Electrolyte for rechargeable lithium battery and rechargeable lithium battery including same

Abstract

The invention provides an electrolyte of a rechargeable lithium battery and a rechargeable lithium battery including the same. An electrolyte of a rechargeable lithium battery includes a lithium salt, a non-aqueous organic solvent, and an additive represented by Formula 1: Formula 1 # imgabs0 # wherein at least one R1 is an isocyanate group and at least one R2 is an isocyanate group.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2023-0115484 filed on August 31, 2023 in the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference. Technical Field

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

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

[0005] A rechargeable lithium battery includes a positive electrode, a negative electrode, and an electrolyte. The positive electrode and the negative electrode each include an active material capable of intercalating and deintercalating lithium ions, and when lithium ions are intercalated and deintercalated, electric energy is generated due to oxidation and reduction reactions.

[0006] Lithium transition metal composite oxides are used as positive electrode active materials for rechargeable lithium batteries. Various types (kinds) of carbon-based materials are used as negative electrode active materials for rechargeable lithium batteries. Lithium salts dissolved in non-aqueous organic solvents are used as electrolytes for rechargeable lithium batteries.

[0007] Rechargeable lithium batteries exhibit characteristics based on complex reactions between a positive electrode and an electrolyte and between a negative electrode and an electrolyte. Accordingly, using a suitable or appropriate electrolyte is one of the important variables for improving rechargeable lithium batteries. Summary of the invention

[0008] One or more aspects of embodiments of the present disclosure relate to an electrolyte for a rechargeable lithium battery having ensured safety and also having excellent or appropriate battery performance.

[0009] One or more aspects of embodiments of the present disclosure are directed to a rechargeable lithium battery including the electrolyte.

[0010] Additional aspects will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the presented embodiments of the disclosure.

[0011] According to one or more embodiments of the present disclosure, an electrolyte of a rechargeable lithium battery may include a lithium salt, a non-aqueous organic solvent, and an additive represented by Formula 1.

[0012] Formula 1

[0013]

[0014] In Formula 1, R1 may be the same or different at each occurrence, and may each independently be hydrogen, halogen, C1-C10 alkyl, or isocyanate. At least one R1 may be an isocyanate.

[0015] In Formula 1, R2 may be the same or different at each occurrence, and may each independently be hydrogen, halogen, C1-C10 alkyl, or isocyanate. At least one R2 may be an isocyanate.

[0016] In Formula 1, R3 may be the same or different at each occurrence and may each independently be hydrogen or a cyclohexyl isocyanate residue.

[0017] In Formula 1, n may be an integer of 1 to 10.

[0018] According to one or more embodiments of the present disclosure, a rechargeable lithium battery may include a positive electrode including a positive electrode active material, a negative electrode including a negative electrode active material, and an electrolyte. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0020] Figure 1 to Figure 5 Each illustrates a simplified diagram showing a rechargeable lithium battery according to one or more embodiments of the present disclosure. DETAILED DESCRIPTION

[0021] In order to fully understand the configuration and aspects of the present disclosure, some example embodiments of the present disclosure will be described with reference to the attached drawings. However, it should be noted that the present disclosure is not limited to the described example embodiments and can be implemented in various forms. On the contrary, only example embodiments are provided to illustrate the present disclosure and allow those skilled in the art to fully understand the scope of the present disclosure.

[0022] In the present 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 intervening elements therebetween. In the accompanying drawings, the thickness of some components may be exaggerated in order to effectively explain the technical content. Throughout the present disclosure, the same reference numerals refer to the same elements, and for the sake of brevity, a repeated description thereof is not provided.

[0023] The example embodiments detailed in the present disclosure will be discussed with reference to the cross-sectional views and / or plan views as ideal exemplary views of the present disclosure. In the accompanying drawings, in order to effectively explain the technical content, the thickness of the layer and the zone can be magnified. Accordingly, the zones exemplarily illustrated in the accompanying drawings have general properties, and the shapes of the zones exemplarily illustrated in the accompanying drawings are used to exemplarily disclose specific shapes, but are not limited to the scope of the present disclosure. It will be understood that although the terms "first", "second", "third", etc. are used to describe various elements in this article, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. The example embodiments explained and illustrated in this article include their complementary embodiments.

[0024] The terms used in this article are only used for the purpose of describing particular embodiments and are not intended to limit the present disclosure. As used in this article, the singular forms "a", "an" and "the" are intended to also include plural forms, unless the context clearly indicates otherwise. Further, when describing embodiments of the present disclosure, the use of "may" refers to "one or more embodiments of the present disclosure". As used in this article, the terms "and / or" and "or" may include any and all combinations of one or more related enumerated items. The terms "comprise(s) / comprising", "include(s) / including" and / or "have / has / having" used in the present disclosure do not exclude the presence or addition of one or more other components.

[0025] As used herein, the term "combination thereof" may refer to a mixture, stack, composite, copolymer, alloy, blend, and / or reaction product of the components.

[0026] Unless specifically defined otherwise in a chemical formula in the present disclosure, if (for example, when) a chemical bond is not drawn at a position where a chemical bond should be given, it means that a hydrogen atom is bonded at the position.

[0027] In the present disclosure, the term "halogen" may refer to (eg, selected from) one or more of F, Cl, Br, and I.

[0028] In the present disclosure, the term "transition metal" includes (for example, selected from) scandium (Sc), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), yttrium (Y), zirconium (Zr), niobium (Nb), molybdenum (Mo), technetium (Tc), ruthenium (Ru), rhodium (Rh), palladium (Pd), silver (Ag), cadmium (Cd), lutetium (Lu), hafnium (Hf), tantalum (Ta), tungsten (W), rhenium (Re), osmium (Os), iridium (Ir), platinum (Pt), gold (Au), mercury (Hg), lawrencium (Lr), (Rf), Thorium (Db), (Sg), (Bh), (Hs), (Mt), (Ds), (Rg) and (Cn) one or more.

[0029] Unless specifically described otherwise in the present specification, the expression "room temperature" means about 25±10°C.

[0030] In the present disclosure, the phrase "reduction in battery cell performance" indicates side effects of a rechargeable lithium battery, such as a reduction in storage capacity and recovery capacity at room temperature and relatively high temperature (45°C), a reduction in capacity retention after 200 cycles, and an increase in the amount of gas generated when stored at high temperature (60°C), but the present disclosure is not limited thereto.

[0031] Figure 1 A simplified conceptual diagram showing a rechargeable lithium battery according to one or more embodiments of the present disclosure is illustrated. Figure 1 , a rechargeable lithium battery may include a positive electrode 100 , a negative electrode 200 , an electrolyte 300 , and a separator 400 .

[0032] The positive electrode 100 and the negative electrode 200 may be separated (e.g., separated) from each other across the separator 400. The separator 400 may be between the positive electrode 100 and the negative electrode 200. The positive electrode 100, the negative electrode 200, and the separator 400 may contact the electrolyte 300. The positive electrode 100, the negative electrode 200, and the separator 400 may be immersed in the electrolyte 300.

[0033] The electrolyte 300 may be a medium through which lithium ions are transferred between the positive electrode 100 and the negative electrode 200. The lithium ions in the electrolyte 300 may move toward the positive electrode 100 or the negative electrode 200 through the separator 400. Each of the positive electrode 100, the negative electrode 200, the electrolyte 300, and the separator 400 of the rechargeable lithium battery according to one or more embodiments of the present disclosure will be described in more detail below.

[0034] Electrolyte for rechargeable lithium batteries

[0035] The electrolyte 300 of the rechargeable lithium battery may include lithium salt, a non-aqueous organic solvent, and additives.

[0036] The lithium salt may be dissolved in a non-aqueous organic solvent to serve as a supply source of lithium ions in a rechargeable lithium battery, and may play a role in ensuring basic operations of the rechargeable lithium battery and facilitating movement of lithium ions between a positive electrode and a negative electrode.

[0037] In one or more embodiments, the lithium salt may include LiPF6.

[0038] The lithium salt may have a concentration of about 0.1M to about 2.0M. For example, in one or more embodiments, the lithium salt may have a concentration equal to or greater than about 0.5M, equal to or greater than about 1.0M, or equal to or greater than about 1.5M. The lithium salt may have a concentration equal to or less than about 2.0M, equal to or less than about 1.7M, or equal to or less than about 1.5M. When the lithium salt has a concentration less than about 0.1M, the electrolyte performance may decrease due to reduced electrolyte conductivity. When the lithium salt has a concentration greater than about 2.0M, the lithium ion mobility may decrease due to increased electrolyte viscosity.

[0039] The non-aqueous organic solvent may be used as a medium for transferring ions participating in the electrochemical reaction of the rechargeable lithium battery.

[0040] The non-aqueous organic solvent may include a carbonate-based solvent, an ester-based solvent, an ether-based solvent, a ketone-based solvent, an alcohol-based solvent, an aprotic solvent, or (eg, any appropriate) combinations thereof.

[0041] Carbonate solvents may include (for example, selected from) one or more of 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) and butylene carbonate (BC). Esters solvents may include (for example, selected from) one or more of methyl acetate, ethyl acetate, n-propyl acetate, dimethyl acetate, methyl propionate, ethyl propionate, propyl propionate, decanoic acid lactone, mevalonate lactone, valerolactone and caprolactone. Ether solvents may include (for example, selected from) one or more of dibutyl ether, tetraethylene glycol dimethyl ether, diethylene glycol dimethyl ether, dimethoxyethane, 2-methyltetrahydrofuran, 2,5-dimethyltetrahydrofuran and tetrahydrofuran. Ketone solvents may include cyclohexanone. Alcohol solvents may include one or more selected from ethanol and isopropanol. Aprotic solvents may include nitriles such as R—CN (wherein R is a hydrocarbon group having a C2 to C20 linear, branched or cyclic structure, and may include a double bond, an aromatic ring or an ether group); amides such as dimethylformamide; dioxolanes such as 1,3-dioxolane and / or 1,4-dioxolane; and / or sulfolane.

[0042] The nonaqueous organic solvent may be used alone or as a mixture of two or more thereof.

[0043] For example, if used as a mixture of two or more thereof, the nonaqueous organic solvent may include one or more of carbonate-based solvents and one or more of propionate-based solvents.

[0044] The content of the propionate-based solvent may be equal to or greater than about 70% by volume of the total amount (eg, total volume) of the non-aqueous organic solvent. As such, high voltage properties and / or high temperature properties of a rechargeable lithium battery may be improved.

[0045] For example, in one or more embodiments, the non-aqueous organic solvent may be a mixed solvent of ethylene carbonate (EC), propyl carbonate (PC), and propyl propionate (PP).

[0046] In one or more embodiments, the content of the additive may be about 0.05 wt % to about 10 wt % of the total amount (e.g., total weight) of the electrolyte. For example, in some embodiments, the amount of the additive may be equal to or greater than about 0.1 wt %, equal to or greater than about 0.5 wt %, equal to or greater than about 1 wt %, or equal to or greater than about 5 wt % of the total amount (e.g., total weight) of the electrolyte. The amount of the additive may be equal to or less than about 8 wt %, equal to or less than about 7 wt %, or equal to or less than about 5 wt % of the total amount (e.g., total weight) of the electrolyte. When the amount of the additive is less than about 0.05 wt % of the total amount (e.g., total weight) of the electrolyte, there will be a negligible effect on solving the problem caused by the dissolution of transition metal ions from the positive electrode. When the amount of the additive is greater than about 10 wt % of the total amount (e.g., total weight) of the electrolyte, there is a risk of shortened life in high temperature charge / discharge cycles.

[0047] The additive according to one or more embodiments of the present disclosure is represented by Formula 1.

[0048] Formula 1

[0049]

[0050] In Formula 1, R1 may be the same or different at each occurrence, and may each independently be hydrogen, halogen, C1-C10 alkyl, or isocyanate. At least one R1 may be an isocyanate.

[0051] In Formula 1, R2 may be the same or different at each occurrence, and may each independently be hydrogen, halogen, C1-C10 alkyl, or isocyanate. At least one R2 may be an isocyanate.

