CN117352711A - Preparation process of novel carbon-coated silicon and graphite composite negative electrode material - Google Patents
Preparation process of novel carbon-coated silicon and graphite composite negative electrode material Download PDFInfo
- Publication number
- CN117352711A CN117352711A CN202311660675.4A CN202311660675A CN117352711A CN 117352711 A CN117352711 A CN 117352711A CN 202311660675 A CN202311660675 A CN 202311660675A CN 117352711 A CN117352711 A CN 117352711A
- Authority
- CN
- China
- Prior art keywords
- silicon
- graphite
- parts
- coated
- preparing
- 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.)
- Granted
Links
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 title claims abstract description 76
- 239000010703 silicon Substances 0.000 title claims abstract description 46
- 229910052710 silicon Inorganic materials 0.000 title claims abstract description 46
- 229910002804 graphite Inorganic materials 0.000 title claims abstract description 41
- 239000010439 graphite Substances 0.000 title claims abstract description 41
- 229910052799 carbon Inorganic materials 0.000 title claims abstract description 23
- 238000002360 preparation method Methods 0.000 title claims abstract description 23
- 239000007773 negative electrode material Substances 0.000 title claims abstract description 21
- 239000002131 composite material Substances 0.000 title claims abstract description 20
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims abstract description 93
- 238000000576 coating method Methods 0.000 claims abstract description 48
- 239000011248 coating agent Substances 0.000 claims abstract description 43
- 239000011863 silicon-based powder Substances 0.000 claims abstract description 30
- 238000003763 carbonization Methods 0.000 claims abstract description 21
- 238000012986 modification Methods 0.000 claims abstract description 20
- 230000004048 modification Effects 0.000 claims abstract description 20
- 239000000725 suspension Substances 0.000 claims abstract description 18
- 238000002156 mixing Methods 0.000 claims abstract description 17
- 238000000034 method Methods 0.000 claims abstract description 16
- 230000008569 process Effects 0.000 claims abstract description 13
- 238000004519 manufacturing process Methods 0.000 claims abstract description 9
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 26
- 239000000463 material Substances 0.000 claims description 26
- 239000010405 anode material Substances 0.000 claims description 25
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical group CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 24
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 claims description 21
- 239000000243 solution Substances 0.000 claims description 18
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 16
- 229910021485 fumed silica Inorganic materials 0.000 claims description 16
- 239000002245 particle Substances 0.000 claims description 16
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 claims description 14
- 229910052757 nitrogen Inorganic materials 0.000 claims description 13
- XEKOWRVHYACXOJ-UHFFFAOYSA-N Ethyl acetate Chemical compound CCOC(C)=O XEKOWRVHYACXOJ-UHFFFAOYSA-N 0.000 claims description 12
- 238000000498 ball milling Methods 0.000 claims description 11
- 238000003756 stirring Methods 0.000 claims description 11
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 10
- 238000001035 drying Methods 0.000 claims description 9
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 9
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 claims description 8
- 229910010271 silicon carbide Inorganic materials 0.000 claims description 8
- 239000001307 helium Substances 0.000 claims description 7
- 229910052734 helium Inorganic materials 0.000 claims description 7
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 claims description 7
- 239000012046 mixed solvent Substances 0.000 claims description 7
- 238000005507 spraying Methods 0.000 claims description 7
- CTQNGGLPUBDAKN-UHFFFAOYSA-N O-Xylene Chemical compound CC1=CC=CC=C1C CTQNGGLPUBDAKN-UHFFFAOYSA-N 0.000 claims description 6
- KRKNYBCHXYNGOX-UHFFFAOYSA-N citric acid Chemical compound OC(=O)CC(O)(C(O)=O)CC(O)=O KRKNYBCHXYNGOX-UHFFFAOYSA-N 0.000 claims description 6
- KXGFMDJXCMQABM-UHFFFAOYSA-N 2-methoxy-6-methylphenol Chemical compound [CH]OC1=CC=CC([CH])=C1O KXGFMDJXCMQABM-UHFFFAOYSA-N 0.000 claims description 5
- WQZGKKKJIJFFOK-GASJEMHNSA-N Glucose Natural products OC[C@H]1OC(O)[C@H](O)[C@@H](O)[C@@H]1O WQZGKKKJIJFFOK-GASJEMHNSA-N 0.000 claims description 5
- 229920003171 Poly (ethylene oxide) Polymers 0.000 claims description 5
- 229910052786 argon Inorganic materials 0.000 claims description 5
- 238000010000 carbonizing Methods 0.000 claims description 5
- 239000008103 glucose Substances 0.000 claims description 5
- 238000010438 heat treatment Methods 0.000 claims description 5
- 229920001568 phenolic resin Polymers 0.000 claims description 5
- 239000005011 phenolic resin Substances 0.000 claims description 5
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 claims description 4
- 238000003760 magnetic stirring Methods 0.000 claims description 4
- 239000011259 mixed solution Substances 0.000 claims description 4
- 229910021382 natural graphite Inorganic materials 0.000 claims description 4
- 239000002904 solvent Substances 0.000 claims description 4
- 238000001132 ultrasonic dispersion Methods 0.000 claims description 4
- 239000008096 xylene Substances 0.000 claims description 4
- QQZOPKMRPOGIEB-UHFFFAOYSA-N 2-Oxohexane Chemical compound CCCCC(C)=O QQZOPKMRPOGIEB-UHFFFAOYSA-N 0.000 claims description 3
