon
nano
negative electrode
electrode material
carbon source
Prior art date
Application number
PCT/CN2021/075668
Other languages
English (en)
French (fr)
Inventor
张小龙
胡亮
张少波
王浩
Original Assignee
马鞍山科达普锐能源科技有限公司
安徽科达铂锐能源科技有限公司
安徽科达新材料有限公司
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by 马鞍山科达普锐能源科技有限公司, 安徽科达铂锐能源科技有限公司, 安徽科达新材料有限公司 filed Critical 马鞍山科达普锐能源科技有限公司
Priority to KR1020227031651A priority Critical patent/KR20220140615A/ko
Priority to JP2022563222A priority patent/JP7470271B2/ja
Priority to US17/912,390 priority patent/US20230135178A1/en
Priority to EP21837229.0A priority patent/EP4109597A4/en
Publication of WO2022007401A1 publication Critical patent/WO2022007401A1/zh

Links

Images

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
    • H01M4/04—Processes of manufacture in general
    • H01M4/0402—Methods of deposition of the material
    • H01M4/0421—Methods of deposition of the material involving vapour deposition
    • 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
    • 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
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/134—Electrodes based on metals, Si or alloys
    • 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
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/139—Processes of manufacture
    • H01M4/1395—Processes of manufacture of electrodes based on metals, Si or alloys
    • 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
    • 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
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • H01M4/583—Carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • 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
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • H01M4/583—Carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • H01M4/587—Carbonaceous material, e.g. graphite-intercalation compounds or CFx for inserting or intercalating light metals
    • 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
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • 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
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/624—Electric conductive fillers
    • H01M4/625—Carbon or graphite
    • 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
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/628—Inhibitors, e.g. gassing inhibitors, corrosion inhibitors
    • 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
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y40/00—Manufacture or treatment of nanostructures
    • 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
    • H01M2004/021—Physical characteristics, e.g. porosity, surface area
    • 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
    • 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

