Electrolyte for rechargeable lithium battery and rechargeable lithium battery including same

Abstract

An electrolyte solution for a rechargeable lithium battery and a rechargeable lithium battery including the electrolyte solution are provided. The electrolyte comprises a lithium salt, a non-aqueous organic solvent and an additive. The non-aqueous organic solvent includes a compound represented by Chemical Formula 1. The additive may include a compound represented by Chemical Formula 2. Chemical formula 1 # imgabs0 # and chemical formula 2 # imgabs1 #

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2024-0033408 filed in the Korean Intellectual Property Office on March 8, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] One or more embodiments of the present disclosure relate to an electrolyte for a rechargeable lithium battery and a rechargeable lithium battery including the electrolyte. Background Art

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

[0005] Rechargeable lithium batteries include a positive electrode, a negative electrode, and an electrolyte. The positive electrode and the negative electrode (each) include an active material capable of intercalating and deintercalating lithium ions, and when the lithium ions are intercalated and deintercalated, electric energy is generated due to oxidation and reduction reactions. Summary of the Invention

[0006] One or more aspects of embodiments of the present disclosure are directed to an electrolyte capable of improving high-temperature characteristics of a rechargeable lithium battery.

[0007] One or more aspects of embodiments of the present disclosure are directed to a rechargeable lithium battery that includes an electrolyte and has desirable high-temperature characteristics under a high-voltage environment.

[0008] Additional aspects will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the presented embodiments of the disclosure.

[0009] According to one or more embodiments of the present disclosure, an electrolyte for a rechargeable lithium battery may include: a lithium salt; a non-aqueous organic solvent; and an additive.

[0010] The non-aqueous organic solvent may include a compound represented by Chemical Formula 1.

[0011] The additive may include a compound represented by Chemical Formula 2.

[0012] Chemical formula 1

[0013]

[0014] In Chemical Formula 1, R 1A and R1B They may each independently be hydrogen, halogen, substituted or unsubstituted C1-C10 alkyl, or substituted or unsubstituted C3-C10 cycloalkyl.

[0015] Chemical formula 2

[0016]

[0017] 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.

[0018] 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.

[0019] In Chemical Formula 2, at least one selected from A and B may be a group represented by Chemical Formula A.

[0020] Chemical formula A

[0021]

[0022] In chemical formula A, 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.

[0023] 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and other aspects, features and advantages of certain embodiments of the present disclosure will be more apparent from the following description taken in conjunction with the accompanying drawings.

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

[0026] Figures 2 to 5 Each illustrates a simplified conceptual diagram showing a rechargeable lithium battery according to one or more embodiments of the present disclosure. DETAILED DESCRIPTION

[0027] In order to fully understand the configuration 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 illustrate the present disclosure and enable those skilled in the art to fully understand the scope of the present disclosure.

[0028] In the present disclosure, it will be understood that if an element is referred to as being on another element (e.g., when an element is referred to as being on another element), the element may be directly on the other element or there may be intervening elements therebetween. In contrast, if an element is referred to as being "directly on" another element (e.g., when an element is referred to as being "directly on" another element), there are no intervening elements. In the accompanying drawings, the size (e.g., thickness) of some components may be exaggerated for the purpose of effectively explaining the technical content. Throughout the present disclosure, the same reference numerals refer to the same elements, and for the sake of brevity, their repeated descriptions may not be provided.

[0029] Unless otherwise specifically stated in this disclosure, the singular forms "a", "an" and "the" are intended to include the plural forms as well. Further, the use of "may" when describing embodiments of the present disclosure refers to "one or more embodiments of the present disclosure". In addition, unless otherwise specifically stated, the phrases "A or B", "A and / or B" or "A / B" may indicate "A but not B", "B but not A" as well as "A and B". The terms "comprises / includes" and / or "comprising / including" used in this disclosure do not exclude the presence or addition of one or more other components.

[0030] As used herein, the term "combination thereof" may refer to a mixture, stack, composite, copolymer, alloy, blend, or reaction product of the components.

[0031] Unless otherwise specifically defined in this description, the particle size may be an average particle size. In addition, the particle size indicates the average particle size (D 50 The average particle size (D) can be measured by a method widely applicable to those skilled in the art. 50 ), for example, by measuring the average particle size (D) by a particle size analyzer, for example, HORIBA, LA-950 laser particle size analyzer, transmission electron microscope (TEM) or scanning electron microscope (SEM). 50 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 then the average particle size (D) is obtained from the data by calculation. 50) value. In some embodiments, laser scattering can be used to measure the average particle size (D 50 In 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 the 50% particle size distribution standard. 50 ). D 50 The term "diameter" refers to the average diameter (or size) of particles whose cumulative volume corresponds to 50% by volume in a particle size distribution (e.g., cumulative distribution), and refers to the value of the particle size corresponding to 50% from the smallest particle when the total number of particles is 100% in a distribution curve accumulated in the order of the smallest particle size to the largest particle size. In the present disclosure, when the particles are spherical, "diameter" indicates the average particle diameter, and when the particles are non-spherical, "diameter" indicates the length of the major axis.

[0032] In the present disclosure, unless otherwise limited, the term "substituted" may refer to a substituent or a compound in which at least one hydrogen is replaced by deuterium, halogen, hydroxy, amino, C1-C30 amine, nitro, C1-C40 silyl, C1-C30 alkyl, C1-C10 alkylsilyl, C6-C30 arylsilyl, C3-C30 cycloalkyl, C3-C30 heterocycloalkyl, C6-C30 aryl, C2-C30 heteroaryl, C1-C20 alkoxy, C1-C10 fluoroalkyl, cyano, or a combination thereof (e.g., any suitable combination).

[0033] For example, 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-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. 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-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. In one or more embodiments, the term "substituted" may refer to a substituent or compound having at least one hydrogen substituted by deuterium, cyano, halogen, methyl, ethyl, propyl, butyl, phenyl, biphenyl, terphenyl, trifluoromethyl, or naphthyl. Alkyl groups may include linear and / or branched alkyl groups, and cycloalkyl groups may include cyclic alkyl groups.

[0034] Figure 1 A simplified 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.

[0035] The positive electrode 10 and the negative electrode 20 may be separated and / or isolated from each other (e.g., spaced apart or separated) by a 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 contact the electrolyte ELL. For example, the positive electrode 10, the negative electrode 20, and the separator 30 may be immersed in and / or impregnated with the electrolyte ELL.

[0036] The electrolyte ELL may be a medium through which lithium ions migrate and transport between the positive electrode 10 and the negative electrode 20. In the electrolyte ELL, the lithium ions may move toward (eg, selected from) one of the positive electrode 10 and the negative electrode 20 through the separator 30.

[0037] Positive electrode 10

[0038] 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 (e.g., in the form of particles) and may further include a binder and / or a conductive material (e.g., an electron conductor).

[0039] For example, in some embodiments, the positive electrode 10 may further include a component that may function as a sacrificial positive electrode.

[0040] The amount of the positive electrode active material may be in a range of about 90 wt % to about 99 wt % based on 100 wt % of the total weight of the positive electrode active material layer AML1. The amount of the binder and the conductive material may each be in a range of about 0.5 wt % to about 5 wt % based on 100 wt % of the total weight of the positive electrode active material layer AML1.

[0041] The binder can be used to improve the attachment of the positive electrode active material particles to each other and also to improve the attachment of the positive electrode active material to the positive electrode current collector COL1. The binder may include, for example, one or more selected from polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene oxide-containing polymers, polyvinyl pyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, (meth)acrylated styrene-butadiene rubber, epoxy resin, (meth)acrylic resin, polyester resin, and nylon, but embodiments of the present disclosure are not limited thereto.

[0042] Conductive materials (e.g., electrically conductive materials or electron-conductive materials) can be used to provide conductivity to the electrodes, 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, a carbon-based material (such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber, carbon nanofiber, and / or carbon nanotube); a metal powder or metal fiber containing (e.g., selected from) one or more of copper, nickel, aluminum, and silver; a conductive polymer (e.g., a polyphenylene derivative); and / or a mixture (e.g., combination) thereof (e.g., any suitable mixture (e.g., combination) thereof).

[0043] In one or more embodiments, an aluminum (Al) foil may be used as the positive electrode current collector COL1 , but embodiments of the present disclosure are not limited thereto.

[0044] Positive electrode active material

[0045] The positive electrode active material in the positive electrode active material layer AML1 may include a compound that can reversibly intercalate and deintercalate lithium (e.g., a lithiated intercalation compound). For example, in one or more embodiments, the positive electrode active material may include at least one type of composite oxide including lithium and a metal selected from cobalt, manganese, nickel, and combinations thereof (e.g., any suitable combination).

[0046] 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 combinations thereof (eg, any appropriate combination).

[0047] For example, in one or more embodiments, the positive electrode active material may include a compound represented by one selected from the following chemical formulas: Li a A 1-b X b O 2-c D c (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 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≤0.1); 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).

[0048] In the aforementioned chemical formula, A may be nickel (Ni), cobalt (Co), manganese (Mn), and / or a combination thereof (e.g., any appropriate combination), X may be Al, Ni, Co, Mn, chromium (Cr), iron (Fe), magnesium (Mg), strontium (Sr), vanadium (V), a rare earth element, and / or a combination thereof (e.g., any appropriate combination), D may be oxygen (O), fluorine (F), sulfur (S), phosphorus (P), and / or a combination thereof (e.g., any appropriate combination), G may be Al, Cr, Mn, Fe, Mg, lanthanum (La), cerium (Ce), Sr, V, and / or a combination thereof (e.g., any appropriate combination), and L 1 is Mn, Al, and / or combinations thereof (eg, any suitable combination).

[0049] For example, in one or more embodiments, 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, based on 100 mol% of the total metal other than lithium in the lithium transition metal composite oxide. The high nickel-based positive electrode active material can achieve high capacity and can therefore be applied to high capacity and high energy density rechargeable lithium batteries.

