CN115483373B - A silicon composite material and its preparation method and application - Google Patents
A silicon composite material and its preparation method and application Download PDFInfo
- Publication number
- CN115483373B CN115483373B CN202211012383.5A CN202211012383A CN115483373B CN 115483373 B CN115483373 B CN 115483373B CN 202211012383 A CN202211012383 A CN 202211012383A CN 115483373 B CN115483373 B CN 115483373B
- Authority
- CN
- China
- Prior art keywords
- silicon
- composite material
- silicon composite
- substrate
- compound
- 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
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 title claims abstract description 68
- 229910052710 silicon Inorganic materials 0.000 title claims abstract description 68
- 239000010703 silicon Substances 0.000 title claims abstract description 68
- 239000002131 composite material Substances 0.000 title claims abstract description 45
- 238000002360 preparation method Methods 0.000 title claims abstract description 13
- 239000000758 substrate Substances 0.000 claims abstract description 30
- 150000001875 compounds Chemical class 0.000 claims abstract description 29
- 238000000034 method Methods 0.000 claims abstract description 22
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 claims abstract description 19
- 229910001416 lithium ion Inorganic materials 0.000 claims abstract description 19
- 238000009210 therapy by ultrasound Methods 0.000 claims abstract description 18
- 239000007773 negative electrode material Substances 0.000 claims abstract description 16
- 239000002904 solvent Substances 0.000 claims abstract description 11
- 238000001035 drying Methods 0.000 claims abstract description 9
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical group O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 25
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 20
- 239000002356 single layer Substances 0.000 claims description 19
- 239000008367 deionised water Substances 0.000 claims description 14
- 229910021641 deionized water Inorganic materials 0.000 claims description 14
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 14
- 229910052786 argon Inorganic materials 0.000 claims description 10
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 claims description 9
- ZMXDDKWLCZADIW-UHFFFAOYSA-N N,N-Dimethylformamide Chemical compound CN(C)C=O ZMXDDKWLCZADIW-UHFFFAOYSA-N 0.000 claims description 9
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 claims description 6
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 4
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 3
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 claims description 3
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 2
- 239000001307 helium Substances 0.000 claims description 2
- 229910052734 helium Inorganic materials 0.000 claims description 2
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 claims description 2
- 239000001257 hydrogen Substances 0.000 claims description 2
- 229910052739 hydrogen Inorganic materials 0.000 claims description 2
- 239000011261 inert gas Substances 0.000 claims description 2
- 229910052757 nitrogen Inorganic materials 0.000 claims description 2
- 239000002245 particle Substances 0.000 claims description 2
- 239000000377 silicon dioxide Substances 0.000 claims description 2
- 235000012239 silicon dioxide Nutrition 0.000 claims 1
- 238000010438 heat treatment Methods 0.000 abstract description 13
- 238000001816 cooling Methods 0.000 abstract description 10
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 abstract description 7
- 229910010271 silicon carbide Inorganic materials 0.000 abstract description 7
- 239000012535 impurity Substances 0.000 abstract description 6
- LIVNPJMFVYWSIS-UHFFFAOYSA-N silicon monoxide Chemical compound [Si-]#[O+] LIVNPJMFVYWSIS-UHFFFAOYSA-N 0.000 abstract 2
- 229910052814 silicon oxide Inorganic materials 0.000 description 21
- 229910052799 carbon Inorganic materials 0.000 description 15
- 239000011248 coating agent Substances 0.000 description 13
- 238000000576 coating method Methods 0.000 description 13
- 229910052744 lithium Inorganic materials 0.000 description 11
- 239000002210 silicon-based material Substances 0.000 description 11
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 10
- 239000000463 material Substances 0.000 description 8
- 238000012360 testing method Methods 0.000 description 8
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 7
- 238000004458 analytical method Methods 0.000 description 7
- 238000009830 intercalation Methods 0.000 description 7
- 230000002687 intercalation Effects 0.000 description 7
- 230000000052 comparative effect Effects 0.000 description 6
- 238000002156 mixing Methods 0.000 description 5
- 239000010405 anode material Substances 0.000 description 4
- 239000002041 carbon nanotube Substances 0.000 description 4
- 229910021393 carbon nanotube Inorganic materials 0.000 description 4
- 239000010406 cathode material Substances 0.000 description 4
- 239000011229 interlayer Substances 0.000 description 4
- 238000011160 research Methods 0.000 description 4
- 230000002441 reversible effect Effects 0.000 description 4
- 239000000203 mixture Substances 0.000 description 3
- 238000003860 storage Methods 0.000 description 3
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 description 2
- 239000002033 PVDF binder Substances 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 238000010277 constant-current charging Methods 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000009831 deintercalation Methods 0.000 description 2
- 238000007599 discharging Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000007772 electrode material Substances 0.000 description 2
- 229910002804 graphite Inorganic materials 0.000 description 2
- 239000010439 graphite Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 2
- 150000003376 silicon Chemical class 0.000 description 2
- 239000002002 slurry Substances 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 229910018068 Li 2 O Inorganic materials 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000007600 charging Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000005253 cladding Methods 0.000 description 1
- 239000011889 copper foil Substances 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 229910052909 inorganic silicate Inorganic materials 0.000 description 1
- 239000010410 layer Substances 0.000 description 1
- ZAUUZASCMSWKGX-UHFFFAOYSA-N manganese nickel Chemical compound [Mn].[Ni] ZAUUZASCMSWKGX-UHFFFAOYSA-N 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000003446 memory effect Effects 0.000 description 1
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 1
- 239000002052 molecular layer Substances 0.000 description 1
- 238000011056 performance test Methods 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000010298 pulverizing process Methods 0.000 description 1
- 229910052596 spinel Inorganic materials 0.000 description 1
- 239000011029 spinel Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000004627 transmission electron microscopy Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/362—Composites
- H01M4/366—Composites as layered products
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
- H01M4/386—Silicon or alloys based on silicon
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
-
- 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
- H01M4/581—Chalcogenides or intercalation compounds thereof
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
- H01M4/583—Carbonaceous material, e.g. graphite-intercalation compounds or CFx
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
- H01M4/624—Electric conductive fillers
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
- H01M2004/027—Negative electrodes
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Inorganic Chemistry (AREA)
- Composite Materials (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Silicon Compounds (AREA)
- Battery Electrode And Active Subsutance (AREA)
Abstract
本发明涉及一种硅复合材料及其制备方法和应用。硅复合材料，包括基材，基材的表面包覆有化合物；所述基材选自硅、碳化硅和氧化亚硅中的一种或多种，所述化合物选自Nb2S2C和Ta2S2C中的一种或两种。本发明还提供硅复合材料的制备方法，包括：将化合物溶于溶剂中，进行超声处理，然后加入基材，干燥得中间体；将中间体置于惰性气氛中，在温度为700‑1200℃条件下，加热处理0.5~6h，冷却后除杂，得到硅复合材料。本发明还提供硅复合材料在锂离子电池中作为负极材料的应用。本发明解决了现有锂离子负极材料存在能量密度低、导电性能和倍率性能差的问题。
The present invention relates to a silicon composite material and a preparation method and application thereof. The silicon composite material comprises a substrate, the surface of the substrate is coated with a compound; the substrate is selected from one or more of silicon, silicon carbide and silicon monoxide , and the compound is selected from one or two of Nb2S2C and Ta2S2C . The present invention also provides a method for preparing a silicon composite material, comprising: dissolving the compound in a solvent, performing ultrasonic treatment, then adding the substrate, and drying to obtain an intermediate; placing the intermediate in an inert atmosphere, heating the intermediate at a temperature of 700-1200°C for 0.5-6h, and removing impurities after cooling to obtain a silicon composite material. The present invention also provides an application of the silicon composite material as a negative electrode material in a lithium ion battery. The present invention solves the problems of low energy density, poor conductivity and rate performance of existing lithium ion negative electrode materials.
Description
Technical Field
The invention relates to the technical field of lithium batteries, in particular to a silicon composite material and a preparation method and application thereof.
Background
With the increasing popularity of new energy automobiles, lithium ion batteries are receiving extensive attention in the field of power batteries due to the advantages of high operating voltage, no memory effect, small self-discharge, large energy density and long cycle life. Currently, power lithium ion batteries mainly develop towards high energy density, low production cost and high safety, which also results in higher and higher requirements on electrode materials. Particularly, the cathode material is an important component in a battery, the theoretical capacity of the current commercial graphite cathode material is 372mAh/g, and the capacity matching requirements of high-energy cathode materials such as lithium-rich materials, nickel-manganese spinel high-voltage materials and the like can not be met.
