CN110902667B - Preparation method of porous Si/C negative electrode material - Google Patents
Preparation method of porous Si/C negative electrode material Download PDFInfo
- Publication number
- CN110902667B CN110902667B CN201911227481.9A CN201911227481A CN110902667B CN 110902667 B CN110902667 B CN 110902667B CN 201911227481 A CN201911227481 A CN 201911227481A CN 110902667 B CN110902667 B CN 110902667B
- Authority
- CN
- China
- Prior art keywords
- lignocellulose
- ball milling
- porous
- dispersion
- mixture
- 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
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/05—Preparation or purification of carbon not covered by groups C01B32/15, C01B32/20, C01B32/25, C01B32/30
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B33/00—Silicon; Compounds thereof
- C01B33/02—Silicon
-
- 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
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/01—Particle morphology depicted by an image
- C01P2004/03—Particle morphology depicted by an image obtained by SEM
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Inorganic Chemistry (AREA)
- Materials Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Battery Electrode And Active Subsutance (AREA)
- Silicon Compounds (AREA)
Abstract
The invention discloses a preparation method of a porous Si/C negative electrode material, which comprises the following steps of (1) dispersing lignocellulose in an alkaline aqueous solution, and performing ball milling dispersion to obtain a lignocellulose dispersion liquid; (2) adjusting the pH value of the lignocellulose dispersion liquid to 5-7; (3) Mixing Si powder and the lignocellulose dispersion liquid after pH adjustment, and placing the mixture in a ball milling tank for ball milling and dispersion; (4) Carrying out negative pressure suction filtration on the dispersion liquid after ball milling, and separating a paper-like solid mixture; (5) And (3) carrying out heat treatment on the separated paper-like solid mixture in an inert atmosphere to carbonize the mixture, cooling to room temperature after the carbonization, washing with water, and drying to obtain the Si/C negative electrode material. According to the invention, by changing the mass ratio of Si powder to wood fiber and other factors, the quantity ratio of Si to carbon and the properties of pore channels and the like in the Si/C cathode material can be regulated and controlled to adapt to the huge volume change in the Si charge-discharge process, so that the volume effect problem of the Si electrode material is solved.
Description
Technical Field
The invention relates to the technical field of lithium ion batteries, in particular to a preparation method of a porous Si/C negative electrode material.
Background
The high specific capacity electrode material is the key to improve the energy density of the lithium ion battery. Compared with the theoretical specific capacity of 372mAh/g of the conventional graphite cathode, si as the cathode theoretically has the specific capacity of 4200mAh/g, so that the application of the Si in a lithium ion battery is concerned. However, practical use of Si in lithium ion batteries suffers from a large volume expansion (up to 300% volume change) and low electronic conductivity. In order to solve the problems of Si, the economic and feasible mode is mainly to compound carbon with good electronic conductivity with Si, so that the structural stability is improved, and the electronic conductivity of the material is improved, thereby realizing the purpose of improving the cyclic charge-discharge stability of the Si material. At present, the method for compounding Si and carbon mainly comprises two types: one is to cover carbon on the surface of Si particles by vapor deposition; and the other is that a mixture is formed by adopting micromolecule organic matters capable of being subjected to condensation polymerization carbonization at high temperature, such as cane sugar and the like, and Si, and then the organic matters are carbonized at high temperature to form the Si/C cathode material. However, the vapor phase carbon deposition method has harsh preparation conditions, low efficiency and high cost, and is difficult to be used for large-scale industrialization; small molecular organic matters such as cane sugar are melted in the process of temperature rise, so that compact coating is easily formed on the surface of Si, and a compact Si/C negative electrode material is easily formed in the process of pyrolysis and carbonization, which is unfavorable for the stable structure of buffer volume change, so that the circulation stability of the Si material cannot be effectively improved.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provide a preparation method of a porous Si/C cathode material, and the method can adjust and control the quantity ratio of Si and carbon in the Si/C cathode material and the properties of pore channels and the like by changing the mass ratio of Si powder to wood fiber and other factors to adapt to the huge volume change in the Si charge-discharge process, thereby solving the volume effect problem of the Si electrode material.
