CN110416523B - Si-O-C composite material, preparation method thereof and silicon-carbon composite material - Google Patents
Si-O-C composite material, preparation method thereof and silicon-carbon composite material Download PDFInfo
- Publication number
- CN110416523B CN110416523B CN201910715571.6A CN201910715571A CN110416523B CN 110416523 B CN110416523 B CN 110416523B CN 201910715571 A CN201910715571 A CN 201910715571A CN 110416523 B CN110416523 B CN 110416523B
- Authority
- CN
- China
- Prior art keywords
- composite material
- sintering
- polymerization reaction
- siloxane
- silane
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 239000002131 composite material Substances 0.000 title claims abstract description 82
- 239000002153 silicon-carbon composite material Substances 0.000 title claims abstract description 23
- 238000002360 preparation method Methods 0.000 title abstract description 7
- 238000005245 sintering Methods 0.000 claims abstract description 50
- 238000010438 heat treatment Methods 0.000 claims abstract description 35
- 238000006116 polymerization reaction Methods 0.000 claims abstract description 35
- BLRPTPMANUNPDV-UHFFFAOYSA-N Silane Chemical compound [SiH4] BLRPTPMANUNPDV-UHFFFAOYSA-N 0.000 claims abstract description 29
- 229910000077 silane Inorganic materials 0.000 claims abstract description 29
- 239000003054 catalyst Substances 0.000 claims abstract description 28
- KPUWHANPEXNPJT-UHFFFAOYSA-N disiloxane Chemical class [SiH3]O[SiH3] KPUWHANPEXNPJT-UHFFFAOYSA-N 0.000 claims abstract description 28
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 26
- 239000010439 graphite Substances 0.000 claims abstract description 24
- 229910002804 graphite Inorganic materials 0.000 claims abstract description 24
- 238000000034 method Methods 0.000 claims abstract description 24
- 238000004321 preservation Methods 0.000 claims abstract description 8
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 14
- 238000003756 stirring Methods 0.000 claims description 13
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 12
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 10
- 239000003795 chemical substances by application Substances 0.000 claims description 9
- 238000005406 washing Methods 0.000 claims description 9
- 239000007789 gas Substances 0.000 claims description 7
- 230000001681 protective effect Effects 0.000 claims description 7
- 229910052710 silicon Inorganic materials 0.000 claims description 7
- KAKZBPTYRLMSJV-UHFFFAOYSA-N Butadiene Chemical group C=CC=C KAKZBPTYRLMSJV-UHFFFAOYSA-N 0.000 claims description 6
- -1 dimethyl siloxane Chemical class 0.000 claims description 6
- 229910052757 nitrogen Inorganic materials 0.000 claims description 6
- BFGYAHCDCHCGHV-UHFFFAOYSA-N dichloro-hexadecyl-methylsilane Chemical compound CCCCCCCCCCCCCCCC[Si](C)(Cl)Cl BFGYAHCDCHCGHV-UHFFFAOYSA-N 0.000 claims description 5
- 229910052799 carbon Inorganic materials 0.000 claims description 4
- QOHMWDJIBGVPIF-UHFFFAOYSA-N n',n'-diethylpropane-1,3-diamine Chemical compound CCN(CC)CCCN QOHMWDJIBGVPIF-UHFFFAOYSA-N 0.000 claims description 4
- YTJSFYQNRXLOIC-UHFFFAOYSA-N octadecylsilane Chemical compound CCCCCCCCCCCCCCCCCC[SiH3] YTJSFYQNRXLOIC-UHFFFAOYSA-N 0.000 claims description 4
- 229910052760 oxygen Inorganic materials 0.000 claims description 4
- 239000000376 reactant Substances 0.000 claims description 4
- 239000002994 raw material Substances 0.000 claims description 3
- 230000000379 polymerizing effect Effects 0.000 claims description 2
- 238000004519 manufacturing process Methods 0.000 claims 6
- 239000000047 product Substances 0.000 abstract description 33
- 230000008569 process Effects 0.000 abstract description 12
- 230000014759 maintenance of location Effects 0.000 abstract description 11
- 230000009286 beneficial effect Effects 0.000 abstract description 5
- 238000011031 large-scale manufacturing process Methods 0.000 abstract description 5
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 abstract description 4
- 239000006227 byproduct Substances 0.000 abstract description 4
- 238000013329 compounding Methods 0.000 abstract description 4
- 229910001416 lithium ion Inorganic materials 0.000 abstract description 4
- 239000002954 polymerization reaction product Substances 0.000 description 8
- 238000007873 sieving Methods 0.000 description 8
- 238000006243 chemical reaction Methods 0.000 description 7
- 238000001816 cooling Methods 0.000 description 5
- 238000002156 mixing Methods 0.000 description 5
- 239000000203 mixture Substances 0.000 description 5
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 4
- 239000008367 deionised water Substances 0.000 description 4
- 229910021641 deionized water Inorganic materials 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 239000010703 silicon Substances 0.000 description 4
- 238000012360 testing method Methods 0.000 description 4
- 230000008859 change Effects 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 2
