Lithium secondary battery, battery module, and battery pack

Abstract

The present invention relates to a lithium secondary including: a positive containing a positive electrode active material; a negative electrode containing a negative electrode active material; a separator provided between the positive electrode and the negative electrode; and an electrolyte, wherein the positive electrode active material includes a lithium composite transition metal compound including nickel (Ni), cobalt (Co), and manganese (Mn); the lithium composite transition metal compound includes at least one of single particles and quasi-single particles, the average particle diameter (D50 =) of the at least one of the single particle and the pseudo-single particle having an average particle diameter (D50) of 1 ㎛ to 10 ㎛ (both inclusive); the single particle is composed of one nodule and the pseudo-single particle is a composite composed of 30 or less nodules; and the negative electrode active material includes silicon oxide represented by SiOx (0<x<2), the silicon oxide represented by SiOx (0<x<2) having an average particle diameter (D50) of 1 ㎛ or greater, and at least one of the single particles and pseudo-single particles having an average particle diameter (D50) smaller than the average particle diameter (D50) of the silicon oxide represented by SiOx(0<x<2).

Description

Lithium secondary batteries, battery modules and battery packs

[0001] This application claims the benefit of Korean Patent Application No. 10-2023-0117757, filed with the Korean Intellectual Property Office on September 5, 2023, and Korean Patent Application No. 2024-0120190, filed with the Korean Intellectual Property Office on September 4, 2024, the entire contents of which are incorporated herein by reference.

[0002] The present application relates to a lithium secondary battery, a battery module, and a battery pack.

[0003] The recent rapid proliferation of battery-powered electronic devices, including mobile phones, laptops, electric vehicles, power tools, and vacuum cleaners, has led to a rapid increase in demand for compact, lightweight, and relatively high-capacity and / or high-output secondary batteries. In particular, lithium secondary batteries, with their lightweight design and high energy density, are attracting significant attention as power sources for electronic devices. Accordingly, active research and development efforts are underway to improve the performance of lithium secondary batteries.

[0004] Lithium secondary batteries produce electrical energy through oxidation and reduction reactions when lithium ions are inserted / deintercalated from the positive and negative electrodes, while an organic electrolyte or polymer electrolyte is charged between the positive and negative electrodes, which are made of active materials capable of intercalating and deintercalating lithium ions.

[0005] Lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), lithium manganese oxide (LiMnO2 or LiMn2O4, etc.), and lithium iron phosphate compound (LiFePO4) have been used as cathode active materials for lithium secondary batteries. Among these, lithium cobalt oxide (LiCoO2) is widely used due to its high operating voltage and excellent capacity characteristics, and is applied as a cathode active material for high voltage. However, due to the rising price of cobalt (Co) and unstable supply, it is difficult to use it in large quantities as a power source in fields such as electric vehicles, and the need for the development of a cathode active material that can replace it has arisen.

[0006] Accordingly, nickel-cobalt-manganese lithium composite transition metal compounds (hereinafter simply referred to as 'NCM-based lithium composite transition metal compounds') in which some of the cobalt (Co) is replaced with nickel (Ni) and manganese (Mn) have been developed. Recently, research has been conducted to increase the capacity by increasing the Ni content in NCM-based lithium composite transition metal compounds. However, in the case of high-concentration nickel (Ni-rich) positive electrode active materials with a high nickel content, there are disadvantages such as decreased thermal stability, increased resistance due to increased side reactions during electrochemical reaction, and increased gas generation.

[0007] Meanwhile, graphite is mainly used as an anode active material for lithium secondary batteries, but because graphite has a low capacity per unit mass of 372 mAh / g, it is difficult to increase the capacity of lithium secondary batteries. Accordingly, non-carbonaceous anode materials with higher energy density than graphite, such as silicon, tin, and their oxides, are being developed to increase the capacity of lithium secondary batteries. However, these non-carbonaceous anode materials have a problem in that although they have a large capacity, they have low initial efficiency, so the amount of lithium consumed during the initial charge and discharge is large, and the irreversible capacity loss is large.

[0008] [Prior Art Literature]

[0009] [Patent Document]

[0010] Korean Patent Publication No. 10-2021-0070933

[0011] The inventors of the present invention have discovered that, in a lithium secondary battery designed within a limited space, optimal battery performance can be achieved through a specific combination of the type, average particle size, and / or content of each component of the active materials constituting each of the positive and negative electrodes, thereby leading to the present invention.

[0012] One embodiment of the present application is a lithium secondary battery comprising 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 positive electrode active material comprises a lithium composite transition metal compound including nickel (Ni), cobalt (Co), and manganese (Mn), and the lithium composite transition metal compound comprises at least one of single particles and pseudo-single particles, and an average particle diameter (D50) of at least one of the single particles and pseudo-single particles is 1 ㎛ or more and 10 ㎛ or less, and the single particle is composed of one nodule, and the pseudo-single particle is a composite composed of 30 or fewer nodules, and the negative electrode active material is SiOx(0 <x<2)로 표시되는 산화실리콘을 포함하고, 상기 SiOx(0<x<2)로 표시되는 산화실리콘의 평균 입경(D50)은 1 ㎛ 이상이며, 상기 단입자 및 유사-단입자 중 적어도 하나의 평균 입경(D50)은 상기 SiOx(0<x<2)로 표시되는 산화실리콘의 평균 입경(D50) 보다 작은 것인 리튬이차전지, 이를 포함하는 전지 모듈 및 전지 팩을 제공한다.

[0013] According to the embodiments described herein, the energy density of a lithium secondary battery designed in a limited space can be increased, high-output performance can be improved, and battery cycle performance can also be improved.

[0014] Hereinafter, the present invention will be described in more detail to facilitate understanding. The present invention may be embodied in various different forms and is not limited to the embodiments described herein. In this regard, terms and words used in this specification and claims should not be construed as limited to their conventional or dictionary meanings. Rather, they should be interpreted in the sense and concept that aligns with the technical spirit of the present invention, based on the principle that the inventor can appropriately define the concept of a term to best explain his or her invention.

[0015] It should be understood that the terms “include,” “comprising,” or “having” used in this specification are intended to specify the presence of a feature, number, step, component, or combination thereof, but do not preclude the possibility of the presence or addition of one or more other features, numbers, steps, components, or combinations thereof.

[0016] Furthermore, when we say that a part of a layer or the like is "above" or "on" another part, this includes not only cases where it is "directly above" that part, but also cases where there is another part in between. Conversely, when we say that a part is "directly above" another part, it means that there is no other part in between. Furthermore, saying that a part is "above" or "on" a reference part means that it is located above or below that reference part, and does not necessarily mean that it is "above" or "on" it in the opposite direction of gravity.

[0017] In the "and / or" of this specification, 'or' indicates that one of the listed items is selected, and 'and' means that all of the listed items are indicated, for example, 'A and / or B' means that both the case of 'A and B' and the case of 'A or B' are described together.

[0018] As used herein, a “single particle” may mean a particle formed by a single nudole. The “nudole” may be a single crystal without a grain boundary, or may be a polycrystal that does not show a grain boundary when observed using a scanning electron microscope (SEM) at 5000x to 20000x. As used herein, a “quasi-single particle” may be an aggregate formed by 30 or fewer nudules. As used herein, a “secondary particle” means a particle formed by the agglomeration of tens to hundreds of primary particles, and specifically, the secondary particle may include a particle formed by the agglomeration of 50 or more primary particles.

[0019] In this specification, “particle” may include at least one of a single particle, a quasi-single particle, a primary particle, a nodule, and a secondary particle.

[0020] In this specification, the "average particle diameter (D50)" can be defined as the particle diameter corresponding to 50% of the volume accumulation amount in the particle diameter distribution curve. The average particle diameter (D50) can be measured using, for example, a laser diffraction method. The laser diffraction method can generally measure particle diameters from the submicron range to several millimeters, and can obtain results with high reproducibility and high resolution.

[0021] The above average particle diameter (D50) can be measured using a Microtrac device (manufacturer: Microtrac model number: S3500) using water and a triton-X100 dispersant. Specifically, the average particle diameter (D50) of the positive electrode active material can be measured in the range of a refractive index of 1.5 to 1.7, and the negative electrode active material can be measured under a refractive index of 1.97 or 2.42. For example, after dispersing the particles in a dispersion medium, the particles can be introduced into a commercially available laser diffraction particle size measuring device, irradiated with ultrasonic waves of about 28 kHz at an output of 60 W, and then a volume cumulative particle size distribution graph can be obtained, and then the particle size corresponding to 50% of the volume cumulative amount can be measured.