In order to achieve the purpose, the invention adopts the following technical scheme:
a preparation method of a porous Si/C negative electrode material comprises the following steps:
(1) Dispersing lignocellulose in an alkaline aqueous solution, and performing ball milling dispersion to obtain a lignocellulose dispersion liquid;
(2) Adjusting the pH value of the lignocellulose dispersion liquid to 5-7;
in this step, the pH of the lignocellulose dispersion is adjusted to the above range in order to avoid dissolution of the Si powder, considering that it is easily soluble in an alkaline solution;
(3) Mixing Si powder and the lignocellulose dispersion liquid after pH adjustment, and placing the mixture in a ball milling tank for ball milling and dispersion;
(4) Carrying out negative pressure suction filtration on the dispersion liquid after ball milling, and separating a paper-like solid mixture;
(5) And (3) carrying out heat treatment on the separated paper-like solid mixture in an inert atmosphere to carbonize the mixture, cooling to room temperature after the carbonization, washing with water, and drying to obtain the Si/C negative electrode material. The negative electrode material forms the negative electrode material of the lithium ion battery.
In the step (1), the alkaline aqueous solution is prepared by alkali and distilled water according to the volume ratio of 1/20-1/50, and the addition amount of the lignocellulose is 1-2% of the concentration of the lignocellulose.
The alkali is strong ammonia water with the mass concentration of 25%. In the step, the alkali can also adopt other alkaline substances such as sodium hydroxide, sodium carbonate and the like, but other impurities can be introduced, and the strong ammonia water is selected and used in the invention because the ammonia water is easy to remove.
In the step (1), the ball milling time is 0.5-2 hours.
In the step (2), the pH of the lignocellulose dispersion liquid is adjusted by adopting liquid organic acid. Wherein the liquid organic acid is acetic acid or formic acid.
In the step (3), the mass ratio of the lignocellulose to the Si powder is 5-10. In the step, if the mass ratio of the lignocellulose to the Si powder is too high, the discharge specific capacity of the prepared negative electrode material is reduced, and if the mass ratio of the lignocellulose to the Si powder is too low, the content of C in the prepared Si/C negative electrode material is low, so that the structural stability in the charging and discharging process is not facilitated.
In the step (3), the average particle diameter of the Si powder is 200nm or less.
In the step (3), the ball milling time is 2-5 h.
In the step (5), the gas used in the inert atmosphere is nitrogen or argon; the carbonization temperature is 500-800 ℃, and the time is 5-10 h.
In the step (5), the heat treatment is carried out in a tube furnace, and the tube furnace is heated to the carbonization temperature at the heating rate of 1-8 ℃/min.
The preparation method comprises the steps of mixing lignocellulose with an ammonia water solution, then carrying out ball milling to enable the lignocellulose to swell, further carrying out ball milling with Si powder to form uniform dispersion liquid, carrying out suction filtration to obtain uniformly dispersed precursors of Si and lignocellulose, and carrying out high-temperature heat treatment to obtain the Si/C negative electrode material. By changing the quantity ratio of Si powder to lignocellulose and other factors, the quantity ratio of Si to carbon in the Si/C negative electrode material can be regulated and controlled to adapt to the huge volume change in the Si charge-discharge process, so that the problem of the volume effect of the Si electrode material is solved.
Compared with the prior art, the invention has the following advantages and beneficial effects:
(1) Swelling lignocellulose under the action of ammonia water to obtain uniform dispersion of Si powder and lignocellulose, then performing suction filtration to obtain a precursor, and preparing the Si/C negative electrode material by high-temperature carbonization, wherein the process is simple and is suitable for industrial production;
(2) Lignocellulose molecules contain a large number of electronegative oxygen-containing groups, so that electrostatic interaction is easily generated between the lignocellulose molecules and Si, the uniform dispersion of Si in lignocellulose is promoted, the uniform dispersion of Si in a carbon carrier is facilitated, and the electrochemical performance of the lignocellulose is facilitated;
(3) The lignocellulose belongs to a natural product, has wide sources, is low in price and easy to obtain, and is extremely favorable for the industrial preparation of Si/C cathode materials.
