CN115282891A - Preparation method of micron silicon-graphene composite aerogel, electrode and preparation method of electrode - Google Patents
Preparation method of micron silicon-graphene composite aerogel, electrode and preparation method of electrode Download PDFInfo
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- CN115282891A CN115282891A CN202210914336.3A CN202210914336A CN115282891A CN 115282891 A CN115282891 A CN 115282891A CN 202210914336 A CN202210914336 A CN 202210914336A CN 115282891 A CN115282891 A CN 115282891A
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J13/00—Colloid chemistry, e.g. the production of colloidal materials or their solutions, not otherwise provided for; Making microcapsules or microballoons
- B01J13/0091—Preparation of aerogels, e.g. xerogels
-
- 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
- H01M4/134—Electrodes based on metals, Si or alloys
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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
- H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
- H01M4/139—Processes of manufacture
- H01M4/1395—Processes of manufacture of electrodes based on metals, Si or alloys
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/362—Composites
- H01M4/366—Composites as layered products
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
- H01M4/386—Silicon or alloys based on silicon
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
- H01M4/628—Inhibitors, e.g. gassing inhibitors, corrosion inhibitors
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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
- H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
- H01M2004/027—Negative electrodes
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- 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 provides a preparation method of a micron silicon-graphene composite aerogel, an electrode and a preparation method of the micron silicon-graphene composite aerogel, and the electrode and the preparation method of the micron silicon-graphene composite aerogel are characterized in that dispersion liquid C of graphene oxide, micron silicon material and a water-soluble reducing agent is added into a closed reactor and heated, and reduction and self-assembly of the graphene oxide are carried out to obtain micron silicon-graphene composite hydrogel; performing low-temperature freezing treatment on the micron silicon-graphene composite hydrogel, and drying by using a freeze dryer to obtain micron silicon-graphene composite aerogel; grinding the micron silicon-graphene composite aerogel into powder, preparing slurry according to the mass ratio of the micron silicon-graphene composite aerogel particles to the conductive agent to the binder of a: b: c, and directly coating the slurry on a current collector to form a negative electrode. The negative electrode aerogel frame structure can well relieve the expansion of the silicon volume, prevent the negative electrode from losing efficacy in the circulating process, and can assist in realizing high rate performance and circulating performance by the graphene and the conductive agent while fully exerting the advantages of high specific capacity and low cost of micron silicon.
Description
Technical Field
The invention belongs to the field of new energy materials, and particularly relates to a preparation method of a micron silicon-graphene composite aerogel, a negative electrode and a preparation method of the micron silicon-graphene composite aerogel.
Background
Lithium ion batteries have been widely used in the fields of portable electronic devices, electric vehicles, power grid energy storage, and the like due to their advantages of high energy density, high open circuit voltage, long cycle life, no memory effect, and the like. However, the current commercial lithium ion battery mainly adopts carbon-based negative electrode materials such as graphite, the theoretical specific capacity of the lithium ion battery is low (372 mAh/g), a lithium intercalation potential platform of the lithium ion battery is close to metal lithium, and the lithium precipitation is easy to occur during rapid charging, so that the potential safety hazard is caused, and the requirement of the future lithium ion battery on high energy density cannot be met.
Silicon is a lithium battery negative electrode material with the highest specific capacity, which is discovered at present, the theoretical specific capacity of the silicon is up to 4200mAh/g, but the most fatal defects are that the volume expansion change in the reaction reaches 320%, the silicon reacts with an electrolyte to grow an SEI film and consume lithium ions, the conductivity of the silicon is poor, and the factors seriously restrict the application of the silicon as the negative electrode material. In order to solve the above problems, a method of compounding with a conductive material is necessary.
In recent years, reports of compounding graphene and silicon as a negative electrode material of a lithium ion battery are frequent. However, the existing production method of the graphene/silicon negative electrode material only adopts a mode of coating graphene on the surface of silicon particles, and partially solves the problems of expansion and poor conductivity of a silicon electrode. The pulverization of the silicon electrode is not well solved, and the graphene and the silicon are very good in stability and very high in melting point and are difficult to combine together, so that the constructed three-dimensional graphene grid is not firm, and the graphene grid can collapse along with the expansion and contraction of the silicon electrode, so that the performance is greatly reduced. Therefore, the development of a silicon-graphene composite negative electrode material with high mechanical strength and long cycle life is a technical problem in the field of lithium ion batteries.
In order to solve the problems, the micron silicon material is embedded into the graphene aerogel, when the compounding condition and the compounding ratio of silicon and graphene are controlled, the graphene aerogel can be used as a better conductive framework supporting material, meanwhile, the preparation process of the negative electrode material is simplified by optimizing the compounding ratio and the preparation method of the negative electrode slurry, and finally, the micron silicon-graphene composite aerogel negative electrode with long service life and high specific capacity is obtained.
Disclosure of Invention
In order to overcome the defects and shortcomings of the prior art, the invention aims to provide a preparation method of a micron silicon-graphene composite aerogel, a lithium ion battery cathode and a preparation method of the lithium ion battery cathode, so as to solve the problems of short service life and complex preparation process of the existing lithium ion battery silicon-carbon cathode.
According to a first aspect of the present invention, there is provided a method for preparing a microsilica-graphene composite aerogel, wherein the microsilica-graphene composite aerogel at least comprises carbon element and silicon element; the carbon element mainly exists in the form of graphene aerogel; the carbon element in the graphene aerogel form accounts for more than 96% of the total mass of the carbon element of the micron silicon-graphene composite aerogel; the silicon element exists in the form of micron silicon material, the silicon element at least partially exists in the form of being wrapped in the graphene aerogel network, and the wrapped silicon element accounts for more than 95% of the total mass of the silicon element; the molar ratio of the silicon element to the carbon element is 1.
The method comprises the following steps:
s1, adding a uniformly mixed graphene oxide solution, a micron silicon material dispersion liquid and a dispersion liquid C of a water-soluble reducing agent into a closed reactor;
s2, heating the closed reactor, and carrying out reduction and self-assembly on graphene oxide to obtain micron silicon-graphene composite hydrogel;
and S3, performing low-temperature freezing treatment on the micron silicon-graphene composite hydrogel, and then drying by using a freeze dryer to obtain the micron silicon-graphene composite aerogel.
Preferably, the micron silicon comprises at least one of silicon micron powder, silicon micron line, silicon micron tube and silicon micron sheet; wherein the effect is better silicon micron powder.
Preferably, the water-soluble reducing agent is one of ascorbic acid, sodium ascorbate, sodium citrate, hydroiodic acid, hydrobromic acid, sodium bisulfite, sodium sulfide and ethylenediamine.
Preferably, the heating temperature in the step S2 is 60-75 ℃; the temperature of freezing in the step S3 is-170 to-20 ℃, and the pressure of freezing and drying is 5 to 20Pa.
Preferably, the microsilica material has a size in the range of 1-10 μm in at least one dimension.
Preferably, step S1 further includes mixing the graphite oxide slurry prepared by the Hummers method with a solvent a, and performing ultrasonic dispersion to obtain a dispersion a; mixing the micron silicon material with a solvent B to obtain a dispersion liquid B; and mixing the dispersion liquid A and the dispersion liquid B with a water-soluble reducing agent, and then uniformly stirring by magnetic force to obtain a dispersion liquid C.
Preferably, the micron silicon is subjected to surface treatment before being mixed and dispersed with the graphene oxide, wherein the surface treatment includes, but is not limited to, coating the micron silicon material with a carbon-based material, and forming a uniform carbon coating layer on the surface of the micron silicon material after sintering; the carbon-based materials include, but are not limited to, phenolic resins, tannic acid, polypyrrole, polymeric dopamine, pitch; the sintering condition is 700-1000 ℃, inert atmosphere, 2-6 hours.
s
According to another aspect of the present invention, there is provided an electrode comprising a current collector layer and an active material coating disposed on the current collector layer, the active material coating comprising the aforementioned microsilica-graphene composite aerogel.
According to a third aspect of the present invention, there is provided a method for preparing a negative electrode of a lithium ion battery, comprising the steps of:
s4, grinding the micron silicon-graphene composite aerogel prepared by the method into micron silicon-graphene composite aerogel particles, and weighing the micron silicon-graphene composite aerogel particles, the conductive agent and the binder according to the mass ratio of a to b to c, wherein a is more than or equal to 85 and less than or equal to 90, b is more than or equal to 5 and less than or equal to 7, c is more than or equal to 5 and less than or equal to 8, and a + b + c =100;
s5, uniformly mixing the micron silicon-graphene composite aerogel particles, a conductive agent, a binder and a solvent to prepare slurry, coating the slurry on a continuous current collector, and then drying and rolling to obtain an electrode roll;
s6, cutting the electrode roll according to the required size;
and S7, packaging, sampling and discharging.
The mixing mode in the step S5 is magnetic stirring after the temperature is raised, and the temperature range is as follows: 38-46 ℃, and the magnetic stirring speed is as follows: 80-200 rpm, and the stirring time is as follows: 20-80 min.
The current collector is selected from copper foil, foam copper or foam nickel.
Advantageous technical effects
1. According to the invention, the hydrogel is formed by self-assembling after the micron silicon material and the graphene oxide are mixed, the micron silicon material is basically dispersed in a frame formed by the graphene hydrogel, and the proportion of the micron silicon material overflowing out of the graphene aerogel frame structure after freeze-drying is extremely low, so that the mass ratio of the micron silicon material to the graphene aerogel is ensured to be within the range of 1.
2. According to the invention, the size distribution of the particles of the micron silicon-graphene composite aerogel ground is limited to D50=100-200 μm, so that the aerogel can be kept in the negative electrode material relative to the frame structure of the micron silicon material, and the mixing and contact of the negative electrode active material micron silicon-graphene composite aerogel, a conductive agent and a binder can be considered, wherein the conductive agent is introduced to reduce the problem of interface conductivity among the micron silicon-graphene composite aerogel particles.
3. Micron silicon is adopted as a main material instead of nano silicon, so that the cost of the product is reduced, and the problem caused by the agglomeration of silicon nano materials is weakened; in order to reduce the failure of the micron silicon, except for coating the micron silicon with the graphene aerogel, the micron silicon is coated with the carbon-based material before being mixed with the graphene, and then is further mixed with the graphene oxide, so that the micron silicon is equivalently provided with double guarantee, and the volume expansion effect of the micron silicon in the circulation process is further weakened.
Drawings
Fig. 1 is a schematic diagram of a preparation process of a micron silicon-graphene composite aerogel according to the present invention;
FIG. 2 is a flow chart of the electrode preparation process of the present invention.
Reference numerals
1. A dispersion of micron silicon/graphene oxide; 2. micron silicon-graphene composite hydrogel; 3. micron silicon-graphene composite aerogel.
Detailed Description
In order to make those skilled in the art better understand the technical solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.
As used herein, "about" or "approximately" includes the stated value and means within an acceptable range of deviation for the particular value as determined by one of ordinary skill in the art in view of the measurement in question and the error associated with the measurement of the particular quantity (i.e., the limitations of the measurement system). For example, "about" may mean a deviation from the stated value in one or more deviation ranges, or in a range of ± 30%, 20%, 10%, or 5%.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the present disclosure and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
Preparation method of micron silicon-graphene composite aerogel
The application firstly provides a preparation method of the micron silicon-graphene composite aerogel, wherein the micron silicon-graphene composite aerogel at least comprises a carbon element and a silicon element;
the carbon element mainly exists in the form of graphene aerogel;
the carbon element existing in the graphene aerogel form accounts for more than 96% of the total mass of the carbon element of the micron silicon-graphene composite aerogel;
the silicon element exists in the form of micron silicon material, the silicon element at least partially exists in the form of being wrapped in the graphene aerogel network, and the wrapped silicon element accounts for more than 95% of the total mass of the silicon element;
the mass ratio of the silicon element to the carbon element is 1.
Preferably, the micron silicon comprises at least one of silicon micron powder, silicon micron line, silicon micron tube and silicon micron sheet; wherein the better effect is silicon micron powder;
the size of the micron silicon material in at least one dimension (micron powder refers to D50 of the micron powder) is 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm.
Before the micron silicon is mixed and dispersed with graphene oxide, surface treatment is carried out, wherein the surface treatment comprises but is not limited to coating the micron silicon material with a carbon-based material, and a uniform carbon coating layer is formed on the surface of the micron silicon material after sintering; the carbon-based materials include, but are not limited to, phenolic resins, tannic acid, polypyrrole, polymeric dopamine, pitch; the sintering condition is 700-1000 ℃, inert atmosphere, 1-6 hours.
Specifically, the sintering temperature may be, for example, 700 ℃, 720 ℃, 740 ℃, 760 ℃, 780 ℃, 800 ℃, 820 ℃, 840 ℃, 860 ℃, 880 ℃, 900 ℃, 920 ℃, 940 ℃, 960 ℃, 980 ℃, 1000 ℃, preferably 800 to 900 ℃; the inert atmosphere may be nitrogen or argon, and the sintering time is preferably 2 to 3 hours.
In order to further show how to achieve that the coated silicon element accounts for more than 95% of the total mass of the silicon element, the preparation method of the micron silicon-graphene composite aerogel will be described in detail below.
The preparation method of the micron silicon-graphene composite aerogel comprises the following steps:
s1, firstly, carrying out surface treatment on micron silicon, wherein the surface treatment comprises but is not limited to coating the micron silicon material with a carbon-based material, and forming a uniform carbon coating layer on the surface of the micron silicon material after sintering; sintering at 700-1000 deg.c in inert atmosphere for 1-6 hr;
mixing the graphite oxide slurry prepared by the Hummers method with deionized water with the volume of V, and performing ultrasonic dispersion to obtain a dispersion liquid A; mixing the coated micron silicon material with the mass m with a solvent B to obtain a dispersion liquid B; then mixing the dispersion liquid A, the dispersion liquid B and a water-soluble reducing agent, and uniformly stirring by magnetic force to obtain a dispersion liquid C; and adding the uniformly mixed graphene oxide solution, the micron silicon material dispersion liquid and the dispersion liquid C of the water-soluble reducing agent into the closed reactor.
Wherein, the solvent b is deionized water.
Carbon-based materials include, but are not limited to, phenolic resins, tannic acid, polypyrrole, polymeric dopamine, pitch;
the water-soluble reducing agent is one of ascorbic acid, sodium ascorbate, sodium citrate, hydroiodic acid, hydrobromic acid, sodium bisulfite, sodium sulfide and ethylenediamine.
Preferably, the micron silicon comprises at least one of silicon micron powder, silicon micron line, silicon micron tube and silicon micron sheet; wherein the better effect is silicon micron powder;
the size of the micron silicon material in at least one dimension (when micron powder, the D50 of the micron powder is referred to) is 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm.
S2, heating the closed reactor, and carrying out reduction and self-assembly on graphene oxide to obtain micron silicon-graphene composite hydrogel; the heating temperature is 60-75 ℃, and the specific optional temperature is as follows: 60 ℃, 61 ℃, 62 ℃, 63 ℃, 64 ℃, 65 ℃, 66 ℃, 67 ℃, 68 ℃, 69 ℃, 70 ℃, 71 ℃, 72 ℃, 73 ℃, 74 ℃ and 75 ℃.
S3, performing low-temperature freezing treatment on the micron silicon-graphene composite hydrogel, and drying by using a freeze dryer to obtain micron silicon-graphene composite aerogel;
the freezing temperature is-170 to-20 ℃, and the specific optional temperatures are as follows: -170 ℃, -165 ℃, -160 ℃, -155 ℃, -150 ℃, -145 ℃, -140 ℃, -135 ℃, -130 ℃, -125 ℃, -120 ℃, -115 ℃, -110 ℃, -105 ℃, -100 ℃, -95 ℃, -90 ℃, -85 ℃, -80 ℃, -75 ℃, -70 ℃, -65 ℃, -60 ℃, -55 ℃, -40 ℃, -45 ℃, -40 ℃, -35 ℃, -30 ℃, -25 ℃, -20 ℃.
Wherein the pressure of freeze drying is 5-20 Pa.
The graphite oxide is prepared by a Hummers method, and the method comprises the following specific process steps:
(1) Adding a reagent at a low temperature: fixing the dry three-neck flask on an iron support, ensuring that half of the flask body is immersed in ice water, and sequentially adding weighed graphite and NaNO 3 And (3) powder. Opening the stirrer, and measuring concentrated H in batches 2 SO 4 Slowly added to the flask, and then weighed KMnO in batches 4 The powder was slowly added to the flask, 12 minutes after each addition, and the temperature in the flask was maintained below 10 ℃.
(2) Heating and adding water: after the reagent is added, the flask is transferred to a constant temperature oil bath device for constant temperature heating reaction. Slowly heating to 35 ℃, continuing to react for 6 hours after the reaction is stabilized, adding deionized water in batches into 400ml, heating to 95 ℃, and continuing to react for half an hour.
(3) Cooling, transferring and removing the oxidant: after cooling to room temperature, all solutions were transferred to a 2000ml beaker and 100ml of hydrogen peroxide was added until a bright yellow color was obtained with no more bubbles, and finally 700ml of deionized water was added.
(4) Acid washing for two times: the HCl solution was prepared as 15% HCl solution in a 500ml volumetric flask and added to the 2000ml beaker of the previous step, followed by addition of water to 2000ml. Standing for layering, pouring out the upper liquid, and performing acid washing again by the same method.
(5) And (4) washing twice: and after the standing of the previous step is finished, pouring out the upper liquid, adding deionized water to 2000ml, standing and layering, pouring out the upper liquid, and performing water washing again by the same method.
(6) Centrifuging: deionized water was added in batches for centrifugation to obtain a graphite oxide slurry with PH = 7.
Electrode for electrochemical cell
According to a second aspect of the present application, there is provided an electrode comprising a current collector layer and an active material coating disposed on the current collector layer, the active material coating comprising the aforementioned microsilica-graphene composite aerogel and a binder. The mass ratio of the micron silicon-graphene composite aerogel to the conductive agent to the binder is a: b: c, wherein a is more than or equal to 85 and less than or equal to 90, b is more than or equal to 5 and less than or equal to 7, c is more than or equal to 5 and less than or equal to 8, and a + b + c =100.
Wherein a can be 85, 85.5, 86, 86.5, 87, 87.5, 88, 88.5, 89, 89.5, 90; b may be 5,5.2,5.3,5.4,5.6,5.7,5.8,5.9,6,6.1,6.2,6.3,6.4,6.5,6.6,6.7,6.8,6.9,7; c can be 5,5.1,5.2,5.3,5.4,5.6,5.7,5.8,5.9,6,6.1,6.2,6.3,6.4,6.5,6.6,6.7,6.8,6.9,7,7.1,7.2,7.3,7.4,7.5,7.6,7.7,7.8,7.9,8.
The electrode can be a negative electrode, and the electrode can be applied to batteries such as lithium ion batteries and sodium ion batteries.
Electrode preparation method
According to a third aspect of the present application, there is provided an electrode preparation method comprising the steps of:
s4, grinding the micron silicon-graphene composite aerogel into micron silicon-graphene composite aerogel particles, and weighing the micron silicon-graphene composite aerogel particles, the conductive agent and the binder according to the mass ratio of a to b to c, wherein a is more than or equal to 85 and less than or equal to 90, b is more than or equal to 5 and less than or equal to 7, c is more than or equal to 5 and less than or equal to 8, and a +, b and c =100.
Wherein a can be 85, 85.5, 86, 86.5, 87, 87.5, 88, 88.5, 89, 89.5, 90; b can be 5,5.2,5.3,5.4,5.6,5.7,5.8,5.9,6,6.1,6.2,6.3,6.4,6.5,6.6,6.7,6.8,6.9,7; c can be 5,5.1,5.2,5.3,5.4,5.6,5.7,5.8,5.9,6,6.1,6.2,6.3,6.4,6.5,6.6,6.7,6.8,6.9,7,7.1,7.2,7.3,7.4,7.5,7.6,7.7,7.8,7.9,8.
The micron silicon-graphene composite aerogel has a graphene frame structure and is good in conductivity, so that excessive conductive agents are not required to be added when negative electrode slurry is manufactured, the size of silicon is smaller than 10 micrometers, preferably, the D50 of micron particles is 3-9 micrometers, the size of one-dimensional and two-dimensional materials of silicon is 3-9 micrometers in at least one dimension, the range of the hole size L of the graphene frame is 20-80 micrometers, and the D50 of the particles is 100-200 micrometers when the composite aerogel is ground into the particles, so that relatively complete graphene frame units can be kept in the particles, the frame units can ensure that the micron silicon materials have sufficient expansion space in charge-discharge circulation, and the micron silicon materials have a good buffering effect on volume expansion of the silicon in the circulation process; it is also noted that if the aerogel is ground with larger particles, the frame structure remains more intact, however, while the frame remains more intact, the overall negative electrode density is greater when the frame is larger, thus providing more room for the silicon to expand, but the energy density is dramatically reduced due to the larger volume; in conclusion, when the micron silicon-graphene composite aerogel is ground into particles, the frame structure cannot be well maintained when the particle size is too small, and the volume of the mixed binder is large and the energy density is reduced when the particle size is too large. Preferably, the D50 of the microsilica-graphene composite aerogel particles can be 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, 160 μm, 170 μm, 180 μm, 190 μm, 200 μm.
S5, uniformly mixing the micron silicon-graphene composite aerogel particles, a conductive agent, a binder and a solvent to prepare slurry, coating the slurry on a continuous current collector, and then drying and rolling to obtain an electrode roll;
wherein the mixing mode is magnetic stirring after the temperature is raised, and the temperature range is as follows: 38-46 ℃, and the magnetic stirring speed is as follows: 80-200 rpm, and the stirring time is as follows: 20-80 min.
And S6, cutting the electrode roll according to the required size.
And S7, packaging, sampling and delivering.
Examples1
S1, firstly, carrying out surface treatment on micron silicon powder with mass m =21g, wherein the surface treatment comprises but is not limited to coating the micron silicon material with a carbon-based material, and forming a uniform carbon coating layer on the surface of the micron silicon powder after sintering; sintering at 700-1000 deg.c in argon atmosphere for 1-6 hr; mixing graphite oxide slurry prepared from 42g of graphite with deionized water, wherein the volume of the deionized water mixed with the graphite is V =7L, and performing ultrasonic dispersion to obtain a graphene dispersion liquid A; mixing the coated micron silicon with 1L of deionized water to obtain a dispersion liquid B; then mixing the dispersion liquid A, the dispersion liquid B and 100g of sodium ascorbate, and then uniformly stirring by magnetic force to obtain a dispersion liquid C; the dispersion C was added to the closed reactor.
S2, heating the closed reactor to 68 ℃, keeping the temperature constant, and carrying out assembly and self-reduction on graphene oxide to obtain graphene-micron silicon material composite hydrogel; the reaction time was 3 hours.
S3, freezing the graphene-micron silicon material composite hydrogel at the low temperature of-170 ℃, and drying by using a freeze dryer to obtain micron silicon-graphene composite aerogel; wherein the pressure of freeze drying is 5-20 Pa.
S4, grinding the micron silicon-graphene composite aerogel into micron silicon-graphene composite aerogel particles by using a ball milling method, wherein the ball milling time is T =3 hours, the D50=150 μm of the ball-milled micron silicon-graphene composite aerogel particles,
weighing the micron silicon-graphene composite aerogel particles, the conductive agent and the binder according to the mass ratio of a: b: c, wherein a =85, b =7 and c =8.
Compared with micron silicon, the micron silicon has poor conductivity, so that the micron silicon is coated by the carbon-based material on the first aspect, the conductivity of the micron silicon is improved, and a first-order expansion limiting structure is formed; the formed graphene aerogel is micron silicon
In the process of preparing the negative electrode, the binder plays a vital role, and because the aerogel is loose and porous, a relatively large amount of binder is selected, the aerogel powder can be well bound, firm binding is provided among powder particles, and the electric conductivity is not greatly lost.
S5, uniformly stirring and mixing the micron silicon-graphene composite aerogel particles (85 wt%), the conductive agent (3 wt% CNT and 4wt% SP), the binder (5.6 wt% CMC and 2.4wt% SBR) and deionized water into slurry, wherein the weight% represents the percentage of each component in the total weight of the core-shell structure composite material, the conductive agent and the binder.
The magnetic stirring is specifically carried out by heating a magnetic stirrer to 40 ℃, stirring for 45min at the speed of 100rpm to prepare slurry, coating the slurry on a continuous current collector, and then drying and rolling to obtain an electrode roll;
s6, cutting the electrode roll according to the required size;
and S7, packaging, sampling and delivering.
Examples 2 to 12
The process steps of examples 2-12 are the same as in example 1, except for the specific compounding ratio parameters, as shown in Table 1.
The process steps of comparative examples 1-12 are the same as example 1, except for the specific compounding ratio parameters, as shown in Table 2.
Test example 1 lithium battery preparation and Performance test
Cutting the electrode plates obtained in the examples 1-12 and the comparative examples 1-12 into round sheets matched with the button half cell to be tested, assembling the round sheets with a counter electrode lithium sheet and a conventional electrolyte into the button half cell, and carrying out charge and discharge tests under the following test conditions: the voltage range of 5mV-0.8V is activated for 2 cycles at 0.1C/0.1C, and the cycle is performed at 0.3C/0.3C. The electrochemical performance parameters of the batteries fabricated with the electrodes of examples 1-12 and comparative examples 1-12 were tested as shown in tables 1-2 below.
Table 1: example associated proportioning parameters and test data
Table 2: comparative example related proportioning parameters
It can be seen by comparing examples 1-12 with comparative examples 1-6 that too few micron silicon particles (comparative examples 1-3) have improved cycle retention, but the capacity is lower because the Si content is too low; with the increase of the addition amount of silicon, the capacity is multiplied, but when the silicon micron is excessive (comparative examples 4-6), although the capacity is high, the cycle retention rate is low, particularly the retention rate is lower than 50% after 100 cycles of the cycle, the excessive Si causes that the aerogel does not keep much, the Si is not completely in the frame structure, and the expansion during the cycle causes that a large amount of Si fails; thus, the mass ratio of the silicon element to the carbon element is selected to be 2.
Comparing example 5 with comparative examples 7 to 9, it can be seen that when the powder particles obtained by grinding the microsilica-graphene composite aerogel are smaller, the cycle retention rate is lower, because the smaller the powder particles are, the more seriously the frame is damaged, and the buffer effect on Si expansion is reduced, which is one of the most critical parameters in the electrode preparation method provided by the present invention, when the powder particles are controlled to be 100 to 200 μm, the buffer structure of the frame can be maintained, and the density of the electrode can not be too low, and in the range of these dimensions, the density of the manufactured negative electrode is in a usable range.
Comparing example 5 with comparative examples 10 to 12, it can be seen that when the powder particles obtained by grinding the micron silicon-graphene composite aerogel are bonded with a proper amount of conductive agent and binder, the content of the conductive agent and the binder is too low, so that firstly the aerogel particles are not well bonded, secondly the conductivity of the micron silicon is not enhanced by the conductive agent, firstly the electrode falls off seriously in the electrolyte, further the cycle retention rate is very low, secondly the electron transport performance of the electrode material is poor, the first reversible capacity is greatly reduced, and the electrode material is not suitable for being used as the electrode material of a battery.
Although the present invention has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that various changes and modifications may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
Claims (10)
1. A preparation method of a micron silicon-graphene composite aerogel, wherein the micron silicon-graphene composite aerogel at least comprises a carbon element and a silicon element; characterized in that the carbon element is mainly present in the form of graphene aerogel; the carbon element in the graphene aerogel form accounts for more than 96% of the total mass of the carbon element of the micron silicon-graphene composite aerogel; the silicon element exists in the form of micron silicon material, the silicon element at least partially exists in the form of being wrapped in the graphene aerogel network, and the wrapped silicon element accounts for more than 95% of the total mass of the silicon element; the molar ratio of the silicon element to the carbon element is 1;
the method is characterized by comprising the following steps:
s1, adding a uniformly mixed graphene oxide solution, a micron silicon material dispersion liquid and a dispersion liquid C of a water-soluble reducing agent into a closed reactor;
s2, heating the closed reactor, and carrying out reduction and self-assembly on graphene oxide to obtain micron silicon-graphene composite hydrogel;
and S3, performing low-temperature freezing treatment on the micron silicon-graphene composite hydrogel, and then drying by using a freeze dryer to obtain the micron silicon-graphene composite aerogel.
2. The method for preparing the microsilica-graphene composite aerogel according to claim 1, wherein the water-soluble reducing agent is one of ascorbic acid, sodium ascorbate, sodium citrate, hydroiodic acid, hydrobromic acid, sodium bisulfite, sodium sulfide, and ethylenediamine.
3. The method for preparing the micron silicon-graphene composite aerogel according to claim 1, wherein the micron silicon comprises at least one of silicon micron powder, silicon micron lines, silicon micron tubes and silicon micron sheets; preferably, the micron silicon is silicon micron powder.
4. The method for preparing the micro silicon-graphene composite aerogel according to claim 1, wherein the heating temperature in the step S2 is 60-75 ℃; the temperature of freezing in the step S3 is-170 to-20 ℃, and the pressure of freezing and drying is 5 to 20Pa.
5. The preparation method of the micron silicon-graphene composite aerogel according to any one of claims 1 to 3, wherein the micron silicon material is silicon micropowder, and the D50 range of the micron silicon material is 1 to 10 μm.
6. The method for preparing the microsilicon-graphene composite aerogel according to any one of claims 1 to 3, wherein the step S1 further comprises mixing the graphite oxide slurry prepared by the Hummers method with a solvent a, and performing ultrasonic dispersion to obtain a dispersion A; mixing the micron silicon material with a solvent B to obtain a dispersion liquid B; and mixing the dispersion liquid A, the dispersion liquid B and a water-soluble reducing agent, and then uniformly stirring by magnetic force to obtain the dispersion liquid C.
7. An electrode comprising a current collector layer and an active material coating disposed on the current collector layer, the active material coating comprising the microsilica-graphene composite aerogel of claim 1 or 2; preferably, the electrode is a negative electrode.
8. A method for preparing the electrode according to claim 7, comprising the steps of:
s4, grinding the micron silicon-graphene composite aerogel prepared by the method claimed in any one of claims 1 to 6 into micron silicon-graphene composite aerogel particles, and weighing the three according to the mass ratio of the micron silicon-graphene composite aerogel particles to the conductive agent to the binder, namely a: b: c, wherein a is more than or equal to 85 and less than or equal to 90, b is more than or equal to 5 and less than or equal to 7, c is more than or equal to 5 and less than or equal to 8, and a + b + c =100;
s5, uniformly mixing the micron silicon-graphene composite aerogel particles, a conductive agent, a binder and a solvent to prepare slurry, coating the slurry on a continuous current collector layer, and then drying and rolling to obtain an electrode roll;
s6, cutting the electrode roll according to the required size;
and S7, packaging, sampling and delivering.
9. The method for preparing an electrode of a lithium ion battery according to claim 8, wherein the mixing manner in step S5 is magnetic stirring after increasing the temperature, and the temperature ranges are as follows: 38-46 ℃, and the magnetic stirring speed is as follows: 80-200 rpm, and the stirring time is as follows: 20-80 min; the current collector is selected from copper foil, foamed copper or foamed nickel.
10. A battery comprising a positive electrode, a negative electrode, a separator and an electrolyte, wherein the negative electrode is the electrode of claim 7.
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|---|---|---|---|---|
| CN116387484A (en) * | 2023-04-07 | 2023-07-04 | 湖南金阳烯碳新材料股份有限公司 | Preparation method of graphene composite material, graphene composite material and application of graphene composite material |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102496719A (en) * | 2011-12-15 | 2012-06-13 | 中国科学院化学研究所 | Silicon/graphene composite material, and preparation method and application of the same |
| US20150044560A1 (en) * | 2013-08-09 | 2015-02-12 | Semiconductor Energy Laboratory Co., Ltd. | Electrode for lithium-ion secondary battery and manufacturing method thereof, and lithium-ion secondary battery |
| CN104810504A (en) * | 2014-01-24 | 2015-07-29 | 中国科学院金属研究所 | Flexible graphene current collector and active material integrated electrode pole piece and preparation method thereof |
| CN105576194A (en) * | 2014-10-10 | 2016-05-11 | 南京工业大学 | Preparation method of graphene-carbon nanotube aerogel supported nano-silicon composite electrode material |
| CN106784765A (en) * | 2016-12-15 | 2017-05-31 | 电子科技大学 | Graphene enhancing Si-C composite material and its production and use |
| CN109473658A (en) * | 2018-12-04 | 2019-03-15 | 清华大学深圳研究生院 | A kind of its lithium ion battery of the preparation method and application of lithium ion battery negative material |
| KR20210035628A (en) * | 2019-09-24 | 2021-04-01 | 한국과학기술연구원 | Porous graphene-silicon aerogel composite containing graphene-wrapped silicon nanoparticles, preparation of the same and lithium secondary battery using the same |
-
2022
- 2022-08-01 CN CN202210914336.3A patent/CN115282891B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102496719A (en) * | 2011-12-15 | 2012-06-13 | 中国科学院化学研究所 | Silicon/graphene composite material, and preparation method and application of the same |
| US20150044560A1 (en) * | 2013-08-09 | 2015-02-12 | Semiconductor Energy Laboratory Co., Ltd. | Electrode for lithium-ion secondary battery and manufacturing method thereof, and lithium-ion secondary battery |
| CN104810504A (en) * | 2014-01-24 | 2015-07-29 | 中国科学院金属研究所 | Flexible graphene current collector and active material integrated electrode pole piece and preparation method thereof |
| CN105576194A (en) * | 2014-10-10 | 2016-05-11 | 南京工业大学 | Preparation method of graphene-carbon nanotube aerogel supported nano-silicon composite electrode material |
| CN106784765A (en) * | 2016-12-15 | 2017-05-31 | 电子科技大学 | Graphene enhancing Si-C composite material and its production and use |
| CN109473658A (en) * | 2018-12-04 | 2019-03-15 | 清华大学深圳研究生院 | A kind of its lithium ion battery of the preparation method and application of lithium ion battery negative material |
| KR20210035628A (en) * | 2019-09-24 | 2021-04-01 | 한국과학기술연구원 | Porous graphene-silicon aerogel composite containing graphene-wrapped silicon nanoparticles, preparation of the same and lithium secondary battery using the same |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116387484A (en) * | 2023-04-07 | 2023-07-04 | 湖南金阳烯碳新材料股份有限公司 | Preparation method of graphene composite material, graphene composite material and application of graphene composite material |
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