CN115832272A - Carbon-coated silicon negative electrode material and preparation method and application thereof - Google Patents
Carbon-coated silicon negative electrode material and preparation method and application thereof Download PDFInfo
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- CN115832272A CN115832272A CN202310163191.2A CN202310163191A CN115832272A CN 115832272 A CN115832272 A CN 115832272A CN 202310163191 A CN202310163191 A CN 202310163191A CN 115832272 A CN115832272 A CN 115832272A
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- negative electrode
- silicon
- porous silicon
- carbon
- electrode material
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Images
Classifications
-
- 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
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- Battery Electrode And Active Subsutance (AREA)
Abstract
The invention provides a carbon-coated silicon negative electrode material and a preparation method and application thereof. The preparation method of the anode material comprises the following steps: preparing a porous silicon source by using a silicon alloy and an acid, and performing surface coating treatment by using a molten polymer; heating and activating the sulfonate to obtain a negatively charged porous silicon solution by the porous silicon source and the sulfonate which are subjected to surface coating treatment; mixing graphite, a dispersing agent and quaternary ammonium salt to obtain a positively charged graphite solution, adding the negatively charged porous silicon solution, stirring, heating and drying to obtain porous silicon-attached graphite powder; and heating and carbonizing the graphite powder attached with the porous silicon in a mixed gas atmosphere, and annealing to obtain the carbon-coated silicon negative electrode material. According to the invention, the porous silicon is compounded by the silicon negative electrode material and the graphite negative electrode material with reasonable particle sizes, so that the compressive strength is improved, the cracking condition of an extrusion material when the silicon negative electrode material is made into a pole piece is reduced, the consumption of electrolyte is reduced, and the electrode stability of the silicon negative electrode piece is improved.
Description
Technical Field
The invention relates to the technical field of lithium ion batteries, in particular to a carbon-coated silicon negative electrode material and a preparation method and application thereof.
Background
Currently, lithium Ion Batteries (LIBs) are widely used in portable devices and electronic products, however, there are still some problems in the application of electric vehicles and renewable energy storage power grids, including energy density, material cost, and safety in use. Therefore, it is an important aspect to improve the energy density and cycle life of the lithium ion battery.
Silicon (Si) has excellent theoretical capacity (4200 mAh/g), is developed as one of attractive candidate anode materials, is about 10 times the current available commercial graphite anode capacity (about 370 mAh/g), and has great application potential. However, in Li + During the alloying/dealloying reaction, a large volume change (-300%) of silicon can cause structural damage to the negative electrode material and produce an unstable Solid Electrolyte Interface (SEI), resulting in a rapid drop in capacity. Currently, various strategies are employed to improve the structural stability of silicon: for example, on a carbon-coated basis, reducing the silicon particle size from bulk to nano-scale for Li + And during the reaction, the remarkable volume expansion and structural damage are controlled, or a macroporous structure is used as an auxiliary material, so that sufficient space is provided for the volume expansion of the silicon cathode material, and the structure is prevented from being damaged due to stress concentration.
However, the specific surface area of the nano-silicon and a large number of porous structures of the nano-silicon-based material is too large, so that the contact area between the nano-silicon and the electrolyte is increased, and in addition, the carbon-coated silicon negative electrode material is difficult to avoid rolling and cracking caused by large roller pressure when a pole piece is manufactured, the material is directly contacted with the electrolyte, side reactions are increased, the consumption of the electrolyte is increased, and the stability of the pole piece is reduced. Therefore, how to design the particle size of the silicon negative electrode material and the porous structure of the silicon negative electrode material, the compressive strength is improved, and the problem of extrusion cracking when the silicon negative electrode material is made into a pole piece is to be solved urgently.
Disclosure of Invention
In order to solve the technical problems, the invention provides a carbon-coated silicon negative electrode material and a preparation method and application thereof. According to the invention, the porous silicon is compounded on the basis of the silicon negative electrode material with reasonable particle size and the graphite negative electrode material, so that the compressive strength is improved, the cracking of an extrusion material when the silicon negative electrode material is made into a pole piece is reduced, the direct contact of the material and an electrolyte is reduced, the consumption of the electrolyte is reduced, and the electrode stability of the silicon negative electrode piece is improved.
The invention is realized by the following scheme:
the invention aims to provide a preparation method of a carbon-coated silicon negative electrode material, which comprises the following steps:
(1) Preparing a porous silicon source by using a silicon alloy and an acid, and performing surface coating treatment by using a molten polymer;
(2) Mixing the porous silicon source subjected to surface coating treatment in the step (1) with sulfonate, activating the sulfonate, and endowing the surface of the material with negative charges to finally obtain a negative-charge porous silicon solution; the activation method is a method conventional in the art, and is preferably heat activation;
(3) Mixing graphite, a dispersing agent and quaternary ammonium salt to obtain a positively charged graphite solution, adding the negatively charged porous silicon solution obtained in the step (2), stirring, heating and drying to obtain porous silicon-attached graphite powder;
(4) And (4) heating and carbonizing the graphite powder with the porous silicon in the step (3) in the atmosphere of mixed gas containing organic gas, and annealing and sieving to obtain the carbon-coated silicon negative electrode material.
In one embodiment of the present invention, in step (1), one or more of the following conditions are satisfied:
1) The silicon alloy is selected from one or more of magnesium silicide, aluminum silicide, calcium silicide and iron silicide; the particle size of the silicon alloy is 0.15-3 mu m; further, the silicon content in the silicon alloy is more than or equal to 80wt%;
2) The acid is selected from one or more of hydrochloric acid, nitric acid, phosphoric acid, acetic acid and formic acid;
3) And the acid content is 0.1wt% -8 wt%. Can be 0.1wt% -1wt%, 1wt% -2wt%, 2wt% -3wt%, 3wt% -4wt%, 4wt% -5wt%, 6wt% -7wt%, 7wt% -8wt%; specifically, 0.1wt%, 0.2wt%, 0.3wt%, 0.4wt%, 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt%, 1.0wt%, 2wt%, 3wt%, 4wt%, 5wt%, 6wt%, 7wt%, 8wt%. Or any concentration value between any two values.
In one embodiment of the present invention, in step (1), the step of preparing the porous silicon source from the silicon alloy and the acid is: mixing silicon alloy and acid, and carrying out hot acid oscillation, filter pressing, acid cleaning with water, filter pressing, drying and dehydration at the temperature of 45-80 ℃ to obtain the porous silicon source.
In one embodiment of the invention, in the step (1), the mass volume ratio of the silicon alloy to the acid is 1 to 10:20 to 50 (kg/L).
In one embodiment of the present invention, in the step (1), the molten polymer is selected from one or more of polystyrene, polyethylene, polystyrene, polypropylene and polyaniline.
In one embodiment of the present invention, in step (1), the surface coating treatment method is as follows: and (3) stirring and mixing the molten polymer and the porous silicon source, and heating and carbonizing to obtain the porous silicon source subjected to surface coating treatment.