In recent years, a silicon material with ultra-high capacity (theoretical capacity 4200 mAh/g) is regarded as an ideal material for replacing graphite negative electrode as a large-reserve rich resource. However, the research shows that the silicon anode material can undergo severe volume expansion (0-300%) in the lithium intercalation reaction process, which leads to structural damage and pulverization of the electrode material, thereby causing the defects of rapid capacity decay and shortened cycle life.
The research shows that the volume expansion rate of the silicon oxide in the lithium intercalation process is obviously lower than that of the silicon anode material, and the silicon oxide can generate inert Li 2 O and Li 4SiO4 in the first lithium intercalation process, so that the volume expansion effect is effectively relieved, and the silicon oxide serving as the anode material has better cycle performance. Although the cycle performance of silicon oxide is improved compared with that of silicon, the conductivity and the multiplying power performance of silicon oxide are still difficult to meet the requirements of practical application.
CN114361427a discloses a method for coating silicon negative electrode material with carbon nanotube, in particular a method for coating a layer of carbon nanotube on the surface of silicon oxide and increasing the conductivity and rate capability of the negative silicon oxide main body by utilizing the strong conductivity of the carbon nanotube coating. The method has the defects that the uniform coating cannot be realized due to the tubular hollow structure of the carbon nano tube, and meanwhile, the carbon nano tube structure can be damaged due to the large shrinkage of the silicon oxide in the charging and discharging process, so that the conductivity of the follow-up silicon oxide is influenced.
Disclosure of Invention
The invention aims to provide a silicon composite material, a preparation method and application thereof, and aims to solve the problems of low energy density, poor conductivity and poor multiplying power performance of the existing lithium ion anode material.
In order to achieve the above purpose, the technical scheme adopted by the invention is as follows:
a silicon composite material comprises a substrate, wherein the surface of the substrate is coated with a compound;
The substrate is selected from one or more of silicon, silicon carbide and silicon oxide, and the compound is selected from one or two of Nb 2S2 C and Ta 2S2 C.
According to the technical means, the surface of the silicon substrate is coated with the compound, the compound is one or two of Nb 2S2 C and Ta 2S2 C, nb 2S2 C and Ta 2S2 C have higher conductivity, the conductivity of the whole silicon composite material is improved after the compound is coated on the surface of the silicon substrate, through research, nb 2S2 C and Ta 2S2 C are of layered two-dimensional structures, the interlayer distance is larger, the compound is coated on the surface of the silicon substrate and used as a negative electrode material of a lithium ion battery, the rapid intercalation and deintercalation of lithium ions are facilitated, and therefore the multiplying power performance of the silicon composite material is improved, meanwhile, the Nb 2S2 C and Ta 2S2 C are also found to have higher lithium storage performance (specific volume is more than 400 mAh/g), and the whole specific volume can still be kept at 400mAh/g after the compound is coated on the surface of the silicon substrate, so that the energy density of the negative electrode material is effectively ensured, and the applicability of the negative electrode material is widened.
Preferably, the substrate is selected from the group consisting of silicon oxide, and the compound is a monolayer of Nb 2S2 C and/or Ta 2S2 C.
Because the silicon oxide has better cycle performance compared with other silicon substrates, and because the interlayer spacing between the multiple layers of Nb 2S2 C and/or Ta 2S2 C is relatively smaller, after the silicon oxide is coated on the surface of the substrate, the lithium intercalation property is poor, so that the silicon oxide is selected as the substrate, and meanwhile, the single-layer Nb 2S2 C and/or Ta 2S2 C is selected as the coating material to prepare the composite material, so that the rate performance and the cycle performance can be further improved.
Preferably, the mass ratio of the compound to the base material is 0.1:99.9-3:17.
By controlling the mass ratio of the compound to the base material, the electrochemical performance of the composite material is effectively ensured.
Preferably, the particle size of the base material is 2-800 nm.
The invention also provides a preparation method of the silicon composite material, which comprises the following steps:
dissolving the compound in a solvent, performing ultrasonic treatment, adding a base material, and drying to obtain an intermediate;
And (3) placing the intermediate in an inert atmosphere, heating at 700-1200 ℃ for 0.5-6 h, and cooling to obtain the silicon composite material.
According to the technical means, the compound is dissolved in the solvent and subjected to ultrasonic treatment, so that the compound is uniformly dispersed in the solvent, a single-layer molecular structure is formed, preconditions are provided for uniform coating of the silicon substrate, and meanwhile, the compound is further ensured to be uniformly coated on the surface of the silicon substrate by adding the substrate and then performing ultrasonic treatment.