[0022] One embodiment of the present application is a lithium secondary battery comprising 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 positive electrode active material comprises a lithium composite transition metal compound including nickel (Ni), cobalt (Co), and manganese (Mn), and the lithium composite transition metal compound comprises at least one of single particles and pseudo-single particles, and an average particle diameter (D50) of at least one of the single particles and pseudo-single particles is 1 ㎛ or more and 10 ㎛ or less, and the single particle is composed of one nodule, and the pseudo-single particle is a composite composed of 30 or fewer nodules, and the negative electrode active material is SiOx(0 <x<2)로 표시되는 산화실리콘을 포함하고, 상기 SiOx(0<x<2)로 표시되는 산화실리콘의 평균 입경(D50)은 1 ㎛ 이상이며, 상기 단입자 및 유사-단입자 중 적어도 하나의 평균 입경(D50)은 상기 SiOx(0<x<2)로 표시되는 산화실리콘의 평균 입경(D50) 보다 작은 것인 리튬이차전지를 제공한다.

[0023] Lithium secondary batteries have specific sizes depending on their intended use, and therefore must be designed within a limited space. While consumer demand for increased energy density and high-power performance is growing, the use of high-capacity cathode materials necessitates increased anode material content to meet these demands. This limits the ability to increase battery efficiency within a limited space. Furthermore, depending on the type of anode material, it's necessary to design a cathode material with an efficiency level that matches that of the anode material.

[0024] For example, if the energy density can be improved, but the porosity of the positive electrode is lowered to increase the electrode density, the rolling may be strengthened to increase the electrode density, which may cause cracks to form in the particles, resulting in a decrease in battery performance.

[0025] The single particles used in the embodiment of the present application have high rigidity of the particles themselves, so that the battery performance degradation is relatively excellent even when the electrode density is high. Therefore, the single particles and the SiOx(0) according to the average particle diameter range <x<2)로 표시되는 산화실리콘을 조합하여 에너지 밀도를 증가시킬 수 있다.

[0026] In particular, the lithium secondary battery according to the present application comprises SiOx(0) among silicon-based active materials. <x<2)로 표시되는 산화실리콘을 사용하는 것을 특징으로 한다. 구체적으로 다른 실리콘계 활물질(예를 들어, Si / C)과 대비하였을 때, 상기와 같은 활물질을 사용하는 경우 전극 품질, 즉 전극에 대한 접착력이 향상되는 특징을 갖게 된다.

[0027] In one embodiment of the present application, the SiOx(0 <x<2)로 표시되는 산화실리콘은 마그네슘 금속 또는 리튬 금속으로 도핑될 수 있다.

[0028] The SiOx(0) according to the present application <x<2)로 표시되는 산화실리콘은 도핑하지 않고 사용될 수 있으며, 또한 상기와 같이 도핑되어 사용될 수 있고, 도핑하는 경우 산화실리콘에 미리 실리케이트를 형성하여 초기 충전 시 비가역 용량이 감소하여 셀의 에너지 밀도를 증가시키는 효과를 나타낼 수 있다.

[0029] According to an additional embodiment of the present application, the positive electrode active material comprises a lithium composite transition metal compound including nickel (Ni), cobalt (Co) and manganese (Mn), wherein the lithium composite transition metal compound comprises single particles and / or pseudo-single particles, and the average particle diameter (D50) of the single particles and / or pseudo-single particles is 1 ㎛ or more and 10 ㎛ or less.

[0030] As the average particle diameter (D50) of the above single particles decreases, the specific surface area increases, and side reactions with the electrolyte increase, which may result in a decrease in electrochemical performance, such as lifespan. If the average particle diameter (D50) of the above single particles is less than 1㎛, it may not be within the range of commercial application, and even if it exists, the lifespan performance may be very low due to the increase in the specific surface area, making it difficult to apply.

[0031] When the average particle diameter (D50) of the above single particles is 1 ㎛ or more, 2 ㎛ or more, or 3 ㎛ or more, the single particles have excellent life performance because side reactions with the electrolyte are reduced.

[0032] At the same time, the negative active material is SiOx(0 <x<2)로 표시되는 산화실리콘을 포함하고, 상기 SiOx(0<x<2)로 표시되는 산화실리콘의 평균 입경(D50)은 1㎛ 이상이며, 상기 단입자 및 / 또는 유사-단입자의 평균 입경(D50)은 상기 실리콘 카본 복합체의 평균 입경(D50) 보다 작은 것을 특징으로 한다.

[0033] The above SiOx(0 <x<2)로 표시되는 산화실리콘의 평균 입경(D50)은 작아질수록 비표면적이 증가되고 전해액과 부반응이 증가되어 수명 등 전기화학 성능이 저하될 수 있다. 상기 SiOx(0<x<2)로 표시되는 산화실리콘의 평균 입경(D50)이 1㎛ 미만인 경우, 비표면적 증가로 부반응이 증가되어 수명 성능이 매우 낮아 적용이 어려울 수 있다.

[0034] The above SiOx(0 <x<2)로 표시되는 산화실리콘의 평균 입경(D50)이 1 ㎛ 이상, 3 ㎛ 이상, 4 ㎛ 이상, 또는 5 ㎛ 이상인 경우, 전해액과 부반응이 감소하여 수명성능이 우수하다.

[0035] The above SiOx(0 <x<2)로 표시되는 산화실리콘은 상기 범위에서 수명성능이 우수하며, 실리콘 카본 복합체 등 다른 실리콘계 대비 초기 용량 및 효율이 우수하고, 전기 화학 성능도 우수하여 상기 단입자와의 평균 입경 조합에서 최적의 전지 성능을 구현할 수 있다.

[0036] Even if the above single particles and / or pseudo-single particles are formed with a small particle size, their particle strength can be excellent, thereby alleviating the phenomenon of fine particle increase in the electrode due to particle breakage, and thereby improving the life characteristics of the battery.

[0037] The average particle diameter (D50) of the above single particles and / or pseudo-single particles is SiOx(0 <x<2)로 표시되는 산화실리콘의 평균 입경(D50) 보다 작은 경우, 상기 단입자 및 / 또는 유사-단입자의 확산(diffusion) 저항이 상대적으로 감소하여 수명 성능이 개선될 수 있다. 즉, 방전 기준으로 리튬이 단입자 및 / 또는 유사-단입자 안으로 들어가게 되는데, 상기 단입자 및 / 또는 유사-단입자의 평균 입경(D50)이 커질수록 확산(diffusion) 저항이 증가할 수 있다. 상기 단입자 및 / 또는 유사-단입자의 평균 입경(D50)이 상기 SiOx(0<x<2)로 표시되는 산화실리콘의 평균 입경(D50) 보다 큰 경우, 확산 저항이 상대적으로 증가함에 따라 리튬이 단입자 및 / 또는 유사-단입자 안으로 들어가지 못하고 석출되어 전지 성능이 저하될 수 있으며 수명성능이 저하될 수 있다.

[0038] In addition, the average particle diameter (D50) of the above single particles is SiOx(0 <x<2)로 표시되는 산화실리콘의 평균 입경(D50) 보다 작은 경우, 상기 단입자의 비표면적 증가에 인한 전해액과의 부반응 발생을 방지하여 수명 성능이 개선될 수 있다.

[0039] The average particle diameter (D50) of the above single particles and / or pseudo-single particles is SiOx(0 <x<2)로 표시되는 산화실리콘의 평균 입경(D50) 보다 작은 경우, 상기 단입자 및 / 또는 유사-단입자의 확산(diffusion) 저항이 상대적으로 감소하여 수명 성능이 개선될 수 있다.

[0040] The above single particles and / or quasi-single particles are SiOx(0 <x<2)로 표시되는 산화실리콘 대비 리튬 확산 저항이 크기 때문에, 상기 단입자 및 / 또는 유사-단입자의 평균 입경(D50)이 상기 SiOx(0<x<2)로 표시되는 산화실리콘의 평균 입경(D50) 보다 큰 경우, 리튬 확산 저항 증가로 충 / 방전이 잘 이뤄지지 않아 수명 성능이 저하될 수 있다. 이에, 상기 단입자 및 / 또는 유사-단입자의 평균 입경(D50)은 상기 SiOx(0<x<2)로 표시되는 산화실리콘의 평균 입경(D50) 보다 작을 수 있다.