Further, the mass ratio of the molten polymer to the porous silicon source is 0.2 to 18:100, respectively; the heating carbonization temperature is 500-900 ℃; can be 500-600 ℃, 600-900 ℃, 700-900 ℃, 800-900 ℃, specifically 500 ℃, 550 ℃, 600 ℃, 650 ℃, 700 ℃, 750 ℃, 800 ℃, 850 ℃ and 900 ℃; or any temperature value between any two values. The heating carbonization time is 1h to 12h; can be 2h to 12h, 3h to 12h, 4h to 12h, 5h to 12h, 6h to 12h, 7h to 12h, 8h to 12h, 9h to 12h, 10h to 12h and 111h to 12h, and can be 1h, 2h, 3h, 4h, 5h, 6h, 7h, 8h, 9h, 10h, 11h and 12h; or any time value between any two values.
In one embodiment of the present invention, in the step (2), the sulfonate is selected from one or more of sodium styrene sulfonate, sodium polystyrene sulfonate, lithium styrene sulfonate, potassium styrene sulfonate, and potassium polystyrene sulfonate. Further, one or more of sodium styrene sulfonate, sodium polystyrene sulfonate, lithium polystyrene sulfonate and lithium styrene sulfonate are preferred; the sulfonate can provide a material with surface negatively charged groups.
In one embodiment of the invention, in the step (2), the mass ratio of the porous silicon source subjected to the surface coating treatment to the sulfonate is 50 to 250:1 to 25; the heating temperature is 60-110 ℃. The porous silicon source is dispersed by ultrasound using the dispersing property of the sulfonate.
In one embodiment of the present invention, in the step (3), the quaternary ammonium salt is one or more of polydimethyl ammonium chloride, polydimethyl ammonium bromide, dodecylmethyl ammonium chloride, tetradecylmethylammonium chloride, hexadecyl methyl ammonium chloride, octadecyl methyl ammonium chloride, dodecylmethyl ammonium bromide, tetradecylmethylammonium bromide, hexadecyl methyl ammonium bromide and octadecyl methyl ammonium bromide.
In one embodiment of the present invention, in step (3), one or more of the following conditions are satisfied:
1) The graphite is obtained by graphitizing one or more of petroleum coke, asphalt cement and needle-like graphite;
2) The density of the glycerol solution is 5-10 wt%;
3) The tap density of the graphite is 0.85g/cm 3 ~1.2g/cm 3 The Dv50 particle size is 3-26 μm;
4) The temperature of the heating and drying is 70-120 ℃.
In one embodiment of the invention, in the step (3), the mass ratio of the graphite to the quaternary ammonium salt is 20 to 100:0.1 to 10; the mass volume ratio of the graphite to the glycerol solution is 100-500: 1 (g/L).
In one embodiment of the invention, in the step (3), the mass ratio of the porous silicon source to the graphite in the electronegative porous silicon solution is 1 to 15:25 to 60.
In one embodiment of the present invention, in step (3), adsorption of both positive and negative polarities on the surface is performed: through the zwitterion polymerization, the negatively charged porous silicon is electrostatically adsorbed by the positively charged graphite.
In one embodiment of the present invention, in the step (3), the dispersant is selected from one or more of alcohol solution, ester solution and polyethylene. The alcohol in the alcohol solution is selected from one or more of glycerol, ethylene glycol, isopropanol, ethanol and propanol; glycerol is preferred. The esters are selected from glycerides.
In one embodiment of the present invention, in the step (4), the mixed gas atmosphere containing the organic gas includes an organic gas and an inert gas.
Further, the organic gas is a hydrocarbon with 1 to 4C; the inactive gas is selected from one or more of nitrogen, helium, neon and argon.
Further, the hydrocarbon of 1 to 4C is selected from one or more of methane, ethane, ethylene, acetylene, propane, propyne, propylene, butyne, butylene and butane.
Further, the volume ratio of the organic gas to the inert gas is 1 to 3:1 to 5.
In one embodiment of the invention, in the step (4), the temperature of heating carbonization is 700 ℃ to 960 ℃, the air pressure is kept from 0kPa to 10kPa, and the heating carbonization time is from 1h to 36h.
In one embodiment of the invention, in the step (4), the temperature is reduced to 400-700 ℃ and is kept constant for 1h-5h.
The second purpose of the invention is to provide a carbon-coated silicon negative electrode material, which takes graphite as an inner core, is externally coated with a carbon coating layer and a porous silicon layer, and the graphite and the porous silicon layer are adsorbed and compounded through positive and negative charges; the porous silicon layer is wrapped by the coated carbon layer.
In one embodiment of the present invention, the carbon-coated silicon anode material meets one or more of the following conditions:
(1) The tap density is 0.7g/cm 3 ~1.35g/cm 3 To (c) to (d);
(2) The Dv50 particle size is between 3.5 and 18 mu m;
(3) The specific surface area SSA is 0.75m 2 /g~5m 2 Between/g;
(4) And the pH value is 7 to 11.5, the pH value is obtained by mixing powder with pure water 9;
(5) And the carbon content is 35wt% to 97wt%.
In one embodiment of the present invention, the carbon coating layer of the carbon-coated silicon anode material is a dense carbon layer, and the dense carbon layer has no or few pores; preferably, the thickness of the carbon coating layer ranges from 2nm to 800nm, and can range from 2nm to 10nm, from 10nm to 20nm, from 20nm to 30nm, from 30nm to 40nm, from 40nm to 50nm, from 50nm to 60nm, from 60nm to 70nm and from 70nm to 80nm; for example, 2nm, 3nm, 4nm, 5nm, 6nm, 7nm, 8nm, 9nm, 10nm, 11nm, 12nm, 13nm, 14nm, 15nm, 16nm, 17nm, 18nm, 19nm, 20nm, 21nm, 22nm, 23nm, 24nm, 25nm, 26nm, 27nm, 28nm, 29nm, 30nm, 40nm, 50nm, 60nm, 65nm, 75nm, 80nm, or any thickness value between any two values.
The third purpose of the invention is to provide a silicon negative electrode plate, which comprises the carbon-coated silicon negative electrode material or the carbon-coated silicon negative electrode material prepared by the preparation method.
The fourth purpose of the invention is to provide a preparation method of the silicon negative plate, which comprises the following steps:
s1, dry-mixing and stirring a carbon-coated silicon negative electrode material and a conductive material, and adding a binder and water to obtain a mixture;
and S2, adding a conductive material, a binder and water into the mixture obtained in the step S1, stirring and mixing to obtain a negative electrode homogenate, coating the negative electrode homogenate on at least one of the front surface and the back surface of a negative electrode current collector to obtain a negative electrode homogenate coating, drying and tabletting to obtain the silicon negative electrode piece.
In one embodiment of the invention, the mass ratio of the carbon-coated silicon negative electrode material to the conductive material to the binder is 80-99.6: 0.2 to 8:0.2 to 15.0.
In one embodiment of the invention, in S1, the stirring speed is 20r/min to 1000r/min, and the stirring time is 5min to 30min.
Further, the mixture utilizes water to adjust the solid content to 60% -80%; preferably 65% to 75%.
In one embodiment of the invention, in S2, the solid content of the anode homogenate is 40% to 60%, preferably 45% to 55%; the viscosity is 2.0Pa.s to 8Pa.s, and preferably 2.7Pa.s to 4Pa.s; the fineness is less than or equal to 0.25mm; the stirring speed is 1200r/min to 3000r/min, and the stirring time is 30min to 200min.
In one embodiment of the invention, in S2, the thickness of the anode homogenate coating is 18-430 μm. Preferably, the thickness is 48 μm to 260 μm, such as 48 μm, 49 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, 85 μm, 90 μm, 95 μm, 100 μm, 105 μm, 110 μm, 120 μm, 125 μm, 130 μm, 135 μm, 140 μm, 145 μm, 150 μm, 155 μm, 160 μm, 180 μm, 200 μm, 210 μm, 220 μm, 230 μm, 240 μm, 250 μm, 260 μm, or any thickness value between any two values.
Furthermore, the obtained anode homogenate surface density on the silicon anode sheet is 0.003g/cm 2 ~0.032g/cm 2 。
In an embodiment of the present invention, in S1 and S2, the conductive material is selected from at least one of conductive carbon black, acetylene black, graphite, graphene, a carbon micro-nano linear conductive material, and a carbon micro-nano tubular conductive material.
In one embodiment of the present invention, in S1 and S2, the binder is selected from one or more of monomers, polymers and copolymers of acrylonitrile, vinylidene fluoride, vinyl alcohol, carboxymethyl cellulose, lithium carboxymethyl cellulose, sodium carboxymethyl cellulose, methacryl, acrylic acid, lithium acrylate, acrylamide, amide, imide, acrylate, styrene butadiene rubber, sodium alginate, chitosan, ethylene glycol and guar gum.
In an embodiment of the invention, in S2, the negative current collector is one or more of a copper foil, a porous copper foil, a foamed nickel/copper foil, a galvanized copper foil, a nickel-plated copper foil, a carbon-coated copper foil, a nickel foil, a titanium foil, and a carbon-containing porous copper foil. Copper foil, copper foil plated with zinc, nickel or the like, carbon-coated copper foil or the like is preferable.
The fifth purpose of the invention is to provide a lithium ion battery, which comprises the silicon negative electrode sheet or the silicon negative electrode sheet prepared by the preparation method.
The sixth purpose of the invention is to provide a preparation method of a lithium ion battery, which comprises the following steps: and winding the silicon negative plate, the isolation film and the positive plate to obtain a battery core, installing the battery core into a battery shell, drying, injecting electrolyte, packaging, forming and grading to obtain the lithium ion battery.
In one embodiment of the present invention, the positive active material in the positive electrode sheet is one or more of lithium cobaltate, lithium nickelate, lithium manganate, lithium nickelate, lithium nickel manganese, lithium nickel cobalt aluminate, lithium manganese phosphate, lithium iron manganese phosphate and lithium iron phosphate.
Compared with the prior art, the technical scheme of the invention has the following advantages:
according to the invention, the sulfonate has higher ionization degree, so that the surface negative charge density of the modified porous silicon source is higher, after zwitterionic polymerization with the graphite modified by the quaternary ammonium salt, the affinity of the graphite with surface positive charges and the porous silicon source can be obviously improved, the zwitterionic polymerization is stable and is not easy to damage, and the subsequent heating and carbonization stability of the graphite powder with the multiple silicon sources can also be improved.
According to the invention, through surface film coating treatment, the conductivity of the surface of the porous silicon source is improved, meanwhile, direct contact between silicon and electrolyte can be avoided, and the formation of a stable SEI film in the circulation process is ensured.
In order to improve the compounding capacity, sulfonate such as sodium styrene sulfonate, sodium polystyrene sulfonate and the like is used for dispersing a porous silicon source to obtain a negatively charged porous silicon source, quaternary ammonium salts such as poly dimethyl ammonium chloride, poly dimethyl ammonium bromide and the like are attached to the surface of graphite to obtain positively charged graphite, zwitterions are polymerized, the positively charged graphite adsorbs the negatively charged porous silicon, mixed gas is wrapped for carbonization, a small-particle porous silicon source is attached to the surface of large-particle graphite, the material rolling fracture caused by large pressure of a squeezing wheel is reduced by utilizing more pore volume of the large-particle graphite, and the compressive strength is further improved.
Drawings
In order that the present disclosure may be more readily and clearly understood, reference is now made to the following detailed description of the present disclosure taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a schematic structural diagram of a carbon-coated silicon anode material according to the present invention.
The specification reference numbers indicate: 1. coating a carbon layer; 2. a carbon coating layer; 3. an aperture; 4. porous silicon; 5. graphite.
Detailed Description
The present invention is further described below in conjunction with the following figures and specific examples so that those skilled in the art may better understand the present invention and practice it, but the examples are not intended to limit the present invention.
The schematic structural diagram of the carbon-coated silicon negative electrode material synthesized in the embodiment of the invention is shown in fig. 1, wherein the structure in the diagram is as follows: 1. coating a carbon layer; 2. a carbon coating layer; 3. a hole; 4. porous silicon; 5. graphite.
Example 1
The embodiment provides a carbon-coated silicon negative electrode material, a preparation method thereof, a corresponding silicon negative electrode piece and application
1. The carbon-coated silicon negative electrode material and the preparation method thereof are as follows:
(1) Silicon alloy magnesium silicide with the grain diameter of 0.3-2.6 mu m and hydrochloric acid with the concentration of 0.36wt% are mixed according to the weight ratio of 5: mixing the raw materials in a mass/volume ratio (kg/L) of 20, sequentially performing hot acid oscillation, filter pressing, deionized water washing hydrochloric acid, filter pressing, drying and dehydration on the obtained mixture at the temperature of 55 ℃ to obtain a porous silicon source, and performing surface coating treatment on the obtained porous silicon source. The method comprises the following specific steps of surface coating treatment: mixing molten polymer polypropylene and a porous silicon source according to the ratio of 5:100, placing the mixture in a reaction kettle, stirring the mixture to enable the porous silicon source to thermally adsorb the molten polymer, and sending the obtained porous silicon source adsorbing the molten polymer to a tube furnace with the temperature of 550 ℃ for carbonization for 12 hours to obtain the porous silicon source with the surface coated.
(2) Adding 200g of the porous silicon source coated on the surface in the step (1) and 2g of sodium polystyrene sulfonate into 1L of deionized water in a reaction kettle with an ultrasonic disperser arranged inside, dispersing the porous silicon source through ultrasonic by utilizing the dispersing performance of the sodium polystyrene sulfonate, and heating to 95 ℃ to thermally activate the sodium polystyrene sulfonate to obtain a negatively charged porous silicon solution;
(3) Dissolving needle coke high-temperature graphitized graphite in glycerol solution containing 6wt%, placing the solution in a reaction kettle, adding polydimethyl ammonium chloride, mixing to obtain positively charged graphite solution (mixing according to the amount of 500g of graphite and 10g of polydimethyl ammonium chloride added into 1L of glycerol solution), adding negatively charged porous silicon solution (controlling the mass ratio of the porous silicon source to the graphite in the negatively charged porous silicon solution to be 5;
(4) Feeding the graphite powder with the porous silicon into a tubular furnace, introducing a mixed gas of acetylene gas and Ar gas (wherein the volume ratio of the acetylene gas to the Ar gas is 2.
2. Silicon negative plate and application:
2.1, the silicon negative plate and the preparation method thereof are as follows:
(1) Placing the carbon-coated silicon negative electrode material and conductive carbon as a conductive material into a container of a stirrer, dry-mixing and stirring at the rotating speed of 500r/min for 10min, adding a binder (obtained by mixing 95wt% and 5wt% of styrene-butadiene rubber and sodium carboxymethyl cellulose) and deionized water into the container, and adding water until the solid content of substances in the container is 74.8%.
(2) And adding the conductive material, the binder and the deionized water into the container again, stirring and mixing uniformly at a high rotating speed of 1800r/min for 120min until the solid content of the substances in the container is 53.3 percent, and obtaining the mixed slurry.
Wherein, the mass percentages of the carbon-coated silicon negative electrode material, the conductive carbon and the binder are respectively 95%, 2% and 3%.
(3) Adjusting the viscosity of the mixed slurry in the step (2) to 3.9Pa.s and the fineness of the mixed slurry to be less than or equal to 0.15mm to obtain a negative pole homogenate, and coating the negative pole homogenate on the front and back surfaces of a copper foil of a negative pole current collector to obtain a negative pole homogenate with the thickness of 116 mu m and the surface density of 0.018g/cm 2 And (3) homogenizing the coating of the negative electrode, drying and tabletting to obtain the silicon negative electrode plate.
2.2, application of the silicon negative plate:
and winding the silicon negative plate, the isolating membrane and the positive plate (the positive active substance is nickel cobalt lithium manganate) to obtain a battery core, and loading the battery core into a battery shell, drying, injecting electrolyte, packaging, forming and grading to obtain the lithium ion battery. (the isolating film and the electrolyte are conventional in the field).
Example 2
The embodiment provides a carbon-coated silicon negative electrode material, a preparation method thereof, a corresponding silicon negative electrode piece and application
1. The carbon-coated silicon negative electrode material and the preparation method thereof are as follows:
(1) Silicon alloy magnesium silicide with the grain diameter of 0.3-2.6 mu m and hydrochloric acid with the concentration of 0.36wt% are mixed according to the weight ratio of 5: mixing the raw materials in a mass/volume ratio (kg/L) of 20, performing hot acid oscillation on the obtained mixture at 55 ℃, performing pressure filtration, washing hydrochloric acid with deionized water, performing pressure filtration, drying and dehydrating to obtain a porous silicon source, and performing surface coating treatment on the obtained porous silicon source. The surface coating treatment comprises the following specific steps: mixing the molten polymer polypropylene with a porous silicon source according to the ratio of 5:100, placing the mixture in a reaction kettle, stirring the mixture to enable the porous silicon source to thermally adsorb the molten polymer, and sending the obtained porous silicon source adsorbing the molten polymer to a tube furnace with the temperature of 550 ℃ for carbonization for 12 hours to obtain the porous silicon source with the surface coated with the film.
(2) And (2) adding 200g of the porous silicon source coated on the surface in the step (1) and 5g of sodium polystyrene sulfonate into 1L of deionized water in a reaction kettle with an ultrasonic disperser arranged inside, and heating to 95 ℃ to thermally activate the sulfonate sodium polystyrene sulfonate by utilizing the dispersing performance of the sodium polystyrene sulfonate and ultrasonically dispersing the porous silicon source coated on the surface to obtain the negatively charged porous silicon solution.
(3) Dissolving needle coke high-temperature graphitized graphite in glycerol solution containing 6wt%, placing the solution in a reaction kettle, adding polydimethyl ammonium chloride, mixing to obtain positively charged graphite solution (mixing according to the amount of 500g of graphite and 10g of polydimethyl ammonium chloride added in 1L of glycerol solution), adding negatively charged porous silicon solution (controlling the mass ratio of the porous silicon source to the graphite in the negatively charged porous silicon solution to be 5.
(4) Feeding the graphite powder with the porous silicon into a tubular furnace, introducing a mixed gas of acetylene gas and Ar gas (wherein the volume ratio of the acetylene gas to the Ar gas is 2.
2. Silicon negative plate and application:
2.1, the silicon negative plate and the preparation method thereof are as follows:
(1) Placing the carbon-coated silicon negative electrode material and conductive carbon as a conductive material into a container of a stirrer, dry-mixing and stirring at the rotating speed of 500r/min for 10min, adding a binder (obtained by mixing 95wt% and 5wt% of styrene-butadiene rubber and sodium carboxymethylcellulose) and deionized water into the container, and adding water until the solid content of substances in the container is 73.1%.
(2) And adding the conductive material, the binder and the deionized water into the container again, stirring and uniformly mixing for 120min at a high rotating speed of 1800r/min until the solid content of the substances in the container is 48.7 percent, and obtaining the mixed slurry.
Wherein the mass percentages of the carbon-coated silicon negative electrode material, the conductive carbon and the binder are 95wt%, 2wt% and 3wt%.
(3) Adjusting the viscosity of the mixed slurry obtained in the step (2) to 3.1Pa.s and the fineness of less than or equal to 0.15mm to obtain a negative pole homogenate, and coating the negative pole homogenate on the front and back surfaces of a copper foil of a negative pole current collector to obtain a negative pole homogenate with the thickness of 126 mu m and the negative pole homogenate surface density of 0.02g/cm 2 And homogenizing the coating, drying and tabletting to obtain the silicon negative plate.
2.2, application of the silicon negative plate:
and winding the silicon negative plate, the isolating membrane and the positive plate (the positive active substance is nickel cobalt lithium manganate) to obtain a battery core, and loading the battery core into a battery shell, drying, injecting electrolyte, packaging, forming and grading to obtain the lithium ion battery.
Example 3
The embodiment provides a carbon-coated silicon negative electrode material, a preparation method thereof, a corresponding silicon negative electrode piece and application
1. The carbon-coated silicon negative electrode material and the preparation method thereof are as follows:
(1) Silicon alloy magnesium silicide with the grain diameter of 0.3-2.6 mu m and hydrochloric acid with the concentration of 0.36wt% are mixed according to the weight ratio of 5: mixing the mixture in an amount of 20 mass/volume ratio (kg/L), performing hot acid oscillation and pressure filtration on the obtained mixture at 55 ℃, washing hydrochloric acid with deionized water, performing pressure filtration, drying and dehydrating to obtain a porous silicon source, and performing surface coating treatment on the obtained porous silicon source, wherein the surface coating treatment specifically comprises the following steps: the molten polymer polyethylene was stirred with a porous silicon source according to a ratio of 5:100, placing the mixture in a reaction kettle, stirring the mixture to enable the porous silicon source to thermally adsorb the molten polymer, and sending the obtained porous silicon source adsorbing the molten polymer to a tube furnace with the temperature of 550 ℃ for carbonization for 12 hours to obtain the porous silicon source with the surface coated with the film.
(2) And (2) adding 200g of the porous silicon source coated on the surface in the step (1) and 10g of sodium polystyrene sulfonate into 1L of deionized water in a reaction kettle with an ultrasonic disperser, and heating to 95 ℃ to thermally activate the sulfonate sodium polystyrene sulfonate by utilizing the dispersing performance of the sodium polystyrene sulfonate and ultrasonically dispersing the porous silicon source coated on the surface to obtain the negatively charged porous silicon solution.
(3) Dissolving needle coke high-temperature graphitized graphite in glycerol solution containing 6wt%, placing the solution in a reaction kettle, adding polydimethyl ammonium chloride, mixing to obtain positively charged graphite solution (mixing according to the amount of 500g of graphite and 10g of polydimethyl ammonium chloride added in 1L of glycerol solution), adding negatively charged porous silicon solution (controlling the mass ratio of the porous silicon source to the graphite in the negatively charged porous silicon solution to be 5.
(4) Feeding the graphite powder with the porous silicon into a tubular furnace, introducing a mixed gas of acetylene gas and Ar gas (wherein the volume ratio of the acetylene gas to the Ar gas is 2.
2. Silicon negative plate and application:
2.1, the silicon negative plate and the preparation method thereof are as follows:
(1) Placing the carbon-coated silicon negative electrode material and conductive carbon as a conductive material into a container of a stirrer, dry-mixing and stirring at the rotating speed of 500r/min for 10min, adding a binder (obtained by mixing 95wt% and 5wt% of styrene-butadiene rubber and sodium carboxymethylcellulose) and deionized water into the container, and adding water until the solid content of substances in the container is 72.8%.
(2) And adding the conductive material, the binder and the deionized water into the container again, stirring and uniformly mixing for 120min at a high rotating speed of 1800r/min until the solid content of the substances in the container is 51.5%, and thus obtaining the mixed slurry.
Wherein, the mass percentages of the carbon-coated silicon negative electrode material, the conductive carbon and the binder are 95wt%, 2wt% and 3wt%.
(3) Adjusting the viscosity of the mixed slurry in the step (2) to 3.4Pa.s and the fineness of less than or equal to 0.15mm to obtain a negative pole homogenate, coating the negative pole homogenate on the front and back surfaces of a copper foil of a negative pole current collector to obtain a negative pole homogenate with the thickness of 153 mu m and the surface density of 0.024g/cm 2 And (3) homogenizing the coating of the negative electrode, drying and tabletting to obtain the silicon negative electrode plate.
2.2, application of the silicon negative plate:
and winding the silicon negative plate, the isolating membrane and the positive plate (the positive active substance is nickel cobalt lithium manganate) to obtain a battery core, and loading the battery core into a battery shell, drying, injecting electrolyte, packaging, forming and grading to obtain the lithium ion battery.
Example 4
The embodiment provides a carbon-coated silicon negative electrode material, a preparation method thereof, a corresponding silicon negative electrode plate and application
1. The carbon-coated silicon negative electrode material and the preparation method thereof are as follows:
(1) Silicon alloy aluminum silicide with the grain diameter of 0.6-2.9 mu m and hydrochloric acid with the concentration of 0.36wt% are mixed according to the weight ratio of 10:30 mass/volume ratio (kg/L), performing hot acid oscillation at 55 ℃, filter pressing, deionized water washing with hydrochloric acid, filter pressing, drying and dewatering to obtain a porous silicon source, and performing surface coating treatment on the porous silicon source, wherein the surface coating treatment specifically comprises the following steps: the molten polymer polypropylene was stirred with a porous silicon source according to 12:100, placing the mixture in a reaction kettle, stirring the mixture to enable the porous silicon source to thermally adsorb the molten polymer, and sending the obtained porous silicon source adsorbing the molten polymer to a tubular furnace with the temperature of 830 ℃ for carbonization for 4 hours to obtain the porous silicon source with the surface coated with the film.
(2) And (2) adding 500g of the porous silicon source coated with the surface film in the step (1) and 8g of sodium polystyrene sulfonate into 1L of deionized water in a reaction kettle with an ultrasonic disperser arranged inside, and heating to 105 ℃ to thermally activate the sulfonate sodium polystyrene sulfonate by using the dispersing property of the sodium polystyrene sulfonate and ultrasonically dispersing the porous silicon source coated with the surface film to obtain the negatively charged porous silicon solution.
(3) Dissolving needle coke high-temperature graphitized graphite in a glycerol solution containing 10wt%, placing the solution in a reaction kettle, adding polydimethyl ammonium chloride, mixing to obtain a positively charged graphite solution (mixing according to the amount of 500g of graphite and 20g of polydimethyl ammonium chloride added into 1L of the glycerol solution), adding a negatively charged porous silicon solution (controlling the mass ratio of the porous silicon source to the graphite in the negatively charged porous silicon solution to be 10.
(4) Feeding the graphite powder with the porous silicon into a tubular furnace, introducing a mixed gas of acetylene gas and Ar gas (wherein the volume ratio of the acetylene gas to the Ar gas is 3.
2. Silicon negative plate and application:
2.1, the silicon negative plate and the preparation method thereof are as follows:
(1) Placing the carbon-coated silicon negative electrode material and conductive carbon material into a container of a stirrer, dry-mixing and stirring at the rotating speed of 1000r/min for 5min, adding a binder (obtained by mixing 95wt% and 5wt% of styrene-butadiene rubber and sodium carboxymethylcellulose) and deionized water into the container, and adding water until the solid content of substances in the container is 69.7%.
(2) And adding the conductive material, the binder and the deionized water into the container again, stirring and mixing uniformly for 100min at a high rotation speed of 2500r/min until the solid content of the substances in the container is 49.7%, and thus obtaining the mixed slurry.
Wherein, the mass percentages of the carbon-coated silicon negative electrode material, the conductive carbon and the binder are 92wt%, 4wt% and 4 wt%.
(3) Adjusting the viscosity of the slurry obtained in the step (2) to 3.3Pa.s and the fineness of the slurry to be less than or equal to 0.15mm to obtain a negative pole homogenate, coating the negative pole homogenate on the front and back surfaces of a copper foil of a negative pole current collector to obtain a negative pole homogenate with the thickness of 56 mu m and the surface density of 0.009g/cm 2 And homogenizing the coating, drying and tabletting to obtain the silicon negative plate.
2.2, application of the silicon negative plate:
and winding the silicon negative plate, the isolating membrane and the positive plate (the positive active substance is nickel cobalt lithium manganate) to obtain a battery core, and loading the battery core into a battery shell, drying, injecting electrolyte, packaging, forming and grading to obtain the lithium ion battery.
Example 5
The embodiment provides a carbon-coated silicon negative electrode material, a preparation method thereof, a corresponding silicon negative electrode plate and application
1. The carbon-coated silicon negative electrode material and the preparation method thereof are as follows:
(1) Silicon alloy aluminum silicide with the grain diameter of 0.6-2.9 mu m and hydrochloric acid with the concentration of 0.36wt% are mixed according to the weight ratio of 10: mixing the mixture according to the mass/volume ratio (kg/L) of 30, performing hot acid oscillation and pressure filtration on the obtained mixture at 55 ℃, washing hydrochloric acid with deionized water, performing pressure filtration, drying and dehydrating to obtain a porous silicon source, and performing surface coating treatment on the obtained porous silicon source, wherein the surface coating treatment specifically comprises the following steps: the molten polymer polypropylene was stirred with a porous silicon source according to 12:100, placing the mixture in a reaction kettle, stirring the mixture to enable the porous silicon source to thermally adsorb the molten polymer, and sending the obtained adsorbed molten polymer, namely the porous silicon source adsorbed molten polymer, to a tubular furnace at the temperature of 830 ℃ for carbonization for 4 hours to obtain the porous silicon source with the surface coated.
(2) Adding 500g of the porous silicon source coated on the surface in the step (1) and 15g of sodium polystyrene sulfonate into 1L of deionized water in a reaction kettle with an ultrasonic disperser arranged inside, and heating to 105 ℃ to thermally activate the sulfonate sodium polystyrene sulfonate by utilizing the dispersing performance of the sodium polystyrene sulfonate and ultrasonically dispersing the porous silicon source coated on the surface to obtain a negatively charged porous silicon solution;
(3) Dissolving needle coke high-temperature graphitized graphite in a glycerol solution containing 10wt%, placing the solution in a reaction kettle, adding polydimethyl ammonium chloride, mixing to obtain a positively charged graphite solution (mixing according to the amount of 500g of graphite and 20g of polydimethyl ammonium chloride added into 1L of the glycerol solution), adding a negatively charged porous silicon solution (controlling the mass ratio of the porous silicon source to the graphite in the negatively charged porous silicon solution to be 10.
(4) Feeding the graphite powder with the porous silicon into a tubular furnace, introducing a mixed gas of acetylene gas and Ar gas (wherein the volume ratio of the acetylene gas to the Ar gas is 3.
2. Silicon negative plate and application:
2.1, preparing the silicon negative plate:
(1) Placing the carbon-coated silicon negative electrode material and conductive carbon as a conductive material into a container of a stirrer, dry-mixing and stirring at the rotating speed of 20-1000r/min for 5-30min, adding a binder (obtained by mixing 95wt% and 5wt% of styrene butadiene rubber and sodium carboxymethylcellulose) and deionized water into the container, and adding water until the solid content of substances in the container is 73.6%.
(2) And adding the conductive material, the binder and the deionized water into the container again, stirring and uniformly mixing for 100min at a high rotating speed of 2500r/min until the solid content of the substances in the container is 54.4%, and thus obtaining the mixed slurry.
Wherein, the mass percentages of the carbon-coated silicon negative electrode material, the conductive carbon and the binder are 92wt%, 4wt% and 4 wt%.
(3) The slurry obtained in the step (2) has the viscosity of 3.8Pa.s and the fineness of less than or equal to 0.15mm to obtain a negative pole homogenate, and the negative pole homogenate is coated on the front and back surfaces of a copper foil of a negative pole current collector to obtain a negative pole homogenate with the thickness of 63 mu m and the surface density of 0.011g/cm 2 And homogenizing the coating, drying and tabletting to obtain the silicon negative plate.
2.2, application of the silicon negative plate:
and (3) winding the silicon negative plate, the isolation film and the positive plate (the positive active substance is nickel cobalt lithium manganate) to obtain a battery core, and filling the battery core into a battery shell, drying, injecting electrolyte, packaging, forming and grading to obtain the lithium ion battery.
Example 6
The embodiment provides a carbon-coated silicon negative electrode material, a preparation method thereof, a corresponding silicon negative electrode piece and application
1. The carbon-coated silicon negative electrode material and the preparation method thereof are as follows:
(1) Silicon alloy aluminum silicide with the grain diameter of 0.6-2.9 mu m and hydrochloric acid with the concentration of 0.36wt% are mixed according to the weight ratio of 10: mixing the mixture according to the mass/volume ratio (kg/L) of 30, performing hot acid oscillation and pressure filtration on the obtained mixture at 55 ℃, washing hydrochloric acid with deionized water, performing pressure filtration, drying and dehydrating to obtain a porous silicon source, and performing surface coating treatment on the obtained porous silicon source, wherein the surface coating treatment specifically comprises the following steps: molten polymer polystyrene was stirred with a porous silicon source according to 12:100, placing the mixture in a reaction kettle, stirring the mixture to ensure that a porous silicon source thermally adsorbs the molten polymer, and sending the obtained porous silicon source for adsorbing the molten polymer to a tubular furnace for carbonization at the temperature of 830 ℃ for 4 hours).
(2) And (2) adding 500g of the porous silicon source coated on the surface in the step (1) and 20g of sodium polystyrene sulfonate into 1L of deionized water in a reaction kettle with an ultrasonic disperser arranged inside, and heating to 105 ℃ to thermally activate the sulfonate sodium polystyrene sulfonate by using the dispersing performance of the sodium polystyrene sulfonate to disperse the porous silicon source coated on the surface through ultrasonic to obtain the negatively charged porous silicon solution.
(3) Dissolving needle coke high-temperature graphitized graphite in a glycerol solution containing 10wt%, placing the solution in a reaction kettle, adding polydimethyl ammonium chloride, mixing to obtain a positively charged graphite solution (mixing according to the amount of 500g of graphite and 20g of polydimethyl ammonium chloride added into 1L of the glycerol solution), adding a negatively charged porous silicon solution (controlling the mass ratio of the porous silicon source to the graphite in the negatively charged porous silicon solution to be 10.
(4) Feeding the graphite powder with the porous silicon into a tubular furnace, introducing a mixed gas of acetylene gas and Ar gas (wherein the volume ratio of the acetylene gas to the Ar gas is 3.
2. Silicon negative plate and application:
2.1, silicon negative plate: (1) Placing the carbon-coated silicon negative electrode material and conductive carbon material into a container of a stirrer, dry-mixing and stirring at a rotating speed of 500r/min for 20min, adding a binder (obtained by mixing 95wt% and 5wt% of styrene butadiene rubber and sodium carboxymethylcellulose) and deionized water into the container, and adding water until the solid content of substances in the container is 70.8%.
(2) And adding the conductive material, the binder and the deionized water into the container again, stirring and uniformly mixing for 100min at a high rotating speed of 2500r/min until the solid content of the substances in the container is 47.4%, and thus obtaining the mixed slurry.
Wherein, the mass percentages of the carbon-coated silicon negative electrode material, the conductive carbon and the binder are 92wt%, 4wt% and 4 wt%.
(3) Adjusting the viscosity of the mixed slurry in the step (2) to 2.8Pa.s and the fineness of less than or equal to 0.15mm to obtain a negative pole homogenate, coating the negative pole homogenate on the front and back surfaces of a copper foil of a negative pole current collector to obtain a negative pole homogenate with the thickness of 98 mu m and the surface density of 0.014g/cm 2 And (3) homogenizing the coating of the negative electrode, drying and tabletting to obtain the silicon negative electrode plate.
2.2, application of the silicon negative plate:
and winding the silicon negative plate, the isolating membrane and the positive plate (the positive active substance is nickel cobalt lithium manganate) to obtain a battery core, and loading the battery core into a battery shell, drying, injecting electrolyte, packaging, forming and grading to obtain the lithium ion battery.
Comparative example 1:
this comparative example is similar to the preparation of example 2, except that the porous silicon source is not surface coated.
Comparative example 2
This comparative example is similar to the preparation method of example 2 except that the carbon-coated silicon anode material does not have a carbon coating layer.
Comparative example 3
The comparative example is similar to the preparation method of the example 2, and is different from the preparation method of the example 2 in that the silicon alloy magnesium silicide with the grain diameter of 4.2-15 mu m is selected and has larger grain diameter than the silicon alloy magnesium silicide in the example 2.
Test example
The carbon-coated silicon negative electrode materials obtained in examples 1 to 6 and comparative examples 1 to 3 and corresponding battery performance tests are as follows:
1. compressive strength, powder resistance, and battery silicon negative plate expansion under full charge of the carbon-coated silicon negative electrode material Dv 10:
(1) Compression strength of Dv 10: the silicon negative electrode materials of the examples and the comparative examples were charged into a square groove, the silicon negative electrode material in the square groove was pressed under a pressure of 1.3MPa and 2.6MPa, and Dv10 before and after pressing was recorded, and the compressive strength of Dv10 = Dv10 after pressing (10% of the particle size (μm) of the silicon negative electrode material in volume distribution)/Dv 10 before pressing, the higher the compressive strength of Dv10, the smaller the change in the particle size of the silicon negative electrode material, and the better the integrity of the particle retention; (2) The powder resistance of the silicon anode materials of the examples and the comparative examples is measured by a powder resistance meter; (3) the expansion condition of the silicon negative plate of the battery under full charge: and measuring the thickness of the pressed silicon negative electrode plate and the thickness of the battery plate under full charge, and calculating an expansion value according to a formula, wherein the formula is silicon negative electrode plate expansion rate = (the thickness of the battery plate under full charge-the thickness of the pressed silicon negative electrode plate)/the thickness of the pressed negative electrode plate. The results are shown in tables 1, 2 and 3.
2. And (3) detecting the electrical property of the battery:
under the normal temperature of 25 ℃, the initial and cut-off voltages are 2.8V, 4.35V,1C is charged to 4.35V,4.35V is charged at constant voltage until the current is reduced to 0.05C, 0.5C is discharged to 2.8V, the battery is charged and discharged in such a circulating way, and the capacity retention ratio conditions of the 100 th circle, the 500 th circle and the 800 th circle are calculated.
TABLE 1 compressive Strength of silicon negative electrode Material Dv10
TABLE 2 powder resistance, silicon negative plate swelling behavior
TABLE 3 Battery capacity retention Rate Condition
As can be seen from Table 1, the compression strength of the Dv10 of the obtained silicon negative electrode materials of comparative examples 1 to 3 is reduced under the extrusion of 1.3MPa and the extrusion of 2.6MPa, and is lower than that of examples 1 to 6, wherein the Dv10 of comparative examples 1 and 2 is respectively reduced from 3.32 mu m to 3.23 mu m and from 3.35 mu m to 3.20 mu m, which respectively shows that the Dv10 of the obtained silicon negative electrode materials is lower in compression strength, more easy to crush and crack and smaller in pulverized particles due to the absence of surface coating treatment and carbon coating layer and the adoption of silicon alloy magnesium silicide with large particle size (4.2 mu m-15 mu m); further, the obtained material can reduce the cracking of the extrusion material when the silicon negative electrode material is made into a pole piece, and the better the particle retention integrity is; in table 2, the powder resistances of comparative examples 1 and 2 are slightly increased, which shows that the conductivity of the silicon negative electrode material can be improved by increasing the surface coating treatment and the carbon coating layer.
Table 2 shows that the expansion rates of comparative examples 1 to 3 are 0.59, 0.57, and 0.52, respectively, and compared with example 1, the highest expansion rates of the silicon negative electrode sheets of comparative examples 1 and 2 indicate that the expansion effect of the silicon negative electrode material is the greatest when the surface coating treatment and the carbon coating layer are absent, and the expansion rate of the silicon negative electrode sheet of comparative example 3 also reaches 0.52, so that the surface coating treatment and the carbon coating layer are utilized to reduce the direct contact between the porous silicon source and the large-particle graphite and the electrolyte, reduce the side reaction, maintain the stability of the silicon negative electrode sheet, disperse the carbon pores to share the expansion of the internal silicon, and effectively slow down the expansion of the silicon negative electrode material in the circulation process.
Table 3 shows that the capacity retention rate and the battery cycle stability can be improved by comprehensively using the surface coating treatment and the carbon coating layer in comparison of comparative examples 1 to 3 and examples 1 to 6.
It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. This need not be, nor should it be exhaustive of all embodiments. And obvious variations or modifications of the invention may be made without departing from the spirit or scope of the invention.
Claims (10)
1. A preparation method of a carbon-coated silicon negative electrode material is characterized by comprising the following steps:
(1) Preparing a porous silicon source by using a silicon alloy and an acid, and performing surface coating treatment by using a molten polymer;
(2) Mixing the porous silicon source subjected to surface coating treatment in the step (1) with sulfonate, and activating the sulfonate to obtain a negatively charged porous silicon solution;
(3) Mixing graphite, a dispersing agent and quaternary ammonium salt to obtain a positively charged graphite solution, adding the negatively charged porous silicon solution obtained in the step (2), stirring, heating and drying to obtain porous silicon-attached graphite powder;
(4) And (4) heating and carbonizing the graphite powder with the porous silicon in the step (3) in the mixed gas atmosphere containing organic gas, and annealing to obtain the carbon-coated silicon negative electrode material.