Drawings
FIG. 1 is a scanning electron micrograph of the Si/C anode material precursor prepared in example 1;
FIG. 2 is a scanning electron micrograph of the Si/C anode material prepared in example 1;
FIG. 3 is a charge and discharge graph of the Si/C anode material prepared in example 1;
FIG. 4 is a charge and discharge graph of the Si/C anode material prepared in example 2;
FIG. 5 is a charge and discharge graph of the Si/C anode material prepared in example 3.
Detailed Description
The invention is further described with reference to the accompanying drawings and the detailed description below:
example 1
A preparation method of a porous Si/C anode material comprises the following steps:
(1) Adding 0.3g of lignocellulose and 1ml of 25% concentrated ammonia water into 20ml of distilled water, and performing ball milling dispersion for 1 hour to obtain lignocellulose dispersion liquid;
(2) Adjusting the pH of the lignocellulosic dispersion to 7 with acetic acid;
(3) Mixing 60mg of Si powder with the average particle size of 100nm and the lignocellulose dispersion liquid after pH adjustment, and placing the mixture in a ball milling tank for ball milling and dispersing for 5 hours;
(4) Carrying out negative pressure suction filtration on the dispersion liquid after ball milling, and separating out a paper-like solid mixture;
(5) And (3) placing the solid mixture in a tube furnace, heating to 700 ℃ at the speed of 2 ℃/min under the nitrogen atmosphere for heat treatment for 5h, cooling to room temperature, washing with water, and drying to obtain the Si/C cathode material.
In the above process, si is uniformly dispersed in lignocellulose to form a precursor, and the structure of the precursor is shown in fig. 1; the structure of the Si/C anode material obtained after the heat treatment of the precursor is shown in fig. 2, and it can be seen from fig. 2 that: si is uniformly dispersed in carbon, and meanwhile, rich pore channels exist in the cathode material. Referring to fig. 3, the charge and discharge curves of the Si/C negative electrode material having a specific discharge capacity of about 960mAh/g at a current density of 200 mA/g.
Example 2
A preparation method of a porous Si/C negative electrode material comprises the following steps:
(1) Adding 0.414g of lignocellulose and 1ml of 25% concentrated ammonia water into 40ml of distilled water, and performing ball milling dispersion for 0.5h to obtain lignocellulose dispersion liquid;
(2) Adjusting the pH of the lignocellulose dispersion to 5 by adopting formic acid;
(3) Mixing 60mg of Si powder with the average particle size of 20nm and the lignocellulose dispersion liquid after pH adjustment, and placing the mixture in a ball milling tank for ball milling and dispersion for 2 hours;
(4) Carrying out negative pressure suction filtration on the dispersion liquid after ball milling, and separating a paper-like solid mixture;
(5) And (3) placing the solid mixture in a tube furnace, heating to 500 ℃ at the speed of 1 ℃/min in the nitrogen atmosphere, carrying out heat treatment for 10 hours, cooling to room temperature, washing with water, and drying to obtain the Si/C negative electrode material.
Referring to fig. 4, the charge and discharge curves of the Si/C negative electrode material prepared in this example, the Si/C negative electrode material has a specific discharge capacity of about 1250mAh/g at a current density of 200 mA/g.