[0041] According to an additional embodiment of the present application, the positive electrode active material includes nickel, cobalt, and manganese, and may further include aluminum. That is, the positive electrode active material may further include aluminum.

[0042] In the present specification, the positive electrode active material contains 80 mol% or more and less than 100 mol% of nickel among metals other than lithium, and the lithium composite transition metal compound containing 80 mol% or more and less than 100 mol% of nickel among metals other than lithium may include one or a mixture of two or more types represented by the following chemical formula 1.

[0043] Additionally, the lithium composite transition metal compound may include single particles and / or quasi-single particles and secondary particles.

[0044] [Chemical Formula 1]

[0045] Li a Ni 1-b-c-d Co b Mn c Q d O 2+δ

[0046] In the above formula, Q is at least one element 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≤20, -0.1≤δ≤1.0이다.

[0047] In the lithium composite transition metal compound of the above chemical formula 1, Li may be included in an amount corresponding to a, that is, 1≤a≤1.5. If a is less than 1, there is a risk of reduced capacity, and if a exceeds 1.5, the particles may be sintered during the sintering process, making it difficult to manufacture a positive electrode active material. Considering the effect of improving the capacity characteristics of the positive electrode active material according to the Li amount control and the balance of sinterability during the manufacture of the active material, the Li may be more preferably included in an amount of 1.1≤a≤1.2.

[0048] In the lithium composite transition metal compound of the above chemical formula 1, Ni may be included in a content corresponding to 1-(b+c+d), for example, 0.8≤1-(b+c+d) < 1. When the content of Ni in the lithium composite transition metal compound of the above chemical formula 1 is 0.8 or more, a sufficient amount of Ni is secured to contribute to charge / discharge, thereby promoting high capacity. Preferably, the content of Ni, 1-(b+c+d), may be 0.88, preferably 0.9 or more, and more preferably 0.93 or more. Preferably, the content of Ni, 1-(b+c+d), may be 0.99 or less, or 0.95 or less.

[0049] In the lithium complex transition metal compound of the above chemical formula 1, Co is in the content corresponding to b, i.e., 0 <b≤0.5로 포함될 수 있다. 상기 화학식 1의 리튬 복합 전이금속 화합물 내 Co의 함량이 0.5를 초과할 경우 비용 증가의 우려가 있다. Co 포함에 따른 용량 특성 개선 효과의 현저함을 고려할 때, 상기 Co는 보다 구체적으로 0.03≤b≤0.2의 함량으로 포함될 수 있다.

[0050] In the lithium complex transition metal compound of the above chemical formula 1, Mn is in the content corresponding to c, i.e., 0 <c≤0.5의 함량으로 포함될 수 있다. 상기 화학식 1의 리튬 복합 전이금속 화합물 내 c가 0.5를 초과하면 오히려 전지의 출력 특성 및 용량 특성이 저하될 우려가 있으며, 상기 Mn은 보다 구체적으로 0.01≤c≤0.2의 함량으로 포함될 수 있다.

[0051] In the lithium composite transition metal compound of the above chemical formula 1, Q may be a doping element included in the crystal structure of the lithium composite transition metal compound, and Q may be included in a content corresponding to d, that is, 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.

[0052] According to an additional embodiment of the present application, the lithium composite transition metal compound in the positive electrode active material may include single particles and / or quasi-single particles and secondary particles.

[0053] The above single particles and / or pseudo-single particles can be manufactured by mixing and calcining a transition metal precursor and a lithium source material. The secondary particles can be manufactured by a method different from the single particles and / or pseudo-single particles, and their composition can be the same as or different from that of the single particles and / or pseudo-single particles.

[0054] For example, the sintering is performed at a temperature capable of forming single particles and / or pseudo-single particles. To form these, the sintering should be performed at a higher temperature than that during the production of secondary particles. For example, when the precursor composition is the same, the sintering should be performed at a temperature that is about 30° C. to 100° C. higher than that during the production of secondary particles. The sintering temperature for forming the single particles and / or pseudo-single particles may vary depending on the metal composition in the precursor. For example, when a high-content nickel (High-Ni) NCM-based lithium composite transition metal oxide having a nickel (Ni) content of 80 mol% or more is intended to be formed into single particles and / or pseudo-single particles, the sintering temperature may be about 700° C. to 1000° C., preferably about 800° C. to 950° C. When the sintering temperature satisfies the above range, a cathode active material including single particles and / or pseudo-single particles having excellent electrochemical properties can be produced. When the sintering temperature is less than 700°C, a cathode active material including a lithium complex transition metal compound in the form of secondary particles can be manufactured, and when it exceeds 950°C, excessive sintering occurs and a layered crystal structure is not properly formed, which may result in a deterioration in electrochemical characteristics.

[0055] In this specification, the term "single particle" and / or "quasi-single particle" is used to distinguish it from secondary particles formed by the agglomeration of tens to hundreds of conventional primary particles.

[0056] Specifically, in the present invention, the single particle is composed of a single nodule, and the pseudo-single particle is a composite composed of 30 or fewer nodules. On the other hand, the secondary particle may be an aggregate of tens to hundreds of primary particles.

[0057] According to an additional embodiment of the present application, the average particle diameter (D50) of the single particles and / or pseudo-single particles is 1 ㎛ or more and 10 ㎛ or less, and the SiOx(0 <x<2)로 표시되는 산화실리콘의 평균 입경(D50)은 1 ㎛ 이상이다.

[0058] The average particle diameter (D50) of the above single particles and / or pseudo-single particles is 1 ㎛ or more and 10 ㎛ or less, and the SiOx(0 <x<2)로 표시되는 산화실리콘은 평균 입경(D50)은 1 ㎛ 초과일 수 있다.

[0059] According to the embodiment of the present application, the average particle diameter (D50) of the single particles and / or pseudo-single particles is 10㎛ or less, and the SiOx(0 <x<2)로 표시되는 산화실리콘의 평균 입경(D50)은 15 ㎛ 미만이다.

[0060] For example, the average particle diameter (D50) of the single particles and / or pseudo-single particles may be 1 ㎛ or more and 10 ㎛ or less, 2 ㎛ or more and 10 ㎛ or less, 3 ㎛ or more and 10 ㎛ or less, more than 1 ㎛ and 10 ㎛ or less, more than 2 ㎛ and 10 ㎛ or less, or more than 2 ㎛ and 5 ㎛ or less.

[0061] Even if the above single particles and / or pseudo-single particles are formed with a small particle size of about 1 ㎛ to 10 ㎛ in average particle diameter (D50), the particle strength can be excellent. For example, the above single particles and / or pseudo-single particles can have a particle strength of 650 kgf / cm 2 When rolled with a force of 100 MPa to 300 MPa, the particle strength can be achieved. Accordingly, the single particle and / or pseudo-single particle can be formed at a strength of 650 kgf / cm 2 Even when rolled with a strong force, the phenomenon of fine particle increase in the electrode due to particle breakage is alleviated, thereby improving the life characteristics of the battery.

[0062] When the average particle diameter (D50) of the above single particles satisfies the above range, the single particles have excellent life performance due to reduced side reactions with the electrolyte, and charge / discharge are performed well, resulting in excellent electrochemical performance.

[0063] If the average particle diameter (D50) of the above single particles is less than 1㎛, the life performance may be very low due to the increase in specific surface area, making application difficult.

[0064] When the average particle diameter (D50) of the above single particles is 10 ㎛ or less, charging / discharging is performed well and the electrochemical performance is excellent.

[0065] The method for forming the above single particles and / or quasi-single particles is not particularly limited, but can generally be formed by increasing the firing temperature to cause underfiring, using an additive such as a grain growth accelerator that helps underfiring, or by changing the starting material.

[0066] According to an additional embodiment of the present application, the SiOx(0 <x<2)로 표시되는 산화실리콘의 평균입경(D50)은 1 ㎛ 이상 15 ㎛ 미만, 2 ㎛ 이상 14 ㎛ 이하, 또는 3 ㎛ 이상 13㎛ 이하일 수 있다.

