Electrolyte for rechargeable lithium battery and rechargeable lithium battery including same

Abstract

The invention provides an electrolyte for a rechargeable lithium battery and a rechargeable lithium battery including the same. The electrolyte solution may include a non-aqueous organic solvent, a lithium salt, a first compound represented by Chemical Formula 1, and a second compound represented by Chemical Formula 2. [Chemical Formula 1] R1A-O-R1B [Chemical Formula 2] # imgabs0 #

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2024-0033397, filed on March 8, 2024, in the Korean Intellectual Property Office, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0003] Embodiments of the present disclosure described herein relate to an electrolyte for a rechargeable lithium battery and a rechargeable lithium battery including the same. Background Art

[0004] Recently, with the rapid popularization of electronic devices using batteries (such as mobile phones, laptop computers and / or electric vehicles), the demand or expectation for rechargeable lithium batteries with relatively high energy density and high capacity has increased rapidly. Therefore, intensive research has been conducted to improve the performance of rechargeable lithium batteries.

[0005] A rechargeable lithium battery includes a positive electrode, a negative electrode, and an electrolyte. The positive electrode and the negative electrode (e.g., each) include an active material in which (e.g., lithium ions) can be intercalated and deintercalated, and if (e.g., when) lithium ions are intercalated and deintercalated, the rechargeable lithium battery generates electrical energy caused by oxidation and reduction reactions. Summary of the Invention

[0006] Aspects according to one or more embodiments relate to an electrolyte for a rechargeable lithium battery, the impregnation property of which is excellent or appropriate.

[0007] Aspects according to one or more embodiments relate to a rechargeable lithium battery including an electrolyte.

[0008] According to one or more embodiments of the present disclosure, an electrolyte for a rechargeable lithium battery may include: a non-aqueous organic solvent; a lithium salt; a first compound represented by Chemical Formula 1; and a second compound represented by Chemical Formula 2.

[0009] [Chemical Formula 1]

[0010]

[0011] In Chemical Formula 1, R 1A and R 1B Each independently may be a substituted or unsubstituted C2-C10 alkyl group.

[0012] In Chemical Formula 1, R 1A and R 1B At least one of the may be a halogenated alkyl group represented by Chemical Formula A1.

[0013] [Chemical Formula A1]

[0014] C n H 2n+1-m X m

[0015] In Formula A1, X may be F, Cl, Br, I, and / or (eg, any appropriate) combination thereof, n may be an integer between 2 and 10, and m may be an integer between 2 and 2n+1.

[0016] [Chemical Formula 2]

[0017]

[0018] In Chemical Formula 2, L 2A and L 2B Each may independently be a single bond, a substituted or unsubstituted C1-C5 alkylene group, a substituted or unsubstituted C2-C5 alkenylene group, a substituted or unsubstituted C2-C5 alkynylene group, or a substituted or unsubstituted C6-C20 arylene group.

[0019] In Chemical Formula 2, A and B may each independently be a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C6-C20 aryl group, or a substituted or unsubstituted C2-C20 heteroaryl group.

[0020] In Chemical Formula 2, at least one selected from A and B may be a group represented by Chemical Formula A2.

[0021] [Chemical Formula A2]

[0022]

[0023] In chemical formula A2, R 2A and R 2B They may each independently be hydrogen, halogen, substituted or unsubstituted C1-C10 alkyl, or substituted or unsubstituted C3-C10 cycloalkyl.

[0024] According to one or more embodiments of the present disclosure, a rechargeable lithium battery may include: a positive electrode including a positive electrode active material; a negative electrode including a negative electrode active material; and the aforementioned electrolyte for a rechargeable lithium battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A conceptual diagram illustrating a rechargeable lithium battery according to one or more embodiments of the present disclosure is illustrated.

[0026] Figures 2 to 5 Conceptual diagrams each illustrating a rechargeable lithium battery according to one or more embodiments of the present disclosure are explained.

[0027] Figure 6 Images showing test results of the impregnation properties of the electrolytic solutions according to Embodiments 1 to 5 and Comparative Examples 1 to 5 are illustrated. DETAILED DESCRIPTION

[0028] In order to fully understand the layout and aspects of the present disclosure, one or more embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be noted that the present disclosure is not limited to the following example embodiments and can be implemented in one or more suitable forms. On the contrary, the example embodiments are provided only to disclose the embodiments of the present disclosure and to enable those skilled in the art to fully understand the scope of the present disclosure.

[0029] In this description, it will be understood that if (for example, when) an element is referred to as being on another element, the element may be directly on the other element, or intervening elements may be present therebetween. In the drawings, the sizes (for example, thickness) of some components are exaggerated for the purpose of effectively explaining the technical content. The same reference numerals refer to the same elements throughout the specification, and their repeated descriptions may not be provided in the specification.

[0030] Unless otherwise specifically stated in this description, expressions in the singular may include expressions in the plural. In addition, unless otherwise specifically stated, the phrase "A or B" may indicate "A but not B," "B but not A," and "A and B." The terms "comprises / includes" and / or "comprising / including" used in this description do not exclude the presence or addition of one or more other components.

[0031] As used herein, the term "combination thereof" may refer to a mixture, stack, composite, copolymer, alloy, blend, or reaction product of the components.

[0032] Unless otherwise specifically defined in the present description, the particle size may be an average particle size. In addition, the particle size indicates the average particle size (D 50 ). Average particle size (D 50 ) can be measured by a method suitable for those skilled in the art (e.g., by a particle size analyzer, a transmission electron microscope (TEM) image, or a scanning electron microscope (SEM) image). In one or more embodiments, a dynamic light scattering measurement device is used for data analysis, the number of particles in each particle size range is counted, and the average particle size (D) is then calculated. 50 ) value. The difference is that the laser scattering method can be used to measure the average particle size (D 50In the laser scattering method, target particles are distributed in a distribution solvent, introduced into a laser scattering particle measuring device (e.g., MT3000 commercially available from Microtrac, Inc.), irradiated with 28 kHz ultrasonic waves at a power of 60 W, and then the average particle size (D) is calculated in the measuring device based on a 50% standard particle size distribution. 50 ).

[0033] As used herein, expressions such as "at least one of," "one of," and "(e.g., selected from)...", when preceding or following a list of elements, modify the entire list of elements and do not modify the individual elements of the list. For example, "at least one of a, b, and c," "at least one selected from a, b, and c," etc. may indicate only a, only b, only c, both a and b (e.g., simultaneously), both a and c (e.g., simultaneously), both b and c (e.g., simultaneously), all of a, b, and c, or variations thereof.

[0034] The terms used in this article are intended to describe only specific embodiments and are not intended to limit the present disclosure. As used in this article, the singular forms "a", "an" and "the" are intended to include plural forms, including "at least one", unless the content (e.g., quantity) is otherwise clearly indicated. "At least one" should not be interpreted as being limited to the singular. As used in this article, the term "and / or" includes any and all combinations of one or more related enumerated items. When used in the detailed description, the terms "includes", "including", "comprises" and / or "comprising" indicate the presence of the described features, regions, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components and / or groups thereof.