- 230000003197 catalytic effect Effects 0.000 description 2
- 230000022131 cell cycle Effects 0.000 description 2
- 238000004132 cross linking Methods 0.000 description 2
- 230000001351 cycling effect Effects 0.000 description 2
- 238000001198 high resolution scanning electron microscopy Methods 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 229910052744 lithium Inorganic materials 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 239000007773 negative electrode material Substances 0.000 description 2
- 238000007086 side reaction Methods 0.000 description 2
- 239000011856 silicon-based particle Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- RPNUMPOLZDHAAY-UHFFFAOYSA-N Diethylenetriamine Chemical compound NCCNCCN RPNUMPOLZDHAAY-UHFFFAOYSA-N 0.000 description 1
- HMDDXIMCDZRSNE-UHFFFAOYSA-N [C].[Si] Chemical compound [C].[Si] HMDDXIMCDZRSNE-UHFFFAOYSA-N 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 239000013543 active substance Substances 0.000 description 1
- 238000005054 agglomeration Methods 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 239000003575 carbonaceous material Substances 0.000 description 1
- 239000010406 cathode material Substances 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000009831 deintercalation Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 239000012153 distilled water Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000002149 energy-dispersive X-ray emission spectroscopy Methods 0.000 description 1
- 229910021385 hard carbon Inorganic materials 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000009830 intercalation Methods 0.000 description 1
- 230000002687 intercalation Effects 0.000 description 1
- 239000011229 interlayer Substances 0.000 description 1
- 230000001788 irregular Effects 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 239000007774 positive electrode material Substances 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 230000002441 reversible effect Effects 0.000 description 1
- 238000001878 scanning electron micrograph Methods 0.000 description 1
- 150000004756 silanes Chemical class 0.000 description 1
- 239000002210 silicon-based material Substances 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- 229910021642 ultra pure water Inorganic materials 0.000 description 1
- 239000012498 ultrapure water Substances 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
-
- 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
- H01M4/62—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
- 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)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Composite Materials (AREA)
- Battery Electrode And Active Subsutance (AREA)
- Silicon Polymers (AREA)
Abstract
The application discloses a Si-O-C composite material, a preparation method thereof and a silicon-carbon composite material, and relates to the technical field of lithium ion batteries. The preparation method comprises the following steps: and (3) carrying out polymerization reaction on silane and/or siloxane in the presence of a catalyst, heating the product of the polymerization reaction to 550-650 ℃ at a preset heating rate under the condition of 250-350 ℃, and carrying out heat preservation and sintering for 2-4h. The application can effectively inhibit byproducts generated in the sintering process on the premise of ensuring the complete sintering, is more beneficial to large-scale production and reduces the cost, the obtained Si-O-C composite material has excellent cycle performance, the capacity retention rate of 98.2% in 10 weeks and the efficiency of over 99% in 6 weeks, and the silicon-carbon composite material formed by compounding the Si-O-C composite material and graphite has excellent cycle performance, and the capacity retention rate is about 91.6% after 300 weeks of cycle.
Description
Technical Field
The invention relates to the technical field of lithium ion batteries, in particular to a Si-O-C composite material, a preparation method thereof and a silicon-carbon composite material.
Background
The lithium ion battery is widely applied to the 3C and power aspects, the requirement on energy density is higher and higher, and the development of positive and negative electrode materials of the lithium battery is important, in particular to a silicon-carbon composite material. In the silicon-carbon composite material in the prior art, the simple substance silicon expands in volume in the circulation process, the circulation stability is poor, and the reversible circulation capacity retention rate is low.
In view of this, the present invention has been made.
Disclosure of Invention
The invention aims to provide a Si-O-C composite material and a preparation method thereof, and the Si-O-C composite material obtained by the preparation method has good cycling stability and good cycling capacity retention rate.
Another object of the present invention is to provide a silicon-carbon composite material with good cycle performance.