[0067] The above SiOx(0 <x<2)로 표시되는 산화실리콘은 평균 입경(D50)이 1㎛ 이상 15㎛ 미만 정도의 소입경으로 형성되더라도, 전지의 수명 특성을 개선할 수 있다. 예를 들면, 상기 SiOx(0<x<2)로 표시되는 산화실리콘의 평균 입경(D50)이 1 ㎛ 이상 15 ㎛ 미만의 범위일 때, 충방전에 따른 부피 팽창 및 수축률이 감소하여, 수명 성능이 개선될 수 있다. 또한, 비표면적이 과도하게 증가되는 것을 방지하여 사이클 진행에 의한 전해액과의 부반응을 하지 않아 수명 성능이 개선될 수 있다.

[0068] The above SiOx(0 <x<2)로 표시되는 산화실리콘의 평균 입경(D50)이 1㎛ 미만인 경우, 비표면적 증가로 수명 성능이 매우 낮아 적용이 어려울 수 있다.

[0069] The above SiOx(0 <x<2)로 표시되는 산화실리콘의 평균 입경(D50)이 15㎛ 미만인 경우, 입자가 작아 충방전이 잘 이 루어지며, 충방전에 따른 입자의 부피 팽창 및 수축율이 감소하여 수명 성능이 개선될 수 있다.

[0070] According to an additional embodiment of the present application, the average particle diameter (D50) of the single particles and / or pseudo-single particles is SiOx(0 <x<2)로 표시되는 산화실리콘의 평균 입경(D50) 보다 작은 것을 특징으로 한다. 이로써, 상기 단입자 및 / 또는 유사-단입자는 소입경으로 형성되더라도 그 입자 강도가 우수할 수 있고, 이로 인하여 입자의 깨짐에 의한 전극 내 미립자 증가 현상이 완화되며, 이에 의해 전지의 수명특성이 개선될 수 있다.

[0071] The average particle diameter (D50) of the above single particles and / or pseudo-single particles is SiOx(0 <x<2)로 표시되는 산화실리콘의 평균 입경(D50) 보다 작은 경우, 상기 SiOx(0<x<2)로 표시되는 산화실리콘 대비 리튬 확산 저항이 큰 상기 단입자 및 / 또는 유사-단입자의 확산 저항이 상대적으로 감소하여 수명 성능이 개선될 수 있다.

[0072] According to one embodiment of the present application, the average particle diameter (D50) of the single particles and / or pseudo-single particles is SiOx(0 <x<2)로 표시되는 산화실리콘의 평균 입경(D50) 보다 1 ㎛ 내지 12 ㎛ 작을 수 있다.

[0073] The average particle diameter (D50) of the above single particles and / or pseudo-single particles is SiOx(0 <x<2)로 표시되는 산화실리콘의 평균 입경(D50) 보다 1.5 ㎛ 내지 11.5 ㎛, 또는 2 ㎛ 내지 11㎛ 작을 수 있다.

[0074] The average particle diameter (D50) of the above single particles and / or pseudo-single particles is SiOx(0 <x<2)로 표시되는 산화실리콘의 평균 입경(D50) 보다 2 ㎛ 이상, 또는 4 ㎛ 이상 작을 수 있다. 상기 단입자의 평균 입경(D50)은 상기 SiOx(0<x<2)로 표시되는 산화실리콘의 평균 입경(D50) 보다 11㎛ 이하, 8㎛ 이하, 또는 6㎛ 이하 작을 수 있다.

[0075] The average particle diameter (D50) of the above single particles and / or pseudo-single particles is SiOx(0 <x<2)로 표시되는 산화실리콘의 평균 입경(D50) 보다 작은 경우, 예컨대 상기 범위를 만족할 때, 상기 단입자 및 / 또는 유사-단입자의 확산(diffusion) 저항이 상대적으로 감소하여 수명 성능이 개선될 수 있다. 즉, 상기 단입자 및 / 또는 유사-단입자의 평균 입경(D50)이 커질수록 확산(diffusion) 저항이 증가할 수 있고, 상기 단입자 및 / 또는 유사-단입자의 평균 입경(D50)이 상기 SiOx(0<x<2)로 표시되는 산화실리콘의 평균 입경(D50) 보다 큰 경우, 확산 저항이 상대적으로 증가함에 따라 리튬 석출 등이 발생하여 전지 성능이 저하될 수 있고 수명성능이 저하될 수 있다.

[0076] In addition, the average particle diameter (D50) of the single particles and / or pseudo-single particles is greater than the SiOx(0 <x<2)로 표시되는 산화실리콘의 평균 입경(D50) 보다 작은 경우, 예컨대 상기 범위를 만족할 때, 비표면적 증가에 인한 전해액과의 부반응 발생을 방지하여 수명 성능이 개선될 수 있다.

[0077] According to one embodiment of the present application, the average particle diameter (D50) of the single particles and / or pseudo-single particles and the SiOx(0 <x<2)로 표시되는 산화실리콘의 평균 입경(D50)의 비가 1.5:2 내지 1.5:20이다.

[0078] The average particle diameter (D50) of the above single particles and the SiOx (0 <x<2)로 표시되는 산화실리콘의 평균 입경(D50)의 비는 1.5:2 내지 1.5:19 또는 1.5:2 내지 1.5:18일 수 있다.

[0079] The average particle diameter (D50) of the above single particles and the SiOx (0 <x<2)로 표시되는 산화실리콘의 평균 입경(D50)의 비는 1.5:2 이상, 1.5:2.5 이상, 1.5:3.5 이상, 또는 1.5:4.5 이상일 수 있다. 상기 단입자의 평균 입경(D50)과 상기 실리콘 카본 복합체의 평균 입경(D50)의 비는 1.5:18 이하, 1.5:16 이하, 1.5:14 이하, 1.5:12 이하, 또는 1.5:10 이하일 수 있다.

[0080] When the above range is satisfied, the diffusion resistance of the single particle and / or pseudo-single particle may be relatively reduced, thereby improving the life performance. That is, as the average particle diameter (D50) of the single particle and / or pseudo-single particle increases, the diffusion resistance may increase, and when the average particle diameter (D50) of the single particle and / or pseudo-single particle is greater than the SiOx(0 <x<2)로 표시되는 산화실리콘의 평균 입경(D50) 보다 큰 경우, 확산 저항이 상대적으로 증가함에 따라 리튬 석출 등이 발생하여 전지 성능이 저하될 수 있고 수명성능이 저하될 수 있다.

[0081] In addition, the average particle diameter (D50) of the single particles and / or pseudo-single particles is greater than the SiOx(0 <x<2)로 표시되는 산화실리콘의 평균 입경(D50) 보다 작은 경우, 예컨대 상기 범위를 만족할 때, 비표면적 증가에 인한 전해액과의 부반응 발생을 방지하여 수명 성능이 개선될 수 있다.

[0082] In one embodiment of the present application, the lithium composite transition metal compound further includes secondary particles, and the average particle diameter (D50) of the single particles and / or pseudo-single particles may be smaller than the average particle diameter (D50) of the secondary particles.

[0083] In the present invention, the single particle may be composed of one nodule, and the pseudo-single particle may be in the form of a complex composed of 30 or fewer nodules.

[0084] The lithium complex transition metal compound described above may further include secondary particles. The secondary particles refer to a form formed by the aggregation of primary particles, and can be distinguished from the concept of a single particle composed of a single nodule or a pseudo-single particle, which is an aggregate composed of 30 or fewer nodules.

[0085] The particle diameter (D50) of the secondary particles may be 1 ㎛ to 20 ㎛, 2 ㎛ to 17 ㎛, and preferably 3 ㎛ to 15 ㎛. The specific surface area (BET) of the secondary particles may be 0.05 m 2 / g to 10 m 2 / g can be, preferably 0.1 m 2 / g to 1 m 2 / g may be, more preferably 0.3 m 2 / g to 0.8 m 2 / g could be.

[0086] In a further embodiment of the present application, the secondary particles may be aggregates of primary particles, and the average particle diameter (D50) of the primary particles may be 0.5 µm to 3 µm. Specifically, the secondary particles may be aggregates of hundreds of primary particles, and the average particle diameter (D50) of the primary particles may be 0.6 µm to 2.8 µm, 0.8 µm to 2.5 µm, or 0.8 µm to 1.5 µm.