- 238000007602 hot air drying Methods 0.000 claims description 3
- 239000003960 organic solvent Substances 0.000 claims description 3
- 229920000178 Acrylic resin Polymers 0.000 claims description 2
- 239000004925 Acrylic resin Substances 0.000 claims description 2
- 229920001661 Chitosan Polymers 0.000 claims description 2
- 239000002033 PVDF binder Substances 0.000 claims description 2
- 239000002202 Polyethylene glycol Substances 0.000 claims description 2
- 239000004372 Polyvinyl alcohol Substances 0.000 claims description 2
- CZMRCDWAGMRECN-UGDNZRGBSA-N Sucrose Chemical compound O[C@H]1[C@H](O)[C@@H](CO)O[C@@]1(CO)O[C@@H]1[C@H](O)[C@@H](O)[C@H](O)[C@@H](CO)O1 CZMRCDWAGMRECN-UGDNZRGBSA-N 0.000 claims description 2
- 229930006000 Sucrose Natural products 0.000 claims description 2
- 229920001807 Urea-formaldehyde Polymers 0.000 claims description 2
- WQZGKKKJIJFFOK-VFUOTHLCSA-N beta-D-glucose Chemical compound OC[C@H]1O[C@@H](O)[C@H](O)[C@@H](O)[C@@H]1O WQZGKKKJIJFFOK-VFUOTHLCSA-N 0.000 claims description 2
- 239000011300 coal pitch Substances 0.000 claims description 2
- 239000011280 coal tar Substances 0.000 claims description 2
- 239000003822 epoxy resin Substances 0.000 claims description 2
- 229920005546 furfural resin Polymers 0.000 claims description 2
- 239000011302 mesophase pitch Substances 0.000 claims description 2
- 239000000203 mixture Substances 0.000 claims description 2
- 239000011301 petroleum pitch Substances 0.000 claims description 2
- 229920000647 polyepoxide Polymers 0.000 claims description 2
- 229920001223 polyethylene glycol Polymers 0.000 claims description 2
- 229920002451 polyvinyl alcohol Polymers 0.000 claims description 2
- 229920000915 polyvinyl chloride Polymers 0.000 claims description 2
- 239000004800 polyvinyl chloride Substances 0.000 claims description 2
- 229920002981 polyvinylidene fluoride Polymers 0.000 claims description 2
- 239000005720 sucrose Substances 0.000 claims description 2
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 claims description 2
- 239000011870 silicon-carbon composite anode material Substances 0.000 abstract description 4
- 238000005253 cladding Methods 0.000 abstract 1
- 230000000052 comparative effect Effects 0.000 description 14
- 229910052744 lithium Inorganic materials 0.000 description 10
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 7
- 229910001416 lithium ion Inorganic materials 0.000 description 7
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 5
- HMDDXIMCDZRSNE-UHFFFAOYSA-N [C].[Si] Chemical compound [C].[Si] HMDDXIMCDZRSNE-UHFFFAOYSA-N 0.000 description 4
- 238000012360 testing method Methods 0.000 description 4
- 239000003575 carbonaceous material Substances 0.000 description 3
- 238000007599 discharging Methods 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 230000007547 defect Effects 0.000 description 2
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical group [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 229910000733 Li alloy Inorganic materials 0.000 description 1
- 229910013870 LiPF 6 Inorganic materials 0.000 description 1
- 239000011149 active material Substances 0.000 description 1
- GZCGUPFRVQAUEE-SLPGGIOYSA-N aldehydo-D-glucose Chemical compound OC[C@@H](O)[C@@H](O)[C@H](O)[C@@H](O)C=O GZCGUPFRVQAUEE-SLPGGIOYSA-N 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 239000011247 coating layer Substances 0.000 description 1
- 239000006258 conductive agent Substances 0.000 description 1
- 239000011889 copper foil Substances 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000001351 cycling effect Effects 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000003792 electrolyte Substances 0.000 description 1
- 239000001989 lithium alloy Substances 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 239000011255 nonaqueous electrolyte Substances 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 238000011056 performance test Methods 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 239000007774 positive electrode material Substances 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 239000002210 silicon-based material Substances 0.000 description 1
- 238000000935 solvent evaporation Methods 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
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
- H01M4/362—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
- 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
- H01M4/38—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
- 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
- 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
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Composite Materials (AREA)
- Engineering & Computer Science (AREA)
- Inorganic Chemistry (AREA)
- Materials Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Silicon Compounds (AREA)
- Carbon And Carbon Compounds (AREA)
Abstract
The invention relates to the technical field of negative electrode materials, in particular to a novel preparation process of a carbon-coated silicon-graphite composite negative electrode material, which comprises the following components in parts by weight: 40 parts of modified graphite and 5-7 parts of carbon-coated silicon powder. The preparation process comprises the following steps: (1) graphite modification; (2) preparing a silicon suspension; (3) preparing a coating solution; (4) a cladding process; (5) carbonization treatment; (6) mixing procedure. The silicon-carbon composite anode material produced by the method has the advantages of simple process, low cost, suitability for mass production and excellent and stable product performance.
Description
Technical Field
The invention relates to the technical field of negative electrode materials, in particular to a preparation process of a novel carbon-coated silicon-graphite composite negative electrode material.
Background
Lithium batteries are a type of battery using a nonaqueous electrolyte solution with lithium metal or a lithium alloy as a positive/negative electrode material. Lithium metal batteries were first proposed and studied by Gilbert n.lewis in 1912. At 70 s of the 20 th century, m.s. Whittingham proposed and began to study lithium ion batteries. The chemical characteristics of lithium metal are very active, so that the processing, storage and use of lithium metal have very high requirements on environment. With the development of science and technology, lithium batteries have become the mainstream.
Lithium batteries can be broadly divided into two categories: lithium metal batteries and lithium ion batteries. Lithium ion batteries do not contain lithium in the metallic state and are rechargeable.
The lithium ion battery has the excellent performances of high working voltage, large energy density, long service life, wide application temperature range, no memory and the like, and is widely applied to the fields such as new energy automobiles and the like.
The silicon-carbon anode material is an anode material with great application potential, and has become a technical hot spot in the field of lithium ion batteries due to the fact that the theoretical ratio is high, the energy density is high and the safety is high. However, the current silicon carbon negative electrode has some problems that limit practical applications, such as electrode breakage due to volume expansion, electrode loss conductivity due to active material peeling from the surface of the current collector, capacity degradation and cycle life reduction due to continuous exposure of fresh surfaces and repeated growth of the SEI film.
Based on the above, we propose a novel carbon-coated silicon and natural graphite composite anode material and preparation process, hopefully solving the defects in the prior art.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides a preparation process of a novel carbon-coated silicon and graphite composite anode material.
In order to achieve the above purpose, the invention provides a preparation process of a novel carbon-coated silicon and graphite composite anode material, which comprises the following steps:
(1) Modification of graphite: placing 40 parts of dried graphite in electromagnetic microwave or light wave equipment, modifying the graphite by electromagnetic microwave or light wave, and introducing nitrogen for protection in the process to obtain modified graphite;
(2) Preparation of a silicon suspension: dispersing 4-6 parts by weight of dried silicon nano powder in a mixed solvent with the mass of 6-9 times of that of the silicon nano powder, and obtaining silicon suspension through magnetic stirring and ultrasonic dispersion;
(3) Preparing a coating solution: taking 3-30 parts by weight of coating material, and dissolving the coating material by using a solvent with the mass being 3-5 times that of the coating material to obtain a coating solution;
(4) The coating process comprises the following steps: mixing the silicon suspension with the coating solution, uniformly stirring, and then spraying and drying the mixture to obtain silicon powder coated by the coating material;
(5) Carbonizing: placing the silicon powder coated by the coating material into a tube furnace, and simultaneously introducing inert atmosphere for protection for carbonization to obtain carbonized silicon powder;
(6) Mixing: putting modified graphite in the anode material into a ball mill, performing ball milling treatment, and then uniformly mixing the modified graphite with carbonized silicon powder, silicon carbide or silicon boride to finally prepare the anode material;
the negative electrode material comprises the following components in parts by mass:
40 parts of modified graphite;
5-7 parts of carbonized silicon powder;
1-2 parts of silicon carbide or 1-2 parts of silicon boride.
The negative electrode material comprises 1-2 parts by weight of silicon carbide or 1-2 parts by weight of silicon boride, wherein the addition of the silicon carbide can improve the service life of the negative electrode material due to high temperature resistance, wear resistance and good heat conductivity of the silicon carbide, and the addition of the silicon boride can improve the performance of a battery and enhance the capacity retention rate of the battery due to the combination of excellent performances of boron atoms and silicon atoms.
Further, in the step (1), the graphite is one of natural graphite or spherical graphite, the graphite is dried for 3-4 hours at the temperature of 60-90 ℃, the nitrogen flow rate is 100-110 mL/min, the electromagnetic microwave or light wave modification power is 800-1000 w, and the modification time is 40-60 s.
Further, in the step (2), the particle size of the silicon nano powder is 50-500nm, the silicon nano powder contains 10wt% of fumed silica, the particle size of the fumed silica is 7-40nm, the mixed solvent is ethanol, isopropanol, acetone or a mixed solution of one organic solvent of ethanol, isopropanol and acetone and water, the volume ratio of the organic solvent to the water is 9:1, the rotating speed of a magnetic stirrer is 400-2000r/min, the stirring time is 30-90min, the ultrasonic frequency is 10-40kHz, and the ultrasonic time is 30-90min. After the fumed silica component is added, the particle size of the fumed silica is smaller, the dispersibility is better, and the fumed silica can be used as crystal nucleus in the step (4) micron spraying and drying process, so that the silicon powder coated by the coating material obtained in the drying process is better and uniform, the particles are smaller, and the fumed silica can resist caking, so that the silicon powder coated by the coating material is prevented from caking.
Further, the coating material in the step (3) is at least one of phenolic resin, epoxy resin, urea-formaldehyde resin, furfural resin, polyvinyl alcohol, polyethylene glycol, polyethylene oxide, polyvinylidene fluoride, acrylic resin, polyvinyl chloride, coal pitch, petroleum pitch, mesophase pitch, coal tar, glucose, sucrose, citric acid and chitosan, and the solvent is one of acetone, ethanol, xylene, ethyl acetate, tetrahydrofuran, ethyl acetate, methyl butyl ketone and xylene.
In the step (4), the mixed solution of the silicon suspension and the coating solution is sprayed out through 1-10 mu m micropores, and the silicon powder coated by the coating material is obtained by hot air drying at the temperature of 100-200 ℃.
Further, in the step (5), during the carbonization treatment, the carbonization treatment temperature is 600-1200 ℃, the heating rate is 1-5 ℃/min, the carbonization time is 3.5-5h, and the inert atmosphere is one of nitrogen, argon and helium, preferably helium. When helium is adopted, the helium can enter the material for internal protection because the radius is smaller, the effect is better, and the helium can be recycled.
Further, in the step (6), the ball milling rotating speed is 500-2000r/min, and the time is 0-2h.
Further, in the negative electrode material, the silicon content is 5-15%, the grain diameter is 10-15 mu m, and the tap density is 0.9-1.2g/cm 3 The true density is 2.9-3.2g/cm 3 。
Compared with the prior art, the invention provides a novel carbon-coated silicon and graphite composite negative electrode material and a preparation process thereof, and the novel carbon-coated silicon and graphite composite negative electrode material has the following beneficial effects:
the invention does not limit the sources and equipment of the raw materials, and the silicon-carbon composite anode material produced by the method has simple process, low cost, suitability for mass production and excellent and stable product performance.
The invention provides a novel simple and efficient preparation method, which improves the performance of the silicon-carbon composite anode material. The preparation process and the silicon-carbon material are suitable for the negative electrode material of the lithium ion battery, can effectively improve the cycle performance and the multiplying power performance of the lithium ion battery, and have wide application prospects.
According to the preparation method, the carbon material is coated on the surface of the silicon by using a carbon coating technology, the cycling stability of the silicon negative electrode is improved after the carbon material is compounded with graphite, the preparation technology can realize low-cost modified graphite negative electrode and is compounded with the carbon-coated silicon material, and a technical path of the silicon-carbon negative electrode material is provided.
In conclusion, the novel preparation process of the silicon-carbon composite anode material has the advantages of simplicity, high efficiency and low cost, and has great practical application potential and market value.
Detailed Description
The technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
Embodiment 1, a novel carbon-coated silicon and graphite composite anode material comprises the following components in parts by mass: 40 parts of modified graphite; 6 parts of carbonized silicon powder.
The preparation method comprises the following steps:
(1) Modification of graphite: placing 40 parts of dried natural graphite in electromagnetic microwave equipment for electromagnetic microwave modification, and introducing nitrogen for protection in the process to obtain modified graphite, wherein the graphite is dried for 3 hours at the temperature of 60-70 ℃, the flow rate of the nitrogen is 100-110 mL/min, the electromagnetic microwave modification power is 800w, and the modification time is 40s;
(2) Preparation of a silicon suspension: dispersing 4.5 parts by mass of dried silicon nano powder and 0.5 part by mass of fumed silica in a mixed solvent of ethanol and water, wherein the mass ratio of the ethanol to the water is 9:1, and carrying out magnetic stirring and ultrasonic dispersion to obtain a silicon suspension, wherein the particle size of the silicon nano powder is 50-500nm, the particle size of the fumed silica is 7-40nm, the rotating speed of a magnetic stirrer is 800r/min, the stirring time is 40min, the ultrasonic frequency is 20kHz, and the ultrasonic time is 40min;
(3) Preparing a coating solution: taking 6 parts by weight of phenolic resin, and dissolving the phenolic resin by adopting acetone with the mass being 4 times of that of the phenolic resin to obtain silicon powder coated by a coating material;
(4) The coating process comprises the following steps: mixing the silicon suspension with the coating solution, stirring uniformly, spraying out through 1-10 mu m micropores, and drying at 100-120 ℃ by hot air to obtain silicon powder coated by the coating material;
(5) Carbonizing: placing the silicon powder coated by the coating material in a tube furnace, and simultaneously introducing nitrogen for protection for carbonization, wherein in the carbonization treatment process, the carbonization treatment temperature is 600-900 ℃, the heating rate is 2 ℃/min, and the carbonization time is 4 hours, so as to obtain carbonized silicon powder;
(6) Mixing: putting modified graphite in the anode material into a ball mill, performing ball milling treatment at the ball milling speed of 500r/min for 1h, and uniformly mixing with other components to obtain the anode material, wherein the silicon content is 11.2%, the particle size is 10-15 mu m, and the tap density is 1.01g/cm 3 The true density is 2.9g/cm 3 。
Embodiment 2, a novel carbon-coated silicon and graphite composite anode material comprises the following components in parts by mass: 40 parts of modified graphite; 7 parts of carbonized silicon powder; 1 part of silicon carbide.
The preparation method comprises the following steps:
(1) Modification of graphite: placing 40 parts of dried natural crystalline flake graphite into electro-optical wave equipment for light wave modification, and introducing nitrogen for protection in the process to obtain modified graphite, wherein the graphite is dried for 3 hours at the temperature of 70-90 ℃, the flow rate of the nitrogen is 100-110 mL/min, the light wave modification power is 1000w, and the modification time is 1min;
(2) Preparation of a silicon suspension: dispersing 5.4 parts by mass of dried silicon nano powder and 0.6 part by mass of fumed silica in isopropanol which is 8 times by mass of the silicon nano powder, and magnetically stirring and ultrasonically dispersing to obtain a silicon suspension, wherein the particle size of the silicon nano powder is 50-500nm, the particle size of the fumed silica is 7-40nm, the rotating speed of a magnetic stirrer is 1500r/min, the stirring time is 60min, the ultrasonic frequency is 30kHz, and the ultrasonic time is 60min;
(3) Preparing a coating solution: taking 12 parts by weight of polyethylene oxide, and dissolving the polyethylene oxide by using dimethylbenzene with the mass being 5 times that of the polyethylene oxide to obtain a coating solution;
(4) The coating process comprises the following steps: mixing the silicon suspension with the coating solution, stirring uniformly, spraying out through 1-10 mu m micropores, and drying at the temperature of 150-200 ℃ by hot air to obtain silicon powder coated by the coating material;
(5) Carbonizing: placing the silicon powder coated by the coating material in a tube furnace, and simultaneously introducing argon for protection for carbonization, wherein in the carbonization treatment process, the carbonization treatment temperature is 900-1100 ℃, the heating rate is 4 ℃/min, and the carbonization time is 5 hours, so as to obtain carbonized silicon powder;
(6) Mixing: putting modified graphite and silicon boride in the anode material into a ball mill, performing ball milling treatment at the ball milling speed of 1000r/min for 2 hours, and then uniformly mixing with other components to finally obtain the anode material, wherein the silicon content is 13.4%, the particle size is 10-15 mu m, and the tap density is 1.11g/cm 3 The true density is 3.0g/cm 3 。
Embodiment 3, a novel carbon-coated silicon and graphite composite anode material comprises the following components in parts by mass: 40 parts of modified graphite; 7 parts of carbonized silicon powder; 1 part of silicon boride.