Example 3
A preparation method of a porous Si/C anode material comprises the following steps:
(1) Adding 1.04g of lignocellulose and 1ml of 25% concentrated ammonia water into 50ml of distilled water, and performing ball milling dispersion for 2 hours to obtain lignocellulose dispersion liquid;
(2) Adjusting the pH of the lignocellulosic dispersion to 7 with acetic acid;
(3) Mixing 104mg of Si powder with the average particle size of 200nm and the lignocellulose dispersion liquid after pH adjustment, and placing the mixture in a ball milling tank for ball milling and dispersion for 5 hours;
(4) Carrying out negative pressure suction filtration on the dispersion liquid after ball milling, and separating a paper-like solid mixture;
(5) And (3) placing the solid mixture in a tube furnace, heating to 800 ℃ at the speed of 8 ℃/min under the argon atmosphere, carrying out heat treatment for 5 hours, cooling to room temperature, washing with water, and drying to obtain the Si/C negative electrode material.
Referring to fig. 5, the charge and discharge curve of the Si/C anode material prepared in this embodiment shows that the Si/C anode material has a specific discharge capacity of about 1070mAh/g at a current density of 200 mA/g.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.
Claims (7)
1. A preparation method of a porous Si/C negative electrode material is characterized by comprising the following steps: the method comprises the following steps:
(1) Dispersing lignocellulose in an alkaline aqueous solution, and performing ball milling dispersion to obtain a lignocellulose dispersion solution; the alkaline aqueous solution is prepared by alkali and distilled water according to the volume ratio of 1/20-1/50, and the alkali is concentrated ammonia water with the mass concentration of 25%;
(2) Adjusting the pH of the lignocellulosic dispersion to 5~7;
(3) Mixing Si powder and the lignocellulose dispersion liquid after pH adjustment, and placing the mixture in a ball milling tank for ball milling and dispersion; the mass ratio of the lignocellulose to the Si powder is 5-10; the average grain diameter of the Si powder is below 200 nm;
(4) Carrying out negative pressure suction filtration on the dispersion liquid after ball milling, and separating a paper-like solid mixture;
(5) And (3) carrying out heat treatment on the separated paper-like solid mixture in an inert atmosphere to carbonize the mixture, cooling the carbonized mixture to room temperature after the carbonization is finished, and washing and drying the cooled mixture to obtain the Si/C negative electrode material.
2. The method for preparing a porous Si/C anode material according to claim 1, wherein: in the step (1), the adding amount of the lignocellulose is 1% -2% of the concentration of the lignocellulose.
3. The method for preparing a porous Si/C anode material according to claim 1, wherein: in the step (1), the ball milling time is 0.5 to 2 hours.
4. The method for preparing a porous Si/C anode material according to claim 1, wherein: in the step (2), the pH of the lignocellulose dispersion liquid is adjusted by adopting liquid organic acid.
5. The method for preparing a porous Si/C anode material according to claim 1, wherein: in the step (3), the ball milling time is 2 to 5 hours.
6. The method for preparing a porous Si/C anode material according to claim 1, wherein: in the step (5), the gas used in the inert atmosphere is nitrogen or argon; the carbonization temperature is 500 to 800 ℃, and the time is 5 to 10 hours.
7. The method for preparing a porous Si/C anode material according to claim 1, wherein: in step (5), the heat treatment is carried out in a tube furnace which is raised to the carbonization temperature at a rate of temperature rise of 1~8 ℃/min.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911227481.9A CN110902667B (en) | 2019-12-04 | 2019-12-04 | Preparation method of porous Si/C negative electrode material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911227481.9A CN110902667B (en) | 2019-12-04 | 2019-12-04 | Preparation method of porous Si/C negative electrode material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110902667A CN110902667A (en) | 2020-03-24 |
| CN110902667B true CN110902667B (en) | 2023-04-18 |
Family
ID=69822274
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911227481.9A Active CN110902667B (en) | 2019-12-04 | 2019-12-04 | Preparation method of porous Si/C negative electrode material |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110902667B (en) |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102013204799A1 (en) * | 2013-03-19 | 2014-09-25 | Wacker Chemie Ag | Si / C composites as anode materials for lithium-ion batteries |
| CN104143629A (en) * | 2014-08-06 | 2014-11-12 | 广东省工业技术研究院(广州有色金属研究院) | Method for preparing Si/C/graphite composite negative electrode material |
| CN106257716B (en) * | 2016-08-30 | 2019-01-11 | 浙江超威创元实业有限公司 | A kind of preparation method and lithium ion battery of silicon-carbon composite cathode material |
| CN108091866B (en) * | 2017-12-22 | 2020-08-21 | 厦门大学 | Preparation method of silicon-carbon negative electrode material for lithium ion battery |
| CN109004188B (en) * | 2018-07-09 | 2022-03-25 | 绍兴文理学院 | Green preparation method of porous carbon-silicon composite material |
| CN109244429B (en) * | 2018-11-06 | 2021-02-19 | 绍兴文理学院 | Preparation method of lithium ion battery negative electrode material |
-
2019
- 2019-12-04 CN CN201911227481.9A patent/CN110902667B/en active Active
Non-Patent Citations (1)
| Title |
|---|
| Si-C Composites Synthesized by Using Si Nanoparticles and Carboxymethyl Cellulose as Anode Materials for Lithium-ion Batteries;Jeong-Boon Koo等;《Journal of the Korean Physical Society》;20151130;第67卷(第10期);第1831-1837页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110902667A (en) | 2020-03-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107170965B (en) | Silicon-carbon composite material and preparation method and application thereof | |
| CN111725504B (en) | Silicon-carbon negative electrode material for lithium ion battery and preparation method thereof | |
| CN115417398B (en) | High first-effect hard carbon negative electrode for sodium ion battery | |
| CN110668418B (en) | Preparation method of hard carbon microspheres with high specific capacitance | |
| CN114188511B (en) | Nitrogen-doped carbon-coated graphite composite material and preparation method and application thereof | |
| CN114447325A (en) | Porous carbon material, preparation method thereof, negative electrode and lithium metal battery | |
| CN111697218A (en) | Silicon-carbon negative electrode material and preparation method thereof | |
| CN113023734A (en) | Porous nitrogen-doped silicon-based negative electrode material and preparation method thereof, negative electrode plate and lithium ion battery | |
| CN110048092B (en) | Lithium battery silicon-carbon composite material and preparation method thereof | |
| CN112125304B (en) | Metal oxide modified micro-nano silicon-graphite composite negative electrode material and preparation method thereof | |
| CN117383540A (en) | Preparation method of high-magnification modified biomass hard carbon material | |
| CN117613218A (en) | Biomass hard carbon composite anode material and preparation method and application thereof | |
| CN109473648B (en) | Silicon-carbon composite material for lithium ion battery and preparation method thereof | |
| CN110902667B (en) | Preparation method of porous Si/C negative electrode material | |
| CN116216692A (en) | Smokeless coal-based nitrogen-doped carbon material and preparation method and application thereof | |
| CN115579470A (en) | Modified asphalt coated microcrystalline graphite negative electrode material and preparation method thereof | |
| CN109244429B (en) | Preparation method of lithium ion battery negative electrode material | |
| CN110600738B (en) | Method for preparing low-temperature lithium ion battery hard carbon negative electrode material | |
| CN113745519A (en) | Silicon-based negative electrode material with artificial SEI film and preparation method and application thereof | |
| CN107658457B (en) | SiO for fused salt electrolysis2-Gc/C composite electrode and preparation method thereof | |
| CN116632233B (en) | High-performance sodium ion battery doped hard carbon negative electrode material and preparation method thereof | |
| CN118136787B (en) | Method for preparing sodium ion battery negative electrode by bamboo wood and sodium ion battery negative electrode | |
| CN110993895B (en) | Preparation method of Si/graphene composite flexible electrode of lithium ion battery | |
| CN112952071B (en) | Porous conductive ceramic composite silicon negative electrode material and preparation method thereof | |
| CN117727918A (en) | Coconut shell-phenolic resin-based silicon-carbon composite material and preparation 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 |