CN113380998A - Silicon-carbon negative electrode material and preparation method and application thereof - Google Patents
Silicon-carbon negative electrode material and preparation method and application thereof Download PDFInfo
- Publication number
- CN113380998A CN113380998A CN202110613163.7A CN202110613163A CN113380998A CN 113380998 A CN113380998 A CN 113380998A CN 202110613163 A CN202110613163 A CN 202110613163A CN 113380998 A CN113380998 A CN 113380998A
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- carbon
- silicon
- negative electrode
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- HMDDXIMCDZRSNE-UHFFFAOYSA-N [C].[Si] Chemical compound [C].[Si] HMDDXIMCDZRSNE-UHFFFAOYSA-N 0.000 title claims abstract description 79
- 239000007773 negative electrode material Substances 0.000 title claims abstract description 62
- 238000002360 preparation method Methods 0.000 title claims abstract description 46
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 110
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- 229910017052 cobalt Inorganic materials 0.000 claims description 2
- 239000010941 cobalt Substances 0.000 claims description 2
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- 229910052808 lithium carbonate Inorganic materials 0.000 claims description 2
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Images
Classifications
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- 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
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- 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
- C01B33/021—Preparation
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- 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
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- 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
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- 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
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
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- 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
- H01M4/628—Inhibitors, e.g. gassing inhibitors, corrosion inhibitors
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- H01M4/02—Electrodes composed of, or comprising, active material
- H01M2004/021—Physical characteristics, e.g. porosity, surface area
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- H—ELECTRICITY
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- 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
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- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Abstract
The invention provides a silicon-carbon negative electrode material and a preparation method and application thereof. The preparation method of the silicon-carbon negative electrode material comprises the following steps: A) coating a carbon substrate by using a catalyst to obtain a pretreated substrate; B) carrying out vapor deposition on the pretreated substrate by using mixed gas containing a carbon source and a silicon source, and carrying out acid washing on a vapor deposition product to obtain a first precursor; C) carrying out pre-lithiation treatment on the first precursor, and then coating the first precursor by adopting a graphitized carbon source to obtain a second precursor; D) and carbonizing the second precursor to obtain the silicon-carbon negative electrode material. The preparation method has simple and feasible process and can realize large-scale production; the silicon-carbon cathode material produced by the method has the advantages of high capacity, high first effect, low volume expansion rate, good cycle performance, environmental friendliness, convenience in use and the like, can be used in the fields of solid lithium ion batteries and the like, and well overcomes the defects of air instability and the like in the use process of a lithium metal material.
Description
Technical Field
The invention relates to the technical field of lithium ion batteries, in particular to a silicon-carbon negative electrode material and a preparation method and application thereof.
Background
A lithium ion battery is a secondary battery that mainly operates by movement of lithium ions between a positive electrode and a negative electrode. The lithium ion battery is used as a new energy storage device, has a very wide application range, can be used for portable electronic equipment such as an electronic watch, a step-counting bracelet and the like, and can also be used for spaceflight and aviation ultra-large equipment such as an airship, an aircraft carrier and the like. Compared with other types of batteries, the lithium ion battery has the advantages of high energy density, long cycle life, high discharge platform, rapid charge and discharge and the like, and the advantages promote the lithium ion battery to be the current main flow battery.
At present, graphite materials are mostly used as the negative electrode materials of commercial lithium ion batteries, mainly because the cycle life of graphite is long and the price is low, but the theoretical specific capacity of the graphite is only 372mA · h/g, so that the requirement of high-energy density equipment cannot be met. Silicon is used as a negative electrode material, and the theoretical specific capacity is up to 4200 mA.h/g (Li)22Si5) It is ten times as large as the theoretical specific capacity of graphite, so it is a hot spot for controversial research of various scientific research institutions and enterprises. However, silicon as a negative electrode material causes more than 300% of volume expansion and contraction in the processes of lithium removal and lithium insertion, and the cycle life of the battery is greatly shortened. In addition, silicon has relatively low conductivity as a semiconductor and a slow electron transfer rate. In combination with the disadvantages of silicon as the negative electrode material of the lithium ion battery, how to inhibit volume expansion and shrinkage, increase cycle life and improve electronic conductivity becomes several problems to be solved.
The rapid development of the new energy industry promotes the further improvement of the performance requirements of the lithium ion battery, and provides higher requirements for the performance improvement of the negative electrode material, particularly the capacity density and the rapid charging capability. At present, the capacities (360mah/g) of natural graphite and artificial graphite are approaching the 372mah/g limit; the coal-based negative electrode, the hard carbon negative electrode and the porous carbon material are more and more widely used as the negative electrode material of the lithium ion battery due to the characteristics of excellent quick charge performance, ultra-long service life and the like, but the defects of low real density, compaction density and volume capacity density seriously hinder the large-scale popularization and application of the materials. Therefore, the development of a negative electrode material having both a higher capacity density and a better rapid charge-discharge capability has been slow.
Chinese patent application publication No. CN 108023084 a discloses a preparation method of a silicon-carbon negative electrode material and a lithium ion battery, and the preparation method includes: A) carrying out chemical vapor deposition on a catalyst precursor and a carbon source to obtain a catalyst with the surface coated with a graphene layer; B) corroding the catalyst with the surface coated with the graphene layer by using acid, and separating to obtain a graphene cage material; C) ball-milling the graphene cage material and the nano-silicon, and drying to obtain a precursor material; D) and carrying out chemical vapor deposition on the precursor material and a carbon source to obtain the silicon-carbon cathode material.
According to the method, a thin layer of graphene is formed on the surface of a catalyst by adopting a chemical vapor deposition method, and the catalyst is removed to form a graphene cage structure; the nano silicon is deposited inside or on the surface of the graphene cage by a ball milling method, and then the amorphous carbon is coated to be used as a buffer body and a conductive agent, so that pulverization of the nano silicon in a circulation process can be inhibited to a certain extent, and the circulation performance of the nano silicon is improved. However, studies have shown that: the silicon-carbon negative electrode material can not effectively solve the problems of uneven local capacity of the material and the like caused by uneven distribution of the interior of silicon negative electrode particles, and uneven capacity density of a negative electrode sheet is easy to occur, so that the problems that the local positive electrode capacity exceeds the negative electrode capacity when a battery is actually used, local lithium precipitation is easy to occur on the surface of the negative electrode, the performance of the battery is quickly attenuated and the like are caused; meanwhile, the problems of volume expansion and particle pulverization of the nano-silicon cannot be inhibited only by coating the surface of the outermost layer with the amorphous carbon layer, the problems of high expansion rate of the negative electrode material, high irreversible capacity of the negative electrode material and the like are caused, the first efficiency of the battery is greatly reduced, and the cycle life of the battery is poor due to continuous consumption of a lithium source in the subsequent charging and discharging processes.
In view of this, the invention is particularly proposed.
Disclosure of Invention
The invention aims to provide a silicon-carbon negative electrode material and a preparation method and application thereof.
