Lithium secondary battery

Description

1 / 50 “SECONDARY LITHIUM BATTERY” TECHNICAL FIELD CROSS-REFERENCE TO RELATED REQUESTS

[001] This application claims priority over Korean Patent Application No. 102023-0126665, filed on September 21, 2023, the disclosure of which is incorporated by reference herein. TECHNICAL FIELD

[002] The present invention relates to a lithium secondary battery. In particular, the present invention relates to a lithium secondary battery including perlithium-rich manganese oxide as a positive electrode active material. PREVIOUS TECHNIQUE

[003] Recently, as the application areas of a secondary lithium battery rapidly expand not only to power supply for electricity, electronics, communication and electronic devices such as computers, but also to energy storage supply for large area devices such as vehicles or energy storage devices, the demand for a secondary battery with high capacity and high output, as well as high stability, is increasing.

[004] A secondary lithium battery generally includes a positive electrode containing a positive electrode active material, a negative electrode containing a negative electrode active material, an electrolyte that serves as a medium for lithium ion transfer, and a separator. Currently, a carbon-based active material, a silicon-based active material, etc., can be used as the negative electrode active material. Additionally, as the positive electrode active material, a lithium transition metal oxide, including lithium-cobalt oxide (LiCoO2), lithium-nickel oxide (LiNiO2), lithium-nickel-cobalt composite oxide. Petition 870250086687, dated 09 / 25 / 2025, page 9 / 67 2 / 50 manganese etc. can be used.

[005] As the next-generation active positive electrode material, pearlite-rich manganese oxide has recently attracted attention. Pearlite-rich manganese oxide has an increased amount of manganese (Mn), which is relatively inexpensive and has abundant reserves, in addition to having the advantage of high capacity. However, due to reactive oxygen generated by phase transformation of the active positive electrode material during formation and charge / discharge processes, the decomposition of an electrolyte intensifies and the amount of gas generation increases significantly, and the transition metal eluted in the active positive electrode material is electrodeposited on a negative electrode, causing a problem of destruction of a SEI film on the negative electrode and, therefore, the use of pearlite-rich manganese oxide has been limited. This is more problematic mainly in high temperature and high voltage operation. DISCLOSURE OF THE INVENTION TECHNICAL PROBLEM

[006] One task of the present invention is to solve the problem described above and provide a lithium secondary battery including perlithium-rich oxide and manganese as a positive electrode active material, wherein gas generation is reduced during initial formation and charge / discharge, and transition metal elution in the positive electrode active material is suppressed, so that high-temperature cycle characteristics and high-temperature storage characteristics are excellent. TECHNICAL SOLUTION

[007] [1] The present invention provides a lithium secondary battery including a positive electrode; a negative electrode; a separator disposed between the positive and negative electrodes; and a non-aqueous electrolyte, wherein the material of the positive electrode includes a perlithium- and manganese-rich oxide containing about 50% Petition 870250086687, dated 09 / 25 / 2025, page 10 / 67 3 / 50 mol or more of Mn based on all metallic elements except lithium, and having a molar ratio of lithium to transition metal exceeding about 1, and the non-aqueous electrolyte includes a lithium salt, a compound represented by Chemical Formula 1 below and a compound represented by Chemical Formula 2 below.

[008] In Chemical Formula 1 above, Ri includes a halogen, a nitrile group, a propargyl group, an ester group, an ether group, a ketone group, a carboxyl group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted alkoxy group, a boron group, a borate group, an isocyanate group, an isothiocyanate group, a silyl group, a siloxane group, a sulfone group, a sulfonate group, a sulfate group, or a combination of two or more of them, en is an integer from 0 to 6. [Chemical Formula 2]

[009] In Chemical Formula 2 above, Fb is fluorine, a C1 to C10 alkyl group substituted with one or more fluorines, a C1 to C10 alkoxy group substituted with one or more fluorines, or a C6 to C20 aryloxy group substituted with one or more fluorines, and Fb and R4 are each independently hydrogen, a C1 to C10 alkyl group, or a Petition 870250086687, dated 09 / 25 / 2025, p. 11 / 67 4 / 50 group C6 to C20 aril.

[010] [2] The present invention provides the lithium secondary battery of [1] above, in which the perlithium and manganese rich oxide includes a compound represented by Chemical Formula A below. [Chemical Formula A] Lii +s[NitCouMnvM1w]02+z

[011] In Chemical Formula A above, M1 is one or more selected from W, Cu, Fe, V, Cr, Ti, Zr, Zn, Al, In, Ta, Y, La, Sr, Ga, Sc, Gd, Sm, Ca, Ce, Nb, Mg, B and Mo, and 0.05 <s<1,0<t<0,5, 0<u<0,3, 0,5<v<1,0, 0<w<0,2, e 0<z<1.

[012] [3] The present invention provides a lithium secondary battery of at least one of [1] and [2] above, wherein the compound represented by Chemical Formula 1 above includes at least one selected from the group consisting of a compound represented by Chemical Formula 1-A below and a compound represented by Chemical Formula 1-B below. [Chemical Formula 1-A] [Chemical Formula 1-B]

[013] In Chemical Formula 1-A and Chemical Formula 1-B above, Ri is as defined by Chemical Formula 1 above.

[014] [4] The present invention provides a lithium secondary battery of at least one of [1] to [3] above, wherein the compound represented by the Chemical Formula Petition 870250086687, dated 09 / 25 / 2025, page 12 / 67 5 / 50 above includes at least one selected compound from the group consisting of compounds represented by Chemical Formula 1-1 to Chemical Formula 1-9 below. [Chemical Formula 1-1] [Chemical Formula 1-5] Petition 870250086687, dated 09 / 25 / 2025, page 13 / 67 6 / 50 [Chemical Formula 1-6] [Chemical Formula 1-8] [Chemical Formula 1-9]

[015] [5] The present invention provides a lithium secondary battery of at least one of [1] to [4] above, wherein the compound represented by Chemical Formula 1 above is included in an amount of 0.01% by weight to 10% by weight based on the weight of the non-aqueous electrolyte.

[016] [6] The present invention provides a lithium secondary battery of at least one of [1] to [5] above, wherein the compound represented by Chemical Formula 2 above includes at least one selected from the group consisting of compounds represented by Chemical Formula 2-1 to Chemical Formula 2-5 below. Petition 870250086687, dated 09 / 25 / 2025, page 14 / 67 7 / 50 [Chemical Formula 2-1] [Chemical Formula 2-2] [Chemical Formula 2-3] |íZCH3 O—S—N f3cZIIXch3 [Chemical Formula 2-4] [Chemical Formula 2-5]

[017] [7] The present invention provides the lithium secondary battery of Petition 870250086687, dated 09 / 25 / 2025, page 15 / 67 8 / 50 minus one of [1] to [6] above, wherein the compound represented by Chemical Formula 2 above is included in an amount of 5% by weight to 40% by weight in the non-aqueous electrolyte.

[018] [8] The present invention provides the lithium secondary battery of at least one of [1] to [7] above, wherein a weight ratio of the compound represented by Chemical Formula 1 above and the compound represented by Chemical Formula 2 above is from 0.01:99.1 to 50:50.

[019] [9] The present invention provides a lithium secondary battery of at least one of [1] to [8] above, wherein the lithium salt includes at least one selected from the group consisting of LiCl, LiBr, LiI, LiBF4 LiClO4 LiAlO4 LiAlCl4, LiPFs, LiSbFs, LiAsF6, LiBioCIio, LiB(C2O4)2 (LiBOB), LiCFsSOe, LiN(SO2F)2 (LiFSI), LiCHaSOe, UCF3CO2, UCH3CO2, and LiN(SO2CF2CF3)2 (LiBETI).

[020]

[10] The present invention provides a lithium secondary battery of at least one of [1] to [9] above, wherein the non-aqueous electrolyte includes an organic solvent, and the organic solvent includes at least one selected from the group consisting of a cyclic carbonate-based organic solvent, a linear carbonate-based organic solvent, a linear ester-based organic solvent and a cyclic ester-based organic solvent.

[021]

[11] The present invention provides a lithium secondary battery of at least one of [1] to

[10] above, wherein the non-aqueous electrolyte further includes at least one additive selected from the group consisting of vinylene carbonate, vinylethylene carbonate, fluoroethylene carbonate, propanesulfone, propenesulfone, succinonitrile, adiponitrile, ethylene sulfate, lithium bis-(oxalato)borate (LiBOB), lithium difluorooxalatoborate (LiODFB), tris(trimethylsilyl)phosphate (TMSPa) and tris(trimethylsilyl)phosphite (TMSPi). ADVANTAGEOUS EFFECTS

[022] A secondary lithium battery of the present invention is characterized Petition 870250086687, dated 09 / 25 / 2025, page 16 / 67 9 / 50 due to the use of pearly- and manganese-rich oxide as a positive electrode active material and the use of the compound represented by Chemical Formula 1 above and the compound represented by Chemical Formula 2 above as components of a non-aqueous electrolyte. The compound represented by Chemical Formula 1 above is a coumarin-based compound, which eliminates reactive oxygen during initial formation to avoid the consumption of an organic solvent in the non-aqueous electrolyte and to prevent gas generation caused by the decomposition of the organic solvent. Furthermore, the compound represented by Chemical Formula 2 above is a sulfonamide-based compound, which can ensure the oxidation stability of the non-aqueous electrolyte to suppress battery deterioration caused by gas generation during charging and discharging.Therefore, if the compound represented by Chemical Formula 1 above is used in combination with the compound represented by Chemical Formula 2 above, gas generation can be reduced during the initial formation and charging / discharging of the secondary lithium battery, including the perlithium- and manganese-rich oxide, and the elution of the transition metal in the active positive electrode material can be suppressed, so that the secondary lithium battery can have significantly improved high-temperature cycle characteristics and high-temperature storage characteristics. METHOD OF CARRYING OUT THE INVENTION

[023] It is understood that the terms or words used in the descriptive report and claims should not be interpreted as having the meaning defined in commonly used dictionaries, and it is further understood that the terms or words should be interpreted as having a meaning or concept that is consistent with the technical idea of ​​the present invention, based on the principle that an inventor can adequately define the meaning of terms or words to better explain the invention.

[024] It will also be understood that the terms “include”, “provide”, “have” or Petition 870250086687, dated 09 / 25 / 2025, p. 17 / 67 Similar 10 / 50 terms, when used in this descriptive report, specify the presence of features, integers, steps, declared elements, or a combination thereof, but do not preclude the presence or addition of one or more other features, integers, steps, elements, or a combination thereof.

[025] Meanwhile, before explaining the present invention, unless specifically noted in the present invention, “*” refers to a connected portion (linking part) between the same or different atoms or end portions of a chemical formula.

[026] Furthermore, in the descriptive report, in the term “Ca to Cb”, “a” and “b” refer to the number of carbon atoms included in a given functional group. That is, the functional group may include carbon atoms from “a” to “b”. For example, “C1 to C5 alkyl group” refers to an alkyl group that includes 1 to 5 carbon atoms, which is CH3-, CH3CH2-, CH3CH2CH2-, (CH3)2CH-, CH3CH2CH2CH2-, (CH3)2CHCH2-, CH3CH2CH2CH2CH2-, (CH3)2CHCH2CH2- etc.

[027] In addition, in this descriptive report, an alkyl group or aryl group may each be substituted or unsubstituted. Unless specifically defined otherwise, "substitution" refers to at least one hydrogen atom bonded to carbon being replaced by an element other than hydrogen, which refers to being replaced by, for example, a C1 to C20 alkyl group, a C2 to C20 alkenyl group, a C2 to C20 alkynyl group, a C1 to C20 alkoxy group, a C3 to C12 cycloalkyl group, a C3 to C12 cycloalkenyl group, a C3 to C12 cycloalkynyl group, a C3 to C12 heterocycloalkyl group, a C3 to C12 heterocycloalkenyl group, a C2 to C12 heterocycloalkynyl group, a C6 to C12 aryloxy group, a halogen atom, a C1 to C20 fluoroalkyl group, a nitro group, a C6 to C20 aryl group, a C2 to C20 heteroaryl group, a C6 to C20 haloaryl etc.

[028] The present invention will be described in more detail below. Petition 870250086687, dated 09 / 25 / 2025, p. 18 / 67 11 / 50

[029] A non-aqueous electrolyte and / or a secondary lithium battery according to the present invention may include at least one of the components disclosed below and may include any technically feasible combination of components among the components below. Lithium secondary battery

[030] The present invention relates to a secondary lithium battery.

[031] A secondary lithium battery according to the present invention includes a positive electrode; a negative electrode; a separator disposed between the positive electrode and the negative electrode; and a non-aqueous electrolyte, the positive electrode includes a positive electrode active material, the positive electrode material includes a pearly-manganese rich oxide containing about 50 mol% or more of Mn based on all metallic elements except lithium, and having a lithium to transition metal molar ratio greater than about 1, and the non-aqueous electrolyte includes a lithium salt, a compound represented by Chemical Formula 1 below and a compound represented by Chemical Formula 2 below.

[032] In Chemical Formula 1 above, Ri includes a halogen, a nitrile group, a propargyl group, an ester group, an ether group, a ketone group, a carboxyl group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted alkoxy group, a boron group, a borate group, an isocyanate group, an isothiocyanate group, a silyl group, a siloxane group, a sulfone group, a sulfonate group, a sulfate group, or a combination of two or more Petition 870250086687, dated 09 / 25 / 2025, p. 19 / 67 12 / 50 of them, where is an integer from 0 to 6. [Chemical Formula 2]

[033] In Chemical Formula 2 above, R2 is fluorine, a C1 to C10 alkyl group substituted with one or more fluorines, a C1 to C10 alkoxy group substituted with one or more fluorines, or a C6 to C20 aryloxy group substituted with one or more fluorines, and R3 and R4 are each independently hydrogen, a C1 to C10 alkyl group, or a C6 to C20 aryl group.

[034] The lithium secondary battery of the present invention is characterized by the use of perlithium- and manganese-rich oxide as a positive electrode active material and by the use of the compound represented by Chemical Formula 1 above and the compound represented by Chemical Formula 2 above as components of the non-aqueous electrolyte. The compound represented by Chemical Formula 1 above is a coumarin-based compound, which eliminates reactive oxygen during initial formation to avoid the consumption of an organic solvent in the non-aqueous electrolyte and to avoid gas generation caused by the decomposition of the organic solvent. Furthermore, the compound represented by Chemical Formula 2 above is a sulfonamide-based compound, which can ensure the oxidation stability of the non-aqueous electrolyte to suppress battery deterioration caused by gas generation during charging and discharging.Therefore, if the compound represented by Chemical Formula 1 above is used in combination with the compound represented by Chemical Formula 2 above, gas generation can be reduced during the initial formation and charging / discharging of the secondary lithium battery, including the perlithium-rich oxide. Petition 870250086687, dated 09 / 25 / 2025, p. 20 / 67 13 / 50 and manganese, and the elution of the transition metal in the active positive electrode material can be suppressed, so that the secondary lithium battery can have significantly improved high-temperature cycle characteristics and high-temperature storage characteristics.

[035] A secondary lithium battery includes a positive electrode; a negative electrode; a separator; and a non-aqueous electrolyte. In particular, a secondary lithium battery includes a positive electrode; a negative electrode opposite the positive electrode; a separator disposed between the positive and negative electrodes; and a non-aqueous electrolyte. A secondary lithium battery can be prepared by placing an electrode assembly, which includes the positive electrode; the negative electrode opposite the positive electrode; and the separator disposed between the positive and negative electrodes, in a battery case, and then injecting the non-aqueous electrolyte into it. (1) Positive Electrode

[036] The positive electrode includes a positive electrode active material.

[037] The positive electrode material includes a pearlite- and manganese-rich oxide. The pearlite- and manganese-rich oxide may contain about 50 mol% or more of Mn based on all metallic elements except lithium, and may have a lithium- to transition metal molar ratio greater than about 1.

[038] Perlithium-rich manganese oxide is receiving attention as a next-generation high-capacity positive electrode active material, but due to the material's unique structural deterioration, its use is being limited. In particular, reactive oxygen, deintercalated from the perlithium-rich manganese oxide during initial formation, decomposes and consumes an organic solvent (ethylene carbonate, etc.) included in the non-aqueous electrolyte, and consequently, gaseous byproducts are generated, thus causing problems of deterioration in service life performance, increased resistance, and deterioration in safety. Furthermore, in the charging and discharging process of the secondary lithium battery, including the perlithium-rich manganese oxide... Petition 870250086687, dated 09 / 25 / 2025, page 21 / 67 14 / 50 Perlithium and manganese, HF, which is a decomposition product of a lithium salt, can cause manganese elution from the perlithium-manganese-rich oxide and, consequently, there is a problem of oxygen deintercalation, particularly reactive oxygen, from the perlithium-manganese-rich oxide to achieve charge balance. The eluted manganese is electrodeposited on the negative electrode, causing a problem of SEI film destruction. The reactive oxygen, deintercalated during the charging and discharging process, continuously decomposes and consumes the organic solvent of the non-aqueous electrolyte, increasing the generation of gaseous byproducts. This consumption of the non-aqueous electrolyte, the structural collapse of the perlithium-manganese-rich oxide, and the increase in gaseous byproducts significantly deteriorate the service life performance, endurance characteristics, and safety of the lithium secondary battery.Furthermore, these problems are further intensified under conditions of high temperature and high voltage.

[039] To solve these problems, the lithium secondary battery according to the present invention is characterized by the use of the compound represented by Chemical Formula 1 in combination with the compound represented by Chemical Formula 2, to be described later, as non-aqueous electrolyte components. In the case of using the compound represented by Chemical Formula 1 above and the compound represented by Chemical Formula 2 above at the same time, the generation of reactive oxygen can be significantly suppressed in the initial formation and operation processes of the lithium secondary battery, the structural collapse of the perlithium- and manganese-rich oxide can be avoided, and the consumption of the organic solvent can be significantly avoided, so that it is possible to obtain the lithium secondary battery with excellent high-temperature cycle characteristics, high-temperature storage characteristics and safety.Such effects are difficult to achieve with other lithium transition metal oxides, where the deintercalation of reactive oxygen is not a major problem and, instead, the increase in... Petition 870250086687, dated 09 / 25 / 2025, page 22 / 67 15 / 50 initial resistance and decreased service life performance, caused by the use of the compounds represented by Chemical Formula 1 and Chemical Formula 2, may be the problems.

[040] The oxide rich in perlithium and manganese may include a compound represented by Chemical Formula A below. [Chemical Formula A] Li1+s[NitCouMnvM1w]O2+z

[041] In Chemical Formula A above, M1 is one or more selected from W, Cu, Fe, V, Cr, Ti, Zr, Zn, Al, In, Ta, Y, La, Sr, Ga, Sc, Gd, Sm, Ca, Ce, Nb, Mg, B and Mo, and 0.05 <s<1, 0<t<0,5, 0<u<0,3, 0,5<v<1,0, 0<w<0,2, e 0<z<1. Preferencialmente, na Fórmula Química X acima, 0,05<s<1,0, 0,1<t<0,5, 0<u<0,1, 0,5<v<1,0, 0<w<0,2 e 0<z<1 podem ser satisfeitos. Mais preferencialmente, na Fórmula Química X acima, 0,10<s<0,50, 0,1<t<0,5, 0<u<0,1, 0,6<v<1,0, 0<w<0,1 e 0<z<0,50 podem ser satisfeitos.

[042] More specifically, the oxide rich in perlithium and manganese may include a compound represented by Chemical Formula A-1 below. [Chemical Formula A-1] X Li2MnO3 •(1-X)Li[Ni1-yz-wMnyCozM1w]O2

[043] In Chemical Formula A-1 above, M1 is one or more selected from W, Cu, Fe, V, Cr, Ti, Zr, Zn, Al, In, Ta, Y, La, Sr, Ga, Sc, Gd, Sm, Ca, Ce, Nb, Mg, B, and Mo. Furthermore, in Chemical Formula Y above, 0.1 <X<0,5, 0,5<y<1, 0<z<0,3 e 0<w<0,2 podem ser satisfeitos, preferencialmente, 0,2<X<0,5, 0,5<y<1, 0<z<0,1 e 0<w<0,2 e, mais preferencialmente, 0,3<X<0,5, 0,6<y<1, 0<z<0,1 e 0<w<0,2 podem ser satisfeitos.

[044] The positive electrode may include a positive electrode current collector; and a layer of positive electrode active material disposed on at least one side of the positive electrode current collector. At this point, the active material Petition 870250086687, dated 09 / 25 / 2025, page 23 / 67 16 / 50 of the positive electrode may be included in the active material layer of the positive electrode.

[045] The positive electrode current collector is not particularly limited, provided it does not cause chemical change in a battery and has high conductivity. In particular, the positive electrode current collector may include at least one selected from the group consisting of copper, stainless steel, aluminum, nickel, titanium, calcined carbon and an aluminum-cadmium alloy, and may preferably include aluminum.

[046] The positive electrode current collector can generally have a thickness of 3 to 500 μm.

[047] The positive electrode current collector may also have microscopic irregularities on a surface to strengthen the bonding force of the active positive electrode material. For example, the positive electrode current collector may be used in various forms, including a film, a sheet, a metal plate, a mesh, a porous body, a foam body, a non-woven fiber body, etc.

[048] The active material layer of the positive electrode may be arranged on at least one side of the positive electrode current collector and, in particular, arranged on one side or on both sides of the positive electrode current collector.

[049] The active positive electrode material may be included in an amount of 80% by weight to 99% by weight, and preferably in an amount of 92% by weight to 98.5% by weight in the active positive electrode material layer, considering the display of sufficient capacity of the active positive electrode material etc.

[050] The remaining descriptions of the active positive electrode material described above will be omitted.

[051] The active material layer of the positive electrode may also include a binder and / or a conductive material, along with the active electrode material. Petition 870250086687, dated 09 / 25 / 2025, page 24 / 67 17 / 50 positive.

[052] The binder is a component that assists in the bonding between the active material and the conductive material etc. and in the bonding to the current collector, and may include at least one selected from the group consisting of, specifically, polyvinylidene fluoride, polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, polytetrafluoroethylene, polyethylene, polypropylene, an ethylene-propylene-diene terpolymer (EPDM), a sulfonated EPDM, a styrene-butadiene rubber and fluorine rubber, and may preferably include polyvinylidene fluoride.

[053] The binder may be included in an amount of 1% by weight to 20% by weight, and preferably in an amount of 1.2% by weight to 10% by weight in the active material layer of the positive electrode in order to ensure sufficient bond strength between the components, such as the active material of the positive electrode.

[054] The conductive material may be used to assist and improve the conductivity of the secondary battery and is not particularly limited, provided it does not cause chemical alteration and has conductivity. Specifically, the positive electrode conductive material may include at least one selected from the group consisting of graphite, such as natural graphite or artificial graphite; carbon black, including carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black, thermal black, etc.; a conductive fiber, such as a carbon fiber or a metallic fiber; a conductive tube, such as a carbon nanotube; fluorocarbon; metallic powder, including aluminum powder, nickel powder, etc.; a conductive whisker, including zinc oxide, potassium titanate, etc.; a conductive metallic oxide, such as titanium oxide; and a polyphenylene derivative, and may preferably include a carbon nanotube in terms of conductivity improvement.

[055] The conductive material may be included in an amount of 1% in Petition 870250086687, dated 09 / 25 / 2025, page 25 / 67 18 / 50 weight to 20% by weight, and preferably in an amount of 1.2% by weight to 10% by weight in the active material layer of the positive electrode in order to ensure sufficient electrical conductivity.

[056] The active material layer of the positive electrode can have a thickness of 30 μm to 400 μm and, preferably, 40 μm to 110 μm.

[057] A fluid positive electrode paste, including the active positive electrode material, selectively the binder and the conductive material, and a solvent to form the fluid positive electrode paste, can be applied to the positive electrode current collector and then dried and pressed to prepare the positive electrode.

[058] The solvent for forming the positive electrode fluid paste may include an organic solvent, such as N-methyl-2-pyrrolidone (NMP). The positive electrode fluid paste may have a solids content of 40% by weight to 90% by weight and, particularly, 50% by weight to 80% by weight. (2) Negative Electrode

[059] The negative electrode can be opposite the positive electrode.

[060] The negative electrode includes an active negative electrode material.

[061] The negative electrode active material is a material capable of reversibly intercalating / deintercalating lithium ions and may include at least one selected from the group consisting of a carbon-based active material, a (semi)metal-based active material and lithium metal, and may specifically include at least one selected from a carbon-based active material and a (semi)metal-based active material.

[062] The carbon-based active material may include at least one selected from the group consisting of artificial graphite, natural graphite, hard carbon, soft carbon, carbon black, graphene and fibrous carbon, and may preferably include at least one selected from the group consisting of graphite Petition 870250086687, dated 09 / 25 / 2025, p. 26 / 67 19 / 50 artificial and natural graphite.

[063] The carbon-based active material may have an average particle diameter (D50) of 10 μm to 30 μm and preferably 15 μm to 25 μm in terms of improved structural stability and reduced side reactions with an electrolytic solution during charging and discharging.

[064] In particular, the active (semi)metal-based material may include at least one (semi)metal selected from the group consisting of Cu, Ni, Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Si, Sb, Pb, In, Zn, Ba, Ra, Ge, Al, V, Ti and Sn; a lithium alloy and at least one (semi)metal selected from the group consisting of Cu, Ni, Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Si, Sb, Pb, In, Zn, Ba, Ra, Ge, Al, V, Ti and Sn; an oxide of at least one (semi)metal selected from the group consisting of Cu, Ni, Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Si, Sb, Pb, In, Zn, Ba, Ra, Ge, Al, V, Ti and Sn; lithium titanium oxide (LTO); lithium oxide and vanadium etc.

[065] More specifically, the (semi)metal-based active material may include a silicon-based active material.

[066] The silicon-based active material may include a compound represented by SiOx(0 <x<2) e um composto de silício-carbono. Uma vez que SiO2 não reage a íons de lítio, o lítio não pode ser armazenado, de modo que é preferível que x esteja dentro da faixa acima, e é mais preferível que o material ativo à base de silício seja SiO.

[067] The silicon-based active material may have an average particle diameter (D50) of 1 μm to 30 μm and preferably 2 μm to 15 μm in terms of improved structural stability and reduced side reactions with an electrolytic solution during charging and discharging.

[068] The negative electrode may include a negative electrode current collector; and a layer of negative electrode active material disposed on at least one side of the negative electrode current collector. At this point, the Petition 870250086687, dated 09 / 25 / 2025, page 27 / 67 20 / 50 negative electrode active material can be included in the negative electrode active material layer.

[069] The negative electrode current collector is not particularly limited, provided it does not cause chemical alteration in a battery and has high conductivity. In particular, copper, stainless steel, aluminum, nickel, titanium, calcined carbon, copper or stainless steel that has a surface treated with carbon, nickel, titanium, silver, etc., an aluminum-cadmium alloy, etc., can be used as a negative electrode current collector.

[070] The negative electrode current collector can generally have a thickness of 3 to 500 μm.

[071] The negative electrode current collector may also have microscopic irregularities on a surface to strengthen the bonding force of the negative electrode active material. For example, the negative electrode current collector may be used in various forms, including a film, a sheet, a metal plate, a mesh, a porous body, a foam body, a non-woven fiber body, etc.

[072] The negative electrode active material layer may be arranged on at least one side of the negative electrode current collector and, in particular, arranged on one side or on both sides of the negative electrode current collector.

[073] The negative electrode active material may be included in an amount of 60% by weight to 99% by weight and, preferably, in an amount of 75% by weight to 95% by weight in the negative electrode active material layer.

[074] The remaining descriptions of the active positive electrode material described above will be omitted.

[075] The negative electrode active material layer may also include a Petition 870250086687, dated 09 / 25 / 2025, page 28 / 67 21 / 50 binder and / or a conductive material together with the active negative electrode material.

[076] The binder is used to improve the performance of a battery by improving the adhesion of the negative electrode active material layer to the negative electrode current collector, and may include at least any one selected from the group consisting of, for example, a copolymer of polyvinylidene hexafluoropropylene fluoride (PVDF-co-HFP), polyvinylidene fluoride (PVDF), polyacrylonitrile, polymethyl methacrylate, polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, polytetrafluoroethylene, polyethylene, polypropylene, polyacrylic acid, an ethylene-propylene-diene monomer (EPDM), a sulfonated EPDM, a styrene-butadiene rubber (SBR), fluorine rubber and materials with hydrogen of the same being replaced by Li, Na, Ca or the like, and may also include various copolymers thereof.

[077] The binder may be included in an amount of 0.5% by weight to 10% by weight and, preferably, 1% by weight to 5% by weight in the negative electrode active material layer.

[078] The conductive material may not be particularly limited, provided that it does not cause chemical alteration in the relevant battery and has conductivity and, for example, graphite, such as natural graphite or artificial graphite; carbon black, including carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black, thermal black, etc.; a conductive fiber, such as a carbon fiber or metallic fiber; a conductive tube, such as a carbon nanotube; fluorocarbon; metallic powder, including aluminum powder, nickel powder, etc.; a conductive whisker, including zinc oxide, potassium titanate, etc.; a conductive metallic oxide, such as titanium oxide; a conductive material, such as a polyphenylene derivative, etc., may be used.

[079] The conductive material may be included in an amount of 0.5% in Petition 870250086687, dated 09 / 25 / 2025, page 29 / 67 22 / 50 weight to 10% by weight and, preferably, in an amount of 1% by weight to 5% by weight in the negative electrode active material layer.

[080] The active material layer of the negative electrode can have a thickness of 10 μm to 200 μm and, preferably, 20 μm to 150 μm.

[081] A fluid negative electrode paste, including the negative electrode active material, the binder, the conductive material and / or a solvent to form the fluid negative electrode paste, may be applied to at least one side of the negative electrode current collector and then dried and pressed to prepare the negative electrode.

[082] The solvent for forming the negative electrode fluid paste may include at least one selected from the group consisting of distilled water, N-methyl-2-pyrrolidone (NMP), ethanol, methanol and isopropyl alcohol, and may preferably include distilled water, for example, to facilitate the dispersion of the negative electrode active material, the binder and / or the conductive material. The negative electrode fluid paste may have a solids content of 30% by weight to 80% by weight and, particularly, of 40% by weight to 70% by weight. (3) Separator

[083] The separator can be placed between the positive electrode and the negative electrode.

[084] In addition, as the separator, a general porous polymer film conventionally used as a separator, for example, a porous polymer film made of a polyolefin-based polymer, such as an ethylene homopolymer, a propylene homopolymer, an ethylene / butene copolymer, an ethylene / hexene copolymer and an ethylene / methacrylate copolymer, may be used alone or used in a lamination thereof, or a general porous nonwoven fiber, for example, a nonwoven fiber made of high-melting-point glass fiber, a polyethylene terephthalate fiber, etc., may be used, but the present invention Petition 870250086687, dated 09 / 25 / 2025, page 30 / 67 23 / 50 is not limited to this. Furthermore, a coated separator including a ceramic component or a polymeric material can also be used to ensure thermal or mechanical strength, and can be selectively used in a single-layer or multi-layer structure. (4) Non-Aqueous Electrolyte

[085] The non-aqueous electrolyte according to the present invention includes a lithium salt, a compound represented by Chemical Formula 1 below and a compound represented by Chemical Formula 2 below. The non-aqueous electrolyte may further include an organic solvent and an additive, depending on the case. Hereinafter, the terms organic solvent and additive are used to distinguish between the compound represented by Chemical Formula 1 above and the compound represented by Chemical Formula 2 above. 1) Lithium Salt

[086] Like the lithium salt used in the present invention, various lithium salts that are commonly used for a non-aqueous electrolyte for a secondary lithium battery may be used without limitation. For example, lithium salt may include Li+ as a positive ion and may include, as a negative ion, at least any one selected from the group consisting of F-, Cl-, Br-, I-, NO3-, N(CN)2-, BF4-, ClO4-, AlO4-, AlCl4-, PFs-, SbFs-, AsFs-, B10Cl10-, BF2C2O4-, BC4O8-, PF4C2O4-, PF2C4O8-, (CF3)2PF4-, (CF3)3PF3-, (CF3)4PF2-, (CF3)5PF-, (CF3)6P-, CF3SO3-, C4F9SO3-, CF3CF2SO3-, (FSO2)2N-, CF3CF2(CF3)2CO-, (CF3SO2)2CH-, CH3SO3-, CF3(CF2)7SO3-, CF3CO2-, CH3CO2-, SCN-, and (CF3CF2SO2)2N-.

[087] In particular, the lithium salt may include at least one selected from the group consisting of LiCl, LiBr, LiI, LiBF4, LiClO4, LiAlO4, LiAlCl4, LiPFs, LiSbFs, LiAsFs, LiBioClIo, LiB(C2O4)2 (LiBOB), UCF3SO3, LiN(SO2F)2 (LiFSI), UCH3SO3, UCF3CO2, UCH3CO2, and LiN(SO2CF2CF3)2 (LiBETI). In particular, the lithium salt may include at least one selected from the group consisting of LiBF4, LiClO4, LiPFs, Petition 870250086687, dated 09 / 25 / 2025, page 31 / 67 24 / 50 LiB(C2O4)2(LiBOB), L1CF3SO3, LiN(SO2CF3)2 (LiTFSI), LíN(SO2F)2(LiFSI), and LiN(SO2CF2CF3)2 (LiBETI).

[088] Lithium salt can be included in the non-aqueous electrolyte at a concentration of 0.5 M to 5 M, and particularly at a concentration of 0.8 M to 4 M, and more particularly at a concentration of 0.8 M to 2.0 M. When the concentration of lithium salt is within the above ranges, the Li+ transfer number and the degree of dissociation of lithium ions can be improved, so that the output characteristics of a battery can be improved.

[089] Alternatively, the lithium salt may be included in the non-aqueous electrolyte as a component of the non-aqueous electrolyte, for example, as a residue excluding the compound represented by Chemical Formula 1, the compound represented by Chemical Formula 2, selectively an organic solvent and an additive. 2) Compound Represented by Chemical Formula 1

[090] The non-aqueous electrolyte of the present disclosure includes a compound represented by Chemical Formula 1 below.

[091] In Chemical Formula 1 above, R1 includes a halogen, a nitrile group, a propargyl group, an ester group, an ether group, a ketone group, a carboxyl group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted alkoxy group, a boron group, a borate group, an isocyanate group, an isothiocyanate group, a silyl group, a siloxane group, a group Petition 870250086687, dated 09 / 25 / 2025, p. 32 / 67 25 / 50 sulfone, a sulfonate group, a sulfate group, or a combination of two or more of them, en is an integer from 0 to 6.

[092] The compound represented by Chemical Formula 1 above is a coumarin-based compound that can capture reactive oxygen disintercalated from the perlithium- and manganese-rich oxide during initial formation. Consequently, the use of the compound represented by Chemical Formula 1 above can prevent the decomposition of the organic solvent and the increase in the generation of gaseous byproducts, which can be caused by reactive oxygen generated during the initial formation process.

[093] Furthermore, the compound represented by Chemical Formula 1 above can have its ring opened during initial formation to form a polyethylene oxide-based polymer-type film on an electrode, and this polymer-type film is excellent in flexibility and restorability. In particular, once an inorganic-type film, such as LiF, formed by the decomposition of the compound represented by Chemical Formula 2 to be described later, is combined with the polymer-type film, the non-aqueous electrolyte of the present invention includes organic / inorganic components, and a film with improved flexibility, restorability, and durability can be formed on the electrode, further improving the high-temperature service life characteristics and high-temperature storage characteristics.

[094] However, in addition to being able to remove reactive oxygen during the initial formation process, the compound represented by Chemical Formula 1 above is not effective in removing reactive oxygen generated during the charging / discharging or storage of the secondary lithium battery. This reactive oxygen generated during the charging / discharging or storage of the secondary lithium battery is a byproduct of the reaction with the electrolyte, which generates H2O by decomposing a lithium salt and generating HF, and this HF causes the elution of manganese from the oxide. Petition 870250086687, dated 09 / 25 / 2025, page 33 / 67 26 / 50 rich in perlithium and manganese and oxygen deintercalation, thus accelerating the deterioration of service life and storage performance. To solve these problems, in the present invention, using the compound represented by Chemical Formula 1 above in combination with the compound represented by Chemical Formula 2 above, the HF generated during charging / discharging, storage, etc. can be removed, so that the possibility of generating reactive oxygen during charging / discharging, storage, etc. of the secondary lithium battery can be avoided.Therefore, in the present invention, since the compound represented by Chemical Formula 1 above and the compound represented by Chemical Formula 2 above are used simultaneously, the generation of reactive oxygen, which is particularly problematic in perlithium- and manganese-rich oxide, can be controlled, the service life performance, storage performance, and safety of the secondary lithium battery can be improved simultaneously, and, particularly, the service life performance, storage performance, and safety in high-temperature and high-voltage operation can be improved to a significant degree.

[095] In Chemical Formula 1, Ri can be particularly a halogen (the halogen can be selected from F, Cl, Br and I and, particularly, can be F), a nitrile group, a propargyl group, an ester group, an ether group or a combination of two or more of these. Such a substituent can improve the reducibility of the compound represented by Chemical Formula 1 above and, thus, along with the ability to capture reactive oxygen, effects of facilitating the formation of a SEI film and improving the lithium ion transfer performance can also be achieved.

[096] In Chemical Formula 1 above, n can be an integer selected from 0 to 6 and, particularly, an integer selected from 1 to 6 and, more particularly, n can be 1. In Chemical Formula 1 above, when n is 2 or greater, Petition 870250086687, dated 09 / 25 / 2025, p. 34 / 67 27 / 50 Laughs can be the same or different from each other.

[097] In particular, the compound represented by Chemical Formula 1 above may include at least one selected from the group consisting of a compound represented by Chemical Formula 1-A below and a compound represented by Chemical Formula 1-B below. [Chemical Formula 1-A] [Chemical Formula 1-B]

[098] In Chemical Formula 1-A and Chemical Formula 1-B above, Ri is as defined by Chemical Formula 1 above.

[099] The compounds represented by Chemical Formula 1-A and Chemical Formula 1-B above have structures in which the substituents exist respectively in the third and seventh positions of the ring structures (according to IUPAC nomenclature) and, in this case, synthesis in the above positions is preferable to the other substitution positions.

[0100] In particular, the compound represented by Chemical Formula 1 above may include at least one selected from the group consisting of compounds represented by Chemical Formula 1-1 below up to Chemical Formula 1-9 below. In terms of smoother reduction to a negative electrode and being more advantageous in SEI film formation, the compound represented by Chemical Formula 1 above may include at least one selected from the group consisting, in particular, of Petition 870250086687, dated 09 / 25 / 2025, page 35 / 67 28 / 50 compounds represented by Chemical Formula 1-1 to Chemical Formula 1-4 below, and Chemical Formula 1-6 and Chemical Formula 1-8 below, more particularly, may include at least one selected from the group consisting of the compounds represented by Chemical Formula 1-1 and Chemical Formula 1-2 below, and even more particularly may include the compound represented by Chemical Formula 1-1 below. [Chemical Formula 1-1] [Chemical Formula 1-2] Petition 870250086687, dated 09 / 25 / 2025, pp. 36 / 67 29 / 50 [Chemical Formula 1-5] [Chemical Formula 1-6] [Chemical Formula 1-8] [Chemical Formula 1-9]

[0101] The compound represented by Chemical Formula 1 above can be included in an amount of 0.01% by weight to 10% by weight, particularly 0.05% by weight to 5% by weight, more particularly 0.1% by weight to 1% by weight, and more particularly 0.3% by weight to 0.7% by weight in the non-aqueous electrolyte. With the amount of the compound represented by Chemical Formula 1 above, the effect of Petition 870250086687, dated 09 / 25 / 2025, pp. 37 / 67 30 / 50 capture of reactive oxygen, generated during the initial formation described earlier, can be sufficiently displayed, and the risk of increased resistance with excessive amounts added can be avoided. 3) Compound Represented by Chemical Formula 2

[0102] The non-aqueous electrolyte according to the present invention includes a compound represented by Chemical Formula 2 below. [Chemical Formula 2]

[0103] In Chemical Formula 2 above, R2 is fluorine, a C1 to C10 alkyl group substituted with one or more fluorines, a C1 to C10 alkoxy group substituted with one or more fluorines, or a C6 to C20 aryloxy group substituted with one or more fluorines, and R3 and R4 are each independently hydrogen, a C1 to C10 alkyl group, or a C6 to C20 aryl group.

[0104] The compound represented by Chemical Formula 2 above is a sulfonamide-based compound including a fluorine-containing substituent, which can significantly improve the oxidation stability of a solvent when included in the non-aqueous electrolyte. In particular, since the compound represented by Chemical Formula 2 above improves the oxidation stability of the solvent during charging and discharging processes, rather than the initial formation process, a side reaction of the electrolyte is avoided, and the resulting gas generation is significantly reduced. Therefore, the non-aqueous electrolyte according to the present invention can suppress gas generation to a significant level during battery operation, as well as the initial formation process, improving Petition 870250086687, dated 09 / 25 / 2025, pp. 38 / 67 31 / 50 significantly improves the high-temperature storage characteristics, high-temperature shelf life characteristics, and endurance characteristics of a secondary lithium battery, including perlithium- and manganese-rich oxide. Since the compound represented by Chemical Formula 2 above has minimal oxygen trapping effect during initial formation, the generation of reactive oxygen, which is the problem in initial formation, cannot be avoided, so the desired effect of the present invention may not be achieved without the use of the compound represented by Chemical Formula 1 in combination with the compound represented by Chemical Formula 2.

[0105] Furthermore, the compound represented by Chemical Formula 2 above may contain fluorine and therefore may provide an inorganic-type film, such as LiF, to an electrode after decomposition. Once the inorganic-type film is combined with a polymer-type film derived from the compound represented by Chemical Formula 1 above, a film with enhanced flexibility, restorability, and durability can be formed on the electrode, further improving high-temperature service life characteristics and high-temperature storage characteristics.

[0106] R2 may be fluorine, a C1 to C10 alkyl group substituted with one or more fluorines, a C1 to C10 alkoxy group substituted with one or more fluorines, or a C6 to C20 aryloxy group substituted with one or more fluorines, particularly fluorine or a C1 to C10 alkoxy group substituted with one or more fluorines, more particularly fluorine or a C1 to C5 alkoxy group substituted with one or more fluorines, even more particularly fluorine, CF3O-, CF3CF2O- or CF3CH2O-, and even more particularly fluorine or CF3CH2O-.

[0107] R3 and R4 can each independently be hydrogen, a C1 to C10 alkyl group, or a C6 to C20 aryl group, particularly hydrogen or a C1 to C5 alkyl group, more particularly a C1 to C5 alkyl group, and further Petition 870250086687, dated 09 / 25 / 2025, p. 39 / 67 32 / 50 specifically, a methyl group.

[0108] In particular, the compound represented by Chemical Formula 2 above may include at least one selected from the group consisting of compounds represented by Chemical Formula 2-1 through Chemical Formula 2-5 below. More particularly, the compound represented by Chemical Formula 2 above may include at least one selected from the compounds represented by Chemical Formula 2-1 through Chemical Formula 2-3 below. Still more particularly, the compound represented by Chemical Formula 2 above may include at least one selected from the group consisting of the compounds represented by Chemical Formula 2-1 and Chemical Formula 2-2 below. [Chemical Formula 2-1] [Chemical Formula 2-2] THE THE [Chemical Formula 2-3] íí / CH3 O—S—N f3czIIxch3 Petition 870250086687, dated 09 / 25 / 2025, pp. 40 / 67 33 / 50 [Chemical Formula 2-4] [Chemical Formula 2-5]

[0109] The compound represented by Chemical Formula 2 above can be included in an amount of 5% by weight to 40% by weight, particularly 8% by weight to 30% by weight, more particularly 10% by weight to 25% by weight, and even more particularly 15% by weight to 22% by weight in the non-aqueous electrolyte. In a case where the compound represented by Chemical Formula 2 above is included in the amount that falls within the above range, the oxidation stability of the solvent can be sufficiently improved, and the problem of decreased electrode impregnation due to increased viscosity of the non-aqueous electrolyte caused by excessive addition, the problem of decreased solubility of the non-aqueous electrolyte component, such as an additive, and the like can be avoided.

[0110] Meanwhile, when the amount of the compound represented by Chemical Formula 2 above in the non-aqueous electrolyte is expressed as a percentage by volume, the compound represented by Chemical Formula 2 can be included in an amount of 5% by volume to 40% by volume, and particularly 12% by volume. Petition 870250086687, dated 09 / 25 / 2025, page 41 / 67 34 / 50 volume at 25% by volume in non-aqueous electrolyte.

[0111] The weight ratio of the compound represented by Chemical Formula 1 above and the compound represented by Chemical Formula 2 above can be from 0.01:99.99 to 50:50, particularly from 0.1:99.9 to 40:60, more particularly from 0.2:99.8 to 30:70, even more particularly from 0.5:99.5 to 10:90, even more particularly from 0.5:99.5 to 7:93, and most particularly from 2:98 to 4:96. When the ratio is within the above ranges, an excellent gas reduction effect can be exhibited overall during the initial battery formation and operation processes described above. 4) Organic Solvent

[0112] The non-aqueous electrolyte may also include an organic solvent along with the components described above.

[0113] Organic solvent is a non-aqueous solvent commonly used for a secondary lithium battery and is not particularly limited, provided that decomposition caused by oxidation reaction etc. can be minimized during the charging and discharging processes of a secondary battery.

[0114] The organic solvent may be included in the non-aqueous electrolyte as a residue, excluding the lithium salt, the compound represented by Chemical Formula 1, the compound represented by Chemical Formula 2, a selectively included additive, etc.

[0115] In particular, the organic solvent may include at least one selected from the group consisting of a cyclic carbonate-based organic solvent, a linear carbonate-based organic solvent, a linear ester-based organic solvent and a cyclic ester-based organic solvent.

[0116] In particular, the organic solvent may include a cyclic carbonate-based organic solvent, a linear carbonate-based organic solvent, or a mixture thereof. Petition 870250086687, dated 09 / 25 / 2025, pp. 42 / 67 35 / 50

[0117] The cyclic carbonate-based organic solvent may be an organic solvent having high viscosity, which has a high dielectric constant and is therefore able to dissociate well a lithium salt in the electrolyte, and may include at least one organic solvent selected from the group consisting of, in particular, ethylene carbonate (EC), fluoroethylene carbonate (FEC), propylene carbonate (PC), 1,2-butylene carbonate, 2,3-butylene carbonate, 1,2-pentylene carbonate, 2,3-pentylene carbonate and vinylidene carbonate, more particularly, it may include at least one selected from the group consisting of ethylene carbonate (EC) and fluoroethylene carbonate (FEC), and even more particularly, it may include ethylene carbonate (EC).

[0118] In addition, the linear carbonate-based organic solvent may be an organic solvent having low viscosity and low dielectric constant, and may include at least one selected from the group consisting of, in particular, dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate, ethylmethyl carbonate (EMC), methylpropyl carbonate and ethylpropyl carbonate, more particularly, it may include at least one selected from the group consisting of ethylmethyl carbonate (EMC) and diethyl carbonate (DEC), and even more particularly, it may include ethylmethyl carbonate (EMC) and diethyl carbonate (DEC). In a case where the linear carbonate-based organic solvent includes ethyl methyl carbonate (EMC) and diethyl carbonate (DEC), the ethyl methyl carbonate (EMC) and diethyl carbonate (DEC) may have a weight ratio of 50:50 to 99:1, particularly 75:25 to 95:5, and more particularly 80:20 to 90:10.

[0119] In particular, the organic solvent may include cyclic carbonate-based organic solvent and linear carbonate-based organic solvent.

[0120] When the organic solvent includes both a cyclic carbonate-based organic solvent and a linear carbonate-based organic solvent, the compound represented by Chemical Formula 2 above and the organic solvent may have a Petition 870250086687, dated 09 / 25 / 2025, pp. 43 / 67 36 / 50 weight ratio of 5:95 to 45:55, particularly 10:90 to 35:65, and more particularly 15:85 to 25:75. When the ratio is within the above range, the effect of improving the oxidation stability of the solvent can be further enhanced.

[0121] When the organic solvent includes both cyclic carbonate-based organic solvent and linear carbonate-based organic solvent, the cyclic carbonate-based organic solvent and the linear carbonate-based organic solvent may have a weight ratio of 10:90 to 50:50, and particularly of 20:80 to 40:60.

[0122] The linear ester-based organic solvent may include at least one selected from the group consisting of, in particular, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate and butyl propionate.

[0123] In addition, the cyclic ester-based organic solvent may include at least one selected from the group consisting of, in particular, γ-butyrolactone, γ-valerolactone, γ-caprolactone, σ-valerolactone and ε-caprolactone.

[0124] Meanwhile, like the organic solvent, any organic solvent commonly used for the non-aqueous electrolyte may be added and used as needed, without limitation. For example, at least one organic solvent among an ether-based organic solvent, a glime-based solvent, and a nitrile-based organic solvent may also be included additionally.

[0125] As the ether-based solvent, at least one selected from the group consisting of dimethyl ether, diethyl ether, dipropyl ether, methyl ethyl ether, methylpropyl ether, ethylpropyl ether, 1,3-dioxolane (DOL) and 2,2-bis(trifluoromethyl)-1,3-dioxolane (TFDOL), or a mixture of two or more thereof may be used, but an embodiment of the present invention is not limited thereto.

[0126] The glime-based solvent may have a higher dielectric constant and lower surface tension, as well as fewer reactions with metal than the linear carbonate-based organic solvent, and may include at least one selected from Petition 870250086687, dated 09 / 25 / 2025, pp. 44 / 67 37 / 50 group consisting of dimethoxyethane (glima, DME), dietoxyethane, diglima, triglima and tetraglima (TEGDME), but an embodiment of the present invention is not limited to this.

[0127] The nitrile-based solvent may be at least one selected from the group consisting of acetonitrile, propionitrile, butyronitrile, valeronitrile, caprylonitrile, heptanonitrile, cyclopentane carbonitrile, cyclohexane carbonitrile, 2-fluorobenzonitrile, 4-fluorobenzonitrile, difluorobenzonitrile, trifluorobenzonitrile, phenylacetonitrile, 2-fluorophenylacetonitrile and 4-fluorophenylacetonitrile, but an embodiment of the present invention is not limited thereto. 5) Additive

[0128] The non-aqueous electrolyte may also include an additive, along with the components described above.

[0129] In particular, the additive may be at least one selected from the group consisting of vinylene carbonate, vinylethylene carbonate, fluoroethylene carbonate, propanesulfone, propenesulfone, succinonitrile, adiponitrile, ethylene sulfate, lithium difluorooxalatoborate (LiODFB), lithium bis-(oxalato)borate (LiBOB), 3-trimethoxysilanylpropyl-N-aniline (TMSPa) and tris(trimethylsilyl)phosphite (TMSPi).

[0130] The additive may be included in an amount of 0.1% by weight to 15% by weight in the non-aqueous electrolyte.

[0131] An external form of the secondary lithium battery of the present invention is not particularly limited, but may include a cylindrical type using a can, a prismatic type, a pouch type, a coin type or the like.

[0132] The present invention is described in more detail herein by means of particular examples. However, the following examples are intended only to aid understanding of the present invention, and the scope of the present invention is not limited to them. It is obvious to those skilled in the art that various alterations and modifications are possible within the scope and technical spirit of the present description. Petition 870250086687, dated 09 / 25 / 2025, pp. 45 / 67 38 / 50 and it is natural that such alterations and modifications fall within the scope of the attached claims. EXAMPLE AND COMPARATIVE EXAMPLE Example 1 (Preparation of Non-Aqueous Electrolyte)

[0133] The compound represented by Chemical Formula 1-2 above, the compound represented by Chemical Formula 2-1 above, LiPF6 as a lithium salt, ethylene carbonate (EC), ethyl methyl carbonate (EMC) and diethyl carbonate (DEC) were mixed in a weight ratio of 0.5:18.5:14.0:20.0:39.5:7.5 to prepare a non-aqueous electrolyte. (Preparation of Secondary Lithium Battery)

[0134] A positive electrode active material (Li1.35[Ni0.360Co0.005Mn0.635]O2, perlithium-rich manganese oxide): a conductive material (carbon nanotube): a binder (polyvinylidene fluoride) were added in a weight ratio of 96.0:1.5:2.5 to an N-methyl-2-pyrrolidone (NMP) solvent to prepare a positive electrode composite fluid paste (65% by weight solid content). The positive electrode composite fluid paste was applied to one side of a positive electrode current collector (Al thin film) having a thickness of 12 μm, and dried and roller-pressed to prepare a positive electrode.

[0135] A negative electrode active material (a mixture of artificial graphite and natural graphite in a weight ratio of 50.3:49.7): a conductive material (carbon black): a binder (a styrene-butadiene rubber) were added in a weight ratio of 96.7:1.0:2.3 to a solvent of distilled water to prepare a fluid negative electrode composite paste (50% by weight solid content). The fluid negative electrode composite paste was applied to one side of a negative electrode current collector (thin Cu film) having a thickness of 8 μm, and dried and roller-pressed to prepare a negative electrode. Petition 870250086687, dated 09 / 25 / 2025, pp. 46 / 67 39 / 50

[0136] A porous polyethylene film separator was placed between the prepared positive electrode and the negative electrode in a dry room, and then the prepared non-aqueous electrolyte was injected to prepare a secondary battery. Example 2

[0137] A secondary lithium battery was prepared by the same method as Example 1, except that the compound represented by Chemical Formula 1-2 above, the compound represented by Chemical Formula 2-1 above, LiPFe as a lithium salt, ethylene carbonate (EC), ethyl methyl carbonate (EMC) and diethyl carbonate (DEC) were mixed in a weight ratio of 1.0:18.5:14.0:20.0:39.0:7.5 to prepare a non-aqueous electrolyte. Example 3

[0138] A secondary lithium battery was prepared by the same method as Example 1, except that the compound represented by Chemical Formula 1-2 above, the compound represented by Chemical Formula 2-1 above, LiPFe as a lithium salt, ethylene carbonate (EC), ethyl methyl carbonate (EMC) and diethyl carbonate (DEC) were mixed in a weight ratio of 0.1:18.5:14.0:20.0:39.7:7.7 to prepare a non-aqueous electrolyte. Example 4

[0139] A secondary lithium battery was prepared by the same method as Example 1, except that the compound represented by Chemical Formula 1-2 above, the compound represented by Chemical Formula 2-1 above, LiPFe as a lithium salt, ethylene carbonate (EC), ethyl methyl carbonate (EMC) and diethyl carbonate (DEC) were mixed in a weight ratio of 0.5:27.0:14.0:20.0:31.0:7.5 to prepare a non-aqueous electrolyte. Example 5

[0140] A secondary lithium battery was prepared by the same method as Example 1, except that the compound represented by Chemical Formula 1-2 above, the Petition 870250086687, dated 09 / 25 / 2025, pp. 47 / 67 40 / 50 compound represented by Chemical Formula 2-1 above, LiPF6 as a lithium salt, ethylene carbonate (EC), ethyl methyl carbonate (EMC) and diethyl carbonate (DEC) were mixed in a weight ratio of 0.5:9.4:14.2:20.6:47.7:7.6 to prepare a non-aqueous electrolyte. Example 6

[0141] A secondary lithium battery was prepared by the same method as Example 1, except that the compound represented by Chemical Formula 1-1 above, the compound represented by Chemical Formula 2-1 above, LiPF6 as a lithium salt, ethylene carbonate (EC), ethyl methyl carbonate (EMC) and diethyl carbonate (DEC) were mixed in a weight ratio of 0.5:18.5:14.0:20.0:39.5:7.5 to prepare a non-aqueous electrolyte. Example 7

[0142] A secondary lithium battery was prepared by the same method as Example 1, except that the compound represented by Chemical Formula 1-2 above, the compound represented by Chemical Formula 2-2 above, LiPF6 as a lithium salt, ethylene carbonate (EC), ethyl methyl carbonate (EMC) and diethyl carbonate (DEC) were mixed in a weight ratio of 0.5:18.5:14.0:20.0:39.5:7.5 to prepare a non-aqueous electrolyte. Example 8

[0143] A secondary lithium battery was prepared by the same method as Example 1, except that the compound represented by Chemical Formula 1-3 above, the compound represented by Chemical Formula 2-1 above, LiPF6 as a lithium salt, ethylene carbonate (EC), ethyl methyl carbonate (EMC) and diethyl carbonate (DEC) were mixed in a weight ratio of 0.5:18.5:14.0:20.0:39.5:7.5 to prepare a non-aqueous electrolyte. Example 9

[0144] A secondary lithium battery was prepared using the same method as Petition 870250086687, dated 09 / 25 / 2025, pp. 48 / 67 41 / 50 Example 1, except that the compound represented by Chemical Formula 1-4 above, the compound represented by Chemical Formula 2-1 above, LiPF6 as a lithium salt, ethylene carbonate (EC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC) were mixed in a weight ratio of 0.5:18.5:14.0:20.0:39.5:7.5 to prepare a non-aqueous electrolyte. Example 10

[0145] A secondary lithium battery was prepared by the same method as Example 1, except that the compound represented by Chemical Formula 1-6 above, the compound represented by Chemical Formula 2-1 above, LiPF6 as a lithium salt, ethylene carbonate (EC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC) were mixed in a weight ratio of 0.5:18.5:14.0:20.0:39.5:7.5 to prepare a non-aqueous electrolyte. Example 11

[0146] A secondary lithium battery was prepared by the same method as Example 1, except that the compound represented by Chemical Formula 1-8 above, the compound represented by Chemical Formula 2-1 above, LiPF6 as a lithium salt, ethylene carbonate (EC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC) were mixed in a weight ratio of 0.5:18.5:14.0:20.0:39.5:7.5 to prepare a non-aqueous electrolyte. Comparative Example 1

[0147] A secondary lithium battery was prepared by the same method as Example 1, except that LiPF6 as a lithium salt, ethylene carbonate (EC), ethyl methyl carbonate (EMC) and diethyl carbonate (DEC) were mixed in a weight ratio of 14.5:21.0:56.8:7.7 to prepare a non-aqueous electrolyte. Comparative Example 2

[0148] A secondary lithium battery was prepared using the same method as Example 1, except that the compound represented by Chemical Formula 1-2 above, Petition 870250086687, dated 09 / 25 / 2025, pp. 49 / 67 42 / 50 LiPF6 as a lithium salt, ethylene carbonate (EC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC) were mixed in a weight ratio of 0.5:14.5:20.9:56.4:7.7 to prepare a non-aqueous electrolyte. Comparative Example 3

[0149] A secondary lithium battery was prepared by the same method as Example 1, except that the compound represented by Chemical Formula 2-1 above, LiPF6 as a lithium salt, ethylene carbonate (EC), ethyl methyl carbonate (EMC) and diethyl carbonate (DEC) were mixed in a weight ratio of 18.6:14.1:20.4:39.4:7.5 to prepare a non-aqueous electrolyte. Experimental Example 1: Evaluation of Load and Discharge Cycle Performance at High Temperature

[0150] 150 charge and discharge cycles were performed, where 1 cycle refers to charging under DC / CV conditions and 0.33 C at 45 °C at 4.35 V and 1 / 20 C, and then to discharging under DC conditions and 0.33 C at 2.5 V, on lithium secondary batteries prepared according to Examples 1 to 11 and Comparative Examples 1 to 3 above, using an electrochemical charge and discharge instrument, and the rate of capacity retention, the rate of resistance increase, the amount of gas generation and the amount of metal elution were evaluated. Experimental Example 1-1: Evaluation of Capacity Retention Rate

[0151] Loading and unloading were carried out under the above conditions, then the capacity retention rate was calculated using the equation below, and the results were listed in Table 1 below. Capacity retention rate (%) = {(discharge capacity after 150 cycles / discharge capacity after 1 cycle)} x 100 Experimental Example 1-2: Evaluation of the Rate of Resistance Increase

[0152] After 1 charge and discharge cycle, using the electrochemical charge and discharge instrument, the discharge capacity after the 1st cycle was measured, SOC was Petition 870250086687, dated 09 / 25 / 2025, pages 50 / 67 43 / 50 adjusted for SOC 50%, and then a 2.5 C pulse was applied for 10 seconds to calculate the initial resistance from the difference between a voltage before the pulse application and a voltage after the pulse application.

[0153] After 150 charge and discharge cycles, the resistance after the 150 cycles was calculated using the same method as above and, using the equation below, the rate of increase in resistance was calculated, and the results were listed in Table 1 below.

[0154] Rate of increase in resistance (%) = (resistance after 150 cycles - initial resistance) / initial resistance x 100 Experimental Example 1-3: Evaluation of Gas Generation Quantity

[0155] After loading and unloading under the above conditions, using gas chromatography-mass spectrometry (GC-MS), the amount of gas generation was measured. The results are listed in Table 1 below. Experimental Example 1-4: Evaluation of the Amount of Metal Elution

[0156] After loading and unloading under the above conditions, using an inductively coupled plasma optical emission spectrometer (ICP-OES), the concentration of all the metal eluted in an electrolytic solution was measured. The amount of metal measured using ICP analysis is listed in Table 1 below. [Table 1] Experimental Example 1-1 Experimental Example 1-2 Experimental Example 1-3 Experimental Example 1-4 Capacity Retention Rate (%) Resistance Increase Rate (%) Gas Generation Amount (pl) Metal Elution Amount (ppm) Example 1 95.3 14.7 4200 230 Example 2 94.1 16.8 4550 250 Example 3 93.5 18.7 4600 240 Example 4 93.1 20.1 4750 260 Example 5 92.4 24.3 4950 310 Example 6 91.8 23.8 4800 275 Example 7 92.1 19.9 4900 320 Example 8 90.5 19.3 4650 295 Petition 870250086687, dated 09 / 25 / 2025, pp. 51 / 67 44 / 50 Example 9 89.2 25.3 4500 340 Example 10 91.7 24.1 6400 380 Example 11 92.1 21.3 7500 410 Comparative Example 1 68.3 35.5 20150 590 Comparative Example 2 79.9 59.7 15850 510 Comparative Example 3 83.8 48.9 14680 495

[0157] Referring to Table 1, it can be observed that the secondary lithium batteries according to Examples 1 to 11, in which perlithium- and manganese-rich oxide was used as a positive electrode active material, and all compounds represented by Chemical Formula 1 and Chemical Formula 2 were included in the non-aqueous electrolyte, exhibited excellent service life performance, resistance reduction effect, low gas generation, and low metal elution during the charge and discharge cycle, compared to those according to Comparative Examples 1 to 3 in which they were not included. Experimental Example 2: Performance Evaluation of High-Temperature Storage

[0158] Lithium secondary batteries prepared according to Examples 1 to 11 and Comparative Examples 1 to 3 above were charged under DC / CV conditions and 0.33 C at 25 °C at 4.35 V and 1 / 20 C, and discharged with 0.33 C at 2.5 V to perform initial charging and discharging, then charged under DC / CV conditions and 0.33 C at 25 °C at 4.35 V and 1 / 20 C, and then stored at 60 °C for 8 weeks. Experimental Example 2-1: Evaluation of Capacity Retention Rate

[0159] After storage, the secondary batteries were charged under DC / CV conditions and 0.33 C at 25 °C at 4.35 V and 1 / 20 C and discharged with 0.33 C at 2.5 V. According to the equation below, the capacity retention rate was evaluated and the results are listed in Table 2 below. Petition 870250086687, dated 09 / 25 / 2025, pp. 52-67 45 / 50

[0160] Capacity retention rate (%) = (Discharge capacity after 8 weeks of storage / initial discharge capacity) x 100 Experimental Example 2-2: Evaluation of the Rate of Resistance Increase

[0161] During the initial charge and discharge, the ambient temperature capacity was verified, then the secondary batteries were charged at SOC 50 based on the discharge capacity and discharged with a current of 3 C for 10 seconds, and by the difference in voltage drop at this time, the resistance was measured as an initial resistance, and the resistance was measured by the same method after storage at 60 °C for 8 weeks as a final resistance, and the rate of resistance increase was calculated from there using the equation below. The results are listed in Table 2 below. Rate of increase in resistance (%) = (final resistance - initial resistance) / (initial resistance) x 100 Experimental Example 2-3: Evaluation of Gas Generation Quantity

[0162] After storage under the above conditions, using gas chromatography-mass spectrometry (GC-MS), the amount of gas generation was measured. The results are listed in Table 2 below. Experimental Example 2-4: Evaluation of the Amount of Metal Elution

[0163] After storage under the above conditions, using an inductively coupled plasma optical emission spectrometer (ICP-OES), the concentration of all metal eluted in an electrolytic solution was measured. The amounts of metal measured using ICP analysis are listed in Table 2 below. Petition 870250086687, dated 09 / 25 / 2025, pp. 53 / 67 46 / 50 [Table 2] Experimental Example 2-1 Experimental Example 2-2 Experimental Example 2-3 Experimental Example 2-4 Capacity Retention Rate (%) Resistance Increase Rate (%) Gas Generation Amount (pl) Metal Elution Amount (ppm) Example 1 94.2 19.8 3800 295 Example 2 93.8 24.8 4100 325 Example 3 93.2 23.3 4250 330 Example 4 92.4 22.8 4380 320 Example 5 92.8 24.1 4870 340 Example 6 91.8 25.8 4950 365 Example 7 89.9 26.9 5870 384 Example 8 92.3 24.1 4750 350 Example 9 91.5 Example 10: 28.3 5500 370 Example 11: 91.1 31.1 6350 410 Example 11: 88.3 24.8 5900 425 Example 1: 43.8 45.8 8750 485 Example 2: 58.6 39.7 6700 585 Example 3: 61.8 41.8 6900 655

[0164] Referring to Table 2, it can be observed that the secondary lithium batteries according to Examples 1 to 11, in which perlithium- and manganese-rich oxide was used as a positive electrode active material, and all compounds represented by Chemical Formula 1 and Chemical Formula 2 were included in the non-aqueous electrolyte, exhibited excellent service life performance, resistance reduction effect, low gas generation, and low metal elution during high-temperature storage, compared to those according to Comparative Examples 1 to 3 in which they were not included. EXAMPLE OF REFERENCE Reference Example 1 (Preparation of Non-Aqueous Electrolyte) Petition 870250086687, dated 09 / 25 / 2025, pp. 54 / 67 47 / 50

[0165] A non-aqueous electrolyte was prepared using the same method as in Example 1. (Preparation of Secondary Lithium Battery)

[0166] A positive electrode active material (Li[Ni0.6Co0.1Mn0.3]O2): a conductive material (carbon nanotube): a binder (polyvinylidene fluoride) were added in a weight ratio of 96.7:1.2:2.3 to an N-methyl-2-pyrrolidone (NMP) solvent to prepare a positive electrode composite fluid paste (65% by weight solid content). The positive electrode composite fluid paste was applied to one side of a positive electrode current collector (Al thin film) having a thickness of 12 μm, and dried and roller-pressed to prepare a positive electrode.

[0167] A negative electrode active material (a mixture of artificial graphite and natural graphite in a weight ratio of 50.3:49.7): a conductive material (carbon black): a binder (a styrene-butadiene rubber) were added in a weight ratio of 96.7:1.0:2.3 to a distilled water solvent to prepare a fluid negative electrode composite paste (50% by weight solid content). The fluid negative electrode composite paste was applied to one side of a negative electrode current collector (thin Cu film) having a thickness of 8 μm, and dried and roller-pressed to prepare a negative electrode.

[0168] A porous polyethylene film separator was placed between the prepared positive electrode and the negative electrode in a dry room, and then the prepared non-aqueous electrolyte was injected to prepare a secondary battery. Example of Reference 2

[0169] A secondary lithium battery was prepared using the same method as in Reference Example 1, except that the non-aqueous electrolyte prepared using the same method as in Comparative Example 2 was used. Example of Reference 3 Petition 870250086687, dated 09 / 25 / 2025, pages 55 / 67 48 / 50

[0170] A secondary lithium battery was prepared using the same method as Reference Example 1, except that the non-aqueous electrolyte prepared using the same method as Comparative Example 3 was used. Reference Experimental Example 1: Evaluation of High-Temperature Cycle Load and Discharge Performance

[0171] 150 charge and discharge cycles were performed, where 1 cycle refers to charging under DC / CV conditions and 0.33 C at 45 °C at 4.35 V and 1 / 20 C, and then to discharging under DC conditions and 0.33 C at 2.5 V, on lithium secondary batteries prepared according to Reference Examples 1 to 3 above, using an electrochemical charge and discharge instrument, and the capacity retention rate, resistance increase rate, amount of gas generation and amount of metal elution were evaluated as below. Reference Experimental Example 1-1: Evaluation of Capacity Retention Rate

[0172] Loading and unloading were carried out under the above conditions, then capacity retention rates were calculated using the equation below, and the results were listed in Table 3 below. Capacity retention rate (%) = {(discharge capacity after 150 cycles / discharge capacity after 1 cycle)} x 100 Reference Experimental Example 1-2: Evaluation of the Rate of Resistance Increase

[0173] After 1 charge and discharge cycle, using the electrochemical charge and discharge instrument, the discharge capacitance after the 1st cycle was measured, SOC was adjusted to SOC 50% and then a 2.5 C pulse was applied for 10 seconds to calculate the initial resistance by a difference between a voltage before the pulse application and a voltage after the pulse application.

[0174] After 150 charge and discharge cycles, the resistance after the 150 cycles Petition 870250086687, dated 09 / 25 / 2025, pages 56 / 67 49 / 50 was calculated using the same method as above, and using the equation below, the rate of increase in resistance was calculated, and the results are listed in Table 3 below.

[0175] Rate of increase in resistance (%) = (resistance after 150 cycles - initial resistance) / initial resistance x 100 Reference Experimental Example 2: High-Temperature Storage Performance Evaluation

[0176] Lithium secondary batteries prepared according to Reference Examples 1 to 3 above were charged under DC / CV conditions and 0.33 C at 25 °C at 4.35 V and 1 / 20 C, and discharged with 0.33 C at 2.5 V to perform initial charging and discharging, then charged under DC / CV conditions and 0.33 C at 25 °C at 4.35 V and 1 / 20 C, and then stored at 60 °C for 8 weeks. Experimental Example 2-1: Evaluation of Capacity Retention Rate

[0177] After storage, the secondary batteries were charged under DC / CV conditions and 0.33 C at 25 °C at 4.35 V and 1 / 20 C, and discharged with 0.33 C at 2.5 V. According to the equation below, the capacity retention rate was evaluated and the results are listed in Table 3 below. Capacity retention rate (%) = (discharge capacity after 8 weeks of storage / initial discharge capacity) x 100 Experimental Example 2-2: Evaluation of the Rate of Resistance Increase

[0178] During the initial charging and discharging, the capacities at room temperature were verified, then the secondary batteries were charged at SOC 50 based on the discharge capacity and discharged with a current of 3 C for 10 seconds, and by the difference in voltage drop at this moment, the resistance was measured as an initial resistance, and the resistance was measured by the same method after storage at 60 °C for 8 weeks as a final resistance, and the rate of resistance increase was calculated from there using the equation below. The Petition 870250086687, dated 09 / 25 / 2025, pages 57 / 67 50 / 50 results were listed in Table 3 below. Rate of increase in resistance (%) = (final resistance - initial resistance) / (initial resistance) x 100 [Table 3 Experimental Reference Example 1 Experimental Reference Example 2 1-1 1-2 2-1 2-2 Capacity retention rate (%) Resistance increase rate (%) Capacity retention rate (%) Resistance increase rate (%) Reference Example 1 89.8 41.8 82.3 38.7 Reference Example 2 93.7 28.4 92.8 26.8 Reference Example 3 92.8 26.1 93.8 24.3]

[0179] Referring to Table 3, it can be observed that the secondary lithium battery according to Reference Example 1, in which the non-aqueous electrolyte including the compounds represented by Chemical Formula 1 and Chemical Formula 2 according to the present invention was applied to a positive electrode active material other than the perlithium- and manganese-rich oxide, had significantly reduced performance in the charge and discharge cycle and high-temperature storage, compared to those according to Reference Examples 2 and 3, in which either the compound represented by Chemical Formula 1 or the compound represented by Chemical Formula 2 was included only in the non-aqueous electrolyte. This result appears to occur because the positive electrode active materials used in Reference Examples 1 to 3 were less affected by reactive oxygen deintercalation, and the increase in resistance due to the two compounds above being used in combination was a greater problem. Petition 870250086687, dated 09 / 25 / 2025, pp. 58 / 67

Claims

1 / 7 CLAIMS 1. A secondary lithium battery, CHARACTERIZED in that it comprises: a positive electrode; a negative electrode; a separator disposed between the positive and negative electrodes; and a non-aqueous electrolyte, wherein the positive electrode includes a positive electrode active material, the positive electrode material includes a pearly-manganese-rich oxide containing about 50 mol% or more of Mn based on all metallic elements except lithium, and having a lithium to transition metal molar ratio greater than about 1, and the non-aqueous electrolyte includes a lithium salt, a compound represented by Chemical Formula 1 below and a compound represented by Chemical Formula 2 below: [Chemical Formula 1] wherein, in Chemical Formula 1 above, Ri is a halogen, a nitrile group, a propargyl group, an ester group, an ether group, a ketone group, a carboxyl group, a substituted or unsubstituted alkyl group,a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted alkoxy group, a boron group, a borate group, an isocyanate group, an isothiocyanate group, a silyl group, a siloxane group, a group Petition 870250086687, dated 09 / 25 / 2025, p. 59 / 67 2 / 7 sulfone, a sulfonate group, a sulfate group, or a combination of two or more of them, en is an integer from 0 to 6, and [Chemical Formula 2] where, in Chemical Formula 2 above, R2 is fluorine, a C1 to C10 alkyl group substituted with one or more fluorines, a C1 to C10 alkoxy group substituted with one or more fluorines, or a C6 to C20 aryloxy group substituted with one or more fluorines, and R3 and R4 are each independently hydrogen, a C1 to C10 alkyl group, or a C6 to C20 aryl group.

2. Lithium secondary battery, according to claim 1, CHARACTERIZED in that the perlithium- and manganese-rich oxide comprises a compound represented by Chemical Formula A below: [Chemical Formula A] Lii+s[NitCouMnvM1 w]O2+z wherein, in Chemical Formula A above, M1 is one or more selected from W, Cu, Fe, V, Cr, Ti, Zr, Zn, Al, In, Ta, Y, La, Sr, Ga, Sc, Gd, Sm, Ca, Ce, Nb, Mg, B and Mo, and 0.05 <s<1,0<t<0,5, 0<u<0,3, 0,5<v<1,0, 0<w<0,2 e 0<z<1.

3. Lithium secondary battery, according to claim 1, CHARACTERIZED in that the compound represented by Chemical Formula 1 comprises at least one selected from the group consisting of a compound represented by Chemical Formula 1-A below and a compound represented by Chemical Formula 1-B below: Petition 870250086687, dated 09 / 25 / 2025, page 60 / 67 3 / 7 [Chemical Formula 1-A] [Chemical Formula 1-B] wherein, in Chemical Formula 1-A and Chemical Formula 1-B above, Ri is as defined by Chemical Formula 1.

4. Secondary lithium battery, according to claim 1, CHARACTERIZED in that the compound represented by Chemical Formula 1 comprises at least one selected from the group consisting of compounds represented by Chemical Formula 1-1 to Chemical Formula 1-9 below: [Chemical Formula 1-1] Petition 870250086687, dated 09 / 25 / 2025, p. 61 / 67 4 / 7 O [Chemical Formula 1-5] [Chemical Formula 1-6] Petition 870250086687, dated 09 / 25 / 2025, p. 62 / 67 5 / 7 [Chemical Formula 1-8] [Chemical Formula 1-9] 5. Secondary lithium battery, according to claim 1, CHARACTERIZED in that the compound represented by Chemical Formula 1 is included in an amount of 0.01% by weight to 10% by weight based on a weight of non-aqueous electrolyte.

6. Secondary lithium battery, according to claim 1, CHARACTERIZED in that the compound represented by Chemical Formula 2 comprises at least one selected from the group consisting of compounds represented by Chemical Formula 2-1 to Chemical Formula 2-5 below: [Chemical Formula 2-1] [Chemical Formula 2-2] OS—NI Petition 870250086687, dated 09 / 25 / 2025, page 63 / 67 6 / 7 [Chemical Formula 2-3] π / CHa O—S—N f3c xch3 [Chemical Formula 2-4] [Chemical Formula 2-5] 7. Lithium secondary battery, according to claim 1, CHARACTERIZED in that the compound represented by Chemical Formula 2 is included in an amount of 5% by weight to 40% by weight in the non-aqueous electrolyte.

8. Lithium secondary battery, according to claim 1, CHARACTERIZED in that the weight ratio of the compound represented by Chemical Formula 1 and the compound represented by Chemical Formula 2 is from 0.01:99.1 to 50:

50.

9. Lithium secondary battery, according to claim 1, CHARACTERIZED in that the lithium salt comprises at least one selected from the group consisting of LiCl, LiBr, Lil, LiBF4, LiClO4, LiAlO4, LiAlCl4, LiPF6, LiSbF6, LiAsF6, LiBioCIio, LiB(C2O4)2 (LiBOB), UCF3SO3, LiN(SO2F)2 (LiFSI), UCH3SO3, LiCF3CO2, LiCH3CO2, and LiN(SÜ2CF2CF3)2 (LiBETI).

10. Lithium secondary battery, according to claim 1, CHARACTERIZED in that the non-aqueous electrolyte comprises an organic solvent, and the organic solvent comprises at least one selected from the group consisting of a cyclic carbonate-based organic solvent, a linear carbonate-based organic solvent, a linear ester-based organic solvent and a cyclic ester-based organic solvent.

11. Secondary lithium battery, according to claim 1, CHARACTERIZED in that the non-aqueous electrolyte further comprises at least one additive selected from the group consisting of vinylene carbonate, vinylethylene carbonate, fluoroethylene carbonate, propanesulfone, propenesulfone, succinonitrile, adiponitrile, ethylene sulfate, lithium bis-(oxalato)borate (LiBOB), lithium difluorooxalatoborate (LiODFB), tris(trimethylsilyl)phosphate (TMSPa) and tris(trimethylsilyl)phosphite (TMSPi). Petition 870250086687, dated 09 / 25 / 2025, pp. 65 / 67