The preparation method comprises the following steps:
(1) Modification of graphite: putting 40 parts of dried spherical graphite into electromagnetic microwave equipment for electromagnetic microwave modification, and introducing nitrogen for protection in the process to obtain modified graphite, wherein the graphite is dried for 3 hours at the temperature of 70-90 ℃, the flow rate of the nitrogen is 100-110 mL/min, the electromagnetic microwave modification power is 1000w, and the modification time is 1min;
(2) Preparation of a silicon suspension: dispersing 5.4 parts by mass of dried silicon nano powder and 0.6 part by mass of fumed silica in a mixed solvent of isopropanol and water, wherein the mass ratio of the isopropanol to the water is 9:1, and carrying out magnetic stirring and ultrasonic dispersion to obtain a silicon suspension, wherein the particle size of the silicon nano powder is 50-500nm, the particle size of the fumed silica is 7-40nm, the rotating speed of a magnetic stirrer is 1500r/min, the stirring time is 60min, the ultrasonic frequency is 30KHz, and the ultrasonic time is 60min;
(3) Preparing a coating solution: taking 15 parts by weight of glucose, and dissolving the glucose by adopting methyl butyl ketone with the mass being 5 times that of the glucose to obtain a coating solution;
(4) The coating process comprises the following steps: mixing the silicon suspension with the coating solution, stirring uniformly, spraying out through 1-10 mu m micropores, and drying at the temperature of 150-200 ℃ by hot air to obtain silicon powder coated by the coating material;
(5) Carbonizing: placing the silicon powder coated by the coating material in a tube furnace, and simultaneously introducing helium for protection for carbonization, wherein in the carbonization treatment process, the carbonization treatment temperature is 900-1100 ℃, the heating rate is 3 ℃/min, and the carbonization time is 5 hours, so as to obtain carbonized silicon powder;
(6) Mixing: putting modified graphite and silicon boride in the anode material into a ball mill, performing ball milling treatment at a ball milling speed of 1500r/min for 2 hours, and then uniformly mixing with other components to obtain the anode material, wherein the silicon content is 13.6%, the particle size is 10-15 mu m, and the tap density is 1.13g/cm 3 The true density is 3.10g/cm 3 。
In example 4, 1 part of silicon boride was added to the negative electrode material of example 1, and the other steps are the same as in example 1, and are not repeated.
Comparative example 1 in step (6) of example 3, silicon powder after carbonization was also added to the ball mill and mixed during the ball milling process, and the other steps are the same as in example 3, and are not repeated.
Comparative example 2 in step (2) of example 3, "5.4 parts of silicon nano-powder and 0.6 parts of fumed silica" was changed to 6 parts of silicon nano-powder, and the other steps are the same as in example 3, and are not repeated.
Comparative example 3 in step (6) of example 1, "hot air drying at 100-120℃through 1-10 μm micropores" was changed to direct solvent evaporation drying, and the other steps are the same as in example 1, and are not described in detail.
In comparative example 4, the modified graphite in example 1 was replaced with unmodified graphite, and the other matters in example 1 are not described in detail.
The negative electrode materials prepared in examples and comparative examples were used as a negative electrode active material according to the following: conductive agent: binder = 94.8:2.2: and 3, uniformly mixing the materials in a mass ratio, coating the materials on a copper foil current collector, and drying to obtain a negative electrode plate for standby.
The obtained battery assembled by the stage sheets was tested, with lithium sheets as a counter electrode, with a polymer porous membrane PP as a separator, and with LiPF 6 Dissolved in a mixed solvent EC: DEC: the solution in DMC (1:1:1) was used as an electrolyte in an argon glove box (oxygen and water values were controlled to be the same as those in the argon glove box<Less than 1 ppm) to form a button cell. The battery manufactured by using the basic conditions is subjected to capacity and first coulombic efficiency test by adopting a blue electric system, the charging current is 0.1C, the discharging current is 0.1C, the charging and discharging voltage range is 5mV-2.0V, and the first discharging specific capacity and the first efficiency test result are shown in table 1.
TABLE 1 results of Performance test of the above examples and comparative examples
| Sequence number | Specific capacity of first discharge, mAh/g | First time efficiency, percent |
| Example 1 | 645 | 95.1 |
| Example 2 | 646 | 95.3 |
| Example 3 | 648 | 95.4 |
| Example 4 | 659 | 96.1 |
| Comparative example 1 | 621 | 92.2 |
| Comparative example 2 | 631 | 93.0 |
| Comparative example 3 | 613 | 90.2 |
| Comparative example 4 | 590 | 89.3 |
As can be seen from the data in the table, the test data of the examples 1-4 are all good, the specific capacity of the first discharge is more than or equal to 645mAh/g, and the first efficiency is more than 95%; comparison of the test data of example 1 and example 4 shows that the addition of silicon boride can improve cell performance; the data of comparative example 1 show that if carbonized silicon powder is ball milled together, the original coating layer is destroyed, and the battery performance is affected; the data of comparative example 2 shows that fumed silica can improve battery performance; the data of comparative example 3 shows that the coating mode has a large influence on the final battery performance; the data of comparative example 4 shows that the negative electrode material prepared from unmodified graphite has poor final properties.
Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.
Claims (8)
1. The preparation process of the novel carbon-coated silicon-graphite composite anode material is characterized by comprising the following steps of:
(1) Modification of graphite: placing 40 parts of dried graphite in electromagnetic microwave or light wave equipment, modifying the graphite by electromagnetic microwave or light wave, and introducing nitrogen for protection in the process to obtain modified graphite;
(2) Preparation of a silicon suspension: dispersing 4-6 parts by weight of dried silicon nano powder in a mixed solvent with the mass of 6-9 times of that of the silicon nano powder, and obtaining silicon suspension through magnetic stirring and ultrasonic dispersion;
(3) Preparing a coating solution: taking 3-30 parts by weight of coating material, and dissolving the coating material by using a solvent with the mass being 3-5 times that of the coating material to obtain a coating solution;
(4) The coating process comprises the following steps: mixing the silicon suspension with the coating solution, uniformly stirring, and then spraying and drying the mixture to obtain silicon powder coated by the coating material;
(5) Carbonizing: placing the silicon powder coated by the coating material into a tube furnace, and simultaneously introducing inert atmosphere for protection for carbonization to obtain carbonized silicon powder;
(6) Mixing: putting modified graphite in the anode material into a ball mill, performing ball milling treatment, and then uniformly mixing the modified graphite with carbonized silicon powder, silicon carbide or silicon boride to finally prepare the anode material;
the negative electrode material comprises the following components in parts by mass:
40 parts of modified graphite;
5-7 parts of carbonized silicon powder;
1-2 parts of silicon carbide or 1-2 parts of silicon boride.
2. The process for preparing the novel carbon-coated silicon-graphite composite anode material according to claim 1, wherein in the step (1), the graphite is one of natural graphite or spherical graphite, the graphite is dried at the temperature of 60-90 ℃ for 3-4 hours, the nitrogen flow rate is 100-110 mL/min, the electromagnetic microwave or light wave modification power is 800-1000 w, and the modification time is 40s-60s.
3. The process for preparing the novel carbon-coated silicon-graphite composite anode material according to claim 1, wherein in the step (2), the silicon nano powder has a particle size of 50-500nm, the silicon nano powder contains 10wt% of fumed silica, the fumed silica has a particle size of 7-40nm, the mixed solvent is ethanol, isopropanol, acetone or a mixed solution of one of ethanol, isopropanol and acetone and water, the volume ratio of the organic solvent to the water is 9:1, the rotation speed of a magnetic stirrer is 400-2000r/min, the stirring time is 30-90min, the ultrasonic frequency is 10-40kHz, and the ultrasonic time is 30-90min.
4. The process for preparing the novel carbon-coated silicon-graphite composite anode material according to claim 1, wherein the coating material in the step (3) is at least one of phenolic resin, epoxy resin, urea resin, furfural resin, polyvinyl alcohol, polyethylene glycol, polyethylene oxide, polyvinylidene fluoride, acrylic resin, polyvinyl chloride, coal pitch, petroleum pitch, mesophase pitch, coal tar, glucose, sucrose, citric acid and chitosan, and the solvent is one of acetone, ethanol, xylene, ethyl acetate, tetrahydrofuran, ethyl acetate, methyl butyl ketone and xylene.
5. The process for preparing the novel carbon-coated silicon-graphite composite negative electrode material according to claim 1, wherein in the step (4), the micron spraying process is that a mixed solution of a silicon suspension and a coating solution is sprayed out through 1-10 mu m micropores, and the silicon powder coated by the coating material is obtained by hot air drying at a temperature of between 100 and 200 ℃.
6. The process for preparing the novel carbon-coated silicon-graphite composite anode material according to claim 1, wherein in the step (5), the carbonization temperature is 600-1200 ℃, the heating rate is 1-5 ℃/min, the carbonization time is 3.5-5h, and the inert atmosphere is one of nitrogen, argon and helium.
7. The process for preparing the novel carbon-coated silicon-graphite composite anode material according to claim 1, wherein in the step (6), the ball milling speed is 500-2000r/min, and the time is 0-2h.