[0035] Spatially relative terms such as "below," "beneath," "below," "above," "on," etc. are used herein to easily describe the relationship of one element or feature to another element or feature. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation illustrated in the drawings. For example, when the device in the drawings is turned over, elements described as "below" or "beneath" other elements or features will be "above" or "on" the other elements or features. In some embodiments, the example term "below" can encompass both (e.g., simultaneously) orientations of above and below. The device can be oriented otherwise (rotated 90 degrees or in other orientations), and the spatially relative terms used herein can be interpreted accordingly.

[0036] As used herein, the term "substantially" and similar terms are used as terms of approximation rather than as terms of degree, and are intended to account for the inherent deviations in measured or calculated values ​​that would be recognized by one of ordinary skill in the art. Furthermore, the term "about" and similar terms, when used herein in conjunction with a value or range of values, include the stated value as well as values ​​within an acceptable range of deviation from the particular value as determined by one of ordinary skill in the art, taking into account the measurement in question and errors associated with the measurement of the particular quantity (e.g., limitations of the measurement system). For example, "about" can mean within one or more standard deviations of the stated value, or within ±30%, ±20%, ±10%, or ±5% of the stated value.

[0037] Furthermore, any numerical range set forth in this article is intended to include all subranges of the same numerical precision included in the range of the setting forth. For example, the range of "1.0 to 10.0" is intended to include all subranges between the minimum value 1.0 set forth and the maximum value 10.0 set forth (and including 1.0 and 10.0), that is, all subranges with a minimum value equal to or greater than 1.0 and a maximum value equal to or less than 10.0 (such as, for example, 2.4 to 7.6). Any maximum numerical limit set forth in this article is intended to include all lower numerical limits contained therein, and any minimum numerical limit set forth in this specification is intended to include all higher numerical limits contained therein. Accordingly, the applicant reserves the right to amend this specification (including claims) to explicitly set forth any subrange contained in the range explicitly set forth in this article.

[0038] In the present description, unless otherwise defined separately, the term "substituted" may refer to a substituent or a compound in which at least one hydrogen is replaced by deuterium, a halo group, a hydroxyl group, an amino group, a C1-C30 amine group, a nitro group, a C1-C40 silyl group, a C1-C30 alkyl group, a C1-C10 alkylsilyl group, a C6-C30 arylsilyl group, a C3-C30 cycloalkyl group, a C3-C30 heterocycloalkyl group, a C6-C30 aryl group, a C2-C30 heteroaryl group, a C1-C20 alkoxy group, a C1-C10 fluoroalkyl group, a cyano group and / or (e.g., any appropriate) combination thereof.

[0039] For example, the term "substituted" may refer to the replacement of at least one hydrogen of a substituent or compound by deuterium, halogen, C1-C30 alkyl, C1-C10 alkylsilyl, C6-C30 arylsilyl, C3-C30 cycloalkyl, C3-C30 heterocycloalkyl, C6-C30 aryl, C2-C30 heteroaryl, C1-C10 fluoroalkyl, or cyano. For example, the term "substituted" may refer to the replacement of at least one hydrogen of a substituent or compound by deuterium, halogen, C1-C20 alkyl, C6-C30 aryl, C1-C10 fluoroalkyl, or cyano. In one or more embodiments, the term "substituted" may refer to the replacement of at least one hydrogen of a substituent or compound by deuterium, halogen, C1-C5 alkyl, C6-C18 aryl, C1-C5 fluoroalkyl, or cyano. For example, the term "substituted" may refer to a substituent or compound having at least one hydrogen substituted by deuterium, cyano, halo, methyl, ethyl, propyl, butyl, phenyl, biphenyl, terphenyl, trifluoromethyl, or naphthyl. Alkyl groups may include linear and / or chain alkyl groups, and cycloalkyl groups may include cyclic alkyl groups.

[0040] Figure 1 A conceptual diagram illustrating a rechargeable lithium battery according to one or more embodiments of the present disclosure is illustrated. Figure 1 , a rechargeable lithium battery may include a positive electrode 10, a negative electrode 20, a separator 30, and an electrolyte ELL.

[0041] The positive electrode 10 and the negative electrode 20 may be spaced and / or separated (e.g., spaced or separated) from each other across the separator 30. The separator 30 may be disposed between the positive electrode 10 and the negative electrode 20. The positive electrode 10, the negative electrode 20, and the separator 30 may be in contact with the electrolyte ELL. The positive electrode 10, the negative electrode 20, and the separator 30 may be immersed in and / or impregnated with the electrolyte ELL.

[0042] The electrolyte ELL may be a medium for lithium ions to be transferred between the positive electrode 10 and the negative electrode 20. In the electrolyte ELL, the lithium ions may move toward one of the positive electrode 10 and the negative electrode 20 through the separator 30.

[0043] Positive electrode 10

[0044] The positive electrode 10 for a rechargeable lithium battery may include a positive electrode current collector COL1 and a positive electrode active material layer AML1 formed on the positive electrode current collector COL1. The positive electrode active material layer AML1 may include a positive electrode active material and further include a binder and / or a conductive material.

[0045] For example, the positive electrode 10 may further include a component that may serve as a sacrificial positive electrode.

[0046] The amount of the positive electrode active material may range from about 90 wt % to about 99 wt % based on 100 wt % of the positive electrode active material layer AML1. The amount of the binder and the conductive material may each range from about 0.5 wt % to about 5 wt % based on 100 wt % of the positive electrode active material layer AML1.

[0047] The binder can be used to improve the adhesion of the positive electrode active material particles to each other and also to improve the adhesion of the positive electrode active material to the positive electrode current collector COL 1. The binder may include, for example, polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, an ethylene oxide-containing polymer, polyvinyl pyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, (meth)acrylated styrene-butadiene rubber, epoxy resin, (meth)acrylic resin, polyester resin, and / or nylon, but the present disclosure is not limited thereto.

[0048] The conductive material can be used to provide conductivity to the electrode, and any suitable conductive material that does not cause chemical changes in the rechargeable lithium battery can be used as the conductive material constituting the rechargeable lithium battery. The conductive material may include, for example, carbon-based materials (such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fibers, carbon nanofibers, and carbon nanotubes); metal powders or metal fibers containing one or more of copper, nickel, aluminum, and silver; conductive polymers (such as polyphenylene derivatives); and / or (for example, any suitable) mixtures thereof.

[0049] An aluminum (Al) foil may be used as the positive electrode current collector COL1 , but the present disclosure is not limited thereto.

[0050] Positive electrode active material

[0051] The positive electrode active material in the positive electrode active material layer AML1 may include a compound that reversibly intercalates and deintercalates lithium (e.g., a lithiated intercalation compound). For example, the positive electrode active material may include at least one type of composite oxide containing lithium and a metal selected from cobalt, manganese, nickel, and / or any suitable combination thereof.

[0052] The composite oxide may include a lithium transition metal composite oxide, such as lithium nickel-based oxides, lithium cobalt-based oxides, lithium manganese-based oxides, lithium iron phosphate-based compounds, cobalt-free nickel manganese-based oxides, and / or (eg, any appropriate) combinations thereof.

[0053] For example, the positive electrode active material may include a compound represented by any one of the following chemical formulas: Li a A 1- b X b O 2-c Dc (0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05), Li a Mn 2-b X b O 4-c D c (0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05), Li a Ni 1-b-c Co b X c O 2-α D α (0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.5, 0 < α < 2), Li a Ni 1-b-c Mn b X c O 2-α D α (0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.5, 0 < α < 2), Li a Ni b Co c L 1 d G[[ID=]] e O2(0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.9, 0 ≤ c ≤ 0.5, 0 ≤ d ≤ 0.5, 0 ≤ e ≤ 0.1), Li a NiG b O2(0.90 ≤ a ≤ 1.8, 0.001 ≤ b ≤ 0.1), Li a CoG b O2(0.90 ≤ a ≤ 1.8, 0.001 ≤ b ≤ 0.1), Li a Mn 1-b G b O2(0.90 ≤ a ≤ 1.8, 0.001 ≤ b ≤ 0.1), Li a Mn2G b O4(0.90 ≤ a ≤ 1.8, 0.001 ≤ b ≤ )、Li a Mn 1-g G g PO4(0.90 ≤ a ≤ 1.8, 0 ≤ g ≤ 0.5), Li (3-f) Fe2(PO4)3(0 ≤ f ≤ 2) and Li a FePO4(0.90 ≤ a ≤ 1.8).

[0054] In the above chemical formula, A is Ni, Co, Mn and / or (e.g., any appropriate) combination thereof, X is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, a rare earth element and / or (e.g., any appropriate) combination thereof, D is O, F, S, P and / or (e.g., any appropriate) combination thereof, G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V and / or (e.g., any appropriate) combination thereof, and L 1 is Mn, Al, and / or (eg, any suitable) combination thereof.

[0055] For example, based on 100 mol% of the lithium-free metal in the lithium transition metal composite oxide, the positive electrode active material may be a high nickel-based positive electrode active material having a nickel content (e.g., amount) of about 80 mol% or more, about 85 mol% or more, about 90 mol% or more, about 91 mol% or more, or about 94 mol% or more and about 99 mol% or less. The high nickel-based positive electrode active material can achieve high capacity and is therefore applicable to high-capacity and high-density rechargeable lithium batteries.

[0056] Negative electrode 20

[0057] The negative electrode 20 for a rechargeable lithium battery may include a negative electrode current collector COL2 and a negative electrode active material layer AML2 on the negative electrode current collector COL2. The negative electrode active material layer AML2 may include a negative electrode active material and may further include a binder and / or a conductive material.

[0058] For example, the negative electrode active material layer AML2 may include about 90 wt % to about 99 wt % of the negative electrode active material, about 0.5 wt % to about 5 wt % of the binder, and about 0 wt % to about 5 wt % of the conductive material.

[0059] The binder can be used to improve the adhesion of the negative electrode active material particles to each other and also to improve the adhesion of the negative electrode active material to the negative electrode current collector COL2. The binder can include a non-aqueous binder, an aqueous binder, a dry binder, and / or any suitable combination thereof.

[0060] The non-aqueous binder may include polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene propylene copolymer, polystyrene, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polyamideimide, polyimide, and / or (eg, any suitable) combinations thereof.

[0061] The aqueous binder may include styrene-butadiene rubber, (meth)acrylated styrene-butadiene rubber, (meth)acrylic rubber, butyl rubber, fluoroelastomer, polyethylene oxide, polyvinyl pyrrolidone, polyepichlorohydrin, polyphosphazene, poly(meth)acrylonitrile, ethylene propylene diene copolymer, polyvinyl pyridine, chlorosulfonated polyethylene, latex, polyester resin, (meth)acrylic resin, phenolic resin, epoxy resin, polyvinyl alcohol and / or (e.g., any suitable) combination thereof.

[0062] When an aqueous binder is used as a binder in the negative electrode active material layer AML2, a cellulose compound capable of providing viscosity may be further included. The cellulose compound may include one or more of carboxymethyl cellulose, hydroxypropyl methyl cellulose, methyl cellulose, and alkali metal salts thereof. The alkali metal may include Na, K, or Li.

[0063] The dry binder may include a fibrillated polymeric material, such as polytetrafluoroethylene, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polyethylene oxide, and / or (eg, any suitable) combinations thereof.

[0064] The conductive material can be used to provide conductivity to the electrode, and any suitable conductive material that does not cause chemical changes in the rechargeable lithium battery can be used as the conductive material constituting the rechargeable lithium battery. For example, the conductive material may include carbon materials (such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fibers, carbon nanofibers, and carbon nanotubes); metal powders or metal fibers including one or more of copper, nickel, aluminum, and silver; conductive polymers (such as polyphenylene derivatives); and / or (for example, any suitable) mixtures thereof.

[0065] The negative electrode current collector COL2 may include copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, a polymer substrate coated with a conductive metal, and / or (eg, any suitable) combinations thereof.

[0066] Negative electrode active material

[0067] The negative electrode active material in the negative electrode active material layer AML2 may include a material that can reversibly intercalate and deintercalate lithium ions, lithium metal, a lithium metal alloy, a material that can dope and dedope lithium, or a transition metal oxide.

[0068] The material that can reversibly intercalate and deintercalate lithium ions may include a carbon-based negative electrode active material, for example, crystalline carbon, amorphous carbon, and / or (e.g., any suitable) combination thereof. For example, the crystalline carbon may include graphite, such as amorphous, flaky, flaky, spherical, or fibrous natural or artificial graphite, and the amorphous carbon may include soft carbon, hard carbon, mesophase pitch carbon, or calcined coke.

[0069] The lithium metal alloy may include an alloy of lithium and a metal selected from Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Si, Sb, Pb, In, Zn, Ba, Ra, Ge, Al, and Sn.

[0070] The material that can be doped and undoped with lithium may include a Si-based negative electrode active material or a Sn-based negative electrode active material. The Si-based negative electrode active material may include silicon, a silicon-carbon composite, SiO x (0 < x ≤ 2), a Si-Q alloy (where Q is an alkali metal, an alkaline earth metal, a Group 13 element, a Group 14 element (except Si), a Group 15 element, a Group 16 element, a transition metal, a rare earth element, and / or a combination thereof (e.g., any suitable combination)), and / or a combination thereof (e.g., any suitable combination). The Sn-based negative electrode active material may include Sn; SnO x (0 < x ≤ 2), such as SnO2; a Sn-based alloy; or a combination thereof.