[0050] Negative electrode 20

[0051] 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 located on the negative electrode current collector COL2. The negative electrode active material layer AML2 may include a negative electrode active material (e.g., in the form of particles) and may further include a binder and / or a conductive material (e.g., an electron conductor).

[0052] For example, in one or more embodiments, the negative electrode active material layer AML2 may include about 90 wt % to about 99 wt % of a negative electrode active material, about 0.5 wt % to about 5 wt % of a binder, and about 0 wt % to about 5 wt % of a conductive material, based on 100 wt % of the total weight of the negative electrode active material layer AML2.

[0053] The binder can be used to improve the attachment of the negative electrode active material particles to each other and also to improve the attachment of the negative electrode active material to the negative electrode current collector COL 2. The binder can include a non-aqueous binder (e.g., a water-insoluble binder), an aqueous binder (e.g., a water-soluble binder), a dry binder, and / or a combination thereof (e.g., any suitable combination).

[0054] 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 combinations thereof (eg, any suitable combination).

[0055] 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 combinations thereof (e.g., any suitable combination).

[0056] 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 selected from carboxymethyl cellulose, hydroxypropyl methyl cellulose, methyl cellulose, and alkali metal salts thereof. The alkali metal may include Na, K, or Li.

[0057] The dry binder may include a fiberizable polymeric material, such as polytetrafluoroethylene, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polyethylene oxide, and / or combinations thereof (eg, any suitable combination).

[0058] Conductive materials (e.g., electrically conductive materials or electronically conductive materials) can be used to provide conductivity to the electrodes, 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, in one or more embodiments, the conductive material may include a carbon-based material (e.g., natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber, carbon nanofiber, and / or carbon nanotube); a metal powder or metal fiber selected from one or more of copper, nickel, aluminum, and silver; a conductive polymer (e.g., a polyphenylene derivative); and / or a mixture thereof (e.g., any suitable mixture).

[0059] 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 combinations thereof (eg, any suitable combination).

[0060] Negative electrode active material

[0061] 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.

[0062] 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 a combination thereof (e.g., any suitable combination). For example, the crystalline carbon may include graphite (such as amorphous (e.g., irregularly shaped), flake-shaped, sheet-shaped, spherical, or fibrous natural graphite and / or artificial graphite), and the amorphous carbon may include soft carbon, hard carbon, mesophase pitch carbon, and / or calcined coke.

[0063] The lithium metal alloy may include an alloy of lithium and a metal selected from sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), francium (Fr), beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), silicon (Si), antimony (Sb), lead (Pb), indium (In), zinc (Zn), barium (Ba), radium (Ra), germanium (Ge), aluminum (Al) and tin (Sn).

[0064] The materials that can be doped and de-doped with lithium may include Si-based negative electrode active materials or Sn-based negative electrode active materials. The Si-based negative electrode active materials may include silicon, silicon-carbon composites, SiO x (0 < x ≤ 2), Si-Q alloys (where Q is an alkali metal, alkaline earth metal, Group 13 element, Group 14 element (excluding Si), Group 15 element, Group 16 element, transition metal, 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 materials may include Sn, SnO k (0 < k ≤ 2) (e.g., SnO2), Sn-based alloys, or a combination thereof (e.g., any suitable combination).

[0065] The silicon-carbon composite may be a composite of silicon and amorphous carbon (e.g., in the form of particles). According to one or more embodiments, the silicon-carbon composite may have a structure in which amorphous carbon is coated on the surface of each of the silicon particles. For example, in one or more embodiments, the silicon-carbon composite may include secondary particles (cores) in which primary silicon particles are aggregated, and an amorphous carbon coating (shell) on the surface of the secondary particles (e.g., 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.

[0066] In one or more embodiments, 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 on the surface of the core.

[0067] In one or more embodiments, the Si-based negative electrode active materials and / or the Sn-based negative electrode active materials may be used in combination with carbon-based negative electrode active materials.

[0068] Separator 30

[0069] 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 selected from a polyethylene separator, a polypropylene separator, and a polyvinylidene fluoride separator, or may be a multilayer separator thereof (such as a polyethylene / polypropylene bilayer separator, a polyethylene / polypropylene / polyethylene trilayer separator, or a polypropylene / polyethylene / polypropylene trilayer separator).

[0070] The separator 30 may include a porous substrate and a coating on the surface (e.g., one surface or two opposite surfaces) of the porous substrate, and the coating may include an organic material, an inorganic material, and / or a combination thereof (e.g., any suitable combination).

[0071] The porous substrate may be a polymer layer comprising 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 a copolymer or mixture comprising two or more thereof.

[0072] The organic material may include a polyvinylidene fluoride-based copolymer and / or a (meth)acrylic acid-based copolymer.

[0073] 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 combinations thereof (e.g., any suitable combination), but embodiments of the present disclosure are not limited thereto.

[0074] In one or more embodiments, 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.