8. The process for preparing a novel carbon-coated silicon-graphite composite anode material according to claim 1, wherein the silicon content is 5% -15%, the particle size is 10-15 μm, and the tap density is 0.9-1.2g/cm 3 The true density is 2.9-3.2g/cm 3 。
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311660675.4A CN117352711B (en) | 2023-12-06 | 2023-12-06 | Preparation process of novel carbon-coated silicon and graphite composite negative electrode material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311660675.4A CN117352711B (en) | 2023-12-06 | 2023-12-06 | Preparation process of novel carbon-coated silicon and graphite composite negative electrode material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN117352711A true CN117352711A (en) | 2024-01-05 |
| CN117352711B CN117352711B (en) | 2024-01-30 |
Family
ID=89367215
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311660675.4A Active CN117352711B (en) | 2023-12-06 | 2023-12-06 | Preparation process of novel carbon-coated silicon and graphite composite negative electrode material |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117352711B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117996038A (en) * | 2024-03-07 | 2024-05-07 | 深圳市德罗伏特科技有限公司 | Composite silicon-carbon negative electrode material coated with nano silicon-graphite and preparation process thereof |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20060003227A1 (en) * | 2004-07-01 | 2006-01-05 | Shin-Etsu Chemical Co., Ltd. | Silicon composite, making method, and non-aqueous electrolyte secondary cell negative electrode material |
| CN102593426A (en) * | 2011-05-07 | 2012-07-18 | 天津锦美碳材科技发展有限公司 | Method for preparing silicon oxide (SiOx) / carbon (C) composite materials and prepared silicon carbon cathode materials for lithium ion battery |
| US20160344018A1 (en) * | 2014-01-13 | 2016-11-24 | James Ching-Hua LI | Anode material composition for a lithium ion battery |
| CN110085842A (en) * | 2019-05-10 | 2019-08-02 | 山西大学 | A kind of silicon-carbon composite cathode material and preparation method thereof |
| CN115108551A (en) * | 2022-08-10 | 2022-09-27 | 中山烯利来设备科技有限公司 | Method for manufacturing graphite negative electrode material |
-
2023
- 2023-12-06 CN CN202311660675.4A patent/CN117352711B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20060003227A1 (en) * | 2004-07-01 | 2006-01-05 | Shin-Etsu Chemical Co., Ltd. | Silicon composite, making method, and non-aqueous electrolyte secondary cell negative electrode material |
| CN102593426A (en) * | 2011-05-07 | 2012-07-18 | 天津锦美碳材科技发展有限公司 | Method for preparing silicon oxide (SiOx) / carbon (C) composite materials and prepared silicon carbon cathode materials for lithium ion battery |
| US20160344018A1 (en) * | 2014-01-13 | 2016-11-24 | James Ching-Hua LI | Anode material composition for a lithium ion battery |
| CN110085842A (en) * | 2019-05-10 | 2019-08-02 | 山西大学 | A kind of silicon-carbon composite cathode material and preparation method thereof |
| CN115108551A (en) * | 2022-08-10 | 2022-09-27 | 中山烯利来设备科技有限公司 | Method for manufacturing graphite negative electrode material |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117996038A (en) * | 2024-03-07 | 2024-05-07 | 深圳市德罗伏特科技有限公司 | Composite silicon-carbon negative electrode material coated with nano silicon-graphite and preparation process thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN117352711B (en) | 2024-01-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110767877B (en) | Lithium ion battery silicon monoxide negative electrode material and preparation method and application thereof | |
| WO2022166059A1 (en) | Boron-doped resin-coated artificial graphite material | |
| CN109616638B (en) | Spherical core-shell structure mixed graphite @ hard carbon composite material and preparation method and application thereof | |
| CN106711461A (en) | Spherical porous silicon/carbon composite material as well as preparation method and application thereof | |
| WO2017024720A1 (en) | Preparation method for high capacity lithium-ion battery negative electrode material | |
| CN111900360B (en) | Quick-charging type high-specific-capacity negative plate and lithium ion battery comprising same | |
| WO2021129126A1 (en) | Modified hard carbon negative electrode material and preparation method therefor | |
| CN114122352B (en) | Silicon-carbon negative electrode material for porous carbon doped induced silicon deposition and preparation method thereof | |
| CN117352711B (en) | Preparation process of novel carbon-coated silicon and graphite composite negative electrode material | |
| CN110931756A (en) | High-performance silicon-carbon composite negative electrode material with adjustable particle size and preparation method thereof | |
| CN111689500A (en) | Preparation method of low-expansibility SiO/graphite composite electrode material | |
| CN113555539A (en) | High-energy-density quick-charging graphite composite negative electrode material, preparation method thereof and lithium ion battery | |
| WO2016192542A1 (en) | Method for manufacturing modified graphite negative electrode material | |
| CN112635712A (en) | Negative plate and lithium ion battery | |
| CN114695894A (en) | High-capacity hard carbon fast-charging negative electrode material and preparation method and application thereof | |
| CN113889595A (en) | Preparation method of solid electrolyte coated graphite composite material | |
| CN115566170A (en) | Preparation method of high-energy-density quick-charging lithium ion battery cathode material | |
| CN114300671B (en) | Graphite composite negative electrode material and preparation method and application thereof | |
| CN114497508A (en) | Power type artificial graphite composite material and preparation method thereof | |
| CN114388738B (en) | Silicon-based anode material and preparation method and application thereof | |
| CN115249799A (en) | Rosin-based nitrogen-doped coated hard carbon negative electrode material of sodium ion battery and preparation method of rosin-based nitrogen-doped coated hard carbon negative electrode material | |
| CN111740110A (en) | Composite negative electrode material, preparation method thereof and lithium ion battery | |
| CN114975974A (en) | High-energy-density graphite composite material, preparation method thereof and lithium ion battery | |
| CN114520328B (en) | Lithium ion battery negative electrode material, preparation method thereof, negative electrode and battery | |
| CN117276523B (en) | Preparation method and application of silicon-carbon composite material |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |