Lithium secondary battery

Abstract

The present invention relates to a lithium secondary battery comprising: a cathode; an anode opposite to the cathode; a separator interposed between the cathode and the anode; and a nonaqueous electrolyte, wherein the cathode includes a cathode active material, the cathode active material includes lithium nickel-based oxide particles represented by chemical formula A, the lithium nickel-based oxide particles are in a single particle form composed of one single nodule or a quasi-single particle that is a composite of 30 nodules or less, the nonaqueous electrolyte includes a lithium salt, an organic solvent and an additive, and the additive includes a cyclic borate-based compound represented by a specific chemical formula, and a compound containing a propazyl group. [Chemical formula A] LiaNibCocMndM1 eO2 In chemical formula A, M1 is at least one selected from the group consisting of Ti, Mg, Al, Zr, Y, Ba, Ca, Sr, W, Ta, Nb and Mo, 0.8≤a≤1.2, 0.5≤b<0.7, 0<c<0.2, 0<d≤0.4, 0≤e≤0.2 and b+c+d+e=1.

Description

lithium secondary battery Cross-citation with related applications This application claims the benefit of priority from Korean Patent Application No. 10-2023-0118665, dated September 6, 2023, the entire contents of which are incorporated herein by reference. Technology field The present invention relates to a lithium secondary battery. Recently, as the application areas of lithium secondary batteries have rapidly expanded to include not only power supply for electronic devices such as electric, electronic, communication, and computer devices, but also power storage for large-area devices such as automobiles and power storage devices, the demand for high-capacity, high-output, and high-stability secondary batteries is increasing. High-capacity, high-power output, and long-life characteristics are becoming increasingly important, especially for lithium secondary batteries used in automotive applications. To increase the capacity of secondary batteries, high-nickel-content cathode active materials, which offer high energy density but low stability, can be used, or the batteries can be operated at high voltages. The above lithium secondary battery is largely composed of a positive electrode made of a composite transition metal oxide containing lithium, a negative electrode capable of storing lithium, an electrolyte that serves as a medium for transferring lithium ions, and a separator. Meanwhile, in the case of the conventionally developed single particle type positive electrode active material, the particle strength is superior to that of the conventional secondary particle type positive electrode active material, so there is an advantage of excellent life characteristics due to less particle breakage, but there is a problem that the capacity characteristics are lowered compared to the case of the secondary particle type positive electrode active material because the interface between the primary particles, which serve as a passage for lithium ions to move within the particle, is small, and thus the lithium mobility is low. One way to increase capacity is to increase the operating voltage. However, when the operating voltage of NCM-based lithium composite transition metal oxides exceeds 4.3 V, especially 4.35 V, side reactions with the electrolyte become severe, and transition metal ions are released, causing a rapid decline in battery performance. In particular, due to the side reaction of the electrolyte, the film formed on the surface of the anode or cathode or the electrode surface structure deteriorates, and transition metal ions may be eluted from the surface of the anode. At this time, the eluted transition metal ions are electro-deposited on the surface of the cathode, thereby lowering the passivation ability of the SEI film (Solid Electrolyte Interface Layer) and causing a problem of reducing the electrochemical stability of the anode. This deterioration phenomenon of secondary batteries tends to be accelerated when the potential of the positive electrode increases or the battery is exposed to high temperatures, and the problem of the capacity and cycle characteristics of the secondary battery deteriorating occurs due to the deterioration phenomenon. Therefore, in order to enable stable operation at high voltage, there is a need for the development of an additive capable of forming a uniform film on the anode and / or cathode during the initial activation process to suppress the elution of metal ions from the anode. The present invention is intended to solve the above problems, and provides a lithium secondary battery having excellent high-temperature storage characteristics and high-temperature lifespan characteristics under high voltage by using lithium nickel-based oxide particles in the form of single particles or pseudo-single particles as a positive electrode active material and including a non-aqueous electrolyte additive capable of forming a uniform and highly durable film on the positive electrode surface. [1] The present invention provides a lithium secondary battery comprising: a positive electrode; a negative electrode facing the positive electrode; a separator interposed between the positive electrode and the negative electrode; and a non-aqueous electrolyte; wherein the positive electrode comprises a positive electrode active material, and the positive electrode active material comprises lithium nickel-based oxide particles represented by the following chemical formula A, wherein the lithium nickel-based oxide particles are in the form of single particles consisting of one single nodule or quasi-single particles that are complexes of 30 or fewer nodules, and the non-aqueous electrolyte comprises a lithium salt, an organic solvent, and an additive, and the additive comprises a cyclic borate-based compound represented by the following chemical formula 1; and a compound containing a propargyl group. [Chemical Formula A] Li a Ni b Co c Mn d M 1 e O2 In the above chemical formula A, M 1 is at least one selected from the group consisting of Ti, Mg, Al, Zr, Y, Ba, Ca, Sr, W, Ta, Nb, and Mo, and 0.8≤a≤1.2, 0.5≤b≤0.7, 0 <c<0.2, 0<d≤0.4, 0≤e≤0.2, b+c+d+e=1이고, [Chemical Formula 1] In the above chemical formula 1, R1 is an alkylene group having 1 to 10 carbon atoms, n1 and n2 are each independently an integer selected from 0 to 5, R2 and R3 are each independently hydrogen, halogen, a nitrile 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 thereof, n3 is 2n1+2, n4 is 2n2+2, and when n3 is an integer of 2 or more, a plurality of R2s may be the same or different from each other, and when n4 is an integer of 2 or more, a plurality of R3s may be the same or different from each other. [2] In the present invention, in the above [1], b / c of ​​the chemical formula A may be 3.2 to 9.0. [3] In the present invention, in the above [1] or [2], b / d of the chemical formula A may be 1.5 to 2.8. [4] In at least one of the above [1] to [3], the chemical formula A may be represented by the following chemical formula A-1. [Chemical Formula A-1] Li a Ni b Co c Mn d M 1 e O2 In the above chemical formula A-1, M 1 is at least one selected from the group consisting of Ti, Mg, Al, Zr, Y, Ba, Ca, Sr, W, Ta, Nb, and Mo, and 0.8≤a≤1.2, 0.55≤b≤0.65, 0 <c≤0.15, 0.2<d≤0.4, 0≤e≤0.1, 3.2≤b / c≤9.0, 1.5≤b / d≤2.8, b+c+d+e=1이다. [5] In at least one of the above [1] to [4], the compound represented by the chemical formula 1 may be a compound represented by the following chemical formula 1-1. [Chemical Formula 1-1] In the above [Chemical Formula 1-1], R2 and R3 are each independently as defined in the above [Chemical Formula 1], n3 is 6, and n4 is 6. [6] In at least one of the above [1] to [5], the compound represented by the chemical formula 1 may be a compound represented by the following chemical formula 1-2. [Chemical Formula 1-2] [7] In at least one of the above [1] to [6], the compound containing the propargyl group may include at least one selected from the group consisting of the following chemical formulas 2 and 3. [Chemical Formula 2] In the above chemical formula 2, R6 is an alkylene group having 1 to 3 carbon atoms that can be substituted with fluorine, R7 to R9 are each independently hydrogen, an alkyl group having 1 to 3 carbon atoms, and a nitrile group, or a combination of two or more thereof, [Chemical Formula 3] In the above chemical formula 3, R 10 is hydrogen, an alkyl group having 1 to 10 carbon atoms, and a cycloalkyl group having 3 to 8 carbon atoms, or a combination of two or more thereof, and R 11 is an alkylene group having 1 to 8 carbon atoms that can be substituted with fluorine. [8] In the present invention, in the above [7], the compound represented by the chemical formula 2 can be represented by the following chemical formula 2-1. [Chemical Formula 2-1] [9] In the present invention, in the above [7], the compound represented by the chemical formula 3 may be a compound represented by the following chemical formula 3-1. [Chemical Formula 3-1]

[0010] In at least one of the above [1] to [9], the cyclic borate compound may be included in the non-aqueous electrolyte in an amount of 0.01 wt% to 12 wt% based on the total weight of the non-aqueous electrolyte.

[0011] In at least one of the above [1] to

[0010] , the compound containing the propargyl group may be included in the non-aqueous electrolyte in an amount of 0.01 wt% to 6 wt% based on the total weight of the non-aqueous electrolyte.

[0012] In at least one of the above [1] to

[0011] , the weight ratio of the cyclic borate compound and the compound containing the propargyl group may be 1:99 to 99:1.

[0012] In at least one of the above [1] to

[0012] , the lithium secondary battery may have a charge termination voltage of 4.30 V or higher during operation. A lithium secondary battery according to the present invention is characterized by including a positive electrode including lithium nickel-based oxide particles having a specific chemical formula and a single particle or pseudo-single particle form as a positive electrode active material, and a non-aqueous electrolyte including a cyclic borate-based compound having a specific structural formula and a compound containing a propargyl group as an additive. The lithium nickel-based oxide particles are Mid-Ni NCM particles having a nickel content of 50 mol% to 70 mol% of the transition metal within the particles, and have the form of single particles or pseudo-single particles. When the operating voltage is increased to increase the capacity characteristics of the lithium nickel-based oxide particles, excessive electrolyte side reactions may occur on the surface of the positive electrode, and problems such as desorption of transition metals or reactive carbons may occur. In response to this, the present invention uses a cyclic borate compound of a specific chemical formula with excellent coverage ability and durability as a non-aqueous electrolyte additive, and uses a compound containing a propargyl group in combination to compensate for steric hindrance and reduced reactivity due to the large molecular structure of the cyclic borate compound, thereby allowing an electrode film with high coverage ability and durability to be quickly formed on the positive and negative electrodes. The electrode film formed through the above non-aqueous electrolyte additive has excellent uniformity and durability, and can prevent structural collapse of lithium nickel-based oxide particles having the above-described characteristics, so that it is possible to implement a lithium secondary battery having remarkably excellent high-temperature life performance and high-temperature storage performance, especially when driven at high voltage. Terms or words used in this specification and claims should not be interpreted as limited to their usual or dictionary meanings, but should be interpreted as meanings and concepts that conform to the technical spirit of the present invention, based on the principle that the inventor can appropriately define the concept of the term to explain his or her own invention in the best possible manner. In the present invention, a "single particle" is a particle composed of one single nodule. In the present invention, a "quasi-single particle" means a composite particle formed of 30 or fewer nodules. In the present invention, "nodule" means a particle unit body constituting a single particle and a pseudo-single particle, and the nodule may be a single crystal lacking a crystalline grain boundary, or a polycrystal having no apparent grain boundary when observed under a field of view of 5,000 to 20,000 times using a scanning electron microscope (SEM). The average particle diameter of the nodule may be measured as the arithmetic mean value of the particle diameters of each nodule measured using a scanning electron microscope (SEM). In the present invention, "secondary particle" refers to a particle formed by the agglomeration of tens to hundreds of primary particles. More specifically, the secondary particle is an agglomerate of 40 or more primary particles. The expression "particle" used in the present invention may include any one or all of single particles, quasi-single particles, primary particles, nodules, and secondary particles. In the present invention, the “specific surface area” is measured by the BET method, and specifically, can be calculated from the nitrogen gas adsorption amount at liquid nitrogen temperature (77K) using BELSORP-mini II of BEL Japan. In the present invention, "average particle diameter D 50 "It refers to the particle size at 50% of the volume cumulative particle size distribution of the cathode powder, and can be measured using the laser diffraction method. For example, after dispersing the cathode powder in a dispersion medium, it can be measured by introducing it into a commercially available laser diffraction particle size measuring device (e.g., Microtrac MT 3000), irradiating it with ultrasonic waves of about 28 kHz at an output of 60 W, obtaining a volume cumulative particle size distribution graph, and then calculating the particle size corresponding to 50% of the volume cumulative amount. In addition, in the description of "carbon atoms a to b" in the present specification, "a" and "b" refer to the number of carbon atoms included in a specific functional group. That is, the functional group may include "a" to "b" carbon atoms. For example, "an alkyl group having 1 to 5 carbon atoms" refers to an alkyl group including 1 to 5 carbon atoms, i.e., CH3-, CH3CH2-, CH3CH2CH2-, (CH3)2CH-, CH3CH2CH2CH2-, (CH3)2CHCH2-, CH3CH2CH2CH2CH2-, (CH3)2CHCH2CH2CH2-, (CH3)2CHCH2CH2CH2-, etc. Additionally, in this specification, both alkyl groups and aryl groups may be substituted or unsubstituted. The above "substitution" means, unless otherwise defined, that at least one hydrogen bonded to carbon is replaced by an element other than hydrogen, for example, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, a cycloalkenyl group having 3 to 12 carbon atoms, a cycloalkynyl group having 3 to 12 carbon atoms, a heterocycloalkyl group having 3 to 12 carbon atoms, a heterocycloalkenyl group having 3 to 12 carbon atoms, a heterocycloalkynyl group having 2 to 12 carbon atoms, an aryloxy group having 6 to 12 carbon atoms, a halogen atom, a fluoroalkyl group having 1 to 20 carbon atoms, a nitro group, an aryl group having 6 to 20 carbon atoms, an aryl group having 2 to 20 carbon atoms, an alkyl ... It means substituted with a heteroaryl group having 20 carbon atoms, a haloaryl group having 6 to 20 carbon atoms, etc. Hereinafter, the present invention will be described in more detail. A lithium secondary battery according to the present invention comprises at least one of the configurations disclosed below, and may comprise any combination between technically possible configurations among the configurations below. lithium secondary battery The present invention relates to a lithium secondary battery. Specifically, a lithium secondary battery according to the present invention comprises: a positive electrode; a negative electrode facing the positive electrode; a separator interposed between the positive electrode and the negative electrode; and a non-aqueous electrolyte; wherein the positive electrode comprises a positive electrode active material, and the positive electrode active material comprises lithium nickel-based oxide particles represented by the following chemical formula A, wherein the lithium nickel-based oxide particles are in the form of single particles consisting of one single nodule or quasi-single particles that are complexes of 30 or fewer nodules, and the non-aqueous electrolyte comprises a lithium salt, an organic solvent, and an additive, and the additive comprises a cyclic borate-based compound represented by the following chemical formula 1; and a compound containing a propargyl group. [Chemical Formula A] Li a Ni b Co c Mn d M 1 e O2 In the above chemical formula A, M 1 is at least one selected from the group consisting of Ti, Mg, Al, Zr, Y, Ba, Ca, Sr, W, Ta, Nb, and Mo, and 0.8≤a≤1.2, 0.5≤b<0.7, 0 <c<0.2, 0<d≤0.4, 0≤e≤0.2, b+c+d+e=1이고, [Chemical Formula 1] In the above chemical formula 1, R1 is an alkylene group having 1 to 10 carbon atoms, n1 and n2 are each independently an integer selected from 0 to 5, R2 and R3 are each independently hydrogen, halogen, a nitrile 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 thereof, n3 is 2n1+2, n4 is 2n2+2, and when n3 is an integer of 2 or more, a plurality of R2s may be the same or different from each other, and when n4 is an integer of 2 or more, a plurality of R3s may be the same or different from each other. A lithium secondary battery according to the present invention is characterized by including a positive electrode including a positive electrode active material including Mid-Ni NCM composite transition metal oxide particles having a single particle or pseudo-single particle shape, and a non-aqueous electrolyte including a cyclic borate compound having a specific structural formula and a compound containing a propargyl group as an additive. When using a cathode active material having a single particle or pseudo-single particle form, if the operating voltage is increased to implement excellent capacity characteristics, the problem of battery performance degradation due to excessive electrolyte side reactions on the cathode surface occurs, but a cyclic borate compound expressed by a specific chemical formula and a compound containing a propargyl group quickly form a uniform and stable film, thereby preventing performance degradation due to electrolyte side reactions. Specifically, the cyclic borate compound can form a uniform film through a ring-opening reaction on the surface of the positive electrode, and can improve the electrochemical characteristics of the battery by suppressing solvent decomposition through interaction with lithium ions. However, the cyclic borate compound has difficulty in the ring-opening reaction due to steric hindrance and reduced reactivity due to its large molecular structure. At this time, a compound containing a propargyl group that readily undergoes a redox reaction resolves the difficulty of the ring-opening reaction due to the steric hindrance of the cyclic borate compound. Specifically, the radical derived from the propargyl group causes radical ring-opening polymerization that breaks the ring structure of the cyclic borate compound, thereby resolving the difficulty of the ring-opening reaction due to the steric hindrance and promoting the borate-based anodic film formation reaction. Accordingly, the lithium secondary battery according to the present invention forms a uniform and durable film on the surface of the positive electrode, thereby suppressing electrolyte side reactions at high voltage and preventing performance degradation, and consequently improving the overall performance of the lithium secondary battery, particularly high-temperature storage performance and high-temperature lifespan performance. At this time, the lithium secondary battery of the present invention can be manufactured according to a conventional method known in the relevant technical field. For example, the positive electrode according to the present invention, the negative electrode opposite the positive electrode, and the separator interposed between the positive electrode and the negative electrode are sequentially laminated to form an electrode assembly, and then the electrode assembly is inserted into a battery can and the non-aqueous electrolyte according to the present invention is injected to manufacture the battery. (1) Bipolar The above positive electrode includes a positive electrode active material. The above positive electrode active material includes lithium nickel-based oxide particles represented by the following chemical formula A. [Chemical Formula A] Li a Ni b Coc Mn d M 1 e O2 In the above chemical formula A, M 1 is at least one selected from the group consisting of Ti, Mg, Al, Zr, Y, Ba, Ca, Sr, W, Ta, Nb, and Mo, and 0.8≤a≤1.2, 0.5≤b≤0.7, 0 <c<0.2, 0<d≤0.4, 0≤e≤0.2, b+c+d+e=1이다. The above a represents the molar ratio of lithium in the lithium nickel-based oxide particles, and may be 0.8≤a≤1.2, 0.9≤a≤1.1, or 0.95≤a≤1.10. When the above range is satisfied, a stable layered crystal structure can be formed. The above b represents the molar ratio of nickel among the total metal excluding lithium in the lithium nickel-based oxide particles, and may be 0.5≤b≤0.7, 0.52≤b≤0.68, or 0.55≤b≤0.65. When the above b is less than 0.5, the content of nickel among the transition metals is low, so that high capacity cannot be realized, which is not preferable. In addition, in the case of a high-nickel lithium composite transition metal oxide in which the above b exceeds 0.7, as the voltage increases, an inactive surface is created due to surface degradation (rock-salt degradation) caused by the phase structure change from H2 to H3 at the cathode, which causes a decrease in performance and limits the operating voltage. Accordingly, there is a disadvantage in that it is difficult to achieve the effect of the present invention, which is to form a uniform film on the anode surface through the ring-opening reaction of the additive according to the present invention, which will be described later under high-voltage conditions. Therefore, when the above range is satisfied, it is easy to form a film on the anode surface through the ring-opening reaction of the additive, which will be described later, so that it can be excellent in high-temperature storage performance and high-temperature life performance, and can be more advantageous in implementing high capacity. The above c represents the molar ratio of cobalt among all metals excluding lithium in lithium nickel oxide particles, and is 0. <c<0.2, 0<c≤0.18, 0<c≤0.16, 또는 0<c≤0.15일 수 있다. 상기 범위를 만족하는 경우, 양호한 저항 특성 및 출력 특성을 구현할 수 있다. The above d represents the molar ratio of manganese among all metals excluding lithium in lithium nickel oxide particles, and is 0. <d≤0.4, 0.1≤d≤0.4, 0.15≤d≤0.4, 또는 0.2<d≤0.4일 수 있다. 상기 범위를 만족하는 경우, 양극 활물질의 구조 안정성이 우수하게 나타날 수 있다. The above e is M of all metals except lithium in lithium nickel oxide particles. 1 Indicates the molar ratio of elements, and the above M 1 is a doping element substituted at the transition metal site, and may be 0≤e≤0.20, 0≤e≤0.15, or 0≤e≤0.10. M 1 When included in an appropriate amount, it can play a role in promoting particle growth during firing or improving crystal structure stability. The above b / c may be 3.2 to 9.0, specifically 4.0 to 8.5, more specifically 5.0 to 8.0, and even more specifically 5.5 to 7.0. When the above range is satisfied, the crystal structure of the positive electrode may not be destroyed even when charge and discharge are repeated under high voltage conditions, so that the cyclic borate-based film described below may be stably formed, and thus the electrochemical characteristics of the battery may be excellent. The above b / d may be 1.5 to 2.8, specifically 1.6 to 2.6, more specifically 1.7 to 2.4, even more specifically 1.8 to 2.3, and even more specifically 1.9 to 2.1. The uniform and stable positive electrode film according to the present invention, which will be described later, can exhibit an effect of improving high-temperature characteristics due to film formation only when microcracks between the positive electrode active material particles are not severely generated. Therefore, when the above range is satisfied, the molar ratio of Ni and Mn in the positive electrode active material particles is appropriately controlled to increase structural stability, and thus the effect of improving high-temperature performance due to uniform and stable film formation can be achieved, and since the variability of the crystallite size (Lc) in the c-axis direction is not severe, microcracks between the particles may not be generated, and thus the effect of forming a uniform and stable film can be increased. The above d / c may be 1.2 to 4.8, specifically 1.6 to 4.4, more specifically 2.0 to 4.0, even more specifically 2.4 to 3.6, and even more specifically 2.8 to 3.2. When the above range is satisfied, an appropriate ratio of cobalt and manganese may be contained, so that good resistance characteristics and output characteristics can be implemented, and the structural stability of the positive electrode active material can be excellent. The lithium nickel-based oxide particle is in the form of a single particle composed of one single nodule or a quasi-single particle which is a composite of 30 or fewer nodules. Specifically, the lithium nickel-based oxide particle may be a quasi-single particle which is a composite of 2 to 20 nodules, more specifically 2 to 10 nodules, or a form including them. If the number of nodules constituting the lithium nickel-based oxide particle exceeds 30, particle breakage increases during electrode manufacturing, and internal cracks occur more due to volume expansion / contraction of the nodules during charge / discharge, which may reduce the effect of improving high-temperature life characteristics and high-temperature storage characteristics. In addition, if a cathode active material particle in the form of a secondary particle rather than a single particle or quasi-single particle is used, the surface area is large, so that a lot of oxygen radical reactions occur under high-voltage conditions. At this time, the oxygen radical can be generated by taking electrons from a propargyl group, and the propargyl group that has had its electrons taken in this way cannot form radicals. That is, since the oxygen radical reaction occurs excessively around the electrode, the amount of propargyl group formed as a radical around the electrode decreases, which causes a problem in that the ring-opening reaction of the cyclic borate described later cannot be promoted. In addition, the possibility of microcracks occurring due to movement of lithium within the lattice during charge and discharge increases, and accordingly, it is difficult to achieve the film-forming effect due to the additive of the present invention, and the organic solvent may be depleted, which reduces the performance of the battery. In addition, when the positive electrode active material in the form of a secondary particle and the additive of the present invention are used, the cyclic borate compound and the compound containing the propargyl group may act like a resistor, thereby reducing the battery characteristics. Therefore, according to the present invention, when the positive electrode active material particles in the form of a single particle or a pseudo-single particle and the additive of the present invention are used, a lithium secondary battery having improved high-temperature storage and high-temperature life characteristics is realized. The average particle diameter (D) of the above positive electrode active material 50) may be 1 ㎛ to 10 ㎛, specifically 2 ㎛ to 8 ㎛, more specifically 3 ㎛ to 7 ㎛, even more specifically 3 ㎛ to 5 ㎛, and even more specifically 3.0 ㎛ to 4.5 ㎛. When the above range is satisfied, the processability during electrode manufacturing may be excellent, the electrolyte impregnation property may be high, so that the electrochemical properties may be increased, and the resistance may be reduced and the output characteristics may be improved. The specific surface area of ​​the above positive electrode active material is 0.1 m 2 / g to 3.0m 2 / g, specifically 0.3m 2 / g to 2.5m 2 / g, more specifically 0.4m 2 / g to 1.8m 2 / g, more specifically 0.5m 2 / g to 1.0m 2 / g. When the above range is satisfied, the rolling characteristics of the electrode can be improved, and particle breakage can be reduced, thereby suppressing side reactions with the electrolyte. The above positive electrode may include a positive electrode current collector; and a positive electrode active material layer disposed on at least one surface of the positive electrode current collector. In this case, the above-described positive electrode active material may be included in the positive electrode active material layer. The positive electrode current collector may include a highly conductive metal, and is not particularly limited as long as it is a material to which the positive electrode active material layer can be easily adhered, but is not reactive within the voltage range of the battery. For example, the positive electrode current collector may be made of stainless steel, aluminum, nickel, titanium, heat-treated carbon, or aluminum or stainless steel surface-treated with carbon, nickel, titanium, silver, etc. The above positive electrode current collector may typically have a thickness of 3 μm to 500 μm. The above-mentioned positive electrode current collector can also form fine irregularities on its surface to enhance the adhesion of the positive electrode active material. It can be used in various forms, such as films, sheets, foils, nets, porous bodies, foams, and non-woven fabrics. The positive electrode active material layer is disposed on at least one surface of the positive electrode current collector. Specifically, the positive electrode active material layer may be disposed on one or both surfaces of the positive electrode current collector. The above positive electrode active material may be included in an amount of 80 wt% to 99 wt%, more specifically 90 wt% to 98 wt%, based on the total weight of the positive electrode active material layer. The above positive electrode active material layer may further include a conductive material and / or a binder together with the positive electrode active material. The above conductive material is used to provide conductivity to the electrode, and in the battery to be formed, as long as it does not cause a chemical change and has electronic conductivity, it can be used without any special restrictions. Specific examples include graphite such as natural graphite or artificial graphite; carbon-based materials such as carbon black, acetylene black, Ketjen black, channel black, furnace black, lamp black, thermal black, and carbon fiber; metal powders or metal fibers such as copper, nickel, aluminum, and silver; conductive tubes such as carbon nanotubes; conductive whiskers such as zinc oxide or potassium titanate; conductive metal oxides such as titanium oxide; or conductive polymers such as polyphenylene derivatives, and the like. One of these may be used alone or a mixture of two or more may be used. The above conductive material may be included in an amount of 0.01 wt% to 10 wt%, specifically 0.1 wt% to 9 wt%, and more specifically 0.1 wt% to 5 wt%, based on the total weight of the positive electrode active material layer. The above binder serves to improve the adhesion between positive electrode active material particles and the adhesion between the positive electrode active material and the current collector. Specific examples include polyvinylidene fluoride (PVDF), polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-co-HFP), polyvinylalcohol, polyacrylonitrile, polymethyl methacrylate, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, polytetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene polymer (EPDM), sulfonated-EPDM, styrene butadiene rubber (SBR), fluoroelastomer, polyacrylic acid, and polymers in which hydrogens of these are substituted with Li, Na, or Ca, or various copolymers thereof, and one of these may be used alone or a mixture of two or more thereof. The above binder may be included in an amount of 1 wt% to 30 wt%, specifically 1 wt% to 20 wt%, and more specifically 1 wt% to 10 wt%, based on the total weight of the positive electrode active material layer. When the above range is satisfied, the adhesion between positive electrode active material particles and the adhesive strength between the positive electrode active material and the current collector can be improved. The thickness of the positive electrode active material layer may be 30 µm to 400 µm, specifically 40 µm to 110 µm. The above-described positive electrode can be manufactured according to a conventional positive electrode manufacturing method, except that the positive electrode active material described above is used. Specifically, the positive electrode slurry composition, prepared by dissolving or dispersing the above-described positive electrode active material and optionally a binder, conductive agent, and dispersant in a solvent, is applied onto a positive electrode current collector, followed by drying and rolling. The solvent may be a solvent generally used in the relevant technical field, such as dimethyl sulfoxide (DMSO), isopropyl alcohol, N-methylpyrrolidone (NMP), dimethyl formamide (DMF), acetone, or water. One of these may be used alone or a mixture of two or more thereof may be used. The amount of the solvent used is sufficient to dissolve or disperse the positive electrode active material, conductive material, binder, and dispersant in consideration of the coating thickness and manufacturing yield of the slurry, and to have a viscosity that can exhibit excellent thickness uniformity when applied thereafter for manufacturing the positive electrode. Alternatively, the positive electrode may be manufactured by casting the positive electrode slurry composition onto a separate support, peeling the resulting film from the support, and laminating the resulting film onto a positive electrode current collector. (2) Cathode The negative electrode opposite the positive electrode may include a negative electrode current collector; and a negative electrode active material layer disposed on at least one surface of the negative electrode current collector. The above negative electrode current collector is not particularly limited as long as it has high conductivity without causing chemical changes in the battery. Specifically, the negative electrode current collector may be made of copper, stainless steel, aluminum, nickel, titanium, calcined carbon, copper or stainless steel surface-treated with carbon, nickel, titanium, silver, etc., or an aluminum-cadmium alloy. The above negative electrode current collector may typically have a thickness of 3 to 500 μm. The above-described negative electrode current collector may have fine irregularities formed on its surface to enhance the bonding strength of the negative electrode active material. For example, the above-described negative electrode current collector may be used in various forms, such as a film, sheet, foil, net, porous body, foam, or non-woven fabric. The negative electrode active material layer is disposed on at least one surface of the negative electrode current collector. Specifically, the negative electrode active material layer may be disposed on one or both surfaces of the negative electrode current collector. The above negative electrode active material layer may include a negative electrode active material. The above negative active material is a material capable of reversibly inserting / de-inserting lithium ions, and may include at least one selected from the group consisting of a carbon-based active material, a silicon-based active material, and lithium metal, and specifically, may include at least one selected from a carbon-based active material and a silicon-based active material, and more specifically, may include a carbon-based active material. The above carbon-based active material may include at least one selected from the group consisting of graphite, hard carbon, soft carbon, carbon black, graphene, and fibrous carbon, and may specifically include graphite. The graphite may include, for example, at least one selected from the group consisting of artificial graphite and natural graphite. The average particle diameter (D) of the above carbon-based active material 50 ) may be 10㎛ to 30㎛, preferably 15㎛ to 25㎛, in order to ensure structural stability during charging and discharging and reduce side reactions with the electrolyte. The above silicon-based active material is SiO x It may include a compound represented by (0≤x<2). In the case of SiO2, since it does not react with lithium ions and thus cannot store lithium, it is preferable that x is within the above range, and more preferably, the silicon-based active material may include SiO. The average particle diameter (D) of the above silicon-based active material 50 ) may be 1㎛ to 30㎛, preferably 2㎛ to 15㎛, in order to reduce side reactions with the electrolyte while ensuring structural stability during charge and discharge. The above negative active material may be included in the negative active material layer in an amount of 60 wt% to 99 wt%, preferably 75 wt% to 95 wt%. The above negative electrode active material layer may further include a binder and / or a conductive material together with the negative electrode active material. The above binder is used to improve the performance of the battery by improving the adhesion between the negative electrode active material layer and the negative electrode current collector, and may include, for example, at least one selected from the group consisting of polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-co-HFP), polyvinylidene fluoride (PVDF), polyacrylonitrile, polymethylmethacrylate, polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, polytetrafluoroethylene, polyethylene, polypropylene, polyacrylic acid, ethylene-propylene-diene monomer (EPDM), sulfonated EPDM, styrene butadiene rubber (SBR), fluororubber, and materials in which hydrogens of these are substituted with Li, Na, Ca, etc., and may also include various copolymers thereof. May include. The above binder may be included in the negative electrode active material layer in an amount of 0.5 wt% to 10 wt%, preferably 1 wt% to 5 wt%. The conductive material is not particularly limited as long as it is conductive and does not cause a chemical change in the battery, and examples thereof include graphite such as natural graphite or artificial graphite; carbon black such as carbon black, acetylene black, Ketjen black, channel black, paneth black, lamp black, thermal black, and the like; conductive fibers such as carbon fibers or metal fibers; conductive tubes such as carbon nanotubes; fluorocarbons; metal powders such as aluminum or nickel powder; conductive whiskers such as zinc oxide or potassium titanate; conductive metal oxides such as titanium oxide; and conductive materials such as polyphenylene derivatives. The above conductive material may be included in the negative electrode active material layer in an amount of 0.5 wt% to 10 wt%, preferably 1 wt% to 5 wt%. The thickness of the negative electrode active material layer may be 10 µm to 100 µm, preferably 50 µm to 80 µm. The above negative electrode can be manufactured by coating a negative electrode slurry including a negative electrode active material, a binder, a conductive material, and / or a solvent for forming a negative electrode slurry on at least one surface of a negative electrode current collector, and then drying and rolling. The solvent for forming the negative electrode slurry may include at least one selected from the group consisting of distilled water, NMP (N-methyl-2-pyrrolidone), ethanol, methanol, and isopropyl alcohol, preferably distilled water, in order to facilitate dispersion of the negative electrode active material, binder, and / or conductive agent, for example. The solid content of the negative electrode slurry may be 30 wt% to 80 wt%, specifically 40 wt% to 70 wt%. (3) Membrane The above separator may be interposed between the positive electrode and the negative electrode. As the above separator, a conventional porous polymer film used as a conventional separator, for example, a porous polymer film made of a polyolefin 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 in a laminated manner, or a conventional porous nonwoven fabric, for example, a nonwoven fabric made of high-melting-point glass fiber, polyethylene terephthalate fiber, etc. may be used, but is not limited thereto. In addition, a coated separator containing a ceramic component or a polymer material may be used to secure heat resistance or mechanical strength, and may optionally be used in a single-layer or multi-layer structure. (4) Non-aqueous electrolyte The non-aqueous electrolyte according to the present invention comprises a lithium salt, an organic solvent and an additive. 1) Lithium salt As the lithium salt used in the present invention, various lithium salts commonly used in non-aqueous electrolytes for lithium secondary batteries can be used without limitation. For example, the lithium salt may be Li as a cation. + , and the anion is F - , Cl - , Br - , I - , NO3 - , N(CN)2 - , BF4 - , ClO4 - , AlO4 - , AlCl4 - , PF6 - , SbF6 - , AsF6 - , B 10 Cl 10 - , 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 -It may include at least one selected from the group consisting of . Specifically, the lithium salt is LiCl, LiBr, LiI, LiBF4, LiClO4, LiAlO4, LiAlCl4, LiPF6, LiSbF6, LiAsF6, LiB 10 Cl 10 , LiBOB (LiB(C2O4)2), LiCF3SO3, LiFSI (LiN(SO2F)2), LiCH3SO3, LiCF3CO2, LiCH3CO2, and LiBETI (LiN(SO2CF2CF3)2). Specifically, the lithium salt may include at least one selected from the group consisting of LiBF4, LiClO4, LiPF6, LiBOB (LiB(C2O4)2), LiCF3SO3, LiTFSI (LiN(SO2CF3)2), LiFSI ((LiN(SO2F)2), and LiBETI (LiN(SO2CF2CF3)2). The lithium salt may be included in the non-aqueous electrolyte at a concentration of 0.1 M to 4.0 M, specifically at a concentration of 0.8 M to 3.0 M, and more specifically at a concentration of 0.8 M to 2.0 M. When the concentration of the lithium salt satisfies the above range, the lithium ion yield (Li + The output characteristics of the battery can be improved by improving the transference number and the degree of dissociation of lithium ions. 2) Organic solvent The above organic solvent is a non-aqueous solvent commonly used in lithium secondary batteries, and is not particularly limited as long as decomposition due to oxidation reactions, etc. during the charge / discharge process of the lithium secondary battery can be minimized. Specifically, 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. Specifically, the organic solvent may include a cyclic carbonate-based organic solvent, a linear carbonate-based organic solvent, or a mixture thereof. The above cyclic carbonate-based organic solvent is a high-viscosity organic solvent with a high dielectric constant that can easily dissociate a lithium salt in an electrolyte, and specifically, may include at least one organic solvent selected from the group consisting of ethylene carbonate (EC), propylene carbonate (PC), 1,2-butylene carbonate, 2,3-butylene carbonate, 1,2-pentylene carbonate, 2,3-pentylene carbonate, and vinylene carbonate, and more specifically, may include ethylene carbonate. In addition, the linear carbonate-based organic solvent is an organic solvent having low viscosity and low dielectric constant, and may specifically include at least one selected from the group consisting of dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate, ethylmethyl carbonate (EMC), methylpropyl carbonate, and ethylpropyl carbonate, and more specifically, may include ethylmethyl carbonate (EMC). The above organic solvent may be a mixture of a cyclic carbonate-based organic solvent and a linear carbonate-based organic solvent. At this time, the cyclic carbonate-based organic solvent and the linear carbonate-based organic solvent may be mixed in a volume ratio of 10:90 to 40:60, specifically, a volume ratio of 10:90 to 30:70, and more specifically, a volume ratio of 15:85 to 30:70. When the mixing ratio of the cyclic carbonate-based organic solvent and the linear carbonate-based organic solvent satisfies the above range, both high dielectric constant and low viscosity characteristics can be satisfied, and excellent ionic conductivity characteristics can be implemented. In addition, the organic solvent may further include at least one carbonate organic solvent selected from the group consisting of the cyclic carbonate organic solvent and the linear carbonate organic solvent, and at least one ester organic solvent selected from the group consisting of the linear ester organic solvent and the cyclic ester organic solvent, in order to produce an electrolyte having high ionic conductivity. The linear ester organic solvent may specifically include at least one selected from the group consisting of methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, and butyl propionate. In addition, the cyclic ester organic solvent may specifically include at least one selected from the group consisting of γ-butyrolactone, γ-valerolactone, γ-caprolactone, γ-valerolactone, and γ-caprolactone. Meanwhile, the organic solvent may be used without limitation by adding organic solvents commonly used in non-aqueous electrolytes as needed. For example, at least one organic solvent among an ether-based organic solvent, a glyme-based solvent, and a nitrile-based organic solvent may be additionally included. As the above ether solvent, any one selected from the group consisting of dimethyl ether, diethyl ether, dipropyl ether, methyl ethyl ether, methyl propyl ether, ethyl propyl 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 is not limited thereto. The above glyme-based solvent has a high dielectric constant and low surface tension compared to linear carbonate-based organic solvents, and is a solvent with low reactivity with metals, and may include at least one selected from the group consisting of dimethoxyethane (glyme, DME), diethoxyethane, diglyme, tri-glyme, and tetra-glyme (TEGDME), but is not limited thereto. The above nitrile solvent may be at least one selected from the group consisting of acetonitrile, propionitrile, butyronitrile, valeronitrile, caprylonitrile, heptanenitrile, cyclopentane carbonitrile, cyclohexane carbonitrile, 2-fluorobenzonitrile, 4-fluorobenzonitrile, difluorobenzonitrile, trifluorobenzonitrile, phenylacetonitrile, 2-fluorophenylacetonitrile, and 4-fluorophenylacetonitrile, but is not limited thereto. 3) Additives The above non-aqueous electrolyte contains an additive. The above additive includes a cyclic borate compound represented by the following chemical formula 1 and a compound containing a propargyl group. [Chemical Formula 1] In the above chemical formula 1, R1 is an alkylene group having 1 to 10 carbon atoms, n1 and n2 are each independently an integer selected from 0 to 5, R2 and R3 are each independently hydrogen, halogen, a nitrile 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 thereof, n3 is 2n1+2, n4 is 2n2+2, and when n3 is an integer of 2 or more, a plurality of R2s may be the same or different from each other, and when n4 is an integer of 2 or more, a plurality of R3s may be the same or different from each other. The cyclic borate compound represented by the above chemical formula 1 can form a uniform anode film through a ring-opening reaction, thereby improving high-temperature storage and high-temperature life characteristics. In particular, the compound of the above chemical formula 1 has a higher HOMO (Highest Occupied Molecular Oribital) energy than ethylene carbonate (EC), so it is easy to donate electrons, and thus can form a uniform and stable anode film through a faster oxidation reaction than a solvent, and PF6 - It can stabilize and reduce side reactions with the electrolyte, and a uniform and stable positive electrode film of a polymer with a lot of oxygen (O) like the above compound has a low barrier energy, which can improve lithium mobility characteristics, thereby improving the performance of a lithium secondary battery. In addition, the compound of the above [chemical formula 1] has two borate ester groups, so that it can suppress solvent decomposition through interaction with lithium ions while performing a ring-opening reaction on the positive electrode surface. However, the cyclic borate compound represented by the above chemical formula 1 has difficulty in forming a film through a ring-opening reaction due to steric hindrance due to its large molecular structure. At this time, the compound containing the propargyl group, which is easy to undergo a redox reaction, promotes the ring-opening reaction of the cyclic borate compound through radical polymerization, thereby resolving the difficulty in the ring-opening reaction due to steric hindrance and facilitating film formation on the anode surface. Therefore, when the cyclic borate compound and the compound containing a propargyl group according to the present invention are used, the radicals from the propargyl group cause a ring-opening reaction that breaks the ring structure of the cyclic borate compound, thereby promoting the borate-based positive electrode film formation reaction. The film formed by the interaction between the cyclic borate compound and the compound containing a propargyl group maintains a stable organic film form even at high temperatures and has the effect of suppressing the dissolution of the positive electrode transition metal. In addition, since the borate-based film is formed thinly and uniformly as the cyclic borate is decomposed, there is the effect of improving the cycle life performance. That is, due to the organic action effect of the cyclic borate compound and the compound containing a propargyl group, a uniform and highly durable positive electrode film can be quickly formed, thereby improving the high-temperature storage characteristics and high-temperature life characteristics of a lithium secondary battery. In the above chemical formula 1, R1 may be an alkylene group having 1 to 5 carbon atoms, and more specifically, an alkylene group having 2 to 4 carbon atoms. When the above range is satisfied, the distance between the two cyclic borate groups is not too close, so that the steric hindrance of the cyclic borate compound can be alleviated. In addition, among the two cyclic borate groups, one interacts with the electrode through a ring-opening reaction to form a film, and the other is a borate ester group that suppresses further decomposition of the solvent. Therefore, when the distance between the two cyclic borate groups becomes too long, the borate ester group may be positioned far from the electrode surface, so that it may be difficult to suppress further decomposition of the organic solvent on the electrode surface. In the above chemical formula 1, specifically, n1 and n2 may each be an integer independently selected from 0 to 4, and more specifically, may each be an integer independently selected from 0 to 3. More specifically, in the above chemical formula 1, each of n1 and n2 may be 2, and in this case, since the difficulty of the ring-opening reaction due to steric hindrance may be improved by not including an excessively small cyclic ring, and since the carbon chain of an appropriate length is formed during the ring-opening reaction by not including an excessively large cyclic ring, the mobility of lithium ions may be improved, which is preferable. In the above chemical formula 1, specifically, R2 and R3 can each independently be hydrogen, halogen (the halogen can be selected from F, Cl, Br, and I, and specifically can be F), a nitrile group, an ester group, an ether group, or a combination of two or more thereof. Such a substituent has excellent reducibility, is advantageous in forming a polymer-type positive electrode film, and also has excellent lithium ion transport performance, thereby improving battery performance. More specifically, the cyclic borate compound represented by the above chemical formula 1 can be represented by the following chemical formula 1-1. [Chemical Formula 1-1] In the above chemical formula 1-1, R2 and R3 are each independently as defined in the above [chemical formula 1]. In the above chemical formula 1-1, n3 is 6 and n4 is 6. The compound represented by the above chemical formula 1-1 can effectively prevent the organic solvent from being decomposed on the electrode surface because the distance between the two cyclic borate groups is not excessively long, and the steric hindrance of the compound can be minimized because the distance between the two cyclic borate groups is appropriately secured. More specifically, the cyclic borate compound represented by the above chemical formula 1 can be represented by the following chemical formula 1-2. [Chemical Formula 1-2] The cyclic borate compound may be included in the non-aqueous electrolyte in an amount of 0.01 wt% to 12 wt%, specifically 0.05 wt% to 10 wt%, more specifically 0.1 wt% to 5.0 wt%, and even more specifically 0.2 wt% to 1.0 wt%, based on the total weight of the non-aqueous electrolyte. When the above range is satisfied, an appropriate film thickness may be formed so that the resistance does not excessively increase, and the cyclic borate compound may be included so as to sufficiently surround the positive electrode, thereby providing excellent coverage. The compound containing the propargyl group may specifically include at least one selected from the group consisting of compounds represented by the following chemical formulas 2 and 3, and more specifically may include a compound represented by the following chemical formula 2. [Chemical Formula 2] [Chemical Formula 3] In the above chemical formula 2, R6 is an alkylene group having 1 to 3 carbon atoms that can be substituted with fluorine, and R7 to R9 are each independently hydrogen, an alkyl group having 1 to 3 carbon atoms, a nitrile group, or a combination of two or more thereof. In the above chemical formula 3, R 10 is hydrogen, an alkyl group having 1 to 10 carbon atoms, and a cycloalkyl group having 3 to 8 carbon atoms, or a combination of two or more thereof, and R 11 is an alkylene group having 1 to 8 carbon atoms that can be substituted with fluorine. The compounds represented by the above chemical formulas 2 and 3 can more easily perform the ring-opening reaction of the cyclic borate compound, thereby rapidly promoting the formation of a positive electrode film, and the propargyl group becomes a cross-link site in the SEI, enabling additional reactions. This additional cross-linking reaction can be effective in forming a robust SEI film, thereby suppressing performance degradation due to cathode electrodeposition of transition metals eluted from the positive electrode. In addition, the cyclic carbonate functional group and imidazole functional group included in the above chemical formulas 2 and 3 can effectively suppress side reactions and positive electrode degradation on the positive electrode surface through the formation of a stable positive electrode film, thereby improving performance and reducing transition metal eluted during high-voltage charging. Specifically, the compound represented by the above chemical formula 2 can be represented by the following chemical formula 2-1. [Chemical Formula 2-1] In addition, the compound represented by the above chemical formula 3 can be represented by the following chemical formula 3-1. [Chemical Formula 3-1] The compound containing the propargyl group may be included in the non-aqueous electrolyte in an amount of 0.01 wt% to 6 wt%, specifically 0.05 wt% to 4 wt%, more specifically 0.1 wt% to 2.0 wt%, and even more specifically 0.2 wt% to 1.0 wt%, based on the total weight of the non-aqueous electrolyte. When the above range is satisfied, an appropriate film thickness may be formed so that the resistance does not become excessively high, and the compound may be included so as to sufficiently cover the positive electrode, thereby providing excellent coverage. The weight ratio of the cyclic borate compound and the compound containing the propargyl group may be 1:99 to 99:1, specifically 5:95 to 95:5, more specifically 10:90 to 95:5, even more specifically 25:75 to 75:25, and even more specifically 40:60 to 60:40. When the above range is satisfied, an anode film having an appropriate thickness can be formed, and the formation of the anode film can be rapidly promoted, so that high-temperature storage characteristics and high-temperature life characteristics can be improved. The above additive may further include additional additives. The additional additives may be included in the non-aqueous electrolyte to prevent the non-aqueous electrolyte from decomposing in a high-power environment, causing the cathode and anode to collapse, or to provide low-temperature high-rate discharge characteristics, high-temperature stability, overcharge prevention, and suppression of battery expansion at high temperatures. Specifically, the additional additive may be at least one selected from the group consisting of vinylene carbonate, vinyl ethylene carbonate, fluoroethylene carbonate, propane sultone, propene sultone, succinonitrile, adiponitrile, ethylene sulfate, lithium bis-(oxalato)borate (LiBOB), 3-trimethoxysilanyl-propyl-N-aniline (TMSPa), and tris(trimethylsilyl) phosphite (TMSPi), and specifically, may be vinylene carbonate. The above additional additive may be included in the non-aqueous electrolyte in an amount of 0.1 wt% to 15 wt%. Since the lithium secondary battery according to the present invention as described above has excellent stability and electrochemical performance even at high voltages, the end-of-charge voltage during operation can be 4.30 V or higher, specifically 4.35 V or higher, and more specifically 4.40 V or higher, and when operated at such a high operating voltage, it can implement superior high-capacity characteristics compared to conventional lithium secondary batteries. The operating voltage of the lithium secondary battery according to the present invention can be 2.0 V to 4.45 V, preferably 2.5 V to 4.4 V. There is no particular limitation on the external shape of the lithium secondary battery of the present invention, but it may be a cylindrical shape using a can, a square shape, a pouch shape, or a coin shape. In addition, since the lithium secondary battery according to the present invention stably exhibits excellent discharge capacity, output characteristics, and capacity retention rate, it is useful in portable devices such as mobile phones, laptop computers, and digital cameras, and electric vehicles such as hybrid electric vehicles (HEVs). Accordingly, according to another embodiment of the present invention, a battery module including the lithium secondary battery as a unit cell and a battery pack including the same are provided. The above battery module or battery pack can be used as a power source for one or more medium- to large-sized devices, such as a power tool; an electric vehicle (EV), a hybrid electric vehicle, and a plug-in hybrid electric vehicle (PHEV); or a power storage system. Hereinafter, the present invention will be described in more detail through specific examples. However, the following examples are merely illustrative and serve to aid understanding of the present invention and do not limit its scope. It will be apparent to those skilled in the art that various modifications and variations are possible within the scope and technical spirit of this disclosure, and such modifications and variations are naturally within the scope of the appended claims. Examples and Comparative Examples Example 1: Manufacturing of a lithium secondary battery (Manufacture of non-aqueous electrolyte) As an organic solvent, a mixture of ethylene carbonate (EC) and ethyl methyl carbonate (EMC) in a volume ratio of 20:80 was used. A non-aqueous electrolyte was prepared by adding LiPF6 as a lithium salt, trimethylene borate (TMEB) as an additive, and a compound represented by the chemical formula 2-1 to the organic solvent. The above LiPF6 was included in the non-aqueous electrolyte at a concentration of 1.2 M. The above trimethylene borate (TMEB) was included in the non-aqueous electrolyte at 0.5 wt%, and the compound represented by the above chemical formula 2-1 was included in the non-aqueous electrolyte at 0.5 wt%. (Lithium secondary battery manufacturing) Single particle or pseudo-single particle type cathode active material (LiNi 0.6 Co 0.1 Mn 0.3 O2): Conductive agent (carbon black): Binder (polyvinylidene fluoride (PVdF)) was added to N-methyl-2-pyrrolidone (NMP), a solvent, in a weight ratio of 97.6:0.8:1.6 to prepare a cathode slurry (solid content 60 wt%). The average particle diameter (D) of the above positive electrode active material 50 ) is 3.7㎛, and the BET surface area is 0.93m 2 / g was. The above positive electrode slurry was applied to a positive electrode current collector (Al thin film) having a thickness of 13.5 μm, and dried and roll pressed to manufacture a positive electrode. A negative electrode slurry (solid content 60 wt%) was prepared by adding negative electrode active material (graphite): conductive material (carbon black): binder (SBR-CMC) to distilled water as a solvent in a weight ratio of 96.75:0.50:2.75. The above negative electrode slurry was applied to a negative electrode current collector (Cu thin film) having a thickness of 6 μm, and dried and roll pressed to manufacture a negative electrode. A porous polymer was interposed as a separator between the positive and negative electrodes manufactured above in a dry room, and then the non-aqueous electrolyte manufactured above was injected to manufacture a lithium secondary battery. Example 2: Manufacturing of lithium secondary batteries A lithium secondary battery was manufactured in the same manner as in Example 1, except that trimethylene borate (TMEB) was included in the non-aqueous electrolyte at 10 wt% as an additive, and the compound represented by the chemical formula 2-1 was included in the non-aqueous electrolyte at 0.5 wt%. Example 3: Manufacturing of lithium secondary batteries A lithium secondary battery was manufactured in the same manner as in Example 1, except that trimethylene borate (TMEB) was included in the non-aqueous electrolyte at 0.05 wt% as an additive, and the compound represented by the chemical formula 2-1 was included in the non-aqueous electrolyte at 0.5 wt%. Example 4: Manufacturing of lithium secondary batteries A lithium secondary battery was manufactured in the same manner as in Example 1, except that trimethylene borate (TMEB) was included in the non-aqueous electrolyte at 0.5 wt% as an additive, and the compound represented by the chemical formula 2-1 was included in the non-aqueous electrolyte at 5 wt%. Example 5: Manufacturing of lithium secondary batteries A lithium secondary battery was manufactured in the same manner as in Example 1, except that trimethylene borate (TMEB) was included in the non-aqueous electrolyte at 0.5 wt% as an additive, and the compound represented by the chemical formula 2-1 was included in the non-aqueous electrolyte at 0.05 wt%. Comparative Example 1: Manufacturing of Lithium Secondary Battery A lithium secondary battery was manufactured in the same manner as in Example 1, except that no additives were included. Comparative Example 2: Manufacturing of Lithium Secondary Battery A lithium secondary battery was manufactured in the same manner as in Example 1, except that only trimethylene borate (TMEB) was included as an additive in the non-aqueous electrolyte at 0.5 wt%. Comparative Example 3: Manufacturing of Lithium Secondary Battery A lithium secondary battery was manufactured in the same manner as in Example 1, except that only the compound represented by the above chemical formula 2-1 was included in the non-aqueous electrolyte at 0.5 wt% as an additive. Comparative Example 4: Manufacturing of Lithium Secondary Battery Instead of a single particle or pseudo-single particle type cathode active material as a cathode active material, a secondary particle type cathode active material (LiNi 0.6 Co 0.1 Mn 0.3 A lithium secondary battery was manufactured in the same manner as in Example 1, except that O2) was used and no additives were included in the non-aqueous electrolyte. The average particle diameter (D) of the above positive electrode active material 50 ) is 5.2㎛, and the BET surface area is 0.638m 2 / g was. Comparative Example 5: Manufacturing of Lithium Secondary Battery Instead of a single particle or pseudo-single particle type cathode active material as a cathode active material, a secondary particle type cathode active material (LiNi 0.6 Co 0.1 Mn 0.3 A lithium secondary battery was manufactured in the same manner as in Example 1, except that O2) was used. The average particle diameter (D) of the above positive electrode active material 50 ) is 5.2㎛, and the BET surface area is 0.638m 2 / g was. Comparative Example 6: Manufacturing of Lithium Secondary Battery Single particle or pseudo-single particle type cathode active material (LiNi 0.6 Co 0.2 Mn 0.2 A lithium secondary battery was manufactured in the same manner as in Example 1, except that O2) was used and no additives were included in the non-aqueous electrolyte. The average particle diameter (D) of the above positive electrode active material 50 ) is 4.0㎛, and the BET surface area is 0.8m 2 / g was. Comparative Example 7: Manufacturing of Lithium Secondary Battery Single particle or pseudo-single particle type cathode active material (LiNi 0.6 Co 0.2 Mn 0.2 A lithium secondary battery was manufactured in the same manner as in Example 1, except that only trimethylene borate (TMEB) was included as an additive in the non-aqueous electrolyte at 0.5 wt% using O2). The average particle diameter (D) of the above positive electrode active material 50 ) is 4.0㎛, and the BET surface area is 0.8m 2 / g was. Comparative Example 8: Manufacturing of Lithium Secondary Battery Single particle or pseudo-single particle type cathode active material (LiNi 0.6 Co 0.2 Mn 0.2 A lithium secondary battery was manufactured in the same manner as in Example 1, except that only the compound represented by the above chemical formula 2-1 was included as an additive in the non-aqueous electrolyte at 0.5 wt%. The average particle diameter (D) of the above positive electrode active material 50 ) is 4.0㎛, and the BET surface area is 0.8m 2 / g was. Comparative Example 9: Manufacturing of Lithium Secondary Battery Single particle or pseudo-single particle type cathode active material (LiNi 0.6 Co 0.2 Mn 0.2 A lithium secondary battery was manufactured in the same manner as in Example 1, except that O2) was used. The average particle diameter (D) of the above positive electrode active material 50 ) is 4.0㎛, and the BET surface area is 0.8m 2 / g was. Cathode active material, non-aqueous electrolyte composition, particle shape, lithium salt (LiPF6), organic solvent, additive, molar concentration (M), TMEB content (wt%) [Chemical formula 2-1], content (wt%), Example 1, LiNi 0.6 Co 0.1Mn 0.3 O2 single particle or pseudo-single particle 1.2 EC:EMC (volume ratio 20:80) 0.5 0.5 Example 2 LiNi 0.6 Co 0.1 Mn 0.3 O2 single particle or pseudo-single particle 1.2 EC:EMC (volume ratio 20:80) 100.5 Example 3 LiNi 0.6 Co 0.1 Mn 0.3 O2 single particle or pseudo-single particle 1.2 EC:EMC (volume ratio 20:80) 0.05 0.5 Example 4 LiNi 0.6 Co 0.1 Mn 0.3 O2 single particle or pseudo-single particle 1.2 EC:EMC (volume ratio 20:80) 0.55 Example 5 LiNi 0.6 Co 0.1 Mn 0.3 O2 single particle or pseudo-single particle 1.2 EC:EMC (volume ratio 20:80) 0.5 0.05 Comparative example 1 LiNi 0.6 Co 0.1 Mn 0.3 O2 single particle or similar-single particle 1.2EC:EMC (volume ratio 20:80)--comparative example 2LiNi 0.6 Co 0.1 Mn 0.3 O2 single particle or similar- single particle 1.2EC:EMC (volume ratio 20:80) 0.5-comparative example 3LiNi 0.6 Co 0.1 Mn 0.3 O2 single particle or similar-single particle 1.2EC:EMC (volume ratio 20:80)-0.5Comparative example 4LiNi 0.6 Co 0.1 Mn 0.3 O22 secondary particles 1.2EC:EMC (volume ratio 20:80)--comparative example 5LiNi 0.6 Co 0.1 Mn 0.3 O22 secondary particle 1.2 EC:EMC (volume ratio 20:80) 0.5 0.5 Comparative example 6 LiNi 0.6 Co 0.2 Mn 0.2 O2 single particle or similar-single particle 1.2EC:EMC (volume ratio 20:80)--comparative example 7LiNi 0.6 Co0.2 Mn 0.2 O2 single particle or similar- single particle 1.2EC:EMC (volume ratio 20:80) 0.5-comparative example 8LiNi 0.6 Co 0.2 Mn 0.2 O2 single particle or similar-single particle 1.2EC:EMC (volume ratio 20:80)-0.5Comparative example 9LiNi 0.6 Co 0.2 Mn 0.2 O2 single particle or similar-single particle 1.2EC:EMC (volume ratio 20:80) 0.5 0.5 Experimental examples and reference examples Experimental Example 1: Evaluation of High-Temperature Storage Characteristics The lithium secondary batteries of Examples 1 to 5 and Comparative Examples 1 to 9 were charged to 4.4 V / 0.2974 mA under 0.1 C / 4.4 V CC-CV conditions at room temperature and discharged to 2.5 V at 0.1 C to perform initial charging and discharging. Thereafter, the batteries were charged to 4.4 V / 0.2974 mA under 0.1 C / 4.4 V CC-CV conditions at room temperature and stored at 60°C for 8 weeks. The resistance of the lithium secondary batteries before storage was measured and set as the resistance of the initial lithium secondary batteries. The lithium secondary batteries stored for the above 8 weeks were charged to 4.4 V / 0.2974 mA under 0.1 C / 4.4 V CC-CV conditions and discharged to 2.5 V at 0.1 C to measure the capacity at discharge, and the resistance increased during the 8-week storage period was calculated. The capacity retention rate and resistance increase rate were evaluated according to the following formula, and the results are shown in Table 2 below. Capacity retention rate (%) = (Discharge capacity after 8 weeks of storage / Initial discharge capacity) X 100 Resistance increase rate (%) = (Resistance after 8 weeks of storage / Initial resistance) X 100 Experimental Example 2: Evaluation of High-Temperature Lifetime Characteristics The lithium secondary batteries of Examples 1 to 5 and Comparative Examples 1 to 9 were charged to 4.4 V at 45°C using an electrochemical charger / discharger at room temperature under CC / CV, 0.3 C conditions, and then discharged to 2.5 V under CC, 0.3 C conditions, which is considered one cycle, and 200 cycles of charge and discharge were performed, and the capacity retention rate and resistance increase rate were evaluated according to the following equation, and the results are shown in Table 2 below. Capacity retention rate (%) = (discharge capacity after 200 cycles / discharge capacity after 1 cycle) X 100 Resistance increase rate (%) = (Resistance after 200 cycles / Resistance after 1 cycle) X 100 Experimental Example 1 (High Temperature Storage Characteristics) Experimental Example 2 (High Temperature Lifetime Characteristics) Capacity Retention Rate (%) Resistance Increase Rate (%) Capacity Retention Rate (%) Resistance Increase Rate (%) Example 192199120 Example 288238822 Example 386218425 Example 489228621 Example 588238822 Comparative Example 178337629 Comparative Example 280317927 Comparative Example 378327829 Comparative Example 465526242 Comparative Example 568286532 Comparative Example 670556548 Comparative Example 772367437 Comparative Example 870546847 Comparative Example 972387335 Referring to Table 2 above, it can be confirmed that the high-temperature storage characteristics and high-temperature life characteristics of Examples 1 to 5 of the present invention are significantly improved compared to Comparative Examples 1 to 9. Specifically, referring to Examples 1 to 5 and Comparative Examples 1 to 3, it can be seen that when neither TMEB nor the compound represented by [Chemical Formula 2-1] was added, the high-temperature storage characteristics and high-temperature life characteristics were significantly reduced. In other words, it can be seen that the effect of improving the high-temperature storage characteristics and high-temperature life characteristics of the present invention is an effect that appears only when the two compounds are simultaneously introduced into the non-aqueous electrolyte. Referring to Comparative Examples 4 and 5, it can be confirmed that when the positive electrode active material is in the form of secondary particles, the high-temperature storage characteristics and high-temperature life characteristics are not significantly improved even when TMEB and the compound represented by [Chemical Formula 2-1] are added simultaneously. Referring to Comparative Examples 6 to 9, it can be confirmed that when the composition of the positive electrode active material does not satisfy the specific relationship described above, the high-temperature storage characteristics and high-temperature life characteristics are not significantly improved even when TMEB and the compound represented by [Chemical Formula 2-1] are added simultaneously. Reference example Reference Example 1 (Manufacturing of non-aqueous electrolyte) The same non-aqueous electrolyte as that used in Example 1 was used, except that no additive was included in the non-aqueous electrolyte. (Lithium secondary battery manufacturing) Positive electrode active material (secondary particle form, LiNi) 0.86 Co 0.08 Mn 0.06 O2): Conductive agent (CNT): Binder (SBR-CMC) were added to N-methyl-2-pyrrolidone (NMP), a solvent, in a weight ratio of 96.78:1.20:2.02 to prepare a cathode slurry (solid content 60 wt%). The average particle diameter (D) of the above positive electrode active material 50 ) is 4.3㎛, and the BET surface area is 0.68m 2 / g was. The above positive electrode slurry was applied to a positive electrode current collector (Al thin film) having a thickness of 13.5 μm, and dried and roll pressed to manufacture a positive electrode. A negative electrode slurry (solid content 60 wt%) was prepared by adding negative electrode active material (graphite): conductive agent (carbon black): binder (polyvinylidene fluoride (PVdF)) to distilled water as a solvent in a weight ratio of 96.15:0.50:3.35. The above negative electrode slurry was applied to a negative electrode current collector (Cu thin film) having a thickness of 6 μm, and dried and roll pressed to manufacture a negative electrode. A porous polymer was interposed as a separator between the positive and negative electrodes manufactured above in a dry room, and then the non-aqueous electrolyte manufactured above was injected to manufacture a lithium secondary battery. Reference Example 2 A lithium secondary battery was manufactured in the same manner as in Reference Example 1, except that only trimethylene borate (TMEB) was included as an additive in the non-aqueous electrolyte at 0.5 wt%. Reference Example 3 A lithium secondary battery was manufactured in the same manner as in Reference Example 1, except that only the compound represented by the above chemical formula 2-1 was included in the non-aqueous electrolyte at 0.5 wt% as an additive. Reference Example 4 A lithium secondary battery was manufactured in the same manner as in Reference Example 1, except that trimethylene borate (TMEB) was included in the non-aqueous electrolyte at 0.5 wt% as an additive, and the compound represented by Chemical Formula 2-1 was included in the non-aqueous electrolyte at 0.5 wt%. Positive electrode active material, non-aqueous electrolyte composition, particle shape, lithium salt (LiPF6), organic solvent, additive, molar concentration (M), TMEB content (weight %) [Chemical formula 2-1], content (weight %), reference example 1, LiNi 0.86 Co 0.08 Mn 0.06 O22 secondary particles 1.5EC:EMC (volume ratio 20:80)--reference example 2LiNi 0.86 Co 0.08 Mn 0.06 O22 secondary particle 1.5EC:EMC (volume ratio 20:80) 0.5-Reference example 3LiNi 0.86 Co 0.08 Mn 0.06 O22 secondary particle 1.5EC:EMC (volume ratio 20:80)-0.5 Reference example 4LiNi 0.86 Co 0.08 Mn0.06 O22 secondary particles 1.5EC:EMC (volume ratio 20:80) 0.50.5 Reference Experimental Example 1: Evaluation of High-Temperature Lifetime Characteristics The lithium secondary batteries manufactured in Reference Examples 1 to 4 were charged to 4.2 V at 45°C using an electrochemical charger / discharger at room temperature under CC / CV, 0.3 C conditions, and then discharged to 2.5 V under CC, 0.3 C conditions, which is considered one cycle, and 200 charge / discharge cycles were performed, and the capacity retention rate and resistance increase rate were evaluated according to the following equations, and the results are shown in [Table 4] below. Capacity retention rate (%) = (discharge capacity after 200 cycles / discharge capacity after 1 cycle) X 100 Resistance increase rate (%) = (Resistance after 200 cycles / Resistance after 1 cycle) X 100 Reference Experimental Example 1 (High Temperature Life Characteristics) Capacity Retention Rate (%) Resistance Increase Rate (%) Reference Example 18225 Reference Example 28326 Reference Example 38228 Reference Example 48424 In the case of high-nickel lithium composite transition metal oxides in which the content of Ni exceeds 70 mol% of the total metals excluding lithium in the lithium composite transition metal oxide, as the voltage increases, an inactive surface is created due to surface degradation (rock-salt degradation) caused by the phase structure change from H2 to H3 at the anode, which results in a decrease in performance and limits the operating voltage. Therefore, it is difficult to achieve the effect of the present invention, which is the formation of an anode film through a ring-opening reaction of the additive according to the present invention under high-voltage conditions. Accordingly, referring to Table 4 above, it can be confirmed that in the case of Reference Example 4 including the additive according to the present invention, the effect on high-temperature life characteristics is minimal compared to Reference Example 1 not including the additive, Reference Example 2 using only TMEB, and Reference Example 3 using only the chemical formula 2-1. Through this, it can be clearly understood that the effect of improving the high-temperature life characteristics and high-temperature storage performance of the present invention, and particularly, the effect of improving the high-temperature life characteristics, is only expressed when the cathode active material according to the present invention and the non-aqueous electrolyte are combined, rather than the high-nickel lithium composite transition metal oxide.

Claims

1. A positive electrode; a negative electrode opposite to the positive electrode; a separator interposed between the positive electrode and the negative electrode; and a non-aqueous electrolyte; The above positive electrode includes a positive electrode active material, The above positive electrode active material includes lithium nickel-based oxide particles represented by the following chemical formula A, The above lithium nickel-based oxide particles are in the form of single particles consisting of one single nodule or pseudo-single particles consisting of a composite of 30 or fewer nodules, The above non-aqueous electrolyte comprises a lithium salt, an organic solvent and an additive, The additive comprises a cyclic borate compound represented by the following chemical formula 1; and a lithium secondary battery comprising a compound containing a propargyl group: [Chemical Formula A] Li a Ni b Co c Mr d M 1 e O2 In the above chemical formula A, M 1 is at least one selected from the group consisting of Ti, Mg, Al, Zr, Y, Ba, Ca, Sr, W, Ta, Nb, and Mo, and 0.8≤a≤1.2, 0.5≤b≤0.7, 0 <c<0.2, 0<d≤0.4, 0≤e≤0.2, b+c+d+e=1이고, [Chemical Formula 1] In the above chemical formula 1, R1 is an alkylene group having 1 to 10 carbon atoms, n1 and n2 are integers independently selected from 0 to 5, R2 and R3 are each independently hydrogen, halogen, nitrile group, ester group, ether group, ketone group, carboxyl group, substituted or unsubstituted alkyl group, substituted or unsubstituted alkenyl group, substituted or unsubstituted alkynyl group, substituted or unsubstituted alkoxy group, boron group, borate group, isocyanate group, isothiocyanate group, silyl group, siloxane group, sulfone group, sulfonate group, sulfate group or a combination of two or more thereof, n3 is 2n1+2, n4 is 2n2+2, If n3 is an integer greater than or equal to 2, multiple R2s can be the same or different, If n4 is an integer greater than or equal to 2, multiple R3s may be the same or different.

2. In paragraph 1, A lithium secondary battery wherein b / c of ​​the above chemical formula A is 3.2 to 9.

0.

3. In paragraph 1, A lithium secondary battery wherein b / d of the above chemical formula A is 1.5 to 2.

8.

4. In paragraph 1, The above chemical formula A is a lithium secondary battery represented by the following chemical formula A-1: [Chemical Formula A-1] Li a Ni b Co c Mr d M 1 e O2 In the above chemical formula A-1, M 1 is at least one selected from the group consisting of Ti, Mg, Al, Zr, Y, Ba, Ca, Sr, W, Ta, Nb, and Mo, and 0.8≤a≤1.2, 0.55≤b≤0.65, 0 <c≤0.15, 0.2<d≤0.4, 0≤e≤0.1, 3.2≤b / c≤9.0, 1.5≤b / d≤2.8, b+c+d+e=1이다.

5. In paragraph 1, The compound represented by the above chemical formula 1 is a lithium secondary battery represented by the following chemical formula 1-1: [Chemical Formula 1-1] In the above [Chemical Formula 1-1], R2 and R3 are each independently as defined in the above [Chemical Formula 1], n3 is 6, and n4 is 6.

6. In paragraph 1, The compound represented by the above chemical formula 1 is a lithium secondary battery represented by the following chemical formula 1-2: [Chemical Formula 1-2] .

7. In paragraph 1, A lithium secondary battery comprising a compound containing the above propargyl group, wherein the compound comprises at least one selected from the group consisting of the following chemical formulas 2 and 3: [Chemical Formula 2] In the above chemical formula 2, R6 is an alkylene group having 1 to 3 carbon atoms that can be substituted with fluorine, R7 to R9 are each independently hydrogen, an alkyl group having 1 to 3 carbon atoms, and a nitrile group, or a combination of two or more thereof, [Chemical Formula 3] In the above chemical formula 3, R 10 is hydrogen, an alkyl group having 1 to 10 carbon atoms, and a cycloalkyl group having 3 to 8 carbon atoms, or a combination of two or more thereof, and R 11 is an alkylene group having 1 to 8 carbon atoms that can be substituted with fluorine.

8. In paragraph 7, The compound represented by the above chemical formula 2 is a lithium secondary battery represented by the following chemical formula 2-1: [Chemical Formula 2-1] .

9. In paragraph 7, The compound represented by the above chemical formula 3 is a lithium secondary battery represented by the following chemical formula 3-1: [Chemical Formula 3-1] .

10. In paragraph 1, A lithium secondary battery, wherein the cyclic borate compound is contained in the non-aqueous electrolyte in an amount of 0.01 wt% to 12 wt% based on the total weight of the non-aqueous electrolyte.

11. In paragraph 1, A lithium secondary battery, wherein the compound containing the propargyl group is included in the non-aqueous electrolyte in an amount of 0.01 wt% to 6 wt% based on the total weight of the non-aqueous electrolyte.

12. In paragraph 1, A lithium secondary battery wherein the weight ratio of the cyclic borate compound and the compound containing the propargyl group is 1:99 to 99:

1.

13. In paragraph 1, The above lithium secondary battery has a charging end voltage when operated. Lithium secondary battery with a voltage of 4.30 V or higher.

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