CN116845225A - Preparation method of nano silicon/graphene lithium ion battery anode material - Google Patents
Preparation method of nano silicon/graphene lithium ion battery anode material Download PDFInfo
- Publication number
- CN116845225A CN116845225A CN202310725304.3A CN202310725304A CN116845225A CN 116845225 A CN116845225 A CN 116845225A CN 202310725304 A CN202310725304 A CN 202310725304A CN 116845225 A CN116845225 A CN 116845225A
- Authority
- CN
- China
- Prior art keywords
- silicon
- graphene
- lithium ion
- anode material
- ion battery
- 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
- 239000005543 nano-size silicon particle Substances 0.000 title claims abstract description 91
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 title claims abstract description 89
- 229910021389 graphene Inorganic materials 0.000 title claims abstract description 66
- 229910001416 lithium ion Inorganic materials 0.000 title claims abstract description 48
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 title claims abstract description 47
- 239000010405 anode material Substances 0.000 title claims abstract description 41
- 238000002360 preparation method Methods 0.000 title claims abstract description 23
- 238000000034 method Methods 0.000 claims abstract description 22
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 claims abstract description 16
- 229910017604 nitric acid Inorganic materials 0.000 claims abstract description 16
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 12
- 238000006459 hydrosilylation reaction Methods 0.000 claims abstract description 11
- 239000002253 acid Substances 0.000 claims abstract description 10
- 238000001035 drying Methods 0.000 claims abstract description 6
- 238000002156 mixing Methods 0.000 claims abstract description 3
- 238000004381 surface treatment Methods 0.000 claims abstract description 3
- 239000000243 solution Substances 0.000 claims description 62
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 claims description 33
- 238000006243 chemical reaction Methods 0.000 claims description 24
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 16
- 239000002033 PVDF binder Substances 0.000 claims description 9
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Natural products CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 claims description 9
- 229920002981 polyvinylidene fluoride Polymers 0.000 claims description 9
- 230000008569 process Effects 0.000 claims description 9
- 238000005530 etching Methods 0.000 claims description 8
- 239000011259 mixed solution Substances 0.000 claims description 7
- FYGHSUNMUKGBRK-UHFFFAOYSA-N 1,2,3-trimethylbenzene Chemical compound CC1=CC=CC(C)=C1C FYGHSUNMUKGBRK-UHFFFAOYSA-N 0.000 claims description 6
- HEDRZPFGACZZDS-UHFFFAOYSA-N Chloroform Chemical compound ClC(Cl)Cl HEDRZPFGACZZDS-UHFFFAOYSA-N 0.000 claims description 6
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 claims description 6
- 150000001345 alkine derivatives Chemical class 0.000 claims description 6
- 238000010438 heat treatment Methods 0.000 claims description 6
- 239000005416 organic matter Substances 0.000 claims description 6
- 239000003960 organic solvent Substances 0.000 claims description 6
- 239000002245 particle Substances 0.000 claims description 6
- 238000001704 evaporation Methods 0.000 claims description 5
- 239000012528 membrane Substances 0.000 claims description 5
- CRSBERNSMYQZNG-UHFFFAOYSA-N 1 -dodecene Natural products CCCCCCCCCCC=C CRSBERNSMYQZNG-UHFFFAOYSA-N 0.000 claims description 4
- SNRUBQQJIBEYMU-UHFFFAOYSA-N Dodecane Natural products CCCCCCCCCCCC SNRUBQQJIBEYMU-UHFFFAOYSA-N 0.000 claims description 4
- 229940069096 dodecene Drugs 0.000 claims description 4
- 238000004519 manufacturing process Methods 0.000 claims description 4
- 238000009210 therapy by ultrasound Methods 0.000 claims description 4
- XMWRBQBLMFGWIX-UHFFFAOYSA-N C60 fullerene Chemical compound C12=C3C(C4=C56)=C7C8=C5C5=C9C%10=C6C6=C4C1=C1C4=C6C6=C%10C%10=C9C9=C%11C5=C8C5=C8C7=C3C3=C7C2=C1C1=C2C4=C6C4=C%10C6=C9C9=C%11C5=C5C8=C3C3=C7C1=C1C2=C4C6=C2C9=C5C3=C12 XMWRBQBLMFGWIX-UHFFFAOYSA-N 0.000 claims description 2
- 230000005587 bubbling Effects 0.000 claims description 2
- 238000001914 filtration Methods 0.000 claims description 2
- 229910003472 fullerene Inorganic materials 0.000 claims description 2
- CCCMONHAUSKTEQ-UHFFFAOYSA-N octadecene Natural products CCCCCCCCCCCCCCCCC=C CCCMONHAUSKTEQ-UHFFFAOYSA-N 0.000 claims description 2
- BDERNNFJNOPAEC-UHFFFAOYSA-N propan-1-ol Chemical compound CCCO BDERNNFJNOPAEC-UHFFFAOYSA-N 0.000 claims description 2
- 125000003944 tolyl group Chemical group 0.000 claims description 2
- 238000001291 vacuum drying Methods 0.000 claims description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 abstract description 21
- 229910052710 silicon Inorganic materials 0.000 abstract description 18
- 239000010703 silicon Substances 0.000 abstract description 18
- 239000000463 material Substances 0.000 abstract description 11