The invention is realized in the following way:
in a first aspect, an embodiment of the present invention provides a method for preparing a si—o—c composite material, including:
polymerizing silane and/or siloxane in the presence of a catalyst;
Heating the polymerization reaction product to 550-650 ℃ at a preset heating rate under the condition of 250-350 ℃, and carrying out heat preservation and sintering for 2-4h;
Preferably, the molar ratio between Si, O and C in the Si-O-C composite is 1: (0.90-0.12): (2.5-3);
Preferably, the Si-O-C composite material is SiO 0.96C2.7;
preferably, the Si-O-C composite is amorphous.
In an alternative embodiment, the preset heating rate is 15-25 ℃/h.
In an alternative embodiment, the sintering equipment is preheated to a temperature of 250-350 ℃ and then the product of the polymerization reaction is added;
Preferably, the air in the sintering equipment is replaced with a protective gas before the sintering equipment is warmed up;
Preferably, the protective gas is nitrogen;
preferably, the sintering equipment is a tube furnace.
In alternative embodiments, the catalyst is one or more of Ph 3 SiCl and Pd 3O4;
the silane in the silane and/or the siloxane comprises one or more of octadecylsilane and hexadecyl methyl dichloro silane, and the siloxane in the silane and/or the siloxane is dimethyl siloxane;
Preferably, the silane and/or siloxane and the catalyst are used in a ratio of 1: (0.05-0.08);
Preferably, the polymerization is carried out in the presence of a curing agent;
Preferably, the curing agent is one or more of divinyl triamine and diethylaminopropylamine;
in an alternative embodiment, the silane and/or siloxane is heated to 150-300 ℃ with stirring prior to mixing the silane and/or siloxane with the catalyst, and after addition of the catalyst, is heated to 320-350 ℃ at a heating rate of 8-12 ℃/h.
In an alternative embodiment, the method further comprises washing the product of the polymerization reaction with an ethanol solution and water sequentially before sintering the product of the polymerization reaction.
In an alternative embodiment, the product is crushed and sieved through a 280-320 mesh sieve.
In a second aspect, an embodiment of the present invention provides a Si-O-C composite material, which is prepared by using the method for preparing a Si-O-C composite material according to any one of the foregoing embodiments.
In a third aspect, an embodiment of the present invention provides a silicon-carbon composite material, where the raw materials include graphite and a Si-O-C composite material prepared by a method for preparing a Si-O-C composite material according to any one of the foregoing embodiments, or a Si-O-C composite material according to the foregoing embodiments.
In an alternative embodiment, the mass ratio of the graphite to the Si-O-C composite is (2-3): 5-6;
preferably, the graphite is nano-layered graphite.
The invention has the following beneficial effects:
In the present application, a silane and/or a siloxane are polymerized in the presence of a catalyst; and sintering the product obtained by the polymerization reaction to obtain the Si-O-C composite material, wherein the sintering parameters are controlled to enable the product of the polymerization reaction to directly start to react at the temperature of 250-350 ℃, and finally the product is subjected to heat preservation and sintering at the sintering temperature of 550-650 ℃, so that the by-product generated in the sintering process can be effectively inhibited on the premise of ensuring the complete sintering, the large-scale production is facilitated, the cost is reduced, the obtained Si-O-C composite material has excellent cycle performance, the 10-week capacity retention rate is 98.2%, the 6-week efficiency is more than 99%, the cycle performance of the silicon-carbon composite material formed by compounding the Si-O-C composite material and graphite is also excellent, and the capacity retention rate is about 91.6% after 300 weeks of cycle.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is an SEM image of a Si-O-C composite material provided in example 1 of the present application;
FIG. 2 is an HRSEM image of a Si-O-C composite material provided in example 1 of the present application;
Fig. 3 is a graph of the full cell cycle life of the silicon carbon composite provided in example 1 of the present application.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below. The specific conditions are not noted in the examples and are carried out according to conventional conditions or conditions recommended by the manufacturer. The reagents or apparatus used were conventional products commercially available without the manufacturer's attention.
The application provides a Si-O-C composite material, which is prepared by the following steps:
s1, carrying out polymerization reaction on silane and/or siloxane in the presence of a catalyst.
Specifically, silane and/or siloxane are placed in a stirrer, the temperature is raised to be 150-300 ℃ by stirring, after a catalyst is added, the temperature is raised to be 320-350 ℃ at the heating rate of 8-12 ℃/h, and the stirring and the heat preservation are continued for 2-3 hours to carry out polymerization reaction, so that a polymerization reaction product is obtained. The polymerization product was then washed with ethanol solution and water in this order.
The curing and crosslinking reaction is carried out by using silane and/or siloxane with crosslinkable groups (i.e. one or a mixture of both of the silane and the siloxane) and a catalyst and an optional curing agent under heating. By preheating the silane and/or siloxane, the silane and/or siloxane can be more easily cured and crosslinked with the catalyst. Specifically, the usage ratio of silane and/or siloxane to catalyst is 1: (0.05-0.08); wherein the silane in the silane and/or the siloxane comprises one or more of octadecylsilane and hexadecyl methyl dichloro silane, and the siloxane in the silane and/or the siloxane is dimethyl siloxane; the catalyst is one or more of Ph 3 SiCl and Pd 3O4. When the reactant of the application selects silane, the catalyst can be Pd 3O4; when the reactants of the present application are selected from siloxanes, the catalyst may be Ph 3 SiCl or Pd 3O4. Optionally, a curing agent may be added during the reaction, and in the present application, the curing agent may be one or more of diethylenetriamine and diethylaminopropylamine.
In the application, silane and/or siloxane are preheated to 150-300 ℃ and then are more easily reacted with a catalyst, then are heated to 320-350 ℃ at the heating speed of 8-12 ℃/h, and are continuously stirred and kept for 2-3h, so that the silane and/or siloxane can be fully crosslinked and cured under the action of the catalyst. While limiting the catalytic systems of the present application to Ph 3 SiCl and Pd 3O4, the specific catalytic system is one that is capable of producing amorphous materials from silanes and/or siloxanes.
The ethanol solution and water are used for washing the products of the polymerization reaction, so that impurities on the surfaces of the products of the polymerization reaction can be removed, and the impurity content of the products of the polymerization reaction is reduced. It should be understood that the water described in the present application includes, but is not limited to, deionized water, ultrapure water, distilled water, and the like.
S2, heating the polymerization reaction product to 550-650 ℃ at a preset heating rate under the condition of 250-350 ℃, and preserving heat and sintering for 2-4h.
In the application, the product of the polymerization reaction is sintered into an amorphous Si-O-C product, specifically, before the washed product of the polymerization reaction is placed in sintering equipment, protective gas is introduced into the sintering equipment to replace the protective gas with air, after the replacement is finished, the sintering equipment is heated to 250-350 ℃, then the product of the polymerization reaction is added, the temperature is heated to 550-650 ℃ at a preset heating speed, the temperature is kept for sintering for 2-4 hours, after the sintering is finished, the temperature is reduced, the Si-O-C product is taken out, and then the Si-O-C product is crushed and then is sieved by a 280-320-mesh sieve.
In the application, the molar ratio of Si, O and C in the Si-O-C composite material is 1: (0.90-0.12): (2.5-3); preferably, the Si-O-C composite material is SiO 0.96C2.7; preferably, the Si-O-C composite is amorphous. The amorphous material has the characteristics of short-range disorder and long-range order, so that the amorphous material has no grain boundary and grain boundary, uniform texture, isotropy in mechanical, electrical, thermal and other properties when no internal stress or defect exists, and is beneficial to reducing the difference of performances.
The inventor researches that the product of the polymerization reaction is added when the sintering equipment is not preheated, and the product of the polymerization reaction is heated together with the temperature of the sintering equipment, so that side reactions are easy to generate in the process. Therefore, in the application, the sintering equipment is preheated in advance, so that the sintering equipment is heated to 250-350 ℃, and then the product of the polymerization reaction is added, at the moment, the product of the polymerization reaction can directly react at 250-350 ℃, and side reactions in the heating process are effectively avoided.
The preset heating rate in the application is 15-25 ℃/h, the specific heating rate can ensure that the sintering equipment is quickly heated to the sintering temperature, and the sintering temperature in the embodiment is 550-650 ℃, and the sintering temperature is lower, so that the products of the polymerization reaction react at low temperature, thereby being more beneficial to large-scale production and reducing the cost.
Preferably, a typical but non-limiting example of the sintering equipment in the present application is a tube furnace, and a typical but non-limiting example of the protective gas in the present application is nitrogen.
In the application, silane and/or siloxane are mixed with a catalyst under heating condition to carry out curing crosslinking reaction, and the product of the polymerization reaction is sintered to obtain the Si-O-C composite material, and the sintering parameters are controlled in the sintering process, so that the product of the polymerization reaction directly starts to react at 250-350 ℃, and finally is subjected to heat preservation and sintering at the sintering temperature of 550-650 ℃, and byproducts generated in the sintering process can be effectively inhibited on the premise of ensuring the sintering is complete, and the method is more beneficial to large-scale production and reduces the cost.
In addition, the application also provides a silicon-carbon composite material, the raw materials of which comprise graphite and the Si-O-C composite material, and the silicon-carbon composite material can be obtained by mixing and stirring the graphite and the Si-O-C composite material and sieving the mixture with a 180-220-mesh sieve. Specifically, the dosage ratio of the graphite to the silicon-carbon composite material is (2-3) to (5-6). Preferably, the graphite is nano-layered graphite with D50 of 10um and a layered structure of particles.
According to the application, the nano layered graphite is compounded with the Si-O-C composite material, so that the internal stress of the Si-O-C composite material is increased, and Si particles are used as active substances in the Si-C composite material to provide lithium storage capacity; the nano lamellar graphite can buffer the volume change of the silicon cathode in the charge-discharge process, improve the conductivity of the Si material, avoid agglomeration of Si particles in the charge-discharge cycle, reduce the interlayer spacing change during lithium ion intercalation and deintercalation, and further relieve and inhibit the silicon volume change in the cycle process. Under the condition of higher capacity than the traditional graphite cathode material, the excellent charge and discharge cycle times are maintained, and the service life of the traditional silicon-carbon material is improved.
According to the application, the Si-O-C sample with amorphous characteristics is prepared by chemical synthesis means, and the surface structure is compact and smooth and has random morphology. The capacity of the Si-O-C composite material reaches 900mAh/g, and after the Si-O-C composite material is compounded with graphite, the capacity retention rate is 91.6% at 300 weeks under the condition of 1C multiplying power charge and discharge.
The features and capabilities of the present invention are described in further detail below in connection with the examples.
Example 1
The application provides a Si-O-C composite material, which is prepared by the following steps:
150g of hexadecyl methyl dichlorosilane and 150g of dimethyl siloxane are placed in a stirrer, the temperature is raised to 175 ℃ at the heating rate of 10 ℃/h, catalyst Ph 3 SiCl is added dropwise at the speed of 3 drops per minute, 15 g of catalyst is added dropwise, the temperature is raised to 300 ℃ at the heating rate of 10 ℃/h, the stirring and the heat preservation are carried out for 3 hours, the polymerization reaction is carried out, and after the temperature is lowered, the ethanol solution is used for washing, and then deionized water is used for full washing.
Introducing nitrogen into the tubular furnace for replacement, heating the tubular furnace to 300 ℃, adding a polymerization reaction product, heating to 580 ℃ at a heating rate of 20 ℃/h, preserving heat for 3 hours, reacting, and cooling. And taking out the product, crushing and sieving with a 300-mesh sieve to obtain the amorphous Si-O-C composite material.
Example 2
The application provides a Si-O-C composite material, which is prepared by the following steps:
500 g of octadecylsilane are heated in a stirrer while stirring, the temperature is raised to 210 ℃,10 g of catalyst Pd 3O4 and 15g of curing agent divinyl triamine are added, the temperature is raised to 320 ℃ at the heating rate of 8 ℃/h, the temperature is kept, and stirring is continued for 2 hours, so that the reaction is completed. And after cooling, washing with ethanol solution, and then fully washing with deionized water.
Introducing nitrogen into the tubular furnace for replacement, heating the tubular furnace to 280 ℃, adding a polymerization reaction product, heating to 600 ℃ at a heating rate of 20 ℃/h, preserving heat for 2 hours, and cooling. And taking out the product, crushing and sieving with a 280-mesh sieve to obtain the amorphous Si-O-C composite material.
Example 3
The application provides a Si-O-C composite material, which is prepared by the following steps:
300 g of hexadecyl methyl dichlorosilane is heated in a stirrer while stirring, the temperature is raised to 300 ℃, 18g of catalyst Pd 3O4 and 16g of curing agent diethylaminopropylamine are added, the temperature is raised to 350 ℃ at the heating rate of 12 ℃/h, the temperature is kept, and the stirring is continued for 2 hours, and the reaction is completed. And after cooling, washing with ethanol solution, and then fully washing with deionized water.
Introducing nitrogen into the tubular furnace for replacement, heating the tubular furnace to 300 ℃, adding the product of the polymerization reaction, heating to 800 ℃ at a heating rate of 15 ℃/h, and preserving the heat for 3 hours to complete the reaction. And (5) cooling. And taking out the product, crushing and sieving with a 320-mesh sieve to obtain the amorphous Si-O-C composite material.
Example 4
The application provides a Si-O-C composite material, which is prepared by the following steps: the temperature rise rate of 20℃per hour after the addition of the polymerization reaction product in example 1 was changed to 10℃per hour.
