Positive electrode and rechargeable lithium battery including same

Abstract

The invention relates to a positive electrode and a rechargeable lithium battery including the same. The positive electrode includes a positive electrode active material, a binder, a conductive material, and an additive represented by Chemical Formula 1-1 or Chemical Formula 1-2. Chemical formula 1-1 and chemical formula 1-2

Description

[0001] Cross-references to related applications

[0002] This application claims priority and benefit to Korean Patent Application No. 10-2024-0112781, filed with the Korean Intellectual Property Office on August 22, 2024, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] Embodiments of this disclosure described herein relate to a positive electrode and a rechargeable lithium battery including a positive electrode. Background Technology

[0004] Recently, with the rapid proliferation of battery-powered electronic devices (such as mobile phones and / or laptops) and electric vehicles, the demand for rechargeable batteries with high energy density and capacity is growing. Consequently, a significant amount of research effort has focused on enhancing the performance of rechargeable batteries, particularly rechargeable lithium-ion batteries.

[0005] A rechargeable lithium-ion battery consists of a positive electrode, a negative electrode, and an electrolyte. Both the positive and negative electrodes contain active materials capable of intercalation and deintercalation. When lithium ions intercalate and deintercalate, the battery generates electrical energy through oxidation and reduction reactions. Summary of the Invention

[0006] One or more aspects of the implementation involve a positive electrode with enhanced stability (e.g., improved stability).

[0007] One or more aspects of an embodiment relate to a rechargeable lithium battery including the positive electrode.

[0008] Other aspects will be set forth in part in the description which follows and will be apparent in part from the description, or may be learned by practicing the embodiments presented in this disclosure.

[0009] According to one or more embodiments of the present disclosure, the positive electrode may include: a positive electrode active material; a binder; a conductive material; and an additive represented by chemical formula 1-1 or chemical formula 1-2.

[0010] Chemical Formula 1-1

[0011]

[0012] Chemical formula 1-2

[0013]

[0014] In chemical formula 1-1,

[0015] L1 can be independently substituted or unsubstituted C1 to C10 alkylene groups.

[0016] R1 can be hydrogen, C1-C20 alkyl, C2-C20 alkenyl, C2-C20 alkynyl, C3-C20 cycloalkyl, or C6-C20 aryl, each independently.

[0017] At least one of R1 can be a C2 to C20 alkenyl group.

[0018] In chemical formulas 1-2,

[0019] R2 can be hydrogen, C1-C20 alkyl, C2-C20 alkenyl, C2-C20 alkynyl, C3-C20 cycloalkyl, or C6-C20 aryl, each independently.

[0020] At least one of R2 can be a C6 to C20 aryl group.

[0021] According to one or more embodiments of this disclosure, a rechargeable lithium battery may include: the positive electrode discussed above; a negative electrode including a negative electrode active material; and an electrolyte for the rechargeable lithium battery. Attached Figure Description

[0022] Figure 1 A simplified conceptual diagram illustrating a rechargeable lithium battery according to one or more embodiments of the present disclosure is provided.

[0023] Figures 2-5 The illustrations depict rechargeable lithium batteries according to one or more embodiments, wherein... Figure 2 A cylindrical battery is shown. Figure 3 A prismatic battery is shown, and Figure 4 and Figure 5 Showing pouch-type (type) batteries. Detailed Implementation

[0024] To fully understand the configuration and effects of this disclosure, one or more embodiments of this disclosure will be described in more detail with reference to the accompanying drawings. However, it should be noted that this disclosure is not limited to the exemplary embodiments described below and can be implemented in one or more suitable forms. Rather, exemplary embodiments are provided only to disclose this disclosure and to enable those skilled in the art to fully understand its scope.

[0025] In this description, it will be understood that if (e.g., when) one element is on another element, then the element may be directly on the other element, or an intervening element may exist between the two. In the accompanying drawings, the dimensions (e.g., thickness) of some components have been enlarged for the purpose of effectively explaining the technical content. The same reference numerals refer to the same elements throughout and their repeated description may not be provided in the specification.

[0026] Unless otherwise specified in this description, singular expressions may include plural expressions. Additionally, unless otherwise specified, the phrase "A or B" may indicate "A but not B", "B but not A", and "A and B". The terms "comprises / includes" and / or "comprising / including" as used in this description do not exclude the presence or addition of one or more other components.

[0027] The term “and / or” as used herein includes any and all combinations of one or more related enumerated items. Expressions such as “at least one of…”, “one of…”, and “selected from…” as used herein, when preceding or following a list of elements, modify the entire list of elements and not individual elements of the list. For example, “at least one of a, b, and c” can 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 a, b, and c, or variations thereof.

[0028] In this disclosure, it will be understood that the terms “comprise(s) / comprising,” “include(s) / including,” or “have / has / having” indicate the presence of the described feature, integer, step, operation, element, component, and / or group thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. Furthermore, the terms “comprise(s) / comprising,” “include(s) / including,” “have / has / having,” or other similar terms include or support the terms “consisting of,” and “substantially consisting of,” indicating the presence of the described feature, integer, step, operation, element, component, and / or group thereof, while other features, integers, steps, operations, elements, components, and / or groups thereof are absent or substantially absent.

[0029] Furthermore, when describing embodiments of the inventive concept, the use of "may" refers to "one or more embodiments of the inventive concept".

[0030] In this description, the term "combination thereof" may refer to a mixture, stack, complex, copolymer, alloy, blend, or reaction product of the components.

[0031] In this description, unless otherwise specified separately, the term "substitution" may refer to a substituent or at least one hydrogen atom of a compound being substituted with: deuterium, halogen, hydroxyl, amino, C1-C30 amino, 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, and / or combinations thereof (e.g., any suitable combination thereof).

[0032] More specifically, the term "substitution" may refer to at least one hydrogen atom of a substituent or compound being substituted with: deuterium, halogroup, 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 "substitution" may refer to at least one hydrogen atom of a substituent or compound being substituted with: deuterium, halogroup, C1-C20 alkyl, C6-C30 aryl, C1-C10 fluoroalkyl, or cyano. In one or more embodiments, the term "substitution" may refer to at least one hydrogen atom of a substituent or compound being substituted with: deuterium, halogroup, C1-C5 alkyl, C6-C18 aryl, C1-C5 fluoroalkyl, or cyano. For example, the term "substitution" can refer to the substitution of at least one hydrogen atom of a substituent or compound by the following: deuterium, cyano, halo, methyl, ethyl, propyl, butyl, phenyl, biphenyl, terphenyl, trifluoromethyl, or naphthyl.

[0033] Figure 1 A simplified conceptual diagram illustrating a rechargeable lithium battery according to one or more embodiments of the present disclosure is provided. References Figure 1 A rechargeable lithium battery may include a positive electrode 10, a negative electrode 20, a separator 30, and an electrolyte ELL.

[0034] The positive electrode 10 and the negative electrode 20 may be spaced apart and / or separated from each other (e.g., spaced apart and / or separated) by a diaphragm 30. The diaphragm 30 may be disposed between the positive electrode 10 and the negative electrode 20. The positive electrode 10, the negative electrode 20, and the diaphragm 30 may be in contact with the electrolyte ELL. The positive electrode 10, the negative electrode 20, and the diaphragm 30 may be immersed in the electrolyte ELL.

[0035] The electrolyte ELL serves as a medium for transferring lithium ions between the positive electrode 10 and the negative electrode 20. In the electrolyte ELL, lithium ions can move through the separator 30 toward one of the positive electrode 10 and the negative electrode 20.

[0036] Positive electrode 10

[0037] The positive electrode 10 for a rechargeable lithium battery may include a positive electrode current collector COL1 and a positive electrode active material layer AML1 formed on the positive electrode current collector COL1. The positive electrode active material layer AML1 may include a positive electrode active material and further include a binder and / or a conductive material (e.g., an electronic conductor).

[0038] For example, the positive electrode 10 may further include components that can be used as a sacrificial positive electrode.

[0039] The amount of positive electrode active material relative to 100 wt% of the positive electrode active material layer AML1 may be about 90 wt% to about 99 wt%. The amount of each of the binder and the conductive material (e.g., electronic conductor) relative to 100 wt% of the positive electrode active material layer AML1 may be about 0.5 wt% to about 5 wt%.

[0040] The binder can be used to improve the adhesion between the positive electrode active material particles and also to improve the adhesion between the positive electrode active material and the positive electrode current collector COL1. The binder may include, for example, polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene oxide-containing polymers, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, (meth)acrylated styrene-butadiene rubber, epoxy resin, (meth)acrylate resin, polyester resin or nylon, but this disclosure is not limited thereto.

[0041] Conductive materials (e.g., electronic conductors) can be used to provide electrode conductivity (e.g., electronic conductors), and any suitable conductive material (e.g., electronic conductor) that does not cause chemical changes in the battery can be used as a conductive material (e.g., electronic conductor). Conductive materials (e.g., electronic conductors) may include: for example, carbon-based materials (such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fibers, carbon nanofibers, and carbon nanotubes); metal powders or metal fibers containing one or more of copper, nickel, aluminum, and silver; conductive polymers (such as polyphenylene derivatives); and / or mixtures thereof (e.g., any suitable mixture thereof).

[0042] Aluminum (Al) foil can be used as the positive electrode current collector COL1, but this disclosure is not limited thereto.

[0043] Positive electrode active material

[0044] The positive electrode active material in the positive electrode active material layer AML1 may include compounds that can reversibly insert and extract lithium (e.g., lithiation intercalation compounds). For example, the positive electrode active material may include at least one type of composite oxide comprising lithium and a metal selected from cobalt, manganese, nickel and / or combinations thereof (e.g., any suitable combination thereof).

[0045] Composite oxides may include lithium transition metal composite oxides, such as lithium nickel oxides, lithium cobalt oxides, lithium manganese oxides, lithium iron phosphate compounds, cobalt-free nickel manganese oxides, and / or combinations thereof (e.g., any suitable combination thereof).

[0046] For example, the positive electrode active material may include a compound represented by one of the chemical formulas: Li a A 1-b X b O 2-c D c (where 0.90≤a≤1.8, 0≤b≤0.5, and 0≤c≤0.05); Li a Mn 2-b X b O 4-c D c (where 0.90≤a≤1.8, 0≤b≤0.5, and 0≤c≤0.05); Li a Ni 1-b-c Co b X c O 2-α D α (where 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 (where 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 (where 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 (where 0.90 ≤ a ≤ 1.8 and 0.001 ≤ b ≤ 0.1); Li a CoG b O2 (where 0.90 ≤ a ≤ 1.8 and 0.001 ≤ b ≤ 0.1); Li a Mn 1-b G b O2 (where 0.90 ≤ a ≤ 1.8 and 0.001 ≤ b ≤ 0.1); Li a Mn2G bO4 (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).

[0047] In the above chemical formulas, A can be Ni, Co, Mn and / or combinations thereof (e.g., any suitable combination thereof), X can be Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, rare earth elements and / or combinations thereof (e.g., any suitable combination thereof), D can be O, F, S, P and / or combinations thereof (e.g., any suitable combination thereof), G can be Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V and / or combinations thereof (e.g., any suitable combination thereof), and L 1 It can be Mn, Al and / or combinations thereof (e.g., any suitable combination thereof).

[0048] For example, relative to 100 mol% of lithium-free (e.g., excluding or excluding) metal in lithium transition metal complex oxides, the positive electrode active material can be a high-nickel positive electrode active material with a nickel content 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%. High-nickel positive electrode active materials can achieve high capacity and are therefore applicable to high-capacity and high-density rechargeable lithium batteries.

[0049] negative electrode 20

[0050] 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 and may further include a binder and / or a conductive material (e.g., an electronic conductor).

[0051] For example, relative to 100 wt% of the negative electrode active material layer AML2, the negative electrode active material layer AML2 may include about 90 wt% to about 99.5 wt% of the negative electrode active material, about 0.5 wt% to about 5 wt% of the binder, and about 0 wt% to about 5 wt% of the conductive material (e.g., an electronic conductor).

[0052] The binder can be used to improve the adhesion between the negative electrode active material particles and also to improve the adhesion between the negative electrode active material and the negative electrode current collector COL2. The binder may include non-aqueous binders, aqueous binders, dry binders and / or combinations thereof (e.g., any suitable combination thereof).