Definitions

  • the invention belongs to the technical field of lithium ion batteries, and particularly relates to a silicon carbon negative electrode material for lithium ion batteries and a preparation method thereof.
  • the conventional lithium ion anode materials are mainly graphite anodes, but the theoretical specific capacity of graphite anodes is only 372mAh/g, which can no longer meet the urgent needs of users.
  • the theoretical capacity of silicon is as high as 4200mAh/g, which is more than 10 times that of the graphite anode material.
  • the coulombic efficiency of the silicon-carbon composite product is also close to that of the graphite anode, and it is cheap, environmentally friendly, and rich in earth reserves. It is a new generation of high-capacity products. The best choice for negative electrode materials.
  • the volume expansion during charging and discharging can easily lead to the collapse of the material structure and the peeling and pulverization of the electrodes, resulting in the loss of active materials, which in turn leads to sharp battery capacity. decrease, the cycle performance is seriously deteriorated.
  • the present invention provides a silicon carbon negative electrode material for lithium ion batteries and a preparation method thereof.
  • the negative electrode material of the present invention comprises nano-silicon and a gas-phase carbon source, and the nano-silicon is prepared by wet grinding. , which can greatly improve the specific capacity of the negative electrode material.
  • the particle size and grain size of the nano-silicon prepared by this method are small, have good kinetics, can be produced on a large scale, and achieve controllable performance;
  • the gap is small, and the carbon source deposited by vapor deposition can achieve a good coating effect, which can protect the shell and improve the electronic conductivity.
  • the present invention relates to a silicon carbon negative electrode material for lithium ion batteries, characterized in that: the negative electrode material comprises nano-silicon and a gas-phase carbon source, the nano-silicon is dispersed in the whole composite material, and a part of the surface of the nano-silicon is covered by the gas-phase carbon source.
  • the nano-silicon contains oxygen, and the mass content of the oxygen element is 5-30%, preferably 10-20%.
  • the negative electrode material contains 60%-90wt.% of nano-silicon and 10%-40wt.% of gas-phase carbon source.
  • the specific surface area of the negative electrode material is 1-20 m 2 /g, preferably 2-10 m 2 /g; the median particle size D50 of the negative electrode material is 1-30 ⁇ m, preferably 3-20 ⁇ m; the negative electrode material
  • the moisture content of the anode material is 0.01-1 wt.%, preferably 0.05-0.5 wt.%; the tap density of the negative electrode material is 0.3-1.4 g/cm 3 , preferably 0.5-1.0 g/cm 3 .
  • the present invention also relates to the preparation method of the silicon carbon negative electrode material for lithium ion batteries described in any one of the above, characterized in that it includes the following steps:
  • step (1) Atomization drying: the nano-silicon slurry in step (1) is atomized and dried by a spray dryer to obtain nano-silicon dry powder;
  • step (3) placing the nano-silicon particles in step (3) in a vapor-phase deposition furnace, feeding a protective gas, and then feeding a carbon source gas, heating at a temperature, so that the gas-phase carbon source is deposited and covered on the nano-silicon On the particles, a silicon carbon negative electrode material is obtained.
  • the silicon powder raw material described in step (1) is polycrystalline silicon, the purity of the silicon powder raw material is more than 99.9%, and the median particle size of the silicon powder raw material is 1-100 ⁇ m, preferably 3-20 ⁇ m;
  • the grinding aids are aluminum chloride, polyolamine, triethanolamine, triisopropanolamine, sodium pyrophosphate, sodium tripolyphosphate, sodium acrylate, sodium octadecate, sodium polyacrylate, and methylene dinaphthalene sulfonate.
  • the organic solvent is methanol, toluene, benzyl alcohol, ethanol, ethylene glycol, chlorinated ethanol, propanol, isopropanol, propylene glycol, butanol, n-butanol, isobutanol, amyl alcohol, neopentyl alcohol, octanol one or more of alcohol, acetone or cyclohexanone;
  • the mass ratio of the silicon powder raw material to the dispersant is 100: (1-20), preferably 100: (5-15); after adding the solvent, the solid content of the mixed solution is 10-40%, preferably 20-30%;
  • the wet grinding equipment is a sand mill, and the structure and shape of the stirring shaft of the sand mill is one of disc type, rod type or rod disc type, and the maximum linear speed of the sand mill is more than 14m/s;
  • the material of the ball mill beads is selected from ceramics, zirconia, alumina or cemented carbide, and the mass ratio of the ball mill beads to the micron silicon powder is (10-30):1.
  • the spray dryer described in step (2) is a closed type spray dryer, and the inlet temperature of the hot air is 150-300°C, preferably 160-280°C; the outlet temperature is 80-140°C, preferably 90-130°C °C;
  • the rotational speed of the atomizing disc in the spray dryer is >10000 rpm.
  • the mechanical shaping described in step (3) includes crushing, grading and sieving, and the specific process steps are:
  • the nano-silicon dry powder obtained in the step (2) is processed by a pulverizer, and the intensity of the main unit is adjusted to 30-50 Hz, and the classification intensity is adjusted to 30-50 Hz, the particle size of the nano-silicon dry powder is reduced, and the fine powder is removed by classification, Then, the powder is sieved to remove large particles, and the mesh number of the sieve is 100-400 mesh to obtain nano-silicon dry powder with concentrated particle size distribution and regular appearance.
  • the heating rate of the vapor-phase carbon source deposition process in step (4) is 1-3°C/min, the carbon deposition temperature is 600-900°C, the flow rate of the organic carbon source gas is 1-5L/min, and the reaction duration is is 1 ⁇ 4h;
  • the organic carbon source gas is methane, ethane, ethylene, acetylene, propane, propylene, acetone, butane, butene, pentane, hexane, benzene, toluene, xylene, styrene, naphthalene, phenol, furan, One or more combinations of pyridine, anthracene and liquefied gas;
  • the protective gas is one of nitrogen, helium, neon and argon.
  • the present invention also relates to a lithium ion battery, characterized in that the lithium ion battery negative electrode material is any one of the silicon carbon negative electrode materials for lithium ion batteries described above.
  • Nano silicon prepared by wet grinding of the silicon carbon negative electrode material prepared by the present invention the median particle size D50 of the obtained nano silicon is below 100 nm, and the crystal grain of the nano silicon is below 10 nm, which reduces the absolute volume expansion of silicon, And improve the kinetics of nano-silicon in the anode material;
  • the silicon-carbon negative electrode material prepared by the present invention processes the nano-silicon slurry through atomization drying and mechanical shaping processes, and on the one hand, uses atomization equipment to recycle the organic solvent in the nano-silicon slurry, so as to achieve environmental protection and save energy At the same time, by adjusting the parameters of the atomization equipment and the mechanical shaping parameters, the nano-silicon particles with concentrated particle size distribution and regular morphology can be obtained;
  • the silicon-carbon negative electrode material prepared by the present invention will deposit the carbon source on the nano-silicon particles by the vapor deposition method to form a carbon coating layer, and the thickness of the vapor-deposited carbon source is measured to be 10-200 nm.
  • the electrical conductivity of the material can reduce the internal resistance, and at the same time, it can isolate the erosion of the electrolyte, which greatly improves the cycle performance of the negative electrode material;
  • the silicon carbon anode material prepared by the present invention has excellent electrochemical performance, high first reversible capacity (>2200mAh/g), and high first coulombic efficiency (>86%).
  • Fig. 1 is the SEM image of the nano-silicon prepared in Example 1 of the present invention.
  • Fig. 2 is the XRD pattern of the nano-silicon obtained in Example 1 of the present invention.
  • Example 3 is a TEM image of the silicon carbon negative electrode material particles prepared in Example 1 of the present invention.
  • Fig. 4 is the first charge-discharge curve of the button battery prepared in Example 1 of the present invention.
  • FIG. 5 is the cycle curve of the 18650 cylindrical battery prepared in Example 1 of the present invention at 1C/1C rate.
  • a preparation method of silicon carbon negative electrode material for lithium ion battery comprising the following steps:
  • the nano-silicon slurry in step (1) is atomized and dried by a closed-type spray dryer, and the hot air inlet temperature of the spray dryer is 190° C., and the outlet temperature is 110° C. to obtain nano-silicon dry powder;
  • step (3) Mechanical shaping: the nano-silicon dry powder obtained in step (2) is processed by a pulverizer, the intensity of the host is adjusted to 50 Hz, and the classification intensity is adjusted to 50 Hz, the particle size of the nano-silicon dry powder is reduced, and the micro-fine particles are removed by classification. Then sieve the powder to remove large particles.
  • the nano-silicon slurry was tested by Mastersizer 3000 particle size analyzer, and the median particle size of nano-silicon was 78nm;
  • the nano-silicon slurry in step (1) is atomized and dried by a closed-type spray dryer, and the hot air inlet temperature of the spray dryer is 280° C., and the outlet temperature is 130° C. to obtain nano-silicon dry powder;
  • the nano-silicon dry powder obtained in the step (2) is processed by a pulverizer, the intensity of the main engine is adjusted to 40 Hz, the classification intensity is adjusted to 40 Hz, the particle size of the nano-silicon dry powder is reduced, and the micro-fine particles are removed by classification. Then sieve the powder to remove large particles.
