CN114220956B - Si @ MnO @ C composite material and preparation method thereof, negative electrode material and battery - Google Patents

Si @ MnO @ C composite material and preparation method thereof, negative electrode material and battery Download PDF

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CN114220956B
CN114220956B CN202111477206.XA CN202111477206A CN114220956B CN 114220956 B CN114220956 B CN 114220956B CN 202111477206 A CN202111477206 A CN 202111477206A CN 114220956 B CN114220956 B CN 114220956B
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CN114220956A (en
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姜春海
邹智敏
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Xiamen University of Technology
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/362—Composites
    • H01M4/366—Composites as layered products
    • 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 MnO 2 -Si composite powder; 3) By in situ polymerization of MnO 2 Coating the-Si composite powder with phenolic resin; 4) MnO coated with phenolic resin under protection of inert gas 2 And 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

Si @ MnO @ C composite material and preparation method thereof, negative electrode material and battery
Technical Field
The invention relates to the technical field of lithium ion battery electrode materials, in particular to a Si @ MnO @ C composite material, a preparation method thereof, a negative electrode material and a battery.
Background
Transition metal oxides, e.g. MnO, moO 2 ，SnO 2 CoO 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 (4200 mAh/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 is compounded with the metal oxide, and then the carbon coating treatment is carried out, so that the problem of overhigh lithium releasing and inserting voltage of the transition metal oxide can be solved to a certain extent, an active lithium storage matrix can be provided for the silicon, and the synergistic effect of the nano-silicon and the metal oxide can be exerted. 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 nano hybrid material integrating positive/negative circulation effects and a preparation method thereof (application number: 201610553665.4), and the nano hybrid material is (Si @ MnO) @ C/RGO, wherein MnO nano particles are adhered to the surfaces of Si nano particles and coated by a layer of carbon to form the (Si @ MnO) @ C nano particles, and the (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 = Mn, fe, zn and Co normal hexane solution is added, 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 heat treatment is carried out under inert gas to obtain Si @ MnO @ C/RGO nano hybrid material.
Invention patent' Si/MnO 2 Preparation method and application of/graphene/carbon lithium ion battery negative electrode material (application number: 201610187143.7) discloses Si/MnO 2 The preparation method of the negative electrode material of the graphene/carbon lithium ion battery comprises the following specific steps: (1) Preparation of nano-Si dispersionsLiquid; (2) MnO of 2 Ultrasonically 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), continuously performing ball milling treatment for 0.5-5 h, centrifuging and drying the reaction product to obtain Si/MnO 2 A graphene composite; (5) Dissolving carbon source in organic solution, adding Si/MnO 2 The graphene compound is stirred to be dried and is calcined at constant temperature to obtain Si/MnO 2 A 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-MoO 2 The preparation method of the-Si-C composite material comprises the steps of utilizing the process of generating the one-dimensional nano rod by in-situ polymerization of ammonium molybdate and aniline, capturing nano silicon powder in a solution on a polymer, and then coating the polymer by phenolic resin carbon to obtain C-MoO 2 -a Si-C composite. However, the microscopic morphology analysis showed that the C-MoO 2 In 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 MoO 2 Lack 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 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, and heatingReaction, cooling, filtration, washing and drying to obtain MnO 2 -Si composite powder;
3) By in situ polymerization of said MnO 2 Coating the-Si composite powder with phenolic resin;
4) MnO coated with phenolic resin under protection of inert gas 2 And 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: 100ml: 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, the solution A is mixed with manganese sulfate, the mixed solution is continuously stirred for 6 to 12 hours at the temperature of between 60 and 90 ℃ after being sealed, and then the mixed solution is cooled, filtered, washed and dried to obtain MnO 2 -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 MnO 2 While the microspheres are being formed, the nano silicon particles suspended in the solution are captured and embedded into echinoid MnO 2 MnO is formed in the gaps of the microspheres 2 -Si composite powder.
Further, in step 3), the operation step of the in-situ polymerization reaction comprises:
i) MnO is added to the mixture 2 Dispersing the-Si composite powder in a mixed solvent of absolute ethyl alcohol and deionized water to obtain a suspension;
ii) adding hexadecyl trimethyl ammonium bromide, resorcinol and formaldehyde into the suspension, and stirring for 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 resin 2 -Si composite powder.
Further, mnO in step i) 2 The adding proportion of the-Si composite powder to the mixed solvent is as follows: 1g:150-250ml; the volume ratio of the absolute ethyl alcohol to the deionized water in the mixed solvent is 1;
optionally, the addition ratio of the substances in step ii) is 0.6 to 2g of cetyltrimethylammonium bromide: 0.16 to 32g 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 to 2ml: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 h, the phenolic resin is converted into carbon, and MnO is simultaneously reduced through a carbothermic reduction reaction 2 Converted 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 an MnO layer, the outer surface of the MnO layer is coated with a carbon layer, and a micron-sized composite material is formed by a plurality of particles of the shell-core structure.
The invention also protects 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 mild hydrothermal conditions, and enabling manganese sulfate to react with ammonium persulfate to generate sea urchin-shaped MnO 2 Simultaneously, the nano particles suspended in the mixed solution are captured and embedded into echinoid MnO 2 Then the phenolic resin is coated and heat treated to convert the phenolic resin into carbon, and MnO is reduced by carbothermic reduction reaction 2 Converted into MnO to be coated on the surface of the nano silicon, and carbon is at the outermost layer, thereby obtaining the shell-core structure Si @ MnO @ C composite material. 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 more clearly illustrate the technical solution of the present invention, the drawings will be briefly introduced, and it is apparent that the drawings in the following description relate only to some embodiments of the present invention and are not limiting to the present invention.
FIG. 1 is an XRD spectrum of a Si @ MnO @ C composite material obtained in example 1.
FIG. 2 is a scanning electron micrograph of a Si @ MnO @ C composite material obtained in example 1.
FIG. 3 is a transmission electron micrograph of a Si @ MnO @ C composite material obtained in example 1.
FIG. 4 is a cyclic voltammogram of a Si @ MnO @ C composite obtained in example 2.
FIG. 5 is a graph showing the rate and cycle characteristics of the Si @ MnO @ C composite obtained in example 2.
Detailed Description
Definitions for some of the terms used in the present invention are given below, and other terms not described 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 MnO 2 -Si composite powder;
3) By in situ polymerization of MnO 2 Carrying out phenolic resin coating treatment on the Si composite powder;
4) MnO coated with phenolic resin under protection of inert gas 2 And 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 with manganese sulfate in the step 2), heating for reaction, preferably sealing the reaction vessel, and continuously stirring the mixed solution at 60-90 ℃ for 6-12 h, for example, sealing a glass vessel containing the mixed solution with a plastic film and placing the sealed glass vessel in an oil bath with magnetic stirring. The step is that ammonium persulfate and manganese sulfate react to generate sea urchin-shaped MnO 2 Microspheres, and nanometer silicon particles suspended in the solution are captured and embedded into echinoid MnO 2 MnO is formed in the pores of the microspheres 2 -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 resin 2 The 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 heating rate is 1-3 ℃/min, the pyrolysis temperature is 600-800 ℃, and the pyrolysis time is 2-5 h, so that the phenolic resin is converted into carbon, and MnO is simultaneously reduced by carbothermic reduction reaction 2 Converted into MnO coated on the surface of the nano silicon, and the carbon is on the outermost layer, thereby obtaining the Si @ MnO @ C composite material.
The purpose of the pyrolysis is to convert the phenolic resin into carbon and simultaneously convert MnO by carbothermic reduction reaction 2 To MnO. Pyrolysis here involves a carbonization process, with the effect of carbothermic reduction. The phenolic resin is coated with acicular MnO 2 Partial 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 combined material is formed by a plurality of spherical or spheroidal particle aggregations, spherical or spheroidal particle is the shell-core structure, and the core is spherical nanometer silicon, the surface cladding MnO layer of spherical nanometer silicon, the surface parcel carbon-coating on MnO layer, the combined material of the particle constitution micron level of a plurality of this kind of shell-core structures. Preferably, the si @ mno @ c composite is about 10 microns in size. Wherein the spherical or spheroidal particle size is 60-90nm. The diameter of spherical nano-silicon at the core part of each single particle is 60-80nm, the thickness of the MnO layer at the middle layer is 6-8nm, and the thickness of the carbon layer wrapped at the outermost layer is 1-3nm.
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 1000 cycles of 1A/g circulation, and shows excellent cycle 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. Those skilled in the art will recognize that the specific techniques or conditions, not specified in the examples, are according to the techniques or conditions described in the literature of the art or according to the product specification. 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 negative electrode 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 MnO 2 -Si composite powder;
4) In situ polymerization of MnO with Resorcinol and Formaldehyde 2 Carrying out phenolic resin coating treatment on the-Si composite powder, and specifically comprising the following steps:
i) 1g of MnO 2 the-Si composite powder is dispersed in 200ml of a mixed solution of absolute ethyl alcohol and deionized water (volume ratio of absolute ethyl alcohol to deionized water)1) 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 the MnO coated with the phenolic resin 2 -Si composite powder;
5) MnO coated with phenolic resin under protection of inert gas 2 And (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 showed 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 FIG. 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 microscope photograph in FIG. 3. Therefore, 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
The Si @ MnO @ C composite negative electrode material prepared in the embodiment 1, conductive carbon black and sodium carboxymethylcellulose are mixed according to the mass ratio of 80:10:10 mixing in deionized water, grinding into paste, coating on a copper foil current collector, drying at 80 ℃ for 12h, cutting a plurality of pole pieces with the diameter of 12mm by a cutting machine, weighing, calculating the mass of a hard carbon material (active substance), and then in an argon protective glove box, taking a metal lithium piece as a cathode, taking Celgard2400 as a diaphragm, and taking 1mol/L LiPF 6 And (c) 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 voltammetry curve 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 simultaneously includes the lithiation process of MnO and Si, that is, mnO is reduced to generate Mn and Li as the voltage is reduced 2 O; as the voltage is further reduced, 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 increasing the voltage causes an oxidation reaction of Mn to MnO.
FIG. 5 shows the rate and cycle curve of the composite anode material with a core-shell 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 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;
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 state 2 Not well mixed with Si, resulting in partially dissolved MnO 2 Can not coat the surface of the nano silicon particles.
Comparative example 2
A comparative material was prepared by the following steps:
i) 1g of MnO 2 -Si composite powder is dispersed in 20ml deionized water, and 0.4g glucose is added;
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 glucose 2 -Si composite powder;
5) MnO coated with glucose under protection of inert gas 2 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 does not have a shell-core structure, which indicates that MnO is not contained in the phenolic resin coating process 2 Is 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 can be made, and the same should be considered as the disclosure of the present invention as long as the idea of the present invention is not violated.

Claims (11)

1. A preparation method of 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 MnO 2 -Si composite powder; the molar ratio of manganese sulfate to ammonium persulfate is 0.9 to 1.1; mixing the solution A with manganese sulfate, sealing, stirring, and reacting ammonium persulfate with manganese sulfate to generate sea urchin-shaped MnO 2 While the microspheres are being formed, the nano silicon particles suspended in the solution are captured and embedded into echinoid MnO 2 MnO is formed in the gaps of the microspheres 2 -Si composite powder;
3) By in situ polymerization of said MnO 2 Carrying out phenolic resin coating treatment on the Si composite powder;
4) MnO coated with phenolic resin under protection of inert gas 2 Pyrolyzing the-Si composite powder at 600-800 ℃ for 2-5h to convert the phenolic resin into carbon, and simultaneously carrying out carbothermic reduction reaction on MnO 2 Converted to MnO to obtain the Si @ MnO @ C composite material.
2. The method of producing Si @ MnO @ C composite material according to claim 1, characterized in that: in the step 1), ammonium persulfate is prepared into 0.5-1.5mol/L ammonium persulfate aqueous solution, and then the nanometer silicon powder is ultrasonically dispersed in the ammonium persulfate aqueous solution, wherein the adding amount ratio of the ammonium persulfate aqueous solution to the nanometer silicon powder is as follows: 100ml:0.2 to 0.4g.
3. The method of producing Si @ MnO @ C composite material according to claim 1, characterized in that: the size of the nano silicon powder is 20 to 60nm.
4. The method of producing Si @ MnO @ C composite material according to claim 1, characterized in that: mixing the solution A with manganese sulfate, sealing, continuously stirring the mixed solution for 6 to 12h at the temperature of 60 to 90 ℃, cooling, filtering, washing and drying to obtain MnO 2 -Si composite powder.
5. A method of preparation of Si @ MnO @ C composite according to any of claims 1-4, characterized in that: in step 3), the operation steps of the in-situ polymerization reaction include:
i) MnO is added to the mixture 2 Dispersing 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 resin 2 -Si composite powder.
6. The process for the preparation of Si @ MnO @ C composite material according to claim 5, characterized in that: mnO in step i) 2 The adding amount ratio of the-Si composite powder to the mixed solvent is as follows: 1g:150-250ml; the volume ratio of the absolute ethyl alcohol to the deionized water in the mixed solvent is 1.
7. The process for the preparation of Si @ MnO @ C composite material according to claim 5, characterized in that: the addition ratio of each substance in the step ii) is 0.6-2g of hexadecyl trimethyl ammonium bromide: 0.16 to 32g of resorcinol: 0.3-0.6ml of formaldehyde solution, wherein the mass content of formaldehyde in the formaldehyde solution is 30-50%.
8. The process for the preparation of Si @ MnO @ C composite material according to claim 5, characterized in that: in the step iii), the mass concentration of the ammonia water is 20-28%, and the addition amount of the ammonia water is as follows: mnO in step i) 2 -Si composite powder =1 to 2ml:1g of the total weight of the composition.
9. A Si @ MnO @ C composite material prepared by the preparation method of any one of claims 1 to 8, characterized in that: si @ MnO @ C combined material is formed by the gathering of a plurality of spherical or quasi-spherical particles, spherical or quasi-spherical particle is the shell-core structure, and the core is spherical nanometer silicon, the surface cladding MnO layer of spherical nanometer silicon, the surface parcel carbon layer on MnO layer, the combined material of micron order is constituteed to the particle of a plurality of this kind of shell-core structure.
10. An anode material, comprising the Si @ MnO @ C composite material of claim 9, or the Si @ MnO @ C composite material prepared by the preparation method of the Si @ MnO @ C composite material of any one of claims 1 to 8.
11. A battery comprising the negative electrode material of claim 10.
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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
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
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

Family Cites Families (11)

* Cited by examiner, † Cited by third party
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
CN103682287B (en) * 2013-12-19 2016-09-14 深圳市贝特瑞新能源材料股份有限公司 A kind of silicon-based composite anode material for Li-ion battery, preparation 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
CN104485456B (en) * 2014-11-20 2017-10-13 深圳市本征方程石墨烯技术股份有限公司 The preparation method and carbon coating manganous oxide of a kind of carbon coating manganous oxide
CN105789608B (en) * 2016-03-29 2019-02-05 华南师范大学 A kind of Si/MnO2The preparation method and application of/graphene/carbon lithium ion battery negative material
CN106207155B (en) * 2016-07-14 2018-09-28 东北师范大学 One kind integrates the nano-hybrid material and preparation method thereof of positive/negative cyclical effect
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
CN107104229B (en) * 2017-06-15 2020-04-14 中南大学 Lithium ion battery cathode material silicon oxide doped manganese oxide/carbon tube and preparation method thereof
CN107445627B (en) * 2017-08-23 2019-09-27 华中科技大学 A kind of preparation method of phenolic resin and manganese dioxide bilayer film coated ceramic powder
CN108511719B (en) * 2018-03-29 2021-01-19 贝特瑞新材料集团股份有限公司 Double-shell-layer-structure composite material, preparation method thereof and lithium ion battery comprising composite material
CN111180714B (en) * 2020-02-14 2021-04-09 厦门理工学院 Carbon/molybdenum dioxide/silicon/carbon composite material, battery cathode comprising same and lithium ion battery

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
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
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

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