Cylindrical lithium secondary battery

Abstract

The invention relates to a cylindrical lithium secondary cell comprising an electrode assembly in which the anode, separator, and cathode are stacked sequentially and wound in one direction, an electrolyte, and a cell housing in which the electrode assembly and electrolyte are contained, in which the electrolyte consists of an ester-based solvent, and the ion diffusion value in the cell (DIB) determined by Equation 1 below is in the range from 162 mS / mm2 to 635 mS / mm2. [Equation 1] In Equation 1 above, h (in mm) is the height of the cylindrical lithium secondary cell, R (in mm) is the diameter of the cylindrical lithium secondary cell, r (in mm) is the radius of the center winding of the electrode assembly, C (in mS / mm) is the ion conductivity of the electrolyte, and t+ is the cation transport rate of the electrolyte.

Description

Cylindrical lithium secondary battery Cross-citation with related applications This application claims the benefit of priority from Korean Patent Application No. 10-2023-0173833, filed December 4, 2023, the entire contents of which are incorporated herein by reference. Technical field The present invention relates to a cylindrical lithium secondary battery, and more specifically, to a cylindrical lithium secondary battery having improved electrolyte impregnation properties and electrolyte ion diffusion properties and excellent life characteristics. With the advancement of technology in electric vehicles, portable electronic devices, etc., the demand for lithium secondary batteries as an energy source is rapidly increasing. Lithium secondary batteries can be classified into cylindrical, square, and pouch-type batteries depending on the shape of the battery case. Among these, a cylindrical battery is manufactured by sequentially stacking a sheet-shaped positive electrode, a separator, and an anode in a cylindrical battery case, and then winding them in one direction to manufacture a jelly-roll-type electrode assembly, and then covering the top of the battery case with a cap plate to seal it. The positive and negative electrodes are each provided with a strip-shaped positive electrode tab and a negative electrode tab, and the positive and negative electrode tabs are connected to electrode terminals and electrically connected to an external power source. For reference, the positive electrode terminal is the cap plate, and the negative electrode terminal is the battery case. However, in the case of a conventional cylindrical battery having such a structure, there is a problem that current is concentrated on the strip-shaped electrode tab, resulting in high resistance, a lot of heat generation, and poor current collection efficiency. However, resistance and heat generation were not major issues for small cylindrical secondary batteries with form factors such as 18650 (cylindrical secondary battery with a diameter of 18 mm x a height of 65 mm) or 21700 (cylindrical secondary battery with a diameter of 21 mm x a height of 70 mm), which were mainly used in the past. However, recently, with the demand for increased driving range and fast charging speed for electric vehicles, the development and use of large cylindrical secondary batteries with larger form factors, such as 4680 (a cylindrical secondary battery with a diameter of 46 mm and a height of 80 mm), are being reviewed. In addition, in order to improve the rapid charging characteristics of such large cylindrical secondary batteries, a so-called tab-less cylindrical secondary battery has been proposed, which utilizes the current collectors themselves of the non-conductive portions of the positive and negative electrodes as electrode tabs instead of using separate electrode tabs in the form of strips. The large-sized cylindrical secondary battery having the above tab-less structure can not only exhibit relatively large capacity characteristics and energy density, but also has the advantage of increasing the production efficiency of cylindrical secondary batteries for electric vehicles and reducing their production costs. In addition, by applying the above tab-less structure, the number of parts is reduced while increasing the electrical connection (contact) area between the electrode tab and the electrode terminal and shortening the movement distance of electrons, thereby improving the output characteristics and dispersing the heat generated during the charging and discharging processes. However, in the case of a large cylindrical lithium secondary battery, since the internal space arrangement and structure are different from those of a conventional small cylindrical lithium secondary battery, the characteristics of the large cylindrical lithium secondary battery are different from those of a conventional cylindrical lithium secondary battery. For example, in a conventional cylindrical lithium secondary battery, as the injection amount increases, the electrolyte can be sufficiently impregnated into the electrode assembly, so that the overall characteristics of the lithium secondary battery tend to increase. However, in a large cylindrical secondary battery applying the tab-less structure, etc., a process is performed to press a part where the active material layer is not coated in order to provide sufficient weldability with the case and terminal parts, so that the electrolyte movement path between the positive electrode, the separator, and the negative electrode inside the wound electrode current collector is blocked, so that the electrolyte movement does not occur properly, and even if the injection amount of the electrolyte increases, there is a limit to the improvement of the electrolyte impregnation property. Accordingly, since large cylindrical secondary batteries have different internal structures and spatial arrangements from conventional cylindrical lithium secondary batteries and different impregnation characteristics of wound electrode assemblies, it is necessary to appropriately control the characteristics of the electrolyte to be injected, and there is a need to develop a technology that can improve the overall performance of the battery by improving the electrolyte impregnation characteristics. The present invention is intended to solve the above problems, and to provide a cylindrical lithium secondary battery having improved electrolyte impregnation properties and electrolyte ion diffusion properties, thereby exhibiting excellent rapid charging characteristics, life characteristics, and high-temperature life characteristics. [1] The present invention is a cylindrical lithium secondary battery including an electrode assembly in which a cathode, a separator, and an anode are sequentially laminated and wound in one direction; an electrolyte; and a battery case in which the electrode assembly and the electrolyte are accommodated, wherein the electrolyte includes an ester solvent and has a DIB (Diffusion of Ions in a Battery) value of 162 mS / mm defined by the following formula 1. 2 Within 635mS / mm 2 A cylindrical lithium secondary battery is provided. [Formula 1] In the above equation 1, h (unit: mm) is the height of the cylindrical lithium secondary battery, R (unit: mm) is the diameter of the cylindrical lithium secondary battery, r (unit: mm) is the radius of the winding center of the electrode assembly, C (unit: mS / mm) is the ionic conductivity of the electrolyte, and t + refers to the cation transport rate of the electrolyte. [2] The present invention provides a cylindrical lithium secondary battery, wherein, in the above [1], C is 1.35 mS / mm to 1.70 mS / mm. [3] The present invention, in the above [1] or [2], the t + Provides a cylindrical lithium secondary battery having an electric field strength of 0.25 to 0.60. [4] The present invention provides a cylindrical lithium secondary battery, wherein the viscosity of the electrolyte at 25° C. is 2.80 cP or less in at least one of the above [1] to [3]. [5] The present invention provides a cylindrical lithium secondary battery, wherein, in at least one of the above [1] to [4], the ester solvent is included in an amount of 10 to 30 volume% with respect to the total volume of the electrolyte. [6] The present invention provides a cylindrical lithium secondary battery, wherein in at least one of the above [1] to [5], the ester solvent includes at least one selected from the group consisting of methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate, ethyl propionate, propyl propionate, and butyl propionate, γ-butyrolactone, γ-valerolactone, γ-caprolactone, σ-valerolactone, and ε-caprolactone. [7] The present invention provides a cylindrical lithium secondary battery, wherein in at least one of the above [1] to [6], the electrolyte includes a lithium salt, and the lithium salt is included in the electrolyte at a concentration of 0.5 M to 2.0 M. [8] The present invention provides a cylindrical lithium secondary battery, wherein in at least one of the above [1] to [7], the electrolyte includes at least one selected from the group consisting of a cyclic carbonate solvent and a linear carbonate solvent. [9] The present invention provides a cylindrical lithium secondary battery, wherein, in at least one of the above [1] to [8], the ratio of R to h (R / h) is 0.4 or more.

[0010] The present invention provides a cylindrical lithium secondary battery, wherein in at least one of the above [1] to [9], the cylindrical lithium secondary battery is a 46110 cell, a 48110 cell, a 4880 cell or a 4680 cell.

[0011] The present invention provides a cylindrical lithium secondary battery, wherein, in at least one of the above [1] to

[0010] , the cylindrical lithium secondary battery includes a non-conductive portion in which an active material layer is not formed on at least a portion of the positive electrode and the negative electrode, and the non-conductive portion of the positive electrode and the non-conductive portion of the negative electrode are defined as electrode tabs.

[0012] The present invention provides a cylindrical lithium secondary battery, wherein, in the above

[0011] , the positive electrode non-coated portion and the negative electrode non-coated portion are formed along the direction in which the electrode assembly is wound on one end of each of the positive and negative electrodes, and a current collecting plate is coupled to each of the positive electrode non-coated portion and the negative electrode non-coated portion, and the current collecting plate is connected to an electrode terminal.

[0013] The present invention provides a cylindrical lithium secondary battery, wherein, in the above

[0011] , the positive and negative electrode non-conductive parts are processed into a plurality of independently foldable segments, and at least some of the plurality of segments are folded toward the winding center of the electrode assembly.

[0014] The present invention provides a cylindrical lithium secondary battery, wherein at least some of the plurality of folded segments in the above

[0013] overlap on the upper and lower sides of the electrode assembly, and the current collecting plate is bonded on the plurality of overlapped segments.

[0015] The present invention provides a battery pack including a cylindrical lithium secondary battery according to at least one of the above [1] to

[0014] as a unit cell. According to the present invention, by including an ester solvent in the electrolyte and controlling the ion conductivity of the electrolyte, the cation transport rate, the diameter and height of the cylindrical secondary battery, and the radius of the center of the winding of the electrode assembly to satisfy a specific relationship, the electrolyte impregnation property can be improved without increasing the electrolyte injection amount, and thus the output and life characteristics of the lithium secondary battery can be improved. In addition, the cylindrical lithium secondary battery according to the present invention can have excellent rapid charging characteristics and excellent high-temperature life characteristics by suppressing the lithium plating phenomenon in which lithium is precipitated from the negative electrode during rapid charging. Figure 1 is a drawing showing a state of lamination before winding of an electrode assembly according to the present invention. FIG. 2 is a cross-sectional view showing the structure of an electrode of an electrode assembly according to one embodiment of the present invention. FIG. 3 is a drawing for explaining the structure of an electrode assembly according to one embodiment of the present invention. FIG. 4 is a cross-sectional view showing the structure of a lithium secondary battery according to one embodiment of the present invention. FIG. 5 is a cross-sectional view showing the structure of a lithium secondary battery according to another embodiment of the present invention. Figure 6 is a drawing for explaining a battery pack according to the present invention. Hereinafter, the present invention will be described in more detail. The 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 having meanings and concepts consistent with the technical idea of ​​the present invention, based on the principle that the inventor can appropriately define the concept of the term in order to explain his or her own invention in the best manner. The terminology used in this specification is for the purpose of describing exemplary embodiments only and is not intended to limit the invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this specification, it should be understood that the terms “include,” “comprising,” or “having” are intended to specify the presence of a feature, number, step, component, or combination thereof, but do not preclude the possibility of the presence or addition of one or more other features, numbers, steps, components, or combinations thereof. In the present invention, the term "single particle type" means a particle formed by an aggregation of 30 or fewer sub-particles. The sub-particle unit constituting the single particle type particle is called a nodule. Single particle type particles include a single particle composed of one nodule and a pseudo-single particle which is a composite of 2 to 30 nodules. The above “nodule” is a sub-particle unit that constitutes a single particle and a pseudo-single particle, and may be a single crystal without a crystalline grain boundary, or a polycrystal that has no apparent grain boundary when observed under a field of view of 5,000 to 20,000 times using a scanning electron microscope. In the present invention, a “secondary particle” means a particle formed by an aggregation of more than 30 sub-particles. In order to distinguish it from the sub-particles forming a single particle, the sub-particles forming a secondary particle are called “primary particles.” In the present invention, “particle” is a concept including any one or all of a single particle, a quasi-single particle, a primary particle, a nodule, and a secondary particle. In this specification, the “ionic conductivity (C) of the electrolyte” can be measured by submerging the ionic conductivity measuring probe in a bath filled with electrolyte at 25°C using Seven Excellence S700 equipment from METTLER TOLEDO, and then measuring the probe through the impregnated probe. At this time, the electrolyte may be an electrolyte that has been injected into a lithium secondary battery and has undergone an activation process, but is not limited thereto. The activation may be performed by charging to 4.2 V at a 0.2 C-rate and 0.01 C cut-off condition, and discharging to 2.8 V at a 0.2 C-rate. In this specification, “cation transport rate (t) of the electrolyte + )” means the ratio of the current carried by cations to the total current flowing in the electrolyte. The “cation transport rate (t) of the electrolyte + )” may be measured at 25°C using a VMP3 Multichannel potentiostat from Bio-logic Science Instruments after a coin cell is manufactured in the form of lithium (Li) metal / electrolyte / lithium (Li) metal using the electrolyte included in the lithium secondary battery according to the present invention. At this time, the electrolyte may be an electrolyte that has been injected into the lithium secondary battery and has undergone an activation process, but is not limited thereto. The activation may be performed by charging to 4.2 V at 0.2 C-rate, 0.01 C cut-off conditions and discharging to 2.8 V at 0.2 C-rate. Specifically, the cation transport rate may be obtained by (1) measuring the resistance and current of a cell in an initial state, (2) applying a voltage of 10 mV to the cell in the initial state and monitoring the current drop, and measuring the resistance and current of the cell in a steady state where the current value remains constant after 10 hours, and (3) calculating the cation transport rate by the following Equation A. [Formula A] Cation transport rate (t + ) = In the above equation A, △V is the applied voltage change (10 mV), and the i 0 is the current (unit: mA) of the cell in the initial state, and R 0 is the resistance (unit: Ω) of the cell in the initial state, and i ss is the current (unit: mA) of the cell in the above normal state, and R ss is the resistance (unit: Ω) of the cell in the above normal state. In this specification, “viscosity of electrolyte at 25°C” can be measured at 25°C, 0.1 to 1 rpm using a Rheometer viscometer (Brookfield DVNXCP Rheometer). At this time, the electrolyte may be an electrolyte that has been injected into a lithium secondary battery and has undergone an activation process, and the activation may be performed by charging to 4.2 V at 0.2 C-rate, 0.01 C cut-off conditions and discharging to 2.8 V at 0.2 C-rate. In this specification, the “radius of the winding center” means the distance from the center point to the winding start point in an electrode assembly in which a separator, a cathode, a separator, and an anode are sequentially laminated and wound, and the winding start point corresponds to the end point where winding of the electrode assembly begins. Conventional cylindrical lithium secondary batteries have improved the electrolyte impregnation property by increasing the porosity of the electrode or the amount of electrolyte solution, thereby increasing the overall performance of the battery. However, in the case of recent large-sized cylindrical lithium secondary batteries, in order to solve problems such as an increase in internal heat generation due to an increase in battery volume, a tab-less structure has been applied, and thus, the internal space arrangement and structure are different from those of conventional cylindrical lithium secondary batteries, and different impregnation characteristics have been obtained. Accordingly, in recent large-sized cylindrical lithium secondary batteries, the amount of electrolyte solution and the effect of improving electrolyte impregnation are not proportional, and when the amount of electrolyte solution is increased beyond a certain level, gas is generated due to the decomposition of components in the electrolyte, which increases the pressure inside the battery, resulting in a decrease in electrolyte impregnation. Therefore, in order to improve the electrolyte impregnation property in large-sized cylindrical lithium secondary batteries, it is necessary to control the characteristics of the electrolyte itself. Accordingly, the inventors of the present invention have conducted repeated studies to develop a cylindrical lithium secondary battery with improved electrolyte impregnation properties and life characteristics without increasing the amount of electrolyte solution beyond a certain level, and as a result, they have found that by including an ester solvent, making the viscosity of the electrolyte satisfy a specific range, and controlling the ion conductivity and cation transport rate of the electrolyte according to the structure of the cylindrical lithium secondary battery, the ion diffusivity and electrolyte impregnation properties in the electrolyte can be improved, thereby improving the life characteristics of the lithium secondary battery, thereby completing the present invention. A cylindrical 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. Hereinafter, the present invention will be described in more detail. Cylindrical lithium secondary battery A cylindrical lithium secondary battery according to the present invention is a cylindrical lithium secondary battery including an electrode assembly in which a cathode, a separator, and an anode are sequentially laminated and wound in one direction; an electrolyte; and a battery case in which the electrode assembly and the electrolyte are accommodated, wherein the electrolyte includes an ester solvent and has a DIB (Diffusion of Ions in a Battery) value defined by the following equation 1 of 162 mS / mm 2 Within 635mS / mm 2 am. [Formula 1] In the above equation 1, h (unit: mm) is the height of the cylindrical lithium secondary battery, R (unit: mm) is the diameter of the cylindrical lithium secondary battery, r (unit: mm) is the radius of the winding center of the electrode assembly, C (unit: mS / mm) is the ionic conductivity of the electrolyte, and t + refers to the cation transport rate of the electrolyte. The above DIB value corresponds to a parameter that defines an organic relationship among the height, diameter, radius of the center of the winding of the electrode assembly, ionic conductivity of the electrolyte, and cation transport rate of the electrolyte of the cylindrical secondary battery. When the height, diameter, radius of the center of the winding of the electrode assembly, ionic conductivity of the electrolyte, and cation transport rate of the electrolyte of the cylindrical secondary battery, which form the DIB value, are mutually adjusted so that the DIB value satisfies a specific range, the rapid charging characteristics and high-temperature storage characteristics of the lithium secondary battery can be improved without excessively increasing the amount of electrolyte injected into the lithium secondary battery. The DIB (Diffusion of Ions in a Battery) value defined by the above equation 1 is 162 mS / mm 2 Within 635mS / mm 2 Specifically, the DIB value defined by the above equation 1 is 162 mS / mm 2 Above, 163mS / mm 2 Above, 164mS / mm2 Above, 165mS / mm 2 Above, 166mS / mm 2 Above, 167mS / mm 2 Above, 168mS / mm 2 Above, 169mS / mm 2 Above, 170mS / mm 2 Above, 171mS / mm 2 Above, 172mS / mm 2 Above, 173mS / mm 2 Above, 174mS / mm 2 Above, 175mS / mm 2 Above, 176mS / mm 2 Above, 177mS / mm 2 Above, 178mS / mm 2 Above, 179mS / mm 2 It can be ideal, 180mS / mm 2 Above, 181mS / mm 2 Above, 182mS / mm 2 Above, 183mS / mm 2 It can be ideal, 635mS / mm 2 Below, 630mS / mm 2 Below, 620mS / mm 2 Below, 610mS / mm 2 Below, 600mS / mm 2 Below, 590mS / mm 2 Below, 580mS / mm 2 Below, 570mS / mm 2 Below, 560mS / mm 2 Below, 550mS / mm 2 Below, 540mS / mm 2 Below, 530mS / mm 2 Below, 520mS / mm 2 Below, 510mS / mm 2 Below, 500mS / mm 2 Below, 490mS / mm 2 Below, 480mS / mm 2 Below, 470mS / mm 2 Below, 460mS / mm 2 Below, 450mS / mm 2Below, 440mS / mm 2 Below, 430mS / mm 2 Below, 420mS / mm 2 Below, 410mS / mm 2 Below, 400mS / mm 2 Below, 390mS / mm 2 Below, 380mS / mm 2 Below, 370mS / mm 2 Below, 360mS / mm 2 Below, 350mS / mm 2 Below, 340mS / mm 2 Below, 330mS / mm 2 Below, 320mS / mm 2 Below, 310mS / mm 2 Below, 300mS / mm 2 Below, 290mS / mm 2 Below, 280mS / mm 2 Below, 280mS / mm 2 Below, 270mS / mm 2 Below, 260mS / mm 2 Below, 250mS / mm 2 Below, 240mS / mm 2 Below, 230mS / mm 2 Below, 220mS / mm 2 Below, 210mS / mm 2 Below, 205mS / mm 2 Below, 204mS / mm 2 Below, 203mS / mm 2 Below, 202mS / mm 2 Below, 201mS / mm 2 Below, 200mS / mm 2 Below, 199mS / mm 2 Below, 198mS / mm 2 Below, 197mS / mm 2 Below, 196mS / mm 2 Below, 195mS / mm 2 Below, 194mS / mm 2 Below, 193mS / mm 2 Below, 192mS / mm 2 Below, 191mS / mm 2Below, 190mS / mm 2 Below, 189mS / mm 2 Below, 188mS / mm 2 Below, 187mS / mm 2 Below, 186mS / mm 2 Below, 185mS / mm 2 or less, or 184 mS / mm 2 may be less than or equal to 162 mS / mm. For example, the DIB value defined by the above equation 1 is 162 mS / mm. 2 Within 635mS / mm 2 Below, 162mS / mm 2 Within 590mS / mm 2 , 162mS / mm 2 Within 500mS / mm 2 , 162mS / mm 2 Within 400mS / mm 2 , 162mS / mm 2 Within 300mS / mm 2 , 162mS / mm 2 Within 250mS / mm 2 , 162mS / mm 2 Within 203mS / mm 2 , 165mS / mm 2 Within 195mS / mm 2 , 168mS / mm 2 Within 190mS / mm 2 , or 175 mS / mm 2 Within 188mS / mm 2 If the above range is satisfied, the electrolyte impregnation property may be excellent, so that the output characteristics and life characteristics of the lithium secondary battery may be excellent. The above h may be 70 mm or more, preferably 75 mm or more, more preferably 80 mm or more, and R may be 40 mm or more, preferably 42 mm or more, more preferably 46 mm or more. When the above ranges are satisfied, excellent capacity characteristics can be implemented. The ratio of R to the above h (R / h, form factor ratio) may be 0.4 or more, preferably 0.4 to 0.8, more preferably 0.5 to 0.8. When the range of the form factor ratio is satisfied, a high-capacity characteristic can be implemented as a large-sized cylindrical lithium secondary battery. The above r may be 1 mm to 10 mm, preferably 2 mm to 9 mm, and more preferably 3 mm to 8 mm. When the above range is satisfied, detachment of the electrode due to stress caused by bending in the electrode assembly in the wound form can be suppressed, and the capacity can be secured to the maximum. The above C may be from 1.35 mS / mm to 1.70 mS / mm. Specifically, the C may be 1.35 mS / mm or more, 1.37 mS / mm or more, 1.40 mS / mm or more, 1.42 mS / mm or more, 1.45 mS / mm or more, 1.47 mS / mm or more, 1.50 mS / mm or more, and may be 1.70 mS / mm or less, 1.67 mS / mm or less, 1.65 mS / mm or less, 1.62 mS / mm or less, 1.60 mS / mm or less, 1.57 mS / mm or less, 1.55 mS / mm or less, 1.52 mS / mm or less. For example, the C may be from 1.35 mS / mm to 1.70 mS / mm, preferably from 1.37 mS / mm to 1.60 mS / mm, more preferably from 1.37 mS / mm to 1.57 mS / mm, and even more preferably from 1.45 mS / mm to 1.55 mS / mm. When the above range is satisfied, lithium ions can move smoothly in the electrolyte, so that the ion diffusion of the electrolyte can be improved. Accordingly, the life characteristics of the lithium secondary battery can be improved, and the high-temperature life characteristics can be excellent. The ionic conductivity C of the above electrolyte can be appropriately controlled by the type and content of the organic solvent, the concentration of the lithium salt, the type and content of the additive, etc. Specifically, the ionic conductivity of the electrolyte during charge and discharge of the lithium secondary battery can be better as the proportion of the salt in the electrolyte existing as a free ion is higher, and at this time, since the form in which the salt in the electrolyte exists when dissolved in the solvent is determined by the type and content of the organic solvent of the electrolyte, the concentration of the lithium salt, the additive, etc., the ionic conductivity C value of the electrolyte can be controlled by the above factors. Above t + can be 0.25 to 0.60. Specifically, the t + may be 0.25 or more, 0.27 or more, 0.30 or more, 0.32 or more, 0.35 or more, 0.37 or more, 0.40 or more, 0.42 or more, and may be 0.60 or less, 0.57 or less, 0.55 or less, 0.52 or less, 0.50 or less, 0.47 or less, 0.45 or less, 0.43 or less. For example, the above t + may be 0.25 to 0.60, preferably 0.30 to 0.55, more preferably 0.35 to 0.50, and even more preferably 0.40 to 0.45. When the above range is satisfied, the mobility of lithium ions in the electrolyte may be excellent, so that the output characteristics and life characteristics may be excellent, and the occurrence of ohmic resistance due to the formation of a concentration gradient in the electrolyte under rapid charging conditions may be prevented, so that the life characteristics may be improved during rapid charging. The cation transport rate t of the above electrolyte +The type and content of the organic solvent, the concentration of the lithium salt, the type and content of the additive, etc. can be appropriately controlled. Specifically, the efficiency of the movement of lithium ions in the electrolyte during charge and discharge of a lithium secondary battery is affected by the solubility and viscosity of lithium ions in the organic solvent, which can affect the mobility of lithium ions, and the polarity of the organic solvent molecules can also affect the dissociation of lithium ions. In addition, if the concentration of the lithium salt is too low, the ion conductivity may decrease, and if it is too high, the formation of ion pairs between lithium ions and anions may increase, which may limit the cation transport rate. In the case of the additive, it may affect the formation of a solid electrolyte interface film (SEI) at the interface between the electrode and the electrolyte, thereby promoting efficient movement of lithium ions, or it may improve the mobility of anions, thereby reducing the cation transport rate. Therefore, the cation transport rate t of the electrolyte + By appropriately adjusting the type and content of the organic solvent, the concentration of the lithium salt, the type and content of the additive, etc., the DIB value is 162 to 635 mS / mm. 2 can be satisfied. Next, each component of the cylindrical lithium secondary battery according to the present invention will be described in more detail. (1) Electrode assembly An electrode assembly according to the present invention is one in which a positive electrode, a separator, and a negative electrode are sequentially laminated and wound in one direction. FIG. 1 illustrates a pre-wound laminated structure of an electrode assembly according to one embodiment of the present invention, FIG. 2 illustrates a cross-sectional structure of an electrode plate (positive electrode or negative electrode) according to one embodiment of the present invention, and FIG. 3 illustrates a structure of an electrode assembly according to one embodiment of the present invention. Referring to FIGS. 1 and 2, the electrode assembly (A) of the present invention can be manufactured by winding a laminate formed by sequentially stacking a separator (12), an anode (10), a separator (12), and a cathode (11) at least once in one direction (X). Hereinafter, each component of the electrode assembly of the present invention will be described in more detail. 1) Bipolar The above positive electrode can be manufactured by a method of applying positive electrode slurry to one side or both sides of a sheet-shaped positive electrode collector, removing the solvent of the positive electrode slurry through a drying process, and then rolling. Meanwhile, a positive electrode including a non-coated region can be manufactured by a method of not applying the positive electrode slurry to some area of ​​the positive electrode collector, for example, one end of the positive electrode collector, during the application of the positive electrode slurry. In addition, the cathode slurry can be prepared by dispersing the cathode material according to the present invention in a solvent such as dimethyl sulfoxide (DMSO), isopropyl alcohol, N-methylpyrrolidone (NMP), acetone, or water. The cathode manufactured thus includes a cathode current collector; and a cathode active material layer; and the cathode active material layer may include a cathode active material. As the positive electrode collector, various positive electrode collectors used in the relevant technical field can be used. For example, as the positive electrode collector, stainless steel, aluminum, nickel, titanium, calcined carbon, or aluminum or stainless steel surface-treated with carbon, nickel, titanium, silver, etc. can be used. The positive electrode collector can typically have a thickness of 3 to 500 ㎛, and fine unevenness can be formed on the surface of the positive electrode collector to increase the adhesion of the positive electrode active material. The positive electrode collector can be used in various forms, such as a film, a sheet, a foil, a net, a porous body, a foam, a non-woven fabric, etc. The above-mentioned positive electrode active material layer may be positioned on the positive electrode current collector, and specifically, may be positioned on one side or both sides of the positive electrode current collector. The above-mentioned positive electrode active material layer may have a single layer or a multilayer structure of two or more layers. The above cathode active material may be cathode active materials generally used in the relevant technical field, and the type thereof is not particularly limited. The above cathode active material is a compound capable of reversible intercalation and deintercalation of lithium, and specifically, may include a lithium-transition metal composite oxide including lithium and at least one transition metal composed of nickel, cobalt, manganese, and aluminum, preferably a lithium-transition metal composite oxide including lithium and a transition metal including nickel, cobalt, and manganese. More specifically, the lithium transition metal composite oxide is a lithium-manganese oxide (e.g., LiMnO 2 , LiMn 2 O 4 etc.), lithium-cobalt oxides (e.g., LiCoO 2 etc.), lithium-nickel oxides (e.g., LiNiO 2 etc.), lithium-nickel-manganese oxides (e.g., LiNi 1-Y Mn Y O 2 (Here, 0 <Y<1), LiMn 2-z Ni z O 4 (wherein, 0<Z<2) etc.), lithium-nickel-cobalt oxides (e.g., LiNi 1-Y1 Co Y1 O 2 (Here, 0 <Y1<1) 등), 리튬-망간-코발트계 산화물(예를 들면, LiCo 1-Y2 Mn Y2 O 2 (Here, 0 <Y2<1), LiMn 2-z1 Co z1 O 4 (wherein, 0<Z1<2) etc.), lithium-nickel-manganese-cobalt oxides (e.g., Li(Nip Co q Mn r1 )O 2 (Here, 0<p<1, 0<q<1, 0<r1<1, p+q+r1=1) or Li(Ni p1 Co q1 Mn r2 )O 4 (wherein, 0<p1<2, 0<q1<2, 0<r2<2, p1+q1+r2=2) etc.), or lithium-nickel-cobalt-transition metal(M) oxide (e.g., Li(Ni p2 Co q2 Mn r3 M S2 )O 2 (wherein, M is selected from the group consisting of Al, Fe, V, Cr, Ti, Ta, Mg and Mo, and p2, q2, r3 and s2 are atomic fractions of independent elements, 0<p2<1, 0<q2<1, 0<r3<1, 0<s2<1, p2+q2+r3+s2=1), etc.), and one or more compounds among these may be included. Among these, the lithium transition metal composite oxide is LiCoO in that it can increase the capacity characteristics and stability of the battery. 2 , LiMnO 2 , LiNiO 2 , lithium nickel cobalt manganese oxide (e.g., Li(Ni 0.6 Mn 0.2 Co 0.2 )O 2 , Li(Ni 0.5 Mn 0.3 Co 0.2 )O 2 , Li(Ni 0.7 Mn 0.15 Co 0.15 )O 2 or Li(Ni 0.8 Mn 0.1 Co 0.1 )O 2 etc.), or lithium nickel cobalt aluminum oxide (e.g., Li(Ni 0.8 Co 0.15 Al 0.05 )O2 etc.), and considering the remarkable improvement effect according to the control of the type and content ratio of the constituent elements forming the lithium transition metal composite oxide, the lithium transition metal composite oxide may be Li(Ni 0.6 Mn 0.2 Co 0.2 )O 2 , Li(Ni 0.5 Mn 0.3 Co 0.2 )O 2 , Li(Ni 0.7 Mn 0.15 Co 0.15 )O 2 or Li(Ni 0.8 Mn 0.1 Co 0.1 )O 2 These may be any one of these or a mixture of two or more of these may be used. Preferably, the positive electrode active material may include a lithium nickel cobalt manganese oxide, and more preferably, it may include a lithium nickel cobalt manganese oxide containing nickel (Ni) in an amount of 80 mol% or more among all metals excluding lithium, and specifically, it may include a lithium nickel cobalt manganese oxide represented by the following chemical formula 1. [Chemical Formula 1] Li a1 [Ni b1 Co c1 Mn d1 M 1 e1 ]O 2 In the above chemical formula 1, M 1 is at least one doping element selected from the group consisting of W, Cu, Fe, V, Cr, Ti, Zr, Zn, In, Ta, Y, La, Sr, Ga, Sc, Gd, Sm, Ca, Ce, Nb, Mg, B or Mo, and 0.8≤a1≤1.2, 0.8≤b1<1, 0 <c1≤0.2, 0<d1≤0.2, 0<e1≤0.1이고, b1+c1+d1+e1 =1이다. In addition, the positive electrode active material may be a single particle, a secondary particle, or a mixture thereof, and among these, it is more preferable to use a mixture of single particle and secondary particles. Since the single particle type positive electrode active material has less side reaction with the electrolyte than the secondary particle type positive electrode active material, there is an advantage in that gas generation can be minimized when it is applied. In the case of a large-capacity battery, the amount of gas generated during charge and discharge increases rapidly compared to a small-capacity battery, which causes a problem in that the life characteristics are reduced. Therefore, it is preferable to improve the life characteristics by applying a single particle type positive electrode active material that can minimize gas generation. However, since the single particle type positive electrode active material has high resistance, there is a problem in that the output and capacity are reduced when it is used alone. Therefore, when considering the life, output, and capacity characteristics, it is preferable to use a mixture of single particle and secondary particles in an appropriate ratio as the positive electrode active material. For example, the cathode active material may be used by mixing single-particle particles and secondary particles in a weight ratio of 50:50 to 90:10, preferably 50:50 to 80:20. When the mixing ratio of the single-particle particles and the secondary particles satisfies the above range, excellent electrochemical properties can be realized even in a large battery having a diameter exceeding 40 mm. Specifically, when the single-particle particle content is less than 50 wt%, the gas generation suppression and life improvement effects are insignificant, and when it exceeds 90 wt%, the resistance may be too high, which may deteriorate the output characteristics. Meanwhile, the cathode active material layer may optionally further include at least one of a cathode conductive material and a cathode binder. The above-described positive electrode 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 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, summer black, carbon fiber, and carbon nanotube; metal powder or metal fiber such as copper, nickel, aluminum, and silver; conductive whiskers such as zinc oxide and potassium titanate; conductive metal oxides such as titanium oxide; or conductive polymers such as polyphenylene derivatives, and the like, and one of these may be used alone or a mixture of two or more may be used. The above-described positive electrode conductive material may be typically included in an amount of 1 to 30 wt%, preferably 1 to 20 wt%, and more preferably 1 to 10 wt%, based on the total weight of the positive electrode active material layer. The above positive electrode binder serves to improve the adhesion between positive electrode particles and the adhesive strength between the positive electrode and the positive electrode current collector, and specific examples thereof include a fluorine resin binder including polyvinylidene fluoride (PVDF) or polytetrafluoroethylene (PTFE); a rubber binder including styrene butadiene rubber (SBR), acrylonitrile-butadiene rubber, and styrene-isoprene rubber; a cellulose binder including carboxyl methyl cellulose (CMC), starch, hydroxy propyl cellulose, and regenerated cellulose; a polyalcohol binder including polyvinyl alcohol; a polyolefin binder including polyethylene and polypropylene; a polyimide binder; and a polyester binder. And silane binders, etc. can be mentioned, and one of these can be used alone or a mixture of two or more can be used. The positive electrode binder can be included in an amount of 1 to 30 wt%, preferably 1 to 20 wt%, and more preferably 1 to 10 wt%, based on the total weight of the positive electrode active material layer. 2) Cathode The above negative electrode can be manufactured by a method of applying negative electrode slurry to one side or both sides of a sheet-shaped negative electrode collector, removing the solvent of the negative electrode slurry through a drying process, and then rolling. Meanwhile, a negative electrode including a non-coated region can be manufactured by a method of not applying the negative electrode slurry to some area of ​​the negative electrode collector, for example, one end of the negative electrode collector, during the application of the negative electrode slurry. The above negative electrode slurry can be prepared by dispersing the negative electrode active material in a solvent such as distilled water, ethanol, methanol, or isopropyl alcohol. Alternatively, the cathode may be manufactured by casting the cathode slurry onto a separate support, peeling the film from the support, and laminating the resulting film onto a cathode current collector. The negative electrode manufactured thus includes a negative electrode current collector; and a negative electrode active material layer; and the negative electrode active material layer may include a negative electrode active material. The above negative electrode current collector is not particularly limited as long as it has high conductivity without causing chemical changes in the battery, and for example, copper, stainless steel, aluminum, nickel, titanium, calcined carbon, copper or stainless steel surface-treated with carbon, nickel, titanium, silver, etc., aluminum-cadmium alloy, etc. can be used. The above negative electrode current collector can typically have a thickness of 3 to 500 ㎛. In addition, the negative current collector, like the positive current collector, can form fine irregularities on the surface of the negative current collector to strengthen the bonding strength of the negative active material. For example, it can be used in various forms such as a film, sheet, foil, net, porous body, foam, and non-woven fabric. The negative electrode active material layer may be positioned on the negative electrode current collector, and specifically, may be positioned on one side or both sides of the negative electrode current collector. The negative electrode active material layer may have a single layer or a multilayer structure of two or more layers. As the negative electrode active material, a compound capable of reversible intercalation and deintercalation of lithium can be used, and the type thereof is not particularly limited. Specific examples include carbonaceous materials such as artificial graphite, natural graphite, graphitized carbon fiber, and amorphous carbon; (semi-)metallic compounds capable of alloying with lithium such as Si, Al, Sn, Pb, Zn, Bi, In, Mg, Ga, Cd, Si alloy, Sn alloy, or Al alloy; SiO β (0 <β < 2), SnO 2, a (semi-)metal oxide capable of doping and dedoping lithium, such as vanadium oxide, lithium vanadium oxide; or a composite comprising the (semi-)metal compound and a carbonaceous material, such as a Si-C composite or a Sn-C composite, and any one of these or a mixture of two or more thereof may be used. Preferably, the negative active material is SiO β (0 <β <2), Si-C composite, or a combination thereof. When the negative active material is included, it has the advantage of being able to implement high-capacity characteristics. The above negative active material may be included in an amount of 60 wt% to 99 wt%, preferably 75 wt% to 95 wt%, based on the total weight of the negative active material layer. Meanwhile, the negative electrode active material layer may optionally further include a negative electrode conductive material and a negative electrode binder in addition to the negative electrode active material. The above-described negative electrode 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 special restrictions. Specific examples include graphite such as natural graphite or artificial graphite; carbon black, acetylene black, Ketjen black, channel black, furnace black, lamp black, summer black, carbon fiber, carbon nanotube, etc.; metal powder or metal fiber such as copper, nickel, aluminum, silver, etc.; conductive whiskers such as zinc oxide or potassium titanate; conductive metal oxides such as titanium oxide; or conductive polymers such as polyphenylene derivatives, etc., and one of these may be used alone or a mixture of two or more may be used. The above-described negative electrode conductive material may be typically included in an amount of 1 to 30 wt%, preferably 1 to 20 wt%, and more preferably 1 to 10 wt%, based on the total weight of the negative electrode active material layer. The above negative electrode binder serves to improve the adhesion between negative electrode active material particles and the adhesive strength between the negative electrode active material and the negative electrode current collector. Specific examples thereof include polyvinylidene fluoride (PVDF), vinylidene fluoride-hexafluoropropylene copolymer (PVDF-co-HFP), polyvinyl alcohol, polyacrylonitrile, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinyl pyrrolidone, polytetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene monomer rubber (EPDM rubber), sulfonated-EPDM, styrene-butadiene rubber (SBR), fluororubber, or various copolymers thereof, and one of these may be used alone or a mixture of two or more thereof may be used. The above negative electrode binder may be included in an amount of 1 to 30 wt%, preferably 1 to 20 wt%, and more preferably 1 to 10 wt%, based on the total weight of the negative electrode active material layer. 3) Membrane The above separator is interposed between the positive electrode and the negative electrode to separate the negative electrode and the positive electrode and to provide a passage for lithium ions to move. If it is commonly used as a separator in a lithium secondary battery, it can be used without special restrictions. Specifically, the separator may be a porous polymer film, 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, or a laminated structure of two or more layers thereof. In addition, a conventional porous nonwoven fabric, for example, a nonwoven fabric made of high-melting-point glass fibers, polyethylene terephthalate fibers, etc. may be used. In addition, a coated separator containing a ceramic component or a polymer material may be used to secure heat resistance or mechanical strength. Meanwhile, the positive electrode (10) and negative electrode (11) have a structure in which an active material layer (21) is formed on a sheet-shaped current collector (20), and may include a non-conductive portion (22) in which the active material layer (21) is not formed in some area of ​​the current collector (20). As described above, by using a positive electrode (10) and a negative electrode (11) including a non-conductive portion (22), a battery having a structure in which at least a portion of the non-conductive portion of the positive electrode (10) and negative electrode (11) defines an electrode tab can be implemented without providing a separate electrode tab. Specifically, the non-conductive portion (22) can be formed long along the winding direction (X) at one end of the current collector (20), and a current collecting plate is combined with each of the positive non-conductive portion and the negative non-conductive portion, and the current collecting plate is connected to an electrode terminal, thereby functioning as an electrode tab. For example, a battery in which the positive electrode non-coated portion and the negative electrode non-coated portion function as electrode tabs can be manufactured by the following method. First, a separator, a positive electrode, a separator, and a negative electrode are sequentially laminated so that the positive electrode non-coated portion and the negative electrode non-coated portion are positioned in opposite directions, and then wound in one direction to manufacture a jelly-roll type electrode assembly. Then, the positive and negative electrode non-coated portions are folded toward the winding center (C), and then current collector plates are welded to the positive electrode non-coated portion and the negative electrode non-coated portion respectively to join them, and the current collector plates are connected to electrode terminals to manufacture a battery. The current collector plates have a larger cross-sectional area than the strip-type electrode tabs, and since resistance is inversely proportional to the cross-sectional area of ​​a path through which current flows, when a secondary battery is formed with the above structure, the cell resistance can be significantly reduced. Meanwhile, the positive and negative electrode portions may be processed into a plurality of independently foldable segments, and at least some of the plurality of segments may be folded toward the winding center (C) of the electrode assembly. The above segments can be formed by processing the positive and negative current collectors through a metal foil cutting process such as laser notching, ultrasonic cutting, or punching. When the non-conductive portions of the positive and negative electrodes are processed in the form of multiple segments, the stress applied to the non-conductive portion during bending can be reduced, thereby preventing deformation or damage to the non-conductive portion, and improving the welding characteristics with the current collecting plate. The collector plate and the plain portion are generally joined by welding. In order to improve the welding characteristics, strong pressure should be applied to the welding area of ​​the plain portion to fold the plain portion as flat as possible. However, during this bending process, the shape of the plain portion may be distorted and deformed irregularly, and the deformed portion may come into contact with an electrode of the opposite polarity, causing an internal short circuit or inducing micro-cracks in the plain portion. However, if the plain portions of the positive and negative electrodes are processed into a plurality of independently bendable segments, the stress applied to the plain portion during bending can be relieved, thereby minimizing deformation and damage to the plain portion. In addition, when the non-conductive portion is processed in the form of segments as described above, overlap occurs between the plurality of segments during folding, which increases the welding strength with the current collector plate, and when using the latest technology such as laser welding, it is possible to prevent the problem of the laser penetrating into the electrode assembly and melting away the separator or active material. Preferably, at least some of the plurality of folded segments may overlap on the upper and lower sides of the electrode assembly, and the current collector plate may be bonded on the plurality of overlapped segments. Meanwhile, the electrode assembly according to the present invention may be formed with a structure in which an insulating layer (24) is additionally formed on the positive electrode (10), as illustrated in FIG. 3. Specifically, the insulating layer (24) may be formed to cover a portion of the positive electrode active material layer and a portion of the non-conductive portion along a direction parallel to the winding direction of the electrode assembly. In the case of a battery having a tab-less structure in which the non-conductive portion (22c) of the positive electrode (10) and the non-conductive portion (22a) of the negative electrode (11) are used as electrode tabs, an electrode assembly is formed so that the positive electrode (10) protrudes above the separator (12) and the negative electrode (11) protrudes below the separator (12), and the protruding positive electrode (10) and / or negative electrode (11) are folded and then combined with a current collecting plate. However, when the positive electrode (10) or negative electrode (11) is folded as described above, the current collector of the positive electrode (10) or negative electrode (11) is positioned close to an electrode of the opposite polarity beyond the separator, which may cause the positive electrode and negative electrode to come into electrical contact, thereby causing an internal short circuit. However, as shown in Fig. 5, when an insulating layer (24) covering the positive electrode active material layer and a portion of the non-conductive portion is formed, the positive electrode (10) and the negative electrode (11) can be prevented from electrically contacting each other by the insulating layer (24), thereby preventing a short circuit from occurring inside the battery. Preferably, the insulating layer (24) may be provided on at least one surface of the positive electrode (10) current collector, and preferably, may be provided on both surfaces of the positive electrode (10). In addition, the insulating layer (24) may be formed in an area of ​​the positive electrode (10) that is likely to face the active material layer (21a) of the negative electrode (11). For example, in the case of the non-coated portion (22c) of the positive electrode (10) that faces the negative electrode (11) after being folded, the insulating layer (24) may be formed to extend to the end of the non-coated portion (22c). However, in the case of the opposite side of the surface that faces the negative electrode (11) after being folded, it is preferable that the insulating layer (24) be formed only in a part of the non-coated portion (22c), for example, up to the point before the bending of the non-coated portion (22c). This is because, if the insulating layer (24) is formed in the entire area of ​​the non-coated portion on the opposite side of the surface that faces the negative electrode (11), electrical contact with the current collecting plate is impossible, and thus, it cannot function as an electrode tab. Meanwhile, the insulating layer (24) can be attached to the anode while securing insulating performance, and its material or component is not particularly limited. For example, the insulating layer can be an insulating coating layer or an insulating tape, and the insulating coating layer can include an organic binder and inorganic particles. At this time, the organic binder can be, for example, styrene-butadiene rubber (SBR), and the inorganic particles can be, but are not limited to, alumina oxide. (2) Electrolyte The electrolyte according to the present invention comprises an ester solvent. The above ester solvent may include at least one selected from the group consisting of methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate, ethyl propionate, propyl propionate, and butyl propionate, γ-butyrolactone, γ-valerolactone, γ-caprolactone, σ-valerolactone, and ε-caprolactone, and preferably may include at least one selected from the group consisting of methyl acetate and ethyl acetate. When the above ester solvent is included, the mobility of ions in the electrolyte can be improved, the viscosity of the electrolyte can be prevented from becoming excessively high, thereby improving electrolyte impregnation properties, and improving low-temperature life characteristics. The ester solvent may be included in an amount of 10 to 30 vol%, preferably 12 to 28 vol%, more preferably 15 to 25 vol%, and even more preferably 17 to 23 vol%, based on the total volume of the electrolyte. When the above range is satisfied, the electrolyte impregnation property within the electrode can be improved, and the ion transfer characteristics of the electrolyte can be improved. In addition, the electrolyte may further include at least one selected from the group consisting of a cyclic carbonate solvent and a linear carbonate solvent as a solvent. The above cyclic carbonate solvent refers to a high viscosity organic solvent, and specifically, the cyclic carbonate solvent may be a non-fluorinated saturated cyclic carbonate solvent. For example, the solvent may include at least one 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 preferably includes ethylene carbonate (EC). When the cyclic carbonate solvent is included, the dielectric constant is high, so that the lithium salt can be smoothly dissociated in the electrolyte, thereby improving the ion conductivity and the current transport rate of the cation. The above cyclic carbonate solvent may be included in an amount of 30 wt% or less, preferably 10 to 25 wt%, and more preferably 15 to 20 wt%, based on the total weight of the electrolyte. The linear carbonate solvent above refers to an organic solvent having low viscosity and low dielectric constant, and specifically, the linear carbonate solvent may be a non-fluorinated linear carbonate solvent. For example, at least one solvent selected from the group consisting of dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate, ethyl methyl carbonate (EMC), methyl propyl carbonate, and ethyl propyl carbonate may be used, and specifically, at least one solvent selected from the group consisting of ethyl methyl carbonate (EMC) and dimethyl carbonate (DMC) may be included. When the linear carbonate solvent is included, the viscosity of the electrolyte can be prevented from becoming excessively high, thereby further improving the electrolyte impregnation property. The linear carbonate solvent may be included in an amount of 40 to 80 wt%, preferably 45 to 75 wt%, and more preferably 50 to 70 wt%, based on the total weight of the electrolyte. The above electrolyte may include a lithium salt. The above lithium salt can be used without any special limitation as long as it is a compound capable of providing lithium ions used in a lithium secondary battery. Specifically, the above lithium salt is LiPF 6 , LiClO 4 , LiAsF 6 , LiBF 4 , LiSbF 6 , LiAl0 4 , LiAlCl 4 , LiCF 3 SO 3 , LiC 4 F 9 SO 3 , LiN(C 2 F 5 SO 3 ) 2 , LiN(C 2 F 5 SO 2 ) 2 , LiN(CF 3 SO 2 ) 2 . LiCl, LiI, or LiB(C 2 O 4 ) 2 The back can be used. The lithium salt may be included in the electrolyte at a concentration of 0.5 M to 2.0 M, preferably 0.7 M to 1.8 M, and more preferably 1.0 M to 1.5 M. When the concentration of the lithium salt is within the above range, the electrolyte has appropriate ionic conductivity and viscosity, so that excellent electrolyte performance can be exhibited, and lithium ions can move effectively, so that the life characteristics, rapid charge characteristics, and high-temperature life characteristics of the cylindrical lithium secondary battery can be improved. Meanwhile, the electrolyte may additionally include additives for the purposes of improving the ion conductivity of the battery, improving the cation transport rate, improving the life characteristics of the battery, suppressing the decrease in battery capacity, and improving the discharge capacity of the battery, in addition to the electrolyte components. For example, the additive may include at least one additive selected from the group consisting of a non-fluorinated unsaturated cyclic carbonate compound, a halogen-substituted carbonate compound, a sultone compound, a sulfate compound, a borate compound, a nitrile compound, a benzene compound, an amine compound, a silane compound, and a lithium salt compound different from a lithium salt included in the electrolyte. Specifically, the other additives include vinylene carbonate (VC), vinylethylene carbonate, fluoroethylene carbonate (FEC), 1,3-propane sultone (PS), 1,4-butane sultone, ethene sultone, 1,3-propene sultone (PRS), 1,4-butene sultone, 1-methyl-1,3-propene sultone, ethylene sulfate (ESA), trimethylene sulfate (TMS), methyl trimethylene sulfate (MTMS), tetraphenylborate, lithium oxalyldifluoroborate, succinonitrile, adiponitrile, acetonitrile, propionitrile, butyronitrile, valeronitrile, caprylonitrile, heptanenitrile, cyclopentane carbonitrile, cyclohexane carbonitrile, 2-Fluorobenzonitrile, 4-Fluorobenzonitrile, Difluorobenzonitrile, Trifluorobenzonitrile, Phenylacetonitrile, 2-Fluorophenylacetonitrile, 4-Fluorophenylacetonitrile, Fluorobenzene, Triethanolamine, Ethylenediamine, Tetravinylsilane, LiN(SO 2 F) 2 (Lithium bis(fluorosulfonyl)imide, LiFSI), LiN(SO 2 CF 3 ) 2(lithium bis(trifluoromethane sulfonyl)imide, LiTFSI), LiPO 2 F 2 , LiODFB, LiBOB (lithium bisoxalate borate (LiB(C 2 O 4 ) 2 ) and LiBF 4 It may be at least one selected from the group consisting of, and preferably, it may be vinylene carbonate. The above electrolyte may contain the additive in an amount of 1.5 wt% or less, preferably 1.2 wt% or less, and more preferably 1.0 wt% or less. If the content of the additive is less than 0.01 wt%, the effects of improving the low-temperature output of the battery and the high-temperature storage characteristics and high-temperature life characteristics are minimal, and if the content of the other additives exceeds 20 wt%, there is a possibility that side reactions may occur excessively in the electrolyte during charge and discharge of the battery. In particular, when the additives for forming the SEI film are added in excessive amounts, they may not be sufficiently decomposed at high temperatures and may exist as unreacted substances or in a precipitated state in the electrolyte at room temperature. Accordingly, side reactions that reduce the life or resistance characteristics of the secondary battery may occur. When the content of the above additive satisfies the above range, the low-temperature output characteristics, high-temperature storage characteristics, and high-temperature life characteristics of the battery can be improved, side reactions within the electrolyte can be suppressed during battery charging and discharging, and the cation transport rate and ion conductivity within the electrolyte can be additionally improved, thereby improving the life characteristics and high-temperature life characteristics of the battery. Meanwhile, the viscosity of the electrolyte at 25°C may be 2.80 cP or less. Specifically, the viscosity of the electrolyte at 25°C may be 2.80 cP or less, 2.75 cP or less, 2.70 cP or less, 2.65 cP or less, 2.60 cP or less, 2.55 cP or less, and 2.00 cP or more, 2.05 cP or more, 2.10 cP or more, 2.15 cP or more, 2.20 cP or more, 2.25 cP or more, 2.30 cP or more, 2.35 cP or more, 2.40 cP or more, 2.45 cP or more, 2.50 cP or more. For example, the viscosity of the electrolyte at 25°C may be 2.80 cP or less, preferably 2.00 cP to 2.80 cP, more preferably 2.40 cP to 2.75 cP, and even more preferably 2.45 cP to 2.60 cP. When the above range is satisfied, the mobility of ions in the electrolyte may be excellent even during rapid charge and discharge, and the electrolyte may be smoothly impregnated into the inside of the electrode. (3) Battery case The above battery case is for accommodating the electrode assembly and the electrolyte, and may be a cylindrical battery case. The form factor ratio (defined as the ratio of the diameter (R) to the height (h) of the cylindrical lithium secondary battery according to the present invention, which is the value obtained by dividing the diameter of the cylindrical battery by the height) is the same as described above, so a detailed description is omitted. The cylindrical lithium secondary battery according to the present invention may be, for example, a 46110 cell (diameter 46 mm, height 110 mm, form factor ratio 0.418), a 4875 cell (diameter 48 mm, height 75 mm, form factor ratio 0.640), a 48110 cell (diameter 48 mm, height 110 mm, form factor ratio 0.436), a 4880 cell (diameter 48 mm, height 80 mm, form factor ratio 0.600), a 4680 cell (diameter 46 mm, height 80 mm, form factor ratio 0.575), a 4695 cell (diameter 46 mm, height 95 mm, form factor ratio 0.484). In the figures representing the form factor, the first two numbers represent the diameter (R) of the lithium secondary battery, and the next two or three numbers represent the height (h) of the lithium secondary battery. Next, the structure of a lithium secondary battery according to the present invention will be described. FIGS. 4 and 5 disclose implementation examples of lithium secondary batteries according to the present invention. Hereinafter, a lithium secondary battery according to the present invention will be described with reference to FIGS. 4 and 5. However, FIGS. 4 and 5 only show one embodiment of the present invention, and the structure of the battery of the present invention is not limited to the range disclosed in FIGS. 4 and 5. FIG. 4 illustrates a cross-sectional view of a lithium secondary battery having a tab-less structure according to one embodiment of the present invention. Referring to FIG. 4, a lithium secondary battery (140) according to the present invention may include an electrode assembly (141), a battery case (142) in which the electrode assembly (141) and an electrolyte (not shown) are stored, and a sealing body (143) that seals an open end of the battery case (142). At this time, the electrode assembly is formed by sequentially stacking a positive electrode, a separator, and a negative electrode, and winding them in one direction. In addition, the positive electrode and the negative electrode of the electrode assembly each include a non-conductive portion on which an active material layer is not formed, and can be stacked and wound so that the positive electrode non-conductive portion and the negative electrode non-conductive portion are positioned at the top and bottom of the electrode assembly, respectively. Since the electrode assembly has been described above, only the remaining components excluding the electrode assembly will be described below. Meanwhile, the battery case (142) is a can-shaped container with an open end formed at the top, and is made of a conductive metal material such as aluminum or steel. The battery case accommodates an electrode assembly (141) in the inner space through the open end at the top, and also accommodates an electrolyte (not shown). Meanwhile, it is preferable that the lithium secondary battery (140) of the present invention does not include a current interruption device (CID). Meanwhile, as illustrated in FIG. 4, the battery case (142) is electrically connected to the negative electrode non-conductive portion (146b) and can function as a negative terminal that contacts an external power source and transmits current applied from the external power source to the negative electrode. If necessary, a beading portion (147) and a crimping portion (148) may be provided on the upper end of the battery case (142). The beading portion (147) may be formed by pressing the outer circumference of the battery case (142) to a distance of D1. The beading portion (147) may prevent the electrode assembly (141) accommodated inside the battery case (142) from coming out through the upper opening of the battery case (142), and may function as a support portion on which the sealing body (143) is secured. The above crimping portion (148) can be formed on the upper portion of the beading portion (147), and has an extended and bent shape to surround the outer surface of the cap plate (143a) placed on the beading portion (147) and a portion of the upper surface of the cap plate (143a). Next, the sealing member (143) is for sealing the open end of the battery case (142), and includes a cap plate (143a), a first gasket (143b) that provides airtightness and insulation between the cap plate (143a) and the battery case (142), and, if necessary, may further include a connecting plate (143c) that is electrically and mechanically coupled to the cap plate (143a). The cap plate (143a) is pressed onto a beading portion (147) formed on the battery case (142), and may be fixed by a crimping portion (148). The cap plate (143a) is a component made of a conductive metal material and covers the upper opening of the battery case (142). The cap plate (143a) is electrically connected to the positive electrode of the electrode assembly (141) and is electrically insulated from the battery case (142) through the first gasket (143b). Therefore, the cap plate (143a) can function as a positive electrode terminal of a lithium secondary battery. The cap plate (143a) can have a protrusion (143d) formed to protrude upward from its center portion C, and the protrusion (143d) can come into contact with an external power source to allow current to be applied from the external power source. A first gasket (143b) may be interposed between the cap plate (143a) and the crimping portion (148) to ensure airtightness of the battery case (142) and to provide electrical insulation between the battery case (142) and the cap plate (143a). Meanwhile, the lithium secondary battery (140) according to the present invention may further include a current collecting plate (144, 145), if necessary. The current collecting plate is coupled to the positive electrode non-conducting portion (146a) and the negative electrode non-conducting portion (146b), and is connected to the electrode terminals (i.e., the positive electrode terminal and the negative electrode terminal). Specifically, a cylindrical battery (140) according to the present invention may include a first current collecting plate (144) coupled to an upper portion of an electrode assembly (141) and a second current collecting plate (145) coupled to a lower portion of the electrode assembly (141). It may further include a first collector plate (144) and / or a second collector plate (145). The first collector plate (144) is coupled to the upper portion of the electrode assembly (141). The first collector plate (144) is made of a conductive metal material such as aluminum, copper, nickel, etc., and is electrically connected to the non-conductive portion (146a) of the positive electrode. A lead (149) may be connected to the first collector plate (144). The lead (149) may extend upward from the electrode assembly (141) and be coupled to the connection plate (143c) or may be directly coupled to the lower surface of the cap plate (143a). The coupling of the lead (149) and other components may be accomplished by welding. Preferably, the first collector plate (144) may be formed integrally with the lead (149). In this case, the lead (149) may have a plate shape that extends outward from the center of the first collector plate (144). Meanwhile, the first collector plate (144) is joined to an end of the non-conductive portion (146a) of the anode, and the joining can be accomplished by, for example, laser welding, resistance welding, ultrasonic welding, soldering, or the like. The second collector plate (145) is coupled to the lower portion of the electrode assembly (141). The second collector plate (145) is made of a conductive metal material such as aluminum, copper, nickel, etc., and is electrically connected to the non-conductive portion (146b) of the negative electrode. One side of the second collector plate (145) can be coupled to the non-conductive portion (146b) of the negative electrode, and the opposite side can be coupled to the inner bottom surface of the battery case (142). At this time, the coupling can be performed by a method such as laser welding, resistance welding, ultrasonic welding, or soldering. Meanwhile, the lithium secondary battery (140) according to the present invention may further include an insulator (146), if necessary. The insulator (146) may be arranged to cover the upper surface of the first current collecting plate (144). Since the insulator (146) covers the first current collecting plate (144), direct contact between the first current collecting plate (144) and the inner surface of the battery case (142) can be prevented. The insulator (146) is provided with a lead hole (151) through which a lead (149) extending upward from the first collector plate (144) can be drawn out. The lead (149) is drawn upward through the lead hole (151) and coupled to the lower surface of the connecting plate (143c) or the lower surface of the cap plate (143a). The insulator (146) may be made of a polymer resin material having insulating properties, such as polyethylene, polypropylene, polyimide, or polybutylene terephthalate. Meanwhile, the lithium secondary battery (140) according to the present invention may further include a venting portion (152) formed on the lower surface of the battery case (142), if necessary. The venting portion (152) corresponds to a region of the lower surface of the battery case (142) that has a thinner thickness than the surrounding region. Since the venting portion (152) is thin, it is structurally weaker than the surrounding region. Therefore, when the pressure inside the lithium secondary battery (140) increases above a certain level, the venting portion (152) ruptures, thereby allowing gas inside the battery case (152) to be discharged to the outside, thereby preventing the battery from exploding. FIG. 5 illustrates a cross-sectional view of a lithium secondary battery having a tab-less structure according to another embodiment of the present invention. Referring to FIG. 5, a lithium secondary battery (170) according to another embodiment of the present invention has a different structure of a battery case and a sealant compared to the lithium secondary battery (140) illustrated in FIG. 4, and the configuration of the electrode assembly and the electrolyte are substantially the same. Specifically, a lithium secondary battery (170) according to another embodiment of the present invention includes a battery case (171) having a rivet terminal (172) installed therethrough. The rivet terminal (172) is installed in a partially closed closed surface (upper surface in the drawing) of one end of the battery case (171). The rivet terminal (172) is riveted to a through hole (first opening of the first end) of the battery case (171) while an insulating second gasket (173) is interposed therebetween. The rivet terminal (172) is exposed to the outside in a direction opposite to the gravity direction. The rivet terminal (172) includes a terminal exposure portion (172a) and a terminal insertion portion (172b). The terminal exposure portion (172a) is exposed to the outside of the closed surface of the battery case (171). The terminal exposure portion (172a) may be located approximately at the center of the partially closed surface of the battery case (171). The maximum diameter of the terminal exposure portion (172a) may be formed larger than the maximum diameter of the through hole formed in the battery case (171). The terminal insertion portion (172b) may penetrate approximately at the center of the closed surface of the battery case (171) and be electrically connected to the non-conductive portion (146a) of the positive electrode. The terminal insertion portion (172b) may be riveted onto the inner surface of the battery case (171). That is, an end of the terminal insertion portion (172b) may have a shape that is bent toward the inner surface of the battery case (171). The maximum diameter of the end of the terminal insertion portion (172b) may be larger than the maximum diameter of the through hole of the battery case (171). The lower surface of the terminal insertion portion (172b) can be welded with the first current collecting plate (144) connected to the non-polar portion (146a) of the positive electrode. An insulating cap (174) made of an insulating material can be interposed between the first current collecting plate (144) and the inner surface of the battery case (171). The insulating cap (174) covers the upper portion of the first current collecting plate (144) and the upper edge portion of the electrode assembly (141). This prevents the outer non-polar portion (B3) of the electrode assembly (141) from coming into contact with the inner surface of the battery case (171) having a different polarity, thereby causing a short circuit. The terminal insertion portion (172b) of the rivet terminal (172) can be welded to the first current collecting plate (144) by penetrating the insulating cap (174). The second gasket (173) is interposed between the battery case (171) and the rivet terminal (172) to prevent the battery case (171) and the rivet terminal (172) having opposite polarities from electrically contacting each other. As a result, the upper surface of the battery case (171) having a substantially flat shape can function as a positive terminal of the lithium secondary battery (170). The second gasket (173) includes a gasket exposure portion (173a) and a gasket insertion portion (173b). The gasket exposure portion (173a) is interposed between the terminal exposure portion (172a) of the rivet terminal (172) and the battery case (171). The gasket insertion portion (173b) is interposed between the terminal insertion portion (172b) of the rivet terminal (172) and the battery case (171). The gasket insertion portion (173b) can be deformed together with the terminal insertion portion (172b) during riveting so as to be in close contact with the inner surface of the battery case (171). The second gasket (173) can be made of, for example, an insulating polymer resin. The gasket exposure portion (173a) of the second gasket (173) may have an extended shape so as to cover the outer surface of the terminal exposure portion (172a) of the rivet terminal (172). When the second gasket (173) covers the outer surface of the rivet terminal (172), a short circuit can be prevented from occurring during the process of connecting an electrical connection component such as a bus bar to the upper surface of the battery case (171) and / or the rivet terminal (172). Although not shown in the drawing, the gasket exposure portion (173a) may have an extended shape so as to cover not only the outer surface of the terminal exposure portion (172a) but also a part of the upper surface. In the case where the second gasket (173) is made of a polymer resin, the second gasket (173) can be joined to the battery case (171) and the rivet terminal (172) by heat fusion. In this case, the sealing at the joining interface between the second gasket (173) and the rivet terminal (172) and the joining interface between the second gasket (173) and the battery case (171) can be strengthened. Meanwhile, in the case where the gasket exposure portion (173a) of the second gasket (173) has a form that extends to the upper surface of the terminal exposure portion (172a), the rivet terminal (172) can be joined integrally with the second gasket (173) by insert injection. The remaining area (175) of the upper surface of the battery case (171), excluding the area occupied by the rivet terminal (172) and the second gasket (173), corresponds to a negative terminal having the opposite polarity to the rivet terminal (172). The second collector plate (176) is coupled to the lower portion of the electrode assembly (141). The second collector plate (176) is made of a conductive metal material such as aluminum, steel, copper, or nickel, and is electrically connected to the unconducted portion (146b) of the cathode. Preferably, the second collector plate (176) is electrically connected to the battery case (171). To this end, at least a portion of an edge portion of the second collector plate (176) may be interposed and fixed between the inner surface of the battery case (171) and the first gasket (178b). In one example, at least a portion of an edge portion of the second collector plate (176) may be fixed to the beading portion (180) formed at the lower end of the battery case (171) by welding while being supported by the lower surface of the beading portion (180). In a variation, at least a portion of an edge portion of the second collector plate (176) may be directly welded to the inner wall surface of the battery case (171). The second collector plate (176) may have a plurality of protrusions (not shown) formed radially on a surface facing the non-conductive portion (146b). When the protrusions are formed, the second collector plate (176) may be pressed to press the protrusions into the non-conductive portion (146b). Preferably, the ends of the second collector plate (176) and the non-conductive portion (146b) can be joined by welding, for example, laser welding. A sealing member (178) for sealing the lower open end of the battery case (171) includes a cap plate (178a) and a first gasket (178b). The first gasket (178b) electrically separates the cap plate (178a) and the battery case (171). A crimping member (181) secures the edge of the cap plate (178a) and the first gasket (178b) together. A vent member (179) is provided in the cap plate (178a). The configuration of the vent member (179) is substantially the same as in the above-described embodiment. Preferably, the cap plate (178a) is made of a conductive metal material. However, since a first gasket (178b) is interposed between the cap plate (178a) and the battery case (171), the cap plate (178a) does not have electrical polarity. The sealing body (178) seals the open end of the lower portion of the battery case (171) and discharges gas when the internal pressure of the battery cell (170) increases above a critical value. Preferably, the rivet terminal (172) electrically connected to the non-conductive portion (146a) of the positive electrode is used as the positive terminal. In addition, a portion (175) of the upper surface of the battery case (171) electrically connected to the non-conductive portion (146b) of the negative electrode through the second current collecting plate (176), excluding the rivet terminal (172), is used as the negative terminal. In this way, when the two electrode terminals are positioned on the upper portion of the lithium secondary battery, it is possible to place electrical connection components such as bus bars on only one side of the lithium secondary battery (170). This can lead to simplification of the battery pack structure and improvement of energy density. In addition, since the portion (175) used as the negative terminal has a substantially flat shape, a sufficient connection area can be secured when connecting electrical connection components such as bus bars. Accordingly, the lithium secondary battery (170) can lower the resistance at the connection portion of the electrical connection components to a desirable level. When a lithium secondary battery is formed with a tab-less structure as described above, the current concentration is less than that of a conventional battery having electrode tabs, so the heat generation inside the battery can be effectively reduced, and thus the thermal safety of the battery can be improved. Battery pack The lithium secondary battery of the present invention as described above can be used as a unit cell in manufacturing a battery pack. FIG. 6 schematically illustrates the configuration of a battery pack according to an embodiment of the present invention. Referring to FIG. 6, a battery pack (3) according to an embodiment of the present invention includes an assembly of lithium secondary batteries (1) electrically connected thereto and a pack housing (2) accommodating the assembly. The lithium secondary battery (1) is a lithium secondary battery according to the embodiment described above. In the drawing, for the convenience of illustration, parts such as a bus bar, a cooling unit, and an external terminal for electrically connecting the lithium secondary batteries (1) are omitted. The above battery pack (3) can be mounted on a vehicle. The vehicle may be, for example, an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle. The vehicle includes a four-wheel vehicle or a two-wheel vehicle. The present invention will be described more specifically through specific examples below. Example 1 <Electrolyte manufacturing> LiPF in an organic solvent containing ethylene carbonate: ethyl methyl carbonate: dimethyl carbonate: methyl acetate in a weight ratio of 20:5:65:10 6 An electrolyte was prepared by adding 1.25 M molar concentration. <Cylindrical Lithium Secondary Battery Manufacturing> A cathode slurry was prepared by adding a cathode active material, a conductive agent, and a binder to N-methylpyrrolidone at a weight ratio of 97.32:0.63:2.05. At this time, the cathode active material was Li[Ni 0.93 Co 0.05 Mn 0.02 ]O 2 was used, carbon nanotubes were used as a conductive material, and PVDF was used as a binder. The positive electrode slurry was applied onto an aluminum current collector, dried, and then roll pressed to manufacture the positive electrode. A negative electrode slurry was prepared by adding a negative electrode active material, a conductive agent, and a binder to distilled water at a weight ratio of 97.875:0.10:1.15. At this time, graphite and SiO were mixed at a weight ratio of 97:3 as the negative electrode active material, carbon nanotubes were used as the conductive agent, and hydrogenated nitrile-based butadiene rubber (HNBR) was used as the conductive agent dispersion agent, and styrene-butadiene rubber (SBR) and carboxymethyl cellulose (CMC) were mixed at a weight ratio of 1.6:0.85 as the binder. At this time, the graphite was a mixture of natural graphite and artificial graphite at a weight ratio of 5:5. The above negative electrode slurry was applied onto a copper current collector, dried, and then roll pressed to manufacture a negative electrode including a negative electrode active material layer. A separator was interposed between the positive and negative electrodes manufactured as described above, and the electrode assembly was then rolled up in the order of separator / positive electrode / separator / negative electrode, thereby manufacturing a jelly-roll type electrode assembly having a radius of 6 mm at the center of the roll. After the electrode assembly was inserted into a cylindrical battery case having a height of 80 mm and a diameter of 46 mm, 42 g of the electrolyte manufactured above was injected to manufacture a cylindrical lithium secondary battery (4680 cell). Example 2 <Electrolyte manufacturing> LiPF in an organic solvent containing ethylene carbonate: dimethyl carbonate: methyl acetate in a weight ratio of 20:70:10 6 An electrolyte was prepared by adding 1.25 M molar concentration. <Cylindrical Lithium Secondary Battery Manufacturing> A lithium secondary battery (4680 cell) was manufactured using the same method except that the electrolyte manufactured above was used. Example 3 <Electrolyte manufacturing> LiPF in an organic solvent containing ethylene carbonate: dimethyl carbonate: methyl acetate in a weight ratio of 20:60:20 6An electrolyte was prepared by adding 1.25 M molar concentration. <Cylindrical Lithium Secondary Battery Manufacturing> A lithium secondary battery (4680 cell) was manufactured using the same method except that the electrolyte manufactured above was used. Example 4 <Electrolyte manufacturing> LiPF in an organic solvent containing ethylene carbonate: dimethyl carbonate: methyl acetate in a weight ratio of 20:50:30 6 An electrolyte was prepared by adding 1.25 M molar concentration. <Cylindrical Lithium Secondary Battery Manufacturing> A lithium secondary battery (4680 cell) was manufactured using the same method except that the electrolyte manufactured above was used. Example 5 <Electrolyte manufacturing> LiPF in an organic solvent containing ethylene carbonate: dimethyl carbonate: methyl acetate in a weight ratio of 20:71:9 6 An electrolyte was prepared by adding 1.25 M molar concentration. <Cylindrical Lithium Secondary Battery Manufacturing> A lithium secondary battery (4680 cell) was manufactured using the same method except that the electrolyte manufactured above was used. Example 6 <Electrolyte manufacturing> LiPF in an organic solvent containing ethylene carbonate:dimethyl carbonate:diethyl carbonate:methyl acetate in a weight ratio of 20:44:5:31 6 An electrolyte was prepared by adding 1.25 M molar concentration. <Cylindrical Lithium Secondary Battery Manufacturing> A lithium secondary battery (4680 cell) was manufactured using the same method except that the electrolyte manufactured above was used. Comparative Example 1 <Electrolyte manufacturing> LiPF in an organic solvent containing ethylene carbonate: ethyl methyl carbonate: dimethyl carbonate in a weight ratio of 20:5:75 6 An electrolyte was prepared by adding 1.25 M molar concentration. <Cylindrical Lithium Secondary Battery Manufacturing> A lithium secondary battery (4680 cell) was manufactured using the same method except that the electrolyte manufactured above was used. Comparative Example 2 <Electrolyte manufacturing> LiPF in an organic solvent containing ethylene carbonate: dimethyl carbonate: methyl acetate in a weight ratio of 20:75:5 6 An electrolyte was prepared by adding 1.25 M molar concentration. <Cylindrical Lithium Secondary Battery Manufacturing> A lithium secondary battery (4680 cell) was manufactured using the same method except that the electrolyte manufactured above was used. Comparative Example 3 <Electrolyte manufacturing> LiPF in an organic solvent containing ethylene carbonate: ethyl methyl carbonate: dimethyl carbonate: methyl acetate in a weight ratio of 20:5:65:10 6 An electrolyte was prepared by adding 1.25 M molar concentration and 0.5 wt% lithium salt compound additive. <Cylindrical Lithium Secondary Battery Manufacturing> A separator was interposed between the positive and negative electrodes manufactured in the same manner as in Example 1, and the electrode assembly was then rolled up in the order of separator / positive electrode / separator / negative electrode and a jelly-roll type electrode assembly having a radius of 3.2 mm at the center of the roll was manufactured. After the electrode assembly was inserted into a cylindrical battery case having a height of 70 mm and a diameter of 21 mm, 6.54 g of the electrolyte manufactured above was injected to manufacture a cylindrical lithium secondary battery (2170 cell). Experimental Example 1: Measurement of DIB value and electrolyte viscosity For each of the cylindrical lithium secondary batteries manufactured in Examples 1 to 6 and Comparative Examples 1 to 3, the DIB value and the viscosity of the electrolyte, as defined by Equation 1 below, were measured and are shown in Table 1 below. (1) DIB value measurement For each of the cylindrical lithium secondary batteries manufactured in the above Examples 1 to 6 and Comparative Examples 1 to 3, the ion conductivity (C) of the electrolyte (unit: mS / mm) and the cation transport rate (t) of the electrolyte + ), the viscosity (unit: cP) of the electrolyte at 25°C was measured by the following method, and the DIB value defined by the following Equation 1 was calculated and shown in Table 1 below. [Formula 1] In the above equation 1, h (unit: mm) is the height of the cylindrical lithium secondary battery, R (unit: mm) is the diameter of the cylindrical lithium secondary battery, r (unit: mm) is the radius of the winding center of the electrode assembly, C (unit: mS / mm) is the ionic conductivity of the electrolyte, and t + refers to the cation transport rate of the electrolyte. 1) Measurement of ionic conductivity (C) of electrolyte The ionic conductivities of the electrolytes applied to the cylindrical lithium secondary batteries manufactured in the above Examples 1 to 6 and Comparative Examples 1 to 3 were measured at 25°C using Seven Excellence S700 equipment from METTLER TOLEDO. Specifically, each of the cylindrical lithium secondary batteries was charged to 4.2 V at 0.2 C-rate and 0.01 C cut-off conditions, and discharged to 2.8 V at 0.2 C-rate to perform an activation process, after which the electrolyte was extracted, and each bath was filled with the electrolyte so that the ionic conductivity measuring probe was immersed, and the ionic conductivity was measured through the impregnated probe. 2) Cation transport rate of the electrolyte (t + ) measurement Each of the cylindrical lithium secondary batteries manufactured in Examples 1 to 6 and Comparative Examples 1 to 3 was charged to 4.2 V at 0.2 C-rate, 0.01 C cut-off conditions, and then activated by discharging to 2.8 V at 0.2 C-rate. Then, the extracted electrolyte was used to manufacture a coin cell in the form of lithium (Li) metal / electrolyte / lithium (Li) metal, and the resultant was measured at 25°C using a VMP3 Multichannel potentiostat from Bio-logic Science Instruments. Specifically, the cation transport rate was obtained by (1) measuring the resistance and current of the coin cell in the initial state, (2) applying a voltage of 10 mV to the coin cell in the initial state and monitoring the current drop, and measuring the resistance and current of the cell in the steady state where the current value was maintained constant after 10 hours, and then (3) calculating the cation transport rate by Equation A below. [Formula A] Cation transport rate (t + ) = In the above formula A, △V is the applied voltage change (10 mV), i0 is the current of the coin cell in the initial state (unit: mA), and R 0 is the resistance (unit: Ω) of the coin cell in the initial state, and i ss is the current (unit: mA) of the coin cell in the above normal state, and R ss is the resistance (unit: Ω) of the coin cell in the above normal state. (2) Measurement of electrolyte viscosity at 25℃ Each of the cylindrical lithium secondary batteries manufactured in Examples 1 to 6 and Comparative Examples 1 to 3 was charged to 4.2 V at 0.2 C-rate and 0.01 C cut-off conditions, and then discharged to 2.8 V at 0.2 C-rate to perform an activation process. Then, the viscosity of the electrolyte was measured at 25°C and 0.1 to 1 rpm using a rheometer (Brookfield DVNXCP Rheometer). C[mS / mm]t + DIB[mS / mm 2 ]Viscosity (25℃) [cP]Example 11.3720.42167.02.77Example 21.3990.42170.32.71Example 31.5070.42183.52.55Example 41.6270.43202.82.33Example 51.3900.42169.22.74Example 61.6000.43199.42.39Comparative Example 11.2740.42155.12.97Comparative Example 21.3480.41160.22.81Comparative Example 31.3700.42639.32.75 Referring to Table 1 above, the cylindrical lithium secondary batteries manufactured in Examples 1 to 6 had a DIB value of 162 mS / mm. 2 Within 635mS / mm 2 The cylindrical lithium secondary batteries manufactured in Comparative Examples 1 to 3 had a DIB value of 162 mS / mm. 2 Within 635mS / mm 2 It can be confirmed that the cylindrical lithium secondary battery manufactured in Comparative Example 3 does not satisfy the requirements. In particular, in the case of the cylindrical lithium secondary battery manufactured in Comparative Example 3, the cation transport rate of the electrolyte and the ion conductivity of the electrolyte have similar values ​​to Example 1, but the height and diameter of the cylindrical lithium secondary battery are different from Examples 1 to 6, so that the DIB value is 162 mS / mm. 2 Within 635mS / mm 2 It can be seen that it is not satisfied. Experimental Example 2: Evaluation of Rapid Charging Characteristics The cylindrical lithium secondary batteries manufactured in Examples 1 to 6 and Comparative Examples 1 to 3 were charged to 4.1 V at 1.0 C at 20°C and then discharged to 3.0 V at 0.05 C for 1 cycle, and then 200 charge-discharge cycles were performed, and then the capacity retention rate and resistance increase rate were measured. The measurement results are shown in Table 2 below. At this time, the capacity maintenance rate and resistance increase rate were calculated according to the following formula. - Capacity retention rate (%) = (discharge capacity after 200 cycles / initial discharge capacity) × 100 - Resistance increase rate (%) = {(Resistance after 200 cycles - Initial resistance) / Initial resistance} × 100 Capacity retention rate [%] (@200 cycle) Resistance increase rate [%] (@200 cycle) Example 172.434 Example 272.430 Example 372.926 Example 471.836 Example 572.425 Example 671.843 Comparative example 162.666 Comparative example 265.663 Comparative example 356.630.31 Referring to Table 2 above, it can be confirmed that the cylindrical lithium secondary batteries manufactured in Examples 1 to 6 have a superior capacity retention rate and resistance increase rate during rapid charging than the cylindrical lithium secondary batteries manufactured in Comparative Examples 1 to 3. In particular, Comparative Example 3 used an electrolyte having a similar level of ion conductivity and cation transport rate to Example 1, but had a DIB value of 162 mS / mm. 2 Within 635mS / mm 2 It can be confirmed that the capacity retention rate during rapid charging is inferior to that of Example 1 because it does not satisfy the requirement. Experimental Example 3: Evaluation of High Temperature Preservation Characteristics The cylindrical lithium secondary batteries manufactured in Examples 1 to 6 and Comparative Examples 1 to 3 above were charged to 4.2 V, 0.01 C cut off under CC / CV, 0.3 C conditions at 25°C and discharged to 2.5 V under CC, 0.2 C conditions to perform initial charge / discharge, and then charged to 4.25 V, 0.01 C cut off under CC / CV, 0.3 C conditions at 25°C and then stored at 55°C for 8 weeks. The cylindrical lithium secondary batteries of Examples 1 to 6 and Comparative Examples 1 to 3, which were stored at high temperatures above, were discharged at a constant current of 0.3 C at 25°C to 4.2 V to confirm the remaining capacity (recovery capacity) of the cylindrical lithium secondary batteries. The measurement results are shown in Table 3 below. In addition, the capacity recovery rate after high-temperature storage [%] was calculated as = 100Х(recovered capacity after high-temperature storage / discharge capacity before high-temperature storage). Discharge capacity before high temperature storage [Wh] Recovery capacity after high temperature storage [Wh] Capacity recovery rate after high temperature storage [%] Example 187.875.886.3 Example 287.575.986.7 Example 387.476.587.5 Example 487.574.785.4 Example 587.776.387.0 Example 687.674.985.5 Comparative Example 187.564.673.8 Comparative Example 287.968.377.7 Comparative Example 319.016.385.78 Referring to Table 3 above, it can be confirmed that the cylindrical lithium secondary batteries manufactured in Examples 1 to 6 have a superior capacity recovery rate after high-temperature storage than the cylindrical lithium secondary batteries manufactured in Comparative Examples 1 to 2. Accordingly, it can be understood that the cylindrical lithium secondary batteries manufactured in Examples 1 to 6 have superior high-temperature life characteristics. (Explanation of symbols) 1: Lithium secondary battery 2: Pack Housing 3: Battery pack 10: Bipolar 11: Negative 12: Membrane 20: Whole house 21: Active material layer 21a: Negative active material layer 22: No-nonsense 22a: Cathode ignorance 22c: The ignorance of the polarity 24: Insulation layer C: Center of winding 140: Lithium secondary battery 141: Electrode assembly 142: Battery Case 143: Seal 143a: Cap plate 143b: 1st gasket 143c: Connecting plate 143d: protrusion 144: 1st Collection Plate 145: 2nd collection plate 146: Insulator 146a: Bipolar ignorance 146b: Negative polarity 147: Bidding Department 148: Crimping section 149: Lead 151: Lead Hall 152: Benting Department 170: Lithium secondary battery 171: Battery Case 172: Rivet terminal 172a: Terminal exposed part 172b: Terminal insertion part 173: 2nd gasket 173a: Gasket exposure area 173b: Gasket insert 174: Insulating cap 176: Second collector plate 178: Seal 178a: Cap plate 178b: 1st gasket 179: Vent 180: Bidding section 181: Crimping section

Claims

1. A cylindrical lithium secondary battery including an electrode assembly in which a positive electrode, a separator, and a negative electrode are sequentially laminated and wound in one direction; an electrolyte; and a battery case in which the electrode assembly and the electrolyte are accommodated. The above electrolyte contains an ester solvent, The DIB (Diffusion of Ions in a Battery) value defined by Equation 1 below is 162 mS / mm 2 Within 635mS / mm 2 A cylindrical lithium secondary battery. [Formula 1] In the above equation 1, h (unit: mm) is the height of the cylindrical lithium secondary battery, R (unit: mm) is the diameter of the cylindrical lithium secondary battery, r (unit: mm) is the radius of the center of the winding of the electrode assembly, C (unit: mS / mm) is the ionic conductivity of the electrolyte, t + refers to the cation transport rate of the electrolyte.

2. In paragraph 1, A cylindrical lithium secondary battery, wherein the above C is 1.35 mS / mm to 1.70 mS / mm.

3. In paragraph 1, Above t + A cylindrical lithium secondary battery having an electric field strength of 0.25 to 0.

60.

4. In paragraph 1, A cylindrical lithium secondary battery, wherein the viscosity of the electrolyte at 25°C is 2.80 cP or less.

5. In paragraph 1, A cylindrical lithium secondary battery, wherein the ester solvent is included in an amount of 10 to 30 volume% based on the total volume of the electrolyte.

6. In paragraph 1, A cylindrical lithium secondary battery, wherein the ester solvent comprises at least one selected from the group consisting of methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate, ethyl propionate, propyl propionate, and butyl propionate, γ-butyrolactone, γ-valerolactone, γ-caprolactone, σ-valerolactone, and ε-caprolactone.

7. In paragraph 1, The above electrolyte contains a lithium salt, A cylindrical lithium secondary battery, wherein the lithium salt is included in the electrolyte at a concentration of 0.5 M to 2.0 M.

8. In paragraph 1, A cylindrical lithium secondary battery, wherein the electrolyte comprises at least one selected from the group consisting of a cyclic carbonate solvent and a linear carbonate solvent.

9. In paragraph 1, A cylindrical lithium secondary battery, wherein the ratio of R to h (R / h) is 0.4 or more.

10. In paragraph 1, The above cylindrical lithium secondary battery is a cylindrical lithium secondary battery, which is a 46110 cell, a 48110 cell, a 4880 cell or a 4680 cell.

11. In paragraph 1, A cylindrical lithium secondary battery, wherein the above cylindrical lithium secondary battery includes a non-conductive portion on which an active material layer is not formed on at least a portion of the positive electrode and the negative electrode, and the non-conductive portion of the positive electrode and the non-conductive portion of the negative electrode are defined as electrode tabs.

12. In paragraph 11, A cylindrical lithium secondary battery, wherein the positive electrode uncoated portion and the negative electrode uncoated portion are formed along the direction in which the electrode assembly is wound on one end of each of the positive and negative electrodes, and a current collecting plate is coupled to each of the positive electrode uncoated portion and the negative electrode uncoated portion, and the current collecting plate is connected to an electrode terminal.

13. In paragraph 11, The above positive and negative electrode parts are processed into a plurality of independently foldable segments, A cylindrical lithium secondary battery, wherein at least some of the plurality of segments are bent toward the winding center of the electrode assembly.

14. In paragraph 13, A cylindrical lithium secondary battery, wherein at least some of the plurality of folded segments overlap on the upper and lower sides of the electrode assembly, and the current collecting plate is bonded to the plurality of overlapped segments.

15. A battery pack comprising a cylindrical lithium secondary battery according to any one of claims 1 to 14 as a unit cell.

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