  • step (3) the nano-silicon dry powder with regular morphology in step (3) is placed in a vapor deposition furnace, and argon gas is introduced to remove the air until the oxygen content is lower than 100 ppm, and then the heating rate is 2°C/min. , heated to 800°C, and then introduced acetylene for vapor deposition, the flow rate was 2L/min, the reaction time was controlled to 2h, and a uniform carbon coating layer with a mass ratio of 20wt% was formed to obtain a silicon carbon anode material; The silicon carbon negative electrode material was scanned, and the thickness of the vapor-deposited carbon source was measured to be 50-80 nm.
  • the nano-silicon slurry in step (1) is atomized and dried by a closed-type spray dryer, and the hot air inlet temperature of the spray dryer is 200°C, and the outlet temperature is 100°C to obtain nano-silicon dry powder;
  • step (3) Mechanical shaping: the nano-silicon dry powder obtained in step (2) is processed by a pulverizer, the intensity of the main engine is adjusted to 35 Hz, the classification intensity is adjusted to 35 Hz, the particle size of the nano-silicon dry powder is reduced, and the micro-fine particles are removed by classification.
  • the nano-silicon dry powder is analyzed by X-ray diffraction
  • the half-peak width of the diffraction peak attributable to Si(111) near 28.4°, the grain size of nano-silicon is calculated by the Scherrer formula to be 8.3 nm
  • the mass content of oxygen in the nano-silicon dry powder is obtained by detecting the oxygen, nitrogen and hydrogen analyzer. is 13%;
  • the solid content of the mixed solution is 30%, and the mixed slurry is introduced into a sand mill, wherein the mass ratio of grinding ceramic balls and silicon powder is 10:1, and the grinding time is 30h to obtain the desired nano-silicon slurry;
  • the nano-silicon slurry was detected by Mastersizer 3000 particle size analyzer, and the median particle size of nano-silicon was 97nm;
  • the nano-silicon slurry in step (1) is atomized and dried by a closed-type spray dryer, and the hot air inlet temperature of the spray dryer is 160° C., and the outlet temperature is 90° C. to obtain nano-silicon dry powder;
  • step (3) Mechanical shaping: the nano-silicon dry powder obtained in step (2) is processed by a pulverizer, the intensity of the host is adjusted to 30 Hz, and the classification intensity is adjusted to 30 Hz, the particle size of the nano-silicon dry powder is reduced, and the micro-fine particles are removed by classification.
  • the powder is then sieved to remove large particles, and the mesh number of the sieve is 200 meshes to obtain nano-silicon dry powder with concentrated particle size distribution and regular morphology; the nano-silicon dry powder is analyzed by X-ray diffraction The half-peak width of the diffraction peak attributable to Si(111) near 28.4°, the grain size of nano-silicon is calculated by the Scherrer formula to be 9.7 nm; the mass content of oxygen in the nano-silicon dry powder is obtained by detecting the oxygen, nitrogen and hydrogen analyzer. 8%;
  • step (1) is not performed, that is, the silicon powder raw material is not nanosized, and the rest are the same as Example 1, and will not be repeated here.
  • step (1) the particle size D50 of the nano-silicon is adjusted to 172 nm by controlling the grinding time and the parameters of the ball-to-material ratio.
  • the rest are the same as in Embodiment 1, and are not repeated here.
  • step (1) the particle size D50 of the nano-silicon is adjusted to 458 nm by controlling the grinding time and the ratio of balls to material, and the grain size of the nano-silicon is calculated to be 52.7 nm from the Scherrer formula.
  • step (1) the particle size D50 of the nano-silicon is adjusted to 458 nm by controlling the grinding time and the ratio of balls to material, and the grain size of the nano-silicon is calculated to be 52.7 nm from the Scherrer formula.
  • the rest are the same as in Embodiment 1, and are not repeated here.
  • step (2) the nano-silicon slurry is not dried by atomization, but conventionally heated and dried, and the rest are the same as those in Example 1, and will not be repeated here.
  • step (3) the nano-silicon dry powder is not subjected to mechanical shaping, and the rest are the same as in Embodiment 1, and will not be repeated here.
  • step (4) is not performed, that is, the nano-silicon dry powder is not covered with carbon, and the rest are the same as Example 1, and will not be repeated here.
  • step (4) the carbon coating layer is not prepared by the vapor deposition method, but solid-phase mixed coating.
  • step (1) the grinding time is extended to 90h, and the rest are the same as in Example 1, and will not be repeated here.
  • the mass content of oxygen in the nano-silicon dry powder was detected by an oxygen, nitrogen and hydrogen analyzer to be 39%.
  • step (4) by increasing the flow rate and time of methane vapor deposition, the mass ratio of the coating layer is 50wt%, and the rest are the same as in Example 1, and will not be repeated here.
  • the particle size range of the material was tested with a Malvern Mastersizer 3000.
  • the morphology and patterning of the materials were analyzed by field emission scanning electron microscopy (SEM) (JSM-7160).
  • the oxygen, nitrogen and hydrogen analyzer (ONH) is used to accurately and quickly determine the oxygen content in materials.
  • XRD diffractometer (X'Pert3 Powder) was used to analyze the phase of the material to determine the grain size of the material.
  • TEM field emission transmission electron microscopy
  • the specific surface area of the negative electrode material was measured by the American Mack ratio meter and pore analyzer (TriStar II 3020).
  • the tap density of the negative electrode material was measured by a tap density analyzer (Canta Autotap single station).
  • the moisture content in the negative electrode material was determined by a coulometric Karl Fischer moisture analyzer.
  • the silicon carbon negative electrode materials obtained in Examples 1 to 4 and Comparative Examples 1 to 9 are mixed by negative electrode material, conductive agent carbon black (Super P), carbon nanotubes and LA133 glue in a mass ratio of 91:2:2:5 In solvent pure water, homogenize, control the solid content at 45%, coat the copper foil current collector, and vacuum dry to prepare the negative pole piece.
  • a button cell was assembled in an argon atmosphere glove box.
  • the charge and discharge test of the button battery is carried out, the voltage range is 5mV ⁇ 1.5V, and the current density is 80mA/g.
  • the first reversible capacity and efficiency of the silicon carbon anode materials in the examples and comparative examples were measured.
  • the silicon carbon anode materials in the examples and the comparative examples were mixed with the same stable artificial graphite.
  • the mixed powder press button battery process was used to prepare the negative pole piece, and the positive pole was the ternary pole piece prepared by the mature process, the separator and the electrode liquid were unchanged, and the 18650 cylindrical single cell was assembled.
  • the charging and discharging test of 18650 cylindrical single cell battery is carried out, the voltage range is 2.5mV ⁇ 4.2V, the current density is 420mA/g button battery and the test equipment of 18650 cylindrical single cell battery is the LAND battery test of Wuhan Jinnuo Electronics Co., Ltd. system.
  • the silicon-carbon negative electrode material prepared by the method described in this application comprises nano-silicon and a gas-phase carbon source, the nano-silicon is dispersed in the entire composite material, and at least a part of the surface of the nano-silicon is covered by the carbon source of vapor deposition. .
  • the grain size of the obtained nano-silicon can be adjusted by the nano-silicon grinding process, and the grain size of the nano-silicon is calculated to be below 10 nm by the Scherrer formula.
  • carbon source coating layers with different thicknesses can be obtained, and the entire composite material is scanned by TEM, and the thickness of the vapor deposition carbon source is measured to be 10-200 nm.
  • the specific surface area, median particle size D50, moisture, tap density and other physical parameters of silicon-carbon composites can be adjusted by atomization drying and mechanical shaping.
  • the silicon carbon negative electrode The specific surface area of the material is gradually decreasing (8.9 ⁇ 2.1m 2 /g), the median particle size D50 is increasing gradually (3.2 ⁇ 18.3 ⁇ m), and the moisture content is increasing gradually (0.19 ⁇ 0.41wt.%) , the tap density is gradually increasing (0.61-0.94g/cm 3 ), the first reversible capacity is gradually decreasing (2236.9-1032.7mAh/g), the first coulombic efficiency is gradually decreasing (86.3-82.1%), cylindrical The cycle performance of the battery showed a decreasing trend (87.2-80.8%).
  • Comparative Examples 1-3 when the silicon powder raw material of the silicon carbon negative electrode material is not nanosized or the median particle size and silicon grain size of the nano silicon are far larger than the specifications of Example 1, the obtained silicon carbon negative electrode material has a The first reversible capacity, first coulombic efficiency and cycle performance are all poor, far inferior to the anode material prepared in Example 1; in Comparative Example 4, the nano-silicon slurry is not dried by atomization, but conventionally heated and dried.
  • Comparative Example 8 the grinding time was extended to 90h, and the mass content of oxygen in the nano-silicon dry powder was detected by an oxygen, nitrogen and hydrogen analyzer to be 39%. affect the cycle performance of the battery.
  • Comparative Example 9 by increasing the flow rate and time of methane vapor deposition, the mass ratio of the coating layer is 50wt%, and the first reversible capacity of the obtained silicon carbon anode material is only 957.1mAh/g, which is far lower than that of Example 1. , and the cycle performance is also poor.
  • the present invention illustrates the detailed process equipment and process flow of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned detailed process equipment and process flow, that is, it does not mean that the present invention must rely on the above-mentioned detailed process equipment and process flow. Process flow can be implemented. Those skilled in the art should understand that any improvement of the present invention, the equivalent replacement of each raw material of the product of the present invention, the addition of auxiliary components, the selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Composite Materials (AREA)
  • Nanotechnology (AREA)
  • Inorganic Chemistry (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Battery Electrode And Active Subsutance (AREA)
  • Silicon Compounds (AREA)
  • Carbon And Carbon Compounds (AREA)

Abstract

本发明属于锂离子电池技术领域，具体涉及一种锂离子电池用硅碳负极材料及其制备方法，所述负极材料包含纳米硅和气相碳源，纳米硅分散于整个复合材料中，纳米硅的表面的一部分被气相沉积的碳源所覆盖，所述纳米硅中值粒度D50在100nm以下；纳米硅的晶粒在10nm以下；气相沉积碳源的平均厚度为10～200nm；所述纳米硅中含有氧，氧元素的质量含量为5～30％，所述负极材料中含有60％～90wt.％的纳米硅，10％～40wt.％的气相碳源；相比于现有技术，本发明制备的锂离子电池用硅碳负极材料具有优异的电化学性能。

Description

一种锂离子电池用硅碳负极材料及其制备方法 技术领域
本发明属于锂离子电池技术领域，具体涉及一种锂离子电池用硅碳负极材料及其制备方法。
背景技术
目前常规的锂离子负极材料以石墨负极为主，但石墨负极的理论比容量仅为372mAh/g，已无法满足用户的迫切需求。硅的理论容量高达4200mAh/g，是石墨负极材料容量的10倍以上，同时，硅碳复合品的库伦效率也和石墨负极接近，且价格便宜、环境友好、地球储量丰富，是新一代高容量负极材料的最优选择。但由于硅材料本身导电性差，且硅在充电时体积膨胀高达300％，充放电过程中的体积膨胀容易导致材料结构的崩塌和电极的剥落、粉化，造成活性材料损失，进而导致电池容量锐减，循环性能严重恶化。
为了稳定充放电过程中硅的结构，缓解膨胀，达到改善电化学性能的效果，急需一种高电导率和高比表面积的碳材料，和硅混合使用作为锂电池负极材料。
发明内容
为了解决上述硅碳负极材料存在的问题，本发明提供一种锂离子电池用硅碳负极材料及其制备方法，本发明所述负极材料包含纳米硅和气相碳源，纳米硅通过湿法研磨制备，能极大的提升负极材料的比容量，同时该方法制备的纳米硅的粒度和晶粒尺寸较小，有良好的动力学，能大规模生产，达到性能可控；由于纳米硅颗粒间的缝隙较小，用气相沉积的碳源能达到良好的包覆效果，起到保护壳和提升电子电导率的作用。
具体的，本发明涉及一种锂离子电池用硅碳负极材料，其特征在于：所述负极材料包含纳米硅和气相碳源，纳米硅分散于整个复合材料中，纳米硅的表面的一部分被气相沉积的碳源所覆盖，所述纳米硅通过Mastersizer 3000粒度分析仪检测，中值粒度D50在100nm以下；所述纳米硅通过X射线衍射图案分析，根据2θ＝28.4°附近的归属于Si(111)的衍射峰的半峰宽值，由Scherrer式计算出纳米硅的晶粒在10nm以下；通过TEM对整个复合材料进行扫描，测得气相沉积碳源的平均厚度为10～200nm。
优选的，所述纳米硅中含有氧，氧元素的质量含量为5～30％，优选10～20％。
优选的，所述负极材料中含有60％～90wt.％的纳米硅，10％～40wt.％的气相碳源。
优选的，所述负极材料的比表面积为1～20m 2/g，优选2～10m 2/g；所述负极材料的中值 粒径D50为1～30μm，优选3～20μm；所述负极材料的水分含量为0.01～1wt.％，优选0.05～0.5wt.％；所述负极材料的振实密度为0.3～1.4g/cm 3，优选0.5～1.0g/cm 3。
本发明还涉及上述任一项所述的锂离子电池用硅碳负极材料的制备方法，其特征在于，包括如下步骤：
(1)纳米硅浆料的制备：将硅粉原料和助磨剂加入到有机溶剂中，混合均匀后，导入研磨设备中，研磨30～60h，得到纳米硅浆料；
(2)雾化干燥：将步骤(1)中的纳米硅浆料通过喷雾干燥机进行雾化干燥，得到纳米硅干粉；
(3)机械整形：将步骤(2)中的纳米硅干粉进行机械整形，得到粒度分布集中，形貌规整的纳米硅颗粒；
(4)气相碳源覆盖：将步骤(3)中的纳米硅颗粒置于气相沉积炉中，通入保护气体，再通入碳源气体，升温加热，使气相碳源沉积并覆盖在纳米硅颗粒上，得到硅碳负极材料。
优选的，步骤(1)中所述的硅粉原料为多晶硅，硅粉原料的纯度＞99.9％，硅粉原料的中值粒径为1～100μm，优选3～20μm；
所述助磨剂为氯化铝、聚合醇胺、三乙醇胺、三异丙醇胺、焦磷酸钠、三聚磷酸钠、丙烯酸钠、十八酸钠、聚丙烯酸钠、亚甲基双萘磺酸钠、柠檬酸钾、环烷酸铅、亚甲基双萘磺酸钠、三乙基己基磷酸、十二烷基硫酸钠、甲基戊醇、纤维素衍生物或古尔胶中的一种或多种；
所述有机溶剂为甲醇、甲苯、苯甲醇、乙醇、乙二醇、氯化乙醇、丙醇、异丙醇、丙二醇、丁醇、正丁醇、异丁醇、戊醇、新戊醇、辛醇、丙酮或环已酮的一种或多种；
所述硅粉原料与分散剂的质量比是100：(1～20)，优选100：(5～15)；加入溶剂后，混合溶液的固含量是10～40％，优选20～30％；
所述湿法研磨设备为砂磨机，砂磨机搅拌轴的结构形状为盘式，棒式或棒盘式中的一种，砂磨机的最高线速度＞14m/s；
所述球磨珠的材质选自陶瓷，氧化锆，氧化铝或硬质合金，球磨珠与微米硅粉的质量比是为(10～30):1。
优选的，步骤(2)中所述的喷雾干燥机为闭式喷雾干燥机，其热空气进口温度为150～300℃，优选160～280℃；出口温度为80～140℃，优选90～130℃；
所述喷雾干燥机中雾化盘的转速＞10000rpm。
优选的，步骤(3)所述的机械整形包括粉碎、分级和过筛，具体工艺步骤为：
将步骤(2)中得到的纳米硅干粉，经粉碎机处理，调节主机强度为30～50Hz，调节分级强度为30～50Hz，将纳米硅干粉的粒度尺寸降低，并通过分级除去微小细粉，再将粉料进行筛 分，除去大颗粒，筛网目数为100～400目，得到粒度分布集中，形貌规整的纳米硅干粉。
优选的，步骤(4)所述气相碳源沉积过程的升温速率是1～3℃/min，碳沉积温度是600～900℃，有机碳源气体的流量为1～5L/min，反应持续时间是1～4h；
所述有机碳源气体是甲烷、乙烷、乙烯、乙炔、丙烷、丙烯、丙酮、丁烷、丁烯、戊烷、己烷、苯、甲苯、二甲苯、苯乙烯、萘、苯酚、呋喃、吡啶、蒽、液化气中的一种或两种以上的组合；
所述保护性气体为氮气、氦气、氖气、氩气中的一种。
本发明还涉及一种锂离子电池，其特征在于，所述锂离子电池负极材料为上述任一项所述的锂离子电池用硅碳负极材料。
与现有技术相比，本发明的优点在于：
(1)本发明制备的硅碳负极材料通过湿法研磨制备的纳米硅，得到的纳米硅的中值粒度D50在100nm以下，纳米硅的晶粒在10nm以下，降低了硅的绝对体积膨胀，并提升了纳米硅在负极材料中的动力学；
(2)本发明制备的硅碳负极材料通过雾化干燥和机械整形工艺对纳米硅浆料进行处理，一方面利用雾化设备对纳米硅浆料中的有机溶剂进行回收利用，达到环保、节省成本的效果，同时通过调节雾化设备的参数以及机械整形参数，得到粒度分布集中，形貌规整的纳米硅颗粒；
(3)本发明制备的硅碳负极材料将通过气相沉积法将碳源沉积在纳米硅颗粒上，形成碳包覆层，测得气相沉积碳源的厚度为10～200nm，一方面可以提升负极材料的电导率、降低内阻，同时可以隔离电解液的侵蚀，极大的提高了负极材料的循环性能；
(4)本发明制备的硅碳负极材料具有优异的电化学性能，首次可逆容量高(＞2200mAh/g)、首次库伦效率高(>86％)。
