Rechargeable lithium battery including positive electrode

Abstract

The invention discloses a rechargeable lithium battery including a positive electrode. A rechargeable lithium battery may include a positive electrode including a positive electrode active material, a negative electrode including a negative electrode active material, and an electrolyte including a non-aqueous (e.g., water-insoluble) organic solvent, a lithium salt, and an additive represented by Chemical Formula 1. The positive electrode active material may include a lithium iron phosphate-based compound. Chemical formula 1

Description

[0001] Cross-references to related applications

[0002] This application claims priority and benefit to Korean Patent Application No. 10-2024-0105353, filed on August 7, 2024, with the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] One or more embodiments of this disclosure relate to a positive electrode for a rechargeable lithium battery and a rechargeable lithium battery including a positive electrode, for example, to a rechargeable lithium battery including a positive electrode, a negative electrode and an electrolyte, wherein the electrolyte includes an additive represented by chemical formula 1 and the positive electrode includes a positive electrode active material comprising a lithium iron phosphate compound. Background Technology

[0004] Recently, with the rapid proliferation and widespread adoption of battery-powered electronic devices (such as mobile phones, laptops, etc.) and / or electric vehicles, the demand for rechargeable batteries (e.g., rechargeable lithium batteries) with high energy density and high capacity (e.g., charge capacity) has increased rapidly. Therefore, in-depth research and development have been conducted to improve or enhance the performance of rechargeable lithium batteries.

[0005] A rechargeable lithium battery includes a positive electrode, a negative electrode, and an electrolyte. The positive and negative electrodes contain active materials in which intercalation and deintercalation can occur. If (for example, when) lithium ions are intercalated and deintercalated, the rechargeable lithium battery generates electrical energy through oxidation and reduction reactions.

[0006] Lithium salts dissolved in non-aqueous (e.g., water-insoluble) organic solvents are used in the electrolytes of rechargeable lithium-ion batteries. The characteristics of rechargeable lithium-ion batteries are demonstrated through complex chemical reactions between the positive electrode and the electrolyte and / or between the negative electrode and the electrolyte. Accordingly, the use of appropriate or suitable electrolytes is an important variable for improving or enhancing rechargeable lithium-ion batteries. Summary of the Invention

[0007] One or more aspects of embodiments of this disclosure relate to rechargeable lithium batteries with improved or enhanced lifetime characteristics and stability (e.g., chemical and / or physical stability) at room temperature and / or relatively high temperatures (e.g., rechargeable lithium batteries with improved lifetime characteristics and stability (e.g., chemical and / or physical stability) at room temperature and / or relatively high temperatures).

[0008] One or more aspects of embodiments of this disclosure relate to positive electrodes with improved or enhanced lifetime characteristics and stability (e.g., chemical and / or physical stability) at room temperature and / or relatively high temperatures (e.g., positive electrodes with improved lifetime characteristics and stability (e.g., chemical and / or physical stability) at room temperature and / or relatively high temperatures).

[0009] Further aspects of the implementation 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 practice of the implementations presented in this disclosure.

[0010] According to one or more embodiments of the present disclosure, a rechargeable lithium battery includes: a positive electrode containing a positive electrode active material; a negative electrode containing a negative electrode active material; and an electrolyte containing a non-aqueous (e.g., water-insoluble) organic solvent, a lithium salt, and an additive represented by Chemical Formula 1.

[0011] The active material for the positive electrode may include lithium iron phosphate compounds.

[0012] Chemical Formula 1

[0013]

[0014] In chemical formula 1,

[0015] R1 to R6 can each independently be hydrogen, a substituted or unsubstituted C1-C20 alkyl, a substituted or unsubstituted C1-C20 alkoxy, a substituted or unsubstituted C2-C20 alkenyl, a substituted or unsubstituted C2-C20 alkynyl, a substituted or unsubstituted C3-C20 cycloalkyl, a substituted or unsubstituted C6-C20 aryl, or a substituted or unsubstituted C2-C20 heteroaryl.

[0016] n can be an integer of 0 or 1.

[0017] According to one or more embodiments of the present disclosure, the positive electrode for a rechargeable lithium battery may include: a positive electrode active material comprising a lithium iron phosphate compound; and an electrolyte comprising an additive represented by chemical formula 1. Attached Figure Description

[0018] The accompanying drawings, together with the specification, illustrate embodiments of the subject matter of this disclosure and, together with the description, serve to explain the principles of embodiments of the subject matter of this disclosure.

[0019] Figure 1 The diagrams are provided to partially illustrate a concept of a rechargeable lithium battery according to one or more embodiments of the present disclosure.

[0020] Figures 2-5A simplified diagram illustrating a rechargeable lithium battery according to one or more embodiments of the present disclosure. Detailed Implementation

[0021] To fully understand the aspects and features of this disclosure, the subject matter will be described in more detail below with reference to the accompanying drawings. However, it should be noted that this disclosure is not limited to the disclosed embodiments and may be implemented in one or more suitable forms. Rather, these embodiments are provided as examples with reference to the accompanying drawings to explain the aspects and features of this disclosure to those skilled in the art.

[0022] In this disclosure, it will be understood that if (for example, when) an element is referred to as being "on" another element, the element may be directly on the other element, or there may be an intermediary element between them. In contrast, if (for example, when) an element is referred to as being "directly on" another element, there is no intermediary element between them.

[0023] In the accompanying drawings, the dimensions (e.g., thickness) of one or more components may be enlarged to effectively illustrate the technical content. The same reference numerals refer to the same elements throughout the drawings, and their repeated descriptions are not required in this disclosure.

[0024] Unless otherwise stated in this disclosure, singular expressions may include plural expressions. Additionally, unless otherwise stated, the phrase “A or B” may indicate “A but not B,” “B but not A,” and “A and B.” The terms “includes / has” and / or “including / having” as used in this disclosure do not exclude the presence or addition of one or more other components.

[0025] In this disclosure, the term "combination thereof" may refer to mixtures, stacks, complexes, copolymers, alloys, blends, reaction products, etc. of the components.

[0026] In this disclosure, unless otherwise defined 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 (e.g., any suitable) combinations thereof.

[0027] For example, 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" may refer to the substitution of at least one hydrogen atom in a substituent or compound by the following: deuterium, cyano, halogroup, methyl, ethyl, propyl, butyl, phenyl, biphenyl, terphenyl, trifluoromethyl, or naphthyl. Alkyl groups may include straight-chain alkyl groups and / or chain alkyl groups. Cycloalkyl groups may include cyclic alkyl groups.

[0028] Figure 1 The diagrams provided partially illustrate a concept of a rechargeable lithium battery according to one or more embodiments of the present disclosure. References Figure 1 A rechargeable lithium battery may include a positive electrode 10, a negative electrode 20, a separator 30, and an electrolyte ELL.

[0029] The positive electrode 10 and the negative electrode 20 may be spaced apart and / or separated from each other across the diaphragm 30 (e.g., spaced apart or separated). The diaphragm 30 may be arranged or provided 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 / impregnated with the electrolyte ELL.

[0030] The electrolyte ELL serves as the medium for the transport of lithium ions between the positive electrode 10 and the negative electrode 20. In the electrolyte ELL, lithium ions can move towards one of the positive electrode 10 and the negative electrode 20 through the membrane 30.

[0031] Based on their shape, rechargeable lithium batteries can be classified into cylindrical, prismatic, pouch, and coin-shaped (or different types). Figures 2-5 To illustrate a simplified diagram of a rechargeable lithium battery according to one or more embodiments of the present disclosure, wherein... Figure 2 Explaining cylindrical rechargeable lithium batteries, Figure 3 Explaining the prismatic rechargeable lithium battery, and Figure 4 and Figure 5 Explain the bag-type (or type) rechargeable lithium battery. (Reference) Figures 2-5The rechargeable lithium battery 100 may include an electrode assembly 40 in which a separator 30 is located between a positive electrode 10 and a negative electrode 20, and may also include a housing 50 in which the electrode assembly 40 is housed or provided. The positive electrode 10, negative electrode 20, and separator 30 may be immersed in / impregnated with an electrolyte. (As in...) Figure 2 As illustrated herein, the rechargeable lithium battery 100 may include a sealing member 60 of the sealed housing 50. In one or more embodiments, such as in Figure 3 As illustrated herein, 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, in... Figure 4 and Figure 5 As illustrated herein, the rechargeable lithium battery 100 may include electrode terminals 70, or positive electrode terminals 71 and negative electrode terminals 72, which serve as or are used as electrical paths to lead the current generated in the electrode assembly 40 to the outside.

[0032] Commonly used rechargeable lithium-ion batteries utilize LiPF6 as the lithium salt in the electrolyte. However, LiPF6 can chemically react with moisture within the lithium-ion battery to form PF5, simultaneously decomposing into HF. The highly reactive HF can induce degradation in the lifespan and high-temperature storage properties of lithium-ion batteries. Although fluorophosphite-based additives are used, which stabilize PF5 by providing electrons and utilizing its Lewis acid properties, the HF released from these additives... - Ions can cause side reactions that degrade the performance of lithium-ion batteries. For example, if (e.g., when) the positive electrode active material includes lithium iron phosphate compounds (such as lithium iron phosphate (LiFePO4, LFP) and / or lithium manganese iron phosphate (LiMnFePO4, LMFP)), side reactions can accelerate the degradation of lithium-ion battery performance.

[0033] A rechargeable lithium battery according to one or more embodiments of this disclosure may include a positive electrode active material comprising a lithium iron phosphate compound, and may also include an electrolyte comprising an additive represented by chemical formula 1, and the rechargeable lithium battery can effectively or appropriately suppress or reduce the degradation caused by F - Ion-induced side reactions (or the extent or occurrence of side reactions), and improve or enhance lifetime properties and stability (e.g., chemical stability and / or physical stability) not only at room temperature but also at relatively high temperatures.

[0034] Positive electrode 10

[0035] A rechargeable lithium battery according to one or more embodiments of the present disclosure may include a positive electrode. For example, a rechargeable lithium battery according to one or more embodiments of the present disclosure may include a positive electrode comprising a positive electrode active material.

[0036] 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 on the positive electrode current collector COL1. The positive electrode active material layer AML1 may include a positive electrode active material and may further include a binder and / or a conductive (e.g., electrically conductive) material (e.g., an electronic conductor).

[0037] The amount of positive electrode active material in the positive electrode active material layer AML1 may be from about 90 wt% to about 99.3 wt% relative to 100 wt% (e.g., based on a total of 100 wt%). For example, the amount of positive electrode active material in the positive electrode active material layer AML1 may be from about 92 wt% to about 99.3 wt% or from about 95 wt% to about 99 wt% relative to 100 wt% (e.g., based on a total of 100 wt%).

[0038] The positive electrode active material may include lithium iron phosphate compounds. For example, the positive electrode active material may include lithium iron phosphate (LiFePO4, LFP) and / or lithium manganese iron phosphate (LiMnFePO4, LMFP).

[0039] The amount of lithium iron phosphate compound relative to the total weight of the positive electrode active material (e.g., based on a total of 100 wt%) can be about 50 wt% to about 98 wt%. For example, the amount of lithium iron phosphate compound relative to the total weight of the positive electrode active material (e.g., based on a total of 100 wt%) can be about 55 wt% to about 98 wt%, about 75 wt% to about 97 wt%, or about 85 wt% to about 96 wt%.

[0040] 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., lithiated intercalation compounds). For example, the positive electrode active material may include at least one type (or class) of a composite oxide comprising lithium and a metal selected from cobalt, manganese, nickel and / or combinations thereof (e.g., any suitable combination).

[0041] 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).

[0042] The positive electrode active material may include lithium composite oxide represented by chemical formula 2.

[0043] Chemical formula 2

[0044] Li x M 1 y M 2 z M 3 1-y-z O 2-a X a

[0045] In chemical formula 2,

[0046] x, y, z, and a can satisfy the relationships 0.5≤x≤1.8, 0≤y≤1, 0≤z≤1, 0≤a≤0.05, and 0≤y+z≤2.

[0047] M 1 M 2 and M 3 Each element may be independently selected from at least one element selected from nickel (Ni), cobalt (Co), manganese (Mn), aluminum (Al), boron (B), barium (Ba), calcium (Ca), cerium (Ce), chromium (Cr), iron (Fe), molybdenum (Mo), niobium (Nb), silicon (Si), strontium (Sr), magnesium (Mg), titanium (Ti), vanadium (V), tungsten (W), zirconium (Zr), yttrium (Y), and lanthanum (La).

[0048] X may be at least one element selected from fluorine (F), sulfur (S), phosphorus (P), and chlorine (Cl).

[0049] For example, lithium composite oxides may include compounds represented by one of the following 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 Xc 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 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); and Li a FePO4 (where 0.90≤a≤1.8).

[0050] In the aforementioned chemical formula, A may be Ni, Co, Mn and / or combinations thereof (e.g., any suitable combination), X may be Al, Ni, Co, Mn, Cr, iron (Fe), Mg, Sr, V, rare earth elements and / or combinations thereof (e.g., any suitable combination), D may be oxygen (O), F, S, P and / or combinations thereof (e.g., any suitable combination), G may be Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V and / or combinations thereof (e.g., any suitable combination), and L 1 It can be Mn, Al and / or combinations thereof (e.g., any suitable combination).

[0051] For example, the positive electrode active material may further include a lithium composite oxide, which may include lithium nickel cobalt aluminum oxide (LiNiCoAlO2, NCA), lithium nickel cobalt manganese oxide (LiNiCoMnO2, NCM), lithium manganese oxide (LiMn2O4, LMO), and lithium nickel manganese oxide (LiNi...0.5 Mn 1.5 One or more of the following: O4 (LNMO) and lithium cobalt oxide (LiCoO2 (LCO)).

[0052] In lithium complex oxides, the amount of nickel present relative to (e.g., based on) 100 mol% of metals other than lithium may be equal to or greater than about 50 mol%. For example, in lithium complex oxides, the amount of nickel present relative to (e.g., based on) 100 mol% of metals other than lithium may be equal to or greater than about 65 mol%, 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%.

[0053] For example, the positive electrode active material may include lithium iron phosphate (LiFePO4, LFP) and lithium nickel cobalt aluminum oxide (LiNiCoAlO2, NCA), and the lithium iron phosphate (LiFePO4, LFP) and lithium nickel cobalt aluminum oxide (LiNiCoAlO2, NCA) may have a weight ratio of about 9:1 to about 5:5, about 9:1 to about 6:4 or about 9:1 to about 8:2.

[0054] The binder can be used to improve or enhance the adhesion between the positive electrode active material particles and also to improve or enhance 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, and / or nylon, but embodiments of this disclosure are not limited thereto.

[0055] For example, the positive electrode may include an adhesive comprising one or more of the following: polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, polyethylene oxide, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, and polypropylene.

[0056] The amount of binder present relative to the total weight of the positive electrode active material layer AML1 (e.g., based on a total of 100 wt%) may be from about 0.5 wt% to about 5 wt%. For example, the amount of binder present relative to the total weight of the positive electrode (e.g., based on a total of 100 wt%) may be from about 1 wt% to about 4.5 wt% or from about 1.5 wt% to about 4 wt%.

[0057] Conductive (e.g., electrically conductive) materials can be used to provide electrode conductivity (e.g., electrical conductivity) and any suitable conductive (e.g., electrically conductive) material that does not cause chemical changes (e.g., undesirable chemical changes) in a rechargeable lithium battery can be used as a conductive (e.g., electrically conductive) material. Conductive (e.g., electrically conductive) materials 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 and / or metal fibers containing one or more of copper, nickel, aluminum, and silver; conductive (e.g., electrically conductive) polymers (such as polyphenylene and / or polyphenylene derivatives); and / or mixtures thereof (e.g., any suitable mixtures).

[0058] For example, the positive electrode may include a conductive (e.g., conductive) material comprising carbon-based materials, metallic materials in the form of metal powder and / or metal fibers, conductive (e.g., electrically conductive) polymers and / or mixtures thereof (e.g., any suitable).

[0059] The amount of positive electrode conductive (e.g., electrically conductive) material present relative to the total weight of the positive electrode active material layer AML1 (e.g., based on a total of 100 wt%) may be from about 0.2 wt% to about 5 wt%. For example, the amount of positive electrode conductive (e.g., electrically conductive) material present relative to the total weight of the positive electrode (e.g., based on a total of 100 wt%) may be from about 0.2 wt% to about 4 wt%, from about 0.3 wt% to about 3.5 wt%, or from about 0.5 wt% to about 2 wt%.

[0060] Aluminum (Al) foil can be used as the positive electrode current collector COL1, but the embodiments of this disclosure are not limited thereto.

[0061] negative electrode 20

[0062] A rechargeable lithium battery according to one or more embodiments of the present disclosure may include a negative electrode. For example, a rechargeable lithium battery according to one or more embodiments of the present disclosure may include a negative electrode comprising a negative electrode active material.

[0063] The negative electrode 20 for a rechargeable lithium battery may include a negative electrode current collector COL2 and a negative electrode active material layer AML2 on the negative electrode current collector COL2. The negative electrode active material layer AML2 may include a negative electrode active material and may further include one or more of a binder and a conductive (e.g., electrically conductive) material.

[0064] The negative electrode active material on the negative electrode active material layer AML2 may include materials that can reversibly insert and deintercalate lithium ions, lithium metal, lithium metal alloys, materials that can be doped and dedoped with lithium, and / or transition metal oxides.

[0065] Materials that can reversibly embed and deembed lithium ions may include carbonaceous negative electrode active materials, such as crystalline carbon, amorphous (e.g., non-crystalline) carbon, and / or combinations thereof (e.g., any suitable combination). For example, crystalline carbon may include graphite (such as amorphous (e.g., substantially amorphous), flaky (e.g., substantially flaky), lamellar (e.g., substantially lamellar), spherical (e.g., substantially spherical), and / or fibrous (e.g., substantially fibrous) natural graphite and / or artificial graphite), and amorphous (e.g., non-crystalline) carbon may include soft carbon, hard carbon, mesophase pitch carbon, and / or calcined coke.

[0066] Lithium metal alloys may include alloys of lithium and metals selected from sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), francium (Fr), beryllium (Be), Mg, Ca, Sr, Si, antimony (Sb), lead (Pb), indium (In), zinc (Zn), Ba, radium (Ra), germanium (Ge), Al, and tin (Sn).

[0067] Materials that can be doped and undoped with lithium may include Si-based negative electrode active materials and / 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 may be an alkali metal, alkaline earth metal, Group 13 element, Group 14 element (except Si), Group 15 element, Group 16 element, transition metal, rare earth element, and / or combinations thereof (e.g., any suitable combination)), and / or combinations thereof (e.g., any suitable combination). Sn-based negative electrode active materials may include Sn, SnO x (where 0 < x ≤ 2; e.g., SnO2), Sn-based alloys, combinations thereof.

[0068] The silicon-carbon composite may be a composite of silicon and amorphous (e.g., non-crystalline) carbon. In one or more embodiments, the silicon-carbon composite may have a structure in which amorphous (e.g., non-crystalline) carbon is coated on the surface of silicon particles. For example, the silicon-carbon composite may include secondary particles (cores) in which primary silicon particles are aggregated and an amorphous (e.g., non-crystalline) carbon coating (shell) on the surface of the secondary particles. Amorphous (e.g., non-crystalline) carbon may also be between the primary silicon particles. For example, the primary silicon particles may be coated with amorphous (e.g., non-crystalline) carbon. The secondary particles may be dispersed in an amorphous (e.g., non-crystalline) carbon matrix.

[0069] 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 (e.g., non-crystalline) carbon coating on the surface of the core.

[0070] 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.

[0071] Relative to the total weight of the negative electrode active material layer AML2 (e.g., based on a total amount of 100 wt%), the amount of the negative electrode active material present in the negative electrode active material layer AML2 can be about 90 wt% to about 99 wt%. For example, relative to the total weight of the negative electrode active material layer AML2 (e.g., based on a total amount of 100 wt%), the amount of the negative electrode active material present can be about 93 wt% to about 99 wt% or about 96 wt% to about 98.5 wt%.

[0072] The negative electrode active material can include at least one selected from graphite and silicon composites.

[0073] If (e.g., when) the negative electrode active material (e.g., simultaneously) includes both a silicon composite and graphite, the silicon composite and graphite can be in the form of a mixture, and in one or more embodiments, the weight ratio of the silicon composite to graphite can be about 1:99 to about 50:50. For example, the weight ratio of the silicon composite to graphite can be about 3:97 to about 20:80 or about 5:95 to about 20:80.

[0074] The silicon composite can include a core containing silicon-based particles and an amorphous (e.g., non-crystalline) carbon coating, and the silicon-based particles can include at least one selected from silicon-carbon composites, SiO x (where 0 < x ≤ 2) and silicon alloys. For example, the silicon-carbon composite can include a core containing silicon particles and crystalline carbon and can also include an amorphous (e.g., non-crystalline) carbon coating on the surface of the core.

[0075] The crystalline carbon can include graphite, e.g., natural graphite, artificial graphite, and / or a mixture thereof (e.g., any suitable mixture).

[0076] The negative electrode can include a binder. The negative electrode binder can be used or is used to improve or enhance the adhesion of the negative electrode active material particles to each other and also improve or enhance the adhesion of the negative electrode active material to the negative electrode current collector COL2. The binder can include a non-aqueous (e.g., water-insoluble) binder, an aqueous (e.g., water-soluble) binder, a dry binder, and / or a combination thereof (e.g., any suitable combination).

[0077] The non-aqueous (e.g., water-insoluble) binder can include polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene propylene copolymer, polystyrene, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polyamideimide, polyimide, and / or a combination thereof (e.g., any suitable combination).

[0078] Waterborne (e.g., water-soluble) 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 resins, (meth)acrylic resins, phenolic resins, epoxy resins, polyvinyl alcohol, and / or combinations thereof (e.g., any suitable combination).

[0079] If (for example, when) an aqueous (e.g., water-soluble) binder is used as a negative electrode binder, it may further include a cellulose compound capable of providing or increasing viscosity. The cellulose compound may include one or more selected from carboxymethyl cellulose, hydroxypropyl methyl cellulose, methyl cellulose, and their alkali metal salts. The alkali metal salt may include sodium (Na), potassium (K), and / or lithium (Li).

[0080] 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).

[0081] The amount of binder present relative to the total weight of the negative electrode active material layer AML2 (e.g., based on a total of 100 wt%) may be from about 0.5 wt% to about 5 wt%. For example, the amount of binder present relative to the total weight of the negative electrode (e.g., based on a total of 100 wt%) may be from about 0.5 wt% to about 3.5 wt% or from about 0.5 wt% to about 2 wt%.

[0082] The negative electrode may comprise a conductive (e.g., electrically conductive) material. The description of a conductive (e.g., electrically conductive) material may be as discussed in one or more embodiments.

[0083] 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 (e.g., electrically conductive) metal, and / or combinations thereof (e.g., any suitable combination).

[0084] Diaphragm 30

[0085] Depending on the type (or variety) of the rechargeable lithium battery, the separator 30 may be located between the positive electrode 10 and the negative electrode 20. The separator 30 may include one or more selected from polyethylene separators, polypropylene separators, and polyvinylidene fluoride separators, and may have multiple layers of such separators (e.g., polyethylene / polypropylene bilayer separators, polyethylene / polypropylene / polypropylene trilayer separators, and / or polypropylene / polypropylene / polypropylene trilayer separators).

[0086] The diaphragm 30 may include a porous substrate and a coating on the side or surface of the porous substrate (e.g., one surface or two surfaces (e.g., two opposite surfaces)), the coating may include organic materials, inorganic materials and / or combinations thereof (e.g., any suitable combination).

[0087] The porous substrate may be a polymer layer comprising a polymer layer selected from 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). TM One of the materials described in one or more embodiments, or a copolymer or (e.g., any suitable) mixture of two or more of the materials described in one or more embodiments.

[0088] Organic materials may include polyvinylidene fluoride copolymers and / or (meth)acrylic acid copolymers.

[0089] 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 any suitable combination thereof, but embodiments of this disclosure are not limited thereto.

[0090] Organic and inorganic materials may be mixed in a single coating or may exist as a stack of coatings comprising organic materials and coatings comprising inorganic materials.

[0091] Electrolyte ELL

[0092] The electrolyte used in a rechargeable lithium battery according to one or more embodiments of the present disclosure may include a non-aqueous (e.g., water-insoluble) organic solvent, a lithium salt, and an additive represented by chemical formula 1.

[0093] Chemical Formula 1

[0094]

[0095] In chemical formula 1,

[0096] R1 to R6 can each independently be hydrogen, substituted or unsubstituted C1-C20 alkyl, substituted or unsubstituted C1-C20 alkoxy, substituted or unsubstituted C2-C20 alkenyl, substituted or unsubstituted C2-C20 alkynyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C6-C20 aryl, or substituted or unsubstituted C2-C20 heteroaryl.

[0097] n can be an integer of 0 or 1.

[0098] Non-aqueous (e.g., water-insoluble) organic solvents can be used as or used as a medium for transporting ions that participate in the electrochemical reactions of rechargeable lithium batteries.

[0099] Non-aqueous (e.g., water-insoluble) organic solvents may include carbonate solvents, ester solvents, ether solvents, ketone solvents, alcohol solvents, aprotic solvents, and / or mixtures thereof (e.g., any suitable). Non-aqueous (e.g., water-insoluble) organic solvents may be used alone or in mixtures of two or more substances.

[0100] Carbonate solvents may include dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), methyl propyl carbonate (MPC), ethyl propyl carbonate (EPC), methyl ethyl carbonate (EMC), ethylene carbonate (EC), propylene carbonate (PC), and / or butyl carbonate (BC).

[0101] Ester solvents may include methyl acetate, ethyl acetate, n-propyl acetate, dimethyl acetate, methyl propionate, ethyl propionate, decanoic acid lactone, mevalonate lactone, valproic acid lactone, and / or caprolactone.

[0102] Ether solvents may include dibutyl ether, tetraethylene glycol dimethyl ether, diethylene glycol dimethyl ether, ethylene glycol dimethyl ether, 2-methyltetrahydrofuran, 2,5-dimethyltetrahydrofuran, and / or tetrahydrofuran. Ketone solvents may include cyclohexanone. Alcohol solvents may include ethanol and / or isopropanol, and aprotic solvents may include nitrile solvents (such as R-CN, where R may be a hydrocarbon group having a C2-C20 straight-chain, branched, or cyclic structure, and may include double bonds, aromatic rings, and / or ether bonds); amides (such as dimethylformamide); dioxolane (such as 1,3-dioxolane and / or 1,4-dioxolane); and / or sulfolane.

[0103] In one or more embodiments, if (for example, when) a carbonate solvent is used as a non-aqueous (e.g., water-insoluble) organic solvent, cyclic carbonates and chain carbonates can be mixed and used, and the cyclic carbonates and chain carbonates can be mixed in a volume ratio of about 1:1 to about 1:9.

[0104] For example, non-aqueous (e.g., water-insoluble) organic solvents may 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), and butyl carbonate (BC).

[0105] For example, a non-aqueous (e.g., water-insoluble) organic solvent may be a mixture of ethylene carbonate (EC), ethyl methyl carbonate (EMC), and dimethyl carbonate (DMC).

[0106] For example, the amount of ethylene carbonate (EC) may be from about 10 vol% to about 30 vol% relative to the total volume of non-aqueous (e.g., water-insoluble) organic solvents (e.g., based on a total volume of 100 vol%). The amount of ethyl methyl carbonate (EMC) may be from about 20 vol% to about 70 vol% relative to the total volume of non-aqueous (e.g., water-insoluble) organic solvents (e.g., based on a total volume of 100 vol%). The amount of dimethyl carbonate (DMC) may be from about 20 vol% to about 70 vol% relative to the total volume of non-aqueous (e.g., water-insoluble) organic solvents (e.g., based on a total volume of 100 vol%).

[0107] Lithium salts can be dissolved in non-aqueous organic solvents to serve as a source of lithium ions in rechargeable lithium batteries, ensuring basic operation and facilitating lithium ion transport 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+1 At least one of the following: lithium trifluoromethanesulfonate (LiSO3CF3), lithium tetrafluoroethanesulfonate, lithium difluorobis(oxalate)phosphate (LiDFBOP), and lithium bis(oxalate)borate (LiBOB).

[0108] For example, lithium salts may include one or more selected from LiPF6, LiClO4, LiBF4, lithium bis(fluorosulfonyl)imide (LiFSI), LiTFSI, LiSO3CF3, LiBOB, LiFOB, LiDFBOP, LiTFOP, LiPO2F2, LiSbF6, LiAsF6, LiAlO2, LiAlCl4, LiCl, LiI, LiN(SO3C2F5)2, and LiC4F9SO3. For example, lithium salts may include LiPF6.

[0109] 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 of about 0.5 M to about 1.0 M, 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. Because the concentration of the lithium salt falls within the aforementioned range, the electrolyte (e.g., an ionic conductor) can suitably or appropriately maintain its conductivity (e.g., ionic conductivity) and viscosity.

[0110] Chemical formula 1 can be represented by chemical formula 1-1 or chemical formula 1-2.

[0111] Chemical Formula 1-1

[0112]

[0113] Chemical formula 1-2

[0114]

[0115] The amount of the additive represented by Formula 1 may be from about 0.01 wt% to about 3 wt% relative to the total weight of the electrolyte (e.g., based on a total of 100 wt%). For example, the amount of the additive represented by Formula 1 may be from about 0.05 wt% to about 2.5 wt%, from about 0.1 wt% to about 2 wt%, from about 0.2 wt% to about 1.5 wt%, or from about 0.5 wt% to about 1 wt% relative to the total weight of the electrolyte (e.g., based on a total of 100 wt%). Since the amount of the additive represented by Formula 1 falls within the aforementioned range, a rechargeable lithium battery with improved or enhanced storage characteristics and lifetime properties at room temperature and / or at relatively high temperatures can be effectively or appropriately implemented or provided.

[0116] Hereinafter, embodiments of the present disclosure will be described in more detail with reference to implementation methods and comparative examples. The following embodiments are merely examples of the present disclosure, and the implementation of the present disclosure is not limited to the following embodiments.

[0117] Implementation

[0118] Manufacturing of rechargeable lithium batteries

[0119] Implementation Method 1

[0120] (1) Manufacturing of the positive electrode

[0121] LiFePO4 as the positive electrode active material, polyvinylidene fluoride as the binder, and acetylene black as the conductive (e.g., electrically conductive) material were mixed in a weight ratio of 96:3:1, and the mixture was dispersed in N-methylpyrrolidone to prepare a positive electrode active material slurry. The positive electrode active material slurry was coated onto an Al foil with a thickness of 15 μm, dried at 100 °C, and then pressed to manufacture the positive electrode.

[0122] (2) Manufacturing of the negative electrode

[0123] A slurry of artificial graphite and silicon composite (mixed in a weight ratio of 93:7 as the negative electrode active material), styrene-butadiene rubber (SBR), and carboxymethyl cellulose (CMC) as a binder was prepared by mixing them in a weight ratio of 98:1:1 and dispersing the mixture in distilled water. The negative electrode active material slurry was coated onto a 10 μm thick Cu foil, dried at 100 °C, and then pressed to manufacture the negative electrode.

[0124] (3) Preparation of electrolyte

[0125] An electrolyte was prepared by dissolving 1.5 M LiPF6 in a non-aqueous (e.g., water-insoluble) organic solvent containing ethylene carbonate (EC), ethyl methyl carbonate (EMC), and dimethyl carbonate (DMC) mixed in a volume ratio of about 20:40:40, and by adding an additive represented by chemical formula 1-1 in an amount of about 0.5 wt%.

[0126] Chemical Formula 1-1

[0127]

[0128] (4) Manufacturing of rechargeable lithium batteries

[0129] The positive electrode manufactured in step (e.g., action or task) (1), the negative electrode manufactured in step (e.g., action or task) (2), and a polyethylene separator with a thickness of 10 μm are assembled to manufacture an electrode assembly, and the electrolyte prepared in step (e.g., action or task) (3) is introduced to manufacture a rechargeable lithium battery.

[0130] Implementation Method 2

[0131] The rechargeable lithium battery is manufactured in a manner substantially the same as in Embodiment 1, except that LiMnFePO4 is used as the positive electrode active material in step (e.g., action or task) (1).

[0132] Implementation Method 3

[0133] The rechargeable lithium battery is manufactured in a manner substantially the same as in Embodiment 1, except that in step (e.g., action or task) (1), a mixture of LiFePO4 and LiNiCoAlO2 (not less than 80 mol% Ni) mixed in a weight ratio of 8:2 is used as the positive electrode active material.

[0134] Comparative Example 1

[0135] The rechargeable lithium battery is manufactured in essentially the same manner as in Embodiment 1, except that no compound represented by chemical formula 1-1 is added in step (e.g., action or task) (3).

[0136] Comparative Example 2

[0137] The rechargeable lithium battery is manufactured in essentially the same manner as in Embodiment 1, except that a compound represented by chemical formula A is used in step (e.g., action or task) (3).

[0138] Chemical formula A

[0139]

[0140] Comparative Example 3

[0141] The rechargeable lithium battery is manufactured in essentially the same way as in Embodiment 2, except that no compound represented by chemical formula 1-1 is added in step (e.g., action or task) (3).

[0142] Comparative Example 4

[0143] The rechargeable lithium battery is manufactured in essentially the same way as in Embodiment 2, except that a compound represented by chemical formula A is used in step (e.g., action or task) (3).

[0144] Chemical formula A

[0145]

[0146] Comparative Example 5

[0147] The rechargeable lithium battery is manufactured in essentially the same way as in embodiment 3, except that no compound represented by chemical formula 1-1 is added in step (e.g., action or task) (3).

[0148] Comparative Example 6

[0149] The rechargeable lithium battery is manufactured in essentially the same way as in embodiment 3, except that a compound represented by chemical formula A is used in step (e.g., action or task) (3).

[0150] Chemical formula A

[0151]

[0152] Evaluation Example

[0153] Evaluation 1: Charge-discharge characteristics at room temperature

[0154] The charge-discharge characteristics at room temperature were evaluated for rechargeable lithium batteries manufactured according to Embodiments 1 to 3 and Comparative Examples 1 to 6. For example, 1000 charge-discharge cycles of the rechargeable lithium batteries were performed at 25°C and under the conditions of 0.33C charging (CC / CV, 4.2V, 0.02C cutoff) / 0.33C discharging (CC, 2.5V cutoff) to measure the changes in discharge capacity (discharge capacity after 1 cycle (initial discharge capacity) and discharge capacity after 1000 cycles) and DC internal resistance (DC-IR). The capacity retention rate was calculated according to Equation A, and the initial DC-IR and the DC-IR after 1000 cycles were obtained based on the voltage change during 30 seconds of discharge while applying a current of 50% of the SOC (based on 100% of the total charge capacity of the rechargeable lithium battery, the current is equal to 50% of the charge capacity), thereby calculating the rate of change of DC-IR according to Equation B.

[0155] Equation A

[0156] Capacity retention (%) = (Discharge capacity after 1,000 cycles / Discharge capacity after 1 cycle) × 100

[0157] Equation B

[0158] DC-IR change rate (%) = (DC-IR after 1,000 cycles / initial DC-IR) × 100

[0159] Evaluation 2: Storage characteristics at high temperature (60°C)

[0160] The storage characteristics at high temperature (60°C) were evaluated for rechargeable lithium batteries manufactured according to Embodiments 1 to 3 and Comparative Examples 1 to 6.

[0161] For example, after measuring ΔV / ΔI (voltage change / current change) as the initial DC internal resistance (DC-IR) of a rechargeable lithium battery, the battery is charged to its maximum energy state (SOC 100%) and stored at high temperature (60°C) for 7 days. Then, it is discharged to 2.5V at a constant current of 0.2C, and the DC internal resistance (DC-IR) after 7 days is measured. The increase in DC-IR (%) is calculated according to Equation C.

[0162] Equation C

[0163] DC-IR increase rate (%) = (DC-IR after 7 days / initial DC-IR) × 100

[0164] In addition, the battery cells were charged to full charge (SOC 100%) after the initial discharge capacity was measured, and stored at high temperature (60°C) for 7 days in the charged state. Then, they were recharged to 4.2V at 0.33C under constant current and cut off at 0.02C under constant voltage, and discharged to 2.5V at 0.33C under constant current to measure the discharge capacity (discharge capacity of the battery cells after 7 days of storage at 60°C). The capacity recovery rate (%) was calculated according to Equation D.

[0165] Equation D

[0166] Capacity recovery rate (%) = (Discharge capacity of a single battery cell after 7 days of storage at 60°C / Initial discharge capacity before high-temperature storage) × 100

[0167] Table 1

[0168]

[0169] Referring to Table 1, compared to the rechargeable lithium batteries of Comparative Examples 1 to 6, the rechargeable lithium batteries of Embodiments 1 to 3 exhibit superior charge-discharge characteristics at room temperature and storage properties at high temperature (60°C). For example, the rechargeable lithium batteries of Embodiments 1 to 3, manufactured using an electrolyte comprising an additive represented by Chemical Formula 1, exhibit a capacity retention rate greater than 90% and a DC-IR change rate less than 120% at room temperature. Furthermore, the rechargeable lithium batteries of Embodiments 1 to 3 exhibit a capacity recovery rate greater than 92% and a DC-IR increase rate less than 125% at high temperature (60°C). Therefore, it can be determined that, compared to the rechargeable lithium batteries of Comparative Examples 1 to 6, which used an electrolyte comprising an additive having a structure different from that of Chemical Formula 1 or did not use any additives, the rechargeable lithium batteries of Embodiments 1 to 3 exhibit superior charge-discharge characteristics at room temperature and storage properties at high temperature (60°C). For example, compared with Embodiments 1 and 2, in which lithium iron phosphate (LFP) or lithium manganese iron phosphate (LMFP) are used alone as the positive electrode active material, Embodiment 3, in which a mixture of lithium iron phosphate (LFP) and lithium nickel cobalt aluminum oxide (NCA) is used as the positive electrode active material, exhibits superior charge-discharge characteristics at room temperature and storage properties at high temperature (60°C).

[0170] The rechargeable lithium batteries according to one or more embodiments of this disclosure exhibit improved or enhanced lifetime characteristics and stability (e.g., chemical stability and / or physical stability) during the activation process of the rechargeable lithium batteries, not only at room temperature but also at relatively high temperatures.

[0171] In summary, compared to the rechargeable lithium batteries of Comparative Examples 1 to 6, the rechargeable lithium batteries of Embodiments 1 to 3, which use an electrolyte containing additives represented by Chemical Formula 1, exhibit superior charge-discharge characteristics at room temperature and storage properties at high temperatures (60°C). For example, these batteries show a capacity retention rate of over 90% and a DC-IR change rate of less than 120% at room temperature, and a capacity recovery rate of over 92% and a DC-IR increase rate of less than 125% at high temperatures. In particular, Embodiment 3, which uses a mixture of lithium iron phosphate (LFP) and lithium nickel cobalt aluminum oxide (NCA) as the positive electrode active material, exhibits better performance than Embodiments 1 and 2, which use LFP or lithium manganese iron phosphate (LMFP) alone. Therefore, the rechargeable lithium batteries of Embodiments 1 to 3 exhibit enhanced lifetime characteristics and stability at both room temperature and high temperatures.

[0172] Battery manufacturing apparatus, battery management system (BMS) apparatus, and / or any other related apparatus or component according to one or more embodiments of this disclosure may be implemented using any suitable hardware, firmware (e.g., application-specific integrated circuit), software, and / or a combination of software, firmware, and hardware (e.g., any suitable). For example, one or more suitable components of the apparatus may be provided on an integrated circuit (IC) chip or a separate IC chip. Further, one or more suitable components may be implemented on a flexible printed circuit film, a tape-on package (TCP), or a printed circuit board (PCB), and / or provided on a substrate. Further, one or more suitable 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 one or more suitable functional processes or threads described herein. The computer program instructions may be stored in memory, which may be implemented using standard storage devices (such as, for example, random access memory (RAM)) in the computing device. The computer program instructions may also be stored in other non-transitory computer-readable media (such as, for example, CD-ROM, flash memory drives, etc.). Furthermore, those skilled in the art will recognize that, without departing from the scope of this disclosure, the functions of one or more suitable computing devices may be combined or integrated into a single computing device, or the functions of a dedicated computing device may be distributed across one or more other computing devices.