[0052] In Formula 1, R3 may be the same or different at each occurrence and may each independently be hydrogen or a cyclohexyl isocyanate residue.

[0053] n can be an integer of 1-10.

[0054] Although the positive electrode active material (e.g., lithium transition metal composite oxide) has a stable structure, transition metal ions are dissolved during the charge / discharge process and high-temperature storage, and side reactions occur between the dissolved transition metal ions and moisture. As a result, the overall performance of the battery cell is reduced.

[0055] The electrolyte of one or more embodiments of the present disclosure using additives can control moisture to effectively inhibit or reduce the dissolution of transition metal ions from the positive electrode and precipitation on the surface of the negative electrode. Accordingly, it can effectively prevent or reduce the degradation of battery cell performance during the charge / discharge process and high temperature storage.

[0056] The additive according to one or more embodiments of the present disclosure may be represented by Formula 1-1.

[0057] Formula 1-1

[0058]

[0059] In Formula 1-1, R1 may be the same or different at each occurrence, and may be each independently hydrogen, halogen, C1-C10 alkyl, or isocyanate. At least one R1 may be an isocyanate.

[0060] In Formula 1-1, R2 may be the same or different at each occurrence, and may be each independently hydrogen, halogen, C1-C10 alkyl, or isocyanate. At least one R2 may be an isocyanate.

[0061] The electrolyte of one or more embodiments of the present disclosure using the additive represented by Formula 1-1 can control moisture to effectively inhibit or reduce the dissolution of transition metal ions from the positive electrode and precipitation on the surface of the negative electrode. Accordingly, it can effectively prevent or reduce the reduction of battery cell performance during the charge / discharge process and high temperature storage.

[0062] The additive according to one or more embodiments of the present disclosure may be represented by Formula 1-2.

[0063] Formula 1-2

[0064]

[0065] In Formula 1-2, R1 may be the same or different at each occurrence, and may each independently be hydrogen, halogen, or C1-C10 alkyl.

[0066] In Formula 1-2, R2 may be the same or different at each occurrence, and may each independently be hydrogen, halogen, or C1-C10 alkyl.

[0067] The electrolyte of one or more embodiments of the present disclosure using the additive represented by Formula 1-2 can control moisture to effectively inhibit or reduce the dissolution of transition metal ions from the positive electrode and precipitation on the surface of the negative electrode. Accordingly, it can effectively prevent or reduce the reduction of battery cell performance during the charge / discharge process and high temperature storage.

[0068] In one or more embodiments, the electrolyte may further include one species (type) of transition metal ions or a mixture of two or more species (types) of transition metal ions.

[0069] In one or more embodiments, the electrolyte may include one or more selected from the group consisting of iron ions, phosphate ions, cobalt ions, manganese ions, nickel ions, aluminum ions, and halogen ions.

[0070] In one or more embodiments, the electrolyte may include iron ions.

[0071] Positive electrode for rechargeable lithium battery

[0072] The positive electrode 100 of the rechargeable lithium battery may include a first current collector COL1 and a positive electrode active material layer AML1 on the first current collector COL1. The positive electrode active material layer AML1 may include a positive electrode active material and may further include one or more selected from a binder and a conductor (eg, an electrical conductor or an electrically conductive material).

[0073] For example, in some embodiments, the positive electrode 100 may further include an additive that serves as a sacrificial positive electrode.

[0074] The content (e.g., amount) of the positive electrode active material may be in the range of about 90 wt % to about 99 wt % relative to 100 wt % of the total weight of the positive electrode active material layer AML1. The content of the binder and the conductor may be in the range of about 0.5 wt % to about 5 wt % respectively relative to 100 wt % of the total weight of the positive electrode active material layer AML1.

[0075] The binder can be used to improve the adhesion of the positive electrode active material particles to each other, and also to improve the adhesion of the positive electrode active material to the first current collector COL1. The binder may include (for example, selected from) polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene oxide-containing polymers, polyvinyl pyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, (meth) acrylated styrene-butadiene rubber, epoxy resin, (meth) acrylic resin, polyester resin and nylon One or more, but the embodiments of the present disclosure are not limited thereto.

[0076] Conductors (e.g., electrical conductors or electrically conductive materials) can be used to provide conductivity to the electrodes, and any suitable conductive material that does not cause chemical changes in the battery can be used as a conductor constituting the battery. Conductors can include carbon materials such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fibers, carbon nanofibers, and / or carbon nanotubes; metal powders or fibers containing (e.g., selected from) one or more of copper, nickel, aluminum, and silver; conductive polymers such as polyphenylene derivatives; or (e.g., any suitable) mixtures thereof.

[0077] In one or more embodiments, the first current collector COL1 may include an aluminum (Al) foil, but embodiments of the present disclosure are not limited thereto.

[0078] Positive electrode active material

[0079] The positive electrode active material may include a compound that can reversibly intercalate and deintercalate lithium (e.g., a lithiated intercalation compound). For example, in one or more embodiments, the positive electrode active material may include at least one composite oxide of lithium and a metal selected from cobalt, manganese, nickel, and (e.g., any suitable) combination thereof.

[0080] The composite oxide may include a lithium transition metal composite oxide, such as a lithium nickel-based oxide, a lithium cobalt-based oxide, a lithium manganese-based oxide, a lithium iron phosphate-based compound, a cobalt-free nickel manganese-based oxide, or (eg, any appropriate) combination thereof.

[0081] For example, in one or more embodiments, the positive electrode active material may include a compound represented by one of the following chemical formulas: Li a A 1-b X b O 2-c D c (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05), Li a Mn 2-b X b O 4-c D c (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05), Li a Ni 1-b-c Co b X c O 2-α D α (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<α<2), Li a Ni 1-b-c Mn b X c O 2-α D α (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<α<2), Li a Ni b Co c L 1 d GeO2(0.90≤a≤1.8,0≤b≤0.9,0≤c≤0.5,0≤d≤0.5,0≤e≤0.1), Li a NeG bO2(0.90≤a≤1.8, 0.001≤b≤0.1), Li a CoG b O2(0.90≤a≤1.8, 0.001≤b≤0.1), Li a Mn 1-b G b O2(0.90≤a≤1.8, 0.001≤b≤0.1), Li a Mn b O4(0.90≤a≤1.8, 0.001≤b≤0.1), Li a Mn 1- g G g PO4(0.90≤a≤1.8, 0≤g≤0.5), Li (3-f) Fe2(PO4)3(0≤f≤2) and Li a FePO4(0.90≤a≤1.8).

[0082] In the aforementioned chemical formula, A may be Ni, Co, Mn, or (for example, any appropriate) combination thereof; X may be Al, Ni, Co, Mn, Cr, Fe, magnesium (Mg), strontium (Sr), V, a rare earth element, or (for example, any appropriate) combination thereof; D may be oxygen (O), fluorine (F), sulfur (S), phosphorus (P), or (for example, any appropriate) combination thereof; G may be Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or (for example, any appropriate) combination thereof; and L 1 It may be Mn, Al, or (eg, any suitable) combination thereof.

[0083] For example, in one or more embodiments, the positive electrode active material may be a high nickel positive electrode active material, wherein the content (e.g., amount) of nickel is in the range of about 80 mol% (e.g., about 85 mol%, about 90 mol%, about 91 mol%, or about 94 mol%) to about 99 mol% relative to 100 mol% of the total metals other than lithium in the lithium transition metal composite oxide. High nickel positive electrode active materials can achieve relatively high capacity and can therefore be applied to high-density rechargeable lithium batteries.

[0084] In one or more embodiments, the positive electrode active material may include a lithium nickel-based oxide represented by Formula 2, a lithium cobalt-based oxide represented by Formula 3, a lithium iron phosphate-based compound represented by Formula 4, a cobalt-free lithium nickel manganese-based oxide represented by Formula 5, or (e.g., any appropriate) combination thereof.

[0085] Formula 2

[0086] Li a1 Ni x1 M1 y1 M 2 z1 O 2-b1 X b1

[0087] In formula 2, 0.9≤a1≤1.8, 0.3≤x1≤1, 0≤y1≤0.7, 0≤z1≤0.7, 0.9≤x1+y1+z1≤1.1, 0≤b1≤0.1, M 1 and M 2 Each of the above elements may be independently selected from the group consisting of Al, B, Ba, Ca, Ce, Co, Cr, Cu, Fe, Mg, Mn, Mo, Nb, Si, Sn, Sr, Ti, V, W and Zr, and X may be selected from the group consisting of F, P and S.

[0088] In some embodiments, in Formula 2, 0.6≤x1≤1, 0≤y1≤0.4, and 0≤z1≤0.4, or 0.8≤x1≤1, 0≤y1≤0.2, and 0≤z1≤0.2.

[0089] Formula 3

[0090] Li a2 Co x2 M 3 y2 O 2-b2 X b2

[0091] In formula 3, 0.9≤a2≤1.8, 0.7≤x2≤1, 0≤y2≤0.3, 0.9≤x2+y2≤1.1, 0≤b2≤0.1, M 3 It may be at least one element selected from Al, B, Ba, Ca, Ce, Cr, Cu, Fe, Mg, Mn, Mo, Ni, Se, Si, Sn, Sr, Ti, V, W, Y, Zn and Zr, and X may be at least one element selected from F, P and S.

[0092] Formula 4

[0093] Li a3 Fe x3 M 4 y3 PO 4-b3 X b3

[0094] In Formula 4, 0.9≤a3≤1.8, 0.6≤x3≤1, 0≤y3≤0.4, 0.9≤x3+y3≤1.1, and 0≤b3≤0.1, M 4may be at least one element selected from Al, B, Ba, Ca, Ce, Co, Cr, Cu, Mg, Mn, Mo, Ni, Se, Si, Sn, Sr, Ti, V, W, Y, Zn, and Zr, and X may be at least one element selected from F, P, and S.

[0095] Formula 5

[0096] Li a4 Ni x4 Mn y4 M 5 z4 O 2-b4 X b4

[0097] In Formula 5, 0.9 ≤ a2 ≤ 1.8, 0.8 ≤ x4 < 1, 0 < y4 ≤ 0.2, 0 ≤ z4 ≤ 0.2, 0.9 ≤ x4 + y4 + z4 ≤ 1.1, and 0 ≤ b4 ≤ 0.1, M 5 may be at least one element selected from Al, B, Ba, Ca, Ce, Cr, Fe, Mg, Mo, Nb, Si, Sn, Sr, Ti, V, W, and Zr, and X may be at least one element selected from F, P, and S.

[0098] For example, according to one or more embodiments, the electrolyte may provide excellent or appropriate improvement in reducing the cell performance of a rechargeable lithium battery using a lithium iron phosphate compound represented by Formula 4.

[0099] The negative electrode of the rechargeable lithium battery

[0100] The negative electrode 200 of the rechargeable lithium battery may include a second current collector COL2 and a negative electrode active material layer AML2 on the second current collector COL2. The negative electrode active material layer AML2 may include a negative electrode active material and may further include one or more selected from a binder and a conductor (e.g., an electrical conductor or a conductive material).

[0101] For example, in one or more embodiments, based on the total weight of the negative electrode active material layer AML2 of 100% by weight, the negative electrode active material layer AML2 may include about 90% to about 99% by weight of the negative electrode active material, about 0.5% to about 5% by weight of the binder, and about 0% to about 5% by weight of the conductor.

[0102] The binder may be used to improve the adhesion of the negative electrode active material particles to each other and also to improve the adhesion of the negative electrode active material to the second current collector COL2. The binder may include a non-aqueous (e.g., water-insoluble) binder, an aqueous (water-soluble) binder, a dry binder, or a combination thereof (e.g., any suitable combination).

[0103] The non-aqueous binder may include polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene propylene copolymer, polystyrene, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polyamideimide, polyimide, or (eg, any suitable) combination thereof.

[0104] The aqueous binder may include styrene-butadiene rubber, (meth)acrylated styrene-butadiene rubber, (meth)acrylic rubber, butyl rubber, fluoroelastomer, polyethylene oxide, polyvinyl pyrrolidone, polyepichlorohydrin, polyphosphazene, poly(meth)acrylonitrile, ethylene propylene diene copolymer, polyvinyl pyridine, chlorosulfonated polyethylene, latex, polyester resin, (meth)acrylic resin, phenolic resin, epoxy resin, polyvinyl alcohol, or (e.g., any suitable) combination thereof.

[0105] When the aqueous binder is used as a binder for the negative electrode, it may further include a cellulose compound that can provide viscosity. The cellulose compound may include (e.g., selected from) one or more of carboxymethyl cellulose, hydroxypropyl methyl cellulose, methyl cellulose, and alkali metal salts thereof. The alkali metal may include Na, K, or Li.

[0106] The dry binder may include a fiberizable polymer material, such as polytetrafluoroethylene, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polyethylene oxide, or (eg, any suitable) combination thereof.

[0107] Conductors (e.g., electrical conductors or electrically conductive materials) can be used to provide conductivity to the electrodes, and any suitable conductive material that does not cause chemical changes in the battery can be used as a conductor constituting the battery. For example, in one or more embodiments, the conductor may include a carbon material such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber, carbon nanofiber and / or carbon nanotube; a metal powder or fiber including (e.g., selected from) one or more of copper, nickel, aluminum and silver; a conductive polymer such as a polyphenylene derivative; or a mixture thereof.

[0108] The second current collector COL2 of the negative electrode may include a copper foil, a nickel foil, a stainless steel foil, a titanium foil, a nickel foam, a copper foam, a polymer substrate coated with a conductive metal, or (eg, any appropriate) combination thereof.

[0109] Negative electrode active material

[0110] The negative electrode active material may include a material that can reversibly intercalate and deintercalate lithium ions, lithium, a lithium alloy, a material that can be doped and dedoped with lithium, or a transition metal oxide.

[0111] Materials capable of reversibly embedding and de-embedding lithium ions may include carbonaceous negative electrode active materials, such as crystalline carbon, amorphous carbon, or (for example, any suitable) combinations thereof. Crystalline carbon may include graphite, such as amorphous natural or artificial graphite, or natural or artificial graphite in the form of plates, flakes, spheres, or fibers. Amorphous carbon may include, for example, soft carbon, hard carbon, mesophase pitch carbide, and / or calcined coke.

[0112] Lithium alloys may include alloys of lithium with metals selected from sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), francium (Fr), beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), silicon (Si), antimony (Sb), lead (Pb), indium (In), zinc (Zn), barium (Ba), radium (Ra), germanium (Ge), aluminum (Al), and tin (Sn).

[0113] Materials capable of being doped and de-doped with lithium may include silicon (Si)-based negative electrode active materials or tin (Sn)-based negative electrode active materials. Silicon-based negative electrode active materials may include silicon, silicon-carbon composites, SiO x (0 < x ≤ 2), Si-Q alloys (where Q is an alkali metal, alkaline earth metal, Group 13 element, Group 14 element (other than Si), Group 15 element, Group 16 element, transition metal, rare earth element, or (for example, any suitable) combinations thereof), or (for example, any suitable) combinations thereof. Tin-based negative electrode active materials may include Sn, SnO k (0 < k ≤ 2) (for example, SnO2), Sn-based alloys, or (for example, any suitable) combinations thereof.

[0114] The silicon-carbon composite may be a composite of silicon and amorphous carbon (for example, in the form of particles). According to one or more embodiments, the silicon-carbon composite may have a structure in which amorphous carbon coats the surface of each silicon particle. For example, in one or more embodiments, the silicon-carbon composite may include secondary particles (cores) in which silicon primary particles are aggregated, and an amorphous carbon coating (shell) on the surface of the secondary particles (for example, located on the surface of the secondary particles). Amorphous carbon may also be located between the silicon primary particles. For example, the silicon primary particles may be coated with amorphous carbon. The secondary particles may be present and dispersed in the amorphous carbon matrix.

[0115] In one or more embodiments, the silicon-carbon composite may further include crystalline carbon. For example, the silicon-carbon composite may include: a core including crystalline carbon and silicon particles, and an amorphous carbon coating on the surface of the core.

[0116] In some embodiments, the silicon-based negative electrode active material and / or the tin-based negative electrode active material may be used by mixing with the carbonaceous negative electrode active material.

[0117] Separator

[0118] Depending on the type or kind of the rechargeable lithium battery, the separator 400 may be present between the positive electrode 100 and the negative electrode 200. The separator 400 may include (e.g., selected from) one or more of a polyethylene separator, a polypropylene separator, and a polyvinylidene fluoride separator, or may be a multilayer separator thereof, such as a polyethylene / polypropylene double-layer separator, a polyethylene / polypropylene / polyethylene three-layer separator, or a polypropylene / polyethylene / polypropylene three-layer separator.

[0119] The separator 400 may include a porous substrate and a coating layer on one surface or both opposite surfaces of the porous substrate, and the coating layer may include an organic material, an inorganic material, or (eg, any appropriate) combination thereof.

[0120] The porous substrate may be a polymer layer comprising: one selected from polyolefins (such as polyethylene and / or polypropylene), polyesters (such as polyethylene terephthalate and / or polybutylene terephthalate), polyacetals, polyamides, polyimides, polycarbonates, polyether ketones, polyaryletherketones, polyetherimides, polyamideimides, polybenzimidazoles, polyethersulfones, polyphenylene oxides, cyclic olefin copolymers, polyphenylene sulfide, polyethylene naphthalate, glass fibers, and polytetrafluoroethylene (e.g., Teflon), or may be a copolymer or mixture comprising two or more thereof.

[0121] The organic material may include a polyvinylidene fluoride-based copolymer and / or a (meth)acrylic acid-based copolymer.

[0122] The inorganic material may include inorganic particles selected from Al2O3, SiO2, TiO2, SnO2, CeO2, MgO, NiO, CaO, GaO, ZnO, ZrO2, Y2O3, SrTiO3, BaTiO3, Mg(OH)2, boehmite, and (e.g., any appropriate) combinations thereof, but embodiments of the present disclosure are not limited thereto.

[0123] In one or more embodiments, the organic material and the inorganic material may exist and be mixed in one coating layer, or may exist in a stacked form of a coating layer including an organic material and a coating layer including an inorganic material.

[0124] Rechargeable lithium battery

[0125] Based on the shape of the rechargeable lithium battery, the rechargeable lithium battery according to one or more embodiments of the present disclosure may be classified into a cylindrical type or type of rechargeable lithium battery, a prismatic type or type of rechargeable lithium battery, a pouch type or type of rechargeable lithium battery, or a coin type or type of rechargeable lithium battery. Figure 2 to Figure 5 Each illustrates a simplified diagram showing a rechargeable lithium battery according to one or more embodiments. Figure 2 A rechargeable lithium battery of a cylindrical type or kind is depicted, Figure 3A rechargeable lithium battery of a prismatic type or kind is depicted, and Figure 4 and Figure 5 Each depicts a pouch type or kind of rechargeable lithium battery. Figure 2 to Figure 5 , the rechargeable lithium battery 1 may include an electrode assembly 500 (in which the separator 400 is inserted between the positive electrode 100 and the negative electrode 200), and may also include a case 600 (in which the electrode assembly 500 is housed). The positive electrode 100, the negative electrode 200, and the separator 400 may be immersed in an electrolyte. In some embodiments, as Figure 2 As explained in , the rechargeable lithium battery 1 may include a sealing member 700 that seals the housing 600. In some embodiments, as Figure 3 As explained in , the rechargeable lithium battery 1 may include a positive electrode lead tab 110, a positive electrode terminal 120, a negative electrode lead tab 210, and a negative electrode terminal 220. Figure 4 and Figure 5 As shown in , in some embodiments, the rechargeable lithium battery 1 may include an electrode tab 800 , or a positive electrode tab 810 and a negative electrode tab 820 , which serve as an electrical path for guiding current generated in the electrode assembly 500 to the outside.

[0126] The rechargeable lithium battery according to one or more embodiments of the present disclosure may be applied to a car, a mobile phone, and / or any other electrical device, but the embodiments of the present disclosure are not limited thereto.

[0127] Embodiments and comparative methods of the present disclosure will be described below. However, the following embodiments are merely exemplary, and the present disclosure is not limited to these embodiments.

[0128] Implementation and comparison

[0129] Electrolytes and rechargeable lithium batteries are manufactured by the methods described herein.

[0130] Implementation Method 1

[0131] (1) Preparation of electrolyte

[0132] 1.15 M LiPF6 was dissolved in a nonaqueous organic solvent in which ethylene carbonate (EC), ethyl methyl carbonate (EMC) and dimethyl carbonate (DMC) were mixed in a volume ratio of 20:40:40, and 0.5 wt% of an additive based on the total weight of the electrolyte was added to prepare an electrolyte.

[0133] The material represented by Formula 1-1-1 is used as an additive.

[0134] Formula 1-1-1

[0135]

[0136] (2) Manufacturing of rechargeable lithium batteries

[0137] LiFePO 4 as a positive electrode active material, polyvinylidene fluoride as a binder, and acetylene black as a conductor were mixed at a weight ratio of 96:3:1 and dispersed in N-methylpyrrolidone to prepare a positive electrode active material slurry.

[0138] The positive electrode active material slurry was coated on a 15 μm thick Al foil, dried at 100° C., and then pressed to produce a positive electrode.

[0139] Artificial graphite as a negative electrode active material, and styrene-butadiene rubber and carboxymethyl cellulose as a binder were mixed at a weight ratio of 98:1:1 and dispersed in distilled water to prepare a negative electrode active material slurry.

[0140] The negative electrode active material slurry was coated on a 10 μm-thick Cu foil, dried at 100° C., and then pressed to produce a negative electrode.

[0141] The positive electrode, the negative electrode, and a 10 μm-thick polyethylene separator were assembled to manufacture an electrode assembly, and an electrolyte was introduced into the electrode assembly to manufacture a rechargeable lithium battery.

[0142] Implementation Method 2

[0143] An electrolyte solution and a rechargeable lithium battery were each independently manufactured in substantially the same manner as in Embodiment 1, except that LiCoO 2 was used as a positive electrode active material.

[0144] Implementation 3

[0145] An electrolyte solution and a rechargeable lithium battery were each independently manufactured in substantially the same manner as in Embodiment 1, except that Li(NiCoAl)O 2 was used as a positive electrode active material.

[0146] Implementation 4

[0147] An electrolyte solution and a rechargeable lithium battery were each independently manufactured in substantially the same manner as in Embodiment 1, except that Li(NiCoMn)O 2 was used as a positive electrode active material.

[0148] Comparison method 1

[0149] The electrolyte and the rechargeable lithium battery were each independently manufactured in substantially the same method as in Embodiment 1, except that no additive was added when the electrolyte was manufactured.

[0150] Comparison method 2

[0151] The electrolyte and the rechargeable lithium battery were each independently manufactured in substantially the same manner as in Embodiment 1, except that when the electrolyte was manufactured, no additive was added and LiCoO 2 was used as a positive electrode active material.

[0152] Comparison method 3

[0153] An electrolyte and a rechargeable lithium battery were each independently manufactured in substantially the same manner as in Embodiment 1, except that no additive was added when the electrolyte was manufactured, and Li(NiCoAl)O 2 was used as a positive electrode active material.

[0154] Comparison method 4

[0155] An electrolyte and a rechargeable lithium battery were each independently manufactured in substantially the same manner as in Embodiment 1, except that no additive was added when the electrolyte was manufactured, and Li(NiCoMn)O 2 was used as a positive electrode active material.

[0156] Comparison method 5

[0157] An electrolyte solution and a rechargeable lithium battery were each independently manufactured in substantially the same method as in Embodiment 1, except that the material represented by Formula 1-1-2 was used as an additive.

[0158] [Formula 1-1-2]

[0159]

[0160] Comparison method 6

[0161] An electrolyte solution and a rechargeable lithium battery were each independently manufactured in substantially the same method as in Embodiment 1, except that a material represented by Formula 1-1-3 was used as an additive.

[0162] [Formula 1-1-3]

[0163]

[0164] Evaluation Example

[0165] The following method is used to evaluate rechargeable lithium batteries.

[0166] Evaluation 1: Storage characteristics at high temperature (60°C) – Evaluation of DCIR increase rate

[0167] For each of the rechargeable lithium batteries according to the embodiment and the comparative embodiment, after measuring the initial direct current resistance (DCIR) as ΔV / ΔI (voltage change / current change), the internal maximum energy state of the rechargeable lithium battery is charged to a fully charged state (SOC 100%) and stored in a charged state at a high temperature (60°C) for 30 days, and then the DC resistance is measured to calculate the DCIR increase rate (%) after high temperature storage according to Equation 1, and the results are listed in Table 1.

[0168] [Equation 1]

[0169] DCIR increase rate after high temperature storage (%) = (DCIR after 30 days of high temperature storage / initial DCIR) × 100

[0170] [Table 1]

[0171]

[0172] Evaluation 2: Evaluation of charge / discharge characteristics at room temperature

[0173] Each of the rechargeable lithium batteries according to the embodiment and the comparative embodiment was evaluated for charge / discharge characteristics at room temperature. Each of the rechargeable lithium batteries according to the embodiment and the comparative embodiment was charged and discharged for 200 cycles at 25°C under the conditions of 0.33C charge (CC / CV, 4.45V, 0.025C cutoff) and 1.0C discharge (CC, 2.5V cutoff).

[0174] The capacity retention rate was calculated according to Equation 2. The results are listed in Table 2.

[0175] Equation 2

[0176] Capacity retention rate (%) = (discharge capacity after 200 cycles / discharge capacity after 1 cycle) × 100

[0177] [Table 2]

[0178]

[0179]

[0180] Evaluation 3: Evaluation of charge / discharge characteristics at relatively high temperature (45°C)

[0181] The charge / discharge characteristics at relatively high temperature were evaluated for each of the rechargeable lithium batteries according to the embodiment and the comparative method. Each of the rechargeable lithium batteries according to the embodiment and the comparative method was charged and discharged for 200 cycles at 45°C under the conditions of 0.33C charge (CC / CV, 4.45V, 0.025C cutoff) and 1.0C discharge (CC, 2.5V cutoff).

[0182] The capacity retention rate was calculated according to Equation 2. The results are listed in Table 3.

[0183] Equation 2

[0184] Capacity retention rate (%) = (discharge capacity after 200 cycles / discharge capacity after 1 cycle) × 100

[0185] [Table 3]

[0186]

[0187] Evaluation 4: Evaluation of gas generation characteristics at high temperature (60°C)

[0188] The gas generation characteristics at high temperature were evaluated for each of the rechargeable lithium batteries according to the embodiment and the comparative method. The internal maximum energy state of the rechargeable lithium battery was charged to a fully charged state (SOC 100%) and stored in a charged state at a high temperature (60°C) for 10 days or 30 days, and then the gas generation amount was evaluated, and the results are listed in Table 4.

[0189] The volume change before and after high-temperature storage was measured, and the volume change was converted into mass change using the Archimedean method.

[0190] [Table 4]

[0191]

[0192] Comprehensive Assessment

[0193] Referring to Table 1, in each comparative example (Comparative Example 1 to Comparative Example 4) using each electrolyte without adding an additive, in the comparative example (Comparative Example 5) using the material represented by Formula 1-1-2 as an additive, and in the comparative example (Comparative Example 6) using the material represented by Formula 1-1-3 as an additive, the DCIR after high temperature (60° C.) storage increased significantly. Therefore, it can be confirmed that the high temperature storage characteristics of the comparative examples are reduced.

[0194] In contrast, it was confirmed that in each of the examples (Embodiment 1 to Embodiment 4) of each electrolyte to which the additive according to the present disclosure was added, the DCIR increase rate was improved even when left standing / stored at a high temperature (60° C.).

[0195] Referring to Tables 2 and 3, in each comparative example (Comparative Example 1 to Comparative Example 4) using each electrolyte without adding an additive, in the comparative example (Comparative Example 5) using the material represented by Formula 1-1-2 as an additive, and in the comparative example (Comparative Example 6) using the material represented by Formula 1-1-3 as an additive, the capacity retention rate depending on the charge / discharge cycle at room temperature and relatively high temperature (45°C) is reduced, which leads to a shortened life depending on the charge / discharge cycle.

[0196] In contrast, it was confirmed that in each of the examples (Embodiment 1 to Embodiment 4) of each electrolyte to which the additive according to the present disclosure was added, the capacity retention rate depending on the charge / discharge cycle at room temperature and at a relatively high temperature (45° C.) was improved.

[0197] Referring to Table 4, it is confirmed that in each comparative example (Comparison Example 1 to Comparison Example 4) of each electrolyte using no additive, in the comparative example (Comparison Example 5) using the material represented by Formula 1-1-2 as an additive, and in the comparative example (Comparison Example 6) using the material represented by Formula 1-1-3 as an additive, a large amount of gas is generated under high temperature (60°C) storage.

[0198] In contrast, it was confirmed that in each of the examples (Embodiment 1 to Embodiment 4) of each electrolyte to which the additive according to the present disclosure was added, gas generation under high temperature (60° C.) storage was effectively suppressed or reduced.

[0199] From the evaluation results discussed, it was determined that the additive according to the present disclosure is remarkably effective in preventing or reducing degradation of battery cell performance.

[0200] For example, unlike Comparative Examples 5 and 6 in which chemical stability is reduced due to relatively high reduction potential and relatively low oxidation potential, the additive according to the present disclosure can stably control moisture to effectively prevent or reduce the reduction in battery cell performance even if (for example, when) the additive includes an isocyanate group.

[0201] A rechargeable lithium battery according to one or more embodiments of the present disclosure may achieve excellent or appropriate performance while ensuring stability.

[0202] In the present disclosure, the expression "and / or" includes any and all combinations of one or more associated listed items. Expressions such as "at least one of...", "one of...", and "selected from...", when before / after a list of elements, modify the entire list of elements without modifying the individual elements of the list. For example, "at least one of a, b, and c", "at least one selected from a, b, and c", and "at least one of a-c" may indicate only a, only b, only c, both a and b (e.g., simultaneously), both a and c (e.g., simultaneously), both b and c (e.g., simultaneously), all a, b, and c, or variations thereof. Depending on the circumstances, the " / " used in this document may be interpreted as "and" or as "or".

[0203] In the present disclosure, the term "Group" used herein refers to a group of the Periodic Table of Elements according to the 1 to 18 grouping system of the International Union of Pure and Applied Chemistry ("IUPAC").

[0204] As used herein, the terms "substantially," "about," and similar terms are used as terms of approximation and not as terms of degree, and are intended to account for the inherent deviations of measured or calculated values ​​that would be recognized by one of ordinary skill in the art. "About" or "approximately" as used herein also includes the stated value and means within an acceptable range of deviation determined by one of ordinary skill in the art taking into account limitations and errors associated with the measurement of that quantity (i.e., limitations of the measurement system). For example, "about" may mean within one or more standard deviations, or ±30%, ±20%, ±10%, or ±5% of the stated value.

[0205] The numerical ranges set forth herein are intended to include all subranges of the same numerical precision contained within the set forth range. For example, the range of "1.0 to 10.0" is intended to include all subranges between the set forth minimum value 1.0 and the set forth maximum value 10.0 (and including the endpoints), that is, having a minimum value equal to or greater than 1.0 and a maximum value equal to or less than 10.0, such as, for example, 2.4 to 7.6. Any maximum numerical limit set forth herein is intended to include all lower numerical limits contained therein, and any minimum numerical limit set forth in this specification is intended to include all higher numerical limits contained therein. Accordingly, the applicant reserves the right to amend this specification (including claims) to explicitly set forth any subrange contained within the range explicitly set forth herein.

[0206] The battery management system (BMS) device and / or any other related device or component according to the embodiments of the present invention described herein may be implemented using any appropriate hardware, firmware (e.g., an application specific integrated circuit), software, or a combination of software, firmware, and hardware. For example, the various components of the device may be formed on an integrated circuit (IC) chip or on separate IC chips. Further, the various components of the device may be implemented on a flexible printed circuit film, a tape carrier package (TCP), or a printed circuit board (PCB), or formed on a substrate. Further, the various components of the device may be processes or threads that run on one or more processors in one or more computing devices, execute computer program instructions, and interact with other system components for performing the various functions described herein. The computer program instructions are stored in a memory that may be implemented in a computing device using a standard storage device, such as, for example, a random access memory (RAM). The computer program instructions may also be stored in other non-temporary computer-readable media, such as, for example, a CD-ROM or a flash drive, etc. Moreover, those skilled in the art should recognize that, without departing from the scope of the present disclosure, the functions of various computing devices may be combined or integrated into a single computing device, or the functions of a particular computing device may be distributed on one or more other computing devices.

[0207] Although the present disclosure has been described in conjunction with what are currently considered to be practical exemplary embodiments, it should be understood that the present disclosure is not limited to the disclosed embodiments and is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the claims and their equivalents, so the aforementioned embodiments should be understood as exemplary rather than limiting the present disclosure in any way.

Claims

1. An electrolyte comprising: Lithium salts; Non-aqueous organic solvents; and The additive represented by Formula 1, Formula 1 Among them, in formula 1, R1 is the same or different at each occurrence and is independently hydrogen, halogen, C1-C10 alkyl or isocyanate, at least one R1 is isocyanate, R2 is the same or different at each occurrence and is independently hydrogen, halogen, C1-C10 alkyl or isocyanate, at least one R2 is isocyanate, R3 is the same or different at each occurrence and is independently hydrogen or a cyclohexyl isocyanate residue, and n is an integer from 1 to 10, and The electrolyte is an electrolyte for a rechargeable lithium battery.

2. The electrolyte according to claim 1, wherein the additive is represented by formula 1-1, Formula 1-1 In formula 1-1, R1 is the same or different at each occurrence and is independently hydrogen, halogen, C1-C10 alkyl or isocyanate, at least one R1 is isocyanate, and R2 is the same or different at each occurrence and is independently hydrogen, halogen, C1-C10 alkyl or isocyanate, at least one R2 is isocyanate.

3. The electrolyte according to claim 1, wherein the additive is represented by Formula 1-2, Formula 1-2 In formula 1-2, R1 is the same or different at each occurrence and is independently hydrogen, halogen or C1-C10 alkyl, and R2 is the same or different at each occurrence and is independently hydrogen, halogen or C1-C10 alkyl. 4 . The electrolyte according to claim 1 , wherein the amount of the additive is 0.05 to 10 weight % of the total weight of the electrolyte. The electrolyte according to claim 1 , wherein the non-aqueous organic solvent comprises a carbonate-based solvent. 6 . The electrolyte according to claim 5 , wherein the carbonate-based solvent comprises ethylene carbonate, ethyl methyl carbonate and dimethyl carbonate.

7. The electrolyte according to claim 6, wherein the volume ratio of the ethylene carbonate, the ethyl methyl carbonate and the dimethyl carbonate is 1:(1-3):(1-3).

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

9. The electrolyte of claim 1, wherein the concentration of the lithium salt is in the range of 0.1M to 2.0M.

10. A rechargeable lithium battery comprising: a positive electrode including a positive electrode active material; a negative electrode including a negative electrode active material; and The electrolyte according to any one of claims 1 to 9.

11. The rechargeable lithium battery of claim 10, wherein the positive electrode active material comprises a lithium iron phosphate-based compound. 12 . The rechargeable lithium battery of claim 10 , wherein the negative electrode active material comprises a carbon-based negative electrode active material, a silicon-based negative electrode active material, a tin-based negative electrode active material, or a combination thereof. 13 . The rechargeable lithium battery of claim 10 , wherein the amount of the additive is 0.05 wt % to 10 wt % of the total weight of the electrolyte.

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