CN117457886A - Double-layer oxide coated silicon-based anode material and preparation method and application thereof - Google Patents
Double-layer oxide coated silicon-based anode material and preparation method and application thereof Download PDFInfo
- Publication number
- CN117457886A CN117457886A CN202311714282.7A CN202311714282A CN117457886A CN 117457886 A CN117457886 A CN 117457886A CN 202311714282 A CN202311714282 A CN 202311714282A CN 117457886 A CN117457886 A CN 117457886A
- Authority
- CN
- China
- Prior art keywords
- silicon
- layer
- double
- anode material
- based anode
- 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
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 title claims abstract description 58
- 229910052710 silicon Inorganic materials 0.000 title claims abstract description 58
- 239000010703 silicon Substances 0.000 title claims abstract description 58
- 239000010405 anode material Substances 0.000 title claims abstract description 54
- 238000002360 preparation method Methods 0.000 title claims abstract description 17
- 239000010410 layer Substances 0.000 claims abstract description 56
- 239000002245 particle Substances 0.000 claims abstract description 30
- 239000012670 alkaline solution Substances 0.000 claims abstract description 21
- 239000011247 coating layer Substances 0.000 claims abstract description 19
- 239000005543 nano-size silicon particle Substances 0.000 claims abstract description 15
- 239000011856 silicon-based particle Substances 0.000 claims abstract description 13
- 238000000034 method Methods 0.000 claims abstract description 12
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 claims abstract description 11
- 229910001416 lithium ion Inorganic materials 0.000 claims abstract description 11
- 229910021419 crystalline silicon Inorganic materials 0.000 claims abstract description 7
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 18
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 12
- WMFOQBRAJBCJND-UHFFFAOYSA-M Lithium hydroxide Chemical compound [Li+].[OH-] WMFOQBRAJBCJND-UHFFFAOYSA-M 0.000 claims description 10
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 10
- 239000001301 oxygen Substances 0.000 claims description 10
- 229910052760 oxygen Inorganic materials 0.000 claims description 10
- 238000006243 chemical reaction Methods 0.000 claims description 9
- 238000003756 stirring Methods 0.000 claims description 8
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 claims description 6
- XEKOWRVHYACXOJ-UHFFFAOYSA-N Ethyl acetate Chemical compound CCOC(C)=O XEKOWRVHYACXOJ-UHFFFAOYSA-N 0.000 claims description 6
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 claims description 6
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims description 6
- 238000001035 drying Methods 0.000 claims description 5
- 238000005406 washing Methods 0.000 claims description 5
- 239000003513 alkali Substances 0.000 claims description 4
- 239000007791 liquid phase Substances 0.000 claims description 4
- 239000003960 organic solvent Substances 0.000 claims description 4
- 238000001291 vacuum drying Methods 0.000 claims description 4
- 238000001914 filtration Methods 0.000 claims description 3
- 238000004108 freeze drying Methods 0.000 claims description 3
- 239000000203 mixture Substances 0.000 claims description 3
- 229910004298 SiO 2 Inorganic materials 0.000 claims description 2
- 239000007788 liquid Substances 0.000 claims description 2
- 238000004519 manufacturing process Methods 0.000 claims description 2
- 239000002904 solvent Substances 0.000 claims description 2
- LIVNPJMFVYWSIS-UHFFFAOYSA-N silicon monoxide Chemical compound [Si-]#[O+] LIVNPJMFVYWSIS-UHFFFAOYSA-N 0.000 abstract description 21
- 239000000463 material Substances 0.000 abstract description 19
- 230000008569 process Effects 0.000 abstract description 4
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 abstract description 3
- 238000007599 discharging Methods 0.000 abstract description 3
- 238000005530 etching Methods 0.000 abstract description 3
- 229910052814 silicon oxide Inorganic materials 0.000 abstract description 3
- 230000007613 environmental effect Effects 0.000 abstract description 2
- 239000002344 surface layer Substances 0.000 abstract description 2
- 230000000052 comparative effect Effects 0.000 description 16
- 239000011258 core-shell material Substances 0.000 description 5
- 239000008367 deionised water Substances 0.000 description 5
- 229910021641 deionized water Inorganic materials 0.000 description 5
- 238000011161 development Methods 0.000 description 5
- 239000007773 negative electrode material Substances 0.000 description 5
- 239000000725 suspension Substances 0.000 description 5
- 239000002131 composite material Substances 0.000 description 4
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 3
- 239000000872 buffer Substances 0.000 description 3
- 239000010406 cathode material Substances 0.000 description 3
- 229910052744 lithium Inorganic materials 0.000 description 3
- 238000010907 mechanical stirring Methods 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- 239000002210 silicon-based material Substances 0.000 description 3
- 239000002002 slurry Substances 0.000 description 3
- 239000000243 solution Substances 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- 230000006978 adaptation Effects 0.000 description 2
