CN113659117A - Preparation method of carbon-doped sandwich-structure lithium ion battery cathode material - Google Patents

Preparation method of carbon-doped sandwich-structure lithium ion battery cathode material Download PDF

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CN113659117A
CN113659117A CN202110857034.2A CN202110857034A CN113659117A CN 113659117 A CN113659117 A CN 113659117A CN 202110857034 A CN202110857034 A CN 202110857034A CN 113659117 A CN113659117 A CN 113659117A
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carbon
lithium ion
doped
ion battery
cathode material
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吕晓欣
邓子啸
邓久军
王梦莲
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Jiangsu University
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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
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y40/00—Manufacture or treatment of nanostructures
    • 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
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/483—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides for non-aqueous cells
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
    • H01M4/523—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron for non-aqueous cells
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/624—Electric conductive fillers
    • H01M4/625—Carbon or graphite
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M2004/021—Physical characteristics, e.g. porosity, surface area
    • 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
    • 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 lithium ion battery cathode material, and particularly relates to a carbon-doped sandwich structure nano TiO2@Fe2O3A preparation method of a lithium ion battery cathode material. Aiming at the existing TiO2The negative electrode material has the defects of low specific capacity and low conductivity, and the invention uses Ti3C2And ferrocene as a precursor, and preparing the carbon-doped sandwich structure nano TiO by one-step annealing treatment2@Fe2O3The compound has the advantages of simple synthesis process, low cost and large-scale production. The carbon-doped sandwich-structure nano TiO prepared by the method2@Fe2O3The particles are uniform and have good electrochemical performance.

Description

Preparation method of carbon-doped sandwich-structure lithium ion battery cathode material
Technical Field
The invention provides a lithium ionA preparation method of a battery cathode material, in particular to a carbon-doped sandwich structure nano TiO2@Fe2O3A preparation method of a lithium ion battery cathode material.
Background
Lithium ion batteries have been widely used in portable electronic devices due to their high energy density, long cycle life, low self-discharge rate, no memory effect, and the like.
The cathode material is used as an important component of the lithium ion battery, and the structure and the composition of the cathode material greatly influence the electrochemical performance of the lithium ion battery. The traditional commercialized negative electrode material is graphitized carbon, and the lower theoretical specific capacity (372mAh/g) of the graphitized carbon cannot meet the requirements of new-generation mobile devices and power batteries. TiO 22Due to its low cost, environmental friendliness, etc., it is considered to be one of the most potential negative electrode materials that can replace graphite, and therefore has received increasing attention. And the characteristic of small volume change in the charge-discharge process of the TiO compound enables the TiO compound to be small in volume change2The lithium ion battery has excellent structural stability and better cycling stability in the processes of lithium ion intercalation and deintercalation. However, TiO2The lower theoretical specific capacity and poor conductivity limit its application in lithium ion batteries. There are two common solutions at present, one is to increase the specific capacity of a metal oxide with a higher theoretical specific capacity by forming a composite material with the metal oxide; and the other is that the conductivity of the lithium-ion battery can be improved by doping C, N, Fe and other exogenous atoms, so that the lithium-ion storage performance of the lithium-ion battery is improved.
Most of the existing carbon doping methods need an external carbon source and are realized by sol-gel, hydrothermal and other methods, the preparation process is complex, and the equipment cost and the production cost are too high. MXene is a novel two-dimensional transition metal carbide or nitride, and the high conductivity and the unique structure of MXene enable the MXene to be widely applied to the field of electrochemistry. Among various MXene materials, Ti has abundant surface properties and excellent structural stability3C2Have received increasing attention. Ti3C2Can be oxidized into TiO under certain conditions2And in the formation of TiO2In the process, Ti3C2C in (3) can be doped into TiO as a suitable dopant2Increasing the TiO content2The conductivity is realized, and no additional carbon dopant is added. The invention is to directly oxidize multi-layer Ti3C2Powder, without additional carbon source, to obtain carbon-doped layered TiO2。
At the same time, Fe2O3The lithium ion battery has the characteristics of high theoretical specific capacity (1005mAh/g), environmental friendliness, low cost and the like, but the electrode material is pulverized and falls off due to severe volume expansion in the circulation process, the capacity is rapidly attenuated, and the application of the lithium ion battery in the lithium ion battery is hindered. To react it with TiO2Compounding, not only can improve the specific capacity of the compound, but also can relieve Fe to a certain extent2O3The volume changes. The traditional compound generally needs more complex synthetic steps, and the preparation process is complex and not easy to obtain.
The invention uses Ti3C2And ferrocene as a precursor, and preparing the carbon-doped sandwich structure nano TiO by a one-step method2@Fe2O3And (c) a complex. The preparation method is simple and easy to operate, and the prepared compound has a sandwich structure with the advantages of large specific surface area and high reaction activity, and is convenient for migration of lithium ions and electrons. Carbon doped layered TiO in composites2The zero-strain characteristic can provide excellent stability for the compound and relieve Fe to a certain extent2O3Volume expansion during cycling. Fe in the composite2O3The nano particles can provide high specific capacity for the compound, and finally the capacity and the stability of the compound are improved.
Disclosure of Invention
The invention aims to provide carbon-doped sandwich-structured nano TiO with simple process, low production cost and convenient large-scale application2@Fe2O3A preparation method of a lithium ion battery cathode material.
In order to achieve the aim of the invention, the method specifically comprises the following steps:
the first step is as follows: weighing ferrocene andmultilayer Ti3C2(Mxene) powder, put into mortar, grind;
the second step is that: placing the ground mixture into a porcelain boat, tightly wrapping the porcelain boat by using an aluminum foil, then placing the whole porcelain boat into a tube furnace, and carrying out annealing treatment for a certain time to obtain the carbon-doped nano TiO with the sandwich structure2@Fe2O3A material;
further, the above-mentioned preparation method, in the first step, ferrocene and multi-layered Ti3C2The mass ratio of the powder is 1: 5-6: 1.
In the second step of the preparation method, the annealing temperature is 300-500 ℃, and the annealing time is 1-3 hours.
Aiming at the existing TiO2The negative electrode material has the defects of low specific capacity and low conductivity, and the invention uses Ti3C2And ferrocene as a precursor, and preparing the carbon-doped sandwich structure nano TiO by one-step annealing treatment2@Fe2O3The compound has the advantages of simple synthesis process, low cost and large-scale production. The carbon-doped sandwich-structure nano TiO prepared by the method2@Fe2O3The particles are uniform and have good electrochemical performance.
Drawings
FIG. 1 shows the preparation of carbon-doped nano TiO with sandwich structure by the method of the present invention2@Fe2O3Reaction scheme of lithium battery negative electrode material.
FIG. 2(a) is a scanning electron micrograph of the product prepared in example 1 of the process of the present invention.
FIG. 2(b) is a graph of the circulating capacity of the product obtained in example 1 of the process of the invention.
FIG. 3(a) is a scanning electron micrograph of the product prepared in example 2 of the present invention.
FIG. 3(b) is a graph of the circulating capacity of the product obtained in example 2 of the process of the present invention.
FIG. 4(a) is a scanning electron micrograph of the product prepared in example 3 of the process of the present invention.
FIG. 4(b) is a graph of the circulating capacity of the product obtained in example 3 of the process of the present invention.
Detailed Description
In order to better understand the present invention, the following examples are further provided to illustrate the present invention, but not to limit the present invention.
Example 1
(1) Weighing a certain amount of ferrocene powder and Ti with the mass ratio of 1:53C2Putting the powder into an agate mortar, and uniformly grinding;
(2) placing the ground mixture in a porcelain boat, tightly wrapping the porcelain boat with aluminum foil, placing the porcelain boat in a tube furnace, and annealing at 450 ℃ for 2 hours to obtain the carbon-doped sandwich structure nano TiO2@Fe2O3The negative electrode material (FIG. 2(a)) was obtained by doping TiO with carbon2Well maintain Ti3C2Of a layered structure of, and Fe2O3The particles are uniformly dispersed in the layered TiO2And the surface to form a sandwich structure;
(3) respectively weighing carbon-doped sandwich structure nano TiO according to the mass ratio of 70:20:102@Fe2O3The composite, conductive carbon black and polyvinylidene fluoride (PVDF) are put in an agate mortar, solvent N-methyl pyrrolidone (NMP) is added and evenly ground. The obtained slurry was coated on the surface of a clean copper foil, and dried in a vacuum drying oven for 12 hours. Cutting the dried copper foil into a circular sheet with the diameter of 12mm by a manual slicer to be used as an electrode pole piece, taking metal lithium as a counter electrode and 1mol/L LiPF6and/DMC + DEC + EC (the volume ratio of DMC, DEC and EC is 1:1:1) is used as electrolyte, and Celgard 2325 is used as a diaphragm to form the button test cell. The battery is subjected to constant-current charge and discharge tests, the charge and discharge voltage range is 0.01-3.0V, and the result shows that the battery has better electrochemical performance, when the test current density is 1000mA/g, the first discharge specific capacity is 225.6mAh/g, and the discharge specific capacity after 400 cycles is 136mAh/g (fig. 2 (b)).
Example 2
(1) Weighing a certain amount of ferrocene powder and Ti with the mass ratio of 4:13C2Placing the powder in an agate mortarAnd grinding uniformly;
(2) placing the ground ferrocene into a porcelain boat, tightly wrapping the porcelain boat by using aluminum foil, placing the porcelain boat into a tube furnace, and annealing at 450 ℃ for 2 hours to obtain carbon-doped sandwich structure nano TiO2@Fe2O3The negative electrode material (FIG. 3(a)) was obtained by the present example, and the carbon-doped TiO was observed in the drawing2Also well maintain Ti3C2Of a layered structure of, Fe2O3The particle size and the density are increased to a certain degree, and the particles are uniformly dispersed in the layered TiO2And the surface, a very obvious sandwich structure is formed;
(3) respectively weighing sandwich structure nano TiO according to the mass ratio of 70:20:102@Fe2O3The composite, conductive carbon black and polyvinylidene fluoride (PVDF) are put in an agate mortar, solvent N-methyl pyrrolidone (NMP) is added and evenly ground. The obtained slurry was coated on the surface of a clean copper foil, and dried in a vacuum drying oven for 12 hours. Cutting the dried copper foil into a circular sheet with the diameter of 12mm by a manual slicer to be used as an electrode pole piece, taking metal lithium as a counter electrode and 1mol/L LiPF6and/DMC + DEC + EC (the volume ratio of DMC, DEC and EC is 1:1:1) is used as electrolyte, and Celgard 2325 is used as a diaphragm to form the button test cell. When the current density is 1000mA/g, the discharge specific capacity after 900 cycles is 403.3mAh/g, and the capacity retention rate is up to 92% (fig. 3 (b)). The better capacity retention rate is attributed to the ferrocene and Ti in the precursor3C2The mass ratio of the powder is proper. And ferrocene and Ti3C2An excessively small mass proportion of powder results in Fe in the resulting composite2O3The occupied proportion is too small, so that the specific capacity of the composite negative electrode is not obviously improved; and ferrocene and Ti3C2An excessive powder mass ratio will result in Fe in the resulting composite2O3The nano particles are agglomerated and grow up, and further the negative cycle stability of the compound is reduced. Thus, ferrocene and Ti are suitable3C2Mass ratio of powderFor example, the effect on the electrochemical performance of the battery is particularly important.
Example 3
(1) Weighing a certain amount of ferrocene powder and Ti with the mass ratio of 6:13C2Putting the powder into an agate mortar, and uniformly grinding;
(2) placing the ground ferrocene into a porcelain boat, tightly wrapping the porcelain boat by using aluminum foil, placing the porcelain boat into a tube furnace, and annealing at 450 ℃ for 2 hours to obtain carbon-doped sandwich structure nano TiO2@Fe2O3The negative electrode material (FIG. 4(a)) was obtained by the present example, and the carbon-doped TiO was observed in the drawing2Also well maintain Ti3C2Of a layered structure of, Fe2O3The particle size and density are increased and are uniformly dispersed in the layered TiO2And the surface to form a very obvious sandwich structure;
(3) respectively weighing sandwich structure nano TiO according to the mass ratio of 70:20:102@Fe2O3The composite, conductive carbon black and polyvinylidene fluoride (PVDF) are put in an agate mortar, solvent N-methyl pyrrolidone (NMP) is added and evenly ground. The obtained slurry was coated on the surface of a clean copper foil, and dried in a vacuum drying oven for 12 hours. Cutting the dried copper foil into a circular sheet with the diameter of 12mm by a manual slicer to be used as an electrode pole piece, taking metal lithium as a counter electrode and 1mol/L LiPF6and/DMC + DEC + EC (the volume ratio of DMC, DEC and EC is 1:1:1) is used as electrolyte, and Celgard 2325 is used as a diaphragm to form the button test cell. The battery is subjected to constant-current charge and discharge tests, the charge and discharge voltage range is 0.01-3.0V, and the result shows that the battery has better electrochemical performance, when the test current density is 1000mA/g, the first discharge specific capacity is 422.3mAh/g, and the discharge specific capacity after 900 cycles is 270.3mAh/g (fig. 4 (b)).

Claims (4)

1. A preparation method of a carbon-doped sandwich structure lithium ion battery cathode material is characterized by comprising the following specific steps:
the first step is as follows: weighing ferrocene and multilayer Ti3C2Placing the powder into a mortar, and grindingGrinding uniformly;
the second step is that: placing the ground mixture into a porcelain boat, tightly wrapping the porcelain boat by using an aluminum foil, then placing the whole porcelain boat into a tube furnace, and carrying out annealing treatment for a certain time to obtain the carbon-doped nano TiO with the sandwich structure2@Fe2O3A material.
2. The method for preparing the carbon-doped sandwich-structure lithium ion battery cathode material of claim 1, wherein in the first step, ferrocene and multiple layers of Ti are added3C2The mass ratio of the powder is 1: 5-6: 1.
3. The method for preparing the carbon-doped sandwich-structure lithium ion battery cathode material of claim 2, wherein in the first step, ferrocene and multiple layers of Ti are added3C2The mass ratio of the powders was 4: 1.
4. The method for preparing the carbon-doped sandwich structure lithium ion battery cathode material of claim 1, wherein in the second step, the annealing temperature is 300-500 ℃ and the annealing time is 1-3 hours.
CN202110857034.2A 2021-07-28 2021-07-28 Preparation method of carbon-doped sandwich-structure lithium ion battery cathode material Pending CN113659117A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116162373A (en) * 2022-11-01 2023-05-26 开滦（集团）有限责任公司 Polyformaldehyde coating based on ferrocenyl polymer coated MXene composite material, and preparation method and application thereof

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116162373A (en) * 2022-11-01 2023-05-26 开滦（集团）有限责任公司 Polyformaldehyde coating based on ferrocenyl polymer coated MXene composite material, and preparation method and application thereof
CN116162373B (en) * 2022-11-01 2023-11-10 开滦（集团）有限责任公司 Polyformaldehyde coating based on ferrocenyl polymer coated MXene composite material, and preparation method and application thereof

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