[0087] When the average particle diameter (D50) of the primary particles aggregated in the secondary particles satisfies the above range, a cathode active material of single particles and / or pseudo-single particles having excellent electrochemical properties can be formed. When the average particle diameter (D50) of the primary particles aggregated in the secondary particles is too small, the number of aggregates of the primary particles forming the lithium nickel-based oxide particles increases, which reduces the effect of suppressing particle breakage during rolling, and when the average particle diameter (D50) of the primary particles aggregated in the secondary particles is too large, the lithium diffusion path within the primary particles becomes longer, which may increase the resistance and deteriorate the output characteristics.

[0088] According to an additional embodiment of the present application, the average particle diameter (D50) of the single particles and / or pseudo-single particles is characterized by being smaller than the average particle diameter (D50) of the secondary particles. Accordingly, even if the single particles and / or pseudo-single particles are formed with a small particle diameter, their particle strength can be excellent, thereby alleviating the phenomenon of fine particles increasing in the electrode due to particle breakage, and thereby improving the life characteristics of the battery.

[0089] In one embodiment of the present application, the average particle diameter (D50) of the single particles and / or pseudo-single particles may be 1 ㎛ to 18 ㎛ smaller than the average particle diameter (D50) of the secondary particles.

[0090] For example, the average particle diameter (D50) of the single particles and / or pseudo-single particles may be 1 μm to 16 μm smaller than the average particle diameter (D50) of the secondary particles, may be 1.5 μm to 15 μm smaller, or may be 2 μm to 14 μm smaller.

[0091] The average particle diameter (D50) of the single particles and / or pseudo-single particles may be 1 μm or more, 2 μm or more, 4 μm or more, or 6 μm or more smaller than the average particle diameter (D50) of the secondary particles. The average particle diameter (D50) of the single particles and / or pseudo-single particles may be 18 μm or less, 16 μm or less, 14 μm or less, 12 μm or less, 10 μm or less, or 8 μm or less smaller than the average particle diameter (D50) of the secondary particles.

[0092] When the average particle diameter (D50) of the single particles and / or pseudo-single particles is smaller than the average particle diameter (D50) of the secondary particles, for example, when the above range is satisfied, the single particles and / or pseudo-single particles can have excellent particle strength even when formed into a small particle diameter, and thus the phenomenon of an increase in fine particles in the electrode due to particle breakage is alleviated, thereby improving the life characteristics of the battery and improving the energy density.

[0093] In one embodiment of the present application, the negative active material further includes graphite, and the SiOx(0 <x<2)로 표시되는 산화실리콘의 평균 입경(D50)은 상기 흑연의 평균 입경(D50) 보다 작을 수 있다.

[0094] The above SiOx(0 <x<2)로 표시되는 산화실리콘의 평균 입경(D50)이 상기 흑연의 평균 입경(D50) 보다 작은 경우, 충방전시 부피팽창 / 수축율 감소로 인하여 입자 깨짐이 감소되어 전지의 수명 성능이 개선되는 효과가 있다.

[0095] According to one embodiment of the present application, the SiOx(0 <x<2)로 표시되는 산화실리콘의 평균 입경(D50)은 상기 흑연의 평균 입경(D50) 보다 1 ㎛ 내지 25 ㎛ 작다.

[0096] For example, the SiOx(0 <x<2)로 표시되는 산화실리콘의 평균 입경(D50)은 상기 흑연의 평균 입경(D50) 보다 2 ㎛ 내지 24 ㎛ 작을 수 있고, 3 ㎛ 내지 23 ㎛ 작을 수 있고, 또는 4 ㎛ 내지 22 ㎛ 작을 수 있다.

[0097] The above SiOx(0 <x<2)로 표시되는 산화실리콘의 평균 입경(D50)은 상기 흑연의 평균 입경(D50) 보다 1 ㎛ 이상, 2 ㎛ 이상, 3 ㎛ 이상, 4 ㎛ 이상, 5 ㎛ 이상, 6 ㎛ 이상, 7 ㎛ 이상, 8 ㎛ 이상, 9 ㎛ 이상, 또는 10 ㎛ 이상 작을 수 있다. 상기 SiOx(0<x<2)로 표시되는 산화실리콘의 평균 입경(D50)은 상기 흑연의 평균 입경(D50) 보다 25 ㎛ 이하, 23 ㎛ 이하, 22 ㎛ 이하, 20 ㎛ 이하, 18 ㎛ 이하, 16 ㎛ 이하, 또는 14 ㎛ 이하 작을 수 있다.

[0098] SiOx(0 <x<2)로 표시되는 산화실리콘의 평균 입경(D50)이 상기 흑연의 평균 입경(D50) 보다 작은 경우, 예컨대 상기 범위를 만족할 때, 전지의 수명 성능이 개선되는 효과가 있다.

[0099] In one embodiment of the present application, the lithium composite transition metal compound further includes secondary particles, the negative electrode active material further includes graphite, and the secondary particles, the single particles and / or pseudo-single particles, the graphite and the SiOx(0 <x<2)로 표시되는 산화실리콘의 평균 입경(D50)이 각각 A, B, C 및 D로 표시되며, B < D ≤ A < C 이다.

[0100] The secondary particles, the single particles and / or quasi-single particles, the graphite and the SiOx(0 <x<2)로 표시되는 산화실리콘의 실시상태는 전술한 바에 따른다.

[0101] The secondary particles, the single particles and / or quasi-single particles, the graphite and the SiOx(0 <x<2)로 표시되는 산화실리콘의 평균 입경(D50)이 각각 A, B, C 및 D일 때, B < D ≤ A < C 인 경우, 전지의 수명 성능이 개선되는 효과가 있다.

[0102] According to one embodiment of the present application, the negative active material further comprises graphite, and the single particle and / or pseudo-single particle, the graphite and the SiOx(0 <x<2)로 표시되는 산화실리콘의 평균 입경(D50)이 각각 B, C 및 D로 표시되며, B < D < C 이다.

[0103] The above secondary particles, the above single particles and / or the above quasi-single particles and the above SiOx(0 <x<2)로 표시되는 산화실리콘의 평균 입경(D50)이 각각 A, B 및 D로 표시되며, B < D ≤ A일 수 있다.

[0104] The average particle diameters (D50) of the above secondary particles, the single particles and / or the pseudo-single particles and the graphite are represented by A, B and C, respectively, and B < A < C may be satisfied.

[0105] The above secondary particles, the graphite and the SiOx(0 <x<2)로 표시되는 산화실리콘의 평균 입경(D50)이 각각 A, C 및 D로 표시되며, D ≤ A < C 일 수 있다.

[0106] When the above range is satisfied, there is an effect of improving the life performance of the battery.

[0107] In one embodiment of the present application, in the lithium secondary battery according to the embodiment described above, the single particles and / or pseudo-single particles are included in an amount of 15 to 100 parts by weight based on 100 parts by weight of the positive electrode active material, and the SiOx(0 <x<2)로 표시되는 산화실리콘은 상기 음극 활물질 100 중량부 대비 3 중량부 내지 30 중량부로 포함될 수 있다.

[0108] According to an additional embodiment of the present application, the single particles and / or quasi-single particles may be included in an amount of 15 to 100 parts by weight relative to 100 parts by weight of the positive electrode active material. The single particles and / or quasi-single particles may be included in an amount of 20 to 100 parts by weight, 30 to 100 parts by weight, 40 to 100 parts by weight, or 50 to 100 parts by weight relative to 100 parts by weight of the positive electrode active material.

[0109] For example, the single particles and / or quasi-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, 45 parts by weight or more, or 50 parts by weight or more, relative to 100 parts by weight of the positive electrode active material. The single particles and / or quasi-single particles may be included in an amount of 100 parts by weight or less relative to 100 parts by weight of the positive electrode active material.

[0110] When the single particles and / or pseudo-single particles within the above range are included, excellent battery characteristics can be exhibited in combination with the aforementioned negative electrode material. In particular, when the single particles and / or pseudo-single particles are present in an amount of 15 parts by weight or more, the phenomenon of an increase in fine particles within the electrode due to particle breakage during the rolling process after electrode production can be alleviated, thereby improving the life characteristics of the battery.

[0111] In one embodiment of the present application, the lithium composite transition metal compound may further include secondary particles, and the secondary particles may be included in an amount of 0 to 85 parts by weight, 0 to 70 parts by weight, or 0 to 50 parts by weight relative to 100 parts by weight of the positive electrode active material.