The invention provides a preparation method of a silicon-carbon negative electrode material, which comprises the following steps:
A) coating a carbon substrate by using a catalyst to obtain a pretreated substrate;
B) carrying out vapor deposition on the pretreated substrate by using mixed gas containing a carbon source and a silicon source, and carrying out acid washing on a vapor deposition product to obtain a first precursor;
C) carrying out pre-lithiation treatment on the first precursor, and then coating the first precursor by adopting a graphitized carbon source to obtain a second precursor;
D) and carbonizing the second precursor to obtain the silicon-carbon negative electrode material.
The silicon-carbon negative electrode material takes a carbon substrate as an inner core; in step A), the carbon substrate is not particularly limited, and may be a diamond-shaped powder obtained by pulverizing artificial graphite or coke powder obtained by high-temperature purification or a porous powder obtained by pulverizing a non-graphitized material obtained by pyrolysis. Specifically, the carbon substrate may be selected from one or more of natural graphite, artificial graphite, a coal-based anode, a hard carbon anode, porous carbon, and the like; furthermore, the particle size of the D50 particle of the carbon substrate may be conventional in the art, preferably 4-12 μm, for example 8 μm.
In step A), the catalyst may comprise an iron-containing compound, which may be selected from iron trichloride FeCl3Fe (NO), iron nitrate3)3Carbonyl iron Fe (CO)5Ferrocene C10H10One or more of Fe and the like, preferably ferric chloride FeCl 3. In addition, the catalyst can also comprise one or more of a nickel-containing compound, a cobalt-containing compound and a copper-containing compound so as to promote the synchronous generation reaction of the carbon nanotubes, the graphene and the silicon nanocrystals. The manner of coating the carbon substrate is not particularly limited, and for example, the carbon substrate may be coated by spray drying or vacuum heat drying; the catalyst can be deposited on the surface of the carbon particles of the carbon substrate by adopting a spray drying mode, so that the carbon substrate uniformly coated by the catalyst is obtained.
More specifically, in step a), a catalyst solution may be used for coating, and the mass content of the catalyst in the catalyst solution may be 0.2 to 4%; further, the mass ratio of the carbon substrate to the catalyst solution may be 100: (0.25-2).
In step B), the carbon source and the silicon source used for vapor deposition are not strictly limited; in particular, the carbon source may be selected from acetylene C2H2Carbon monoxide CO and carbon dioxide CO2Methane CH4Ethane C2H6And ethylene C2H4Preferably C2H2Or C2H2A mixed carbon source with CO; SiH can be used as silicon source4And the like. In addition, the volume ratio of the silicon source to the carbon source in the mixed gas may be (3-5): 1, preferably 4: 1. the vapor deposition is carried out in an inert atmosphere; the inert atmosphere may be nitrogen, helium or argon, preferably an argon atmosphere having a purity of more than 99.99%.
The equipment used for vapor deposition is not strictly limited; in particular, the vapor deposition can be carried out in a rotary vacuum tube furnace, a multi-temperature zone vacuum atmosphere tube furnace or a continuous atmosphere protection rotary furnace, preferably a rotary vacuum tube furnace. The conditions for vapor deposition are not strictly limited; specifically, the temperature of vapor deposition can be controlled to be 650-1300 ℃, preferably 900-1100 ℃; the temperature rise rate of the pretreated substrate can be 3-8 ℃/min, and preferably 5 ℃/min; the mixed gas can be introduced at a rate of 20-60 ml/min. In addition, the time for introducing the mixed gas may be controlled to be 5 to 7 hours or the content of silicon crystals in the vapor deposition product may be controlled to be 2 to 25%, preferably 3 to 15%, more preferably 4 to 10%. The vapor deposition can synchronously and tightly generate the symbiotic layer shell with uniformly deposited nano-silicon crystals, graphene and carbon nanotubes on the surface of the carbon substrate, and the vapor deposition product is the symbiotic layer shell with uniformly deposited nano-silicon crystals, graphene and carbon nanotubes on the surface of the carbon substrate core.
In the present invention, acid washing with an inorganic acid may be performed to dissolve the catalyst; the inorganic acid is not critical and may be selected from HCl and HNO3Sulfuric acid H2SO4One or more of hydrofluoric acid (HF), etc.
In step C), a pre-lithiation treatment is carried out by using a lithiation solutionThe solution may be an alkaline solution containing an inorganic lithium salt and/or an organic lithium salt; specifically, the inorganic solution is Li2C2O4、Li2CO3、LiNO3LiOH and Li2SiO3One solution or a plurality of mixed solutions. Specifically, Li of the present invention2SiO3Refers to lithium silicate series materials, which may be Li, for example8SiO6、Li4SiO4、Li2SiO3、Li6Si2O7、Li2Si2O5、Li2Si5O11Etc. in combination with one or more lithium salts, not specifically designated Li2SiO3A lithium salt.
In the present invention, the method of preparing the organolithiation solution may include:
a) in an inert atmosphere, dissolving a polycyclic aromatic compound in an organic solvent to obtain a composite solution;
b) and adding metal lithium into the composite solution in an inert atmosphere, and standing or stirring to obtain a lithiation solution.
In the above step a) and step b), the inert atmosphere may be helium or argon, preferably argon with a purity of more than 99.99%; the polycyclic aromatic compound can be selected from one or more of naphthalene, biphenyl, terphenyl, quaterphenyl, anthracene, phenanthrene and derivatives thereof, and is preferably biphenyl; the organic solvent can be an ether solvent, preferably one or more of dimethyl ether, diethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, propylene glycol dimethyl ether, propylene glycol dihexyl ether, diethylene glycol monopropyl ether and diethylene glycol dibutyl ether; the lithium metal can be in the form of lithium powder, lithium flakes, lithium rods or lithium tapes, preferably lithium tapes; the molar percentage of the polycyclic aromatic compound in the composite solution may be 8 mol% to 12 mol%, more preferably 10 mol%; the lithium content in the lithiation solution may be from 0.001 to 100g/L, preferably from 40 to 60g/L, more preferably 50 g/L. Further, the time for standing or stirring may be controlled to be 2 to 12 hours, more preferably 8 to 10 hours.
The graphitized carbon source is not strictly limited and can be asphalt or high molecular organic polymer; specifically, the asphalt may be selected from at least one of petroleum asphalt, natural asphalt, and pitch; the high molecular organic polymer may be one or more selected from polyfurfuryl alcohol, polyonol resin, ceramomene resin, propionitrile resin, epoxy resin, phenolic resin, furfural resin, glucose and sucrose. It is understood that the graphitized carbon source may be dissolved in a solvent, and the solvent for dissolving the graphitized carbon source may be selected from one or more of carbon disulfide, n-hexane, xylene, and carbon tetrachloride, and is preferably carbon disulfide. The coating method of the graphitized carbon source is not particularly limited, and for example, a solvent sol method in combination with a spray drying method, a mechanical ball milling method, or the like may be used. Specifically, the solvent sol method in combination with the spray drying method may include: dissolving a graphitized carbon source in a solvent to prepare a graphitized carbon solution; and then, adding the pre-lithiated first precursor into the graphitized carbon solution, stirring and uniformly mixing, and then carrying out spray drying.
