CN114220956A - Si @ MnO @ C composite material, preparation method thereof, negative electrode material and battery - Google Patents
Si @ MnO @ C composite material, preparation method thereof, negative electrode material and battery Download PDFInfo
- Publication number
- CN114220956A CN114220956A CN202111477206.XA CN202111477206A CN114220956A CN 114220956 A CN114220956 A CN 114220956A CN 202111477206 A CN202111477206 A CN 202111477206A CN 114220956 A CN114220956 A CN 114220956A
- Authority
- CN
- China
- Prior art keywords
- mno
- composite
- solution
- powder
- nano silicon
- 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.)
- Granted
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
- H01M4/366—Composites as layered products
-
- 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
-
- 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
- H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
- H01M4/386—Silicon or alloys based on silicon
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
- H01M4/50—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
-
- 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
-
- 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 relates to a Si @ MnO @ C composite material and a preparation method thereof, a negative electrode material and a battery, wherein the preparation method of the material comprises the following steps: 1) ultrasonically dispersing ammonium persulfate and nano silicon powder in a solvent to obtain a solution A; 2) mixing the solution A with manganese sulfate, heating for reaction, cooling, filtering, washing and drying to obtain MnO2-Si composite powder; 3) by in situ polymerization of MnO2Coating the-Si composite powder with phenolic resin; 4) MnO coated with phenolic resin under protection of inert gas2And pyrolyzing the-Si composite powder to obtain the material. The material is used for a lithium ion battery, and shows excellent specific capacity and rate capability, for example, the specific discharge capacity at 0.1A/g reaches 1025mAh/g, the specific discharge capacity at 1A/g reaches 712mAh/g, the specific capacity after 1A/g is cycled for 1000 times is 697mAh/g, and the excellent cycling stability is shown.
Description
Technical Field
The invention relates to the technical field of lithium ion battery electrode materials, in particular to a Si @ MnO @ C composite material and a preparation method thereof, a negative electrode material and a battery.
Background
Transition metal oxides, e.g. MnO, MoO2，SnO2CoO and the like, which are used as the negative electrode material of the conversion type lithium ion battery, have the advantages of high specific capacity, rich raw materials, low price and the like, and attract the wide attention of researchers. However, such negative electrode materials generally have poor conductivity and undergo a conversion reaction with lithium to cause a large volume expansion, resulting in poor cycle stability. In addition, the voltage of the redox reaction between the cathode material and lithium is generally high, and the polarization is large, which is not favorable for forming a wide working voltage of the full battery.
Silicon is another lithium ion battery cathode material with a good application prospect, and has the advantages of low lithium intercalation platform, high theoretical lithium storage capacity (4200mAh/g), abundant reserves, low price and the like. However, the semiconducting properties of silicon and its volume expansion of up to 300% after lithium insertion also make the cycling stability and rate capability of silicon anodes extremely poor and must be modified before use.
In the prior art, a mechanical ball milling method is adopted to mix nano silicon powder with a graphite cathode and then coat a layer of carbon, which is a common strategy for preparing practical silicon-based cathode materials. However, the volume expansion problem of the nano silicon still exists, so the mass addition amount of the nano silicon is generally less than 10%, and the specific capacity of the composite negative electrode cannot be effectively improved. Compounding nano-silicon with other substrates is also a common idea for developing novel high specific capacity anode materials. For example, the nano silicon and the metal oxide are compounded and then subjected to carbon coating treatment, so that the problem of overhigh lithium release voltage of the transition metal oxide can be solved to a certain extent, and an active lithium storage matrix can be provided for the silicon to play a synergistic effect of the nano silicon and the metal oxide. However, due to the high surface energy of nano-silicon, the agglomeration problem is always a difficult problem to be solved in the industry. It is a technical challenge how to compound nano-silicon with transition metal oxides in a highly dispersed manner.
In the prior art, the invention provides a (Si @ MnO) @ C/RGO nano hybrid material and a preparation method thereof (application number: 201610553665.4). MnO nano particles are adhered to the surfaces of Si nano particles and coated by a layer of carbon to form (Si @ MnO) @ C nano particles, (Si @ MnO) @ C nano particles are uniformly dispersed and adhered between two-dimensional RGO nano sheet layers to form a three-dimensional micro-nano network structure. The preparation process involves complex chemical displacement reaction, Mx (oleate) y is obtained firstly, wherein M is Mn, Fe, Zn and Co normal hexane solution, then Si-based material and reduced graphene oxide RGO are added in sequence under the stirring condition to obtain precursor solution, final precursor is obtained by rotary evaporation, and then Si @ MnO @ C/RGO nano hybrid material is obtained by heat treatment under inert gas.
Invention patent' Si/MnO2Preparation method and application of/graphene/carbon lithium ion battery negative electrode material (application number: 201610187143.7) and discloses Si/MnO2The preparation method of the negative electrode material of the graphene/carbon lithium ion battery comprises the following specific steps: (1) preparing a nano Si dispersion liquid; (2) MnO of2Ultrasonically stirring the nano Si dispersion liquid, and then putting the mixture into a stainless steel ball milling tank for ball milling; (3) preparing GO according to a modified Hummer method, and then preparing GO dispersion liquid; (4) dropwise adding the GO dispersed liquid into the ball milling tank in the step (2), continuing ball milling for 0.5-5 h, centrifuging and drying the reaction product to obtain Si/MnO2A graphene composite; (5) dissolving carbon source in organic solution, adding Si/MnO2The/graphene compound is stirred to be dried and is calcined at constant temperature to obtain Si/MnO2A graphene/carbon lithium ion battery negative electrode material.
As can be seen, the graphene is required to be used in the technology, and the technology has the advantages of multiple process steps, long flow and unsuitability for batch production.
The invention discloses a carbon/molybdenum dioxide/silicon/carbon composite material, a battery cathode containing the same and a lithium ion battery (application number: 202010093614.4), and discloses a C-MoO2The preparation method of the-Si-C composite material utilizes the process of in-situ polymerization of ammonium molybdate and aniline to generate the one-dimensional nano rod and simultaneously leads the one-dimensional nano rod to be in solutionThe nanometer silicon powder is captured on the polymer and then coated by phenolic resin carbon to obtain C-MoO2-a Si-C composite. However, the microscopic morphology analysis showed that the C-MoO2In the-Si-C composite material, nano silicon particles are only attached to the surface of a one-dimensional carbon material and are in contact with MoO2Lack of necessary synergy, and limited product performance.
Disclosure of Invention
The invention aims to overcome the problems of the existing silicon-based anode material, and provides a Si @ MnO @ C composite material, so that nano silicon powder is uniformly dispersed in an oxide matrix, and an outer-layer carbon coating and reducing process is assisted, so that the composite anode material with excellent performance is obtained.
The specific scheme is as follows:
a preparation method of a Si @ MnO @ C composite material comprises the following steps:
1) ultrasonically dispersing ammonium persulfate and nano silicon powder in a solvent to obtain a solution A;
2) mixing the solution A with manganese sulfate, heating for reaction, cooling, filtering, washing and drying to obtain MnO2-Si composite powder;
3) by in situ polymerization of said MnO2Coating the-Si composite powder with phenolic resin;
4) MnO coated with phenolic resin under protection of inert gas2And pyrolyzing the-Si composite powder to obtain the Si @ MnO @ C composite material.
Further, in the step 1), ammonium persulfate is prepared into 0.5-1.5mol/L ammonium persulfate aqueous solution, and then the nano silicon powder is ultrasonically dispersed in the ammonium persulfate aqueous solution, wherein the adding amount ratio of the ammonium persulfate aqueous solution to the nano silicon powder is as follows: 100 ml: 0.2-0.4 g;
optionally, the size of the nano silicon powder is 20-60 nm.
Further, in the step 2), the molar ratio of manganese sulfate to ammonium persulfate is 0.9-1.1;
optionally, mixing the solution A with manganese sulfate, sealing, continuously stirring the mixed solution for 6-12 h at the temperature of 60-90 ℃, and then coolingFiltering, washing and drying to obtain MnO2-Si composite powder.
Further, the sealing in the step 2) refers to mixing the solution A with manganese sulfate, stirring after sealing, and reacting ammonium persulfate with manganese sulfate to generate sea urchin-shaped MnO2While the microspheres are being formed, the nano silicon particles suspended in the solution are captured and embedded into echinoid MnO2MnO is formed in the gaps of the microspheres2-Si composite powder.
Further, in step 3), the operation step of the in-situ polymerization reaction comprises:
i) MnO is added to the mixture2Dispersing the-Si composite powder in a mixed solvent of absolute ethyl alcohol and deionized water to obtain a suspension;
ii) adding cetyl trimethyl ammonium bromide, resorcinol and formaldehyde into the suspension, and stirring and dissolving to obtain a mixed solution;
iii) adding ammonia water into the mixed solution, continuously stirring, filtering, washing and drying to obtain MnO coated with phenolic resin2-Si composite powder.
Further, MnO in step i)2The adding proportion of the-Si composite powder to the mixed solvent is as follows: 1 g: 150-; the volume ratio of the absolute ethyl alcohol to the deionized water in the mixed solvent is 1: 2-3;
optionally, the addition ratio of the substances in the step ii) is 0.6-2 g of hexadecyl trimethyl ammonium bromide: 0.16-32 g of resorcinol: 0.3-0.6ml of formaldehyde solution, wherein the mass content of formaldehyde in the formaldehyde solution is 30-50%;
optionally, the mass concentration of the ammonia water in the step iii) is 20-28%, and the addition amount of the ammonia water is as follows: MnO in step i)2-Si composite powder 1-2 ml: 1g of the total weight of the composition.
Further, in the step 4), the pyrolysis temperature is 600-800 ℃, the pyrolysis time is 2-5 hours, the phenolic resin is converted into carbon, and MnO is simultaneously subjected to a carbothermic reduction reaction2Converted to MnO, thereby obtaining a Si @ MnO @ C composite.
The invention also discloses a Si @ MnO @ C composite material, which is formed by aggregating a plurality of spherical or sphere-like particles, wherein the spherical or sphere-like particles are of a shell-core structure, the core part is spherical nano silicon, the outer surface of the spherical nano silicon is coated with a MnO layer, the outer surface of the MnO layer is coated with a MnO layer, and a micron-sized composite material is formed by a plurality of particles with the shell-core structure.
The invention also provides a negative electrode material which comprises the Si @ MnO @ C composite material.
The invention also protects a battery comprising the negative electrode material.
Has the advantages that:
the invention provides a preparation method of a Si @ MnO @ C composite material, which comprises the steps of firstly dispersing nano-silicon into an ammonium persulfate aqueous solution, then mixing the nano-silicon with a manganese sulfate solution, stirring the mixture under a mild hydrothermal condition to enable manganese sulfate to react with ammonium persulfate to generate sea urchin-shaped MnO2Simultaneously, the nano particles suspended in the mixed solution are captured and embedded into echinoid MnO2Then the phenolic resin is coated and heat treated to convert the phenolic resin into carbon, and MnO is reduced by carbothermic reduction reaction2Converted into MnO to be coated on the surface of the nano silicon, and the carbon is on the outermost layer, so that the shell-core structure Si @ MnO @ C composite material is obtained. The whole preparation process of the composite material is simple in process, and the obtained composite material has excellent lithium storage performance when being used as a lithium ion battery cathode.
Drawings
In order to illustrate the technical solution of the present invention more clearly, the drawings will be briefly described below, and it is apparent that the drawings in the following description relate only to some embodiments of the present invention and are not intended to limit the present invention.
FIG. 1 is an XRD spectrum of the Si @ MnO @ C composite material obtained in example 1.
FIG. 2 is a scanning electron micrograph of the Si @ MnO @ C composite obtained in example 1.
FIG. 3 is a transmission electron micrograph of the Si @ MnO @ C composite obtained in example 1.
FIG. 4 is a cyclic voltammogram of the Si @ MnO @ C composite obtained in example 2.
FIG. 5 is a graph of the rate and cycle performance of the Si @ MnO @ C composite obtained in example 2.
Detailed Description
The definitions of some of the terms used in the present invention are given below, and other non-mentioned terms have definitions and meanings known in the art:
the preparation method of the Si @ MnO @ C composite material comprises the following steps:
1) ultrasonically dispersing ammonium persulfate and nano silicon powder in a solvent to obtain a solution A;
2) mixing the solution A with manganese sulfate, heating for reaction, cooling, filtering, washing and drying to obtain MnO2-Si composite powder;
3) by in situ polymerization of MnO2Coating the-Si composite powder with phenolic resin;
4) MnO coated with phenolic resin under protection of inert gas2And pyrolyzing the-Si composite powder to obtain the Si @ MnO @ C composite material.
Wherein the diameter of the nano silicon powder in the step 1) is 20-60 nm, preferably 30-50 nm; the addition amount of the nano silicon powder is 0.2-0.4 g, and the nano silicon powder is used for regulating and controlling the content of the silicon nano particles in the shell-core structure Si @ MnO @ C composite material.
Mixing the solution A and manganese sulfate in the step 2), heating for reaction, preferably sealing a reaction container, and continuously stirring the mixed solution at 60-90 ℃ for 6-12 h, for example, sealing a glass container containing the mixed solution with a plastic film and placing the sealed glass container in an oil bath with magnetic stirring. The step is that ammonium persulfate and manganese sulfate react to generate sea urchin-shaped MnO2Microspheres, and nanometer silicon particles suspended in the solution are captured and embedded into echinoid MnO2MnO is formed in the pores of the microspheres2-Si composite powder.
In the step 3), the phenolic resin coating is carried out by polymerizing resorcinol and formaldehyde under the catalysis of ammonia water and simultaneously adding MnO into the phenolic resin2The outer surface of the nano Si particles is coated in a dissolving way.
The pyrolysis in the step 4) is carried out under the protection of inert gas, the temperature rise rate is 1-3 ℃/min, the pyrolysis temperature is 600-800 ℃, and the pyrolysis is carried out at the time of pyrolysisThe time is 2-5 h, the effect is to convert phenolic resin into carbon and simultaneously carry out carbothermic reduction reaction on MnO2Converted into MnO to be coated on the surface of the nano silicon, and the carbon is on the outermost layer, so that the Si @ MnO @ C composite material is obtained.
The purpose of the pyrolysis is to convert the phenolic resin into carbon and simultaneously convert MnO by carbothermic reduction reaction2To MnO. Pyrolysis here involves a carbonization process, and also a carbothermic reduction. Phenolic resin coating has the acicular MnO2Partial dissolution effect, so that MnO is coated on the surface of nano Si in the subsequent heat treatment, but other carbon sources such as glucose are not coated.
Si @ MnO @ C composite is formed by the gathering of a plurality of spherical or quasi-spherical particles, spherical or quasi-spherical particles are shell-core structures, and the core is spherical nano silicon, the surface cladding MnO layer of spherical nano silicon, the surface parcel carbon-layer on MnO layer, the micron-scale composite is constituteed to the particle of a plurality of this kind of shell-core structures. Preferably, the Si @ MnO @ C composite has a size of about 10 microns. Wherein the spherical or spheroidal particle size is 60-90 nm. The diameter of the spherical nano-silicon in the core part of each single particle is 60-80nm, the thickness of the MnO layer in the middle layer is 6-8nm, and the thickness of the carbon layer wrapped on the outermost layer is 1-3 nm.
The Si @ MnO @ C composite material can be used as a lithium ion battery cathode material, has good rate capability, has a specific discharge capacity of 1025mAh/g at 0.1A/g, has a specific discharge capacity of 712mAh/g at 1A/g, has a specific discharge capacity of 697mAh/g after 1A/g is cycled for 1000 times, and shows excellent cycling stability.
Preferred embodiments of the present invention will be described in more detail below. While the following describes preferred embodiments of the present invention, it should be understood that the present invention may be embodied in various forms and should not be limited by the embodiments set forth herein. The examples do not specify particular techniques or conditions, and are performed according to the techniques or conditions described in the literature in the art or according to the product specifications. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products commercially available. In the following examples, "%" means weight percent, unless otherwise specified.
Example 1
A preparation method of a Si @ MnO @ C composite anode material comprises the following steps:
1) preparing 100ml of 1mol/L ammonium persulfate solution, and ultrasonically dispersing 0.2g of nano silicon powder (-60 nm) in the solution to obtain solution A;
2) preparing 100ml of 1mol/L manganese sulfate solution to obtain solution B;
3) adding the solution B into the solution A under the stirring condition, then sealing the container, continuously stirring the mixed solution at 90 ℃ for 6 hours, then cooling, filtering, washing with deionized water, and drying to obtain MnO2-Si composite powder;
4) in situ polymerization of MnO with Resorcinol and Formaldehyde2Carrying out phenolic resin coating treatment on the-Si composite powder, and specifically comprising the following steps:
i) mixing 1gMnO2Dispersing the-Si composite powder in 200ml of a mixed solution of absolute ethyl alcohol and deionized water (the volume ratio of the absolute ethyl alcohol to the deionized water is 1:3) to obtain a suspension;
ii) adding 0.6g of cetyltrimethylammonium bromide (CTAB), 0.16g of resorcinol and 0.3ml of formaldehyde solution (content 40%) to the suspension, and stirring to dissolve;
iii) adding 1ml of ammonia water (28%) into the mixed solution, continuously stirring for 12h at 30 ℃, filtering, washing with deionized water, and drying to obtain MnO coated with phenolic resin2-Si composite powder;
5) MnO coated with phenolic resin under protection of inert gas2And (3) pyrolyzing the-Si composite powder, wherein the inert gas is high-purity nitrogen or argon, the heating rate is 3 ℃/min, the pyrolysis temperature is 600 ℃, and the heat preservation time is 2h, so that the Si @ MnO @ C composite material is obtained.
The prepared Si @ MnO @ C composite material has a shell-core structure, the core part is spherical nano silicon, MnO and a carbon layer are respectively coated on the surface of the spherical nano silicon from inside to outside, and a plurality of particles with the shell-core structure form a micron-sized composite material. The phase composition is shown by an X-ray diffraction pattern shown in figure 1 and mainly comprises MnO and Si. The carbon coating layer shows a broadened diffraction peak at about 2-theta 26 ° as amorphous carbon.
The microstructure of the prepared Si @ MnO @ C composite material is shown in a scanning electron micrograph of figure 2. As can be seen, the composite material is formed by the aggregation of a plurality of spherical particles, the outer surface of which is coated with a carbon layer.
The microstructure of the prepared Si @ MnO @ C composite material is further shown in a transmission electron micrograph of FIG. 3. As can be seen, the core of each spherical particle is spherical nano-silicon, and the surface of each spherical particle is coated with MnO and a carbon layer from inside to outside respectively to form a shell-core structure Si @ MnO @ C.
Example 2
Mixing the Si @ MnO @ C composite anode material prepared in the embodiment 1, conductive carbon black and sodium carboxymethyl cellulose according to a mass ratio of 80: 10: 10 mixing the mixture in deionized water, grinding the mixture into paste, coating the paste on a copper foil current collector, drying the paste at 80 ℃ for 12 hours, cutting a plurality of pole pieces with the diameter of 12mm by using a cutting machine, weighing the pole pieces, calculating the mass of a hard carbon material (active substance), and then taking a metal lithium piece as a negative pole, taking Celgard2400 as a diaphragm and taking 1mol/L LiPF in an argon protection glove box6And (4) assembling a 2025 button type simulation half cell by using the EC + DMC solution as an electrolyte, and performing charge-discharge test on the lithium ion half cell in a constant current charge-discharge mode, wherein the current density range is 0.1-3A/g, and the voltage range is 0.01-3V.
FIG. 4 is a cyclic voltammogram of a lithium ion half cell using a shell-core structure Si @ MnO @ C as a composite anode material, and it can be clearly seen that the electrochemical lithium intercalation process includes a process of lithiation of MnO and Si simultaneously, i.e., MnO is reduced as the voltage is reduced to generate Mn and Li2O; as the voltage is further decreased, Li and Si undergo an alloying reaction to form a LixSi alloy. During subsequent charging, Li is extracted from the alloy, forming amorphous silicon. Further increase in voltage causes oxidation of Mn to MnO.
Fig. 5 is a multiplying power and a cycle curve of the composite anode material with the shell-core structure Si @ MnO @ C obtained in this example. The charge and discharge tests show that the specific capacity of the material reaches 1025mAh/g at 0.1A/g, 712mAh/g at 1A/g, 697mAh/g after 1A/g circulation for 1000 times, and the material shows excellent circulation stability.
Comparative example 1
A comparative material was prepared by the following steps:
1) uniformly mixing 4g of manganese dioxide powder and 0.2g of nano silicon powder to obtain mixed powder,
2) the method comprises the following steps of performing phenolic resin coating treatment on mixed powder by adopting in-situ polymerization reaction of resorcinol and formaldehyde:
i) dispersing 1g of the mixed powder into 200ml of a mixed solution of absolute ethyl alcohol and deionized water (the volume ratio of the absolute ethyl alcohol to the deionized water is 1:3) to obtain a suspension;
ii) adding 0.6g of cetyltrimethylammonium bromide (CTAB), 0.16g of resorcinol and 0.3ml of formaldehyde solution (content 40%) to the suspension, and stirring to dissolve;
iii) adding 1ml of ammonia water (28%) into the mixed solution, continuously stirring for 12h at 30 ℃, filtering, washing with deionized water, and drying to obtain mixed powder coated with phenolic resin;
5) and (3) pyrolyzing the mixed powder coated with the phenolic resin under the protection of inert gas, wherein the inert gas is high-purity nitrogen or argon, the heating rate is 3 ℃/min, the pyrolysis temperature is 600 ℃, and the heat preservation time is 2 hours, so that the comparative composite material is obtained.
Microscopic analysis showed that the resulting composite was also a mixture of MnO and Si coated with a carbon layer, but the MnO did not form a shell structure on the outer surface of the Si. This is because MnO in the initial state2Not well mixed with Si, resulting in partially dissolved MnO2Can not be coated on the surface of the nano silicon particles.
Comparative example 2
A comparative material was prepared by the following steps:
i) mixing 1gMnO2Dispersing the-Si composite powder in 20ml of deionized water, and adding 0.4g of glucose;
ii) placing the beaker containing the solution in an oil bath at the temperature of 80 ℃, stirring and evaporating to dryness to obtain MnO coated with glucose2-Si composite powder;
5) MnO coated with glucose under protection of inert gas2-Si composite powderAnd (3) pyrolyzing the mixture, wherein the inert gas is high-purity nitrogen or argon, the heating rate is 3 ℃/min, the pyrolysis temperature is 600 ℃, and the heat preservation time is 2h, so that the Si @ MnO @ C composite material is obtained.
The prepared Si @ MnO @ C composite material does not have a shell-core structure, which indicates that MnO is generated in the phenolic resin coating process2Is critical to the formation of the core-shell structure.
The preferred embodiments of the present invention have been described in detail, however, the present invention is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present invention within the technical idea of the present invention, and these simple modifications are within the protective scope of the present invention.
It should be noted that the various features described in the above embodiments may be combined in any suitable manner without departing from the scope of the invention. The invention is not described in detail in order to avoid unnecessary repetition.
In addition, any combination of the various embodiments of the present invention is also possible, and the same should be considered as the disclosure of the present invention as long as it does not depart from the spirit of the present invention.
Claims (10)
1. A preparation method of a Si @ MnO @ C composite material is characterized by comprising the following steps: the method comprises the following steps:
1) ultrasonically dispersing ammonium persulfate and nano silicon powder in a solvent to obtain a solution A;
2) mixing the solution A with manganese sulfate, heating for reaction, cooling, filtering, washing and drying to obtain MnO2-Si composite powder;
3) by in situ polymerization of said MnO2Coating the-Si composite powder with phenolic resin;
4) MnO coated with phenolic resin under protection of inert gas2And pyrolyzing the-Si composite powder to obtain the Si @ MnO @ C composite material.
2. The method of making the Si @ MnO @ C composite of claim 1, wherein: in the step 1), ammonium persulfate is prepared into 0.5-1.5mol/L ammonium persulfate aqueous solution, and then the nano silicon powder is ultrasonically dispersed in the ammonium persulfate aqueous solution, wherein the adding amount ratio of the ammonium persulfate aqueous solution to the nano silicon powder is as follows: 100 ml: 0.2-0.4 g;
optionally, the size of the nano silicon powder is 20-60 nm.
3. The method of making the Si @ MnO @ C composite of claim 1, wherein: in the step 2), the molar ratio of manganese sulfate to ammonium persulfate is 0.9-1.1;
optionally, mixing the solution A with manganese sulfate, sealing, continuously stirring the mixed solution at 60-90 ℃ for 6-12 h, cooling, filtering, washing and drying to obtain MnO2-Si composite powder.
4. The method of making the Si @ MnO @ C composite of claim 3, wherein: the step 2) of sealing refers to mixing the solution A with manganese sulfate, sealing, stirring, and reacting ammonium persulfate with manganese sulfate to generate sea urchin-shaped MnO2While the microspheres are being formed, the nano silicon particles suspended in the solution are captured and embedded into echinoid MnO2MnO is formed in the gaps of the microspheres2-Si composite powder.
5. The method of making the Si @ MnO @ C composite of any one of claims 1 to 4, wherein: in step 3), the operation steps of the in-situ polymerization reaction include:
i) MnO is added to the mixture2Dispersing the-Si composite powder in a mixed solvent of absolute ethyl alcohol and deionized water to obtain a suspension;
ii) adding cetyl trimethyl ammonium bromide, resorcinol and formaldehyde into the suspension, and stirring and dissolving to obtain a mixed solution;
iii) adding ammonia water into the mixed solution, continuously stirring, filtering, washing and drying to obtain MnO coated with phenolic resin2-Si composite powder.
6. The method of making the Si @ MnO @ C composite of claim 5, wherein: MnO in step i)2The adding proportion of the-Si composite powder to the mixed solvent is as follows: 1 g: 150-; the volume ratio of the absolute ethyl alcohol to the deionized water in the mixed solvent is 1: 2-3;
optionally, the addition ratio of the substances in the step ii) is 0.6-2 g of hexadecyl trimethyl ammonium bromide: 0.16-32 g of resorcinol: 0.3-0.6ml of formaldehyde solution, wherein the mass content of formaldehyde in the formaldehyde solution is 30-50%;
optionally, the mass concentration of the ammonia water in the step iii) is 20-28%, and the addition amount of the ammonia water is as follows: MnO in step i)2-Si composite powder 1-2 ml: 1g of the total weight of the composition.
7. The method of making the Si @ MnO @ C composite of any one of claims 1 to 4, wherein: in the step 4), the pyrolysis temperature is 600-800 ℃, the pyrolysis time is 2-5 h, the phenolic resin is converted into carbon, and MnO is simultaneously subjected to a carbothermic reduction reaction2Converted to MnO, thereby obtaining a Si @ MnO @ C composite.
8. A Si @ MnO @ C composite material is characterized in that: si @ MnO @ C composite is formed by the gathering of a plurality of spherical or quasi-spherical particles, spherical or quasi-spherical particles are shell-core structures, and the core is spherical nano silicon, the surface cladding MnO layer of spherical nano silicon, the surface parcel carbon-layer on MnO layer, the micron-scale composite is constituteed to the particle of a plurality of this kind of shell-core structures.
9. An anode material comprising the Si @ MnO @ C composite of claim 8 or a Si @ MnO @ C composite prepared by the method of making the Si @ MnO @ C composite of any one of claims 1 to 7.
10. A battery comprising the negative electrode material of claim 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111477206.XA CN114220956B (en) | 2021-12-06 | 2021-12-06 | Si @ MnO @ C composite material and preparation method thereof, negative electrode material and battery |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111477206.XA CN114220956B (en) | 2021-12-06 | 2021-12-06 | Si @ MnO @ C composite material and preparation method thereof, negative electrode material and battery |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114220956A true CN114220956A (en) | 2022-03-22 |
| CN114220956B CN114220956B (en) | 2023-03-28 |
Family
ID=80699875
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111477206.XA Active CN114220956B (en) | 2021-12-06 | 2021-12-06 | Si @ MnO @ C composite material and preparation method thereof, negative electrode material and battery |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114220956B (en) |
Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100728783B1 (en) * | 2005-11-02 | 2007-06-19 | 삼성에스디아이 주식회사 | Negatvie active material for rechargeable lithium battery, method of preparing same and rechargeable lithium battery compring same |
| CN103594254A (en) * | 2013-11-26 | 2014-02-19 | 华东理工大学 | Method for preparing manganese dioxide/mesoporous carbon nanometer graded composite electrode material |
| CN104485456A (en) * | 2014-11-20 | 2015-04-01 | 刘剑洪 | Method for preparing carbon-coated manganous oxide and carbon-coated manganous oxide |
| JP2015118911A (en) * | 2013-12-19 | 2015-06-25 | 深▲セン▼市貝特瑞新能源材料股▲ふん▼有限公司 | Silicon-based composite negative electrode material for lithium ion secondary batteries, manufacturing method, and battery |
| US20150295227A1 (en) * | 2014-04-11 | 2015-10-15 | Xin Zhao | Silicon and graphene-incorporated rechargeable li-ion batteries with enhanced energy delivery and cycling life by using silecon and graphene based anode for energy storage |
| CN105789608A (en) * | 2016-03-29 | 2016-07-20 | 华南师范大学 | Preparation method and application of Si/MnO2/graphene/carbon lithium ion battery anode material |
| CN106207155A (en) * | 2016-07-14 | 2016-12-07 | 东北师范大学 | One class integrates nano-hybrid material of positive/negative cyclical effect and preparation method thereof |
| CN106654230A (en) * | 2017-01-21 | 2017-05-10 | 深圳市朗能动力技术有限公司 | Method for preparing silicon-carbon negative electrode material employing suspended emulsion polymerization method |
| CN107104229A (en) * | 2017-06-15 | 2017-08-29 | 中南大学 | Lithium ion battery negative material silica-doping manganese oxide/carbon pipe and preparation method |
| CN107445627A (en) * | 2017-08-23 | 2017-12-08 | 华中科技大学 | A kind of preparation method of phenolic resin and manganese dioxide bilayer film coated ceramic powder |
| CN108511719A (en) * | 2018-03-29 | 2018-09-07 | 深圳市贝特瑞新能源材料股份有限公司 | A kind of bivalve layer structural composite material, preparation method and the lithium ion battery comprising the composite material |
| CN111180714A (en) * | 2020-02-14 | 2020-05-19 | 厦门理工学院 | Carbon/molybdenum dioxide/silicon/carbon composite material, battery cathode comprising same and lithium ion battery |
| CN112467120A (en) * | 2020-12-01 | 2021-03-09 | 桐乡市华璟科技有限公司 | Preparation method of nitrogen-phosphorus-doped porous carbon-coated manganese dioxide cathode material |
-
2021
- 2021-12-06 CN CN202111477206.XA patent/CN114220956B/en active Active
Patent Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100728783B1 (en) * | 2005-11-02 | 2007-06-19 | 삼성에스디아이 주식회사 | Negatvie active material for rechargeable lithium battery, method of preparing same and rechargeable lithium battery compring same |
| CN103594254A (en) * | 2013-11-26 | 2014-02-19 | 华东理工大学 | Method for preparing manganese dioxide/mesoporous carbon nanometer graded composite electrode material |
| JP2015118911A (en) * | 2013-12-19 | 2015-06-25 | 深▲セン▼市貝特瑞新能源材料股▲ふん▼有限公司 | Silicon-based composite negative electrode material for lithium ion secondary batteries, manufacturing method, and battery |
| US20150295227A1 (en) * | 2014-04-11 | 2015-10-15 | Xin Zhao | Silicon and graphene-incorporated rechargeable li-ion batteries with enhanced energy delivery and cycling life by using silecon and graphene based anode for energy storage |
| CN104485456A (en) * | 2014-11-20 | 2015-04-01 | 刘剑洪 | Method for preparing carbon-coated manganous oxide and carbon-coated manganous oxide |
| CN105789608A (en) * | 2016-03-29 | 2016-07-20 | 华南师范大学 | Preparation method and application of Si/MnO2/graphene/carbon lithium ion battery anode material |
| CN106207155A (en) * | 2016-07-14 | 2016-12-07 | 东北师范大学 | One class integrates nano-hybrid material of positive/negative cyclical effect and preparation method thereof |
| CN106654230A (en) * | 2017-01-21 | 2017-05-10 | 深圳市朗能动力技术有限公司 | Method for preparing silicon-carbon negative electrode material employing suspended emulsion polymerization method |
| CN107104229A (en) * | 2017-06-15 | 2017-08-29 | 中南大学 | Lithium ion battery negative material silica-doping manganese oxide/carbon pipe and preparation method |
| CN107445627A (en) * | 2017-08-23 | 2017-12-08 | 华中科技大学 | A kind of preparation method of phenolic resin and manganese dioxide bilayer film coated ceramic powder |
| CN108511719A (en) * | 2018-03-29 | 2018-09-07 | 深圳市贝特瑞新能源材料股份有限公司 | A kind of bivalve layer structural composite material, preparation method and the lithium ion battery comprising the composite material |
| CN111180714A (en) * | 2020-02-14 | 2020-05-19 | 厦门理工学院 | Carbon/molybdenum dioxide/silicon/carbon composite material, battery cathode comprising same and lithium ion battery |
| CN112467120A (en) * | 2020-12-01 | 2021-03-09 | 桐乡市华璟科技有限公司 | Preparation method of nitrogen-phosphorus-doped porous carbon-coated manganese dioxide cathode material |
Non-Patent Citations (2)
| Title |
|---|
| IIGEUN OH ET AL.: "Carbon-coated Si/MnO2 nanoneedle composites with optimum carbon layer activation for supercapacitor applications", 《CHEMICAL ENGINEERING JOURNAL》 * |
| 刘代伙: "高性能锰基负极复合材料的设计制备与锂/钠电性能研究", 《中国博士学位论文全文数据库 工程科技Ⅰ辑》 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114220956B (en) | 2023-03-28 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP3989315A1 (en) | Mof derivative-coated ncm ternary positive electrode material and preparation method therefor | |
| CN102208608B (en) | Preparation method of carbon-sulfur composite material for lithium ion battery carbon cathode material | |
| CN102479949B (en) | Anode active material of lithium ion battery, preparation method thereof and lithium ion battery | |
| CN109980179B (en) | Nitrogen-carbon doped modified manganese dioxide composite material and preparation method thereof | |
| CN109244427B (en) | Preparation method of carbon-coated zinc sulfide loaded graphene as potassium ion battery cathode | |
| CN111180714B (en) | Carbon/molybdenum dioxide/silicon/carbon composite material, battery cathode comprising same and lithium ion battery | |
| CN104733708B (en) | A kind of preparation method of the nickle cobalt lithium manganate composite of Surface coating LiFePO4 | |
| CN111362254A (en) | Preparation method and application of nitrogen-doped carbon nanotube-loaded phosphorus-doped cobaltosic oxide composite material | |
| CN105355875B (en) | A kind of tungsten oxide nano wound composite, preparation method and application | |
| CN101826617B (en) | Preparation method of lithium iron phosphate | |
| CN107768617B (en) | Lithium-sulfur battery composite cathode material and preparation method thereof | |
| CN109192956B (en) | Lithium nickel cobalt aluminate anode material coated by lithium zirconium phosphate fast ion conductor and preparation method thereof | |
| CN113764642A (en) | Lithium-silicon oxide-containing composite negative electrode material, preparation method thereof and lithium ion battery | |
| CN107732235A (en) | A kind of ternary cathode material of lithium ion battery NCA preparation method | |
| US20200194782A1 (en) | Double layer-coated nano-silicon negative electrode material, a method for preparing the same and use thereof | |
| CN110137465A (en) | A kind of carbon@Fe2O3@carbosphere composite material and its application | |
| CN107528060A (en) | A kind of nickelic positive electrode of gradient and preparation method thereof and lithium ion battery | |
| CN108400296B (en) | Heterogeneous element doped ferroferric oxide/graphene negative electrode material | |
| CN107394178B (en) | Cobalt carbonate/graphene composite material for sodium-ion battery cathode and preparation method and application thereof | |
| CN110854373B (en) | Composite negative electrode material and preparation method thereof | |
| CN110085823B (en) | Nano composite negative electrode material and preparation method and application thereof | |
| CN108550848A (en) | Rich lithium carbon material, preparation method and application | |
| CN103531789A (en) | Iron oxide-carbon nanotube ternary composite material and preparation method thereof | |
| CN107180965B (en) | A kind of nano-scale lithium iron phosphate/graphene composite material and its preparation method and application | |
| CN111554905B (en) | Preparation method, product and application of zinc oxide-based carbon composite nano material |
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 |