[0053] Non-aqueous adhesives may include polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene-propylene copolymer, polystyrene, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polyamide-imide, polyimide and / or combinations thereof (e.g., any suitable combination thereof).

[0054] Waterborne adhesives may include styrene-butadiene rubber, (meth)acrylated styrene-butadiene rubber, (meth)acrylonitrile-butadiene rubber, (meth)acrylic rubber, butyl rubber, fluoroelastomers, polyethylene oxide, polyvinylpyrrolidone, polyepoxychloropropane, 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 combinations thereof (e.g., any suitable combination thereof).

[0055] When the aqueous binder is used as a negative electrode binder, it may further include a cellulose compound capable of providing viscosity. The cellulose compound may include one or more of carboxymethyl cellulose, hydroxypropyl methyl cellulose, methyl cellulose, and their alkali metal salts. The alkali metal may include Na, K, or Li.

[0056] Dry adhesives may include fibrous polymeric materials, such as polytetrafluoroethylene, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polyethylene oxide and / or combinations thereof (e.g., any suitable combination thereof).

[0057] Conductive materials (e.g., electronic conductors) can be used to provide electrode conductivity, and as conductive materials (e.g., electronic conductors), any suitable conductive material (e.g., electronic conductor) that does not cause chemical changes in the battery can be used. For example, conductive materials (e.g., electronic conductors) may include: carbon-based materials (such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fibers, carbon nanofibers, and carbon nanotubes); metal powders or metal fibers including one or more of copper, nickel, aluminum, and silver; conductive polymers (such as polyphenylene derivatives); and / or mixtures thereof (e.g., any suitable mixture thereof).

[0058] 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 (e.g., any suitable combination thereof).

[0059] Negative electrode active material

[0060] The negative electrode active material in the negative electrode active material layer AML2 may include materials that can reversibly intercalate and deintercalate lithium ions, lithium metal, lithium metal alloys, materials that can be doped and undoped with lithium, or transition metal oxides.

[0061] Materials that can reversibly intercalate and deintercalate lithium ions may include carbon-based negative electrode active materials, such as crystalline carbon, amorphous carbon, and / or combinations thereof (e.g., any suitable combination thereof). For example, crystalline carbon may include graphite (such as amorphous, flaky, lamellar, spherical, or fibrous natural graphite or artificial graphite), and amorphous carbon may include soft carbon, hard carbon, mesophase pitch carbon, or calcined coke.

[0062] Lithium metal alloys may include alloys of lithium and metals selected from Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Si, Sb, Pb, In, Zn, Ba, Ra, Ge, Al, and Sn.

[0063] Materials that can be doped and undoped with lithium may include Si-based negative electrode active materials or Sn-based negative electrode active materials. Si-based negative electrode active materials may include silicon, silicon-carbon composites, SiO x (where 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 combinations thereof (e.g., any suitable combination thereof)) and / or combinations thereof (e.g., any suitable combination thereof). Sn-based negative electrode active materials may include Sn, SnO x (where 0 < x ≤ 2) (e.g., SnO2), Sn-based alloys, and / or combinations thereof (e.g., any suitable combination thereof).

[0064] The silicon-carbon composite may be a composite of silicon and amorphous carbon. According to one or more embodiments, the silicon-carbon composite may have a structure in which amorphous carbon is coated on the surface of silicon particles. For example, the silicon-carbon composite may include secondary particles (cores) in which primary silicon particles are aggregated (e.g., in the form of secondary particles) and an amorphous carbon coating (shell) on the surface of the secondary particles. Amorphous carbon may also be present between the primary silicon particles, and for example, the primary silicon particles may be coated with amorphous carbon. The secondary particles may be dispersed in an amorphous carbon matrix.

[0065] 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.

[0066] Si-based negative electrode active materials or Sn-based negative electrode active materials may be used in combination with carbon-based negative electrode active materials.

[0067] Diaphragm 30

[0068] Depending on the type of rechargeable lithium battery, the separator 30 may be present between the positive electrode 10 and the negative electrode 20. The separator 30 may include one or more of polyethylene separators, polypropylene separators, and polyvinylidene fluoride separators, and may have multiple layers, such as polyethylene / polypropylene double-layer separators, polyethylene / polypropylene / polypropylene triple-layer separators, and polypropylene / polypropylene / polypropylene triple-layer separators.

[0069] The diaphragm 30 may include a porous substrate and a coating located on one or opposite surfaces of the porous substrate, the coating comprising organic materials, inorganic materials and / or combinations thereof (e.g., any suitable combination thereof).

[0070] The porous substrate may be a polymer layer comprising a selection from the following: polyolefins (such as polyethylene and polypropylene), polyesters (such as polyethylene terephthalate and polybutylene terephthalate), polyacetal, polyamide, polyimide, polycarbonate, polyetherketone, polyaryletherketone, polyetherimide, polyamideimide, polybenzimidazole, polyethersulfone, polyphenylene ether, cyclic olefin copolymers, polyphenylene sulfide, polyethylene naphthalate, glass fiber, and polytetrafluoroethylene (e.g., Teflon), or the polymer layer may comprise copolymers or mixtures comprising two or more of the materials mentioned above.

[0071] Organic materials may include polyvinylidene fluoride copolymers or (meth)acrylic acid copolymers.

[0072] Inorganic materials 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 / or combinations thereof (e.g., any suitable combination thereof), but this disclosure is not limited thereto.

[0073] Organic and inorganic materials can be mixed in a single coating, or they can exist in the form of a stack of coatings comprising organic and inorganic materials. That is, a coating comprising organic materials may be on top of a coating comprising inorganic materials, or vice versa. For example, organic and inorganic materials can be mixed together in a single coating, or arranged in separate layers stacked on top of each other. In the latter case, the organic material layer may be on top of the inorganic material layer, or vice versa.

[0074] Electrolyte ELL

[0075] Electrolytes (ELLs) used in rechargeable lithium batteries may include non-aqueous organic solvents and lithium salts.

[0076] Non-aqueous organic solvents can be used as media for transporting ions that participate in the electrochemical reactions of a battery.

[0077] Non-aqueous organic solvents may include carbonate solvents, ester solvents, ether solvents, ketone solvents, alcohol solvents, aprotic solvents and / or combinations thereof (e.g., any suitable combination thereof).