- 238000005275 alloying Methods 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000003792 electrolyte Substances 0.000 description 2
- 238000004146 energy storage Methods 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 238000001878 scanning electron micrograph Methods 0.000 description 2
- 239000011257 shell material Substances 0.000 description 2
- IXPNQXFRVYWDDI-UHFFFAOYSA-N 1-methyl-2,4-dioxo-1,3-diazinane-5-carboximidamide Chemical compound CN1CC(C(N)=N)C(=O)NC1=O IXPNQXFRVYWDDI-UHFFFAOYSA-N 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 229910013870 LiPF 6 Inorganic materials 0.000 description 1
- 230000004913 activation Effects 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 239000011889 copper foil Substances 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- IDGUHHHQCWSQLU-UHFFFAOYSA-N ethanol;hydrate Chemical compound O.CCO IDGUHHHQCWSQLU-UHFFFAOYSA-N 0.000 description 1
- 239000008187 granular material Substances 0.000 description 1
- 239000007770 graphite material Substances 0.000 description 1
- 230000003446 memory effect Effects 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
- 238000002715 modification method Methods 0.000 description 1
- 238000007709 nanocrystallization Methods 0.000 description 1
- 238000011056 performance test Methods 0.000 description 1
- 229920000767 polyaniline Polymers 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 235000010413 sodium alginate Nutrition 0.000 description 1
- 239000000661 sodium alginate Substances 0.000 description 1
- 229940005550 sodium alginate Drugs 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 239000013077 target material 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
- H01M4/366—Composites as layered products
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y40/00—Manufacture or treatment of nanostructures
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- 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
-
- 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
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Electrochemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Nanotechnology (AREA)
- Composite Materials (AREA)
- Physics & Mathematics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Materials Engineering (AREA)
- Crystallography & Structural Chemistry (AREA)
- Manufacturing & Machinery (AREA)
- Battery Electrode And Active Subsutance (AREA)
- Silicon Compounds (AREA)
Abstract
The invention provides a silicon-based anode material coated by double-layer oxide, and a preparation method and application thereof, and relates to the technical field of lithium ion batteries. The silicon-based anode material comprises an inner core composed of crystalline silicon particles and SiO composed of an inner layer and an outer layer x A double-layer coating layer formed by stacking and arranging particles; inner SiO layer in double-layer coating layer x The particles are uniformly and tightly distributed, the inner core is completely wrapped, and the outer layer is SiO x The particles are partially agglomerated in oneAnd is adhered to the inner SiO layer in a more dispersed way x The surface of the particles. According to the method, the surface layer of the silicon particles is dissolved and precipitated through alkaline solution etching, silicon oxide is attached to the surface of the silicon particles, a double-layer oxide coating layer is formed, and the volume expansion of the nano silicon material in the charging and discharging processes is relieved. The silicon-based anode material of the present invention exhibits excellent capacity and cycle stability in lithium ion secondary batteries. The preparation method provided by the invention has the advantages of short flow, low cost and environmental friendliness, and can be popularized on a large scale.
Description
Technical Field
The invention relates to the technical field of lithium ion battery anode materials, in particular to a silicon-based anode material coated by double-layer oxide, and a preparation method and application thereof.
Background
The rapid consumption of traditional fossil energy makes the problem of energy shortage deepened continuously. The development of renewable energy sources is an urgent need for the development of the world energy industry, however, renewable energy sources have the problems of non-centralized distribution, low energy density, poor stability and the like, and the renewable energy sources need to be reused through energy storage and conversion. In the existing energy storage technology, the lithium ion battery has the advantages of high energy density, high coulombic efficiency, long service life, no memory effect and the like, and is widely applied to the fields of portable electronic equipment, electric automobiles, aerospace and the like. The high-capacity anode and cathode materials with excellent development performance are key to improving the energy density of the battery, and commercial anode materials widely applied at the present stage are mainly graphite materials, and the theoretical specific capacity of the commercial anode materials is only 372mAh/g, so that the further development of the lithium ion battery is limited. Therefore, development of a high-performance lithium ion battery anode material is desired.