[0071] The silicon-carbon composite may be a composite of silicon and amorphous carbon. According to one or more embodiments, the silicon-carbon composite may have a structure in which amorphous carbon is coated on the surface of silicon particles. For example, the silicon-carbon composite may include secondary particles (cores) in which primary silicon particles are aggregated and an amorphous carbon coating (shell) located on the surface of the secondary particles. Amorphous carbon may also be located between the primary silicon particles. For example, the primary silicon particles may be coated with amorphous carbon. The secondary particles may be dispersed in an amorphous carbon matrix.

[0072] The silicon-carbon composite may further include crystalline carbon. For example, the silicon-carbon composite may include a core containing crystalline carbon and silicon particles, and may also include an amorphous carbon coating located on the surface of the core.

[0073] The Si-based negative electrode active material or the Sn-based negative electrode active material may be used in combination with a carbon-based negative electrode active material.

[0074] Separator 30

[0075] Based on the type or kind of the rechargeable lithium battery, the separator 30 may be present between the positive electrode 10 and the negative electrode 20. The separator 30 may include one or more of a polyethylene separator, a polypropylene separator, and a polyvinylidene fluoride separator, and may be a multilayer separator thereof, such as a polyethylene / polypropylene bilayer separator, a polyethylene / polypropylene / polyethylene trilayer separator, and a polypropylene / polyethylene / polypropylene trilayer separator.

[0076] The separator 30 may include a porous substrate and a coating located on one surface or the opposite surface of the porous substrate. The coating may include an organic material, an inorganic material, and / or a combination thereof (e.g., any suitable combination).

[0077] The porous substrate may be a polymer layer comprising at least one selected from polyolefins (such as polyethylene and polypropylene), polyesters (such as polyethylene terephthalate and polybutylene terephthalate), polyacetals, polyamides, polyimides, polycarbonates, polyetherketones, polyaryletherketones, polyetherimides, polyamideimides, polybenzimidazoles, polyethersulfones, polyphenylene oxides, cyclic olefin copolymers, polyphenylene sulfide, polyethylene naphthalate, glass fibers, and polytetrafluoroethylene (e.g., Teflon), or may be a copolymer or mixture comprising two or more of the above-mentioned materials.

[0078] The organic material may include a polyvinylidene fluoride-based copolymer or a (meth)acrylic acid-based copolymer.

[0079] The inorganic material may include inorganic particles selected from Al2O3, SiO2, TiO2, SnO2, CeO2, MgO, NiO, CaO, GaO, ZnO, ZrO2, Y2O3, SrTiO3, BaTiO3, Mg(OH)2, boehmite, and inorganic particles selected from (e.g., any suitable) combinations thereof, but the present disclosure is not limited thereto.

[0080] The organic material and the inorganic material may be present as a mixture in one coating layer, or may be present as a stack of a coating layer including an organic material and a coating layer including an inorganic material.

[0081] Electrolyte ELL

[0082] The electrolyte ELL for a rechargeable lithium battery may include a non-aqueous organic solvent and a lithium salt.

[0083] The non-aqueous organic solvent may be used as a medium for transporting ions participating in the electrochemical reaction of the rechargeable lithium battery.

[0084] The non-aqueous organic solvent may include a carbonate-based solvent, an ester-based solvent, an ether-based solvent, a ketone-based solvent, an alcohol-based solvent, an aprotic solvent, and / or (eg, any appropriate) combinations thereof.

[0085] The carbonate-based solvent may include dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), methylpropyl carbonate (MPC), ethylpropyl carbonate (EPC), ethylmethyl carbonate (EMC), ethylene carbonate (EC), propylene carbonate (PC), or butylene carbonate (BC).

[0086] The ester solvent may include methyl acetate, ethyl acetate, n-propyl acetate, dimethyl acetate, methyl propionate, ethyl propionate, propyl propionate, decanoic acid lactone, mevalonolactone, valerolactone, or caprolactone.

[0087] Ether solvents may include dibutyl ether, tetraglyme, diglyme, ethylene glycol dimethyl ether, 2-methyltetrahydrofuran, 2,5-dimethyltetrahydrofuran, or tetrahydrofuran. Ketone solvents may include cyclohexanone. Alcohol solvents may include ethanol or isopropanol. Aprotic solvents may include nitriles (such as R-CN, where R is a hydrocarbon group having a C2 to C20 linear, branched, or cyclic structure and may include a double bond, an aromatic ring, or an ether group); amides (such as dimethylformamide); dioxolanes (such as 1,3-dioxolane or 1,4-dioxolane); or sulfolane.

[0088] The nonaqueous organic solvent may be used alone or as a mixture of two or more species.

[0089] In addition, if (for example, when) a carbonate-based solvent is used, cyclic carbonate and chain carbonate may be mixed and used, and may be mixed in a volume ratio of about 1:1 to about 1:9.

[0090] The lithium salt may be a material dissolved in a non-aqueous organic solvent to serve as a supply source of lithium ions in a rechargeable lithium battery, and plays a role in ensuring the basic operation of the rechargeable lithium battery and promoting the movement of lithium ions between the positive electrode and the negative electrode. The lithium salt may include, for example, a material selected from LiPF6, LiBF4, LiSbF6, LiAsF6, LiClO4, LiAlO2, LiAlCl4, LiPO2F2, LiCl, LiI, LiN(SO3C2F5)2, Li(FSO2)2N, lithium bis(fluorosulfonyl)imide (LiFSI), LiC4F9SO3, LiN(C x F 2x+1 SO2)(C y F 2y+1 SO2) (wherein x and y are integers between 1 and 20), at least one of lithium trifluoromethanesulfonate, lithium tetrafluoroethanesulfonate, lithium difluorobis(oxalato)phosphate (LiDFBOP) and lithium bis(oxalato)borate (LiBOB).

[0091] An electrolyte for a rechargeable lithium battery according to one or more embodiments will be described in more detail below.

[0092] An electrolyte for a rechargeable lithium battery according to one or more embodiments of the present disclosure may include a non-aqueous organic solvent, a lithium salt, a first compound represented by Chemical Formula 1, and a second compound represented by Chemical Formula 2.

[0093] [Chemical Formula 1]

[0094] R1A—O-R1B

[0095] In Chemical Formula 1, R 1A and R 1BEach independently may be a substituted or unsubstituted C2-C10 alkyl group.

[0096] In Chemical Formula 1, R 1A and R 1B At least one of may be a halogenated alkyl group represented by Chemical Formula A1. In one or more embodiments, R 1A and R 1B One of the groups may be a halogenated alkyl group represented by Chemical Formula A1, and R 1A and R 1B The other of may be a substituted or unsubstituted C2 to C10 alkyl group. In one or more embodiments, R 1A and R 1B Both (eg, simultaneously) may be halogenated alkyl groups represented by Chemical Formula A1.

[0097] [Chemical Formula A1]

[0098] CnH 2n+1-m X m

[0099] In Chemical Formula A1, X may be F, Cl, Br, I, and / or (eg, any appropriate) combinations thereof.

[0100] In Chemical Formula A1, n may be an integer between 2 and 10.

[0101] In Chemical Formula A1, m may be an integer between 2 and 2n+1.

[0102] For example, X may be F.

[0103] [Chemical Formula 2]

[0104]

[0105] In Chemical Formula 2, L 2A and L 2B Each of them can be independently a single bond, a substituted or unsubstituted C1-C5 alkylene group, a substituted or unsubstituted C2-C5 alkenylene group, a substituted or unsubstituted C2-C5 alkynylene group or a substituted or unsubstituted C6-C20 arylene group. 2A When L is a single bond, A can be directly connected to S via a single bond. 2B When it is a single bond, B can be directly connected to S via the single bond.

[0106] In Chemical Formula 2, A and B may each independently be a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C6-C20 aryl group, or a substituted or unsubstituted C2-C20 heteroaryl group.

[0107] In Chemical Formula 2, at least one selected from A and B may be a group represented by Chemical Formula A2. In one or more embodiments, one of A and B may be a group represented by Chemical Formula A2, and the other of A and B may be a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C6-C20 aryl group, or a substituted or unsubstituted C2-C20 heteroaryl group. In one or more embodiments, both A and B (e.g., simultaneously) may be a group represented by Chemical Formula A2.

[0108] [Chemical Formula A2]

[0109]

[0110] In chemical formula A2, R 2A and R 2B They may each independently be hydrogen, halogen, substituted or unsubstituted C1-C10 alkyl, or substituted or unsubstituted C3-C10 cycloalkyl.

[0111] For example, the first compound can include 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether, 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether, and / or (eg, any suitable) mixtures thereof.

[0112] For example, Chemical Formula 1 can be represented by Chemical Formula 1-1.

[0113] [Chemical Formula 1-1]

[0114]

[0115] 1,1,2,2-Tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (CAS No.: 16627-68-2)

[0116] Increasing the electrode mix density can increase the energy density, but can relatively reduce the electrolyte impregnation characteristics. Fluorine compounds can improve the wettability of the electrolyte and the adhesion of the electrode, and can reduce the surface tension of the electrolyte.

[0117] The first compound may be added to an electrolyte for a rechargeable lithium battery to improve the impregnation characteristics of the electrolyte. The first compound may improve the impregnation properties of the electrolyte in a rechargeable lithium battery using an electrode having a high mixing density.

[0118] The first compound may be included in an amount of about 0.01 wt % to about 20 wt % relative to the total weight of the electrolyte for a rechargeable lithium battery.

[0119] For example, the first compound may be included in an amount of about 0.1 wt % to about 20 wt %, about 0.1 wt % to about 15 wt %, about 0.1 wt % to about 10 wt %, about 1 wt % to about 10 wt %, or 5 wt % to about 10 wt %, relative to the total weight of the electrolyte for a rechargeable lithium battery.

[0120] In rechargeable lithium batteries, the electrolyte may decompose during the initial charge-discharge period to form a film with passivation ability on the surface of the positive electrode and the negative electrode, thereby improving high-temperature storage characteristics, but the film may degrade due to the acid (such as HF and PF5) generated by the thermal decomposition of the lithium salt (LiPF6, etc.) used in the rechargeable lithium battery. This acid corrosion may dissolve transition metals from the positive electrode and increase the surface resistance of the electrode caused by structural changes on the surface, and the theoretical capacity may be reduced due to the loss of metal elements as redox (reduction and oxidation) centers, which may lead to capacity reduction. In addition, the dissolved transition metal ions may be electrodeposited on the negative electrode, which reacts in a strong reduction potential range, not only consuming electrons, but also destroying the film during the electrodeposition process to expose the surface of the negative electrode, thereby causing another electrolyte decomposition reaction. Therefore, the surface resistance and irreversible capacity of the negative electrode may increase, and accordingly there may be a problem of substantially continuous reduction in the capacity of the battery cell. In the present disclosure, the triazole group and the sulfone group of the above-mentioned second compound represented by Chemical Formula 2 can provide an unshared electron pair to capture PF5 and stabilize LiPF6 salt, and as a result, acid caused by decomposition of the lithium salt can be removed.

[0121] The sulfone group included in Chemical Formula 2 may form a film on the surface of the positive electrode to suppress or reduce decomposition of the positive electrode active material, thereby suppressing or reducing dissolution of gas and transition metals generated by decomposition of the positive electrode active material.

[0122] In addition, the above-mentioned second compound represented by Chemical Formula 2 may strengthen the solid electrolyte interface (SEI) layer on the surface of the negative electrode while preventing or reducing degradation of the SEI layer or dissolution of transistor metal from the positive electrode during high-temperature storage.

[0123] For example, selected from L 2A and L 2B At least one of them may be a substituted or unsubstituted C1-C5 alkylene group.

[0124] For example, L 2A and L 2B Each independently may be a substituted or unsubstituted C1-C5 alkylene group.

[0125] For example, selected from L 2A and L 2B At least one of them may be a substituted or unsubstituted C2-C5 alkylene group.

[0126] For example, L 2A and L 2B Each independently may be a substituted or unsubstituted C2-C5 alkylene group.

[0127] For example, Chemical Formula 2 can be represented by Chemical Formula 2-1.

[0128] [Chemical Formula 2-1]

[0129]

[0130] In Chemical Formula 2-1, L 1 and L 2 Each independently may be a substituted or unsubstituted C2-C5 alkylene group.

[0131] In Chemical Formula 2-1, R 21A 、R 21B 、R 21C and R 21D They may each independently be hydrogen, halogen, substituted or unsubstituted C1-C10 alkyl, or substituted or unsubstituted C3-C10 cycloalkyl.

[0132] In one or more embodiments, the second compound can be selected from the compounds listed in Group 1.

[0133] [Group 1]

[0134]

[0135] The second compound may be included in an amount of about 0.01 wt % to about 10 wt % relative to the total weight of the electrolyte for a rechargeable lithium battery.

[0136] For example, the second compound may be included in an amount of about 0.1 wt % to about 10 wt %, about 0.5 wt % to about 10 wt %, about 1 wt % to about 10 wt %, or about 1 wt % to about 5 wt % relative to the total weight of the electrolyte for a rechargeable lithium battery.

[0137] An electrolyte for a rechargeable lithium battery may include a first compound and a second compound in a weight ratio of about 1:1 to about 20:1.

[0138] For example, the electrolyte for a rechargeable lithium battery may include the first compound and the second compound in a weight ratio of about 1:1 to about 15:1, about 1:1 to about 10:1, or about 5:1 to about 10:1.

[0139] When the first compound and the second compound are mixed in the ratio discussed above, the electrolyte can have the most improved impregnation characteristics.

[0140] The first compound and the second compound may each be included in an amount of about 0.01 wt % to about 30 wt % relative to the total weight of the electrolyte for a rechargeable lithium battery.

[0141] For example, the first compound and the second compound may each be included in an amount of about 0.01 wt % to about 25 wt %, about 0.01 wt % to about 15 wt %, about 0.01 wt % to about 10 wt %, about 0.1 wt % to about 10 wt %, or about 1 wt % to about 10 wt %, relative to the total weight of the electrolyte for a rechargeable lithium battery. When the content (e.g., amount) range is as described above, an increase in high-temperature resistance can be prevented or reduced to achieve a rechargeable lithium battery with improved lifespan and output characteristics.

[0142] The electrolyte of the rechargeable lithium battery may further include at least one selected from vinylene carbonate (VC), fluoroethylene carbonate (FEC), difluoroethylene carbonate, chloroethylene carbonate, dichloroethylene carbonate, bromoethylene carbonate, dibromoethylene carbonate, nitroethylene carbonate, cyanoethylene carbonate, vinylethylene carbonate (VEC), adiponitrile (AN), succinonitrile (SN), 1,3,6-hexanetricyanide (HTCN), propane sultone (PST), propane sultone (PS), lithium tetrafluoroborate (LiBF4), lithium difluorophosphate (LiPO2F2) and 2-fluorobiphenyl (2-FBP) as other additives.

[0143] The additional inclusion of the aforementioned other additives can further increase the lifespan or effectively control gas generation from the positive electrode and the negative electrode during high-temperature storage.

[0144] The other additives may be included in an amount of about 0.1 wt % to about 20 wt %, about 0.2 wt % to about 15 wt %, or about 0.2 wt % to about 10 wt % relative to the total weight of the electrolyte for a rechargeable lithium battery.

[0145] When the amounts of other additives are as described above, an increase in high-temperature resistance can be minimized or reduced, thereby contributing to improved battery performance.

[0146] Rechargeable lithium battery

[0147] Based on the shape of the rechargeable lithium battery, the rechargeable lithium battery can be classified into cylindrical, prismatic, pouch type and coin type (types). Figures 2 to 5 middle, Figure 2 A cylindrical rechargeable lithium battery is shown, Figure 3 A prismatic rechargeable lithium battery is shown, and Figure 4 and Figure 5 Shows the pouch type or kind of rechargeable lithium battery. Figures 2 to 4 , the rechargeable lithium battery 100 may include an electrode assembly 40 (in which the separator 30 is inserted between the positive electrode 10 and the negative electrode 20), and may further include a case 50 (in which the electrode assembly 40 is housed). The positive electrode 10, the negative electrode 20, and the separator 30 may be immersed in an electrolyte. The rechargeable lithium battery 100 may include a sealing member 60 that seals the case 50, as in Figure 2 In addition, as in Figure 3 As explained in FIG, the rechargeable lithium battery 100 may include a positive electrode lead tab 11, a positive electrode terminal 12, a negative electrode lead tab 21, and a negative electrode terminal 22. Figure 4 and Figure 5 As shown in FIG, the rechargeable lithium battery 100 may include an electrode tab 70 serving as an electrical path for guiding current generated in the electrode assembly 40 outward, or may include a positive electrode tab 71 and a negative electrode tab 72.

[0148] The rechargeable lithium battery according to one or more embodiments of the present disclosure may be applied to automobiles, mobile phones, and / or any other electric devices, but the present disclosure is not limited thereto.

[0149] The following describes embodiments of the present disclosure and comparative examples. The following examples are merely one or more embodiments of the present disclosure, and the present disclosure is not limited to the following examples.

[0150] Embodiments and Comparative Examples

[0151] The electrolyte and the rechargeable lithium battery were manufactured by the following methods.

[0152] Implementation Method 1

[0153] (1) Preparation of electrolyte

[0154] 1.3 M LiPF6 was dissolved in a non-aqueous organic solvent (in which ethylene carbonate (EC), propylene carbonate (PC), ethylpropyl carbonate (EPC) and propyl propionate (PP) were mixed in a volume ratio of 10:15:30:45), and an electrolyte was prepared by adding the first compound represented by Chemical Formula 1-1 and the second compound represented by Chemical Formula 2-1-1.

[0155] The first compound was mixed at 5 wt % with respect to 100 wt % of the total electrolyte, and the second compound was mixed at 1 wt % with respect to 100 wt % of the total electrolyte.

[0156] [Chemical Formula 1-1]

[0157]

[0158] 1,1,2,2-Tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (CAS No.: 16627-68-2)

[0159] [Formula 2-1-1]

[0160]

[0161] (2) Manufacturing of rechargeable lithium batteries

[0162] LiCoO 2 as a positive electrode active material, polyvinylidene fluoride as a binder, and acetylene black as a conductive material were mixed at a weight ratio of 96:3:1, and the mixture was dispersed in N-methylpyrrolidone to prepare a positive electrode active material slurry.

[0163] The positive electrode active material slurry was coated on an Al foil having a thickness of 15 μm, dried at a temperature of 100° C., and then pressed to manufacture a positive electrode.

[0164] Artificial graphite as a negative electrode active material, a styrene-butadiene rubber binder, and carboxymethyl cellulose were mixed at a weight ratio of 98:1:1 and dispersed in distilled water to prepare a negative electrode active material slurry.

[0165] The negative electrode active material slurry was coated on a Cu foil having a thickness of 10 μm, dried at 100° C., and then pressed to produce a negative electrode. In this step (eg, action or task), the negative electrode was adjusted to have a mixed density of 1.7 g / cc.

[0166] The positive electrode, the negative electrode, and a polyethylene separator having a thickness of 10 μm were assembled to manufacture an electrode assembly, and an electrolyte was introduced to manufacture a rechargeable lithium battery.

[0167] Implementation Method 2

[0168] An electrolyte and a rechargeable lithium battery were manufactured by substantially the same method as that of Embodiment 1, except that 10 wt % of the first compound and 1 wt % of the second compound were added if (eg, when) preparing the electrolyte.

[0169] Implementation 3

[0170] An electrolyte and a rechargeable lithium battery were manufactured by substantially the same method as that of Embodiment 1, except that 10 wt % of the first compound and 2 wt % of the second compound were added if (eg, when) preparing the electrolyte.

[0171] Implementation 4

[0172] An electrolyte and a rechargeable lithium battery were manufactured by substantially the same method as that of Embodiment 3, except that if (eg, when) a negative electrode was formed, the negative electrode was adjusted to have a mixed density of 1.75 g / cc.

[0173] Implementation 5

[0174] An electrolyte and a rechargeable lithium battery were manufactured by substantially the same method as that of Embodiment 3, except that if (eg, when) a negative electrode was formed, the negative electrode was adjusted to have a mixed density of 1.8 g / cc.

[0175] Comparative Example 1

[0176] An electrolyte and a rechargeable lithium battery are manufactured by a method substantially the same as that of embodiment 1, except that if (for example, when) the electrolyte is prepared, neither the first compound nor the second compound is added, and if (for example, when) the negative electrode is formed, the negative electrode is adjusted to have a mixed density of 1.65 g / cc.

[0177] Comparative Example 2

[0178] An electrolyte and a rechargeable lithium battery are manufactured by a method substantially the same as that of embodiment 1, except that if (for example, when) the electrolyte is prepared, neither the first compound nor the second compound is added, and if (for example, when) the negative electrode is formed, the negative electrode is adjusted to have a mixed density of 1.67 g / cc.

[0179] Comparative Example 3

[0180] The electrolyte and the rechargeable lithium battery are manufactured by substantially the same method as that of Embodiment 1, except that neither the first compound nor the second compound is added if (eg, when) preparing the electrolyte.

[0181] Comparative Example 4

[0182] An electrolyte and a rechargeable lithium battery were manufactured by substantially the same method as that of Embodiment 1, except that if (eg, when) the electrolyte was prepared, 5 wt % of the first compound was added and the second compound was not added.

[0183] Comparative Example 5

[0184] An electrolyte and a rechargeable lithium battery were manufactured by substantially the same method as in Embodiment 1, except that if (eg, when) the electrolyte was prepared, 1 wt % of the second compound was added and the first compound was not added.

[0185] Evaluation Example

[0186] The following methods were used to evaluate the negative electrodes and rechargeable lithium batteries.

[0187] Evaluation 1: Impregnation of electrolyte into negative electrode

[0188] The negative electrode according to Embodiment 1 was manufactured as a sample having a width of 3 cm and a length of 4 cm. 1 g of the electrolyte according to Embodiment 1 was dropped on the sample, and after a standing time of 1 minute, an image showing the area of ​​the electrolyte on the negative electrode surface was captured, and Figure 6 Shown in.

[0189] In addition, in 100 wt % of the electrolyte solution dropped on the sample, the amount of the electrolyte solution impregnated in the sample was evaluated as a numerical value of 0 to 5 according to the following standard, and the evaluation results are shown in Table 1.

[0190] 0: The amount of the electrolyte impregnated into the sample is equal to or greater than 0 wt % and less than 10 wt %.

[0191] 1: The amount of the electrolyte impregnated into the sample is equal to or greater than 10 wt % and less than 20 wt %.

[0192] 2: The amount of the electrolyte impregnated into the sample is equal to or greater than 20 wt % and less than 40 wt %.

[0193] 3: The amount of the electrolyte impregnated into the sample is equal to or greater than 40 wt % and less than 60 wt %.

[0194] 4: The amount of the electrolyte impregnated into the sample is equal to or greater than 60 wt % and less than 80 wt %.

[0195] 5: The amount of the electrolyte impregnated into the sample is equal to or greater than 80 wt % and less than 100 wt %.

[0196] The same method was used to evaluate Embodiments 2 to 5 and Comparative Examples 1 to 5, and the evaluation results are listed in Table 1.

[0197] Figure 6 Part (1) in FIG. 1 depicts an image obtained after a standing time of 1 minute according to Evaluation 1 by using the electrolytic solution of Embodiment 1.

[0198] Figure 6 Part (2) in FIG. 1 depicts an image obtained after a standing time of 1 minute according to Evaluation 1 by using the electrolyte solution of Embodiment 2.

[0199] Figure 6 Part (3) in FIG. 1 depicts an image obtained after a standing time of 1 minute according to Evaluation 1 by using the electrolyte solution of Embodiment 3.

[0200] Figure 6Part (4) in FIG. 1 depicts an image obtained after a standing time of 1 minute according to Evaluation 1 by using the electrolyte solution of Embodiment 4.

[0201] Figure 6 Part (5) in FIG. 1 depicts an image obtained after a standing time of 1 minute according to Evaluation 1 by using the electrolyte solution of Embodiment 5.

[0202] For reference, Figure 6 Part (6) in FIG. 1 depicts an image obtained after a standing time of 1 minute according to Evaluation 1 by using the electrolyte of Comparative Example 1.

[0203] For reference, Figure 6 Part (7) in FIG. 1 depicts an image obtained after a standing time of 1 minute according to Evaluation 1 by using the electrolyte of Comparative Example 2.

[0204] For reference, Figure 6 Part (8) in FIG. 1 depicts an image obtained after a standing time of 1 minute according to Evaluation 1 by using the electrolyte of Comparative Example 3.

[0205] For reference, Figure 6 Part (9) in FIG. 1 depicts an image obtained after a standing time of 1 minute according to Evaluation 1 by using the electrolyte of Comparative Example 4.

[0206] For reference, Figure 6 Part (10) in FIG. 1 depicts an image obtained after a standing time of 1 minute according to Evaluation 1 by using the electrolyte of Comparative Example 5.

[0207] [Table 1]

[0208]

[0209] *The unit wt% of the first compound and the second compound is based on 100 wt% of the total electrolyte.

[0210] **The hyphen (-) mark means no addition during the preparation of the electrolyte.

[0211] Evaluation 2: Charge / discharge characteristics at high temperatures

[0212] The rechargeable lithium battery was charged and discharged for 200 cycles at 45° C. under the conditions of 0.33 C charge (CC / CV, 4.3 V, 0.025 C cutoff) and 1.0 C discharge (CC, 2.5 V cutoff).

[0213] The thickness increase rate was calculated according to Equation 1, and the capacity retention rate was calculated according to Equation 2, and the results are listed in Table 2.

[0214] [Equation 1]

[0215] Thickness increase rate = 100 × {(fully charged thickness after 200 cycles) – (fully charged thickness after 1 cycle)} / (fully charged thickness after 1 cycle)

[0216] In Equation 1, the term "fully charged thickness" may refer to the thickness of a rechargeable lithium battery measured after charging to SOC 100% (a 100% fully charged state if (e.g., when) the total charge capacity of the battery is set to 100%) after each cycle.

[0217] [Equation 2]

[0218] Capacity retention rate = (discharge capacity after 200 cycles / discharge capacity after 1 cycle) × 100

[0219] [Table 2]

[0220]

[0221] *The unit wt% of the first compound and the second compound is based on 100 wt% of the total electrolyte.

[0222] **The hyphen (-) mark means no addition during the preparation of the electrolyte.

[0223] Comprehensive Assessment

[0224] Refer to Table 1 and Table 2 and Figure 6 When neither the first compound nor the second compound is used (Comparative Examples 1 to 3), as the mixing density of the negative electrode increases from 1.65 g / cc to 1.7 g / cc, the impregnation of the electrolyte into the negative electrode is reduced, the battery thickness is increased (i.e., the electrode swells), and the life is shortened.

[0225] When the negative electrode has the same mixing density of 1.7 g / cc, the case where an electrolyte containing the first compound and the second compound is used (embodiment 1 to embodiment 3) can increase the impregnation of the electrolyte into the negative electrode, reduce the battery thickness, and increase the lifespan, compared with the case where an electrolyte is used that does not contain the first compound and the second compound or contains only one of the first compound and the second compound (Comparative Examples 3 to 5).

[0226] In the case of using an electrolyte including a compound in which a first compound and a second compound are mixed with each other, even when (for example, when) the mixing density of the negative electrode is increased from 1.7 g / cc to 1.8 g / cc, an increase in battery thickness and a shortening of battery life can be suppressed or reduced (embodiments 4 and 5).

[0227] The electrolyte for a rechargeable lithium battery according to one or more embodiments may improve impregnation properties, high-temperature lifespan, and electrode swelling.

[0228] The battery management system (BMS) device and / or any other related devices or components according to the embodiments of the present disclosure described herein may be implemented using any appropriate hardware, firmware (e.g., an application-specific integrated circuit), software, or a combination of software, firmware, and hardware. For example, one or more appropriate components of the device may be formed on a single integrated circuit (IC) chip or on separate IC chips. Further, one or more appropriate components may be implemented on a flexible printed circuit film, a tape carrier package (TCP), or a printed circuit board (PCB), or formed on a single substrate. Further, one or more appropriate components of the device may be processes or threads running on one or more processors in one or more computing devices, executing computer program instructions and interacting with other system components to perform one or more appropriate functions described herein. The computer program instructions are stored in a memory, which may be implemented in the computing device using standard storage devices (such as, for example, random access memory (RAM)). The computer program instructions may also be stored in other non-transitory computer-readable media (such as, for example, CD-ROMs, flash drives, etc.). Furthermore, those skilled in the art will recognize that, without departing from the scope of the present disclosure, the functionality of one or more appropriate computing devices may be combined or integrated into a single computing device, or the functionality of a dedicated computing device may be distributed across one or more other computing devices.

[0229] Although the present disclosure has been described in conjunction with what are presently considered to be practical example embodiments, it is to be understood that the disclosure is not limited to the disclosed embodiments and is intended to cover one or more suitable modifications and equivalent arrangements included within the spirit and scope of the claims and their equivalents. Therefore, the foregoing embodiments are to be understood as examples and not as limiting the present disclosure in any way.

Claims

1. An electrolyte comprising: Non-aqueous organic solvents; lithium salts; a first compound represented by Chemical Formula 1; and The second compound represented by Chemical Formula 2, Chemical formula 1 R 1A -O-R 1B , Wherein in Chemical Formula 1, R 1A and R 1B are each independently a substituted or unsubstituted C2-C10 alkyl group, and Selected from R 1A and R 1B At least one of them is a halogenated alkyl group represented by Chemical Formula A1, Chemical formula A1 C n H 2n+1-m X m , Wherein in Chemical Formula A1, X is F, Cl, Br, I or a combination thereof, n is an integer between 2 and 10, and m is an integer between 2 and 2n+1, Chemical formula 2 Wherein in Chemical Formula 2, L 2A and L 2B Each is independently a single bond, a substituted or unsubstituted C1-C5 alkylene group, a substituted or unsubstituted C2-C5 alkenylene group, a substituted or unsubstituted C2-C5 alkynylene group, or a substituted or unsubstituted C6-C20 arylene group, A and B are each independently a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C6-C20 aryl group, or a substituted or unsubstituted C2-C20 heteroaryl group, and At least one selected from A and B is a group represented by Chemical Formula A2, Chemical formula A2 In the chemical formula A2, R 2A and R 2B are each independently hydrogen, halogen, substituted or unsubstituted C1-C10 alkyl, or substituted or unsubstituted C3-C10 cycloalkyl, and The electrolyte is used in rechargeable lithium batteries.

2. The electrolyte of claim 1, wherein R 1A and R 1B Each is independently a halogenated alkyl group represented by Chemical Formula A1. The electrolyte according to claim 1 , wherein X is F. . 4 . The electrolyte of claim 1 , wherein the first compound comprises 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether, 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether, or a mixture thereof.

5. The electrolyte according to claim 1, wherein Chemical Formula 1 is represented by Chemical Formula 1-1, Chemical formula 1-1 6. The electrolyte according to claim 1, wherein the 2A and L 2B At least one of them is a substituted or unsubstituted C1-C5 alkylene group.

7. The electrolyte according to claim 1, wherein the 2A and L 2B At least one of them is a substituted or unsubstituted C2-C5 alkylene group.

8. The electrolyte of claim 1, wherein L 2A and L 2B Each is independently a substituted or unsubstituted C2-C5 alkylene group.

9. The electrolyte according to claim 1, wherein Chemical Formula 2 is represented by Chemical Formula 2-1, Chemical formula 2-1 In Chemical Formula 2-1, L 1 and L 2 are each independently a substituted or unsubstituted C2-C5 alkylene group, and R 21A 、R 21B 、R 21C and R 21D Each is independently hydrogen, halogen, substituted or unsubstituted C1-C10 alkyl, or substituted or unsubstituted C3-C10 cycloalkyl.

10. The electrolyte of claim 1, wherein the second compound comprises at least one compound selected from the group consisting of: Group 1 11 . The electrolyte according to claim 1 , wherein a weight ratio of the first compound to the second compound is 1:1 to 20:

1. 12 . The electrolyte according to claim 1 , wherein a weight ratio of the first compound to the second compound is 5:1 to 10:

1. 13 . The electrolyte of claim 1 , wherein an amount of the first compound is 0.01 wt % to 30 wt % relative to a total weight of the electrolyte for the rechargeable lithium battery. 14 . The electrolyte of claim 1 , wherein an amount of the second compound is 0.01 wt % to 30 wt % relative to a total weight of the electrolyte for the rechargeable lithium battery.

15. The electrolyte of claim 1 , further comprising at least one selected from the group consisting of vinylene carbonate, fluoroethylene carbonate, difluoroethylene carbonate, chloroethylene carbonate, dichloroethylene carbonate, bromoethylene carbonate, dibromoethylene carbonate, nitroethylene carbonate, cyanoethylene carbonate, vinylethylene carbonate, adiponitrile, succinonitrile, 1,3,6-hexanetricyanide, propene sultone, propane sultone, lithium tetrafluoroborate, lithium difluorophosphate, and 2-fluorobiphenyl.

16. A rechargeable lithium battery comprising: a positive electrode comprising a positive electrode active material; a negative electrode comprising a negative electrode active material; and The electrolyte according to any one of claims 1 to 15.

17. The rechargeable lithium battery of claim 16, wherein the negative electrode has a mixed density equal to or greater than 1.7 g / cc.

Images