WO2015141952A1 - Lithium sulfur battery - Google Patents

Lithium sulfur battery Download PDF

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Publication number
WO2015141952A1
WO2015141952A1 PCT/KR2015/001788 KR2015001788W WO2015141952A1 WO 2015141952 A1 WO2015141952 A1 WO 2015141952A1 KR 2015001788 W KR2015001788 W KR 2015001788W WO 2015141952 A1 WO2015141952 A1 WO 2015141952A1
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Prior art keywords
sulfur battery
lithium sulfur
space forming
active material
positive electrode
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PCT/KR2015/001788
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French (fr)
Korean (ko)
Inventor
김철환
홍영진
정민영
최경린
김병주
박범우
강성환
이기대
Original Assignee
(주)오렌지파워
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Priority claimed from KR1020140092516A external-priority patent/KR20150109240A/en
Application filed by (주)오렌지파워 filed Critical (주)오렌지파워
Publication of WO2015141952A1 publication Critical patent/WO2015141952A1/en

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    • 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
    • H01M4/136—Electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/489—Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
    • H01M50/497—Ionic conductivity
    • 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
    • H01M4/04—Processes of manufacture in general
    • H01M4/0402—Methods of deposition of the material
    • H01M4/0404—Methods of deposition of the material by coating on electrode collectors
    • 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
    • H01M4/139—Processes of manufacture
    • H01M4/1397—Processes of manufacture of electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/362—Composites
    • H01M4/366—Composites as layered products
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • H01M4/581—Chalcogenides or intercalation compounds thereof
    • H01M4/5815—Sulfides
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/624—Electric conductive fillers
    • H01M4/625—Carbon or graphite
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/46—Separators, membranes or diaphragms characterised by their combination with electrodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/489—Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M2004/021—Physical characteristics, e.g. porosity, surface area
    • 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 lithium sulfur battery, and more particularly, to a lithium sulfur battery including a space forming layer formed on one or both surfaces of a positive electrode active material layer to support lithium polysulfide as a discharge product to prevent leakage into an electrolyte.
  • a lithium sulfur battery including a positive electrode.
  • Lithium sulfur batteries are in the spotlight as next generation high capacity battery candidates.
  • Lithium sulfur battery is a galvanic cell using lithium and sulfur-based compounds as an active material and using an electrolyte, and has characteristics of low cost and high energy density (2,600 Wh / kg).
  • the reaction formula at the time of discharge of a lithium sulfur battery is as follows.
  • Lithium sulfur battery uses an oxidation-reduction reaction in which the oxidation rate of S decreases as the SS bond is broken during the reduction reaction (discharge) and the SS bond is formed again as the oxidation number of S increases during the oxidation reaction (charging). Store and generate energy.
  • the dissolution of polysulfide increases the viscosity of the electrolyte, thereby lowering the ionic conductivity.
  • the polysulfide reacts with lithium metal through continuous charge / discharge reaction, when Li 2 S adheres to the surface of the lithium metal, the reaction activity is lowered and dislocation characteristics are decreased. There is a problem that goes bad.
  • elemental sulfur is generally an insulator that is not electrically conductive, and thus an electroconductive material must be used to provide a smooth electrochemical reaction site in order for an electrochemical reaction to occur.
  • sulfur is melted to prevent elution of polysulfide, which is a discharge product, by placing in mesoporous carbon having pores or mesopores of porous activated carbon having a very high surface area, or sulfur and polyacrylonitrile.
  • Efforts have been made to improve the cycle characteristics by producing a composite of sulfur and carbon by reacting at a high temperature, but have not yet achieved satisfactory results.
  • an object of the present invention is to provide a lithium sulfur battery including a positive electrode for a lithium sulfur battery having a new structure capable of preventing elution of polysulfide.
  • the present invention to solve the above problems,
  • a cathode active material layer comprising a cathode active material
  • the cathode active material layer includes a cathode active material, and the cathode active material is selected from the group consisting of elemental sulfur (S 8 ), a sulfur-based compound, and a combination thereof.
  • the space forming layer is a layer capable of providing an empty space for holding the polysulfide in order to prevent the polysulfide generated during charging and discharging of the lithium sulfur battery into the electrolyte. In other words, it serves as a buffer layer.
  • the space forming layer is characterized in that it comprises an average porosity of 10% to 90%.
  • the average porosity can be measured from the following equation.
  • the average porosity means the ratio of the voids in the total volume in the space forming layer, and can be obtained by the above formula using the density of the raw material, the volume of the space forming layer, and the weight of the space forming layer.
  • the space forming layer is characterized by having an electrical conductivity of 10 S / cm or more. Since the space forming layer of the present invention has a high electrical conductivity of 10 S / cm or more, it may serve as a current collector, and therefore, the positive electrode of the present invention does not necessarily need to further include a separate current collector.
  • the space forming layer is characterized in that made of porous carbon.
  • the porous carbon not only provides a space for holding polysulfide through pores, but also forms a conductive network so that the space forming layer is conductive.
  • the space forming layer is carbon black, denka black, ketjen black, acetylene black, activated carbon powder, carbon molecular sieve, carbon nanotube, carbon fiber, activated carbon having fine pores, mesoporous It is characterized by consisting of any one selected from carbon, graphite, carbon paper, carbon felt, carbon cloth and combinations thereof.
  • the carbon fiber refers to a fiber having a carbon content of 90% or more that is produced by carbonizing and graphitizing a carbon precursor such as polyacrylonitrile (PAN), rayon, or pitch at a high temperature of 1500 ° C. or higher.
  • PAN polyacrylonitrile
  • the lithium sulfur battery positive electrode according to the present invention is further characterized by further comprising a mixed layer formed between the positive electrode active material layer and the space forming layer.
  • the mixed layer means a layer in which a positive electrode active material is filled in the space forming layer while the positive electrode active material layer is in contact with the space forming layer.
  • the mixed layer is characterized in that the positive electrode active material concentration gradient in the thickness direction from the positive electrode active material layer to the space forming layer.
  • the positive electrode for lithium sulfur battery it is possible to adjust the thickness and concentration gradient inclination of the mixed layer by the pressure applied when the positive electrode active material is applied or filled to the space forming layer.
  • the positive electrode active material slurry is applied onto the space forming layer, the positive electrode active material slurry is mixed into the space forming layer or when the space forming layer forming material is mixed and applied onto the positive electrode active material layer to the positive electrode active material layer.
  • a mixed layer may be naturally formed.
  • the ratio of the sum of the thicknesses of the mixed layer and the space forming layer with respect to the thickness of the positive electrode active material layer is 1: 0.01 to 1: 0.5. If the sum of the thicknesses of the mixed layer and the space forming layer is 0.01 or less, the effect of confining the lithium polysulfide by the space forming layer is less likely to occur. If the thickness is 0.5 or more, the movement of lithium ions is inhibited to deteriorate battery performance.
  • the positive electrode for a lithium sulfur battery according to the present invention may further include a protective film covering the positive electrode active material layer, the mixed layer, and the space forming layer.
  • the protective film is a film formed on the positive electrode active material layer, the mixed layer, and the space forming layer in order to prevent the polysulfide generated in the positive electrode active material layer from being discharged into the electrolyte during charging and discharging of the lithium sulfur battery.
  • the protective film is not formed only on one surface of the space forming layer, but is formed to cover the surface of the cathode active material layer constituting the anode, the space forming layer formed on one or both surfaces of the cathode active material layer, and the mixed layer.
  • the present invention forms a protective film to cover the front and side surfaces of the positive electrode active material layer, the space forming layer formed on one or both surfaces of the positive electrode active material layer, and the mixed layer.
  • a manufacturing method for forming a protective film is not particularly limited, but dip coating, spin coating, spraying using a solution containing a compound forming a protective film. Spray coating, roll to roll, bar ocating, slot die coating, printing or self-assembled monolayer (SAM) coating may be used.
  • SAM self-assembled monolayer
  • the protective film is characterized by an ionic conductivity of 1 ⁇ 10 ⁇ 6 S / cm or more.
  • the protective film is excellent in ionic conductivity and low electrical resistance can play a role as a separator, the lithium sulfur battery of the present invention does not necessarily need to include a separator between the positive electrode and the negative electrode.
  • the protective film comprises a polymer compound including at least one functional group selected from a carboxyl group, a carboxylate group, a cyan group, a phosphoric acid group, a phosphonate group, a sulfonic acid group, and a sulfonate group. It is characterized by.
  • the functional group selected from the carboxyl group, the carboxylate group, the cyan group, the phosphoric acid group, the phosphonic acid group, the sulfonic acid group, and the sulfonate group included in the high molecular compound forming the protective film may be subjected to poly reactivity with the polysulfide (Electric Repulsion).
  • the elution of sulfide into the electrolyte is suppressed, and the conductivity of lithium ions is improved to facilitate the diffusion of lithium ions in the lithium sulfur battery.
  • polymer compound examples include a fluorine polymer, a benzimidazole polymer, a polyimide polymer, a polyetherimide polymer, a polyphenylene sulfide polymer, a polysulfone polymer, a polyether sulfone polymer, a polyether ketone polymer , Polyether-etherketone-based polymer or polyphenylquinoxaline-based polymer may include one or more selected from poly (perfluorosulfonic acid), poly (perfluorocarboxylic acid), polystyrene sulfonic acid, polystyrene Acids, sulfonated polyethersulfones, sulfonated polyetherketones, sulfonated polyetheretherketones, sulfonated polyarylethersulfones, sulfonated polysulfones, sulfonated polyimides, sulfonated polyphosphazene
  • the protective film is formed on the surface of the positive electrode active material and the space forming layer at a ratio of 0.1 to 5 parts by weight per 100 parts by weight of the positive electrode active material.
  • the protective film has a thickness of 0.1 to 20 ⁇ m.
  • the present invention also provides
  • a positive electrode for a lithium sulfur battery according to the present invention is a positive electrode for a lithium sulfur battery according to the present invention.
  • It provides a lithium sulfur battery comprising an electrolyte.
  • FIGS. 2 to 4 show the structure of a lithium sulfur battery according to the present invention.
  • the conventional lithium sulfur battery includes a current collector 10, a cathode active material layer 20 in which an elemental sulfur or a sulfur-based compound formed on the current collector 10 and a conductive material are mixed, a separator 60, And a cathode 70.
  • the cathode active material layer 200, the space forming layer 400, and the cathode active material layer 200 are formed in the space forming layer ( An anode including a mixed layer 300 formed by filling an anode active material in the space forming layer at a portion in contact with 400; Separator 600; Cathode 700; And an electrolyte.
  • the lithium sulfur battery manufactured according to an exemplary embodiment of the present invention not only effectively prevents the space forming layer from dissolving polysulfide into the electrolyte, but also separates the battery by the electrical conductivity of the space forming layer itself.
  • the space forming layer may serve as a current collector without including the whole.
  • the lithium sulfur battery manufactured according to the embodiment of the present invention shown in FIG. 2 has a completely different structure from the conventional lithium sulfur battery shown in FIG. 1, and may manufacture a lithium sulfur battery having reduced weight or volume. It works.
  • the stacking order and the number of stacking of the cathode active material layer 200 and the space forming layer 400 are not limited. That is, in the lithium sulfur battery manufactured by one embodiment of the present invention, the space forming layer may be formed on one surface or both surfaces of the cathode active material layer as shown in Figure 2 (b) and 2 (c). It may also be formed between the positive electrode active material layer as shown in Figure 2 (d).
  • the positive electrode may further include a separate current collector 100 as shown in FIG.
  • the positive electrode according to the present invention does not necessarily include a current collector by including a space forming layer exhibiting electrical conductivity, but a current collector may be additionally used as desired by a person skilled in the art.
  • the present invention also provides
  • a positive electrode for a lithium sulfur battery according to the present invention is a positive electrode for a lithium sulfur battery according to the present invention.
  • It provides a lithium sulfur battery comprising an electrolyte.
  • the positive electrode may further include a protective film 500.
  • the protective layer 500 should cover all of the front and side surfaces of the cathode active material layer 200, the mixed layer 300, and the space forming layer 400 to effectively prevent the dissolution of lithium polysulfide. Can be.
  • such a protective film not only prevents the dissolution of polysulfide into the electrolyte more effectively, but also can be used as a separator, so that the lithium sulfur battery according to the present invention is shown in FIG. As shown in, it may not include a separate separator between the positive electrode and the negative electrode.
  • the positive electrode when the positive electrode further comprises a protective film 500, the separator 600, the current collector 100 It is possible to include more as needed.
  • the electrolyte used in the lithium sulfur battery of the present invention may include a lithium salt as a supporting electrolyte salt and may include a non-aqueous organic solvent.
  • the organic solvent may be benzene, fluorobenzene, toluene, trifluorotoluene, xylene, cyclohexane, tetrahydrofuran, 2-methyl tetrahydrofuran, cyclohexanone, ethanol, isopropyl alcohol, dimethyl carbonate, ethyl Methyl carbonate, diethyl carbonate, methylpropyl carbonate, methyl propionate, ethyl propionate, methyl acetate, ethyl acetate, propyl acetate, dimethoxyethane, 1,3-dioxolane, diglyme, tetraglyme, ethylene carbonate At least one solvent selected from the group consisting of propylene carbonate, ⁇ -butyrolactone and sulfolane.
  • the electrolytic salt lithium salt is lithium trifluoromethansulfonimide (lithium trifluoromethansulfonimide), lithium triflate (lithium triflate), lithium perchlorate (lithium perclorate), lithium hexafluoro azenate (LiAsF 6 ), lithium trifluor Romethanesulfonate (CF 3 SO 3 Li), LiPF 6 , LiBF 4 or tetraalkylammonium, for example tetrabutylammonium tetrafluoroborate, or a liquid salt at room temperature, for example 1-ethyl-3-methyl
  • imidazolium salts such as imidazolium bis (perfluoroethyl sulfonyl) imide and the like can be used.
  • the electrolyte contains lithium salt at a concentration of 0.5 to 2.0 M.
  • the electrolyte may be used as a liquid electrolyte, or may be used in the form of a solid electrolyte separator.
  • the space forming layer may play a role as a current collector, and a protective film may play a role as a separator, thereby manufacturing a lithium sulfur battery that does not include a current collector and / or a separator.
  • the lithium sulfur battery including the positive electrode for a lithium sulfur battery including the space forming layer according to the present invention prevents the dissolution of polysulfide into the electrolyte by trapping the polysulfide generated during the charge and discharge in the space forming layer to initially charge the lithium sulfur battery. Discharge efficiency and lifespan characteristics can be improved.
  • FIG. 1 shows a schematic diagram of a structure of a conventional lithium sulfur battery.
  • FIGS. 2 to 4 show a schematic view of a lithium sulfur battery produced by one embodiment of the present invention.
  • Figure 5 shows the life characteristics results of the lithium sulfur battery produced by one embodiment of the present invention.
  • Figure 6 shows the results of the rate characteristic of the lithium sulfur battery produced according to an embodiment of the present invention.
  • Figure 9 shows the results of the rate characteristic of the lithium sulfur battery produced according to an embodiment of the present invention.
  • FIG. 10 is a graph showing charge and discharge efficiency measurement results of a lithium sulfur battery manufactured according to an embodiment of the present invention.
  • FIG 11 shows the life characteristics and rate characteristics results of the lithium sulfur battery manufactured according to one embodiment of the present invention.
  • the slurry was coated on an aluminum current collector and then dried in a vacuum oven at 80 ° C. for at least 12 hours.
  • a mixture of 70 wt% Ketjen Black and 30 wt% of polyvinylidene fluoride binder was applied to the dried slurry to a thickness of 50 ⁇ m, followed by drying in a vacuum oven at 80 ° C. for at least 12 hours to form a space forming layer.
  • a positive electrode plate was prepared by forming a mixed layer at an interface where the dried slurry and the mixture meet.
  • a lithium sulfur battery was manufactured using the prepared positive electrode plate and lithium foil negative electrode. At this time, 1 M LiTFSI was dissolved in a solvent in which 1,3-dioxolane and dimethoxyethane were mixed at a ratio of 1: 1.
  • Ketjen black and polyvinylidene fluoride binders were coated on an aluminum current collector to a thickness of 25 ⁇ m, and then dried to form a first space forming layer, and then coated with a cathode active material slurry on the first space forming layer, followed by drying. Thereafter, the lithium sulfur battery was manufactured in the same manner as in Example 1-1 except that the mixture was again coated on the dried active material slurry and then dried to form a second space forming layer.
  • Ketjen black and polyvinylidene fluoride binder were applied to an aluminum current collector to a thickness of 50 ⁇ m, and then dried to form a space forming layer, except that a cathode active material slurry was coated on the space forming layer.
  • a lithium sulfur battery was manufactured in the same manner as in Example 1-1.
  • a lithium sulfur battery was manufactured in the same manner as in Example 1-1 except that only a positive electrode active material slurry was applied on an aluminum current collector.
  • the lithium sulfur battery including the space forming layer of the present invention has excellent capacity and life characteristics.
  • Example 1-1 The C-rate characteristics of the lithium sulfur battery prepared in Example 1-1 and Comparative Example were evaluated and the results are shown in FIG. 6. As shown in Figure 6, the discharge characteristics according to the rate was evaluated to 0.1 C, 0.2 C, 0.5 C, 1.0 C.
  • the charge and discharge efficiency of the comparative example drops to 90% after 40 cycles, while in Examples 1-1 to 1-3, 94% to 98% may be maintained.
  • a lithium sulfur battery was manufactured in the same manner as in Example 1-1 except that 100 ⁇ m thick carbon paper was used instead of the mixture of Ketjen black and polyvinylidene fluoride binder.
  • a lithium sulfur battery was manufactured in the same manner as in Example 2-1, except that the cathode active material slurry was coated on the carbon paper formed on the cathode active material layer once more.
  • a lithium sulfur battery was manufactured in the same manner as in Example 1-3, except that 100 ⁇ m thick carbon paper was used instead of the mixture of Ketjen black and polyvinylidene fluoride binder.
  • the lithium sulfur battery including the space forming layer of the present invention has excellent capacity and life characteristics.
  • the charge and discharge efficiency of the comparative example drops to 88% after 50 cycles, while in Examples 2-1 to 2-3, 94% to 99% may be maintained.
  • a slurry for the positive electrode active material was coated on a 100 ⁇ m thick carbon paper and dried to prepare a positive electrode active material layer formed on the space forming layer.
  • Nafion 117 (DuPont) solution was spray coated to a thickness of 4 ⁇ m to prepare a cathode plate.
  • the Nafion 117 (DuPont) solution was prepared to be a 15 wt% Nafion 117 (DuPont) solution using a mixed solvent of 1-propanol and water.
  • a lithium sulfur battery was manufactured using the positive electrode plate and the lithium foil negative electrode.
  • the space forming layer was arranged in the order of the cathode active material layer-mixed layer-space forming layer
  • 1M LiTFSI was dissolved in 1,3-dioxolane and dimethoxyethane in a ratio of 1: 1 and used.
  • the lithium sulfur battery of the present invention may show excellent life characteristics and rate characteristics.
  • the lithium sulfur battery according to the present invention includes a lithium sulfur battery positive electrode including a space forming layer, thereby trapping polysulfide generated during charging and discharging in the space forming layer to prevent the dissolution of polysulfide into the electrolyte, thereby preventing the initial stage of the lithium sulfur battery.
  • the charging and discharging efficiency and lifespan characteristics can be improved.

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Abstract

The present invention relates to a lithium sulfur battery comprising a positive electrode for a lithium sulfur battery, including a space forming layer and, more specifically, to a lithium sulfur battery comprising a positive electrode for a lithium sulfur battery, in which a space forming layer serves as a buffer layer. In the lithium sulfur battery comprising a positive electrode for a lithium sulfur battery, including a space forming layer according to the present invention, polysulfide generated at the time of charging and discharging is held in the space forming layer to prevent the elution of the polysulfide into an electrolyte, thereby improving the initial charging and discharging efficiency and lifespan characteristics of the lithium sulfur battery, and the space forming layer can be used as a current collector, thereby manufacturing a lithium sulfur battery with a reduced weight or volume.

Description

리튬 설퍼 전지Lithium sulfur battery
본 발명은 리튬 설퍼 전지에 관한 것으로, 보다 상세하게는 양극활물질층의 일면 또는 양면에 형성되어 방전 생성물인 리튬폴리설파이드를 담지하여 전해액으로의 유출을 방지할 수 있는 공간 형성층을 포함하는 리튬 설퍼 전지용 양극을 포함하는 리튬 설퍼 전지에 관한 것이다.The present invention relates to a lithium sulfur battery, and more particularly, to a lithium sulfur battery including a space forming layer formed on one or both surfaces of a positive electrode active material layer to support lithium polysulfide as a discharge product to prevent leakage into an electrolyte. A lithium sulfur battery including a positive electrode.
차세대 고용량 배터리 후보로써 리튬 설퍼 전지가 각광 받고 있다. 리튬 설퍼 전지는 리튬과 황 계열 화합물을 활물질로 하고 전해질을 이용하는 갈바닉셀로서 저가격 및 고에너지밀도(2,600Wh/kg)의 특징을 갖고 있다. 리튬 설퍼 전지의 방전시의 반응식은 아래와 같다.Lithium sulfur batteries are in the spotlight as next generation high capacity battery candidates. Lithium sulfur battery is a galvanic cell using lithium and sulfur-based compounds as an active material and using an electrolyte, and has characteristics of low cost and high energy density (2,600 Wh / kg). The reaction formula at the time of discharge of a lithium sulfur battery is as follows.
음 극: 2Li → 2Li+ + 2e- The negative: 2Li → 2Li + + 2e -
양 극: S + 2e- → S2- Both poles: S + 2e - → S 2-
전체반응: 2Li + S → Li2STotal reaction: 2Li + S → Li 2 S
리튬 설퍼 전지는 환원 반응시(방전시) S-S 결합이 끊어지면서 S의 산화수가 감소하고, 산화 반응시(충전시) S의 산화수가 증가하면서 S-S 결합이 다시 형성되는 산화-환원 반응을 이용하여 전기적 에너지를 저장 및 생성한다.Lithium sulfur battery uses an oxidation-reduction reaction in which the oxidation rate of S decreases as the SS bond is broken during the reduction reaction (discharge) and the SS bond is formed again as the oxidation number of S increases during the oxidation reaction (charging). Store and generate energy.
리튬 설퍼 전지는 방전시, S8 → Li2S8 → Li2S6 → Li2S4 → Li2S3 → Li2S2 → Li2S 의 순서로 방전 생성물이 발생하며, 이 중 리튬폴리설파이드(Li2S8, Li2S6, Li2S4, Li2S3)는 사용되는 액체 전해질에 용해되는 특성을 갖고 있다.When the lithium sulfur battery is discharged, a discharge product is generated in the order of S 8 → Li 2 S 8 → Li 2 S 6 → Li 2 S 4 → Li 2 S 3 → Li 2 S 2 → Li 2 S, among which lithium Polysulfides (Li 2 S 8 , Li 2 S 6 , Li 2 S 4 , Li 2 S 3 ) have the property of dissolving in the liquid electrolyte used.
상기 방전 생성물인 리튬폴리설파이드가 전해질에 용해되어 양극으로부터 이탈하게 되면 리튬 설퍼 전지의 수명 특성이 저하되는 문제가 발생한다. 구체적으로, 황 양극으로부터 폴리설파이드가 용출되어 반대극으로 확산되면 양극의 전기화학 반응 영역을 벗어나므로 양극에서 반응에 참여하는 황의 양이 감소하여 용량 감소(capacity loss)로 나타난다. 또한, 폴리설파이드의 용출은 전해질의 점도를 증가시켜 이온 전도성을 저하시키며, 지속적인 충방전 반응으로 폴리설파이드가 리튬 금속과 반응하여 리튬 금속 표면에 Li2S가 고착되면 반응 활성도가 낮아지고 전위 특성이 나빠지는 문제점이 있다.When the lithium polysulfide, which is the discharge product, is dissolved in the electrolyte and is separated from the positive electrode, a problem occurs in that the life characteristics of the lithium sulfur battery are deteriorated. Specifically, when the polysulfide is eluted from the sulfur anode and diffused to the opposite electrode, it is out of the electrochemical reaction region of the anode, so the amount of sulfur participating in the reaction at the anode decreases, resulting in capacity loss. In addition, the dissolution of polysulfide increases the viscosity of the electrolyte, thereby lowering the ionic conductivity.As the polysulfide reacts with lithium metal through continuous charge / discharge reaction, when Li 2 S adheres to the surface of the lithium metal, the reaction activity is lowered and dislocation characteristics are decreased. There is a problem that goes bad.
또한, 원소 황은 일반적으로 전기 전도성이 없는 부도체이므로 전기화학 반응이 일어나기 위해서는 원활한 전기화학적 반응 사이트를 제공할 수 있는 전기적 도전재를 반드시 사용하여야 한다. In addition, elemental sulfur is generally an insulator that is not electrically conductive, and thus an electroconductive material must be used to provide a smooth electrochemical reaction site in order for an electrochemical reaction to occur.
상기와 같은 문제점을 해결하기 위하여 황을 용융시켜 표면적이 매우 큰 다공성 활성탄의 기공 또는 메조기공을 갖는 메조포러스 탄소에 넣어 방전 생성물인 폴리설파이드의 용출을 방지하려고 하거나 황과 폴리아크릴로니트릴(polyacrylonitrile)을 고온에서 반응시켜 황과 탄소의 복합체(composite)를 제조하여 사이클 특성을 개선하려는 노력이 있어 왔으나 아직까지 만족할 만한 성과를 얻지 못한 실정이다.In order to solve the above problems, sulfur is melted to prevent elution of polysulfide, which is a discharge product, by placing in mesoporous carbon having pores or mesopores of porous activated carbon having a very high surface area, or sulfur and polyacrylonitrile. Efforts have been made to improve the cycle characteristics by producing a composite of sulfur and carbon by reacting at a high temperature, but have not yet achieved satisfactory results.
본 발명은 상기와 같은 과제를 해결하기 위하여 폴리설파이드의 용출을 방지할 수 있는 새로운 구조의 리튬 설퍼 전지용 양극을 포함하는 리튬 설퍼 전지를 제공하는 것을 목적으로 한다.In order to solve the above problems, an object of the present invention is to provide a lithium sulfur battery including a positive electrode for a lithium sulfur battery having a new structure capable of preventing elution of polysulfide.
본 발명은 상기와 같은 과제를 해결하기 위하여,The present invention to solve the above problems,
양극활물질을 포함하는 양극활물질층; A cathode active material layer comprising a cathode active material;
상기 양극활물질층의 일면 또는 양면에 형성된 공간 형성층; 및 A space forming layer formed on one or both surfaces of the cathode active material layer; And
상기 양극활물질층과 공간 형성층 사이에 형성되고, 상기 공간 형성층에 양극활물질이 충진되어 형성되는 혼합층; 을 포함하는 리튬 설퍼 전지용 양극을 제공한다.A mixed layer formed between the cathode active material layer and the space forming layer and filled with the cathode active material in the space forming layer; It provides a positive electrode for a lithium sulfur battery comprising a.
본 발명에 의한 리튬 설퍼 전지용 양극에 있어서, 상기 양극활물질층은 양극활물질을 포함하고, 상기 양극활물질은 원소 황(S8), 황 계열 화합물, 및 이들의 조합으로 이루어진 군에서 선택된 것을 특징으로 한다. 상기 황 계열 화합물은 Li2Sn(n≥1), 유기 황 화합물, 및 탄소-황 폴리머((C2Sx)n: x= 2.5 내지 50, n≥2)로 이루어진 군에서 선택되는 것을 사용할 수 있다.In the cathode for a lithium sulfur battery according to the present invention, the cathode active material layer includes a cathode active material, and the cathode active material is selected from the group consisting of elemental sulfur (S 8 ), a sulfur-based compound, and a combination thereof. . The sulfur-based compound is selected from the group consisting of Li 2 S n (n ≧ 1), an organic sulfur compound, and carbon-sulfur polymer ((C 2 S x ) n : x = 2.5 to 50, n ≥ 2) Can be used.
본 발명에 의한 리튬 설퍼 전지용 양극에 있어서, 상기 공간 형성층은 리튬 설퍼 전지의 충방전시 발생하는 폴리설파이드가 전해질로 용출되는 것을 방지하기 위하여 폴리설파이드를 붙잡아둘 수 있는 빈 공간을 제공할 수 있는 층을 말하며, 버퍼층으로서 기능하게 된다.In the positive electrode for a lithium sulfur battery according to the present invention, the space forming layer is a layer capable of providing an empty space for holding the polysulfide in order to prevent the polysulfide generated during charging and discharging of the lithium sulfur battery into the electrolyte. In other words, it serves as a buffer layer.
본 발명에 의한 리튬 설퍼 전지용 양극에 있어서, 상기 공간 형성층은 10 % 내지 90 %의 평균 기공도를 포함하는 것을 특징으로 한다. In the positive electrode for a lithium sulfur battery according to the present invention, the space forming layer is characterized in that it comprises an average porosity of 10% to 90%.
상기 평균 기공도는 아래의 식으로부터 측정할 수 있다.The average porosity can be measured from the following equation.
평균 기공도(%) = 1-(공간 형성층의 밀도/원료의 밀도)×100 = 1-[(공간 형성층의 중량/공간 형성층의 부피)/ 원료의 밀도]×100Average porosity (%) = 1- (density of raw material / density of raw material) × 100 = 1-[(weight of spatial forming layer / volume of spatial forming layer) / density of raw material] × 100
상기 평균 기공도는 공간 형성층 내에서 공극이 전체 부피에서 차지하는 비율을 의미하는 것으로서, 원료의 밀도, 공간 형성층의 부피, 공간 형성층의 무게를 이용하여 상기 식에 의해 얻을 수 있다.The average porosity means the ratio of the voids in the total volume in the space forming layer, and can be obtained by the above formula using the density of the raw material, the volume of the space forming layer, and the weight of the space forming layer.
본 발명에 의한 리튬 설퍼 전지용 양극에 있어서, 상기 공간 형성층은 전기 전도도가 10 S/cm 이상인 것을 특징으로 한다. 본 발명의 공간 형성층은 전기 전도도가 10 S/cm 이상으로 높기 때문에 집전체로서 역할을 수행할 수 있으며, 따라서 본 발명의 양극은 별도의 집전체를 반드시 더 포함할 필요가 없다. In the positive electrode for lithium sulfur battery according to the present invention, the space forming layer is characterized by having an electrical conductivity of 10 S / cm or more. Since the space forming layer of the present invention has a high electrical conductivity of 10 S / cm or more, it may serve as a current collector, and therefore, the positive electrode of the present invention does not necessarily need to further include a separate current collector.
본 발명에 의한 리튬 설퍼 전지용 양극에 있어서, 상기 공간 형성층은 다공성 탄소로 이루어진 것을 특징으로 한다. 상기 다공성 탄소는 기공을 통해 폴리설파이드를 잡아둘 수 있는 공간을 제공할 뿐 아니라 탄소가 도전성 네트워크를 형성하여 상기 공간 형성층이 도전성을 갖도록 한다.In the positive electrode for lithium sulfur battery according to the present invention, the space forming layer is characterized in that made of porous carbon. The porous carbon not only provides a space for holding polysulfide through pores, but also forms a conductive network so that the space forming layer is conductive.
본 발명에 의한 리튬 설퍼 전지용 양극에 있어서, 상기 공간 형성층은 카본 블랙, 덴카 블랙, 케첸 블랙, 아세틸렌 블랙, 활성 탄소 분말, 탄소분자체, 탄소 나노 튜브, 탄소 섬유, 미세 기공을 갖고 있는 활성탄, 메조포러스 카본, 그래파이트, 카본 페이퍼, 카본 펠트, 카본 클로스 및 이들의 조합에서 선택된 어느 하나로 이루어진 것을 특징으로 한다. 상기 탄소 섬유란 PAN(polyacrylonitrile), 레이온 또는 피치(pitch) 등의 탄소 전구체를 1500 ℃ 이상의 고온에서 탄화와 흑연화 공정을 통하여 만들어지는 탄소 함유율이 90% 이상인 섬유를 의미한다.In the positive electrode for lithium sulfur battery according to the present invention, the space forming layer is carbon black, denka black, ketjen black, acetylene black, activated carbon powder, carbon molecular sieve, carbon nanotube, carbon fiber, activated carbon having fine pores, mesoporous It is characterized by consisting of any one selected from carbon, graphite, carbon paper, carbon felt, carbon cloth and combinations thereof. The carbon fiber refers to a fiber having a carbon content of 90% or more that is produced by carbonizing and graphitizing a carbon precursor such as polyacrylonitrile (PAN), rayon, or pitch at a high temperature of 1500 ° C. or higher.
본 발명에 의한 리튬 설퍼 전지용 양극은, 상기 양극활물질층과 공간형성층 사이에 형성되는 혼합층을 더 포함하는 것을 특징으로 한다. 본 발명에 의한 리튬 설퍼 전지용 양극에 있어서, 상기 혼합층은 양극활물질층과 공간형성층이 접하면서 상기 공간 형성층에 양극활물질이 충진되어 형성되는 층을 의미한다. The lithium sulfur battery positive electrode according to the present invention is further characterized by further comprising a mixed layer formed between the positive electrode active material layer and the space forming layer. In the positive electrode for a lithium sulfur battery according to the present invention, the mixed layer means a layer in which a positive electrode active material is filled in the space forming layer while the positive electrode active material layer is in contact with the space forming layer.
본 발명에 의한 리튬 설퍼 전지용 양극에 있어서, 상기 혼합층은 양극활물질층으로부터 공간 형성층까지 두께방향으로 양극활물질 농도 구배를 나타내는 것을 특징으로 한다.In the positive electrode for lithium sulfur battery according to the present invention, the mixed layer is characterized in that the positive electrode active material concentration gradient in the thickness direction from the positive electrode active material layer to the space forming layer.
본 발명에 의한 리튬 설퍼 전지용 양극에 있어서, 상기 공간 형성층에 양극활물질을 도포 또는 충진시 인가하는 압력 등에 의해 혼합층의 두께 및 농도 구배 기울기를 조정하는 것이 가능하다. 또한 공간 형성층 상에 양극활물질 슬러리를 도포하는 경우 상기 양극활물질 슬러리가 공간 형성층으로 혼입되거나 또는 양극활물질층 상에 공간 형성층 형성 재료를 바인더 등과 혼합하여 도포하는 경우 상기 공간 형성층 형성 재료가 양극활물질층으로 혼입되면서 자연스럽게 혼합층이 형성될 수 있다. In the positive electrode for lithium sulfur battery according to the present invention, it is possible to adjust the thickness and concentration gradient inclination of the mixed layer by the pressure applied when the positive electrode active material is applied or filled to the space forming layer. In addition, when the positive electrode active material slurry is applied onto the space forming layer, the positive electrode active material slurry is mixed into the space forming layer or when the space forming layer forming material is mixed and applied onto the positive electrode active material layer to the positive electrode active material layer. By mixing, a mixed layer may be naturally formed.
본 발명에 의한 리튬 설퍼 전지용 양극에 있어서, 상기 양극활물질층의 두께에 대하여 상기 혼합층 및 공간 형성층의 두께의 합의 비율이 1:0.01 내지 1:0.5 인 것을 특징으로 한다. 상기 혼합층 및 공간 형성층의 두께의 합이 0.01 이하이면 공간 형성층에 의한 리튬폴리설파이드를 가두는 효과가 발생하기 어려우며, 0.5 이상이면 오히려 리튬 이온의 이동을 저해하여 전지 성능을 악화시키게 된다. In the positive electrode for lithium sulfur battery according to the present invention, the ratio of the sum of the thicknesses of the mixed layer and the space forming layer with respect to the thickness of the positive electrode active material layer is 1: 0.01 to 1: 0.5. If the sum of the thicknesses of the mixed layer and the space forming layer is 0.01 or less, the effect of confining the lithium polysulfide by the space forming layer is less likely to occur. If the thickness is 0.5 or more, the movement of lithium ions is inhibited to deteriorate battery performance.
본 발명에 의한 리튬 설퍼 전지용 양극은 상기 양극활물질층, 상기 혼합층 및 상기 공간 형성층을 덮는 보호막을 더 포함하는 것을 특징으로 한다.The positive electrode for a lithium sulfur battery according to the present invention may further include a protective film covering the positive electrode active material layer, the mixed layer, and the space forming layer.
본 발명에 의한 리튬 설퍼 전지용 양극에 있어서 상기 보호막은 리튬 설퍼 전지의 충방전시 양극활물질층에서 발생하는 폴리설파이드가 전해질로 용출되는 것을 방지하기 위하여 양극활물질층, 혼합층 및 공간 형성층 상에 형성되는 막으로, 상기 보호막은 공간 형성층의 일면에만 형성되는 것이 아니라, 양극을 구성하는 양극활물질층, 양극활물질층의 일면 또는 양면에 형성된 공간 형성층, 및 혼합층의 표면을 전부 덮도록 형성되어 있다.In the positive electrode for a lithium sulfur battery according to the present invention, the protective film is a film formed on the positive electrode active material layer, the mixed layer, and the space forming layer in order to prevent the polysulfide generated in the positive electrode active material layer from being discharged into the electrolyte during charging and discharging of the lithium sulfur battery. The protective film is not formed only on one surface of the space forming layer, but is formed to cover the surface of the cathode active material layer constituting the anode, the space forming layer formed on one or both surfaces of the cathode active material layer, and the mixed layer.
일반적인 리튬 이차 전지의 경우에 양극활물질의 결정 구조 내로 리튬 이온이 삽입되고 탈리되는 과정을 거치면서 충전과 방전이 이루어지게 되므로, 음극에 대향하는 양극활물질층의 전면을 통해 리튬 이온이 이동하기 때문에 상기 양극활물질층의 전면 만을 보호막으로 커버하더라도 양극활물질층 보호 효과를 나타낸다. 반면, 리튬 설퍼 전지의 경우 S-S 결합의 형성 및 분해에 의해 충전과 방전이 이루어지게 되고, 특히 방전시 S-S 결합이 끊어지면서 형성되는 폴리설파이드는 전해질로 용해되기 쉬울 뿐만 아니라, 음극에 대향하는 양극활물질층의 전면뿐 아니라 양극활물질층의 측면을 통해서도 전해질로 용출되기 때문에 본 발명의 경우 양극활물질층의 전면 및 측면을 모두 보호막으로 커버하여야만 양극활물질층 보호 효과가 발휘된다. 따라서 본 발명은 양극활물질층, 상기 양극활물질층의 일면 또는 양면에 형성된 공간 형성층, 및 혼합층의 전면 및 측면을 전부 덮도록 보호막을 형성하게 된다.In the case of a general lithium secondary battery, since charging and discharging are performed while lithium ions are inserted into and removed from the crystal structure of the positive electrode active material, lithium ions move through the front surface of the positive electrode active material layer opposite to the negative electrode. Even if only the entire surface of the positive electrode active material layer is covered with a protective film, the positive electrode active material layer has a protective effect. On the other hand, in the case of lithium sulfur batteries, charging and discharging are performed by the formation and decomposition of SS bonds. In particular, polysulfide formed by breaking SS bonds during discharging is not only easy to dissolve into an electrolyte, but also a cathode active material facing the negative electrode. Since the electrolyte is eluted not only through the front surface of the layer but also through the side surface of the positive electrode active material layer, in the case of the present invention, only the front and side surfaces of the positive electrode active material layer should be covered with a protective film to exhibit the positive electrode active material layer protection effect. Accordingly, the present invention forms a protective film to cover the front and side surfaces of the positive electrode active material layer, the space forming layer formed on one or both surfaces of the positive electrode active material layer, and the mixed layer.
본 발명에 의한 리튬 설퍼 전지용 양극에 있어서, 보호막을 형성하기 위한 제조 방법은 특별히 한정되지 않으나, 보호막을 이루는 화합물을 포함하는 용액을 이용하여 딥 코팅(dip coating), 스핀 코팅(spin coating), 분무 코팅(spray coating), 롤투롤(roll to roll), 바 코팅(bar ocating), 슬롯 다이 코팅(slot die coating), 프린팅 방법(printing) 또는 Self-assembled monolayer(SAM) 코팅 방법을 이용할 수 있다.In the positive electrode for a lithium sulfur battery according to the present invention, a manufacturing method for forming a protective film is not particularly limited, but dip coating, spin coating, spraying using a solution containing a compound forming a protective film. Spray coating, roll to roll, bar ocating, slot die coating, printing or self-assembled monolayer (SAM) coating may be used.
본 발명의 리튬 설퍼 전지용 양극에 있어서, 상기 보호막은 이온 전도도가 1 × 10-6 S/cm 이상인 것을 특징으로 한다. 본 발명에 의한 리튬 설퍼 전지용 양극에 있어서, 상기 보호막은 이온 전도도가 우수하고 전기 저항이 낮아 분리막으로서의 역할이 가능하므로 본 발명의 리튬 설퍼 전지는 양극과 음극 사이에 분리막을 반드시 포함할 필요는 없다.In the positive electrode for a lithium sulfur battery of the present invention, the protective film is characterized by an ionic conductivity of 1 × 10 −6 S / cm or more. In the positive electrode for lithium sulfur battery according to the present invention, the protective film is excellent in ionic conductivity and low electrical resistance can play a role as a separator, the lithium sulfur battery of the present invention does not necessarily need to include a separator between the positive electrode and the negative electrode.
본 발명에 의한 리튬 설퍼 전지용 양극에 있어서, 상기 보호막은 카복시기, 카복실레이트기, 시안기, 인산기, 포스포닌산기, 술폰산기, 및 술포네이트기에서 선택된 작용기를 하나 이상 포함하는 고분자 화합물을 포함하는 것을 특징으로 한다. In the positive electrode for a lithium sulfur battery according to the present invention, the protective film comprises a polymer compound including at least one functional group selected from a carboxyl group, a carboxylate group, a cyan group, a phosphoric acid group, a phosphonate group, a sulfonic acid group, and a sulfonate group. It is characterized by.
상기 보호막을 형성하는 고분자 화합물에 포함되는 카복시기, 카복실레이트기, 시안기, 인산기, 포스포닌산기, 술폰산기, 및 술포네이트기에서 선택된 작용기는 폴리설파이드와의 전기적 반발력(Electric Repulsion)을 통해 폴리설파이드가 전해질로 용출되는 것을 억제하고, 리튬 이온의 전도도를 향상시켜 리튬 설퍼 전지에서의 리튬 이온의 확산을 용이하게 한다.The functional group selected from the carboxyl group, the carboxylate group, the cyan group, the phosphoric acid group, the phosphonic acid group, the sulfonic acid group, and the sulfonate group included in the high molecular compound forming the protective film may be subjected to poly reactivity with the polysulfide (Electric Repulsion). The elution of sulfide into the electrolyte is suppressed, and the conductivity of lithium ions is improved to facilitate the diffusion of lithium ions in the lithium sulfur battery.
상기 고분자 화합물의 예로는 플루오르계 고분자, 벤즈이미다졸계 고분자, 폴리이미드계 고분자, 폴리에테르이미드계 고분자, 폴리페닐렌설파이드계 고분자, 폴리술폰계 고분자, 폴리에테르술폰계 고분자, 폴리에테르케톤계 고분자, 폴리에테르-에테르케톤계 고분자 또는 폴리페닐퀴녹살린계 고분자 중에서 선택되는 1종 이상을 포함할 수 있고, 폴리(퍼플루오로술폰산), 폴리(퍼플루오로카르복실산), 폴리스티렌술폰산, 폴리스티렌카르복실산, 술폰화 폴리에테르술폰, 술폰화 폴리에테르케톤, 술폰화 폴리에테르에테르케톤, 술폰화 폴리아릴에테르술폰, 술폰화 폴리술폰, 술폰화 폴리이미드, 술폰화 폴리포스파젠, 술폰화 폴리벤즈이미다졸, 술폰화 폴리아릴렌에테르술폰, 술폰화 폴리페닐렌술피드, 술폰화 폴리비닐알코올, 실란 및 술폰산기를 포함하는 테트라플루오로에틸렌과 플루오로비닐에테르의 공중합체 중에서 선택되는 1종 이상일 수 있으며, 상업적으로 이용 가능한 고분자로 듀폰(du Pont)사의 나피온(Nafion, 등록상표), 아사히 글라스사의 프레미온(등록상표) 또는 아사히 가세이사의 아시플렉스(등록상표)가 있다.Examples of the polymer compound include a fluorine polymer, a benzimidazole polymer, a polyimide polymer, a polyetherimide polymer, a polyphenylene sulfide polymer, a polysulfone polymer, a polyether sulfone polymer, a polyether ketone polymer , Polyether-etherketone-based polymer or polyphenylquinoxaline-based polymer may include one or more selected from poly (perfluorosulfonic acid), poly (perfluorocarboxylic acid), polystyrene sulfonic acid, polystyrene Acids, sulfonated polyethersulfones, sulfonated polyetherketones, sulfonated polyetheretherketones, sulfonated polyarylethersulfones, sulfonated polysulfones, sulfonated polyimides, sulfonated polyphosphazenes, sulfonated polybenziimi Contains dozol, sulfonated polyarylene ether sulfone, sulfonated polyphenylene sulfide, sulfonated polyvinyl alcohol, silane and sulfonic acid groups It may be one or more selected from copolymers of tetrafluoroethylene and fluorovinyl ether, and are commercially available polymers such as Dupont's Nafion (registered trademark) and Asahi Glass's premion (registered) Trademark) or Asiplex Kasei Corporation.
본 발명에 의한 리튬 설퍼 전지용 양극에 있어서, 상기 보호막은 양극활물질 100 중량부 당 0.1 내지 5 중량부의 비율로 상기 양극활물질 및 공간 형성층 표면에 형성되는 것을 특징으로 한다. In the positive electrode for a lithium sulfur battery according to the present invention, the protective film is formed on the surface of the positive electrode active material and the space forming layer at a ratio of 0.1 to 5 parts by weight per 100 parts by weight of the positive electrode active material.
본 발명에 의한 리튬 설퍼 전지용 양극에 있어서, 상기 보호막의 두께는 0.1 내지 20 ㎛ 인 것을 특징으로 한다. In the positive electrode for lithium sulfur battery according to the present invention, the protective film has a thickness of 0.1 to 20 μm.
본 발명은 또한,The present invention also provides
본 발명에 의한 리튬 설퍼 전지용 양극; A positive electrode for a lithium sulfur battery according to the present invention;
음극; cathode;
분리막; 및 Separator; And
전해질;을 포함하는 리튬 설퍼 전지를 제공한다.It provides a lithium sulfur battery comprising an electrolyte.
도 1은 종래 리튬 설퍼 전지의 개략도, 도 2 내지 도 4는 본 발명에 의한 리튬 설퍼 전지의 구조를 나타낸다. 1 is a schematic view of a conventional lithium sulfur battery, and FIGS. 2 to 4 show the structure of a lithium sulfur battery according to the present invention.
도 1에서 보는 바와 같이 종래 리튬 설퍼 전지는 집전체(10), 상기 집전체(10) 상에 형성된 원소 황 또는 황 계열 화합물 및 도전재가 혼합되어 있는 양극활물질층(20), 분리막(60), 및 음극(70)을 포함한다. As shown in FIG. 1, the conventional lithium sulfur battery includes a current collector 10, a cathode active material layer 20 in which an elemental sulfur or a sulfur-based compound formed on the current collector 10 and a conductive material are mixed, a separator 60, And a cathode 70.
이에 비해 본 발명의 일 실시예에 의해 제조된 리튬 설퍼 전지는 도 2(a)에서 보는 바와 같이 양극활물질층(200), 공간 형성층(400) 및 상기 양극활물질층(200)이 상기 공간 형성층(400)과 접하는 부분에 상기 공간 형성층에 양극활물질이 충진되어 형성되는 혼합층(300)을 포함하는 양극; 분리막(600); 음극(700); 및 전해질을 포함하는 것을 특징으로 한다. In contrast, in the lithium sulfur battery manufactured according to the exemplary embodiment of the present invention, as shown in FIG. 2A, the cathode active material layer 200, the space forming layer 400, and the cathode active material layer 200 are formed in the space forming layer ( An anode including a mixed layer 300 formed by filling an anode active material in the space forming layer at a portion in contact with 400; Separator 600; Cathode 700; And an electrolyte.
도 2에서 보는 바와 같이 본 발명의 일 실시예에 의해 제조된 리튬 설퍼 전지는 공간 형성층이 폴리설파이드의 전해질로의 용출을 효과적으로 방지할 수 있을 뿐 아니라, 공간 형성층 자체의 전기전도도에 의해 별도의 집전체를 포함하지 않고, 상기 공간 형성층이 집전체로 작용할 수 있다. 이에 따라 도 2에 나타낸 본 발명의 일 실시예에 의하여 제조된 리튬 설퍼 전지는 도 1에 나타낸 기존의 리튬 설퍼 전지와는 구조가 전혀 다르며, 무게 또는 부피가 감소된 리튬 설퍼 전지를 제조할 수 있는 효과가 있다.As shown in FIG. 2, the lithium sulfur battery manufactured according to an exemplary embodiment of the present invention not only effectively prevents the space forming layer from dissolving polysulfide into the electrolyte, but also separates the battery by the electrical conductivity of the space forming layer itself. The space forming layer may serve as a current collector without including the whole. Accordingly, the lithium sulfur battery manufactured according to the embodiment of the present invention shown in FIG. 2 has a completely different structure from the conventional lithium sulfur battery shown in FIG. 1, and may manufacture a lithium sulfur battery having reduced weight or volume. It works.
본 발명에 의한 리튬 설퍼 전지용 양극에 있어서, 상기 양극활물질층(200) 및 공간 형성층(400)의 적층 순서 및 적층 횟수는 제한되지 않는다. 즉, 본 발명의 일 실시예에 의해 제조된 리튬 설퍼 전지에 있어서, 상기 공간 형성층은 도 2(b) 및 도 2(c)에서 보는 바와 같이 양극활물질층의 일면 또는 양면에 형성될 수 있다. 또한 도 2(d)에서 보는 바와 같이 양극활물질층 사이에 형성되는 것도 가능하다. In the cathode for a lithium sulfur battery according to the present invention, the stacking order and the number of stacking of the cathode active material layer 200 and the space forming layer 400 are not limited. That is, in the lithium sulfur battery manufactured by one embodiment of the present invention, the space forming layer may be formed on one surface or both surfaces of the cathode active material layer as shown in Figure 2 (b) and 2 (c). It may also be formed between the positive electrode active material layer as shown in Figure 2 (d).
본 발명에 의한 리튬 설퍼 전지에 있어서, 상기 양극은 도 3에서 보는 바와 같이 별도의 집전체(100)를 더 포함할 수 있다. 본 발명에 의한 양극은 전기전도도를 나타내는 공간 형성층을 포함함으로써 집전체를 반드시 포함할 필요는 없으나 통상의 기술자가 목적하는 바에 따라 집전체를 추가로 이용할 수 있다.In the lithium sulfur battery according to the present invention, the positive electrode may further include a separate current collector 100 as shown in FIG. The positive electrode according to the present invention does not necessarily include a current collector by including a space forming layer exhibiting electrical conductivity, but a current collector may be additionally used as desired by a person skilled in the art.
본 발명은 또한,The present invention also provides
본 발명에 의한 리튬 설퍼 전지용 양극;A positive electrode for a lithium sulfur battery according to the present invention;
상기 양극을 덮는 보호막; A protective film covering the anode;
음극; 및 cathode; And
전해질;을 포함하는 리튬 설퍼 전지를 제공한다.It provides a lithium sulfur battery comprising an electrolyte.
도 4(a)에서 보는 바와 같이 본 발명에 의한 리튬 설퍼 전지에 있어서, 양극은 보호막(500)을 더 포함할 수 있다. 상기 보호막(500)은 도 4(a)에서 보는 바와 같이 상기 양극활물질층(200), 혼합층(300) 및 공간형성층(400)의 전면 및 측면을 모두 커버하여야 리튬폴리설파이드의 용출을 효과적으로 방지할 수 있다. As shown in FIG. 4A, in the lithium sulfur battery according to the present invention, the positive electrode may further include a protective film 500. As shown in FIG. 4A, the protective layer 500 should cover all of the front and side surfaces of the cathode active material layer 200, the mixed layer 300, and the space forming layer 400 to effectively prevent the dissolution of lithium polysulfide. Can be.
본 발명에 의한 리튬 설퍼 전지에 있어서, 이와 같은 보호막은 폴리설파이드의 전해질로의 용출을 한층 더 효과적으로 방지할 뿐만 아니라, 분리막으로 이용될 수 있어, 본 발명에 의한 리튬 설퍼 전지는 도 4(a)에서 보는 바와 같이 양극과 음극 사이에 별도의 분리막을 포함하지 않을 수 있다. 또한, 도 4(b) 내지 도 4(d) 에서 보는 바와 같이 본 발명에 의한 리튬 설퍼 전지에 있어서, 상기 양극이 보호막(500)을 더 포함하는 경우 분리막(600), 집전체(100)를 필요에 따라 더 포함하는 것이 가능하다. In the lithium sulfur battery according to the present invention, such a protective film not only prevents the dissolution of polysulfide into the electrolyte more effectively, but also can be used as a separator, so that the lithium sulfur battery according to the present invention is shown in FIG. As shown in, it may not include a separate separator between the positive electrode and the negative electrode. In addition, in the lithium sulfur battery according to the present invention as shown in Figure 4 (b) to Figure 4 (d), when the positive electrode further comprises a protective film 500, the separator 600, the current collector 100 It is possible to include more as needed.
본 발명의 리튬 설퍼 전지에 사용되는 전해질은 지지 전해염으로 리튬염을 포함하고, 비수성 유기 용매를 포함할 수 있다. 리튬 설퍼 전지에서 사용되는 전해질의 유기 용매는 적절히 황 원소(S8), 리튬 설파이드(Li2S), 리튬 폴리설파이드(Li2Sn, n = 2, 4, 6, 8...)를 잘 용해시키는 것을 사용한다. 상기 유기 용매로는 벤젠, 플루오로벤젠, 톨루엔, 트리플루오로톨루엔, 자일렌, 사이클로헥산, 테트라하이드로퓨란, 2-메틸 테트라하이드로퓨란, 사이클록헥사논, 에탄올, 이소프로필알콜, 디메틸 카보네이트, 에틸메틸 카보네이트, 디에틸 카보네이트, 메틸프로필 카보네이트, 메틸프로피오네이트, 에틸프로피오네이트, 메틸아세테이트, 에틸 아세테이트, 프로필 아세테이트, 디메톡시에탄, 1,3-디옥솔란, 디글라임, 테트라글라임, 에틸렌 카보네이트, 프로필렌 카보네이트, γ-부티로락톤 및 설포란으로 이루어진 군에서 선택되는 용매를 하나 이상 사용한다.The electrolyte used in the lithium sulfur battery of the present invention may include a lithium salt as a supporting electrolyte salt and may include a non-aqueous organic solvent. The organic solvent of the electrolyte used in the lithium sulfur battery is appropriately selected from elemental sulfur (S 8 ), lithium sulfide (Li 2 S), and lithium polysulfide (Li 2 S n , n = 2, 4, 6, 8 ...). Use something that dissolves well. The organic solvent may be benzene, fluorobenzene, toluene, trifluorotoluene, xylene, cyclohexane, tetrahydrofuran, 2-methyl tetrahydrofuran, cyclohexanone, ethanol, isopropyl alcohol, dimethyl carbonate, ethyl Methyl carbonate, diethyl carbonate, methylpropyl carbonate, methyl propionate, ethyl propionate, methyl acetate, ethyl acetate, propyl acetate, dimethoxyethane, 1,3-dioxolane, diglyme, tetraglyme, ethylene carbonate At least one solvent selected from the group consisting of propylene carbonate, γ-butyrolactone and sulfolane.
상기 전해염인 리튬염으로는 리튬 트리플루오로메탄설폰이미드(lithium trifluoromethansulfonimide), 리튬 트리플레이트(lithium triflate), 리튬 퍼클로레이트(lithium perclorate), 리튬 헥사플루오로아제네이트(LiAsF6), 리튬 트리플루오로메탄설포네이트(CF3SO3Li), LiPF6, LiBF4 또는 테트라알킬암모늄, 예를 들어 테트라부틸암모늄 테트라플루오로보레이트, 또는 상온에서 액상인 염, 예를 들어 1-에틸-3-메틸이미다졸리움 비스(퍼플루오로에틸 설포닐) 이미드와 같은 이미다졸리움 염 등을 하나 이상 사용할 수 있다. 상기 전해질은 리튬염을 0.5 내지 2.0 M의 농도로 포함한다.The electrolytic salt lithium salt is lithium trifluoromethansulfonimide (lithium trifluoromethansulfonimide), lithium triflate (lithium triflate), lithium perchlorate (lithium perclorate), lithium hexafluoro azenate (LiAsF 6 ), lithium trifluor Romethanesulfonate (CF 3 SO 3 Li), LiPF 6 , LiBF 4 or tetraalkylammonium, for example tetrabutylammonium tetrafluoroborate, or a liquid salt at room temperature, for example 1-ethyl-3-methyl One or more imidazolium salts such as imidazolium bis (perfluoroethyl sulfonyl) imide and the like can be used. The electrolyte contains lithium salt at a concentration of 0.5 to 2.0 M.
상기 전해질은 액상 전해질로 사용할 수도 있고, 고체 상태의 전해질 세퍼레이터 형태로도 사용할 수 있다.The electrolyte may be used as a liquid electrolyte, or may be used in the form of a solid electrolyte separator.
본 발명에 의한 리튬 설퍼 전지는 공간 형성층이 집전체로서의 역할을 수행할 수 있고, 보호막이 분리막으로서의 역할을 수행할 수 있어, 집전체 및/또는 분리막을 포함하지 않는 리튬 설퍼 전지의 제조가 가능하다. In the lithium sulfur battery according to the present invention, the space forming layer may play a role as a current collector, and a protective film may play a role as a separator, thereby manufacturing a lithium sulfur battery that does not include a current collector and / or a separator. .
본 발명에 따른 공간 형성층을 포함하는 리튬 설퍼 전지용 양극을 포함하는 리튬 설퍼 전지는 충방전시 발생하는 폴리설파이드를 공간 형성층에 잡아둠으로써 폴리설파이드의 전해질로의 용출을 방지하여 리튬 설퍼 전지의 초기 충방전 효율 및 수명 특성을 향상시킬 수 있다.The lithium sulfur battery including the positive electrode for a lithium sulfur battery including the space forming layer according to the present invention prevents the dissolution of polysulfide into the electrolyte by trapping the polysulfide generated during the charge and discharge in the space forming layer to initially charge the lithium sulfur battery. Discharge efficiency and lifespan characteristics can be improved.
도 1은 종래의 리튬 설퍼 전지의 구조의 개략도를 나타낸다.1 shows a schematic diagram of a structure of a conventional lithium sulfur battery.
도 2 내지 4는 본 발명의 일 실시예에 의해 제조된 리튬 설퍼 전지의 개략도를 나타낸다.2 to 4 show a schematic view of a lithium sulfur battery produced by one embodiment of the present invention.
도 5는 본 발명의 일 실시예에 의하여 제조되는 리튬 설퍼 전지의 수명 특성 결과를 나타낸다. Figure 5 shows the life characteristics results of the lithium sulfur battery produced by one embodiment of the present invention.
도 6은 본 발명의 일 실시예에 의하여 제조되는 리튬 설퍼 전지의 율 특성 결과를 나타낸다. Figure 6 shows the results of the rate characteristic of the lithium sulfur battery produced according to an embodiment of the present invention.
도 7은 본 발명의 일 실시예에 의하여 제조되는 리튬 설퍼 전지의 충방전 효율 측정 결과를 나타낸다. 7 shows the results of measuring charge and discharge efficiency of the lithium sulfur battery manufactured according to one embodiment of the present invention.
도 8은 본 발명의 일 실시예에 의하여 제조되는 리튬 설퍼 전지의 수명 특성 결과를 나타낸다. 8 shows the life characteristics results of the lithium sulfur battery manufactured by one embodiment of the present invention.
도 9는 본 발명의 일 실시예에 의하여 제조되는 리튬 설퍼 전지의 율 특성 결과를 나타낸다. Figure 9 shows the results of the rate characteristic of the lithium sulfur battery produced according to an embodiment of the present invention.
도 10은 본 발명의 일 실시예에 의하여 제조되는 리튬 설퍼 전지의 충방전 효율 측정 결과를 나타낸다. 10 is a graph showing charge and discharge efficiency measurement results of a lithium sulfur battery manufactured according to an embodiment of the present invention.
도 11은 본 발명의 일 실시예에 의하여 제조되는 리튬 설퍼 전지의 수명 특성 및 율 특성 결과를 나타낸다.11 shows the life characteristics and rate characteristics results of the lithium sulfur battery manufactured according to one embodiment of the present invention.
이하에서는 본 발명을 더욱 상세히 설명한다. 그러나 본 발명이 이하의 실시예에 의하여 제한되는 것은 아니다.Hereinafter, the present invention will be described in more detail. However, the present invention is not limited by the following examples.
<실시예 1> 리튬 설퍼 전지의 제조Example 1 Fabrication of Lithium Sulfur Battery
<실시예 1-1><Example 1-1>
황 원소 64 중량%, 담지체로 케첸 블랙 16 중량%, 도전재로 Super-P 10 중량%, 및 바인더로 폴리비닐리덴플루오라이드 10 중량%를 N-메틸피롤리돈 용매에서 혼합하여 리튬 설퍼 전지용 양극활물질 슬러리를 제조하였다. 64% by weight of elemental sulfur, 16% by weight of Ketjen Black as a support, 10% by weight of Super-P as a conductive material, and 10% by weight of polyvinylidene fluoride as a binder in a N-methylpyrrolidone solvent to form a positive electrode for a lithium sulfur battery. An active material slurry was prepared.
상기 슬러리를 알루미늄 전류 집전체 위에 코팅한 후 12 시간 이상 80 ℃ 진공 오븐에서 건조하였다.The slurry was coated on an aluminum current collector and then dried in a vacuum oven at 80 ° C. for at least 12 hours.
상기 건조된 슬러리 위에 케첸 블랙 70 중량%와 폴리비닐리덴플루오라이드 바인더 30 중량 %를 혼합한 혼합물을 50 ㎛ 두께로 도포한 후 12 시간 이상 80 ℃ 진공 오븐에서 건조함으로써 공간 형성층을 형성시킴과 동시에 상기 건조된 슬러리와 상기 혼합물이 만나는 계면에 혼합층을 형성시켜 양극판을 제조하였다.A mixture of 70 wt% Ketjen Black and 30 wt% of polyvinylidene fluoride binder was applied to the dried slurry to a thickness of 50 μm, followed by drying in a vacuum oven at 80 ° C. for at least 12 hours to form a space forming layer. A positive electrode plate was prepared by forming a mixed layer at an interface where the dried slurry and the mixture meet.
상기 제조된 양극판과 리튬 호일 음극을 사용하여 리튬 설퍼 전지를 제조하였다. 이 때 전해질로는 1M LiTFSI 를 1,3-디옥솔란, 디메톡시에탄이 1:1의 비율로 혼합된 용매에 용해시켜 사용하였다.A lithium sulfur battery was manufactured using the prepared positive electrode plate and lithium foil negative electrode. At this time, 1 M LiTFSI was dissolved in a solvent in which 1,3-dioxolane and dimethoxyethane were mixed at a ratio of 1: 1.
<실시예 1-2><Example 1-2>
알루미늄 전류 집전체 위에 케첸 블랙 및 폴리비닐리덴플루오라이드 바인더를 혼합한 혼합물을 25 ㎛ 두께로 도포한 후 건조하여 제 1 공간 형성층을 형성하고, 상기 제 1 공간 형성층 위에 양극활물질 슬러리를 도포한 후 건조한 뒤, 상기 건조된 활물질 슬러리 위에 상기 혼합물을 다시 도포한 후 건조하여 제 2 공간 형성층을 형성한 것을 제외하고는 실시예 1-1과 동일하게 하여 리튬 설퍼 전지를 제조하였다.A mixture of Ketjen black and polyvinylidene fluoride binders was coated on an aluminum current collector to a thickness of 25 μm, and then dried to form a first space forming layer, and then coated with a cathode active material slurry on the first space forming layer, followed by drying. Thereafter, the lithium sulfur battery was manufactured in the same manner as in Example 1-1 except that the mixture was again coated on the dried active material slurry and then dried to form a second space forming layer.
<실시예 1-3> <Example 1-3>
알루미늄 전류 집전체 위에 케첸 블랙 및 폴리비닐리덴플루오라이드 바인더를 혼합한 혼합물을 50 ㎛ 두께로 도포한 후 건조하여 공간 형성층을 형성한 뒤, 상기 공간 형성층 위에 양극활물질 슬러리를 코팅한 것을 제외하고는 실시예 1-1과 동일하게 하여 리튬 설퍼 전지를 제조하였다.A mixture of Ketjen black and polyvinylidene fluoride binder was applied to an aluminum current collector to a thickness of 50 μm, and then dried to form a space forming layer, except that a cathode active material slurry was coated on the space forming layer. A lithium sulfur battery was manufactured in the same manner as in Example 1-1.
<비교예>Comparative Example
알루미늄 전류 집전체 위에 양극활물질 슬러리만을 도포한 것을 제외하고는 실시예 1-1과 동일하게 하여 리튬 설퍼 전지를 제조하였다.A lithium sulfur battery was manufactured in the same manner as in Example 1-1 except that only a positive electrode active material slurry was applied on an aluminum current collector.
<실험예> 전지의 수명 특성 평가Experimental Example Evaluation of Battery Life Characteristics
상기 실시예 1-1 내지 1-3 및 비교예에서 제조된 리튬 설퍼 전지에 대해 수명 특성을 측정하고 그 결과를 도 5에 나타내었다. 충방전 시험은 0.1C로 3 사이클을 수행한 다음, 0.2C로 고정하여 100 사이클 충방전을 수행하였다.The life characteristics of the lithium sulfur batteries prepared in Examples 1-1 to 1-3 and Comparative Examples were measured and the results are shown in FIG. 5. Charge / discharge test was performed three cycles at 0.1C, then fixed to 0.2C to perform 100 cycles charge and discharge.
도 5에서 보는 바와 같이 본 발명의 공간 형성층을 포함하는 리튬 설퍼 전지의 경우 용량 및 수명 특성이 매우 우수한 것을 확인할 수 있다. As shown in FIG. 5, the lithium sulfur battery including the space forming layer of the present invention has excellent capacity and life characteristics.
<실험예> 전지의 C-rate 특성 평가Experimental Example Evaluation of C-rate Characteristics of Battery
상기 실시예 1-1 및 비교예에서 제조된 리튬 설퍼 전지에 대해 C-rate 특성을 평가하고 그 결과를 도 6에 나타내었다. 도 6에서 보는 바와 같이 율속에 따른 방전 특성은 0.1 C, 0.2 C, 0.5 C, 1.0 C로 평가되었다.The C-rate characteristics of the lithium sulfur battery prepared in Example 1-1 and Comparative Example were evaluated and the results are shown in FIG. 6. As shown in Figure 6, the discharge characteristics according to the rate was evaluated to 0.1 C, 0.2 C, 0.5 C, 1.0 C.
<실험예> 전지의 사이클 효율 측정Experimental Example Measuring Cycle Efficiency of a Battery
상기 실시예 1-1 내지 1-3 및 비교예에서 제조된 리튬 설퍼 전지에 대해 사이클 효율을 측정하고 그 결과를 도 7에 나타내었다. Cycle efficiency was measured for the lithium sulfur batteries prepared in Examples 1-1 to 1-3 and Comparative Examples, and the results are shown in FIG. 7.
도 7에서 보는 바와 같이 비교예의 경우 40 사이클 이후 충방전 효율이 90 %로 떨어지는 반면 실시예 1-1 내지 1-3의 경우 94 % 내지 98 %를 유지하는 것을 확인할 수 있다. As shown in FIG. 7, the charge and discharge efficiency of the comparative example drops to 90% after 40 cycles, while in Examples 1-1 to 1-3, 94% to 98% may be maintained.
<실시예 2><Example 2>
<실시예 2-1><Example 2-1>
케첸 블랙 및 폴리비닐리덴플루오라이드 바인더를 혼합한 혼합물 대신 100 ㎛ 두께의 카본 페이퍼를 사용한 것을 제외하고는 실시예 1-1과 동일하게 하여 리튬 설퍼 전지를 제조하였다.A lithium sulfur battery was manufactured in the same manner as in Example 1-1 except that 100 μm thick carbon paper was used instead of the mixture of Ketjen black and polyvinylidene fluoride binder.
<실시예 2-2><Example 2-2>
양극활물질층상에 형성된 카본 페이퍼 상에 양극활물질 슬러리 코팅을 한번 더 수행한 것을 제외하고는 실시예 2-1과 동일하게 하여 리튬 설퍼 전지를 제조하였다.A lithium sulfur battery was manufactured in the same manner as in Example 2-1, except that the cathode active material slurry was coated on the carbon paper formed on the cathode active material layer once more.
<실시예 2-3><Example 2-3>
케첸 블랙 및 폴리비닐리덴플루오라이드 바인더를 혼합한 혼합물 대신 100 ㎛ 두께의 카본 페이퍼를 사용한 것을 제외하고는 실시예 1-3과 동일하게 하여 리튬 설퍼 전지를 제조하였다. A lithium sulfur battery was manufactured in the same manner as in Example 1-3, except that 100 µm thick carbon paper was used instead of the mixture of Ketjen black and polyvinylidene fluoride binder.
<실험예> 전지의 수명 특성 평가Experimental Example Evaluation of Battery Life Characteristics
상기 실시예 2-1 내지 2-3 및 비교예에서 제조된 리튬 설퍼 전지에 대해 수명 특성을 측정하고 그 결과를 도 8에 나타내었다.The life characteristics of the lithium sulfur batteries prepared in Examples 2-1 to 2-3 and Comparative Examples were measured and the results are shown in FIG. 8.
도 8에서 보는 바와 같이 본 발명의 공간 형성층을 포함하는 리튬 설퍼 전지의 경우 용량 및 수명 특성이 매우 우수한 것을 확인할 수 있다. As shown in FIG. 8, the lithium sulfur battery including the space forming layer of the present invention has excellent capacity and life characteristics.
<실험예> 전지의 C-rate 특성 평가Experimental Example Evaluation of C-rate Characteristics of Battery
상기 실시예 2-1 내지 2-3 및 비교예에서 제조된 리튬 설퍼 전지에 대해 C-rate 특성을 평가하고 그 결과를 도 9에 나타내었다.The C-rate characteristics of the lithium sulfur batteries prepared in Examples 2-1 to 2-3 and Comparative Examples were evaluated and the results are shown in FIG. 9.
<실험예> 전지의 사이클 효율 측정Experimental Example Measuring Cycle Efficiency of a Battery
상기 실시예 2-1 내지 2-3 및 비교예에서 제조된 리튬 설퍼 전지에 대해 수명 특성을 측정하고 그 결과를 도 10에 나타내었다. The life characteristics of the lithium sulfur batteries prepared in Examples 2-1 to 2-3 and Comparative Examples were measured and the results are shown in FIG. 10.
도 10에서 보는 바와 같이 비교예의 경우 50 사이클 이후 충방전 효율이 88 %로 떨어지는 반면 실시예 2-1 내지 2-3의 경우 94 % 내지 99 %를 유지하는 것을 확인할 수 있다.As shown in FIG. 10, the charge and discharge efficiency of the comparative example drops to 88% after 50 cycles, while in Examples 2-1 to 2-3, 94% to 99% may be maintained.
<실시예 3><Example 3>
100 ㎛ 두께의 카본 페이퍼 위에 양극활물질용 슬러리를 코팅하고 건조하여 공간 형성층 상에 형성된 양극활물질층을 제조하였다. A slurry for the positive electrode active material was coated on a 100 μm thick carbon paper and dried to prepare a positive electrode active material layer formed on the space forming layer.
상기 양극활물질층, 양극활물질층 상에 형성된 공간 형성층, 및 혼합층에 보호막을 형성시키기 위하여 Nafion117(DuPont사) 용액을 4 ㎛ 두께로 스프레이 코팅하여 양극판을 제조하였다. 상기 Nafion117(DuPont사) 용액은 1-프로판올과 물의 혼합 용매를 사용하여 15 wt% 농도의 Nafion117(DuPont사) 용액이 되도록 제조된 것이다.In order to form a protective film on the cathode active material layer, the space forming layer formed on the cathode active material layer, and the mixed layer, Nafion 117 (DuPont) solution was spray coated to a thickness of 4 μm to prepare a cathode plate. The Nafion 117 (DuPont) solution was prepared to be a 15 wt% Nafion 117 (DuPont) solution using a mixed solvent of 1-propanol and water.
상기 양극판과 리튬 호일 음극을 사용하여 리튬 설퍼 전지를 제조하였다. 이 때 공간 형성층이 음극과 더 가깝게 놓이도록 양극활물질층-혼합층-공간형성층|음극의 순서로 배열되도록 하였다. 전해질로는 1M LiTFSI를 1,3-디옥솔란, 디메톡시에탄에 1:1의 비율로 용해시켜 사용하였다.A lithium sulfur battery was manufactured using the positive electrode plate and the lithium foil negative electrode. At this time, the space forming layer was arranged in the order of the cathode active material layer-mixed layer-space forming layer | cathode so that the space forming layer was closer to the cathode. As an electrolyte, 1M LiTFSI was dissolved in 1,3-dioxolane and dimethoxyethane in a ratio of 1: 1 and used.
<실험예> 전지의 특성 평가Experimental Example Evaluation of Battery Characteristics
상기 실시예 3에서 제조된 리튬 설퍼 전지에 대해 수명 특성 및 율 특성을 측정하고 그 결과를 도 11에 나타내었다.The life characteristics and rate characteristics of the lithium sulfur battery prepared in Example 3 were measured and the results are shown in FIG. 11.
도 11에서 보는 바와 같이 양극 집전체 및 분리막을 추가로 더 포함하지 않더라고 본 발명의 리튬 설퍼 전지는 우수한 수명 특성 및 율 특성을 나타내는 것을 확인할 수 있다.As shown in FIG. 11, even if the cathode current collector and the separator are not further included, the lithium sulfur battery of the present invention may show excellent life characteristics and rate characteristics.
본 발명에 의한 리튬 설퍼 전지는, 공간 형성층을 포함하는 리튬 설퍼 전지용 양극을 포함함으로써 충방전시 발생하는 폴리설파이드를 공간 형성층에 잡아둠으로써 폴리설파이드의 전해질로의 용출을 방지하여 리튬 설퍼 전지의 초기 충방전 효율 및 수명 특성을 향상시킬 수 있다.The lithium sulfur battery according to the present invention includes a lithium sulfur battery positive electrode including a space forming layer, thereby trapping polysulfide generated during charging and discharging in the space forming layer to prevent the dissolution of polysulfide into the electrolyte, thereby preventing the initial stage of the lithium sulfur battery. The charging and discharging efficiency and lifespan characteristics can be improved.

Claims (15)

  1. 양극활물질층; A cathode active material layer;
    상기 양극활물질층의 일면 또는 양면에 형성된 공간 형성층; 및 A space forming layer formed on one or both surfaces of the cathode active material layer; And
    상기 양극활물질층과 공간 형성층 사이에 형성되고, 상기 공간 형성층에 양극활물질이 충진되어 형성되는 혼합층; 을 포함하는 리튬 설퍼 전지용 양극;A mixed layer formed between the cathode active material layer and the space forming layer and filled with the cathode active material in the space forming layer; A lithium sulfur battery positive electrode comprising a;
    음극; cathode;
    전해질; 및 Electrolyte; And
    상기 양극의 양극활물질층, 상기 공간 형성층 및 상기 혼합층을 덮는 보호막; 을 포함하는 리튬 설퍼 전지.A protective film covering the cathode active material layer, the space forming layer, and the mixed layer of the anode; Lithium sulfur battery comprising a.
  2. 제 1 항에 있어서,The method of claim 1,
    상기 양극활물질층은 원소 황(S8), 황 계열 화합물, 및 이들의 조합으로 이루어진 군에서 선택된 양극활물질을 포함하는 것인 리튬 설퍼 전지.The cathode active material layer is a lithium sulfur battery comprising a cathode active material selected from the group consisting of elemental sulfur (S 8 ), sulfur-based compounds, and combinations thereof.
  3. 제 1 항에 있어서,The method of claim 1,
    상기 공간 형성층은 10 % 내지 90 %의 평균 기공도를 포함하는 것인 리튬 설퍼 전지.The space forming layer is a lithium sulfur battery comprising an average porosity of 10% to 90%.
  4. 제 1 항에 있어서,The method of claim 1,
    상기 공간 형성층은 전기 전도도가 10 S/cm 이상인 것을 특징으로 하는 리튬 설퍼 전지.The space forming layer is a lithium sulfur battery, characterized in that the electrical conductivity is 10 S / cm or more.
  5. 제 1 항에 있어서,The method of claim 1,
    상기 공간 형성층은 다공성 탄소로 이루어진 것을 특징으로 하는 리튬 설퍼 전지.The space forming layer is lithium sulfur battery, characterized in that made of porous carbon.
  6. 제 1 항에 있어서,The method of claim 1,
    상기 공간 형성층은 카본 블랙, 덴카 블랙, 케첸 블랙, 아세틸렌 블랙, 활성 탄소 분말, 탄소분자체, 탄소 나노 튜브, 탄소 섬유, 미세 기공을 갖고 있는 활성탄, 메조포러스 카본, 그래파이트, 카본 페이퍼, 카본 펠트, 카본 클로스 및 이들의 조합에서 선택된 어느 하나로 이루어진 것을 특징으로 하는 리튬 설퍼 전지.The space forming layer is carbon black, denka black, ketjen black, acetylene black, activated carbon powder, carbon molecule, carbon nanotube, carbon fiber, activated carbon having fine pores, mesoporous carbon, graphite, carbon paper, carbon felt, carbon Lithium sulfur battery, characterized in that any one selected from cloth and combinations thereof.
  7. 제 1 항에 있어서,The method of claim 1,
    상기 혼합층은 양극활물질의 농도가 양극활물질층으로부터 공간 형성층까지 두께 방향으로 구배를 나타내는 것을 특징으로 하는 리튬 설퍼 전지.The mixed layer is a lithium sulfur battery, characterized in that the concentration of the positive electrode active material gradient in the thickness direction from the positive electrode active material layer to the space forming layer.
  8. 제 1 항에 있어서,The method of claim 1,
    상기 양극활물질층의 두께에 대하여 상기 혼합층 및 공간 형성층의 두께의 합의 비율이 1:0.01 내지 1:0.5 인 것을 특징으로 하는 리튬 설퍼 전지.A ratio of the sum of the thicknesses of the mixed layer and the space forming layer to the thickness of the positive electrode active material layer is 1: 0.01 to 1: 0.5, lithium lithium battery.
  9. 제 1 항에 있어서,The method of claim 1,
    상기 보호막은 이온 전도도가 1 × 10-6 S/cm 이상인 것을 특징으로 하는 리튬 설퍼 전지.The protective film is a lithium sulfur battery, characterized in that the ion conductivity is 1 × 10 -6 S / cm or more.
  10. 제 1 항에 있어서,The method of claim 1,
    상기 보호막은 카복시기, 카복실레이트기, 시안기, 인산기, 포스포닌산기, 술폰산기, 및 술포네이트기로 이루어진 그룹에서 선택된 작용기를 하나 이상 포함하는 고분자 화합물인 리튬 설퍼 전지.The protective film is a lithium sulfur battery which is a high molecular compound comprising at least one functional group selected from the group consisting of carboxyl group, carboxylate group, cyan group, phosphoric acid group, phosphonate group, sulfonic acid group, and sulfonate group.
  11. 제 10 항에 있어서, The method of claim 10,
    상기 고분자 화합물은 폴리(퍼플루오로술폰산), 폴리(퍼플루오로카르복실산), 폴리스티렌술폰산, 폴리스티렌카르복실산, 술폰화 폴리에테르술폰, 술폰화 폴리에테르케톤, 술폰화 폴리에테르에테르케톤, 술폰화 폴리아릴에테르술폰, 술폰화 폴리술폰, 술폰화 폴리이미드, 술폰화 폴리포스파젠, 술폰화 폴리벤즈이미다졸, 술폰화 폴리아릴렌에테르술폰, 술폰화 폴리페닐렌술피드, 술폰화 폴리비닐알코올, 실란, 술폰산기를 포함하는 테트라플루오로에틸렌과 플루오로비닐에테르의 공중합체 및 이들의 조합에서 선택된 것인 리튬 설퍼 전지.The polymer compound may be poly (perfluorosulfonic acid), poly (perfluorocarboxylic acid), polystyrenesulfonic acid, polystyrenecarboxylic acid, sulfonated polyether sulfone, sulfonated polyether ketone, sulfonated polyether ether ketone, Sulfonated polyarylethersulfone, sulfonated polysulfone, sulfonated polyimide, sulfonated polyphosphazene, sulfonated polybenzimidazole, sulfonated polyarylene ether sulfone, sulfonated polyphenylene sulfide, sulfonated polyvinyl alcohol, A silane, a lithium sulfur battery selected from a copolymer of tetrafluoroethylene and fluorovinyl ether containing a sulfonic acid group and a combination thereof.
  12. 제 1 항에 있어서,The method of claim 1,
    상기 보호막은 상기 양극활물질 100 중량부 당 0.1 내지 5 중량부의 비율로 포함하는 것을 특징으로 하는 리튬 설퍼 전지.The protective film is a lithium sulfur battery, characterized in that it comprises a ratio of 0.1 to 5 parts by weight per 100 parts by weight of the positive electrode active material.
  13. 제 1 항에 있어서,The method of claim 1,
    상기 보호막의 두께는 0.1 내지 20 ㎛ 인 것을 특징으로 하는 리튬 설퍼 전지.The thickness of the protective film is a lithium sulfur battery, characterized in that 0.1 to 20 ㎛.
  14. 제 1 항에 있어서,The method of claim 1,
    상기 양극은 집전체를 더 포함하는 것을 특징으로 하는 리튬 설퍼 전지.The positive electrode further comprises a current collector lithium sulfur battery.
  15. 제 1 항 또는 제 14 항에 있어서,The method according to claim 1 or 14,
    상기 양극 및 음극 사이에 분리막을 더 포함하는 것을 특징으로 하는 리튬 설퍼 전지.Lithium sulfur battery, characterized in that it further comprises a separator between the positive electrode and the negative electrode.
PCT/KR2015/001788 2014-03-19 2015-02-25 Lithium sulfur battery WO2015141952A1 (en)

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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105374982A (en) * 2015-12-11 2016-03-02 中国电子科技集团公司第十八研究所 Electrode structure of lithium sulfur battery and processing technology therefor
WO2017053142A1 (en) * 2015-09-25 2017-03-30 Board Of Regents, The University Of Texas System Multi-layer carbon-sulfur cathodes
CN108140899A (en) * 2015-10-14 2018-06-08 株式会社杰士汤浅国际 Non-aqueous electrolyte secondary battery
CN110380051A (en) * 2019-07-05 2019-10-25 合肥国轩高科动力能源有限公司 A kind of lithium ion battery anode glue size and preparation method and based lithium-ion battery positive plate
US10756333B2 (en) 2016-08-10 2020-08-25 Lg Chem, Ltd. Cathode active material comprising polyimide, manufacturing method thereof, and lithium-sulfur battery comprising same

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20050022567A (en) * 2003-08-27 2005-03-08 대한민국 (경상대학교 총장) Lithium/sulfur secondary batteries inserted with graphitic nano fiber membrane
KR20070004670A (en) * 2004-02-06 2007-01-09 폴리플러스 배터리 컴퍼니 Protected active metal electrode and battery cell structures with non-aqueous interlayer architecture
JP2012238448A (en) * 2011-05-11 2012-12-06 Sony Corp Secondary battery, method for manufacturing secondary battery, positive electrode for secondary battery, method for manufacturing positive electrode for secondary battery, battery pack, electronic device, electric vehicle, electrical power system, and power supply for power storage
KR20130119432A (en) * 2010-10-07 2013-10-31 바텔리 메모리얼 인스티튜트 Graphene-sulfur nanocomposites for rechargeable lithium-sulfur battery electrodes
KR101365679B1 (en) * 2012-08-16 2014-02-20 부산대학교 산학협력단 Method for manufacturing positive electrode for lithium-sulfur battery and lithium-sulfur battery

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20050022567A (en) * 2003-08-27 2005-03-08 대한민국 (경상대학교 총장) Lithium/sulfur secondary batteries inserted with graphitic nano fiber membrane
KR20070004670A (en) * 2004-02-06 2007-01-09 폴리플러스 배터리 컴퍼니 Protected active metal electrode and battery cell structures with non-aqueous interlayer architecture
KR20130119432A (en) * 2010-10-07 2013-10-31 바텔리 메모리얼 인스티튜트 Graphene-sulfur nanocomposites for rechargeable lithium-sulfur battery electrodes
JP2012238448A (en) * 2011-05-11 2012-12-06 Sony Corp Secondary battery, method for manufacturing secondary battery, positive electrode for secondary battery, method for manufacturing positive electrode for secondary battery, battery pack, electronic device, electric vehicle, electrical power system, and power supply for power storage
KR101365679B1 (en) * 2012-08-16 2014-02-20 부산대학교 산학협력단 Method for manufacturing positive electrode for lithium-sulfur battery and lithium-sulfur battery

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2017053142A1 (en) * 2015-09-25 2017-03-30 Board Of Regents, The University Of Texas System Multi-layer carbon-sulfur cathodes
CN108140899A (en) * 2015-10-14 2018-06-08 株式会社杰士汤浅国际 Non-aqueous electrolyte secondary battery
EP3364486A4 (en) * 2015-10-14 2019-05-22 GS Yuasa International Ltd. Nonaqueous electrolyte secondary battery
EP3364490A4 (en) * 2015-10-14 2019-06-05 GS Yuasa International Ltd. Nonaqueous electrolyte secondary battery
US10892513B2 (en) 2015-10-14 2021-01-12 Gs Yuasa International Ltd. Nonaqueous electrolyte secondary battery
US11196078B2 (en) 2015-10-14 2021-12-07 Gs Yuasa International, Ltd. Nonaqueous electrolyte secondary battery
CN105374982A (en) * 2015-12-11 2016-03-02 中国电子科技集团公司第十八研究所 Electrode structure of lithium sulfur battery and processing technology therefor
US10756333B2 (en) 2016-08-10 2020-08-25 Lg Chem, Ltd. Cathode active material comprising polyimide, manufacturing method thereof, and lithium-sulfur battery comprising same
CN110380051A (en) * 2019-07-05 2019-10-25 合肥国轩高科动力能源有限公司 A kind of lithium ion battery anode glue size and preparation method and based lithium-ion battery positive plate
CN110380051B (en) * 2019-07-05 2022-05-17 合肥国轩高科动力能源有限公司 Lithium ion battery positive electrode slurry, preparation method thereof and lithium ion battery positive electrode plate

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