CN116314734A - Preparation method of silicon-carbon composite material, silicon-carbon composite material and application of silicon-carbon composite material - Google Patents
Preparation method of silicon-carbon composite material, silicon-carbon composite material and application of silicon-carbon composite material Download PDFInfo
- Publication number
- CN116314734A CN116314734A CN202310232493.0A CN202310232493A CN116314734A CN 116314734 A CN116314734 A CN 116314734A CN 202310232493 A CN202310232493 A CN 202310232493A CN 116314734 A CN116314734 A CN 116314734A
- Authority
- CN
- China
- Prior art keywords
- silicon
- activation
- carbon composite
- composite material
- carbon
- 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.)
- Pending
Links
- 239000002153 silicon-carbon composite material Substances 0.000 title claims abstract description 65
- 238000002360 preparation method Methods 0.000 title claims abstract description 21
- 230000004913 activation Effects 0.000 claims abstract description 91
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 claims abstract description 78
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 74
- 229910002092 carbon dioxide Inorganic materials 0.000 claims abstract description 39
- 239000001569 carbon dioxide Substances 0.000 claims abstract description 39
- BLRPTPMANUNPDV-UHFFFAOYSA-N Silane Chemical compound [SiH4] BLRPTPMANUNPDV-UHFFFAOYSA-N 0.000 claims abstract description 36
- 229910000077 silane Inorganic materials 0.000 claims abstract description 36
- 239000000463 material Substances 0.000 claims abstract description 33
- 229910002804 graphite Inorganic materials 0.000 claims abstract description 28
- 239000010439 graphite Substances 0.000 claims abstract description 28
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 16
- 230000009471 action Effects 0.000 claims abstract description 7
- 238000000034 method Methods 0.000 claims description 28
- 230000008021 deposition Effects 0.000 claims description 19
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 19
- 229910003481 amorphous carbon Inorganic materials 0.000 claims description 11
- 239000011149 active material Substances 0.000 claims description 8
- 238000010438 heat treatment Methods 0.000 claims description 8
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 claims description 7
- 229910001416 lithium ion Inorganic materials 0.000 claims description 7
- 239000011148 porous material Substances 0.000 claims description 5
- 239000003054 catalyst Substances 0.000 abstract description 6
- 239000012535 impurity Substances 0.000 abstract description 3
- 230000000630 rising effect Effects 0.000 abstract 1
- 239000007789 gas Substances 0.000 description 41
- 230000000052 comparative effect Effects 0.000 description 28
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 18
- 238000012360 testing method Methods 0.000 description 18
- 230000003213 activating effect Effects 0.000 description 17
- 239000005543 nano-size silicon particle Substances 0.000 description 11
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 9
- 229910052757 nitrogen Inorganic materials 0.000 description 9
- 230000008569 process Effects 0.000 description 9
- 239000000243 solution Substances 0.000 description 9
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 8
- 229910052710 silicon Inorganic materials 0.000 description 8
- 239000010703 silicon Substances 0.000 description 8
- -1 water vapor activated graphite Chemical class 0.000 description 5
- HMDDXIMCDZRSNE-UHFFFAOYSA-N [C].[Si] Chemical compound [C].[Si] HMDDXIMCDZRSNE-UHFFFAOYSA-N 0.000 description 4
- 239000002994 raw material Substances 0.000 description 4
- 239000002904 solvent Substances 0.000 description 4
- 238000005054 agglomeration Methods 0.000 description 3
- 230000002776 aggregation Effects 0.000 description 3
- 239000010405 anode material Substances 0.000 description 3
- 239000011230 binding agent Substances 0.000 description 3
- 239000003792 electrolyte Substances 0.000 description 3
- 239000007773 negative electrode material Substances 0.000 description 3
- 239000000843 powder Substances 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- OIFBSDVPJOWBCH-UHFFFAOYSA-N Diethyl carbonate Chemical compound CCOC(=O)OCC OIFBSDVPJOWBCH-UHFFFAOYSA-N 0.000 description 2
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 2
- 239000005977 Ethylene Substances 0.000 description 2
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 2
- 239000004698 Polyethylene Substances 0.000 description 2
- 239000004743 Polypropylene Substances 0.000 description 2
- HSFWRNGVRCDJHI-UHFFFAOYSA-N alpha-acetylene Natural products C#C HSFWRNGVRCDJHI-UHFFFAOYSA-N 0.000 description 2
- 238000007600 charging Methods 0.000 description 2
- 239000002131 composite material Substances 0.000 description 2
- 239000006258 conductive agent Substances 0.000 description 2
- 238000010277 constant-current charging Methods 0.000 description 2
- 125000002534 ethynyl group Chemical group [H]C#C* 0.000 description 2
- 238000009830 intercalation Methods 0.000 description 2
- 230000002687 intercalation Effects 0.000 description 2
- 229910052744 lithium Inorganic materials 0.000 description 2
- 230000014759 maintenance of location Effects 0.000 description 2
- 229920000573 polyethylene Polymers 0.000 description 2
- 229920001155 polypropylene Polymers 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 229910001228 Li[Ni1/3Co1/3Mn1/3]O2 (NCM 111) Inorganic materials 0.000 description 1
- 239000013543 active substance Substances 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 229910021383 artificial graphite Inorganic materials 0.000 description 1
- 230000003139 buffering effect Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000010280 constant potential charging Methods 0.000 description 1
- 230000008602 contraction Effects 0.000 description 1