In step D), carbonization may include sequential curing and graphitization; wherein, the temperature during curing can be controlled to be 300-500 ℃, preferably 400 ℃, the curing time is 0.5-8h, preferably 2-6h, and the heating rate during curing is 2.5-3.5 ℃/min, preferably 3 ℃/min; controlling the temperature of graphitization to be 800-1300 ℃, preferably 1050 ℃, and the graphitization time to be 3-5 h; the temperature rise rate during graphitization is 4.5-5.5 deg.C/min, preferably 5 deg.C/min.
The preparation method comprises the steps of carrying out primary coating heat treatment and secondary coating heat treatment on a carbon substrate; wherein the first coating agent adopted in the first coating heat treatment contains carbon and silicon elements and can be decomposed at the temperature of 1300 ℃ to generate a symbiotic layer shell containing silicon crystals, carbon nano-tubes and graphene; and (3) pickling the product after the first coating heat treatment to remove the catalyst, carrying out pre-lithiation treatment, and then carrying out second coating heat treatment in a spray drying mode, wherein the second coating heat treatment comprises two stages of low-temperature curing and high-temperature cracking, and a second coating agent adopted in the second coating heat treatment is a solid carbon-containing organic substance which can be cured at a temperature of below 500 ℃ and can be carbonized at a temperature of below 1300 ℃ to form a crystalline carbon layer. According to the preparation method, natural graphite, artificial graphite, a coal-based negative electrode, a hard carbon negative electrode, a porous carbon material and the like are used as the inner core, so that the expansion of the first-time coated silicon crystal is greatly inhibited and relieved, and the service performance of the material is improved; the carbon source is adopted for secondary coating, so that the first efficiency and the conductivity of the material can be greatly improved.
The invention also provides a silicon-carbon cathode material which is prepared according to the preparation method; specifically, the content of silicon in the silicon-carbon anode material can be 2-25%, more preferably 3-15%, and still more preferably 4-10%; in addition, the particle size D50 of the silicon-carbon negative electrode material is 8-16 μm, and the BET specific surface area is less than or equal to 2.5m2/g。
The silicon-carbon negative electrode material takes natural graphite, artificial graphite, a coal-based negative electrode, a hard carbon negative electrode, a porous carbon material and the like as base materials, and graphene, a carbon nano-tube and a nano-silicon crystal are synchronously and uniformly generated on the surface of base material particles, so that the problem of inward and outward volume expansion of the nano-silicon crystal is well solved, and the conductivity of a silicon-carbon interface is improved; silicon crystals are uniformly and tightly coated on the carbon substrate, so that the fatal defects of uneven distribution of the silicon-carbon negative electrode capacity and the like are perfectly overcome; the outermost layer of the particles is tightly coated with the graphitized carbon source for the second time, so that outward expansion of the nano silicon crystals can be well inhibited, direct contact between the nano silicon and electrolyte is isolated, and the first efficiency and the cycle performance of the silicon-carbon cathode can be greatly improved.
The invention also provides a preparation method of the silicon-carbon cathode material, which comprises the following steps:
C1) pre-lithiating the precursor, and coating with a graphitized carbon source to obtain a second precursor;
D1) and carbonizing the second precursor to obtain the silicon-carbon negative electrode material.
Specifically, in step C1), the precursor may be one or more of nano-silicon, micro-silicon, porous silicon and silicon monoxide, preferably nano-silicon; in this case, the above steps a) and B) are not required to be performed, and the process is simpler. The content of silicon in the silicon-carbon negative electrode material prepared by the steps of C1) and D1) can be 5-35%, more preferably 8-25%, and still more preferably 15-20%.
The invention also provides application of the silicon-carbon negative electrode material in preparation of a lithium ion battery negative electrode.
The implementation of the invention has at least the following advantages:
1. the method takes natural graphite, artificial graphite, a coal-based negative electrode, a hard carbon negative electrode, a porous carbon material and the like as base materials, and synchronously and uniformly generates graphene, a carbon nano-tube and a nano-silicon crystal on the surface of base material particles, so that the problem of volume expansion of the nano-silicon crystal towards the inside and the outside is well solved, and the conductivity of a silicon-carbon interface is improved; silicon crystals are uniformly and tightly coated on the base material, so that the defects of uneven distribution of the silicon-carbon cathode capacity and the like are perfectly overcome; the outermost layer of the particles is tightly coated with a graphitized carbon source for the second time, so that outward expansion of nano silicon crystals can be well inhibited, direct contact between the nano silicon and electrolyte is isolated, and the first efficiency and the cycle performance of the silicon-carbon cathode are greatly improved; the preparation method has simple and feasible process, can realize large-scale production, can effectively solve the problems in the prior art, and is particularly favorable for greatly promoting the commercial application of the silicon-carbon cathode;
2. the silicon-carbon negative electrode material has the particle size D50 of 8-16 mu m and the specific surface area (BET method) of less than or equal to 2.5m2(ii)/g; when the electrode prepared by the method is used for a button type half cell, the electrode has high capacity, high first efficiency and excellent cycle performance, for example, the specific capacity (0.1C) can reach more than 1000mAh/g at most, the first efficiency can reach more than 95.6 percent at most, and the capacity retention rate can reach more than 91 percent after 200 cycles; meanwhile, the silicon-carbon cathode material also has the characteristics of environmental friendliness, convenience in use and the like; in addition, the silicon-carbon negative electrode material can resist the corrosion of moisture and atmosphere in the environment under the conditions of room temperature and humidity of not more than 70 percent, thereby improving the process compatibility of negative electrode substrate preparation and battery preparation; the cathode plate made of the silicon-carbon cathode material has the advantages of low volume expansion rate, high energy density and primary efficiency, long cycle service life, safety, reliability and the like, and can be well applied to the fields of liquid lithium ion batteries, solid lithium ion batteries and the like.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.
FIG. 1 is an SEM image of a silicon-carbon anode material prepared in example 1 of the present invention;
FIG. 2 is an XRD pattern of a silicon carbon anode material prepared in example 1 of the present invention;
FIG. 3 is an EDS diagram of a silicon carbon anode material prepared in example 1 of the present invention.
Detailed Description
It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.
It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms also include the plural forms unless the context clearly dictates otherwise, and further, it is understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of the stated features, steps, operations, devices, components, and/or combinations thereof.
The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments, and it should be understood that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1
The preparation method of the silicon-carbon anode material of the embodiment comprises the following steps:
firstly, pretreatment of base material
Taking 1kg of artificial graphite (carbon substrate) with a medium particle size of about 8 μm, and FeCl with a mass content of 1%3Uniformly mixing the aqueous solution (i.e. catalyst) and controlling the artificial graphite and FeCl3The mass ratio of Fe in the aqueous solution is 100: 0.5, followed by drying the mixture by spray drying to remove the solvent moisture, to obtain a carbon substrate (i.e., pretreated substrate) uniformly coated with the catalyst.
