Electrolyte for rechargeable lithium battery, electrolyte additive, and rechargeable lithium battery including electrolyte

Abstract

The invention relates to an electrolyte for a rechargeable lithium battery, an electrolyte additive, and a rechargeable lithium battery including the electrolyte. The electrolyte includes a non-aqueous organic solvent, a lithium salt, and an additive represented by Chemical Formula 1. Detailed description of Chemical Formula 1 of the additive is disclosed. Chemical formula 1

Description

[0001] Cross Reference to Related Applications

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2024-0051634, filed on April 17, 2024, in the Korean Intellectual Property Office, 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, an electrolyte additive, and a rechargeable lithium battery including the electrolyte. BACKGROUND

[0004] With the widespread use of battery-powered electronic devices, such as mobile phones and laptop computers, and electric vehicles, it is desirable to develop rechargeable lithium batteries that provide both high energy density and high capacity. Extensive research efforts have been devoted to enhancing the characteristics of rechargeable lithium batteries.

[0005] A rechargeable lithium battery contains a positive electrode, a negative electrode, and an electrolyte. The positive electrode and the negative electrode include active materials in which the intercalation and deintercalation of lithium ions can occur, and generate electrical energy produced by oxidation and reduction reactions. SUMMARY

[0006] One or more aspects of embodiments of the present disclosure relate to an electrolyte for a rechargeable lithium battery having improved high-temperature stability.

[0007] One or more aspects of embodiments of the present disclosure relate to a rechargeable lithium battery including an electrolyte as described in one or more embodiments of the present disclosure.

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

[0009] Chemical Formula 1

[0010]

[0011] In Chemical Formula 1, L A and L B may each independently be a substituted or unsubstituted C1-C5 alkylene, a substituted or unsubstituted C2-C5 alkenylene, a substituted or unsubstituted C2-C5 alkynylene, or a substituted or unsubstituted C6-C20 arylene.

[0012] In Chemical Formula 1, A and B may each independently be a substituted or unsubstituted C1-C20 alkyl, a substituted or unsubstituted C6-C20 aryl, a substituted or unsubstituted C2-C20 heteroaryl, or an azide group.

[0013] In Chemical Formula 1, at least one selected from A and B may include an azide group. For example, the azide group may be indirectly bonded to "S" of Chemical Formula 1 and / or may be a substituent of a substituted C1-C20 alkyl group, a substituent of a substituted C6-C20 aryl group, and / or a substituent of a substituted C2-C20 heteroaryl group, such that A and B may each independently be an azide group, a C1-C20 alkyl group that is unsubstituted or substituted with an azide group, a C6-C20 aryl group that is unsubstituted or substituted with an azide group, or a C2-C20 heteroaryl group that is unsubstituted or substituted with an azide group.

[0014] According to one or more embodiments of the present disclosure, the additive may be represented by Chemical Formula 1-2.

[0015] Chemical formula 1-2

[0016]

[0017] One or more aspects of embodiments of the present disclosure relate to a rechargeable lithium battery, wherein the rechargeable lithium battery includes: a positive electrode, wherein the positive electrode includes a positive electrode active material; a negative electrode, wherein the negative electrode includes a negative electrode active material; and an electrolyte for a rechargeable lithium battery as described in one or more embodiments of the present disclosure.

[0018] Additional aspects of the embodiments 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above and other aspects and advantages of certain embodiments of the present disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings.

[0020] Figure 1 A simplified conceptual diagram illustrating a rechargeable lithium battery according to one or more embodiments of the present disclosure.

[0021] Figures 2 to 5 Each is a simplified diagram illustrating a rechargeable lithium battery according to one or more embodiments of the present disclosure.

[0022] Figure 6 Graph showing cyclic voltammetry results of a solution including an additive and a solution not including an additive prepared according to Synthesis Example 1.

[0023] Figure 7 To show that Figure 6 A graph showing cyclic voltammetry results of a solution including an additive and a solution not including an additive prepared according to Synthesis Example 1 under different conditions.

[0024] Figure 8 For the compound according to Synthesis Example 1 1 H nuclear magnetic resonance (NMR) spectrum. DETAILED DESCRIPTION

[0025] To fully appreciate the configuration and aspects of the embodiments 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 example embodiments described below, and can be implemented in one or more suitable forms. Rather, the example embodiments are provided only to illustrate the present disclosure and to enable a person of ordinary skill in the art to fully appreciate the scope of the present disclosure.

[0026] In the present disclosure, it will be understood that if an element is referred to as being "on" another element, it can be directly on the other element or intervening elements can be present therebetween. In some embodiments, 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 present. In the drawings, the size (e.g., thickness) of some components can be exaggerated for effective explanation of the technical content of the present disclosure. Throughout the present disclosure, the same reference numerals refer to the same elements, and for the sake of brevity, repeated descriptions thereof can not be provided.

[0027] Unless specifically stated otherwise in the present disclosure, the singular forms "a," "an," and "the" are intended to include plural forms. Further, when describing the embodiments of the present disclosure, the use of "can" indicates "one or more embodiments of the present disclosure." In embodiments, unless specifically stated otherwise, the phrase "A or B," "A and / or B," or "A / B" can indicate "A but not B," "B but not A," and "A and B." The terms "comprises," "comprises," and / or "comprising," as used in the present disclosure, do not exclude the presence or addition of one or more other components.

[0028] As used herein, the term "combination thereof" can refer to a mixture, a stack, a composite, a copolymer, an alloy, a blend, or a reaction product of ingredients.

[0029] In one or more embodiments of the present disclosure, unless otherwise limited, the term "substituted" may refer to a substituent or at least one hydrogen of a compound being replaced by deuterium, a halide, a hydroxyl, 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 a combination thereof (e.g., any suitable combination).