- 230000002776 aggregation Effects 0.000 abstract description 3
- 238000005054 agglomeration Methods 0.000 abstract description 2
- 230000005518 electrochemistry Effects 0.000 abstract description 2
- 239000011863 silicon-based powder Substances 0.000 abstract description 2
- 239000002131 composite material Substances 0.000 description 25
- 229910002804 graphite Inorganic materials 0.000 description 10
- 239000010439 graphite Substances 0.000 description 10
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 6
- 229910052744 lithium Inorganic materials 0.000 description 6
- 239000006185 dispersion Substances 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 239000007773 negative electrode material Substances 0.000 description 5
- 239000002210 silicon-based material Substances 0.000 description 5
- 239000011856 silicon-based particle Substances 0.000 description 5
- 230000007547 defect Effects 0.000 description 4
- 238000011161 development Methods 0.000 description 4
- 238000002474 experimental method Methods 0.000 description 4
- 238000009830 intercalation Methods 0.000 description 4
- 230000002687 intercalation Effects 0.000 description 4
- 230000014759 maintenance of location Effects 0.000 description 4
- 238000009831 deintercalation Methods 0.000 description 3
- 239000008367 deionised water Substances 0.000 description 3
- 229910021641 deionized water Inorganic materials 0.000 description 3
- 238000007709 nanocrystallization Methods 0.000 description 3
- 238000011160 research Methods 0.000 description 3
- 238000003860 storage Methods 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- 229910010661 Li22Si5 Inorganic materials 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 239000003575 carbonaceous material Substances 0.000 description 2
- 238000013329 compounding Methods 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 239000011159 matrix material Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 230000010355 oscillation Effects 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 229910005001 Li12Si7 Inorganic materials 0.000 description 1
- HMDDXIMCDZRSNE-UHFFFAOYSA-N [C].[Si] Chemical compound [C].[Si] HMDDXIMCDZRSNE-UHFFFAOYSA-N 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 239000011149 active material Substances 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 238000004220 aggregation Methods 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 238000005275 alloying Methods 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- OJIJEKBXJYRIBZ-UHFFFAOYSA-N cadmium nickel Chemical compound [Ni].[Cd] OJIJEKBXJYRIBZ-UHFFFAOYSA-N 0.000 description 1
- 239000006229 carbon black Substances 0.000 description 1
- 239000002041 carbon nanotube Substances 0.000 description 1
- 229910021393 carbon nanotube Inorganic materials 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 239000010406 cathode material Substances 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000000739 chaotic effect Effects 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 230000008602 contraction Effects 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 239000003792 electrolyte Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 230000002427 irreversible effect Effects 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 230000003446 memory effect Effects 0.000 description 1
- 239000002120 nanofilm Substances 0.000 description 1
- 239000002105 nanoparticle Substances 0.000 description 1
- 239000002071 nanotube Substances 0.000 description 1
- 239000002070 nanowire Substances 0.000 description 1
- 231100000252 nontoxic Toxicity 0.000 description 1
- 230000003000 nontoxic effect Effects 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 238000010298 pulverizing process Methods 0.000 description 1
- 150000003377 silicon compounds Chemical class 0.000 description 1
- 239000002153 silicon-carbon composite material Substances 0.000 description 1
- 239000002356 single layer Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 238000010301 surface-oxidation reaction Methods 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- 230000002194 synthesizing effect Effects 0.000 description 1
- 229910052718 tin Inorganic materials 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
- H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
- H01M4/386—Silicon or alloys based on silicon
-
- 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
- H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
- H01M4/624—Electric conductive fillers
- H01M4/625—Carbon or graphite
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
- H01M2004/027—Negative electrodes
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Nanotechnology (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Physics & Mathematics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Crystallography & Structural Chemistry (AREA)
- Materials Engineering (AREA)
- Composite Materials (AREA)
- Battery Electrode And Active Subsutance (AREA)
Abstract
A preparation method of a nano silicon/graphene lithium ion battery anode material belongs to the technical field of new energy materials and electrochemistry. Firstly, treating silicon nano particles by using mixed acid of HF/HNO3 to obtain Si-H surfaces, then, carrying out hydrosilylation reaction on the silicon nano particles subjected to surface treatment by using various carbon-containing organic matters containing double bonds or triple bonds, and finally, directly mixing graphene with the silicon nano particles subjected to hydrosilylation reaction, and drying to obtain the nano silicon/graphene anode material. According to the preparation method of the nano silicon/graphene lithium ion battery anode material, on one hand, the silicon nano particles are adopted, so that the problem of volume expansion of silicon is effectively restrained, in addition, silicon powder prepared by adopting a hydrosilylation method in post-treatment has good monodispersity, the occurrence of silicon agglomeration is effectively avoided, and the rate performance and the cycle performance of the lithium ion battery are effectively improved by combining the excellent conductivity of graphene.
Description
Technical Field
The invention belongs to the technical field of new energy materials and electrochemistry, and particularly relates to a preparation method of a nano silicon/graphene lithium ion battery anode material.
Background
Compared with nickel-cadmium batteries, nickel-hydrogen batteries and the like, the lithium ion battery has the advantages of high energy density, good cycle life, good safety, low self-discharge rate, no memory effect and small pollution, and is widely applied to electric automobiles, portable electronic equipment and the like.
The negative electrode material is used as a storage main body of the lithium ion battery, and is a key for improving battery parameters such as capacity and coulomb efficiency, cycle performance and the like of the lithium ion battery along with intercalation and deintercalation of lithium ions in the working process of the battery. Since the first commercial use of lithium ion batteries by Sony corporation in 1991, graphite has been used as the negative electrode material for commercial lithium ion batteries. However, the theoretical specific capacity of graphite is only 372mAh/g, and the specific capacity of graphite is close to the theoretical value in practical commercial application, so that the further improvement of the capacity of the lithium ion battery is greatly limited. Therefore, development and research of a negative electrode material having a high specific capacity are urgent.
During electrochemical lithium storage, silicon and lithium can form Li12Si7, li13Si4, li7Si3 and Li22Si5 alloys, and the theoretical specific capacity of Li22Si5 can reach up to 4200mAh/g, which is 10 times that of graphite, and is highest among elements (Sn, pb, al, au, pt, zn, cd, ag and Mg) capable of alloying lithium storage. In addition, the lithium intercalation potential of silicon (0.4V vs Li/Li+) is low. In view of safety performance, the voltage platform of silicon is slightly higher than that of graphite, and the phenomenon of surface lithium precipitation can not occur during charging. Moreover, the silicon source is wide, nontoxic and harmless. Therefore, silicon is a hot spot for research of lithium ion battery anode materials.
However, since silicon has a volume expansion (up to 300%) during charge and discharge of lithium ions, pulverization of materials and collapse of structures are caused, resulting in deterioration of electrical contact between active materials and a current collector, which eventually leads to rapid degradation of capacity and cycle performance of a battery.
In order to solve these problems, it is currently common to adopt measures such as nanocrystallization of a silicon material, compounding of a silicon material with another material, and combination of nanocrystallization and compounding. The nanocrystallization of the silicon material is realized by adopting materials such as synthesized nano particles, nano wires, nano tubes, nano films and the like, so that the volume expansion and contraction of silicon in the lithium intercalation/deintercalation process are reduced, and the adverse effect on the battery performance is reduced. The literature reports that when the size of silicon particles is less than 10nm, the volume expansion phenomenon of silicon disappears, and the use of silicon nanoparticles of 10nm or less as a battery anode material is of great interest to researchers.
The silicon material and other materials are compounded by synthesizing a silicon-compound, a silicon-metal compound and a silicon-carbon compound, and the researches can relieve the volume expansion, effectively improve the cycle performance of the silicon-based anode material, improve the specific capacity of a battery and reduce the irreversible capacity.
Combining the two methods is currently the most widely used method. Among the many matrix materials, carbon materials have been toughed for their advantages of good electrical conductivity, small volume expansion, and the like. Compared with pure silicon materials, the silicon-carbon composite material is used as the negative electrode of the lithium ion battery, so that the battery performance is obviously improved. Among the numerous carbon-based materials, graphene is widely used in lithium ion batteries due to its good conductivity, large specific surface area, flexibility, chemical stability, and the like. Compared with other carbon substrate materials such as graphite, carbon black and carbon nanotubes, the graphene can provide good dispersibility for the silicon nanoparticles, ensures the conductivity of the whole electrode structure, and is beneficial to realizing high multiplying power of the battery. Therefore, the nano silicon/graphene composite material is expected to be the development direction of the lithium ion battery anode material.
The conductivity of the nano silicon/graphene composite material is improved, and the nano silicon/graphene composite material is mainly realized by the following modes:
1. conductive bridging action: graphene is added between the nano silicon particles and the battery current collector, so that a conductive bridging effect can be formed, and electrons can be transmitted between the particles more quickly. This can effectively improve the electrical conductivity of the composite material.
2. Improving the conductivity of the electrode: the high conductivity of graphene can improve the overall conductivity of the electrode, thereby reducing the resistance of the electrode and improving the power density and energy density of the electrode.
3. Increasing the surface area of the electrode: the single-layer structure and the high specific surface area of the graphene can increase the surface area of the electrode, so that the contact area between the electrode and the electrolyte is increased, and the transmission of ions is promoted.
At present, the nano silicon/graphene composite material is used as a lithium ion battery negative electrode material, and has the defects of low specific capacity, unstable cycle performance and the like, so that the development of the nano silicon/graphene composite material and the lithium ion battery negative electrode material is influenced, and the development is still to be further improved. These drawbacks are mainly due to the following reasons:
1. intrinsic defects of nano-silicon: the nano silicon is used as a cathode material, and the currently mainstream synthesis means often cannot synthesize silicon particles with small size (such as 10nm or smaller) and high dispersion performance, and is insufficient to inhibit volume change in the charge and discharge process, so that the nano silicon can be aggregated, peeled and the like, and the nano silicon particles are broken and fall off. These defects can lead to capacity fade and cycle performance instability of the composite.
2. Technological method and parameters: the properties of the nano-silicon/graphene composite material depend largely on the preparation process method and the choice of parameters. For example, the mass ratio of graphene to nano-silicon, solvent selection during the preparation process, preparation temperature and time, etc. all affect the performance of the composite material. Different preparation methods and parameters may lead to different drawbacks and limitations, such as aggregation, non-uniform dispersion, surface oxidation, etc.
Therefore, in order to improve the cycle performance of the nano-silicon/graphene composite material, optimization is required in terms of selection of process methods and parameters, and new preparation methods and material combinations are explored. At the same time, the intrinsic mechanisms of the intrinsic defects of nano-silicon need to be further studied in order to better solve these problems.
Disclosure of Invention
Aiming at the problems in the prior art, the invention aims to design and provide a technical scheme of a preparation method of a nano silicon/graphene lithium ion battery anode material, wherein the prepared anode material has high specific capacity and stable cycle performance.
The preparation method of the nano silicon/graphene lithium ion battery anode material is characterized by comprising the following steps of: firstly, treating silicon nano particles by using mixed acid of HF/HNO3 to obtain Si-H surfaces, then, carrying out hydrosilylation reaction on the silicon nano particles subjected to surface treatment by using various carbon-containing organic matters containing double bonds or triple bonds, and finally, directly mixing graphene with the silicon nano particles subjected to hydrosilylation reaction, and drying to obtain the nano silicon/graphene anode material.
The preparation method of the nano silicon/graphene lithium ion battery anode material is characterized by comprising the following steps of:
1) Production of Si-H surface of silicon nanoparticles: dissolving 10-100mg of silicon nano particles in 1-100mL of alcohol solution, carrying out ultrasonic treatment for 30-60min, adding HF/HNO3 mixed acid into the obtained solution for etching, reducing the particle size in the etching process, reacting for 5-10min, adding 10-100mL of alcohol solution into the solution, filtering and collecting a PVDF film, and rapidly moving into a glove box after vacuum drying;
2) Hydrosilylation of surface treated silicon nanoparticles with carbon containing organics containing double or triple bonds: dispersing the nano silicon particles treated in the step 1) in a mixed solution of a carbon-containing organic matter containing double bonds or triple bonds and an organic solvent in a glove box, and heating the reaction solution to 150-300 ℃ until the reaction solution becomes clear;
3) Production of nano silicon/graphene anode material: and 2) adding graphene into the clear solution obtained in the step 2), and evaporating the solution to dryness to obtain the nano silicon/graphene lithium ion battery anode material.
The preparation method of the nano silicon/graphene lithium ion battery anode material is characterized by comprising the following steps of: the mass fraction of HF in the HF/HNO3 mixed acid is 45-50%, the mass fraction of HNO3 is 65-72%, the mass fraction of HF is preferably 48%, and the mass fraction of HNO3 is preferably 68%; the volume ratio of HF to HNO3 is 5-30: 1, preferably 10-25: 1, more preferably 15-20:1.
the preparation method of the nano silicon/graphene lithium ion battery anode material is characterized by comprising the following steps of: the alcohol solution is methanol, ethanol or propanol; the aperture of the PVDF membrane is 0.2-0.3 μm, and the aperture is preferably 0.25-0.27 μm.
The preparation method of the nano silicon/graphene lithium ion battery anode material is characterized by comprising the following steps of: the weight volume ratio of the silicon nano-particles to the alcohol solution is 20-80mg:10-90ml, preferably 30-70mg:20-80ml; more preferably 40-60mg:30-60ml; after the ultrasonic treatment is carried out for 40-50min and the reaction is carried out for 5-10min, 20-80mL of alcohol solution, preferably 40-60mL of alcohol solution, is added into the solution.
The preparation method of the nano silicon/graphene lithium ion battery anode material is characterized by comprising the following steps of: the carbon-containing organic matter containing double bond or triple bond is dodecene/alkyne, octadecene/alkyne, styrene/alkyne or fullerene, and the organic solvent is toluene, chloroform or trimethylbenzene.
The preparation method of the nano silicon/graphene lithium ion battery anode material is characterized by comprising the following steps of: the carbon-containing organic matter containing double bond or triple bond: the volume ratio of the mixed solution of the organic solvents is 1:10-20, and the preferred volume ratio is 1:13-16; bubbling treatment is carried out 1.1-1.3h in advance.
The preparation method of the nano silicon/graphene lithium ion battery anode material is characterized by comprising the following steps of: the reaction solution is heated to a temperature of 180 to 270 ℃, preferably 200 to 250 ℃.
As described above, the silicon nano-silicon with small size and high dispersion property is a key point of the composite anode material with high specific volume and stable cycle performance. There is much evidence in academic circles that nano-scale and high-dispersity silicon particles have good performance, however, in general, the silicon nanoparticles can be agglomerated in the process, and after graphene is compounded, the excellent conductivity of the silicon nanoparticles cannot be fully exerted, so that the improvement of multiplying power and cycle performance is limited, and therefore, hydrosilylation treatment is further needed for the silicon nanoparticles to obtain the high-dispersity silicon nanoparticles, and the graphene can be further uniformly dispersed in a matrix to exert the excellent conductivity of the graphene. Because of the very difficult preparation of small-sized, highly dispersible silicon nanoparticles, materials of this type have very few sources in the industry, and since a long time ago, scientific researchers have not been able to perform this work substantially because of the difficulty in preparing materials.
According to the preparation method of the nano silicon/graphene lithium ion battery anode material, on one hand, the silicon nano particles are adopted, so that the problem of volume expansion of silicon is effectively restrained, in addition, silicon powder prepared by adopting a hydrosilylation method in post-treatment has good monodispersity, the occurrence of silicon agglomeration is effectively avoided, and the rate performance and the cycle performance of the lithium ion battery are effectively improved by combining the excellent conductivity of graphene.
Detailed Description
The technical solutions of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, but not all embodiments. The following examples are illustrative and are intended to be illustrative of the invention and are not to be construed as limiting the invention.
Example 1
1) 40mg of silicon nanoparticles were dissolved in 10mL of methanol solution and sonicated for 30min. 11mL of HF/HNO3 mixed acid (volume ratio is 10:1) is added into the obtained solution for etching, during the etching process, the particle size is reduced, and after 5min of reaction, 10mL of methanol solution is added into the reaction solution. The silicon nanoparticles obtained by the reaction were collected on PVDF membrane and washed three times with 200mL of methanol/deionized water (volume ratio of 1:3), and after drying in a vacuum oven for 12 hours, the sample was quickly transferred to a glove box.
2) In a glove box, the nano-silicon particles treated in the step 1) are dispersed in a mixed solution of dodecene and trimethylbenzene (volume ratio is 1:10), and the reaction solution is heated to 165 ℃ until the reaction solution becomes clear.
3) And adding 10mg of graphene into the clarified solution obtained in the step 2), and evaporating the solution to dryness to obtain the nano silicon/graphene lithium ion battery anode material.
Example 2
1) 50mg of silicon nanoparticles were dissolved in 10mL of methanol solution and sonicated for 30min. 11mL of HF/HNO3 mixed acid (volume ratio: 15:1) was added to the obtained solution, the particle size was reduced during etching, and after reacting for 8min, 30mL of methanol solution was added to the reaction solution. The silicon nanoparticles obtained by the reaction were collected on PVDF membrane and washed three times with 200mL of methanol/deionized water (volume ratio of 1:3), and after drying in a vacuum oven for 15 hours, the sample was quickly transferred to a glove box.
2) In a glove box, the nano silicon particles treated in the step 1) are dispersed in a mixed solution of dodecene and toluene (volume ratio is 1:15), the reaction solution is heated to 185 ℃, and the reaction solution is heated by a heating sleeve until the reaction solution becomes clear.
3) And adding 30mg of graphene into the clarified solution obtained in the step 2), and evaporating the solution to dryness to obtain the nano silicon/graphene lithium ion battery anode material.
Example 3
1) 50mg of silicon nanoparticles were dissolved in 10mL of methanol solution and sonicated for 30min. 11mL of HF/HNO3 mixed acid (volume ratio: 20:1) was added to the obtained solution, the particle size was reduced during etching, and after 10 minutes of reaction, 50mL of methanol solution was added to the reaction solution. The silicon nanoparticles obtained by the reaction were collected on PVDF membrane and washed three times with 200mL of methanol/deionized water (volume ratio of 1:3), and after drying in a vacuum oven for 12 hours, the sample was quickly transferred to a glove box.
2) Dispersing the nano silicon particles treated in the step 1) in a mixed solution of styrene and chloroform (the volume ratio is 1:10-20) in a glove box, heating the reaction solution to 175 ℃, and heating the reaction solution by using a heating sleeve until the reaction solution becomes clear.
3) And adding 20mg of graphene into the clarified solution obtained in the step 2), and evaporating the solution to dryness to obtain the nano silicon/graphene lithium ion battery anode material.
The beneficial effects of the invention are further demonstrated by corresponding experimental data below.
In example 1, a silicon nanoparticle and graphene composite material was synthesized and used as a lithium ion battery anode material. Compared with the traditional graphite cathode, the composite material has better performance in the aspects of rate performance and cycle performance. The composite material can achieve capacity of up to 1178 mA h/g, and the traditional graphite cathode can only achieve capacity of 312 mA h/g. After 100 cycles, the capacity of the composite material is still kept at 990 mA h/g, the capacity retention rate is 84%, and the graphite cathode is 267 mA h/g, and the capacity retention rate is 85%. This indicates that the silicon nanoparticle and graphene composite material has excellent cycle performance compared with the conventional graphite anode. In addition, the composite material can still achieve a capacity of up to 850 mA h/g at high magnification (2C), and the capacity of the composite material is still maintained at 765 mAh/g at high magnification (10C). After 100 cycles, the capacity retention was still 81%, indicating that the silicon nanoparticle and graphene composite has excellent rate capability. The same experiment as in example 2 and example 3 was performed to achieve the advantageous effects of the present invention.
In the embodiment 2, the silicon nanoparticle and graphene composite material is used as a lithium ion battery anode material, so that the volume expansion of silicon in the process of lithium ion intercalation/deintercalation can be effectively inhibited. The volume expansion rate of the composite material was only 8.5%, while that of the comparative micron-sized silicon anode was 143%. After 100 cycles, the capacity retention rate of the micron-sized silicon negative electrode is only 50%, which indicates that the silicon nanoparticle and graphene composite material can effectively inhibit the volume expansion of silicon and has better cycle stability. The same experiment as in example 1 and example 3 was performed to achieve the advantageous effects of the present invention.
In example 3, the composite was tested for solvent dispersion properties. 100mg of the composite material of the silicon nano particles and the graphene is dissolved in 100ml of toluene solvent, after ultrasonic oscillation is carried out for two minutes, the solution is clear, and the solution mixture can pass through PVDF filter paper with the pore diameter of 0.2 micrometer under the condition of pressurization and is still clear. In contrast, 100mg of a mixed material of micron-sized silicon particles and graphene was dissolved in 100ml of toluene solvent, and after two minutes of ultrasonic oscillation, the solution was cloudy, and the solution mixture was unable to pass through PVDF filter paper with a pore size of 0.2 microns under pressurized conditions, and was still a chaotic solution. This experiment demonstrates that the composite material has good solution dispersion properties for silicon particles. The same experiment as in example 1 and example 2 was performed to achieve the advantageous effects of the present invention.
The present invention is not limited to the above preferred embodiments, and any person skilled in the art, based on the technical solution of the present invention and the inventive concept thereof, can be replaced or changed within the scope of the present invention.
Claims (8)
1. A preparation method of a nano silicon/graphene lithium ion battery anode material is characterized by comprising the following steps: firstly, treating silicon nano particles by using mixed acid of HF/HNO3 to obtain Si-H surfaces, then, carrying out hydrosilylation reaction on the silicon nano particles subjected to surface treatment by using various carbon-containing organic matters containing double bonds or triple bonds, and finally, directly mixing graphene with the silicon nano particles subjected to hydrosilylation reaction, and drying to obtain the nano silicon/graphene anode material.
2. The preparation method of the nano silicon/graphene lithium ion battery anode material as claimed in claim 1, which is characterized by comprising the following steps:
1) Production of Si-H surface of silicon nanoparticles: dissolving 10-100mg of silicon nano particles in 1-100mL of alcohol solution, carrying out ultrasonic treatment for 30-60min, adding HF/HNO3 mixed acid into the obtained solution for etching, reducing the particle size in the etching process, reacting for 5-10min, adding 10-100mL of alcohol solution into the solution, filtering and collecting a PVDF film, and rapidly moving into a glove box after vacuum drying;
2) Hydrosilylation of surface treated silicon nanoparticles with carbon containing organics containing double or triple bonds: dispersing the nano silicon particles treated in the step 1) in a mixed solution of a carbon-containing organic matter containing double bonds or triple bonds and an organic solvent in a glove box, and heating the reaction solution to 150-300 ℃ until the reaction solution becomes clear;
3) Production of nano silicon/graphene anode material: and 2) adding graphene into the clear solution obtained in the step 2), and evaporating the solution to dryness to obtain the nano silicon/graphene lithium ion battery anode material.
3. The method for preparing the nano silicon/graphene lithium ion battery anode material as claimed in claim 2, wherein in step 1): the mass fraction of HF in the HF/HNO3 mixed acid is 45-50%, the mass fraction of HNO3 is 65-72%, the mass fraction of HF is preferably 48%, and the mass fraction of HNO3 is preferably 68%; the volume ratio of HF to HNO3 is 5-30: 1, preferably 10-25: 1, more preferably 15-20:1.
4. the method for preparing the nano silicon/graphene lithium ion battery anode material as claimed in claim 2, wherein in step 1): the alcohol solution is methanol, ethanol or propanol; the aperture of the PVDF membrane is 0.2-0.3 μm, and the aperture is preferably 0.25-0.27 μm.
5. The method for preparing the nano silicon/graphene lithium ion battery anode material as claimed in claim 2, wherein in step 1): the weight volume ratio of the silicon nano-particles to the alcohol solution is 20-80mg:10-90ml, preferably 30-70mg:20-80ml; more preferably 40-60mg:30-60ml; after the ultrasonic treatment is carried out for 40-50min and the reaction is carried out for 5-10min, 20-80mL of alcohol solution, preferably 40-60mL of alcohol solution, is added into the solution.
6. The method for preparing the nano silicon/graphene lithium ion battery anode material as claimed in claim 2, wherein in the step 2): the carbon-containing organic matter containing double bond or triple bond is dodecene/alkyne, octadecene/alkyne, styrene/alkyne or fullerene, and the organic solvent is toluene, chloroform or trimethylbenzene.
7. The method for preparing the nano silicon/graphene lithium ion battery anode material as claimed in claim 2, wherein in the step 2): the carbon-containing organic matter containing double bond or triple bond: the volume ratio of the mixed solution of the organic solvents is 1:10-20, and the preferred volume ratio is 1:13-16; bubbling treatment is carried out 1.1-1.3h in advance.
8. The method for preparing the nano silicon/graphene lithium ion battery anode material as claimed in claim 2, wherein in the step 2): the reaction solution is heated to a temperature of 180 to 270 ℃, preferably 200 to 250 ℃.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310725304.3A CN116845225A (en) | 2023-06-19 | 2023-06-19 | Preparation method of nano silicon/graphene lithium ion battery anode material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310725304.3A CN116845225A (en) | 2023-06-19 | 2023-06-19 | Preparation method of nano silicon/graphene lithium ion battery anode material |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116845225A true CN116845225A (en) | 2023-10-03 |
Family
ID=88173564
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310725304.3A Pending CN116845225A (en) | 2023-06-19 | 2023-06-19 | Preparation method of nano silicon/graphene lithium ion battery anode material |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116845225A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117117159A (en) * | 2023-10-24 | 2023-11-24 | 琥崧智能装备(太仓)有限公司 | Silicon-carbon negative electrode material and preparation method and application thereof |
-
2023
- 2023-06-19 CN CN202310725304.3A patent/CN116845225A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117117159A (en) * | 2023-10-24 | 2023-11-24 | 琥崧智能装备(太仓)有限公司 | Silicon-carbon negative electrode material and preparation method and application thereof |
| CN117117159B (en) * | 2023-10-24 | 2023-12-26 | 琥崧智能装备(太仓)有限公司 | Silicon-carbon negative electrode material and preparation method and application thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Wang et al. | Silicon/carbon nanocomposite pyrolyzed from phenolic resin as anode materials for lithium-ion batteries | |
| CN107634207B (en) | Silicon-inlaid redox graphene/graphite-phase carbon nitride composite material and preparation and application thereof | |
| Fu et al. | A facile route to controllable synthesis of Fe3O4/graphene composites and their application in lithium-ion batteries | |
| Wu et al. | Sb@ C/expanded graphite as high-performance anode material for lithium ion batteries | |
| WO2014032595A1 (en) | Negative electrode material, method for producing the same, negative electrode, and battery comprising the same | |
| JP2014519136A (en) | Nanostructured multi-component electrode material and method of making same | |
| Liu et al. | A facile one-step hydrothermal synthesis of α-Fe 2 O 3 nanoplates imbedded in graphene networks with high-rate lithium storage and long cycle life | |
| CN100344016C (en) | Method for preparing silicon/carbon composite lithium ion battery cathode material under room temperature | |
| CN105702958B (en) | Preparation method and application of tin dioxide quantum dot solution and composite material thereof | |
| US20240258523A1 (en) | Phosphorus-carbon cathode material based on red phosphorus and preparation method thereof | |
| KR20210035628A (en) | Porous graphene-silicon aerogel composite containing graphene-wrapped silicon nanoparticles, preparation of the same and lithium secondary battery using the same | |
| CN113346054A (en) | Preparation method and application of MXene-carbon nanocage-sulfur composite material | |
| CN111668472A (en) | Silicon-based composite negative electrode material, preparation method thereof and lithium ion battery | |
| CN112357956B (en) | Carbon/titanium dioxide coated tin oxide nanoparticle/carbon assembled mesoporous sphere material and preparation and application thereof | |
| Fu et al. | Engineering MnO/C microsphere for enhanced lithium storage | |
| CN116845225A (en) | Preparation method of nano silicon/graphene lithium ion battery anode material | |
| Xu et al. | Cyanometallic framework-derived dual-buffer structure of Sn-Co based nanocomposites for high-performance lithium storage | |
| CN116314812A (en) | Graphene conductive agent and preparation method thereof | |
| CN110098402B (en) | Silicon-carbon negative electrode material for lithium ion battery and preparation method thereof | |
| CN113054170B (en) | Preparation method of nickel-nickel molybdenum oxide-graphene composite material and application of nickel-nickel molybdenum oxide-graphene composite material in lithium ion battery | |
| Yang et al. | One-pot synthesis of SnO2/C nanocapsules composites as anode materials for lithium-ion batteries | |
| CN113725409A (en) | Silicon-based negative electrode material and preparation method thereof | |
| CN113526566A (en) | Preparation method of nano carbon sphere composite cobalt oxide negative electrode material | |
| EP3402748A1 (en) | Nanoparticle/porous graphene composite, synthesizing methods and applications of same | |
| CN115224241A (en) | Negative plate for lithium battery 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 |