WO2017135597A1 - Electrolyte for lithium-sulfur battery and lithium-sulfur battery comprising same - Google Patents

Electrolyte for lithium-sulfur battery and lithium-sulfur battery comprising same Download PDF

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Publication number
WO2017135597A1
WO2017135597A1 PCT/KR2017/000627 KR2017000627W WO2017135597A1 WO 2017135597 A1 WO2017135597 A1 WO 2017135597A1 KR 2017000627 W KR2017000627 W KR 2017000627W WO 2017135597 A1 WO2017135597 A1 WO 2017135597A1
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Prior art keywords
lithium
sulfur battery
electrolyte
nitrate
nitrite
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PCT/KR2017/000627
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French (fr)
Korean (ko)
Inventor
박인태
홍성원
송기석
옥유화
양두경
이창훈
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주식회사 엘지화학
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Priority claimed from KR1020170008309A external-priority patent/KR102050837B1/en
Application filed by 주식회사 엘지화학 filed Critical 주식회사 엘지화학
Priority to US15/758,115 priority Critical patent/US10770754B2/en
Priority to CN201780003228.8A priority patent/CN108028430B/en
Priority to JP2018531285A priority patent/JP6568317B2/en
Priority to EP17747642.1A priority patent/EP3333963B1/en
Publication of WO2017135597A1 publication Critical patent/WO2017135597A1/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
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
    • H01M10/0566—Liquid materials
    • H01M10/0568—Liquid materials characterised by the solutes
    • 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
    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
    • H01M10/0566—Liquid materials
    • H01M10/0569—Liquid materials characterised by the solvents
    • 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 an electrolyte for a lithium-sulfur battery and a lithium-sulfur battery comprising the same.
  • Lithium-sulfur battery is a secondary battery that uses a sulfur-based material having an SS bond (Sulfur-sulfur bond) as a positive electrode active material and a lithium metal as a negative electrode active material.
  • Sulfur the main material of the positive electrode active material, is very rich in resources and toxic. There is no advantage, and it has the advantage of having a low weight per atom.
  • the theoretical discharge capacity of the lithium-sulfur battery is 1672mAh / g-sulfur, and the theoretical energy density is 2,600 Wh / kg.
  • the theoretical energy density of other battery systems currently under investigation (Ni-MH battery: 450 Wh / kg, Li- FeS cells: 480 Wh / kg, Li-MnO 2 batteries: 1,000 Wh / kg, Na-S cells: 800 Wh / kg) is very high compared to the attention has been attracting attention as a battery having a high energy density characteristics.
  • lithium-sulfur batteries have not been commercialized yet due to low sulfur utilization, insufficient capacity is secured as theoretical capacity, and a short circuit problem due to dendrite formation of lithium metal electrodes. Accordingly, in order to overcome the above problems, development of an anode material having an increased sulfur impregnation amount and an electrolyte solution capable of increasing sulfur utilization has been made.
  • a mixed solvent of 1,3-dioxolane (DOL) and 1,2-dimethoxyethane (DME) is most used as an electrolyte solvent of a lithium-sulfur battery.
  • the electrolyte solution using the solvent exhibits excellent properties in terms of sulfur utilization.
  • a swelling phenomenon in which gas was generated inside the battery during operation of the battery to which the electrolyte was applied was inflated was observed. Such swelling not only depletes the electrolyte solution and causes deformation of the battery, but also causes problems such as desorption of the active material from the electrode, thereby degrading battery performance.
  • the present inventors studied the electrolyte solvent composition of the lithium-sulfur battery to solve the above problems, and as a result, the present invention was completed.
  • an object of the present invention to provide an electrolyte for lithium-sulfur batteries that significantly reduces the amount of gas generated during battery operation.
  • Another object of the present invention to provide a lithium-sulfur battery comprising the electrolyte.
  • the non-aqueous solvent is N-aqueous solvent
  • the cyclic ether solvent may be a 5 to 7 membered cyclic ether unsubstituted or substituted with a C1 to C4 alkyl group or an alkoxy group, preferably tetrahydro unsubstituted or substituted with a C1 to C4 alkyl group or alkoxy group It may be furan or tetrahydropyran.
  • R may be methyl, ethyl, propyl, isopropyl, or butyl.
  • the volume ratio of the cyclic ether solvent and the linear ether solvent may be 5:95 to 95: 5, preferably 30:70 to 70:30.
  • the lithium salt is LiCl, LiBr, LiI, LiClO 4 , LiBF 4 , LiB 10 Cl 10 , LiPF 6 , LiCF 3 SO 3 , LiCF 3 CO 2 , LiC 4 BO 8 , LiAsF 6 , LiSbF 6 , LiAlCl 4 , CH 3 SO 3 Li, CF 3 SO 3 Li, (CF 3 SO 2 ) 2 NLi, (C 2 F 5 SO 2 ) 2 NLi, (SO 2 F) 2 NLi, (CF 3 SO 2 ) 3 CLi, Chloro It may be one selected from the group consisting of lithium borane, lower aliphatic lithium carbonate, lithium 4-phenyl borate, lithium imide, and combinations thereof.
  • the electrolyte solution of the present invention may further include an additive having an intramolecular N-O bond.
  • the additive is lithium nitrate, potassium nitrate, cesium nitrate, barium nitrate, ammonium nitrate, lithium nitrite, potassium nitrite, cesium nitrite, ammonium nitrite, methyl nitrate, dialkyl imidazolium nitrate, guanidine nitrate, imida Zolium nitrate, pyridinium nitrate, ethyl nitrite, propyl nitrite, butyl nitrite, pentyl nitrite, octyl nitrite, nitromethane, nitropropane, nitrobutane, nitrobenzene, dinitrobenzene, nitro pyridine, dinitro It may be at least one selected from the group consisting of pyridine, nitrotoluene, dinitrotoluene, pyridine N-oxide, alkylpyridine N-oxide, and
  • the additive may be included in 0.01 to 10% by weight relative to 100% by weight of the electrolyte.
  • the present invention also provides a lithium-sulfur battery comprising the electrolyte solution.
  • the electrolyte solution for a lithium-sulfur battery according to the present invention has excellent stability and significantly reduces gas generation during battery operation. Thus, the swelling phenomenon of the battery can be improved.
  • FIG. 1 is a graph of gas generation amount in Experimental Example 1.
  • FIG. 2 is a graph comparing battery life characteristics of Experimental Example 2.
  • a cyclic ether containing one oxygen in the molecular structure as an electrolyte solvent and represented by the formula It provides an electrolyte solution for lithium-sulfur battery containing a linear ether.
  • R is a C1 to C6 alkyl group or a C6 to C12 aryl group
  • x 1 or 2)
  • DOL 1,3-dioxolane
  • DME 1,2-dimethoxyethane
  • the electrolyte solution using the mixed solvent shows excellent performance in terms of suppression of battery capacity reduction, battery life, and battery efficiency when applied to small batteries, but when applied to large batteries such as large-area pouch cells, hydrogen and methane are A significant amount of gas, such as, ethene, is generated, and swelling of the battery is observed.
  • the electrolyte of the present invention exhibits improved stability by including the cyclic ether and linear ether solvent in a specific content ratio, and when applied to a lithium-sulfur battery, hydrogen when driving the battery
  • the amount of back gas generated is significantly reduced.
  • the electrolyte solution of the present invention when applied to a lithium-sulfur battery, has a gas generation amount of 300 ⁇ L or less, preferably 100 ⁇ L or less, measured after the battery is driven. In this case, the smaller the value, the smaller the amount of gas generation.
  • the reduction in the amount of gas generated is a value that does not significantly affect the battery stability even if the swelling phenomenon that the battery is hardly generated or occurs.
  • the gas generation amount is significantly lower when using the electrolyte solution proposed in the present invention, thereby increasing battery stability.
  • the problem of deterioration of battery performance due to swelling and deterioration of quality due to battery deformation may be overcome.
  • the alkyl group of C1 to C6 referred to herein is, for example, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group or an isomer thereof.
  • isomers include both structural isomers having the same carbon number but different bond relationships of carbons, and stereoisomers having different geometrical positions of the bonds.
  • C6 to C12 aryl group referred to herein may be, for example, a phenyl group unsubstituted or substituted with a C1 to C6 alkyl group, or a naphthyl group.
  • the cyclic ether containing one oxygen in the molecular structure is a 5 or more membered cyclic ether unsubstituted or substituted with an alkyl group, preferably a 5 to 7 membered ring unsubstituted or substituted with a C1 to C4 alkyl group or an alkoxy group. It is a type ether, More preferably, they are tetrahydrofuran or tetrahydropyran unsubstituted or substituted by the C1-C4 alkyl group or the alkoxy group.
  • tetrahydrofuran 2-methyltetrahydrofuran, 3-methyltetrahydrofuran, 2,3-dimethyltetrahydrofuran, 2,4-dimethyltetrahydrofuran, 2,5-dimethyltetrahydrofuran , 2-methoxytetrahydrofuran, 3-methoxytetrahydrofuran, 2-ethoxytetrahydrofuran, 3-ethoxytetrahydrofuran, tetrahydropyran, 2-methyltetrahydropyran, 3-methyltetrahydropyran , 4-methyltetrahydropyran, and the like.
  • the cyclic ether has a low viscosity, good ion mobility, and high redox stability, thus showing high stability even for long-term operation of the battery.
  • the linear ether is an ethylene glycol derivative, and has a structure in which ethylene glycol or diethylene glycol is a basic skeleton and an ethyl group is linked to an ether bond at one end thereof.
  • R is methyl, ethyl, propyl, isopropyl, or butyl.
  • the linear ether appears to have at least one ethoxy group which contributes to electrolyte stability during battery operation.
  • the volume ratio of the cyclic ether and the linear ether is 5:95 to 95: 5, preferably 30:70 to 70:30. If it is out of the above range, the gas generation suppression effect during driving of the battery is insignificant, so that the desired effect cannot be obtained.
  • the electrolyte of the present invention includes a lithium salt added to the electrolyte to increase the ionic conductivity.
  • the lithium salt is not particularly limited in the present invention, and may be used without limitation as long as it is commonly used in a lithium secondary battery.
  • the lithium salt is LiCl, LiBr, LiI, LiClO 4 , LiBF 4 , LiB 10 Cl 10 , LiPF 6 , LiCF 3 SO 3 , LiCF 3 CO 2 , LiC 4 BO 8 , LiAsF 6 , LiSbF 6 , LiAlCl 4 , CH 3 SO 3 Li, CF 3 SO 3 Li, (CF 3 SO 2 ) 2 NLi, (C 2 F 5 SO 2 ) 2 NLi, (SO 2 F) 2 NLi, (CF 3 SO 2 ) 3 CLi,
  • One selected from the group consisting of lithium chloroborane, lower aliphatic lithium carbonate, lithium phenyl borate, lithium imide and combinations thereof is possible, preferably (
  • the concentration of the lithium salt may be determined in consideration of ionic conductivity and the like, preferably 0.1 to 4.0 M, or 0.5 to 2.0 M. If the concentration of the lithium salt is less than the above range it is difficult to secure the ionic conductivity suitable for driving the battery, if it exceeds the above range, the viscosity of the electrolyte may be increased to reduce the mobility of lithium ions and the decomposition reaction of the lithium salt itself increases to increase the battery Since the performance of may be degraded, it is appropriately adjusted within the above range.
  • the non-aqueous electrolyte solution for lithium-sulfur batteries of the present invention may further include an additive having an intramolecular NO bond.
  • the additive has an effect of forming a stable film on the lithium electrode and greatly improves the charge and discharge efficiency.
  • Such additives may be nitric acid or nitrous acid compounds, nitro compounds and the like.
  • Examples include lithium nitrate, potassium nitrate, cesium nitrate, barium nitrate, ammonium nitrate, lithium nitrite, potassium nitrite, cesium nitrite, ammonium nitrite, methyl nitrate, dialkyl imidazolium nitrate, guanidine nitrate, imidazolium nitrate , Pyridinium nitrate, ethyl nitrite, propyl nitrite, butyl nitrite, pentyl nitrite, octyl nitrite, nitromethane, nitropropane, nitrobutane, nitrobenzene, dinitrobenzene, nitropyridine, dinitropyridine, nitro One or more selected from the group consisting of toluene, dinitrotoluene, pyridine N-oxide, alkylpyridine N-oxide, and tetramethyl piperidinyloxy
  • the additive is used within the range of 0.01 to 10% by weight, preferably 0.1 to 5% by weight within 100% by weight of the total electrolyte composition. If the content is less than the above range, the above-described effects cannot be secured. On the contrary, if the content exceeds the above range, the resistance may be increased by the film, so that the above-mentioned range is appropriately adjusted.
  • the lithium-sulfur battery electrolyte according to the present invention uses a mixed solvent of a cyclic ether and a linear ether as a solvent in order to secure electrolyte stability, thereby generating gas in the battery during charge and discharge without deteriorating battery performance. Can be suppressed and the swelling phenomenon can be improved.
  • the preparation method of the electrolyte according to the present invention is not particularly limited in the present invention, and may be prepared by conventional methods known in the art.
  • the lithium-sulfur battery according to the present invention includes a positive electrode and a negative electrode and a separator and an electrolyte interposed therebetween, and use the non-aqueous electrolyte solution for a lithium-sulfur battery according to the present invention as an electrolyte.
  • the amount of gas generated such as hydrogen gas during driving is significantly reduced, thereby improving the battery performance caused by detachment of the active material from the electrode and the quality deterioration caused by the deformation of the battery.
  • the structure of the positive electrode, the negative electrode, and the separator of the lithium-sulfur battery is not particularly limited in the present invention, and is known in the art.
  • the positive electrode according to the present invention includes a positive electrode active material formed on a positive electrode current collector.
  • any one that can be used as a current collector in the technical field is possible, and specifically, it may be preferable to use foamed aluminum, foamed nickel, and the like having excellent conductivity.
  • the cathode active material may include elemental sulfur (S8), a sulfur-based compound, or a mixture thereof.
  • the conductive material may be porous. Therefore, the conductive material may be used without limitation as long as it has porosity and conductivity, and for example, a carbon-based material having porosity may be used. As such a carbon-based material, carbon black, graphite, graphene, activated carbon, carbon fiber, or the like can be used. Moreover, metallic fibers, such as a metal mesh; Metallic powders such as copper, silver, nickel and aluminum; Or organic conductive materials, such as a polyphenylene derivative, can also be used. The conductive materials may be used alone or in combination.
  • the positive electrode may further include a binder for coupling the positive electrode active material and the conductive material and the current collector.
  • the binder may include a thermoplastic resin or a thermosetting resin.
  • polyethylene polyethylene oxide, polypropylene, polytetrafluoro ethylene (PTFE), polyvinylidene fluoride (PVDF), styrene-butadiene rubber, tetrafluoroethylene-perfluoro alkylvinyl ether copolymer, vinyl fluoride Liden-hexafluoropropylene copolymer, vinylidene fluoride-chlorotrifluoroethylene copolymer, ethylene-tetrafluoroethylene copolymer, polychlorotrifluoroethylene, vinylidene fluoride-pentafluoro propylene copolymer, propylene Tetrafluoroethylene copolymer, ethylene-chlorotrifluoroethylene copolymer, vinylidene fluoride-he
  • the positive electrode as described above may be manufactured according to a conventional method. Specifically, a positive electrode active material layer-forming composition prepared by mixing a positive electrode active material, a conductive material, and a binder on an organic solvent is applied and dried on a current collector, and optionally In order to improve the electrode density, the current collector may be manufactured by compression molding.
  • the organic solvent may uniformly disperse the positive electrode active material, the binder, and the conductive material, and preferably evaporates easily. Specifically, acetonitrile, methanol, ethanol, tetrahydrofuran, water, isopropyl alcohol, etc. are mentioned.
  • the negative electrode according to the present invention includes a negative electrode active material formed on the negative electrode current collector.
  • the negative electrode current collector may be specifically selected from the group consisting of copper, 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.
  • calcined carbon, a nonconductive polymer surface-treated with a conductive material, or a conductive polymer may be used.
  • a material capable of reversibly intercalating or deintercalating lithium ions (Li + ), a material capable of reacting with lithium ions to form a reversibly lithium-containing compound, a lithium metal or a lithium alloy can be used.
  • the material capable of reversibly occluding or releasing the lithium ions (Li + ) may be, for example, crystalline carbon, amorphous carbon or a mixture thereof.
  • the material capable of reacting with the lithium ions (Li + ) to form a lithium-containing compound reversibly may be, for example, tin oxide, titanium nitrate or silicon.
  • the lithium alloy is, for example, lithium (Li) and sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), francium (Fr), beryllium (Be), magnesium (Mg), calcium ( It may be an alloy of a metal selected from the group consisting of Ca), strontium (Sr), barium (Ba), radium (Ra), aluminum (Al) and tin (Sn).
  • the negative electrode may further include a binder for coupling the negative electrode active material and the conductive material and the current collector.
  • the binder is the same as described above for the binder of the positive electrode.
  • the negative electrode may be lithium metal or a lithium alloy.
  • the negative electrode may be a thin film of lithium metal, and at least one metal selected from lithium and Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, Ra, Al, and Sn groups. It may be an alloy with.
  • a conventional separator may be interposed between the positive electrode and the negative electrode.
  • the separator is a physical separator having a function of physically separating the electrode, and can be used without particular limitation as long as it is used as a conventional separator, and in particular, it is preferable that the separator has a low resistance to electrolyte migration and excellent electrolyte-moisture capability.
  • the separator enables the transport of lithium ions between the positive electrode and the negative electrode while separating or insulating the positive electrode and the negative electrode from each other.
  • a separator may be made of a porous and nonconductive or insulating material.
  • the separator may be 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 ethylene homopolymer, propylene homopolymer, ethylene / butene copolymer, ethylene / hexene copolymer and ethylene / methacrylate copolymer may be used alone. It may be used as a lamination or or a conventional porous non-woven fabric, for example, a non-woven fabric made of glass fibers, polyethylene terephthalate fibers of high melting point, etc. may be used, but is not limited thereto.
  • the positive electrode, the negative electrode, and the separator included in the lithium-sulfur battery may be prepared according to conventional components and manufacturing methods, respectively, and the appearance of the lithium-sulfur battery is not particularly limited, but may be cylindrical, rectangular, or pouch using a can. It may be a pouch type or a coin type.
  • EGEME Ethyleneglycol ethyl methyl ether
  • EGDEE Ethyleneglycol diethyl ether
  • a positive electrode active material 65% by weight of sulfur, 25% by weight of carbon black, and 10% by weight of polyethylene oxide were mixed with acetonitrile to prepare a positive electrode active material.
  • the cathode active material was coated on an aluminum current collector and dried to prepare a cathode having a loading amount of 5 mAh / cm 2 having a size of 30 ⁇ 50 mm 2 .
  • a lithium metal having a thickness of 150 ⁇ m was used as the cathode.
  • the positive electrode and the negative electrode thus prepared were placed to face each other, and a polyethylene separation membrane was interposed therebetween, followed by injecting the respective electrolyte solutions of (1).
  • the lithium-sulfur batteries of Examples and Comparative Examples were measured for gas generation in the battery after charging and discharging five times at a rate of 0.1C at 25 ° C., and the results are shown in Table 2 and FIG. 1.
  • Examples 1, 4, and 5 showed a significantly improved capacity retention compared to Comparative Example 1. From the above test results, it can be seen that the electrolyte solution of the present invention can significantly reduce the amount of gas generated to prevent the swelling phenomenon of the battery, and to improve the life characteristics of the lithium-sulfur battery.

Abstract

The present invention relates to an electrolyte for a lithium-sulfur battery and a lithium-sulfur battery comprising the same. The electrolyte for a lithium-sulfur battery according to the present invention exhibits excellent stability and can suppress gas generation during the operation of the lithium-sulfur battery, thereby reducing a swelling phenomenon.

Description

리튬-설퍼 전지용 전해액 및 이를 포함하는 리튬-설퍼 전지Electrolyte for lithium-sulfur battery and lithium-sulfur battery comprising same
본 출원은 2016년 2월 3일자 한국 특허 출원 제10-2016-0013248호 및 2017년 1월 17일자 한국 특허 출원 제10-2017-0008309호에 기초한 우선권의 이익을 주장하며, 해당 한국 특허 출원의 문헌에 개시된 모든 내용을 본 명세서의 일부로서 포함한다.This application claims the benefit of priority based on Korean Patent Application No. 10-2016-0013248 dated February 3, 2016 and Korean Patent Application No. 10-2017-0008309 dated January 17, 2017. All content disclosed in the literature is included as part of this specification.
본 발명은 리튬-설퍼 전지용 전해액 및 이를 포함하는 리튬-설퍼 전지에 관한 것이다.The present invention relates to an electrolyte for a lithium-sulfur battery and a lithium-sulfur battery comprising the same.
최근 휴대용 전자기기, 전기자동차 및 대용량 전력저장 시스템 등이 발전함에 따라 대용량 전지의 필요성이 대두되고 있다. 리튬-설퍼 전지는 S-S 결합(Sulfur - sulfur bond)을 갖는 황 계열 물질을 양극 활물질로 사용하고, 리튬 금속을 음극 활물질로 사용하는 이차전지로, 양극 활물질의 주재료인 황은 자원이 매우 풍부하고, 독성이 없으며, 낮은 원자당 무게를 가지고 있는 장점이 있다. Recently, with the development of portable electronic devices, electric vehicles and large-capacity power storage systems, the need for a large-capacity battery is emerging. Lithium-sulfur battery is a secondary battery that uses a sulfur-based material having an SS bond (Sulfur-sulfur bond) as a positive electrode active material and a lithium metal as a negative electrode active material. Sulfur, the main material of the positive electrode active material, is very rich in resources and toxic. There is no advantage, and it has the advantage of having a low weight per atom.
또한 리튬-설퍼 전지의 이론 방전용량은 1672mAh/g-sulfur이며, 이론 에너지밀도가 2,600Wh/kg로서, 현재 연구되고 있는 다른 전지시스템의 이론 에너지밀도(Ni-MH 전지: 450Wh/kg, Li-FeS 전지: 480Wh/kg, Li-MnO2 전지: 1,000Wh/kg, Na-S 전지: 800Wh/kg)에 비하여 매우 높기 때문에 고에너지 밀도 특성을 갖는 전지로서 주목 받고 있다. In addition, the theoretical discharge capacity of the lithium-sulfur battery is 1672mAh / g-sulfur, and the theoretical energy density is 2,600 Wh / kg. The theoretical energy density of other battery systems currently under investigation (Ni-MH battery: 450 Wh / kg, Li- FeS cells: 480 Wh / kg, Li-MnO 2 batteries: 1,000 Wh / kg, Na-S cells: 800 Wh / kg) is very high compared to the attention has been attracting attention as a battery having a high energy density characteristics.
그러나 리튬-설퍼 전지는 황 이용률이 낮아 이론 용량만큼 충분한 용량이 확보되지 않는 점, 리튬 금속 전극의 덴드라이트 형성에 의한 전지 단락 문제 등으로 인하여 아직까지 상용화 되지 못하고 있다. 이에, 상기 문제점을 극복하기 위하여 황 함침량을 높인 양극 재료, 황 이용률을 높일 수 있는 전해액의 개발 등이 이루어지고 있다.However, lithium-sulfur batteries have not been commercialized yet due to low sulfur utilization, insufficient capacity is secured as theoretical capacity, and a short circuit problem due to dendrite formation of lithium metal electrodes. Accordingly, in order to overcome the above problems, development of an anode material having an increased sulfur impregnation amount and an electrolyte solution capable of increasing sulfur utilization has been made.
현재 리튬-설퍼 전지의 전해액 용매로는 1,3-디옥솔란(DOL) 및 1,2-디메톡시에탄(DME)의 혼합용매가 가장 많이 사용되고 있다. 상기 용매를 사용한 전해액은 황 이용률 측면에서 우수한 특성을 나타낸다. 그러나 본 발명자들의 실험 결과 상기 전해액을 적용한 전지의 구동 중 내부에서 가스가 발생하여 전지가 부풀어 오르는 스웰링 현상이 관찰되었다. 이러한 스웰링 현상은 전해액을 고갈시키고 전지의 변형을 일으킬 뿐만 아니라, 전극으로부터 활물질의 탈리를 일으켜 전지 성능을 저하시키는 문제를 수반한다.Currently, a mixed solvent of 1,3-dioxolane (DOL) and 1,2-dimethoxyethane (DME) is most used as an electrolyte solvent of a lithium-sulfur battery. The electrolyte solution using the solvent exhibits excellent properties in terms of sulfur utilization. However, as a result of the experiments of the present inventors, a swelling phenomenon in which gas was generated inside the battery during operation of the battery to which the electrolyte was applied was inflated was observed. Such swelling not only depletes the electrolyte solution and causes deformation of the battery, but also causes problems such as desorption of the active material from the electrode, thereby degrading battery performance.
상기와 같은 전지 내 기체 발생에 의한 스웰링 현상은 그 원인과 발생 메커니즘이 아직까지 밝혀지지 않았으며, 따라서 대응책 또한 전무한 실정이다.The cause and mechanism of the swelling caused by the gas generation in the battery as described above have not been found so far, therefore, there is no countermeasure.
[선행기술문헌][Preceding technical literature]
미합중국 등록특허 제6218054호, Dioxolane and dimethoxyethane electrolyte solvent systemU.S. Pat.No.6218054, Dioxolane and dimethoxyethane electrolyte solvent system
본 발명자들은 상기 문제를 해결하기 위해 리튬-설퍼 전지의 전해액 용매 조성에 관하여 연구하였고, 그 결과 본 발명을 완성하였다.The present inventors studied the electrolyte solvent composition of the lithium-sulfur battery to solve the above problems, and as a result, the present invention was completed.
따라서, 본 발명의 목적은 전지 구동 중 가스 발생량을 현저히 감소시키는 리튬-설퍼 전지용 전해액을 제공하는 것이다.Accordingly, it is an object of the present invention to provide an electrolyte for lithium-sulfur batteries that significantly reduces the amount of gas generated during battery operation.
또한, 본 발명의 또 다른 목적은 상기 전해액을 포함하는 리튬-설퍼 전지를 제공하는 것이다.In addition, another object of the present invention to provide a lithium-sulfur battery comprising the electrolyte.
상기 목적을 달성하기 위해, 본 발명은 In order to achieve the above object, the present invention
리튬염 및 비수계 용매를 포함하는 리튬-설퍼 전지용 전해액에 있어서,In the electrolyte for lithium-sulfur batteries containing a lithium salt and a non-aqueous solvent,
상기 비수계 용매는 The non-aqueous solvent is
분자구조 내 하나의 산소를 포함하는 고리형 에테르; 및 Cyclic ethers containing one oxygen in the molecular structure; And
하기 화학식 1로 표시되는 선형 에테르를 포함하는 것을 특징으로 하는 리튬-설퍼 전지용 전해액을 제공한다:It provides a lithium-sulfur battery electrolyte comprising a linear ether represented by the formula (1):
[화학식 1][Formula 1]
R-O-(CH2CH2O)x-CH2CH3 RO- (CH 2 CH 2 O) x -CH 2 CH 3
(상기 화학식 1에서, R 및 x는 명세서 내에서 설명한 바와 같다.)(In Formula 1, R and x are as described in the specification.)
이때, 상기 고리형 에테르 용매는 C1 내지 C4의 알킬기 또는 알콕시기로 치환 또는 비치환된 5 내지 7원 고리형 에테르일 수 있고, 바람직하기로 C1 내지 C4의 알킬기 또는 알콕시기로 치환 또는 비치환된 테트라히드로퓨란 또는 테트라히드로피란일 수있다.In this case, the cyclic ether solvent may be a 5 to 7 membered cyclic ether unsubstituted or substituted with a C1 to C4 alkyl group or an alkoxy group, preferably tetrahydro unsubstituted or substituted with a C1 to C4 alkyl group or alkoxy group It may be furan or tetrahydropyran.
이때, 상기 화학식 1에서 R은 메틸, 에틸, 프로필, 이소프로필, 또는 부틸일 수 있다.In this case, in Chemical Formula 1, R may be methyl, ethyl, propyl, isopropyl, or butyl.
이때, 상기 고리형 에테르 용매 및 선형 에테르 용매의 부피비는 5:95 내지 95:5일 수 있고, 바람직하기로 30:70 내지 70:30일 수 있다.In this case, the volume ratio of the cyclic ether solvent and the linear ether solvent may be 5:95 to 95: 5, preferably 30:70 to 70:30.
이때, 상기 리튬염은 LiCl, LiBr, LiI, LiClO4, LiBF4, LiB10Cl10, LiPF6, LiCF3SO3, LiCF3CO2, LiC4BO8, LiAsF6, LiSbF6, LiAlCl4, CH3SO3Li, CF3SO3Li, (CF3SO2)2NLi, (C2F5SO2)2NLi, (SO2F)2NLi, (CF3SO2)3CLi, 클로로 보란 리튬, 저급지방족 카르본산 리튬, 4 페닐 붕산 리튬, 리튬 이미드 및 이들의 조합으로 이루어진 군에서 선택된 1종일 수 있다.At this time, the lithium salt is LiCl, LiBr, LiI, LiClO 4 , LiBF 4 , LiB 10 Cl 10 , LiPF 6 , LiCF 3 SO 3 , LiCF 3 CO 2 , LiC 4 BO 8 , LiAsF 6 , LiSbF 6 , LiAlCl 4 , CH 3 SO 3 Li, CF 3 SO 3 Li, (CF 3 SO 2 ) 2 NLi, (C 2 F 5 SO 2 ) 2 NLi, (SO 2 F) 2 NLi, (CF 3 SO 2 ) 3 CLi, Chloro It may be one selected from the group consisting of lithium borane, lower aliphatic lithium carbonate, lithium 4-phenyl borate, lithium imide, and combinations thereof.
본 발명의 전해액은 분자 내 N-O 결합을 갖는 첨가물을 더 포함할 수 있다.The electrolyte solution of the present invention may further include an additive having an intramolecular N-O bond.
이때, 상기 첨가물은 질산리튬, 질산칼륨, 질산세슘, 질산바륨, 질산암모늄, 아질산리튬, 아질산칼륨, 아질산세슘, 아질산암모늄, 메틸 니트레이트, 디알킬 이미다졸륨 니트레이트, 구아니딘 니트레이트, 이미다졸륨 니트레이트, 피리디늄 니트레이트, 에틸 니트라이트, 프로필 니트라이트, 부틸 니트라이트, 펜틸 니트라이트, 옥틸 니트라이트, 니트로메탄, 니트로프로판, 니트로부탄, 니트로벤젠, 디니트로벤젠, 니트로 피리딘, 디니트로피리딘, 니트로톨루엔, 디니트로톨루엔, 피리딘 N-옥사이드, 알킬피리딘 N-옥사이드, 및 테트라메틸 피페리디닐옥실로 이루어지는 군에서 선택되는 1종 이상일 수 있다.At this time, the additive is lithium nitrate, potassium nitrate, cesium nitrate, barium nitrate, ammonium nitrate, lithium nitrite, potassium nitrite, cesium nitrite, ammonium nitrite, methyl nitrate, dialkyl imidazolium nitrate, guanidine nitrate, imida Zolium nitrate, pyridinium nitrate, ethyl nitrite, propyl nitrite, butyl nitrite, pentyl nitrite, octyl nitrite, nitromethane, nitropropane, nitrobutane, nitrobenzene, dinitrobenzene, nitro pyridine, dinitro It may be at least one selected from the group consisting of pyridine, nitrotoluene, dinitrotoluene, pyridine N-oxide, alkylpyridine N-oxide, and tetramethyl piperidinyloxyl.
이때, 상기 첨가물은 전해액 100 중량% 에 대하여 0.01 내지 10 중량% 로 포함될 수 있다.In this case, the additive may be included in 0.01 to 10% by weight relative to 100% by weight of the electrolyte.
또한, 본 발명은 상기 전해액을 포함하는 리튬-설퍼 전지를 제공한다.The present invention also provides a lithium-sulfur battery comprising the electrolyte solution.
본 발명에 따른 리튬-설퍼 전지용 전해액은 안정성이 우수하여 전지 구동 중 가스 발생량이 현저히 적다. 이에, 전지의 스웰링 현상을 개선할 수 있다.The electrolyte solution for a lithium-sulfur battery according to the present invention has excellent stability and significantly reduces gas generation during battery operation. Thus, the swelling phenomenon of the battery can be improved.
도 1은 실험예 1의 가스 발생량 그래프이다. 1 is a graph of gas generation amount in Experimental Example 1. FIG.
도 2는 실험예 2의 전지 수명 특성 비교 그래프이다.2 is a graph comparing battery life characteristics of Experimental Example 2. FIG.
이하, 본 발명이 속하는 기술 분야에서 통상의 지식을 가진 자가 용이하게 실시할 수 있도록 본 발명의 실시예에 대하여 첨부한 도면을 참고로 하여 상세히 설명한다. 그러나 본 발명은 여러 가지 상이한 형태로 구현될 수 있으며, 여기에서 설명하는 실시예에 한정되지 않는다.Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.
리튬-설퍼 전지용 전해액Electrolyte for Lithium Sulfur Battery
본 발명에서는 리튬-설퍼 전지의 구동 시 발생하는 수소 등 가스로 인한 스웰링(swelling)현상을 개선하기 위하여, 전해액 용매로서 분자구조 내 하나의 산소를 포함하는 고리형 에테르 및 하기 화학식 1로 표시되는 선형 에테르를 포함하는 리튬-설퍼 전지용 전해액을 제공한다.In the present invention, in order to improve the swelling phenomenon caused by the gas such as hydrogen generated when driving the lithium-sulfur battery, a cyclic ether containing one oxygen in the molecular structure as an electrolyte solvent and represented by the formula It provides an electrolyte solution for lithium-sulfur battery containing a linear ether.
[화학식 1][Formula 1]
R-O-(CH2CH2O)x-CH2CH3 RO- (CH 2 CH 2 O) x -CH 2 CH 3
(상기 화학식 1에서,(In Formula 1,
R은 C1 내지 C6의 알킬기, 또는 C6 내지 C12의 아릴기이고,R is a C1 to C6 alkyl group or a C6 to C12 aryl group,
x는 1 또는 2이다)x is 1 or 2)
현재 리튬-설퍼 전지의 전해액 용매로 가장 널리 사용되고 있는 것은 1,3-디옥솔란(DOL) 및 1,2-디메톡시에탄(DME)의 혼합용매이다. DOL 및 DME의 혼합 용매를 사용할 경우 황 이용률이 향상되어 전지 용량 측면에서 우수한 결과를 나타낸다.Currently, the most widely used solvents for electrolytes of lithium-sulfur batteries are mixed solvents of 1,3-dioxolane (DOL) and 1,2-dimethoxyethane (DME). The use of a mixed solvent of DOL and DME improves the sulfur utilization resulting in excellent results in terms of battery capacity.
상기 혼합 용매를 사용하는 전해액은 소형 전지에 적용 시 전지 용량 저하 억제, 전지 수명, 전지 효율 면에서 대체로 우수한 성능을 보이지만, 대면적 파우치 셀 등 대형 전지에 적용될 경우, 전지 구동 중 전지 내에 수소, 메탄, 에텐 등의 가스가 상당량 발생하여 전지가 부푸는 스웰링(swelling)현상이 관찰된다.The electrolyte solution using the mixed solvent shows excellent performance in terms of suppression of battery capacity reduction, battery life, and battery efficiency when applied to small batteries, but when applied to large batteries such as large-area pouch cells, hydrogen and methane are A significant amount of gas, such as, ethene, is generated, and swelling of the battery is observed.
본 발명은 상기 문제를 해결하기 위하여 안출된 것으로, 본 발명의 전해액은 상기 고리형 에테르 및 선형 에테르 용매를 특정 함량비로 포함하여 개선된 안정성을 나타내며, 리튬-설퍼 전지에 적용할 경우 전지 구동 시 수소 등 가스 발생량이 현저히 저감된다. 하기 실험예에 나타난 바와 같이, 본 발명의 전해액은 리튬-설퍼 전지에 적용되었을 때, 전지 구동 후 측정된 전지 내부의 가스 발생량이 300 μL 이하, 바람직하기로 100 μL 이하의 수치를 갖는다. 이때 상기 수치가 적을수록 가스 발생량이 적음을 의미하며, 이러한 가스 발생량의 저감은 전지가 부푸는 스웰링 현상이 거의 발생하지 않거나 발생하더라도 전지 안정성에 크게 영향을 미치지 않는 수치이다. 즉, 종래 다른 전해액을 사용할 경우(비교예 1 참조)의 약 500 μL 수준의 가스 발생량과 비교하여 본 발명에서 제시하는 전해액을 사용할 경우 가스 발생량이 현저히 낮으며, 이에 따라 전지 안정성을 높일 수 있고, 스웰링 현상에 의한 전지 성능 저하 및 전지 변형에 따른 품질 저하 문제를 극복할 수 있다.The present invention has been made to solve the above problems, the electrolyte of the present invention exhibits improved stability by including the cyclic ether and linear ether solvent in a specific content ratio, and when applied to a lithium-sulfur battery, hydrogen when driving the battery The amount of back gas generated is significantly reduced. As shown in the following experimental example, the electrolyte solution of the present invention, when applied to a lithium-sulfur battery, has a gas generation amount of 300 μL or less, preferably 100 μL or less, measured after the battery is driven. In this case, the smaller the value, the smaller the amount of gas generation. The reduction in the amount of gas generated is a value that does not significantly affect the battery stability even if the swelling phenomenon that the battery is hardly generated or occurs. That is, compared with the gas generation amount of about 500 μL level when using another electrolyte solution (see Comparative Example 1), the gas generation amount is significantly lower when using the electrolyte solution proposed in the present invention, thereby increasing battery stability. The problem of deterioration of battery performance due to swelling and deterioration of quality due to battery deformation may be overcome.
본 명세서에서 언급하는 C1 내지 C6의 알킬기는 예를 들어 메틸기, 에틸기, 프로필기, 부틸기, 펜틸기, 헥실기 또는 이들의 이성질체이다. 여기서 이성질체라 함은 같은 탄소수를 가지되 탄소의 결합관계가 다른 구조 이성질체 및 결합의 기하학적 위치에 차이가 있는 입체 이성질체를 모두 포함하는 것이다.The alkyl group of C1 to C6 referred to herein is, for example, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group or an isomer thereof. Here, isomers include both structural isomers having the same carbon number but different bond relationships of carbons, and stereoisomers having different geometrical positions of the bonds.
또한 본 명세서에서 언급하는 C6 내지 C12의 아릴기는 예를 들어 C1 내지 C6의 알킬기로 치환 또는 비치환된 페닐기, 또는 나프틸기일 수 있다.In addition, the C6 to C12 aryl group referred to herein may be, for example, a phenyl group unsubstituted or substituted with a C1 to C6 alkyl group, or a naphthyl group.
상기 분자구조 내 하나의 산소를 포함하는 고리형 에테르는 알킬기로 치환 또는 비치환된 5원 이상의 고리형 에테르로서, 바람직하게는 C1 내지 C4의 알킬기 또는 알콕시기로 치환 또는 비치환된 5 내지 7원 고리형 에테르이며, 더욱 바람직하게는 C1 내지 C4의 알킬기 또는 알콕시기로 치환 또는 비치환된 테트라히드로퓨란 또는 테트라히드로피란이다. 비제한적인 예로서, 테트라히드로퓨란, 2-메틸테트라히드로퓨란, 3-메틸테트라히드로퓨란, 2,3-디메틸테트라히드로퓨란, 2,4-디메틸테트라히드로퓨란, 2,5-디메틸테트라히드로퓨란, 2-메톡시테트라히드로퓨란, 3-메톡시테트라히드로퓨란, 2-에톡시테트라히드로퓨란, 3-에톡시테트라히드로퓨란, 테트라히드로피란, 2-메틸테트라히드로피란, 3-메틸테트라히드로피란, 4-메틸테트라히드로피란 등을 들 수 있다. 상기 고리형 에테르는 점도가 낮아 이온 이동성이 좋으며, 높은 산화-환원 안정성을 가지므로 전지의 장기 구동에도 높은 안정성을 보인다.The cyclic ether containing one oxygen in the molecular structure is a 5 or more membered cyclic ether unsubstituted or substituted with an alkyl group, preferably a 5 to 7 membered ring unsubstituted or substituted with a C1 to C4 alkyl group or an alkoxy group. It is a type ether, More preferably, they are tetrahydrofuran or tetrahydropyran unsubstituted or substituted by the C1-C4 alkyl group or the alkoxy group. As non-limiting examples, tetrahydrofuran, 2-methyltetrahydrofuran, 3-methyltetrahydrofuran, 2,3-dimethyltetrahydrofuran, 2,4-dimethyltetrahydrofuran, 2,5-dimethyltetrahydrofuran , 2-methoxytetrahydrofuran, 3-methoxytetrahydrofuran, 2-ethoxytetrahydrofuran, 3-ethoxytetrahydrofuran, tetrahydropyran, 2-methyltetrahydropyran, 3-methyltetrahydropyran , 4-methyltetrahydropyran, and the like. The cyclic ether has a low viscosity, good ion mobility, and high redox stability, thus showing high stability even for long-term operation of the battery.
또한, 상기 선형 에테르는 에틸렌 글리콜계 유도체로서, 에틸렌 글리콜 또는 디에틸렌 글리콜을 기본 골격으로 하고 일측 말단에 에틸기가 에테르 결합으로 연결된 구조를 갖는다. 바람직하기로 상기 R은 메틸, 에틸, 프로필, 이소프로필, 또는 부틸이다. 상기 선형 에테르는 적어도 하나의 에톡시기를 가짐으로써 전지 구동 중 전해액 안정성에 기여하는 것으로 보인다.In addition, the linear ether is an ethylene glycol derivative, and has a structure in which ethylene glycol or diethylene glycol is a basic skeleton and an ethyl group is linked to an ether bond at one end thereof. Preferably R is methyl, ethyl, propyl, isopropyl, or butyl. The linear ether appears to have at least one ethoxy group which contributes to electrolyte stability during battery operation.
상기 고리형 에테르 및 선형 에테르의 부피비는 5:95 내지 95:5 이며, 바람직하게는 30:70 내지 70:30 이다. 상기 범위를 벗어나는 경우, 전지 구동 중 가스 발생 억제 효과가 미미하여 원하는 효과를 얻을 수 없으므로, 상기 범위 내에서 적절히 조절한다.The volume ratio of the cyclic ether and the linear ether is 5:95 to 95: 5, preferably 30:70 to 70:30. If it is out of the above range, the gas generation suppression effect during driving of the battery is insignificant, so that the desired effect cannot be obtained.
본 발명의 전해질은 이온 전도성을 증가시키기 위해 전해질에 첨가되는 리튬염을 포함한다. 상기 리튬염은 본 발명에서 특별히 한정하지 않으며, 리튬 이차 전지에서 통상적으로 사용 가능한 것이라면 제한 없이 사용될 수 있다. 구체적으로, 상기 리튬염은 LiCl, LiBr, LiI, LiClO4, LiBF4, LiB10Cl10, LiPF6, LiCF3SO3, LiCF3CO2, LiC4BO8, LiAsF6, LiSbF6, LiAlCl4, CH3SO3Li, CF3SO3Li, (CF3SO2)2NLi, (C2F5SO2)2NLi, (SO2F)2NLi, (CF3SO2)3CLi, 클로로 보란 리튬, 저급지방족 카르본산 리튬, 4 페닐 붕산 리튬, 리튬 이미드 및 이들의 조합으로 이루어진 군에서 선택된 1종이 가능하며, 바람직하기로 (CF3SO2)2NLi이다.The electrolyte of the present invention includes a lithium salt added to the electrolyte to increase the ionic conductivity. The lithium salt is not particularly limited in the present invention, and may be used without limitation as long as it is commonly used in a lithium secondary battery. Specifically, the lithium salt is LiCl, LiBr, LiI, LiClO 4 , LiBF 4 , LiB 10 Cl 10 , LiPF 6 , LiCF 3 SO 3 , LiCF 3 CO 2 , LiC 4 BO 8 , LiAsF 6 , LiSbF 6 , LiAlCl 4 , CH 3 SO 3 Li, CF 3 SO 3 Li, (CF 3 SO 2 ) 2 NLi, (C 2 F 5 SO 2 ) 2 NLi, (SO 2 F) 2 NLi, (CF 3 SO 2 ) 3 CLi, One selected from the group consisting of lithium chloroborane, lower aliphatic lithium carbonate, lithium phenyl borate, lithium imide and combinations thereof is possible, preferably (CF 3 SO 2 ) 2 NLi.
상기 리튬염의 농도는 이온 전도도 등을 고려하여 결정될 수 있으며, 바람직하게는 0.1 내지 4.0 M, 또는 0.5 내지 2.0 M 이다. 만약 리튬염의 농도가 상기 범위 미만이면 전지의 구동에 적합한 이온 전도도의 확보가 어려우며, 상기 범위를 초과하면 전해액의 점도가 증가하여 리튬 이온의 이동성이 떨어질 수 있고 리튬염 자체의 분해 반응이 증가하여 전지의 성능이 저하될 수 있으므로 상기 범위 내에서 적절히 조절한다.The concentration of the lithium salt may be determined in consideration of ionic conductivity and the like, preferably 0.1 to 4.0 M, or 0.5 to 2.0 M. If the concentration of the lithium salt is less than the above range it is difficult to secure the ionic conductivity suitable for driving the battery, if it exceeds the above range, the viscosity of the electrolyte may be increased to reduce the mobility of lithium ions and the decomposition reaction of the lithium salt itself increases to increase the battery Since the performance of may be degraded, it is appropriately adjusted within the above range.
본 발명의 리튬-설퍼 전지용 비수계 전해액은 분자 내 N-O 결합을 갖는 첨가물을 더 포함할 수 있다. 상기 첨가물은 리튬 전극에 안정적인 피막을 형성하고 충ㆍ방전 효율을 크게 향상시키는 효과가 있다. 이러한 첨가물은 질산 또는 아질산계 화합물, 니트로 화합물 등일 수 있다. 일례로 질산리튬, 질산칼륨, 질산세슘, 질산바륨, 질산암모늄, 아질산리튬, 아질산칼륨, 아질산세슘, 아질산암모늄, 메틸 니트레이트, 디알킬 이미다졸륨 니트레이트, 구아니딘 니트레이트, 이미다졸륨 니트레이트, 피리디늄 니트레이트, 에틸 니트라이트, 프로필 니트라이트, 부틸 니트라이트, 펜틸 니트라이트, 옥틸 니트라이트, 니트로메탄, 니트로프로판, 니트로부탄, 니트로벤젠, 디니트로벤젠, 니트로 피리딘, 디니트로피리딘, 니트로톨루엔, 디니트로톨루엔, 피리딘 N-옥사이드, 알킬피리딘 N-옥사이드, 및 테트라메틸 피페리디닐옥실로 이루어지는 군에서 선택되는 1종 이상이 사용될 수 있다. 본 발명의 일 실시예에 따르면 질산리튬(LiNO3)을 사용할 수 있다.The non-aqueous electrolyte solution for lithium-sulfur batteries of the present invention may further include an additive having an intramolecular NO bond. The additive has an effect of forming a stable film on the lithium electrode and greatly improves the charge and discharge efficiency. Such additives may be nitric acid or nitrous acid compounds, nitro compounds and the like. Examples include lithium nitrate, potassium nitrate, cesium nitrate, barium nitrate, ammonium nitrate, lithium nitrite, potassium nitrite, cesium nitrite, ammonium nitrite, methyl nitrate, dialkyl imidazolium nitrate, guanidine nitrate, imidazolium nitrate , Pyridinium nitrate, ethyl nitrite, propyl nitrite, butyl nitrite, pentyl nitrite, octyl nitrite, nitromethane, nitropropane, nitrobutane, nitrobenzene, dinitrobenzene, nitropyridine, dinitropyridine, nitro One or more selected from the group consisting of toluene, dinitrotoluene, pyridine N-oxide, alkylpyridine N-oxide, and tetramethyl piperidinyloxyl can be used. According to one embodiment of the present invention, lithium nitrate (LiNO 3 ) may be used.
상기 첨가물은 전체 전해액 조성 100 중량% 내에서 0.01 내지 10 중량% 범위 내에서, 바람직하게는 0.1 내지 5 중량%로 사용한다. 만약 그 함량이 상기 범위 미만이면 상기한 효과를 확보할 수 없고, 이와 반대로 상기 범위를 초과하게 되면 피막에 의해 오히려 저항이 증가할 우려가 있으므로, 상기 범위 내에서 적절히 조절한다.The additive is used within the range of 0.01 to 10% by weight, preferably 0.1 to 5% by weight within 100% by weight of the total electrolyte composition. If the content is less than the above range, the above-described effects cannot be secured. On the contrary, if the content exceeds the above range, the resistance may be increased by the film, so that the above-mentioned range is appropriately adjusted.
전술한 바와 같이 본 발명에 따른 리튬-설퍼 전지용 전해액은 전해액 안정성을 확보하기 위하여 용매로 고리형 에테르 및 선형 에테르의 혼합 용매를 이용하며, 이에 따라 전지 성능의 저하 없이 충ㆍ방전 중 전지 내 기체 발생을 억제하고, 스웰링 현상을 개선할 수 있다. As described above, the lithium-sulfur battery electrolyte according to the present invention uses a mixed solvent of a cyclic ether and a linear ether as a solvent in order to secure electrolyte stability, thereby generating gas in the battery during charge and discharge without deteriorating battery performance. Can be suppressed and the swelling phenomenon can be improved.
본 발명에 따른 상기 전해액의 제조방법은 본 발명에서 특별히 한정하지 않으며, 당업계에 공지된 통상적인 방법에 의해 제조될 수 있다.The preparation method of the electrolyte according to the present invention is not particularly limited in the present invention, and may be prepared by conventional methods known in the art.
리튬-설퍼 전지Lithium-sulfur battery
본 발명에 따른 리튬-설퍼 전지는 양극 및 음극과 이들 사이에 개재되는 분리막 및 전해액을 포함하고, 전해액으로서 본 발명에 따른 리튬-설퍼 전지용 비수계 전해액을 사용한다.The lithium-sulfur battery according to the present invention includes a positive electrode and a negative electrode and a separator and an electrolyte interposed therebetween, and use the non-aqueous electrolyte solution for a lithium-sulfur battery according to the present invention as an electrolyte.
본 발명에 따른 리튬-설퍼 전지는 구동 시 수소 기체 등 가스 발생량이 현저히 줄어들어, 전극으로부터 활물질이 탈리되어 발생하는 전지 성능 저하 및 전지의 변형에 따른 품질 저하 문제를 개선할 수 있다.In the lithium-sulfur battery according to the present invention, the amount of gas generated such as hydrogen gas during driving is significantly reduced, thereby improving the battery performance caused by detachment of the active material from the electrode and the quality deterioration caused by the deformation of the battery.
상기 리튬-설퍼 전지의 양극, 음극 및 분리막의 구성은 본 발명에서 특별히 한정하지 않으며, 이 분야에서 공지된 바를 따른다.The structure of the positive electrode, the negative electrode, and the separator of the lithium-sulfur battery is not particularly limited in the present invention, and is known in the art.
양극anode
본 발명에 따른 양극은 양극 집전체 상에 형성된 양극 활물질을 포함한다.The positive electrode according to the present invention includes a positive electrode active material formed on a positive electrode current collector.
상기 양극 집전체로는 기술분야에서 집전체로 사용될 수 있는 것이라면 모두 가능하고, 구체적으로 우수한 도전성을 갖는 발포 알루미늄, 발포 니켈 등을 사용하는 것이 바람직할 수 있다.As the cathode current collector, any one that can be used as a current collector in the technical field is possible, and specifically, it may be preferable to use foamed aluminum, foamed nickel, and the like having excellent conductivity.
상기 양극 활물질은 황 원소(Elemental sulfur, S8), 황 계열 화합물 또는 이들의 혼합물을 포함할 수 있다. 상기 황 계열 화합물은 구체적으로, Li2Sn(n≥1),유기황 화합물 또는 탄소-황 폴리머((C2Sx)n:x=2.5~50,n≥2)등일 수 있다. 이들은 도전재와 복합하여 적용될 수 있다.The cathode active material may include elemental sulfur (S8), a sulfur-based compound, or a mixture thereof. Specifically, the sulfur-based compound may be Li 2 S n (n ≧ 1), an organic sulfur compound or a carbon-sulfur polymer ((C 2 S x ) n : x = 2.5 to 50, n ≧ 2). These can be applied in combination with the conductive material.
상기 도전재는 다공성일 수 있다. 따라서, 상기 도전재로는 다공성 및 도전성을 갖는 것이라면 제한 없이 사용할 수 있으며, 예를 들어 다공성을 갖는 탄소계 물질을 사용할 수 있다. 이와 같은 탄소계 물질로는 카본 블랙, 그라파이트, 그래핀, 활성탄, 탄소 섬유 등을 사용할 수 있다. 또한, 금속 메쉬 등의 금속성 섬유; 구리, 은, 니켈, 알루미늄 등의 금속성 분말; 또는 폴리페닐렌 유도체 등의 유기 도전성 재료도 사용할 수 있다. 상기 도전성 재료들은 단독 또는 혼합하여 사용될 수 있다. The conductive material may be porous. Therefore, the conductive material may be used without limitation as long as it has porosity and conductivity, and for example, a carbon-based material having porosity may be used. As such a carbon-based material, carbon black, graphite, graphene, activated carbon, carbon fiber, or the like can be used. Moreover, metallic fibers, such as a metal mesh; Metallic powders such as copper, silver, nickel and aluminum; Or organic conductive materials, such as a polyphenylene derivative, can also be used. The conductive materials may be used alone or in combination.
상기 양극은 양극 활물질과 도전재의 결합과 집전체에 대한 결합을 위하여 바인더를 더 포함할 수 있다. 상기 바인더는 열가소성 수지 또는 열경화성 수지를 포함할 수 있다. 예를 들어, 폴리에틸렌, 폴리에틸렌옥사이드, 폴리프로필렌, 폴리테트라플루오로 에틸렌(PTFE), 폴리불화비닐리덴(PVDF), 스티렌-부타디엔 고무, 테트라플루오로에틸렌-퍼플루오로 알킬비닐에테르 공중합체, 불화비닐리덴-헥사 플루오로프로필렌 공중합체, 불화비닐리덴-클로로트리플루오로에틸렌 공중합체, 에틸렌-테트라플루오로에틸렌 공중합체, 폴리클로로트리플루오로에틸렌, 불화비니리덴-펜타프루오로 프로필렌 공중합체, 프로필렌-테트라플루오로에틸렌 공중합체, 에틸렌-클로로트리플루오로에틸렌 공중합체, 불화비닐리덴-헥사플루오로프로필렌-테트라 플루오로에틸렌 공중합체, 불화비닐리덴-퍼플루오로메틸비닐에테르-테트라플루오로 에틸렌 공중합체, 에틸렌-아크릴산 공중합제 등을 단독 또는 혼합하여 사용할 수 있으나, 반드시 이들로 한정되지 않으며 당해 기술분야에서 바인더로 사용될 수 있는 것이라면 모두 가능하다.The positive electrode may further include a binder for coupling the positive electrode active material and the conductive material and the current collector. The binder may include a thermoplastic resin or a thermosetting resin. For example, polyethylene, polyethylene oxide, polypropylene, polytetrafluoro ethylene (PTFE), polyvinylidene fluoride (PVDF), styrene-butadiene rubber, tetrafluoroethylene-perfluoro alkylvinyl ether copolymer, vinyl fluoride Liden-hexafluoropropylene copolymer, vinylidene fluoride-chlorotrifluoroethylene copolymer, ethylene-tetrafluoroethylene copolymer, polychlorotrifluoroethylene, vinylidene fluoride-pentafluoro propylene copolymer, propylene Tetrafluoroethylene copolymer, ethylene-chlorotrifluoroethylene copolymer, vinylidene fluoride-hexafluoropropylene-tetra fluoroethylene copolymer, vinylidene fluoride-perfluoromethylvinylether-tetrafluoro ethylene aerial Copolymers, ethylene-acrylic acid copolymers, and the like may be used alone or in combination. It is not limited as long as they can both be used as binders in the art.
상기와 같은 양극은 통상의 방법에 따라 제조될 수 있으며, 구체적으로는 양극 활물질과 도전재 및 바인더를 유기 용매 상에서 혼합하여 제조한 양극 활물질층 형성용 조성물을 집전체 위에 도포 및 건조하고, 선택적으로 전극 밀도의 향상을 위하여 집전체에 압축 성형하여 제조할 수 있다. 이때 상기 유기 용매로는 양극 활물질, 바인더 및 도전재를 균일하게 분산시킬 수 있으며, 쉽게 증발되는 것을 사용하는 것이 바람직하다. 구체적으로는 아세토니트릴, 메탄올, 에탄올, 테트라하이드로퓨란, 물, 이소프로필알코올 등을 들 수 있다.The positive electrode as described above may be manufactured according to a conventional method. Specifically, a positive electrode active material layer-forming composition prepared by mixing a positive electrode active material, a conductive material, and a binder on an organic solvent is applied and dried on a current collector, and optionally In order to improve the electrode density, the current collector may be manufactured by compression molding. In this case, the organic solvent may uniformly disperse the positive electrode active material, the binder, and the conductive material, and preferably evaporates easily. Specifically, acetonitrile, methanol, ethanol, tetrahydrofuran, water, isopropyl alcohol, etc. are mentioned.
음극cathode
본 발명에 따른 음극은 음극 집전체 상에 형성된 음극 활물질을 포함한다.The negative electrode according to the present invention includes a negative electrode active material formed on the negative electrode current collector.
상기 음극 집전체는 구체적으로 구리, 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, 도전재로 표면 처리된 비전도성 고분자, 또는 전도성 고분자 등이 사용될 수도 있다.The negative electrode current collector may be specifically selected from the group consisting of copper, 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, calcined carbon, a nonconductive polymer surface-treated with a conductive material, or a conductive polymer may be used.
상기 음극 활물질로는 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. 상기 리튬 이온(Li+)을 가역적으로 흡장 또는 방출할 수 있는 물질은 예컨대 결정질 탄소, 비정질 탄소 또는 이들의 혼합물일 수 있다. 상기 리튬 이온(Li+)과 반응하여 가역적으로 리튬 함유 화합물을 형성할 수 있는 물질은 예를 들어, 산화주석, 티타늄나이트레이트 또는 실리콘일 수 있다. 상기 리튬 합금은 예를 들어, 리튬(Li)과 나트륨(Na), 칼륨(K), 루비듐(Rb), 세슘(Cs), 프랑슘(Fr), 베릴륨(Be), 마그네슘(Mg), 칼슘(Ca), 스트론튬(Sr), 바륨(Ba), 라듐(Ra), 알루미늄(Al) 및 주석(Sn)으로 이루어지는 군에서 선택되는 금속의 합금일 수 있다.As the negative active material, a material capable of reversibly intercalating or deintercalating lithium ions (Li + ), a material capable of reacting with lithium ions to form a reversibly lithium-containing compound, a lithium metal or a lithium alloy Can be used. The material capable of reversibly occluding or releasing the lithium ions (Li + ) may be, for example, crystalline carbon, amorphous carbon or a mixture thereof. The material capable of reacting with the lithium ions (Li + ) to form a lithium-containing compound reversibly may be, for example, tin oxide, titanium nitrate or silicon. The lithium alloy is, for example, lithium (Li) and sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), francium (Fr), beryllium (Be), magnesium (Mg), calcium ( It may be an alloy of a metal selected from the group consisting of Ca), strontium (Sr), barium (Ba), radium (Ra), aluminum (Al) and tin (Sn).
상기 음극은 음극 활물질과 도전재의 결합과 집전체에 대한 결합을 위하여 바인더를 더 포함할 수 있으며, 구체적으로 상기 바인더는 앞서 양극의 바인더에서 설명한 바와 동일하다.The negative electrode may further include a binder for coupling the negative electrode active material and the conductive material and the current collector. Specifically, the binder is the same as described above for the binder of the positive electrode.
또한 상기 음극은 리튬 금속 또는 리튬 합금일 수 있다. 비제한적인 예로, 음극은 리튬 금속의 박막일 수도 있으며, 리튬과 Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, Ra, Al 및 Sn 군으로부터 선택되는 1종 이상의 금속과의 합금일 수 있다.In addition, the negative electrode may be lithium metal or a lithium alloy. As a non-limiting example, the negative electrode may be a thin film of lithium metal, and at least one metal selected from lithium and Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, Ra, Al, and Sn groups. It may be an alloy with.
분리막Separator
양극과 음극 사이는 통상적인 분리막이 개재될 수 있다. 상기 분리막은 전극을 물리적으로 분리하는 기능을 갖는 물리적인 분리막으로서, 통상의 분리막으로 사용되는 것이라면 특별한 제한 없이 사용 가능하며, 특히 전해액의 이온 이동에 대하여 저저항이면서 전해액 함습 능력이 우수한 것이 바람직하다.A conventional separator may be interposed between the positive electrode and the negative electrode. The separator is a physical separator having a function of physically separating the electrode, and can be used without particular limitation as long as it is used as a conventional separator, and in particular, it is preferable that the separator has a low resistance to electrolyte migration and excellent electrolyte-moisture capability.
또한, 상기 분리막은 양극과 음극을 서로 분리 또는 절연시키면서 양극과 음극 사이에 리튬 이온의 수송을 가능하게 한다. 이러한 분리막은 다공성이고 비전도성 또는 절연성인 물질로 이루어질 수 있다. 상기 분리막은 필름과 같은 독립적인 부재이거나, 또는 양극 및/또는 음극에 부가된 코팅층일 수 있다.In addition, the separator enables the transport of lithium ions between the positive electrode and the negative electrode while separating or insulating the positive electrode and the negative electrode from each other. Such a separator may be made of a porous and nonconductive or insulating material. The separator may be 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, 이에 한정되는 것은 아니다.Specifically, a porous polymer film made of a polyolefin-based polymer such as ethylene homopolymer, propylene homopolymer, ethylene / butene copolymer, ethylene / hexene copolymer and ethylene / methacrylate copolymer may be used alone. It may be used as a lamination or or a conventional porous non-woven fabric, for example, a non-woven fabric made of glass fibers, polyethylene terephthalate fibers of high melting point, etc. may be used, but is not limited thereto.
상기 리튬-설퍼 전지에 포함되는 상기 양극, 음극 및 분리막은 각각 통상적인 성분과 제조 방법에 따라 준비될 수 있으며, 또한 리튬-설퍼 전지의 외형은 특별한 제한이 없으나, 캔을 사용한 원통형, 각형, 파우치(Pouch)형 또는 코인(Coin)형 등이 될 수 있다.The positive electrode, the negative electrode, and the separator included in the lithium-sulfur battery may be prepared according to conventional components and manufacturing methods, respectively, and the appearance of the lithium-sulfur battery is not particularly limited, but may be cylindrical, rectangular, or pouch using a can. It may be a pouch type or a coin type.
이하 본 발명의 이해를 돕기 위하여 바람직한 실시예를 제시하나, 하기 실시예는 본 발명을 예시하는 것일 뿐 본 발명의 범주 및 기술사상 범위 내에서 다양한 변경 및 수정이 가능함은 당업자에게 있어서 명백한 것이며, 이러한 변경 및 수정이 첨부된 특허청구범위에 속하는 것도 당연한 것이다.Hereinafter, preferred examples are provided to help the understanding of the present invention, but the following examples are merely for exemplifying the present invention, and various changes and modifications within the scope and spirit of the present invention are apparent to those skilled in the art. It goes without saying that changes and modifications belong to the appended claims.
[실시예]EXAMPLE
실시예 1 내지 6 및 비교예 1Examples 1 to 6 and Comparative Example 1
(1) 전해액의 제조 (1) Preparation of Electrolyte
하기 표 1의 조성으로 실시예 1 내지 6 및 비교예 1의 비수계 전해액을 제조하였다. 사용된 용매는 다음과 같다(v/v는 부피비를 의미함).To prepare a non-aqueous electrolyte solution of Examples 1 to 6 and Comparative Example 1 in the composition of Table 1. Solvents used are as follows (v / v means volume ratio).
THF: 테트라히드로퓨란 (Tetrahydrofuran)THF: Tetrahydrofuran
THP: 테트라히드로피란 (Tetrahydropyran)THP: Tetrahydropyran
EGEME: 에틸렌글리콜 에틸메틸에테르 (Ethyleneglycol ethyl methyl ether)EGEME: Ethyleneglycol ethyl methyl ether
EGDEE: 에틸렌글리콜 디에틸에테르 (Ethyleneglycol diethyl ether)EGDEE: Ethyleneglycol diethyl ether
DOL: 1,3-디옥솔란 (1,3-Dioxolane)DOL: 1,3-dioxolane (1,3-Dioxolane)
DME: 1,2-디메톡시에탄 (1,2-Dimethoxyethane)DME: 1,2-dimethoxyethane
Figure PCTKR2017000627-appb-T000001
Figure PCTKR2017000627-appb-T000001
(2) 리튬-설퍼 전지의 제조(2) Preparation of lithium-sulfur battery
황 65 중량%, 카본 블랙 25 중량%, 및 폴리에틸렌 옥사이드 10 중량%를 아세토니트릴과 혼합하여 양극 활물질을 준비하였다. 상기 양극 활물질을 알루미늄 집전체 상에 코팅하고 이를 건조하여 30 × 50 ㎟ 크기를 가진, 로딩량 5 mAh/cm2의 양극을 제조하였다. 또, 두께 150㎛의 리튬 금속을 음극으로 하였다.65% by weight of sulfur, 25% by weight of carbon black, and 10% by weight of polyethylene oxide were mixed with acetonitrile to prepare a positive electrode active material. The cathode active material was coated on an aluminum current collector and dried to prepare a cathode having a loading amount of 5 mAh / cm 2 having a size of 30 × 50 mm 2 . In addition, a lithium metal having a thickness of 150 µm was used as the cathode.
상기 제조한 양극과 음극을 대면하도록 위치시키고 그 사이에 폴리에틸렌 분리막을 개재한 후, 상기 (1)의 각 전해액을 주입하였다. The positive electrode and the negative electrode thus prepared were placed to face each other, and a polyethylene separation membrane was interposed therebetween, followed by injecting the respective electrolyte solutions of (1).
실험예 1: 리튬-설퍼 전지 제조 및 충·방전 후 가스 발생량 분석Experimental Example 1: Lithium-Sulfur Battery Preparation and Analysis of Gas Generation after Charge and Discharge
상기 실시예 및 비교예의 리튬-설퍼 전지를 25 ℃에서 율속 0.1C로 5회 충·방전 후 전지 내 가스 발생량을 측정하였고, 그 결과를 하기 표 2 및 도 1에 나타내었다.The lithium-sulfur batteries of Examples and Comparative Examples were measured for gas generation in the battery after charging and discharging five times at a rate of 0.1C at 25 ° C., and the results are shown in Table 2 and FIG. 1.
하기 표 2에 나타난 바와 같이, 실시예 1 내지 6의 경우 가스 발생량이 12.7 ~ 86.5 μL 로, 비교예 1의 473 μL 과 비교하여 현저히 감소된 것을 확인할 수 있다. As shown in Table 2, in the case of Examples 1 to 6 it can be seen that the gas generation amount is 12.7 ~ 86.5 μL, significantly reduced compared to 473 μL of Comparative Example 1.
Figure PCTKR2017000627-appb-T000002
Figure PCTKR2017000627-appb-T000002
실험예Experimental Example 2: 전지 수명 특성 평가 2: Battery Life Characterization
상기 실시예 1, 4, 5 및 비교예 1의 전지에 대하여 하기 조건으로 충전 및 방전하면서 전지의 용량유지율을 측정하였으며, 그 결과를 도 2에 나타내었다.For the batteries of Examples 1, 4, 5 and Comparative Example 1, the capacity retention ratio of the batteries was measured while charging and discharging under the following conditions, and the results are shown in FIG. 2.
충전: 율속 0.1C, 전압 2.8V, CC/CV (5% current cut at 0.1C)Charge: 0.1C at rate, 2.8V, CC / CV (5% current cut at 0.1C)
방전: 율속 0.1C, 전압 1.5V, CCDischarge: Rate 0.1C, Voltage 1.5V, CC
도 2에 나타난 바와 같이 실시예 1, 4, 및 5의 경우 비교예 1에 비하여 현저히 개선된 용량유지율을 나타내었다. 상기 실험 결과들로부터, 본 발명의 전해액은 가스 발생량이 현저히 저감되어 전지의 스웰링 현상을 방지할 수 있으며, 리튬-설퍼 전지의 수명 특성을 향상시킬 수 있음을 확인할 수 있다.As shown in Figure 2, Examples 1, 4, and 5 showed a significantly improved capacity retention compared to Comparative Example 1. From the above test results, it can be seen that the electrolyte solution of the present invention can significantly reduce the amount of gas generated to prevent the swelling phenomenon of the battery, and to improve the life characteristics of the lithium-sulfur battery.

Claims (12)

  1. 리튬염 및 비수계 용매를 포함하는 리튬-설퍼 전지용 전해액에 있어서,In the electrolyte for lithium-sulfur batteries containing a lithium salt and a non-aqueous solvent,
    상기 비수계 용매는 The non-aqueous solvent is
    분자구조 내 하나의 산소를 포함하는 고리형 에테르; 및 Cyclic ethers containing one oxygen in the molecular structure; And
    하기 화학식 1로 표시되는 선형 에테르를 포함하는 것을 특징으로 하는 리튬-설퍼 전지용 전해액.An electrolyte solution for a lithium-sulfur battery, comprising a linear ether represented by Formula 1 below.
    [화학식 1][Formula 1]
    R-O-(CH2CH2O)x-CH2CH3 RO- (CH 2 CH 2 O) x -CH 2 CH 3
    (상기 화학식 1에서,(In Formula 1,
    R은 C1 내지 C6의 알킬기, 또는 C6 내지 C12의 아릴기이고,R is a C1 to C6 alkyl group or a C6 to C12 aryl group,
    x는 1 또는 2이다)x is 1 or 2)
  2. 제1항에 있어서,The method of claim 1,
    상기 고리형 에테르 용매는 C1 내지 C4의 알킬기 또는 알콕시기로 치환 또는 비치환된 5 내지 7원 고리형 에테르인 것을 특징으로 하는 리튬-설퍼 전지용 전해액.The cyclic ether solvent is a 5-7 membered cyclic ether unsubstituted or substituted with an alkyl group or an alkoxy group of C1 to C4 electrolyte for lithium-sulfur battery.
  3. 제1항에 있어서,The method of claim 1,
    상기 고리형 에테르 용매는 C1 내지 C4의 알킬기 또는 알콕시기로 치환 또는 비치환된 테트라히드로퓨란 또는 테트라히드로피란인 것을 특징으로 하는 리튬-설퍼 전지용 전해액.The cyclic ether solvent is tetrahydrofuran or tetrahydropyran unsubstituted or substituted with an alkyl or alkoxy group of C1 to C4.
  4. 제1항에 있어서,The method of claim 1,
    상기 R은 메틸, 에틸, 프로필, 이소프로필, 또는 부틸인 것을 특징으로 하는 리튬-설퍼 전지용 전해액.R is methyl, ethyl, propyl, isopropyl, or butyl, the electrolyte solution for lithium-sulfur battery.
  5. 제1항에 있어서, The method of claim 1,
    상기 고리형 에테르 용매 및 선형 에테르 용매의 부피비는 5:95 내지 95:5 인 것을 특징으로 하는 리튬-설퍼 전지용 전해액.The volume ratio of the cyclic ether solvent and the linear ether solvent is 5:95 to 95: 5 electrolyte solution for a lithium-sulfur battery.
  6. 제1항에 있어서,The method of claim 1,
    상기 고리형 에테르 용매 및 선형 에테르 용매의 부피비는 30:70 내지 70:30 인 것을 특징으로 하는 리튬-설퍼 전지용 전해액.The volume ratio of the cyclic ether solvent and the linear ether solvent is 30:70 to 70:30 electrolyte for lithium-sulfur battery.
  7. 제1항에 있어서,The method of claim 1,
    상기 리튬염은 LiCl, LiBr, LiI, LiClO4, LiBF4, LiB10Cl10, LiPF6, LiCF3SO3, LiCF3CO2, LiC4BO8, LiAsF6, LiSbF6, LiAlCl4, CH3SO3Li, CF3SO3Li, (CF3SO2)2NLi, (C2F5SO2)2NLi, (SO2F)2NLi, (CF3SO2)3CLi, 클로로 보란 리튬, 저급지방족 카르본산 리튬, 4 페닐 붕산 리튬, 리튬 이미드 및 이들의 조합으로 이루어진 군에서 선택된 1종을 포함하는 것을 특징으로 하는 리튬-설퍼 전지용 전해액.The lithium salt is LiCl, LiBr, LiI, LiClO 4 , LiBF 4 , LiB 10 Cl 10 , LiPF 6 , LiCF 3 SO 3 , LiCF 3 CO 2 , LiC 4 BO 8 , LiAsF 6 , LiSbF 6 , LiAlCl 4 , CH 3 SO 3 Li, CF 3 SO 3 Li, (CF 3 SO 2 ) 2 NLi, (C 2 F 5 SO 2 ) 2 NLi, (SO 2 F) 2 NLi, (CF 3 SO 2 ) 3 CLi, chloroborane lithium An electrolyte solution for a lithium-sulfur battery, comprising one selected from the group consisting of lower aliphatic lithium carbonate, lithium phenyl borate, lithium imide, and combinations thereof.
  8. 제1항에 있어서,The method of claim 1,
    상기 리튬염은 0.1 내지 4.0 M 농도로 포함되는 것을 특징으로 하는 리튬-설퍼 전지용 전해액.The lithium salt is a lithium-sulfur battery electrolyte, characterized in that it is included in a concentration of 0.1 to 4.0 M.
  9. 제1항에 있어서,The method of claim 1,
    상기 전해액은 분자 내 N-O 결합을 갖는 첨가물을 더 포함하는 것을 특징으로 하는 리튬-설퍼 전지용 전해액.The electrolyte solution further comprises an additive having an intramolecular N-O bond.
  10. 제9항에 있어서,The method of claim 9,
    상기 첨가물은 질산리튬, 질산칼륨, 질산세슘, 질산바륨, 질산암모늄, 아질산리튬, 아질산칼륨, 아질산세슘, 아질산암모늄, 메틸 니트레이트, 디알킬 이미다졸륨 니트레이트, 구아니딘 니트레이트, 이미다졸륨 니트레이트, 피리디늄 니트레이트, 에틸 니트라이트, 프로필 니트라이트, 부틸 니트라이트, 펜틸 니트라이트, 옥틸 니트라이트, 니트로메탄, 니트로프로판, 니트로부탄, 니트로벤젠, 디니트로벤젠, 니트로 피리딘, 디니트로피리딘, 니트로톨루엔, 디니트로톨루엔, 피리딘 N-옥사이드, 알킬피리딘 N-옥사이드, 및 테트라메틸 피페리디닐옥실로 이루어지는 군에서 선택되는 1종 이상인 것을 특징으로 하는 리튬-설퍼 전지용 전해액.The additives include lithium nitrate, potassium nitrate, cesium nitrate, barium nitrate, ammonium nitrate, lithium nitrite, potassium nitrite, cesium nitrite, ammonium nitrite, methyl nitrate, dialkyl imidazolium nitrate, guanidine nitrate, imidazolium nitrate Latex, pyridinium nitrate, ethyl nitrite, propyl nitrite, butyl nitrite, pentyl nitrite, octyl nitrite, nitromethane, nitropropane, nitrobutane, nitrobenzene, dinitrobenzene, nitro pyridine, dinitropyridine, An electrolyte solution for lithium-sulfur batteries, which is at least one member selected from the group consisting of nitrotoluene, dinitrotoluene, pyridine N-oxide, alkylpyridine N-oxide, and tetramethyl piperidinyloxyl.
  11. 제9항에 있어서,The method of claim 9,
    상기 첨가물은 전해액 100 중량% 에 대하여 0.01 내지 10 중량% 로 포함되는 것을 특징으로 하는 리튬-설퍼 전지용 전해액.The additive is an electrolyte solution for a lithium-sulfur battery, characterized in that contained in 0.01 to 10% by weight relative to 100% by weight of the electrolyte.
  12. 양극; 음극; 상기 양극과 음극 사이에 개재되는 분리막; 및 전해액을 포함하는 리튬-설퍼 전지에 있어서,anode; cathode; A separator interposed between the anode and the cathode; And a lithium-sulfur battery comprising an electrolyte solution,
    상기 전해액은 제1항 내지 제11항 중 어느 한 항의 전해액인 것을 특징으로 하는 리튬-설퍼 전지.The electrolyte solution is a lithium-sulfur battery, characterized in that the electrolyte solution of any one of claims 1 to 11.
PCT/KR2017/000627 2016-02-03 2017-01-18 Electrolyte for lithium-sulfur battery and lithium-sulfur battery comprising same WO2017135597A1 (en)

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6218054B1 (en) 1991-08-13 2001-04-17 Eveready Battery Company, Inc. Dioxolane and dimethoxyethane electrolyte solvent system
KR101167334B1 (en) * 2004-01-06 2012-07-19 싸이언 파워 코포레이션 Electrolytes for Lithium Sulfur Cells
KR20120090969A (en) * 2009-09-29 2012-08-17 미쓰비시 가가꾸 가부시키가이샤 Nonaqueous electrolyte battery and nonaqueous electrolyte solution
KR20130073971A (en) * 2010-10-29 2013-07-03 아사히 가세이 이-매터리얼즈 가부시키가이샤 Nonaqueous electrolyte and nonaqueous secondary battery
KR20150038276A (en) * 2006-12-06 2015-04-08 미쓰비시 가가꾸 가부시키가이샤 Nonaqueous electrolyte solution and nonaqueous electrolyte secondary battery
KR101548851B1 (en) * 2005-10-20 2015-09-01 미쓰비시 가가꾸 가부시키가이샤 Lithium secondary cell and nonaqueous electrolytic solution for use therein

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6218054B1 (en) 1991-08-13 2001-04-17 Eveready Battery Company, Inc. Dioxolane and dimethoxyethane electrolyte solvent system
KR101167334B1 (en) * 2004-01-06 2012-07-19 싸이언 파워 코포레이션 Electrolytes for Lithium Sulfur Cells
KR101548851B1 (en) * 2005-10-20 2015-09-01 미쓰비시 가가꾸 가부시키가이샤 Lithium secondary cell and nonaqueous electrolytic solution for use therein
KR20150038276A (en) * 2006-12-06 2015-04-08 미쓰비시 가가꾸 가부시키가이샤 Nonaqueous electrolyte solution and nonaqueous electrolyte secondary battery
KR20120090969A (en) * 2009-09-29 2012-08-17 미쓰비시 가가꾸 가부시키가이샤 Nonaqueous electrolyte battery and nonaqueous electrolyte solution
KR20130073971A (en) * 2010-10-29 2013-07-03 아사히 가세이 이-매터리얼즈 가부시키가이샤 Nonaqueous electrolyte and nonaqueous secondary battery

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