Silicon negative electrode material toolHas high theoretical specific lithium storage capacity (3579 mAh/g) and moderate alloying reaction potential (0.4V vs Li/Li) + ) The advantages of abundant resources and the like are considered as one of the most advantageous cathode materials of the new generation of lithium ion batteries. However, the silicon negative electrode material has a large volume expansion during alloying, which causes the particles to crush and break down with each other, and during dealloying, the silicon material contracts to lose electrical contact with the surrounding current collector, and repeated volume changes reduce the interfacial stability of the material.
Nanocrystallization of the silicon anode material is a common modification means of the silicon anode material, can effectively relieve the volume effect of the silicon material, and improves the electrochemical performance of the material. However, the nano silicon material has large specific surface area and high reactivity, so that the interface stability is poor. In order to further improve the electrochemical performance of the nano silicon material, the nano silicon material can be treated by a surface modification method, for example, 201210334388.X discloses a preparation method of polyaniline/silicon composite material for a lithium ion battery cathode with a core-shell structure, the composite material is provided with a double-layer core-shell structure, a hollow buffer volume exists between two layers of core-shell materials, and the composite material buffers the volume change of the silicon material in the charging and discharging process through the hollow buffer volume between a first layer of core-shell material and a second layer of core-shell material. But the manufacturing process of the composite material is complex.
Based on the above, the invention designs a double-layer oxide coated silicon-based anode material, and a preparation method and application thereof.
Disclosure of Invention
The invention provides a silicon-based anode material coated by double-layer oxide, and a preparation method and application thereof, and aims to solve the problems in the prior art.
In order to achieve the above object, an embodiment of the present invention provides a double-layer oxide coated silicon-based anode material, a preparation method and applications thereof, the silicon-based anode material comprising a core composed of crystalline silicon particles and an inner and an outer SiO layers x A double-layer coating layer formed by stacking and arranging particles; wherein, the inner layer SiO in the double-layer coating layer x The particles are uniformly and tightly distributed, the inner core is completely wrapped, and the outer layer is SiO x Granule partAre clustered together and are adhered to the inner SiO layer in a more dispersed way x The surface of the particles. In addition, the method is characterized in that the surface layer of the silicon particles is dissolved and precipitated by alkaline solution etching, and silicon oxide is attached to the surface of the silicon particles, so that a double-layer oxide coating layer is formed, and the high-capacity exertion and the structural stability of the material are effectively ensured. The silicon-based anode material of the present invention exhibits excellent capacity and cycle stability in lithium ion secondary batteries.
The embodiment of the invention provides a double-layer oxide coated silicon-based anode material, which comprises a core composed of crystalline silicon particles and a double-layer coating layer; wherein,
the double-layer coating layer consists of inner and outer layers of SiO x The particles are piled up and arranged;
inner SiO layer in double-layer coating layer x The particles are uniformly and tightly distributed, the inner core is completely wrapped, and the outer layer is SiO x The particle parts are clustered together and are adhered to the SiO of the inner layer in a more dispersed way x The surface of the particles.
Further, the grain diameter of the crystalline silicon particles is 50-500 nm; siO in the double-layer coating layer x The particle size of the particles is 1-30 nm. The surfaces of the crystalline silicon particles are etched to form gaps.
Further, the SiO x The particles are SiO 2 、SiO 1.5 、SiO、SiO 0.5 At least one of (a) and (b); the SiO is x The oxygen content in the particles accounts for 1-10% of the mass of the silicon-based anode material.
Based on one general inventive concept, the embodiment of the invention provides a preparation method of the double-layer oxide coated silicon-based anode material, which comprises the following steps:
s1, preparing an alkaline solution;
s2, adding the nano silicon into the prepared alkaline solution, stirring, and carrying out liquid phase reaction;
s3, after the liquid phase reaction is finished, filtering, washing and drying to obtain the silicon-based anode material.
Further, in step S1, the alkali in the alkaline solution includes NH 4 OH、LiOH、NaOH、KOH、Ca(OH) 2 、Ba(OH) 2 At least one of the above, the concentration of the alkali is 0.01 to 0.5mol/L.
In step S1, the alkaline solution is prepared by mixing water and an organic solvent, wherein the volume ratio of water is 1% -100%.
Further, the organic solvent comprises at least one of ethanol, methanol, acetone and ethyl acetate.
In step S2, stirring time is 0.1-24 h, and reaction temperature is 20-60 ℃.