附图说明
下面结合附图对本发明进一步说明。
图1是本发明实施例1制得的纳米硅的SEM图；
图2是本发明实施例1制得的纳米硅的XRD图；
图3是本发明实施例1制得的硅碳负极材料颗粒的TEM图；
图4是本发明实施例1制得的扣式电池的首次充放电曲线；
图5是本发明实施例1制得的18650圆柱电池的在1C/1C倍率下的循环曲线。
具体实施方式
为便于理解本发明，本发明列举实施例如下。本领域技术人员应该明了，所述实施例仅仅是帮助理解本发明，不应视为对本发明的具体限制。
实施例1
一种锂离子电池用硅碳负极材料的制备方法，包括如下步骤：
(1)纳米硅浆料的制备：将中值粒径为3μm多晶硅粉1000g和聚乙烯吡咯烷酮10g，按照质量比硅粉：聚乙烯吡咯烷酮＝100：1，加入到甲醇中，混合溶液固含量是20％，将混合浆料导入砂磨机中，其中研磨珠氧化锆球和硅粉的质量比是10:1，研磨时间为50h，得到所需的纳米硅浆料；该纳米硅浆料通过Mastersizer 3000粒度分析仪检测，纳米硅的中值粒径为72nm；
(2)雾化干燥：将步骤(1)中的纳米硅浆料通过闭式喷雾干燥机进行雾化干燥，喷雾干燥机的热空气进口温度为190℃，出口温度为110℃，得到纳米硅干粉；
(3)机械整形：将步骤(2)中得到的纳米硅干粉，经粉碎机处理，调节主机强度为50Hz，调节分级强度为50Hz，将纳米硅干粉的粒度尺寸降低，并通过分级除去微小细粉，再将粉料进行筛分，除去大颗粒，筛网目数为400目，得到粒度分布集中，形貌规整的纳米硅干粉；所述纳米硅干粉通过X射线衍射图案分析，根据2θ＝28.4°附近的归属于Si(111)的衍射峰的半峰宽值，由Scherrer式计算出纳米硅的晶粒为6.9nm；通过氧氮氢分析仪检测得到纳米硅干粉中氧元素的质量含量为17％；
(4)气相碳源覆盖：将步骤(3)中形貌规整的纳米硅干粉置于气相沉积炉中，通入氮气排除空气至氧含量低于100ppm，然后以3℃/min的升温速度，升温到900℃，再通入甲烷进行气相沉积，流量为1L/min，控制反应时间为1h，形成均匀的质量占比为10wt％的碳包覆层，得到硅碳负极材料；通过TEM对硅碳负极材料进行扫描，测得气相沉积碳源的厚度为10～30nm。
实施例2
(1)纳米硅浆料的制备：将中值粒径为8μm多晶硅粉1000g和十二烷基硫酸钠50g，按照质量比硅粉：十二烷基硫酸钠＝100：5，加入到丙醇中，混合溶液固含量是20％，将混合浆料导入砂磨机中，其中研磨珠硬质合金球和硅粉的质量比是10:1，研磨时间为60h，得到所需的纳米硅浆料；该纳米硅浆料通过Mastersizer 3000粒度分析仪和检测，纳米硅的中值粒径为78nm；
(2)雾化干燥：将步骤(1)中的纳米硅浆料通过闭式喷雾干燥机进行雾化干燥，喷雾干燥机的热空气进口温度为280℃，出口温度为130℃，得到纳米硅干粉；
(3)机械整形：将步骤(2)中得到的纳米硅干粉，经粉碎机处理，调节主机强度为40Hz， 调节分级强度为40Hz，将纳米硅干粉的粒度尺寸降低，并通过分级除去微小细粉，再将粉料进行筛分，除去大颗粒，筛网目数为300目，得到粒度分布集中，形貌规整的纳米硅干粉；所述纳米硅干粉通过X射线衍射图案分析，根据2θ＝28.4°附近的归属于Si(111)的衍射峰的半峰宽值，由Scherrer式计算出纳米硅的晶粒为7.4nm；通过氧氮氢分析仪检测得到纳米硅干粉中氧元素的质量含量为26％；
(4)气相碳源覆盖：将步骤(3)中形貌规整的纳米硅干粉置于气相沉积炉中，通入氩气排除空气至氧含量低于100ppm，然后以2℃/min的升温速度，升温到800℃，再通入乙炔进行气相沉积，流量为2L/min，控制反应时间为2h，形成均匀的质量占比为20wt％的碳包覆层，得到硅碳负极材料；通过TEM对硅碳负极材料进行扫描，测得气相沉积碳源的厚度为50～80nm。
实施例3
(1)纳米硅浆料的制备：将中值粒径为15μm多晶硅粉1000g和古尔胶100g，按照质量比硅粉：古尔胶＝100：10，加入到丙酮中，混合溶液固含量是30％，将混合浆料导入砂磨机中，其中研磨珠不锈钢球和硅粉的质量比是10:1，研磨时间为40h，得到所需的纳米硅浆料；该纳米硅浆料通过Mastersizer 3000粒度分析仪检测，纳米硅的中值粒径为85nm；
(2)雾化干燥：将步骤(1)中的纳米硅浆料通过闭式喷雾干燥机进行雾化干燥，喷雾干燥机的热空气进口温度为200℃，出口温度为100℃，得到纳米硅干粉；
(3)机械整形：将步骤(2)中得到的纳米硅干粉，经粉碎机处理，调节主机强度为35Hz，调节分级强度为35Hz，将纳米硅干粉的粒度尺寸降低，并通过分级除去微小细粉，再将粉料进行筛分，除去大颗粒，筛网目数为250目，得到粒度分布集中，形貌规整的纳米硅干粉；所述纳米硅干粉通过X射线衍射图案分析，根据2θ＝28.4°附近的归属于Si(111)的衍射峰的半峰宽值，由Scherrer式计算出纳米硅的晶粒为8.3nm；通过氧氮氢分析仪检测得到纳米硅干粉中氧元素的质量含量为13％；
(4)气相碳源覆盖：将步骤(3)中形貌规整的纳米硅干粉置于气相沉积炉中，通入氮气排除空气至氧含量低于100ppm，然后以3℃/min的升温速度，升温到700℃，再通入甲烷进行气相沉积，流量为3L/min，控制反应时间为3h，形成均匀的质量占比为30wt％的碳包覆层，得到硅碳负极材料；通过TEM对硅碳负极材料进行扫描，测得气相沉积碳源的厚度为90～130nm。
实施例4
(1)纳米硅浆料的制备：将中值粒径为20μm多晶硅粉1000g和脂肪酸聚乙二醇酯150g，按照质量比硅粉：脂肪酸聚乙二醇酯＝100：15，加入到异丙醇中，混合溶液固含量是30％，将混合浆料导入砂磨机中，其中研磨陶瓷球和硅粉的质量比是10:1，研磨时间为30h，得到所 需的纳米硅浆料；该纳米硅浆料通过Mastersizer 3000粒度分析仪检测，纳米硅的中值粒径为97nm；
(2)雾化干燥：将步骤(1)中的纳米硅浆料通过闭式喷雾干燥机进行雾化干燥，喷雾干燥机的热空气进口温度为160℃，出口温度为90℃，得到纳米硅干粉；
(3)机械整形：将步骤(2)中得到的纳米硅干粉，经粉碎机处理，调节主机强度为30Hz，调节分级强度为30Hz，将纳米硅干粉的粒度尺寸降低，并通过分级除去微小细粉，再将粉料进行筛分，除去大颗粒，筛网目数为200目，得到粒度分布集中，形貌规整的纳米硅干粉；所述纳米硅干粉通过X射线衍射图案分析，根据2θ＝28.4°附近的归属于Si(111)的衍射峰的半峰宽值，由Scherrer式计算出纳米硅的晶粒为9.7nm；通过氧氮氢分析仪检测得到纳米硅干粉中氧元素的质量含量为8％；
(4)气相碳源覆盖：将步骤(3)中形貌规整的纳米硅干粉置于气相沉积炉中，通入氦气排除空气至氧含量低于100ppm，然后以3℃/min的升温速度，升温到600℃，再通入天然气进行气相沉积，流量为5L/min，控制反应时间为4h，形成均匀的质量占比为40wt％的碳包覆层，得到硅碳负极材料；通过TEM对硅碳负极材料进行扫描，测得气相沉积碳源的厚度为150～200nm。
对比例1
与实施例1的区别在于不进行步骤(1)，即硅粉原料不进行纳米化，其余同实施例1，这里不再赘述。
对比例2
与实施例1的区别在于步骤(1)中，通过控制研磨时间和球料比参数，将纳米硅的粒径D50调整为172nm，由Scherrer式计算出此时纳米硅的晶粒为19.6nm。其余同实施例1，这里不再赘述。
对比例3
与实施例1的区别在于步骤(1)中，通过控制研磨时间和球料比参数，将纳米硅的粒径D50调整为458nm，由Scherrer式计算出纳米硅的晶粒为52.7nm。其余同实施例1，这里不再赘述。
对比例4
与实施例1的区别在于步骤(2)中，纳米硅浆料不通过雾化干燥，而是常规的加热干燥，其余同实施例1，这里不再赘述。
对比例5
与实施例1的区别在于步骤(3)中，纳米硅干粉不经过机械整形，其余同实施例1，这里不 再赘述。
对比例6
与实施例1的区别在于不进行步骤(4)，即，纳米硅干粉不进行碳包覆，其余同实施例1，这里不再赘述。
对比例7
与实施例1的区别在于步骤(4)中碳包覆层不是通过气相沉积法制备，而是固相混合包覆，其余同实施例1，这里不再赘述。
对比例8
与实施例1的区别在于步骤(1)中，延长研磨时间到90h，其余同实施例1，这里不再赘述。
通过氧氮氢分析仪检测得到纳米硅干粉中氧元素的质量含量为39％。
对比例9
与实施例1的区别在于步骤(4)中，通过提高甲烷气相沉积的流量和时间，使包覆层的质量占比为50wt％，其余同实施例1，这里不再赘述。
采用以下方法对实施例1至4和对比例1至9中硅碳负极材料进行测试：
采用马尔文激光粒度仪Mastersizer 3000测试材料粒度范围。
采用场发射扫描电镜(SEM)(JSM-7160)分析材料的形貌和图形处理。
采用氧氮氢分析仪(ONH)精准、快速的测定材料中的氧元素含量。
采用XRD衍射仪(X’Pert3 Powder)对材料进行物相分析，确定材料的晶粒尺寸。
采用场发射型透射电子显微镜(TEM)(JEM-F200)分析材料的形貌和无定型碳的状态。
采用美国麦克比表与孔隙分析仪(TriStar II 3020)测定负极材料的比表面积。
采用振实密度分析仪(康塔Autotap单站)测定负极材料的振实密度。
采用库仑法卡氏水分测定仪测定负极材料中的水分含量。
将实施例1至4和对比例1至9中得到的硅碳负极材料，按负极材料、导电剂炭黑(Super P)、碳纳米管和LA133胶按质量比91:2:2:5混合在溶剂纯水中，进行匀浆，控制固含量在45％，涂覆于铜箔集流体上，真空烘干、制得负极极片。在氩气气氛手套箱中组装扣式电池，所用隔膜为Celgard2400，电解液为1mol/L的LiPF6/EC+DMC+EMC(v/v＝1:1:1)，对电极是金属锂片。对扣式电池进行充放电测试，电压区间是5mV～1.5V，电流密度为80mA/g。测得实施例和对比例中硅碳负极材料的首次可逆容量和效率。
根据扣式电池中实测的首次可逆容量，将实施例和对比例中的硅碳负极材料与同一款稳定的人造石墨进行混合，混合后粉末的扣式电池测试的首次可逆容量为420±2mAh/g。将混合后 的粉末按扣式电池工艺制备负极极片，正极为成熟工艺制备的三元极片、隔离膜和电极液不变，组装成18650圆柱单体电池。对18650圆柱单体电池进行充放电测试，电压区间是2.5mV～4.2V，电流密度为420mA/g扣式电池和18650圆柱单体电池的测试设备均为武汉金诺电子有限公司的LAND电池测试系统。
实施例1至4与对比例1至9中硅碳负极材料的性能测试结果：
表1实施例1至4与对比例1至9中硅碳负极材料的物性指标和扣电测试结果：
Figure PCTCN2021075668-appb-000001
由表1可见，采用本申请所述方法制备的硅碳负极材料，包含纳米硅和气相碳源，纳米硅分散于整个复合材料中，纳米硅的表面的至少一部分被气相沉积的碳源所覆盖。可通过纳米硅研磨工艺调整所得纳米硅的晶粒尺寸，由Scherrer式计算出纳米硅的晶粒在10nm以下。通过气相沉积碳源工艺，可得到不同厚度的碳源包覆层，通过TEM对整个复合材料进行扫描，测得气相沉积碳源的厚度为10～200nm。通过雾化干燥和机械整形可调节硅碳复合材料的比表面 积、中值粒径D50、水分、振实密度等物性参数指标。实施例1-4中，随着纳米硅中值粒径的逐渐增大、硅晶粒尺寸逐渐增大、气相沉积碳源质量比例逐渐增高和雾化干燥、机械整形参数的调整，硅碳负极材料的比表面积呈逐渐降低趋势(8.9～2.1m 2/g)、中值粒径D50呈逐渐增大趋势(3.2～18.3μm)、水分含量呈逐渐增大趋势(0.19～0.41wt.％)、振实密度呈逐渐增大趋势(0.61～0.94g/cm 3)、首次可逆容量呈逐渐降低趋势(2236.9～1032.7mAh/g)、首次库伦效率呈逐渐降低趋势(86.3～82.1％)、圆柱电池的循环性能呈逐渐降低趋势(87.2～80.8％)。
对比例1-3中，硅碳负极材料的硅粉原料不进行纳米化或者纳米硅的中值粒径尺寸和硅晶粒尺寸远远大于实施例1的规格时，得到的硅碳负极材料的首次可逆容量、首次库伦效率和循环性能都较差，远远比不上实施例1中制备的负极材料；对比例4中，纳米硅浆料不通过雾化干燥，而是常规的加热干燥，不仅得到的硅碳负极材料的首次可逆容量(1419.3mAh/g)和首次库伦效率较差(75.9％)，而且硅碳负极材料的中值粒径D50(21.9μm)和水分含量偏大(1.58wt.％)；对比例5中，纳米硅干粉不经过机械整形，得到的硅碳负极材料的中值粒径D50(32.4μm)明显过大，也恶化了首次可逆容量、首次库伦效率性能和循环性能；对比例6中，纳米硅干粉不进行碳包覆，得到的硅碳负极材料的比表面积太大(47.4m 2/g)，虽其首次可逆容量发挥较高，但首次库伦效率性能明显偏低，仅57.1％，且循环性能明显变差，仅21.9％；对比例7中，碳包覆层不是通过气相沉积法制备，而是固相混合包覆，得到的硅碳负极材料的首次库伦效率偏低，为82.6％，循环性能也较差，为81.7％。对比例8中，延长研磨时间到90h，通过氧氮氢分析仪检测得到纳米硅干粉中氧元素的质量含量为39％，得到的硅碳负极材料的首次容量发挥和首次效率明显变差，同时影响电池的循环性能。对比例9中，通过提高甲烷气相沉积的流量和时间，使包覆层的质量占比为50wt％，得到的硅碳负极材料的首次可逆容量仅957.1mAh/g，远远低于实施例1，而且循环性能也较差。
申请人声明，本发明通过上述实施例来说明本发明的详细工艺设备和工艺流程，但本发明并不局限于上述详细工艺设备和工艺流程，即不意味着本发明必须依赖上述详细工艺设备和工艺流程才能实施。所属技术领域的技术人员应该明了，对本发明的任何改进，对本发明产品各原料的等效替换及辅助成分的添加、具体方式的选择等，均落在本发明的保护范围和公开范围之内。

