CN114899402A - Lithium-sulfur battery positive electrode material with sandwich layered structure and preparation method and application thereof - Google Patents

Lithium-sulfur battery positive electrode material with sandwich layered structure and preparation method and application thereof Download PDF

Info

Publication number
CN114899402A
CN114899402A CN202210569524.7A CN202210569524A CN114899402A CN 114899402 A CN114899402 A CN 114899402A CN 202210569524 A CN202210569524 A CN 202210569524A CN 114899402 A CN114899402 A CN 114899402A
Authority
CN
China
Prior art keywords
lithium
cobalt
positive electrode
sulfur battery
electrode material
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.)
Pending
Application number
CN202210569524.7A
Other languages
Chinese (zh)
Inventor
尹海宏
周宇祥
赵晨媛
吴云峰
王辅志
钱之润
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.)
Nantong University
Original Assignee
Nantong University
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 Nantong University filed Critical Nantong University
Priority to CN202210569524.7A priority Critical patent/CN114899402A/en
Publication of CN114899402A publication Critical patent/CN114899402A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/624—Electric conductive fillers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/362—Composites
    • H01M4/366—Composites as layered products
    • 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
    • H01M4/628—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
    • H01M2004/026—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

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Composite Materials (AREA)
  • Nanotechnology (AREA)
  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Materials Engineering (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • Battery Electrode And Active Subsutance (AREA)

Abstract

The application discloses a lithium-sulfur battery positive electrode material with a sandwich layered structure and a preparation method and application thereof, which belong to the technical field of preparation of lithium-sulfur battery positive electrode materials, and the method comprises the steps of dissolving cobalt chloride hexahydrate and aminotriacetic acid in deionized water, and obtaining a cobalt selenide carbon nanowire precursor through a first hydrothermal reaction; then dissolving the precursor and glucose in deionized water, and obtaining the cobalt-carbon nanowire through a second hydrothermal reaction; selenizing the cobalt-carbon nanowire in a tube furnace to obtain a cobalt selenide carbon nanowire; then carrying out hydrothermal reaction with graphene oxide to obtainTo sandwich layered CoSe 2 CNWs @ rGO, and then the powder and sulfur are prepared into CoSe through a melting method 2 -CNWs @ rGO/S composites. The cathode material is applied to the lithium-sulfur battery, can improve the cycle stability and the rate capability of the lithium-sulfur battery, simultaneously inhibits the shuttle effect problem in the lithium-sulfur battery, and improves the electrochemical performance of the lithium-sulfur battery.

Description

Lithium-sulfur battery positive electrode material with sandwich layered structure and preparation method and application thereof
Technical Field
The invention belongs to the technical field of preparation of lithium-sulfur battery positive electrode materials, and particularly relates to a lithium-sulfur battery positive electrode material with a sandwich layered structure, and a preparation method and application thereof.
Background
Due to the development of new energy technology, the low energy density and low specific capacity of lithium batteries increasingly become bottlenecks that hinder the development of industries. The Lithium Sulfur Battery (LSB) has a high energy density (2600Wh kg) compared to the lithium battery -1 ) High theoretical specific capacity (1675mAh g) -1 ) Sulfur continues to be spotlighted due to its advantages of low cost, excellent environmental friendliness, etc., but its application is hindered by some key problems. 1) Elemental sulfur and lithium sulfide generated by discharge are insulators, and the insulators are used as electrode materials and have low utilization rate of active substances and poor conductivity; 2) in the charging and discharging process, the conversion of elemental sulfur and lithium sulfide can cause the volume of the positive electrode to expand, so that the capacity of the battery is attenuated, and even the structure of the battery is damaged; 3) the shuttling effect of polysulfides, when lithium polysulfide dissolves in an organic electrolyte, creates a concentration difference between the positive and negative electrodes of the battery resulting in shuttling of lithium polysulfide between the positive and negative electrodes. Low lithium sulfide (Li) with electronic insulation due to shuttle effect 2 S/Li 2 S 2 ) The lithium deposits on the surface of the negative electrode, reduces the ion conduction capability and loses a large amount of active substances (sulfur), thereby reducing the capacity and the service life of the battery. Therefore, the shuttle effect, the severe volume expansion, the poor conductivity, the poor cycling stability and the poor safety performance of the lithium-sulfur battery in the prior art become technical problems to be solved by the technical personnel in the field.
Disclosure of Invention
The technical problem to be solved is as follows:
the lithium-sulfur battery positive electrode material with the sandwich layered structure can improve the cycling stability and the rate capability of the lithium-sulfur battery, simultaneously inhibit the shuttle effect problem in the lithium-sulfur battery, and improve the electrochemical performance of the lithium-sulfur battery.
The technical scheme is as follows:
in order to achieve the purpose, the application is realized by the following technical scheme:
the positive electrode material of the lithium-sulfur battery with the sandwich layered structure is CoSe 2 The positive electrode material of the lithium-sulfur battery comprises a cobalt selenide carbon nanowire and peripheral layered reduced graphene oxide, wherein the diameter of the cobalt selenide carbon nanowire is 100-150 nm; the reduced graphene oxide is a layered nanostructure, allowing for rapid electron/ion transfer.
A preparation method of a positive electrode material of a lithium-sulfur battery with a sandwich layer structure comprises the following steps:
the first step is as follows: under the magnetic stirring of 60r/min, 1.9-2.4g of cobalt chloride hexahydrate is dissolved in 45-60mL of deionized water according to the dosage ratio, 0.9-1.2g of nitrilotriacetic acid is added, the hydrothermal reaction is carried out for 12h at 180 ℃, then the mixture is cooled to room temperature, the mixture is centrifuged for 20min at 5500r/s, the deionized water and absolute ethyl alcohol are respectively washed for 5min, and the cobalt-carbon nanowire precursor is obtained after the vacuum drying at 60 ℃ for 12 h;
the second step is that: under the magnetic stirring at 60r/min, dissolving 1.5g-2g of cobalt-carbon nanowire precursor in 45mL-60mL of deionized water, adding 1.5g-3g of glucose, carrying out hydrothermal reaction for 12h, cooling to room temperature, centrifuging for 20min at 5500r/s, washing with deionized water and absolute ethyl alcohol for 5min respectively, and carrying out vacuum drying at 60 ℃ for 12h to obtain the cobalt-carbon nanowire;
the third step: transferring the cobalt-carbon nanowire to a tubular furnace before, placing a quartz boat with selenium powder in the quartz boat at an upstream air inlet in the furnace, and then directly blowing the selenium powder at the air inlet into the cobalt-carbon nanowire under the protection of inert gas for reaction to obtain the cobalt selenide carbon nanowire, wherein the reaction temperature is 550 ℃, the reaction time is 4 hours, and the dosage ratio of the cobalt-carbon nanowire to the selenium powder is 0.5-1 g: 2-4 g;
the fourth step: carrying out ultrasonic dispersion on graphene oxide, adding the cobalt selenide carbon nanowire, carrying out hydrothermal reaction for 5h at 180 ℃, then cooling to room temperature, centrifuging for 20min at 5500r/s, washing for 5min with deionized water and absolute ethyl alcohol respectively, and carrying out vacuum drying for 12h at 60 ℃ to obtain CoSe 2 -CNWs @ rGO, the dosage ratio of the cobalt selenide carbon nanowires to the graphene being 2g-3.5g:1g-1.5 g;
the fifth step: subjecting the CoSe to 2 mixing-CNWs @ rGO and sulfur powder, grinding for 20-30 minutes, and reacting under the protection of inert gas to obtain CoSe 2 -CNWs @ rGO/S composite material, wherein the reaction temperature is 155 ℃, and the reaction time is 12 h.
Further, the stirring time in the first step is 30min, and the dosage ratio of the cobalt chloride hexahydrate, the nitrilotriacetic acid and the deionized water is 1.9g:0.9g:60 mL.
Further, the reaction temperature in the second step is 170 ℃, and the dosage ratio of the cobalt-carbon nanowire precursor, the glucose and the deionized water is 1.5g:1.5g:50 mL.
Furthermore, the inert gas in the third step is nitrogen, and the dosage ratio of the cobalt-carbon nanowires to the selenium powder is 2g:0.5 g.
Further, in the fourth step, the inert gas is nitrogen, the ultrasonic frequency is 50Hz, the ultrasonic dispersion time is 10min, the reaction temperature is 180 ℃, and the dosage ratio of the cobalt selenide carbon nanowire to the graphene is 2g:1 g.
Further, the inert gas in the fifth step is argon, CoSe 2 The ratio of the amounts of-CNWs @ rGO and sulfur powder was 0.2: 0.3.
The application also discloses an application of the positive electrode material of the lithium-sulfur battery with the sandwich layered structure in the lithium-sulfur battery, the lithium-sulfur battery comprises a positive electrode, a negative electrode and electrolyte, and the positive electrode is the positive electrode material of the lithium-sulfur battery with the sandwich layered structure or the positive electrode material of the lithium-sulfur battery prepared by the preparation method.
Further, the application of the positive electrode material of the lithium-sulfur battery with the sandwich layer structure in the lithium-sulfur battery comprises the following steps:
step a, preparing slurry: mixing CoSe 2 Mixing the-CNWs @ rGO/S composite material, conductive carbon black and a binder PVDF in a mass ratio of 7:2:1, grinding to prepare slurry, uniformly coating the slurry on a current collector by adopting a blade coating method, and drying at 60 ℃ for 10-12 hours to obtain a positive sheet;
step b, manufacturing the lithium-sulfur battery: and c, cutting the positive electrode sheet obtained in the step a into a circular pole piece with the diameter of 16mm, taking the circular pole piece as a positive electrode, taking Celgard 2500 as a diaphragm, taking a commercial metal Li piece as a negative electrode, adding ether electrolyte or carbonate electrolyte, and finishing the assembly of the lithium-sulfur battery in the argon protection.
The positive electrode material of the lithium-sulfur battery with the sandwich layered structure and the preparation method and the application thereof have the working principle that: during discharging, the negative electrode reacts to change lithium into lithium ions after losing electrons, sulfur reacts with the lithium ions and the electrons to generate sulfide, the polysulfide easily shuttles back and forth in the middle of the diaphragm, at the moment, the polar material cobalt selenide carbon nanowire in the sandwich layered structure performs chemical adsorption, and the periphery of the sandwich layered structure is reduced to reduce graphene oxide to perform physical blocking. Under the action of an applied voltage, the reaction of the positive electrode and the negative electrode of the lithium-sulfur battery is carried out reversely, namely, the charging process is carried out. At this time, elemental sulfur is generated in the positive electrode, and the sandwich structure provides a large number of pores, so that the damage of the positive electrode caused by the expansion of the system is prevented.
Has the advantages that:
the application provides a lithium-sulfur battery cathode material with a sandwich layered structure and a preparation method and application thereof, and compared with the prior art, the lithium-sulfur battery cathode material has the following beneficial effects:
1. the application provides a positive electrode material of a lithium-sulfur battery with a sandwich layered structure, a preparation method and an application thereof, and CoSe is used for preparing the positive electrode material 2 the-CNWs network is used as an inner layer framework for loading sulfur, then the rGO outer layer is coated to obtain the lithium sulfur battery anode material with a sandwich layered structure, in the anode material, the cobalt selenide carbon nanowire is used as an inner conductive framework for providing a rapid electron/ion transmission channel, and the carbon nanotubeThe modified zinc selenide quantum dots are polar materials, the particle size is small, the dispersibility is good, more active sites can be provided by modifying the carbon nano tube, on one hand, the zinc selenide quantum dots are uniformly distributed on the surface of the carbon nano tube in a dotted manner, the direct contact of sulfur and the carbon nano tube is ensured, the conductivity and the stability of the anode material are favorably improved, on the other hand, the cobalt selenide can effectively and chemically adsorb polysulfide, and the shuttle effect of the polysulfide on the positive pole and the negative pole can be remarkably inhibited.
2. In the cathode material, the porous network structure of the cobalt selenide carbon nanowire inside one part can accommodate volume expansion caused by conversion of sulfur into lithium sulfide, and a certain space is reserved between the outside reduced graphene oxide and the inside part of the other part to relieve the volume expansion, so that the structural integrity of the cathode material is ensured.
3. The outside of this application cathode material is reduction oxidation graphite alkene, but physics restriction active substance sulphur wears out the shell and dissolves in electrolyte, alleviates the battery capacity reduction problem that leads to because of the active substance reduces.
4. The specific capacity of the positive electrode material used for the lithium-sulfur battery at 0.2C is up to 1138mAh g -1 And at 2C, 650mAh g is reached -1 . Meanwhile, the composite material has good cycle performance, and the capacity retention rate is 86.1% after 150 cycles of 0.5C.
5. In contrast to the article published by Yakun Bu et al entitled "Sandwich-type porous carbon/sulfur/polyaniline composite as a cathode material for high-performance lithium-sulfur batters", this article was maintained at 834mAh g after 100 cycles at 0.1C rate in terms of cycles -1 The sandwich material made by the people obtains better effect under higher multiplying power and longer circulation, and the circulation of 150 circles at 0.5C keeps 840mAh g -1 . Compared with Yu Wang et al, entitled "Sandwich structured NASICON-type electrolytic coated with sulfurised olyacrylic acid for high performance solid-state batteries", we obtained 731mAh g at 1C rate -1 This article only has 362.3mAh g -1 Indicating that better performance can be maintained at relatively higher rates.
Drawings
FIG. 1 shows CoSe obtained from the preparation of example 1 of the present application 2 -Scanning Electron Microscopy (SEM) image of CNWs @ rGO/S;
fig. 2 is a Scanning Electron Microscope (SEM) image of cobalt carbon nanowires obtained in example 1 of the present application;
fig. 3 is a Scanning Electron Microscope (SEM) image of cobalt selenide carbon nanowires obtained in example 1 of the present application;
fig. 4 is a Transmission Electron Microscope (TEM) image of cobalt selenide carbon nanowires obtained in example 1 of the present application;
FIG. 5 shows CoSe obtained in example 1 of the present application 2 -CNWs @ rGO/S structural schematic;
FIG. 6 shows CoSe obtained in example 1 of the present application 2 -High Resolution Transmission Electron Microscopy (HRTEM) image of CNWs @ rGO/S;
FIG. 7 is a graph of the specific capacity and cycling performance of the lithium sulfur batteries of example 1 and comparative examples 1 and 2 provided in the practice of the present application over a 150 cycle period at 0.5C;
fig. 8 is a graph of the specific capacity and rate performance of the lithium sulfur batteries of example 1 and comparative examples 1 and 2 provided herein.
Detailed Description
In order to facilitate an understanding of the invention, the principles and features of the invention are described in full detail below with reference to the accompanying drawings and the preferred embodiments, which are provided for illustration only and are not limiting on the scope of the invention.
All of the starting materials of the present invention, without particular limitation as to their source, may be purchased commercially or prepared according to conventional methods well known to those skilled in the art.
In order to further illustrate the present invention, the following will describe in detail the preparation method and application of the positive electrode material of lithium-sulfur battery with sandwich structure provided by the present invention with reference to the examples.
Example 1:
a preparation method and application of a positive electrode material of a lithium-sulfur battery with a sandwich layered structure are disclosed, and the preparation method comprises the following steps:
the first step is as follows: under the magnetic stirring of 60r/min, dissolving 1.9g of cobalt chloride hexahydrate and 0.9g of triethylammonium chloride in 60mL of deionized water, carrying out hydrothermal reaction for 12h at 180 ℃, then cooling to room temperature, centrifuging for 20min at 5500r/s, washing the deionized water and absolute ethyl alcohol for 5min respectively, and carrying out vacuum drying for 12h at 60 ℃ to obtain a cobalt-carbon nanowire precursor;
the second step is that: under the magnetic stirring of 60r/min, dissolving 1.5g of the cobalt-carbon nanowire precursor obtained in the first step in 50mL of deionized water, adding 1g of glucose, carrying out hydrothermal reaction for 12h at 180 ℃, then cooling to room temperature, centrifuging for 20min at 5500r/s, washing for 5min with deionized water and absolute ethyl alcohol respectively, and carrying out vacuum drying for 12h at 60 ℃ to obtain cobalt-carbon nanowire Co-CNWs;
the third step: transferring 2g of cobalt-carbon nanowire obtained in the second step into a tube furnace, placing a quartz boat with 10g of selenium powder at an upstream air inlet in the furnace, and reacting at 550 ℃ for 4 hours under the protection of nitrogen atmosphere to obtain the cobalt selenide carbon nanowire, wherein the reaction temperature is 550 ℃ to obtain CoSe 2 -CNWs；
The fourth step: performing 50Hz ultrasonic dispersion on 2g of graphene oxide, adding the cobalt selenide carbon nano wire in the third step, performing hydrothermal reaction for 5 hours at 180 ℃, cooling to room temperature, centrifuging for 20 minutes at 5500r/s, washing for 5 minutes by deionized water and absolute ethyl alcohol respectively, and performing vacuum drying for 12 hours at 60 ℃ to obtain the CoSe 2 -CNWs@rGO；
The fifth step: 0.2g of CoSe obtained in the fourth step 2 mixing-CNWs @ rGO and 0.3g of sulfur powder, grinding for 20-30 minutes, putting the ground powder into a reaction kettle in a glove box under the argon atmosphere, and finally placing the reaction kettle in a forced air drying box at 155 ℃ for reaction for 12 hours to obtain CoSe 2 -CNWs@rGO/S；
FIG. 1 shows CoSe obtained in example 1 of the present invention 2 A Scanning Electron Microscope (SEM) image of CNWs @ rGO/S, wherein a sandwich layered structure can be seen, the inner part is provided with a cobalt selenide carbon nanowire, and the outer part is provided with reduced graphene oxide. FIG. 2 is a Scanning Electron Microscope (SEM) image of the cobalt-carbon nanowires obtained in the preparation process of the present embodiment, and it can be seen from FIG. 2 that a plurality of cobalt-carbon nanowires are interlaced and spaced, and the diameter is about 100-150 nm. Fig. 3 is a scanning electron microscope SEM image of cobalt selenide carbon nanowires. From FIG. 3, it can be seen that the cobalt-carbon nanoparticlesThe appearance of the wire is basically kept unchanged after selenization, and the wire shape is still maintained. Fig. 4 is a Transmission Electron Microscope (TEM) of cobalt selenide carbon nanowires with cobalt selenide nanoparticles uniformly distributed within the nanowires. FIG. 5 shows CoSe obtained in example 1 of the present invention 2 The structural schematic diagram of-CNWs @ rGO/S shows that the material has a sandwich layered structure, CoSe 2 The inner layer is wrapped around the outer layer of rGO, while the sulfur is distributed inside the interlayer. FIG. 6 is CoSe 2 High Resolution Transmission Electron Microscopy (HRTEM) of CNWs @ rGO/S, the cobalt selenide lattice spacing and amorphous carbon are clearly visible.
Sixthly, preparing slurry: 0.35g of CoSe 2 Mixing CNWs @ rGO/S, 0.1g of conductive carbon black and 0.05g of PVDF as a binder, grinding and mixing the mixture in an agate mortar to prepare slurry, uniformly coating the slurry on an aluminum foil by adopting a blade coating method, and drying the aluminum foil at 60 ℃ for 12 hours to obtain a positive plate;
and seventhly, manufacturing an electrode plate: the positive sheet was cut into circular pole pieces with a diameter of 16 mm.
And eighth step, manufacturing the lithium-sulfur battery: the round pole piece is used as the anode, Celgard 2500 is used as the diaphragm, the commercial lithium metal piece is used as the cathode, and 0.1M LiNO is added 3 And assembling a 2032 type button cell in an argon-filled glove box with the water oxygen content lower than 0.1ppm by using electrolyte of DOL/DME (volume ratio of 1:1) of +1M LiTFSI, and standing for 12h to test the electrochemical performance.
Comparative example 1:
a preparation method of a positive electrode material and application of the positive electrode material in a lithium-sulfur battery comprise the following steps:
step1, dissolving 1.9g of cobalt chloride hexahydrate and 0.9g of triethylammonium chloride in 60mL of deionized water, carrying out hydrothermal reaction for 12h at 180 ℃, then cooling to room temperature, and then centrifuging, washing and drying to obtain a cobalt-carbon nanowire precursor;
step2, dissolving 1.5g of the cobalt-carbon nanowire precursor obtained in the Step one and 1g of glucose in 50mL of deionized water, carrying out hydrothermal reaction at 180 ℃ for 12h, then cooling to room temperature, and then carrying out centrifugation, washing and drying to obtain a cobalt-carbon nanowire (Co-CNWs);
step3, mixing 0.2g of Co-CNWs obtained in the Step (II) with 0.3g of sulfur powder, grinding for 20-30 minutes, then putting the ground powder into a reaction kettle in a glove box under the argon atmosphere, and finally placing the reaction kettle in a forced air drying oven at 160 ℃ for reaction for 14 hours to obtain Co-CNWs/S;
step4, preparation of slurry: mixing 0.45g of Co-CNWs/S, 0.13g of conductive carbon black and 0.065g of binder PVDF obtained in the step (three), grinding and mixing in an agate mortar to prepare slurry, uniformly coating the slurry on an aluminum foil by adopting a blade coating method, and drying at 60 ℃ for 12 hours to obtain a positive plate;
step5, preparation of electrode slice: cutting the dried positive sheet into circular pole pieces with the diameter of 16 mm;
step6, preparation of lithium sulfur battery: the round pole piece is used as the anode, Celgard 2500 is used as the diaphragm, the commercial lithium metal piece is used as the cathode, and 0.1M LiNO is added 3 And assembling a 2032 type button cell in an argon-filled glove box with the water oxygen content lower than 0.1ppm by using electrolyte of DOL/DME (volume ratio of 1:1) of +1M LiTFSI, and standing for 12h to test the electrochemical performance.
Comparative example 2:
a preparation method of a positive electrode material and application of the positive electrode material in a lithium-sulfur battery comprise the following steps:
dissolving 1.9g of cobalt chloride hexahydrate and 0.9g of triethylammonium chloride in 60mL of deionized water, carrying out hydrothermal reaction for 12h at 180 ℃, then cooling to room temperature, and then centrifuging, washing and drying to obtain the cobalt-carbon nanowire precursor.
And (II) dissolving 1.5g of the cobalt-carbon nanowire precursor obtained in the step (I) and 1g of glucose in 50mL of deionized water, carrying out hydrothermal reaction at 180 ℃ for 12h, then cooling to room temperature, and then centrifuging, washing and drying to obtain the cobalt-carbon nanowire (Co-CNWs).
Transferring the 2g of cobalt-carbon nanowire obtained in the step (II) to a tubular furnace, placing a quartz boat with 10g of selenium powder at an upstream air inlet in the furnace, and reacting under the protection of inert gas to obtain the cobalt selenide carbon nanowire, wherein the reaction temperature is 550 ℃ and the reaction time is 4 hours to obtain CoSe 2 -CNWs。
Step (IV) 0.2g of CoSe obtained in step (III) 2 mixing-CNWs and 0.3g of sulfur powder, grinding for 20-30 minutes, putting the ground powder into a reaction kettle in a glove box under the argon atmosphere, and finally placing the reaction kettle in a forced air drying box at 160 ℃ for reaction for 14 hours to obtain the zinc selenide quantum dot modified carbon nanotube/sulfur composite material (CoSe) 2 -CNWs/S)。
Preparing slurry in the step (V): 0.45g of CoSe 2 mixing-CNWs/S, 0.13g of conductive carbon black and 0.065g of binder PVDF, grinding and mixing in an agate mortar to prepare slurry, uniformly coating the slurry on an aluminum foil by adopting a blade coating method, and drying at 60 ℃ for 12 hours to obtain the positive plate.
Step (six) manufacturing the electrode slice: the dried positive electrode sheet was cut into circular pole pieces with a diameter of 16 mm.
And (seventhly) manufacturing the lithium-sulfur battery: the round pole piece is used as the anode, Celgard 2500 is used as the diaphragm, the commercial lithium metal piece is used as the cathode, and 0.1M LiNO is added 3 And assembling a 2032 type button cell in an argon-filled glove box with the water oxygen content lower than 0.1ppm by using electrolyte of DOL/DME (volume ratio of 1:1) of +1M LiTFSI, and standing for 12h to test the electrochemical performance.
Test example
The lithium sulfur batteries obtained in example 1 and comparative examples 1 and 2 were subjected to constant current charging and discharging, cycle performance testing and rate performance testing by using a charging and discharging instrument of xinwei limited corporation in shenzhen, wherein the testing temperature is 25 ℃ at the ambient temperature, the cut-off range of the charging and discharging voltage is 1.7-2.8V, and the testing results are shown in fig. 7 and 8.
Fig. 7 is a graph of specific capacity and cycling performance of the lithium-sulfur batteries of example 1 and comparative examples 1 and 2 provided by the present invention over 150 cycling periods at 0.5C. CoSe provided in example 1 2 -CNWs @ rGO/S is used as a positive electrode material to assemble a lithium-sulfur battery with specific discharge capacity of 975mAh g from the first circle -1 The specific discharge capacity after 150 circles is 840mAh g -1 The capacity retention rate is 86.1%, the coulombic efficiency is about 99%, the cycling stability is very good, as can be seen from fig. 7, while the specific capacities of comparative examples 1 and 2 are significantly lower than that of CoSe 2 -CNWs @ rGO/S as the positive electrode. Fig. 8 is a graph of specific capacity and rate performance of the lithium-sulfur batteries of example 1 and comparative examples 1 and 2 provided by the present invention. As can be seen from FIG. 8, CoSe provided in this example 1 2 The rate performance of the lithium-sulfur battery assembled by taking CNWs @ rGO/S as a positive electrode material is 0.1C to 2C, and the specific discharge capacities of the lithium-sulfur battery at 0.1C, 0.2C, 0.5C, 1C and 2C are 1137, 999, 843, 731 and 650mAh g -1 . When the current density rose back to 0.2C, the corresponding capacity recovered to 933mAh g -1 . The lithium-sulfur batteries using the materials of comparative examples 1 and 2 as electrodes have the advantages of rapid capacity attenuation, poor discharge specific capacity and stability, serious shuttle effect and extremely low utilization rate of active substances. CoSe 2 The lithium-sulfur battery with the-CNWs @ rGO/S material as the electrode has excellent rate performance, high stability, excellent electrochemical performance, and good initial specific capacity, cycle performance and rate performance.
The invention has been described in an illustrative manner, and it is to be understood that any simple variations, modifications or other equivalent changes which can be made by one skilled in the art without departing from the spirit of the invention fall within the scope of the invention.

Claims (9)

1. The positive electrode material of the lithium-sulfur battery with the sandwich layered structure is characterized in that the positive electrode material is CoSe 2 The positive electrode material of the lithium-sulfur battery comprises a cobalt selenide carbon nanowire and peripheral layered reduced graphene oxide, wherein the diameter of the cobalt selenide carbon nanowire is 100-150 nm; the reduced graphene oxide is a layered nanostructure, allowing for rapid electron/ion transfer.
2. A preparation method of a positive electrode material of a lithium-sulfur battery with a sandwich layer structure is characterized by comprising the following steps:
the first step is as follows: under the magnetic stirring of 60r/min, 1.9-2.4g of cobalt chloride hexahydrate is dissolved in 45-60mL of deionized water according to the dosage ratio, 0.9-1.2g of nitrilotriacetic acid is added, the hydrothermal reaction is carried out for 12h at 180 ℃, then the mixture is cooled to room temperature, the mixture is centrifuged for 20min at 5500r/s, the deionized water and absolute ethyl alcohol are respectively washed for 5min, and the cobalt-carbon nanowire precursor is obtained after the vacuum drying at 60 ℃ for 12 h;
the second step is that: under the magnetic stirring at 60r/min, dissolving 1.5g-2g of cobalt-carbon nanowire precursor in 45mL-60mL of deionized water, adding 1.5g-3g of glucose, carrying out hydrothermal reaction for 12h, cooling to room temperature, centrifuging for 20min at 5500r/s, washing with deionized water and absolute ethyl alcohol for 5min respectively, and carrying out vacuum drying at 60 ℃ for 12h to obtain the cobalt-carbon nanowire;
the third step: transferring the cobalt-carbon nanowire to a tubular furnace before, placing a quartz boat with selenium powder in the quartz boat at an upstream air inlet in the furnace, and then directly blowing the selenium powder at the air inlet into the cobalt-carbon nanowire under the protection of inert gas for reaction to obtain the cobalt selenide carbon nanowire, wherein the reaction temperature is 550 ℃, the reaction time is 4 hours, and the dosage ratio of the cobalt-carbon nanowire to the selenium powder is 0.5-1 g: 2-4 g;
the fourth step: carrying out ultrasonic dispersion on graphene oxide, adding the cobalt selenide carbon nanowire, carrying out hydrothermal reaction for 5h at 180 ℃, then cooling to room temperature, centrifuging for 20min at 5500r/s, washing for 5min with deionized water and absolute ethyl alcohol respectively, and carrying out vacuum drying for 12h at 60 ℃ to obtain CoSe 2 -CNWs @ rGO, the dosage ratio of the cobalt selenide carbon nanowires to the graphene being 2g-3.5g:1g-1.5 g;
the fifth step: subjecting the CoSe to 2 mixing-CNWs @ rGO and sulfur powder, grinding for 20-30 minutes, and reacting under the protection of inert gas to obtain CoSe 2 -CNWs @ rGO/S composite material, wherein the reaction temperature is 155 ℃, and the reaction time is 12 h.
3. The method for preparing a positive electrode material for a lithium-sulfur battery having a sandwich layered structure according to claim 2, wherein: the stirring time in the first step is 30min, and the dosage ratio of the cobalt chloride hexahydrate, the nitrilotriacetic acid and the deionized water is 1.9g:0.9g:60 mL.
4. The method for preparing a positive electrode material for a lithium-sulfur battery having a sandwich layered structure according to claim 2, wherein: in the second step, the reaction temperature is 170 ℃, and the dosage ratio of the cobalt-carbon nanowire precursor, the glucose and the deionized water is 1.5g:1.5g:50 mL.
5. The method for preparing a positive electrode material for a lithium-sulfur battery having a sandwich layered structure according to claim 2, wherein: in the third step, the inert gas is nitrogen, and the dosage ratio of the cobalt-carbon nanowires to the selenium powder is 2g to 0.5 g.
6. The method for preparing a positive electrode material for a lithium-sulfur battery having a sandwich layered structure according to claim 2, wherein: and in the fourth step, the inert gas is nitrogen, the ultrasonic frequency is 50Hz, the ultrasonic dispersion time is 10min, the reaction temperature is 180 ℃, and the dosage ratio of the cobalt selenide carbon nanowire to the graphene is 2g to 1 g.
7. The method for preparing a positive electrode material for a lithium-sulfur battery having a sandwich layered structure according to claim 2, wherein: in the fifth step, the inert gas is argon gas, CoSe 2 The ratio of the amounts of-CNWs @ rGO and sulfur powder was 0.2: 0.3.
8. The application of the positive electrode material of the lithium-sulfur battery with the sandwich layer structure in the lithium-sulfur battery is characterized in that: the positive electrode material is the positive electrode material of the lithium-sulfur battery with the sandwich layered structure in the claim 1 or the positive electrode material of the lithium-sulfur battery prepared by the preparation method in any one of the claims 2 to 7.
9. The use of the positive electrode material for lithium-sulfur batteries with a sandwich layered structure according to claim 8 in lithium-sulfur batteries, characterized in that it comprises the following steps:
step a, preparing slurry: mixing CoSe 2 Mixing the-CNWs @ rGO/S composite material, conductive carbon black and a binder PVDF in a mass ratio of 7:2:1, grinding to prepare slurry, uniformly coating the slurry on a current collector by adopting a blade coating method, and drying at 60 ℃ for 10-12 hours to obtain a positive sheet;
step b, manufacturing the lithium-sulfur battery: and c, cutting the positive electrode sheet obtained in the step a into a circular pole piece with the diameter of 16mm, taking the circular pole piece as a positive electrode, taking Celgard 2500 as a diaphragm, taking a commercial metal Li piece as a negative electrode, adding ether electrolyte or carbonate electrolyte, and finishing the assembly of the lithium-sulfur battery in the argon protection.
CN202210569524.7A 2022-05-24 2022-05-24 Lithium-sulfur battery positive electrode material with sandwich layered structure and preparation method and application thereof Pending CN114899402A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210569524.7A CN114899402A (en) 2022-05-24 2022-05-24 Lithium-sulfur battery positive electrode material with sandwich layered structure and preparation method and application thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210569524.7A CN114899402A (en) 2022-05-24 2022-05-24 Lithium-sulfur battery positive electrode material with sandwich layered structure and preparation method and application thereof

Publications (1)

Publication Number Publication Date
CN114899402A true CN114899402A (en) 2022-08-12

Family

ID=82723341

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210569524.7A Pending CN114899402A (en) 2022-05-24 2022-05-24 Lithium-sulfur battery positive electrode material with sandwich layered structure and preparation method and application thereof

Country Status (1)

Country Link
CN (1) CN114899402A (en)

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108461303A (en) * 2018-03-27 2018-08-28 哈尔滨理工大学 The preparation method of titanium dioxide nano thread-graphene composite material
CN109473643A (en) * 2018-10-17 2019-03-15 长沙学院 A kind of CoSe2/ graphene composite material preparation method and purposes

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108461303A (en) * 2018-03-27 2018-08-28 哈尔滨理工大学 The preparation method of titanium dioxide nano thread-graphene composite material
CN109473643A (en) * 2018-10-17 2019-03-15 长沙学院 A kind of CoSe2/ graphene composite material preparation method and purposes

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
KEREN ZHOU等: "Self-assembled CoSe2 nanocrystals embedded into carbon nanowires as highly efficient catalyst for hydrogen evolution reaction", 《ELECTROCHIMICA ACTA》, pages 626 - 631 *

Similar Documents

Publication Publication Date Title
CN107425185B (en) Preparation method of carbon nanotube-loaded molybdenum carbide material and application of carbon nanotube-loaded molybdenum carbide material in lithium-sulfur battery positive electrode material
CN102810673B (en) Method for preparing carbon-coated MnO coaxial nanowire cathode material for lithium ion batteries
CN111613789B (en) Nano carbon/metal sulfide composite porous material and preparation method and application thereof
CN109524649B (en) Sodium-ion battery positive electrode material with coating structure and preparation method and application thereof
CN107732203B (en) Preparation method of nano cerium dioxide/graphene/sulfur composite material
CN109755544B (en) Lithium-sulfur battery positive electrode material and preparation method thereof
CN110734097B (en) ZIF 67-containing derived composite carbon material lithium-sulfur battery positive electrode material, preparation method thereof, positive electrode plate containing positive electrode material and lithium-sulfur battery
CN112117444A (en) Carbon-coated cobalt sulfide positive electrode material, preparation method, positive electrode and aluminum ion battery
CN114291796A (en) Potassium ion battery negative electrode material and preparation method and application thereof
CN114530601A (en) Preparation method of boron-doped porous carbon material and application of boron-doped porous carbon material in potassium ion battery
CN109755542B (en) Sodium-sulfur battery positive electrode material and preparation method thereof
CN109279663B (en) Borate sodium-ion battery negative electrode material and preparation and application thereof
CN109286002B (en) Multi-bark biomass carbon-loaded red phosphorus sodium ion battery negative electrode material and preparation method thereof
CN108923027B (en) Organic acid modified Si/TiO2Negative electrode material of/rGO @ C lithium ion battery and preparation method and application thereof
CN114497475A (en) Zinc-containing nitrogen-doped porous carbon-coated zinc-based negative electrode material for lithium ion battery
CN113871605A (en) Pre-lithiated silicon-based negative electrode material and preparation method and application thereof
CN111554905B (en) Preparation method, product and application of zinc oxide-based carbon composite nano material
CN114551891B (en) Tin disulfide/titanium dioxide/carbon composite material and preparation method and application thereof
CN113611866B (en) Flexible self-supporting sodium ion battery negative electrode material and preparation method thereof
CN114899402A (en) Lithium-sulfur battery positive electrode material with sandwich layered structure and preparation method and application thereof
CN112038617A (en) Micro-nano double-particle-size porous silicon material and preparation method and application thereof
CN106848267B (en) A kind of Ti3C2Tx/ MCM-41 type is classified sulphur carbon composite
CN111293297A (en) Carbon-coated MoSe2Black phosphorus composite material and preparation method thereof
Zhang et al. A Li+-conductive Porous Carbon/Polyacrylonitrile/Sulfur Composite for Li-S Batteries
CN108807914A (en) A kind of anode material of lithium battery of graphene coated and preparation method 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