[0112] The secondary particles may be 85 parts by weight or less, 80 parts by weight or less, 75 parts by weight or less, 70 parts by weight or less, 65 parts by weight or less, 60 parts by weight or less, 55 parts by weight or less, or 50 parts by weight or less, relative to 100 parts by weight of the positive electrode active material. The secondary particles may be 0 parts by weight or more, or 20 parts by weight or more, relative to 100 parts by weight of the positive electrode active material.

[0113] When the above range is satisfied, the aforementioned effect due to the presence of the single particle and / or pseudo-single particle positive electrode active material can be maximized. When the secondary particle positive electrode active material is included, the component may be the same component as the single particle and / or pseudo-single particle positive electrode active material exemplified above, or may be a different component, and may mean a form in which the single particle form is aggregated.

[0114] In one embodiment of the present application, the positive electrode active material may be included in 100 parts by weight of the positive electrode active material layer 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 still more preferably 98 parts by weight or more and 99.9 parts by weight or less.

[0115] According to one embodiment of the present application, the positive electrode according to the above-described embodiment may further include a positive electrode binder and a conductive material.

[0116] The above-described positive electrode binder can serve to improve adhesion between positive electrode active material particles and adhesion between positive electrode active material particles and positive electrode current collector. Those known in the art can be used as the positive electrode binder, and non-limiting examples thereof include polyvinylidene fluoride (PVDF), polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-co-HFP), polyvinyl alcohol, polyacrylonitrile, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinyl pyrrolidone, polytetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene polymer (EPDM), sulfonated-EPDM, styrene butadiene rubber (SBR), fluororubber, or various copolymers thereof, and one of these may be used alone or a mixture of two or more thereof.

[0117] The positive electrode binder may be included in an amount of 0.1 to 50 parts by weight based on 100 parts by weight of the positive electrode active material layer, for example, preferably 0.3 to 35 parts by weight, more preferably 0.5 to 20 parts by weight.

[0118] The conductive material included in the above-described positive electrode active material layer is used to provide conductivity to the electrode, and can be used without special restrictions as long as it does not cause chemical changes within the battery and has electronic conductivity. Specific examples include graphite such as natural graphite or artificial graphite; carbon-based materials such as carbon black, acetylene black, Ketjen black, channel black, furnace black, lamp black, summer black, and carbon fiber; metal powder or metal fiber such as copper, nickel, aluminum, and silver; conductive whiskey such as zinc oxide or potassium titanate; conductive metal oxides such as titanium oxide; or conductive polymers such as polyphenylene derivatives, and the like. One of these may be used alone or a mixture of two or more may be used.

[0119] Specifically, in one embodiment, the conductive material may include at least one of single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs). The conductive material may be included in an amount of 0.1 parts by weight or more and 2 parts by weight or less based on 100 parts by weight of the composition for forming the positive electrode active material layer, 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.

[0120] According to the above-described embodiment of the present application, the negative electrode active material layer comprises SiOx (0) out of 100 parts by weight of the total negative electrode active material. <x<2)로 표시되는 산화실리콘을 3 중량부 내지 30 중량부 포함할 수 있다. 일 예에 따르면, 상기 음극 활물질층은 총 음극 활물질 100 중량부 중 SiOx(0<x<2)로 표시되는 산화실리콘을 3 중량부 내지 20 중량부, 또는 3 중량부 내지 13 중량부, 바람직하게는 5 중량부 내지 10 중량부를 포함할 수 있다.

[0121] The above negative electrode active material layer is SiOx (0) out of 100 parts by weight of the total negative electrode active material. <x<2)로 표시되는 산화실리콘을 3 중량부 이상, 4 중량부 이상, 또는 5 중량부 이상 포함할 수 있다. 상기 음극 활물질층은 총 음극 활물질 100 중량부 중 SiOx(0<x<2)로 표시되는 산화실리콘을 30 중량부 이하, 20 중량부 이하, 또는 10 중량부 이하 포함할 수 있다.

[0122] SiOx(0) in this range <x<2)로 표시되는 산화실리콘을 사용함으로써 전술한 양극 재료와 조합되어 우수한 전지 특성을 나타낼 수 있다. 특히, SiOx(0<x<2)로 표시되는 산화실리콘을 3 중량부 이상 포함하는 경우, 상기 SiOx(0<x<2)로 표시되는 산화실리콘의 사용에 따른 효과를 충분히 나타낼 수 있다. 또한, SiOx(0<x<2)로 표시되는 산화실리콘은 SiC 활물질에 비하여 용량이 낮아, SiC 대비 과량 사용이 가능하고, 특히 SiOx(0<x<2)로 표시되는 산화실리콘을 30 중량부 이하 포함하는 경우에는 충방전시 팽창을 방지하여 사이클 특성이 향상될 수 있다.

[0123] According to an additional embodiment of the present application, in the lithium secondary battery according to the above-described embodiment, the negative electrode active material 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.

[0124] Based on 100 parts by weight of the total negative electrode active material, the 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, the 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. When the graphite is a mixture of artificial graphite and natural graphite, based on 100 parts by weight of the graphite, the artificial graphite and natural graphite may be included in an amount of 90:10 parts by weight to 50:50 parts by weight, 85:15 parts by weight to 60:40 parts by weight, or 80:20 parts by weight to 65:35 parts by weight.

[0125] In one embodiment of the present application, the negative electrode active material may be included in 100 parts by weight of the negative electrode active material layer 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 still more preferably 98 parts by weight or more and 99.9 parts by weight or less.

[0126] According to an additional embodiment of the present application, in the lithium secondary battery according to the embodiment described above, the negative electrode active material layer is SiOx(0 <x<2)로 표시되는 산화실리콘 및 흑연 외에 추가로 음극 바인더를 더 포함할 수 있다.

[0127] The above negative electrode binder can play a role in improving the adhesion between negative electrode active material particles and the adhesive strength between the negative electrode active material particles and the negative electrode current collector. The above-mentioned negative electrode binder may be one known in the art, and non-limiting examples thereof include at least one selected from the group consisting of polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-co-HFP), polyvinylidene fluoride, polyacrylonitrile, polymethylmethacrylate, polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, polytetrafluoroethylene, polyethylene, polypropylene, polyacrylic acid, ethylene-propylene-diene monomer (EPDM), sulfonated EPDM, styrene butadiene rubber (SBR), fluoroelastomer, polyacrylic acid, and a material in which hydrogens of these are substituted with Li, Na, Ca, etc., and may also include various copolymers thereof.

[0128] The above negative electrode binder may be included in an amount of 0.1 to 50 parts by weight based on 100 parts by weight of the negative electrode active material layer, for example, preferably 0.3 to 35 parts by weight, more preferably 0.5 to 10 parts by weight.

[0129] The above-described negative electrode active material layer may not include a conductive material, but may further include a conductive material as needed. The conductive material included in the negative electrode active material layer is not particularly limited as long as it has conductivity and does not cause a chemical change in the battery. For example, graphite such as natural graphite or artificial graphite; carbon black such as acetylene black, Ketjen black, channel black, paneth black, lamp black, thermal black; conductive fibers such as carbon fiber or metal fiber; conductive tubes such as carbon nanotubes; metal powders such as fluorocarbon, aluminum, and nickel powder; conductive whiskers such as zinc oxide and potassium titanate; conductive metal oxides such as titanium oxide; and conductive materials such as polyphenylene derivatives may be used. The content of the conductive material in the negative electrode active material layer may be 0.01 to 30 parts by weight, and preferably 0.03 to 25 parts by weight, based on 100 parts by weight of the negative electrode active material layer.

[0130] In one embodiment of the present application, the positive electrode may include a positive electrode current collector and a positive electrode active material layer formed on the positive electrode current collector, and including the positive electrode active material.

[0131] The positive electrode current collector is not particularly limited as long as it is conductive and does not cause a chemical change in the battery, and for example, stainless steel, aluminum, nickel, titanium, calcined carbon, or aluminum or stainless steel surface-treated with carbon, nickel, titanium, silver, etc. may be used. In addition, the positive electrode current collector may typically have a thickness of 1 ㎛ to 500 ㎛, and fine unevenness may be formed on the surface of the positive electrode current collector to increase the adhesive strength of the positive electrode active material. For example, it may be used in various forms such as a film, sheet, foil, net, porous body, foam, or non-woven fabric.

[0132] In one embodiment of the present application, the negative electrode may include a negative electrode current collector and a negative electrode active material layer formed on the negative electrode current collector and including the negative electrode active material.

[0133] The negative electrode current collector may be any conductive material that does not cause a chemical change in the battery, and is not particularly limited thereto. For example, the negative electrode current collector may be made of copper, stainless steel, aluminum, nickel, titanium, calcined carbon, or aluminum or stainless steel surface-treated with carbon, nickel, titanium, silver, or the like. Specifically, a transition metal that adsorbs carbon well, such as copper or nickel, may be used as the current collector. The thickness of the negative electrode current collector may be 1 μm to 500 μm, but the thickness of the current collector is not limited thereto.

[0134] In one embodiment of the present application, the positive electrode further includes a positive electrode active material layer including the positive electrode active material, and the negative electrode further includes a negative electrode active material layer including the negative electrode active material, and the thicknesses of the positive electrode and negative electrode active material layers may each be 10 ㎛ to 500 ㎛. The thickness of the positive electrode active material layer may be 90% to 110%, for example, 95% to 105%, of the thickness of the negative electrode active material layer, and these thicknesses may be the same. Specifically, the thicknesses of the positive electrode and negative electrode active material layers may each be 15 ㎛ to 400 ㎛, 20 ㎛ to 300 ㎛, 25 ㎛ to 200 ㎛, or 30 ㎛ to 100 ㎛.

[0135] In one embodiment of the present application, the positive electrode further includes a positive electrode active material layer including the positive electrode active material, and the loading amount per unit volume of the positive electrode active material layer is 250 mg / 25 cm 2 900 mg / 25cm 2, and the negative electrode further includes a negative electrode active material layer including the negative electrode active material, and the loading amount per unit volume of the negative electrode active material layer is 100 mg / 25cm 2 600 mg / 25cm 2 It can be. Specifically, the loading amount per unit volume of the positive electrode active material layer is 270 mg / 25cm 2 800 mg / 25cm 2 , 285 mg / 25cm 2 700 mg / 25cm 2 , or 300 mg / 25cm 2 600 mg / 25cm 2 The loading amount per unit volume of the negative active material layer may be 120 mg / 25cm 2 500 mg / 25cm 2 , 135 mg / 25cm 2 400 mg / 25cm 2 , or 150 mg / 25cm 2 300 mg / 25cm 2 It could be.

[0136] The positive electrode and the negative electrode can be manufactured according to a conventional method for manufacturing positive and negative electrodes, except that the positive and negative electrode active materials described above are used. Specifically, the composition for forming an active material layer, which includes the active material and optionally a binder and a conductive material, is applied to a current collector, followed by drying and rolling. At this time, the types and contents of the positive and negative electrode active materials, binder, and conductive material are as described above. The solvent may be a solvent generally used in the relevant technical field, and examples thereof include dimethyl sulfoxide (DMSO), isopropyl alcohol, N-methylpyrrolidone (NMP), acetone, and water. One type alone or a mixture of two or more types thereof may be used. The amount of the solvent used is sufficient to dissolve or disperse the active material, conductive material, and binder in consideration of the coating thickness and manufacturing yield of the slurry, and to have a viscosity that can exhibit excellent thickness uniformity during subsequent coating for manufacturing the positive and negative electrodes. Alternatively, the positive and negative electrodes may be manufactured by casting the composition for forming the active material layer on a separate support, then peeling the film from the support and laminating the resulting film on a current collector.

[0137] The separator is used to separate the negative electrode and the positive electrode and to provide a passage for lithium ions. Any separator commonly used in secondary batteries can be used without any particular restrictions, and in particular, one having low resistance to ion movement of the electrolyte and excellent electrolyte moisture retention capacity is preferable. Specifically, a porous polymer film, for example, a porous polymer film made of a polyolefin polymer such as an ethylene homopolymer, a propylene homopolymer, an ethylene / butene copolymer, an ethylene / hexene copolymer, and an ethylene / methacrylate copolymer, or a laminated structure of two or more layers thereof, may be used. In addition, a conventional porous nonwoven fabric, for example, a nonwoven fabric made of high-melting-point glass fiber, polyethylene terephthalate fiber, etc. may be used. In addition, a coated separator containing a ceramic component or a polymer material may be used to secure heat resistance or mechanical strength, and may optionally be used in a single-layer or multi-layer structure.

[0138] Examples of the electrolyte include, but are not limited to, organic liquid electrolytes, inorganic liquid electrolytes, solid polymer electrolytes, gel-type polymer electrolytes, solid inorganic electrolytes, and molten inorganic electrolytes that can be used in the manufacture of lithium secondary batteries.

[0139] Specifically, the electrolyte may include a non-aqueous organic solvent and a metal salt.

[0140] As the above 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-methyl tetrahydrofuran, dimethylsulfoxide, 1,3-dioxolan, formamide, dimethylformamide, dioxolan, acetonitrile, nitromethane, methyl formate, methyl acetate, triester phosphate, trimethoxy methane, dioxolan derivatives, sulfolane, methyl sulfolane, 1,3-dimethyl-2-imidazolidinone, propylene carbonate derivatives, tetrahydrofuran derivatives, ethers, methyl pyrropionate, ethyl propionate, etc. can be used.

[0141] In particular, among the above carbonate-based organic solvents, ethylene carbonate and propylene carbonate, which are cyclic carbonates, are high-viscosity organic solvents with high dielectric constants and thus can be preferably used because they easily dissociate lithium salts. In addition, when low-viscosity, low-dielectric constant linear carbonates such as dimethyl carbonate and diethyl carbonate are mixed and used in an appropriate ratio with these cyclic carbonates, an electrolyte with high electrical conductivity can be produced, so that they can be used even more preferably.

[0142] The metal salt may be a lithium salt, and the lithium salt is a substance that is easily dissolved in the non-aqueous electrolyte, for example, the anion of the lithium salt is 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 - One or more selected from the group consisting of may be used.

[0143] In addition to the electrolyte components, the electrolyte may further include one or more additives, such as, for example, a haloalkylene carbonate compound such as difluoroethylene carbonate, pyridine, triethylphosphite, triethanolamine, a cyclic ether, ethylene diamine, n-glyme, hexaphosphoric acid triamide, nitrobenzene derivatives, sulfur, quinone imine dyes, N-substituted oxazolidinones, N,N-substituted imidazolidines, ethylene glycol dialkyl ethers, ammonium salts, pyrrole, 2-methoxyethanol, or aluminum trichloride, for the purpose of improving the life characteristics of the battery, suppressing battery capacity decrease, and improving the discharge capacity of the battery.

[0144] The energy density of a lithium secondary battery according to one embodiment of the present application is 400 Wh / L to 900 Wh / L. Specifically, the energy density of the lithium secondary battery may be 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 a lithium secondary battery designed within a limited space can be increased, high-output performance can be improved, and battery cycle performance can also be improved.

[0145] A lithium secondary battery according to one embodiment of the present invention may be a cylindrical battery. The cylindrical battery may mean that the battery itself, which includes an assembly including a positive electrode, a negative electrode, a separator, and an electrolyte, has a cylindrical shape, and specifically, may be composed of a cylindrical can, a battery assembly provided inside the cylindrical can, and a top cap. However, the lithium secondary battery is not limited thereto, and may be a square battery or a pouch-type battery.

[0146] A further embodiment of the present invention provides a battery module including the aforementioned cylindrical battery as a unit cell and a battery pack including the same. In addition, a battery pack including the cylindrical battery is provided.

[0147] A further embodiment of the present invention provides a battery module including the aforementioned lithium secondary battery and a battery pack including the same. In addition, a battery pack including the aforementioned lithium secondary battery is provided.

[0148] The above battery module and battery pack include the secondary battery having high capacity, high rate characteristics and cycle characteristics, and thus can be used as a power source for medium and large-sized devices selected from the group consisting of electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles and power storage systems.

[0149] The lithium secondary battery according to the embodiments of the present invention stably exhibits excellent discharge capacity, output characteristics, and cycle performance, and therefore can be used as a power source for portable devices such as mobile phones, laptop computers, and digital cameras, as well as medium- to large-sized devices selected from the group consisting of electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, and power storage systems. For example, the battery module or battery pack can be used as a power source for any one or more medium- to large-sized devices selected from the group consisting of power tools; electric vehicles including electric vehicles (EVs), hybrid electric vehicles, and plug-in hybrid electric vehicles (PHEVs); or power storage systems.