- 239000011889 copper foil Substances 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000009831 deintercalation Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000012153 distilled water Substances 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000007772 electrode material Substances 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 239000007770 graphite material Substances 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000011259 mixed solution Substances 0.000 description 1
- 238000007709 nanocrystallization Methods 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 239000007774 positive electrode material Substances 0.000 description 1
- 238000004537 pulping Methods 0.000 description 1
- 238000010298 pulverizing process Methods 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 239000000523 sample Substances 0.000 description 1
- 238000001878 scanning electron micrograph Methods 0.000 description 1
- 239000002210 silicon-based material Substances 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- 238000012795 verification Methods 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B33/00—Silicon; Compounds thereof
- C01B33/02—Silicon
- C01B33/021—Preparation
- C01B33/027—Preparation by decomposition or reduction of gaseous or vaporised silicon compounds other than silica or silica-containing material
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/15—Nano-sized carbon materials
- C01B32/182—Graphene
- C01B32/194—After-treatment
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B33/00—Silicon; Compounds thereof
- C01B33/02—Silicon
- C01B33/021—Preparation
-
- 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
- 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
-
- 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
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Inorganic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Nanotechnology (AREA)
- Manufacturing & Machinery (AREA)
- Carbon And Carbon Compounds (AREA)
Abstract
The invention discloses a preparation method of a silicon-carbon composite material, the silicon-carbon composite material and application thereof, wherein the operation steps at least comprise: s10), sequentially carrying out steam activation and carbon dioxide activation on graphite paper placed in an activation device to prepare a modified graphite paper material: s20), placing the modified graphite paper material obtained in the step S10) into a microwave reaction cavity, and sequentially introducing silane gas and carbon source gas into the microwave reaction cavity under the action of microwaves to obtain the silicon-carbon composite material; the preparation method has the advantages of high preparation efficiency, high temperature rising speed, no need of any catalyst, no negative influence on the battery performance caused by the introduction of impurities into the catalyst, and excellent performances of high specific capacity, low expansion, good cycle performance and the like of the applied battery.
Description
Technical Field
The invention belongs to the field of lithium ion battery material preparation, and particularly relates to a preparation method of a silicon-carbon composite material, and the silicon-carbon composite material prepared by the preparation method and application thereof.
Background
In recent years, silicon-carbon anode materials have been successfully applied to the fields of new energy automobiles and the like, and exhibit excellent energy density. However, because the conductivity of the silicon material is poor, and silicon is accompanied by huge volume change (up to 300%) in the lithium intercalation process, the volume of the material expands and contracts along with the intercalation and deintercalation of lithium ions, and the mechanical acting force generated by the expansion and contraction can cause the gradual pulverization of the material in the circulation process, so that the electrode material is separated from a current collector and loses electrical contact, and finally the circulation performance of the battery is greatly reduced.
Aiming at the problems of the silicon-carbon anode material, the current solution thinking comprises: the silicon is combined with a buffering base material mainly comprising graphite after nanocrystallization to inhibit volume expansion and improve electrical performance, but the method has the advantages of complex process, easy agglomeration of nano silicon and high preparation cost, and limits the application of the nano silicon. For example, patent application publication number CN111755682a discloses a silicon-carbon negative electrode material and a preparation method thereof, which is mainly prepared by nano silicon dry powder: the nano silicon agglomerates are added into an organic solvent, and after the nano silicon dry powder and carbon are uniformly stirred, the nano silicon dry powder is dried and carbonized to obtain the silicon-carbon negative electrode material, the preparation process is complex, the defects of self agglomeration, poor consistency and the like of the nano silicon are easily caused, and the obtained silicon-carbon composite material has lower specific capacity and larger expansion.
For this reason, based on the intensive research experience of the applicant in the field, a new technical solution is desired to solve the above technical problems.
Disclosure of Invention
In view of the above, the invention aims to provide a preparation method of a silicon-carbon composite material, the silicon-carbon composite material and application thereof, which have the advantages of high preparation efficiency, high heating speed, no need of any catalyst, no negative influence on battery performance caused by the introduction of impurities into the catalyst, and excellent performances of high specific capacity, low expansion, good cycle performance and the like of the applied battery.
The technical scheme adopted by the invention is as follows:
the preparation method of the silicon-carbon composite material at least comprises the following operation steps:
s10), sequentially carrying out steam activation and carbon dioxide activation on graphite paper placed in an activation device to prepare a modified graphite paper material:
s20), placing the modified graphite paper material obtained in the step S10) into a microwave reaction cavity, and sequentially introducing silane gas and carbon source gas into the microwave reaction cavity under the action of microwaves to obtain the silicon-carbon composite material.
Preferably, in the step S10), the water vapor activation includes: and introducing steam into the activation device, wherein the flow rate of the steam is not lower than 0.1kg/h, and/or the activation temperature is 250-600 ℃ and/or the activation time is not lower than 1 hour.
Preferably, in the step S10), the water vapor activation includes: and introducing steam into the activation device, wherein the steam flow rate is 0.1-1kg/h, and/or the activation temperature is 300-500 ℃ and/or the activation time is 1-3 hours.
Preferably, in the step S10), after the water vapor activation is finished, the introducing of the water vapor is stopped, and then the carbon dioxide activation is performed, and the carbon dioxide activation includes: and introducing carbon dioxide into the activation device, wherein the flow rate of introducing the carbon dioxide is not lower than 0.1kg/h, and the activation device is heated to not lower than 650 ℃ at a rate of not lower than 1 ℃/min and kept for not lower than 3 hours.
Preferably, in said step S10), the carbon dioxide is introduced at a flow rate of 0.1-0.5Kg/h, and said activation device is warmed up to 700-900 ℃ at a rate of 1-10 ℃/min and maintained for 3-6 hours.
Preferably, in the step S10), the porosity of the graphite paper is 20 to 80%, and/or the thickness of the graphite paper is 0.1 to 10mm, and/or the pore diameter of the graphite paper is 5 to 20nm.
Preferably, in the step S20), the microwave reaction chamber is vacuumized and then silane gas is introduced, the pressure in the microwave reaction chamber is kept at 0.5-1Mpa, and silane deposition is performed for at least 1 hour, preferably 1-6 hours after heating to not lower than 300 ℃; the silane gas is then stopped and the carbon source gas is introduced instead for amorphous carbon deposition for at least 1 hour, preferably 1 to 6 hours.
Preferably, in the step S20), the microwave power in the microwave reaction chamber is set to be 30-200W, preferably 50-100W; and/or the flow rate of the silane gas is not lower than 10ml/min, preferably 10-100ml/min; and/or the carbon source gas introduction flow rate is not less than 1m l/min, preferably 1-10ml/min.
Preferably, a silicon-carbon composite material is obtained by adopting the preparation method of the silicon-carbon composite material.
Preferably, the silicon-carbon composite material is used as an active material raw material for preparing a battery pole piece, preferably as an active material raw material for a lithium ion battery negative pole piece.
The application surprisingly finds that the modified graphite paper material with specific performance can be obtained by sequentially carrying out steam activation and carbon dioxide activation on the graphite paper, has specific excellent performances of strong carbon skeleton and proper pore diameter, avoids the problem of nano silicon agglomeration caused by deposition of excessive nano silicon on the surface of a matrix, and can obviously reduce expansion; meanwhile, compared with the traditional sanding method, the method has the advantages of high preparation efficiency, high heating speed and the like, and can reduce the rapid growth of nano silicon, further reduce the size of silicon grains and further reduce expansion; in addition, the preparation method provided by the application has low energy consumption, does not need to use any catalyst, and avoids negative influence on battery performance caused by introduction of impurities into the catalyst.
Drawings
FIG. 1 is a block diagram of steps for preparing a silicon-carbon composite material according to an embodiment of the present invention;
fig. 2 is an SEM image of the silicon carbon composite material prepared in example 1 of the present invention.
Detailed Description
Referring to fig. 1, the present embodiment provides a method for preparing a silicon-carbon composite material, which at least includes the following steps:
s10), sequentially carrying out steam activation and carbon dioxide activation on graphite paper placed in an activation device to prepare a modified graphite paper material; preferably, in this step S10), the porosity of the graphite paper is 20 to 80%, and/or the thickness of the graphite paper is 0.1 to 10mm, and/or the pore diameter of the graphite paper is 5 to 20nm;
preferably, in this step S10), the water vapor activation includes: introducing steam into the activation device, wherein the flow rate of the steam is not lower than 0.1kg/h, and/or the activation temperature is 250-600 ℃ and/or the activation time is not lower than 1 hour; more preferably, in this step S10), the water vapor activation includes: introducing steam into the activation device, wherein the flow rate of the steam is 0.1-1kg/h, and/or the activation temperature is 300-500 ℃ and/or the activation time is 1-3 hours;
preferably, in the present step S10), after the completion of the steam activation, the introduction of steam is stopped, and then the carbon dioxide activation is performed, the carbon dioxide activation including: introducing carbon dioxide into an activation device, wherein the flow rate of the introduced carbon dioxide is not lower than 0.1kg/h, and the activation device is heated to not lower than 650 ℃ at a rate of not lower than 1 ℃/min and kept for not lower than 3 hours; more preferably, in this step S10), the carbon dioxide is introduced at a flow rate of 0.1 to 0.5Kg/h, and the activation device is warmed up to 700 to 900 ℃ at a rate of 1 to 10 ℃/min and maintained for 3 to 6 hours.
S20), placing the modified graphite paper material obtained in the step S10) in a microwave reaction cavity, and sequentially introducing silane gas and carbon source gas (any known carbon source can be adopted in implementation, and the embodiment does not limit the carbon source) into the microwave reaction cavity under the action of microwaves to obtain a silicon-carbon composite material; preferably, in the step S20), the microwave reaction cavity is vacuumized and then silane gas is introduced, the pressure in the microwave reaction cavity is kept at 0.5-1Mpa, and silane deposition is carried out for at least 1 hour, preferably 1-6 hours after heating to not lower than 300 ℃; then stopping introducing the silane gas, and introducing the carbon source gas instead to perform amorphous carbon deposition for at least 1 hour, preferably 1-6 hours; more preferably, in the present step S20), in the step S20), the microwave power in the microwave reaction chamber is set to 30-200W, preferably 50-100W; and/or the flow rate of the silane gas is not lower than 10m l/min, preferably 10-100m l/min; and/or the carbon source gas inflow rate is not less than 1m l/min, preferably 1-10m l/min.
Preferably, the present embodiment provides a silicon-carbon composite material, which is obtained by adopting the preparation method of the silicon-carbon composite material as described in the present embodiment.
Preferably, the embodiment also provides an application of the silicon-carbon composite material, and the silicon-carbon composite material provided by the embodiment is used as an active material raw material for preparing a battery pole piece, preferably as an active material raw material for a lithium ion battery negative pole piece.
The specific application can be carried out according to practical needs by those skilled in the art, and the specific application method should belong to the conventional technical means of those skilled in the art, so the application mode of the embodiment is not particularly limited.
In order to make the technical solution of the present invention better understood by those skilled in the art, the technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings in 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 present invention without making any inventive effort, shall fall within the scope of the present invention.
On the basis of the embodiments described above, the present application further proposes the following specific examples:
example 1: this example 1 prepares a silicon carbon composite material according to the following procedure:
s10), sequentially carrying out steam activation and carbon dioxide activation on graphite paper placed in an activation device to prepare a modified graphite paper material, wherein the specific operation process is as follows:
placing graphite paper (the porosity of which is 50%, the thickness of which is 1mm, and the aperture of which is 10 nm) into an activating device, introducing nitrogen to discharge air in the activating device, then introducing water vapor into the activating device, and carrying out water vapor activation according to the conditions that the water vapor inlet flow is 0.5kg/h and the activation temperature is 400 ℃ for 2 hours to obtain water vapor activated graphite paper; stopping introducing the steam after the activation of the steam is finished, introducing carbon dioxide instead, and carrying out carbon dioxide activation for 4 hours under the condition that the carbon dioxide introducing flow is 0.2Kg/h and the activating device is heated to 800 ℃ at the speed of 5 ℃/min, and after the activation of the carbon dioxide is finished, introducing nitrogen into the activating device to cool to room temperature to obtain the modified graphite paper material.
S20), placing the modified graphite paper material obtained in the step S10) into a microwave reaction cavity, and sequentially introducing silane gas and carbon source gas into the microwave reaction cavity under the action of microwaves to obtain a silicon-carbon composite material; the specific operation process is as follows:
placing the modified graphite paper material in a microwave reaction cavity (the microwave power is set to be 80W), vacuumizing the microwave reaction cavity, introducing silane gas, maintaining the pressure in the microwave reaction cavity to be 0.75Mpa, heating to 400 ℃, and then carrying out silane deposition for 3 hours, wherein the flow rate of the silane gas is 50m l/min; and stopping introducing silane gas, and introducing methane gas instead to perform amorphous carbon deposition, wherein the flow rate of the methane gas is 5m l/min, and the amorphous carbon deposition time is 3 hours, so as to obtain the silicon-carbon composite material of the embodiment 1.
SEM (scanning electron microscope) morphology test is carried out on the silicon-carbon composite material obtained in the embodiment 1, the test result is shown in figure 2, and as can be seen from figure 2, the silicon-carbon composite material has a granular structure, the size distribution is uniform, and the particle size D50 is between 5 and 10 mu m.
Example 2: this example 2 prepares a silicon carbon composite material according to the following procedure:
s10), sequentially carrying out steam activation and carbon dioxide activation on graphite paper placed in an activation device to prepare a modified graphite paper material, wherein the specific operation process is as follows:
placing graphite paper (the porosity of which is 20%, the thickness of which is 0.1mm, and the aperture of which is 5 nm) into an activation device, introducing nitrogen to discharge air in the activation device, then introducing steam into the activation device, and performing steam activation according to the conditions that the steam inlet flow is 0.1kg/h and the activation temperature is 300 ℃ for 3 hours to obtain steam activated graphite paper; stopping introducing the steam after the activation of the steam is finished, introducing carbon dioxide instead, and carrying out carbon dioxide activation for 3 hours under the condition that the carbon dioxide introducing flow is 0.1Kg/h and the activating device is heated to 700 ℃ at the speed of 1 ℃/min, and introducing nitrogen into the activating device after the activation of the carbon dioxide is finished, so as to obtain the modified graphite paper material.
S20), placing the modified graphite paper material obtained in the step S10) into a microwave reaction cavity, and sequentially introducing silane gas and carbon source gas into the microwave reaction cavity under the action of microwaves to obtain a silicon-carbon composite material; the specific operation process is as follows:
placing the modified graphite paper material in a microwave reaction cavity (the microwave power is set to be 50W), vacuumizing the microwave reaction cavity, introducing silane gas, maintaining the pressure in the microwave reaction cavity to be 1Mpa, heating to 500 ℃, and then carrying out silane deposition for 1 hour, wherein the flow of the silane gas is 10m l/min; and stopping introducing silane gas, and introducing acetylene gas instead to perform amorphous carbon deposition, wherein the flow rate of the acetylene gas is 1m l/min, and the amorphous carbon deposition time is 6 hours, so as to obtain the silicon-carbon composite material of the embodiment 2.
Example 3: this example 3 prepares a silicon carbon composite material according to the following procedure:
s10), sequentially carrying out steam activation and carbon dioxide activation on graphite paper placed in an activation device to prepare a modified graphite paper material, wherein the specific operation process is as follows:
placing graphite paper (the porosity of which is 80%, the thickness of which is 10mm, and the aperture of which is 20 nm) into an activating device, introducing nitrogen to discharge air in the activating device, then introducing water vapor into the activating device, and carrying out water vapor activation according to the conditions that the water vapor inlet flow is 1kg/h and the activation temperature is 500 ℃ for 1 hour to obtain water vapor activated graphite paper; stopping introducing the steam after the activation of the steam is finished, introducing carbon dioxide instead, and carrying out carbon dioxide activation for 3 hours under the condition that the carbon dioxide introducing flow is 0.5Kg/h and the activating device is heated to 900 ℃ at the speed of 10 ℃/min, and introducing nitrogen into the activating device after the activation of the carbon dioxide is finished, so as to obtain the modified graphite paper material.
S20), placing the modified graphite paper material obtained in the step S10) into a microwave reaction cavity, and sequentially introducing silane gas and carbon source gas into the microwave reaction cavity under the action of microwaves to obtain a silicon-carbon composite material; the specific operation process is as follows:
placing the modified graphite paper material in a microwave reaction cavity (the microwave power is set to be 100W), vacuumizing the microwave reaction cavity, introducing silane gas, maintaining the pressure in the microwave reaction cavity to be 0.5Mpa, heating to 300 ℃, and then carrying out silane deposition for 6 hours, wherein the flow rate of the silane gas is 100m l/min; and then stopping introducing silane gas, and introducing ethylene gas instead to perform amorphous carbon deposition, wherein the ethylene gas inlet flow is 10m l/min, and the amorphous carbon deposition time is 1 hour, so as to obtain the silicon-carbon composite material of the embodiment 3.
Comparative example 1: the other technical schemes of the comparative example 1 are the same as those of the example 1, except that in the comparative example 1, the step S20) is omitted, the modified graphite paper obtained in the step S10) is transferred into a vacuum cavity, silane gas is introduced after the vacuum cavity is vacuumized, the flow rate of the silane gas is 50m l/min, and silane deposition is carried out for 3 hours after the silane gas is heated to 500 ℃; and stopping introducing silane gas, and introducing methane gas instead to perform amorphous carbon deposition, wherein the flow rate of the methane gas is 5m l/min, and the amorphous carbon deposition time is 3 hours, so as to obtain the silicon-carbon composite material of the comparative example 1.
Comparative example 2: the other technical aspects of this comparative example 2 are the same as those of example 1, except that in this comparative example 2, step S10) is eliminated and step S20) is directly performed; in this step S20), the modified graphite paper material obtained in step S10) was replaced with the graphite paper (porosity: 50%, thickness: 1mm, pore diameter: 10 nm) in step S10) of example 1.
Comparative example 3: the remaining technical solutions of this comparative example 3 are the same as those of example 1, except that the specific operation procedure of step S10) of this comparative example 3 is as follows:
and placing graphite paper (the porosity of the graphite paper is 50%, the thickness of the graphite paper is 1mm, the aperture of the graphite paper is 10 nm) in an activating device, introducing nitrogen to discharge air in the activating device, then introducing water vapor into the activating device, and carrying out water vapor activation according to the conditions that the water vapor inlet flow is 0.5kg/h and the activating temperature is 400 ℃, wherein the activating time is 2 hours, so as to obtain the modified graphite paper material.
Comparative example 4: the remaining technical solutions of this comparative example 4 are the same as those of example 1, except that the specific operation procedure of step S10) of this comparative example 4 is as follows:
and (3) placing graphite paper (the porosity of which is 50%, the thickness of which is 1mm, and the aperture of which is 10 nm) in an activation device, introducing nitrogen to discharge air in the activation device, then introducing carbon dioxide into the activation device, and performing carbon dioxide activation for 4 hours under the condition that the carbon dioxide introducing flow is 0.2Kg/h and the activation device is heated to 800 ℃ at the speed of 5 ℃/min, and after the carbon dioxide activation is finished, introducing nitrogen into the activation device to cool to room temperature to obtain the modified graphite paper material.
Comparative example 5: the other technical aspects of this comparative example 5 are the same as those of example 1, except that in this comparative example 5, step S10) is eliminated and step S20) is directly performed; in this step S20), the porous graphite material used in example 1 of the prior publication CN115172723a was used instead of the modified graphite paper material obtained in step S10).
Comparative example 6: the other technical aspects of this comparative example 6 are the same as those of example 1, except that in this comparative example 6, step S10) is eliminated and step S20) is directly performed; in this step S20), the modified graphite paper material obtained in step S10) was replaced with the modified graphite paper used in example 1 of the prior-published patent CN112194121 a.
To perform effect comparison verification on the above examples and comparative examples, the present application performed the following physicochemical tests on the silicon carbon composite materials obtained in the above examples 1 to 3 and comparative examples 1 to 6:
1) Button cell test:
the silicon-carbon composite materials obtained in the examples 1-3 and the comparative examples 1-6 are respectively and correspondingly prepared as active substances of battery negative electrode plates to be assembled into 9 button batteries, and the button batteries are marked as A1, A2, A3, B1, B2, B3, B4, B5 and B6 in sequence; the specific preparation process of each button cell comprises the following steps:
preparing a battery negative electrode plate: respectively adding a binder, a conductive agent and a solvent into each silicon-carbon composite material (serving as an active material of a battery negative electrode plate) corresponding to examples 1-3 and comparative examples 1-6, stirring and pulping, coating the materials on a copper foil, and drying and rolling the materials to obtain each battery negative electrode plate; wherein, the binder adopts LA136D binder, the conductive agent adopts SP (conductive carbon black), the solvent is secondary distilled water, the proportion is: silicon-carbon composite material: SP: LA136D: redistilled water = 95g:1g:4g:220 ml;
preparing a button cell: the electrolyte adopts Li PF 6 Solution in which Li PF 6 The concentration of (2) is 1.2 mol/L, and the weight ratio of the solvent is 1:1 and diethyl carbonate (DMC); adopts a metal lithium sheet as a counter electrode, adopts a Polyethylene (PE), polypropylene (PP) or polyethylene propylene (PEP) composite film as a diaphragm, and is used for simulating the assembly of a battery in a glove box filled with argon,the electrochemical performance is carried out on a Wuhan blue electric Xinwei 5V/10mA battery tester, and the test conditions are as follows: the charge-discharge voltage ranges from 0.005V to 2.0V, and the charge-discharge rate is 0.1C; the test results are shown in table 1 below.
2) The specific surface area test is carried out on each silicon-carbon composite material obtained in the examples 1-3 and the comparative examples 1-6 according to the method in the national standard GB/T24533-2019 lithium ion battery graphite anode material, and simultaneously the silicon grain size and O I value in each silicon-carbon composite material are tested through XRD, wherein EDS is adopted for element component analysis, and a four-probe tester is adopted for testing the conductivity of each silicon-carbon composite material; the test results are shown in table 1 below.
TABLE 1
As can be seen from table 1 above, the button cells prepared by using the silicon-carbon composite materials provided in examples 1 to 3 of the present application are significantly superior to comparative examples 1 to 6 in both discharge capacity and efficiency; the experimental result shows that the silicon-carbon composite material (serving as the active material of the negative electrode plate of the battery) can enable the lithium ion battery applied by the silicon-carbon composite material to have obviously excellent discharge capacity and efficiency performance; the reason for this is mainly that the silicon-carbon composite material provided in this embodiment can effectively reduce the rapid growth of nano silicon, reduce the size of silicon grains, reduce the expansion of silicon grains, and simultaneously has excellent characteristics such as low impedance and low O I value.
3) Soft package battery test:
each of the silicon-carbon composite materials obtained in examples 1 to 3 and comparative examples 1 to 6 was respectively doped with 90% of artificial graphite as a negative electrode material, and a ternary material NCM111 as a positive electrode material, an electrolyte and a separator were assembled into a 5Ah soft-pack battery; wherein, the diaphragm of the soft package battery is Ce l egard 2400, and the electrolyte is Li PF 6 Solution in which Li PF 6 The solvent of the solution is a mixed solution of EC and DEC with the volume ratio of 1:1, and Li PF 6 Is 1.3 mol/L; each of examples 1 to 3 and comparative examples 1 to 6 corresponds to silicon carbonEach soft package battery prepared from the composite material is respectively marked as C1, C2, C3, D1, D2, D3, D4, D5 and D6 and corresponding battery negative pole pieces, and the full-charge rebound of each negative pole piece and the cycle performance of each soft package battery are tested by the specific test method as follows:
3.1, full-charge rebound test (full-charge rebound rate of pole piece) is carried out on the negative pole piece of each battery: dissecting each soft package battery after volume fixing, adopting a micrometer to measure the thickness D1 of the negative pole piece, fully charging the corresponding soft package battery, dissecting the negative pole piece again, adopting the micrometer to measure the thickness D2 of the full-electrode negative pole piece again, and calculating
The test results are shown in Table 2 below.
3.2 each pouch cell was subjected to a cycle test (500 capacity retention): the test conditions were set as follows: the voltage range is 2.5-4.2V, the charge and discharge is 1C/1C, and the cycle is 500 times; the test results are shown in Table 2 below.
3.3 multiplying power test (2C constant current ratio) was performed on each soft pack battery: fully charging each soft package battery with the multiplying power of 2C, and testing the ratio of the constant current charging capacity to the constant current and constant voltage charging capacity; the test results are shown in Table 2 below.
TABLE 2
As can be seen from table 2 above, the capacity and the capacity retention rate of the soft-pack battery manufactured by adopting the silicon-carbon composite materials provided in examples 1 to 3 of the present application after multiple cycles are significantly higher than those of comparative examples 1 to 6, mainly because: the silicon-carbon composite material provided by the embodiment of the application has the excellent characteristics that the silicon crystal grains are small and the expansion can be reduced, and the silicon-carbon composite material provided by the embodiment of the application has high electronic conductivity, so that the constant current ratio performance of an applied battery is obviously improved, and meanwhile, the silicon-carbon composite material provided by the embodiment of the application has low OI value, further proves that the silicon-carbon composite material has good dynamics performance and structural stability, and further obviously improves the cycle performance of the applied battery.
It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.
Furthermore, it should be understood that although the present disclosure describes embodiments, not every embodiment is provided with a separate embodiment, and that this description is provided for clarity only, and that the disclosure is not limited to the embodiments described in detail below, and that the embodiments described in the examples may be combined as appropriate to form other embodiments that will be apparent to those skilled in the art.
Claims (10)
1. The preparation method of the silicon-carbon composite material is characterized by comprising the following operation steps:
s10), sequentially carrying out steam activation and carbon dioxide activation on graphite paper placed in an activation device to prepare a modified graphite paper material:
s20), placing the modified graphite paper material obtained in the step S10) into a microwave reaction cavity, and sequentially introducing silane gas and carbon source gas into the microwave reaction cavity under the action of microwaves to obtain the silicon-carbon composite material.
2. The method of producing a silicon-carbon composite according to claim 1, wherein in the step S10), the water vapor activation includes: and introducing steam into the activation device, wherein the flow rate of the steam is not lower than 0.1kg/h, and/or the activation temperature is 250-600 ℃ and/or the activation time is not lower than 1 hour.
3. The method of producing a silicon-carbon composite according to claim 2, wherein in the step S10), the water vapor activation includes: and introducing steam into the activation device, wherein the steam flow rate is 0.1-1kg/h, and/or the activation temperature is 300-500 ℃ and/or the activation time is 1-3 hours.
4. The method according to claim 1, wherein in the step S10), the steam is stopped after the steam activation, and then the carbon dioxide activation is performed, and the carbon dioxide activation includes: and introducing carbon dioxide into the activation device, wherein the flow rate of introducing the carbon dioxide is not lower than 0.1kg/h, and the activation device is heated to not lower than 650 ℃ at a speed of not lower than 1 ℃/min and kept for not lower than 3 hours.
5. The method according to claim 4, wherein in the step S10), the carbon dioxide is introduced at a flow rate of 0.1 to 0.5Kg/h, and the activation device is heated to 700 to 900 ℃ at a rate of 1 to 10 ℃/min and maintained for 3 to 6 hours.
6. The method of producing a silicon-carbon composite material according to claim 1, wherein in the step S10), the porosity of the graphite paper is 20 to 80%, and/or the thickness of the graphite paper is 0.1 to 10mm, and/or the pore diameter of the graphite paper is 5 to 20nm.
7. The method according to claim 1, wherein in the step S20), the silane gas is introduced after the microwave reaction chamber is vacuumized, the pressure in the microwave reaction chamber is kept at 0.5-1Mpa, and the silane deposition is performed for at least 1 hour, preferably 1-6 hours after heating to 300 ℃; the silane gas is then stopped and the carbon source gas is introduced instead for amorphous carbon deposition for at least 1 hour, preferably 1 to 6 hours.
8. The method of producing a silicon-carbon composite material according to claim 7, wherein in the step S20), the microwave power in the microwave reaction chamber is set to 30-200W, preferably 50-100W; and/or the flow rate of the silane gas is not lower than 10ml/min, preferably 10-100ml/min; and/or the carbon source gas introduction flow rate is not less than 1ml/min, preferably 1-10ml/min.
9. A silicon-carbon composite material, characterized in that it is obtained by a method for preparing a silicon-carbon composite material according to any one of claims 1 to 8.
10. Use of a silicon-carbon composite according to claim 9, as active material for the preparation of battery pole pieces, preferably as active material for lithium ion battery negative pole pieces.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310232493.0A CN116314734A (en) | 2023-03-10 | 2023-03-10 | Preparation method of silicon-carbon composite material, silicon-carbon composite material and application of silicon-carbon composite material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310232493.0A CN116314734A (en) | 2023-03-10 | 2023-03-10 | Preparation method of silicon-carbon composite material, silicon-carbon composite material and application of silicon-carbon composite material |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116314734A true CN116314734A (en) | 2023-06-23 |
Family
ID=86812683
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310232493.0A Pending CN116314734A (en) | 2023-03-10 | 2023-03-10 | Preparation method of silicon-carbon composite material, silicon-carbon composite material and application of silicon-carbon composite material |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116314734A (en) |
-
2023
- 2023-03-10 CN CN202310232493.0A patent/CN116314734A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111470486B (en) | Three-dimensional silicon-carbon composite negative electrode material, preparation method thereof and application thereof in lithium ion battery | |
| CN109119592B (en) | Lithium titanate negative electrode piece, preparation method and lithium titanate battery | |
| CN112133896B (en) | High-capacity graphite-silicon oxide composite material and preparation method and application thereof | |
| CN108899522B (en) | High-capacity silicon-carbon negative electrode material, preparation method and application | |
| CN113401897B (en) | Preparation method of black phosphorus-based graphite composite lithium ion battery negative electrode material | |
| CN115566170B (en) | Preparation method of high-energy-density quick-charging lithium ion battery anode material | |
| CN114552125B (en) | Nondestructive lithium supplement composite diaphragm and preparation method and application thereof | |
| CN112751075A (en) | Lithium ion battery and preparation method thereof | |
| CN113540416A (en) | Solid electrolyte coated graphite composite material, preparation method and application thereof, and lithium ion battery | |
| CN108172744B (en) | Sb for lithium-sulfur battery diaphragm2Se3Method for preparing composite material | |
| CN106099066A (en) | A kind of germanium dioxide/graphene composite material and preparation method thereof | |
| CN112017870A (en) | Coal-based porous carbon, preparation method and application thereof, and lithium ion capacitor | |
| CN114300671B (en) | Graphite composite negative electrode material and preparation method and application thereof | |
| CN114122329A (en) | Negative plate and lithium ion battery comprising same | |
| CN114497508A (en) | Power type artificial graphite composite material and preparation method thereof | |
| CN109921098B (en) | Preparation method of water system super nano lithium iron phosphate battery | |
| CN115020682B (en) | Preparation method of high-energy-density quick-charging graphite cathode material | |
| CN108565431B (en) | Method for preparing silicon-carbon composite negative electrode material of lithium ion battery by taking konjac flour as carbon source | |
| CN116387447A (en) | Lithium ion battery fast-charge negative plate, electrochemical device and electronic device | |
| CN115566167A (en) | Silicon-based composite material prepared by gaseous atomization method and preparation method | |
| CN115207304A (en) | Graphite cathode composite material, preparation method thereof and lithium ion battery | |
| CN109560280B (en) | Nano tin-molybdenum disulfide compound anode material and preparation method and application thereof | |
| CN114122360A (en) | High-energy-density quick-charging composite negative electrode material and preparation method thereof | |
| CN116314734A (en) | Preparation method of silicon-carbon composite material, silicon-carbon composite material and application of silicon-carbon composite material | |
| CN109860527B (en) | Carbon-based composite material for preparing lithium battery cathode and preparation method thereof |
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 |