Example 5
The application provides a Si-O-C composite material, which is prepared by the following steps: the temperature rise rate of 20℃per hour after the addition of the polymerization reaction product in example 1 was changed to 30℃per hour.
Example 6
The application provides a silicon-carbon composite material, which is prepared by stirring and mixing nano lamellar graphite and a Si-O-C composite material prepared in the embodiment 1 according to the mass ratio of 2:5 and sieving the mixture with a 200-mesh sieve.
Example 7
The application provides a silicon-carbon composite material, which is prepared by stirring and mixing nano lamellar graphite and a Si-O-C composite material prepared in the embodiment 2 according to the mass ratio of 2:5.2 and sieving the mixture with a 200-mesh sieve.
Example 8
The application provides a silicon-carbon composite material, which is prepared by stirring and mixing nano lamellar graphite and a Si-O-C composite material prepared in the embodiment 3 according to the mass ratio of 2:6 and sieving the mixture with a 250-mesh sieve.
Comparative example 1
The application provides a Si-O-C composite material, which is prepared by the following steps: the polymerization reaction product of example 1 was directly placed in a tube furnace, heated to 300℃together with the tube furnace, then heated to 580℃at a heating rate of 20℃per hour, kept for 3 hours for reaction, and cooled. And taking out the product, crushing and sieving with a 300-mesh sieve to obtain the amorphous Si-O-C composite material.
Comparative example 2
The application provides a Si-O-C composite material, which is prepared by the following steps: the sintering temperature in example 1 was changed from 580 ℃ to 900 ℃.
Experimental example
EDS analysis was performed on the Si-O-C composite material obtained in example 1, and the data obtained were as follows:
The powder EDS element of the Si-O-C composite material shows that the Si-O-C composite material only contains three elements of silicon, carbon and oxygen, and the chemical formula of the Si-O-C composite material can be represented as SiO 0.96C2.7.
Meanwhile, the Si-O-C composite material obtained in the embodiment 1 is subjected to SEM and HRSEM analysis, and referring to fig. 1 and 2, it can be seen that the Si-O-C composite material has a random block structure, the surface of the block structure is smooth and compact, similar to a hard carbon structure, the irregular shape is caused when the Si-O-C composite material is crushed and graded, and meanwhile, the smooth and compact structure of the surface is consistent with the polymerization curing process of the process.
In addition, a test was also conducted for ten weeks of cycle for charge and discharge of the si—o—c composite material provided in example 1, and the results of the cycle test were as follows:
From the above table, ten-week cycle data show that the 10-week capacity retention rate is 98.2%, and the 6-week efficiency is more than 99%, and the present application has very excellent cycle effect compared to the existing silicon-based materials.
The silicon carbon composite material obtained in example 6 was subjected to full cell cycle, and the cycle result is shown in fig. 3. As can be seen from fig. 3, the aluminum-shell battery prepared by compounding the Si-O-C composite material with nano lamellar graphite was charged and discharged at a 1C rate, and the cycle performance of the negative electrode material was examined. After 300 weeks of circulation, the capacity retention rate was about 91.6%.
The Si-O-C composite materials obtained in examples 1 to 5 and comparative examples 1 to 2 were each subjected to a cycle test for ten weeks, and the cycle test results were as follows:
From the table above, the composite material has higher cycle efficiency and excellent performance.
In summary, in the application, the Si-O-C composite material is obtained by carrying out polymerization reaction on silane and/or siloxane in the presence of a catalyst and sintering the product of the polymerization reaction, the product of the polymerization reaction directly starts to react at the temperature of 250-350 ℃ and finally is subjected to heat preservation and sintering at the sintering temperature of 550-650 ℃ by controlling the sintering parameters in the sintering process, the byproducts generated in the sintering process can be effectively inhibited on the premise of ensuring the complete sintering, the large-scale production is facilitated, the cost is reduced, the cycle performance of the obtained Si-O-C composite material is excellent, the 10-week capacity retention rate is 98.2%, the 6-week efficiency is more than 99%, the cycle performance of the silicon-carbon composite material formed by compounding the Si-O-C composite material and graphite is also excellent, and the capacity retention rate is about 91.6% after 300 weeks of cycle.
The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (15)
1. A method for preparing a Si-O-C composite material, comprising:
Polymerizing silane and/or siloxane in the presence of a catalyst; the silane comprises one or more of octadecylsilane and hexadecyl methyl dichlorosilane, and the siloxane is dimethyl siloxane; the catalyst is Pd 3O4 when the reactant selects silane, and one or more of Ph 3SiCl、Pd3O4 when the reactant selects siloxane; the dosage ratio of the silane and/or siloxane to the catalyst is 1: (0.05-0.08);
Heating sintering equipment to 250-350 ℃ in advance, then adding the product of the polymerization reaction, heating the product of the polymerization reaction to 550-650 ℃ at a preset heating rate under the condition of 250-350 ℃, and carrying out heat preservation and sintering for 2-4h;
the Si-O-C composite material is amorphous;
The molar ratio of Si, O and C in the Si-O-C composite material is 1: (0.90-0.12): (2.5-3).
2. The method of preparing a Si-O-C composite according to claim 1, wherein said Si-O-C composite is SiO 0.96C2.7.
3. The method for preparing a Si-O-C composite material according to claim 1, wherein the preset heating rate is 15-25 ℃/h.
4. The method for producing a Si-O-C composite material according to claim 1, wherein the air in the sintering equipment is replaced with a protective gas before the sintering equipment is warmed up.
5. The method for producing a Si-O-C composite material according to claim 4, wherein said protective gas is nitrogen.
6. The method for producing a Si-O-C composite material according to claim 4, wherein the sintering apparatus is a tube furnace.
7. The method for producing a Si-O-C composite material according to claim 1, wherein said polymerization reaction is performed in the presence of a curing agent.
8. The method for preparing a Si-O-C composite according to claim 7, wherein said curing agent is one or more of divinyl triamine and diethylaminopropylamine.
9. The method for producing a Si-O-C composite according to claim 1, wherein the silane and/or siloxane is stirred and heated to 150 to 300 ℃ before being mixed with the catalyst, and the catalyst is added and then heated to 320 to 350 ℃ at a heating rate of 8 to 12 ℃/h, followed by stirring and heat-preserving for 2 to 3 hours.
10. The method for producing a Si-O-C composite material according to claim 1, further comprising washing the product of the polymerization reaction with an ethanol solution and water in sequence before sintering the product of the polymerization reaction.
11. The method of producing a Si-O-C composite material according to claim 1, wherein said Si-O-C composite material is crushed and sieved through a 280-320 mesh sieve.
12. A Si-O-C composite material prepared by the method of any one of claims 1-11.
13. A silicon-carbon composite material, characterized in that the raw materials thereof comprise graphite and the Si-O-C composite material prepared by the method for preparing a Si-O-C composite material according to any one of claims 1 to 11 or the Si-O-C composite material according to claim 12.
14. The silicon-carbon composite of claim 13 wherein the mass ratio of the graphite to the Si-O-C composite is (2-3): 5-6.
15. The silicon-carbon composite of claim 14 wherein the graphite is nanolayered graphite.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910715571.6A CN110416523B (en) | 2019-08-05 | 2019-08-05 | Si-O-C composite material, preparation method thereof and silicon-carbon composite material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910715571.6A CN110416523B (en) | 2019-08-05 | 2019-08-05 | Si-O-C composite material, preparation method thereof and silicon-carbon composite material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110416523A CN110416523A (en) | 2019-11-05 |
| CN110416523B true CN110416523B (en) | 2024-06-11 |
Family
ID=68365848
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910715571.6A Active CN110416523B (en) | 2019-08-05 | 2019-08-05 | Si-O-C composite material, preparation method thereof and silicon-carbon composite material |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110416523B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115380404A (en) * | 2020-04-27 | 2022-11-22 | 宁德新能源科技有限公司 | Negative electrode material, negative electrode plate comprising same, electrochemical device and electronic device |
| CN113424336A (en) * | 2021-03-30 | 2021-09-21 | 宁德新能源科技有限公司 | Electrochemical device and electronic device |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5892087A (en) * | 1997-01-22 | 1999-04-06 | Jae-Kun Yang | Process for decomposing siloxane bond-containing compound |
| CN1758466A (en) * | 2004-07-30 | 2006-04-12 | 信越化学工业株式会社 | Si-C-O composite, making method, and non-aqueous electrolyte secondary cell negative electrode material |
| CN103165870A (en) * | 2011-12-13 | 2013-06-19 | 上海杉杉科技有限公司 | Silicon-based composite material, lithium ion battery, and preparation method and application thereof |
| CN103450690A (en) * | 2013-08-01 | 2013-12-18 | 广东信翼新材料股份有限公司 | Heating-forming polysiloxane composition for LED (light emitting diode) components |
| WO2014030853A1 (en) * | 2012-08-22 | 2014-02-27 | 동국대학교 산학협력단 | Method for preparing silicon oxide/carbon composite for anode active material of lithium secondary battery |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9806332B2 (en) * | 2011-12-06 | 2017-10-31 | Lg Chem, Ltd. | Anode active material for lithium secondary batteries |
-
2019
- 2019-08-05 CN CN201910715571.6A patent/CN110416523B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5892087A (en) * | 1997-01-22 | 1999-04-06 | Jae-Kun Yang | Process for decomposing siloxane bond-containing compound |
| CN1758466A (en) * | 2004-07-30 | 2006-04-12 | 信越化学工业株式会社 | Si-C-O composite, making method, and non-aqueous electrolyte secondary cell negative electrode material |
| CN103165870A (en) * | 2011-12-13 | 2013-06-19 | 上海杉杉科技有限公司 | Silicon-based composite material, lithium ion battery, and preparation method and application thereof |
| WO2014030853A1 (en) * | 2012-08-22 | 2014-02-27 | 동국대학교 산학협력단 | Method for preparing silicon oxide/carbon composite for anode active material of lithium secondary battery |
| CN103450690A (en) * | 2013-08-01 | 2013-12-18 | 广东信翼新材料股份有限公司 | Heating-forming polysiloxane composition for LED (light emitting diode) components |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110416523A (en) | 2019-11-05 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105355870B (en) | Expanded graphite and nanometer silicon composite material and preparation method thereof, electrode slice, battery | |
| KR101522963B1 (en) | Negative electrode material for rechargeable battery with nonaqueous electrolyte, negative electrode for rechargeable battery with nonaqueous electrolyte, rechargeable battery with nonaqueous electrolyte, and process for producing polycrystalline silicon particles for active material for negative electrode material for rechargeable battery with nonaqueous electrolyte | |
| EP2778130B1 (en) | Nano-silicon/carbon composite material and preparation method therefor | |
| EP2876710B1 (en) | Negative active material of lithium-ion secondary battery and preparation method therefor, negative plate of lithium-ion secondary battery, and lithium-ion secondary battery | |
| CN106410158A (en) | Graphene modified silicon monoxide and carbon composite microsphere, and preparation method and application thereof | |
| US11027978B2 (en) | Silicon nanoparticle-containing hydrogen polysilsesquioxane, calcined product thereof, production method therefor, active material, negative electrode, and lithium ion battery | |
| JP6987358B2 (en) | A core-shell structure, a method for manufacturing the same, a composition for a negative electrode using the core-shell structure as a negative electrode active material, a negative electrode, and a secondary battery. | |
| CN104103821B (en) | The preparation method of silicon-carbon cathode material | |
| WO2015003568A1 (en) | Method for preparing positive electrode active material of lithium ion battery | |
| CN101035743A (en) | Titanium and dense lithium mixed oxide powder compound, method for producing said compound and compound-containing electrode | |
| CN104037417B (en) | A kind of modified natural graphite and preparation method thereof | |
| CN115472816A (en) | Silica particles and preparation method and application thereof | |
| CN110416523B (en) | Si-O-C composite material, preparation method thereof and silicon-carbon composite material | |
| CN107093711B (en) | Monodispersed SiOxThe magnanimity preparation method of-C complex microsphere | |
| CN106410177A (en) | Ellipsoidal SiOx/graphite cathode composite material and preparation method and application thereof | |
| WO2016169150A1 (en) | Method for graphite fine powder to be doped and used as negative electrode material | |
| CN106252622B (en) | A kind of silica/carbon composite nano line negative electrode material, preparation method and lithium ion battery | |
| CN104347858A (en) | Lithium ion secondary cell cathode active material and preparation method thereof, lithium ion secondary cell cathode pole piece and lithium ion secondary cell | |
| JP2019121488A (en) | Composition for secondary battery negative electrode, secondary battery negative electrode arranged by use thereof, and secondary battery | |
| WO2012105672A1 (en) | Silicon-containing carbonaceous composite material | |
| KR20160076060A (en) | Negative electrode active material for rechargeable battery, the preparation method thereof, and rechargeable battery including the same | |
| KR101036288B1 (en) | Sio-c composite powder for lithium secondary battery and method for manufacturing the same | |
| CN114141998B (en) | Preparation method of self-assembled silicon-carbon composite material | |
| CN115132982A (en) | Preparation method of silicon-based negative electrode material | |
| EP3322007A1 (en) | Negative electrode active substance for lithium ion secondary battery and method for producing same |
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 |