CN112635731B - Preparation method of composite nano-silicon negative electrode material based on conductive carbon aerogel and product thereof - Google Patents

Preparation method of composite nano-silicon negative electrode material based on conductive carbon aerogel and product thereof Download PDF

Info

Publication number
CN112635731B
CN112635731B CN202011498724.5A CN202011498724A CN112635731B CN 112635731 B CN112635731 B CN 112635731B CN 202011498724 A CN202011498724 A CN 202011498724A CN 112635731 B CN112635731 B CN 112635731B
Authority
CN
China
Prior art keywords
silicon
carbon aerogel
preparation
negative electrode
nano
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202011498724.5A
Other languages
Chinese (zh)
Other versions
CN112635731A (en
Inventor
张亚光
王振
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Yunnan lichen New Material Technology Co.,Ltd.
Original Assignee
Zhejiang Lichen New Material Technology Co ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Zhejiang Lichen New Material Technology Co ltd filed Critical Zhejiang Lichen New Material Technology Co ltd
Priority to CN202011498724.5A priority Critical patent/CN112635731B/en
Publication of CN112635731A publication Critical patent/CN112635731A/en
Application granted granted Critical
Publication of CN112635731B publication Critical patent/CN112635731B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/362—Composites
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/4235—Safety or regulating additives or arrangements in electrodes, separators or electrolyte
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
    • H01M4/386—Silicon or alloys based on silicon
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • H01M4/583—Carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/624—Electric conductive fillers
    • H01M4/625—Carbon or graphite
    • 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 discloses a preparation method of a composite nano-silicon anode material based on conductive carbon aerogel and a product thereof, wherein the preparation method comprises the following steps: (1) dissolving the pretreated waste biomass and a fiber additive into an aqueous solution of an alkaline substance together, and stirring to obtain a reticular solid gel; (2) drying the reticular solid gel, and screening to obtain a carbon aerogel precursor; (3) taking gaseous silicon source and carbon aerogel precursor as raw materials, and preparing a carbon aerogel and nano-silicon compound by a chemical vapor deposition process; (4) and (3) blending the carbon aerogel and nano-silicon compound with a carbon source, and heating and carbonizing to obtain the conductive carbon aerogel-based composite nano-silicon negative electrode material. The preparation method disclosed by the invention takes the waste biomass as the raw material, the cost is low, the prepared cathode material is high in strength and good in conductivity, and the assembled battery has higher first effect.

Description

Preparation method of composite nano-silicon negative electrode material based on conductive carbon aerogel and product thereof
Technical Field
The invention relates to the field of battery cathode materials, in particular to a preparation method of a composite nano-silicon cathode material based on conductive carbon aerogel and a product thereof.
Background
The most advanced lithium ion batteries at present have failed to meet the increasing demand for electric vehicles and large-scale energy batteries. Silicon is considered to be the most promising candidate for replacing graphite. It is the second most abundant element in the earth crust, is environment-friendly and has ultrahigh theoretical capacity (4200 mAh/g). However, during cycling, the volume of the silicon particles expands and contracts dramatically with intercalation and delamination of lithium ions (Li-ion). This drastic volume change leads to pulverization of silicon particles, destruction of silicon-based electrodes, and repeated regeneration of solid electrolyte interface layers.
Graphite and silicon composite materials are not available in the market, but the void structure of graphite limits the proportion of silicon composite, and the contribution to solving the problems of silicon volume expansion and contraction is very limited. However, the electrical conductivity of the carbon-silicon composite material is inferior to that of graphite and silicon, so that the design of a composite material with good electrical conductivity, abundant mesoporous pore structures and high theoretical specific capacity is an urgent technical problem to be solved.
The carbon aerogel has good conductivity, high specific surface area and abundant mesoporous pores, is favorable for being combined with silicon with ultrahigh theoretical capacity, relieves the problems of volume expansion and contraction, and is also favorable for the insertion and extraction of lithium ions due to abundant pore structures.
For example, chinese patent publication No. CN 110247046 a discloses a method for preparing a lithium ion battery CA/nano Si/graphene composite negative electrode material, in which resorcinol and formaldehyde are mixed to prepare a carbon aerogel, then the carbon aerogel and a nano silicon solution are added into deionized water, PVP is added, and the carbon aerogel and the nano silicon solution are transferred to a high-pressure reaction kettle to be heated and insulated, and the obtained CA/nano silicon composite material is blended with sodium dodecyl sulfate and graphene to obtain a final composite negative electrode material.
The technical scheme combines the high specific surface area of the carbon aerogel and the excellent conductivity of the graphene to prepare the composite negative electrode material, but in the preparation process, the carbon aerogel is prepared from petrochemical raw materials, so that the production cost is high and the composite negative electrode material is not environment-friendly; the prepared carbon aerogel and the nano silicon liquid are mixed and then subjected to hydrothermal reaction, and the hydrothermal reaction is carried out at high temperature and high pressure, so that the gas and liquid raw materials are always in a boiling state, the carbon aerogel is easy to collapse, and the compounding of silicon and the carbon aerogel is not facilitated. In addition, as the graphene has sparse characteristics, the CA/nano silicon composite material cannot be well wrapped, and the risk of direct contact between silicon and electrolyte exists in the charging and discharging process, so that the capacity is consumed, and irreversible damage is caused.
Disclosure of Invention
Aiming at the problems, the invention discloses a preparation method of a conductive carbon aerogel-based composite nano-silicon negative electrode material, which takes waste biomass as a raw material, has low cost, and the prepared negative electrode material has high strength and good conductivity, and the assembled battery has higher first effect.
The specific technical scheme is as follows:
a preparation method of a composite nano-silicon negative electrode material based on conductive carbon aerogel comprises the following steps:
(1) dissolving the pretreated waste biomass and a fiber additive into an aqueous solution of an alkaline substance together, and stirring to obtain a reticular solid gel;
(2) drying the reticular solid gel prepared in the step (1), and screening to obtain a carbon aerogel precursor;
(3) taking a gaseous silicon source and the carbon aerogel precursor prepared in the step (2) as raw materials, and preparing a compound of carbon aerogel and nano-silicon by a chemical vapor deposition process;
(4) and (4) blending the carbon aerogel and nano-silicon composite prepared in the step (3) with a carbon source, and heating and carbonizing to obtain the conductive carbon aerogel based composite nano-silicon negative electrode material.
The preparation process disclosed by the invention has the advantages that the waste biomass is used as the raw material to prepare the carbon aerogel, the preparation process is green and environment-friendly, the mechanical property of the carbon aerogel is further improved by adding the fiber additive, and the premise is provided for the subsequent smooth deposition of nano silicon; directly mixing the prepared carbon aerogel precursor with a gaseous silicon source to synchronously carry out carbonization and silicon deposition, and better matching the carbonization process with the silicon deposition process by controlling the chemical vapor deposition process and specific process parameters to prepare a compound of the carbon aerogel and the nano silicon; and finally, uniformly coating the carbon aerogel and the nano-silicon composite by a carbon layer formed after the carbon source is carbonized through blending with the carbon source and heating, so as to prepare the conductive carbon aerogel-based composite nano-silicon negative electrode material.
In the step (1):
the waste biomass is selected from one or more of waste crab shells, waste shrimp shells, enteromorpha, moso bamboos and waste fallen leaves; preferably waste crab shells.
The compositions of the waste crab shells and the shrimp shells are similar, but tests show that the BET of the prepared intermediate product, namely the carbon aerogel and nano silicon compound, is higher by adopting the preparation process of the application and the waste crab shells as raw materials, and the first efficiency of the finally assembled battery is higher.
The waste biomass needs to be pretreated before use, and the purpose of the pretreatment is to remove wax, pesticide residue and other substances remained on the surface of the waste biomass. Comprises the processes of dipping, alkali washing and drying. The method specifically comprises the following steps:
the waste biomass is washed by deionized water, then dipped in alkali liquor, and then washed by the deionized water and dried.
The alkali liquor is selected from common types in the field, such as sodium hydroxide aqueous solution, potassium hydroxide aqueous solution and the like, and the concentration is 1-5 mol/L.
When the selected waste biomass is waste crab shells or shrimp shells, on the basis of the conventional pretreatment process, preferably adding one step of acid treatment, specifically:
and coarsely crushing the dried raw materials, soaking the crushed raw materials into an acid solution to further remove calcium components in the crab shells, washing the crab shells to be neutral by deionized water, and drying the crab shells. Tests show that the BET of the intermediate product, namely the carbon aerogel and nano-silicon compound, is higher after the acid treatment in the step is added.
The acid solution is common, such as hydrochloric acid aqueous solution, nitric acid aqueous solution, sulfuric acid aqueous solution, and the like. The concentration is 1-2 mol/L.
The pretreated waste biomass and the fiber additive are dissolved in an aqueous solution of an alkaline substance together, a micron-sized unit dispersion liquid is obtained by stirring, and molecules are crosslinked and gelatinized mutually through the actions of chemical bonds, hydrogen bonds, van der waals force and the like to obtain the reticular solid gel.
The carbon aerogel prepared by using the waste biomass as the raw material has the advantage of environmental friendliness, but the prepared carbon aerogel has poor mechanical properties, and the structure of the carbon aerogel collapses due to high temperature in the subsequent silicon deposition process, so that the electrochemical properties of the final product are influenced. According to the invention, the fiber additive is added in the raw material stage to improve the mechanical property of the carbon aerogel, so that a premise is provided for the subsequent smooth deposition of nano silicon; and moreover, the BET of the intermediate product, namely the carbon aerogel and nano silicon compound is greatly improved due to the addition of the nano silicon compound, so that the battery assembled by the finally prepared negative electrode material has more excellent first effect. And the fiber additive is added at the raw material stage, so that the fiber additive can be uniformly distributed in the carbon aerogel, and the overall mechanical property of the final product is better.
The fiber additive is selected from one or more of glass fiber, ceramic fiber, brucite fiber, mullite fiber and carbon nanotube fiber; preferably carbon nanotube fibres.
Preferably, the mass ratio of the waste biomass to the fiber additive is 100: 0.5 to 1.
The alkaline substance is selected from common species, such as one or more of sodium hydroxide, potassium hydroxide, calcium hydroxide, lithium hydroxide, rubidium hydroxide, cesium hydroxide, magnesium hydroxide, urea; the concentration of the aqueous solution of the alkaline substance is 1-2 mol/L.
In the step (2):
the drying treatment is selected from atmospheric drying, freeze drying or CO2Supercritical drying, preferably freeze drying.
After screening, selecting a product with the D50 of 5-30 μm as a carbon aerogel precursor, and finding through experiments that the finally prepared negative electrode material prepared by using the carbon aerogel precursor with the size has more excellent electrical property.
In the step (3):
the chemical vapor deposition process is carried out under inert protective atmosphere, and specifically, a reaction device is firstly vacuumized, and then inert protective gas is introduced. The inert shielding gas is selected from one or more of helium, neon, argon, krypton, xenon and radon, which are conventionally selected in the field.
The silicon source is selected from silane (mainly SiH)4) One or more of dichlorosilane, trichlorosilane and silicon tetrachloride; and vaporizing the silicon source and then introducing the vaporized silicon source into a reaction device, wherein the flow rate of the gaseous silicon source is 20-80L/h.
The deposition amount of the nano-silicon is 10-20% of the total mass of the prepared carbon aerogel and nano-silicon composite; the electrical properties of the finally prepared anode material are better.
Preferably:
the chemical vapor deposition process adopts heating step by step, firstly heating to 400-500 ℃ and preserving heat for 2-6 h, then heating to 600-900 ℃ and preserving heat for 1-2 h.
Tests show that the BET of the anode material prepared by the step heating is far larger than that of the anode material prepared by the step heating. It was found that the reinforcing effect of the fiber additive does not fully exert its effect during the one-step heating process.
In the chemical vapor deposition process, the carbon aerogel precursor is controlled to rotate continuously so as to ensure that nano silicon particles are deposited uniformly. Preferably, the rotating speed of the carbon aerogel precursor is controlled to be 5-10 Hz.
The carbon aerogel and nano-silicon composite prepared in the step also needs to be subjected to post-treatment, including acid washing, deionized water washing, drying and the like.
The acid solution for acid washing is selected from one or more of carbonic acid, metasilicic acid, acetic acid, sulfurous acid and nitrous acid.
In the step (4):
the carbon coating process is a conventional technical means in the field, and the carbon source can be selected from conventional types in the field, such as asphalt with low cost and excellent performance.
The mass ratio of the carbon aerogel and nano silicon compound to the carbon source is 10: 1-3;
the heating and carbonizing temperature is 700-900 ℃ and the heat preservation time is 1-2 h.
Further preferably:
the waste biomass is selected from waste crab shells, and the pretreatment comprises washing, alkali washing, drying and acid treatment;
the fiber additive is selected from carbon nanotube fibers.
The invention also discloses the conductive carbon aerogel-based composite nano silicon negative electrode material prepared by the method.
Compared with the prior art, the invention has the following beneficial effects:
the invention discloses a preparation method of a conductive carbon aerogel-based composite nano silicon negative electrode material, which takes waste biomass as a raw material, improves the mechanical property of carbon aerogel by adding a fiber additive, and simultaneously carries out carbonization of a carbon aerogel precursor and deposition of nano silicon particles, thereby fully utilizing the structure of the carbon aerogel and a large amount of lithium ion channel energy, increasing the insertion position of lithium ions, and relieving volume expansion and contraction caused by the release and insertion of lithium by silicon so as to improve the excellent performance of the lithium battery negative electrode material.
Drawings
FIG. 1 is an SEM photograph of the intermediate product of example 1, a composite of carbon aerogel and nano-silicon, at different magnifications;
fig. 2 is a graph showing electrical properties of batteries assembled with the negative electrode materials respectively prepared in examples 1 to 5 and comparative example 1.
Detailed Description
The present invention is described in detail below with reference to specific embodiments, but the scope of the present invention is not limited to the following examples.
Example 1
(1) Washing waste crab shells with deionized water, soaking in 2mol/L NaOH for 2 hours, removing wax and pesticide residues on the surfaces, washing with deionized water, drying, performing coarse crushing, soaking in 1mol/L hydrochloric acid solution for 30 minutes, stirring at a rotating speed of 100r/min, removing calcium components in the crab shells, washing with deionized water to be neutral, drying, and selecting crab shell powder with D50 of 13-15 mu m as a raw material for the next step;
(2) dissolving the pretreated crab shell powder in 4mol/L NaOH aqueous solution, adding 1 wt% of carbon nanotube fiber (calculated by the mass of the pretreated waste biomass being 100%, the same applies below), and stirring to obtain a reticular solid gel;
(3) freeze-drying the reticular solid gel at-60 ℃, screening after drying, and selecting a product with the D50 being 8-9 mu m as a carbon aerogel precursor;
(4) placing a carbon aerogel precursor in a chemical vapor deposition furnace, pumping to a vacuum state, filling inert protective gas at a rate of 60L/h, heating to 500 ℃ at a rate of 5 ℃/min, heating to a set temperature, filling silicon source gas at a rate of 60L/h, carrying out procedure heat preservation for 4h, closing a silicon source gas pipeline, heating to 800 ℃ again for carbonization treatment, cooling to normal temperature after heat preservation for 1h, taking out, carrying out acid pickling by using 1mol/L hydrofluoric acid, repeatedly washing to be neutral by using deionized water, and drying to obtain the compound of the carbon aerogel and the nano silicon.
(5) Placing the carbon aerogel and nano-silicon composite in a mixer to mix with asphalt, mixing at normal temperature and 200r/min for 120min, taking out, placing in a tank type atmosphere furnace filled with inert gas, heating to 800 ℃ at 10 ℃/min, keeping for 8h, performing asphalt carbonization coating treatment, entering a program to automatically cool after heat preservation is finished, cooling to normal temperature, and taking out to obtain the conductive carbon aerogel based composite nano-silicon negative electrode material.
Example 2
The preparation process was the same as in example 1 except that the carbon nanotube fiber added in step (2) was replaced with a ceramic fiber.
Example 3
The preparation process was the same as in example 1 except that the carbon nanotube fiber added in step (2) was replaced with a glass fiber.
Example 4
(1) Washing the waste crab shells with deionized water, soaking in 2mol/L NaOH for 2h, removing wax and pesticide residues on the surfaces, washing with deionized water, drying, crushing, and selecting crab shell powder with D50 of 13-15 mu m as a raw material for the next step;
steps (2) to (5) were exactly the same as in example 1.
Example 5
The preparation process is the same as that of example 1, except that in step (4), the temperature is raised to 600 ℃ at the rate of 5 ℃/min, and then is maintained for 4h, and then is raised to 800 ℃.
Example 6
(1) Washing waste shrimp shells with deionized water, soaking in 2mol/L NaOH for 2h, removing wax and pesticide residue on the surface, washing with deionized water, and oven dryingRear endCoarsePulverizingAfter coarse grinding, 1mol/L hydrochloric acid solution is usedSoaking for 30min, stirring at the rotating speed of 100r/min, removing calcium components in the shrimp shells, washing with deionized water to be neutral, drying, and selecting shrimp shell powder with the D50 of 13-15 mu m as a raw material for the next step;
(2) dissolving the pretreated shrimp shell powder in 4mol/L NaOH aqueous solution, adding 1 wt% of carbon nanotube fiber, and stirring to obtain a reticular solid gel;
(3) freeze-drying the reticular solid gel at-60 ℃, screening after drying, and selecting a product with the D50 being 8-9 mu m as a carbon aerogel precursor;
(4) placing a carbon aerogel precursor in a chemical vapor deposition furnace, pumping to a vacuum state, filling inert protective gas at a rate of 60L/h, heating to 500 ℃ at a rate of 5 ℃/min, heating to a set temperature, filling silicon source gas at a rate of 60L/h, carrying out procedure heat preservation for 4h, closing a silicon source gas pipeline, heating to 800 ℃ again for carbonization treatment, cooling to normal temperature, taking out, carrying out acid pickling by using 2mol/L hydrofluoric acid, repeatedly washing to neutrality by using deionized water, and drying to obtain a carbon aerogel and nano silicon composite.
(5) Placing the carbon aerogel and nano-silicon composite in a mixer to mix with asphalt, mixing at normal temperature and 200r/min for 120min, taking out, placing in a tank type atmosphere furnace filled with inert gas, heating to 800 ℃ at 10 ℃/min, keeping for 8h, performing asphalt carbonization coating treatment, entering a program to automatically cool after heat preservation is finished, cooling to normal temperature, and taking out to obtain the conductive carbon aerogel based composite nano-silicon negative electrode material.
Example 7
Steps (1) to (3) were exactly the same as in example 1.
(4) Placing a carbon aerogel precursor in a chemical vapor deposition furnace, pumping to a vacuum state, filling inert protective gas at a rate of 60L/h, heating to 800 ℃ at a rate of 5 ℃/min, heating to a set temperature, filling silicon source gas at a rate of 60L/h, carrying out procedure heat preservation for 5h, closing a silicon source gas pipeline, entering an automatic cooling procedure, taking out after cooling to normal temperature, carrying out acid cleaning by using 1mol/L hydrofluoric acid, repeatedly washing to be neutral by using deionized water, and drying to obtain a compound of carbon aerogel and nano silicon.
(5) Placing the carbon aerogel and nano-silicon composite in a mixer to mix with asphalt, mixing at normal temperature and 200r/min for 120min, taking out, placing in a tank type atmosphere furnace filled with inert gas, heating to 800 ℃ at 10 ℃/min, keeping for 8h, performing asphalt carbonization coating treatment, entering a program to automatically cool after heat preservation is finished, cooling to normal temperature, and taking out to obtain the conductive carbon aerogel based composite nano-silicon negative electrode material.
Comparative example 1
The preparation process is identical to that of example 1, except that no carbon nanotube fiber is added in step (2).
Application example
All the pole pieces are prepared by adopting carbon black (SP) as a conductive agent and sodium carboxymethyl cellulose (CMC) as a binder, and the mass ratio of the conductive agent to the active material synthesized in each embodiment or comparative example is 1: 1: 8, mixing and dissolving the mixture in deionized water and alcohol (the volume ratio of the deionized water to the alcohol is 1: 5), and magnetically stirring for more than 8 hours to prepare the uniformly dispersed battery slurry for later use. And (3) uniformly coating the battery slurry on the surface of an electrode (the cut foam copper or copper foil), carrying out vacuum drying at 85 ℃ for 12h, tabletting and weighing for later use. The electrochemical performance of the electrodes was tested by assembling a button-type half cell (CR2025) using a glove box (model Mbraun) from Labstar, Germany. The button half cell assembly completely adopts a lithium sheet as a counter electrode, a foam nickel sheet as a buffer gasket, and the water oxygen content of the manufacturing environment is respectively as follows: water concentration<2ppm, oxygen concentration<2 ppm. The adopted electrolyte component is 1M LiPF6Dissolved in an EC and DMC organic solvent (EC to DMC volume ratio of 1: 1). The battery cycle formation is tested on a Xinwei device, wherein the test conditions of the first discharge specific capacity and the first coulombic efficiency are as follows: the charge-discharge multiplying power is 0.1C, and the voltage range is 0.005V-1.5V.
The BET values of the carbon aerogel and nano-silicon composites respectively prepared in examples 1 to 7 and comparative example 1, the young's modulus and conductivity values of the finally prepared negative electrode material, and the first effect data of the battery assembled with the negative electrode material are shown in table 1 below.
TABLE 1
Figure BDA0002842974410000101
Figure BDA0002842974410000111
By comparing the example 1 with the comparative example 1 and the examples 2-3, it can be found that in the preparation process of the invention, the BET value of the intermediate product, namely the composite of the carbon aerogel and the nano silicon, can be remarkably improved by adding the fiber additive, and the Young modulus and the conductivity of the finally prepared negative electrode material, so that the first efficiency of the finally assembled battery is also remarkably improved; when different fiber additives are adopted for reinforcement, the BET value of the prepared carbon aerogel and nano silicon compound is not greatly influenced, but when the carbon nano tube fiber is adopted, the battery assembled by the finally prepared cathode material has higher first effect, and particularly the conductivity advantage is more obvious.
By comparing example 1 with example 4, it can be found that the carbon aerogel and nano-silicon composite prepared by acid pretreatment has a higher specific surface area, and the first effect and the conductivity are both significantly improved.
It can be found by comparing example 1, example 5 and example 7 that the specific surface area and first effect of the prepared composite of carbon aerogel and nano silicon can be significantly improved when stepwise heating is adopted in the chemical vapor deposition process; however, if the time range of the stepwise heating is not properly selected, the improvement of the first effect is limited, and the analysis of the first effect may be caused by the fact that the first effect is reduced due to the fact that the high-temperature deposited silicon content is high and the free silicon content is increased. By comparing example 1 with example 6, it can be found that the battery assembled by the negative electrode material finally prepared by using the waste crab shell material as the raw material has higher first efficiency and is superior to the shrimp shell material.
The invention is well implemented in accordance with the above-described embodiments. It should be noted that, based on the above design, even if some insubstantial modifications or colorings are made on the present invention to solve the same technical problems, the adopted technical solution is still the same as the present invention, and therefore, the technical solution should be within the protection scope of the present invention.

Claims (10)

1. A preparation method of a composite nano-silicon negative electrode material based on conductive carbon aerogel is characterized by comprising the following steps:
(1) dissolving the pretreated waste biomass and a fiber additive into an aqueous solution of an alkaline substance together, and stirring to obtain a reticular solid gel;
the fiber additive is selected from one or more of glass fiber, ceramic fiber, brucite fiber, mullite fiber and carbon nanotube fiber;
(2) drying the reticular solid gel prepared in the step (1), and screening to obtain a carbon aerogel precursor;
(3) taking a gaseous silicon source and the carbon aerogel precursor prepared in the step (2) as raw materials, and preparing a compound of carbon aerogel and nano-silicon by a chemical vapor deposition process;
(4) and (4) blending the carbon aerogel and nano-silicon composite prepared in the step (3) with a carbon source, and heating and carbonizing to obtain the conductive carbon aerogel based composite nano-silicon negative electrode material.
2. The preparation method of the conductive carbon aerogel composite nano-silicon negative electrode material based on claim 1, wherein in the step (1):
the waste biomass is selected from one or more of waste crab shells, waste shrimp shells, enteromorpha, moso bamboos and waste fallen leaves;
the alkaline substance is selected from one or more of sodium hydroxide, potassium hydroxide, calcium hydroxide, lithium hydroxide, rubidium hydroxide, cesium hydroxide, magnesium hydroxide and urea.
3. The preparation method of the conductive carbon aerogel composite nano-silicon negative electrode material based on claim 1, wherein in the step (1):
the mass ratio of the pretreated waste biomass to the fiber additive is 100: 0.5 to 1;
the concentration of the aqueous solution of the alkaline substance is 1-2 mol/L.
4. The preparation method of the conductive carbon aerogel composite nano-silicon negative electrode material based on claim 1, wherein in the step (1):
the pretreatment comprises dipping, alkali washing and drying.
5. The preparation method of the conductive carbon aerogel composite nano-silicon negative electrode material based on claim 1, wherein in the step (2):
the drying treatment is selected from atmospheric drying, freeze drying or CO2Supercritical drying;
and selecting a product with D50= 5-30 μm as a carbon aerogel precursor after screening.
6. The preparation method of the conductive carbon aerogel composite nano-silicon negative electrode material based on claim 1, wherein in the step (3):
the silicon source is selected from one or more of silane, dichlorosilane, trichlorosilane and silicon tetrachloride;
the deposition amount of the nano-silicon is 10-20% of the total mass of the prepared carbon aerogel and nano-silicon composite;
the chemical vapor deposition process adopts heating step by step, firstly heating to 400-500 ℃ and preserving heat for 2-6 h, then heating to 600-900 ℃ and preserving heat for 1-2 h.
7. The preparation method of the conductive carbon aerogel composite nano-silicon negative electrode material based on claim 1, wherein in the step (4):
the carbon source is selected from pitch;
the mass ratio of the carbon aerogel and nano silicon compound to the carbon source is 10: 1-3;
the heating and carbonizing temperature is 700-900 ℃ and the heat preservation time is 1-2 h.
8. The preparation method of the conductive carbon aerogel composite nano-silicon-based negative electrode material as claimed in any one of claims 1 to 7, wherein the preparation method comprises the following steps:
the waste biomass is selected from waste crab shells;
the fiber additive is selected from carbon nanotube fibers.
9. The preparation method of the conductive carbon aerogel composite nano-silicon-based negative electrode material as claimed in claim 8, wherein the preparation method comprises the following steps:
the pretreatment of the waste biomass further comprises an acid treatment after the drying treatment.
10. The conductive carbon aerogel composite nano-silicon-based negative electrode material prepared by the method according to any one of claims 1 to 9.
CN202011498724.5A 2020-12-17 2020-12-17 Preparation method of composite nano-silicon negative electrode material based on conductive carbon aerogel and product thereof Active CN112635731B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202011498724.5A CN112635731B (en) 2020-12-17 2020-12-17 Preparation method of composite nano-silicon negative electrode material based on conductive carbon aerogel and product thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202011498724.5A CN112635731B (en) 2020-12-17 2020-12-17 Preparation method of composite nano-silicon negative electrode material based on conductive carbon aerogel and product thereof

Publications (2)

Publication Number Publication Date
CN112635731A CN112635731A (en) 2021-04-09
CN112635731B true CN112635731B (en) 2021-11-02

Family

ID=75316534

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202011498724.5A Active CN112635731B (en) 2020-12-17 2020-12-17 Preparation method of composite nano-silicon negative electrode material based on conductive carbon aerogel and product thereof

Country Status (1)

Country Link
CN (1) CN112635731B (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114447313B (en) * 2022-01-28 2024-01-16 江苏集芯半导体硅材料研究院有限公司 Preparation method and production device of silicon-based anode material
CN117577818B (en) * 2024-01-15 2024-03-29 中国第一汽车股份有限公司 Silicon-carbon composite aerogel and preparation method and application thereof

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101821813A (en) * 2007-10-04 2010-09-01 劳伦斯·利弗莫尔国家安全有限责任公司 The solid hollow core fuel that is used for fusion-fission engine
CN102781570A (en) * 2010-02-26 2012-11-14 摩根先进材料与技术公司 Carbon-based containment system
CN107565115A (en) * 2017-08-30 2018-01-09 北方奥钛纳米技术有限公司 Preparation method, silicon-carbon cathode material and the lithium ion battery of silicon-carbon cathode material

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6524707B1 (en) * 1999-07-09 2003-02-25 Powerstor Corporation Carbon-bonded metal structures and methods of fabrication
KR101458846B1 (en) * 2004-11-09 2014-11-07 더 보드 오브 리전츠 오브 더 유니버시티 오브 텍사스 시스템 The fabrication and application of nanofiber ribbons and sheets and twisted and non-twisted nanofiber yarns
CN103515582A (en) * 2013-10-10 2014-01-15 中国海洋石油总公司 Preparation method of lithium ion battery silicon-carbon composite cathode material
KR101576276B1 (en) * 2014-04-09 2015-12-09 국립대학법인 울산과학기술대학교 산학협력단 Negative electrode active material, methode for synthesis the same, and lithium rechargable battery including the same
CN110268553B (en) * 2016-12-20 2023-09-12 纳米技术仪器公司 Flexible and conformal cable-type alkali metal cell
CN206843332U (en) * 2017-02-22 2018-01-05 南京航空航天大学 A kind of netted hollow foam enhancing charcoal-aero gel high temperature insulating core
CN108654579B (en) * 2018-05-17 2020-02-21 江苏大学 Preparation method of sodium alginate/typha orientalis/graphene oxide composite aerogel
CN110846741B (en) * 2019-10-09 2020-10-23 清华大学 Flexible mullite fiber aerogel material and preparation method thereof

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101821813A (en) * 2007-10-04 2010-09-01 劳伦斯·利弗莫尔国家安全有限责任公司 The solid hollow core fuel that is used for fusion-fission engine
CN102781570A (en) * 2010-02-26 2012-11-14 摩根先进材料与技术公司 Carbon-based containment system
CN107565115A (en) * 2017-08-30 2018-01-09 北方奥钛纳米技术有限公司 Preparation method, silicon-carbon cathode material and the lithium ion battery of silicon-carbon cathode material

Also Published As

Publication number Publication date
CN112635731A (en) 2021-04-09

Similar Documents

Publication Publication Date Title
US11929484B2 (en) Compound, preparation method therefore, and use in lithium ion secondary battery
CN107507972B (en) Preparation method of silicon-carbon negative electrode material, silicon-carbon negative electrode material and lithium ion battery
CN114142011B (en) Hard carbon composite material and preparation method and application thereof
Guo et al. Lithiophilic Co/Co 4 N nanoparticles embedded in hollow N-doped carbon nanocubes stabilizing lithium metal anodes for Li–air batteries
CN107959006B (en) Lignin-based hard carbon/carbon nanotube composite material, preparation method thereof and application thereof in lithium ion battery cathode material
CN103730645B (en) Coated carbon fiber nanometer composite material of a kind of silicon and its preparation method and application
CN111180691A (en) Double-layer carbon-coated silicon-based composite material and preparation method and application thereof
CN112635731B (en) Preparation method of composite nano-silicon negative electrode material based on conductive carbon aerogel and product thereof
CN112794324B (en) High-mesoporosity lignin hierarchical pore carbon material and preparation method and application thereof
CN112768688B (en) Lithium iron phosphate material, preparation method thereof and lithium ion battery
CN108682830B (en) Silicon-carbon composite negative electrode material of lithium ion battery and preparation method thereof
CN114122372A (en) Low-expansion silicon-carbon negative electrode material for lithium ion battery and preparation method thereof
Liu et al. Porous nitrogen-doped carbon derived from peanut shell as anode material for lithium ion battery
CN114583093A (en) Preparation method and application of high-energy-density hard carbon composite negative electrode material
CN116803899A (en) Biomass-derived hard carbon material, preparation method thereof, sodium ion battery negative electrode plate and sodium ion battery
CN111370656B (en) Silicon-carbon composite material and preparation method and application thereof
CN116544386A (en) Starch-based hard carbon sodium ion battery negative electrode material, and preparation method and application thereof
CN111816879B (en) Lithium ion battery cathode binder, slurry and cathode material thereof
TWI434453B (en) Modification of artificial graphite as a lithium battery anode material preparation method
CN113054179B (en) Double-particle-size asphalt multi-coating shaping graphite silicon carbon negative electrode material and preparation method and application thereof
Song et al. Biomass‐Derived Hierarchically Porous (Nitrogen, Phosphorus) Co‐Doped SiOx/C Composite Nanosheet Architectures for Superior Lithium Storage and Ultra‐Long Cycle Performance
CN110690423B (en) Heteroatom doped carbon material and preparation method and application thereof
CN107658457B (en) SiO for fused salt electrolysis2-Gc/C composite electrode and preparation method thereof
CN114914408A (en) Silicon-carbon composite material and preparation method and application thereof
CN111785963A (en) High-carbon-residue-rate negative electrode material precursor and preparation method and application thereof

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant
TR01 Transfer of patent right

Effective date of registration: 20220411

Address after: 675000 new material industrial park, Yingxin Road, Xiangjiaba Town, Shuifu City, Zhaotong City, Yunnan Province

Patentee after: Yunnan lichen New Material Technology Co.,Ltd.

Address before: Room 236, building 12, National University Science Park, no.669 high speed railway, Changxing Economic and Technological Development Zone, Huzhou City, Zhejiang Province, 313100

Patentee before: Zhejiang lichen New Material Technology Co.,Ltd.

TR01 Transfer of patent right