WO2022247375A1 - 一种二次电池用含硫正极材料、其制备方法及二次电池 - Google Patents

一种二次电池用含硫正极材料、其制备方法及二次电池 Download PDF

Info

Publication number
WO2022247375A1
WO2022247375A1 PCT/CN2022/078705 CN2022078705W WO2022247375A1 WO 2022247375 A1 WO2022247375 A1 WO 2022247375A1 CN 2022078705 W CN2022078705 W CN 2022078705W WO 2022247375 A1 WO2022247375 A1 WO 2022247375A1
Authority
WO
WIPO (PCT)
Prior art keywords
sulfur
positive electrode
polyacrylonitrile
electrode material
secondary battery
Prior art date
Application number
PCT/CN2022/078705
Other languages
English (en)
French (fr)
Inventor
王久林
雷靖宇
杨军
Original Assignee
上海交通大学
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 上海交通大学 filed Critical 上海交通大学
Priority to JP2023557272A priority Critical patent/JP2024510027A/ja
Priority to US18/283,457 priority patent/US20240178393A1/en
Publication of WO2022247375A1 publication Critical patent/WO2022247375A1/zh

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/60—Selection of substances as active materials, active masses, active liquids of organic compounds
    • H01M4/602—Polymers
    • H01M4/604—Polymers containing aliphatic main chain polymers
    • 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
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J3/00—Processes of treating or compounding macromolecular substances
    • C08J3/24—Crosslinking, e.g. vulcanising, of macromolecules
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J3/00—Processes of treating or compounding macromolecular substances
    • C08J3/24—Crosslinking, e.g. vulcanising, of macromolecules
    • C08J3/247—Heating methods
    • 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
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/054—Accumulators with insertion or intercalation of metals other than lithium, e.g. with magnesium or aluminium
    • 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
    • H01M4/04—Processes of manufacture in general
    • H01M4/0471—Processes of manufacture in general involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis
    • 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
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • 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
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2333/00—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Derivatives of such polymers
    • C08J2333/18—Homopolymers or copolymers of nitriles
    • C08J2333/20—Homopolymers or copolymers of acrylonitrile
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K3/00—Use of inorganic substances as compounding ingredients
    • C08K3/02—Elements
    • C08K3/06—Sulfur
    • 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
    • H01M2004/027—Negative electrodes
    • 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

Definitions

  • the invention relates to a sulfur-containing positive electrode material, in particular to a sulfur-containing positive electrode material which can be assembled with lithium, sodium, potassium, magnesium, calcium or aluminum negative electrodes to form a secondary battery and a preparation method thereof.
  • the present invention also relates to a sulfur-containing positive electrode material containing the Sulfur cathode material for secondary batteries.
  • Secondary batteries using lithium, sodium, potassium, magnesium, or aluminum as the negative electrode and sulfur as the positive electrode have significant advantages such as high energy density, abundant sulfur resources, low cost, and environment optimization.
  • lithium-sulfur battery due to its theoretical energy density as high as 2600Wh/kg, low cost and environmental friendliness, it has received extensive attention.
  • the literature J.Wang et al, Advanced materials, 2002, 13-14, 963 reported for the first time that sulfur and polyacrylonitrile (PAN) reacted at high temperature to prepare sulfurized polyacrylonitrile (S@PAN) Composite positive electrode material
  • the positive electrode material has no polysulfide ion dissolution and shuttling phenomenon in carbonate-based electrolyte, high charge and discharge efficiency, low self-discharge, stable cycle, and excellent rate performance.
  • linear polyacrylonitrile is used as the precursor, the sulfur content in the obtained S@PAN cathode material is limited, less than 50wt%, usually around 45wt%, resulting in a low specific capacity of the material and affecting the energy density of the secondary battery. Therefore, it is of great significance to improve the energy density of secondary batteries by preparing S@PAN cathode materials with high sulfur content and high specific capacity.
  • Chinese patent CN106957443A discloses a polyacrylonitrile-sulfur-composite material with improved electric capacity
  • Chinese patent CN106957443A discloses a polyacrylonitrile-sulfur-composite material with improved electrical capacity, using polyacrylonitrile and sulfur to react with at least one crosslinking agent, which is a surface modification technology for polymer particles, which cannot Internal influence has limited effect on increasing sulfur content.
  • the porous polymer disclosed in the literature uses electrospinning to form mesoporous pores with a pore size of 2-50 nm, or even as large as 100 nm. pores, and the size of sulfur molecules is about 1nm, which is not suitable for containing monodisperse sulfur molecules, that is, amorphous sulfur cannot be formed.
  • the literature discloses a mesoporous polymer synthesized from a molecular sieve SBA-15 hard template, with a pore size of 2-50nm. Since the molecular size of sulfur is only 1nm and the pore diameter exceeds 2nm, the filled sulfur is a molecular aggregate, and the kinetics of the electrochemical reaction will be very slow, so the mesoporous is not suitable for accommodating monodispersed sulfur molecules.
  • the object of the present invention is to provide a sulfur-containing cathode material for a secondary battery, a preparation method thereof and a secondary battery.
  • the present invention starts with the precursor of polyacrylonitrile (PAN), and constructs polyacrylonitrile with abundant micropores (pore diameter less than 2nm).
  • PAN polyacrylonitrile
  • a large number of micropores can accommodate sulfur materials, thereby significantly increasing the sulfur content in vulcanized polyacrylonitrile, and also It is the specific capacity of the positive electrode of the battery, and the method is simple, easy to enlarge, and has strong practicability.
  • the first aspect of the present invention provides a sulfur-containing positive electrode material for secondary batteries, including sulfur and microporous polyacrylonitrile.
  • the microporous polyacrylonitrile is obtained by the polymerization reaction of acrylonitrile monomer and cross-linking agent, Polyacrylonitrile (CPAN).
  • the pore size of the microporous polyacrylonitrile is 0.2-2nm, and does not contain 2nm.
  • the polymerization reaction of microporous polyacrylonitrile also includes the following raw materials: initiator, surfactant and solvent, and the mass ratio of the acrylonitrile monomer, initiator, crosslinking agent, surfactant and solvent is 1 :0.01-0.1:0.01-0.1:0.01-0.1:4-10.
  • the crosslinking agent is divinylbenzene, diallyl phthalate, ethylene glycol dimethacrylate, 1,4-butylene diacrylate, polyethylene glycol di One or more of methyl methacrylate and polyethylene glycol diacrylate.
  • the initiator is one or more of potassium persulfate, ammonium persulfate, azobisisobutyronitrile (AIBN) and dibenzoyl peroxide (BPO).
  • AIBN azobisisobutyronitrile
  • BPO dibenzoyl peroxide
  • the surfactant is one of sodium dodecylsulfonate (SDS), polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA) and cetyltrimethylamine bromide (CTAB) or Several kinds.
  • SDS sodium dodecylsulfonate
  • PVP polyvinylpyrrolidone
  • PVA polyvinyl alcohol
  • CTAB cetyltrimethylamine bromide
  • the solvent is one of water, toluene, ethylbenzene, dimethylsulfoxide (DMSO), N,N-dimethylformamide (DMF) and N,N-dimethylacetamide (DMAC). species or several.
  • DMSO dimethylsulfoxide
  • DMF N,N-dimethylformamide
  • DMAC N,N-dimethylacetamide
  • the time of the polymerization reaction is 3h-12h, and the temperature of the polymerization reaction is 50°C-100°C.
  • the initiators, cross-linking agents, surfactants and solvents used, as well as the polymerization temperature and time process conditions have an important impact on microporous polyacrylonitrile.
  • the second aspect of the present invention provides the preparation method of the sulfur-containing positive electrode material for secondary batteries. After mixing elemental sulfur and microporous polyacrylonitrile at a mass ratio of 2-16:1, heat it to 250-450°C and keep it warm for 1 -16h to obtain the sulfurized polyacrylonitrile positive electrode material, which is the sulfur-containing positive electrode material for secondary batteries.
  • elemental sulfur and microporous polyacrylonitrile are mixed at a mass ratio of 3-8:1, heated to 300-400°C and kept for 4-10 hours to obtain a vulcanized polyacrylonitrile positive electrode material, which is the described Sulfur-containing cathode materials for secondary batteries.
  • the sulfur content is 45-70wt%.
  • the sulfur content is 50-65 wt%.
  • the third aspect of the present invention provides a secondary battery, which has a negative electrode and a positive electrode, and the positive electrode contains the sulfur-containing positive electrode material for the secondary battery.
  • the negative electrode is lithium, sodium, potassium, magnesium, calcium or aluminum.
  • the positive electrode is obtained by the following preparation method: the binder, the sulfur-containing positive electrode material for secondary batteries, and the conductive agent are uniformly dispersed in a solvent at a mass ratio of 7-9:0.5-1.5:0.5-1.5, and then coated On the current collector, it is dried and pressed to obtain a positive electrode.
  • microporous polyacrylonitrile has a porous structure and a large specific surface area, it provides more space for sulfur molecules, thus obtaining a high sulfur content in the sulfurized polyacrylonitrile positive electrode material.
  • the specific capacity is large and the secondary battery is significantly improved.
  • the energy density of the secondary battery; and the preparation method is simple, environmentally friendly, low in cost, high in practical value, and has great application prospects.
  • the present invention has the following beneficial effects:
  • the sulfur content in the sulfur material S@pPAN prepared from linear polyacrylonitrile as a precursor exceeds 50wt%, a large amount of sulfur will be adsorbed on its surface, which will affect the cycle performance and rate discharge capability of the material.
  • the present invention uses acrylonitrile monomers and cross-linking agents to polymerize to form microporous polyacrylonitrile with a pore diameter of 0.2-2nm (and not including 2nm). Compared with linear polyacrylonitrile, the specific surface area is increased by 18.5 times.
  • the microporous structure provides additional space for sulfur.
  • Figure 1 shows the linear polyacrylonitrile (a), the microporous cross-linked polyacrylonitrile (b) obtained in Example 1, and the corresponding sulfur cathode material S@pPAN (c) prepared from linear polyacrylonitrile as a precursor. Transmission electron micrograph of the corresponding sulfur cathode material S@pCPAN(d) prepared from microporous polyacrylonitrile as the precursor.
  • Fig. 2 is a graph comparing the absorption and desorption curves of the linear polyacrylonitrile PAN of the comparative example, the microporous polyacrylonitrile CPAN obtained in Example 2, and the prepared positive electrode material.
  • Fig. 3 is a comparison chart of the pore size distribution of the linear polyacrylonitrile PAN of the comparative example, the microporous polyacrylonitrile CPAN obtained in Example 2, and the prepared positive electrode material.
  • Fig. 4 is a cycle comparison diagram of the sulfurized polyacrylonitrile cathode material prepared by using the linear polyacrylonitrile PAN and the microporous polyacrylonitrile CPAN obtained in Example 3 as precursors.
  • Fig. 5 is a graph showing the cycle rate comparison of the sulfurized polyacrylonitrile cathode material prepared as a precursor of the linear polyacrylonitrile PAN and the microporous polyacrylonitrile CPAN obtained in Example 3.
  • a kind of sulfur-containing positive electrode material for secondary batteries including sulfur and microporous polyacrylonitrile, described microporous polyacrylonitrile is obtained by the polymerization reaction of acrylonitrile monomer and cross-linking agent, also known as cross-linked polyacrylonitrile (CPAN ).
  • CPAN cross-linked polyacrylonitrile
  • the pore diameter of the microporous polyacrylonitrile is 0.2-2 nm, and does not contain 2 nm.
  • the polymerization reaction of microporous polyacrylonitrile also includes the following raw materials: initiator, surfactant and solvent, described acrylonitrile monomer, initiator, crosslinking agent, surfactant and solvent
  • the mass ratio is 1:0.01-0.1:0.01-0.1:0.01-0.1:4-10.
  • the crosslinking agent is divinylbenzene, diallyl phthalate, ethylene glycol dimethacrylate, 1,4-butylene glycol diacrylate, One or more of polyethylene glycol dimethacrylate and polyethylene glycol diacrylate.
  • the initiator is one or more of potassium persulfate, ammonium persulfate, azobisisobutyronitrile (AIBN) and dibenzoyl peroxide (BPO).
  • the surfactant is sodium dodecylsulfonate (SDS), polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA) and cetyltrimethylamine bromide (CTAB ) of one or more.
  • the solvent is water, toluene, ethylbenzene, dimethylsulfoxide (DMSO), N,N-dimethylformamide (DMF) and N,N-dimethylacetamide (DMAC) one or more.
  • DMSO dimethylsulfoxide
  • DMF N,N-dimethylformamide
  • DMAC N,N-dimethylacetamide
  • the time of the polymerization reaction is 3h-12h, and the temperature of the polymerization reaction is 50°C-100°C.
  • the preparation method of the sulfur-containing positive electrode material for secondary batteries after mixing elemental sulfur and microporous polyacrylonitrile at a mass ratio of 2-16:1, heating to 250-450°C and keeping it warm for 1-16h to obtain vulcanized polypropylene
  • the nitrile positive electrode material is the above-mentioned sulfur-containing positive electrode material for secondary batteries.
  • the present invention in the above preparation method, after mixing elemental sulfur and microporous polyacrylonitrile in a mass ratio of 3-8:1, heating to 300-400°C and keeping it warm for 4-10h to obtain a sulfurized polyacrylonitrile positive electrode
  • the material is the above-mentioned sulfur-containing positive electrode material for secondary batteries.
  • the sulfur content is 45-70 wt%.
  • the sulfur content is 50-65 wt%.
  • a secondary battery has a negative electrode and a positive electrode, and the positive electrode contains the sulfur-containing positive electrode material for the secondary battery.
  • the negative electrode is lithium, sodium, potassium, magnesium, calcium or aluminum.
  • the positive electrode is obtained by the following preparation method: the binder, the sulfur-containing positive electrode material for secondary batteries, and the conductive agent are uniformly dispersed in the The solvent is then coated on the current collector, and after drying, it is pressed into a tablet to obtain the positive electrode.
  • Figure 1(b) and Figure 1(d) are transmission electron microscope images of the microporous cross-linked polyacrylonitrile prepared in this example and the corresponding sulfur cathode material S@pCPAN prepared from microporous polyacrylonitrile as a precursor.
  • Battery assembly and testing are as follows: metal lithium is used as a negative electrode to assemble a lithium-sulfur secondary battery, and the electrolyte is 1M LiPF 6 /EC:DMC (1:1 volume ratio, EC: ethylene carbonate, DMC: dimethyl carbonate ); the charge and discharge cut-off voltage is 1-3V (vs. Li + /Li). The specific capacity of the first discharge is 1150.8mAh g -1 .
  • the obtained microporous polyacrylonitrile 2g and elemental sulfur 4g were added to ethanol and ball milled for 3 hours, and after drying, the obtained powder was heated in a tube furnace at 250°C for 10 hours under a nitrogen atmosphere to obtain a vulcanized polyacrylonitrile positive electrode material.
  • the medium sulfur content is 45.1 wt%.
  • FIG. 2 The adsorption and desorption curves of the microporous polyacrylonitrile CPAN and the positive electrode material prepared in this example are shown in FIG. 2 .
  • FIG. 3 The pore size distribution of the microporous polyacrylonitrile CPAN and positive electrode material prepared in this example is shown in FIG. 3 .
  • Battery assembly and testing are as follows: metal lithium is used as a negative electrode to assemble a lithium-sulfur secondary battery, and the electrolyte is 1M LiPF 6 /EC:DMC (1:1 volume ratio, EC: ethylene carbonate, DMC: dimethyl carbonate ); the charge and discharge cut-off voltage is 1-3V (vs. Li + /Li). The specific capacity reaches 732mAh g -1 under the condition of 0.2C rate.
  • Battery assembly and testing are as follows: metal lithium is used as a negative electrode to assemble a lithium-sulfur secondary battery, and the electrolyte is 1M LiPF 6 /EC:DMC (1:1 volume ratio, EC: ethylene carbonate, DMC: dimethyl carbonate ); the charge and discharge cut-off voltage is 1-3V (vs. Li + /Li). Under the condition of 0.2C rate, the first discharge specific capacity is 1048.8mAh g -1 , the reversible specific capacity is 849.9mAh g -1 , as shown in Figure 4, and the large rate discharge capacity is shown in Figure 5.
  • microporous polyacrylonitrile 2g and elemental sulfur 10g were added to ethanol and ball milled for 3 hours, and after drying, the obtained powder was heated in a tube furnace at 450°C for 1 hour in a nitrogen atmosphere to obtain a vulcanized polyacrylonitrile positive electrode material.
  • Medium sulfur content is 65.2wt%.
  • Battery assembly and testing are as follows: sodium metal is used as the negative electrode to assemble a sodium-sulfur secondary battery, and the electrolyte is 1M NaPF 6 /EC:DMC (1:1 volume ratio, EC: ethylene carbonate, DMC: dimethyl carbonate ); the charge and discharge cut-off voltage is 1-2.7V (vs.Na + /Na). The specific capacity reaches 620mAh g -1 under the condition of 0.2C rate.
  • microporous polyacrylonitrile 2g and elemental sulfur 6g were added to ethanol and ball milled for 3 hours, and after drying, the obtained powder was heated in a tube furnace at 300°C for 5 hours in a nitrogen atmosphere to obtain a vulcanized polyacrylonitrile positive electrode material.
  • Medium sulfur content is 55.5wt%.
  • Battery assembly and testing are as follows: sodium metal is used as the negative electrode to assemble a sodium-sulfur secondary battery, and the electrolyte is 1M NaPF 6 /EC:DMC (1:1 volume ratio, EC: ethylene carbonate, DMC: dimethyl carbonate ); the charge and discharge cut-off voltage is 1-2.7V (vs.Na + /Na). The specific capacity reaches 550mAh g -1 under the condition of 0.2C rate.
  • the obtained intramolecular cross-linked polyacrylonitrile 2g and elemental sulfur 10g were added to ethanol and ball milled for 3h, and after drying, the obtained powder was heated in a tube furnace at 400°C for 10h in a nitrogen atmosphere to obtain a vulcanized polyacrylonitrile cathode material , the sulfur content in the material is 45wt%.
  • the obtained microporous polyacrylonitrile 2g and elemental sulfur 16g were added to ethanol and ball milled for 3 hours, and after drying, the obtained powder was heated in a tube furnace at 300°C for 10 hours in a nitrogen atmosphere to obtain a vulcanized polyacrylonitrile positive electrode material.
  • the medium sulfur content is 46.73wt%.
  • microporous polyacrylonitrile 2g and elemental sulfur 16g were added to ethanol and ball milled for 3 hours, and after drying, the obtained powder was heated in a tube furnace at 300°C for 10 hours in a nitrogen atmosphere to obtain a vulcanized polyacrylonitrile positive electrode material.
  • Medium sulfur content is 47.2wt%.
  • microporous polyacrylonitrile 2g and elemental sulfur 16g were added to ethanol and ball milled for 3 hours, and after drying, the obtained powder was heated in a tube furnace at 300°C for 10 hours in a nitrogen atmosphere to obtain a vulcanized polyacrylonitrile positive electrode material.
  • Medium sulfur content is 56.6wt%.
  • microporous polyacrylonitrile 2g and elemental sulfur 16g were added to ethanol and ball milled for 3 hours, and after drying, the obtained powder was heated in a tube furnace at 400°C for 5 hours in a nitrogen atmosphere to obtain a vulcanized polyacrylonitrile positive electrode material.
  • Medium sulfur content is 55.2wt%.
  • the obtained microporous polyacrylonitrile 2g and elemental sulfur 16g were added to ethanol and ball milled for 3 hours, and after drying, the obtained powder was heated in a tube furnace at 300°C for 16 hours in a nitrogen atmosphere to obtain a vulcanized polyacrylonitrile positive electrode material.
  • the medium sulfur content is 46.4wt%.
  • Battery assembly and testing are as follows: metal lithium is used as a negative electrode to assemble a lithium-sulfur secondary battery, and the electrolyte is 1M LiPF 6 /EC:DMC (1:1 volume ratio, EC: ethylene carbonate, DMC: dimethyl carbonate ); the charge and discharge cut-off voltage is 1-3V (vs. Li + /Li). Under the condition of 0.2C rate, the first discharge specific capacity is 951.2mAh g -1 , and the reversible specific capacity is 718.9mAh g -1 (Fig. 4). See Figure 5 for cycle rate performance.
  • Table 1 shows the linear polyacrylonitrile PAN prepared in Comparative Example and the microporous polyacrylonitrile CPAN prepared in Example 2 and Example 3, and the comparison of properties of corresponding sulfur-containing materials.
  • Figure 1 shows linear polyacrylonitrile (a), microporous cross-linked polyacrylonitrile (b), the corresponding sulfur cathode material S@pPAN (c) prepared from linear polyacrylonitrile as precursor, and microporous polypropylene Transmission electron micrograph of the corresponding sulfur cathode material S@pCPAN(d) prepared with nitrile as the precursor.
  • Figure 1(a) shows that the linear PAN is a compact structure;
  • Figure 1(b) the microporous PAN prepared by the cross-linking method has a pore size between 0.75-1.5nm.
  • Fig. 2 is a graph comparing the absorption and desorption curves of the linear polyacrylonitrile PAN of the comparative example, the microporous polyacrylonitrile CPAN obtained in Example 2, and the prepared positive electrode material. It can be seen that the specific surface area of linear PAN is 16.8m 2 g -1 ; while the specific surface area of microporous PAN prepared by cross-linking method is increased by 18 times due to the existence of a large number of micropores.
  • Fig. 3 is a comparison chart of the pore size distribution of the linear polyacrylonitrile PAN of the comparative example, the microporous polyacrylonitrile CPAN obtained in Example 2, and the prepared positive electrode material. Consistent with the morphology and structure in Figure 1, the linear PAN is a dense structure; the microporous PAN prepared by the cross-linking method has a pore size between 0.75-1.5nm.
  • Fig. 4 is a cycle comparison diagram of the sulfurized polyacrylonitrile cathode material prepared by using the linear polyacrylonitrile PAN and the microporous polyacrylonitrile CPAN obtained in Example 3 as precursors. It can be seen from the figure that due to the rich microporous structure, more monodisperse sulfur molecules can be accommodated, the sulfur content is effectively increased (from 47.3% to 54.8%), and the corresponding first discharge specific capacity is 1048.8mAh g -1 , the reversible specific capacity is 849.9mAh g -1 ; while the first discharge specific capacity of the comparative sample is 951.2mAh g -1 , and the reversible specific capacity is 718.9mAh g -1 .

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Medicinal Chemistry (AREA)
  • Health & Medical Sciences (AREA)
  • Battery Electrode And Active Subsutance (AREA)
  • Secondary Cells (AREA)

Abstract

本发明涉及一种二次电池用含硫正极材料、其制备方法及二次电池，含硫正极材料采用微孔(孔径为0.2-2nm)聚丙烯腈为前驱体，与单质硫均匀混合后，加热处理得到；微孔聚丙烯腈是由丙烯腈单体和交联剂通过自由基聚合得到的。与现有技术相比，本发明由于微孔聚丙烯腈具有多孔结构，与线性聚丙烯腈相比，比表面积提高了18.5倍，在高温烧结过程中，大量的硫分子可以填充到聚丙烯腈微孔中，由此获得硫化聚丙烯腈正极材料中硫含量高，作为二次电池正极时，比容量大，显著提升二次电池能量密度；并且制备方法简单易行，环境友好，成本低廉，实用价值高，应用前景大。

Description

一种二次电池用含硫正极材料、其制备方法及二次电池 技术领域
本发明涉及一种含硫正极材料，尤其是涉及一种可以与锂、钠、钾、镁、钙或铝负极组装成二次电池的含硫正极材料及其制备方法，本发明还涉及含有该硫正极材料的二次电池。
背景技术
以锂、钠、钾、镁或铝作为负极、硫作为正极的二次电池具有能量密度高、硫资源丰富、成本低廉、环境优化等显著优势。以锂硫电池为例，由于其理论能量密度高达2600Wh/kg，且具低成本和环境友好等特点，受到了广泛的关注。早在2002年，文献(J.Wang et al，Advanced materials，2002,13-14,963)首次报道了硫和聚丙烯腈(PAN)在高温下反应，制备成了硫化聚丙烯腈(S@PAN)复合正极材料，该正极材料在碳酸酯基电解质中无多硫离子溶解穿梭现象，充放电效率高，自放电低，循环稳定，倍率性能优异。但是，采用线性聚丙烯腈为前驱体时，获得S@PAN正极材料中硫含量有限，低于50wt％，通常在45wt％左右，导致该材料比容量不高，影响二次电池能量密度。因此，通过制备具有高硫含量和高比容量的S@PAN正极材料，对于提高二次电池能量密度具有重要的意义。
相关现有技术文献：
(1)中国专利CN106957443A公开了具有提高的电容量的聚丙烯腈-硫-复合材料；
(2)文献(Science advances,2018,4(6):eaat1687)公开了热裂解聚丙烯腈/二硫化硒复合物；
(3)文献(The Journal of Physical Chemistry C,2017,121,26172-26179)公开了分子筛SBA-15硬模板合成的介孔聚合物。
发明内容
本发明申请人经过深入研究后发现：
中国专利CN106957443A公开的具有提高的电容量的聚丙烯腈-硫-复合材料，采用聚丙烯腈和硫磺与至少一种交联剂反应，是一种聚合物颗粒表面修饰技术，不能对聚合物颗粒内部造成影响，对提高硫含量效果有限。
文献(Science advances,2018,4(6):eaat1687)公开的热裂解聚丙烯腈/二硫化硒复合物中多孔聚合物采用静电纺丝形成孔径在2-50nm的介孔，甚至是100nm的大孔，而硫分子的大小在1nm左右，该孔径大小不适合容纳单分散的硫分子，也就是不能形成无定型的硫。
文献(The Journal of Physical Chemistry C,2017,121,26172-26179)公开的分子筛SBA-15硬模板合成的介孔聚合物，孔径在2-50nm。由于硫分子大小只有1nm，孔径超过2nm，填充的硫为分子团聚体，电化学反应动力学将十分缓慢，因此介孔也不适合容纳单 分散的硫分子。
本发明的目的就是为了提供一种二次电池用含硫正极材料、其制备方法及二次电池。
本发明从聚丙烯腈(PAN)前驱体入手，构建具有丰富微孔(孔径小于2nm)的聚丙烯腈，大量的微孔可以容纳硫材料，从而显著提升硫化聚丙烯腈中硫的含量，也就是电池正极的比容量，并且方法简单，易于放大，实用性强。
本发明的目的可以通过以下技术方案来实现：
本发明第一方面提供一种二次电池用含硫正极材料，包括硫和微孔聚丙烯腈，所述的微孔聚丙烯腈由丙烯腈单体与交联剂聚合反应得到，也称交联聚丙烯腈(CPAN)。
优选地，所述的微孔聚丙烯腈的孔径为0.2-2nm，且不含2nm。
优选地，微孔聚丙烯腈的聚合反应还包括以下原料：引发剂、表面活性剂和溶剂，所述的丙烯腈单体、引发剂、交联剂、表面活性剂和溶剂的质量比例为1:0.01-0.1:0.01-0.1:0.01-0.1:4-10。
优选地，所述的交联剂为二乙烯基苯、聚苯二甲酸二烯丙酯、二甲基丙烯酸乙二醇酯、二丙烯酸-1,4-丁二醇酯、聚乙二醇二甲基丙烯酸甲酯和聚乙二醇二丙烯酸酯的一种或几种。
优选地，所述的引发剂为过硫酸钾、过硫酸铵、偶氮二异丁腈(AIBN)和过氧化二苯甲酰(BPO)的一种或几种。
优选地，所述的表面活性剂为十二烷基磺酸钠(SDS)、聚乙烯吡咯烷酮(PVP)、聚乙烯醇(PVA)和溴化十六烷基三甲胺(CTAB)的一种或几种。
优选地，所述的溶剂为水、甲苯、乙苯、二甲亚砜(DMSO)、N,N-二甲基甲酰胺(DMF)和N,N-二甲基乙酰胺(DMAC)的一种或几种。
优选地，聚合反应的时间为3h-12h，聚合反应的温度50℃-100℃。
所采用的引发剂、交联剂、表面活性剂和溶剂，以及聚合温度和时间工艺条件对于微孔聚丙烯腈具有重要的影响。
本发明第二方面提供所述的二次电池用含硫正极材料的制备方法，将单质硫与微孔聚丙烯腈按质量比2-16:1混合后，加热至250-450℃并保温1-16h得到硫化聚丙烯腈正极材料，即为所述的二次电池用含硫正极材料。
优选上述制备方法中，将单质硫与微孔聚丙烯腈按质量比3-8:1混合后，加热至300-400℃并保温4-10h得到硫化聚丙烯腈正极材料，即为所述的二次电池用含硫正极材料。
优选地，二次电池用含硫正极材料中，硫的含量为45-70wt％。优选硫的含量为50-65wt％。
本发明第三方面提供一种二次电池，具有负极和正极，所述的正极含有所述的二次电池用含硫正极材料。
优选地，所述的负极为锂、钠、钾、镁、钙或铝。
优选地，所述正极采用以下制备方法得到：将粘接剂与二次电池用含硫正极材料、导电剂按质量比7-9:0.5-1.5:0.5-1.5均匀分散于溶剂中然后涂覆在集流体上，干燥后压片得到正极。
由于微孔聚丙烯腈具有多孔结构，比表面积大，为硫分子提供更多空间，由此获得硫化聚丙烯腈正极材料中硫含量高，作为二次电池正极时，比容量大，显著提升二次电池能量密度；并且制备方法简单易行，环境友好，成本低廉，实用价值高，应用前景大。
与现有技术相比，本发明具有以下有益效果：
现有技术中由线性聚丙烯腈作为前驱体制备的硫材料S@pPAN中硫的含量超过50wt％时，将会有大量硫吸附在其表面，影响材料的循环性能和倍率放电能力。本发明采用丙烯腈单体与交联剂进行聚合，形成微孔聚丙烯腈，孔径在0.2-2nm(且不含2nm)，与线性聚丙烯腈相比，比表面积提高了18.5倍，丰富的微孔结构为硫提供额外的空间，在高温烧结过程中，大量的硫分子可以填充到聚丙烯腈微孔中，制得S@pPAN中硫的含量达到70wt％，材料的可逆比容量达到了818mAh g -1。效果显著，工艺简单，容易放大，实用性强。
附图说明
图1所示为线性聚丙烯腈(a)、实施例1所得微孔交联聚丙烯腈(b)、由线性聚丙烯腈为前驱体制备的相应硫正极材料S@pPAN(c)，由微孔聚丙烯腈为前驱体制备的相应硫正极材料S@pCPAN(d)透射电镜图。
图2所示为对比实施例线性聚丙烯腈PAN、实施例2所得微孔聚丙烯腈CPAN和制备的正极材料的吸脱附曲线对比图。
图3所示为对比实施例线性聚丙烯腈PAN、实施例2所得微孔聚丙烯腈CPAN和制备的正极材料的孔径分布对比图。
图4所示为以线性聚丙烯腈PAN和实施例3所得微孔聚丙烯腈CPAN为前驱体制备的硫化聚丙烯腈正极材料的循环对比图。
图5所示为线性聚丙烯腈PAN和实施例3所得微孔聚丙烯腈CPAN的为前驱体制备的硫化聚丙烯腈正极材料的循环倍率对比图。
具体实施方式
一种二次电池用含硫正极材料，包括硫和微孔聚丙烯腈，所述的微孔聚丙烯腈由丙烯腈单体与交联剂聚合反应得到，也称交联聚丙烯腈(CPAN)。
作为本发明优选的实施方式，所述的微孔聚丙烯腈的孔径为0.2-2nm，且不含2nm。
作为本发明优选的实施方式，微孔聚丙烯腈的聚合反应还包括以下原料：引发剂、表面活性剂和溶剂，所述的丙烯腈单体、引发剂、交联剂、表面活性剂和溶剂的质量比例为1:0.01-0.1:0.01-0.1:0.01-0.1:4-10。
作为本发明优选的实施方式，所述的交联剂为二乙烯基苯、聚苯二甲酸二烯丙酯、二甲基丙烯酸乙二醇酯、二丙烯酸-1,4-丁二醇酯、聚乙二醇二甲基丙烯酸甲酯和聚乙二醇二丙烯酸酯的一种或几种。
作为本发明优选的实施方式，所述的引发剂为过硫酸钾、过硫酸铵、偶氮二异丁腈(AIBN)和过氧化二苯甲酰(BPO)的一种或几种。
作为本发明优选的实施方式，所述的表面活性剂为十二烷基磺酸钠(SDS)、聚乙烯吡咯烷酮(PVP)、聚乙烯醇(PVA)和溴化十六烷基三甲胺(CTAB)的一种或几种。
作为本发明优选的实施方式，所述的溶剂为水、甲苯、乙苯、二甲亚砜(DMSO)、N,N-二甲基甲酰胺(DMF)和N,N-二甲基乙酰胺(DMAC)的一种或几种。
作为本发明优选的实施方式，聚合反应的时间为3h-12h，聚合反应的温度50℃-100℃。
所述的二次电池用含硫正极材料的制备方法，将单质硫与微孔聚丙烯腈按质量比2-16:1混合后，加热至250-450℃并保温1-16h得到硫化聚丙烯腈正极材料，即为所述的二次电池用含硫正极材料。
作为本发明优选的实施方式，上述制备方法中，将单质硫与微孔聚丙烯腈按质量比3-8:1混合后，加热至300-400℃并保温4-10h得到硫化聚丙烯腈正极材料，即为所述的二次电池用含硫正极材料。
作为本发明优选的实施方式，二次电池用含硫正极材料中，硫的含量为45-70wt％。优选硫的含量为50-65wt％。
一种二次电池，具有负极和正极，所述的正极含有所述的二次电池用含硫正极材料。
作为本发明优选的实施方式，所述的负极为锂、钠、钾、镁、钙或铝。
作为本发明优选的实施方式，所述正极采用以下制备方法得到：将粘接剂与二次电池用含硫正极材料、导电剂按质量比7-9:0.5-1.5:0.5-1.5均匀分散于溶剂中然后涂覆在集流体上，干燥后压片得到正极。
下面结合附图和具体实施例对本发明进行详细说明。
实施例1
将5g丙烯腈、0.25g AIBN，0.2g二丙烯酸-1，4-丁二醇酯和0.5g PVP加入到50ml DMAC中，经过80℃磁力搅拌4h，产生白色沉淀，将白色沉淀用盐酸/丙酮混合液和蒸馏水洗涤后，烘干得到微孔聚丙烯腈。
将得到的微孔聚丙烯腈2g和单质硫32g，加入乙醇球磨3h，烘干后将得到的粉体于管式炉中在氮气气氛下300℃加热5h，得到硫化聚丙烯腈正极材料，材料中硫含量为70wt％。
本实施例制得的微孔交联聚丙烯腈以及由微孔聚丙烯腈为前驱体制备的相应硫正极材料S@pCPAN的透射电镜图件图1(b)和图1(d)。
电池组装和测试为：采用金属锂作为负极组装成锂硫二次电池，电解液为1M的LiPF 6/EC:DMC(1:1体积比，EC:碳酸乙烯酯，DMC:二甲基碳酸酯)；充放电截止电压为1-3V(vs.Li +/Li)。第一次放电比容量为1150.8mAh g -1。
实施例2
将5g丙烯腈、0.1g过硫酸铵，0.1g二甲基丙烯酸乙二醇酯和0.25g SDS加入到40ml水/DMSO(m:m＝1:1)中，经过60℃磁力搅拌10h，产生白色沉淀，将白色沉淀用盐酸/丙酮混合液和蒸馏水洗涤后，烘干得到微孔聚丙烯腈。
取得到的微孔聚丙烯腈2g和单质硫4g，加入乙醇球磨3h，烘干后将得到的粉体于管式炉中在氮气气氛下250℃加热10h，得到硫化聚丙烯腈正极材料，材料中硫含量为45.1 wt％。
本实施例制得的微孔聚丙烯腈CPAN和正极材料的吸脱附曲线参见图2。本实施例制得的微孔聚丙烯腈CPAN和正极材料的孔径分布参见图3。
电池组装和测试为：采用金属锂作为负极组装成锂硫二次电池，电解液为1M的LiPF 6/EC:DMC(1:1体积比，EC:碳酸乙烯酯，DMC:二甲基碳酸酯)；充放电截止电压为1-3V(vs.Li +/Li)。以0.2C倍率的条件下比容量达到732mAh g -1。
实施例3
将5g丙烯腈、0.05g过硫酸钾，0.05g二乙烯基苯和0.1g PVA加入到20ml水中，经过65℃磁力搅拌5h，产生白色沉淀，将白色沉淀用盐酸/丙酮混合液和蒸馏水洗涤后，烘干得到微孔聚丙烯腈。
取制备的微孔聚丙烯腈2g和单质硫16g，加入乙醇球磨3h，烘干后将得到的粉体于管式炉中在氮气气氛下300℃加热5h，得到硫化聚丙烯腈正极材料，材料中硫含量为54.8wt％。
电池组装和测试为：采用金属锂作为负极组装成锂硫二次电池，电解液为1M的LiPF 6/EC:DMC(1:1体积比，EC:碳酸乙烯酯，DMC:二甲基碳酸酯)；充放电截止电压为1-3V(vs.Li +/Li)。以0.2C倍率的条件下第一次放电比容量为1048.8mAh g -1，可逆比容量为849.9mAh g -1，见图4，大倍率放电能力见图5。
实施例4
将5g丙烯腈、0.1g BPO，0.5g聚乙二醇二甲基丙烯酸甲酯和0.25g SDS加入到40ml水/DMF(m:m＝1:1)中，经过50℃磁力搅拌12h，产生白色沉淀，将白色沉淀用盐酸/丙酮混合液和蒸馏水洗涤后，烘干得到微孔聚丙烯腈。
取得到的微孔聚丙烯腈2g和单质硫10g，加入乙醇球磨3h，烘干后将得到的粉体于管式炉中在氮气气氛下450℃加热1h，得到硫化聚丙烯腈正极材料，材料中硫含量为65.2wt％。
电池组装和测试为：采用金属钠作为负极组装成钠硫二次电池，电解液为1M的NaPF 6/EC:DMC(1:1体积比，EC:碳酸乙烯酯，DMC:二甲基碳酸酯)；充放电截止电压为1-2.7V(vs.Na +/Na)。以0.2C倍率的条件下比容量达到620mAh g -1。
实施例5
将5g丙烯腈、0.5g过硫酸钾，0.05g聚乙二醇二丙烯酸酯和0.05g PVP加入到50ml乙苯中，经过65℃磁力搅拌5h，产生白色沉淀，将白色沉淀用盐酸/丙酮混合液和蒸馏水洗涤后，烘干得到微孔聚丙烯腈。
取得到的微孔聚丙烯腈2g和单质硫6g，加入乙醇球磨3h，烘干后将得到的粉体于管式炉中在氮气气氛下300℃加热5h，得到硫化聚丙烯腈正极材料，材料中硫含量为55.5wt％。
电池组装和测试为：采用金属钠作为负极组装成钠硫二次电池，电解液为1M的NaPF 6/EC:DMC(1:1体积比，EC:碳酸乙烯酯，DMC:二甲基碳酸酯)；充放电截止电压为1-2.7V(vs.Na +/Na)。以0.2C倍率的条件下比容量达到550mAh g -1。
实施例6
将5g丙烯腈、0.1gAIBN，0.1g聚乙二醇二甲基丙烯酸甲酯和0.05g二乙烯基苯，0.1g PVP加入到30ml水/DMAC(m:m＝1:1)中，经过60℃磁力搅拌5h，产生白色沉淀，将白色沉淀用盐酸/丙酮混合液和蒸馏水洗涤后，烘干得到分子内交联聚丙烯腈。
取得到的分子内交联聚丙烯腈2g和单质硫10g，加入乙醇球磨3h，烘干后将得到的粉体于管式炉中在氮气气氛下400℃加热10h，得到硫化聚丙烯腈正极材料，材料中硫含量为45wt％。
实施例7
将5g丙烯腈、0.1g过硫酸铵，0.2g二丙烯酸-1，4-丁二醇酯和0.25g CTAB加入到50ml DMSO中，经过100℃磁力搅拌3h，产生白色沉淀，将白色沉淀用盐酸/丙酮混合液和蒸馏水洗涤后，烘干得到微孔聚丙烯腈。
取得到的微孔聚丙烯腈2g和单质硫16g，加入乙醇球磨3h，烘干后将得到的粉体于管式炉中在氮气气氛下300℃加热10h，得到硫化聚丙烯腈正极材料，材料中硫含量为46.73wt％。
实施例8
将5g丙烯腈、0.2gBPO，0.5g聚乙二醇二甲基丙烯酸甲酯和0.5g SDS加入到30ml乙苯中，经过65℃磁力搅拌5h，产生白色沉淀，将白色沉淀用盐酸/丙酮混合液和蒸馏水洗涤后，烘干得到微孔聚丙烯腈。
取得到的微孔聚丙烯腈2g和单质硫16g，加入乙醇球磨3h，烘干后将得到的粉体于管式炉中在氮气气氛下300℃加热10h，得到硫化聚丙烯腈正极材料，材料中硫含量为47.2wt％。
实施例9
将5g丙烯腈、0.05g过硫酸钾，0.05g聚乙二醇二丙烯酸酯和0.05g二乙烯基苯，0.5g CTAB加入到30ml水/DMF(m:m＝1:1)中，经过60℃磁力搅拌5h，产生白色沉淀，将白色沉淀用盐酸/丙酮混合液和蒸馏水洗涤后，烘干得到微孔聚丙烯腈。
取得到的微孔聚丙烯腈2g和单质硫16g，加入乙醇球磨3h，烘干后将得到的粉体于管式炉中在氮气气氛下300℃加热10h，得到硫化聚丙烯腈正极材料，材料中硫含量为56.6wt％。
实施例10
将5g丙烯腈、0.5g过硫酸铵，0.1g二乙烯基苯和0.1gCTAB加入到40ml水/DMSO(m:m＝1:1)中，经过75℃磁力搅拌5h，产生白色沉淀，将白色沉淀用盐酸/丙酮混合液和蒸馏水洗涤后，烘干得到微孔聚丙烯腈。
取得到的微孔聚丙烯腈2g和单质硫16g，加入乙醇球磨3h，烘干后将得到的粉体于管式炉中在氮气气氛下400℃加热5h，得到硫化聚丙烯腈正极材料，材料中硫含量为55.2wt％。
实施例11
将5g丙烯腈、0.1g AIBN，0.25g二丙烯酸-1，4-丁二醇酯和0.5g SDS加入到30ml 甲苯中，经过50℃磁力搅拌12h，产生白色沉淀，将白色沉淀用盐酸/丙酮混合液和蒸馏水洗涤后，烘干得到微孔聚丙烯腈。
取得到的微孔聚丙烯腈2g和单质硫16g，加入乙醇球磨3h，烘干后将得到的粉体于管式炉中在氮气气氛下300℃加热16h，得到硫化聚丙烯腈正极材料，材料中硫含量为46.4wt％。
对比实施例
不加交联剂制备线性聚丙烯腈，将5g丙烯腈、0.05g过硫酸钾加入到20ml水中，经过65℃磁力搅拌5h，产生白色沉淀，将白色沉淀用盐酸/丙酮混合液和蒸馏水洗涤后，烘干得到线性聚丙烯腈。透射电镜图参见图1(a)，吸脱附曲线参见图2，孔径分布参见图3。
取制备的线性聚丙烯腈2g和单质硫16g，加入乙醇球磨3h，烘干后将得到的粉体于管式炉中在氮气气氛下300℃加热5h，得到硫化聚丙烯腈正极材料，材料中硫含量为47.3wt％。硫化聚丙烯腈正极材料的透射电镜图参见图1(c)。
电池组装和测试为：采用金属锂作为负极组装成锂硫二次电池，电解液为1M的LiPF 6/EC:DMC(1:1体积比，EC:碳酸乙烯酯，DMC:二甲基碳酸酯)；充放电截止电压为1-3V(vs.Li +/Li)。以0.2C倍率的条件下第一次放电比容量为951.2mAh g -1，可逆比容量为718.9mAh g -1(图4)。循环倍率性能参见图5。
表1所示为对比实施例制备的线性聚丙烯腈PAN和实施例2、实施例3制备的微孔聚丙烯腈CPAN，以及相应含硫材料性质对比。
表1
Figure PCTCN2022078705-appb-000001
图1所示为线性聚丙烯腈(a)、微孔交联聚丙烯腈(b)、由线性聚丙烯腈为前驱体制备的相应硫正极材料S@pPAN(c)，由微孔聚丙烯腈为前驱体制备的相应硫正极材料S@pCPAN(d)透射电镜图。图1(a)可以看出线性PAN是致密结构；图1(b)交联方法制备的微孔PAN孔径在0.75-1.5nm之间。
图2所示为对比实施例线性聚丙烯腈PAN、实施例2所得微孔聚丙烯腈CPAN和制 备的正极材料的吸脱附曲线对比图。可以看出线性PAN比表面积为16.8m 2g -1；而由交联方法制备的微孔PAN由于存在大量微孔，比表面积增大了18倍。
图3所示为对比实施例线性聚丙烯腈PAN、实施例2所得微孔聚丙烯腈CPAN和制备的正极材料的孔径分布对比图。与图1形貌结构结构一致，线性PAN是致密结构；交联方法制备的微孔PAN孔径在0.75-1.5nm之间。
图4所示为以线性聚丙烯腈PAN和实施例3所得微孔聚丙烯腈CPAN为前驱体制备的硫化聚丙烯腈正极材料的循环对比图。从图中可以看出，由于存在丰富的微孔结构，可以容纳更多的单分散的硫分子，硫的含量得到有效提升(从47.3％提高到54.8％)，相应第一次放电比容量为1048.8mAh g -1，可逆比容量为849.9mAh g -1；而对比样第一次放电比容量为951.2mAh g -1，可逆比容量为718.9mAh g -1。
上述对实施例的描述是为便于该技术领域的普通技术人员能理解和使用发明。熟悉本领域技术的人员显然可以容易地对这些实施例做出各种修改，并把在此说明的一般原理应用到其他实施例中而不必经过创造性的劳动。因此，本发明不限于上述实施例，本领域技术人员根据本发明的揭示，不脱离本发明范畴所做出的改进和修改都应该在本发明的保护范围之内。

Claims (10)

  1. 一种二次电池用含硫正极材料，其特征在于，包括硫和微孔聚丙烯腈，所述的微孔聚丙烯腈由丙烯腈单体与交联剂聚合反应得到。
  2. 根据权利要求1所述的一种二次电池用含硫正极材料，其特征在于，所述的微孔聚丙烯腈的孔径为0.2-2nm，且不含2nm。
  3. 根据权利要求1所述的一种二次电池用含硫正极材料，其特征在于，微孔聚丙烯腈的聚合反应还包括以下原料：引发剂、表面活性剂和溶剂，所述的丙烯腈单体、引发剂、交联剂、表面活性剂和溶剂的质量比例为1:0.01-0.1:0.01-0.1:0.01-0.1:4-10。
  4. 根据权利要求1或3所述的一种二次电池用含硫正极材料，其特征在于，所述的交联剂为二乙烯基苯、聚苯二甲酸二烯丙酯、二甲基丙烯酸乙二醇酯、二丙烯酸-1,4-丁二醇酯、聚乙二醇二甲基丙烯酸甲酯和聚乙二醇二丙烯酸酯的一种或几种。
  5. 根据权利要求3所述的一种二次电池用含硫正极材料，其特征在于，包括以下条件中的任一项或多项：
    (i)所述的引发剂为过硫酸钾、过硫酸铵、偶氮二异丁腈和过氧化二苯甲酰的一种或几种；
    (ii)所述的表面活性剂为十二烷基磺酸钠、聚乙烯吡咯烷酮、聚乙烯醇和溴化十六烷基三甲胺的一种或几种；
    (iii)所述的溶剂为水、甲苯、乙苯、二甲亚砜、N,N-二甲基甲酰胺和N,N-二甲基乙酰胺的一种或几种。
  6. 根据权利要求1或3所述的一种二次电池用含硫正极材料，其特征在于，聚合反应的时间为3h-12h，聚合反应的温度50℃-100℃。
  7. 如权利要求1～6任一所述的二次电池用含硫正极材料的制备方法，其特征在于，将单质硫与微孔聚丙烯腈按质量比2-16:1混合后，加热至250-450℃并保温1-16h得到硫化聚丙烯腈正极材料，即为所述的二次电池用含硫正极材料；优选将单质硫与微孔聚丙烯腈按质量比3-8:1混合后，加热至300-400℃并保温4-10h得到硫化聚丙烯腈正极材料，即为所述的二次电池用含硫正极材料。
  8. 根据权利要求7所述的二次电池用含硫正极材料的制备方法，其特征在于，二次电池用含硫正极材料中，硫的含量为45-70wt％，优选为50-65wt％。
  9. 一种二次电池，其特征在于，具有负极和正极，所述的正极含有权利要求1～6任一所述的二次电池用含硫正极材料。
  10. 根据权利要求9所述的一种二次电池，其特征在于，所述的负极为锂、钠、钾、镁、钙或铝。
PCT/CN2022/078705 2021-05-24 2022-03-02 一种二次电池用含硫正极材料、其制备方法及二次电池 WO2022247375A1 (zh)

Priority Applications (2)

Application Number Priority Date Filing Date Title
JP2023557272A JP2024510027A (ja) 2021-05-24 2022-03-02 二次電池用の硫黄を含む正極材料、その製造方法および二次電池
US18/283,457 US20240178393A1 (en) 2021-05-24 2022-03-02 Sulfur-containing positive electrode material for secondary battery, preparation method thereof, and secondary battery

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202110566526.6 2021-05-24
CN202110566526.6A CN113346080B (zh) 2021-05-24 2021-05-24 一种二次电池用含硫正极材料、其制备方法及二次电池

Publications (1)

Publication Number Publication Date
WO2022247375A1 true WO2022247375A1 (zh) 2022-12-01

Family

ID=77471076

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2022/078705 WO2022247375A1 (zh) 2021-05-24 2022-03-02 一种二次电池用含硫正极材料、其制备方法及二次电池

Country Status (4)

Country Link
US (1) US20240178393A1 (zh)
JP (1) JP2024510027A (zh)
CN (1) CN113346080B (zh)
WO (1) WO2022247375A1 (zh)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113346080B (zh) * 2021-05-24 2023-01-24 上海交通大学 一种二次电池用含硫正极材料、其制备方法及二次电池
CN114613990A (zh) * 2022-03-17 2022-06-10 武汉船用电力推进装置研究所（中国船舶重工集团公司第七一二研究所） 一种聚合物基硫正极材料及其制备方法

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2000064953A1 (en) * 1999-03-19 2000-11-02 Vinod Chintamani Malshe A process for production of micro-porous microspheres of polymers and polymeric pigments therefrom
CN102820454A (zh) * 2011-06-11 2012-12-12 苏州宝时得电动工具有限公司 电极复合材料及其制备方法、正极、具有该正极的电池
CN102938475A (zh) * 2012-11-08 2013-02-20 中国科学院化学研究所 钠-硫电池及其制备方法
CN109070049A (zh) * 2016-03-04 2018-12-21 康奈尔大学 稳定的室温钠-硫电池
CN113346080A (zh) * 2021-05-24 2021-09-03 上海交通大学 一种二次电池用含硫正极材料、其制备方法及二次电池

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP6021947B2 (ja) * 2012-02-16 2016-11-09 ローベルト ボツシユ ゲゼルシヤフト ミツト ベシユレンクテル ハフツングＲｏｂｅｒｔ Ｂｏｓｃｈ Ｇｍｂｈ リチウム−硫黄電池に使用される硫黄含有複合材、それを含む電極材料およびリチウム−硫黄電池
CN104347850A (zh) * 2013-07-25 2015-02-11 苏州宝时得电动工具有限公司 电极复合材料及其制备方法、正极、具有该正极的电池
US10710065B2 (en) * 2015-04-03 2020-07-14 The Regents Of The University Of California Polymeric materials for electrochemical cells and ion separation processes
EP3304623B1 (en) * 2015-06-05 2020-10-07 Robert Bosch GmbH Sulfur-carbon composite comprising micro-porous carbon nanosheets for lithium-sulfur batteries and process for preparing the same
CN105858634B (zh) * 2016-03-27 2017-12-01 华南理工大学 一种乳液凝胶基聚丙烯腈/碳多孔材料及其制备方法
CN106384828A (zh) * 2016-10-19 2017-02-08 天津力神电池股份有限公司 一种交联式多孔复合锂硫电池正极及其制备方法
CN107417853A (zh) * 2017-09-14 2017-12-01 湖南理工学院 一种多孔聚丙烯腈的制备方法
WO2020105980A1 (ko) * 2018-11-22 2020-05-28 주식회사 엘지화학 리튬-황 이차전지
CN111773932A (zh) * 2020-07-21 2020-10-16 杭州瑞纳膜工程有限公司 一种孔径可调的纳滤膜及制备方法

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2000064953A1 (en) * 1999-03-19 2000-11-02 Vinod Chintamani Malshe A process for production of micro-porous microspheres of polymers and polymeric pigments therefrom
CN102820454A (zh) * 2011-06-11 2012-12-12 苏州宝时得电动工具有限公司 电极复合材料及其制备方法、正极、具有该正极的电池
CN102938475A (zh) * 2012-11-08 2013-02-20 中国科学院化学研究所 钠-硫电池及其制备方法
CN109070049A (zh) * 2016-03-04 2018-12-21 康奈尔大学 稳定的室温钠-硫电池
CN113346080A (zh) * 2021-05-24 2021-09-03 上海交通大学 一种二次电池用含硫正极材料、其制备方法及二次电池

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
LEI JINGYU; LU HUICHAO; CHEN JIAHANG; YANG JUN; NULI YANNA; WANG JIULIN: "Crosslinked polyacrylonitrile precursor for S@pPAN composite cathode materials for rechargeable lithium batteries", JOURNAL OF ENERGY CHEMISTRY, ELSEVIER, AMSTERDAM, NL, vol. 65, 12 June 2021 (2021-06-12), AMSTERDAM, NL , pages 186 - 193, XP086864032, ISSN: 2095-4956, DOI: 10.1016/j.jechem.2021.05.006 *

Also Published As

Publication number Publication date
JP2024510027A (ja) 2024-03-05
US20240178393A1 (en) 2024-05-30
CN113346080A (zh) 2021-09-03
CN113346080B (zh) 2023-01-24

Similar Documents

Publication Publication Date Title
CN106784690B (zh) 一种复合正极材料及其制备方法以及全固态锂硫电池
JP3627586B2 (ja) リチウムイオン二次電池電極用バインダー、およびその利用
WO2022247375A1 (zh) 一种二次电池用含硫正极材料、其制备方法及二次电池
CN109103399B (zh) 一种锂硫电池用功能性隔膜及其制备方法和在锂硫电池中的应用
JP6273956B2 (ja) 二次電池多孔膜用バインダー、二次電池多孔膜用スラリー組成物、二次電池用多孔膜及び二次電池
CN106920936B (zh) 一种高性能有机锂离子电池正极材料及其制备方法
WO2020164353A1 (zh) 一种金属原子掺杂多孔碳纳米复合材料及其制备方法和应用
CN111293312B (zh) 一种柔性多功能的交联粘接剂及其制备方法和应用
CN108400297B (zh) 一种硅基锂离子电池负极材料及其制备方法
CN108539142B (zh) 一种锂硫电池正极材料的制备方法
CN110190284B (zh) 一种锂硫电池正极用水系粘结剂及其制备方法和应用
Feng et al. Nitrogen and oxygen dual-doped porous carbon derived from natural ficus microcarpas as host for high performance lithium-sulfur batteries
CN112635706B (zh) 石墨烯-二氧化锰纳米棒状负极材料的制备方法
CN102386382A (zh) Cmk-5型介孔炭-纳米无机物复合材料、制法及应用
CN111684633B (zh) 锂硫二次电池用粘结剂和包含所述锂硫二次电池用粘结剂的锂硫二次电池
CN106848250B (zh) 一种高硫含量的碳硫材料及其制备方法
KR20150142832A (ko) 리튬설퍼 전지용 양극조성물, 이를 포함하는 리튬설퍼 전지용 양극 및 이의 제조 방법
CN115064663B (zh) 一种MXene基凝胶态正极的制备方法及其应用
CN113651935A (zh) 一种多孔聚合物-硫复合材料及其制备方法和用途
US20220293946A1 (en) A Cathode Material and a Method of Preparing The Same
Zhang et al. Preparation and optimization of nanoporous hollow carbon spheres/S composite cathode materials for Li-S battery
CN114188603B (zh) 纳米相分离的固体聚合物电解质薄膜及其制备方法和应用
CN114751395A (zh) 一种氮掺杂多孔碳球/s复合材料及其制备方法和在锂硫电池中的应用
Shen et al. Carbon nanotube (CNT) foams as sulfur hosts for high performance lithium sulfur battery
WO2013181967A1 (zh) 离子聚合物膜材料及其制备方法和锂二次电池

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 22810109

Country of ref document: EP

Kind code of ref document: A1

WWE Wipo information: entry into national phase

Ref document number: 2023557272

Country of ref document: JP

WWE Wipo information: entry into national phase

Ref document number: 18283457

Country of ref document: US

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 22810109

Country of ref document: EP

Kind code of ref document: A1