Claims (10)

  1. 一种锂离子电池用硅碳负极材料，其特征在于：所述负极材料包含纳米硅和气相碳源，纳米硅分散于整个复合材料中，纳米硅的表面的一部分被气相沉积的碳源所覆盖，所述纳米硅通过Mastersizer 3000粒度分析仪检测，中值粒度D50在100nm以下；所述纳米硅通过X射线衍射图案分析，根据2θ＝28.4°附近的归属于Si(111)的衍射峰的半峰宽值，由Scherrer式计算出纳米硅的晶粒在10nm以下；通过TEM对整个复合材料进行扫描，测得气相沉积碳源的平均厚度为10～200nm。
  2. 根据权利要求1所述的一种锂离子电池用硅碳负极材料，其特征在于：所述纳米硅中含有氧，氧元素的质量含量为5～30％，优选10～20％。
  3. 根据权利要求1所述的一种锂离子电池用硅碳负极材料，其特征在于：所述负极材料中含有60％～90wt.％的纳米硅，10％～40wt.％的气相碳源。
  4. 根据权利要求1所述的一种锂离子电池用硅碳负极材料，其特征在于：所述负极材料的比表面积为1～20m 2/g，优选2～10m 2/g；所述负极材料的中值粒径D50为1～30μm，优选3～20μm；所述负极材料的水分含量为0.01～1wt.％，优选0.05～0.5wt.％；所述负极材料的振实密度为0.3～1.4g/cm 3，优选0.5～1.0g/cm 3。
  5. 一种权利要求1至4任一项所述的锂离子电池用硅碳负极材料的制备方法，其特征在于，包括如下步骤：
    (1)纳米硅浆料的制备：将硅粉原料和助磨剂加入到有机溶剂中，混合均匀后，导入研磨设备中，研磨30～60h，得到纳米硅浆料；
    (2)雾化干燥：将步骤(1)中的纳米硅浆料通过喷雾干燥机进行雾化干燥，得到纳米硅干粉；
    (3)机械整形：将步骤(2)中的纳米硅干粉进行机械整形，得到粒度分布集中，形貌规整的纳米硅颗粒；
    (4)气相碳源覆盖：将步骤(3)中的纳米硅颗粒置于气相沉积炉中，通入保护气体，再通入碳源气体，升温加热，使气相碳源沉积并覆盖在纳米硅颗粒上，得到硅碳负极材料。
  6. 根据权利要求5所述的制备方法，其特征在于，步骤(1)中所述的硅粉原料为多晶硅，硅粉原料的纯度＞99.9％，硅粉原料的中值粒径为1～100μm，优选3～20μm；
    所述助磨剂为氯化铝、聚合醇胺、三乙醇胺、三异丙醇胺、焦磷酸钠、三聚磷酸钠、丙烯酸钠、十八酸钠、聚丙烯酸钠、亚甲基双萘磺酸钠、柠檬酸钾、环烷酸铅、亚甲基双萘磺酸钠、三乙基己基磷酸、十二烷基硫酸钠、甲基戊醇、纤维素衍生物或古尔胶中的一种或多种；
    所述有机溶剂为甲醇、甲苯、苯甲醇、乙醇、乙二醇、氯化乙醇、丙醇、异丙醇、丙二醇、丁醇、正丁醇、异丁醇、戊醇、新戊醇、辛醇、丙酮或环已酮的一种或多种；
    所述硅粉原料与分散剂的质量比是100：(1～20)，优选100：(5～15)；加入溶剂后，混合溶液的固含量是10～40％，优选20～30％；
    所述湿法研磨设备为砂磨机，砂磨机搅拌轴的结构形状为盘式，棒式或棒盘式中的一种，砂磨机的最高线速度＞14m/s；
    所述球磨珠的材质选自陶瓷，氧化锆，氧化铝或硬质合金，球磨珠与微米硅粉的质量比是为(10～30):1。
  7. 根据权利要求5所述的制备方法，其特征在于，步骤(2)中所述的喷雾干燥机为闭式喷雾干燥机，其热空气进口温度为150～300℃，优选160～280℃；出口温度为80～140℃，优选90～130℃；
    所述喷雾干燥机中雾化盘的转速＞10000rpm。
  8. 如权利要求5所述的制备方法，其特征在于，步骤(3)所述的机械整形包括粉碎、分级和过筛，具体工艺步骤为：
    将步骤(2)中得到的纳米硅干粉，经粉碎机处理，调节主机强度为30～50Hz，调节分级强度为30～50Hz，将纳米硅干粉的粒度尺寸降低，并通过分级除去微小细粉，再将粉料进行筛分，除去大颗粒，筛网目数为100～400目，得到粒度分布集中，形貌规整的纳米硅干粉。
  9. 根据权利要求5所述的制备方法，其特征在于，步骤(4)所述气相碳源沉积过程的升温速率是1～3℃/min，碳沉积温度是600～900℃，有机碳源气体的流量为1～5L/min，反应持续时间是1～4h；
    所述有机碳源气体是甲烷、乙烷、乙烯、乙炔、丙烷、丙烯、丙酮、丁烷、丁烯、戊烷、己烷、苯、甲苯、二甲苯、苯乙烯、萘、苯酚、呋喃、吡啶、蒽、液化气中的一种或两种以上的组合；
    所述保护性气体为氮气、氦气、氖气、氩气中的一种。
  10. 一种锂离子电池，其特征在于，所述锂离子电池负极材料为权利要求1-4任一项所述的锂离子电池用硅碳负极材料。
PCT/CN2021/075668 2020-07-06 2021-02-06 一种锂离子电池用硅碳负极材料及其制备方法 WO2022007401A1 (zh)

Priority Applications (4)

Application Number Priority Date Filing Date Title
KR1020227031651A KR20220140615A (ko) 2020-07-06 2021-02-06 리튬 이온 전지용 실리콘 탄소 음극재료 및 이의 제조 방법
JP2022563222A JP7470271B2 (ja) 2020-07-06 2021-02-06 リチウムイオン電池用シリコン－カーボン負極材とその作製方法
US17/912,390 US20230135178A1 (en) 2020-07-06 2021-02-06 Silicon-carbon negative electrode material for lithium ion battery and preparation method therefor
EP21837229.0A EP4109597A4 (en) 2020-07-06 2021-02-06 SILICON-CARBON NEGATIVE ELECTRODE MATERIAL FOR LITHIUM-ION BATTERY AND PREPARATION METHOD THEREFOR

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202010639966.5A CN111755684B (zh) 2020-07-06 2020-07-06 一种锂离子电池用硅碳负极材料及其制备方法
CN202010639966.5 2020-07-06

Publications (1)

Publication Number Publication Date
WO2022007401A1 true WO2022007401A1 (zh) 2022-01-13

Family

ID=72679447

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2021/075668 WO2022007401A1 (zh) 2020-07-06 2021-02-06 一种锂离子电池用硅碳负极材料及其制备方法

Country Status (6)

Country Link
US (1) US20230135178A1 (zh)
EP (1) EP4109597A4 (zh)
JP (1) JP7470271B2 (zh)
KR (1) KR20220140615A (zh)
CN (1) CN111755684B (zh)
WO (1) WO2022007401A1 (zh)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114497509A (zh) * 2022-02-08 2022-05-13 格龙新材料科技(常州)有限公司 一种硅碳复合负极材料的制备方法
CN114975909A (zh) * 2022-04-06 2022-08-30 宁波广新纳米材料有限公司 用作锂离子电池负极材料的碳包覆纳米硅粉的生产方法
CN115939402A (zh) * 2023-01-09 2023-04-07 天目湖先进储能技术研究院有限公司 一种硅基材料及其制备方法和在负极中的应用

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111755684B (zh) * 2020-07-06 2022-05-24 马鞍山科达普锐能源科技有限公司 一种锂离子电池用硅碳负极材料及其制备方法
CN113422020A (zh) * 2021-06-24 2021-09-21 湖南中科星城石墨有限公司 一种硅氧材料及其处理方法
CN114665083A (zh) * 2022-03-21 2022-06-24 深圳市贝特瑞新能源技术研究院有限公司 负极材料及其制备方法、锂离子电池
CN114976317B (zh) * 2022-06-29 2023-12-12 广东邦普循环科技有限公司 一种废旧硅碳材料的修复方法及其应用
CN116544398B (zh) * 2023-07-03 2023-10-20 宁德新能源科技有限公司 硅材料及其制备方法、负极极片、电化学装置、用电设备
CN117673335A (zh) * 2024-01-31 2024-03-08 贝特瑞新材料集团股份有限公司 负极材料及其制备方法、锂离子电池
CN117727915B (zh) * 2024-02-07 2024-05-14 长沙矿冶研究院有限责任公司 一种微细硅晶尺寸的硅碳复合材料及其制备方法和应用