Preferably, the intermediate is heated at 800 ℃ for 3.5 hours in an inert atmosphere.
By setting the temperature of the heating treatment to 800 ℃ and the time to 3.5 hours, the effective coating of the compound is ensured.
Preferably, the ultrasonic treatment time is 0.5-6 hours;
the drying temperature is 80-200 ℃.
The compound is uniformly dispersed in the solvent by controlling the ultrasonic treatment time to be 0.5-6 h.
Preferably, the time of the ultrasonic treatment is 2 hours.
Preferably, the solvent is selected from one or more of deionized water, absolute ethanol, acetone, dimethylformamide and tetrahydrofuran.
Deionized water, absolute ethyl alcohol, acetone, dimethylformamide and tetrahydrofuran are selected as solvents, so that uniformity of compound dispersion is effectively ensured.
Preferably, the inert gas in the inert atmosphere is selected from one or more of nitrogen, helium, argon and hydrogen.
The invention also provides application of the silicon composite material, which is used as a negative electrode material of a lithium ion battery.
According to the technical means, the silicon composite material is used as the negative electrode material of the lithium ion battery, so that the specific energy, the multiplying power performance and the conductivity of the lithium ion battery can be obviously improved.
The invention has the beneficial effects that:
1) According to the silicon composite material, the surface of the silicon substrate is coated with the compound, the compound is one or two selected from Nb 2S2 C and Ta 2S2 C, nb 2S2 C and Ta 2S2 C have high conductivity, and the conductivity of the whole cathode material is improved after the surface of the silicon substrate is coated with the compound; the research shows that Nb 2S2 C and Ta 2S2 C with layered two-dimensional structures have larger interlayer spacing, are used as the negative electrode material of the lithium ion battery after being coated on the surface of the silicon substrate, facilitate the rapid intercalation and deintercalation of lithium ions, thereby improving the rate capability of the negative electrode material, and meanwhile, nb 2S2 C and Ta 2S2 C have higher lithium storage capability (specific volume is more than 400 mAh/g) and remain the whole specific volume above 400mAh/g after being coated on the surface of the silicon substrate, thereby effectively ensuring the energy density of the negative electrode material and widening the applicability of the negative electrode material;
2) According to the preparation method of the silicon composite material, the compound is dissolved in the solvent and subjected to ultrasonic treatment, so that the compound is uniformly dispersed in the solvent and a single molecular layer is formed, a precondition is provided for uniform coating of the silicon substrate, and the preparation method has the advantages of simple process, low cost and contribution to large-scale commercial application;
3) The negative electrode material of the invention has the advantages of high specific energy, good multiplying power performance and excellent electrochemical performance when being used for preparing the negative electrode material of the lithium battery, and has popularization and application values in the technical field of lithium ion batteries.
Drawings
FIG. 1 is a schematic atomic structure diagram of a single layer Nb 2S2 C;
fig. 2 is a transmission electron microscopic image of the silicon composite material prepared in example 1.
Detailed Description
Further advantages and effects of the present invention will become readily apparent to those skilled in the art from the disclosure herein, by referring to the accompanying drawings and the preferred embodiments. The invention may be practiced or carried out in other embodiments that depart from the specific details, and the details of the present description may be modified or varied from the spirit and scope of the present invention. It should be understood that the preferred embodiments are presented by way of illustration only and not by way of limitation.
It should be noted that the illustrations provided in the following embodiments merely illustrate the basic concept of the present invention by way of illustration, and only the components related to the present invention are shown in the drawings and are not drawn according to the number, shape and size of the components in actual implementation, and the form, number and proportion of the components in actual implementation may be arbitrarily changed, and the layout of the components may be more complicated.
In the following description, numerous details are discussed to provide a more thorough explanation of embodiments of the present application, however, it will be apparent to one skilled in the art that embodiments of the present application may be practiced without these specific details.
Example 1
A method for preparing a silicon composite material, comprising the steps of:
S1, dissolving 0.1g of Nb 2S2 C in deionized water, and carrying out ultrasonic treatment at normal temperature for 3 hours to obtain a single-layer Nb 2S2 C solution;
S2, adding 99.9g of silicon oxide into a single-layer Nb 2S2 C (shown in figure 1) solution, uniformly mixing, and then placing in a 100 ℃ oven for drying to obtain an intermediate;
and S3, placing the intermediate into a furnace under the protection of argon, heating to 900 ℃ and preserving heat for 5 hours, and naturally cooling and removing impurities after the completion of the heating to obtain the silicon composite material.