[0030] In some 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. 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 some 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 in which at least one hydrogen is replaced by deuterium, cyano, halo, methyl, ethyl, propyl, butyl, phenyl, biphenyl, terphenyl, trifluoromethyl, or naphthyl. Alkyl groups may include linear and / or chain alkyl groups. Cycloalkyl groups may include cyclic alkyl groups.

[0031] 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.

[0032] 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. In some embodiments, the positive electrode 10, the negative electrode 20, and the separator 30 may be immersed in (and / or impregnated with) the electrolyte ELL.

[0033] The electrolyte ELL may be a medium in which lithium ions migrate and are transported 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.

[0034] positive electrode 10

[0035] The positive electrode 10 for the rechargeable lithium battery can include a positive electrode current collector COL1 and a positive electrode active material layer AML1 on the positive electrode current collector COL1. The positive electrode active material layer AML1 can include a positive electrode active material (e.g., in the form of particles), and can further include a binder and / or a conductive material (e.g., an electrically conductive material).

[0036] For example, in some embodiments, the positive electrode 10 can further include a component that can serve as a sacrificial positive electrode.

[0037] The amount of the positive electrode active material can be in the range of about 90 wt% to about 99 wt% with respect to the total weight of 100 wt% of the positive electrode active material layer AML1. The amount of each of the binder and the conductive material can be in the range of about 0.5 wt% to about 5 wt% with respect to the total weight of 100 wt% of the positive electrode active material layer AML1.

[0038] The binder can serve to improve the attachment of the positive electrode active material particles to each other, and can also serve to improve the attachment of the positive electrode active material particles to the positive electrode current collector COL1. The binder can include, for example, one or more selected from the group consisting of polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, an oxirane-containing polymer, polyvinylpyrrolidone, 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.

[0039] The conductive material (e.g., electrically conductive material or electronic conductor) can serve to provide electrical conductivity (e.g., electrical conductivity) to the electrode, and any appropriate conductive material that does not cause chemical changes (e.g., does not cause undesired chemical changes) to the battery can be used as the conductive material constituting the battery. The conductive material can include, for example, carbon-based materials (such as natural graphite, artificial graphite, carbon black, acetylene black, ketjen black, carbon fiber, carbon nanofiber, and / or carbon nanotube); metal powder and / or metal fiber containing one or more selected from the group consisting of copper, nickel, aluminum, and silver; electrically conductive polymer (e.g., electrically conductive polymer) such as polyphenylene derivative; and / or a mixture (e.g., any appropriate mixture) thereof.

[0040] In some embodiments, an aluminum (Al) foil can be used as the positive electrode current collector COL1, but embodiments of the present disclosure are not limited thereto.

[0041] positive electrode active material

[0042] The positive electrode active material in the positive electrode active material layer AML1 can include a compound that can reversibly intercalate and deintercalate lithium (e.g., a lithiated intercalation compound). For example, the positive electrode active material can include at least one kind of composite oxide including lithium and a metal that can be selected from cobalt, manganese, and nickel.

[0043] The composite oxide can include a lithium transition metal composite oxide, for example, a lithium nickel-based oxide, a lithium cobalt-based oxide, a lithium manganese-based oxide, a lithium iron phosphate-based compound, a cobalt-free nickel manganese-based oxide, and / or a combination (e.g., any suitable combination) thereof.

[0044] For example, the positive electrode active material can include a compound represented by one selected from the group consisting of: a A 1-b X b O 2- c D c (wherein 0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, and 0≤α<2); Li a Mn 2-b X b O 4-c D c (wherein 0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, and 0≤α<2); Li a Ni 1-b-c Co b X c O 2-α D α (wherein 0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, and 0≤α<2); Li a Ni 1-b-c Mn b X c O 2-α D α (wherein 0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, and 0≤α<2); Li a Ni b Co c L 1 d G e O2(wherein 0.90≤a≤1.8, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5, and 0≤e≤0.1); Li a NiG b O2(wherein 0.90≤a≤1.8 and 0.001≤b≤0.1); Li a CoG b O2(wherein 0.90≤a≤1.8 and 0.001≤b≤0.1); Lia Mn 1-b G b O2(where 0.90≤a≤1.8 and 0.001≤b≤0.1); Li a Mn2G b O4(where 0.90≤a≤1.8 and 0.001≤b≤0.1); Li a Mn 1-g G g PO4(where 0.90≤a≤1.8 and 0≤g≤0.5); Li (3-f) Fe2(PO4)3(where 0≤f≤2); Li a FePO4(where 0.90≤a≤1.8); and / or combinations thereof (e.g., any suitable combination).

[0045] In the foregoing chemical formulas, A can be nickel (Ni), cobalt (Co), manganese (Mn), and / or combinations thereof (e.g., any suitable combination), X can be Al, Ni, Co, Mn, chromium (Cr), iron (Fe), magnesium (Mg), strontium (Sr), vanadium (V), a rare earth element, and / or combinations thereof (e.g., any suitable combination), D can be oxygen (O), fluorine (F), sulfur (S), phosphorus (P), and / or combinations thereof (e.g., any suitable combination), G can be Al, Cr, Mn, Fe, Mg, lanthanum (La), cerium (Ce), Sr, V, and / or combinations thereof (e.g., any suitable combination), and L 1 may be Mn, Al, or combinations thereof.

[0046] For example, the positive electrode active material can be a high-nickel type positive electrode active material having a nickel amount equal to or greater than about 80 mol%, equal to or greater than about 85 mol%, equal to or greater than about 90 mol%, equal to or greater than about 91 mol%, or equal to or greater than about 94 mol% and equal to or less than about 99 mol% relative to 100 mol% of total metals other than lithium in a lithium transition metal complex oxide. The high-nickel type positive electrode active material can achieve a high capacity, and thus can be applied to a high-capacity and high-energy-density rechargeable lithium battery.

[0047] Negative electrode 20

[0048] The negative electrode 20 for the rechargeable lithium battery can 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 can include a negative electrode active material (e.g., in the form of particles), and can further include a binder and / or a conductive material (e.g., an electrically conductive material).

[0049] For example, the negative electrode active material layer AML2 can 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 a total weight of 100 wt% of the negative electrode active material layer AML2.

[0050] The binder can be used to improve attachment of the negative electrode active material particles to each other, and can also be used to improve attachment of the negative electrode active material particles to the negative electrode current collector COL2. 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 (e.g., any suitable combination) thereof.

[0051] The non-aqueous binder can include polyvinyl chloride, carboxylated polyvinyl chloride, polyfluoroethylene, ethylene propylene copolymer, polystyrene, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polyamide imide, polyimide, and / or a combination (e.g., any suitable combination) thereof.

[0052] The aqueous binder can include styrene-butadiene rubber, (meth)acrylated styrene-butadiene rubber, (meth)acrylonitrile-butadiene rubber, (meth)acrylic rubber, butyl rubber, fluoroelastomer, polyethylene oxide, polyvinylpyrrolidone, polyepichlorohydrin, polyphosphazene, poly(meth)acrylonitrile, ethylene propylene diene copolymer, polyvinylpyridine, chlorosulfonated polyethylene, latex, polyester resin, (meth)acrylic resin, phenolic resin, epoxy resin, polyvinyl alcohol, and / or a combination (e.g., any suitable combination) thereof.

[0053] If the aqueous binder is used as the binder in the negative electrode active material layer AML2 (e.g., when the aqueous binder is used as the binder in the negative electrode active material layer AML2), a cellulose-based compound capable of providing or increasing viscosity can be further included. The cellulose-based compound can include one or more selected from carboxymethyl cellulose, hydroxypropyl methyl cellulose, methyl cellulose, and alkali metal salts thereof. The alkali metal can include Na, K, and / or Li.

[0054] The dry binder can include a fibrillatable polymeric material, for example, polytetrafluoroethylene, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polyethylene oxide, and / or a combination (e.g., any suitable combination) thereof.

[0055] A conductive material (e.g., an electrically conductive material or an electronic conductor) can be used to provide electrical conductivity (e.g., electrical conductivity) to the electrode, and any suitable electrically conductive material that does not cause chemical changes (e.g., does not cause undesirable chemical changes) to the battery can be used as the electrically conductive material that constitutes the battery. For example, the electrically conductive material can include carbon-based materials (such as natural graphite, artificial graphite, carbon black, acetylene black, ketjen black, carbon fiber, carbon nanofiber, and / or carbon nanotube); metal powders and / or metal fibers including one or more selected from copper, nickel, aluminum, and silver; electrically conductive polymers (e.g., electrically conductive polymers) such as polyphenylene derivatives; and / or mixtures (e.g., any suitable mixture) thereof.

[0056] The negative electrode current collector COL2 can include a copper foil, a nickel foil, a stainless steel foil, a titanium foil, a nickel foam, a copper foam, a polymer substrate coated with an electrically conductive metal, and / or a combination (e.g., any suitable combination) thereof.

[0057] The negative electrode active material

[0058] The negative electrode active material in the negative electrode active material layer AML2 can include a material that can reversibly intercalate and deintercalate lithium ions, lithium metal, a lithium metal alloy, a material that can be doped and undoped with lithium, and / or a transition metal oxide.

[0059] The material that can reversibly intercalate and deintercalate lithium ions can include a carbon-based negative electrode active material, for example, crystalline carbon, amorphous carbon, and / or a combination (e.g., any suitable combination) thereof. For example, the crystalline carbon can include graphite (such as amorphous (e.g., irregularly shaped), flaky, sheet-like, spherical, and / or fibrous natural graphite and / or artificial graphite), and the amorphous carbon can include soft carbon, hard carbon, mesocarbon microbead carbon, and / or calcined coke.

[0060] The lithium metal alloy can 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), tin (Sn), and / or a combination (e.g., any suitable combination) thereof.

[0061] The material that can be doped and undoped with lithium can include a Si-based negative electrode active material and / or a Sn-based negative electrode active material. The Si-based negative electrode active material can include silicon (e.g., silicon nanoparticles), a silicon-carbon composite, SiO x(where 0 < x < 2), Si-Q alloys (where Q is an alkali metal, an alkaline earth metal, a Group 13 element, a Group 14 element (excluding Si), a Group 15 element, a Group 16 element, a transition metal, a rare earth element, or a combination thereof (e.g., any suitable combination)), and / or combinations thereof (e.g., any suitable combination). Sn-based negative electrode active materials can include Sn, SnO k (where 0 < k < 2) (e.g., SnO2), Sn-based alloys, and / or combinations thereof (e.g., any suitable combination).

[0062] Silicon-carbon composites can be a composite (e.g., in the form of a particle) of silicon and amorphous carbon. In some embodiments, a silicon-carbon composite can have a structure in which amorphous carbon coats the surface of each of the silicon particles. For example, a silicon-carbon composite can include secondary particles (cores) in which primary silicon particles are aggregated and an amorphous carbon coating (shell) on the surface of the secondary particles. Amorphous carbon can also be between the primary silicon particles, e.g., the primary silicon particles can be coated with amorphous carbon. The secondary particles can be present dispersed in an amorphous carbon matrix.

[0063] Silicon-carbon composites can further include crystalline carbon. For example, a silicon-carbon composite can include a core including crystalline carbon and silicon particles, and can also include an amorphous carbon coating on the surface of the core.

[0064] Si-based negative electrode active materials and / or Sn-based negative electrode active materials can be used in combination with carbon-based negative electrode active materials.

[0065] Separator 30

[0066] A separator 30 can be present between the positive electrode 10 and the negative electrode 20, based on the type or kind of rechargeable lithium battery. The separator 30 can include one or more selected from among a polyethylene separator, a polypropylene separator, and a polyvinylidene fluoride separator, or can have a multi-layer separator thereof (such as a polyethylene / polypropylene double-layer separator, a polyethylene / polypropylene / polyethylene triple-layer separator, and / or a polypropylene / polyethylene / polypropylene triple-layer separator).

[0067] The separator 30 can include a porous substrate and a coating on the surface (e.g., one surface or both opposite surfaces) of the porous substrate, and the coating can include an organic material, an inorganic material, and / or a combination thereof (e.g., any suitable combination).

[0068] The porous substrate can be a polymeric layer including one selected from among a polyolefin (such as polyethylene and polypropylene), a polyester (such as polyethylene terephthalate and polybutylene terephthalate), a polyacetal, a polyamide, a polyimide, a polycarbonate, a polyether ketone, a polyaryletherketone, a polyetherimide, a polyamideimide, a polybenzimidazole, a polyethersulfone, a polyphenylene ether, a cyclic olefin copolymer, a polyphenylene sulfide, a polyethylene naphthalate, a glass fiber, and a polytetrafluoroethylene (e.g., TeflonTM ) or can be a copolymer or mixture including two or more thereof.

[0069] The organic material can include a polyvinylidene fluoride-based copolymer and / or a (meth)acrylic-based copolymer.

[0070] The inorganic material can include inorganic particles selected from Al2O3, SiO2, TiO2, SnO2, CeO2, MgO, NiO, CaO, GaO, ZnO, ZrO2, Y2O3, SrTiO3, BaTiO3, Mg(OH)2, boehmite, and / or a combination (e.g., any suitable combination) thereof, although embodiments of the present disclosure are not limited thereto.

[0071] The organic material and the inorganic material can be mixedly present in one coating layer or can be present as a stack of a coating layer including the organic material and a coating layer including the inorganic material.

[0072] Electrolyte ELL

[0073] The electrolyte (e.g., electrolytic solution) ELL for the rechargeable lithium battery can include a non-aqueous organic solvent and a lithium salt.

[0074] The non-aqueous organic solvent can serve as a medium for transporting ions participating in an electrochemical reaction of the battery.

[0075] The non-aqueous organic solvent can 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 a combination (e.g., any suitable combination) thereof.

[0076] The carbonate-based solvent can include dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), methyl propyl carbonate (MPC), ethyl propyl carbonate (EPC), ethyl methyl carbonate (EMC), ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), and / or a combination (e.g., any suitable combination) thereof.

[0077] The ester-based solvent can include methyl acetate, ethyl acetate, n-propyl acetate, dimethyl acetate, methyl propionate, ethyl propionate, decanolide, mevalonolactone, valerolactone, caprolactone, and / or a combination (e.g., any suitable combination) thereof.

[0078] Ether solvents can include dibutyl ether, tetraethylene glycol dimethyl ether, diethylene glycol dimethyl ether, ethylene glycol dimethyl ether, 2-methyltetrahydrofuran, 2,5-dimethyltetrahydrofuran, tetrahydrofuran, and / or combinations (e.g., any suitable combinations) thereof. Ketone solvents can include cyclohexanone. Alcohol solvents can include ethanol, isopropyl alcohol, and / or combinations thereof. Aprotic solvents can include nitriles (such as R-CN, where R can be a hydrocarbon group having a C2 to C20 linear, branched, or cyclic structure, and can include a double bond, an aromatic ring, or an ether bond); amides (such as dimethylformamide); dioxolanes (such as 1,3-dioxolane and / or 1,4-dioxolane); sulfolanes; and / or combinations (e.g., any suitable combinations) thereof.

[0079] A single non-aqueous organic solvent can be used, or a mixture of two or more non-aqueous organic solvents can be used.

[0080] In some embodiments, if a carbonate solvent is used (e.g., when a carbonate solvent is used), a cyclic carbonate and a chain carbonate can be mixed and used, and the cyclic carbonate and the chain carbonate can be mixed in a volume ratio of about 1:1 to about 1:9.

[0081] The lithium salt can be a material dissolved in the non-aqueous organic solvent to serve as a supply source of lithium ions in the rechargeable lithium battery, and to function to ensure the basic operation of the rechargeable lithium battery and to facilitate the movement of lithium ions between the positive electrode and the negative electrode. The lithium salt can include, for example, at least one selected from the group consisting of 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)(where x and y are integers between 1 and 20), lithium trifluoromethanesulfonate, lithium tetrafluoroethanesulfonate, lithium difluorobis(oxalato)phosphate (LiDFBOP), and lithium bis(oxalato)borate (LiBOB).

[0082] An electrolyte for a rechargeable lithium battery according to one or more embodiments of the present disclosure is described in more detail below.

[0083] An electrolyte for a rechargeable lithium battery according to one or more embodiments of the present disclosure can include a non-aqueous organic solvent, a lithium salt, and an additive represented by Chemical Formula 1 below.

[0084] Chemical Formula 1

[0085]

[0086] In Chemical Formula 1, L A and L B may each independently be substituted or unsubstituted C1-C5 alkylene, substituted or unsubstituted C2-C5 alkenylene, substituted or unsubstituted C2-C5 alkynylene, or substituted or unsubstituted C6-C20 arylene.

[0087] In Chemical Formula 1, A and B may each independently be substituted or unsubstituted C1-C20 alkyl, substituted or unsubstituted C6-C20 aryl, substituted or unsubstituted C2-C20 heteroaryl, or an azide group.

[0088] In Chemical Formula 1, at least one selected from A and B can include an azide group. For example, the azide group can be directly bonded to "S" of Chemical Formula 1 and / or can be a substituent of the substituted C1-C20 alkyl, a substituent of the substituted C6-C20 aryl, and / or a substituent of the substituted C2-C20 heteroaryl, such that A and B may, independently, be an azide group, unsubstituted or substituted with an azide group C1-C20 alkyl, unsubstituted or substituted with an azide group C6-C20 aryl, or unsubstituted or substituted with an azide group C2-C20 heteroaryl.

[0089] The electrolyte solution can be prepared by a mixing process in which a lithium salt is dissolved in a non-aqueous organic solvent, and an additive represented by Chemical Formula 1 as described in one or more embodiments of the present disclosure is added, and the solution is mixed. The mixing process of the electrolyte solution can be any appropriate process commonly used or commonly available in the field of electrolyte manufacturing, and a person skilled in the art can appropriately select and use the process after reading the present disclosure.

[0090] The non-aqueous organic solvent can include at least one selected from ethylene carbonate (EC), propylene carbonate (PC), propyl propionate (PP), ethyl methyl carbonate (EMC), dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), methyl propyl carbonate (MPC), ethyl propyl carbonate (EPC), ethyl methyl carbonate (EMC), and butylene carbonate (BC).

[0091] In some embodiments, the non-aqueous organic solvent can be a mixed solvent of ethylene carbonate (EC), ethyl methyl carbonate (EMC), and / or dimethyl carbonate (DMC).

[0092] For example, the amount of included ethylene carbonate (EC) solvent can be about 5 vol% to about 40 vol% or about 10 vol% to about 30 vol% with respect to the total volume of the nonaqueous organic solvent. The amount of included ethyl methyl carbonate (EMC) solvent can be about 20 vol% to about 60 vol% or about 30 vol% to about 50 vol% with respect to the total volume of the nonaqueous organic solvent. The amount of included dimethyl carbonate (DMC) solvent can be about 20 vol% to about 60 vol% or about 30 vol% to about 50 vol% with respect to the total volume of the nonaqueous organic solvent.

[0093] In the electrolyte according to one or more embodiments of the disclosure, the lithium salt can include LiPF6.

[0094] The lithium salt can have a concentration of about 0.1 M to about 2.0 M. For example, the lithium salt can have a concentration equal to or greater than about 0.5 M or equal to or greater than about 1.0 M. The lithium salt can have a concentration equal to or less than about 2.0 M, equal to or less than about 1.7 M, or equal to or less than about 1.5 M. In one or more embodiments of the disclosure, if the lithium salt has a concentration of about 0.1 M to about 2.0 M (e.g., when the lithium salt has a concentration of about 0.1 M to about 2.0 M), the electrolyte can suitably or appropriately maintain its electrical conductivity (e.g., electric conductivity) and viscosity.

[0095] Additive

[0096] The additive according to one or more embodiments of the disclosure can be represented by the following Chemical Formula 1.

[0097] Chemical Formula 1

[0098]

[0099] In Chemical Formula 1, L A and L B may each independently be a substituted or unsubstituted C1 to C5 alkylene, a substituted or unsubstituted C2 to C5 alkenylene, a substituted or unsubstituted C2 to C5 alkynylene, or a substituted or unsubstituted C6 to C20 arylene.

[0100] In Chemical Formula 1, A and B can each independently be a substituted or unsubstituted C1 to C20 alkyl, a substituted or unsubstituted C6 to C20 aryl, a substituted or unsubstituted C2 to C20 heteroaryl, or an azide group.

[0101] In Chemical Formula 1, at least one selected from A and B can include an azide group.

[0102] In Chemical Formula 1, at least one selected from L A and L BAt least one of L may be a substituted or unsubstituted C1-C5 alkylene group or a substituted or unsubstituted C2-C4 alkylene group. A and L B Each may independently be a substituted or unsubstituted C1-C5 alkylene group or a substituted or unsubstituted C2-C4 alkylene group.

[0103] In some embodiments, the additive may be represented by the following Chemical Formula 1-1.

[0104] Chemical formula 1-1

[0105]

[0106] In Chemical Formula 1-1, L A and L B Each independently may be a substituted or unsubstituted C2-C4 alkylene group.

[0107] In some embodiments, the additive may include at least one selected from the group consisting of a compound represented by the following Chemical Formula 1-2 and a compound represented by the following Chemical Formula 1-3.

[0108] Chemical formula 1-2

[0109]

[0110] Chemical formula 1-3

[0111]

[0112] In some embodiments, the additive according to one or more embodiments of the present disclosure may include the compound represented by Chemical Formula 1-2 as described in one or more embodiments of the present disclosure.

[0113] The electrolyte additive according to one or more embodiments of the present disclosure may include a sulfone group and at least one azide group.

[0114] The sulfone group included in the additive can be oxidized during the decomposition process to form and strengthen the cathode electrolyte interface (CEI). For example, the sulfone group can be oxidized during the decomposition process to form a coordination bond with the transition metal on the surface of the positive electrode or to form a coordination bond with the transition metal released from the surface of the positive electrode, thereby forming CEI. The coordination bond can also be referred to as a coordinated covalent bond or a coordinate bond. Therefore, the gas generation caused by the side reaction between the electrolyte and the cathode interface can be reduced, and the gas generation and transition metal dissolution caused by the decomposition of the positive electrode active material can be suppressed or reduced. At high temperatures, the effect of reducing side reactions can become obvious.

