CN110797532A - Lithium-sulfur battery composite positive electrode material and preparation method thereof - Google Patents
Lithium-sulfur battery composite positive electrode material and preparation method thereof Download PDFInfo
- Publication number
- CN110797532A CN110797532A CN201911098999.7A CN201911098999A CN110797532A CN 110797532 A CN110797532 A CN 110797532A CN 201911098999 A CN201911098999 A CN 201911098999A CN 110797532 A CN110797532 A CN 110797532A
- Authority
- CN
- China
- Prior art keywords
- lithium
- positive electrode
- electrode material
- graphene
- sulfur battery
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000002131 composite material Substances 0.000 title claims abstract description 48
- JDZCKJOXGCMJGS-UHFFFAOYSA-N [Li].[S] Chemical compound [Li].[S] JDZCKJOXGCMJGS-UHFFFAOYSA-N 0.000 title claims abstract description 44
- 239000007774 positive electrode material Substances 0.000 title claims abstract description 43
- 238000002360 preparation method Methods 0.000 title claims abstract description 11
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 54
- 229910021389 graphene Inorganic materials 0.000 claims abstract description 54
- 239000002210 silicon-based material Substances 0.000 claims abstract description 30
- 229920000767 polyaniline Polymers 0.000 claims abstract description 23
- 238000000034 method Methods 0.000 claims abstract description 8
- ROOXNKNUYICQNP-UHFFFAOYSA-N ammonium persulfate Chemical compound [NH4+].[NH4+].[O-]S(=O)(=O)OOS([O-])(=O)=O ROOXNKNUYICQNP-UHFFFAOYSA-N 0.000 claims description 48
- PAYRUJLWNCNPSJ-UHFFFAOYSA-N Aniline Chemical compound NC1=CC=CC=C1 PAYRUJLWNCNPSJ-UHFFFAOYSA-N 0.000 claims description 46
- 229910001870 ammonium persulfate Inorganic materials 0.000 claims description 24
- 238000002156 mixing Methods 0.000 claims description 23
- 229910052909 inorganic silicate Inorganic materials 0.000 claims description 17
- 238000001027 hydrothermal synthesis Methods 0.000 claims description 15
- GELKBWJHTRAYNV-UHFFFAOYSA-K lithium iron phosphate Chemical compound [Li+].[Fe+2].[O-]P([O-])([O-])=O GELKBWJHTRAYNV-UHFFFAOYSA-K 0.000 claims description 15
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 15
- 238000001354 calcination Methods 0.000 claims description 14
- 239000010406 cathode material Substances 0.000 claims description 12
- 238000006116 polymerization reaction Methods 0.000 claims description 10
- YUKQRDCYNOVPGJ-UHFFFAOYSA-N thioacetamide Chemical compound CC(N)=S YUKQRDCYNOVPGJ-UHFFFAOYSA-N 0.000 claims description 9
- DLFVBJFMPXGRIB-UHFFFAOYSA-N thioacetamide Natural products CC(N)=O DLFVBJFMPXGRIB-UHFFFAOYSA-N 0.000 claims description 9
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 6
- 239000000203 mixture Substances 0.000 claims description 6
- 229910020700 Na3VO4 Inorganic materials 0.000 claims description 5
- 238000011068 loading method Methods 0.000 claims description 5
- 238000002791 soaking Methods 0.000 claims description 5
- 229910007562 Li2SiO3 Inorganic materials 0.000 claims description 4
- 239000000377 silicon dioxide Substances 0.000 claims description 3
- 235000012239 silicon dioxide Nutrition 0.000 claims description 3
- 239000010405 anode material Substances 0.000 abstract description 16
- 239000000463 material Substances 0.000 abstract description 15
- 230000008569 process Effects 0.000 abstract description 7
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 abstract description 6
- 238000006243 chemical reaction Methods 0.000 abstract description 5
- 239000013543 active substance Substances 0.000 abstract description 4
- 230000009286 beneficial effect Effects 0.000 abstract description 2
- 230000008859 change Effects 0.000 abstract description 2
- 238000003487 electrochemical reaction Methods 0.000 abstract description 2
- 230000005611 electricity Effects 0.000 abstract 1
- 230000001681 protective effect Effects 0.000 abstract 1
- 239000000243 solution Substances 0.000 description 26
- 239000010410 layer Substances 0.000 description 25
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 16
- 239000000047 product Substances 0.000 description 14
- 239000007788 liquid Substances 0.000 description 9
- 238000005303 weighing Methods 0.000 description 9
- 239000007864 aqueous solution Substances 0.000 description 8
- 239000008367 deionised water Substances 0.000 description 8
- 229910021641 deionized water Inorganic materials 0.000 description 8
- 238000010438 heat treatment Methods 0.000 description 8
- 238000003756 stirring Methods 0.000 description 8
- 229910052493 LiFePO4 Inorganic materials 0.000 description 7
- 238000001291 vacuum drying Methods 0.000 description 7
- 230000000052 comparative effect Effects 0.000 description 6
- 239000005457 ice water Substances 0.000 description 6
- 229910052717 sulfur Inorganic materials 0.000 description 6
- 239000011593 sulfur Substances 0.000 description 6
- 229910010710 LiFePO Inorganic materials 0.000 description 5
- 235000019441 ethanol Nutrition 0.000 description 5
- 239000007795 chemical reaction product Substances 0.000 description 4
- 238000007599 discharging Methods 0.000 description 4
- 239000002245 particle Substances 0.000 description 4
- FFRBMBIXVSCUFS-UHFFFAOYSA-N 2,4-dinitro-1-naphthol Chemical compound C1=CC=C2C(O)=C([N+]([O-])=O)C=C([N+]([O-])=O)C2=C1 FFRBMBIXVSCUFS-UHFFFAOYSA-N 0.000 description 3
- 238000004140 cleaning Methods 0.000 description 3
- 229910052593 corundum Inorganic materials 0.000 description 3
- 239000010431 corundum Substances 0.000 description 3
- 229910000155 iron(II) phosphate Inorganic materials 0.000 description 3
- 229910052808 lithium carbonate Inorganic materials 0.000 description 3
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 3
- 239000012299 nitrogen atmosphere Substances 0.000 description 3
- 239000000843 powder Substances 0.000 description 3
- 238000004321 preservation Methods 0.000 description 3
- 238000012216 screening Methods 0.000 description 3
- 239000011247 coating layer Substances 0.000 description 2
- 238000005034 decoration Methods 0.000 description 2
- 239000003792 electrolyte Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 1
- BOTDANWDWHJENH-UHFFFAOYSA-N Tetraethyl orthosilicate Chemical compound CCO[Si](OCC)(OCC)OCC BOTDANWDWHJENH-UHFFFAOYSA-N 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 239000011258 core-shell material Substances 0.000 description 1
- 125000004122 cyclic group Chemical group 0.000 description 1
- 238000009831 deintercalation Methods 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 238000009830 intercalation Methods 0.000 description 1
- 230000002687 intercalation Effects 0.000 description 1
- 229910052744 lithium Inorganic materials 0.000 description 1
- 230000003446 memory effect Effects 0.000 description 1
- 239000002954 polymerization reaction product Substances 0.000 description 1
- 229920001021 polysulfide Polymers 0.000 description 1
- 239000005077 polysulfide Substances 0.000 description 1
- 150000008117 polysulfides Polymers 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 150000003377 silicon compounds Chemical class 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000001132 ultrasonic dispersion Methods 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/58—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
- H01M4/5825—Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines
-
- 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
- H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
- H01M4/624—Electric conductive 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
- H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
- H01M4/624—Electric conductive fillers
- H01M4/625—Carbon or graphite
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- 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 batteries, and particularly relates to a lithium-sulfur battery composite positive electrode material and a preparation method thereof. In the invention, the polyaniline layer has a protective effect on the composite anode material, has higher conductivity and a more complete structure, and is beneficial to realizing charge and discharge under high current density; the PANI conducting layer does not participate in electrochemical reaction, so that the conducting performance of the PANI conducting layer is improved, the PANI conducting layer can be well suitable for the charge-discharge process under high current density, meanwhile, the PANI layer reduces the loss of active substances in the charge-discharge process, and the structural integrity is kept; PANI layer of silicon-containing compound and VS4Better accommodating Li+The volume change caused by the embedding and the de-embedding improves the charge-discharge cycle stability of the composite anode material; the large specific surface area of the graphene material can enable the graphene material to have a large contact area with elemental sulfur, and the improvement of electricity is facilitated(iii) daughter transport Rate and reaction area, with silicon containing Compound and VS4The specific capacity of the composite anode material can be further improved.
Description
Technical Field
The invention belongs to the technical field of lithium-sulfur batteries, and particularly relates to a lithium-sulfur battery composite positive electrode material and a preparation method thereof.
Background
The lithium-sulfur battery has the advantages of large specific energy, high working voltage, long cycle life, low self-discharge rate, no memory effect, environmental friendliness and the like, and is widely applied to the field of portable electronic equipment. The material used as the anode material is also continuously expanded, and is used as an important component in the lithium-sulfur battery, so that the large-scale popularization and application of the lithium-sulfur battery are always restricted. When the sulfur is used as a positive electrode material of the lithium-sulfur battery, the problems of poor electrochemical performance, low utilization rate and the like of the sulfur in an electrode are caused because the ionic conductivity and the electronic conductivity of the sulfur are very low, and during the charging and discharging processes, the generated lithium polysulfide can be irreversibly dissolved in electrolyte, and dispersed sulfur particles can be agglomerated. In addition, the conductive structure of the electrode can be changed in the charging and discharging processes, and the factors cause the reduction of the cycle charging and discharging performance and the specific capacity of the battery.
Disclosure of Invention
In view of the above, the present invention provides a composite positive electrode material for a lithium-sulfur battery and a preparation method thereof. The lithium-sulfur battery composite positive electrode material provided by the invention has good cyclic charge and discharge performance and high specific capacity.
In order to achieve the purpose of the invention, the invention provides the following technical scheme:
the invention provides a lithium-sulfur battery composite positive electrode material which comprises a lithium iron phosphate layer, a graphene wrapping layer and a polyaniline layer which are sequentially stacked, wherein the graphene wrapping layer comprises a silicon-containing compound and VS4Said silicon-containing compound and VS4The graphene is loaded on the graphene.
Preferably, the mass content of the graphene coating layer is 15-20%.
Preferably, the mass content of the polyaniline layer is 5-10%.
Preferably, the silicon-containing compound comprises Li2SiO3、Li4SiO4And silicon dioxide.
Preferably, the silicon-containing compound and VS4The loading amount on the graphene is 30-40 wt%.
Preferably, the silicon-containing compound and VS4The mass ratio of (A) to (B) is 1: 1-5.
The invention also provides a preparation method of the composite cathode material of the lithium-sulfur battery, which comprises the following steps:
providing a lithium iron phosphate positive electrode material;
mixing graphene oxide, water and Na3VO4Mixing the mixture with thioacetamide and then carrying out hydrothermal reaction to obtain a hydrothermal product;
mixing the lithium iron phosphate positive electrode material, a silicon-containing compound solution and a hydrothermal product, and calcining to obtain a graphene-coated positive electrode material;
and soaking the positive electrode material wrapped by the graphene in aniline for polymerization reaction to obtain the lithium-sulfur battery composite positive electrode material.
Preferably, the temperature of the hydrothermal reaction is 160-180 ℃, and the time of the hydrothermal reaction is 20-24 h.
Preferably, the calcining temperature is 400-600 ℃, and the time is 1-2 h.
Preferably, the aniline is polymerized in the presence of ammonium persulfate, and the molar ratio of the aniline to the ammonium persulfate is 1: 1.
The invention provides a lithium-sulfur battery composite positive electrode material which comprises a lithium iron phosphate layer, a graphene wrapping layer and a polyaniline layer which are sequentially stacked, wherein the graphene wrapping layer comprises a silicon-containing compound and VS4Said silicon-containing compound and VS4The graphene is loaded on the graphene. According to the invention, the core-shell structure material taking PANI (polyaniline) as the shell has the advantages of simple structure, low cost, stable circulation and high circulation capacity, the polyaniline layer has a protection effect on the composite anode material, and compared with the composite material directly exposed in the electrolyte environment, the composite anode material coated by the polyaniline layer has higher conductivity and a more complete structure, and is beneficial to realizing charge and discharge under high current density, so that the development and application of the lithium-sulfur battery have greater potential; the PANI conducting layer does not participate in electrochemical reaction, is coated on the surface of the silicon-containing compound to improve the conducting performance, can be well suitable for the charge-discharge process under high current density, and simultaneously reduces the loss of active substances of the silicon-containing compound in the charge-discharge process, such as the falling and dissolution of the active substances in the charge-discharge process, thereby maintaining the structural integrity; PANI layer of silicon-containing compound and VS4Better accommodating Li+The volume change caused by the intercalation and deintercalation is reduced, and the loss of active substances on a current collector is reduced, so that the charge-discharge cycle stability of the positive electrode material is obviously improved; silicon-containing compounds and VS4The graphene is loaded on graphene, and the graphene material has large specific surface area, so that the graphene material has large contact area with sulfur simple substance, and is favorable for improving the electron transmission rate and the reaction area so as to improveHigh-sulfur elemental positive material conductivity and cycle performance, and simultaneously silicon-containing compound and VS4The specific capacity of the composite anode material can be further improved. The data of the embodiment shows that the first specific discharge capacity of the composite cathode material of the lithium-sulfur battery provided by the invention is 1782-1947 mAh/g under the charging and discharging current density of 100mA/g, and the specific discharge capacity is kept at 90-94% after 50 cycles.
Detailed Description
The invention provides a lithium-sulfur battery composite positive electrode material which comprises a lithium iron phosphate layer, a graphene wrapping layer and a polyaniline layer which are sequentially stacked, wherein the graphene wrapping layer comprises a silicon-containing compound and VS4Said silicon-containing compound and VS4The graphene is loaded on the graphene.
In the invention, the mass content of the graphene coating layer is preferably 15-20%.
In the invention, the mass content of the polyaniline layer is preferably 5-10%.
In the present invention, the silicon-containing compound preferably includes Li2SiO3、Li4SiO4And silicon dioxide.
In the present invention, the silicon-containing compound and VS4The preferable load amount on the graphene is 30-40 wt%.
In the present invention, the silicon-containing compound and VS4The mass ratio of (A) to (B) is preferably 1: 1-5.
The invention also provides a preparation method of the composite cathode material of the lithium-sulfur battery, which comprises the following steps:
providing a lithium iron phosphate positive electrode material;
mixing graphene oxide, water and Na3VO4Mixing the mixture with thioacetamide and then carrying out hydrothermal reaction to obtain a hydrothermal product;
mixing the lithium iron phosphate positive electrode material, a silicon-containing compound solution and a hydrothermal product, and calcining to obtain a graphene-coated positive electrode material;
and soaking the positive electrode material wrapped by the graphene in aniline for polymerization reaction to obtain the lithium-sulfur battery composite positive electrode material.
The invention provides a lithium iron phosphate positive electrode material. In the present invention, the lithium iron phosphate positive electrode material is preferably spherical. In the invention, the lithium iron phosphate cathode material is preferably pretreated before use, the pretreatment preferably comprises screening and calcination, the screening and calcination are not particularly limited in specific mode, in the embodiment of the invention, the screening is preferably carried out to obtain material particles with the particle size of 1-10 μm, and then the material particles are calcined at 400-600 ℃ to remove impurities.
The invention uses graphene oxide, water and Na3VO4Mixing with thioacetamide, and carrying out hydrothermal reaction to obtain a hydrothermal product.
In the invention, the temperature of the hydrothermal reaction is preferably 160-180 ℃, and the time of the hydrothermal reaction is preferably 20-24 h.
In the present invention, the Na is3VO4The preferred molar ratio of thioacetamide to thioacetamide is 1: 5-1: 6.
In the invention, the graphene oxide is mixed with Na3VO4The mass ratio of (A) to (B) is preferably 1: 27 to 1: 28, and more preferably 1: 27.5 to 1: 28.
After the hydrothermal reaction is finished, the invention preferably uses deionized water and ethanol to alternately clean the obtained hydrothermal reaction product, and then carries out vacuum drying to obtain the hydrothermal product. In the present invention, the number of times of the alternate washing is independently preferably 4 to 6 times. In the invention, the temperature of the vacuum drying is preferably 60-80 ℃, more preferably 65-85 ℃, and the time of the vacuum drying is preferably 10-12 h.
After the lithium iron phosphate anode material and the hydrothermal product are obtained, the lithium iron phosphate anode material, the silicon-containing compound solution and the hydrothermal product are mixed and calcined to obtain the graphene-coated anode material.
In the invention, the calcination temperature is preferably 400-600 ℃, the time is preferably 1-2 h, and the heating rate of heating to the calcination temperature is preferably 5-10 ℃/min. In the present invention, the calcination is preferably carried out in air. In the present invention, the said catalyst containsThe silicon compound solution preferably comprises Li2SiO3Aqueous solution, Li4SiO4One or more of an aqueous solution and an absolute ethyl alcohol solution of ethyl orthosilicate. In the invention, the concentration of the silicon-containing compound solution is preferably 0.01-1 mmol/L.
In the invention, the mixing is preferably carried out for 0.5-2 h by ultrasonic dispersion.
After the positive electrode material wrapped by the graphene is obtained, the positive electrode material wrapped by the graphene is soaked in aniline for polymerization reaction, and the lithium-sulfur battery composite positive electrode material is obtained.
In the present invention, the aniline is preferably polymerized in the presence of ammonium persulfate, and the molar ratio of the aniline to the ammonium persulfate is preferably 1: 1.
In the invention, the ammonium persulfate is preferably added in the form of an HCl solution of ammonium persulfate, and the HCl solution of the ammonium persulfate is preferably dropwise added under the conditions of ice-water bath and stirring. In the present invention, the dropwise addition is preferably dropwise addition.
In the invention, the polymerization reaction is preferably carried out in an ice-water bath, and the time of the polymerization reaction is preferably 8-10 h.
After the polymerization reaction is finished, the polymerization reaction product is preferably alternately cleaned by deionized water and ethanol, and then vacuum drying is carried out to obtain the lithium-sulfur battery composite positive electrode material.
In order to further illustrate the present invention, the following examples are provided to describe the composite cathode material for lithium-sulfur battery and the preparation method thereof in detail, but they should not be construed as limiting the scope of the present invention. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. 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.
Example 1
(1) Mixing Fe3(PO4)2Powder with Li2CO3Pressing into a prescriptionAfter fully and uniformly mixing the stoichiometric ratio, calcining the mixture for 10 hours at 400 ℃ in nitrogen atmosphere to obtain LiFePO4。
(2) Weighing graphene oxide powder in 150mL of deionized water, ultrasonically dispersing until the solution is golden yellow, and sequentially adding Na with the metering ratio of 1: 53VO4(2.0125g) and thioacetamide, stirred for 1 h. And transferring the solution into a hydrothermal reaction kettle, and reacting for 24 hours at 160 ℃. After the reaction is finished, alternately cleaning the reaction product for 4-6 times by using deionized water and ethanol, and performing vacuum drying at 60 ℃ for 12 hours to obtain a hydrothermal product, wherein VS is4The loading on graphene was 32 wt%;
according to Li4SiO4The content of Li accounts for 8 wt% of the mass of graphene, and Li is weighed4SiO4Obtaining 0.01mmol/L Li in water solution4SiO4An aqueous solution. Mixing LiFePO4Hydrothermal product and Li4SiO4Ultrasonically dispersing the aqueous solution for 1h to obtain uniformly dispersed turbid liquid, transferring the turbid liquid to a magnetic heating stirrer, continuing to magnetically stir and heating the turbid liquid at 30 ℃ until the material is dried, transferring the dried material into a corundum boat, carrying out temperature programming in a muffle furnace to 600 ℃, and carrying out heat preservation for 4h to obtain a graphene-coated LiFePO layer4The mass of the graphene accounts for 20% of the total mass of the composite cathode material;
(3) weighing aniline according to the mass content of a polyaniline layer accounting for 10 wt% of the total mass of the composite cathode material, weighing ammonium persulfate according to the molar ratio of 1: 1 of the aniline to the ammonium persulfate, mixing the ammonium persulfate and an HCl solution to obtain an HCl solution of the ammonium persulfate, dropwise adding the HCl solution of the ammonium persulfate into the aniline under the conditions of ice-water bath and stirring, and adding Li to the aniline under the conditions of ice-water bath and stirring4SiO4Coated LiFePO4And soaking the lithium-sulfur battery anode material in aniline for polymerization reaction for 8 hours to obtain the lithium-sulfur battery composite anode material.
The electrochemical performance of the composite cathode material of the lithium-sulfur battery prepared in this example was tested, and the results are as follows: the first discharge specific capacity is 1947mAh/g under the charge-discharge current density of 100mA/g, and the discharge specific capacity is maintained at 94% after 50 cycles.
Comparative example 1
The same as example 1, except that the lithium sulfur battery composite positive electrode material did not contain a polyaniline layer.
The electrochemical performance of the composite positive electrode material of the lithium-sulfur battery prepared by the comparative example is tested, and the results are as follows: the first discharge specific capacity is 1647mAh/g under the charge-discharge current density of 100mA/g, and the discharge specific capacity is kept at 70% after 50 cycles.
Example 2
(1) Mixing Fe3(PO4)2Powder with Li2CO3Fully and uniformly mixing the raw materials according to the stoichiometric ratio, calcining the mixture for 10 hours at 400 ℃ in nitrogen atmosphere to obtain LiFePO4。
(2) Weighing graphene oxide powder in 150mL of deionized water, ultrasonically dispersing until the solution is golden yellow, and sequentially adding Na with the metering ratio of 1: 53VO4(2.0125g) and thioacetamide, stirred for 1 h. And transferring the solution into a hydrothermal reaction kettle, and reacting for 24 hours at 160 ℃. After the reaction is finished, alternately cleaning the reaction product for 4-6 times by using deionized water and ethanol, and performing vacuum drying at 60 ℃ for 12 hours to obtain a hydrothermal product, wherein VS is4The loading on graphene was 15 wt%;
according to Li4SiO4The content of Li accounts for 15 wt% of the mass of graphene, and Li is weighed4SiO4Obtaining 0.01mmol/L Li in water solution4SiO4An aqueous solution. Mixing LiFePO4Hydrothermal product and Li4SiO4Ultrasonically dispersing the aqueous solution for 1h to obtain uniformly dispersed turbid liquid, transferring the turbid liquid to a magnetic heating stirrer, continuing to magnetically stir and heating the turbid liquid at 30 ℃ until the material is dried, transferring the dried material into a corundum boat, carrying out temperature programming in a muffle furnace to 600 ℃, and carrying out heat preservation for 4h to obtain a graphene-coated LiFePO layer4The mass of the graphene accounts for 15% of the total mass of the composite cathode material;
(3) weighing aniline according to the mass content of a polyaniline layer accounting for 5 wt% of the total mass of the composite anode material, weighing ammonium persulfate according to the molar ratio of 1: 1 of the aniline to the ammonium persulfate, mixing the ammonium persulfate and an HCl solution to obtain an HCl solution of the ammonium persulfate, dropwise adding the HCl solution of the ammonium persulfate into the aniline under the conditions of ice-water bath and stirring, and adding LiFePO coated by graphene4Is soaked inAnd carrying out polymerization reaction in aniline for 8h to obtain the lithium-sulfur battery composite positive electrode material.
The electrochemical performance of the composite cathode material of the lithium-sulfur battery prepared in this example was tested, and the results are as follows: the first discharge specific capacity is 1782mAh/g under the charge-discharge current density of 100mA/g, and the discharge specific capacity is kept at 90% after 50 cycles.
Comparative example 2
Same as example 2, except that no VS was added4。
The electrochemical performance of the composite positive electrode material of the lithium-sulfur battery prepared by the comparative example is tested, and the results are as follows: the first discharge specific capacity is 1467mAh/g under the charge-discharge current density of 100mA/g, and the discharge specific capacity is maintained at 78% after 50 cycles.
Example 3
(1) Mixing Fe3(PO4)2 powder with Li2CO3Fully and uniformly mixing the raw materials according to the stoichiometric ratio, calcining the mixture for 10 hours at 400 ℃ in nitrogen atmosphere to obtain LiFePO4。
(2) Weighing graphene oxide powder in 150mL of deionized water, ultrasonically dispersing until the solution is golden yellow, and sequentially adding Na with the metering ratio of 1: 53VO4(2.0125g) and thioacetamide, stirred for 1 h. And transferring the solution into a hydrothermal reaction kettle, and reacting for 24 hours at 160 ℃. After the reaction is finished, alternately cleaning the reaction product for 4-6 times by using deionized water and ethanol, and performing vacuum drying at 60 ℃ for 12 hours to obtain a hydrothermal product, wherein VS is4The loading on graphene was 30 wt%;
according to Li4SiO4The content of Li accounts for 6 wt% of the mass of graphene, and Li is weighed4SiO4Obtaining 0.01mmol/L Li in water solution4SiO4An aqueous solution. Mixing LiFePO4Hydrothermal product and Li4SiO4Ultrasonically dispersing the aqueous solution for 1h to obtain uniformly dispersed turbid liquid, transferring the turbid liquid to a magnetic heating stirrer, continuing to magnetically stir and heating the turbid liquid at 30 ℃ until the material is dried, transferring the dried material into a corundum boat, carrying out temperature programming in a muffle furnace to 600 ℃, and carrying out heat preservation for 4h to obtain a graphene-coated LiFePO layer4The mass of the graphene accounts for the total mass of the composite cathode material18% of the mass;
(3) weighing aniline according to the mass content of a polyaniline layer accounting for 6 wt% of the total mass of the composite anode material, weighing ammonium persulfate according to the molar ratio of 1: 1 of the aniline to the ammonium persulfate, mixing the ammonium persulfate and an HCl solution to obtain an HCl solution of the ammonium persulfate, dropwise adding the HCl solution of the ammonium persulfate into the aniline under the conditions of ice-water bath and stirring, and adding LiFePO coated by graphene4And soaking the lithium-sulfur battery anode material in aniline for polymerization reaction for 8 hours to obtain the lithium-sulfur battery composite anode material.
The electrochemical performance of the composite cathode material of the lithium-sulfur battery prepared in this example was tested, and the results are as follows: the first discharge specific capacity is 1872mAh/g under the charge-discharge current density of 100mA/g, and the discharge specific capacity is kept at 92% after 50 cycles.
Comparative example 3
The only difference is that no silicon-containing compound is added, as in example 3.
The electrochemical performance of the composite positive electrode material of the lithium-sulfur battery prepared by the comparative example is tested, and the results are as follows: the first discharge specific capacity is 1501mAh/g under the charge-discharge current density of 100mA/g, and the discharge specific capacity is kept at 76% after 50 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 decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.
Claims (10)
1. The composite cathode material for the lithium-sulfur battery is characterized by comprising a lithium iron phosphate layer, a graphene wrapping layer and a polyaniline layer which are sequentially stacked, wherein the graphene wrapping layer comprises a silicon-containing compound and VS4Said silicon-containing compound and VS4The graphene is loaded on the graphene.
2. The composite positive electrode material for the lithium-sulfur battery as claimed in claim 1, wherein the graphene wrapping layer is 15-20% by mass.
3. The composite positive electrode material for the lithium-sulfur battery according to claim 1 or 2, wherein the mass content of the polyaniline layer is 5 to 10%.
4. The lithium sulfur battery composite positive electrode material according to claim 1 or 2, wherein the silicon-containing compound comprises Li2SiO3、Li4SiO4And silicon dioxide.
5. The lithium sulfur battery composite positive electrode material of claim 1 or 2, wherein the silicon-containing compound and VS4The loading amount on the graphene is 30-40 wt%.
6. The lithium sulfur battery composite positive electrode material of claim 1 or 2, wherein the silicon-containing compound and VS4The mass ratio of (A) to (B) is 1: 1-5.
7. The method for preparing the composite positive electrode material for the lithium-sulfur battery according to any one of claims 1 to 6, comprising the steps of:
providing a lithium iron phosphate positive electrode material;
mixing graphene oxide, water and Na3VO4Mixing the mixture with thioacetamide and then carrying out hydrothermal reaction to obtain a hydrothermal product;
mixing the lithium iron phosphate positive electrode material, a silicon-containing compound solution and a hydrothermal product, and calcining to obtain a graphene-coated positive electrode material;
and soaking the positive electrode material wrapped by the graphene in aniline for polymerization reaction to obtain the lithium-sulfur battery composite positive electrode material.
8. The preparation method according to claim 7, wherein the temperature of the hydrothermal reaction is 160 to 180 ℃ and the time of the hydrothermal reaction is 20 to 24 hours.
9. The preparation method according to claim 7, wherein the calcining temperature is 400-600 ℃ and the calcining time is 1-2 h.
10. The preparation method according to claim 7, wherein the aniline is polymerized in the presence of ammonium persulfate, and the molar ratio of the aniline to the ammonium persulfate is 1: 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911098999.7A CN110797532B (en) | 2019-11-12 | 2019-11-12 | Composite positive electrode material of lithium-sulfur battery and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911098999.7A CN110797532B (en) | 2019-11-12 | 2019-11-12 | Composite positive electrode material of lithium-sulfur battery and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110797532A true CN110797532A (en) | 2020-02-14 |
| CN110797532B CN110797532B (en) | 2023-11-14 |
Family
ID=69443987
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911098999.7A Active CN110797532B (en) | 2019-11-12 | 2019-11-12 | Composite positive electrode material of lithium-sulfur battery and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110797532B (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1162677A2 (en) * | 1996-05-22 | 2001-12-12 | Moltech Corporation | Electrochemical cells comprising composite cathodes, and processes for fabricating same |
| CN105514378A (en) * | 2015-12-22 | 2016-04-20 | 湘潭大学 | Lithium-sulfur battery positive-pole composite material with imitated cellular structure and preparation method thereof |
| CN106876699A (en) * | 2015-12-13 | 2017-06-20 | 中国科学院大连化学物理研究所 | A kind of combination electrode and its preparation and application |
| CN108987725A (en) * | 2018-08-21 | 2018-12-11 | 南开大学 | A kind of anode composite material of lithium sulfur battery and preparation method thereof |
| CN109585828A (en) * | 2018-11-29 | 2019-04-05 | 济南大学 | RGO/VS is prepared in situ in one-step method4/ S compound is as lithium sulfur battery anode material |
| CN109755553A (en) * | 2019-03-20 | 2019-05-14 | 北京航空航天大学 | A kind of magnesium lithium Dual-ion cell composite positive pole and its preparation method and application, battery system |
-
2019
- 2019-11-12 CN CN201911098999.7A patent/CN110797532B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1162677A2 (en) * | 1996-05-22 | 2001-12-12 | Moltech Corporation | Electrochemical cells comprising composite cathodes, and processes for fabricating same |
| CN106876699A (en) * | 2015-12-13 | 2017-06-20 | 中国科学院大连化学物理研究所 | A kind of combination electrode and its preparation and application |
| CN105514378A (en) * | 2015-12-22 | 2016-04-20 | 湘潭大学 | Lithium-sulfur battery positive-pole composite material with imitated cellular structure and preparation method thereof |
| CN108987725A (en) * | 2018-08-21 | 2018-12-11 | 南开大学 | A kind of anode composite material of lithium sulfur battery and preparation method thereof |
| CN109585828A (en) * | 2018-11-29 | 2019-04-05 | 济南大学 | RGO/VS is prepared in situ in one-step method4/ S compound is as lithium sulfur battery anode material |
| CN109755553A (en) * | 2019-03-20 | 2019-05-14 | 北京航空航天大学 | A kind of magnesium lithium Dual-ion cell composite positive pole and its preparation method and application, battery system |
Non-Patent Citations (1)
| Title |
|---|
| LIYAZHU等: "Lithium storage performance and mechanism of VS4/rGO as an electrode material associated with lithium-sulfur batteries", 《JOURNAL OF ALLOYS AND COMPOUNDS》 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110797532B (en) | 2023-11-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103474625B (en) | A kind of Olivine-type Cathode Material in Li-ion Batteries method for coating of nucleocapsid structure | |
| CN108878877B (en) | Positive electrode active material for aqueous zinc ion secondary battery and aqueous zinc ion secondary battery | |
| CN104577061B (en) | Battery, negative material and preparation method thereof | |
| CN104638242A (en) | Method for synthesizing lithium ion battery cathode material lithium iron phosphate through in situ polymerizing and cladding | |
| CN103403932A (en) | Electrode active substance and method for producing same | |
| CN109888247B (en) | Preparation method of lithium zinc titanate/carbon nano composite negative electrode material for lithium ion battery | |
| CN103682290A (en) | Modified lithium-rich manganese-based cathode material for lithium ion battery | |
| CN108539133A (en) | Li3V2（PO4）3The preparation method of nanocrystalline/conducting polymer anode material for lithium-ion batteries | |
| CN107528060A (en) | A kind of nickelic positive electrode of gradient and preparation method thereof and lithium ion battery | |
| CN111056544B (en) | Sodium iron phosphate composite material and preparation method and application thereof | |
| CN104810513B (en) | A kind of lithium ion battery negative material and preparation method thereof | |
| CN114094068A (en) | Cobalt-coated positive electrode material, preparation method thereof, positive plate and lithium ion battery | |
| CN113629242A (en) | Preparation method of polyanionic vanadium iron sodium phosphate positive electrode material | |
| CN110444741A (en) | Graphene modified LiFePO4 quantum dot composite material and its preparation method and application | |
| CN109920985B (en) | Lithium-sulfur battery positive electrode material and preparation method thereof | |
| CN114284476A (en) | Preparation method of carbon composite sodium-ion battery positive electrode material | |
| CN106058221B (en) | A kind of preparation method of the compound manganese salt cladding lithium-rich manganese-based anode material of phosphate radical polyanion | |
| CN110563052B (en) | Preparation method of carbon and lanthanum oxide co-coated modified lithium nickel manganese oxide positive electrode material | |
| CN112234172A (en) | Carbon-coated tubular halloysite sulfur-loaded active material and preparation method thereof | |
| CN106684353A (en) | Preparation method for carbon-coated potassium vanadium phosphate and application of carbon-coated potassium vanadium phosphate | |
| CN110828793A (en) | Flexible conductive compound coated Na2CoTi(PO4)3Positive electrode material and method for producing same | |
| CN110474046A (en) | The rich lithium manganese anode material and preparation method thereof of Spinel LiMn2O4 cladding | |
| CN105355878A (en) | Material used as positive electrode of lithium ion battery and preparation method therefor | |
| CN110797532B (en) | Composite positive electrode material of lithium-sulfur battery and preparation method thereof | |
| CN115832471A (en) | Modified positive electrode lithium supplement additive and preparation method and application thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |