Lithium secondary battery, battery module and battery pack

Abstract

The present invention relates to a lithium secondary battery, a battery module, and a battery pack. The lithium secondary battery comprises: a positive electrode including a positive electrode active material; a negative electrode including a negative electrode active material; a separator disposed between the positive electrode and the negative electrode; and an electrolyte, wherein the positive electrode active material includes a lithium composite transition metal compound containing nickel (Ni), cobalt (Co), and manganese (Mn), the lithium composite transition metal compound contains single particles, the negative electrode active material includes a silicon oxide, and the grain size of Si in the silicon oxide is at most 10% of the grain size of the lithium composite transition metal compound.

Description

1 / 46 “LITHIUM SECONDARY BATTERY, BATTERY MODULE AND BATTERY PACK” [Technical Field]

[001] This application claims priority and the benefits of Korean Patent Application No. 10-2023-0105599 filed with the Korean Intellectual Property Office on August 11, 2023, the full content of which is incorporated herein by reference.

[002] The present invention relates to a secondary lithium battery, a battery module and a battery pack. [Background of the Technique]

[003] Recently, with the rapid spread of electronic devices that use batteries, such as cell phones, laptops, electric vehicles, power tools and electric cleaning appliances, the demand for small, lightweight secondary batteries with relatively high capacity and / or high power is rapidly increasing. In particular, a lithium secondary battery stands out as a driving energy source for electronic devices because it is lightweight and has high energy density. Thus, research and development efforts to improve the performance of lithium secondary batteries are being actively conducted.

[004] In a secondary lithium battery, in a state where an organic electrolyte solution or a polymer electrolyte solution is filled between a positive electrode and a negative electrode, each made of an active material capable of intercalating and deintercalating lithium ions, electrical energy is produced by oxidation / reduction reactions when lithium ions are intercalated / deintercalated in / from the positive electrode and the negative electrode.

[005] Lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), lithium manganese oxide (LiMnO2 or LiMn2O4 etc.), an iron phosphate compound of Petition 870250073323, dated 08 / 19 / 2025, page 9 / 58 Lithium oxide (LiFePO4) or similar materials have been used as the active material for the positive electrode of secondary lithium batteries. Among these materials, lithium cobalt oxide (LiCoO2) is advantageous due to its high operating voltage and excellent capacitance characteristics, and is therefore widely used and applied as the active material for the positive electrode of high-voltage lithium-ion batteries. However, since there is a limitation in the use of large quantities of lithium cobalt oxide as an energy source for applications such as electric vehicles, due to the rising price and unstable supply of cobalt (Co), the need arises to develop a positive electrode active material capable of replacing lithium cobalt oxide.

[006] Thus, a nickel-cobalt-manganese-based lithium composite transition metal compound (hereinafter referred to simply as “NCM-based lithium composite transition metal compound”) was developed, in which a portion of the cobalt (Co) is replaced by nickel (Ni) and manganese (Mn). Recently, research is being conducted to increase capacity by increasing the Ni content in the NCM-based lithium composite transition metal compound. However, in the case of a Ni-rich positive electrode active material with a high nickel content, there are disadvantages such as deterioration of thermal stability, increased resistance due to increased side reactions during an electrochemical reaction, and increased gas generation.

[007] Note that graphite is mainly used as the active material for the negative electrode of lithium secondary batteries. However, graphite has a low capacity per unit mass of 372 mAh / g, making it difficult to increase the capacity of lithium secondary batteries. Thus, to increase the capacity of lithium secondary batteries, negative electrode materials such as silicon, tin, and oxides thereof are being developed as non-carbon-based negative electrode materials with higher energy densities than graphite. Petition 870250073323, dated 08 / 19 / 2025, page 10 / 58 3 / 46 Although these non-carbon-based negative electrode materials have high capacitance, the initial efficiency is low. Therefore, there are problems where lithium consumption during initial charging and discharging is high, and irreversible capacitance loss is significant.

[008] Furthermore, a secondary lithium battery has a required size depending on its application and therefore must be designed within a limited space. Consumer demands for higher energy density and improved high-power performance are increasing, but when a high-capacity positive electrode material is used, the content of the negative electrode material must be correspondingly increased to match the positive electrode material. Consequently, there is a limit to increasing battery efficiency within a limited space. Therefore, there is a need to develop batteries with enhanced performance, such as efficiency and lifespan, within a limited space. List of Citations Patent Literature

[009] (Patent Literature 1) Korean Patent Application Publication No. 10-2011-0112215 [Detailed Description of the Invention] [Technical Problem]

[010] The inventors discovered that it is possible to obtain optimal battery performance in a lithium secondary battery designed in a limited space through a specific combination obtained by adjusting the crystal grain size of an active material of the positive electrode and the Si crystal grain size of an active material of the negative electrode, resulting in the present invention.

[011] The present invention relates to a secondary lithium battery, a battery module and a battery pack. [Technical Solution] Petition 870250073323, dated 08 / 19 / 2025, page 11 / 58 4 / 46

[012] An exemplary embodiment of the present invention provides a lithium secondary battery including: a positive electrode including a positive electrode active material; a negative electrode including a negative electrode active material; a separator provided between the positive electrode and the negative electrode; and an electrolyte, wherein the active material of the positive electrode includes a lithium composite transition metal compound including nickel (Ni), cobalt (Co) and manganese (Mn), the lithium composite transition metal compound includes single particles, the active material of the negative electrode includes a silicon oxide and a Si crystal grain size of the silicon oxide is 10% or less of a crystal grain size of the lithium composite transition metal compound.

[013] An exemplary embodiment of the present invention provides a battery module including the secondary lithium battery described above.

[014] An exemplary embodiment of the present invention provides a battery pack that includes the secondary lithium battery described above.

[015] An exemplary embodiment of the present invention provides a battery pack that includes the battery module described above. [Beneficial Effects]

[016] According to a secondary lithium battery of an exemplary embodiment of the present invention, the Si crystal grain size of a silicon oxide included in a negative electrode active material is 10% or less of the crystal grain size of a lithium composite transition metal compound included in a positive electrode active material, and when the above crystal grain size is satisfied, the cycle characteristics can be improved and the expansion can be reduced. Therefore, by controlling the crystal grains of the lithium composite transition metal compound and the Si crystal grains of the negative electrode active material, as described above, the fast charging performance, efficiency, lifespan and / or energy density of a secondary lithium battery can be improved. Petition 870250073323, dated 08 / 19 / 2025, page 12 / 58 5 / 46 scales designed in a limited space can be easily improved. [Best Mode]

[017] The present descriptive report will be described in more detail below.

[018] In this descriptive report, when a part is referred to as “including” a particular component, this means that the part may include yet another component, without excluding another component, unless explicitly stated otherwise.

[019] Throughout this descriptive report, when a member is referred to as being “on” another member, the member may be in direct contact with the other member or an intermediary member may also be present.

[020] It should be understood that the terms or words used throughout the descriptive report should not be interpreted as being limited to their common or dictionary meanings, but rather as having meanings and concepts consistent with the technical idea of ​​the present invention, based on the principle that an inventor can adequately define the concepts of words or terms to better explain the invention.

[021] As used in this document, the singular terms “a / an” and “the” are intended to include plural forms as well, unless the context clearly indicates otherwise.

[022] In this descriptive report, the term “single particle” is used to distinguish it from a positive electrode active material particle in the form of a secondary particle resulting from the agglomeration of tens to hundreds of primary particles, and refers both to a single particle consisting of one primary particle and to a form of almost single particle that is an agglomeration of 30 or fewer primary particles.

[023] In this descriptive report, the average particle diameter (D50) can be defined as the particle diameter corresponding to 50% of the volume. Petition 870250073323, dated 08 / 19 / 2025, page 13 / 58 6 / 46 cumulative in the particle size distribution curve (particle size distribution graph). The average particle diameter can be measured using, for example, a laser diffraction method. In the laser diffraction method, particle diameters ranging from a submicrometer region to several millimeters can generally be measured, and results with high reproducibility and high resolution can be obtained.

[024] The measurement of the average particle diameter can be confirmed using water and Triton-X100 dispersant with a Microtrac instrument (manufacturer: Microtrac, model name: S3500). Specifically, the average particle diameter of a positively electrode active material can be measured under a refractive index condition of 1.5 to 1.7, and the average particle diameter of a negatively electrode active material can be measured under a refractive index condition of 1.97 or 2.42. For example, after dispersing the particles in a dispersion medium, the resulting dispersion is introduced into a commercially available laser diffraction particle size measuring device and irradiated with an ultrasonic wave of approximately 28 kHz with a power of 60 W.Subsequently, a particle size distribution graph is obtained in cumulative volume, and then the average particle diameter can be measured, obtaining the particle size corresponding to 50% of the cumulative volume.

[025] Preferred embodiments of the present invention will be described in detail below. However, it should be understood that exemplary embodiments of the present invention may be modified in various ways and that the scope of the present invention is not limited to the exemplary embodiments described below.

[026] An exemplary embodiment of the present invention provides a lithium secondary battery including: a positive electrode including a positive electrode active material; a negative electrode including a negative electrode active material; a separator provided between the positive electrode and the negative electrode; and a Petition 870250073323, dated 08 / 19 / 2025, page 14 / 58 7 / 46 electrolyte, wherein the active material of the positive electrode includes a lithium composite transition metal compound including nickel (Ni), cobalt (Co) and manganese (Mn), the lithium composite transition metal compound includes single particles, the active material of the negative electrode includes a silicon oxide and the Si crystal grain size of the silicon oxide is 10% or less of the crystal grain size of the lithium composite transition metal compound.

[027] In general, a secondary lithium battery has a required size depending on its application and, consequently, must be designed in a limited space. Consumer demands for higher energy density and better high-power performance are increasing, but when a high-capacity positive electrode material is used, the content of the negative electrode material must be increased correspondingly to match the positive electrode material. Consequently, there is a limit to increasing battery efficiency in a limited space. Furthermore, it is necessary to design a positive electrode material with efficiency adapted to the efficiency of the negative electrode material, depending on the type of negative electrode material.

[028] A secondary lithium battery according to the present invention has a feature in which the Si crystal grain size of the silicon oxide included in the active material of the negative electrode is 10% or less of the crystal grain size of the lithium composite transition metal compound included in the active material of the positive electrode. Due to the properties of the silicon oxide material, the larger the crystal grain size, the more lithium (Li) remains in the material, which can lead to greater degradation of cycle performance and increased expansion. The present inventors have found that the aforementioned degradation of cycle performance and degree of expansion can be reduced by controlling the crystal grain size of the active material of the positive electrode so that it falls within a specific range relative to the crystal grain size of the silicon oxide. Petition 870250073323, dated 08 / 19 / 2025, page 15 / 58 8 / 46 silicon. Specifically, the intercalation of Li into the silicon oxide of the negative electrode is accompanied by the amorphization of the crystalline silicon oxide. Therefore, the larger the crystal grain size of the silicon oxide, the greater the resistance during lithium intercalation and deintercalation, leading to degraded cycle performance and increased expansion. Conversely, for active materials of the positive electrode, the greater the crystallinity, the less the structure changes, even with repeated intercalation and deintercalation of Li, allowing the lithium diffusion path to be maintained stably.When the crystal grain size of the active material of the positive electrode is larger than the crystal grain size of the silicon oxide within the range mentioned above, a relatively stable crystalline structure is maintained, allowing an electrochemical reaction to occur easily even with a small amount of lithium (Li), thus avoiding a relative decrease in capacity and expansion. Furthermore, when the crystal grain size of the silicon oxide is within the range mentioned above, the voltage caused by the volume expansion of the particles of the active material of the negative electrode during charging and discharging can be reduced, thus preventing particle breakage, leading to better cycle characteristics and reduced expansion.Therefore, by controlling the crystal grains of the lithium composite transition metal compound and the Si crystal grains of the negative electrode active material, as described above, the fast charging performance, efficiency, lifespan, and / or energy density of a lithium secondary battery designed in a limited space can be easily improved.

[029] According to an exemplary embodiment of the present invention, silicon oxide may include SiOx (0 < x < 2).

[030] The active material including SiOx (0 < x < 2) can be a silicon oxide particle including SiOx (0 < x < 2) and a pore.

[031] SiOx (0 < x < 2) corresponds to a matrix in the oxide particle Petition 870250073323, dated 08 / 19 / 2025, p. 16 / 58 9 / 46 silicon. SiOx (0 < x < 2) can be a form that includes Si and SiO2, and Si can form a phase. That is, x corresponds to a ratio of the number of O to Si included in SiOx (0 < x < 2). When silicon oxide particles include SiOx (0 < x < 2), the discharge capacity of a secondary battery can be improved.

[032] The silicon oxide particle may also include at least one Mg compound and one Li compound. The Mg compound and the Li compound may correspond to a dopant in the silicon oxide particle.

[033] The Mg compound and / or the Li compound may be present in SiOx (0 < x < 2) and / or on the surface of SiOx (0 < x < 2). The initial efficiency of the battery may be improved by the Mg compound and / or Li compound.

[034] The Mg compound may include at least one selected from the group consisting of Mg silicate, Mg silicide, and Mg oxide. Mg silicate may include at least one of Mg2SiO4 and MgSiO3. Mg silicide may include Mg2Si. Mg oxide may include MgO.

[035] In an exemplary embodiment of this descriptive report, the element Mg may be included in an amount of 0.1 to 20% by weight or 0.1 to 10% by weight based on 100% by weight of the total silicon oxide particles. Specifically, the element Mg may be included in an amount of 0.5 to 8% by weight or 0.8 to 4% by weight. When the above range is satisfied, the Mg compound may be included in a suitable content in the silicon oxide particles, so that the volume variation of the silicon oxide particles during battery charging and discharging may be easily suppressed, and the discharge capacity and initial efficiency of the battery may be improved.

[036] The Li compound may include at least one selected from the group consisting of Li silicate, Li silicide and Li oxide. Li silicate may include at least one of the following: Li2SiO3, Li4SiO4 and Li2Si2O5. Lithium silicide may include Li7Si2. Lithium oxide may include U2O. Petition 870250073323, dated 08 / 19 / 2025, page 17 / 58 10 / 46

[037] In an exemplary embodiment of the present invention, the Li compound may include a form of lithium silicate. Lithium silicate is represented by LiaSibOc (2 < a < 4, 0 < b < 2, 2 < c < 5) and may be divided into crystalline lithium silicate and amorphous lithium silicate. Crystalline lithium silicate may be present in the silicon oxide particle in the form of at least one lithium silicate selected from the group consisting of Li2SiO3, Li4SiO4 and Li2Si2O5, and amorphous lithium silicate may be in the form of LiaSibOc (2 < a < 4, 0 < b < 2, 2 < c < 5). However, such a limitation is not intended.

[038] In an exemplary embodiment of this descriptive report, the element Li may be included in an amount of 0.1 to 20% by weight or 0.1 to 10% by weight based on 100% by weight of the total silicon oxide particles. Specifically, the element Li may be included in an amount of 0.5 to 8% by weight and, more specifically, 0.5 to 4% by weight. When the above range is satisfied, the Li compound may be included in a suitable content in the silicon oxide particles, so that the volume variation of the active material of the negative electrode during battery charging and discharging may be easily suppressed and the discharge capacity and initial efficiency of the battery may be improved.

[039] The content of the element Mg or the element Li can be confirmed by ICP analysis. For ICP analysis, a predetermined amount (about 0.01 g) of an active negative electrode material is precisely aliquoted, transferred to a platinum crucible, and completely decomposed on a hot plate by the addition of nitric acid, hydrofluoric acid, and sulfuric acid. Then, using an inductively coupled plasma atomic emission spectrometer (ICP-AES, Perkin-Elmer 7300), a reference calibration curve is obtained by measuring the intensity of a standard liquid, which has been prepared using a standard solution (5 mg / kg), at an intrinsic wavelength of the element Mg or the element Li. Subsequently, a pre-treated sample solution and a sample in Petition 870250073323, dated 08 / 19 / 2025, page 18 / 58 11 / 46 blanks are introduced into the spectrometer and, by measuring the intensity of each component to calculate a true intensity, calculating the concentration of each component based on the calibration curve obtained, and then performing a conversion so that the sum of the calculated concentrations of the components equals a theoretical value, the content of Mg or Li in the prepared silicon oxide particles can be analyzed.

[040] In an exemplary embodiment of the present invention, the silicon oxide may include an additional metal atom. The metal atom may be present in the form of at least one metal atom, a metal silicate, a metal silicide, and a metal oxide in the silicon oxide. The metal atom may include at least one selected from the group consisting of Mg, Li, Al, and Ca. Thus, the initial efficiency of the active material of the negative electrode may be improved.

[041] In an exemplary embodiment of the present invention, a carbon layer is provided on at least part of a silicon oxide surface. In this case, the carbon layer may be coated on at least part of the surface, i.e., it may be partially coated on the particle surface, or it may be coated on the entire particle surface. Conductivity is imparted to the active material of the negative electrode by the carbon layer, so that the initial efficiency, service life characteristics and capacity characteristics of the secondary battery can be improved.

[042] In an exemplary embodiment of the present invention, the carbon layer includes amorphous carbon. In addition, the carbon layer may also include crystalline carbon.

[043] Crystalline carbon can further improve the conductivity of the negative electrode active material. Crystalline carbon can include at least one selected from the group consisting of fullerene, carbon nanotubes and graphene.

[044] Amorphous carbon can adequately maintain the strength of Petition 870250073323, dated 08 / 19 / 2025, page 19 / 58 12 / 46 carbon layer to suppress the expansion of silicon oxide. The amorphous carbon may be a carbide of at least one material selected from the group consisting of tar, pitch and other organic materials, or it may be a carbon-based material formed using hydrocarbon as a source of chemical vapor deposition.

[045] The carbide of other organic materials may be a carbide of an organic material selected from sucrose, glucose, galactose, fructose, lactose, mannose, ribose, aldohexose, ketohexose and combinations thereof.

[046] The hydrocarbon may be a substituted or unsubstituted aliphatic or alicyclic hydrocarbon or a substituted or unsubstituted aromatic hydrocarbon. The substituted or unsubstituted aliphatic or alicyclic hydrocarbon may be methane, ethane, ethylene, acetylene, propane, butane, butene, pentane, isobutane, hexane or the like. The substituted or unsubstituted aromatic hydrocarbon may be benzene, toluene, xylene, styrene, ethylbenzene, diphenylmethane, naphthalene, phenol, cresol, nitrobenzene, chlorobenzene, indene, coumarone, pyridine, anthracene, phenanthrene or the like.

[047] In an exemplary embodiment of the present invention, the carbon layer may be an amorphous carbon layer.

[048] In an exemplary embodiment of the present invention, the carbon layer may be included in an amount of 0.1 to 50 parts by weight, 0.1 to 30 parts by weight, or 0.1 to 20 parts by weight based on 100 parts by weight of the total silicon oxide. More specifically, the carbon layer may be included in an amount of 0.5 to 15 parts by weight, 1 to 10 parts by weight, or 1 to 5 parts by weight. When the above range is satisfied, it is possible to avoid reducing the capacity and efficiency of the active material of the negative electrode.

[049] In an exemplary embodiment of the present invention, the thickness of the carbon layer can be from 1 nm to 500 nm and, specifically, from 5 nm to 300 Petition 870250073323, dated 08 / 19 / 2025, p. 20 / 58 13 / 46 nm. When the above range is satisfied, the conductivity of the negative electrode active material is improved, the variation in the volume of the negative electrode active material is easily suppressed, and the side reaction between the electrolyte solution and the negative electrode active material is suppressed, thus improving the initial efficiency and / or battery life.

[050] Specifically, the carbon layer can be formed by chemical vapor deposition (CVD) using at least one hydrocarbon gas selected from the group consisting of methane, ethane and acetylene.

[051] In the present invention, the crystallinity of the carbon layer can be confirmed by calculating the D / G band ratio according to Raman spectroscopy. Specifically, measurements can be made using a Renishaw 2000 Raman microscope system and 532 nm laser excitation, and using a 100x optical lens with low laser power density and an exposure time of 30 seconds in order to avoid the effect of laser heat. To reduce position-dependent deviation, a total of 25 points can be determined for a 5 μm x 5 μm region and fitted using the Lorentzian function. Subsequently, the average values ​​of the D and G bands can be calculated.

[052] In an exemplary embodiment of the present invention, the average particle diameter (D50) of silicon oxide may be equal to or greater than 1 μm. In addition, the average particle diameter of silicon oxide may be equal to or less than 10 μm. For example, the average particle diameter (D50) of silicon oxide may be equal to or greater than 1 μm and equal to or less than 10 μm, equal to or greater than 2 μm and equal to or less than 10 μm, equal to or greater than 3 μm and equal to or less than 10 μm, 3 μm to 10 μm, 4 μm to 8 μm or 5 μm to 8 μm.

[053] Even when silicon oxide is formed to have a small particle diameter of about 1 μm or more and 10 μm or less, it can improve battery life characteristics. For example, when the average diameter of Petition 870250073323, dated 08 / 19 / 2025, p. 21 / 58 14 / 46 silicon oxide particles are within the range of 1 μm or more and 10 μm or less, the rate of volume expansion and contraction due to charging and discharging is reduced, so that service life performance can be improved. Furthermore, it is possible to prevent the specific surface area from increasing excessively, thus preventing side reactions with the electrolyte due to cycling and improving service life performance.

[054] In an exemplary embodiment of the present invention, the active material of the negative electrode may also include graphite.

[055] Graphite can be natural graphite, artificial graphite, or a mixture of natural and artificial graphite.

[056] In the case where the graphite is a mixture of natural graphite and artificial graphite, the weight ratio of natural graphite to artificial graphite can be 50:50 to 90:10 and, specifically, 60:40 to 80:20 or 65:35 to 75:25.

[057] In an exemplary embodiment of the present invention, the average particle diameter (D50) of the graphite can be from 10 μm to 20 μm and, specifically, from 15 μm to 20 μm. When the average diameter of the graphite particles is within the range mentioned above, the influence of particle agglomeration is reduced and the dispersibility of the paste can be improved.

[058] In an exemplary embodiment of the present invention, the active material of the positive electrode may include a lithium composite transition metal compound, including nickel (Ni), cobalt (Co) and manganese (Mn).

[059] In an exemplary embodiment of the present invention, the active material of the positive electrode may include nickel, cobalt and manganese, and may also include aluminum.

[060] In the present descriptive report, the active material of the positive electrode may include 80 mol% or more and less than 100 mol% nickel among the metals, except lithium, and the lithium composite transition metal compound, including 80 Petition 870250073323, dated 08 / 19 / 2025, p. 22 / 58 15 / 46 mol% or more and less than 100 mol% nickel among the metals, except lithium, may include one species or a mixture of two or more species represented by Chemical Formula 1 below. [Chemical Formula 1] LiaNi1-bc-dCobMncQdO2+δ

[061] In the Chemical Formula, Q is any one or more elements selected from the group consisting of Na, K, Mg, Ca, Sr, Ni, Co, Ti, Al, Si, Sn, Mn, Cr, Fe, V and Zr, and 1 < a < 1.5, 0 < b < 0.5, 0 < c < 0.5, 0 < d < 0.1, 0 < b+c+d < 0.2 and -0.1 < δ < 1.0.

[062] In the lithium composite transition metal compound of Chemical Formula 1, Li can be included in an amount corresponding to, i.e., 1 < a < 1.5. If a is less than 1, the capacity may be reduced, and if a exceeds 1.5, the particles are sintered in a baking process, making the fabrication of the positive electrode active material difficult. Considering the balance between improving the capacity characteristics of the positive electrode active material and the sinterability during the fabrication of the active material according to the control of the Li content, Li can more preferably be included in an amount of 1.1 < a < 1.2.

[063] In the lithium composite transition metal compound of Chemical Formula 1, Ni may be included in an amount corresponding to 1-(b+c+d), for example, 0.8 < 1-(b+c+d) < 1. When the Ni content in the lithium composite transition metal compound of Chemical Formula 1 is 0.8 or more, a sufficient amount of Ni is ensured to contribute to charging and discharging, and high capacity may be promoted. The Ni content, 1-(b+c+d), may be equal to or greater than 0.88, preferably equal to or greater than 0.9, and more preferably equal to or greater than 0.93. Preferably, the Ni content, 1-(b+c+d), may be equal to or less than 0.99 or equal to or less than 0.95.

[064] In the lithium composite transition metal compound of Chemical Formula 1, Co can be included in an amount corresponding to ab, that is, 0 Petition 870250073323, dated 08 / 19 / 2025, p. 23 / 58 16 / 46 < b < 0.5. If the Co content in the lithium composite transition metal compound of Chemical Formula 1 exceeds 0.5, there is a concern about increased cost. Considering the notable improvement effect on capacity characteristics according to the inclusion of Co, Co can be more specifically included at a content of 0.03 < b < 0.2.

[065] In the lithium composite transition metal compound of Chemical Formula 1, Mn may be included at a content corresponding to ac, i.e., a content of 0 < c < 0.5. If c in the lithium composite transition metal compound of Chemical Formula 1 exceeds 0.5, there is concern that the output characteristics and capacity characteristics of the battery will deteriorate and, more specifically, Mn may be included at a content of 0.01 < c < 0.2.

[066] In the lithium composite transition metal oxide of Chemical Formula 1, Q may be a dopant element included in a crystal structure of the lithium composite transition metal compound, and Q may be included in a content corresponding to ad, i.e., 0 < d < 0.1. Q may be one or two or more selected from Na, K, Mg, Ca, Sr, Ni, Co, Ti, Al, Si, Sn, Mn, Cr, Fe, V and Zr and, for example, Q may be Al.

[067] In an exemplary embodiment of the present invention, the lithium composite transition metal compound may include single particles.

[068] In an exemplary embodiment of the present invention, the lithium composite transition metal compound may also include secondary particles.

[069] Single particles can be manufactured by mixing and burning a transition metal precursor and a lithium source material. Secondary particles can be manufactured by a different method than single particles, and their composition can be the same as or different from single particles.

[070] For example, combustion is carried out at a temperature at which unique particles can be formed. For this purpose, combustion must be carried out at a Petition 870250073323, dated 08 / 19 / 2025, page 24 / 58 17 / 46 temperature higher than the temperature during the manufacture of the secondary particles. For example, when the precursor composition is the same, the firing should be carried out at a temperature approximately 30 °C to 100 °C higher than the temperature during the manufacture of the secondary particles. The firing temperature for forming the single particles may vary depending on the metal composition in the precursor. For example, when forming single particles of a lithium-based NCM composite transition metal oxide with a high nickel (Ni) content of 80 mol% or more, the firing temperature may be approximately 700 °C to 1000 °C and preferably approximately 800 °C to 950 °C. When the firing temperature meets the above range, a positively charged electrode active material including single particles with excellent electrochemical properties can be manufactured.If the firing temperature is below 790 °C, an active positive electrode material can be manufactured including a lithium composite transition metal compound in the form of secondary particles, and if the firing temperature exceeds 950 °C, over-firing occurs and a layered crystalline structure is not properly formed, so the electrochemical properties may deteriorate.

[071] In this descriptive report, single particle is a term used to distinguish it from typical secondary particles resulting from the agglomeration of tens to hundreds of primary particles, and is a concept that includes a single particle consisting of one primary particle and a form of near single particle that is an agglomeration of 30 or fewer primary particles.

[072] Specifically, in the present invention, the single particle can be a single particle consisting of a primary particle or a nearly single particle form that is an agglomeration of 30 or fewer primary particles, and the secondary particle can be an agglomerated form of hundreds of primary particles.

[073] In this descriptive report, the size of the Si crystal grains included in silicon oxide can be confirmed through diffraction analysis of Petition 870250073323, dated 08 / 19 / 2025, page 25 / 58 18 / 46 X-rays, and X-ray diffraction analysis can be performed using an X-ray diffraction analyzer (XRD) (product name: D4-endavor, manufacturer: Bruker). Specifically, XRD measurement can be performed by sampling a powder sample on a support and using Cu K alpha X-rays. The Si crystal grain size can be calculated by fitting the XRD results using the Scherrer equation and, in this case, the crystal grain size can be measured based on Si (220) (2θ = 47.5° to 48.5°).

[074] In an exemplary embodiment of the present invention, the silicon oxide may have a Si crystal grain size equal to or greater than 0.1 nm and equal to or less than 20 nm. Specifically, the Si crystal grain size may be equal to or greater than 0.5 nm and equal to or less than 15 nm, 1 nm or greater and 15 nm or less, 1.5 nm or greater and 12 nm or less, 1.5 nm or greater and 10 nm or less, 2 nm or greater and 10 nm or less, 3 nm or greater and 10 nm or less, or 4 nm or greater and 9 nm or less.

[075] This crystal grain size allows ions to diffuse uniformly, thus maintaining the structure of the Si particles stable during charging and discharging. On the other hand, if the Si crystal grain size exceeds the above range, cracks may form in the particles due to stress caused by the contraction / expansion of the Si material during charging and discharging, and Li ions cannot diffuse into the crystal grains, resulting in accelerated deterioration of the material due to the irregularity of the reaction, which causes a reduction in the cell's lifespan.

[076] In this descriptive report, the crystal grain size of the lithium composite transition metal compound can refer, for example, to the crystal size of the structure of Chemical Formula 1 above. In this descriptive report, the crystal grain size of the lithium composite transition metal compound can be confirmed by X-ray diffraction analysis. Petition 870250073323, dated 08 / 19 / 2025, page 26 / 58 19 / 46 and X-ray diffraction analysis can be performed using an X-ray diffraction analyzer (XRD) (product name: D4-endavor, manufacturer: Bruker). Specifically, XRD measurement can be performed by sampling a powder sample on a support and using Cu K alpha X-rays. The crystal grain size of the lithium and transition metal compound can be calculated by fitting the XRD results using the Scherrer equation, and in this case, the crystal grain size can be measured based on the largest peak that appears around 2Θ = 10° to 12°.

[077] In an exemplary embodiment of the present invention, the lithium composite transition metal compound may have a crystal grain size of 70 nm or higher and 200 nm or lower. Specifically, the crystal grain size may be 70 nm or higher and 180 nm or lower, 70 nm or higher and 160 nm or lower, or 80 nm or higher and 130 nm or lower.

[078] When the crystal grain size of the lithium composite transition metal compound is within the above range, the lithium composite transition metal compound has excellent phase stability and can react stably with Li. On the other hand, if the crystal grain size of the lithium composite transition metal compound is below the above range, the reaction with Li occurs over a long period, leading to a reduction in the efficiency of the positive electrode. If the crystal grain size of the lithium composite transition metal compound exceeds the above range, particle breakage of the active material of the positive electrode occurs during the roller pressing step of the electrode manufacturing process.

[079] In an exemplary embodiment of the present invention, the Si crystal grain size of the silicon oxide may be 10% or less of the crystal grain size of the lithium composite transition metal compound. Specifically, the Si crystal grain size of the silicon oxide may be 0.5% or more and 10% or less. Petition 870250073323, dated 08 / 19 / 2025, page 27 / 58 20 / 46 less, 1% or more and 10% or less, or 1% or more and 9.5% or less of the crystal grain size of the lithium composite transition metal compound. When the Si crystal grain size of the silicon oxide and the crystal grain size of the lithium composite transition metal compound satisfy the above ratio, the stress caused by the volume expansion of the particles of the negative electrode active material during charging and discharging can be reduced, which prevents particle breakage. Furthermore, the negative electrode may deteriorate depending on the crystallinity of the silicon oxide, and in this case, some lithium ions may be consumed due to secondary reactions with the silicon oxide.However, the stable crystalline structure provided by the relatively large size of the crystal grains of the active material of the positive electrode can facilitate electrochemical reactions, even with a small amount of lithium (Li), leading to improved cycle characteristics and a reduction in expansion. That is, the consumption of lithium ions that occurs during intercalation and deintercalation can be minimized, and a certain level or more of capacity can be maintained even with the reduction of lithium ions due to consumption, thus compensating for the overall deterioration of the battery cell.

[080] On the other hand, even when the Si crystal grain size of silicon oxide and the crystal grain size of lithium composite transition metal compound satisfy the aforementioned grain sizes, if the Si crystal grain size of silicon oxide exceeds 10% of the crystal grain size of lithium composite transition metal compound, the degrees of degradation of cycle and expansion performance may increase due to lithium (Li) remaining in the silicon oxide, and cycle performance deteriorates due to particle cracks caused by an increase in Si internal stress during loading and unloading.

[081] In an exemplary embodiment of the present invention, a diameter Petition 870250073323, dated 08 / 19 / 2025, page 28 / 58 The average diameter (D50) of single particles can be equal to or greater than 1 μm. Furthermore, the average diameter of single particles can be equal to or less than 10 μm. For example, the average diameter of single particles can be equal to or greater than 1 μm and equal to or less than 10 μm, equal to or greater than 1 μm and equal to or less than 8 μm, equal to or greater than 1 μm and equal to or less than 6 μm, greater than 1 μm and equal to or less than 6 μm, equal to or greater than 2 μm and equal to or less than 6 μm, or equal to or greater than 3 μm and equal to or less than 5 μm.

[082] Single particles can exhibit excellent resistance, even if they are formed with a small diameter, of about 1 μm or more and 10 μm or less, and consequently, the microparticle buildup on an electrode due to particle breakage is attenuated, which can improve battery life characteristics. For example, a single particle can have a resistance of 100 to 300 MPa when compressed with a force of 650 kgf / cm2. Thus, even when single particles are compressed with a strong force of 650 kgf / cm2, the microparticle buildup on an electrode due to particle breakage is attenuated, which improves battery life characteristics.

[083] The method of forming single particles is not particularly limited, but generally single particles can be formed by overfiring at high firing temperatures, or they can be manufactured using additives such as grain growth promoters that aid in overfiring, or by altering a starting material.

[084] The single particles have high intrinsic rigidity, exhibiting relatively excellent resistance to battery performance degradation, even when the electrode density is high. Therefore, the energy density can be increased by controlling the average diameter ranges of the single particles and silicon oxide.

[085] In an exemplary embodiment of the present invention, the average diameter of the individual particles may be smaller than the average diameter of the oxide particles. Petition 870250073323, dated 08 / 19 / 2025, page 29 / 58 22 / 46 silicon.

[086] When the average diameter of the individual particles is smaller than the average diameter of the silicon oxide individual particles, the diffusion resistance of the individual particles is relatively reduced, which can lead to better service life performance. That is, as the average diameter of the individual particles increases, the diffusion resistance can increase. If the average diameter of the individual particles is larger than the average diameter of the silicon oxide particles, lithium or similar precipitation may occur as the diffusion resistance increases relatively, which can deteriorate battery performance and reduce service life performance.

[087] Furthermore, when the average diameter of the individual particles is smaller than the average diameter of the silicon oxide particles, side reactions with the electrolytic solution are avoided due to an increase in specific surface area, which can lead to improved service life performance.

[088] According to an exemplary embodiment of the present invention, the average diameter of the individual particles can be 0.1 μm to 5 μm smaller, specifically 1 μm to 3 μm smaller than the average diameter of the silicon oxide particles.

[089] When the average diameter of the individual particles is smaller than the average diameter of the individual particles of silicon oxide, for example, when the above range is satisfied, the diffusion resistance of the individual particles is relatively reduced, which can lead to better service life performance. That is, as the average diameter of the individual particles increases, the diffusion resistance can increase. If the average diameter of the individual particles is larger than the average diameter of the silicon oxide particles, lithium precipitation or similar may occur as the diffusion resistance increases relatively, which can deteriorate battery performance and reduce service life performance.

[090] Furthermore, when the average diameter of the individual particles is less than Petition 870250073323, dated 08 / 19 / 2025, page 30 / 58 23 / 46 that the average diameter of silicon oxide particles, for example, when the above range is satisfied, side reactions with the electrolytic solution are avoided due to an increase in specific surface area, which can lead to better service life performance.

[091] According to an exemplary embodiment of the present invention, a ratio between the average diameter of the individual particles and the average diameter of the silicon oxide particles can be from 1:1 to 1:2, for example, 1:1.1 to 1:2.

[092] When the above range is satisfied, the diffusion resistance of the single particle is relatively reduced, which can lead to better service life performance. That is, as the average diameter of the single particles increases, the diffusion resistance can increase. If the average diameter of the single particles is larger than the average diameter of the silicon oxide particles, lithium or similar precipitation may occur as the diffusion resistance increases relatively, which can deteriorate battery performance and reduce service life performance.

[093] Furthermore, when the average diameter of the individual particles is smaller than the average diameter of the silicon oxide particles, for example, when the above range is satisfied, side reactions with the electrolytic solution due to an increase in specific surface area are avoided, which can lead to better service life performance.

[094] In the exemplary embodiment of the present invention, the lithium composite transition metal compound also includes secondary particles, and the average diameter of the single particles is smaller than the average diameter of the secondary particles.

[095] In the present invention, the single particle can be a single particle consisting of a primary particle or a nearly single form that is an agglomeration of 30 or fewer primary particles, and the secondary particle can be an agglomerated form of hundreds of primary particles. Petition 870250073323, dated 08 / 19 / 2025, p. 31 / 58 24 / 46

[096] The lithium composite transition metal compound described above may also include secondary particles. A secondary particle means a form formed by the agglomeration of primary particles and may be distinguished from the concept of a single particle including a primary particle, a single particle and a quasi-single form, which is an agglomeration of 30 or fewer primary particles.

[097] The average particle diameter (D50) of secondary particles can be from 1 μm to 20 μm, and specifically from 2 μm to 17 μm, 3 μm to 15 μm, 5 μm to 15 μm, 7 μm to 15 μm or 9 μm to 15 μm.

[098] In an exemplary embodiment of the present application, the secondary particle is an agglomerate of primary particles, and the average diameter of the primary particles is from 0.5 μm to 3 μm. Specifically, the secondary particle may be an aggregated form of hundreds of primary particles, and the average diameter of the primary particles may be from 0.6 μm to 2.8 μm, 0.8 μm to 2.5 μm or 0.8 μm to 1.5 μm.

[099] When the average diameter of the primary particles is within the above range, a single-particle positive electrode active material with excellent electrochemical properties can be formed. If the average diameter of the primary particles is too small, the number of primary particle agglomerates that form nickel-lithium based oxide particles increases, reducing the effect of suppressing particle breakage during roller pressing. If the average diameter of the primary particles is too large, a lithium diffusion path within the primary particles can be elongated and narrowed, increasing resistance and degrading the output characteristic.

[0100] In an exemplary embodiment of the present invention, the average diameter of the single particles may be smaller than the average diameter of the secondary particles. As a result, single particles may have excellent strength, even if they are formed with a small particle diameter and, Petition 870250073323, dated 08 / 19 / 2025, p. 32 / 58 25 / 46 consequently, the increase in microparticles on an electrode due to particle breakup is attenuated, which can improve battery life characteristics.

[0101] In an exemplary embodiment of the present invention, the average diameter of the single particles is 1 μm to 18 μm smaller than the average diameter of the secondary particles.

[0102] For example, the average diameter of single particles may be 1 μm to 16 μm smaller, 1.5 μm to 15 μm smaller, 2 μm to 14 μm smaller, or 5 μm to 8 μm smaller than the average diameter of secondary particles.

[0103] When the average diameter of single particles is smaller than the average diameter of secondary particles, for example, when the above range is satisfied, the single particles can exhibit excellent strength, even though they are formed with a small particle diameter and, consequently, the microparticle buildup on an electrode due to particle breakage is attenuated, which can improve the battery's lifespan characteristics and energy density.

[0104] In the secondary lithium battery according to the exemplary embodiment, the active material of the negative electrode may also include a carbon-based active material. Specifically, the carbon-based active material may be graphite. The graphite may be natural graphite, artificial graphite, or a mixture thereof.

[0105] In an exemplary embodiment of the present invention, the average diameter of the silicon oxide particles may be smaller than the average diameter of the graphite particles. When the average diameter of the silicon oxide particles is smaller than the average diameter of the graphite particles, particle breakage is reduced due to a change in the volume expansion / contraction rate during charging and discharging, leading to improved battery life performance. Petition 870250073323, dated 08 / 19 / 2025, p. 33 / 58 26 / 46

[0106] According to an exemplary embodiment of the present invention, the average diameter of the silicon oxide particles can be 1 μm to 25 μm smaller than the average diameter of the graphite particles. For example, the average diameter of the silicon oxide particles can be 2 μm to 24 μm smaller, 3 μm to 23 μm smaller, 4 μm to 22 μm smaller, or 5 μm to 15 μm smaller than the average diameter of the graphite particles.

[0107] When the average diameter of silicon oxide particles is smaller than the average diameter of graphite particles, for example, when the above range is met, battery life performance is further improved.

[0108] In an exemplary embodiment of the present invention, when the average diameters of the secondary particles, single particles, graphite and silicon oxide included in the lithium secondary battery are designated by A, B, C and D respectively, a relationship B < D < A < C can be satisfied.

[0109] Exemplary embodiments of secondary particles, single particles, graphite and silicon oxide are described above.

[0110] When the average diameters of secondary particles, single particles, graphite and silicon oxide are designated as A, B, C and D, respectively, and a relationship B < D < A < C is satisfied, the battery life performance is improved.

[0111] According to an exemplary embodiment of the present invention, the active material of the negative electrode further includes graphite and, when the average diameters of single particles, graphite and silicon oxide are designated B, C and D respectively, a relationship B < D < C can be satisfied.

[0112] When the average diameters of secondary particles, single particles and silicon oxide are designated A, B and D respectively, a relationship B < D < A can be satisfied.

[0113] When the average diameters of the secondary particles, of Petition 870250073323, dated 08 / 19 / 2025, p. 34 / 58 27 / 46 single particles and graphite are indicated as A, B, and C respectively, a relationship B < A < C can be satisfied.

[0114] When the average diameters of the secondary particles, graphite and silicon oxide, are indicated as A, C and D respectively, a relationship D < A < C can be satisfied.

[0115] When the above ranges are met, battery life performance is improved.

[0116] In an exemplary embodiment of the present invention, in the secondary lithium battery according to the exemplary embodiment described above, the single particles are included in an amount of 15 to 100 parts by weight relative to 100 parts by weight of the active material of the positive electrode, and the silicon oxide is included in an amount of 3 to 30 parts by weight relative to 100 parts by weight of the active material of the negative electrode.

[0117] In an exemplary embodiment of the present application, the single particles are included in an amount of 15 to 100 parts by weight relative to 100 parts by weight of the active material of the positive electrode. The single particles may be included in an amount of 20 parts by weight to 100 parts by weight, or 30 parts by weight to 100 parts by weight based on 100 parts by weight of the active material of the positive electrode.

[0118] For example, single particles may be included in an amount of 15 parts by weight or more, 20 parts by weight or more, 25 parts by weight or more, 30 parts by weight or more, 35 parts by weight or more, 40 parts by weight or more, or 45 parts by weight or more, relative to 100 parts by weight of the active material of the positive electrode. For example, single particles may be included in an amount of 100 parts by weight or less, 90 parts by weight or less, 80 parts by weight or less, 70 parts by weight or less, or 60 parts by weight or less relative to 100 parts by weight of the active material of the electrode. Petition 870250073323, dated 08 / 19 / 2025, page 35 / 58 28 / 46 positive.

[0119] When single particles are included within the above range, excellent battery characteristics can be exhibited in combination with the negative electrode material described above. In particular, when single particles are included in an amount of 15 parts by weight or more, the increase in microparticles in an electrode due to particle breakage during roller pressing after electrode manufacturing is attenuated, which can improve battery life characteristics.

[0120] In an exemplary embodiment of the present invention, the lithium composite transition metal compound may further include secondary particles, and the secondary particles may be included in an amount of 85 parts by weight or less relative to 100 parts by weight of the active material of the positive electrode. The secondary particles may be included in an amount of 80 parts by weight or less, 75 parts by weight or less, 70 parts by weight or less, or 60 parts by weight or less relative to 100 parts by weight of the active material of the positive electrode. The secondary particles may be included in an amount of 10 parts by weight or more, 20 parts by weight or more, 30 parts by weight or more, or 40 parts or more relative to 100 parts by weight of the active material of the positive electrode.

[0121] In an exemplary embodiment of the present invention, the weight ratio between single particles and secondary particles can be 1:9 to 9:1, 2:8 to 8:2, 3:7 to 7:3 or 4:6 to 6:4.

[0122] When the above range is satisfied, the effects described above due to the existence of single particles in the active material of the positive electrode can be maximized. In the case where the active material of the positive electrode of secondary particles is included, its components may be the same as or different from those exemplified in the active material of the single-particle positive electrode described. Petition 870250073323, dated 08 / 19 / 2025, page 36 / 58 29 / 46 above, and may signify a clustered form of individual particles.

[0123] In an exemplary embodiment of the present invention, the active material of the positive electrode in 100 parts by weight of the active material layer of the positive electrode may be included in an amount of 80 parts by weight or more and 99.9 parts by weight or less, preferably 90 parts by weight or more and 99.9 parts by weight or less, more preferably 95 parts by weight or more and 99.9 parts by weight or less, and even more preferably 98 parts by weight or more and 99.9 parts by weight or less.

[0124] According to an exemplary embodiment of the present invention, the positive electrode according to the exemplary embodiment described above further includes a positive electrode ligand and a conductive material.

[0125] The positive electrode binder can serve to improve the adhesion between the particles of the active material of the positive electrode and the adhesive force between the particles of the active material of the positive electrode and the current collector of the positive electrode. For the positive electrode binder, those known in the art can be used. Non-limiting examples thereof may include polyvinylidene fluoride (PVDF), polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-co-HFP), polyvinyl alcohol, polyacrylonitrile, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, polytetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene monomer (EPDM), sulfonated EPDM, styrene-butadiene rubber (SBR), fluorinated rubber, various copolymers thereof and the like, and any one of the same alone or a mixture of two or more of the same may be used.

[0126] The positive electrode ligand may be included in an amount of 0.1 part by weight or more and 50 parts by weight or less, for example, preferably 0.3 parts by weight or more and 35 parts by weight or less, and more preferably 0.5 parts by weight or more and 20 parts by weight or less, with Petition 870250073323, dated 08 / 19 / 2025, page 37 / 58 30 / 46 based on 100 parts by weight of the active material layer of the positive electrode.

[0127] The conductive material included in the active material layer of the positive electrode is used to impart conductivity to the electrode and may be used without particular limitations, provided that the conductive material has electronic conductivity without causing a chemical change in the battery. Specific examples may include graphite, such as natural graphite and artificial graphite; a carbon-based material, such as carbon black, acetylene black, Ketjen black, channel black, furnace black, lamp black, thermal black and carbon fiber; metallic powders or metallic fibers, such as copper, nickel, aluminum and silver; a conductive whisker, such as zinc oxide and potassium titanate; a conductive metallic oxide, such as titanium oxide; or a conductive polymer, such as a polyphenylene derivative, or similar, and any one of the same or a mixture of two or more of the same may be used.

[0128] Specifically, in an exemplary embodiment, the conductive material may include one or more of a single-walled carbon nanotube (SWCNT) and a multi-walled carbon nanotube (MWCNT). The conductive material may be included in an amount of 0.1 parts by weight or more and 2 parts by weight or less, for example, preferably 0.3 parts by weight or more and 1.5 parts by weight or less, and more preferably 0.5 parts by weight or more and 1.2 parts by weight or less based on 100 parts by weight of the composition for a layer of active material of the positive electrode.

[0129] According to the exemplary embodiment of the present application, the active material layer of the negative electrode includes 3 to 30 parts by weight of silicon oxide based on 100 parts by weight of the total active material of the negative electrode. According to an exemplary embodiment, the active material layer of the negative electrode may include 3 to 20 parts by weight, or 3 to 13 parts by weight, preferably 5 to 10 parts by weight of silicon oxide based on 100 parts by weight of the total active material of the negative electrode. Silicon oxide is used Petition 870250073323, dated 08 / 19 / 2025, page 38 / 58 31 / 46 within the aforementioned range, therefore excellent battery characteristics can be exhibited in combination with the positive electrode material described above. In particular, when silicon oxide is included in an amount of 3 parts by weight or more, the effect of using silicon oxide can be sufficiently displayed. Furthermore, since silicon oxide has a high capacitance, it can be difficult to balance the capacitance with the active material of the positive electrode when used in excess. In particular, when silicon oxide is included in an amount of 30 parts by weight or less, expansion during charging and discharging can be avoided, which can lead to improved cycle characteristics.

[0130] According to an exemplary embodiment of the present invention, in the secondary lithium battery according to the exemplary embodiment, the active material of the negative electrode may further include a carbon-based active material. Specifically, the carbon-based active material may be graphite. The graphite may be natural graphite, artificial graphite, or a mixture thereof. The graphite may be included in an amount of 70 parts by weight or more and 97 parts by weight or less, based on 100 parts by weight of the total negative electrode active material included in the negative electrode active material layer.

[0131] Graphite may be included in an amount of 75 parts by weight or more, 80 parts by weight or more, or 85 parts by weight or more, based on 100 parts by weight of the total negative electrode active material. Graphite may be included in an amount of 95 parts by weight or less, 93 parts by weight or less, or 90 parts by weight or less, based on 100 parts by weight of the total negative electrode active material. When the graphite is a mixture of artificial graphite and natural graphite, the artificial graphite and natural graphite may be included in a ratio of 90:10 to 50:50 parts by weight, 85:15 to 60:40 parts by weight, or 80:20 to 65:35 parts by weight based on 100 parts by weight of graphite. Petition 870250073323, dated 08 / 19 / 2025, page 39 / 58 32 / 46

[0132] In an exemplary embodiment of the present invention, the weight ratio of the carbon-based active material and silicon oxide may be 0.1:99.9 to 30:70, 1:99 to 20:80, 5:95 to 20:80, 5:95 to 15:85, 8:92 to 12:88 or 10:90 to 12:88.

[0133] In an exemplary embodiment of the present invention, the active material of the negative electrode in 100 parts by weight of the active material layer of the negative electrode may be included in an amount of 80 parts by weight or more and 99.9 parts by weight or less, preferably 90 parts by weight or more and 99.9 parts by weight or less, more preferably 95 parts by weight or more and 99.9 parts by weight or less, and even more preferably 98 parts by weight or more and 99.9 parts by weight or less.

[0134] According to an exemplary embodiment of the present invention, in the secondary lithium battery according to the exemplary embodiment, the active material layer of the negative electrode may also include a negative electrode ligand, in addition to silicon oxide and graphite.

[0135] The negative electrode binder can serve to improve the adhesion between the particles of the negative electrode's active material and the adhesive force between the particles of the negative electrode's active material and the negative electrode's current collector. For the negative electrode binder, those known in the art can be used.Non-limiting examples thereof may include at least one selected from the group consisting of polyvinylidene hexafluoropropylene fluoride copolymer (PVDF-co-HFP), polyvinylidene fluoride, polyacrylonitrile, polymethyl methacrylate, polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, polytetrafluoroethylene, polyethylene, polypropylene, polyacrylic acid, ethylene-propylene-diene monomer (EPDM), sulfonated EPDM, styrene-butadiene rubber (SBR), fluorinated rubber, polyacrylic acid and the aforementioned materials in which a hydrogen is replaced by Li, Na, Ca etc., and may also include various copolymers thereof. Petition 870250073323, dated 08 / 19 / 2025, pages 40 / 58 33 / 46

[0136] The negative electrode binder may be included in an amount of 0.1 parts by weight or more and 50 parts by weight or less, for example, preferably 0.3 parts by weight or more and 35 parts by weight or less, and more preferably 0.5 parts by weight or more and 10 parts by weight or less based on 100 parts by weight of the active material layer of the negative electrode.

[0137] The active material layer of the negative electrode may not include a conductive material, but may still include a conductive material if necessary. The conductive material included in the active material layer of the negative electrode is not particularly limited, provided it has conductivity without causing a chemical change in the battery and, for example, graphite, such as natural graphite or artificial graphite; carbon black, such as acetylene black, Ketjen black, channel black, furnace black, lamp black and thermal black; a conductive fiber, such as a carbon fiber and a metallic fiber; a conductive tube, such as a carbon nanotube; fluorocarbon; metallic powders, such as aluminum and nickel powders; a conductive whisker, such as zinc oxide and potassium titanate; a conductive metallic oxide, such as titanium oxide; a conductive material, such as a polyphenylene derivative, and the like may be used.The content of conductive material in the active material layer of the negative electrode can be from 0.01 parts by weight to 30 parts by weight and, preferably, from 0.03 parts by weight to 25 parts by weight, based on 100 parts by weight of the active material layer of the negative electrode.

[0138] In an exemplary embodiment of the present invention, the positive electrode includes a positive electrode current collector and a layer of positive electrode active material formed over the positive electrode current collector and including the positive electrode active material.

[0139] The current collector of the positive electrode is not particularly limited, provided it has conductivity without causing a chemical change in the battery. For example, stainless steel, aluminum, nickel, titanium can be used, Petition 870250073323, dated 08 / 19 / 2025, pp. 41 / 58 34 / 46 burnt carbon, aluminum, or stainless steel, each with a surface treated with carbon, nickel, titanium, silver, or similar materials. Furthermore, the current collector of the positive electrode can typically have a thickness of 1 to 500 μm, and the current collector surface may be formed with microscopic irregularities to increase the adhesive strength of the active material of the positive electrode. For example, the current collector of the positive electrode can be used in various forms, such as a film, a sheet, a blade, a mesh, a porous body, a foamed body, and a nonwoven fabric body.

[0140] In an exemplary embodiment of the present invention, the negative electrode includes a negative electrode current collector and a layer of negative electrode active material formed on the negative electrode current collector and including the negative electrode active material.

[0141] The current collector of the negative electrode is not particularly limited, provided it has conductivity without causing chemical changes in the battery. For example, for the current collector, copper, stainless steel, aluminum, nickel, titanium, burnt carbon, aluminum or stainless steel can be used, each with surface treatment with carbon, nickel, titanium, silver or similar. Specifically, transition metals that adsorb carbon well, such as copper and nickel, can be used for the current collector. The thickness of the current collector can be from 1 μm to 500 μm. However, the thickness of the current collector is not limited to this.

[0142] In an exemplary embodiment of the present invention, the positive electrode further includes a layer of active material of the positive electrode, including the active material of the positive electrode, the negative electrode further includes a layer of active material of the negative electrode, including the active material of the negative electrode, and the thicknesses of the layers of active material of the positive electrode and the negative electrode are each 10 μm or more and 500 μm or less. The thickness of the layer Petition 870250073323, dated 08 / 19 / 2025, pp. 42 / 58 35 / 46 of the active material of the positive electrode can be 90% to 110%, for example, 95% to 105% of the thickness of the active material layer of the negative electrode, and the thicknesses can be the same. Specifically, the thicknesses of the active material layers of the positive electrode and the negative electrode can each be 15 μm or more and 400 μm or less, 20 μm or more and 300 μm or less, 25 μm or more and 200 μm or less, or 30 μm or more and 100 μm or less.

[0143] In an exemplary embodiment of the present invention, the positive electrode further includes a layer of active material of the positive electrode, including the active material of the positive electrode, an amount of charge per unit volume of the layer of active material of the positive electrode is 250 mg / 25 cm2 to 900 mg / 25 cm2, the negative electrode further includes a layer of active material of the negative electrode which includes the active material of the negative electrode, and an amount of charge per unit volume of the layer of active material of the negative electrode is 100 mg / 25 cm2 to 600 mg / 25 cm2. Specifically, the amount of charge per unit volume of the active material layer of the positive electrode can be from 270 mg / 25 cm2 to 800 mg / 25 cm2, 285 mg / 25 cm2 to 700 mg / 25 cm2, or 300 mg / 25 cm2 to 600 mg / 25 cm2, and the amount of charge per unit volume of the active material layer of the negative electrode can be from 120 mg / 25 cm2 to 500 mg / 25 cm2, 135 mg / 25 cm2 to 400 mg / 25 cm2, or 150 mg / 25 cm2 to 300 mg / 25 cm2.

[0144] The positive and negative electrodes can be manufactured according to a conventional method for manufacturing a positive and a negative electrode, except by using the active materials of the positive and negative electrodes described above. Specifically, the electrodes can be manufactured by applying a composition for the formation of the active material layer, including the active material described above and, optionally, a binder and a conductive material, onto a current collector, followed by drying and roller pressing. In this case, the types and content of the active materials of the positive and negative electrodes, Petition 870250073323, dated 08 / 19 / 2025, pp. 43 / 58 36 / 46 of the binder and conductive material are as described above. The solvent can be a solvent commonly used in the art, such as dimethyl sulfoxide (DMSO), isopropyl alcohol, N-methylpyrrolidone (NMP), acetone, or water, and any one of them or a mixture of two or more of them can be used. Considering the applied thickness of a paste and the manufacturing yield, the amount of solvent used is sufficient if it is able to dissolve or disperse the active material, the conductive material, and the binder, and then allow a viscosity capable of exhibiting excellent thickness uniformity when applied to fabricate a positive electrode and a negative electrode. Alternatively, the positive and negative electrodes can be fabricated by rolling, in a current collector, a film obtained by molding the composition to form the active material layer onto a separate support and removing it from the support.

[0145] The separator serves to separate the negative electrode and the positive electrode and to provide a migration path for lithium ions, in which any separator can be used without particular restrictions, provided that it is typically used as a separator in a secondary battery and, in particular, a separator with high moisture retention capacity for an electrolyte solution, as well as low resistance to electrolyte ion migration, may preferably be used. Specifically, a porous polymer film may be used, for example, a porous polymer film made from a polyolefin-based polymer, such as an ethylene homopolymer, a propylene homopolymer, an ethylene / butene copolymer, an ethylene / hexene copolymer and an ethylene / methacrylate copolymer, or a laminated structure with two or more layers thereof.In addition, a common porous nonwoven fabric can be used, for example, a nonwoven fabric made of high-melting-point glass fibers, polyethylene terephthalate fibers, or similar. Furthermore, a coated separator including a ceramic component can be used. Petition 870250073323, dated 08 / 19 / 2025, pp. 44 / 58 37 / 46 polymeric material, in order to guarantee heat resistance or mechanical strength, and a separator with a single-layer or multi-layer structure can be selectively used.

[0146] Examples of electrolytes may include, but are not limited to, an organic liquid electrolyte, an inorganic liquid electrolyte, a solid polymer electrolyte, a gel-type polymer electrolyte, a solid inorganic electrolyte, or a molten-type inorganic electrolyte that may be used in the manufacture of the secondary lithium battery.

[0147] Specifically, the electrolyte may include a non-aqueous organic solvent and a metallic salt.

[0148] As a non-aqueous organic solvent, for example, an aprotic organic solvent, such as N-methyl-2-pyrrolidinone, propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, gamma-butyrolactone, 1,2-dimethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, dimethyl sulfoxide, 1,3-dioxolane, formamide, dimethylformamide, dioxolane, acetonitrile, nitromethane, methyl formate, methyl acetate, phosphoric acid triester, trimethoxymethane, dioxolane derivative, sulfolane, methylsulfolane, 1,3-dimethyl-2-imidazolidinone, propylene carbonate derivative, tetrahydrofuran derivative, ether, methyl propionate or ethyl propionate.

[0149] In particular, among carbonate-based organic solvents, ethylene carbonate and propylene carbonate, which are cyclic carbonates, are high-viscosity organic solvents and may be preferentially used because they have high permittivity for dissociating a lithium salt well. When the cyclic carbonate is mixed with a linear carbonate with low viscosity and low permittivity, such as dimethyl carbonate and diethyl carbonate, in a suitable ratio and used, an electrolyte with high electrical conductivity can be prepared and, therefore, such combined use may be more preferable. Petition 870250073323, dated 08 / 19 / 2025, pages 45 / 58 38 / 46

[0150] A lithium salt can be used as a metallic salt, the lithium salt being a material readily soluble in non-aqueous electrolytic solution, in which, for example, one or more selected from the group consisting of F-, Cl-, I-, NO3-, N(CN)2-, BF4-, ClO4-, PF6-, (CF3)2PF4-, (CF3)3PF3-, (CF3)4PF2-, (CF3)5PF-, (CF3)6P-, CF3SO3-, CF3CF2SO3-, (CF3SO2)2N-, (FSO2)2N-, CF3CF2(CF3)2CO-, (CF3SO2)2CH-, (SF5)3C-, (CF3SO2)3C-, CF3(CF2)7SO3-, CF3CO2-, CH3CO2-, SCN- and (CF3CF2SO2)2N- can be used as Lithium salt anions.

[0151] One or more additives, for example, a haloalkylene carbonate-based compound, such as difluoroethylene carbonate, pyridine, triethyl phosphite, triethanolamine, cyclic ether, ethylenediamine, n-glycol, hexamethylphosphoric triamide, a nitrobenzene derivative, sulfur, a quinone imine dye, N-substituted oxazolidinone, N,N-substituted imidazolidine, ethylene glycol dialkyl ether, an ammonium salt, pyrrole, 2-methoxyethanol or aluminum trichloride, may be included in the electrolyte for the purpose of improving battery life characteristics, suppressing a decrease in battery capacity, improving battery discharge capacity and the like, in addition to the electrolytic components described above.

[0152] The energy density of the secondary lithium battery according to an exemplary embodiment of the present invention can be from 400 Wh / L to 900 Wh / L. Specifically, the energy density of the secondary lithium battery can be from 425 Wh / L to 875 Wh / L, 450 Wh / L to 850 Wh / L, 475 Wh / L to 825 Wh / L, or 500 Wh / L to 800 Wh / L. When the above range is satisfied, the energy density of the designed secondary lithium battery in a limited space can be increased, and the high-power performance and battery cycle performance can be improved.

[0153] The secondary lithium battery according to an exemplary embodiment of the present invention may be a cylindrical battery. The cylindrical battery may Petition 870250073323, dated 08 / 19 / 2025, pp. 46 / 58 39 / 46 means that the shape of the battery itself, including an assembly containing a positive electrode, a negative electrode, a separator, and an electrolyte, is cylindrical and, specifically, may include a cylindrical can, a battery pack housed within the cylindrical can, and a top cap. However, secondary lithium batteries are not limited to this and may be prismatic or pouch-type batteries.

[0154] An exemplary embodiment of the present invention provides a battery module including the cylindrical battery as a unit cell and a battery pack including the same. Since the battery module and the battery pack include the secondary battery with high capacity, high rate capacity and high cycle characteristics, the battery module and the battery pack can be used as a power source for a medium to large-sized device selected from the group consisting of an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle and an energy storage system.

[0155] Since the secondary lithium battery according to the embodiments of the present invention stably exhibits excellent discharge capacity, output characteristics and cycle performance, the secondary lithium battery can be used as a power source for a portable device, such as a mobile phone, a laptop computer and a digital camera, as well as a medium to large-sized device selected from the group consisting of electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles and energy storage systems. For example, the battery module or battery can be used as a power source for a medium to large-sized device of any one or more of an electric tool; an electric vehicle, including an electric vehicle (EV), a hybrid electric vehicle and a plug-in hybrid electric vehicle (PHEV); or an energy storage system. Invention Modality Petition 870250073323, dated 08 / 19 / 2025, pp. 47 / 58 40 / 46

[0156] Preferred examples will be provided below for a better understanding of the present invention. It will be evident to a person skilled in the art that the examples are provided only to illustrate the present invention and that various modifications and alterations are possible within the scope and technical spirit of the present invention. Such modifications and alterations naturally fall within the scope of the claims included in this document. <Exemplos e Exemplos Comparativos> Example 1

[0157] A composition was prepared to form a positive electrode active material layer, including, based on 100 parts by weight of the positive electrode active material layer, 98.04 parts by weight (single particles: secondary particles = 50:50 by weight) of a lithium composite transition metal compound serving as the positive electrode active material with contents of 93.3 mol% Ni, 4.9 mol% Co and 1.8 mol% Mn among the metals, except lithium, and including single particles and secondary particles, 1 part by weight of PVDF serving as a binder, and a CNT pre-dispersion solution including 0.8 part by weight of CNT serving as a conductive material and 0.16 part by weight of a dispersant.

[0158] Lithium composite transition metal compound with a crystal grain size of 110 nm was used, and single particles were prepared with a size of D50 = 3.57 μm and secondary particles were prepared with a size of D50 = 11.1 μm by an airflow spraying method. An aluminum foil with a thickness of 30 μm was coated with the composition to form a layer of active material for the positive electrode, so as to have a thickness of 103 μm in the dry state, and then dried to prepare a positive electrode.

[0159] A composition was prepared to form a layer of material Petition 870250073323, dated 08 / 19 / 2025, pp. 48 / 58 41 / 46 active negative electrode, including, based on 100 parts by weight of the active negative electrode layer, 97.7 parts by weight of graphite (artificial graphite:natural graphite = 70:30 by weight, 90 parts by weight based on 100 parts by weight of the active negative electrode) and silicon dioxide (SiOx, x = 0.9 to 1, the amount of carbon coating and the amount of Mg doping based on 100% by weight of carbon-coated silicon dioxide are listed in Table 1 below, 10 parts by weight based on 100 parts by weight of the active negative electrode) serving as the active negative electrode, 1.15 parts by weight of SBR (styrene-butadiene rubber) as a binder and 1 part by weight of CMC (carboxymethylcellulose), and further including a solution of CNT predispersion including 0.09 parts by weight of a dispersant and 0.06 parts by weight of single-walled CNT.

[0160] Silicon oxide with a Si crystal grain size of 5 nm was used, and the silicon oxide was prepared with a size of D50 = 5.2 μm, and graphite was prepared with a size of D50 = 17 pm by an airflow spraying method. A copper foil with a thickness of 15 pm was coated with the composition to form a layer of active material for the negative electrode, so as to have a thickness of 86 pm in the dry state, and then dried to prepare a negative electrode.

[0161] The negative electrode and the positive electrode were stacked with a separator interposed between them and an electrolyte solution (1.0 MLiPF6), ethylene carbonate (EC) / ethyl methyl carbonate (EMC) = 30 / 70 (% by vol), vinylene carbonate (VC) 1.5%) was injected to prepare a battery. Examples 2 to 4

[0162] A secondary lithium battery was prepared in the same manner as in Example 1, except that active materials were used for the positive and negative electrodes, with crystal grain sizes of the metal transition compound. Petition 870250073323, dated 08 / 19 / 2025, pp. 49 / 58 42 / 46 lithium compound, silicon oxide Si crystal grain sizes and particle diameters with the values ​​described in Table 1 below. Comparative Examples 1 and 2

[0163] A secondary lithium battery was prepared in the same manner as in Example 1, except that active materials for the positive and negative electrodes were used, with the crystal grain sizes of the lithium and transition metal compound, the Si crystal grain sizes of the silicon oxide, and the particle diameters with the values ​​described in Table 1 below.

[0164] The configurations of the active materials of the positive electrode and the active materials of the negative electrode prepared in the Examples and Comparative Examples are shown in Table 1 below. Petition 870250073323, dated 08 / 19 / 2025, pages 50 / 58 [Table 1] Crystal grain size Active material of the positive electrode Active material of the negative electrode Crystal grain size (A) (nm) of the lithium composite transition metal compound Crystal grain size of Si (B) (nm) of silicon oxide Ratio between B and A (%) Single particle D50 (μm) Single particle content (% by weight) Secondary particle D50 (μm) Secondary particle content (% by weight) Silicon oxide D50 (μm) Silicon oxide content (% by weight) Graphite D50 (μm) Graphite content (% by weight) Amount of Mg doping (by weight) in silicon oxide Amount of carbon coating (by weight) in silicon oxide Example 1 1 5 4.5 3.5 50 11.1 50 5.2 10 17 90 6.2 5 Example 2 88 5 6.25 3.63 50 10.5 50 5.7 10 17 90 6.2 5 Example 3 110 9 8.18 3.63 50 9.5 50 6.2 10 17 90 7.5 3.5 Example 4 110 11 10 3.57 5 9.5 50 5.9 10 17 90 8 4.5 Comparative Example 1 83 9 11.25 3.52 50 12.5 50 6.2 10 17 90 7.5 3.5 Comparative Example 2 100 11 13.75 3.5 50 12.5 50 5.9 10 17 90 8 4.5 43 / 46 Petition 870250073323, dated 08 / 19 / 2025, pp. 51 / 58 44 / 46

[0165] The crystal grain sizes of the lithium composite transition metal compound and the Si crystal grains in silicon oxide can be confirmed by X-ray diffraction analysis, and the X-ray diffraction analysis was performed using an X-ray diffraction analyzer (XRD) (product name: D4-endavor, manufacturer: Bruker). Specifically, the XRD measurement was performed by sampling a powder sample on a support and using Cu K alpha X-rays.

[0166] The crystal grain size of the lithium composite transition metal compound was calculated by fitting the XRD results using the Scherrer equation and, in this case, the crystal grain size was measured based on the peak that appears at the corresponding position (2θ = 10° to 12°).

[0167] The Si crystal grain size was calculated by fitting the XRD results using the Scherrer equation and, in this case, the crystal grain size was measured based on Si (220) (2θ = 47.4° to 48.5°).

[0168] The D50 of the active materials of the positive and negative electrodes was analyzed by a PSD measurement method using a Microtrac instrument. <Exemplo Experimental: Avaliação das Características de Capacidade de Descarga, Eficiência Inicial e Vida Útil (taxa de retenção de capacidade)>

[0169] The secondary lithium batteries prepared in the Examples and Comparative Examples were charged and discharged to evaluate discharge capacity, initial efficiency and capacity retention rate, and the evaluation results are presented in Table 2 below.

[0170] Charging and discharging were performed at 0.1 C for the first and second cycles, and charging and discharging were performed at 0.5 C from the third cycle to the 199th cycle. In the 200th cycle, charging and discharging were terminated in a charged state (with lithium contained in the negative electrode).

[0171] Load conditions: DC (constant current) / CV (constant voltage) Petition 870250073323, dated 08 / 19 / 2025, pp. 52 / 58 45 / 46 (5 mV / 0.005 C current cut)

[0172] Discharge conditions: DC (constant current) condition 1.5 V

[0173] The discharge capacity (mAh / g) and initial efficiency (%) were obtained from the result after a charge and discharge. Specifically, the initial efficiency (%) was obtained using the following calculation.

[0174] Initial efficiency (%) = (first discharge capacity / first charge capacity) χ 100 %

[0175] The capacity retention rate was obtained using the following calculation.

[0176] Capacity retention rate (%) = (199th discharge capacity / first discharge capacity) χ 100 %<Exemplo Experimental: Avaliação da Espessura da Célula>

[0177] The thicknesses of the prepared secondary batteries were compared before and after the cycle was performed, as follows.

[0178] Charging and discharging were performed at 0.1°C for the first and second cycles, and charging and discharging were performed at 0.5°C from the third cycle to the 200th cycle. The cell thickness after 2 cycles was considered the initial thickness, and the cell thickness after 200 cycles was considered the final thickness, and the thickness was calculated using the following formula. The calculated cell thickness of Example 1 was set to 100%, and the cell thicknesses of Examples 2 to 4 and Comparative Examples 1 and 2 were calculated relative to the defined thickness and are listed in Table 2 below.

[0179] Cell thickness = (Thickness after cycle - Initial thickness) / (Initial thickness) X 100% Petition 870250073323, dated 08 / 19 / 2025, pages 53 / 58 46 / 46 [Table 2] Battery Discharge Capacity (mAh / g) Initial Efficiency (%) Capacity Retention Rate (200 cycles at room temperature, %) Cell Thickness (based on Example 1) (200 cycles at room temperature, %) Example 1 492 95 92 1 Example 2 492 94.5 91.8 110 Example 3 492 93.1 91.5 107 Example 4 492 91.5 91.2 113 Comparative Example 1 492 89.8 88.2 117 Comparative Example 2 492 89.5 86.3 125

[0180] According to Tables 1 and 2, it was confirmed that the secondary batteries of Examples 1 to 4, in which the Si crystal grain size of the silicon oxide satisfies 10% or less of the crystal grain size of the lithium composite transition metal compound, have smaller cell thicknesses and exhibit superior capacity retention rates compared with Comparative Examples 1 and 2. This appears to be due to the fact that the Si crystal grain size of the silicon oxide is 10% or less of the crystal grain size of the lithium composite transition metal compound, so that the stress caused by the volume expansion of the particles of the negative electrode active material during charging and discharging can be reduced, thus reducing particle breakage, improving cycle characteristics and reducing swelling.

[0181] On the other hand, in Comparative Examples 1 and 2, in which the Si crystal grain size of silicon oxide exceeded 10% of the crystal grain size of the lithium composite transition metal compound, it was confirmed that cracks formed in the particles due to an increase in Si internal stress during charging and discharging, resulting in a deterioration in cycle performance. Petition 870250073323, dated 08 / 19 / 2025, pages 54 / 58

Claims

1 / 3 CLAIMS 1. Lithium secondary battery comprising: a positive electrode comprising a positive electrode active material; a negative electrode comprising a negative electrode active material; a separator provided between the positive electrode and the negative electrode; and an electrolyte, CHARACTERIZED in that the active material of the positive electrode comprises a lithium composite transition metal compound comprising nickel (Ni), cobalt (Co) and manganese (Mn), wherein the lithium composite transition metal compound comprises a single particle, wherein the active material of the negative electrode comprises a silicon oxide, and wherein the Si crystal grain size of the silicon oxide is 10% or less of the crystal grain size of the lithium composite transition metal compound.

2. Secondary lithium battery, according to claim 1, CHARACTERIZED in that the Si crystal grain size of the silicon oxide is 0.1 nm or higher and 20 nm or lower.

3. Secondary lithium battery, according to claim 1, CHARACTERIZED in that the crystal grain size of the lithium composite transition metal compound is equal to or greater than 70 nm and equal to or less than 200 nm.

4. Secondary lithium battery, according to claim 1, CHARACTERIZED in that the lithium composite transition metal compound further comprises a secondary particle.

5. Secondary lithium battery, according to claim 1, Petition 870250073323, dated 08 / 19 / 2025, page 55 / 58 2 / 3 CHARACTERIZED in that the active material of the negative electrode further comprises graphite.

6. Secondary lithium battery, according to claim 1, CHARACTERIZED in that the average diameter of the individual particles is equal to or greater than 1 μm and less than or equal to 10 μm.

7. Secondary lithium battery, according to claim 1, CHARACTERIZED in that the average diameter of the silicon oxide particles is equal to or greater than 1 μm and equal to or less than 10 μm.

8. Secondary lithium battery, according to claim 1, CHARACTERIZED in that the average diameter of the individual particles is smaller than the average diameter of the silicon oxide particles.

9. Secondary lithium battery, according to claim 5, CHARACTERIZED in that the average diameter of the silicon oxide particles is smaller than the average diameter of the graphite particles.

10. Lithium secondary battery, according to claim 1, CHARACTERIZED in that the single particle is included in an amount of 15 to 100 parts by weight relative to 100 parts by weight of the active material of the positive electrode, and in that the silicon oxide is included in an amount of 3 to 30 parts by weight relative to 100 parts by weight of the active material of the negative electrode.

11. Secondary lithium battery, according to claim 1, CHARACTERIZED in that the lithium composite transition metal compound comprises 80 mol% or more of nickel among the metals, excluding lithium.

12. Secondary lithium battery, according to claim 1, CHARACTERIZED in that the positive electrode further comprises a layer of active material of the positive electrode comprising the active material of the positive electrode, Petition 870250073323, dated 19 / 08 / 2025, page 56 / 58 3 / 3 wherein the negative electrode further comprises a layer of active material of the negative electrode comprising the active material of the negative electrode, and wherein the thicknesses of the layers of active material of the positive electrode and the negative electrode are each 10 μm or more and 500 μm or less.

13. Battery module, CHARACTERIZED in that it comprises a secondary lithium battery according to any one of claims 1 to 12.

14. Battery pack, CHARACTERIZED in that it comprises a secondary lithium battery according to any one of claims 1 to 12.

15. Battery pack, CHARACTERIZED in that it comprises the battery module according to claim 13. Petition 870250073323, dated 19 / 08 / 2025, pp. 57 / 58