Example 2
A method for preparing a silicon composite material, comprising the steps of:
S1, dissolving 10g of Nb 2S2 C in deionized water, and carrying out ultrasonic treatment at normal temperature for 4 hours to obtain a single-layer Nb 2S2 C solution;
S2, adding 90g of silicon oxide into a single-layer Nb 2S2 C solution, uniformly mixing, and then placing in a 90 ℃ oven for drying to obtain an intermediate;
and S3, placing the intermediate into a furnace, heating to 1000 ℃ under the protection of argon, preserving heat for 6 hours, and naturally cooling and removing impurities after the completion of the heating to obtain the silicon composite material.
Example 3
A method for preparing a silicon composite material, comprising the steps of:
S1, dissolving 5g of Nb 2S2 C in deionized water, and carrying out ultrasonic treatment at normal temperature for 6 hours to obtain a single-layer Nb 2S2 C solution;
S2, adding 95g of silicon oxide into a single-layer Nb 2S2 C solution, uniformly mixing, and then placing in a baking oven at 120 ℃ to obtain an intermediate;
And S3, placing the intermediate into a furnace, heating to 1100 ℃ under the protection of argon, preserving heat for 6 hours, and naturally cooling and removing impurities after the completion of the process to obtain the silicon composite material.
Example 4
A method for preparing a silicon composite material, comprising the steps of:
S1, dissolving 5g of Nb 2S2 C in deionized water, and carrying out ultrasonic treatment at normal temperature for 6 hours to obtain a single-layer Nb 2S2 C solution;
S2, adding 95g of silicon into a single-layer Nb 2S2 C solution, uniformly mixing, and then placing in a 120 ℃ oven for drying to obtain an intermediate;
And S3, placing the intermediate into a furnace, heating to 1100 ℃ under the protection of argon, preserving heat for 6 hours, and naturally cooling and removing impurities after the completion of the process to obtain the silicon composite material.
Example 5
A method for preparing a silicon composite material, comprising the steps of:
S1, dissolving 5g of Nb 2S2 C in deionized water, and carrying out ultrasonic treatment at normal temperature for 6 hours to obtain a single-layer Nb 2S2 C solution;
s2, adding 95g of silicon carbide into a single-layer Nb 2S2 C solution, uniformly mixing, and then placing in a 120 ℃ oven for drying to obtain an intermediate;
And S3, placing the intermediate into a furnace, heating to 1100 ℃ under the protection of argon, preserving heat for 6 hours, and naturally cooling and removing impurities after the completion of the process to obtain the silicon composite material.
Comparative example 1
A method for preparing a silicon material, comprising the steps of:
S1, carrying out ultrasonic treatment on 50ml of deionized water at normal temperature for 3 hours;
S2, adding 95g of silicon oxide into 50ml of deionized water, and then placing the mixture in a baking oven at 120 ℃ to obtain an intermediate;
and S3, placing the intermediate into a furnace, heating to 1100 ℃ under the protection of argon, preserving heat for 6 hours, and naturally cooling after finishing to obtain the silicon material.
Comparative example 2
A method for preparing a silicon material, comprising the steps of:
s1, carrying out ultrasonic treatment on 50ml of deionized water at normal temperature for 4 hours;
s2, adding 95g of silicon into 50ml of deionized water, and then placing the mixture in a baking oven at 120 ℃ to obtain an intermediate;
And S3, placing the intermediate into a furnace, heating to 1100 ℃ under the protection of argon, preserving heat for 4 hours, and naturally cooling after finishing to obtain the silicon material.
Comparative example 3
A method for preparing a silicon material, comprising the steps of:
S1, carrying out ultrasonic treatment on 50ml of deionized water at normal temperature for 3 hours;
s2, adding 95g of silicon carbide into 50ml of deionized water, and then placing the mixture in a baking oven at 120 ℃ to obtain an intermediate;
And S3, placing the intermediate into a furnace, heating to 1100 ℃ under the protection of argon, preserving heat for 2 hours, and naturally cooling after finishing to obtain the silicon material.
Detection analysis
1. Transmission electron microscope analysis
The silicon composite material obtained in example 1 was subjected to transmission electron microscopy analysis, and the results are shown in fig. 2.