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102157731A (zh) * 2011-03-18 2011-08-17 上海交通大学 一种锂离子电池硅碳复合负极材料及其制备方法
CN104638237A (zh) * 2015-01-20 2015-05-20 深圳市贝特瑞新能源材料股份有限公司 一种锂离子电池氧化亚硅复合材料、制备方法及其用途
CN111146430A (zh) * 2020-02-10 2020-05-12 马鞍山科达普锐能源科技有限公司 一种锂离子电池用多孔核壳结构硅碳负极材料的及其制备方法
CN111755684A (zh) * 2020-07-06 2020-10-09 马鞍山科达普锐能源科技有限公司 一种锂离子电池用硅碳负极材料及其制备方法

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10446838B2 (en) 2014-01-31 2019-10-15 Kabushiki Kaisha Toyota Jidoshokki Negative electrode for nonaqueous secondary battery and nonaqueous secondary battery, negative electrode active material and method for producing same, complex including nano silicon, carbon layer, and cationic polymer layer, and method for producing complex formed of nano silicon and carbon layer
CN106328909B (zh) * 2016-11-18 2020-01-24 深圳市贝特瑞新能源材料股份有限公司 纳米二氧化硅-硅基复合材料、制备方法及包含该复合材料的锂离子电池
GB2563455B (en) * 2017-06-16 2019-06-19 Nexeon Ltd Particulate electroactive materials for use in metal-ion batteries
CN109638229A (zh) * 2017-10-09 2019-04-16 珠海市三顺纳米新材料有限公司 硅碳复合负极材料及其制备方法和锂离子电池
CN108134063B (zh) * 2017-12-21 2019-11-22 哈尔滨工业大学深圳研究生院 一种硅碳复合材料的制备方法及其应用
CN109802120A (zh) * 2019-01-24 2019-05-24 广东凯金新能源科技股份有限公司 一种硅碳复合材料及其制法
CN109873146A (zh) * 2019-02-27 2019-06-11 陕西煤业化工技术研究院有限责任公司 一种锂离子电池用硅碳负极材料及其制备方法
CN111180713B (zh) * 2020-02-10 2022-11-01 马鞍山科达普锐能源科技有限公司 一种锂离子电池用硅碳负极材料及制备方法
CN111261864A (zh) * 2020-02-10 2020-06-09 马鞍山科达普锐能源科技有限公司 一种锂离子电池用硅碳负极材料及其制备方法

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102157731A (zh) * 2011-03-18 2011-08-17 上海交通大学 一种锂离子电池硅碳复合负极材料及其制备方法
CN104638237A (zh) * 2015-01-20 2015-05-20 深圳市贝特瑞新能源材料股份有限公司 一种锂离子电池氧化亚硅复合材料、制备方法及其用途
CN111146430A (zh) * 2020-02-10 2020-05-12 马鞍山科达普锐能源科技有限公司 一种锂离子电池用多孔核壳结构硅碳负极材料的及其制备方法
CN111755684A (zh) * 2020-07-06 2020-10-09 马鞍山科达普锐能源科技有限公司 一种锂离子电池用硅碳负极材料及其制备方法

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
XU LONG: "Mechanism and Experimental Study of Laser Cladding Boron Doped Nanometer Silicon Slurry", MASTER THESIS, TIANJIN POLYTECHNIC UNIVERSITY, CN, 1 March 2019 (2019-03-01), CN , pages 1 - 86, XP055887773, ISSN: 1674-0246 *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114497509A (zh) * 2022-02-08 2022-05-13 格龙新材料科技(常州)有限公司 一种硅碳复合负极材料的制备方法
CN114975909A (zh) * 2022-04-06 2022-08-30 宁波广新纳米材料有限公司 用作锂离子电池负极材料的碳包覆纳米硅粉的生产方法
CN114975909B (zh) * 2022-04-06 2024-04-19 江苏博迁新材料股份有限公司 用作锂离子电池负极材料的碳包覆纳米硅粉的生产方法
CN115939402A (zh) * 2023-01-09 2023-04-07 天目湖先进储能技术研究院有限公司 一种硅基材料及其制备方法和在负极中的应用

Also Published As

Publication number Publication date
CN111755684B (zh) 2022-05-24
KR20220140615A (ko) 2022-10-18
US20230135178A1 (en) 2023-05-04
EP4109597A4 (en) 2024-06-05
EP4109597A1 (en) 2022-12-28
CN111755684A (zh) 2020-10-09
JP2023522086A (ja) 2023-05-26
JP7470271B2 (ja) 2024-04-18

Similar Documents

Publication Publication Date Title
WO2022007401A1 (zh) 一种锂离子电池用硅碳负极材料及其制备方法
WO2021056981A1 (zh) 一种锂电池硅基复合负极材料的制备方法
CN108736007B (zh) 一种高压实密度锂离子电池硅碳负极材料的制备方法
WO2020151093A1 (zh) 一种硅碳复合材料及其制法
JP6563477B2 (ja) 多元系複合負極材料、その製造方法及びそれを含むリチウムイオン電池
WO2021128603A1 (zh) 一种用于锂离子电池负极的改性一氧化硅材料及其制备方法
WO2015139660A1 (zh) 多孔碳纳米管微球及其制备方法与应用、金属锂-骨架碳复合材料及其制备方法、负极和电池
Huang et al. Porous silicon–graphene–carbon composite as high performance anode material for lithium ion batteries
CN111755677B (zh) 一种锂离子电池用核壳结构多孔硅负极材料及其制备方法
CN111628162B (zh) 一种锂离子电池用多孔硅负极材料及其制备方法
CN109860548B (zh) 一种纳米硅材料的制备方法及其应用
WO2021238600A1 (zh) 一种锂离子电池用硅碳负极材料及其制备方法
CN112366299B (zh) 一种石墨-硅基锂离子电池负极材料的制备方法及其产品
CN108232141A (zh) 一种高压实的锂离子电池硅碳复合负极材料及其制备方法
CN115332523B (zh) 以高分子凝胶为基体衍生的硅碳负极材料及其制备方法
WO2019051662A1 (zh) 一种新型高电位多层碳包覆聚阴离子型钠离子电池正极材料及其制备方法
CN108063242A (zh) 一种硅基合金材料及其制备方法和应用
CN111180713B (zh) 一种锂离子电池用硅碳负极材料及制备方法
CN111755676A (zh) 一种锂离子电池用硅合金负极材料及其制备方法
CN112661132A (zh) 一种硅基复合负极材料及其制备方法
WO2022007402A1 (zh) 一种锂离子电池负极材料用含硅粉末及其制备方法
CN107195897B (zh) 一种纳米FeNbO4/石墨烯复合材料及其制备和应用
WO2019019413A1 (zh) 金属锂负极、其制备方法和包含该金属锂负极的锂电池
CN109560280B (zh) 一种纳米锡-二硫化钼复合物负极材料及其制备方法和应用
CN111755678A (zh) 一种锂离子电池用硅碳负极材料及其制备方法

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 21837229

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 20227031651

Country of ref document: KR

Kind code of ref document: A

ENP Entry into the national phase

Ref document number: 2021837229

Country of ref document: EP

Effective date: 20220920

ENP Entry into the national phase

Ref document number: 2022563222

Country of ref document: JP

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE