WO2018236060A1 - Method for preparing iron hydroxide (feooh), and lithium-sulfur battery cathode comprising iron hydroxide - Google Patents

Method for preparing iron hydroxide (feooh), and lithium-sulfur battery cathode comprising iron hydroxide Download PDF

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WO2018236060A1
WO2018236060A1 PCT/KR2018/006003 KR2018006003W WO2018236060A1 WO 2018236060 A1 WO2018236060 A1 WO 2018236060A1 KR 2018006003 W KR2018006003 W KR 2018006003W WO 2018236060 A1 WO2018236060 A1 WO 2018236060A1
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Prior art keywords
feooh
iron hydroxide
lithium
sulfur
sulfur battery
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PCT/KR2018/006003
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French (fr)
Korean (ko)
Inventor
한승훈
손권남
양두경
이동욱
문정미
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주식회사 엘지화학
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Priority claimed from KR1020180059572A external-priority patent/KR102229454B1/en
Application filed by 주식회사 엘지화학 filed Critical 주식회사 엘지화학
Priority to US16/324,249 priority Critical patent/US11038174B2/en
Priority to EP18821299.7A priority patent/EP3490038A4/en
Priority to JP2019505215A priority patent/JP6758679B2/en
Priority to CN201880003777.XA priority patent/CN109792039B/en
Publication of WO2018236060A1 publication Critical patent/WO2018236060A1/en

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    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G49/00—Compounds of iron
    • C01G49/02—Oxides; Hydroxides
    • 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
    • H01M4/13—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
    • 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
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/485—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy
    • 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
    • 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 present invention relates to a process for preparing iron hydroxide (FeOOH) applicable as a cathode additive for a lithium-sulfur battery, a lithium-sulfur battery anode containing iron hydroxide (FeOOH) as a cathode additive, - about sulfur cells.
  • FeOOH iron hydroxide
  • the secondary battery is an electric storage device capable of continuous charging and discharging, and has become an important electronic component of portable electronic devices since 1990's.
  • the lithium ion secondary battery was commercialized by Sony Japan in 1992, it has been leading the information age as a core component of portable electronic devices such as smart phones, digital cameras, and notebook computers.
  • a lithium ion secondary battery has been widely used as an electric vehicle (EV), hybrid electric vehicle (hybrid electric vehicle), and the like in a mid-sized battery for use in fields such as power supplies for cleaners, power tools, electric bicycles, to high-capacity batteries for applications such as HEVs, plug-in hybrid electric vehicles (PHEVs), robots and large electric power storage systems (ESS) Demand is increasing.
  • EV electric vehicle
  • hybrid electric vehicle hybrid electric vehicle
  • ESS large electric power storage systems
  • lithium secondary batteries having the most excellent characteristics among the secondary batteries described so far have some problems in being actively used in transporting apparatuses such as electric vehicles and PHEVs, and the biggest problem is capacity.
  • Lithium secondary batteries are basically composed of materials such as anodes, electrolytes, and cathodes. Among them, the anode and cathode materials determine the capacity of the battery. Therefore, the lithium ion secondary battery is limited by the material limitations of the anode and the cathode Capacity. In particular, a secondary battery to be used in applications such as electric vehicles and PHEVs must be used for as long as possible after a single charge, so that the discharge capacity of the secondary battery is very important.
  • One of the biggest constraints to the sale of electric vehicles is that the distance traveled after one charge is much shorter than that of a conventional gasoline engine.
  • Lithium-sulfur batteries surpass capacity limits determined by the intercalation reaction of lithium ions into metal oxide and graphite, which is the basic principle of existing lithium ion secondary batteries. High-capacity, low-cost battery system.
  • the lithium-sulfur cell has a theoretical capacity of 1,675 mAh / g derived from the conversion reaction of lithium ions and sulfur at the anode (S 8 + 16Li + + 16e - ⁇ 8Li 2 S) and the cathode is lithium metal (theoretical capacity: 3,860 mAh / g) can be used to increase the capacity of the battery system. Since the discharge voltage is about 2.2 V, the energy density is theoretically 2,600 Wh / kg based on the amount of the anode and the anode active material. This is 6 to 7 times higher than the energy theoretical energy density of 400 Wh / kg of commercial lithium secondary batteries (LiCoO 2 / graphite) using layered metal oxide and graphite.
  • Lithium-sulfur battery has been attracting attention as a new high-capacity, eco-friendly, low-cost lithium secondary battery since it is known that battery performance can be dramatically improved through the formation of nanocomposite around 2010, .
  • the size of the particles as in the example of LiFePO 4, which is one of other cathode active materials, (Melt impregnation into nano-sized porous carbon nanostructure or metal oxide structure) and physical methods (high energy ball milling) are reported. .
  • Lithium polysulfide causes a shuttle reaction during the charging process, which causes the charging capacity to increase continuously, resulting in a drastic reduction in charge / discharge efficiency.
  • a variety of methods have been proposed to solve these problems, including a method of improving the electrolyte, a method of improving the surface of the cathode, and a method of improving the characteristics of the anode.
  • a new electrolyte such as a functional liquid electrolyte of a new composition, a polymer electrolyte, and an ionic liquid is used to suppress the dissolution of the polysulfide into an electrolyte or control the dispersion rate to the cathode To suppress the shuttle reaction as much as possible.
  • an electrolyte additive such as LiNO 3 is added to form an oxide film of Li x NO y , Li x SO y , A method of forming a thick functional SEI layer on the surface of lithium metal, and the like.
  • a method for improving the properties of the anode there is a method of forming a coating layer on the surface of the anode particles or adding a porous material capable of catching the dissolved polysulfide so as to prevent the dissolution of polysulfide.
  • a method of coating the surface of the anode structure with a metal oxide on which lithium ions are transferred a method of coating a porous metal oxide having a large specific surface area and a large pore size, which can absorb a large amount of lithium polysulfide, , A method of attaching a functional group capable of adsorbing lithium polysulfide on the surface of a carbon structure, and a method of enclosing sulfur particles using graphene or graphene oxide.
  • Patent Document 1 Korean Patent Registration No. 10-1996-0065174 (July 27, 2000), " Method for producing reedocrocite "
  • Patent Document 2 Korean Patent Laid-Open Publication No. 10-2015-0091280 (Apr. 14, 2017), " Lithium Sulfate Battery and Method for Producing the Same &
  • the inventors of the present invention have anticipated that battery performance can be improved most directly by improving the anode characteristics of the lithium-sulfur battery.
  • FeOOH was introduced into the positive electrode of a lithium-sulfur battery, it was confirmed that lithium polysulfide (LiPS) could be adsorbed, thus completing the present invention.
  • NaBH 4 is reacted with Fe (NO 3 ) 3 .9H 2 O or FeCl 3 .6H 2 O in an appropriate aqueous solution.
  • FeOOH iron hydroxide
  • ⁇ -FeOOH iron hydroxide
  • an object of the present invention is to provide a process for producing iron hydroxide of high purity through a simple process.
  • M 1 is any one selected from Li, Na, Mg, K, and Ca, and X is 1 or 2.
  • One embodiment of the present invention is an aqueous solution of 0.04 to 0.08 M of Fe (NO 3 ) 3 .9H 2 O or FeCl 3 .6H 2 O.
  • the reducing agent represented by Formula 1 is an aqueous solution of 0.2 to 0.5 M.
  • the mixing is carried out for 10 to 120 seconds.
  • the reaction temperature is 20 to 25 ⁇ ⁇ .
  • the reaction time is 10 minutes to 10 hours.
  • the reaction time is 40 minutes to 2 hours.
  • One embodiment of the present invention further comprises a step of filtration and drying after the reaction step.
  • the drying is carried out at 70 to 90 DEG C for 6 to 12 hours.
  • the iron hydroxide (FeOOH) is lepidocrocite ( ⁇ -FeOOH).
  • the iron hydroxide (FeOOH) is crystalline.
  • the iron hydroxide (FeOOH) is a plate-like type.
  • the iron hydroxide has a particle diameter of 50 to 500 nm.
  • a positive electrode for a lithium-sulfur battery including an active material, a conductive material and a binder,
  • the positive electrode provides a positive electrode for a lithium-sulfur battery including iron hydroxide (FeOOH).
  • the iron hydroxide (FeOOH) is lepidocrocite ( ⁇ -FeOOH).
  • the iron hydroxide (FeOOH) is crystalline.
  • the iron hydroxide (FeOOH) is a plate-like type.
  • the average diameter of the iron hydroxide (FeOOH) is 50 to 500 nm.
  • the amount of iron hydroxide (FeOOH) contained in the positive electrode for a lithium-sulfur battery is 0.1 to 15 parts by weight based on 100 parts by weight of the base solid content.
  • the active material is a sulfur-carbon composite.
  • the positive electrode provides the lithium-sulfur battery which is the positive electrode for the lithium-sulfur battery.
  • high purity iron hydroxide FeOOH
  • FeOOH high purity iron hydroxide
  • the shape and purity of the produced iron hydroxide (FeOOH) can be controlled by controlling the reaction temperature and the reaction time in the reaction of NaBH 4 with Fe (NO 3 ) 3 .9H 2 O or FeCl 3 .6H 2 O.
  • the present invention can selectively produce lepidocrocite ( ⁇ -FeOOH), which is also crystalline iron hydroxide. Also, when iron hydroxide (FeOOH) is applied to the anode of a lithium-sulfur battery, the reactivity of the lithium-sulfur battery anode is increased by adsorbing lithium polysulfide generated during charging and discharging, and the lithium- It is possible to exhibit an effect of increasing
  • FIG. 1 shows a scanning electron microscope (SEM) image of iron hydroxide (FeOOH) according to the production example of the present invention and the comparative preparation example.
  • FIG. 2 shows a scanning electron microscope (SEM) image of iron hydroxide (FeOOH) according to the production example of the present invention.
  • FIG. 3 shows X-ray diffraction (XRD) results of iron hydroxide (FeOOH) according to the preparation examples and comparative preparation examples of the present invention.
  • Li 2 S 6 lithium polysulfide (Li 2 S 6 ) adsorption reaction of iron hydroxide (FeOOH) according to the present invention as a result of UV absorbance measurement.
  • FIG. 8 shows the discharge capacity measurement results of a lithium-sulfur battery including a positive electrode according to Examples and Comparative Examples of the present invention.
  • FIG. 9 shows the results of measurement of lifetime characteristics of a lithium-sulfur battery including a positive electrode according to Experimental Examples and Comparative Experimental Examples of the present invention.
  • FIG. 10 shows the results of measurement of lifetime characteristics of a lithium-sulfur battery including a positive electrode according to Examples and Comparative Examples of the present invention.
  • &quot refers to a material that combines two or more materials to form a physically and chemically distinct phase while exhibiting a more effective function.
  • the present invention relates to a process for producing iron hydroxide (FeOOH), and more particularly, to a process for producing iron hydroxide (FeOOH) having a shape and physical properties capable of improving the discharge capacity by applying it as a cathode material of a lithium-sulfur battery.
  • the process for producing iron hydroxide (FeOOH) according to the present invention comprises the steps of: Fe (NO 3 ) 3 .9H 2 O or FeCl 3 .6H 2 O; And
  • M 1 is any one selected from Li, Na, Mg, K, and Ca, and X is 1 or 2.
  • the Fe (NO 3) 3 ⁇ 9H 2 O or FeCl 3 ⁇ 6H 2 O and a reducing agent represented by Formula 1 may be in both the form of an aqueous solution, wherein the reducing agent aqueous solution of the formula (1) Fe (NO 3 ) 3 ⁇ 9H 2 O aqueous solution or FeCl 3 ⁇ 6H 2 O aqueous solution may be added, followed by mixing and reacting.
  • the purity of the produced iron hydroxide (FeOOH) may be lowered. That is, when the aqueous solution of the reducing agent represented by Formula 1 is added to the Fe (NO 3 ) 3 .9H 2 O aqueous solution or FeCl 3 .6H 2 O aqueous solution and mixed and reacted, the purity of the iron hydroxide (FeOOH) .
  • the Fe (NO 3 ) 3 .9H 2 O aqueous solution or FeCl 3 .6H 2 O aqueous solution may be 0.04 to 0.08 M, preferably 0.05 to 0.06 M, and if it is less than 0.04 M, the production yield of iron hydroxide (FeOOH) If it is more than 0.08 M, the physical properties of the produced iron hydroxide (FeOOH) may not be suitable as a cathode material for a lithium-sulfur battery.
  • the reducing agent aqueous solution represented by the above formula (1) may be 0.2 to 0.5 M, preferably 0.3 to 0.4 M. If it is less than 0.2 M, iron hydroxide (FeOOH) can not be produced, and if it exceeds 0.5 M, the reaction may not proceed.
  • FeOOH iron hydroxide
  • the additive represented by Formula 1 may be NaBH 4 .
  • iron hydroxide FeOOH
  • the mixing of the Fe (NO 3 ) 3 .9H 2 O or FeCl 3 .6H 2 O and the reducing agent represented by the above formula (1) may be performed within a short time, and may be performed within 10 to 120 seconds, preferably 50 to 80 seconds have. If the mixing time is less than 10 seconds, the mixing may occur excessively and the gas may be generated all at once, so that the reaction may proceed unevenly. If the mixing time is more than 120 seconds, the mixing speed is slow, The phase of the material may be different.
  • the reaction temperature may be 10 to 60 ° C, preferably 20 to 50 ° C, more preferably 20 to 25 ° C. If the reaction temperature is less than 10 ° C, the reaction may not proceed, and if it is more than 60 ° C
  • the physical properties of the produced iron hydroxide (FeOOH) may be denatured. Further, it may be preferable to conduct the reaction while maintaining the temperature at 20 to 25 DEG C for controlling the reaction rate.
  • the reaction time may be from 10 minutes to 10 hours, preferably from 40 minutes to 2 hours. If it is less than 10 minutes, iron hydroxide (FeOOH) may not be formed, and if it exceeds 20 hours, Shape may not be suitable as a cathode material of a lithium-sulfur battery. In particular, when reacting for 40 minutes to 2 hours, desired properties of FeOOH can be maintained without being lost.
  • FeOOH iron hydroxide
  • the filtration step may be performed by a filtration process commonly used in the art, for example, a filter paper may be used.
  • the drying may be carried out at 70 to 90 ° C for 6 to 12 hours.
  • the drying temperature is lower than 70 ° C or the drying time is less than 6 hours, it is not completely dried to obtain particles of iron hydroxide (FeOOH). If the drying temperature exceeds 90 ° C or exceeds 12 hours, the remaining water will boil, The physical properties may be denatured.
  • the iron hydroxide (FeOOH) produced by the method as described above may be crystalline, and specifically may be lepidocrocite ( ⁇ -FeOOH).
  • the prepared iron hydroxide (FeOOH) may be in the form of a plate, and in this case, it may be advantageous to improve the discharge capacity when applied to the cathode material of the lithium-sulfur battery.
  • the shape of the prepared iron hydroxide (FeOOH) can be controlled as needed by controlling the reaction time, and they are all applicable to the cathode material of a lithium-sulfur battery.
  • the produced iron hydroxide (FeOOH) may have a particle size of more than 0 and 500 nm or less, preferably 50 to 500 nm. As the particle size decreases within the above range, it is suitable as a cathode material for a lithium-sulfur battery. If the particle diameter is larger than the above range, the particle size is large and is not suitable as a cathode material of a lithium-sulfur battery.
  • iron hydroxide for example, crystalline lepidocrocite ( ⁇ -FeOOH) produced by the above-described method for producing iron hydroxide (FeOOH) is applied to a lithium-sulfur battery, It is possible to adsorb the polysulfide to be eluted and to improve the performance of the lithium-sulfur battery.
  • the process for producing the iron hydroxide (FeOOH) according to the present invention can selectively produce crystalline lepidocrocite (? -FeOOH) in iron hydroxide (FeOOH), and is suitable for a cathode material supply technology of a lithium-sulfur battery.
  • Figs. 1 and 2 show scanning electron microscope (SEM) images of the iron hydroxide (FeOOH) produced by the above-mentioned production method.
  • SEM scanning electron microscope
  • Fig. 4 shows the X-ray diffraction (XRD) data of the iron hydroxide (FeOOH) produced by the above-mentioned production method of reedocrocite (y-FeOOH).
  • XRD X-ray diffraction
  • a significant or effective peak in X-ray diffraction analysis means a peak that is repeatedly detected in the same pattern without being greatly affected by analysis conditions or analysts in XRD data.
  • intensity, intensity, etc. of at least 1.5 times, preferably at least 2 times, more preferably at least 2.5 times the backgound level.
  • the present invention provides a positive electrode for a lithium-sulfur battery including an active material, a conductive material and a binder, wherein the positive electrode comprises a positive electrode for a lithium-sulfur battery including iron hydroxide (FeOOH).
  • FeOOH iron hydroxide
  • the anode of the lithium-sulfur battery may have a base solid portion including an active material, a conductive material, and a binder on a current collector.
  • the current collector it is preferable to use aluminum or nickel excellent in conductivity.
  • 0.1 to 15 parts by weight, and preferably 1 to 10 parts by weight, of iron hydroxide (FeOOH) may be contained based on 100 parts by weight of base solids including the active material, the conductive material, and the binder. If it is less than the lower limit of the above-mentioned numerical range, the adsorption effect of polysulfide may be insignificant, and if it exceeds the upper limit value, the capacity of the electrode is decreased.
  • the iron hydroxide (FeOOH) may be iron hydroxide (FeOOH) produced by the production method proposed in the present invention, and preferably it may be lepidocrocite ( ⁇ -FeOOH).
  • the iron hydroxide (FeOOH) may be crystalline and may be in the form of a plate having an average particle size of 50 to 500 nm.
  • the positive electrode for a lithium-sulfur battery according to the present invention may include an active material of a sulfur-carbon composite. Since the sulfur material alone does not have electrical conductivity, it can be used in combination with a conductive material. The addition of iron hydroxide (FeOOH) according to the present invention does not affect the structure maintenance of this sulfur-carbon complex.
  • FeOOH iron hydroxide
  • the active material is composed of 50 to 95 parts by weight, more preferably 70 parts by weight, of 100 parts by weight of the base solid content. If the active material is contained in an amount less than the above range, it is difficult to sufficiently exert the reaction of the electrode. Even if the active material is contained in an amount exceeding the above range, the amount of other conductive materials and binders is relatively insufficient, It is desirable to determine the titratable content.
  • the conductive material is a material that electrically connects the electrolyte and the cathode active material and serves as a path through which electrons move from the current collector to the sulfur. And is not particularly limited as long as it has porosity and conductivity.