In step S3, the drying mode is freeze drying or vacuum drying; the temperature of vacuum drying is 50-90 ℃; the liquid used in the washing process is at least one of water and ethanol.
The embodiment of the invention also provides a lithium ion battery, which comprises the double-layer oxide coated silicon-based anode material or the double-layer oxide coated silicon-based anode material prepared by the preparation method.
The scheme of the invention has the following beneficial effects:
(1) According to the invention, the nano silicon material is treated by adopting the alkaline solution, the alkaline solution has an etching effect on the silicon particle body, the size and the shape of the silicon particle can be effectively regulated and controlled, and meanwhile, an oxide coating layer with adjustable components and structure can be generated on the surface of the nano silicon particle, so that the double-layer oxide coated silicon-based negative electrode material is obtained, the volume expansion of the nano silicon material in the charging and discharging processes is relieved, the interface stability of the material is improved, and the cycle performance of the silicon-based negative electrode is improved.
(2) The preparation method provided by the invention has the advantages of short flow, low cost and environmental friendliness, and can be popularized on a large scale.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is the results of oxygen content testing of silicon-based anode materials in comparative examples of the present invention and examples 1 to 3;
fig. 2 is XPS graphs of silicon-based negative electrode materials in comparative examples and examples 2 to 3 of the present invention;
fig. 3 is an SEM image of the silicon-based anode material in comparative example and example 2 of the present invention;
fig. 4 is a cycle performance chart of the silicon-based anode materials in comparative examples and examples 1 to 3 of the present invention.
Detailed Description
In order to make the technical problems, technical solutions and advantages to be solved more apparent, the following detailed description will be given with reference to the accompanying drawings and specific embodiments.
Unless defined otherwise, all technical and scientific terms used hereinafter have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the scope of the present invention.
Unless otherwise specifically indicated, the various raw materials, reagents, instruments, equipment and the like used in the present invention are commercially available or may be prepared by existing methods.
Aiming at the existing problems, the invention provides a silicon-based anode material coated by double-layer oxide, and a preparation method and application thereof.
The nano silicon raw material used in the following examples of the present invention has a particle size of 50 to 200nm.
In testing the electrochemical properties of the following examples and comparative examples, a button cell was first assembled from the target materials by: mixing the cathode material, sodium alginate and SuperP according to the mass ratio of 7:2:1, adding a proper ethanol-water mixed solution to prepare uniform slurry, and coating the slurry on a copper foil by using a coating machine, wherein the thickness of the slurry is 100 mu m. The pole piece is put into a vacuum oven at 70 ℃ for drying for 12 hours, so that the thorough volatilization of the solvent in the pole piece is ensured. The pole piece was cut into small disks of 12mm diameter as working electrodes.
Celgard 2325 diaphragm with diameter of 19mm and adopting metal lithium sheet with diameter of 16mm as counter electrodeAnd LiPF 6 An organic solution of/EC+DEC (volume ratio 1:1)/FEC (mass fraction 10%) is an electrolyte. Glove box under argon protection (H) 2 O≤0.1ppm，O 2 Less than or equal to 0.1 ppm), the battery positive electrode shell, the pole piece, the diaphragm, the electrolyte, the lithium sheet, the gasket, the elastic sheet and the battery negative electrode shell are placed in sequence from bottom to top, and the assembled battery is sealed by a button battery sealing machine.
In the battery cycle performance test process, the first three periods complete activation under the current density of 200mA/g, and then charge and discharge are carried out 100 times under the current density of 1000mA/g, and the voltage range is 0.01V-2V.
The following will be described by way of specific examples.
Example 1
The preparation method of the double-layer oxide coated silicon-based anode material comprises the following steps:
s1: mixing and stirring 2mmol of LiOH, 15ml of deionized water and 35ml of ethanol to obtain a uniform alkaline solution; 0.5g of nano silicon particles are added into 50ml of ethanol, and the uniform suspension is obtained through ultrasonic and mechanical stirring.
S2: the above alkaline solution was added to the suspension, and stirring was continued at room temperature for 1 hour.
S3: and finally, filtering the suspension after the reaction, washing with deionized water and ethanol for 3 times, and freeze-drying to obtain the silicon-based anode material coated with the oxide.
Example 2
The preparation method of the double-layer oxide coated silicon-based anode material comprises the following steps:
s1: adding 2mmol of LiOH into 50ml of deionized water and stirring to obtain uniform alkaline solution; 0.5g of nano silicon particles are added into 50ml of ethanol, and the uniform suspension is obtained through ultrasonic and mechanical stirring.