2. The production method according to claim 1, wherein in step (1), one or more of the following conditions are satisfied:
1) The silicon alloy is selected from one or more of magnesium silicide, aluminum silicide, calcium silicide and iron silicide; 2) The acid is selected from one or more of hydrochloric acid, nitric acid, phosphoric acid, acetic acid and formic acid;
3) And the acid content is 0.1wt% -8 wt%.
3. The production method according to claim 1, wherein in the step (1), the following condition is satisfied:
i) The method comprises the following steps The surface coating treatment method comprises the following steps: stirring and mixing the molten polymer and the porous silicon source, and heating and carbonizing to obtain the porous silicon source subjected to surface coating treatment;
II): the molten polymer is selected from one or more of polystyrene, polyethylene, polypropylene and polyaniline.
4. The preparation method according to claim 3, wherein the mass ratio of the molten polymer to the porous silicon source is 0.2 to 18:100, respectively; the heating carbonization temperature is 500-900 ℃, and the heating carbonization time is 1h-12h.
5. The production method according to claim 1, wherein in the step (2), one or more of the following conditions are satisfied:
a) The sulfonate is selected from one or more of sodium styrene sulfonate, sodium polystyrene sulfonate, lithium styrene sulfonate, potassium styrene sulfonate and potassium polystyrene sulfonate;
b) The mass ratio of the porous silicon source subjected to surface coating treatment to the sulfonate is 50 to 250:1 to 25; the heating temperature is 60-110 ℃.
6. The method according to claim 1, wherein in the step (3), the quaternary ammonium salt is one or more of polydimethyl ammonium chloride, polydimethyl ammonium bromide, dodecylmethyl ammonium chloride, tetradecylmethylammonium chloride, hexadecyl methyl ammonium chloride, octadecyl methyl ammonium chloride, dodecylmethyl ammonium bromide, tetradecylmethylammonium bromide, hexadecyl methyl ammonium bromide, and octadecyl methyl ammonium bromide.
7. The carbon-coated silicon negative electrode material is characterized in that graphite is used as an inner core, a carbon coating layer and a porous silicon layer are attached to the outer core, and the graphite and the porous silicon layer are adsorbed and compounded through positive and negative charges; the porous silicon layer is wrapped by the coated carbon layer.
8. A silicon negative electrode sheet, characterized by comprising the carbon-coated silicon negative electrode material prepared by the preparation method of any one of claims 1 to 6 or the carbon-coated silicon negative electrode material of claim 7.
9. The method for preparing the silicon negative electrode sheet according to claim 8, comprising the following steps:
s1, dry-mixing and stirring a carbon-coated silicon negative electrode material and a conductive material, and adding a binder and water to obtain a mixture;
and S2, adding a conductive material, a binder and water into the mixture obtained in the step S1, stirring and mixing to obtain a negative electrode homogenate, coating the negative electrode homogenate on at least one of the front surface and the back surface of a negative electrode current collector to obtain a negative electrode homogenate coating, drying and tabletting to obtain the silicon negative electrode piece.
10. A lithium ion battery, which is characterized by comprising the silicon negative electrode sheet as set forth in claim 8 or the silicon negative electrode sheet prepared by the preparation method as set forth in claim 9.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116995221A (en) * | 2023-09-28 | 2023-11-03 | 江苏正力新能电池技术有限公司 | Porous composite negative electrode and preparation method and application thereof |
| CN117199363A (en) * | 2023-08-29 | 2023-12-08 | 深圳市贝特瑞新能源技术研究院有限公司 | Graphite negative electrode material, preparation method thereof and battery |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102651476A (en) * | 2012-05-28 | 2012-08-29 | 深圳市贝特瑞新能源材料股份有限公司 | Lithium ion battery silicon carbide composite anode material and preparation method thereof |
| CN104617276A (en) * | 2015-02-10 | 2015-05-13 | 南开大学 | Lithium ion secondary battery porous silicon/carbon composite negative electrode material and preparation method thereof |
| CN104868095A (en) * | 2014-02-25 | 2015-08-26 | 江门市荣炭电子材料有限公司 | Carbon-silicon composite electrode material and preparation method thereof |
| CN106784743A (en) * | 2017-02-28 | 2017-05-31 | 山东泰纳新材料科技有限公司 | A kind of low thermal expansion porous silicon/graphite combination electrode material and preparation method thereof |
| WO2019039856A1 (en) * | 2017-08-25 | 2019-02-28 | 동아대학교 산학협력단 | Method for producing porous silicon-carbon complex, secondary battery negative electrode comprising porous silicon-carbon complex produced by production method, and secondary battery comprising secondary battery negative electrode |
| CN109873152A (en) * | 2019-02-27 | 2019-06-11 | 陕西煤业化工技术研究院有限责任公司 | A kind of lithium ion battery graphene-silicon substrate composite negative pole material and preparation method thereof |
| CN112366294A (en) * | 2020-07-31 | 2021-02-12 | 万向一二三股份公司 | Graphite/silicon/carbon composite negative electrode material and preparation method thereof |
-
2023
- 2023-02-24 CN CN202310163191.2A patent/CN115832272B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102651476A (en) * | 2012-05-28 | 2012-08-29 | 深圳市贝特瑞新能源材料股份有限公司 | Lithium ion battery silicon carbide composite anode material and preparation method thereof |
| CN104868095A (en) * | 2014-02-25 | 2015-08-26 | 江门市荣炭电子材料有限公司 | Carbon-silicon composite electrode material and preparation method thereof |
| CN104617276A (en) * | 2015-02-10 | 2015-05-13 | 南开大学 | Lithium ion secondary battery porous silicon/carbon composite negative electrode material and preparation method thereof |
| CN106784743A (en) * | 2017-02-28 | 2017-05-31 | 山东泰纳新材料科技有限公司 | A kind of low thermal expansion porous silicon/graphite combination electrode material and preparation method thereof |
| WO2019039856A1 (en) * | 2017-08-25 | 2019-02-28 | 동아대학교 산학협력단 | Method for producing porous silicon-carbon complex, secondary battery negative electrode comprising porous silicon-carbon complex produced by production method, and secondary battery comprising secondary battery negative electrode |
| CN109873152A (en) * | 2019-02-27 | 2019-06-11 | 陕西煤业化工技术研究院有限责任公司 | A kind of lithium ion battery graphene-silicon substrate composite negative pole material and preparation method thereof |
| CN112366294A (en) * | 2020-07-31 | 2021-02-12 | 万向一二三股份公司 | Graphite/silicon/carbon composite negative electrode material and preparation method thereof |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117199363A (en) * | 2023-08-29 | 2023-12-08 | 深圳市贝特瑞新能源技术研究院有限公司 | Graphite negative electrode material, preparation method thereof and battery |
| CN116995221A (en) * | 2023-09-28 | 2023-11-03 | 江苏正力新能电池技术有限公司 | Porous composite negative electrode and preparation method and application thereof |
| CN116995221B (en) * | 2023-09-28 | 2023-12-01 | 江苏正力新能电池技术有限公司 | Porous composite negative electrode and preparation method and application thereof |
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