As can be seen from the analysis in fig. 2, nb 2S2 C was uniformly coated on the surface of the silica.
2. Conductivity test
The silicon composite materials prepared in examples 1 to 5 and the silicon materials prepared in comparative examples 1 to 3 were measured for electrical conductivity using the mitsubishi chemical MCP-PD51 powder resistivity measuring system of japan, and the results are shown in table 1.
TABLE 1 conductivity test results for silicon composites and silicon materials
From the analysis in table 1, a) the surface coating by using single-layer Nb 2S2 C can respectively increase the conductivity orders of magnitude of the silicon oxide, silicon and silicon carbide by 4, 1 and 2, and the conductivity orders of magnitude can also be gradually increased along with the increase of the coating amount of Nb 2S2 C, so that the effective demonstration that the coating of Nb 2S2 C can obviously increase the conductivity of the silicon cathode.
3. Charge and discharge test
The silicon composite materials prepared in examples 1 to 5, the silicon materials prepared in comparative examples 1 to 3, conductive carbon black and polyvinylidene fluoride (PVDF) were ground and mixed uniformly in a mass ratio of 7:2:1, a proper amount of N-methylpyrrolidone (NMP) was added to prepare a slurry, the slurries were coated on copper foil and dried in a drying oven at 110 ℃ for 10 hours, and then cut into pieces to prepare a lithium ion battery negative plate. And respectively assembling the prepared lithium ion battery negative electrode pieces into button batteries, and performing electrochemical performance test. The charge and discharge test of the button cell is carried out on a LAND cell test system of the Wuhan Jino electronic Co., ltd. Under the parameter condition that the constant current charging is carried out at the normal temperature and the constant current charging is carried out at the temperature of 0.3C, the constant current discharging is carried out at the temperature of 0.5C/1C/2C/5C/10C, the charge and discharge voltage is limited to 0.005-2V, and the test result is shown in the table 2.
Table 2 results of testing reversible capacity and percent discharge of silicon composites and silicon materials
From the analysis of the reversible capacity data obtained in table 2, it is found that, although the reversible capacities of Nb 2S2 C and Ta 2S2 C of the single layer are lower than those of silicon, silicon carbide and silicon oxide, the specific capacities of the composite materials after Nb 2S2 C is coated on the surfaces of silicon, silicon carbide and silicon oxide remain high because Nb 2S2 C and Ta 2S2 C have certain lithium storage properties, and there is a lot of applicable space, and the reversible capacities of the silicon composite materials prepared in examples 1 to 5 are all above 1000mAh/g after discharge test at normal temperature and 0.5C, thus proving that the silicon composite material of the present invention has the advantage of high energy density.
From the analysis of the discharge percentage data obtained in table 2, the silicon composite materials prepared in examples 1 to 5 showed a significant increase in discharge percentage compared with comparative examples 1 to 3, thus demonstrating that the rate performance of the lithium ion battery can be rapidly improved after coating the silicon substrate with Nb 2S2 C and Ta 2S2 C, and the more significant the rate performance improvement with an increase in Nb 2S2 C coating amount. The reason is that the single-layer Nb 2S2 C has larger interlayer spacing, so that the single-layer Nb 2S2 C can be used as a negative electrode material of a lithium ion battery after being compounded with a silicon substrate, and can facilitate rapid release and intercalation of lithium ions, so that the rate capability can be rapidly improved through the cladding of Nb 2S2 C and Ta 2S2 C.
The above embodiments are merely illustrative of the principles of the present application and its effectiveness, and are not intended to limit the application. Modifications and variations may be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the application. It is therefore intended that all equivalent modifications and changes made by those skilled in the art without departing from the spirit and technical spirit of the present application shall be covered by the appended claims.
Claims (8)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211012383.5A CN115483373B (en) | 2022-08-23 | 2022-08-23 | A silicon composite material and its preparation method and application |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211012383.5A CN115483373B (en) | 2022-08-23 | 2022-08-23 | A silicon composite material and its preparation method and application |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115483373A CN115483373A (en) | 2022-12-16 |
| CN115483373B true CN115483373B (en) | 2025-01-21 |
Family
ID=84421865
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211012383.5A Active CN115483373B (en) | 2022-08-23 | 2022-08-23 | A silicon composite material and its preparation method and application |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115483373B (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107394185A (en) * | 2017-08-23 | 2017-11-24 | 长沙小新新能源科技有限公司 | A kind of preparation method of high energy graphene battery negative material |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10538431B2 (en) * | 2015-03-04 | 2020-01-21 | Drexel University | Nanolaminated 2-2-1 MAX-phase compositions |
| CN107706372B (en) * | 2017-09-12 | 2020-05-22 | 山东大学 | A kind of Mxene-coated composite electrode material and preparation method thereof |
-
2022
- 2022-08-23 CN CN202211012383.5A patent/CN115483373B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107394185A (en) * | 2017-08-23 | 2017-11-24 | 长沙小新新能源科技有限公司 | A kind of preparation method of high energy graphene battery negative material |
Non-Patent Citations (1)
| Title |
|---|
| 基于密度泛函理论计算的新颖二维储能材料设计与模拟;刘杰;《中国优秀硕士学位论文全文数据库 工程科技Ⅰ辑》;20200215(第2期);B020-835 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115483373A (en) | 2022-12-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110048101B (en) | A kind of silicon oxygen carbon microsphere composite negative electrode material and its preparation method and application | |
| CN105355870B (en) | Expanded graphite and nano-silicon composite material, preparation method thereof, electrode plate and battery | |
| JP6563477B2 (en) | Multi-component composite negative electrode material, method for producing the same, and lithium ion battery including the same | |
| CN112758911B (en) | Hard carbon material, preparation method and application thereof, and lithium ion battery | |
| CN108682787B (en) | A kind of lithium ion battery pole piece and preparation method thereof | |
| CN113555539A (en) | A high-energy-density fast-charging graphite composite negative electrode material and preparation method thereof, and lithium ion battery | |
| CN113206249B (en) | Lithium battery silicon-oxygen composite anode material with good electrochemical performance and preparation method thereof | |
| CN110098387B (en) | Lithium phosphate and conductive carbon material coated ternary cathode material and preparation method and application thereof | |
| CN115566170B (en) | Preparation method of high-energy-density quick-charging lithium ion battery anode material | |
| CN111146416A (en) | Nitrogen-doped silicon-based material, preparation method thereof and application thereof in battery | |
| CN114520328B (en) | Lithium-ion battery negative electrode material and its preparation and negative electrode and battery | |
| CN111244414A (en) | A kind of method for preparing silicon carbon anode material by magnesium thermal reduction | |
| CN114583137B (en) | Method for modifying carbon surface by sulfur doped phosphorus and application thereof | |
| WO2024031867A1 (en) | Nitrogen-doped graphene-coated silicon-carbon composite material, and preparation method therefor and use thereof | |
| CN110783564A (en) | Nitrogen-doped carbon-coated ternary positive electrode material and preparation method thereof | |
| CN113113572B (en) | High-rate natural graphite-based composite material for lithium ion battery and preparation method and application thereof | |
| CN110429282A (en) | Novel nano carbon sphere negative electrode material for lithium ion battery | |
| CN102130336B (en) | A kind of hierarchical pore structure carbon negative electrode material for lithium ion battery and preparation method thereof | |
| CN102479939B (en) | Electrode and manufacture method thereof for lithium ion battery | |
| WO2017197675A1 (en) | Lithium titanate-modified material and manufacturing method thereof | |
| CN108807903B (en) | Preparation method of composite modified lithium battery negative electrode material for lithium battery | |
| CN108183216B (en) | A carbon-coated lithium-rich manganese-based positive electrode material, preparation method thereof, and lithium ion battery | |
| CN119381422A (en) | A modified silicon-carbon composite material and its preparation method and application | |
| CN112768657A (en) | High-performance carbon negative electrode PTCDA hard carbon coated graphite material and preparation method thereof | |
| CN112397701A (en) | Rice husk-based silicon oxide/carbon composite negative electrode material and preparation method and application 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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CP03 | Change of name, title or address | ||
| CP03 | Change of name, title or address |
Address after: 401133 room 208, 2 house, 39 Yonghe Road, Yu Zui Town, Jiangbei District, Chongqing Patentee after: Deep Blue Automotive Technology Co.,Ltd. Country or region after: China Address before: Room 208, Building 2, No. 39 Yonghe Road, Yuzui Town, Jiangbei District, Chongqing City Patentee before: CHONGQING CHANGAN NEW ENERGY AUTOMOBILE TECHNOLOGY Co.,Ltd. Country or region before: China |