[0075] Electrolyte ELL

[0076] The electrolyte ELL for a rechargeable lithium battery may include a non-aqueous organic solvent, a lithium salt, and additives.

[0077] The non-aqueous organic solvent according to one or more embodiments of the present disclosure will be described below.

[0078] The non-aqueous organic solvent may serve as a medium for transporting ions participating in the electrochemical reaction of the rechargeable lithium battery.

[0079] The non-aqueous organic solvent may include an ester solvent, a carbonate solvent, an ether solvent, a ketone solvent, an alcohol solvent, an aprotic solvent, and / or a combination thereof (eg, any appropriate combination).

[0080] In one or more embodiments, the non-aqueous organic solvent may include an ester-based solvent and a carbonate-based solvent.

[0081] The ester solvent and the carbonate solvent may be mixed in a volume ratio of about 1:1 to about 9:1. For example, the ester solvent and the carbonate solvent may be mixed in a volume ratio of about 1:1 to about 6:1, about 1:1 to about 4:1, or about 2:1 to about 4:1.

[0082] The ester-based solvent according to one or more embodiments of the present disclosure may include a compound represented by Chemical Formula 1.

[0083] Chemical formula 1

[0084]

[0085] In Chemical Formula 1, R 1A and R 1B They may each independently be hydrogen, halogen, substituted or unsubstituted C1-C10 alkyl, or substituted or unsubstituted C3-C10 cycloalkyl.

[0086] In one or more embodiments, R 1A It may be a substituted or unsubstituted C3-C10 alkyl group.

[0087] In one or more embodiments, R 1A It may be a substituted or unsubstituted C3 alkyl group.

[0088] In one or more embodiments, R 1A It may be an unsubstituted C3 alkyl group.

[0089] In one or more embodiments, R 1B It may be a substituted or unsubstituted C1-C2 alkyl group.

[0090] In one or more embodiments, R 1B It may be a substituted or unsubstituted C2 alkyl group.

[0091] In one or more embodiments, R 1B It may be an unsubstituted C2 alkyl group.

[0092] The compound represented by Chemical Formula 1 may include at least one selected from the group consisting of methyl butyrate, ethyl butyrate, propyl butyrate, propyl propionate, methyl propionate, and ethyl propionate.

[0093] The amount of the compound represented by Chemical Formula 1 that can be included relative to 100% by volume of the total volume of the electrolyte for a rechargeable lithium battery is about 50% to about 95% by volume. For example, in one or more embodiments, the amount of the compound represented by Chemical Formula 1 that can be included relative to 100% by volume of the total volume of the electrolyte for a rechargeable lithium battery is about 60% to about 95% by volume or about 70% to about 80% by volume. Within the above amount range, a stable film can be formed on the electrode surface even under high temperature and high voltage environments, and a film of suitable or appropriate thickness can be formed on the electrode surface under high temperature and high voltage environments to prevent or reduce resistance increase, thereby realizing a rechargeable lithium battery with improved lifespan and output characteristics.

[0094] The ester solvent according to one or more embodiments of the present disclosure may include methyl acetate, ethyl acetate, n-propyl acetate, dimethyl acetate, methyl propionate (MP), ethyl propionate (EP), propyl propionate (PP), methyl butyrate, ethyl butyrate (EB), propyl butyrate, decanoic acid lactone, mevalonolactone, valerolactone and / or caprolactone.

[0095] The carbonate-based solvent according to one or more embodiments of the present disclosure 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) and / or butylene carbonate (BC).

[0096] The carbonate-based solvent according to one or more embodiments of the present disclosure may include ethylene carbonate (EC) and propylene carbonate (PC).

[0097] Ethylene carbonate (EC) and propylene carbonate (PC) may be mixed in a volume ratio of about 1:1 to about 1:9. For example, in one or more embodiments, ethylene carbonate (EC) and propylene carbonate (PC) may be mixed in a volume ratio of about 1:1 to about 1:5, about 1:1 to about 1:3, or about 1:1 to about 1:1.5.

[0098] Ether solvents may include dibutyl ether, tetraglyme, diglyme, ethylene glycol dimethyl ether, 2-methyltetrahydrofuran, 2,5-dimethyltetrahydrofuran and / or tetrahydrofuran. Ketone solvents may include cyclohexanone. Alcohol solvents may include ethanol and / 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 and / or 1,4-dioxolane); and / or sulfolane.

[0099] The non-aqueous organic solvent may be used alone or as a mixture of two or more non-aqueous organic solvents.

[0100] In addition, if a carbonate-based solvent is used (for example, when a carbonate-based solvent is used), cyclic carbonate and chain carbonate may be mixed and used, and the cyclic carbonate and chain carbonate may be mixed in a volume ratio of about 1:1 to about 1:9.

[0101] 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).

[0102] Additives for an electrolyte according to one or more embodiments will be described below.

[0103] The additive according to one or more embodiments of the present disclosure may include a compound represented by Chemical Formula 2.

[0104] Chemical formula 2

[0105]

[0106] 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.

[0107] 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.

[0108] In Chemical Formula 2, at least one selected from A and B may be a group represented by Chemical Formula A. In one or more embodiments, one selected from A and B may be a group represented by Chemical Formula A, and the other selected from 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 (each) be a group represented by Chemical Formula A.

[0109] Chemical formula A

[0110]

[0111] In chemical formula A, 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.

[0112] In rechargeable lithium batteries, the electrolyte may decompose during the initial charge-discharge period, forming a film with passivation ability on the surface of the positive electrode and the negative electrode to improve high-temperature storage characteristics. However, due to the acid (such as HF and PF5) generated by the thermal decomposition of lithium salts (LiPF6, etc.) widely used in rechargeable lithium batteries, the film may degrade. This acid corrosion may cause transition metals to dissolve from the positive electrode and increase the surface resistance of the positive electrode due to structural changes on the surface. The theoretical capacity may be reduced due to the loss of metal elements that serve as redox (reduction and oxidation) centers, which may lead to a decrease in capacity. In addition, the dissolved transition metal ions may be electrodeposited on the negative electrode, which reacts in a strong reduction potential range. During the electrodeposition process, not only electrons are consumed but also the film is destroyed, exposing the surface of the negative electrode, thereby causing another electrolyte decomposition reaction. Therefore, the surface resistance and irreversible capacity of the negative electrode may be increased, and accordingly, there may be a problem of continuous reduction in battery cell capacity. In the present disclosure, the triazole and sulfone groups of the compound represented by Chemical Formula 2 can provide unshared electron pairs to capture PF5 and stabilize the LiPF6 salt, thereby removing the acid caused by the decomposition of the lithium salt. For example, the compound represented by Chemical Formula 2 contains both a triazole and a sulfone group. These groups can play a role in capturing PF5 and stabilizing the LiPF6 salt. As a result, they can potentially help remove the acid generated during the decomposition of the lithium salt.

[0113] 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 possibly suppressing or reducing gas generation and dissolution of transition metals due to decomposition of the positive electrode active material.

[0114] In addition, the compound represented by Chemical Formula 2 described herein may strengthen a solid electrolyte interface (SEI) layer on the surface of a negative electrode while preventing or reducing degradation of the SEI layer or dissolution of transition metals from a positive electrode during high-temperature storage.

[0115] For example, in one or more embodiments, the 2A and L 2B At least one of them may be a substituted or unsubstituted C1-C5 alkylene group.

[0116] For example, in one or more embodiments, L 2A and L 2B Each independently may be a substituted or unsubstituted C1-C5 alkylene group.

[0117] For example, in one or more embodiments, the 2A and L 2B At least one of them may be a substituted or unsubstituted C2-C5 alkylene group.

[0118] For example, in one or more embodiments, L 2A and L 2B Each independently may be a substituted or unsubstituted C2-C5 alkylene group.

[0119] For example, in one or more embodiments, the compound represented by Chemical Formula 2 may be represented by Chemical Formula 2-1.

[0120] Chemical formula 2-1

[0121]

[0122] In Chemical Formula 2-1, L 1 and L 2 Each independently may be a substituted or unsubstituted C2-C5 alkylene group.

[0123] 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.

[0124] In one or more embodiments, the compound represented by Chemical Formula 2 may be selected from the compounds listed in Group 1.

[0125] Group 1

[0126]

[0127] The compound represented by Chemical Formula 2 may be included in an amount of about 0.1 to 10 parts by weight relative to a total of 100 parts by weight of the electrolyte for a rechargeable lithium battery.

[0128] For example, in one or more embodiments, the amount of the compound represented by Chemical Formula 2 included relative to a total of 100 parts by weight of the electrolyte for a rechargeable lithium battery may be about 0.5 to 10 parts by weight, about 1 to 10 parts by weight, or about 1 to 5 parts by weight. Within the above amount range, an increase in resistance and / or membrane resistance at high temperatures can be prevented or reduced to achieve a rechargeable lithium battery with improved lifespan and output characteristics.

[0129] In one or more embodiments, the electrolyte for a rechargeable lithium battery may further include at least one other additive selected from the group consisting of 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-hexanetrinitrile (HTCN), propene sultone (PST), propane sultone (PS), lithium tetrafluoroborate (LiBF4), lithium difluorophosphate (LiPO2F2), and 2-fluorobiphenyl (2-FBP).

[0130] The additional inclusion of the aforementioned other additives may further increase the lifespan or effectively control gas generation from the positive and negative electrodes during high temperature storage.

[0131] The other additives may be included in an amount of about 0.2 to 20 parts by weight, for example, about 0.2 to 15 parts by weight or about 0.2 to 10 parts by weight, relative to a total of 100 parts by weight of the electrolyte for a rechargeable lithium battery.

[0132] When the amount of other additives is within the above range, an increase in resistance at high temperature and / or membrane resistance may be minimized or reduced, thereby contributing to improved battery performance.

[0133] The amount of the additive may be 0.1 to 30 parts by weight relative to 100 parts by weight of the electrolyte.

[0134] The electrolyte for a rechargeable lithium battery according to the present disclosure may include both (eg, simultaneously) the compound represented by Chemical Formula 1 and the compound represented by Chemical Formula 2, and thus may prevent or reduce damage to the SEI layer to improve high-temperature storage characteristics.

[0135] Rechargeable lithium battery

[0136] Based on the shape of the rechargeable lithium battery, the rechargeable lithium battery can be classified into cylindrical, prismatic, pouch or coin type (types). Figures 2 to 5 , each illustrating a simplified conceptual diagram showing a rechargeable lithium battery according to one or more embodiments of the present disclosure, Figure 2 shows a cylindrical battery, Figure 3 A prismatic cell is shown, and Figure 4 and Figure 5 Each shows a pouch type or type battery. Figures 2 to 5 , the rechargeable lithium battery 100 may include an electrode assembly 40 in which a separator 30 is interposed between a positive electrode 10 and a negative electrode 20, and may also 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. In some embodiments, as Figure 2 As explained in , the rechargeable lithium battery 100 may include a sealing member 60 that seals the housing 50. In some embodiments, as Figure 3 As explained in , 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. In some embodiments, as Figure 4 and Figure 5 As shown in FIG, the rechargeable lithium battery 100 may include an electrode tab 70, or a positive electrode tab 71 and a negative electrode tab 72, serving as an electrical path for guiding current generated in the electrode assembly 40 to the outside.

[0137] The rechargeable lithium battery according to one or more embodiments of the present disclosure may be applied to motor vehicles, mobile phones, and / or any other electric devices, but the embodiments of the present disclosure are not limited thereto.

[0138] The following will describe embodiments of the present disclosure and comparative examples. The following examples are merely one or more embodiments of the present disclosure, and the embodiments of the present disclosure are not limited to the following examples.

[0139] Embodiments and Comparative Examples

[0140] The electrolyte solution and the rechargeable lithium battery were each manufactured by the following method.

[0141] Implementation Method 1

[0142] (1) Preparation of electrolyte

[0143] 1.3 M of LiPF 6 was dissolved in a non-aqueous organic solvent in which ethylene carbonate (EC), propylene carbonate (PC), and ethyl butyrate (EB) were mixed at a volume ratio of about 10:15:75, and additives were added to prepare an electrolyte.

[0144] An electrolytic solution was prepared in which 1 wt % of the compound represented by Chemical Formula 2-1-1 (first compound) was mixed with respect to 100 wt % of the total weight of the electrolytic solution.

[0145] Chemical formula 2-1-1

[0146]

[0147] (2) Manufacturing of rechargeable lithium batteries

[0148] 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 distributed in N-methylpyrrolidone to prepare a positive electrode active material slurry.

[0149] The positive electrode active material slurry was coated on an Al foil having a thickness of 15 μm, dried at 100° C., and then pressed to manufacture a positive electrode.

[0150] 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 the mixture was dispersed in distilled water to prepare a negative electrode active material slurry.

[0151] 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 manufacture a negative electrode.

[0152] The positive electrode, the negative electrode, and a polyethylene separator having a thickness of 10 μm were assembled together to manufacture an electrode assembly, and an electrolyte was introduced to manufacture a rechargeable lithium battery.

[0153] Implementation Method 2

[0154] An electrolyte and a rechargeable lithium battery were each manufactured by substantially the same method as that of Embodiment 1, except that when the electrolyte was prepared, an additive in which 3 wt % of the first compound was mixed relative to 100 wt % of the total weight of the electrolyte was added.

[0155] Implementation 3

[0156] An electrolyte and a rechargeable lithium battery were each manufactured by substantially the same method as that of Embodiment 1, except that when the electrolyte was prepared, an additive in which 5 wt % of the first compound was mixed relative to 100 wt % of the total weight of the electrolyte was added.

[0157] Implementation 4

[0158] An electrolyte and a rechargeable lithium battery were each manufactured by a method substantially the same as that of Embodiment 2, except that a non-aqueous organic solvent in which ethylene carbonate (EC), propylene carbonate (PC), and ethyl butyrate (EB) were mixed in a volume ratio of approximately 10:20:70 was used when preparing the electrolyte.

[0159] Implementation 5

[0160] An electrolyte and a rechargeable lithium battery were each manufactured by a method substantially the same as that of Embodiment 2, except that a non-aqueous organic solvent in which ethylene carbonate (EC), propylene carbonate (PC), and ethyl butyrate (EB) were mixed in a volume ratio of approximately 10:10:80 was used when preparing the electrolyte.

[0161] Implementation Method 6

[0162] An electrolyte and a rechargeable lithium battery were each manufactured by a method substantially the same as that of Embodiment 1, except that a non-aqueous organic solvent in which ethylene carbonate (EC), propylene carbonate (PC), and propyl propionate (PP) were mixed in a volume ratio of approximately 10:15:75 was used when preparing the electrolyte.

[0163] Implementation 7

[0164] An electrolyte and a rechargeable lithium battery were each manufactured by a method substantially the same as that of Embodiment 1, except that a non-aqueous organic solvent in which ethylene carbonate (EC), propylene carbonate (PC), and methyl propionate (MP) were mixed in a volume ratio of approximately 10:15:75 was used when preparing the electrolyte.

[0165] Implementation 8

[0166] An electrolyte and a rechargeable lithium battery were each manufactured by a method substantially the same as that of Embodiment 1, except that a non-aqueous organic solvent in which ethylene carbonate (EC), propylene carbonate (PC), and ethyl propionate (EP) were mixed in a volume ratio of approximately 10:15:75 was used when preparing the electrolyte.

[0167] Comparative Example 1

[0168] An electrolyte solution and a rechargeable lithium battery were each manufactured by substantially the same method as that of Embodiment 1, except that no additive was added when preparing the electrolyte solution.

[0169] Comparative Example 2

[0170] An electrolyte and a rechargeable lithium battery were each manufactured by a method substantially the same as that of Embodiment 1, except that when preparing the electrolyte, an electrolyte in which 1 wt % of the compound (second compound) represented by Chemical Formula 3 was mixed relative to 100 wt % of the total weight of the electrolyte was prepared.

[0171] Chemical formula 3

[0172]

[0173] Evaluation example: High-temperature storage characteristics (capacity retention / DC-IR change rate)

[0174] The rechargeable lithium batteries manufactured according to Embodiments 1 to 8 and Comparative Examples 1 and 2 were each charged and discharged once at 0.2 C to measure the charge capacity and the discharge capacity as the initial discharge capacity (before high-temperature storage).

[0175] In addition, the rechargeable lithium batteries manufactured according to Embodiments 1 to 8 and Comparative Examples 1 and 2 were each charged to SOC 100% (i.e., a state in which the battery is charged to 100% of the charge capacity when the total charge capacity is set to 100%), stored at 60°C for 28 days, discharged to 3.0V at 0.2C under constant current conditions, and then measured for the first discharge capacity. The ratio of the first discharge capacity to the initial discharge capacity is shown as the capacity retention rate.

[0176] The rechargeable lithium batteries manufactured according to Embodiments 1 to 8 and Comparative Examples 1 and 2 were respectively measured for ΔV / ΔI (voltage change / current change) as initial DC-IR, and the DC-IR was measured as DC-IR after 28 days by changing the internal maximum energy state of the rechargeable lithium battery to a fully charged state (SOC 100%) and storing the rechargeable lithium battery at a high temperature (60°C) for 28 days in this state. The DC-IR increase rate (%) was calculated according to Equation 1, and the calculated results are listed in Table 1.

[0177] Equation 1

[0178] DC-IR increase rate = ((DC-IR after 28 days - initial DC-IR) / initial DC-IR) × 100

[0179] Table 1

[0180]

[0181] * The unit wt% of the additive is based on 100wt% of the total weight of the electrolyte.

[0182] *The hyphen (-) mark means that the corresponding material was not added during the preparation of the electrolyte.

[0183] Referring to Table 1, compared with the case where an electrolyte without additives is used (Comparative Example 1), in the case where ethyl butyrate (EB) is selected as a solvent and the first compound is selected as an additive (Embodiment 1 to Embodiment 5), the capacity retention rate can be maintained and the DC-IR increase rate may not be high.

[0184] When the amount (e.g., concentration) of the additive is the same (Implementation Example 1 and Comparative Example 2), even if a sulfone additive is used, the capacity retention rate can be improved in the case where the first compound is selected as the additive (Implementation Example 1) compared to the case where the second compound is selected as the additive (Comparative Example 2), and the DC-IR increase rate may not be high.

[0185] In the case of having the same amount of the first compound (Embodiment 2, Embodiment 4, and Embodiment 5), if the solvent of ethyl butyrate (EB) has an amount of about 75 volume % (for example, when the solvent of ethyl butyrate (EB) has an amount of about 75 volume %), the DC-IR increase rate may have a minimum value and the capacity retention rate may have a maximum value.

[0186] A rechargeable lithium battery including an electrolyte according to one or more embodiments may have excellent or appropriate high-temperature characteristics under a high-voltage environment.

[0187] In the present disclosure, expressions such as "at least one of," "one of," and "selected from," when preceding / 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," "at least one selected from a-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. As utilized herein, " / " may be interpreted as "and" or as "or," as the case may be.

[0188] In the context of this disclosure, and unless otherwise limited, the terms "use," "using," and "used" may be considered synonymous with the terms "utilize," "utilizing," and "utilized," respectively.

[0189] In the present disclosure, the term "Group" as utilized herein refers to a Group of the Periodic Table of the Elements according to the Group 1 to Group 18 system of the International Union of Pure and Applied Chemistry ("IUPAC").

[0190] As used herein, the terms "substantially," "about," and similar terms are used as terms of approximation and not as terms of degree, and are intended to take into account the inherent deviations in measured or calculated values ​​that one of ordinary skill in the art would recognize. As used herein, "about" or "approximately" also include the recited value and mean within the range of acceptable deviation for the particular value as determined by one of ordinary skill in the art taking into account the measurements in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system). For example, "about" can mean within one or more standard deviations of the recited value, or within ±30%, ±20%, ±10%, or ±5% of the recited value.

[0191] Any numerical range set forth in this article is intended to include all sub-ranges of the same numerical precision falling within the range set forth. For example, the range of "1.0 to 10.0" is intended to be included between the minimum value of 1.0 set forth and the maximum value of 10.0 set forth (and including 1.0 and 10.0), that is, all sub-ranges 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 falling therein and any minimum numerical limit set forth in this specification is intended to include all higher numerical limits falling therein. Accordingly, the applicant reserves the right to amend this specification (including claims) to explicitly set forth any sub-range falling within the range explicitly set forth in this article.

[0192] The battery management system (BMS) device and / or any other related devices or components according to embodiments of the present invention 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, the various components of the device may be formed on a single integrated circuit (IC) chip or on separate IC chips. Further, the various components of the device 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, the various components of the device may be processes or threads that run on one or more processors in one or more computing devices, execute computer program instructions, and interact with other system components to perform the various functions described herein. The computer program instructions are stored in a memory that may be implemented in a 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, a CD-ROM, a flash drive, etc. Furthermore, those skilled in the art will recognize that, without departing from the scope of this disclosure, the functions of various computing devices may be combined or integrated into a single computing device, or the functions of a particular computing device may be distributed across one or more other computing devices.

[0193] In view of the overall content of the present disclosure, a person skilled in the art will recognize that each appropriate feature of the various embodiments of the present disclosure can be combined partially or completely or combined with each other, and can be technically interlocked and operated in various appropriate ways, and unless otherwise described or implied, each embodiment can be implemented independently of each other or in combination with each other in any appropriate manner.

[0194] Although the present disclosure has been described in conjunction with presently considered example embodiments, it should be understood that the present 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 appended claims and their equivalents. Therefore, the foregoing embodiments should be construed as illustrative and not limiting the present disclosure in any way.

Claims

1. An electrolyte, comprising: lithium salts; Non-aqueous organic solvents; and additive, wherein the non-aqueous organic solvent comprises a compound represented by Chemical Formula 1, wherein the additive comprises a compound represented by Chemical Formula 2, Chemical formula 1 In Chemical Formula 1, R 1A and R 1B are each independently hydrogen, halogen, substituted or unsubstituted C1-C10 alkyl, or substituted or unsubstituted C3-C10 cycloalkyl, Chemical formula 2 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 A, Chemical formula A In chemical formula A, 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 according to claim 1, wherein R 1A is a substituted or unsubstituted C3-C10 alkyl group.

3. The electrolyte according to claim 1, wherein R 1A is a substituted or unsubstituted C3 alkyl group.

4. The electrolyte according to claim 1, wherein R 1A is an unsubstituted C3 alkyl group. 5 . The electrolyte according to claim 1 , wherein the compound represented by Chemical Formula 1 comprises at least one selected from the group consisting of methyl butyrate, ethyl butyrate, propyl butyrate, propyl propionate, methyl propionate, and ethyl propionate. The electrolyte according to claim 1 , wherein the amount of the compound represented by Chemical Formula 1 is 50 volume % to 95 volume % relative to 100 volume % of the total volume of the electrolyte. The electrolyte according to claim 1 , wherein the non-aqueous organic solvent further comprises a carbonate-based solvent.

8. The electrolyte according to claim 1, wherein the electrolyte is selected from L 2A and L 2B At least one of them is a substituted or unsubstituted C1-C5 alkylene group.

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

10. The electrolyte according to claim 1, wherein the compound represented by 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.

11. The electrolyte according to claim 1, wherein the compound represented by Chemical Formula 2 comprises at least one selected from the compounds listed in Group 1, Group 1 12 . The electrolyte according to claim 1 , wherein an amount of the compound represented by Chemical Formula 2 is 0.1 to 10 parts by weight relative to a total of 100 parts by weight of the electrolyte.

13. The electrolyte according to claim 1, wherein the additive further comprises 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-hexanetrinitrile, propylene sultone, propane sultone, lithium tetrafluoroborate, lithium difluorophosphate and 2-fluorobiphenyl. 14 . The electrolyte according to claim 1 , wherein the amount of the additive is 0.1 to 30 parts by weight relative to a total of 100 parts by weight of the electrolyte.

15. The electrolyte of claim 1, wherein the lithium salt comprises LiPF6.

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 positive electrode active material comprises lithium nickel-based oxide, lithium cobalt-based oxide, lithium manganese-based oxide, lithium iron phosphate-based compound, nickel manganese-based oxide without cobalt, or a combination thereof. 18 . The rechargeable lithium battery of claim 16 , wherein the negative electrode active material comprises a carbon-based negative electrode active material, a silicon-based negative electrode active material, or a combination thereof. The rechargeable lithium battery according to claim 16 , wherein the rechargeable lithium battery is a pouch type battery.

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