Second, first, second precursor preparation
1. Chemical Vapor Deposition (CVD) preparation of a first precursor
Putting the pretreated carbon substrate powder into a vacuum rotary furnace, vacuumizing for many times, and filling inert gas (argon with the purity of more than 99.99%) to remove air; the carbon substrate powder was heated to 1000 ℃ at a heating rate of about 5 ℃/min, and then SiH was charged at a rate of 40ml/min4And C2H2Mixed gas (SiH in mixed gas)4And C2H2Is 4: 1) the rotation speed of the vacuum rotary furnace is 5 minutes/circle, the gas is continuously filled for 6 hours or the SiH is stopped to be filled after the content of silicon crystals in the powder is controlled to be about 6 percent4And C2H2And filling inert gas into the mixed gas to cool, thus obtaining the first precursor coated by the nano silicon-graphene-carbon nano tubes.
2. Acid wash and prelithiation treatment
1) Preparation of lithiation solution
Dissolving biphenyl in dimethyl ether in an inert atmosphere (argon with the purity of more than 99.99 percent) to obtain a biphenyl solution (the molar percentage of the biphenyl is 10mol percent); then, metallic lithium was added to the above biphenyl solution, and stirred for 9 hours to obtain a lithiated solution (lithium content: 50 g/L).
2) Acid pickling
Soaking and cleaning the cooled first precursor for more than 12 hours by using dilute hydrochloric acid (HCl) to remove the Fe catalyst in the first precursor; and then, adopting clear water or an inorganic lithium salt solution for leakage extraction to remove HCl and most of water, and adopting a forced air drying oven for drying at 100 ℃ for 6 hours to dry the residual water in the solid powder.
3) Prelithiation treatment
Soaking and stirring the dried first precursor for 4 hours by using the lithiation solution in an inert atmosphere (argon with the purity of more than 99.99%), wherein the mass ratio of the lithiation solution to the first precursor is 1: 2. and then baking the soaked first precursor for 4 hours at 80 ℃ by using a vacuum drying oven, and removing the solvent to obtain the pre-lithiated nano silicon-graphene-carbon nanotube-graphite precursor.
3. Preparing a second precursor by adopting a solvent sol method
Asphalt (namely graphitized carbon source) is completely dissolved in carbon disulfide CS by 10 percent of the mass of the prelithiated nano-silicon-graphene-nano carbon tube-graphite precursor2In the solvent, the mixture is uniformly mixed with the pre-lithiated nano silicon-graphene-carbon nanotube-graphite precursor under the protective gas atmosphere, and then the mixture is dried by a spray drying method to remove the solvent, so as to obtain the nano silicon-graphene-carbon nanotube-graphite precursor (namely, the second precursor) coated by the graphitized carbon source.
Third, high temperature carbonization
Carbonizing the obtained second precursor in a tubular furnace using argon as protective gas, heating to 400 ℃ at a heating rate of 3 ℃/min, preserving heat at 400 ℃ for 5h, continuing to heat to 1050 ℃ at a heating rate of 5 ℃/min, and preserving heat at 1050 ℃ for 4 h; and (3) crushing the carbonized material, and sieving the crushed material with a 200-mesh sieve to obtain the silicon carbon-graphite composite negative electrode material (namely the silicon carbon negative electrode material).
FIG. 1 is an SEM image of the silicon-carbon negative electrode material prepared as above; as can be seen from FIG. 1, the prepared silicon-carbon negative electrode material has natural particle distribution, smooth surface and no obvious defects and adhesion.
FIG. 2 is an XRD pattern (scanning mode theta-2 theta, step by 2 deg./s) of the silicon-carbon negative electrode material prepared as above; as can be seen from fig. 2, the prepared silicon-carbon negative electrode material has a low degree of crystallization, and has no other obvious diffraction peaks except for silicon and carbon elements, which indicates that the material is uniformly coated and is beneficial to improving the electrical properties.
Fig. 3 is an EDS diagram of the silicon carbon anode material prepared as described above; the results of the silicon content in the silicon carbon anode material calculated by the method are shown in table 1.
Example 2
SiH is filled in the step of preparing the first precursor by Chemical Vapor Deposition (CVD)4And C2H2The same as in example 1 was repeated except that the mixed gas was used for the same time.
The preparation of the silicon-carbon negative electrode material of the present example was carried out according to the method of example 1, SiH in the case of preparing the first precursor by Chemical Vapor Deposition (CVD) only4And C2H2The gas continuous charging time of the mixed gas is reduced to 3 hours or the SiH charging is stopped after the content of silicon crystals in the powder is controlled to be about 3 percent4And C2H2And mixing the gases, and filling inert gas for cooling.
Example 3
The preparation method of the silicon-carbon anode material of the embodiment comprises the following steps:
firstly, pretreatment of base material
1kg of coal-based graphite with the medium particle size of about 4 mu m is taken and uniformly mixed with 1% of ferric nitrate aqueous solution, and the mass ratio of the coal-based graphite to Fe in the ferric nitrate aqueous solution is controlled to be 100: 0.5, followed by drying the mixture by spray drying to remove the solvent moisture, to obtain a carbon substrate (i.e., pretreated substrate) uniformly coated with the catalyst.
Second, first, second precursor preparation
1. Chemical Vapor Deposition (CVD) preparation of a first precursor
Putting the pretreated carbon substrate powder into a vacuum rotary furnace, vacuumizing for many times, and filling inert gas (argon with the purity of more than 99.99%) to remove air; the carbon substrate powder was heated to 900 ℃ at a heating rate of about 4 ℃/min, and then SiH was charged at a rate of 40ml/min4And C2H2Mixed gas (SiH in mixed gas)4And C2H2Is 4: 1) the rotation rate of the vacuum rotary furnace is 5 minutes/circle, the gas is continuously filled for 9 hours or the SiH is stopped to be filled after the content of silicon crystals in the powder is controlled to be about 9 percent4And C2H2And filling inert gas into the mixed gas to cool, thus obtaining the first precursor coated by the nano silicon-graphene-carbon nano tubes.
2. Acid wash and prelithiation treatment
1) Preparation of lithiation solution
Dissolving naphthalene in ethylene glycol dimethyl ether in an inert atmosphere (argon with the purity of more than 99.99 percent) to obtain a naphthalene solution (the mole percent of the naphthalene is 12mol percent); then, metallic lithium was added to the above naphthalene solution, and stirred for 8 hours to obtain a lithiated solution (lithium content 40 g/L).
2) Acid pickling
Soaking and cleaning the cooled first precursor for more than 12h by using dilute hydrochloric acid (HCl) to remove the Fe catalyst in the first precursor; and then, adopting clear water or an inorganic lithium salt solution for leakage extraction to remove HCl and most of water, and adopting a forced air drying oven for drying at 100 ℃ for 6 hours to dry the residual water in the solid powder.
3) Prelithiation treatment
Soaking and stirring the dried first precursor for 4 hours by using the lithiation solution in an inert atmosphere (argon with the purity of more than 99.99%), wherein the mass ratio of the lithiation solution to the first precursor is 1: 2. and then baking the soaked first precursor for 4 hours at 80 ℃ by using a vacuum drying oven, and removing the solvent to obtain the pre-lithiated nano silicon-graphene-carbon nanotube-graphite precursor.
3. Preparing a second precursor by adopting a solvent sol method
Asphalt (namely graphitized carbon source) is completely dissolved in carbon disulfide CS by 10 percent of the mass of the prelithiated nano-silicon-graphene-nano carbon tube-graphite precursor2In the solvent, the mixture is uniformly mixed with the pre-lithiated nano silicon-graphene-carbon nanotube-graphite precursor under the protective gas atmosphere, and then the mixture is dried by a spray drying method to remove the solvent, so as to obtain the nano silicon-graphene-carbon nanotube-graphite precursor (namely, the second precursor) coated by the graphitized carbon source.
Third, high temperature carbonization
Carbonizing the obtained second precursor in a tubular furnace using argon as protective gas, heating to 300 ℃ at a heating rate of 2.5 ℃/min, keeping the temperature at 300 ℃ for 6h, continuing to heat to 950 ℃ at a heating rate of 4.5 ℃/min, and keeping the temperature at 950 ℃ for 5 h; and (3) crushing the carbonized material, and sieving the crushed material with a 200-mesh sieve to obtain the silicon carbon-graphite composite negative electrode material (namely the silicon carbon negative electrode material).
Example 4
SiH is filled in the step of preparing the first precursor by Chemical Vapor Deposition (CVD)4And C2H2The same as example 3 except that the time of the mixed gas was changed.
The preparation of the silicon-carbon negative electrode material of the present example was carried out according to the method of example 3, SiH in the case of preparing the first precursor by Chemical Vapor Deposition (CVD) only4And C2H2The gas of the mixed gas is continuously filled for 12 hours or the SiH is stopped filling after the content of silicon crystals in the powder is controlled to be about 12 percent4And C2H2And mixing the gases, and filling inert gas for cooling.
Example 5
SiH is filled in the step of preparing the first precursor by Chemical Vapor Deposition (CVD)4And C2H2The same as example 3 except that the time of the mixed gas was changed.
The preparation of the silicon-carbon negative electrode material of the present example was carried out according to the method of example 3, SiH in the case of preparing the first precursor by Chemical Vapor Deposition (CVD) only4And C2H2The gas of the mixed gas is continuously filled for 15 hours or the SiH is stopped filling after the content of silicon crystals in the powder is controlled to be about 15 percent4And C2H2And mixing the gases, and filling inert gas for cooling.
Example 6
The preparation method of the silicon-carbon anode material of the embodiment comprises the following steps:
firstly, pretreatment of base material
Taking 1kg of natural graphite with the medium particle size of about 12 mu m, uniformly mixing the natural graphite with a ferric trichloride aqueous solution with the mass content of 1%, and controlling the mass ratio of the natural graphite to Fe in the ferric trichloride aqueous solution to be 100: 0.5, followed by drying the mixture by spray drying to remove the solvent moisture, to obtain a carbon substrate (i.e., pretreated substrate) uniformly coated with the catalyst.
Second, first, second precursor preparation
1. Chemical Vapor Deposition (CVD) preparation of a first precursor
Putting the pretreated carbon substrate powder into a vacuum rotary furnace, vacuumizing for many times, and filling inert gas (argon with the purity of more than 99.99%) to remove air; the carbon substrate powder was heated to 1100 ℃ at a heating rate of about 6 ℃/min, and then SiH was charged at a rate of 40ml/min4And C2H2Mixed gas (SiH in mixed gas)4And C2H2Is 4: 1) the rotation speed of the vacuum rotary furnace is 5 minutes/circle, the gas is continuously filled for 18 hours or the SiH is stopped to be filled after the content of silicon crystals in the powder is controlled to be about 18 percent4And C2H2And filling inert gas into the mixed gas to cool, thus obtaining the first precursor coated by the nano silicon-graphene-carbon nano tubes.
2. Acid wash and prelithiation treatment
1) Preparation of lithiation solution
Dissolving biphenyl in diethyl ether under an inert atmosphere (argon with purity of more than 99.99%) to obtain a biphenyl solution (8 mol% of biphenyl); then, metallic lithium was added to the above biphenyl solution, and stirred for 10 hours to obtain a lithiated solution (lithium content 60 g/L).
2) Acid pickling
Soaking and cleaning the cooled first precursor for more than 12h by using dilute hydrochloric acid (HCl) to remove the Fe catalyst in the first precursor; and then, adopting clear water or an inorganic lithium salt solution for leakage extraction to remove HCl and most of water, and adopting a forced air drying oven for drying at 100 ℃ for 6 hours to dry the residual water in the solid powder.
3) Prelithiation treatment
Soaking and stirring the dried first precursor for 4 hours by using the lithiation solution in an inert atmosphere (argon with the purity of more than 99.99%), wherein the mass ratio of the lithiation solution to the first precursor is 1: 2. and then baking the soaked first precursor for 4 hours at 80 ℃ by using a vacuum drying oven, and removing the solvent to obtain the pre-lithiated nano silicon-graphene-carbon nanotube-graphite precursor.
3. Preparing a second precursor by adopting a solvent sol method
Asphalt (namely graphitized carbon source) is completely dissolved in carbon disulfide CS by 10 percent of the mass of the prelithiated nano-silicon-graphene-nano carbon tube-graphite precursor2In the solvent, the mixture is uniformly mixed with the pre-lithiated nano silicon-graphene-carbon nanotube-graphite precursor under the protective gas atmosphere, and then the mixture is dried by a spray drying method to remove the solvent, so as to obtain the nano silicon-graphene-carbon nanotube-graphite precursor (namely, the second precursor) coated by the graphitized carbon source.
Third, high temperature carbonization
Carbonizing the obtained second precursor in a tubular furnace using argon as protective gas, heating to 500 ℃ at a heating rate of 3.5 ℃/min, preserving heat at 500 ℃ for 2h, continuing to heat to 1200 ℃ at a heating rate of 5.5 ℃/min, and preserving heat at 1200 ℃ for 3 h; and (3) crushing the carbonized material, and sieving the crushed material with a 200-mesh sieve to obtain the silicon carbon-graphite composite negative electrode material (namely the silicon carbon negative electrode material).
Example 7
SiH is filled in the step of preparing the first precursor by Chemical Vapor Deposition (CVD)4And C2H2The same as in example 6 was repeated except that the mixed gas was used for the same time.
The preparation of the silicon-carbon negative electrode material of the present example was carried out according to the method of example 6, SiH in the case of preparing the first precursor by Chemical Vapor Deposition (CVD) only4And C2H2The gas of the mixed gas is continuously filled for 20 hours or the SiH is stopped to be filled after the content of silicon crystals in the powder is controlled to be about 20 percent4And C2H2And mixing the gases, and filling inert gas for cooling.
Comparative example 1
The preparation method of the silicon-carbon negative electrode material of the comparative example comprises the following steps:
the silicon carbon negative electrode material was prepared according to the method of example 1, with precursor preparation being performed directly (i.e. chemical vapour deposition of the carbon substrate without pretreatment) only by eliminating the substrate pretreatment step.
Comparative example 2
The preparation method of the silicon-carbon negative electrode material of the comparative example comprises the following steps:
the silicon carbon negative electrode material was prepared according to the method of example 1, eliminating the substrate pretreatment step and the gas C during the Chemical Vapor Deposition (CVD) preparation of the first precursor2H2Use of (i.e. using SiH only)4Chemical vapor deposition of the carbon substrate without pretreatment).
Test example 1
The negative electrode sheet and the lithium secondary battery comprising the same were prepared using the silicon carbon active materials of examples 1 to 7 and comparative examples 1 to 2 in this test example; the specific method comprises the following steps:
A. preparation of Pole pieces
A1, preparing negative plate
The silicon-carbon active materials of examples 1 to 7 and comparative examples 1 to 2 were used as anode active materials, respectively, and the anode active material, SBR binder, CMC-Li, PAA-Li, and acetylene black were added to water at a weight ratio of 93.7:1.5:1.8:2:1 to prepare an anode mixture.
Uniformly coating the negative electrode mixture on a copper foil with the thickness of 8 mu m, wherein the drying temperature is 90 ℃, and the coating single-side density is 59g/m2And the coating rate was 0.2 m/min. The coated negative electrode was subjected to roll pressing so that its compacted density was 1.55g/mm3To achieve the target thickness. Then, the mixture was dried in a vacuum oven at 100 ℃ for 12 hours to obtain a negative electrode sheet.
A2, preparing the positive plate
LiFePO to be used as a positive electrode active material4PVDF, CNT, and acetylene black were added to NMP at a weight ratio of 94.8:2.2:1:2 to prepare a positive electrode mixture.
The positive electrode mixture was uniformly coated on an aluminum foil of 16 μm at a drying temperature of 120 ℃ with a single-side density of 160g/m2And is andthe coating rate was 0.2 m/min. The coated negative electrode was subjected to roll pressing so that its compacted density was 2.35g/mm3To reach the target thickness, and dried in a vacuum oven at 120 ℃ for 12 hours to prepare a positive electrode sheet.
B. Preparation and testing of button cell
B1 preparation of electrode
And (3) rolling the prepared single-sided negative plate, cutting the single-sided negative plate into a wafer with the diameter of 1.58cm to prepare a working electrode, and baking the working electrode in a vacuum oven at 100 ℃ for 4-6 hours.
B2, snap-on Assembly
At room temperature, the area is 2cm2Using a metal lithium sheet as a negative electrode and a counter electrode, using the product obtained in the step B1 as a working electrode, using a 20-micron polypropylene porous membrane of Celgard company as a diaphragm, and using 1mol/LLIPF6And the solution of/FEC and EMC (the mass ratio is 3: 7) is taken as electrolyte and assembled into the CR-2032 type button cell in a de-oxygenation and dehumidification glove box.
B3 testing of specific volume and capacitance holding ratio
Electrochemical testing was started after the assembled cell was allowed to stand at room temperature for 24 h. On a Xinwei battery testing system, the capacitance is calculated according to the designed capacity of a negative electrode, the current of 0.1C is adopted in the first test cycle, and the charging and discharging voltage interval is 5 mV-2.0V. The mixture was left for 5 minutes after the completion of the charge or discharge.
C. Preparation of soft package single battery
The positive electrode and the silicon-carbon negative electrode are cut into pole piece specifications required by the soft package single battery process, and the 10AH soft package single battery is prepared according to the sequence of negative electrode/separator (polypropylene material porous membrane, 20 mu m, Celgard)/positive electrode/separator/negative electrode. The electrolyte solution was injected after 36 hours from the assembly of the unit cell. At this time, the organic solvent in the electrolyte solution was a mixture of fluoroethylene carbonate (FEC) and ethylmethyl carbonate (EMC) in a mass ratio of 3:7, and the electrolyte in the electrolyte solution was LiPF6The concentration is 1 mol/L. And the 10AH soft package single battery made of the silicon-carbon cathode is stored at a high temperature of 45 ℃ for 12-24 hours after liquid injection operation is finished.
D. Formation, capacity grading and cycle life test of soft package battery
D1, chemical formula
The formation process adopted by the 10AH soft package single battery is as follows: 0.05C (0.5A) for 1 hour; 0.1C (1A) for 1 hour; 0.2C (2A) for 1 hour; the formation temperature of the battery is 45 ℃, and the formation pressure is 5kg/cm2。
D2 aging
The battery after the formation operation was left at 45 ℃ for 72 hours.
D3, capacity grading
The 10AH soft package single battery adopts a capacity grading process as follows: charging for 400 minutes at 0.2C (2A) constant current and constant voltage of 3.65V, and finishing the current of 0.02C (0.2A); standing for 30 minutes; constant current discharging of 0.2C (2A) to 2.5V; standing for 30 minutes; charging for 200 minutes at 0.5C (5A) constant current and constant voltage of 3.65V, and finishing the current of 0.02C (0.2A); standing for 30 minutes; constant current discharging to 2.5V at 0.5C (5A); standing for 30 minutes; charging for 150 minutes at 1C (10A) constant current and constant voltage of 3.65V, and finishing the current of 0.02C (0.2A); standing for 30 minutes; 1C (10A) was discharged to 2.5V with constant current.
D4, Battery first Effect calculation
And multiplying the 0.2C discharge capacity/(battery formation charge capacity + battery 0.2C constant-current constant-voltage 3.65V charge capacity) of the battery by 100 percent to obtain the first efficiency of the battery.
D5, Battery cycling test
The batteries after capacity grading are subjected to 100 percent SOC cycle life test between 2.5V and 3.65V at a current of 1C (10A), and the cut-off capacity of the batteries is 80 percent of the highest discharge capacity.
E. Effects of the implementation
Tests prove that the silicon content, the first effect and the gram capacity of the button half cell, the specific surface area, the expansion rate of the negative plate of the soft package lithium ion battery, the first effect and the capacity retention rate after 1000 cycles of the negative plate of the silicon-carbon negative electrode materials prepared in the examples 1-7 and the comparative examples 1-2 are shown in the table 1.
TABLE 1
As can be seen from Table 1:
the high-capacity silicon-carbon negative electrode materials prepared in the examples 1 to 7 have the characteristics of high capacity and high first-efficiency, while the silicon-carbon negative electrode material in the comparative example 1 has the characteristics of capacity reduction and first-efficiency reduction compared with the silicon-carbon negative electrode material in the example 1; comparative example 2, although the capacity was close to that of example, the first effect was much lower than that of example 1; the above data show that the presence of carbon nanotubes and graphene has a large impact on the improvement of the capacity and first effect of the material. For the negative electrode material of the lithium battery, the higher the first effect, the more the positive electrode material can be saved, so that the energy density of the lithium battery can be improved, and the comprehensive cost of the battery can be reduced.
In addition, the capacity retention rate of the high-capacity silicon-carbon anode material prepared in the embodiments 1-3 of the invention after 200 cycles is much higher than that of the silicon-carbon anode material prepared in the comparative examples 1-2. The capacity retention rate attenuation of the high-capacity silicon-carbon negative electrode material prepared in the embodiments 4 to 7 is increased rapidly after 200 cycles, which shows that the expansion rate of the silicon-carbon negative electrode material is increased along with the increase of the silicon content, and the first effect and the cycle life of the material are reduced rapidly. Therefore, the silicon content of the silicon-carbon negative electrode material of the invention can be controlled within a certain range, or the thickness of the outer graphitized carbon layer can be increased, or the prelithiation effect of the first precursor can be increased to achieve the purpose of increasing the first effect and the service life, and the silicon content in the silicon-carbon negative electrode material can be controlled to be 2-25%, preferably 3-15%.
As can be seen from the characteristics of high capacity and high first-effect of the high-capacity silicon-carbon anode materials prepared in embodiments 1 to 7, by adjusting the process parameters of each stage, the preferred embodiments of the present invention can be obtained, or the advantages of both capacity and first-effect can be obtained, and the advantages of the other aspect can be highlighted. The high-capacity silicon-carbon negative electrode material prepared by any embodiment of the invention exceeds the current process level, and has the advantages of high capacity, high first effect, low volume expansion rate, good cycle performance, environmental friendliness, convenience in use and the like.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.
Claims (10)
1. The preparation method of the silicon-carbon negative electrode material is characterized by comprising the following steps of:
A) coating a carbon substrate by using a catalyst to obtain a pretreated substrate;
B) carrying out vapor deposition on the pretreated substrate by using mixed gas containing a carbon source and a silicon source, and carrying out acid washing on a vapor deposition product to obtain a first precursor;
C) carrying out pre-lithiation treatment on the first precursor, and then coating the first precursor by adopting a graphitized carbon source to obtain a second precursor;
D) and carbonizing the second precursor to obtain the silicon-carbon negative electrode material.
2. The production method according to claim 1, wherein in step a), the carbon substrate is selected from one or more of natural graphite, artificial graphite, a coal-based negative electrode, a hard carbon negative electrode, and porous carbon;
preferably, the carbon substrate has a D50 of 4-12 μm.
3. The preparation method according to claim 1, wherein in the step a), the catalyst comprises an iron-containing compound, the iron-containing compound is one or more selected from the group consisting of ferric trichloride, ferric nitrate, carbonyl iron and ferrocene, and is preferably ferric trichloride;
preferably, the catalyst further comprises one or more of a nickel-containing compound, a cobalt-containing compound, and a copper-containing compound;
preferably, a catalyst solution is adopted for coating, and the mass content of the catalyst in the catalyst solution is 0.2-4%;
preferably, the mass ratio of the carbon substrate to the metal component in the catalyst solution is 100: (0.25-2);
preferably, the carbon substrate is coated by spray drying or vacuum heat drying.
4. The method according to claim 1, wherein in step B), the carbon source is selected from the group consisting of C2H2、CO、CO2、CH4、C2H6And C2H4Preferably C2H2Or C2H2A mixed carbon source with CO; the silicon source is SiH4；
Preferably, the volume ratio of the silicon source to the carbon source in the mixed gas is (3-5): 1, more preferably 4: 1;
preferably, the vapor deposition is carried out in an inert atmosphere;
preferably, the inert atmosphere is nitrogen, helium or argon, preferably an argon atmosphere with a purity of more than 99.99%;
preferably, the vapor deposition is carried out in a rotary vacuum tube furnace, a multi-temperature zone vacuum atmosphere tube furnace or a continuous atmosphere-protected rotary furnace, more preferably a rotary vacuum tube furnace.
5. The method according to claim 1, wherein the temperature of the vapor deposition in step B) is controlled to be 650-1300 ℃, preferably 900-1100 ℃;
preferably, the temperature rise rate of the pretreated substrate is controlled to be 3-8 ℃/min, more preferably 5 ℃/min;
preferably, the feeding rate of the mixed gas is controlled to be 20-60 ml/min;
preferably, the time for introducing the mixed gas is controlled to be 2-25h or the content of silicon crystals in the vapor deposition product is controlled to be 2-25%, more preferably 3-15%, and even more preferably 4-10%;
preferably, the vapor deposition product is a symbiotic layer shell in which nano silicon crystals, graphene and carbon nanotubes are uniformly deposited on the surface of the carbon substrate core;
preferably, the acid-washing is performed using an inorganic acid selected from one or more of hydrochloric acid, nitric acid, sulfuric acid, and hydrofluoric acid.
6. The preparation method according to claim 1, characterized in that, in step C), the prelithiation treatment is performed with a lithiation solution, and the lithiation solution is an alkaline solution containing an inorganic lithium salt and/or an organic lithium salt;
preferably, the inorganic lithiation solution is Li2C2O4、Li2CO3、LiNO3LiOH and Li2SiO3One or more mixed solutions;
preferably, the method of preparing the organolithiation solution includes:
a) in an inert atmosphere, dissolving a polycyclic aromatic compound in an organic solvent to obtain a composite solution;
b) adding metal lithium into the composite solution in an inert atmosphere, and standing or stirring to obtain a lithiation solution;
preferably, in step a) and step b), the inert atmosphere is helium or argon, more preferably an argon atmosphere with a purity of more than 99.99%;
preferably, the polycyclic aromatic compound is selected from one or more of naphthalene, biphenyl, terphenyl, quaterphenyl, anthracene, phenanthrene and derivatives thereof, more preferably biphenyl;
preferably, the organic solvent is an ether solvent, more preferably one or more of dimethyl ether, diethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, propylene glycol dimethyl ether, propylene glycol dihexyl ether, diethylene glycol monopropyl ether and diethylene glycol dibutyl ether;
preferably, the molar percentage of polycyclic aromatic compounds in the composite solution is 8 mol% to 12 mol%, more preferably 10 mol%;
preferably, the lithium metal is in the form of lithium powder, lithium flakes, lithium rods or lithium tapes, more preferably lithium tapes;
preferably, the standing or stirring time is controlled to be 2-12h, more preferably 8-10 h;
preferably, the lithium content in the lithiation solution is 0.001 to 100g/L, more preferably 40 to 60g/L, and still more preferably 50 g/L.
7. The method according to claim 1, wherein in step C), the graphitized carbon source is pitch or a high molecular organic polymer;
preferably, the asphalt is selected from at least one of petroleum asphalt, natural asphalt and tar asphalt;
preferably, the high molecular organic polymer is selected from one or more of polyfurfuryl alcohol, polyfuran resin, ceramomene resin, propionitrile resin, epoxy resin, phenolic resin, furfural resin, glucose and sucrose;
preferably, the solvent for dissolving the graphitized carbon source is selected from one or more of carbon disulfide, n-hexane, xylene and carbon tetrachloride, more preferably carbon disulfide;
preferably, the method for coating by adopting the graphitized carbon source is a solvent sol method combined with a spray drying method or a mechanical ball milling method;
preferably, the solvent sol process in combination with the spray drying process comprises: dissolving a graphitized carbon source in a solvent to prepare a graphitized carbon solution; and then, adding the pre-lithiated first precursor into the graphitized carbon solution, stirring and uniformly mixing, and then carrying out spray drying.
8. The method according to claim 1, wherein in step D), the carbonization comprises sequential curing and graphitization; wherein the temperature during curing is controlled to be 300-500 ℃, preferably 400 ℃, the curing time is 0.5-8h, preferably 2-6h, and the heating rate during curing is 2-5 ℃/min, preferably 3 ℃/min; controlling the temperature of graphitization to be 800-1300 ℃, preferably 1050 ℃, and the graphitization time to be 3-5 h; the temperature rise rate during graphitization is 3-8 deg.C/min, preferably 5 deg.C/min.
9. A silicon carbon negative electrode material, characterized by being produced by the production method according to any one of claims 1 to 8;
preferably, the content of silicon in the silicon-carbon negative electrode material is 2-25%, more preferably 3-15%, and still more preferably 4-10%;
preferably, the particle size D50 of the silicon-carbon negative electrode material is 8-16 mu m, and the BET specific surface area is less than or equal to 2.5m2/g。
Preferably, the capacity of the silicon-carbon anode material is 400-1000mah/g, and more preferably 450-600 mah/g.
10. The use of the silicon carbon negative electrode material of claim 9 in the preparation of a lithium ion battery negative electrode.
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| CN114122352A (en) * | 2021-10-29 | 2022-03-01 | 西安交通大学 | Silicon-carbon negative electrode material for inducing silicon deposition by doping porous carbon and preparation method thereof |
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| CN115050966A (en) * | 2022-08-11 | 2022-09-13 | 楚能新能源股份有限公司 | Silicon-carbon negative electrode material and preparation method thereof |
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Citations (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20080020282A1 (en) * | 2006-07-14 | 2008-01-24 | Dong Hwan Kim | Anode active material hybridizing carbon nano fibers for lithium secondary battery |
| CN102530931A (en) * | 2011-12-14 | 2012-07-04 | 天津大学 | Graphene-based nano composite material and preparation method thereof |
| CN102637874A (en) * | 2012-04-11 | 2012-08-15 | 中国科学院过程工程研究所 | Lithium ion battery silicon-carbon composite negative-electrode material and preparation method thereof |
| CN103247802A (en) * | 2013-05-03 | 2013-08-14 | 深圳市贝特瑞新能源材料股份有限公司 | Graphite composite negative electrode material for lithium ion battery, preparation method of material, and lithium ion battery |
| CN104577084A (en) * | 2015-01-20 | 2015-04-29 | 深圳市贝特瑞新能源材料股份有限公司 | Nano silicon composite negative electrode material for lithium ion battery, preparation method and lithium ion battery |
| CN106848268A (en) * | 2017-04-11 | 2017-06-13 | 深圳市贝特瑞新能源材料股份有限公司 | A kind of carbon-silicon composite material, Preparation Method And The Use |
| WO2017099456A1 (en) * | 2015-12-07 | 2017-06-15 | 강원대학교산학협력단 | Negative electrode active material for lithium secondary battery comprising core composed of carbon, manufacturing method therefor, and lithium secondary battery including same |
| CN107851780A (en) * | 2016-05-27 | 2018-03-27 | 株式会社Lg化学 | Negative active core-shell material and the lithium secondary battery for including it |
| CN109244377A (en) * | 2017-07-10 | 2019-01-18 | 力信（江苏）能源科技有限责任公司 | A kind of preparation method of negative electrode of lithium ion battery Si-C composite material |
| CN109802120A (en) * | 2019-01-24 | 2019-05-24 | 广东凯金新能源科技股份有限公司 | A kind of Si-C composite material and its preparation method |
| CN110311125A (en) * | 2019-08-15 | 2019-10-08 | 马鞍山科达普锐能源科技有限公司 | A kind of lithium-ion battery silicon-carbon anode material and preparation method thereof |
| CN110620223A (en) * | 2019-09-25 | 2019-12-27 | 福建翔丰华新能源材料有限公司 | Lithium ion battery pre-lithiation silicon-carbon multilayer composite negative electrode material and preparation method thereof |
| CN111554910A (en) * | 2020-05-19 | 2020-08-18 | 溧阳天目先导电池材料科技有限公司 | Lithium battery negative electrode material containing pre-lithiated silylene material, preparation method thereof and lithium battery |
| CN112234197A (en) * | 2020-09-08 | 2021-01-15 | 中南大学 | Amorphous carbon-silicon-carbon nanofiber-graphite composite material and preparation method and application thereof |
| CN112234171A (en) * | 2020-09-08 | 2021-01-15 | 中南大学 | Silicon-natural graphite composite material, application thereof and method for preparing silicon-natural graphite composite material by catalyzing with trace harmless impurities |
| CN112310361A (en) * | 2019-07-30 | 2021-02-02 | 宁波杉杉新材料科技有限公司 | Silicon monoxide negative electrode material, electrode, preparation method and application thereof |
-
2021
- 2021-06-02 CN CN202110613163.7A patent/CN113380998A/en active Pending
Patent Citations (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20080020282A1 (en) * | 2006-07-14 | 2008-01-24 | Dong Hwan Kim | Anode active material hybridizing carbon nano fibers for lithium secondary battery |
| CN102530931A (en) * | 2011-12-14 | 2012-07-04 | 天津大学 | Graphene-based nano composite material and preparation method thereof |
| CN102637874A (en) * | 2012-04-11 | 2012-08-15 | 中国科学院过程工程研究所 | Lithium ion battery silicon-carbon composite negative-electrode material and preparation method thereof |
| CN103247802A (en) * | 2013-05-03 | 2013-08-14 | 深圳市贝特瑞新能源材料股份有限公司 | Graphite composite negative electrode material for lithium ion battery, preparation method of material, and lithium ion battery |
| CN104577084A (en) * | 2015-01-20 | 2015-04-29 | 深圳市贝特瑞新能源材料股份有限公司 | Nano silicon composite negative electrode material for lithium ion battery, preparation method and lithium ion battery |
| WO2017099456A1 (en) * | 2015-12-07 | 2017-06-15 | 강원대학교산학협력단 | Negative electrode active material for lithium secondary battery comprising core composed of carbon, manufacturing method therefor, and lithium secondary battery including same |
| CN107851780A (en) * | 2016-05-27 | 2018-03-27 | 株式会社Lg化学 | Negative active core-shell material and the lithium secondary battery for including it |
| CN106848268A (en) * | 2017-04-11 | 2017-06-13 | 深圳市贝特瑞新能源材料股份有限公司 | A kind of carbon-silicon composite material, Preparation Method And The Use |
| CN109244377A (en) * | 2017-07-10 | 2019-01-18 | 力信（江苏）能源科技有限责任公司 | A kind of preparation method of negative electrode of lithium ion battery Si-C composite material |
| CN109802120A (en) * | 2019-01-24 | 2019-05-24 | 广东凯金新能源科技股份有限公司 | A kind of Si-C composite material and its preparation method |
| CN112310361A (en) * | 2019-07-30 | 2021-02-02 | 宁波杉杉新材料科技有限公司 | Silicon monoxide negative electrode material, electrode, preparation method and application thereof |
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