[0173] In view of the whole of this disclosure, those skilled in the art will recognize that each suitable feature of one or more embodiments of this disclosure may be combined in part or in whole or in combination with one another, and may be technically interlocked and operated in a variety of suitable ways, and that, unless otherwise stated or implied, each embodiment may be implemented independently of one another or in combination with one another in any suitable way.

[0174] Although the subject matter of this disclosure has been described in conjunction with embodiments now considered practical, it should be understood that this disclosure is not limited to the disclosed embodiments. In contrast, it is intended to cover one or more suitable modifications and equivalent arrangements included within the spirit and scope of the claims and their equivalents, and therefore it will be understood that the foregoing one or more embodiments are illustrative in all respects and not restrictive.

Claims

1. A rechargeable lithium battery, comprising: Positive electrode, containing positive electrode active material; The negative electrode contains the negative electrode active material; and The electrolyte comprises a non-aqueous organic solvent, a lithium salt, and an additive represented by chemical formula 1. The positive electrode active material includes lithium iron phosphate compounds. Chemical Formula 1 In chemical formula 1, R1 to R6 are each independently hydrogen, a substituted or unsubstituted C1-C20 alkyl, a substituted or unsubstituted C1-C20 alkoxy, a substituted or unsubstituted C2-C20 alkenyl, a substituted or unsubstituted C2-C20 alkynyl, a substituted or unsubstituted C3-C20 cycloalkyl, a substituted or unsubstituted C6-C20 aryl, or a substituted or unsubstituted C2-C20 heteroaryl. n is an integer that is either 0 or 1. "Substitution" refers to the substitution of at least one hydrogen atom in a substituent or compound by the following: 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 or cyano.

2. The rechargeable lithium battery according to claim 1, wherein the amount of the lithium iron phosphate compound is 50 wt% to 98 wt% based on 100 wt% of the total amount of the positive electrode active material.

3. The rechargeable lithium battery according to claim 1, wherein the positive electrode active material comprises lithium iron phosphate and / or lithium manganese iron phosphate.

4. The rechargeable lithium battery according to claim 1, wherein the positive electrode active material further comprises a lithium composite oxide 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 and in, In chemical formula 2, 0.5≤x≤1.8, 0≤y≤1, 0≤z≤1, 0≤a≤0.05, and 0≤y+z≤2. M 1 M 2 and M 3 Each element is independently selected from at least one element chosen from Ni, Co, Mn, Al, B, Ba, Ca, Ce, Cr, Fe, Mo, Nb, Si, Sr, Mg, Ti, V, W, Zr, Y, and La. X is at least one element selected from F, S, P and Cl.

5. The rechargeable lithium battery according to claim 1, wherein the positive electrode active material further comprises a lithium composite oxide, the lithium composite oxide comprising one or more selected from lithium nickel cobalt aluminum oxide, lithium nickel cobalt manganese oxide, lithium manganese oxide, lithium nickel manganese oxide and lithium cobalt oxide.

6. The rechargeable lithium battery according to claim 4 or 5, wherein, In the lithium composite oxide, nickel is present in an amount equal to or greater than 50 mol% based on 100 mol% of metals other than lithium.

7. The rechargeable lithium battery according to claim 1, wherein the positive electrode active material comprises lithium iron phosphate and lithium nickel cobalt aluminum oxide in a weight ratio of 9:1 to 5:

5.

8. The rechargeable lithium battery of claim 1, wherein the positive electrode comprises a binder selected from one or more of the following: polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, polyethylene oxide, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, and polypropylene.

9. The rechargeable lithium battery according to claim 8, wherein the amount of binder is 0.5 wt% to 5 wt% based on the total amount of 100 wt% of the positive electrode active material layer.

10. The rechargeable lithium battery according to claim 1, wherein the positive electrode comprises a conductive material comprising a carbon-based material, a metallic material in the form of metal powder or metal fiber, a conductive polymer, or a mixture thereof.

11. The rechargeable lithium battery according to claim 10, wherein the amount of the conductive material is 0.2 wt% to 5 wt% based on the total amount of the positive electrode active material layer of 100 wt%.

12. The rechargeable lithium battery according to claim 1, wherein the negative electrode active material comprises carbon-based negative electrode active material, Si-based negative electrode active material, Sn-based negative electrode active material, or a combination thereof.

13. The rechargeable lithium battery according to claim 1, wherein chemical formula 1 is represented by chemical formula 1-1 or chemical formula 1-2. Chemical Formula 1-1 Chemical formula 1-2 14. The rechargeable lithium battery according to claim 1, wherein the amount of the additive represented by chemical formula 1 is 0.01 wt% to 3 wt% based on the total amount of the electrolyte of 100 wt%.

15. The rechargeable lithium battery according to claim 1, wherein the non-aqueous organic solvent comprises one or more selected from ethylene carbonate, propylene carbonate, propyl propionate, methyl ethyl carbonate, dimethyl carbonate, diethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, and butyl carbonate (BC).

16. The rechargeable lithium battery according to claim 1, wherein the lithium salt comprises one or more selected from LiPF6, LiClO4, LiBF4, lithium bis(fluorosulfonyl)imide, LiTFSI, LiSO3CF3, LiBOB, LiFOB, LiDFBOP, LiTFOP, LiPO2F2, LiSbF6, LiAsF6, LiAlO2, LiAlCl4, LiCl, LiI, LiN(SO3C2F5)2, and LiC4F9SO3, and The concentration of the lithium salt is 0.1M to 2.0M.

17. The rechargeable lithium battery according to claim 1, wherein the rechargeable lithium battery is a cylindrical battery, a prismatic battery, a pouch battery, or a coin-shaped battery.

Images