[0115] The azide group can form and strengthen a solid electrolyte interface (SEI). In some embodiments, the lone pair of electrons of the azide group can act on a Lewis acid (e.g., PF5) that can exist in the electrolyte to stabilize the Lewis acid, thereby protecting the SEI. Also, the azide group can improve the ionic conductivity of the electrolyte to achieve fast charging.

[0116] In the additive of one or more embodiments of the present disclosure, the sulfone group and the azide group can be linked by an alkylene group. If the sulfone group and the azide group are directly linked to each other (e.g., when the sulfone group and the azide group are directly linked to each other), the additive can be decomposed such that a bond (e.g., S-N bond) between the sulfone group and the azide group can be broken and such that there can be no functional group on the sulfone group. In some embodiments, if the sulfone group and the azide group are linked by an alkylene group (e.g., when the sulfone group and the azide group are linked by an alkylene group), even if the additive is decomposed to shed the azide group (e.g., when the additive is decomposed to shed the azide group), a functional group (i.e., alkylene group) can remain on the sulfone group. The functional group remaining on the sulfone group can then protect the SEI and the CEI as another functional additive.

[0117] In the electrolyte for a rechargeable lithium battery according to the present disclosure, an additive can be included to protect the SEI and the CEI and to reduce side reactions between the electrolyte and the electrode and within the electrolyte. Accordingly, the rechargeable lithium battery can improve life characteristics and high-temperature storage characteristics. For example, the rechargeable lithium battery including the electrolyte as described in one or more embodiments of the present disclosure can maintain its capacity retention rate at a high temperature and can suppress or reduce an increase in impedance (e.g., resistance) during high-temperature storage. Further, the electrolyte according to one or more embodiments of the present disclosure can have improved ionic conductivity to exhibit enhanced fast charging characteristics.

[0118] The additive can have an amount of about 0.01 wt% to about 10 wt%, about 0.1 wt% to about 5 wt%, about 0.1 wt% to about 3 wt%, or about 0.5 wt% to about 3 wt% with respect to the total weight of 100 wt% of the electrolyte.

[0119] If the additive has an amount within the above range (e.g., when the additive has an amount within the above range), the electrolyte can have an appropriate or suitable viscosity and can appropriately satisfy wettability to the negative electrode and the positive electrode. In some embodiments, if the additive has an amount within the above range (e.g., when the additive has an amount within the above range), an effect as a surfactant can be exhibited.

[0120] Rechargeable lithium battery

[0121] Based on the shape of the rechargeable lithium battery, the rechargeable lithium battery can be classified into a cylindrical, a prismatic, a pouch, or a coin type (or kind). Figures 2 to 5 Each is a simplified diagram illustrating a rechargeable lithium battery according to one or more embodiments of the present disclosure, Figure 2 A cylindrical battery is illustrated, Figure 3 A prismatic battery is illustrated, and Figure 4 and Figure 5 Each illustrates a pouch type / kind battery. Referring to Figures 2 to 4 The rechargeable lithium battery 100 can include an electrode assembly 40 in which a separator 30 is between a positive electrode 10 and a negative electrode 20, and can also include a case 50 in which the electrode assembly 40 is accommodated. The positive electrode 10, the negative electrode 20, and the separator 30 can be impregnated in an electrolyte. As Figure 2 The rechargeable lithium battery 100 can include a sealing member 60 that seals the case 50, as explained in Figure 3 The rechargeable lithium battery 100 can include a positive electrode lead tab 11, a positive electrode terminal 12, a negative electrode lead tab 21, and a negative electrode terminal 22, as explained in Figure 4 and Figure 5 The rechargeable lithium battery 100 can include an electrode tab 70, or a positive electrode tab 71 and a negative electrode tab 72, which functions as an electrical path for guiding an electrical current generated in the electrode assembly 40 to the outside, as illustrated in

[0122] The rechargeable lithium battery according to one or more embodiments of the present disclosure can be applied to a motor vehicle, a mobile phone, and / or any other appropriate electronic device, but embodiments of the present disclosure are not limited thereto.

[0123] Synthesis examples, embodiments, and comparative examples of the present disclosure will be described below. However, the following embodiments are merely examples, and embodiments of the present disclosure are not limited to the embodiments described below.

[0124] Synthesis Example 1

[0125] One equivalent of 1,1'-thiobis[2-bromoethane], three equivalents of sodium azide, and dimethyl sulfoxide (DMSO) were added to a round-bottom flask, and then stirred at room temperature for 12 hours. The resulting reaction mixture was extracted with dichloromethane, and then concentrated. After concentration, the mixture was dried using a vacuum pump, and then a compound represented by Chemical Formula 1-2-1 below was obtained.

[0126] Chemical Formula 1-2-1

[0127]

[0128] After that, 10 times the amount of hydrogen peroxide and 20 times the amount of acetic acid, by volume, relative to the compound represented by Chemical Formula 1-2-1 were added to a round bottom flask, and heated at 60°C for 12 hours, and then the resulting mixture was cooled to room temperature. The reaction mixture was extracted with dichloromethane and concentrated, and then dried to obtain a compound represented by the following Chemical Formula 1-2. Figure 8 for synthesizing the compound represented by the following Chemical Formula 1-2 1 H NMR spectrum.

[0129] Chemical Formula 1-2

[0130]

[0131] 1 H NMR (400 MHz, CDCl3, 25°C) δ (ppm): 3.8 (4H), 3.25 (4H))

[0132] Embodiments and Comparative Examples

[0133] An electrolyte and a rechargeable lithium battery were manufactured by the following methods.

[0134] Embodiment 1

[0135] (1) Preparation of an electrolyte

[0136] 1.15M LiPF6was dissolved in a non-aqueous organic solvent containing ethylene carbonate (EC), ethyl methyl carbonate (EMC), and dimethyl carbonate (DMC) mixed at a volume ratio of about 20:40:40, respectively, and 0.5 wt% of the additive represented by Chemical Formula 1-2 obtained in Synthesis Example 1 was added relative to 100 wt% of the electrolyte, to prepare an electrolyte.

[0137] (2) Manufacture of a rechargeable lithium battery

[0138] LiNi 0.91 Co 0.07 Al 0.02 O2, polyvinylidene fluoride as a binder, and carbon black as a conductive material were mixed at a weight ratio of 97:2:1, respectively, and the resulting mixture was dispersed in N-methylpyrrolidone to prepare a positive electrode active material slurry.

[0139] The positive electrode active material slurry was coated on an aluminum (Al) current collector having a thickness of 14 µm, dried at 110°C, and then pressed to manufacture a positive electrode.

[0140] ​The artificial graphite and silicon nanoparticles mixed at a weight ratio of 93:7 as the negative electrode active material, styrene butadiene rubber (SBR) as the binder, and carboxymethyl cellulose (CMC) as the tackifier were mixed at a weight ratio of 97:1:2, respectively, and the resulting mixture was dispersed in distilled water to prepare a negative electrode active material slurry.

[0141] The negative electrode active material slurry was coated on a copper (Cu) current collector having a thickness of 10 μm, dried at 100°C, and then pressed to manufacture a negative electrode.

[0142] The positive electrode, the negative electrode, and a polyethylene separator having a thickness of 25 μm were assembled together to manufacture an electrode assembly, and an electrolyte was introduced to manufacture a rechargeable lithium battery.

[0143] Embodiment 2

[0144] The electrolyte and the rechargeable lithium battery were manufactured in substantially the same manner as described in Embodiment 1, except that 1 wt% of the additive was added when the electrolyte was prepared.

[0145] Embodiment 3

[0146] The electrolyte and the rechargeable lithium battery were manufactured in substantially the same manner as described in Embodiment 1, except that 3 wt% of the additive was added when the electrolyte was prepared.

[0147] Comparative Example 1

[0148] The electrolyte and the rechargeable lithium battery were manufactured in substantially the same manner as described in Embodiment 1, except that no additive was added when the electrolyte was prepared.

[0149] Comparative Example 2

[0150] The electrolyte and the rechargeable lithium battery were manufactured in substantially the same manner as described in Embodiment 1, except that 1 wt% of the additive represented by Chemical Formula 2 below was added when the electrolyte was prepared.

[0151] Chemical Formula 2

[0152]

[0153] Comparative Example 3

[0154] The electrolyte and the rechargeable lithium battery were manufactured in substantially the same manner as described in Embodiment 1, except that 1 wt% of the additive represented by Chemical Formula 3 below was added when the electrolyte was prepared.

[0155] Chemical Formula 3

[0156]

[0157] Comparative Example 4

[0158] An electrolyte and a rechargeable lithium battery were manufactured in substantially the same manner as described in Embodiment 1, except that 1 wt% of an additive represented by Chemical Formula 4 below was added when preparing the electrolyte.

[0159] Chemical Formula 4

[0160]

[0161] Evaluation 1: Cyclic voltammetry characteristics - reduction decomposition

[0162] The electrolyte prepared according to Embodiment 1, a graphite working electrode, and a lithium (Li) counter electrode were used to measure the cyclic voltammetry voltage of a 3-electrode (scan rate: 1.0 mV / sec), and the results are shown in Figure 6 .

[0163] The electrolyte prepared according to Comparative Example 1, a graphite working electrode, and a lithium (Li) counter electrode were used to measure the cyclic voltammetry voltage of a 3-electrode (scan rate: 1.0 mV / sec), and the results are shown in Figure 6 .

[0164] Referring to Figure 6 , the electrolyte prepared according to Embodiment 1 or the electrolyte including the additive prepared according to Synthesis Example 1 exhibited a decomposition peak or a reduction peak near 1.6 V. The electrolyte prepared according to Comparative Example 1 or the electrolyte not including the additive exhibited a reduction peak near 0.6 V. This result is considered to mean that the additive undergoes reduction decomposition earlier than the solvent, and contributes to the formation of an SEI.

[0165] Evaluation 2: Cyclic voltammetry characteristics - oxidation decomposition

[0166] The electrolyte prepared according to Embodiment 1, a platinum (Pt) working electrode, and a lithium (Li) counter electrode were used to measure the cyclic voltammetry voltage of a 3-electrode (scan rate: 1.0 mV / sec), and the results are shown in Figure 7 .

[0167] The electrolyte prepared according to Comparative Example 1, a platinum (Pt) working electrode, and a lithium (Li) counter electrode were used to measure the cyclic voltammetry voltage of a 3-electrode (scan rate: 1.0 mV / sec), and the results are shown in Figure 7 .

[0168] Referring to Figure 7The electrolyte prepared according to the Example 1 or the electrolyte including the additive prepared according to the Synthesis Example 1 underwent oxidative decomposition from about 5 V. The electrolyte prepared according to the Comparative Example 1 or the electrolyte not including the additive did not exhibit an oxidation peak even up to 5.5 V. This result is considered to mean that the additive undergoes oxidative decomposition from 5 V, and contributes to the formation of the CEI.

[0169] Evaluation 3: Resistance increase rate during high-temperature storage

[0170] The rechargeable lithium batteries manufactured in the Examples and Comparative Examples were charged to SOC 100% (i.e., initial full charge state) under constant current-constant voltage (CC / CV), 0.33C, 4.25V, and 0.025C cutoff conditions at room temperature (25℃), and then the initial battery resistance (DC-IR) and the battery resistance after storage for 90 days at 60℃ (i.e., DC-IR after high-temperature storage) were measured. The resistance increase rate was measured, and the results are listed in Table 1 below. After discharging at 1C for 30 seconds in the initial full charge state, the resistance (DC-IR) (such as the initial battery resistance (DC-IR) and the battery resistance after 90 days DC-IR) was obtained using Ohm's law ΔR = ΔV / ΔI, which is calculated from the difference in current and the difference in voltage when different currents are applied. The resistance increase rate (i.e., DC-IR increase rate) was calculated according to Equation 1 below.

[0171] Equation 1

[0172] Resistance increase rate (%) = [Battery resistance after 90 days / Initial battery resistance] x 100

[0173] Table 1

[0174]

[0175] Referring to Table 1, the rechargeable lithium batteries according to the Examples 1 to 3 have a reduced resistance increase rate during high-temperature (60℃) storage, compared to the rechargeable lithium batteries according to the Comparative Examples 1 to 4.

[0176] Evaluation 4: Life capacity retention rate at high temperature

[0177] The rechargeable lithium batteries according to the Examples and Comparative Examples were continuously charged and discharged under the conditions of 0.5C charging and 0.5C discharging at 45℃ to 300 cycles, and then the capacity retention rate after 300 cycles was listed in Table 2 below.

[0178] The capacity retention rate was calculated according to Equation 2 below.

[0179] Equation 2

[0180] Capacity retention rate (%) = (discharge capacity at the 300th cycle / initial discharge capacity) x 100

[0181] Table 2

[0182]

[0183] Referring to Table 2, the rechargeable lithium batteries according to the embodiments 1 to 3 have increased capacity retention rates at high temperature (45°C) compared to the rechargeable lithium batteries according to the comparative examples 1 to 4.

[0184] The rechargeable lithium battery according to one or more embodiments of the present disclosure can have improved life characteristics, and inhibit or reduce an increase in battery impedance (e.g., resistance) during high-temperature storage.

[0185] Although the subject matter of the present disclosure has been described in connection with the presently preferred example embodiments, it will be understood that the present disclosure is not limited to the disclosed embodiments, and it is intended to cover various appropriate modifications and equivalent arrangements included within the spirit and scope of the claims and their equivalents, and therefore the foregoing embodiments should be understood only as examples, and not in a limiting sense.

Claims

1. An electrolyte comprising: a non-aqueous organic solvent; a lithium salt; and an additive represented by Chemical Formula 1, Chemical Formula 1 wherein, in Chemical Formula 1, L A and L B each independently is substituted or unsubstituted C1-C5alkylene, substituted or unsubstituted C2-C5alkenylene, substituted or unsubstituted C2-C5alkynylene, or substituted or unsubstituted C6-C20arylene, A and B are each independently a substituted or unsubstituted C1-C20 alkyl, a substituted or unsubstituted C6-C20 aryl, a substituted or unsubstituted C2-C20 heteroaryl, or an azide group, and at least one selected from A and B includes an azide group, wherein the electrolyte is an electrolyte for a rechargeable lithium battery, and substitution refers to substitution of at least one hydrogen of a substituent or a compound with 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 a combination thereof.

2. The electrolyte of claim 1, wherein at least one selected from L A and L B is a substituted or unsubstituted C1-C5 alkylene.

3. The electrolyte of claim 1, wherein L A and L B each independently is substituted or unsubstituted C1-C5 alkylene.

4. The electrolyte of claim 1, wherein at least one selected from L A and L B is a substituted or unsubstituted C2-C4 alkylene.

5. The electrolyte of claim 1, wherein L A and L B each independently is substituted or unsubstituted C2-C4alkylene. 6.The electrolyte of claim 1, wherein the additive represented by Chemical Formula 1 is represented by Chemical Formula 1-1, Chemical Formula 1-1 wherein In Chemical Formula 1-1, L A and L B each independently is substituted or unsubstituted C2-C4alkylene. 7.The electrolyte of claim 1, wherein the additive is represented by Chemical Formula 1-2 or Chemical Formula 1-3, Chemical Formula 1-2 Chemical Formula 1-3 8.The electrolyte of claim 1, wherein the additive is present in an amount of 0.01 wt% to 10.0 wt% relative to a total weight of 100 wt% of the electrolyte for a rechargeable lithium battery. 9.The electrolyte of claim 1, wherein the non-aqueous organic solvent includes a carbonate-based solvent. 10.The electrolyte of claim 9, wherein the carbonate-based solvent includes methyl ethyl carbonate, ethylene carbonate, and / or dimethyl carbonate. 11.The electrolyte of claim 1, wherein the lithium salt includes LiPF 6. 12.The electrolyte of claim 1, wherein a concentration of the lithium salt is in a range of 0.1 M to 2.0 M. 13.An electrolyte additive represented by Chemical Formula 1-2, Chemical Formula 1-2 14.A rechargeable lithium battery comprising: a positive electrode, wherein the positive electrode includes a positive electrode active material; a negative electrode, wherein the negative electrode includes a negative electrode active material; and the electrolyte for a rechargeable lithium battery according to any one of claims 1 to 12. 15.The rechargeable lithium battery of claim 14, wherein the positive electrode active material includes a compound represented by Chemical Formula 2', Chemical Formula 2' Li x Ni 1-y-z Co y X z O 2-a D a , wherein, in Chemical Formula 2', 0.9≤x≤1.8, 0≤y≤0.5, 0≤z≤0.5, and 0≤a<2, X includes at least one selected from aluminum, nickel, cobalt, manganese, chromium, iron, magnesium, strontium, vanadium, and a rare earth element, and D includes at least one selected from oxygen, fluorine, sulfur, and phosphorus. 16.The rechargeable lithium battery of claim 14, wherein the negative electrode active material includes a carbon-based negative electrode active material, a Sn-based negative electrode active material, and / or a Si-based negative electrode active material.

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