[0078] Carbonate solvents may 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), or butyl carbonate (BC).

[0079] Ester solvents may include methyl acetate, ethyl acetate, n-propyl acetate, dimethyl acetate, methyl propionate, ethyl propionate, decanoic acid lactone, mevalonate lactone, valonate lactone, or caprolactone.

[0080] Ether solvents may include dibutyl ether, tetraethylene glycol dimethyl ether, diethylene glycol dimethyl ether, ethylene glycol dimethyl ether, 2-methyltetrahydrofuran, 2,5-dimethyltetrahydrofuran, or tetrahydrofuran. Ketone solvents may include cyclohexanone. Alcohol solvents may include ethanol or isopropanol, and aprotic solvents may include nitrile solvents (such as R-CN, where R is a hydrocarbon group having a C2-C20 straight-chain, branched, or cyclic structure, and may include double bonds, aromatic rings, or ether bonds); amides (such as dimethylformamide); dioxolane (such as 1,3-dioxolane or 1,4-dioxolane); or sulfolane.

[0081] Non-aqueous organic solvents can be used alone or in mixtures of two or more substances.

[0082] Additionally, if (for example, when) a carbonate solvent is used, cyclic carbonates and chain carbonates can be mixed and used, and cyclic carbonates and chain carbonates can be mixed in a volume ratio of about 1:1 to about 1:9.

[0083] Lithium salts can be materials dissolved in non-aqueous organic solvents to serve as a source of lithium ions in batteries and play a role in ensuring the basic operation of rechargeable lithium batteries and facilitating the movement of lithium ions between the positive and negative electrodes. Lithium salts may include, for example, those 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+1SO2 (where x and y are integers from 1 to 20), lithium trifluoromethane sulfonate, lithium tetrafluoroethane sulfonate, lithium difluoro(oxalate)borate (LiDFOB), lithium difluorobis(oxalate)phosphate (LiDFBOP), and lithium bis(oxalate)borate (LiBOB).

[0084] Rechargeable lithium batteries

[0085] Based on their shape, rechargeable lithium batteries can be classified into cylindrical batteries, prismatic batteries, pouch batteries, and coin-type batteries. This section explains rechargeable lithium batteries according to one or more embodiments. Figures 2-5 middle, Figure 2 A cylindrical battery is shown. Figure 3 A prismatic battery is shown, and Figure 4 and Figure 5 This shows pouch-type (type) batteries. (Reference) Figures 2-5 The rechargeable lithium battery 100 may include an electrode assembly 40 (with a separator 30 inserted between a positive electrode 10 and a negative electrode 20), and may also include a housing 50 (containing the electrode assembly 40). The positive electrode 10, negative electrode 20, and separator 30 may be immersed in an electrolyte. The rechargeable lithium battery 100 may include a sealing member 60 of the sealing housing 50, such as... Figure 2 The explanation is as follows. Additionally, as... Figure 3 The text explains that the rechargeable lithium battery 100 may include a positive electrode lead connector 11, a positive electrode terminal 12, a negative electrode lead connector 21, and a negative electrode terminal 22. For example... Figure 4 and Figure 5 As shown, the rechargeable lithium battery 100 may include electrode terminals 70 or positive electrode terminals 71 and negative electrode terminals 72, which serve as electrical paths for guiding current generated in the electrode assembly 40 to the outside.

[0086] The following description will focus on the positive electrode according to one or more embodiments of the present disclosure.

[0087] The positive electrode according to one or more embodiments may include a positive electrode active material, a binder, a conductive material (e.g., an electronic conductor), and additives. Additives according to one or more embodiments of this disclosure may be represented by chemical formula 1-1 or chemical formula 1-2.

[0088] Chemical Formula 1-1

[0089]

[0090] Chemical formula 1-2

[0091]

[0092] In chemical formula 1-1, L1 can be independently substituted or unsubstituted C1-C10 alkylene groups, and R1 can be independently hydrogen, C1-C20 alkyl, C2-C20 alkenyl, C2-C20 alkynyl, C3-C20 cycloalkyl, or C6-C20 aryl, and at least one of R1 can be C2-C20 alkenyl.

[0093] In chemical formulas 1-2, R2 can be hydrogen, C1-C20 alkyl, C2-C20 alkenyl, C2-C20 alkynyl, C3-C20 cycloalkyl, or C6-C20 aryl, and at least one of R2 can be C6-C20 aryl.

[0094] Additives according to one or more embodiments of this disclosure may include the structure SS=O, wherein oxygen atoms are bonded to disulfide bonds by double bonds. This bonding structure can stabilize the positive electrode by eliminating unstable oxygen (e.g., reactive oxygen species) generated around the positive electrode active material due to positive electrode degradation. Additionally, this bonding structure can stabilize the positive electrode by promoting the formation of a robust cathode electrolyte interface (CEI) on the surface of the positive electrode.

[0095] In rechargeable lithium batteries, unstable oxygen may be generated internally with repeated charge and discharge cycles. This unstable oxygen can corrode the surface of the positive electrode, leading to its degradation. This bonding structure can effectively or appropriately remove unstable oxygen, significantly improving the degradation of the positive electrode. Therefore, the additive according to this disclosure can improve battery performance. The positive electrode stability effect of this bonding structure becomes more pronounced at high temperatures. For example, the high temperature can be equal to or greater than about 138°C or equal to or greater than about 200°C.

[0096] In Formula 1-1, at least one of R1 may include a carbon atom with a double bond. For example, in Formula 1-1, all R1 may have an allyl structure. Alternatively, in Formula 1-1, only one R1 may include an allyl structure.

[0097] In one or more embodiments, Formula 1-1 may be a compound represented by Formula 1-1A, Formula 1-1B, or Formula 1-1C. For example, the additive represented by Formula 1-1 may be at least one selected from S-allylprop-2-ene-1-sulfinothioate, S-propylprop-2-ene-1-sulfinothioate, or S-allyl ethanesulfinothioate.

[0098] Chemical formula 1-1A

[0099]

[0100] Chemical formula 1-1B

[0101]

[0102] Chemical formula 1-1C

[0103]

[0104] The additives according to one or more embodiments of this disclosure may include allyl groups. For example, the additive represented by chemical formula 1-1 may include allyl groups located at the ends, so that the polymerization reaction can easily and continuously occur during SEI film formation. Therefore, the additives according to one or more embodiments of this disclosure can form relatively thick and high-density SEI films due to chain polymerization.

[0105] In formula 1-2, at least one of R2 may include an aryl group. For example, in formula 1-2, all R2 may have a phenyl structure. Alternatively, in formula 1-2, only one R2 may include a phenyl structure.

[0106] In one or more embodiments, chemical formulas 1-2 may be compounds represented by chemical formulas 1-2A or 1-2B. For example, the additive represented by chemical formulas 1-2 may be one or both (e.g., simultaneously) of S-phenyl thiobenzene sulfonate and S-phenyl ethanesulfinothioate.

[0107] Chemical formula 1-2A

[0108]

[0109] Chemical formula 1-2B

[0110]

[0111] Additives according to one or more embodiments of this disclosure may include at least one phenyl group. For example, additives represented by chemical formulas 1-2 may include a phenyl group at the end to promote the formation of a robust cathode electrolyte interface (CEI) on the surface of the positive electrode, thereby stabilizing the positive electrode.

[0112] Because the additives according to this disclosure include a structure in which oxygen atoms are bonded to disulfide bonds by double bonds (SS=O) and specific functional groups at the ends, the effects discussed above can be achieved even more effectively or appropriately. Compared to additives containing only allyl or phenyl groups, the structural features of the additives according to this disclosure can exhibit significantly superior or appropriate positive electrode stability effects.

[0113] With respect to a total of 100 parts by weight of the positive electrode active material, binder, and conductive material (e.g., electronic conductor), the additive can be included in an amount of about 0.01 part by weight to about 10 parts by weight, about 0.03 part by weight to about 8 parts by weight, about 0.05 part by weight to about 7 parts by weight, or about 0.1 part by weight to about 5 parts by weight. In one or more embodiments, with respect to a total of 100 parts by weight of the positive electrode active material, binder, and conductive material (e.g., electronic conductor), the additive can be included in an amount of about 0.1 part by weight to about 5 parts by weight. When the amount of the additive is less than the above range, the additive may not be able to sufficiently remove unstable oxygen, resulting in insufficient positive electrode stability effect. When the amount of the additive is greater than the above range, the additive itself may act as a resistance-inducing material, thereby resulting in insufficient positive electrode stability effect. When the amount of the additive falls within the above range, due to the positive electrode stability, the resistance increase suppression effect and high-temperature storage effect at high temperatures can be maximized or increased.

[0114] The positive electrode active material can include a compound (e.g., a lithiated insertion compound) that can reversibly insert and extract lithium. The positive electrode active material can include a lithium composite oxide represented by Chemical Formula 2.

[0115] Chemical Formula 2

[0116] Li x M 1 y M 2 z M 3 1-y-z O 2-a X a

[0117] In Chemical Formula 2,

[0118] a, x, y, and z can satisfy the relationships of 0.5 ≤ x ≤ 1.8, 0 ≤ a ≤ 0.05, 0 < y ≤ 1, 0 ≤ z ≤ 1, and 0 < y + z ≤ 1.

[0119] M 1 、M 2 和M 3 can each independently include at least one element selected from Ni, Co, Mn, Al, B, Ba, Ca, Ce, Cr, Fe, Mo, Nb, Si, Sr, Mg, Ti, V, W, Y, Zr, and La.

[0120] X can include at least one element selected from F, S, P, and Cl.

[0121] In one or more embodiments, in Chemical Formula 2, M 1It can be Ni, y can be 0.8≤y≤1, and z can be 0≤z≤0.2. In one or more embodiments, in chemical formula 2, M 1 It can be Ni, M 2 It can be Co, and M 3 It can be Al. However, in chemical formula 2, M... 1 It can be Ni, M 2 It can be Co, and M 3 It can be Mn.

[0122] The positive electrode active material may be present in an amount of about 90 wt% to about 98 wt% relative to the total weight of the positive electrode active material layer. Each of the conductive material (e.g., an electronic conductor) and the binder may be present in an amount of about 1 wt% to about 5 wt% relative to the total weight of the positive electrode active material layer.

[0123] Conductive materials (e.g., electronic conductors) can be used to provide electrode conductivity (e.g., electrical conductivity), and in constituting a battery, any suitable conductive material (e.g., electronic conductor) that does not cause chemical changes in the battery can be used, such as carbon-based materials (e.g., natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fibers, carbon nanofibers, and carbon nanotubes); metallic materials containing one or more of copper, nickel, aluminum, and silver (e.g., metal powders or metal fibers); conductive polymers (e.g., polyphenylene derivatives); and / or mixtures thereof (e.g., any suitable mixture thereof).

[0124] The binder can be used to improve the adhesion between the positive electrode active material particles and the positive electrode current collector, and may include, but is not limited to, polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene oxide-containing polymers, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, acrylated styrene-butadiene rubber, epoxy resin or nylon.

[0125] In one or more embodiments of this disclosure, a rechargeable lithium battery may be provided, comprising the positive electrode discussed above, a negative electrode comprising a negative electrode active material, and an electrolyte for the rechargeable lithium battery.

[0126] The positive electrode may include a positive electrode current collector and a positive electrode active material layer located on the positive electrode current collector, and the positive electrode active material layer may include the positive electrode active material mentioned above.

[0127] A positive electrode active material, a binder, and a conductive material (e.g., an electronic conductor) can be mixed and dispersed in an organic solvent to prepare a positive electrode paste composition, and the positive electrode paste composition can be coated on a positive electrode current collector, dried, and then pressed to fabricate a positive electrode.

[0128] A negative electrode may include a negative electrode current collector and a negative electrode active material layer formed on the negative electrode current collector, and the negative electrode active material layer includes a negative electrode active material.

[0129] The negative electrode active material may include a material capable of reversibly inserting and extracting lithium ions, lithium metal, a lithium metal alloy, a material capable of doping and dedoping lithium, or a transition metal oxide.

[0130] In one or more embodiments, the negative electrode active material may include at least one selected from graphite and a silicon composite.

[0131] When the negative electrode active material includes both (e.g., simultaneously) a silicon composite and graphite, the silicon composite and graphite may exist in the form of a mixture, and in this case, the silicon composite and graphite may be included in a weight ratio of about 1:99 to about 50:50. For example, the silicon composite and graphite may be included in a weight ratio of about 3:97 to about 20:80 or about 5:95 to about 20:80.

[0132] The silicon composite may include a core containing silicon-based particles and an amorphous carbon coating, and the silicon-based particles may include at least one selected from silicon particles, a silicon-carbon composite, SiO x (where 0 < x ≤ 2) and a silicon alloy. For example, the silicon-carbon composite may include a core containing silicon particles and crystalline carbon, and may further include an amorphous carbon coating on the surface of the core. The crystalline carbon may include graphite, e.g., natural graphite, artificial graphite, and / or a mixture thereof (e.g., any suitable mixture thereof).

[0133] An electrolyte can be prepared by the following mixing process: in which a lithium salt is dissolved in a non-aqueous organic solvent, and additives are added for mixing. The electrolyte mixing process is applicable to the field of electrolyte manufacturing, and those skilled in the art will be able to select and use it appropriately or suitably.

[0134] The non-aqueous organic solvent may include at least one selected from ethyl methyl carbonate (EMC), ethylene carbonate (EC), dimethyl carbonate (DMC), propylene carbonate (PC), propyl propionate (PP), diethyl carbonate (DEC), dipropyl carbonate (DPC), methyl propyl carbonate (MPC), ethyl propyl carbonate (EPC), ethyl methyl carbonate (EMC), and butylene carbonate (BC).

[0135] In one or more embodiments, the non-aqueous organic solvent may be a mixture of ethyl methyl carbonate (EMC), ethylene carbonate (EC), and dimethyl carbonate (DMC).

[0136] For example, ethylene carbonate (EC) may be included in an amount of about 10 vol% to about 40 vol% relative to the total volume of the non-aqueous organic solvent. Ethyl methyl carbonate (EMC) may be included in an amount of about 20 vol% to about 70 vol% relative to the total volume of the non-aqueous organic solvent. Dimethyl carbonate (DMC) may be included in an amount of about 20 vol% to about 70 vol% relative to the total volume of the non-aqueous organic solvent.

[0137] For example, lithium salts may include one or more of LiPF6, LiClO4, LiBF4, lithium bis(fluorosulfonyl)imide (LiFSI), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), LiSO3CF3, LiBOB, LiFOB, LiDFBP, LiTFOP, LiPO2F2, LiSbF6, LiAsF6, LiAlO2, LiAlCl4, LiCl, LiI, LiN(SO3C2F5)2, Li(FSO2)2N, and LiC4F9SO3. According to one or more embodiments, the lithium salt may include LiPF6.

[0138] The lithium salt may have a concentration of about 0.1 M to about 2.0 M. For example, the lithium salt may 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 may 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 this disclosure, if (for example, when) the lithium salt has a concentration of about 0.1 M to about 2.0 M, the electrolyte may suitably or appropriately maintain its conductivity and viscosity.

[0139] In rechargeable lithium-ion batteries, the positive and negative electrode films can deteriorate due to the erosion of acids generated within the battery. In rechargeable lithium-ion batteries according to one or more embodiments of this disclosure, the electrolyte can decompose during the initial charge / discharge to form a passivating film on the surfaces of the positive and negative electrodes, thereby improving high-temperature storage characteristics. Acids (such as HF and PF5) generated from the thermal decomposition of lithium salts (LiPF6, etc.) used in lithium-ion batteries can degrade the films. In the prior art, this acid erosion can dissolve transition metal elements from the positive electrode and increase the electrode surface resistance due to changes in surface structure. Therefore, the theoretical capacity may decrease due to the loss of metal elements that serve as redox (reduction and oxidation) centers, potentially leading to capacity reduction. Additionally, the dissolved transition metal ions may electrodeposit on the negative electrode, which reacts within a strong reduction potential range. These transition metal ions may consume electrons while electrodepositing on the negative electrode and may damage or destroy the film, exposing the negative electrode surface. This can lead to additional decomposition reactions of the electrolyte. Therefore, the resistance and irreversible capacity of the negative electrode may increase, resulting in a potential problem of continuous (e.g., essentially continuous) reduction in the capacity of individual battery cells.

[0140] In the rechargeable lithium battery according to this disclosure, since the additives all (e.g., simultaneously) include a structure in which oxygen atoms are bonded to disulfide by double bonds (SS=O) and specific functional groups located at the ends, reactive oxygen species can be removed and the positive electrode film strengthened. Therefore, the degradation of the positive electrode can be effectively prevented or reduced. As a result, the rechargeable lithium battery according to this disclosure can exhibit excellent or adequate electrochemical performance. These effects become more pronounced at high temperatures.

[0141] Similarly, in rechargeable lithium-ion batteries, acids generated within the battery can degrade both the positive and negative electrode films, leading to reduced capacity and increased resistance. This degradation occurs due to the decomposition of lithium salts, and the resulting acids corrode the electrodes. Dissolved transition metal ions can deposit on the negative electrode, further damaging it and causing additional electrolyte decomposition. However, in the disclosed batteries, additives with specific structures can remove reactive oxygen species and strengthen the positive electrode film, effectively preventing or reducing degradation and enhancing or improving electrochemical performance, especially at high temperatures.

[0142] Rechargeable lithium batteries can be used in automobiles, mobile phones and / or any other electrical devices, but this disclosure is not limited thereto.

[0143] One or more embodiments and comparative examples of this disclosure will be described below. However, the embodiments described below are merely examples, and this disclosure is not limited to the one or more embodiments discussed.

[0144] Implementation methods and comparative examples

[0145] Implementation Method 1: Manufacturing of the Positive Electrode

[0146] The additive was added to a mixed solution in which the positive electrode active material, conductive material, and binder were dispersed in N-methyl-2-pyrrolidone (NMP) at a weight ratio of 97.7:1.2:1.1. The mixture was then stirred using a mechanical stirrer for 30 minutes to prepare a positive electrode active material slurry. The amount of additive added was 0.1 parts by weight relative to a total of 100 parts by weight of positive electrode active material, conductive material, and binder.

[0147] LiNi 0.91 Co 0.08 Al 0.01 O2 (NCA) is used as the positive electrode active material, artificial graphite is used as the conductive material, and polyvinylidene fluoride (PVdF) is used as the binder. Substances represented by chemical formula 1-1A are used as additives.

[0148] Chemical formula 1-1A

[0149]

[0150] The prepared positive electrode active material slurry was coated with a thickness of 60 μm onto an aluminum current collector with a thickness of 20 μm using a scraper. It was dried in a hot air dryer at 100 °C for 0.5 hours and then dried again under vacuum at 120 °C for 4 hours. Finally, it was rolled to manufacture the positive electrode.

[0151] (2) Manufacturing of rechargeable lithium batteries

[0152] A negative electrode active material containing 98 wt% of a composite of artificial graphite and silicon in a weight ratio of 95.8:4.2, 1 wt% of styrene-butadiene rubber (SBR), and 1 wt% of carboxymethyl cellulose (CMC) was mixed and added to distilled water. The mixture was then stirred for 60 minutes using a mechanical stirrer to prepare a negative electrode active material slurry. The prepared negative electrode active material slurry was coated onto a 10 μm thick copper current collector using a doctor blade. The slurry was dried in a hot air dryer at 100 °C for 0.5 hours, and then dried again under vacuum at 120 °C for 4 hours. Finally, the mixture was rolled to fabricate the negative electrode.

[0153] An electrolyte was prepared by dissolving 1.15 M LiPF6 in a non-aqueous organic solvent containing ethylene carbonate (EC), ethyl methyl carbonate (EMC), and dimethyl carbonate (DMC) mixed in a volume ratio of approximately 20:40:40.

[0154] The positive electrode, negative electrode, and 16μm thick polyethylene separator are assembled to manufacture the electrode assembly, and an electrolyte is introduced to manufacture the rechargeable lithium battery.

[0155] Implementation Method 2

[0156] The positive electrode and the rechargeable lithium battery are manufactured independently using a method substantially the same as that used in Embodiment 1, except that 0.3 parts by weight of an additive represented by chemical formula 1-1A are used.

[0157] Implementation Method 3

[0158] The positive electrode and the rechargeable lithium battery are manufactured independently using a method substantially the same as that used in Embodiment 1, except that 0.5 parts by weight of an additive represented by chemical formula 1-1A are used.

[0159] Implementation Method 4

[0160] The positive electrode and the rechargeable lithium battery are manufactured independently using a method substantially the same as that in Embodiment 1, except that 5.0 parts by weight of an additive represented by chemical formula 1-1A are used.

[0161] Implementation Method 5

[0162] The positive electrode and the rechargeable lithium battery are manufactured independently using a method substantially the same as that in Embodiment 1, except that 0.1 parts by weight of the additive represented by chemical formula 1-2A are used instead of the additive represented by chemical formula 1-1A.

[0163] Chemical formula 1-2A

[0164]

[0165] The positive electrode and the rechargeable lithium battery are manufactured independently using essentially the same method as in Embodiment 1, except that, if (for example, when) the positive electrode is manufactured, the additive represented by chemical formula 1-1A is not used.

[0166] Comparative Example 2

[0167] The positive electrode and the rechargeable lithium battery are manufactured independently using a method substantially the same as that in Embodiment 1, except that 0.1 parts by weight of the additive represented by Chemical Formula 3-1 is used instead of the additive represented by Chemical Formula 1-1A.

[0168] Chemical formula 3-1

[0169]

[0170] Comparative Example 3

[0171] The positive electrode and the rechargeable lithium battery are manufactured independently using a method substantially the same as that in Embodiment 1, except that 0.1 parts by weight of the additive represented by Chemical Formula 3-2 is used instead of the additive represented by Chemical Formula 1-1A.

[0172] Chemical formula 3-2

[0173]

[0174] Table 1 lists the positive electrode composition according to the embodiments and comparative examples.

[0175] Table 1

[0176]

[0177]

[0178] Evaluation Example

[0179] The following methods were used to evaluate rechargeable lithium batteries.

[0180] Evaluation 1: Charge / discharge characteristics at room temperature

[0181] Each of the rechargeable lithium batteries manufactured according to the embodiments and comparative examples was subjected to 300 charge and discharge cycles at 25°C under the conditions of 0.5C charging (CC / CV, 4.25V, 0.05C cutoff) and 0.5C discharging (CC, 2.8V cutoff). The capacity retention rate was calculated and listed in Table 2. The capacity retention rate was calculated according to Equation 1.

[0182] Equation 1

[0183] Capacity retention (%) = (Discharge capacity after 300 cycles / Initial discharge capacity) × 100

[0184] Table 2

[0185] category Capacity retention rate (%) Comparative Example 1 85.6 Comparative Example 2 89.0 Comparative Example 3 87.2 Implementation Method 1 93.2 Implementation Method 2 93.7 Implementation Method 3 95.7 Implementation Method 4 96.5 Implementation Method 5 92.4

[0186] Evaluation 2: High-Temperature Resistance Test

[0187] Each of the rechargeable lithium batteries manufactured in the embodiments and comparative examples was charged to 4.3V (CC / CV, 0.05C cutoff) at 45°C, and the initial resistance value and the resistance value after 7 days at 60°C were measured. The results are then listed in Table 3. The resistance value was measured using electrochemical impedance spectroscopy (EIS).

[0188] Table 3

[0189]

[0190]

[0191] Assessment 3: Heat Exposure

[0192] Each of the rechargeable lithium batteries manufactured according to the embodiments and comparative examples was exposed to a target temperature (high temperature) for 1 hour to assess whether ignition occurred, and the results are shown in Table 4. When the temperature was increased from room temperature to the target temperature, the heating rate was maintained at 5°C / min. At this time, it was checked whether ignition occurred, and the results are shown in Table 4.

[0193] Table 4

[0194] Target temperature 134℃ 136℃ 138℃ 140℃ Comparative Example 1 No fire on fire - - Comparative Example 2 No fire on fire - - Comparative Example 3 No fire on fire - - Implementation Method 1 No fire No fire No fire No fire Implementation Method 2 No fire No fire No fire No fire Implementation Method 3 No fire No fire No fire No fire Implementation Method 4 No fire No fire No fire on fire Implementation Method 5 No fire No fire No fire on fire

[0195] Comprehensive assessment

[0196] Referring to Table 2, it can be determined that, compared with the comparative example, in each of the embodiments (Embodiments 1 to 5) using a positive electrode with additives according to the present disclosure, the capacity retention rate is improved according to charge / discharge cycles at room temperature (25°C).

[0197] Referring to Table 3, it can be determined that, compared with the comparative examples, the resistance at high temperature (60°C) was more effectively suppressed or reduced in each of the embodiments (Embodiments 1 to 5) using a positive electrode with additives according to the present disclosure.

[0198] Referring to Table 4, if (for example, when) the positive electrode according to this disclosure (Embodiments 1 to 5) is used, it can withstand heat up to 136°C to 138°C; if (for example, when) the positive electrode according to this disclosure (Embodiments 1 to 3) is used, it can withstand heat up to 136°C to 140°C. Therefore, it can be confirmed that, compared with the comparative examples, the thermal stability characteristics (thermal runaway and positive electrode degradation) are improved in each of the embodiments using a positive electrode with additives according to this disclosure.

[0199] In the positive electrode according to one or more embodiments, additives may be used to exhibit improved stability.

[0200] Rechargeable lithium batteries, including the positive electrode, can have excellent or adequate lifespan characteristics and stability.

[0201] The battery manufacturing apparatus, battery management system (BMS) apparatus, and / or any other related apparatus or components according to embodiments of the invention described herein can be implemented using any suitable hardware, firmware (e.g., application-specific integrated circuits), software, or a combination of software, firmware, and hardware. For example, various components of the apparatus may be formed on a single integrated circuit (IC) chip or on a separate IC chip. Furthermore, various components of the apparatus may be implemented on a flexible printed circuit film, a tape-on package (TCP), or a printed circuit board (PCB), or formed on a substrate. Additionally, various components of the apparatus 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 memory, which may be implemented using standard memory devices in the computing device, 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 or a flash drive. Moreover, those skilled in the art will recognize that, without departing from the scope of this disclosure, the functionality of various computing devices may be combined or integrated into a single computing device, or the functionality of a dedicated computing device may be distributed across one or more other computing devices.

[0202] Upon consideration of this disclosure in its entirety, those skilled in the art will recognize that each suitable feature of the various embodiments of this disclosure may be combined in part or in whole, or combined with one another, and may be technically interlocked and operated in various suitable ways, and that each embodiment may be implemented independently of one another or in combination with one another in any suitable way, unless otherwise stated or implied.

[0203] Although this disclosure has been described in conjunction with exemplary embodiments, it should be understood that this disclosure is not limited to these embodiments. It is intended to cover appropriate modifications and equivalent arrangements within the spirit and scope of the appended claims and their equivalents. Therefore, the foregoing embodiments should be considered as examples and should not be construed as limiting this disclosure in any way.

Claims

1. A positive electrode, comprising: A positive electrode active material; A binder; A conductive material; And An additive represented by Chemical Formula 1-1 or Chemical Formula 1-2, Chemical Formula 1-1 Chemical Formula 1-2 Wherein, in Chemical Formula 1-1, L1 is each independently a substituted or unsubstituted C1-C10 alkylene group, R1 is each independently hydrogen, a C1-C20 alkyl group, a C2-C20 alkenyl group, a C2-C20 alkynyl group, a C3-C20 cycloalkyl group or a C6-C20 aryl group, and At least one of R1 is a C2-C20 alkenyl group, Wherein, in Chemical Formula 1-2, R2 is each independently hydrogen, a C1-C20 alkyl group, a C2-C20 alkenyl group, a C2-C20 alkynyl group, a C3-C20 cycloalkyl group or a C6-C20 aryl group, and At least one of R2 is a C6-C20 aryl group, and Where the positive electrode is for a rechargeable lithium battery.

2. The positive electrode according to claim 1, wherein Chemical Formula 1-1 includes at least one selected from the compounds represented by Chemical Formula 1-1A, Chemical Formula 1-1B and Chemical Formula 1-1C, Chemical Formula 1-1A Chemical Formula 1-1B Chemical Formula 1-1C 3. The positive electrode according to claim 1, wherein Chemical Formula 1-2 includes at least one selected from the compounds represented by Chemical Formula 1-2A and Chemical Formula 1-2B, Chemical Formula 1-2A Chemical Formula 1-2B 4. The positive electrode according to claim 1, wherein the additive is included in an amount of 0.1 parts by weight to 5 parts by weight relative to the total of 100 parts by weight of the positive electrode active material, the binder and the conductive material.

5. The positive electrode according to claim 1, wherein the positive electrode active material is represented by Chemical Formula 2, Chemical Formula 2 Li x M 1 y M 2 z M 3 1-y-z O 2-a X a , in, In Chemical Formula 2, 0.5 ≤ x ≤ 1.8, 0 ≤ a ≤ 0.05, 0 < y ≤ 1, 0 ≤ z ≤ 1, and 0 < y + z ≤ 1, M 1 M 2 and M 3 Each element independently comprises at least one element selected from Ni, Co, Mn, Al, B, Ba, Ca, Ce, Cr, Fe, Mo, Nb, Si, Sr, Mg, Ti, V, W, Y, Zr, and La, and X includes at least one element selected from F, S, P and Cl.

6. The positive electrode as claimed in claim 5, wherein M of chemical formula 2 1 For Ni.

7. A rechargeable lithium battery, comprising: The positive electrode according to any one of claims 1 to 6; A negative electrode including a negative electrode active material; And An electrolyte for the rechargeable lithium battery.

8. The rechargeable lithium battery according to claim 7, wherein the electrolyte includes a lithium salt and a non-aqueous organic solvent.

9. The rechargeable lithium battery according to claim 7, wherein the negative electrode active material includes at least one selected from graphite and a silicon composite.

10. The rechargeable lithium battery according to claim 9, wherein the silicon composite includes: A core including silicon-based particles; And A coating including amorphous carbon.

11. The rechargeable lithium battery of claim 10, wherein the silicon particles include silicon particles, silicon-carbon composites, and SiO₂. x and one or more of silicon alloys, wherein, 0<x≤2。 12. The rechargeable lithium battery according to claim 7, wherein the rechargeable lithium battery is a cylindrical battery, a prismatic battery, a pouch-type battery or a coin-type battery.

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