CN110098396B - Lithium-sulfur battery composite positive electrode material, preparation method thereof and battery - Google Patents

Lithium-sulfur battery composite positive electrode material, preparation method thereof and battery Download PDF

Info

Publication number
CN110098396B
CN110098396B CN201910371857.7A CN201910371857A CN110098396B CN 110098396 B CN110098396 B CN 110098396B CN 201910371857 A CN201910371857 A CN 201910371857A CN 110098396 B CN110098396 B CN 110098396B
Authority
CN
China
Prior art keywords
sulfur
metal
battery
positive electrode
carbon
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201910371857.7A
Other languages
Chinese (zh)
Other versions
CN110098396A (en
Inventor
刘全兵
李栋
南皓雄
谢盈基
郑育英
方岩雄
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Guangdong University of Technology
Original Assignee
Guangdong University of Technology
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Guangdong University of Technology filed Critical Guangdong University of Technology
Priority to CN201910371857.7A priority Critical patent/CN110098396B/en
Publication of CN110098396A publication Critical patent/CN110098396A/en
Application granted granted Critical
Publication of CN110098396B publication Critical patent/CN110098396B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/362—Composites
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • 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
    • 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
    • H01M4/626—Metals
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/628—Inhibitors, e.g. gassing inhibitors, corrosion inhibitors
    • 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
    • H01M2004/028—Positive 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 belongs to the technical field of lithium-sulfur battery positive electrode materials, and particularly relates to a lithium-sulfur battery composite positive electrode material, a preparation method thereof and a battery. The invention provides a battery composite anode material, which has a core-shell structure; the core-shell structure comprises a metal-carbon shell and a sulfur core arranged in the metal-carbon shell; the metal-carbon shell is formed by metal hydroxide and/or metal oxide and carbon, and the metal hydroxide and/or metal oxide are coated in the carbon; the sulfur core is formed from elemental sulfur. The battery composite positive electrode material has a core-shell structure, the metal-carbon shell can improve the conductivity of the battery composite positive electrode material and can play a role in limiting the sulfur and polysulfide intermediate product, and the metal hydroxide and/or metal oxide can adsorb polysulfide through the lithium-philic or sulfur-philic effect, so that the shuttle effect is inhibited, a sulfur analysis site is provided, the conversion of the sulfur and polysulfide can be catalyzed, the electrode process dynamics is improved, and the electrode conversion rate is improved.

Description

Lithium-sulfur battery composite positive electrode material, preparation method thereof and battery
Technical Field
The invention belongs to the technical field of lithium-sulfur battery positive electrode materials, and particularly relates to a lithium-sulfur battery composite positive electrode material, a preparation method thereof and a battery.
Background
Lithium-sulfur batteries are becoming increasingly valuable for research because of their high theoretical energy density (2600Wh/kg) and high theoretical specific capacity (1675mAh/g), and sulfur has many advantages, such as abundant reserves on earth, non-toxicity and environmental friendliness, and lithium-sulfur batteries are the most promising next-generation high-specific-energy secondary battery system.
However, lithium sulfur batteries have some problems that prevent their wide practical use, such as: the low conductivity of sulfur and discharge products makes the capacity difficult to perform; the intermediate polysulfides readily dissolve in the electrolyte, leading to low coulombic efficiency and rapid capacity fade during long cycling; the volume expansion during charge/discharge may destroy the electrode structure of the lithium sulfur battery, etc.
In recent years, many methods have been used to solve the above problems, such as nanocarbon-based materials being widely used as carriers of lithium sulfur batteries due to their high conductivity and stable structure, however, nanocarbon-based materials can only significantly improve the conductivity of electrodes, and have very limited effects in increasing the conversion rate of lithium sulfur electrodes, limiting the shuttling of polysulfides, and the like.
Disclosure of Invention
In view of the above, the invention provides a battery composite positive electrode material, a preparation method thereof and a battery, which are used for solving the problems that the conversion rate of the conventional lithium-sulfur battery positive electrode material is slow and the polysulfide shuttling effect is to be reduced.
The specific technical scheme of the invention is as follows:
a battery composite positive electrode material has a core-shell structure;
the core-shell structure comprises a metal-carbon shell and a sulfur core arranged in the metal-carbon shell;
the metal-carbon shell is formed from a metal hydroxide and/or a metal oxide and carbon, the metal hydroxide and/or metal oxide being encapsulated within the carbon;
the sulfur core is formed from elemental sulfur.
Preferably, the metal is a transition metal;
the transition metal is selected from one or more of titanium, iron, nickel, zinc, copper and cobalt.
Preferably, the mass content of the elemental sulfur in the battery composite positive electrode material is 40-70%;
the mass content of the metal hydroxide and/or the metal oxide in the battery composite positive electrode material is 5-30%;
the mass content of the carbon in the battery composite positive electrode material is 20-40%.
Preferably, the diameter of the core-shell structure is 100 nm-600 nm;
the thickness of the metal-carbon shell is 10 nm-50 nm;
the diameter of the sulfur core is 30 nm-200 nm;
the particle size of the metal hydroxide and/or the metal oxide is 5 nm-30 nm.
Preferably, a cavity is provided between the metal-carbon shell and the sulfur core.
The invention also provides a preparation method of the battery composite positive electrode material, which comprises the following steps:
a) depositing metal hydroxide and/or metal oxide on the surface of the microsphere to obtain a composite microsphere with the metal hydroxide and/or metal oxide deposited on the surface;
b) coating macromolecules on the surfaces of the composite microspheres, and carbonizing the macromolecules to obtain carbon-coated composite microspheres;
c) and etching the carbon-coated composite microspheres to remove the microspheres to obtain a metal-carbon shell, and loading elemental sulfur in the metal-carbon shell, wherein the elemental sulfur forms a sulfur core in the metal-carbon shell to obtain the battery composite positive electrode material.
Preferably, the step c) of loading elemental sulfur in the metal-carbon shell specifically comprises:
and mixing the metal-carbon shell with elemental sulfur, placing the mixture in a vacuum condition, and heating the mixture to ensure that the elemental sulfur is molten and diffused into the metal-carbon shell.
Preferably, the step c) of loading elemental sulfur in the metal-carbon shell specifically comprises:
and dispersing the metal-carbon shell in a sulfur source solution, adding a surfactant, and then adding a precipitator to stir so as to deposit elemental sulfur into the metal-carbon shell.
Preferably, the sulfur source is selected from Na2S2O3、Na2SXAnd thiourea;
the surfactant is selected from one or more of cetyl trimethyl ammonium bromide, sodium dodecyl benzene sulfonate, octyl phenyl polyoxyethylene ether and tween;
the precipitant is one or more selected from hydrochloric acid, oxalic acid, phosphoric acid and acetic acid.
The invention also provides a battery, and the positive electrode material of the battery comprises the battery composite positive electrode material in the technical scheme and/or the battery composite positive electrode material prepared by the preparation method in the technical scheme.
In summary, the invention provides a battery composite positive electrode material, which has a core-shell structure; the core-shell structure comprises a metal-carbon shell and a sulfur core arranged in the metal-carbon shell; the metal-carbon shell is formed from a metal hydroxide and/or a metal oxide and carbon, the metal hydroxide and/or metal oxide being encapsulated within the carbon; the sulfur core is formed from elemental sulfur. The battery composite positive electrode material has a core-shell structure and comprises a metal-carbon shell formed by metal hydroxide and/or metal oxide and carbon and a sulfur core arranged in the metal-carbon shell, wherein the metal-carbon shell can improve the conductivity of the battery composite positive electrode material and can play a role in limiting the sulfur and an intermediate polysulfide, and the metal hydroxide and/or the metal oxide in the metal-carbon shell adsorb the polysulfide through the lithium-philic effect or the sulfur-philic effect on one hand, so that the shuttle effect is inhibited, sulfur analysis sites are provided, on the other hand, the conversion of the sulfur and the polysulfide can be catalyzed, the process dynamics of an electrode is improved, and the conversion rate of the electrode is improved.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below.
Fig. 1 is a schematic flow chart of a method for preparing a battery composite positive electrode material according to an embodiment of the present invention;
FIG. 2 is a TEM image of a composite positive electrode material of a battery provided in example 2 of the present invention;
fig. 3 is a charge-discharge curve diagram of a battery using the composite positive electrode material of the battery provided in embodiment 3 of the present invention as a positive electrode;
fig. 4 is a graph showing the cycle performance of a battery using the composite positive electrode material of the battery provided in example 3 of the present invention as a positive electrode;
fig. 5 is a graph showing the cycle performance of a battery using a composite positive electrode material for a battery according to example 8 of the present invention as a positive electrode;
FIG. 6 is a charge-discharge curve diagram of a battery using a composite positive electrode material for a battery according to comparative example 1 of the present invention as a positive electrode;
FIG. 7 is a graph showing the cycle characteristics of a battery using a composite positive electrode material for a battery according to comparative example 1 of the present invention as a positive electrode;
illustration of the drawings: 1. a sulfur nucleus; 2. metal hydroxides and/or metal oxides; 3. carbon; 4. microspheres; 5. a polymer; 6. compounding the microspheres; 7. polymer coated composite microspheres; 8. carbon-coated composite microspheres; 9. a metal-carbon shell; 10. a battery composite positive electrode material.
Detailed Description
The invention provides a battery composite positive electrode material, a preparation method thereof and a battery, which are used for solving the problems that the conversion rate of the conventional lithium-sulfur battery positive electrode material is slow and the shuttle effect of polysulfide is to be reduced.
The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
A battery composite anode material, a battery composite anode material 10 has a core-shell structure;
the core-shell structure comprises a metal-carbon shell 9 and a sulfur core 1 arranged in the metal-carbon shell 9;
the metal-carbon shell 9 is formed by metal hydroxide and/or metal oxide 2 and carbon 3, and the metal hydroxide and/or metal oxide 2 is coated in the carbon 3;
the sulfur core 1 is formed from elemental sulfur.
In the embodiment of the invention, the battery composite positive electrode material 10 has a core-shell structure, and comprises a metal-carbon shell 9 formed by metal hydroxide and/or metal oxide 2 and carbon 3 and a sulfur core 1 arranged in the metal-carbon shell 9, wherein the metal-carbon shell 9 can improve the electrical conductivity of the battery composite positive electrode material 10 and can play a role in limiting the sulfur core 1 and polysulfide intermediate products, and the metal hydroxide and/or metal oxide 2 in the metal-carbon shell 9 can adsorb polysulfide through the lithium-philic effect or the sulfur-philic effect to form chemical bonding, so that a shuttle effect is inhibited, sulfur precipitation sites are provided, and the conversion of sulfur and polysulfide can be catalyzed, the electrode process dynamics is improved, and the conversion rate of an electrode is improved.
In the embodiment of the invention, the core-shell structure is a spherical structure or a sphere-like structure.
In the embodiment of the present invention, the metal in the metal hydroxide and/or the metal oxide 2 is a transition metal;
the transition metal is selected from one or more of titanium, iron, nickel, zinc, copper and cobalt.
The metal hydroxide and/or metal oxide 2 includes titanium dioxide, iron hydroxide (Fe (OH)3) Nickel oxide, zinc oxide, copper hydroxide (Cu (OH)2) And cobalt hydroxide (Co (OH)3) One or more of (a).
In the embodiment of the invention, the mass content of elemental sulfur in the battery composite positive electrode material 10 is 40-70%;
the mass content of the metal hydroxide and/or the metal oxide 2 in the battery composite positive electrode material 10 is 5-30%;
the mass content of the carbon 3 in the battery composite positive electrode material 10 is 20-40%.
In the embodiment of the invention, the diameter of the core-shell structure is 100 nm-600 nm;
the thickness of the metal-carbon shell 9 is 10nm to 50 nm;
the diameter of the sulfur core is 30 nm-200 nm;
the particle size of the metal hydroxide and/or the metal oxide 2 is 5 nm-30 nm, and the metal hydroxide and/or the metal oxide 2 is continuously or discontinuously coated on the sulfur core 1.
In the embodiment of the invention, the surface of the battery composite positive electrode material 10 is provided with micropores and mesopores, the pore diameter of the micropores is 1 nm-2 nm, and the pore diameter of the mesopores is 2 nm-30 nm.
In the prior art, due to the density difference between elemental sulfur and lithium sulfide, volume expansion occurs in an electrode in the charging and discharging processes, on one hand, electron and ion channels in the electrochemical reaction process are easily blocked, and on the other hand, active substances are easily dropped from a current collector to lose activity, so that the lithium-sulfur battery is not applied in a large scale.
In the embodiment of the invention, a cavity is arranged between the metal-carbon shell 9 and the sulfur core 1. The volume change stress of the lithium-sulfur reaction can be relieved, the blocking of electrons and ion channels in the electrochemical reaction process can be avoided, and the loss of activity caused by the falling of active substances from a current collector is avoided.
In the embodiment of the invention, the volume ratio of the cavity in the battery composite positive electrode material 10 is 10-60%, and preferably 50%.
It should be noted that the loading of the sulfur core 1 in the battery composite positive electrode material 10 can be adjusted as required, and no cavity may exist between the metal-carbon shell 9 and the sulfur core 1.
In the embodiment of the invention, the battery composite positive electrode material 10 has a core-shell structure, and comprises a metal-carbon shell 9 and a sulfur core 1 formed by metal hydroxide and/or metal oxide 2 and carbon 3, wherein the metal-carbon shell 9 and the sulfur core 1 can play a synergistic effect, the metal-carbon shell 9 can improve the electrical conductivity of the battery composite positive electrode material 10 and can play a domain limiting effect on the sulfur core 1 and an intermediate polysulfide, on one hand, the metal hydroxide and/or metal oxide 2 in the metal-carbon shell 9 adsorbs the polysulfide through a lithium-philic effect or a sulfur-philic effect to form chemical bonding, thereby inhibiting a shuttle effect, providing a sulfur analysis site, on the other hand, the conversion of sulfur and polysulfide can be catalyzed, the electrode process dynamics is improved, the electrode conversion rate is improved, the content of the sulfur core 1 in the battery composite positive electrode material 10 is high, the cavity arranged between the metal-carbon shell 9 and the sulfur core 1 can relieve the volume change of lithium-sulfur reaction, and has great application prospect in the aspect of energy storage.
The invention also provides a preparation method of the battery composite positive electrode material, which comprises the following steps:
a) depositing metal hydroxide and/or metal oxide 2 on the surface of the microsphere 4 to obtain a composite microsphere 6 with the metal hydroxide and/or metal oxide 2 deposited on the surface;
b) coating the surface of the composite microsphere 6 with macromolecules, and carbonizing the macromolecules by carbonization treatment to obtain a carbon-coated composite microsphere 8;
c) and etching the carbon-coated composite microspheres 8, removing the microspheres 4 to obtain a metal-carbon shell 9, loading elemental sulfur in the metal-carbon shell 9, and forming sulfur cores 1 in the elemental sulfur in the metal-carbon shell 9 to obtain the battery composite anode material.
In the embodiment of the present invention, in step a), the microspheres 4 are preferably dispersed in a metal salt solution, and the metal salt is hydrolyzed and dried to obtain the composite microspheres 6 with the metal hydroxide and/or the metal oxide 2 deposited on the surface.
The pH value of the hydrolysis is 7-10; the hydrolysis temperature is 25-50 ℃; the hydrolysis time is 3-6 h.
The step a) of dispersing the microspheres 4 in the metal salt solution specifically comprises the following steps: dispersing the aqueous solution of the microspheres 4 in a metal salt solution by ultrasonic; after hydrolysis and before drying, the method further comprises the following steps: centrifuging or filtering, and cleaning.
Preferably, in step b), the composite microspheres 6 are dispersed in a polymer solution to obtain polymer-coated composite microspheres 7, and then the polymer-coated composite microspheres 7 are carbonized to carbonize the polymers 5 to obtain carbon-coated composite microspheres 8.
The atmosphere of the carbonization treatment is nitrogen and/or inert gas; the temperature of the carbonization treatment is 600-1000 ℃; the temperature of the carbonization treatment is 1 h-6 h.
In the embodiment of the invention, the composite microspheres 6 in the step b) are dispersed in the polymer solution by ultrasonic, and the ultrasonic dispersion time is 1-3 h; after dispersing the composite microsphere 6 in the polymer solution, before obtaining the polymer-coated composite microsphere 7, the method further comprises: stirring, centrifugally cleaning and drying are sequentially carried out; the carbonization treatment is carried out in a tube furnace, and the temperature rise rate of the carbonization treatment is 2-10 ℃/min.
Step c) is preferably carried out by etching in an HF or NaOH solution.
In the embodiment of the invention, the microsphere 4 is preferably SiO with the diameter of 100 nm-300 nm2Microspheres;
metal saltSelected from tetrabutyl titanate and FeCl3、AlCl3、ZnCl2、CuSO4And Co (NO)3)3One or more of;
the polymer 5 is preferably a phenol resin.
Microspheres 4 are more preferably SiO of different diameters2The microspheres can provide a large lithium ion transmission channel after being etched, and can increase the load of elemental sulfur; and the microspheres with small diameters have larger specific surface area and can provide more reactive sites.
In the embodiment of the invention, use
Figure BDA0002050249140000071
Method for preparing SiO with different diameters2The microsphere specifically comprises: sequentially adding ethanol, water and ammonia water into a beaker, uniformly stirring the mixture by using a magnetic stirrer at room temperature, slowly dropwise adding Tetraethoxysilane (TEOS) into the uniformly mixed solution under the stirring condition to perform hydrolysis reaction, sealing the opening of the beaker by using a polyethylene film after the dropwise adding is finished, allowing white precipitate to appear in 1-5 min, stirring the mixture to allow the reaction to be finished, and performing centrifugal cleaning to obtain SiO2And (4) microspheres.
In the embodiment of the present invention, in step c), elemental sulfur may be loaded in the metal-carbon shell 9 by a solid-phase melting diffusion method, which specifically includes:
the metal-carbon shell 9 is mixed with elemental sulfur and placed in a vacuum condition, and heating treatment is carried out to ensure that the elemental sulfur is melted and diffused into the metal-carbon shell.
Further, the volatilization temperature of the elemental sulfur is 100-300 ℃, and the elemental sulfur is preferably sublimed sulfur; the mass ratio of the metal-carbon shell 9 to elemental sulfur is 1: 0.25 to 0.8; the mixing is specifically that the materials are fully ground in a mortar; the heating treatment is specifically constant temperature treatment at 140-160 ℃ for 2-10 h, and preferably adopts an oil bath pan for heating treatment.
In the embodiment of the present invention, in step c), elemental sulfur may be loaded in the metal-carbon shell 9 by a liquid phase deposition method, which specifically includes:
dispersing the metal-carbon shell 9 in a sulfur source solution, adding a surfactant, and then adding a precipitator to stir so as to deposit elemental sulfur into the metal-carbon shell.
The sulfur source is selected from Na2S2O3、Na2SXAnd thiourea, the concentration of the sulfur source solution is 0.05 mol/L-0.2 mol/L; the surfactant is selected from one or more of Cetyl Trimethyl Ammonium Bromide (CTAB), Sodium Dodecyl Benzene Sulfonate (SDBS), octyl phenyl polyoxyethylene ether (TX-100) and tween; the precipitant is selected from one or more of hydrochloric acid, oxalic acid, phosphoric acid and acetic acid, and the concentration of the precipitant is 0.05 mol/L-0.2 mol/L.
After the surfactant is added and before the precipitator is added, the method also comprises the following steps: ultrasonic treatment is carried out for 1-3 h. Adding a precipitator and stirring for 1-3 h. After stirring, the method further comprises the following steps: filtering, washing and drying are carried out in sequence, and the drying temperature is 60-120 ℃.
In order to uniformly diffuse elemental sulfur in the metal-carbon shell 9, the sulfur core is tightly combined with the metal-carbon shell 9, and after the elemental sulfur is loaded in the metal-carbon shell, the method further comprises the following steps: carrying out heat treatment at 250-400 ℃, preferably 300 ℃; the time of the heat treatment is 10min to 60min, preferably 30 min; the heating rate of the heat treatment is 2-10 ℃/min.
After the heat treatment, removing sulfur on the surface of the battery composite positive electrode material 10, so that the mass content of the sulfur on the surface of the battery composite positive electrode material 10 in the battery composite positive electrode material is 0-10%.
The preparation method of the invention adopts
Figure BDA0002050249140000081
Method for preparing SiO with different diameters2Microspheres, then SiO2The microspheres are used as a precursor template, coated with metal hydroxide and/or metal oxide 2 and polymer 5 in sequence, carbonized at high temperature to form a polymer shell, and etched to remove SiO2And (4) carrying out microsphere preparation to obtain a metal-carbon shell 9, and compounding with sulfur to obtain the battery composite positive electrode material. The battery composite positive electrode material 10 has a core-shell structure, and comprises a metal-carbon shell 9 formed by metal hydroxide and/or metal oxide 2 and carbon 3, and a positive electrode material arranged in the metal-carbon shell 9The sulfur core 1 can strengthen the functions of electric conduction, adsorption, confinement and catalysis of the sulfur electrode, and the composite anode material of the battery has high sulfur carrying capacity, rapid electrode reaction kinetics and high stability.
The invention also provides a battery, and the positive electrode material of the battery comprises the battery composite positive electrode material 10 in the technical scheme and/or the battery composite positive electrode material 10 prepared by the preparation method in the technical scheme.
According to the battery adopting the technical scheme, the positive electrode material can realize a good sulfur fixing effect, the problems of sulfur volume expansion, dissolution and the like can be solved, the sulfur shuttle effect can be avoided, the mass content of sulfur in the battery composite positive electrode material is 40-70%, and the battery can show good electrochemical energy storage property.
For a further understanding of the invention, reference will now be made in detail to the following examples.
Example 1
In this example, the preparation of the composite positive electrode material for a battery was performed, and includes the following steps:
1) respectively measuring 20mL of deionized water, 70mL of absolute ethyl alcohol and 5mL of 30 wt% ammonia water, sequentially adding the deionized water, 70mL of absolute ethyl alcohol and 5mL of 30 wt% ammonia water into a beaker, uniformly stirring the mixture at room temperature by using a magnetic stirrer, weighing 1.0g of Tetraethoxysilane (TEOS), slowly dropwise adding the Tetraethoxysilane (TEOS) into the uniformly mixed solution, sealing the opening of the beaker by using a polyethylene film after the dropwise adding is finished, continuously stirring the mixture at room temperature for 6 hours to finish the reaction, and centrifugally cleaning the mixture to obtain SiO with different diameters2Microspheres of SiO2The diameter of the microsphere is 100 nm-300 nm.
2) 1.0g FeCl was weighed3Adding into deionized water, stirring at room temperature to form a metal salt solution A. Separately, 1.3g of SiO were weighed2Dissolving the microspheres in deionized water to obtain a solution B. Dropwise adding the solution B into the metal salt solution A, adjusting pH to 7, and continuously stirring at 25 deg.C for 3h with FeCl3Hydrolyzing, centrifugally cleaning and drying to obtain the composite microsphere, namely the composite microsphere with Fe (OH) deposited on the surface3The microspheres of (1). Wherein, Fe (OH)3Has a thickness of 20nm, Fe (OH)3The content is 10%.
3) Weighing 1.5g of phenolic resin, dissolving in deionized water, adding 1.0g of composite microspheres, continuously stirring for 5 hours at room temperature, centrifugally cleaning, and drying to obtain polymer-coated composite microspheres; and then putting the carbon-coated composite microspheres into a tube furnace, heating to 800 ℃ at a heating rate of 2 ℃/min in an argon atmosphere, and carrying out constant-temperature carbonization treatment for 3h to carbonize the phenolic resin, thereby obtaining the carbon-coated composite microspheres with the carbon content of 20%.
4) Adding the obtained carbon-coated composite microspheres into 2 wt% hydrofluoric acid solution, stirring for 10h for etching treatment to remove SiO2Centrifuging, washing and drying to obtain Fe (OH)3A metal-carbon shell. 0.1g of Fe (OH) is weighed out3Grinding and mixing metal-carbon shell and 0.3g sublimed sulfur uniformly, placing the obtained mixture into a reactor, vacuumizing, placing the reactor into an oil bath kettle, heating to 120 ℃, preserving heat for 10 hours, and melting the sublimed sulfur into Fe (OH)3Naturally cooling the hollow inner cavity of the metal-carbon shell to room temperature to obtain the battery composite positive electrode material, wherein the content of S is 40 percent, and Fe (OH)3A cavity is arranged between the metal-carbon shell and the sulfur core.
Example 2
In this example, the preparation of the composite positive electrode material for a battery includes the following steps:
1) respectively measuring 20mL of deionized water, 70mL of absolute ethyl alcohol and 5mL of 30 wt% ammonia water, sequentially adding the deionized water, 70mL of absolute ethyl alcohol and 5mL of 30 wt% ammonia water into a beaker, uniformly stirring the mixture at room temperature by using a magnetic stirrer, weighing 1.0g of Tetraethoxysilane (TEOS), slowly dropwise adding the Tetraethoxysilane (TEOS) into the uniformly mixed solution, sealing the opening of the beaker by using a polyethylene film after the dropwise adding is finished, continuously stirring the mixture at room temperature for 6 hours to finish the reaction, and centrifugally cleaning the mixture to obtain SiO with different diameters2Microspheres of SiO2The diameter of the microsphere is 100 nm-300 nm.
2) Weighing 1.2g Co (NO)3)3Adding into deionized water, stirring at room temperature to form a metal salt solution A. Separately, 1.4g of SiO were weighed2Dissolving the microspheres in deionized water to obtain a solution B. Dropwise adding the solution B into the metal salt solution A, adjusting pH to 7.5, and continuously stirring at 30 deg.C for 3.5h, Co (NO)3)3Hydrolyzing, centrifugally cleaning and drying to obtain the compoundSynthetic microspheres, i.e. having Co (OH) deposited on the surface3The microspheres of (1). Wherein, Co (OH)3Has a thickness of 22nm, Co (OH)3The content is 12%.
3) Weighing 1.5g of phenolic resin, dissolving in deionized water, adding 1.0g of composite microspheres, continuously stirring for 5 hours at room temperature, centrifugally cleaning, and drying to obtain polymer-coated composite microspheres; and then putting the carbon-coated composite microspheres into a tube furnace, heating to 600 ℃ at a heating rate of 2 ℃/min in an argon atmosphere, and carrying out constant-temperature carbonization treatment for 5 hours to carbonize the phenolic resin, thereby obtaining the carbon-coated composite microspheres with the carbon content of 22%.
4) Adding the obtained carbon-coated composite microspheres into a sodium hydroxide solution with the concentration of 2 wt%, stirring for 10h for etching treatment, and removing SiO2Centrifuging, washing and drying to obtain Co (OH)3A metal-carbon shell. 0.12g of Co (OH) is weighed3Grinding and mixing metal-carbon shell and 0.35g sublimed sulfur uniformly, placing the obtained mixture into a reactor, vacuumizing, placing the reactor into an oil bath pan, heating to 130 ℃, preserving heat for 8 hours to enable the sublimed sulfur to be molten into Co (OH)3Naturally cooling the hollow inner cavity of the metal-carbon shell to room temperature to obtain the battery composite positive electrode material, wherein the content of S is 45 percent, and Co (OH)3A cavity is arranged between the metal-carbon shell and the sulfur core.
For this example, Co (OH)3The metal-carbon shell was examined by transmission electron microscopy, the results are shown in FIG. 2, which shows Co (OH)3The metal-carbon shell is a hollow structure.
Example 3
In this example, the preparation of the composite positive electrode material for a battery includes the following steps:
1) respectively measuring 20mL of deionized water, 70mL of absolute ethyl alcohol and 5mL of 30 wt% ammonia water, sequentially adding the deionized water, 70mL of absolute ethyl alcohol and 5mL of 30 wt% ammonia water into a beaker, uniformly stirring the mixture at room temperature by using a magnetic stirrer, weighing 1.0g of Tetraethoxysilane (TEOS), slowly dropwise adding the Tetraethoxysilane (TEOS) into the uniformly mixed solution, sealing the opening of the beaker by using a polyethylene film after the dropwise adding is finished, continuously stirring the mixture at room temperature for 6 hours to finish the reaction, and centrifugally cleaning the mixture to obtain SiO with different diameters2Microspheres of SiO2The diameter of the microsphere is 100 nm-300 nm.
2) 1.3g of tetrabutyl titanate was weighed into deionized water and stirred at room temperature to form solution A. Separately, 1.5g of SiO were weighed2Dissolving the microspheres in deionized water to obtain a solution B. Dropwise adding the solution B into the solution A, adjusting the pH value to 8, continuously stirring for 4 hours at 35 ℃, hydrolyzing tetrabutyl titanate, centrifugally cleaning, and drying to obtain composite microspheres, namely the composite microspheres with TiO deposited on the surfaces2The microspheres of (1). Wherein, TiO2Of 21nm, TiO2The content is 18%.
3) Weighing 1.5g of phenolic resin, dissolving in deionized water, adding 1.2g of composite microspheres, continuously stirring for 5 hours at room temperature, centrifugally cleaning, and drying to obtain polymer-coated composite microspheres; and then putting the carbon-coated composite microspheres into a tubular furnace, heating to 800 ℃ at a heating rate of 2 ℃/min in a nitrogen atmosphere, and carrying out constant-temperature carbonization treatment for 3h to carbonize the phenolic resin, thereby obtaining the carbon-coated composite microspheres with the carbon content of 27%.
4) Adding the obtained carbon-coated composite microspheres into 2 wt% hydrofluoric acid solution, stirring for 10h for etching treatment to remove SiO2Centrifugally separating, washing and drying to obtain TiO2A metal-carbon shell. 0.13g of TiO was weighed2Grinding and uniformly mixing a metal-carbon shell and 0.4g of sublimed sulfur, putting the obtained mixture into a reactor, vacuumizing, putting the reactor into an oil bath kettle, heating to 155 ℃, and preserving heat for 4 hours to ensure that the sublimed sulfur is molten and enters TiO2Naturally cooling the hollow inner cavity of the metal-carbon shell to room temperature to obtain the battery composite anode material, wherein the content of S is 52 percent, and TiO is used as a cathode material2A cavity is arranged between the metal-carbon shell and the sulfur core.
Example 4
In this example, the preparation of the composite positive electrode material for a battery includes the following steps:
1) respectively measuring 20mL of deionized water, 70mL of absolute ethyl alcohol and 5mL of 30 wt% ammonia water, sequentially adding the deionized water, 70mL of absolute ethyl alcohol and 5mL of 30 wt% ammonia water into a beaker, uniformly stirring the mixture at room temperature by using a magnetic stirrer, weighing 1.0g of Tetraethoxysilane (TEOS), slowly dropwise adding the Tetraethoxysilane (TEOS) into the uniformly mixed solution, sealing the mouth of the beaker by using a polyethylene film after the dropwise adding is finished, continuously stirring the mixture at room temperature for 6 hours to finish the reaction, and centrifugally cleaning the mixture to obtain the catalystSiO of different diameters2Microspheres of SiO2The diameter of the microsphere is 100 nm-300 nm.
2) 1.4g of CuSO are weighed out4Adding into deionized water, stirring at room temperature to form a metal salt solution A. Separately, 1.7g of SiO were weighed2Dissolving the microspheres in deionized water to obtain a solution B. Dropwise adding the solution B into the metal salt solution A, adjusting pH to 8, and continuously stirring at 40 deg.C for 4 hr to obtain CuSO4Hydrolyzing, centrifugally cleaning and drying to obtain the composite microsphere, namely the surface of which is deposited with Cu (OH)2The microspheres of (1). Wherein, Cu (OH)2Has a thickness of 23nm, Cu (OH)2The content is 22%.
3) Weighing 1.5g of phenolic resin, dissolving in deionized water, adding 1.0g of composite microspheres, continuously stirring for 5 hours at room temperature, centrifugally cleaning, and drying to obtain polymer-coated composite microspheres; and then putting the carbon-coated composite microspheres into a tube furnace, heating to 900 ℃ at a heating rate of 3 ℃/min in an argon atmosphere, and carrying out constant-temperature carbonization treatment for 2h to carbonize the phenolic resin, thereby obtaining the carbon-coated composite microspheres with the carbon content of 32%.
4) Adding the obtained carbon-coated composite microspheres into 2 wt% hydrofluoric acid solution, stirring for 10h for etching treatment to remove SiO2Centrifuging, washing and drying to obtain Cu (OH)2A metal-carbon shell. 0.15g of Cu (OH) was weighed2Grinding and uniformly mixing a metal-carbon shell and 0.35g of sublimed sulfur, putting the obtained mixture into a reactor, vacuumizing, putting the reactor into an oil bath kettle, heating to 160 ℃, and preserving heat for 5 hours to ensure that the sublimed sulfur is molten and enters TiO2Naturally cooling the hollow inner cavity of the metal-carbon shell to room temperature to obtain the battery composite anode material, wherein the content of S is 59 percent, and Cu (OH)2A cavity is arranged between the metal-carbon shell and the sulfur core.
Example 5
In this example, the preparation of the composite positive electrode material for a battery includes the following steps:
1) respectively measuring 20mL of deionized water, 70mL of absolute ethyl alcohol and 5mL of 30 wt% ammonia water, sequentially adding the deionized water, 70mL of absolute ethyl alcohol and 5mL of 30 wt% ammonia water into a beaker, uniformly stirring the mixture at room temperature by using a magnetic stirrer, and slowly dropwise adding 1.0g of Tetraethoxysilane (TEOS) into the mixtureMixing the above solutions, sealing the beaker with polyethylene film, stirring at room temperature for 6 hr to obtain SiO with different diameters2Microspheres of SiO2The diameter of the microsphere is 100 nm-300 nm.
2) Weighing 1.2g ZnCl2Adding into deionized water, stirring at room temperature to form a metal salt solution A. Separately, 1.5g of SiO were weighed2Dissolving the microspheres in deionized water to obtain a solution B. Dropwise adding the solution B into the metal salt solution A, adjusting the pH value to 8.5, and continuously stirring at 45 ℃ for 4h to obtain ZnCl2Hydrolyzing, centrifugally cleaning and drying to obtain the composite microsphere, namely the microsphere with ZnO deposited on the surface. Wherein the ZnO thickness is 25nm, and the ZnO content is 27%.
3) Weighing 1.5g of phenolic resin, dissolving in deionized water, adding 1.3g of composite microspheres, continuously stirring for 5 hours at room temperature, centrifugally cleaning, and drying to obtain polymer-coated composite microspheres; and then putting the carbon-coated composite microspheres into a tubular furnace, heating to 900 ℃ at a heating rate of 3 ℃/min in a nitrogen atmosphere, and carrying out constant-temperature carbonization treatment for 2h to carbonize the phenolic resin, so as to obtain the carbon-coated composite microspheres with the carbon content of 37%.
4) Adding the obtained carbon-coated composite microspheres into a sodium hydroxide solution with the concentration of 2 wt%, stirring for 10h for etching treatment, and removing SiO2And centrifugally separating, cleaning and drying to obtain the ZnO metal-carbon shell. 0.3g NaS is weighed out2O3Dissolving in deionized water, weighing 0.2g of ZnO metal-carbon shell, adding into the solution, adding a surfactant CTAB, stirring for 3h, dropwise adding 0.1mol/L hydrochloric acid into the solution, stirring for 1h, centrifugally cleaning, and drying to obtain the battery composite anode material, wherein the S content is 63%, in order to uniformly diffuse elemental sulfur in the metal-carbon shell, a sulfur core is tightly combined with the metal-carbon shell, loading the elemental sulfur in the metal-carbon shell, placing the battery composite anode material in a tubular furnace, heating to 250 ℃ at a heating rate of 2 ℃/min for 30min for heat treatment, and removing the redundant sulfur on the surface of the battery composite anode material.
Example 6
In this example, the preparation of the composite positive electrode material for a battery includes the following steps:
1) respectively measuring 20mL of deionized water, 70mL of absolute ethyl alcohol and 5mL of 30 wt% ammonia water, sequentially adding the deionized water, 70mL of absolute ethyl alcohol and 5mL of 30 wt% ammonia water into a beaker, uniformly stirring the mixture at room temperature by using a magnetic stirrer, weighing 1.0g of Tetraethoxysilane (TEOS), slowly dropwise adding the Tetraethoxysilane (TEOS) into the uniformly mixed solution, sealing the opening of the beaker by using a polyethylene film after the dropwise adding is finished, continuously stirring the mixture at room temperature for 6 hours to finish the reaction, and centrifugally cleaning the mixture to obtain SiO with different diameters2Microspheres of SiO2The diameter of the microsphere is 100 nm-300 nm.
2) Weighing 1.5g Ni (NO3)2Adding into deionized water, stirring at room temperature to form a metal salt solution A. Separately, 1.2g of SiO were weighed2Dissolving the microspheres in deionized water to obtain a solution B. Dropwise adding the solution B into the metal salt solution A, adjusting pH to 9, and continuously stirring at 50 deg.C for 4 hr to obtain Ni (NO)3)2Hydrolyzing, centrifugally cleaning and drying to obtain the composite microspheres, namely the microspheres with NiO deposited on the surfaces. Wherein the thickness is 27nm, and the NiO content is 30%.
3) Weighing 1.5g of phenolic resin, dissolving in deionized water, adding 1.5g of composite microspheres, continuously stirring for 5 hours at room temperature, centrifugally cleaning, and drying to obtain polymer-coated composite microspheres; and then putting the carbon-coated composite microspheres into a tube furnace, heating to 1000 ℃ at a heating rate of 10 ℃/min in an argon atmosphere, and carrying out constant-temperature carbonization treatment for 1h to carbonize the phenolic resin, so as to obtain the carbon-coated composite microspheres with the carbon content of 40%.
4) Adding the obtained carbon-coated composite microspheres into 2 wt% hydrofluoric acid solution, stirring for 10h for etching treatment to remove SiO2And centrifugally separating, cleaning and drying to obtain the NiO metal-carbon shell. Weighing 0.35g of thiourea, dissolving in deionized water, weighing 0.15g of NiO metal-carbon shell, adding the NiO metal-carbon shell into the solution, adding a surfactant SDBS, stirring for 3 hours, dropwise adding 0.1mol/L phosphoric acid into the solution, stirring for 1 hour, centrifugally cleaning, and drying to obtain the battery composite anode material, wherein the S content is 70%, in order to uniformly diffuse elemental sulfur in the metal-carbon shell, the sulfur core is tightly combined with the metal-carbon shell, and after the elemental sulfur is loaded in the metal-carbon shell, the battery composite anode material is placed in a tubular furnaceAnd heating to 300 ℃ at the heating rate of 5 ℃/min for 30min for heat treatment, and removing the redundant sulfur on the surface of the battery composite anode material.
Example 7
In the embodiment, the battery composite positive electrode material in the embodiment 3 and polyvinylidene fluoride (PVDF) are mixed according to the mass ratio of 8: 1, transferring the mixture into a 5mL beaker, dripping a proper amount of NMP (N-methyl pyrrolidone), magnetically stirring for 24 hours to obtain anode slurry, coating the slurry on an aluminum foil by using a scraper, drying the aluminum foil in a 60 ℃ forced air drying oven for 12 hours, punching the aluminum foil into 13mm round pieces by using a punching machine, and weighing the mass of each round piece by using an analytical balance to calculate the content of active substances in the round pieces. And placing the liquid-transferring gun, the diaphragm, the positive electrode shell, the negative electrode shell, the gasket, the elastic sheet, the positive electrode sheet and the lithium sheet which are used for assembling the battery in the glove box. In the glove box according to the following assembly sequence: assembling the battery by using a negative electrode shell, a lithium sheet, electrolyte, a diaphragm, the electrolyte, a positive electrode sheet, a gasket, an elastic sheet and a positive electrode shell, wherein the amount of the electrolyte is calculated by 25 microliter/mg sulfur, and the electrolyte comprises 1.0M LiTFSI and 1 wt% LiNO3DME: DOL solution (DME: DOL ═ 1:1 Vol%), assembled into 2032 coin cells. And (3) carrying out charge-discharge test at constant temperature of 25 ℃ and within the voltage range of 1.7V-2.8V and at the current density of 0.05C, and testing the electrochemical performance of the material.
Referring to fig. 3 and 4, fig. 3 is a graph showing charge and discharge curves of a battery using a composite positive electrode material for a battery according to embodiment 3 of the present invention as a positive electrode, and fig. 4 is a graph showing cycle performance of a battery using a composite positive electrode material for a battery according to embodiment 3 of the present invention as a positive electrode. Fig. 3 shows that the initial capacity of the lithium-sulfur battery prepared by using the composite cathode material of the battery in example 3 is 1143mAh/g, and after 30 cycles of cycling, the capacity of the lithium-sulfur battery is relatively less attenuated and still maintains 807mAh/g, which indicates that the capacity of the lithium-sulfur battery is slowly attenuated during cycling. Fig. 4 shows that the charging and discharging efficiency of the lithium-sulfur battery prepared by using the composite cathode material of the battery of example 3 is close to 100%, the capacity of the first 20 circles shows that the capacity decays slowly, and the capacity tends to be stable after 20 circles.
Example 8
In this example, the preparation of the composite positive electrode material for a battery includes the following steps:
1) respectively measuring 20mL of deionized water, 70mL of absolute ethyl alcohol and 5mL of 30 wt% ammonia water, sequentially adding the deionized water, 70mL of absolute ethyl alcohol and 5mL of 30 wt% ammonia water into a beaker, uniformly stirring the mixture at room temperature by using a magnetic stirrer, weighing 1.0g of Tetraethoxysilane (TEOS), slowly dropwise adding the Tetraethoxysilane (TEOS) into the uniformly mixed solution, sealing the opening of the beaker by using a polyethylene film after the dropwise adding is finished, continuously stirring the mixture at room temperature for 6 hours to finish the reaction, and centrifugally cleaning the mixture to obtain SiO with different diameters2Microspheres of SiO2The diameter of the microsphere is 100 nm-300 nm.
2) Weighing 1.2g Co (NO)3)3Adding into deionized water, and stirring at room temperature to form a metal salt solution A. Separately, 1.4g of SiO were weighed2Dissolving the microspheres in deionized water to obtain a solution B. Dropwise adding the solution B into the metal salt solution A, adjusting pH to 7.5, and continuously stirring at 30 deg.C for 3.5h, Co (NO)3)3Hydrolyzing, centrifugally cleaning and drying to obtain the composite microsphere, namely the surface of which is deposited with Co (OH)3The microspheres of (1). Wherein, Co (OH)3Has a thickness of 22nm, Co (OH)3The content is 12%.
3) Weighing 1.5g of phenolic resin, dissolving in deionized water, adding 1.0g of composite microspheres, continuously stirring for 5 hours at room temperature, centrifugally cleaning, and drying to obtain polymer-coated composite microspheres; and then putting the carbon-coated composite microspheres into a tube furnace, heating to 600 ℃ at a heating rate of 2 ℃/min in an argon atmosphere, and carrying out constant-temperature carbonization treatment for 5 hours to carbonize the phenolic resin, thereby obtaining the carbon-coated composite microspheres with the carbon content of 22%.
4) Adding the obtained carbon-coated composite microspheres into a sodium hydroxide solution with the concentration of 2 wt%, stirring for 10h for etching treatment, and removing SiO2Centrifuging, washing and drying to obtain Co (OH)3A metal-carbon shell. 0.12g of Co (OH) is weighed3Grinding and mixing metal-carbon shell and 0.35g sublimed sulfur uniformly, placing the obtained mixture into a reactor, placing the reactor into an oil bath kettle, heating to 130 ℃, preserving heat for 8 hours to enable the sublimed sulfur to be molten and enter Co (OH)3Naturally cooling the hollow cavity of the metal-carbon shell to room temperature to obtain the composite anode material of the battery, Co (OH)3MetalA cavity is provided between the carbon shell and the sulphur core.
The same method as that of example 7 was used to assemble the battery and perform the electrochemical performance test, and please refer to fig. 5, which is a graph illustrating the cycle performance of the battery using the composite positive electrode material as the positive electrode in example 8. The result shows that the initial capacity of the lithium-sulfur battery prepared by adopting the composite cathode material of the battery in the embodiment is 975mAh/g, the capacity of the lithium-sulfur battery is relatively attenuated more after 30 cycles of circulation, and the specific discharge capacity is 627mAh/g, which indicates that the capacity of the lithium-sulfur battery is rapidly attenuated in the circulation process.
Comparative example 1
In this example, the preparation of the composite positive electrode material for a battery includes the following steps:
1) respectively measuring 20mL of deionized water, 70mL of absolute ethyl alcohol and 5mL of 30 wt% ammonia water, sequentially adding the deionized water, 70mL of absolute ethyl alcohol and 5mL of 30 wt% ammonia water into a beaker, uniformly stirring the mixture at room temperature by using a magnetic stirrer, weighing 1.0g of Tetraethoxysilane (TEOS), slowly dropwise adding the Tetraethoxysilane (TEOS) into the uniformly mixed solution, sealing the opening of the beaker by using a polyethylene film after the dropwise adding is finished, continuously stirring the mixture at room temperature for 6 hours to finish the reaction, and centrifugally cleaning the mixture to obtain SiO with different diameters2Microspheres of SiO2The diameter of the microsphere is 100 nm-300 nm.
2) Weighing 1.5g of phenolic resin, dissolving in deionized water, adding 1.0g of SiO2Continuously stirring the microspheres for 5 hours at room temperature, centrifugally cleaning and drying to obtain the SiO coated with the polymer2Microspheres; then coating carbon on SiO2Putting the microspheres into a tube furnace, heating to 600 ℃ at the heating rate of 2 ℃/min in the argon atmosphere, and carrying out constant-temperature carbonization treatment for 5h to carbonize the phenolic resin to obtain carbon-coated SiO2And (3) microspheres.
3) The obtained carbon-coated SiO2Adding the microspheres into 2 wt% hydrofluoric acid solution, stirring for 10h for etching treatment to remove SiO2And centrifugally separating, and cleaning and drying to obtain the hollow carbon shell. Weighing 0.1g of hollow carbon shell and 0.3g of sublimed sulfur, grinding and uniformly mixing, placing the obtained mixture in a reactor, vacuumizing, placing the reactor in an oil bath pot, heating to 120 ℃, preserving heat for 10 hours to enable the sublimed sulfur to be molten and enter the carbon shellAnd naturally cooling the hollow inner cavity to room temperature to obtain the battery composite cathode material, wherein a cavity is arranged between the hollow carbon shell and the sulfur core.
And (2) mixing the composite positive electrode material of the battery in the comparative example 1 and PVDF according to the mass ratio of 8: 1, transferring the mixture into a 5mL beaker, dripping a proper amount of NMP (N-methyl pyrrolidone), magnetically stirring for 24 hours to obtain anode slurry, coating the slurry on an aluminum foil by using a scraper, drying the aluminum foil in a 60 ℃ forced air drying oven for 12 hours, punching the aluminum foil into 13mm round pieces by using a punching machine, and weighing the mass of each round piece by using an analytical balance to calculate the content of active substances in the round pieces. Lithium sulfur batteries were assembled and tested for electrochemical performance as in example 7.
Referring to fig. 6 and 7, fig. 6 is a graph showing charge and discharge of a battery using a composite positive electrode material for a battery provided in comparative example 1 as a positive electrode, and fig. 7 is a graph showing cycle performance of a battery using a composite positive electrode material for a battery provided in comparative example 1 as a positive electrode. Fig. 6 shows that the initial capacity of the lithium-sulfur battery prepared by using the composite cathode material of the battery of the comparative example 1 is 824mAh/g, the capacity of the lithium-sulfur battery relatively decays more after 30 cycles of cycling, the specific discharge capacity is 422mAh/g, and the capacity decays more rapidly in the cycling process. Fig. 7 shows that the lithium-sulfur battery prepared by using the composite positive electrode material of the battery of comparative example 1 has charge-discharge efficiency close to 100%, a low first discharge capacity, and a rapid capacity fade after 30 cycles.
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and amendments can be made without departing from the principle of the present invention, and these modifications and amendments should also be considered as the protection scope of the present invention.

Claims (4)

1. The battery composite positive electrode material is characterized by having a core-shell structure;
the core-shell structure comprises a metal-carbon shell and a sulfur core disposed within the metal-carbon shell;
the metal-carbon shell is formed from cobalt hydroxide and carbon, the cobalt hydroxide being encapsulated within the carbon;
the sulfur core is formed from elemental sulfur;
the diameter of the core-shell structure is 100 nm-600 nm;
the thickness of the metal-carbon shell is 10 nm-50 nm;
the diameter of the sulfur core is 30 nm-200 nm;
the particle size of the cobalt hydroxide is 5 nm-30 nm;
the surface of the battery composite positive electrode material is provided with micropores and mesopores;
the aperture of the micropores is 1 nm;
the aperture of the mesopores is 2 nm.
2. The battery composite positive electrode material according to claim 1, wherein the mass content of the elemental sulfur in the battery composite positive electrode material is 40-70%;
the mass content of the cobalt hydroxide in the battery composite positive electrode material is 5-30%;
the mass content of the carbon in the battery composite positive electrode material is 20-40%.
3. The battery composite positive electrode material of claim 1, wherein a cavity is disposed between the metal-carbon shell and the sulfur core.
4. A battery, wherein a positive electrode material of the battery comprises the battery composite positive electrode material according to any one of claims 1 to 3.
CN201910371857.7A 2019-05-06 2019-05-06 Lithium-sulfur battery composite positive electrode material, preparation method thereof and battery Active CN110098396B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201910371857.7A CN110098396B (en) 2019-05-06 2019-05-06 Lithium-sulfur battery composite positive electrode material, preparation method thereof and battery

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201910371857.7A CN110098396B (en) 2019-05-06 2019-05-06 Lithium-sulfur battery composite positive electrode material, preparation method thereof and battery

Publications (2)

Publication Number Publication Date
CN110098396A CN110098396A (en) 2019-08-06
CN110098396B true CN110098396B (en) 2022-05-10

Family

ID=67447027

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201910371857.7A Active CN110098396B (en) 2019-05-06 2019-05-06 Lithium-sulfur battery composite positive electrode material, preparation method thereof and battery

Country Status (1)

Country Link
CN (1) CN110098396B (en)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110492071A (en) * 2019-08-19 2019-11-22 西京学院 Inner wall is loaded with the hollow carbon sphere and preparation method and purposes of nickel hydroxide and sulphur
CN110931752B (en) * 2019-12-09 2021-05-28 华南师范大学 Nitrogen-doped porous carbon loaded metal nickel lithium-sulfur battery positive electrode material and preparation method and application thereof
CN114583166A (en) * 2020-12-01 2022-06-03 河南大学 Lithium-sulfur battery and preparation method thereof
CN114583165A (en) * 2020-12-01 2022-06-03 河南大学 Metal/metal oxide lithium-sulfur battery positive electrode framework structure
CN112786856B (en) * 2021-01-15 2022-04-22 西安理工大学 Lithium-sulfur battery positive electrode material and preparation method thereof
CN114744174B (en) * 2022-04-14 2023-10-27 桂林理工大学 Positive electrode composite material of lithium-sulfur battery and preparation method thereof

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104201339B (en) * 2014-09-18 2016-08-17 厦门大学 Anode and preparation method thereof and the application in lithium-sulfur cell
EP3168905A1 (en) * 2015-11-10 2017-05-17 Grabat Energy, S.L. Carbon composites
CN105449209B (en) * 2016-01-25 2018-11-09 大连理工大学 A kind of lithium sulfur battery anode material of richness nitrogen eggshell type, preparation method and applications
CN107359321B (en) * 2017-06-09 2018-07-27 深圳启辰新能源科技有限公司 The lithium sulfur battery anode material and preparation method thereof of the nitrogen-doped carbon of spherical structure/titanium oxide bivalve cladding titanium oxide/sulphur
CN108305997A (en) * 2017-12-28 2018-07-20 肇庆市华师大光电产业研究院 A kind of sulphur/two-layer titanium dioxide composite material and preparation method and application

Also Published As

Publication number Publication date
CN110098396A (en) 2019-08-06

Similar Documents

Publication Publication Date Title
CN110098396B (en) Lithium-sulfur battery composite positive electrode material, preparation method thereof and battery
CN111384377B (en) Positive electrode material and preparation method and application thereof
CN111193019B (en) Lithium supplement additive, preparation method thereof and lithium ion battery
JP5731276B2 (en) Positive electrode active material for lithium secondary battery, method for producing the same, and lithium secondary battery
KR20220092556A (en) Anode active material for battery and manufacturing method thereof, battery negative electrode, battery
CN108511786B (en) All-solid-state lithium battery and preparation method thereof
CN112151773B (en) Positive active material, preparation method thereof and lithium battery
JP6524610B2 (en) Positive electrode active material for non-aqueous secondary battery and method for producing the same
CN112542589B (en) Preparation method, product and application of positive electrode prelithiation material
CN108899545B (en) Mesoporous core-shell structure surface-coated lithium battery ternary cathode material and preparation method thereof
CN112670492B (en) Positive electrode material, method for producing same, and electrochemical device
CN108987683A (en) A kind of preparation method of carbon coating tertiary cathode material
CN111342031B (en) Multi-element gradient composite high-first-efficiency lithium battery negative electrode material and preparation method thereof
JP2009245917A (en) Positive electrode active material for nonaqueous electrolyte secondary battery, method for manufacturing same, and positive electrode for nonaqueous electrolyte secondary battery, and nonaqueous electrolyte secondary battery
CN116014104A (en) Lithium-rich nickel positive electrode material, preparation method thereof, positive electrode sheet and secondary battery
CN112186166B (en) Molybdenum/cobalt oxide-carbon composite material and preparation method thereof, lithium ion battery negative electrode piece and lithium ion battery
CN112289982B (en) Positive electrode material, preparation method thereof and solid-state lithium battery
CN116598449A (en) Lithium-rich positive electrode material, preparation method thereof, positive electrode plate and secondary battery
CN109309228B (en) Positive electrode active material, preparation method, positive electrode and high-specific-energy power battery
CN109817968B (en) Surface-coated lithium nickel manganese oxide particles and method for producing same
CN114142172B (en) Functional diaphragm, preparation method thereof and lithium ion battery containing functional diaphragm
CN115911324A (en) Positive electrode material, secondary battery, and electric device
CN113517438B (en) Internal confinement heterojunction yolk-shell electrode material and preparation method and application thereof
KR102628740B1 (en) Precursor for anode materials for rechargeable lithium-ion batteries
CN113113588A (en) Method for preparing lithium fast ion conductor material coated high-nickel ternary layered oxide by using covalent interface engineering strategy

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