  • a graphite-based material such as KS6; Carbon black such as super P, carbon black, denka black, acetylene black, ketjen black, channel black, furnace black, lamp black, and summer black; Carbon derivatives such as fullerene; Conductive fibers such as carbon fiber and metal fiber; Metal powders such as carbon fluoride, aluminum, and nickel powder; Or conductive polymers such as polyaniline, polythiophene, polyacetylene, and polypyrrole may be used alone or in combination.
  • the conductive material may preferably be 1 to 10 parts by weight, preferably 5 parts by weight, based on 100 parts by weight of the base solid content. If the content of the conductive material contained in the electrode is less than the above range, the portion of the electrode in which sulfur does not react increases and eventually the capacity is reduced. If the content exceeds the above range, the high efficiency discharge characteristic and the charge and discharge cycle life are adversely affected It is preferable to determine the optimum content within the above-mentioned range.
  • the binder is a material that contains a base solids slurry composition that forms the anode to adhere well to the current collector, and is a material that is well dissolved in the solvent and can well constitute the conductive network of the cathode active material and the conductive material use.
  • binders known in the art can be used and are preferably selected from the group consisting of poly (vinyl) acetate, polyvinyl alcohol, polyethylene oxide, polyvinylpyrrolidone, alkylated polyethylene oxide, crosslinked polyethylene oxide , Copolymers of polyvinyl ether, poly (methyl methacrylate), polyvinylidene fluoride (PVdF), polyhexafluoropropylene, polyvinylidene fluoride (trade name: Kynar), poly (ethyl acrylate) Siloxane series such as tetrafluoroethylene polyvinyl chloride, polytetrafluoroethylene, polyacrylonitrile, polyvinylpyridine, polystyrene, carboxymethylcellulose, polydimethylsiloxane, styrene-butadiene rubber, acrylonitrile-butadiene Rubber, a rubber-based binder including a styrene-isoprene rubber,
  • the binder may comprise 1 to 10 parts by weight, preferably 5 parts by weight, of 100 parts by weight of the base composition contained in the electrode. If the content of the binder resin is less than the above range, the physical properties of the positive electrode may deteriorate and the positive electrode active material and the conductive material may fall off. If the amount exceeds the above range, the ratio of the active material and the conductive material may be relatively decreased, Therefore, it is desirable to determine the optimum content within the above-mentioned range.
  • the positive electrode containing the iron hydroxide (FeOOH) and the base solid can be produced by a conventional method.
  • iron hydroxide FeOOH
  • a solvent for preparing an organic compound
  • an active material for forming an organic compound
  • a conductive material for forming an organic compound
  • a binder for forming an organic compound
  • This slurry composition is then coated on a current collector and dried to complete the anode. At this time, if necessary, it can be manufactured by compression-molding the current collector to improve the electrode density.
  • a cathode active material, a binder, and a conductive material can be uniformly dispersed and a material capable of easily dissolving iron hydroxide (FeOOH) is used.
  • a solvent water is most preferable as an aqueous solvent, and the water may be distilled water (DW) or deionized water (DIW), which is a third distillation.
  • DW distilled water
  • DIW deionized water
  • a lower alcohol which can be easily mixed with water may be used. Examples of the lower alcohol include methanol, ethanol, propanol, isopropanol, butanol, etc., and they can be used in combination with water.
  • the present invention provides a lithium-sulfur battery having an anode, a cathode, a separator interposed therebetween, and an electrolyte, wherein the anode is the anode as described above.
  • the cathode, the separator, and the electrolyte may be composed of conventional materials that can be used in a lithium-sulfur battery.
  • the negative electrode may include a material capable of reversibly intercalating or deintercalating lithium ions (Li + ) as an active material, a material capable of reversibly forming a lithium-containing compound by reacting with lithium ions, Or a lithium alloy may be used.
  • the material capable of reversibly storing or releasing lithium ions may be, for example, crystalline carbon, amorphous carbon, or a mixture thereof.
  • the material capable of reacting with the lithium ion (Li + ) to reversibly form a lithium-containing compound may be, for example, tin oxide, titanium nitrate or silicon.
  • the lithium alloy may be, for example, an alloy of lithium and a metal selected from the group consisting of Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, Ra, Al and Sn.
  • the negative electrode may further include a binder optionally in combination with the negative electrode active material.
  • the binder acts as a paste for the anode active material, mutual adhesion between the active materials, adhesion between the active material and the current collector, buffering effect on expansion and contraction of the active material, and the like. Specifically, the binder is the same as described above.
  • the negative electrode may further include a current collector for supporting the negative electrode active layer including the negative electrode active material and the binder.
  • the current collector may be specifically selected from the group consisting of copper, aluminum, stainless steel, titanium, silver, palladium, nickel, alloys thereof, and combinations thereof.
  • the stainless steel may be surface-treated with carbon, nickel, titanium or silver, and an aluminum-cadmium alloy may be used as the alloy.
  • fired carbon, a nonconductive polymer surface treated with a conductive agent, or a conductive polymer may be used.
  • the negative electrode may be a thin film of lithium metal.
  • the separation membrane is made of a material capable of separating or inserting the positive electrode and the negative electrode from each other while allowing the lithium ion to be transported therebetween, and can be used without any particular limitation as long as it is used as a separation membrane in a lithium-sulfur battery. Particularly, It is preferable that the electrolyte has a low resistance to migration and an excellent ability to hinder the electrolyte.
  • the separation membrane material may be a porous, nonconductive or insulating material, such as an independent member such as a film, or a coating layer added to the anode and / or the cathode.
  • a porous polymer film made of a polyolefin-based polymer such as an ethylene homopolymer, a propylene homopolymer, an ethylene / butene copolymer, an ethylene / hexene copolymer and an ethylene / methacrylate copolymer may be used alone Or they may be laminated.
  • a nonwoven fabric made of a conventional porous nonwoven fabric for example, glass fiber of high melting point, polyethylene terephthalate fiber or the like may be used, but not always limited thereto.
  • the electrolyte is a non-aqueous electrolyte containing a lithium salt, and is composed of a lithium salt and an electrolyte.
  • Non-aqueous organic solvents, organic solid electrolytes, and inorganic solid electrolytes are used as the electrolyte.
  • the lithium salt is a material that can easily be dissolved in non-aqueous organic solvent, for example, LiCl, LiBr, LiI, LiClO 4, LiBF 4, LiB 10 Cl 10, LiB (Ph) 4, LiPF 6, LiCF 3 SO 3, LiCF 3 CO 2, LiAsF 6, LiSbF 6, LiAlCl 4, LiSO 3 CH 3, LiSO 3 CF 3, LiSCN, LiC (CF 3 SO 2) 3, LiN (CF 3 SO 2) 2, chloroborane lithium, lower aliphatic Lithium tetraborate, lithium tetraborate, lithium tetraborate, lithium tetraborate, lithium tetraborate, and imide.
  • the concentration of the lithium salt may be in the range of 0.2 to 2 M, preferably in the range of 0.2 to 2 M, depending on various factors such as the precise composition of the electrolyte mixture, the solubility of the salt, the conductivity of the dissolved salt, the charging and discharging conditions of the battery, Preferably 0.6 to 2 M, and more preferably 0.7 to 1.7 M. If the concentration of the lithium salt is less than the above range, the conductivity of the electrolyte may be lowered and the performance of the electrolyte may be deteriorated. If the concentration exceeds the above range, the viscosity of the electrolyte may increase and the mobility of lithium ions (Li + ) may decrease. It is preferable to select an appropriate concentration.
  • the non-aqueous organic solvent is a substance capable of dissolving a lithium salt well, preferably 1,2-dimethoxyethane, 1,2-diethoxyethane, 1,2-dibutoxyethane, Dioxolane, DOL ), 1,4-dioxane, tetrahydrofuran, 2-methyltetrahydrofuran, dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), methyl propyl carbonate (EP), toluene, xylene, dimethyl ether (DME), diethyl ether, triethylene glycol monomethyl ether (TEGME), dipropyl carbonate, butyl ethyl carbonate, ethyl propanoate Hexamethylphosphoric triamide, gamma butyrolactone (GBL), acetonitrile, propionitrile, ethylene carbonate (EC), propylene carbonate (PC), N-methylpiperaz
  • the organic solid electrolyte is selected from the group consisting of a polyethylene derivative, a polyethylene oxide derivative, a polypropylene oxide derivative, a phosphate ester polymer, an agitation lysine, a polyester sulfide, a polyvinyl alcohol, a polyvinylidene fluoride, A polymer including a dissociation group, and the like may be used.
  • the inorganic solid electrolytes of the present invention are preferably Li 3 N, LiI, Li 5 NI 2 , Li 3 N-LiI-LiOH, LiSiO 4 , LiSiO 4 -LiI-LiOH, Li 2 SiS 3 , Li 4 SiO 4 , Li 4 SiO 4 -LiI-LiOH, Li 3 PO 4 -Li 2 S-SiS 2, and the like can be used.
  • the shape of the above-described lithium-sulfur battery is not particularly limited and may be, for example, a jelly-roll type, a stack type, a stack-folding type (including a stack-Z-folding type), or a lamination- May be a stack-folding type.
  • An electrode assembly in which the positive electrode, the separator, and the negative electrode are sequentially stacked is manufactured, and the electrode assembly is inserted into a battery case. Then, an electrolyte is injected into the upper portion of the case, and the assembly is sealed with a cap plate and a gasket. do.
  • the lithium-sulfur battery may be classified into a cylindrical type, a rectangular type, a coin type, a pouch type, and the like depending on the type, and may be divided into a bulk type and a thin type depending on the size.
  • the structure and the manufacturing method of these cells are well known in the art, and detailed description thereof will be omitted.
  • iron hydroxide for example, crystalline lepidocrocite ( ⁇ -FeOOH) produced by the above-described method for producing iron hydroxide (FeOOH) is applied to a lithium-sulfur battery
  • ⁇ -FeOOH crystalline lepidocrocite
  • the reactivity of the lithium-sulfur battery is increased by adsorbing the polysulfide to be eluted, and the lithium-sulfur battery to which the lithium-sulfur battery is applied has the effect of improving the discharge capacity and the life characteristic.
  • NaBH 4 is a product of TCI, having a purity of> 95%
  • Fe (NO 3 ) 3 .9H 2 O is a product of Aldrich, having a purity of 98%.
  • Ferric hydroxide was prepared by adding 10 L of an aqueous solution of sodium hydroxide having a concentration of 1.6 M / L to 40 L of an aqueous ferrous chloride solution having a concentration of 0.8 M / L, and then subjected to an oxidation reaction at a reaction temperature of 25 ° C. At this time, the seed crystal formation reaction was proceeded at different oxidation rates of the ferrous hydroxide.
  • the reaction rate of ferrous hydroxide is less than 0.15 mol / min, the reaction rate is slowed down and the goethite is incorporated.
  • the ferrous hydroxide can be sludged without being oxidized. If the oxidation rate is more than 0.4 mol / min, The grown lepidocrocite is formed into an unstable particle and may be redissolved as Fe 2 + and OH - .
  • iron hydroxide FeOOH
  • solid base material active material, conductive material and binder
  • iron hydroxide (FeOOH) prepared in Production Example 1 was added as a solvent, based on the total solid weight (100 parts by weight) Lt; / RTI >
  • 90 parts by weight of the sulfur-carbon composite (S / C 7: 3) as the active material 5 parts by weight of the conductive black rode black, and 5 parts by weight of the styrene butadiene rubber / And 5 parts by weight of carboxymethylcellulose (SBR / CMC 7: 3) were added and mixed to prepare a positive electrode slurry composition.
  • SBR / CMC 7: 3 carboxymethylcellulose
  • the slurry composition prepared above was coated on a collector (Al Foil) and dried at 50 DEG C for 12 hours to prepare a positive electrode.
  • the loading amount was 3.5 mAh / cm 2
  • the porosity of the electrode was 60%.
  • the coin cell of the lithium-sulfur battery including the positive electrode, separator, negative electrode and electrolyte prepared according to the above was prepared as follows. Specifically, the anode was used as a 14-phi circular electrode, and a polyethylene (PE) membrane was used at 19 phi and a 150- ⁇ m lithium metal was used at 16 phi as a cathode.
  • PE polyethylene
  • the slurry composition prepared above was coated on a collector (Al Foil) and dried at 50 DEG C for 12 hours to prepare a positive electrode.
  • the loading amount was 3.5 mAh / cm 2
  • the porosity of the electrode was 60%.
  • the coin cell of the lithium-sulfur battery including the positive electrode, separator, negative electrode and electrolyte prepared according to the above was prepared as follows. Specifically, the anode was used as a 14-phi circular electrode, and a polyethylene (PE) membrane was used at 19 phi and a 150- ⁇ m lithium metal was used at 16 phi as a cathode.
  • PE polyethylene
  • FeOOH / Co prepared by mixing Fe (NO 3 ) 3 / CoCl 2 and NaBH 4 in place of iron hydroxide (FeOOH).
  • Example 1 The procedure of Example 1 was repeated, except that Fe (OH) 3 was used in place of iron hydroxide (FeOOH).
  • FIG. 3 is a graph showing the results of XRD analysis of the lepidocrocite prepared in Production Example 1 and Comparative Production Example 1, respectively.
  • the lithium-sulfur battery prepared in Examples 1 and 2 and Comparative Examples 1 to 3 was used to measure the discharge capacity according to the type of cathode material.
  • the positive electrode of Example 1 contains 10 parts by weight of sulfur-carbon composite and iron hydroxide (FeOOH), and the positive electrode of Example 2 contains 5 parts by weight of sulfur-carbon composite and iron hydroxide (FeOOH).
  • the positive electrode of Comparative Example 1 was comprised of a sulfur-carbon composite, and the positive electrode of Comparative Example 2 was composed of a sulfur-carbon composite and 10 parts by weight of gamma-FeOOH / Co.
  • the positive electrode of Comparative Example 3 was composed of a sulfur- And 10 parts by weight of (OH) 3 . At this time, the measurement current was 0.1 C and the voltage range was 1.8 to 2.5 V.
  • the measured discharge capacity data are shown in Table 1 and FIG.
  • Example 1 Metallic lithium Sulfur-carbon composite + FeOOH (10 parts by weight) of Production Example 1 1222
  • Example 2 Metallic lithium Sulfur-carbon composite + FeOOH (5 parts by weight) of Production Example 1 1165
  • Comparative Example 1 Metallic lithium Sulfur-carbon complex 1073
  • Comparative Example 2 Metallic lithium Sulfur-carbon composite + ⁇ -FeOOH / Co (10 parts by weight) 1160
  • Comparative Example 3 Metallic lithium Sulfur-carbon composite + Fe (OH) 3 (10 parts by weight) 1118
  • the positive electrode of Experimental Example (1) includes a sulfur-carbon composite, and the positive electrode of Experimental Example (1) contains a sulfur-carbon composite and the iron hydroxide of Production Example 1 (FeOOH) (FeOOH) of Comparative Production Example 1 and discharged at a rate of 0.1 C, and the results are shown in Table 2 and FIG.
  • Example 1 The lithium-sulfur battery according to Example 1, Example 2, and Comparative Example 1 was used to measure the change pattern of the discharge capacity according to the cycle of the battery and charge / discharge efficiency at 90 cycles. At this time, the initial discharge / charge proceeded to 0.1 C / 0.1 C for 2.5 cycles, and then to 0.5 C / 0.3 C thereafter. The voltage range was set to 1.8 to 2.5V.
  • the discharge capacity reduction rate during the course of the battery cycle is significantly smaller than that of Comparative Example 1 which does not contain iron hydroxide (FeOOH) in the anode. Further, it is confirmed that the decrease of the discharge capacity is smaller as the content of iron hydroxide (FeOOH) is further decreased.
  • Comparative Example 1 the battery is degenerated from 60 cycles, but in Example 1, the degeneration of the battery starts after 70 cycles .
  • the anode and anode of the lithium-sulfur battery were constituted as shown in Table 3 below, and the discharge capacity was measured.
  • the positive electrode of Comparative Experiment Example (1) was composed of a sulfur-carbon composite, and the positive electrode of Experimental Example (1) was composed of sulfur-carbon composite material and iron hydroxide of Production Example 1 (FeOOH) 0.3 C / 0.5 C 10 cycles were repeated to evaluate the lifetime characteristics.
  • the results are shown in Table 3 and FIG.
  • the Coulombic Efficiency which represents the ratio of the charging capacity to the discharging capacity, is also maintained at 100%.
  • the adsorption capacity of lithium polysulfide was visually checked through the change of chromaticity. As a result, it was confirmed that the red color of lithium polysulfide (FIG. 5, blank) reacted with iron hydroxide (FeOOH) , And iron hydroxide (FeOOH) were excellent in the adsorption performance of lithium polysulfide.

Abstract

The present invention relates to a method for preparing iron hydroxide (FeOOH), and a lithium-sulfur battery cathode comprising iron hydroxide. More specifically, crystalline iron hydroxide, particularly lepidocrocite (γ-FeOOH), can be prepared by controlling a reaction time and a reaction temperature, and the discharge capacity and lifespan characteristics of a battery can be improved by applying the prepared high-purity iron hydroxide to a lithium-sulfur battery cathode.

Description

수산화철(FeOOH)의 제조방법 및 수산화철을 포함하는 리튬-황 전지용 양극Process for preparing iron hydroxide (FeOOH) and anode for lithium-sulfur battery containing iron hydroxide
본 출원은 2017년 06월 20일자 한국 특허 출원 제10-2017-0078017호, 2017년 07월 13일자 한국 특허 출원 제10-2017-0089104호 및 2018년 05월 25일자 한국 특허 출원 제10-2018-0059572호에 기초한 우선권의 이익을 주장하며, 해당 한국 특허 출원의 문헌에 개시된 모든 내용은 본 명세서의 일부로서 포함한다.This application is related to Korean Patent Application No. 10-2017-0078017 filed on June 20, 2017, Korean Patent Application No. 10-2017-0089104 filed on July 13, 2017, and Korean Patent Application No. 10-2018 filed on May 25, 2018 -0059572, the contents of which are incorporated herein by reference in their entirety.
본 발명은 리튬-황 전지용 양극 첨가제로 적용 가능한 수산화철(FeOOH)의 제조방법, 수산화철(FeOOH)을 양극 첨가제로 포함한 리튬-황 전지용 양극 및 이를 구비하여 방전 용량이 증가되고 전지의 수명이 개선된 리튬-황 전지에 관한 것이다.The present invention relates to a process for preparing iron hydroxide (FeOOH) applicable as a cathode additive for a lithium-sulfur battery, a lithium-sulfur battery anode containing iron hydroxide (FeOOH) as a cathode additive, - about sulfur cells.
이차전지는 1회 방전만 가능한 일차전지와 달리 지속적인 충전 및 방전이 가능한 전기저장기구로서 1990년대 이후 휴대용 전자기기의 중요 전자부품으로 자리를 잡았다. 특히, 리튬 이온 이차전지는 1992년 일본 소니(Sony)사에 의해 상용화된 이후, 스마트폰, 디지털 카메라, 노트북 컴퓨터 등과 같은 휴대용 전자기기의 핵심부품으로 정보화 시대를 이끌어 왔다. Unlike a primary battery, which can only be discharged once, the secondary battery is an electric storage device capable of continuous charging and discharging, and has become an important electronic component of portable electronic devices since 1990's. Particularly, since the lithium ion secondary battery was commercialized by Sony Japan in 1992, it has been leading the information age as a core component of portable electronic devices such as smart phones, digital cameras, and notebook computers.
근래에 리튬 이온 이차전지는 그 활용 영역을 더욱 넓혀가면서 청소기, 전동공구의 전원과 전기자전거, 전기스쿠터와 같은 분야에 사용될 중형전지에서, 전기자동차(electric vehicle; EV), 하이브리드 전기자동차(hybrid electric vehicle; HEV), 플러그-인 하이브리드 전기자동차(Plug-in hybrid electric vehicle; PHEV), 각종 로봇 및 대형 전력저장장치(Electric Storage System; ESS)와 같은 분야에 사용되는 대용량 전지에 이르기까지 빠른 속도로 수요를 늘려가고 있다.2. Description of the Related Art In recent years, a lithium ion secondary battery has been widely used as an electric vehicle (EV), hybrid electric vehicle (hybrid electric vehicle), and the like in a mid-sized battery for use in fields such as power supplies for cleaners, power tools, electric bicycles, to high-capacity batteries for applications such as HEVs, plug-in hybrid electric vehicles (PHEVs), robots and large electric power storage systems (ESS) Demand is increasing.
그러나, 현재까지 나와 있는 이차전지 중 가장 우수한 특성을 가진 리튬 이차전지도 전기자동차, PHEV와 같은 수송기구에 활발히 사용되기에는 몇 가지 문제점이 있으며, 그 중 가장 큰 문제점은 용량의 한계이다.However, lithium secondary batteries having the most excellent characteristics among the secondary batteries described so far have some problems in being actively used in transporting apparatuses such as electric vehicles and PHEVs, and the biggest problem is capacity.
리튬 이차전지는 기본적으로 양극, 전해질, 음극 등과 같은 소재들로 구성되며, 그 중에서 양극 및 음극 소재가 전지의 용량(capacity)을 결정하기 때문에 리튬 이온 이차전지는 양극과 음극의 물질적인 한계로 인해 용량의 제약을 받는다. 특히, 전기자동차, PHEV와 같은 용도에 사용될 이차전지는 한 번 충전 후 최대한 오래 사용할 수 있어야 하므로, 이차전지의 방전 용량이 매우 중요시 된다. 전기자동차의 판매에 가장 큰 제약점으로 지적되는 것은 1회 충전 후 주행할 수 있는 거리가 일반 가솔린엔진의 자동차보다 매우 짧다는 점이다.Lithium secondary batteries are basically composed of materials such as anodes, electrolytes, and cathodes. Among them, the anode and cathode materials determine the capacity of the battery. Therefore, the lithium ion secondary battery is limited by the material limitations of the anode and the cathode Capacity. In particular, a secondary battery to be used in applications such as electric vehicles and PHEVs must be used for as long as possible after a single charge, so that the discharge capacity of the secondary battery is very important. One of the biggest constraints to the sale of electric vehicles is that the distance traveled after one charge is much shorter than that of a conventional gasoline engine.
이와 같은 리튬 이차전지의 용량 한계는 많은 노력에도 불구하고 리튬 이차전지의 구조 및 재료적인 제약으로 인해 완전한 해결이 어렵다. 따라서, 리튬 이차전지의 용량 문제를 근본적으로 해결하기 위해서는 기존의 이차전지 개념을 뛰어 넘는 신개념의 이차전지 개발이 요구된다.The capacity limit of such a lithium secondary battery is difficult to be completely solved due to the structure and material constraints of the lithium secondary battery despite a lot of efforts. Therefore, in order to fundamentally solve the capacity problem of the lithium secondary battery, it is required to develop a new concept secondary battery which goes beyond the conventional secondary battery concept.
리튬-황 전지는 기존의 리튬 이온 이차전지의 기본원리인 리튬 이온의 층상구조의 금속산화물 및 흑연으로의 삽입/탈리(intercalation) 반응에 의해 결정되는 용량 한계를 뛰어넘고 전이금속 대체 및 비용 절감 등을 가져올 수 있는 새로운 고용량, 저가 전지 시스템이다. Lithium-sulfur batteries surpass capacity limits determined by the intercalation reaction of lithium ions into metal oxide and graphite, which is the basic principle of existing lithium ion secondary batteries. High-capacity, low-cost battery system.
리튬-황 전지는 양극에서 리튬 이온과 황의 변환(conversion) 반응(S8 + 16Li+ + 16e- → 8Li2S)으로부터 나오는 이론 용량이 1,675 mAh/g에 이르고 음극은 리튬 금속(이론용량: 3,860 mAh/g)을 사용하여 전지 시스템의 초고용량화가 가능하다. 또한 방전전압은 약 2.2 V이므로 이론적으로 양극, 음극 활물질의 양을 기준으로 2,600 Wh/kg의 에너지 밀도를 나타낸다. 이는 층상구조의 금속 산화물 및 흑연을 사용하는 상용 리튬 이차전지(LiCoO2/graphite)의 에너지 이론적 에너지 밀도인 400 Wh/kg보다도 6배 내지 7배 가량이 높은 수치이다. The lithium-sulfur cell has a theoretical capacity of 1,675 mAh / g derived from the conversion reaction of lithium ions and sulfur at the anode (S 8 + 16Li + + 16e - → 8Li 2 S) and the cathode is lithium metal (theoretical capacity: 3,860 mAh / g) can be used to increase the capacity of the battery system. Since the discharge voltage is about 2.2 V, the energy density is theoretically 2,600 Wh / kg based on the amount of the anode and the anode active material. This is 6 to 7 times higher than the energy theoretical energy density of 400 Wh / kg of commercial lithium secondary batteries (LiCoO 2 / graphite) using layered metal oxide and graphite.
리튬-황 전지는 2010년경 나노 복합체 형성을 통해 전지성능이 획기적으로 개선될 수 있다는 것이 알려진 이후 새로운 고용량, 친환경성, 저가의 리튬 이차전지로 주목받고 있으며 현재 차세대 전지 시스템으로 세계적으로 집중적인 연구가 이루어지고 있다.Lithium-sulfur battery has been attracting attention as a new high-capacity, eco-friendly, low-cost lithium secondary battery since it is known that battery performance can be dramatically improved through the formation of nanocomposite around 2010, .
현재까지 밝혀진 리튬-황 전지의 주요한 문제점 중에 하나는 황의 전기전도도가 5.0 x 10-14 S/cm가량으로 부도체에 가까워 전극에서 전기화학반응이 용이하지 않고 매우 큰 과전압으로 인해 실제 방전용량 및 전압이 이론에 훨씬 미치지 못한다는 점이다. 초기 연구자들은 황과 카본의 기계적인 볼밀링이나 카본을 이용한 표면 코팅과 같은 방법으로 성능을 개선해보고자 하였으나 큰 실효가 없었다.One of the major problems of the lithium-sulfur battery revealed to date is that the electrical conductivity of sulfur is about 5.0 x 10 -14 S / cm, which is close to non-conducting, so that the electrochemical reaction at the electrode is not easy and the actual discharge capacity and voltage It is far less than theory. Early researchers tried to improve the performance by methods such as mechanical ball milling of sulfur and carbon or surface coating using carbon, but there was no great effect.
전기전도도에 의해 전기화학반응이 제한되는 문제를 효과적으로 해결하기 위해서는 다른 양극 활물질 중의 하나인 LiFePO4의 예와 같이(전기전도도: 10-9 내지 10-10 S/cm) 입자의 크기를 수십 나노미터 이하의 크기로 줄이고 전도성 물질로 표면처리를 할 필요가 있는데, 이를 위하여 여러 가지 화학적(나노 크기의 다공성 탄소 나노 구조체 혹은 금속산화물 구조체로의 melt impregnation), 물리적 방법(high energy ball milling) 등이 보고되고 있다.In order to effectively solve the problem that the electrochemical reaction is limited by the electric conductivity, the size of the particles (electrical conductivity: 10 -9 to 10 -10 S / cm) as in the example of LiFePO 4, which is one of other cathode active materials, (Melt impregnation into nano-sized porous carbon nanostructure or metal oxide structure) and physical methods (high energy ball milling) are reported. .
다른 한 가지 리튬-황 전지와 관련된 주요 문제점은 방전도중 생성되는 황의 중간생성체인 리튬 폴리설파이드(lithium polysulfide)의 전해질로의 용해이다. 방전이 진행됨에 따라 황(S8)은 리튬 이온과 연속적으로 반응하여 S8 → Li2S8 → (Li2S6) → Li2S4 → Li2S2 → Li2S 등으로 그 상(phase)이 연속적으로 변하게 되는데 그 중 황이 길게 늘어선 체인형태인 Li2S8, Li2S4(리튬 폴리설파이드) 등은 리튬 이온전지에서 쓰이는 일반적인 전해질에서 쉽게 용해되는 성질이 있다. 이러한 반응이 발생하면 가역 양극용량이 크게 줄어들 뿐만 아니라 용해된 리튬 폴리설파이드가 음극으로 확산되어 여러 가지 부반응(side reaction)을 일으키게 된다.Another major problem associated with lithium-sulfur batteries is the dissolution of lithium polysulfide into the electrolyte, an intermediate product of sulfur generated during discharge. As the discharge progresses, sulfur (S 8 ) continuously reacts with lithium ions to form S 8 → Li 2 S 8 → (Li 2 S 6 ) → Li 2 S 4 → Li 2 S 2 → Li 2 S, etc., the phases of which are continuously changed. Among them, Li 2 S 8 and Li 2 S 4 (lithium polysulfide), which are long chains of sulfur, are easily dissolved in a general electrolyte used in a lithium ion battery . When this reaction occurs, not only the reversible anode capacity is greatly reduced but also the dissolved lithium polysulfide diffuses into the cathode and causes various side reactions.
리튬 폴리설파이드는 특히 충전과정 중 셔틀반응(shuttle reaction)을 일으키는데 이로 인하여 충전용량이 계속 증가하게 되어 충방전 효율이 급격히 저하된다. 최근 이러한 문제를 해결하기 위하여 다양한 방법이 제시되었는데 크게 전해질을 개선하는 방법, 음극의 표면을 개선하는 방법, 양극의 특성을 개선하는 방법 등으로 나눌 수 있다.Lithium polysulfide causes a shuttle reaction during the charging process, which causes the charging capacity to increase continuously, resulting in a drastic reduction in charge / discharge efficiency. Recently, a variety of methods have been proposed to solve these problems, including a method of improving the electrolyte, a method of improving the surface of the cathode, and a method of improving the characteristics of the anode.
전해질을 개선하는 방법은 신규 조성의 기능성 액체전해질, 고분자 전해질, 이온성 액체(ionic liquid) 등 새로운 전해질을 사용하여 폴리설파이드의 전해질로의 용해를 억제하거나 점도 등의 조절을 통하여 음극으로의 분산 속도를 제어하여 셔틀반응을 최대한 억제하는 방법이다.As a method for improving the electrolyte, a new electrolyte such as a functional liquid electrolyte of a new composition, a polymer electrolyte, and an ionic liquid is used to suppress the dissolution of the polysulfide into an electrolyte or control the dispersion rate to the cathode To suppress the shuttle reaction as much as possible.
음극표면에 형성되는 SEI의 특성을 개선하여 셔틀반응을 제어하는 연구가 활발히 이루어지고 있는데 대표적으로 LiNO3과 같은 전해질 첨가제를 투입하여 리튬음극의 표면에 LixNOy, LixSOy 등의 산화막을 형성하여 개선하는 방법, 리튬금속의 표면에 두꺼운 기능형 SEI 층을 형성하는 방법 등이 있다.Researches have been actively conducted to control the shuttle reaction by improving the characteristics of SEI formed on the surface of the cathode. Typically, an electrolyte additive such as LiNO 3 is added to form an oxide film of Li x NO y , Li x SO y , A method of forming a thick functional SEI layer on the surface of lithium metal, and the like.
마지막으로 양극의 특성을 개선하는 방법은 폴리설파이드의 용해를 막을 수 있도록 양극입자 표면에 코팅층을 형성하거나 용해된 폴리설파이드를 잡을 수 있는 다공성 물질을 첨가하는 방법 등이 있는데 대표적으로 전도성 고분자로 황 입자가 들어있는 양극 구조체의 표면을 코팅하는 방법, 리튬 이온이 전도되는 금속산화물로 양극 구조체의 표면을 코팅하는 방법, 리튬 폴리설파이드를 다량 흡수할 수 있는 비표면적이 넓고 기공이 큰 다공성 금속산화물을 양극에 첨가하는 방법, 탄소 구조체의 표면에 리튬 폴리설파이드를 흡착할 수 있는 작용기(functional group)를 부착하는 방법, graphene 혹은 graphene oxide 등을 이용하여 황 입자를 감싸는 방법 등이 제시되었다. Finally, as a method for improving the properties of the anode, there is a method of forming a coating layer on the surface of the anode particles or adding a porous material capable of catching the dissolved polysulfide so as to prevent the dissolution of polysulfide. Typically, A method of coating the surface of the anode structure with a metal oxide on which lithium ions are transferred, a method of coating a porous metal oxide having a large specific surface area and a large pore size, which can absorb a large amount of lithium polysulfide, , A method of attaching a functional group capable of adsorbing lithium polysulfide on the surface of a carbon structure, and a method of enclosing sulfur particles using graphene or graphene oxide.
이와 같은 노력이 진행되고는 있으나, 이러한 방법이 다소 복잡할 뿐만 아니라 활물질인 황을 넣을 수 있는 양이 제한된다는 문제가 있다. 따라서 이러한 문제들을 복합적으로 해결하고 리튬-황 전지의 성능을 개선하기 위한 새로운 기술의 개발이 필요한 실정이다.Although such efforts have been made, there is a problem that this method is somewhat complicated, and the amount of sulfur, which is an active material, is limited. Therefore, it is necessary to develop a new technology to solve these problems and to improve the performance of the lithium-sulfur battery.
[선행기술문헌][Prior Art Literature]
[특허문헌][Patent Literature]
(특허문헌 1) 대한민국 등록특허 제10-1996-0065174호(2000.7.27), "레피도크로사이트의 제조방법"(Patent Document 1) Korean Patent Registration No. 10-1996-0065174 (July 27, 2000), " Method for producing reedocrocite "
(특허문헌 2) 대한민국 공개특허 제10-2015-0091280호(2017.1.4), "리튬 황 전지 및 이의 제조방법"(Patent Document 2) Korean Patent Laid-Open Publication No. 10-2015-0091280 (Apr. 14, 2017), " Lithium Sulfate Battery and Method for Producing the Same &
상술한 문제점을 해결하기 위하여, 본 발명의 발명자들은 리튬-황 전지의 양극 특성을 개선하면 가장 직접적으로 전지 성능을 향상시킬 수 있을 것으로 예상하고, 이러한 관점에서 다각적인 연구를 수행한 끝에, 수산화철(FeOOH)을 리튬-황 전지의 양극에 도입함으로써 리튬 폴리설파이드(LiPS)의 흡착이 가능하다는 것을 확인하여 본 발명을 완성하였다.In order to solve the above-described problems, the inventors of the present invention have anticipated that battery performance can be improved most directly by improving the anode characteristics of the lithium-sulfur battery. In view of this, FeOOH) was introduced into the positive electrode of a lithium-sulfur battery, it was confirmed that lithium polysulfide (LiPS) could be adsorbed, thus completing the present invention.
이를 위해 NaBH4를 Fe(NO3)3·9H2O 또는 FeCl3·6H2O와 적정 농도의 수용액 상태로 반응시키되, 반응 시간과 반응 온도를 제어함으로써 수산화철(FeOOH), 특히 결정성의 레피도크로사이트(γ-FeOOH)를 선택적으로 고순도로 제조할 수 있다는 것을 확인하였다.For this purpose, NaBH 4 is reacted with Fe (NO 3 ) 3 .9H 2 O or FeCl 3 .6H 2 O in an appropriate aqueous solution. By controlling the reaction time and the reaction temperature, iron hydroxide (FeOOH) (Γ-FeOOH) can be selectively produced with high purity.
따라서, 본 발명의 목적은 간소한 공정을 통해 높은 순도의 수산화철의 제조방법을 제공하는 것이다.Accordingly, an object of the present invention is to provide a process for producing iron hydroxide of high purity through a simple process.
또한, 본 발명의 목적은 리튬 폴리설파이드를 흡착하여 양극의 반응성을 높임으로써, 리튬-황 전지의 방전 용량 증가에 기여하고 리튬-황 전지의 수명을 증가시키는 것이다.It is also an object of the present invention to increase the reactivity of the positive electrode by adsorbing lithium polysulfide, thereby contributing to an increase in the discharge capacity of the lithium-sulfur battery and increasing the lifetime of the lithium-sulfur battery.
상기 목적을 달성하기 위해, 본 발명은,In order to achieve the above object,
Fe(NO3)3·9H2O 또는 FeCl3·6H2O; 및 Fe (NO 3 ) 3 .9H 2 O or FeCl 3 .6H 2 O; And
하기 화학식 1로 표시되는 환원제;를 혼합하여 반응시키는 단계를 포함하는 수산화철(FeOOH)의 제조방법을 제공한다.And a reducing agent represented by the following general formula (1), followed by a reaction.
[화학식 1][Chemical Formula 1]
M1(BH4)X M 1 (BH 4 ) X
상기 화학식 1에서, M1은 Li, Na, Mg, K 및 Ca 중에서 선택되는 어느 하나이고, X는 1 또는 2이다.In Formula 1, M 1 is any one selected from Li, Na, Mg, K, and Ca, and X is 1 or 2.
본 발명의 일 구체예는 상기 Fe(NO3)3·9H2O 또는 FeCl3·6H2O가 0.04 내지 0.08 M의 수용액인 것이다.One embodiment of the present invention is an aqueous solution of 0.04 to 0.08 M of Fe (NO 3 ) 3 .9H 2 O or FeCl 3 .6H 2 O.
본 발명의 일 구체예는 상기 화학식 1로 표시되는 환원제가 0.2 내지 0.5 M의 수용액인 것이다.In one embodiment of the present invention, the reducing agent represented by Formula 1 is an aqueous solution of 0.2 to 0.5 M.
본 발명의 일 구체예는 상기 혼합이 10 내지 120 초 동안 실시되는 것이다.In one embodiment of the present invention, the mixing is carried out for 10 to 120 seconds.
본 발명의 일 구체예는 상기 반응 온도가 20 내지 25 ℃인 것이다.In one embodiment of the present invention, the reaction temperature is 20 to 25 占 폚.
본 발명의 일 구체예는 상기 반응 시간이 10분 내지 10시간인 것이다.In one embodiment of the present invention, the reaction time is 10 minutes to 10 hours.
본 발명의 일 구체예는 상기 반응 시간이 40분 내지 2시간인 것이다.In one embodiment of the present invention, the reaction time is 40 minutes to 2 hours.
본 발명의 일 구체예는 상기 반응 단계 이후에 여과 및 건조 단계를 더 포함하는 것이다.One embodiment of the present invention further comprises a step of filtration and drying after the reaction step.
본 발명의 일 구체예는 상기 건조가 70 내지 90 ℃에서 6 내지 12 시간 동안 실시되는 것이다.In one embodiment of the present invention, the drying is carried out at 70 to 90 DEG C for 6 to 12 hours.
본 발명의 일 구체예는 상기 수산화철(FeOOH)이 레피도크로사이트(γ-FeOOH)인 것이다.In one embodiment of the present invention, the iron hydroxide (FeOOH) is lepidocrocite (γ-FeOOH).
본 발명의 일 구체예는 상기 수산화철(FeOOH)이 결정성인 것이다.In one embodiment of the present invention, the iron hydroxide (FeOOH) is crystalline.
본 발명의 일 구체예는 상기 수산화철(FeOOH)이 판상형인 것이다.In one embodiment of the present invention, the iron hydroxide (FeOOH) is a plate-like type.
본 발명의 일 구체예는 상기 수산화철(FeOOH)이 입경 50 내지 500 nm 인 것이다.In one embodiment of the present invention, the iron hydroxide (FeOOH) has a particle diameter of 50 to 500 nm.
또한 본 발명은,Further, according to the present invention,
활물질, 도전재 및 바인더를 포함하는 리튬-황 전지용 양극으로서,A positive electrode for a lithium-sulfur battery including an active material, a conductive material and a binder,
상기 양극은 수산화철(FeOOH)을 포함하는 리튬-황 전지용 양극을 제공한다.The positive electrode provides a positive electrode for a lithium-sulfur battery including iron hydroxide (FeOOH).
본 발명의 일 구체예는 상기 수산화철(FeOOH)이 레피도크로사이트(γ-FeOOH)인 것이다.In one embodiment of the present invention, the iron hydroxide (FeOOH) is lepidocrocite (γ-FeOOH).
본 발명의 일 구체예는 상기 수산화철(FeOOH)이 결정성인 것이다.In one embodiment of the present invention, the iron hydroxide (FeOOH) is crystalline.
본 발명의 일 구체예는 상기 수산화철(FeOOH)이 (200), (210), (301) 및 (020) 면의 XRD 피크가 각각 2θ=14.1±0.1°, 27.0±0.1°, 36.3±0.1° 및 46.9±0.1°에 나타나는 것이다.In one embodiment of the present invention, the iron hydroxide (FeOOH) has XRD peaks of (200), (210), (301) and (020) planes of 2θ = 14.1 ± 0.1 °, 27.0 ± 0.1 °, 36.3 ± 0.1 ° And 46.9 ± 0.1 °.
본 발명의 일 구체예는 상기 수산화철(FeOOH)이 판상형인 것이다.In one embodiment of the present invention, the iron hydroxide (FeOOH) is a plate-like type.
본 발명의 일 구체예는 상기 수산화철(FeOOH)의 평균 입경이 50 내지 500 nm인 것이다.In one embodiment of the present invention, the average diameter of the iron hydroxide (FeOOH) is 50 to 500 nm.
본 발명의 일 구체예는 상기 리튬-황 전지용 양극에 포함되는 수산화철(FeOOH)의 함량이 베이스 고형분 100 중량부 대비 0.1 내지 15 중량부인 것이다.In one embodiment of the present invention, the amount of iron hydroxide (FeOOH) contained in the positive electrode for a lithium-sulfur battery is 0.1 to 15 parts by weight based on 100 parts by weight of the base solid content.
본 발명의 일 구체예는 상기 활물질이 황-탄소 복합체인 것이다.In one embodiment of the present invention, the active material is a sulfur-carbon composite.
또한 본 발명은,Further, according to the present invention,
양극, 음극, 이들 사이에 개재된 분리막 및 전해질을 구비하되,An anode, a cathode, a separator interposed therebetween, and an electrolyte,
상기 양극은 상술한 리튬-황 전지용 양극인 리튬-황 전지를 제공한다.The positive electrode provides the lithium-sulfur battery which is the positive electrode for the lithium-sulfur battery.
본 발명에 따르면, NaBH4와 Fe(NO3)3·9H2O 또는 FeCl3·6H2O를 반응시키는 단계를 포함하는 간소한 공정에 의해 고순도의 수산화철(FeOOH)을 제조할 수 있다.According to the present invention, high purity iron hydroxide (FeOOH) can be produced by a simple process including a step of reacting NaBH 4 with Fe (NO 3 ) 3 .9H 2 O or FeCl 3 .6H 2 O.
상기 NaBH4와 Fe(NO3)3·9H2O 또는 FeCl3·6H2O의 반응시 반응 온도와 반응 시간을 조절하는 것만으로도 제조되는 수산화철(FeOOH)의 형상 및 순도를 조절할 수 있다.The shape and purity of the produced iron hydroxide (FeOOH) can be controlled by controlling the reaction temperature and the reaction time in the reaction of NaBH 4 with Fe (NO 3 ) 3 .9H 2 O or FeCl 3 .6H 2 O.
이에, 본 발명은 수산화철 중에서도 결정성인 레피도크로사이트(γ-FeOOH)를 선택적으로 제조할 수 있다. 또한 수산화철(FeOOH)을 리튬-황 전지의 양극에 적용하면, 충방전시 발생하는 리튬 폴리설파이드를 흡착하여 리튬-황 전지 양극의 반응성이 증가하고, 그것이 적용된 리튬-황 전지는 방전용량과 수명을 증가시키는 효과를 나타낼 수 있다.Accordingly, the present invention can selectively produce lepidocrocite (γ-FeOOH), which is also crystalline iron hydroxide. Also, when iron hydroxide (FeOOH) is applied to the anode of a lithium-sulfur battery, the reactivity of the lithium-sulfur battery anode is increased by adsorbing lithium polysulfide generated during charging and discharging, and the lithium- It is possible to exhibit an effect of increasing
도 1은 본 발명의 제조예 및 비교제조예에 따른 수산화철(FeOOH)의 주사전자현미경(SEM) 이미지를 나타낸 것이다.1 shows a scanning electron microscope (SEM) image of iron hydroxide (FeOOH) according to the production example of the present invention and the comparative preparation example.
도 2는 본 발명의 제조예에 따른 수산화철(FeOOH)의 주사전자현미경(SEM) 이미지를 나타낸 것이다.2 shows a scanning electron microscope (SEM) image of iron hydroxide (FeOOH) according to the production example of the present invention.
도 3은 본 발명의 제조예 및 비교제조예에 따른 수산화철(FeOOH)의 X-선 회절분석(XRD)결과를 나타낸 것이다.3 shows X-ray diffraction (XRD) results of iron hydroxide (FeOOH) according to the preparation examples and comparative preparation examples of the present invention.
도 4는 본 발명의 제조예에 따른 수산화철(FeOOH)의 X-선 회절분석(XRD)결과를 나타낸 것이다.4 shows X-ray diffraction (XRD) results of iron hydroxide (FeOOH) according to the production example of the present invention.
도 5는 본 발명에 따른 수산화철(FeOOH)의 리튬 폴리설파이드 흡착 실험의 색변화를 나타낸 것이다.5 shows the color change of the experiment of adsorbing lithium polysulfide of iron hydroxide (FeOOH) according to the present invention.
도 6은 본 발명에 따른 수산화철(FeOOH)의 리튬 폴리설파이드(Li2S6) 흡착 반응의 색도 변화를 UV 흡광도 측정 결과로 나타낸 것이다.6 is a graph showing the change in chromaticity of a lithium polysulfide (Li 2 S 6 ) adsorption reaction of iron hydroxide (FeOOH) according to the present invention as a result of UV absorbance measurement.
도 7은 본 발명의 실험예 및 비교실험예에 따른 양극을 포함하는 리튬-황 전지의 방전용량 측정 결과를 나타낸다.7 shows the results of measurement of the discharge capacity of a lithium-sulfur battery including a positive electrode according to Experimental Examples and Comparative Examples of the present invention.
도 8은 본 발명의 실시예 및 비교예에 따른 양극을 포함하는 리튬-황 전지의 방전용량 측정 결과를 나타낸다.FIG. 8 shows the discharge capacity measurement results of a lithium-sulfur battery including a positive electrode according to Examples and Comparative Examples of the present invention.
도 9는 본 발명의 실험예 및 비교실험예에 따른 양극을 포함하는 리튬-황 전지의 수명특성 측정 결과를 나타낸다.FIG. 9 shows the results of measurement of lifetime characteristics of a lithium-sulfur battery including a positive electrode according to Experimental Examples and Comparative Experimental Examples of the present invention.
도 10은 본 발명의 실시예 및 비교예에 따른 양극을 포함하는 리튬-황 전지의 수명특성 측정 결과를 나타낸다.FIG. 10 shows the results of measurement of lifetime characteristics of a lithium-sulfur battery including a positive electrode according to Examples and Comparative Examples of the present invention.
이하, 본 발명이 속하는 기술 분야에서 통상의 지식을 가진 자가 용이하게 실시할 수 있도록 첨부한 도면을 참고로 하여 상세히 설명한다. 그러나 본 발명은 여러 가지 상이한 형태로 구현될 수 있으며, 본 명세서에 한정되지 않는다.DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.
본 명세서 및 청구범위에 사용된 용어나 단어는 통상적이거나 사전적인 의미로 한정해서 해석되어서는 아니되며, 발명자는 그 자신의 발명을 가장 최선의 방법으로 설명하기 위해 용어의 개념을 적절하게 정의할 수 있다는 원칙에 입각하여 본 발명의 기술적 사상에 부합하는 의미와 개념으로 해석되어야만 한다.The terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms and the inventor may appropriately define the concept of the term in order to best describe its invention It should be construed as meaning and concept consistent with the technical idea of the present invention.
본 명세서에서 사용되고 있는 용어 “복합체(composite)”란 두 가지 이상의 재료가 조합되어 물리적, 화학적으로 서로 다른 상(phase)를 형성하면서 보다 유효한 기능을 발현하는 물질을 의미한다.As used herein, the term " composite " refers to a material that combines two or more materials to form a physically and chemically distinct phase while exhibiting a more effective function.
수산화철(FeOOH)의Of iron hydroxide (FeOOH) 제조방법 Manufacturing method
본 발명은 수산화철(FeOOH)의 제조방법에 관한 것으로서, 리튬-황 전지의 양극재로 적용하여 방전 용량을 향상시킬 수 있는 형태 및 물성을 가지는 수산화철(FeOOH)을 제조할 수 있는 방법에 관한 것이다.The present invention relates to a process for producing iron hydroxide (FeOOH), and more particularly, to a process for producing iron hydroxide (FeOOH) having a shape and physical properties capable of improving the discharge capacity by applying it as a cathode material of a lithium-sulfur battery.
본 발명에 따른 수산화철(FeOOH)의 제조방법은 Fe(NO3)3·9H2O 또는 FeCl3·6H2O; 및 The process for producing iron hydroxide (FeOOH) according to the present invention comprises the steps of: Fe (NO 3 ) 3 .9H 2 O or FeCl 3 .6H 2 O; And
하기 화학식 1로 표시되는 표시되는 환원제;를 혼합하여 반응시키는 단계를 포함할 수 있다:And a reducing agent represented by the following formula (1): < EMI ID =
[화학식 1][Chemical Formula 1]
M1(BH4)X M 1 (BH 4 ) X
상기 화학식 1에서, M1은 Li, Na, Mg, K 및 Ca 중에서 선택되는 어느 하나이고, X는 1 또는 2이다.In Formula 1, M 1 is any one selected from Li, Na, Mg, K, and Ca, and X is 1 or 2.
이때, 상기 Fe(NO3)3·9H2O 또는 FeCl3·6H2O 및 상기 화학식 1로 표시되는 환원제는 모두 수용액 형태일 수 있으며, 상기 화학식 1로 표시되는 환원제 수용액에 상기 Fe(NO3)3·9H2O 수용액 또는 FeCl3·6H2O 수용액을 첨가시켜 혼합하고 반응시키는 것일 수 있다.In this case, the Fe (NO 3) 3 · 9H 2 O or FeCl 3 · 6H 2 O and a reducing agent represented by Formula 1 may be in both the form of an aqueous solution, wherein the reducing agent aqueous solution of the formula (1) Fe (NO 3 ) 3 · 9H 2 O aqueous solution or FeCl 3 · 6H 2 O aqueous solution may be added, followed by mixing and reacting.
만약, 반대로 혼합과 반응을 진행할 경우 제조되는 수산화철(FeOOH)의 순도가 저하될 수 있다. 즉, 상기 Fe(NO3)3·9H2O 수용액 또는 FeCl3·6H2O 수용액에 상기 화학식 1로 표시되는 환원제 수용액을 첨가시켜 혼합하고 반응시킬 경우 제조되는 수산화철(FeOOH)의 순도가 저하될 수 있다.If, on the other hand, mixing and reacting are carried out, the purity of the produced iron hydroxide (FeOOH) may be lowered. That is, when the aqueous solution of the reducing agent represented by Formula 1 is added to the Fe (NO 3 ) 3 .9H 2 O aqueous solution or FeCl 3 .6H 2 O aqueous solution and mixed and reacted, the purity of the iron hydroxide (FeOOH) .
상기 Fe(NO3)3·9H2O 수용액 또는 FeCl3·6H2O 수용액은 0.04 내지 0.08 M, 바람직하게는 0.05 내지 0.06 M 일 수 있으며, 0.04 M 미만이면 수산화철(FeOOH)의 제조 수율이 낮아질 수 있고, 0.08 M 초과이면 제조되는 수산화철(FeOOH)의 물성이 리튬-황 전지의 양극재로 적용하기에 적합하지 않을 수 있다. The Fe (NO 3 ) 3 .9H 2 O aqueous solution or FeCl 3 .6H 2 O aqueous solution may be 0.04 to 0.08 M, preferably 0.05 to 0.06 M, and if it is less than 0.04 M, the production yield of iron hydroxide (FeOOH) If it is more than 0.08 M, the physical properties of the produced iron hydroxide (FeOOH) may not be suitable as a cathode material for a lithium-sulfur battery.
상기 화학식 1로 표시되는 환원제 수용액은 0.2 내지 0.5 M, 바람직하게는 0.3 내지 0.4 M 일 수 있으며, 0.2 M 미만이면 수산화철(FeOOH)이 제조되지 않고, 0.5 M 초과이면 반응이 진행되지 않을 수 있다.The reducing agent aqueous solution represented by the above formula (1) may be 0.2 to 0.5 M, preferably 0.3 to 0.4 M. If it is less than 0.2 M, iron hydroxide (FeOOH) can not be produced, and if it exceeds 0.5 M, the reaction may not proceed.
본 발명의 바람직한 일 구현예에 의하면, 상기 화학식 1로 표시되는 첨가물은 NaBH4 일 수 있다.According to a preferred embodiment of the present invention, the additive represented by Formula 1 may be NaBH 4 .
Fe(NO3)3·9H2O 수용액 또는 FeCl3·6H2O 과 NaBH4 수용액을 반응시킬 경우, Fe3+ 양이온이 Fe 금속 형태로 전환된 이후 수용액 상에서 자연스럽게 수산화철(FeOOH)이 합성될 수 있다.When Fe (NO 3 ) 3 · 9H 2 O aqueous solution or FeCl 3 · 6H 2 O and NaBH 4 aqueous solution are reacted, iron hydroxide (FeOOH) can be synthesized naturally in aqueous solution after conversion of Fe 3+ cation to Fe metal form have.
상기 Fe(NO3)3·9H2O 또는 FeCl3·6H2O 과 상기 화학식 1로 표시되는 환원제의 혼합은 단시간 내에 이루어질 수 있으며, 10 내지 120초, 바람직하게는 50 내지 80초 내에 이루어질 수 있다. 상기 혼합 시간이 10초 미만이면 혼합이 지나치게 빠르게 이루어져 기체가 한꺼번에 발생하므로 반응이 불균일하게 진행될 수 있고, 120 초 초과이면 혼합 속도가 느리므로 혼합 시 초기에 반응하여 생성된 물질과 후기에 반응하여 생성된 물질의 상이 다를 수 있다.The mixing of the Fe (NO 3 ) 3 .9H 2 O or FeCl 3 .6H 2 O and the reducing agent represented by the above formula (1) may be performed within a short time, and may be performed within 10 to 120 seconds, preferably 50 to 80 seconds have. If the mixing time is less than 10 seconds, the mixing may occur excessively and the gas may be generated all at once, so that the reaction may proceed unevenly. If the mixing time is more than 120 seconds, the mixing speed is slow, The phase of the material may be different.
또한, 상기 반응 온도는 10 내지 60 ℃, 바람직하게는 20 내지 50 ℃, 보다 바람직하게는 20 내지 25 ℃일 수 있으며, 반응 온도가 10 ℃ 미만이면 반응이 진행되지 않을 수 있고, 60 ℃ 초과이면 제조되는 수산화철(FeOOH)의 물성이 변성될 수 있다. 또한, 반응속도 조절을 위해서 20 내지 25 ℃로 유지시키며 반응시키는 것이 바람직할 수 있다.The reaction temperature may be 10 to 60 ° C, preferably 20 to 50 ° C, more preferably 20 to 25 ° C. If the reaction temperature is less than 10 ° C, the reaction may not proceed, and if it is more than 60 ° C The physical properties of the produced iron hydroxide (FeOOH) may be denatured. Further, it may be preferable to conduct the reaction while maintaining the temperature at 20 to 25 DEG C for controlling the reaction rate.
또한, 상기 반응 시간은 10 분 내지 10 시간, 바람직하게는, 40 분 내지 2 시간일 수 있으며, 10 분 미만일 경우 수산화철(FeOOH)이 형성되지 않을 수 있고, 20 시간 초과일 경우 수산화철(FeOOH)의 형상이 리튬-황 전지의 양극재로 적합하지 않을 수 있으며, 특히 40분 내지 2시간 동안 반응시킬 경우 수산화철(FeOOH)의 원하는 물성을 잃어버리지 않고 유지할 수 있다.The reaction time may be from 10 minutes to 10 hours, preferably from 40 minutes to 2 hours. If it is less than 10 minutes, iron hydroxide (FeOOH) may not be formed, and if it exceeds 20 hours, Shape may not be suitable as a cathode material of a lithium-sulfur battery. In particular, when reacting for 40 minutes to 2 hours, desired properties of FeOOH can be maintained without being lost.
한편, 상기 Fe(NO3)3·9H2O 또는 FeCl3·6H2O 수용액과 상기 화학식 1로 표시되는 첨가제 수용액을 반응시키는 단계 이후에, 여과 및 건조시키는 단계를 더 포함할 수 있다. On the other hand, after the step of reacting the aqueous solution of Fe (NO 3 ) 3 .9H 2 O or FeCl 3 .6H 2 O with the aqueous solution of the additive represented by the above formula (1), filtration and drying may be further carried out.
상기 여과시키는 단계는 당업계에서 통상적으로 사용되는 여과 공정에 의해 실시될 수 있으며, 예컨대, 여과지를 이용할 수 있다.The filtration step may be performed by a filtration process commonly used in the art, for example, a filter paper may be used.
상기 건조시키는 단계는 70 내지 90 ℃에서 6 내지 12 시간 동안 실시될 수 있다.The drying may be carried out at 70 to 90 ° C for 6 to 12 hours.
상기 건조 온도가 70 ℃ 미만이거나 건조 시간이 6 시간 미만이면 완전히 건조되지 않아 입자 형태의 수산화철(FeOOH)을 얻을 수 없고, 90 ℃ 초과이거나 12 시간 초과이면 남아 있는 물이 끓게 되어 수산화철(FeOOH)의 물성이 변성될 수 있다. If the drying temperature is lower than 70 ° C or the drying time is less than 6 hours, it is not completely dried to obtain particles of iron hydroxide (FeOOH). If the drying temperature exceeds 90 ° C or exceeds 12 hours, the remaining water will boil, The physical properties may be denatured.
전술한 바와 같은 방법에 의해 제조된 수산화철(FeOOH)은 결정성일 수 있으며, 구체적으로는 레피도크로사이트(γ-FeOOH) 일 수 있다. The iron hydroxide (FeOOH) produced by the method as described above may be crystalline, and specifically may be lepidocrocite (γ-FeOOH).
상기 제조된 수산화철(FeOOH)은 판상형일 수 있으며, 이 경우 리튬-황 전지의 양극재로 적용시 방전 용량 향상에 유리할 수 있다. 그러나, 상기 제조된 수산화철(FeOOH)의 형상은 반응 시간을 제어하여 필요에 따라 조절할 수 있으며, 이들은 모두 리튬-황 전지의 양극재로 적용 가능하다.The prepared iron hydroxide (FeOOH) may be in the form of a plate, and in this case, it may be advantageous to improve the discharge capacity when applied to the cathode material of the lithium-sulfur battery. However, the shape of the prepared iron hydroxide (FeOOH) can be controlled as needed by controlling the reaction time, and they are all applicable to the cathode material of a lithium-sulfur battery.
또한, 상기 제조된 수산화철(FeOOH)은 입경이 0 초과 500 nm 이하일 수 있고, 바람직하게는 50 내지 500 nm 인 입자 형태일 수 있다. 상기 범위 내에서 입경이 감소할수록 리튬-황 전지의 양극재로서 적합하고, 입경이 상기 범위 초과이면 입자 크기가 커 리튬-황 전지의 양극재로 적합하지 않다.The produced iron hydroxide (FeOOH) may have a particle size of more than 0 and 500 nm or less, preferably 50 to 500 nm. As the particle size decreases within the above range, it is suitable as a cathode material for a lithium-sulfur battery. If the particle diameter is larger than the above range, the particle size is large and is not suitable as a cathode material of a lithium-sulfur battery.
전술한 바와 같은 수산화철(FeOOH)의 제조방법에 의해 제조된 수산화철(FeOOH), 예컨대, 결정성 레피도크로사이트(γ-FeOOH)를 리튬-황 전지에 적용할 경우, 리튬-황 전지의 충방전시 용출되는 폴리설파이드를 흡착할 수 있어 리튬-황 전지의 성능을 향상시킬 수 있다.When iron hydroxide (FeOOH), for example, crystalline lepidocrocite (γ-FeOOH) produced by the above-described method for producing iron hydroxide (FeOOH) is applied to a lithium-sulfur battery, It is possible to adsorb the polysulfide to be eluted and to improve the performance of the lithium-sulfur battery.
본 발명에 따른 상기 수산화철(FeOOH)의 제조방법은 수산화철(FeOOH) 중 결정성 레피도크로사이트(γ-FeOOH)를 선택적으로 제조할 수 있어, 리튬-황 전지의 양극재 공급 기술로 적합하다.The process for producing the iron hydroxide (FeOOH) according to the present invention can selectively produce crystalline lepidocrocite (? -FeOOH) in iron hydroxide (FeOOH), and is suitable for a cathode material supply technology of a lithium-sulfur battery.
도 1 및 도 2는 상기 제조방법에 의해 제조된 수산화철(FeOOH)인 레피도크로사이트(γ-FeOOH) 주사전자현미경(SEM) 이미지를 나타낸다. 도면에서 확인할 수 있는 바와 같이, 상기 일 구현예에 따라 제조된 ‘판상형(plate type)'수산화철(FeOOH)이 제조되었음을 확인할 수 있고, 상기의 제조방법으로 제조된 수산화철(FeOOH)은 그 평균 입경이 50 내지 500nm이고, 판상형 구조일 수 있다.Figs. 1 and 2 show scanning electron microscope (SEM) images of the iron hydroxide (FeOOH) produced by the above-mentioned production method. As can be seen from the figure, it can be seen that the 'plate type' iron hydroxide (FeOOH) produced according to the above embodiment was prepared, and the iron hydroxide (FeOOH) prepared by the above- 50 to 500 nm, and may be a plate-like structure.
도 4는 상기의 제조방법에 의해 제조된 수산화철(FeOOH)인 레피도크로사이트(γ-FeOOH)의 X-선 회절 분석(XRD) 데이터 결과를 나타낸다. 도 4의 CuKα선을이용한 X-선 회절 분석 결과, (200), (210), (301) 및 (020) 면의 XRD 피크가 각각 2θ=14.1±0.1°, 27.0±0.1°, 36.3±0.1° 및 46.9±0.1°에 나타났다. 도 4의 유효 피크 검출을 통해서 수산화철(FeOOH)이 합성된 것을 확인할 수 있다.Fig. 4 shows the X-ray diffraction (XRD) data of the iron hydroxide (FeOOH) produced by the above-mentioned production method of reedocrocite (y-FeOOH). As a result of X-ray diffraction analysis using the CuK? Ray of FIG. 4, the XRD peaks of the (200), (210), (301) and (020) planes were 2θ = 14.1 ± 0.1 °, 27.0 ± 0.1 °, ° and 46.9 ± 0.1 °, respectively. It can be confirmed that iron hydroxide (FeOOH) is synthesized through the effective peak detection of FIG.
X-선 회절 분석(XRD)에서 유효(significant or effective) 피크란 XRD 데이터에서 분석 조건이나 분석 수행자에 크게 영향을 받지 않고 실질적으로 동일한 패턴으로 반복 검출되는 피크를 의미하고, 이를 달리 표현하면 백그라운드 수준(backgound level) 대비 1.5배 이상일 수 있고, 바람직하게는 2배 이상, 더욱 바람직하게는 2.5배 이상의 높이, 세기, 강도 등을 갖는 피크를 의미한다. A significant or effective peak in X-ray diffraction analysis (XRD) means a peak that is repeatedly detected in the same pattern without being greatly affected by analysis conditions or analysts in XRD data. In other words, intensity, intensity, etc., of at least 1.5 times, preferably at least 2 times, more preferably at least 2.5 times the backgound level.
리튬-황 전지용 양극Anode for lithium-sulfur battery
본 발명은 활물질, 도전재 및 바인더를 포함하는 리튬-황 전지용 양극으로서, 상기 양극은 수산화철(FeOOH)을 포함하는 리튬-황 전지용 양극을 제공한다.The present invention provides a positive electrode for a lithium-sulfur battery including an active material, a conductive material and a binder, wherein the positive electrode comprises a positive electrode for a lithium-sulfur battery including iron hydroxide (FeOOH).
이때, 리튬-황 전지의 양극은 전류 집전체 상에 활물질, 도전재 및 바인더를 포함하는 베이스 고형분이 위치한 것일 수 있다.At this time, the anode of the lithium-sulfur battery may have a base solid portion including an active material, a conductive material, and a binder on a current collector.
상기 집전체로는 도전성이 우수한 알루미늄, 니켈 등을 사용하는 것이 바람직할 수 있다. As the current collector, it is preferable to use aluminum or nickel excellent in conductivity.
일 구현예로, 상기 활물질, 도전재, 및 바인더를 포함하는 베이스 고형분 100 중량부 기준으로 수산화철(FeOOH)을 0.1 내지 15 중량부를 포함할 수 있고 바람직하게는 1 내지 10 중량부를 포함할 수 있다. 상기 수치 범위의 하한값 미만인 경우에는 폴리설파이드의 흡착 효과가 미미할 수 있고, 상한값을 초과하는 경우에는 전극의 용량이 줄어들어, 바람직하지 않다.In one embodiment, 0.1 to 15 parts by weight, and preferably 1 to 10 parts by weight, of iron hydroxide (FeOOH) may be contained based on 100 parts by weight of base solids including the active material, the conductive material, and the binder. If it is less than the lower limit of the above-mentioned numerical range, the adsorption effect of polysulfide may be insignificant, and if it exceeds the upper limit value, the capacity of the electrode is decreased.
상기 수산화철(FeOOH)은 본 발명에서 제시하는 제조방법에 의해 제조된 수산화철(FeOOH)을 사용할 수 있고, 바람직하게는 레피도크로사이트(γ-FeOOH)일 수 있다. 상기 수산화철(FeOOH)은 결정성일 수 있으며 평균 입경이 50 내지 500 nm 의 판상형일 수 있다.The iron hydroxide (FeOOH) may be iron hydroxide (FeOOH) produced by the production method proposed in the present invention, and preferably it may be lepidocrocite (γ-FeOOH). The iron hydroxide (FeOOH) may be crystalline and may be in the form of a plate having an average particle size of 50 to 500 nm.
한편, 본 발명의 양극을 구성하는 베이스 고형분 중 활물질로는 황 원소(Elemental sulfur, S8), 황 계열 화합물 또는 이들의 혼합물을 포함할 수 있으며, 상기 황 계열 화합물은 구체적으로, Li2Sn(n≥1), 유기황 화합물 또는 탄소-황 복합체((C2Sx)n: x=2.5 ~ 50, n≥2) 등일 수 있다.Meanwhile, the active material of the base solid constituting the anode of the present invention may include sulfur (S 8 ), a sulfur-based compound, or a mixture thereof, and the sulfur-based compound is specifically Li 2 S n (n? 1), an organic sulfur compound or a carbon-sulfur complex ((C 2 S x ) n : x = 2.5 to 50, n≥2), and the like.
본 발명에 따른 리튬-황 전지용 양극은 바람직하기로 황-탄소 복합체의 활물질을 포함할 수 있으며, 황 물질은 단독으로는 전기 전도성이 없기 때문에 도전재와 복합하여 사용할 수 있다. 본 발명에 따른 수산화철(FeOOH)의 첨가는 이러한 황-탄소 복합체 구조 유지에 영향을 주지 않는다.The positive electrode for a lithium-sulfur battery according to the present invention may include an active material of a sulfur-carbon composite. Since the sulfur material alone does not have electrical conductivity, it can be used in combination with a conductive material. The addition of iron hydroxide (FeOOH) according to the present invention does not affect the structure maintenance of this sulfur-carbon complex.
상기 활물질은 바람직하기로 베이스 고형분 100 중량부 중 50 내지 95 중량부를 구성하도록 하고, 보다 바람직하기로는 70 중량부 내외로 할 수 있다. 만약 활물질이 상기 범위 미만으로 포함되면 전극의 반응을 충분하게 발휘하기 어렵고, 상기 범위 초과로 포함되어도 기타 도전재 및 바인더의 포함량이 상대적으로 부족하여 충분한 전극 반응을 발휘하기 어렵기 때문에 상기 범위 내에서 적정 함량을 결정하는 것이 바람직하다.Preferably, the active material is composed of 50 to 95 parts by weight, more preferably 70 parts by weight, of 100 parts by weight of the base solid content. If the active material is contained in an amount less than the above range, it is difficult to sufficiently exert the reaction of the electrode. Even if the active material is contained in an amount exceeding the above range, the amount of other conductive materials and binders is relatively insufficient, It is desirable to determine the titratable content.
본 발명의 양극을 구성하는 베이스 고형분 중 상기 도전재는 전해질과 양극 활물질을 전기적으로 연결시켜 주어 전자가 집전체(Current collector)로부터 황까지 이동하는 경로의 역할을 하는 물질로서, 전지에 화학적 변화를 유발하지 않으면서 다공성 및 도전성을 갖는 것이라면 특별히 한정되지 않는다. 예컨대, KS6과 같은 흑연계 물질; 슈퍼 P(Super-P), 카본 블랙, 덴카 블랙, 아세틸렌 블랙, 케첸 블랙, 채널 블랙, 퍼네이스 블랙, 램프 블랙, 서머 블랙과 같은 카본 블랙; 플러렌 등의 탄소 유도체; 탄소 섬유나 금속 섬유 등의 도전성 섬유; 불화 카본, 알루미늄, 니켈 분말 등의 금속 분말; 또는 폴리아닐린, 폴리티오펜, 폴리아세틸렌, 폴리피롤 등의 전도성 고분자를 단독 또는 혼합하여 사용할 수 있다. Among the base solid components constituting the anode of the present invention, the conductive material is a material that electrically connects the electrolyte and the cathode active material and serves as a path through which electrons move from the current collector to the sulfur. And is not particularly limited as long as it has porosity and conductivity. A graphite-based material such as KS6; Carbon black such as super P, carbon black, denka black, acetylene black, ketjen black, channel black, furnace black, lamp black, and summer black; Carbon derivatives such as fullerene; Conductive fibers such as carbon fiber and metal fiber; Metal powders such as carbon fluoride, aluminum, and nickel powder; Or conductive polymers such as polyaniline, polythiophene, polyacetylene, and polypyrrole may be used alone or in combination.
상기 도전재는 바람직하기로 베이스 고형분 100 중량부 중 1 ~ 10 중량부를 구성하도록 하고, 바람직하기로는 5 중량부 내외로 할 수 있다. 만약, 전극에 포함되는 도전재의 함량이 상기 범위 미만이면 전극 내 황 중 반응하지 못하는 부분이 증가하게 되고, 결국은 용량감소를 일으키게 되며, 상기 범위 초과이면 고효율 방전 특성과 충, 방전 사이클 수명에 악영향을 미치게 되므로 상술한 범위 내에서 적정 함량을 결정하는 것이 바람직하다.The conductive material may preferably be 1 to 10 parts by weight, preferably 5 parts by weight, based on 100 parts by weight of the base solid content. If the content of the conductive material contained in the electrode is less than the above range, the portion of the electrode in which sulfur does not react increases and eventually the capacity is reduced. If the content exceeds the above range, the high efficiency discharge characteristic and the charge and discharge cycle life are adversely affected It is preferable to determine the optimum content within the above-mentioned range.
베이스 고형분으로서 상기 바인더는 양극을 형성하는 베이스 고형분의 슬러리 조성물을 집전체에 잘 부착하기 위하여 포함하는 물질로서, 용매에 잘 용해되고 양극 활물질과 도전재와의 도전 네트워크를 잘 구성할 수 있는 물질을 사용한다. 특별한 제한이 없는 한 당해 업계에서 공지된 모든 바인더들을 사용할 수 있으며, 바람직하기로 폴리(비닐)아세테이트, 폴리비닐 알코올, 폴리에틸렌 옥사이드, 폴리비닐 피롤리돈, 알킬레이티드 폴리에틸렌 옥사이드, 가교결합된 폴리에틸렌 옥사이드, 폴리비닐 에테르, 폴리(메틸 메타크릴레이트), 폴리비닐리덴 플루오라이드(PVdF), 폴리헥사플루오로프로필렌, 폴리비닐리덴플루오라이드의 코폴리머(상품명: Kynar), 폴리(에틸 아크릴레이트), 폴리테트라플루오로에틸렌폴리비닐클로라이드, 폴리테트라플루오로에틸렌, 폴리아크릴로니트릴, 폴리비닐피리딘, 폴리스티렌, 카르복시메틸 셀룰로오즈, 폴리디메틸실록세인과 같은 실록세인계, 스티렌-부타디엔 고무, 아크릴로니트릴-부티디엔 고무, 스티렌-이소프렌 고무를 포함하는 고무계 바인더, 폴리에틸렌 글리콜 디아크릴레이트와 같은 에틸렌글리콜계 및 이들의 유도체, 이들의 블랜드, 이들의 공중합체 등이 사용될 수 있으나, 이에 한정되는 것은 아니다.As the base solids, the binder is a material that contains a base solids slurry composition that forms the anode to adhere well to the current collector, and is a material that is well dissolved in the solvent and can well constitute the conductive network of the cathode active material and the conductive material use. All binders known in the art can be used and are preferably selected from the group consisting of poly (vinyl) acetate, polyvinyl alcohol, polyethylene oxide, polyvinylpyrrolidone, alkylated polyethylene oxide, crosslinked polyethylene oxide , Copolymers of polyvinyl ether, poly (methyl methacrylate), polyvinylidene fluoride (PVdF), polyhexafluoropropylene, polyvinylidene fluoride (trade name: Kynar), poly (ethyl acrylate) Siloxane series such as tetrafluoroethylene polyvinyl chloride, polytetrafluoroethylene, polyacrylonitrile, polyvinylpyridine, polystyrene, carboxymethylcellulose, polydimethylsiloxane, styrene-butadiene rubber, acrylonitrile-butadiene Rubber, a rubber-based binder including a styrene-isoprene rubber, Ethylene glycol type or derivatives thereof, blends thereof, copolymers thereof, and the like can be used, but the present invention is not limited thereto.
상기 바인더는 전극에 포함되는 베이스 조성물 100 중량부 중 1 내지 10 중량부를 구성하도록 하고, 바람직하기로는 5 중량부 내외로 할 수 있다. 만약, 바인더 수지의 함량이 상기 범위 미만이면 양극의 물리적 성질이 저하되어 양극 활물질과 도전재가 탈락할 수 있고, 상기 범위 초과이면 양극에서 활물질과 도전재의 비율이 상대적으로 감소되어 전지 용량이 감소될 수 있으므로 상술한 범위 내에서 적정 함량을 결정하는 것이 바람직하다.The binder may comprise 1 to 10 parts by weight, preferably 5 parts by weight, of 100 parts by weight of the base composition contained in the electrode. If the content of the binder resin is less than the above range, the physical properties of the positive electrode may deteriorate and the positive electrode active material and the conductive material may fall off. If the amount exceeds the above range, the ratio of the active material and the conductive material may be relatively decreased, Therefore, it is desirable to determine the optimum content within the above-mentioned range.
상술한 바와 같이 수산화철(FeOOH) 및 베이스 고형분을 포함하는 양극은 통상의 방법에 따라 제조될 수 있다.As described above, the positive electrode containing the iron hydroxide (FeOOH) and the base solid can be produced by a conventional method.
이를테면, 상기 양극 슬러리 제조 시 먼저 수산화철(FeOOH)을 용매에 분산한 후 얻어진 용액을 활물질, 도전재 및 바인더와 믹싱하여 양극 형성을 위한 슬러리 조성물을 얻는다. 이후 이러한 슬러리 조성물을 집전체 상에 코팅한 후 건조하여 양극을 완성한다. 이때 필요에 따라 전극 밀도의 향상을 위하여 집전체에 압축 성형하여 제조할 수 있다. For example, in the preparation of the positive electrode slurry, firstly, iron hydroxide (FeOOH) is dispersed in a solvent, and the obtained solution is mixed with an active material, a conductive material and a binder to obtain a slurry composition for forming an anode. This slurry composition is then coated on a current collector and dried to complete the anode. At this time, if necessary, it can be manufactured by compression-molding the current collector to improve the electrode density.
이때 상기 용매로는 양극 활물질, 바인더 및 도전재를 균일하게 분산시킬 수 있는 것은 물론, 수산화철(FeOOH)을 용이하게 용해할 수 있는 것을 사용한다. 이러한 용매로는 수계 용매로서 물이 가장 바람직하며, 이때 물은 2차 증류한 DW(Distilled Water), 3차 증류한 DIW(Deionzied Water)일 수 있다. 다만 반드시 이에 한정하는 것은 아니며, 필요한 경우 물과 쉽게 혼합이 가능한 저급 알코올이 사용될 수 있다. 상기 저급 알코올로는 메탄올, 에탄올, 프로판올, 이소프로판올, 및 부탄올 등이 있으며, 바람직하기로 이들은 물과 함께 혼합하여 사용될 수 있다.At this time, as the solvent, a cathode active material, a binder, and a conductive material can be uniformly dispersed and a material capable of easily dissolving iron hydroxide (FeOOH) is used. As such a solvent, water is most preferable as an aqueous solvent, and the water may be distilled water (DW) or deionized water (DIW), which is a third distillation. However, it is not necessarily limited thereto, and if necessary, a lower alcohol which can be easily mixed with water may be used. Examples of the lower alcohol include methanol, ethanol, propanol, isopropanol, butanol, etc., and they can be used in combination with water.
리튬-황 전지Lithium-sulfur battery
한편, 본 발명은On the other hand,
양극, 음극, 이들 사이에 개재된 분리막 및 전해질을 구비하되, 상기 양극은 전술한 바의 양극인 것을 특징으로 하는 리튬-황 전지를 제공한다.The present invention provides a lithium-sulfur battery having an anode, a cathode, a separator interposed therebetween, and an electrolyte, wherein the anode is the anode as described above.
이때 상기 음극, 분리막 및 전해질은 리튬-황 전지에 사용될 수 있는 통상의 물질들로 구성될 수 있다.At this time, the cathode, the separator, and the electrolyte may be composed of conventional materials that can be used in a lithium-sulfur battery.
구체적으로, 상기 음극은 활물질로서 리튬 이온(Li+)을 가역적으로 흡장(Intercalation) 또는 방출(Deintercalation)할 수 있는 물질, 리튬 이온과 반응하여 가역적으로 리튬 함유 화합물을 형성할 수 있는 물질, 리튬 금속 또는 리튬 합금을 사용할 수 있다.Specifically, the negative electrode may include a material capable of reversibly intercalating or deintercalating lithium ions (Li + ) as an active material, a material capable of reversibly forming a lithium-containing compound by reacting with lithium ions, Or a lithium alloy may be used.
상기 리튬 이온(Li+)을 가역적으로 흡장 또는 방출할 수 있는 물질은 이를테면 결정질 탄소, 비정질 탄소 또는 이들의 혼합물일 수 있다. 또한, 상기 리튬 이온(Li+)과 반응하여 가역적으로 리튬 함유 화합물을 형성할 수 있는 물질은 이를테면, 산화주석, 티타늄나이트레이트 또는 실리콘일 수 있다. 또한, 상기 리튬 합금은 예를 들어, 리튬과 Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, Ra, Al 및 Sn으로 이루어지는 군으로부터 선택되는 금속의 합금일 수 있다.The material capable of reversibly storing or releasing lithium ions (Li < + & gt ; ) may be, for example, crystalline carbon, amorphous carbon, or a mixture thereof. The material capable of reacting with the lithium ion (Li + ) to reversibly form a lithium-containing compound may be, for example, tin oxide, titanium nitrate or silicon. The lithium alloy may be, for example, an alloy of lithium and a metal selected from the group consisting of Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, Ra, Al and Sn.
또, 상기 음극은 음극 활물질과 함께 선택적으로 바인더를 더 포함할 수 있다. 상기 바인더는 음극 활물질의 페이스트화, 활물질간 상호 접착, 활물질과 전류 집전체와의 접착, 활물질 팽창 및 수축에 대한 완충 효과 등의 역할을 한다. 구체적으로 상기 바인더는 앞서 설명한 바와 동일하다.The negative electrode may further include a binder optionally in combination with the negative electrode active material. The binder acts as a paste for the anode active material, mutual adhesion between the active materials, adhesion between the active material and the current collector, buffering effect on expansion and contraction of the active material, and the like. Specifically, the binder is the same as described above.
또, 상기 음극은 음극 활물질 및 바인더를 포함하는 음극 활성층의 지지를 위한 전류 집전체를 더 포함할 수도 있다. 상기 전류 집전체는 구체적으로 구리, 알루미늄, 스테인리스스틸, 티타늄, 은, 팔라듐, 니켈, 이들의 합금 및 이들의 조합으로 이루어진 군에서 선택되는 것일 수 있다. 상기 스테인리스스틸은 카본, 니켈, 티탄 또는 은으로 표면 처리될 수 있으며, 상기 합금으로는 알루미늄-카드뮴 합금이 사용될 수 있다. 그 외에도 소성 탄소, 도전제로 표면 처리된 비전도성 고분자, 또는 전도성 고분자 등이 사용될 수도 있다.The negative electrode may further include a current collector for supporting the negative electrode active layer including the negative electrode active material and the binder. The current collector may be specifically selected from the group consisting of copper, aluminum, stainless steel, titanium, silver, palladium, nickel, alloys thereof, and combinations thereof. The stainless steel may be surface-treated with carbon, nickel, titanium or silver, and an aluminum-cadmium alloy may be used as the alloy. In addition, fired carbon, a nonconductive polymer surface treated with a conductive agent, or a conductive polymer may be used.
또, 상기 음극은 리튬금속의 박막일 수도 있다.The negative electrode may be a thin film of lithium metal.
상기 분리막은 양극과 음극을 서로 분리 또는 절연시키면서 이들 사이에 리튬 이온의 수송을 가능하게 하는 물질을 사용하되, 통상 리튬-황 전지에서 분리막으로 사용되는 것이라면 특별한 제한 없이 사용가능하며, 특히 전해질의 이온 이동에 대하여 낮은 저항을 가지면서 전해질 함습 능력이 우수한 것이 바람직하다.The separation membrane is made of a material capable of separating or inserting the positive electrode and the negative electrode from each other while allowing the lithium ion to be transported therebetween, and can be used without any particular limitation as long as it is used as a separation membrane in a lithium-sulfur battery. Particularly, It is preferable that the electrolyte has a low resistance to migration and an excellent ability to hinder the electrolyte.
보다 바람직하기로 상기 분리막 물질로는 다공성이고 비전도성 또는 절연성인 물질을 사용할 수 있으며, 이를테면 필름과 같은 독립적인 부재이거나, 또는 양극 및/또는 음극에 부가된 코팅층을 사용할 수 있다.More preferably, the separation membrane material may be a porous, nonconductive or insulating material, such as an independent member such as a film, or a coating layer added to the anode and / or the cathode.
구체적으로는 다공성 고분자 필름, 예를 들어 에틸렌 단독중합체, 프로필렌 단독중합체, 에틸렌/부텐 공중합체, 에틸렌/헥센 공중합체 및 에틸렌/메타크릴레이트 공중합체 등과 같은 폴리올레핀계 고분자로 제조한 다공성 고분자 필름을 단독으로 또는 이들을 적층하여 사용할 수 있으며, 또는 통상적인 다공성 부직포, 예를 들어 고융점의 유리 섬유, 폴리에틸렌테레프탈레이트 섬유 등으로 된 부직포를 사용할 수 있으나 반드시 이에 한정되는 것은 아니다.Specifically, a porous polymer film made of a polyolefin-based polymer such as an ethylene homopolymer, a propylene homopolymer, an ethylene / butene copolymer, an ethylene / hexene copolymer and an ethylene / methacrylate copolymer may be used alone Or they may be laminated. Alternatively, a nonwoven fabric made of a conventional porous nonwoven fabric, for example, glass fiber of high melting point, polyethylene terephthalate fiber or the like may be used, but not always limited thereto.
상기 전해질은 리튬염을 함유하는 비수계 전해질로서 리튬염과 전해액으로 구성되어 있으며, 전해액으로는 비수계 유기 용매, 유기 고체 전해질 및 무기 고체 전해질 등이 사용된다.The electrolyte is a non-aqueous electrolyte containing a lithium salt, and is composed of a lithium salt and an electrolyte. Non-aqueous organic solvents, organic solid electrolytes, and inorganic solid electrolytes are used as the electrolyte.
상기 리튬염은 비수계 유기 용매에 쉽게 용해될 수 있는 물질로서, 예컨대, LiCl, LiBr, LiI, LiClO4, LiBF4, LiB10Cl10, LiB(Ph)4 , LiPF6, LiCF3SO3, LiCF3CO2, LiAsF6, LiSbF6, LiAlCl4, LiSO3CH3, LiSO3CF3, LiSCN, LiC(CF3SO2)3, LiN(CF3SO2)2, 클로로 보란 리튬, 저급 지방족 카르본산 리튬, 4 페닐 붕산 리튬, 이미드로 이루어진 군으로부터 하나 이상일 수 있다.The lithium salt is a material that can easily be dissolved in non-aqueous organic solvent, for example, LiCl, LiBr, LiI, LiClO 4, LiBF 4, LiB 10 Cl 10, LiB (Ph) 4, LiPF 6, LiCF 3 SO 3, LiCF 3 CO 2, LiAsF 6, LiSbF 6, LiAlCl 4, LiSO 3 CH 3, LiSO 3 CF 3, LiSCN, LiC (CF 3 SO 2) 3, LiN (CF 3 SO 2) 2, chloroborane lithium, lower aliphatic Lithium tetraborate, lithium tetraborate, lithium tetraborate, lithium tetraborate, lithium tetraborate, and imide.
상기 리튬염의 농도는, 전해질 혼합물의 정확한 조성, 염의 용해도, 용해된 염의 전도성, 전지의 충전 및 방전 조건, 작업 온도 및 리튬 배터리 분야에 공지된 다른 요인과 같은 여러 요인에 따라, 0.2 ~ 2M, 바람직하기로 0.6 ~ 2M, 보다 바람직하기로 0.7 ~ 1.7M일 수 있다. 만약, 리튬염의 농도가 상기 범위 미만이면 전해질의 전도도가 낮아져서 전해질 성능이 저하될 수 있고, 상기 범위 초과이면 전해질의 점도가 증가하여 리튬 이온(Li+)의 이동성이 감소될 수 있으므로 상기 범위 내에서 적정 농도를 선택하는 것이 바람직하다.The concentration of the lithium salt may be in the range of 0.2 to 2 M, preferably in the range of 0.2 to 2 M, depending on various factors such as the precise composition of the electrolyte mixture, the solubility of the salt, the conductivity of the dissolved salt, the charging and discharging conditions of the battery, Preferably 0.6 to 2 M, and more preferably 0.7 to 1.7 M. If the concentration of the lithium salt is less than the above range, the conductivity of the electrolyte may be lowered and the performance of the electrolyte may be deteriorated. If the concentration exceeds the above range, the viscosity of the electrolyte may increase and the mobility of lithium ions (Li + ) may decrease. It is preferable to select an appropriate concentration.
상기 비수계 유기 용매는 리튬염을 잘 용해시킬 수 있는 물질로서, 바람직하기로 1,2-디메톡시에탄, 1,2-디에톡시에탄, 1,2-디부톡시에탄, 디옥솔란 (Dioxolane, DOL), 1,4-디옥산, 테트라하이드로퓨란, 2-메틸테트라하이드로퓨란, 디메틸카보네이트(DMC), 디에틸카보네이트(DEC), 에틸메틸카보네이트(EMC), 메틸프로필카보네이트(MPC), 에틸프로필카보네이트, 디프로필카보네이트, 부틸에틸카보네이트, 에틸프로파노에이트(EP), 톨루엔, 자일렌, 디메틸에테르(dimethyl ether, DME), 디에틸에테르, 트리에틸렌글리콜모노메틸에테르(Triethylene glycol monomethyl ether, TEGME), 디글라임, 테트라글라임, 헥사메틸 포스포릭 트리아마이드(hexamethyl phosphoric triamide), 감마부티로락톤(GBL), 아세토니트릴, 프로피오니트릴, 에틸렌카보네이트(EC), 프로필렌카보네이트(PC), N-메틸피롤리돈, 3-메틸-2-옥사졸리돈, 아세트산에스테르, 부티르산에스테르 및 프로피온산에스테르, 디메틸포름아마이드, 설포란(SL), 메틸설포란, 디메틸아세트아마이드, 디메틸설폭사이드, 디메틸설페이트, 에틸렌글리콜 디아세테이트, 디메틸설파이트, 또는 에틸렌글리콜설파이트 등의 비양자성 유기 용매가 사용될 수 있으며, 이들 중 하나 또는 둘 이상의 혼합 용매 형태로 사용될 수 있다.The non-aqueous organic solvent is a substance capable of dissolving a lithium salt well, preferably 1,2-dimethoxyethane, 1,2-diethoxyethane, 1,2-dibutoxyethane, Dioxolane, DOL ), 1,4-dioxane, tetrahydrofuran, 2-methyltetrahydrofuran, dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), methyl propyl carbonate (EP), toluene, xylene, dimethyl ether (DME), diethyl ether, triethylene glycol monomethyl ether (TEGME), dipropyl carbonate, butyl ethyl carbonate, ethyl propanoate Hexamethylphosphoric triamide, gamma butyrolactone (GBL), acetonitrile, propionitrile, ethylene carbonate (EC), propylene carbonate (PC), N-methylpiperazine 3-methyl-2 Dimethyl sulfoxide (SL), methylsulfolane, dimethylacetamide, dimethylsulfoxide, dimethylsulfate, ethylene glycol diacetate, dimethylsulfite, or ethylene glycol monomethyl ether acetate Glycol sulfite and the like can be used, and they can be used in the form of one or two or more of these mixed solvents.
상기 유기 고체 전해질로는 바람직하기로, 폴리에틸렌 유도체, 폴리에틸렌 옥사이드 유도체, 폴리프로필렌 옥사이드 유도체, 인산 에스테르 폴리머, 폴리 에지테이션 리신(Agitation lysine), 폴리에스테르 설파이드, 폴리비닐 알코올, 폴리 불화 비닐리덴, 이온성 해리기를 포함하는 중합체 등이 사용될 수 있다.Preferably, the organic solid electrolyte is selected from the group consisting of a polyethylene derivative, a polyethylene oxide derivative, a polypropylene oxide derivative, a phosphate ester polymer, an agitation lysine, a polyester sulfide, a polyvinyl alcohol, a polyvinylidene fluoride, A polymer including a dissociation group, and the like may be used.
본 발명의 무기 고체 전해질로는 바람직하기로, Li3N, LiI, Li5NI2, Li3N-LiI-LiOH, LiSiO4, LiSiO4-LiI-LiOH, Li2SiS3, Li4SiO4, Li4SiO4-LiI-LiOH, Li3PO4-Li2S-SiS2 등의 Li의 질화물, 할로겐화물, 황산염 등이 사용될 수 있다.The inorganic solid electrolytes of the present invention are preferably Li 3 N, LiI, Li 5 NI 2 , Li 3 N-LiI-LiOH, LiSiO 4 , LiSiO 4 -LiI-LiOH, Li 2 SiS 3 , Li 4 SiO 4 , Li 4 SiO 4 -LiI-LiOH, Li 3 PO 4 -Li 2 S-SiS 2, and the like can be used.
전술한 바의 리튬-황 전지의 형태는 특별히 제한되지 않으며, 예를 들어 젤리-롤형, 스택형, 스택-폴딩형(스택-Z-폴딩형 포함), 또는 라미네이션-스택 형일 수 있으며, 바람직하기로 스택-폴딩형일 수 있다.The shape of the above-described lithium-sulfur battery is not particularly limited and may be, for example, a jelly-roll type, a stack type, a stack-folding type (including a stack-Z-folding type), or a lamination- May be a stack-folding type.
이러한 상기 양극, 분리막, 및 음극이 순차적으로 적층된 전극 조립체를 제조한 후, 이를 전지 케이스에 넣은 다음, 케이스의 상부에 전해액을 주입하고 캡 플레이트 및 가스켓으로 밀봉하여 조립하여 리튬-황 전지를 제조한다.An electrode assembly in which the positive electrode, the separator, and the negative electrode are sequentially stacked is manufactured, and the electrode assembly is inserted into a battery case. Then, an electrolyte is injected into the upper portion of the case, and the assembly is sealed with a cap plate and a gasket. do.
상기 리튬-황 전지는 형태에 따라 원통형, 각형, 코인형, 파우치형 등으로 분류될 수 있으며, 사이즈에 따라 벌크 타입과 박막 타입으로 나눌 수 있다. 이들 전지의 구조와 제조 방법은 이 분야에 널리 알려져 있으므로 상세한 설명은 생략한다.The lithium-sulfur battery may be classified into a cylindrical type, a rectangular type, a coin type, a pouch type, and the like depending on the type, and may be divided into a bulk type and a thin type depending on the size. The structure and the manufacturing method of these cells are well known in the art, and detailed description thereof will be omitted.
전술한 바와 같은 수산화철(FeOOH)의 제조방법에 의해 제조된 수산화철(FeOOH), 예컨대, 결정성 레피도크로사이트(γ-FeOOH)를 리튬-황 전지에 적용할 경우, 리튬-황 전지의 충방전시 용출되는 폴리설파이드를 흡착하여 리튬-황 전지의 반응성이 증가하고, 그것이 적용된 리튬-황 전지는 방전 용량 및 수명 특성이 향상되는 효과를 가진다.When iron hydroxide (FeOOH), for example, crystalline lepidocrocite (γ-FeOOH) produced by the above-described method for producing iron hydroxide (FeOOH) is applied to a lithium-sulfur battery, The reactivity of the lithium-sulfur battery is increased by adsorbing the polysulfide to be eluted, and the lithium-sulfur battery to which the lithium-sulfur battery is applied has the effect of improving the discharge capacity and the life characteristic.
이하에서 실시예 등을 통해 본 발명을 더욱 상세히 설명하고자 하며, 다만 이하에 실시예 등에 의해 본 발명의 범위와 내용이 축소되거나 제한되어 해석될 수 없다. 또한, 이하의 실시예를 포함한 본 발명의 개시 내용에 기초한다면, 구체적으로 실험 결과가 제시되지 않은 본 발명을 통상의 기술자가 용이하게 실시할 수 있음은 명백한 것이며, 이러한 변형 및 수정이 첨부된 특허청구범위에 속하는 것도 당연하다.Hereinafter, the present invention will be described in more detail with reference to Examples and the like, but the scope and content of the present invention can not be construed to be limited or limited by the following Examples. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the present invention as set forth in the following claims. It is natural that it belongs to the claims.
[실시예][Example]
[[ 제조예Manufacturing example 1]  One] 수산화철Iron hydroxide (( FeOOHFeOOH ) 제조) Produce
0.3 M NaBH4 수용액에 0.05 M Fe(NO3)3·9H2O 수용액을 400 rpm 으로 스터링 하면서 50초 동안 혼합하였다. 이때, NaBH4는 TCI社 제품으로서 순도가 > 95%이고, Fe(NO3)3·9H2O 는 Aldrich社 제품으로서 순도가 98% 이다. 0.3 M NaBH 4 Aqueous solution of 0.05 M Fe (NO 3 ) 3 .9H 2 O was mixed for 50 seconds while stirring at 400 rpm. At this time, NaBH 4 is a product of TCI, having a purity of> 95%, and Fe (NO 3 ) 3 .9H 2 O is a product of Aldrich, having a purity of 98%.
혼합 후, 24 ℃에서 40분 동안 반응시키고 여과지를 이용하여 여과한 후, 80 ℃에서 8 시간 동안 건조시켜 수산화철(FeOOH)을 제조하였다.After mixing, the mixture was reacted at 24 ° C for 40 minutes, filtered using a filter paper, and then dried at 80 ° C for 8 hours to prepare iron hydroxide (FeOOH).
[[ 비교제조예Comparative Manufacturing Example 1]  One] 수산화철Iron hydroxide (( FeOOHFeOOH ) 제조) Produce
제조예 1과 동일하게 제조하되, 반응 시간을 12 시간으로 하여 수산화철(FeOOH)을 제조하였다.(FeOOH) was prepared in the same manner as in Preparation Example 1 except that the reaction time was changed to 12 hours.
[[ 비교제조예Comparative Manufacturing Example 2]  2] 레피도크로사이트Lepidocrosite 제조 (한국등록특허 10-0270077) Manufacturing (Korean Patent No. 10-0270077)
농도가 0.8 M/ℓ 인 염화제1철 수용액 40ℓ에 농도가 1.6M/ℓ인 수산화 나트륨 수용액 10ℓ를 첨가하여 수산화 제1철을 제조한 후 25 ℃ 반응온도에서 산화반응을 시켰다. 이때 수산화제1철의 산화속도를 달리하여 종결정 생성반응을 진행시켰다.Ferric hydroxide was prepared by adding 10 L of an aqueous solution of sodium hydroxide having a concentration of 1.6 M / L to 40 L of an aqueous ferrous chloride solution having a concentration of 0.8 M / L, and then subjected to an oxidation reaction at a reaction temperature of 25 ° C. At this time, the seed crystal formation reaction was proceeded at different oxidation rates of the ferrous hydroxide.
수산화 제1철의 산화속도가 0.15 mol/min이하인 경우에는 반응속도가 느려져 괴타이트가 혼입되며 수산화 제1철이 산화되지않은 상태로 슬러지화될수 있으며, 0.4 mol/min이상인 경우에는 빠른 산화반응조건이 되어 성장된 레피도크로사이트가 불안정 입자상으로 형성되며, Fe2 + 및 OH-로 재용해될 수도 있다.When the oxidation rate of ferrous hydroxide is less than 0.15 mol / min, the reaction rate is slowed down and the goethite is incorporated. The ferrous hydroxide can be sludged without being oxidized. If the oxidation rate is more than 0.4 mol / min, The grown lepidocrocite is formed into an unstable particle and may be redissolved as Fe 2 + and OH - .
[[ 실시예Example 1]  One] 수산화철(FeOOH)이Iron hydroxide (FeOOH) 첨가된 양극을 포함한 리튬-황 전지의 제조 Preparation of lithium-sulfur battery with added anode
먼저, 용매로서 물에 제조예 1에서 제조한 수산화철(FeOOH)을 투입할 베이스 고형분(활물질, 도전재 및 바인더)에 베이스 고형분 총 중량(100 중량부) 대비 10 중량부 수산화철(FeOOH)을 투입하여 용해하였다. 이후, 얻어진 용액에 대하여, 베이스 고형분 총 100 중량부, 즉 활물질로 황-탄소 복합체(S/C 7:3)를 90 중량부, 도전재로 덴카블랙을 5 중량부, 바인더로 스티렌 부타디엔 고무/카르복시메틸 셀룰로오스(SBR/CMC 7:3) 5 중량부를 투입하고 믹싱하여 양극 슬러리 조성물을 제조하였다.First, 10 parts by weight of iron hydroxide (FeOOH) was added to the solid base material (active material, conductive material and binder) to which the iron hydroxide (FeOOH) prepared in Production Example 1 was added as a solvent, based on the total solid weight (100 parts by weight) Lt; / RTI > Then, 90 parts by weight of the sulfur-carbon composite (S / C 7: 3) as the active material, 5 parts by weight of the conductive black rode black, and 5 parts by weight of the styrene butadiene rubber / And 5 parts by weight of carboxymethylcellulose (SBR / CMC 7: 3) were added and mixed to prepare a positive electrode slurry composition.
이어서 상기 제조된 슬러리 조성물을 집전체(Al Foil) 상에 코팅하고 50℃ 에서 12시간 동안 건조하여 양극을 제조하였다. 이때 로딩양은 3.5mAh/cm2이고, 전극의 공극률(porosity)은 60%로 하였다.Then, the slurry composition prepared above was coated on a collector (Al Foil) and dried at 50 DEG C for 12 hours to prepare a positive electrode. At this time, the loading amount was 3.5 mAh / cm 2 , and the porosity of the electrode was 60%.
이후 상술한 바에 따라 제조된 양극, 분리막, 음극, 전해액을 포함한 리튬-황 전지의 코인셀을 하기와 같이 제조하였다. 구체적으로, 상기 양극은 14phi 원형 전극으로 타발하여 사용하였으며, 폴리에틸렌(PE) 분리막은 19phi, 150um 리튬 금속은 음극으로서 16phi로 타발하여 사용하였다.Then, the coin cell of the lithium-sulfur battery including the positive electrode, separator, negative electrode and electrolyte prepared according to the above was prepared as follows. Specifically, the anode was used as a 14-phi circular electrode, and a polyethylene (PE) membrane was used at 19 phi and a 150-μm lithium metal was used at 16 phi as a cathode.
[[ 실시예Example 2]  2] 수산화철(FeOOH)이Iron hydroxide (FeOOH) 첨가된 양극을 포함한 리튬-황 전지의 제조 Preparation of lithium-sulfur battery with added anode
수산화철(FeOOH)을 5 중량부 투입한 것을 제외하고는 실시예 1과 동일하게 진행하였다.Except that 5 parts by weight of iron hydroxide (FeOOH) was added.
[[ 비교예Comparative Example 1]  One] 수산화철(FeOOH)이Iron hydroxide (FeOOH) 첨가되지 않은 양극을 포함한 리튬-황 전지의 제조 Preparation of Lithium-sulfur Battery Containing Uncoupled Anode
용매로서 물에 베이스 고형분 총 100 중량부, 즉 활물질로 황-탄소 복합체(S/C 7:3)를 90 중량부, 도전재로 덴카블랙을 5 중량부, 바인더로 스티렌부타디엔 고무/카르복시메틸 셀룰로오스(SBR/CMC 7:3) 5 중량부를 투입하고 믹싱하여 양극 슬러리 조성물을 제조하였다. 90 parts by weight of a sulfur-carbon composite (S / C 7: 3) as an active material, 5 parts by weight of a conductive material rhodenk black as a solvent, and 100 parts by weight of a total amount of base solids in water as a solvent, (SBR / CMC 7: 3) were added and mixed to prepare a positive electrode slurry composition.
이어서 상기 제조된 슬러리 조성물을 집전체(Al Foil) 상에 코팅하고 50℃ 에서 12시간 동안 건조하여 양극을 제조하였다. 이때 로딩양은 3.5mAh/cm2이고, 전극의 공극률(porosity)은 60%로 하였다.Then, the slurry composition prepared above was coated on a collector (Al Foil) and dried at 50 DEG C for 12 hours to prepare a positive electrode. At this time, the loading amount was 3.5 mAh / cm 2 , and the porosity of the electrode was 60%.
이후 상술한 바에 따라 제조된 양극, 분리막, 음극, 전해액을 포함한 리튬-황 전지의 코인셀을 하기와 같이 제조하였다. 구체적으로, 상기 양극은 14phi 원형 전극으로 타발하여 사용하였으며, 폴리에틸렌(PE) 분리막은 19phi, 150um 리튬 금속은 음극으로서 16phi로 타발하여 사용하였다.Then, the coin cell of the lithium-sulfur battery including the positive electrode, separator, negative electrode and electrolyte prepared according to the above was prepared as follows. Specifically, the anode was used as a 14-phi circular electrode, and a polyethylene (PE) membrane was used at 19 phi and a 150-μm lithium metal was used at 16 phi as a cathode.
[[ 비교예Comparative Example 2] γ-  2]? - FeOOHFeOOH /Co가 첨가된 양극을 포함한 리튬-황 전지의 제조/ Preparation of Lithium-sulfur Battery Containing Co
수산화철(FeOOH) 대신 Fe(NO3)3/CoCl2와 NaBH4를 혼합하여 제조한 γ- FeOOH/Co를 사용한 것을 제외하고, 실시예 1과 동일하게 진행하였다.FeOOH / Co prepared by mixing Fe (NO 3 ) 3 / CoCl 2 and NaBH 4 in place of iron hydroxide (FeOOH).
[ 비교예 3] Fe(OH)3 가 첨가된 양극을 포함한 리튬-황 전지의 제조 [ Comparative Example 3] Production of lithium-sulfur battery including a positive electrode to which Fe (OH) 3 was added
수산화철(FeOOH) 대신 Fe(OH)3를 사용한 것을 제외하고, 실시예 1과 동일하게 진행하였다.The procedure of Example 1 was repeated, except that Fe (OH) 3 was used in place of iron hydroxide (FeOOH).
[[ 실험예Experimental Example 1]  One] SEMSEM (scanning electron microscope) 분석(scanning electron microscope) analysis
제조예 1 및 비교제조예 1에서 각각 제조된 수산화철(FeOOH)인 레피도크로사이트에 대하여 SEM 분석(Hitachi社의 S-4800 FE-SEM)을 실시하였다.SEM analysis (S-4800 FE-SEM by Hitachi) was performed on the reversoidal cations, iron hydroxide (FeOOH) prepared in Production Example 1 and Comparative Production Example 1, respectively.
도 1 및 2는 제조예 1 및 비교제조예 1에서 각각 제조된 레피도크로사이트에 대한 SEM 사진이다.1 and 2 are SEM photographs of lepidocrocite prepared in Production Example 1 and Comparative Production Example 1, respectively.
도 1을 참조하면, 배율을 각각 50k 및 100k 로 하여 SEM 분석을 실시한 결과, 반응시간이 40분인 제조예 1의 경우, 수백 nm의 판상형 레피도크로사이트가 관찰되었으나, 반응시간이 12 시간인 비교제조예 1의 경우, 판상형 구조가 대부분 사라진 것으로 나타났다.Referring to FIG. 1, SEM analysis was performed with magnifications of 50 k and 100 k, respectively. As a result, in the case of Production Example 1 in which the reaction time was 40 minutes, plate-shaped lepidocrocites of several hundred nm were observed. In the case of Production Example 1, it was found that the plate-like structure largely disappeared.
[[ 실험예Experimental Example 2]  2] XRDXRD 분석 analysis
제조예 1 및 비교제조예 1에서 각각 제조된 수산화철(FeOOH)인 레피도크로사이트에 대하여 XRD 분석(Bruker社의 D4 Endeavor)을 실시하였다.XRD analysis (D4 Endeavor by Bruker) was performed on the red iron oxide (FeOOH) produced in Production Example 1 and Comparative Production Example 1, respectively.
도 3은 제조예 1 및 비교제조예 1에서 각각 제조된 레피도크로사이트에 대한 XRD 분석결과를 나타낸 그래프이다.FIG. 3 is a graph showing the results of XRD analysis of the lepidocrocite prepared in Production Example 1 and Comparative Production Example 1, respectively.
도 3을 참조하면, 제조예 1에서 순수한 상의 결정성 레피도크로사이트가 제조된 것을 알 수 있다.Referring to FIG. 3, it can be seen that crystalline lepidocrocite of pure phase was prepared in Preparation Example 1.
비교제조예 1의 레피도크로사이트의 경우 XRD 피크가 사라진 것으로 확인되며 이로 인하여 결정성이 대부분 사라진 것을 알 수 있다.In the case of the lepidocrocite of Comparative Production Example 1, it was confirmed that the XRD peak disappeared, and thus, most of the crystallinity disappeared.
[[ 실험예Experimental Example 3] 리튬-황 전지 방전 용량 비교 실험 (1) 3] Comparison of discharge capacity of lithium-sulfur battery (1)
상기 실시예 1 및 2, 비교예 1 내지 3에서 제조한 리튬-황 전지를 이용하여 양극재 종류에 따른 방전 용량을 측정하였다. 실시예 1의 양극은 황-탄소 복합체와 수산화철(FeOOH) 10 중량부를 포함하고, 실시예 2의 양극은 황-탄소 복합체와 수산화철(FeOOH) 5 중량부를 포함한다. 비교예 1의 양극은 황-탄소 복합체를 포함하도록 하였고, 비교예 2의 양극은 황-탄소 복합체와 γ- FeOOH/Co 10 중량부를 포함하도록 하였고, 비교예 3의 양극은 황-탄소 복합체와 Fe(OH)3 10 중량부를 포함하도록 하였 다. 이때, 측정 전류는 0.1C, 전압 범위 1.8 ~ 2.5V로 하였다.The lithium-sulfur battery prepared in Examples 1 and 2 and Comparative Examples 1 to 3 was used to measure the discharge capacity according to the type of cathode material. The positive electrode of Example 1 contains 10 parts by weight of sulfur-carbon composite and iron hydroxide (FeOOH), and the positive electrode of Example 2 contains 5 parts by weight of sulfur-carbon composite and iron hydroxide (FeOOH). The positive electrode of Comparative Example 1 was comprised of a sulfur-carbon composite, and the positive electrode of Comparative Example 2 was composed of a sulfur-carbon composite and 10 parts by weight of gamma-FeOOH / Co. The positive electrode of Comparative Example 3 was composed of a sulfur- And 10 parts by weight of (OH) 3 . At this time, the measurement current was 0.1 C and the voltage range was 1.8 to 2.5 V.
측정된 방전 용량 데이터를 표 1 및 도 8에 제시하였다.The measured discharge capacity data are shown in Table 1 and FIG.
리튬-황 전지Lithium-sulfur battery 방전용량(mAh/g)Discharge capacity (mAh / g)
음극cathode 양극anode
실시예 1Example 1 금속 리튬Metallic lithium 황-탄소 복합체 + 제조예 1의 FeOOH(10 중량부)Sulfur-carbon composite + FeOOH (10 parts by weight) of Production Example 1 12221222
실시예 2Example 2 금속 리튬Metallic lithium 황-탄소 복합체 + 제조예 1의 FeOOH(5 중량부)Sulfur-carbon composite + FeOOH (5 parts by weight) of Production Example 1 11651165
비교예 1Comparative Example 1 금속 리튬Metallic lithium 황-탄소 복합체Sulfur-carbon complex 10731073
비교예 2Comparative Example 2 금속 리튬Metallic lithium 황-탄소 복합체 + γ- FeOOH/Co(10 중량부)Sulfur-carbon composite + γ-FeOOH / Co (10 parts by weight) 11601160
비교예 3Comparative Example 3 금속 리튬Metallic lithium 황-탄소 복합체 + Fe(OH)3(10 중량부)Sulfur-carbon composite + Fe (OH) 3 (10 parts by weight) 11181118
그 결과, 표 1 및 도 8에 나타난 바와 같이, 양극 내 수산화철(FeOOH)을 함유하지 않은 비교예 1 및 γ- FeOOH/Co, Fe(OH)3를 함유한 비교예 2, Fe(OH)3를 함유한 비교예 3에 비하여 수산화철(FeOOH)을 함유한 본 발명의 실시예 1 및 2의 리튬-황 전지에서 초기 방전 용량이 더 높은 것을 확인할 수 있다. 또한 수산화철(FeOOH)을 10 중량부 함유한 실시예 1이 5중량부 함유한 실시예 2에 비해 전지의 방전 용량이 더 증가한 것을 알 수 있었다.As a result, Table 1 and as shown in Fig. 8, the anode within the iron hydroxide (FeOOH) to the Comparative Example 1 and γ- FeOOH / Co, Fe (OH ) Comparative Example 2, Fe (OH) containing 33 that contains The initial discharge capacity of the lithium-sulfur battery of Examples 1 and 2 of the present invention containing iron hydroxide (FeOOH) was higher than that of Comparative Example 3 containing lithium hydroxide (FeOOH). It was also found that the discharge capacity of the battery was further increased as compared with Example 2 containing 5 parts by weight of Example 1 containing 10 parts by weight of iron hydroxide (FeOOH).
[[ 실험예Experimental Example 4] 리튬-황 전지 방전용량 비교 실험 (2) 4] Comparison of discharge capacity of lithium-sulfur battery (2)
양극재 종류에 따른 리튬-황 전지의 방전용량을 실험하기 위하여, 하기 표 2에 기재된 바와 같이 리튬-황 전지의 양극 및 음극을 구성한 후 방전용량을 측정하였다.In order to test the discharge capacity of the lithium-sulfur battery according to the kind of the anode material, the post-discharge capacity of the anode and the cathode of the lithium-sulfur battery was measured as shown in Table 2 below.
비교실험예 (1)의 양극은 황-탄소 복합체, 실험예 (1)의 양극은 황-탄소 복합체와 제조예 1의 수산화철(FeOOH)을 포함하고, 실험예 (2)의 양극은 황-탄소 복합체와 비교제조예 1의 수산화철(FeOOH) 포함하도록 하여, 0.1C 속도로 방전되도록 하여 그 결과를 표 2 및 도 7을 통해 나타내었다.The positive electrode of Experimental Example (1) includes a sulfur-carbon composite, and the positive electrode of Experimental Example (1) contains a sulfur-carbon composite and the iron hydroxide of Production Example 1 (FeOOH) (FeOOH) of Comparative Production Example 1 and discharged at a rate of 0.1 C, and the results are shown in Table 2 and FIG.
리튬-황 전지Lithium-sulfur battery 방전용량(mAh/g)Discharge capacity (mAh / g)
음극cathode 양극anode
비교실험예 (1)Comparative Experimental Example (1) 금속 리튬Metallic lithium 황-탄소 복합체Sulfur-carbon complex 1,1271,127
실험예 (1)Experimental Example (1) 금속 리튬Metallic lithium 황-탄소 복합체 + 제조예 1의 수산화철(FeOOH)Sulfur-carbon composite + iron hydroxide (FeOOH) of Production Example 1 1,2001,200
실험예 (2)Experimental Example (2) 금속 리튬Metallic lithium 황-탄소 복합체 + 비교제조예 1의 수산화철(FeOOH)Sulfur-carbon composite + iron hydroxide (FeOOH) of Comparative Production Example 1 1,1191,119
그 결과, 표 2 및 도 7에 나타난 바와 같이, 실험예 (1)은 비교실험예 1 및 실험예 (2)에 비해 방전용량이 증가한 것을 알 수 있다.As a result, as shown in Table 2 and FIG. 7, it can be seen that the discharge capacity of Experimental Example (1) is increased compared to Comparative Experimental Example 1 and Experimental Example (2).
[[ 실험예Experimental Example 5] 리튬-황 전지 수명 특성 비교 실험 (1) 5] Comparison of life characteristics of lithium-sulfur battery (1)
실시예 1, 실시예 2 및 비교예 1에 따른 리튬-황 전지를 이용하여 전지의 사이클에 따른 방전 용량의 변화 양상 및 90 사이클에서의 충/방전 효율을 측정하였다. 이때 초기 방전/충전은 2.5 사이클 동안은 0.1C/0.1C로 진행하고, 이후부터는 0.5C/0.3C로 진행하였다. 또한 전압 범위는 1.8 ~ 2.5V로 하였다.The lithium-sulfur battery according to Example 1, Example 2, and Comparative Example 1 was used to measure the change pattern of the discharge capacity according to the cycle of the battery and charge / discharge efficiency at 90 cycles. At this time, the initial discharge / charge proceeded to 0.1 C / 0.1 C for 2.5 cycles, and then to 0.5 C / 0.3 C thereafter. The voltage range was set to 1.8 to 2.5V.
전지 사이클의 진행에 따라 측정된 방전 용량 값은 도 10의 그래프로 제시하였다.The discharge capacity values measured in accordance with the progress of the battery cycle are shown in the graph of FIG.
도 10을 참조하면, 양극 내 수산화철(FeOOH)을 함유하지 않은 비교예 1에 비하여 전지 사이클 진행 동안의 방전 용량 감소율이 현저히 작은 것을 알 수 있다. 또한 방전 용량의 저하는 수산화철(FeOOH)을 더욱 함유할 수록 적으며, 비교예 1의 경우 60 사이클부터 전지가 퇴화되나, 실시예 1의 경우 70 사이클 이후부터 전지의 퇴화가 시작되는 것을 확인할 수 있다.Referring to FIG. 10, it can be seen that the discharge capacity reduction rate during the course of the battery cycle is significantly smaller than that of Comparative Example 1 which does not contain iron hydroxide (FeOOH) in the anode. Further, it is confirmed that the decrease of the discharge capacity is smaller as the content of iron hydroxide (FeOOH) is further decreased. In the case of Comparative Example 1, the battery is degenerated from 60 cycles, but in Example 1, the degeneration of the battery starts after 70 cycles .
결과적으로 수산화철(FeOOH)을 함유한 경우 초기 방전 용량값을 잘 유지할 수 있음을 확인할 수 있다.As a result, it can be confirmed that the initial discharge capacity value can be maintained well when containing iron hydroxide (FeOOH).
[[ 실험예Experimental Example 6] 리튬-황 전지 수명 실험 (2) 6] Lithium-sulfur battery life test (2)
양극재 종류에 따른 리튬-황 전지의 수명특성을 실험하기 위하여, 하기 표 3에 기재된 바와 같이 리튬-황 전지의 양극 및 음극을 구성한 후 방전용량을 측정하였다.In order to test the lifetime characteristics of the lithium-sulfur battery according to the kind of the anode material, the anode and anode of the lithium-sulfur battery were constituted as shown in Table 3 below, and the discharge capacity was measured.
비교실험예 (1)의 양극은 황-탄소 복합체, 실험예 (1)의 양극은 황-탄소 복합체와 제조예 1의 수산화철(FeOOH)을 포함하도록 하여, 0.1C 2.5 cycles, 0.2C 3 cycles, 0.3C/0.5C 10 cycles 를 반복하여 수명 특성을 실험하여 그 결과를 표 3 및 도 9에 나타내었다. The positive electrode of Comparative Experiment Example (1) was composed of a sulfur-carbon composite, and the positive electrode of Experimental Example (1) was composed of sulfur-carbon composite material and iron hydroxide of Production Example 1 (FeOOH) 0.3 C / 0.5 C 10 cycles were repeated to evaluate the lifetime characteristics. The results are shown in Table 3 and FIG.
리튬-황 전지Lithium-sulfur battery 방전용량(mAh/g)Discharge capacity (mAh / g) Coulombic Efficiency (%)Coulombic Efficiency (%)
음극cathode 양극anode
비교실험예 (1)Comparative Experimental Example (1) 금속 리튬Metallic lithium 황-탄소 복합체Sulfur-carbon complex 781781 100.29100.29
실험예 (1)Experimental Example (1) 금속 리튬Metallic lithium 황-탄소 복합체 + 제조예 1의 수산화철(FeOOH)Sulfur-carbon composite + iron hydroxide (FeOOH) of Production Example 1 831831 100.23100.23
그 결과, 표 3 및 도 9에 나타난 바와 같이, 비교실험예 (1) 및 실험예 (1) 모두 100 cycles 수명을 나타내며, 실험예 (1)의 경우 비교실험예 (1)에 비해 높은 방전용량을 나타내는 것을 알 수 있다.As a result, as shown in Table 3 and FIG. 9, both of the Comparative Experimental Examples (1) and (1) exhibited 100 cycles life, and in the case of Experimental Example (1) . ≪ / RTI >
또한, 충전용량과 방전용량의 비율을 나타내는 쿨롱 효율(Coulombic Efficiency) 또한 100%로 유지되는 것으로 나타났다. Also, the Coulombic Efficiency, which represents the ratio of the charging capacity to the discharging capacity, is also maintained at 100%.
이와 같은 결과로부터, 제조예 1에서 제조된 수산화철(FeOOH)이 리튬-황 전지의 양극에 첨가되었을 때 방전용량 효과가 우수한 동시에 수명 저해 요소는 없는 것을 확인할 수 있었다. From these results, it was confirmed that when the iron hydroxide (FeOOH) produced in Production Example 1 was added to the positive electrode of the lithium-sulfur battery, the discharge capacity effect was excellent and there was no life span hindrance factor.
[[ 실험예Experimental Example 7]  7] 수산화철(FeOOH)의Of iron hydroxide (FeOOH) 폴리설파이드Polysulfide 흡착능력 실험 Adsorption capacity experiment
상기 제조예 1에서 제조한 수산화철(FeOOH)의 리튬 폴리설파이드 흡착 능력의 자외선(UV, Agilent社의 Agilent 8453 UV-visible spectrophotometer) 흡광도 결과와 육안 비교실험결과를 통해 확인하여, 도 5 및 도 6에 나타내었다.The absorbance of lithium polysulfide adsorbing ability of iron hydroxide (FeOOH) prepared in Preparation Example 1 was confirmed through ultraviolet ray (UV, Agilent 8453 Agilent 8453 UV-visible spectrophotometer) Respectively.
먼저, 도 6에 나타난 것과 같이, 200 ~ 1000nm 파장의 범위에서 수산화철(FeOOH)이 리튬 폴리설파이드를 흡착하여 자외선 흡광도의 세기(intensity)가 줄어든 것을 확인하였다.First, as shown in FIG. 6, it was confirmed that the intensity of ultraviolet absorbance was reduced by adsorbing lithium polysulfide on iron oxide (FeOOH) in a wavelength range of 200 to 1000 nm.
또한, 도 5에 나타난 것과 같이, 리튬 폴리설파이드의 흡착능력을 색도의 변화를 통해 육안으로 확인한 결과, 수산화철(FeOOH)과 반응한 리튬 폴리설파이드(도 5, blank)의 붉은색이 옅어짐을 확인하여, 수산화철(FeOOH)의 리튬 폴리설파이드 흡착 성능이 우수함을 알 수 있었다.As shown in FIG. 5, the adsorption capacity of lithium polysulfide was visually checked through the change of chromaticity. As a result, it was confirmed that the red color of lithium polysulfide (FIG. 5, blank) reacted with iron hydroxide (FeOOH) , And iron hydroxide (FeOOH) were excellent in the adsorption performance of lithium polysulfide.

Claims (22)

  1. Fe(NO3)3·9H2O 또는 FeCl3·6H2O; 및 Fe (NO 3 ) 3 .9H 2 O or FeCl 3 .6H 2 O; And
    하기 화학식 1로 표시되는 환원제;를 혼합하여 반응시키는 단계를 포함하는 수산화철(FeOOH)의 제조방법.And a reducing agent represented by the following formula (1).
    [화학식 1][Chemical Formula 1]
    M1(BH4)X M 1 (BH 4 ) X
    상기 화학식 1에서, M1은 Li, Na, Mg, K 및 Ca 중에서 선택되는 어느 하나이고, X는 1 또는 2이다.In Formula 1, M 1 is any one selected from Li, Na, Mg, K, and Ca, and X is 1 or 2.
  2. 제1항에 있어서,The method according to claim 1,
    상기 Fe(NO3)3·9H2O 또는 FeCl3·6H2O는 0.04 내지 0.08 M의 수용액인 것을 특징으로 하는 수산화철(FeOOH)의 제조방법.Wherein the Fe (NO 3 ) 3 .9H 2 O or FeCl 3 .6H 2 O is an aqueous solution of 0.04 to 0.08 M.
  3. 제1항에 있어서,The method according to claim 1,
    상기 화학식 1로 표시되는 환원제는 0.2 내지 0.5 M의 수용액인 것을 특징으로 하는 수산화철(FeOOH)의 제조방법.Wherein the reducing agent represented by the general formula (1) is an aqueous solution of 0.2 to 0.5 M of iron hydroxide (FeOOH).
  4. 제1항에 있어서,The method according to claim 1,
    상기 혼합은 10 내지 120 초 동안 실시되는 것을 특징으로 하는 수산화철(FeOOH)의 제조방법.Wherein the mixing is carried out for 10 to 120 seconds.
  5. 제1항에 있어서,The method according to claim 1,
    상기 반응 온도는 20 내지 25 ℃인 것을 특징으로 하는 수산화철(FeOOH)의 제조방법.Wherein the reaction temperature is 20 to 25 占 폚.
  6. 제1항에 있어서,The method according to claim 1,
    상기 반응 시간은 10분 내지 10시간인 것을 특징으로 하는 수산화철(FeOOH)의 제조방법.Wherein the reaction time is from 10 minutes to 10 hours.
  7. 제1항에 있어서,The method according to claim 1,
    상기 반응 시간은 40분 내지 2시간인 것을 특징으로 하는 수산화철(FeOOH)의 제조방법.Wherein the reaction time is from 40 minutes to 2 hours.
  8. 제1항에 있어서,The method according to claim 1,
    상기 반응 단계 이후에 여과 및 건조 단계를 더 포함하는 것을 특징으로 하는 수산화철(FeOOH)의 제조방법.Further comprising the step of filtering and drying after the reaction step.
  9. 제8항에 있어서,9. The method of claim 8,
    상기 건조는 70 내지 90 ℃에서 6 내지 12 시간 동안 실시되는 것을 특징으로 하는 수산화철(FeOOH)의 제조방법.Wherein the drying is carried out at 70 to 90 DEG C for 6 to 12 hours.
  10. 제1항에 있어서,The method according to claim 1,
    상기 수산화철(FeOOH)은 레피도크로사이트(γ-FeOOH)인 것을 특징으로 하는 수산화철(FeOOH)의 제조방법.Wherein the iron hydroxide (FeOOH) is lepidocrocite (? -FeuOH).
  11. 제1항에 있어서,The method according to claim 1,
    상기 수산화철(FeOOH)은 결정성인 것을 특징으로 하는 수산화철(FeOOH)의 제조방법.Wherein the iron hydroxide (FeOOH) is crystalline.
  12. 제1항에 있어서,The method according to claim 1,
    상기 수산화철(FeOOH)은 판상형인 것을 특징으로 하는 수산화철(FeOOH)의 제조방법.Wherein the iron hydroxide (FeOOH) is in a plate-like form.
  13. 제1항에 있어서,The method according to claim 1,
    상기 수산화철(FeOOH)은 입경 50 내지 500 nm 인 것을 특징으로 하는 수산화철(FeOOH)의 제조방법.Wherein the iron hydroxide (FeOOH) has a particle diameter of 50 to 500 nm.
  14. 활물질, 도전재 및 바인더를 포함하는 리튬-황 전지용 양극으로서,A positive electrode for a lithium-sulfur battery including an active material, a conductive material and a binder,
    상기 양극은 수산화철(FeOOH)을 포함하는 리튬-황 전지용 양극.Wherein the positive electrode comprises iron hydroxide (FeOOH).
  15. 제14항에 있어서,15. The method of claim 14,
    상기 수산화철(FeOOH)은 레피도크로사이트(γ-FeOOH)인 것을 특징으로 하는 리튬-황 전지용 양극.Wherein the iron hydroxide (FeOOH) is lepidocrocite (? -FeOOH).
  16. 제14항에 있어서,15. The method of claim 14,
    상기 수산화철(FeOOH)은 결정성인 것을 특징으로 하는 리튬-황 전지용 양극.Wherein the iron hydroxide (FeOOH) is crystalline.
  17. 제14항에 있어서,15. The method of claim 14,
    상기 수산화철(FeOOH)은 (200), (210), (301) 및 (020) 면의 XRD 피크가 각각 2θ=14.1±0.1°, 27.0±0.1°, 36.3±0.1° 및 46.9±0.1°에 나타나는 것을 특징으로 하는 리튬-황 전지용 양극.The iron hydroxide (FeOOH) has an XRD peak at (200), (210), (301) and (020) planes of 2θ = 14.1 ± 0.1 °, 27.0 ± 0.1 °, 36.3 ± 0.1 ° and 46.9 ± 0.1 ° Lt; RTI ID = 0.0 > Li-sulfur < / RTI >
  18. 제14항에 있어서,15. The method of claim 14,
    상기 수산화철(FeOOH)은 판상형인 것을 특징으로 하는 리튬-황 전지용 양극.Wherein the iron hydroxide (FeOOH) is a plate-like type.
  19. 제14항에 있어서,15. The method of claim 14,
    상기 수산화철(FeOOH)은 평균 입경이 50 내지 500 nm인 것을 특징으로 하는 리튬-황 전지용 양극.Wherein the iron hydroxide (FeOOH) has an average particle diameter of 50 to 500 nm.
  20. 제14항에 있어서,15. The method of claim 14,
    상기 리튬-황 전지용 양극에 포함되는 수산화철(FeOOH)의 함량은 베이스 고형분 100 중량부 대비 0.1 내지 15 중량부인 것을 특징으로 하는 리튬-황 전지용 양극.Wherein the content of iron hydroxide (FeOOH) in the positive electrode for a lithium-sulfur battery is 0.1 to 15 parts by weight based on 100 parts by weight of a base solid content.
  21. 제14항에 있어서,15. The method of claim 14,
    상기 활물질은 황-탄소 복합체인 것을 특징으로 하는 리튬-황 전지용 양극.Wherein the active material is a sulfur-carbon composite.
  22. 양극, 음극, 이들 사이에 개재된 분리막 및 전해질을 구비하되,An anode, a cathode, a separator interposed therebetween, and an electrolyte,
    상기 양극은 제14항 내지 제21항 중 어느 한 항의 리튬-황 전지용 양극인 리튬-황 전지.The positive electrode is a positive electrode for a lithium-sulfur battery according to any one of claims 14 to 21.
PCT/KR2018/006003 2017-06-20 2018-05-28 Method for preparing iron hydroxide (feooh), and lithium-sulfur battery cathode comprising iron hydroxide WO2018236060A1 (en)

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CN116605916A (en) * 2023-05-31 2023-08-18 湖北虹润高科新材料有限公司 Preparation method of alpha-FeOOH and preparation method of ferric phosphate
CN116605916B (en) * 2023-05-31 2024-02-20 湖北虹润高科新材料有限公司 Preparation method of alpha-FeOOH and preparation method of ferric phosphate

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