Steps S2 and S3 are the same as in example 1.
Example 3
The preparation method of the double-layer oxide coated silicon-based anode material comprises the following steps:
s1: adding 2mmol of LiOH into 50ml of deionized water and stirring to obtain uniform alkaline solution; 0.5g of nano silicon particles are added into 50ml of deionized water, and the uniform suspension is obtained through ultrasonic and mechanical stirring.
Steps S2 and S3 are the same as in example 1.
Comparative example
As a comparative example, a nano-silicon material without any treatment was used.
Fig. 1 shows the oxygen content test results of the silicon-based anode materials in comparative examples and examples 1 to 3, and the oxygen content of the silicon-based anode materials in examples 1 to 3 after the alkaline solution treatment is obviously improved compared with the oxygen content of the silicon-based anode materials in comparative examples, which indicates that the alkaline solution treatment can generate oxides in the silicon-based anode materials. In comparative examples 1 to 3, when the water ratio in the alkaline solution is increased, the oxygen content of the prepared silicon-based anode material is also increased and reaches the limit.
Fig. 2 is XPS graphs of silicon-based anode materials in comparative examples and examples 2 to 3, all of which have silicon oxide present on the surface. The oxide on the surface of the material in the comparative example is composed of SiO and SiO 0.5 The composition is that the silicon contacts with air to form an oxide layer naturally. The oxide on the surface of the material in examples 2 to 3 was composed of SiO 1.5 And SiO 0.5 The composition shows that the alkaline solution treatment can promote the valence state of silicon in the oxide on the surface of the material.
Fig. 3 is an SEM image of the silicon-based negative electrode material in comparative example and example 2, the surface of the nano-silicon material without any treatment is smooth, and no other particles are attached; the material treated by the alkaline solution has a layer of small particles closely arranged on the surface of the particles to form an inner coating layer, and aggregates of the small particles are distributed above the inner coating layer to form an outer coating layer.
Fig. 4 is a graph showing the cycle performance of the silicon-based anode materials of comparative examples and examples 1 to 3, wherein the first charge specific capacity of example 1 is slightly improved compared with that of comparative example, and the first charge specific capacities of examples 2 to 3 are all significantly reduced, which means that the release of the silicon-based anode material capacity is facilitated when the surface oxygen content of the material is slightly improved, and the specific volume of the material is reduced when the oxygen content of the material is gradually increased. Compared with the comparative examples, the silicon-based anode materials in examples 1-3 have significantly improved cycle stability, have oxygen content of about 5%, and have optimal cycle performance after forming a double-layer oxide coating layer.
While the foregoing is directed to the preferred embodiments of the present invention, it will be appreciated by those skilled in the art that various modifications and adaptations can be made without departing from the principles of the present invention, and such modifications and adaptations are intended to be comprehended within the scope of the present invention.
Claims (10)
1. The double-layer oxide coated silicon-based anode material is characterized by comprising an inner core composed of crystalline silicon particles and a double-layer coating layer; wherein,
the double-layer coating layer consists of inner and outer layers of SiO x The particles are piled up and arranged;
inner SiO layer in double-layer coating layer x The particles are uniformly and tightly distributed, the inner core is completely wrapped, and the outer layer is SiO x The particle parts are clustered together and are adhered to the SiO of the inner layer in a more dispersed way x The surface of the particles.
2. The double oxide-coated silicon-based anode material according to claim 1, wherein the particle size of the crystalline silicon particles is 50 to 500nm; siO in the double-layer coating layer x The particle size of the particles is 1-30 nm.
3. The double oxide-coated silicon-based anode material according to claim 1 or 2, wherein the SiO x The particles are SiO 2 、SiO 1.5 、SiO、SiO 0.5 At least one of (a) and (b); the SiO is x The oxygen content in the particles accounts for 1-10% of the mass of the silicon-based anode material.
4. A method for preparing a double oxide coated silicon-based anode material according to any one of claims 1 to 3, comprising the steps of:
s1, preparing an alkaline solution;
s2, adding the nano silicon into the prepared alkaline solution, stirring, and carrying out liquid phase reaction;
s3, after the liquid phase reaction is finished, filtering, washing and drying to obtain the silicon-based anode material.
5. The method for producing a double oxide-coated silicon-based anode material according to claim 4, wherein in step S1, the alkali in the alkaline solution comprises NH 4 OH、LiOH、NaOH、KOH、Ca(OH) 2 、Ba(OH) 2 At least one of the above, the concentration of the alkali is 0.01 to 0.5mol/L.
6. The method for preparing a double oxide coated silicon-based anode material according to claim 5, wherein in step S1, the solvent of the alkaline solution is a mixture of water and an organic solvent, and the volume ratio of water is 1-100%.
7. The method for preparing a double oxide-coated silicon-based anode material according to claim 6, wherein the organic solvent comprises at least one of ethanol, methanol, acetone, and ethyl acetate.
8. The method for preparing a double oxide coated silicon-based anode material according to claim 7, wherein in the step S2, the stirring time is 0.1 to 24 hours, and the reaction temperature is 20 to 60 ℃.
9. The method for preparing a double oxide coated silicon-based anode material according to claim 8, wherein in step S3, the drying mode is freeze drying or vacuum drying; the temperature of vacuum drying is 50-90 ℃; the liquid used in the washing process is at least one of water and ethanol.
10. A lithium ion battery, characterized by comprising the double-layer oxide coated silicon-based anode material according to any one of claims 1 to 3 or the double-layer oxide coated silicon-based anode material prepared by the preparation method according to any one of claims 4 to 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311714282.7A CN117457886A (en) | 2023-12-14 | 2023-12-14 | Double-layer oxide coated silicon-based anode material and preparation method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311714282.7A CN117457886A (en) | 2023-12-14 | 2023-12-14 | Double-layer oxide coated silicon-based anode material and preparation method and application thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117457886A true CN117457886A (en) | 2024-01-26 |
Family
ID=89587830
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311714282.7A Pending CN117457886A (en) | 2023-12-14 | 2023-12-14 | Double-layer oxide coated silicon-based anode material and preparation method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117457886A (en) |
-
2023
- 2023-12-14 CN CN202311714282.7A patent/CN117457886A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109192940B (en) | Titanium dioxide/graphene multi-element modified Mxene composite material and preparation method thereof | |
| CN108598444B (en) | Vanadium trioxide/graphene composite negative electrode material of lithium ion battery and preparation method | |
| CN112018344B (en) | Carbon-coated nickel sulfide electrode material and preparation method and application thereof | |
| CN101937994A (en) | Graphene/aluminum composite cathode material of lithium ion battery and preparation method thereof | |
| CN107204433B (en) | silicon/PEDOT composite material, preparation method thereof and application of silicon/PEDOT composite material as lithium ion battery cathode material | |
| CN112652758B (en) | Silicon oxide/carbon microsphere composite negative electrode material for lithium ion battery and preparation method thereof | |
| CN108807912B (en) | C @ SnOx(x=0,1,2)Preparation and application of @ C mesoporous nano hollow sphere structure | |
| CN113346054A (en) | Preparation method and application of MXene-carbon nanocage-sulfur composite material | |
| CN112110448A (en) | Nitrogen-doped carbon and nano-silicon composite anode material and preparation method thereof | |
| CN111517374A (en) | Fe7S8Preparation method of/C composite material | |
| CN110600680A (en) | Positive electrode slurry, positive plate comprising positive electrode slurry and lithium ion battery | |
| CN111540868A (en) | Preparation method and application of two-dimensional manganese dioxide modified polypropylene diaphragm | |
| CN111193022B (en) | Preparation and application of modified ammonium trifluorooxotitanate for lithium ion battery | |
| CN113823781A (en) | Composite negative electrode material and preparation method thereof | |
| CN112670486B (en) | Modified lithium titanate electrode material and preparation method thereof | |
| CN113571681A (en) | Hollow titanium dioxide/nickel/carbon composite material and preparation method and application thereof | |
| CN110165201B (en) | Preparation method of Si @ Cu hollow core-shell composite material | |
| CN112028045A (en) | Conductive lithium iron phosphate and preparation method and application thereof | |
| CN109461917B (en) | Preparation method of lanthanum zirconate in-situ coated high-nickel ternary cathode material | |
| CN111146007A (en) | Zinc ion hybrid supercapacitor and preparation method thereof | |
| CN112331812B (en) | MoO (MoO) 2 Preparation method of nanorod anode material | |
| CN109273670B (en) | Metal lithium cathode with high-specific-surface-area mesoporous protective film and preparation method thereof | |
| CN116169339A (en) | Secondary battery and electric equipment comprising same | |
| CN111525097A (en) | Negative electrode material, preparation method and application thereof | |
| CN111261866B (en) | Preparation method of ZnO/C nano composite microsphere material with capsule structure |
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 |