CN112614973A - Silicon-carbon negative electrode material and preparation method thereof, negative plate and lithium ion battery - Google Patents

Silicon-carbon negative electrode material and preparation method thereof, negative plate and lithium ion battery Download PDF

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CN112614973A
CN112614973A CN202011416598.4A CN202011416598A CN112614973A CN 112614973 A CN112614973 A CN 112614973A CN 202011416598 A CN202011416598 A CN 202011416598A CN 112614973 A CN112614973 A CN 112614973A
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silicon
carbon
negative electrode
material body
silicon material
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张敏
袁号
胡大林
廖兴群
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Huizhou Highpower Technology Co Ltd
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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
    • 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
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/131—Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
    • 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
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/134—Electrodes based on metals, Si or alloys
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
    • H01M4/386—Silicon or alloys based on silicon
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/483—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides for non-aqueous cells
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • 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
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/628—Inhibitors, e.g. gassing inhibitors, corrosion inhibitors
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Abstract

The invention belongs to the technical field of battery materials, and particularly relates to a silicon-carbon negative electrode material, a preparation method thereof, a negative plate and a lithium ion battery. The silicon-carbon negative electrode material comprises a silicon material body and a carbon tube, wherein a plurality of holes are formed in the silicon material body, at least one end of each hole extends to the surface of the silicon material body, and the carbon tube is arranged in each hole. In the invention, the carbon tubes are positioned in the silicon material body instead of around the silicon material body, and the carbon tubes can greatly increase the elastic strength of the silicon material body, inhibit the pulverization of the silicon material body, enable the silicon material body to exert the maximum capacity and avoid the problem that the capacity cannot be exerted due to the poor internal conductivity of the silicon material body. And the carbon tubes can provide a good conductive network for the silicon material body, so that the disconnection of the conductive network caused by the volume expansion of the silicon material body is avoided, the stable film formation of SEI is facilitated, and the cycle performance is greatly improved.

Description

Silicon-carbon negative electrode material and preparation method thereof, negative plate and lithium ion battery
Technical Field
The invention belongs to the technical field of battery materials, and particularly relates to a silicon-carbon negative electrode material, a preparation method thereof, a negative plate and a lithium ion battery.
Background
The lithium ion battery is widely applied to the fields of electronic equipment, electric appliances, electric automobiles and the like as an efficient, light and portable energy storage device. At present, graphite (370 mAhg) with lower specific capacity is mostly adopted in commercial lithium ion batteries-1) Silicon (Li) with higher theoretical specific capacity as negative active material15Si4，3590mAh g-1) The lithium ion battery cathode material is very suitable for preparing a high-performance lithium ion battery.
However, silicon as an anode material has a large volume expansion (about 400%) during charge and discharge cycles, which severely limits the amount of silicon anode material used. In the prior art, a silicon material is often surface-coated, or porous silicon is formed, or a combination of the two is formed. For example, in chinese patent publication No. CN105406050A, a double-layer shell is coated on the surface of a nano silicon, the core is nano silicon, the middle layer is a silicon-oxygen compound and a metal alloy, and the outermost layer is a conductive carbon layer, so that volume expansion of the nano silicon is effectively reduced and high conductivity of the silicon material is maintained. Chinese patent publication No. CN 10350181A discloses a preparation method of porous silicon negative electrode material by using H2O2And the metal nano-particle assisted chemical etching method, the prepared porous nano-silicon has the functions of well inhibiting silicon volume expansion and improving cycle performance. In summary, many technologies for silicon materials only stay in the modification of the surface coating and the porous structure of the silicon materials, but do not modify the silicon materials from the root cause of the cyclic failure of the silicon materials, and the invention bases on the root cause of the cyclic failure of the silicon materialsThe body is modified in order to solve the problem of cycle failure.
Disclosure of Invention
The technical problem to be solved by the invention is as follows: aiming at the problem of low battery cycle life caused by volume expansion of a silicon negative electrode material in the prior art, the silicon-carbon negative electrode material, the preparation method thereof, the negative plate and the lithium ion battery are provided.
In order to solve the above technical problem, in one aspect, an embodiment of the present invention provides a silicon-carbon negative electrode material, including a silicon material body and a carbon tube, where the silicon material body is provided with a plurality of pores, at least one end of each pore extends to a surface of the silicon material body, and the carbon tube is disposed in the pore.
Preferably, the mass fraction of the silicon material body in the silicon-carbon negative electrode material is 3-99%, and the mass fraction of the carbon tube in the silicon-carbon negative electrode material is 1-97%.
Preferably, the specific surface area of the silicon-carbon negative electrode material is 0.1-3000 m2/g。
Preferably, the particle diameter of the silicon material body is 10 nm-100 μm, and the diameter of the cross section of the pore channel is 1 nm-50 μm.
Preferably, the carbon tubes have a diameter of 0.5nm to 100nm and a length of 10nm to 50 μm.
Preferably, the silicon material body comprises one or more of crystalline silicon, amorphous silicon, silicon oxygen material and silicon carbon material;
the carbon tube includes one or more of a single-walled carbon tube, a multi-walled carbon tube, a hollow carbon tube, and a carbon fiber.
On the other hand, the embodiment of the invention provides a preparation method of a silicon-carbon anode material, which comprises the following steps:
placing the silicon material in a first acid solution, and removing part of metal in the silicon material to form a silicon material body with a plurality of pores;
drying the silicon material body, placing the silicon material body in a tubular furnace, introducing carbon source gas and carrier gas at high temperature, and generating a carbon tube in the pore channel;
and placing the silicon material body with the generated carbon tubes in an excessive second acid solution, and enlarging the pore channel to obtain the silicon-carbon composite material.
Preferably, the carbon source gas comprises one or more of alkanes, alkynes, alkenes, benzene rings and carbon-containing gas;
the carrier gas comprises one or more of hydrogen, nitrogen, helium, neon and argon.
In another aspect, an embodiment of the present invention provides a negative electrode sheet, including the foregoing silicon-carbon negative electrode material, or including the silicon-carbon negative electrode material prepared by the foregoing preparation method of the silicon-carbon negative electrode material.
On the other hand, an embodiment of the present invention provides a lithium ion battery, including a positive plate, a negative plate and a separator, where the negative plate is the negative plate as described above.
In the embodiment of the invention, a plurality of pore channels are formed on the silicon material body, carbon tubes are generated in the pore channels, and the carbon tubes have excellent electrical conductivity, high mechanical strength and tensile strength, low density and other properties, and also have certain chemical stability and excellent thermal conductivity. The carbon tubes are positioned in the silicon material body instead of around the silicon material body, and the carbon tubes do not completely fill the pore channels, and the pore channels contain gaps, so the carbon tubes can greatly increase the elastic strength of the silicon material body, the silicon material body leaves gaps for internal expansion and also contains gaps for external expansion, and the pulverization of the silicon material body is inhibited. In the invention, the carbon tubes grow in situ in the silicon material body, so that the silicon material body can exert the maximum capacity, thereby avoiding the problem that the capacity cannot be exerted due to poor internal conductivity of the silicon material body.
The carbon tubes can provide a good conductive network for the silicon material body, and meanwhile, the plurality of pore channels provide a good buffer space for the silicon material body, so that disconnection of the conductive network caused by volume expansion of the silicon material body is avoided. According to the invention, silicon particle expansion is reduced on the premise of not inhibiting silicon lattice expansion, silicon material pulverization is effectively inhibited, stable film formation of SEI is facilitated, and the cycle performance is greatly improved.
Drawings
Fig. 1 is a schematic structural diagram of a silicon-carbon negative electrode material provided by the invention.
The reference numerals in the specification are as follows:
1. a silicon material body; 2. a carbon tube; 3. a tunnel.
Detailed Description
In order to make the technical problems, technical solutions and advantageous effects solved by the present invention more apparent, the present invention is further described in detail below with reference to the embodiments and the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
As shown in fig. 1, a silicon-carbon negative electrode material provided in an embodiment of the present invention includes a silicon material body 1 and carbon tubes 2, wherein a plurality of channels 3 are disposed in the silicon material body 1, at least one end of each channel 3 extends to a surface of the silicon material body 1, and the carbon tubes 2 are criss-cross inserted in the channels 3.
In the current silicon-carbon negative electrode material, in order to limit the expansion of the silicon material, the scheme of coating a carbon layer on the surface of nano silicon is adopted to reduce the expansion of the silicon volume, and a large amount of experimental researches show that the root of the expansion of the silicon negative electrode material is that an old SEI layer is continuously broken and a new SEI layer is continuously formed in the charging and discharging process, so that the pulverization of the silicon material is serious, silicon particles are mutually extruded and pulverized due to stress generated by volume change in the pulverization process of the silicon material, and in addition, the huge expansion of the silicon material can cause the disconnection of a conductive network, further the electrical contact is lost, the rapid attenuation of the battery capacity is caused, and the cycle life of the silicon negative electrode is seriously influenced. Furthermore, the volume effect of the silicon material may also destabilize the SEI film, further affecting the capacity and cycle life of the battery.
In the invention, a plurality of pore channels 3 are formed on the silicon material body 1, carbon tubes 2 are generated in the pore channels 3, the carbon tubes 2 are nano materials composed of carbon atom two-dimensional hexagonal lattices, and due to the nano structure and the interatomic bonding strength of the carbon tubes 2, the carbon tubes 2 have excellent electrical conductivity, high mechanical strength and tensile strength, low density and other properties, and also have certain chemical stability and excellent thermal conductivity. Because the carbon tubes 2 are located inside the silicon material body 1, but not around the silicon material body 1, and the carbon tubes 2 do not completely fill the pore channels 3, and the pore channels 3 contain gaps, the carbon tubes 2 can greatly increase the elastic strength of the silicon material body 1, so that the silicon material body 1 has gaps for internal expansion and also has gaps for external expansion, and pulverization of the silicon material body 1 is inhibited. In the invention, the carbon tube 2 grows in situ in the silicon material body 1, so that the silicon material body 1 can exert the maximum capacity, thereby avoiding the problem that the capacity cannot be exerted due to poor internal conductivity of the silicon material body 1.
The carbon tubes 2 can provide a good conductive network for the silicon material body 1, and meanwhile, the pore channels 3 provide a good buffer space for the silicon material body 1, so that disconnection of the conductive network caused by volume expansion of the silicon material body 1 is avoided. According to the invention, silicon particle expansion is reduced on the premise of not inhibiting silicon lattice expansion, silicon material pulverization is effectively inhibited, stable film formation of SEI is facilitated, and the cycle performance is greatly improved.
According to the present invention, in the present embodiment, at least one end of the pore 3 extends to the surface of the silicon material body 1, specifically, the pore 3 may have a closed structure at one end and is located in the silicon material body 1, and the other end of the pore 3 has an open structure and is located on the surface of the silicon material and is communicated with the outside. Or, the pore 3 penetrates through the silicon material body 1, and both ends of the pore 3 are located on the surface of the silicon material and are communicated with the outside.
In one embodiment, the mass fraction of the silicon material body 1 in the silicon-carbon negative electrode material is 3-99%, and the mass fraction of the carbon tube 2 in the silicon-carbon negative electrode material is 1-97%.
In one embodiment, the specific surface area of the silicon-carbon negative electrode material is 0.1-3000 m2(ii) in terms of/g. The larger the specific surface area is, the larger the number of the channels 3 in the silicon material body 1 is, and the smaller the specific surface area is, the larger the number of the channels 3 in the silicon material body 1 isLess. According to the invention, the number of the pore channels 3 does not influence the capacity and the cycle performance of the silicon-carbon negative electrode material.
In an embodiment, the particle diameter of the silicon material body 1 is 10nm to 100 μm, the diameter of the cross section of the pore 3 is 1nm to 50 μm, the pore 3 may be communicated with each other or isolated from each other, and the pore 3 may be disposed on the surface of the silicon material body 1 or extend into the silicon material body 1.
In one embodiment, the diameter of the carbon tube 2 is 0.5nm to 100nm, and the length of the carbon tube 2 is 10nm to 50 μm.
In an embodiment, the silicon material body 1 includes one or more of crystalline silicon, amorphous silicon, silicon oxygen material, and silicon carbon material. The carbon tube 2 includes one or more of a single-walled carbon tube, a multi-walled carbon tube, a hollow carbon tube, and a carbon fiber.
Another embodiment of the present invention provides a method for preparing a silicon-carbon negative electrode material, including the steps of:
placing a silicon material in a first acid solution, removing part of metal in the silicon material, and forming a silicon material body 1 with a plurality of pores 3;
drying the silicon material body 1, placing the dried silicon material body in a tubular furnace, introducing carbon source gas and carrier gas at high temperature, and generating a carbon tube 2 in the pore channel 3;
and placing the silicon material body 1 with the generated carbon tubes 2 in an excessive second acid solution, and enlarging the pore channel 3 to obtain the silicon-carbon composite material.
In one embodiment, the metal element in the silicon material comprises one or more of iron, cobalt, nickel, aluminum, magnesium, copper, manganese, vanadium, niobium, tantalum and oxides thereof, the first acid solution comprises one or more of hydrochloric acid, sulfuric acid and nitric acid solution, the solubility of the first acid solution is 0.1-5 mol/L, and the silicon material is placed in the first acid solution for 0.5-24 hours.
And placing the silicon material in a first acid solution for acid washing, controlling the proportion of the silicon material to the first acid solution, removing part of metal in the silicon material, and simultaneously, remaining some metal as a metal catalyst for growing the carbon tube 2, so as to be beneficial to the generation of the carbon tube 2.
In one embodiment, the prepared silicon material body 1 with the pore channel 3 is placed in a tube furnace, the total flow of the carbon source gas and the carrier gas introduced into the tube furnace is 1-3000 ml/min, the carbon source gas accounts for 1-90% of the total flow, the high temperature in the tube furnace is 500-1200 ℃, and the time is 0.5-10 hours.
In one embodiment, the carbon source gas includes one or more of alkanes, alkynes, alkenes, benzene rings, and carbon-containing gas, and further includes one or more of methane, ethane, propane, butane, ethylene, propylene, butylene, acetylene, propyne, butyne, and carbon monoxide.
The carrier gas comprises one or more of hydrogen, nitrogen, helium, neon and argon.
In one embodiment, after the carbon tubes 2 are formed, the silicon material body 1 with the carbon tubes 2 is placed in an excessive amount of the second acid solution to remove excess metal particles, and at the same time, the size of the pores 3 in the silicon material body 1 can be further enlarged. The second acid solution comprises one or more of hydrochloric acid, sulfuric acid and nitric acid solution, the time for placing the silicon material body 1 with the carbon tubes 2 in the excessive second acid solution is 0.5-10 hours, and the concentration of the second acid solution is 0.1-5 mol/L.
Another embodiment of the invention provides a negative electrode sheet, which includes the silicon-carbon negative electrode material as described above, or includes the silicon-carbon negative electrode material prepared by the preparation method of the silicon-carbon negative electrode material as described above.
The negative plate comprises a negative active material and a negative current collector used for leading out current, and the negative active material covers the negative current collector. The negative active material comprises 80-95 parts of silicon-carbon negative material, 0.5-5 parts of binder, 0.5-5 parts of dispersant, 0.5-5 parts of conductive agent, 0.2-5 parts of thickener and 100-150 parts of water.
The preparation method of the negative plate comprises the following steps: firstly, adding a thickening agent into water with a half formula amount, then sequentially adding a binder, a dispersing agent, a conductive agent and a silicon-carbon negative electrode material under the stirring condition, uniformly dispersing, then adding the rest water, then grinding and sieving to obtain active layer slurry, coating the active layer slurry on a current collector, drying and rolling to obtain a negative plate.
The binder comprises one or more of polyvinylidene fluoride (PVDF), Polytetrafluoroethylene (PTFE), Polyethyleneimine (PEI), Polyaniline (PAN), polyacrylic acid (PAA), polyvinyl alcohol (PVA), Polyacrylonitrile (PAN), polyethylene oxide (PEO), sodium alginate, Styrene Butadiene Rubber (SBR), sodium carboxymethylcellulose (CMC), phenolic resin or epoxy resin and other high polymer.
The conductive agent comprises one or more of Carbon Nano Tubes (CNTs), carbon fibers (VGCF), conductive graphite (KS-6, SFG-6), mesocarbon microbeads (MCMB), graphene, Ketjen black, Super P, acetylene black, conductive carbon black or hard carbon and other conductive agents which are common in the industry.
The thickening agent is sodium carboxymethyl cellulose (CMC).
Another embodiment of the present invention provides a lithium ion battery, including a positive plate, a negative plate and a diaphragm, where the negative plate is the negative plate described above.
The positive plate is a conventional lithium cobaltate positive plate.
The diaphragm is arranged between the positive plate and the negative plate, and the diaphragm is a conventional diaphragm in the field of lithium ion batteries, and is not repeated here.
The present invention will be further illustrated by the following examples.
The silicon material is purchased from Aladdin reagent company Limited, and the carbon material is purchased from Shanghai fir technology company Limited; the binder, dispersant, conductive agent and thickener used were all purchased from Aladdin reagents, Inc.
The diaphragm is a Polyethylene (PE) porous diaphragm, is a wet diaphragm produced by Shanghai Enjie New Material science and technology, and has a thickness of 12 μm.
The electrolyte is carbonate solution purchased from New Zebra, and the main additives are VC and FEC.
The anode material is purchased from Xiamen tungsten industry Co Ltd, and the surface density of the anode is 23mg/cm2The charge-discharge voltage is 3.0-4.45V, and the charge-discharge current is 0.5C/0.5C.
In each of the following examples and comparative examples, the current collector was a 6 μm copper foil.
Example 1
The embodiment is used for explaining the silicon-carbon negative electrode material, the preparation method thereof, the negative electrode sheet and the lithium ion battery, and comprises the following steps:
(1) adding 10mol of silicon-aluminum-copper alloy material (the atomic ratio is 2:2:1) into 2mol/L hydrochloric acid solution with the volume of 3L, stirring for 5h at room temperature, and removing aluminum elements to form porous silicon-copper alloy with a plurality of pore channels;
(2) placing the porous silicon-copper alloy prepared in the step 1 in a high-temperature tube furnace, introducing argon gas carrying methane gas, introducing the methane gas at 800 ℃ for 2h, wherein the flow of the methane gas is 20ml/min, and the flow of the argon gas is 200ml/min, and generating a carbon tube-penetrating porous silicon-copper material;
(3) placing the carbon tube-penetrating porous silicon copper material prepared in the step 2 in an excessive 1mol/L nitric acid solution, fully reacting for 5 hours at room temperature, further reaming after removing copper, increasing the pore diameter of a pore channel, washing for several times by using deionized water, drying and drying to obtain a silicon-carbon composite material;
(4) adding deionized water in an amount which is 1.3 times that of the silicon-carbon composite material into the prepared silicon-carbon composite material, conductive agent SP, binder PAA and thickening agent CMC in a mass ratio of 92:3:2:1:2, uniformly stirring to prepare negative electrode slurry, further coating, drying and rolling to obtain a negative electrode sheet, and preparing the battery by matching with a lithium cobaltate positive electrode sheet, a diaphragm, electrolyte and an aluminum plastic film through a winding process.
Example 2
(1) Adding 10mol of silicon-iron-nickel alloy material (the atomic ratio is 1:2:1) into a 2mol/L hydrochloric acid solution with the volume of 5L, stirring for 8h at room temperature, and removing iron elements to form porous silicon-nickel alloy with a plurality of pore channels;
(2) placing the porous silicon-nickel alloy prepared in the step 1 in a high-temperature tubular furnace, introducing argon carrying acetylene gas at 500 ℃, introducing the argon for 5 hours, wherein the flow of the acetylene gas is 10ml/min, and the flow of the argon gas is 100ml/min, and preparing a carbon tube-penetrating porous silicon-nickel material;
(3) placing the prepared carbon tube-penetrating porous silicon-nickel material in excessive 1mol/L sulfuric acid solution, fully reacting for 10h at room temperature, further reaming after removing nickel, increasing the pore diameter of a pore channel, washing for several times by deionized water, drying and drying to obtain a silicon-carbon composite material;
(4) adding deionized water in an amount which is 1.3 times that of the silicon-carbon composite material into the prepared silicon-carbon composite material, conductive agent SP, binder PAA and thickening agent CMC in a mass ratio of 92:3:2:1:2, uniformly stirring to prepare negative electrode slurry, further coating, drying and rolling to obtain a negative electrode sheet, and preparing the battery by matching with a lithium cobaltate positive electrode sheet, a diaphragm, electrolyte and an aluminum plastic film through a winding process.
Example 3
(1) Taking 10mol of silicon-iron alloy material (the atomic ratio is 1:1), adding the silicon-iron alloy material into 1mol/L sulfuric acid solution with the volume of 4L, stirring for 10 hours at room temperature, removing part of iron element, and forming porous silicon-iron alloy with a plurality of pore channels;
(2) placing the porous silicon-iron alloy prepared in the step 1 in a high-temperature tubular furnace, introducing nitrogen gas carrying ethylene gas at 600 ℃, introducing the nitrogen gas for 5 hours, wherein the flow rate of the ethylene gas is 20ml/min, and the flow rate of the nitrogen gas is 500ml/min, and preparing a carbon tube-penetrating porous silicon-iron material;
(3) placing the prepared porous silicon-iron alloy material of the carbon tube in excessive 1mol/L sulfuric acid solution, fully reacting for 10h at room temperature, further reaming after removing iron, increasing the pore diameter of a pore passage, washing for several times by deionized water, drying and drying to obtain a silicon-carbon composite material;
(4) adding deionized water in an amount which is 1.3 times that of the silicon-carbon composite material into the prepared silicon-carbon composite material, conductive agent SP, binder PAA and thickening agent CMC in a mass ratio of 92:3:2:1:2, uniformly stirring to prepare negative electrode slurry, further coating, drying and rolling to obtain a negative electrode sheet, and preparing the battery by matching with a lithium cobaltate positive electrode sheet, a diaphragm, electrolyte and an aluminum plastic film through a winding process.
Example 4
(1) Adding 10mol of silicon-magnesium alloy material (atomic ratio is 1:2) into 1mol/L sulfuric acid solution with the volume of 5L, stirring for 5h at room temperature, oxidizing magnesium into magnesium hydroxide and consuming part of magnesium element to form a mixture of porous silicon and magnesium hydroxide;
(2) placing the mixture prepared in the step 1 in a high-temperature tubular furnace, introducing argon carrying carbon monoxide at 1000 ℃, introducing the argon for 2 hours, wherein the gas flow of the carbon monoxide is 20ml/min, and the gas flow of the argon is 200ml/min, and preparing a carbon tube-penetrating porous silicon-magnesium alloy material;
(3) placing the prepared carbon tube-penetrating porous silicon-magnesium alloy material in an excessive 1mol/L sulfuric acid solution, fully reacting for 2h, further reaming after removing magnesium, increasing the pore diameter of a pore passage, washing for several times by using deionized water, drying and drying to obtain a silicon-carbon composite material;
(4) adding deionized water in an amount which is 1.3 times that of the silicon-carbon composite material into the prepared silicon-carbon composite material, conductive agent SP, binder PAA and thickening agent CMC in a mass ratio of 92:3:2:1:2, uniformly stirring to prepare negative electrode slurry, further coating, drying and rolling to obtain a negative electrode sheet, and preparing the battery by matching with a lithium cobaltate positive electrode sheet, a diaphragm, electrolyte and an aluminum plastic film through a winding process.
Example 5
(1) Taking 10mol of silicon-cobalt-nickel alloy material (atomic ratio is 1:2:2), adding the silicon-cobalt-nickel alloy material into 2mol/L hydrochloric acid solution with the volume of 6L, stirring for 5h at room temperature, and removing cobalt element and part of nickel element to form porous silicon-nickel alloy;
(2) placing the porous silicon-nickel alloy prepared in the step 1 in a high-temperature tubular furnace, introducing argon carrying propylene gas at 800 ℃ for 5 hours, wherein the flow of the propylene gas is 10ml/min, and the flow of the argon gas is 200ml/min, and preparing a carbon tube-penetrating porous silicon-nickel material;
(3) putting the prepared carbon tube penetrating through the porous silicon-nickel material into excessive 1mol/L hydrochloric acid solution, fully reacting for 5 hours at room temperature, further expanding holes after removing nickel, increasing the pore diameter of a pore passage, washing for several times by deionized water, drying and drying to obtain a silicon-carbon composite material;
(4) adding deionized water in an amount which is 1.3 times that of the silicon-carbon composite material into the prepared silicon-carbon composite material, conductive agent SP, binder PAA and thickening agent CMC in a mass ratio of 92:3:2:1:2, uniformly stirring to prepare negative electrode slurry, further coating, drying and rolling to obtain a negative electrode sheet, and preparing the battery by matching with a lithium cobaltate positive electrode sheet, a diaphragm, electrolyte and an aluminum plastic film through a winding process.
Example 6
(1) Adding 10mol of silicon-cobalt-vanadium alloy material (the atomic ratio is 3:1:1) into 4L of 2mol/L hydrochloric acid solution, stirring for 8h at room temperature, and removing vanadium element and part of cobalt element to form porous silicon-cobalt alloy;
(2) placing the porous silicon-cobalt alloy prepared in the step 1 in a high-temperature tube furnace, introducing neon gas carrying methane gas at 1200 ℃, introducing the neon gas for 8 hours, wherein the flow rate of the methane gas is 10ml/min, and the flow rate of the neon gas is 100ml/min, and preparing a carbon tube-penetrating porous silicon-cobalt material;
(3) placing the prepared carbon tube penetrating through the porous silicon-cobalt material in excessive 1mol/L hydrochloric acid solution, fully reacting at room temperature for 10h, removing cobalt, further expanding pores, increasing pore diameter of pore channels, washing with deionized water for several times, drying and drying to obtain a silicon-carbon composite material;
(4) adding deionized water in an amount which is 1.3 times that of the silicon-carbon composite material into the prepared silicon-carbon composite material, conductive agent SP, binder PAA and thickening agent CMC in a mass ratio of 92:3:2:1:2, uniformly stirring to prepare negative electrode slurry, further coating, drying and rolling to obtain a negative electrode sheet, and preparing the battery by matching with a lithium cobaltate positive electrode sheet, a diaphragm, electrolyte and an aluminum plastic film through a winding process.
Comparative example 1
The preparation process is basically the same as that in example 1, except that: and (2) putting the silicon alloy material into a sufficient amount of acid solution in the step (1), completely removing metal in the silicon alloy to form porous silicon, and not carrying out the step (2) and the step (3) and keeping the rest conditions unchanged.
Comparative example 2
The preparation process is basically the same as that in example 2, except that: and (2) putting the silicon alloy material into a sufficient amount of acid solution in the step (1), completely removing metal in the silicon alloy to form porous silicon, and not carrying out the step (2) and the step (3) and keeping the rest conditions unchanged.
Comparative example 3
The preparation process is basically the same as that in example 3, except that: and (2) putting the silicon alloy material into a sufficient amount of acid solution in the step (1), completely removing metal in the silicon alloy to form porous silicon, and not carrying out the step (2) and the step (3) and keeping the rest conditions unchanged.
Comparative example 4
The preparation process is basically the same as that in example 4, except that: and (2) putting the silicon alloy material into a sufficient amount of acid solution in the step (1), completely removing metal in the silicon alloy to form porous silicon, and not carrying out the step (2) and the step (3) and keeping the rest conditions unchanged.
Comparative example 5
The preparation process is basically the same as that in example 5, except that: and (2) putting the silicon alloy material into a sufficient amount of acid solution in the step (1), completely removing metal in the silicon alloy to form porous silicon, and not carrying out the step (2) and the step (3) and keeping the rest conditions unchanged.
Comparative example 6
The preparation process is basically the same as that in example 6, except that: and (2) putting the silicon alloy material into a sufficient amount of acid solution in the step (1), completely removing metal in the silicon alloy to form porous silicon, and not carrying out the step (2) and the step (3) and keeping the rest conditions unchanged.
Comparative example 7
The same silicon alloy material as that in example 1 was used to directly prepare a negative electrode plate, and the preparation process was the same as that in step (4) in example 1.
Comparative example 8
The same silicon alloy material as that in example 2 was used to directly prepare a negative electrode plate, and the preparation process was the same as that in step (4) in example 1.
Comparative example 9
The same silicon alloy material as that in example 3 was used to directly prepare a negative electrode plate, and the preparation process was the same as that in step (4) in example 1.
Comparative example 10
The same silicon alloy material as that in example 4 was used to directly prepare a negative electrode plate, and the preparation process was the same as that in step (4) in example 1.
Comparative example 11
The same silicon alloy material as that in example 5 was used to directly prepare a negative electrode sheet, and the preparation process was the same as that in step (4) in example 1.
Comparative example 12
The same silicon alloy material as that in example 6 was used to directly prepare a negative electrode sheet, and the preparation process was the same as that in step (4) in example 1.
Comparative example 13
The cathode plate is directly prepared by using pure silicon material as an active material, and the preparation process is the same as the step (4) in the example 1.
The negative electrode materials prepared in examples 1 to 6 and comparative examples 1 to 13 were prepared into lithium ion batteries, and the expansion rate of the negative electrode sheet, the resistivity of the sheet, and the capacity fading to 80% of the cycle times of the lithium ion batteries at 25 ℃ and 0.5C/0.5C energy density after 300 cycles were tested, and the test results are shown in Table 1.
Table 1 test performance of lithium ion batteries prepared in examples 1 to 6 and comparative examples 1 to 13
Figure BDA0002820245330000131
From the experimental data of the examples 1 to 6 in table 1, it can be seen that the silicon-carbon composite material prepared by the present invention has good energy density, low expansion rate and resistivity of the electrode plate, and excellent cycle life.
In comparative examples 1 to 6, the silicon alloy material is placed in a sufficient amount of acid solution to completely remove the metal in the silicon alloy, the silicon material body 1 obtained after acid washing does not have a metal catalyst for catalyzing the generation of carbon tubes, the negative electrode material prepared in comparative examples 1 to 6 does not contain carbon tubes, and the porous silicon material containing carbon tubes is beneficial to improving the conductivity and the cycle life of the pole piece by combining the experimental data of examples 1 to 6 and comparative examples 1 to 6, and the lithium ion battery prepared in comparative examples 1 to 6 has obviously poor performances such as energy density, expansion rate, pole piece resistivity, cycle frequency and the like.
In comparative examples 7 to 12, the silicon alloy material is directly mixed with the conductive agent, the binder, the thickening agent and the like according to the mixture ratio to prepare the negative plate, the pulverization of the silicon material and the disconnection of the conductive network can be caused when the silicon material expands, and the experimental data of the examples 1 to 6 and the comparative examples 7 to 12 show that the energy density of the battery is reduced along with the increase of the expansion of the silicon material, and the battery has high expansion rate and low cycle life. Therefore, the control of the particle size of the silicon particles is of great significance.
Similarly, the negative plate directly made of the silicon material not doped with other metal elements in comparative example 13 has a larger expansion ratio and a poorer cycle life.
Therefore, the synthesized carbon tube-penetrating porous silicon material has comprehensive performance superior to that of untreated silicon material. In conclusion, the carbon tube through porous silicon material prepared by the method has excellent performance, and the preparation method is simple and is beneficial to large-scale production.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims (10)

1. The silicon-carbon negative electrode material is characterized by comprising a silicon material body and a carbon tube, wherein a plurality of pore channels are arranged in the silicon material body, at least one end part of each pore channel extends to the surface of the silicon material body, and the carbon tube is arranged in the pore channel.
2. The silicon-carbon negative electrode material as claimed in claim 1, wherein the silicon material body has a mass fraction of 3 to 99% in the silicon-carbon negative electrode material, and the carbon tubes have a mass fraction of 1 to 97% in the silicon-carbon negative electrode material.
3. The silicon-carbon negative electrode material as claimed in claim 1, wherein the specific surface area of the silicon-carbon negative electrode material is 0.1 to 3000m2/g。
4. The silicon-carbon negative electrode material as claimed in claim 1, wherein the silicon material body has a particle size of 10nm to 100 μm, and the diameter of the cross section of the pore channel is 1nm to 50 μm.
5. The silicon-carbon negative electrode material according to claim 1, wherein the carbon tubes have a diameter of 0.5nm to 100nm and a length of 10nm to 50 μm.
6. The silicon-carbon anode material of claim 1, wherein the silicon material body comprises one or more of crystalline silicon, amorphous silicon, a silicon oxygen material, and a silicon-carbon material;
the carbon tube includes one or more of a single-walled carbon tube, a multi-walled carbon tube, a hollow carbon tube, and a carbon fiber.
7. The preparation method of the silicon-carbon negative electrode material is characterized by comprising the following steps of:
placing the silicon material in a first acid solution, and removing part of metal in the silicon material to form a silicon material body with a plurality of pores;
drying the silicon material body, placing the silicon material body in a tubular furnace, introducing carbon source gas and carrier gas at high temperature, and generating a carbon tube in the pore channel;
and placing the silicon material body with the generated carbon tubes in an excessive second acid solution, and enlarging the pore channel to obtain the silicon-carbon composite material.
8. The method for preparing the silicon-carbon anode material of claim 7, wherein the carbon source gas comprises one or more of alkanes, alkynes, alkenes, benzene rings, and carbon-containing gases;
the carrier gas comprises one or more of hydrogen, nitrogen, helium, neon and argon.
9. A negative plate is characterized in that: comprising the silicon-carbon anode material according to any one of claims 1 to 6, or comprising the silicon-carbon anode material prepared by the preparation method according to any one of claims 7 to 8.
10. A lithium ion battery, characterized by: the negative electrode plate comprises a positive electrode plate, a negative electrode plate and a diaphragm, wherein the negative electrode plate is the negative electrode plate according to claim 9.
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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102208636A (en) * 2011-05-12 2011-10-05 北京科技大学 Method for preparing porous silicon/carbon composite material by using diatomite as raw material and application
CN105845911A (en) * 2016-05-15 2016-08-10 东北电力大学 Method for preparing porous silicon carbon nanotube composite negative electrode material of lithium ion battery by diatomite
CN106549149A (en) * 2016-10-28 2017-03-29 浙江天能能源科技股份有限公司 A kind of preparation method and application of Si-C composite material
CN107507972A (en) * 2017-08-29 2017-12-22 北方奥钛纳米技术有限公司 Preparation method, silicon-carbon cathode material and the lithium ion battery of silicon-carbon cathode material
CN110518213A (en) * 2019-08-30 2019-11-29 深圳市德方纳米科技股份有限公司 A kind of porous silicon-carbon nano tube compound material and its preparation method and application
CN111403694A (en) * 2019-08-22 2020-07-10 杭州师范大学 Preparation method of carbon-coated porous silicon negative electrode material
CN111525110A (en) * 2020-04-29 2020-08-11 深圳市德方纳米科技股份有限公司 Silicon-based composite anode material and preparation method and application thereof

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102208636A (en) * 2011-05-12 2011-10-05 北京科技大学 Method for preparing porous silicon/carbon composite material by using diatomite as raw material and application
CN105845911A (en) * 2016-05-15 2016-08-10 东北电力大学 Method for preparing porous silicon carbon nanotube composite negative electrode material of lithium ion battery by diatomite
CN106549149A (en) * 2016-10-28 2017-03-29 浙江天能能源科技股份有限公司 A kind of preparation method and application of Si-C composite material
CN107507972A (en) * 2017-08-29 2017-12-22 北方奥钛纳米技术有限公司 Preparation method, silicon-carbon cathode material and the lithium ion battery of silicon-carbon cathode material
CN111403694A (en) * 2019-08-22 2020-07-10 杭州师范大学 Preparation method of carbon-coated porous silicon negative electrode material
CN110518213A (en) * 2019-08-30 2019-11-29 深圳市德方纳米科技股份有限公司 A kind of porous silicon-carbon nano tube compound material and its preparation method and application
CN111525110A (en) * 2020-04-29 2020-08-11 深圳市德方纳米科技股份有限公司 Silicon-based composite anode material and preparation method and application thereof

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