[0150] Hereinafter, preferred embodiments are presented to help understand the present invention, but the above embodiments are only illustrative of the present disclosure, and it is obvious to those skilled in the art that various changes and modifications are possible within the scope and technical idea of ​​the present disclosure, and it is natural that such changes and modifications fall within the scope of the appended patent claims.

[0151] <Example 1>

[0152] A composition for forming a positive electrode active material layer was prepared, comprising 98.04 parts by weight of a lithium composite transition metal compound having a content of 93.3 mol% of Ni, 4.9 mol% of Co, and 1.8 mol% of Mn among metals other than lithium as a positive electrode active material and including single particles and / or pseudo-single particles and secondary particles (single particles and / or pseudo-single particles: secondary particles = 50:50 weight ratio), 1 part by weight of PVDF as a binder, and a CNT pre-dispersion liquid including 0.8 parts by weight of CNT as a conductive material and 0.16 parts by weight of a dispersant, based on 100 parts by weight of a composition for a positive electrode active material layer. At this time, the single particles and / or pseudo-single particles were prepared to have a size of D50=3 μm by an airflow pulverization method, and the secondary particles were prepared to have a size of D50=7 μm. The composition for forming the positive electrode active material layer was coated on aluminum foil having a thickness of 30 μm to a dry thickness of 103 μm, and then dried to manufacture a positive electrode including a positive electrode active material layer.

[0153] Based on 100 parts by weight of a composition for forming a negative electrode active material layer, a composition for forming a negative electrode active material layer was prepared, which included 97.7 parts by weight of graphite (artificial graphite: natural graphite = 70:30 weight ratio, 90 parts by weight based on 100 parts by weight of the negative electrode active material) and SiO (10 parts by weight based on 100 parts by weight of the negative electrode active material) as negative electrode active materials, 1.15 parts by weight of SBR (styrene-butadiene rubber) and 1 part by weight of CMC (carboxymethyl cellulose) as a binder, and further including 0.09 parts by weight of a dispersant and 0.06 parts by weight of a single-wall CNT, a CNT pre-dispersion liquid. At this time, the silicon oxide was prepared to have a D50=5㎛ size by an airflow grinding method, and the graphite was prepared to have a D50=17㎛ size. The composition for forming the negative electrode active material layer was coated on a copper foil having a thickness of 15 μm to a dry thickness of 86 μm, and then dried to manufacture a negative electrode including a negative electrode active material layer.

[0154] The above positive and negative electrodes were laminated with a separator between them, and an electrolyte (1.0 M LiPF6, EC(ethylene carbonate) / EMC(ethylmethyl carbonate)=30 / 70 (Vol%), VC(vinylene carbonate) 1.5%) was injected to manufacture a battery.

[0155] <Example 2>

[0156] A positive electrode was manufactured in the same manner as in Example 1, except that the weight ratio of the lithium composite transition metal compound in the form of single particles and / or pseudo-single particles and secondary particles was 80:20 based on 100 parts by weight of the positive electrode active material.

[0157] <Example 3>

[0158] A positive electrode was manufactured in the same manner as in Example 1, except that the single particles and / or pseudo-single particles were 100 parts by weight based on 100 parts by weight of the positive electrode active material.

[0159] <Example 4>

[0160] A negative electrode was manufactured in the same manner as in Example 3, except that the single particles and / or pseudo-single particles included in the positive active material layer were manufactured to have a size of D50=7 μm, and the SiO included in the negative active material layer was manufactured to have a size of D50=10 μm.

[0161] <Example 5>

[0162] A negative electrode was manufactured in the same manner as in Example 3, except that the D50 of SiO included in the negative electrode active material layer was 10 μm.

[0163] <Example 6>

[0164] A negative electrode was manufactured in the same manner as Example 3, except that SiO was 5 parts by weight based on 100 parts by weight of the negative active material.

[0165] <Example 7>

[0166] A negative electrode was manufactured in the same manner as in Example 1, except that the D50 of the single particles and / or pseudo-single particles included in the positive active material layer was 4.5 μm.

[0167] <Example 8>

[0168] A negative electrode was manufactured in the same manner as in Example 2, except that the D50 of the single particles and / or pseudo-single particles included in the positive active material layer was 4.5 μm.

[0169] <Example 9>

[0170] A negative electrode was manufactured in the same manner as in Example 2, except that the D50 of the single particle and / or quasi-single particle included in the positive active material layer was 1 μm, the D50 of the lithium composite transition metal compound in the form of a secondary particle was 14 μm, and the D50 of the SiO included in the negative active material layer was 13.5 μm.

[0171] <Comparative Example 1>

[0172] A positive electrode was manufactured in the same manner as in Example 1, except that the lithium composite transition metal compound in the form of secondary particles was 100 parts by weight based on 100 parts by weight of the positive electrode active material.

[0173] <Comparative Example 2>

[0174] A positive electrode was manufactured in the same manner as in Example 3, except that the D50 of the single particles and / or pseudo-single particles included in the positive electrode active material layer was 0.5 μm.

[0175] <Comparative Example 3>

[0176] A positive electrode was manufactured in the same manner as in Example 3, except that the D50 of the single particles and / or pseudo-single particles included in the positive electrode active material layer was 15 μm.

[0177] Comparative Example 4

[0178] A negative electrode was manufactured in the same manner as in Example 3, except that the D50 of SiO included in the negative electrode active material layer was 0.7 μm.

[0179] Comparative Example 5

[0180] A negative electrode was manufactured in the same manner as Example 3, except that 100 parts by weight of graphite was used based on 100 parts by weight of the negative active material.

[0181] <Experimental Example 1> Energy density characteristic evaluation

[0182] The energy density of the manufactured battery was evaluated and is shown in Table 1 below.

[0183] The energy density of Example 1 was derived by the following calculation.

[0184] Cell volume measurement (unit: L): width (100 mm) x length (300 mm) x thickness (8 mm)

[0185] Cell energy measurement (unit: Wh): cell capacity (40 Ah) x average voltage (3.65 V)

[0186] Energy density measurement (unit: Wh / L): cell energy (Wh) / cell volume (L) = 608 W / L

[0187] <Experimental Example 2> Evaluation of lifespan (capacity retention rate) characteristics

[0188] The manufactured battery was charged and discharged to evaluate the capacity retention rate, which is shown in Table 1 below.

[0189] The first and second cycles were charged and discharged at 0.1 C, and from the third cycle onwards, the charging and discharging was performed at 0.5 C. The 100th cycle was completed in a charged state (with lithium in the negative electrode).

[0190] Charging conditions: CC (constant current) / CV (constant voltage) (4.25V / 0.05C current cut-off)

[0191] Discharge conditions: CC (constant current) condition 2.5 V

[0192] The capacity retention rate was derived by the following calculations.

[0193] Capacity retention rate (%) = (100 discharge capacity / 1 discharge capacity) × 100 (%)

[0194] Table 1 below shows the values ​​for energy density (based on Example 1, %) and capacity retention rate (100 cycles, %) of examples and comparative examples.

[0195] Energy density (based on Example 1, %) Capacity retention rate (100 cycles, %) Example 1 10092 Example 2 10497 Example 3 11094 Example 4 11095 Example 5 10995 Example 6 10795 Example 79991 Example 8 10296 Example 99989 Comparative Example 19078 Comparative Example 29880 Comparative Example 33782 Comparative Example 49979 Comparative Example 59175

[0196] The present application can increase the energy density of a lithium secondary battery, improve high-output performance, and also improve battery cycle performance. When Examples 1 to 9 were compared with Comparative Examples 1 to 5, it was confirmed that the energy density and / or capacity retention rate were excellent. Specifically, Examples 1 to 3 showed a performance comparison according to the content of single particles and / or pseudo-single particles of the positive electrode, and it was confirmed that as the content of single particles and / or pseudo-single particles increased, the energy density increased and the life performance also had the same or superior characteristics.

[0197] In the case of Example 4, the D50 particle size of the positive electrode single particles and / or pseudo-single particles was increased, and in this case as well, the energy density and capacity retention rate were excellent, and in Examples 5 and 6, the energy density and capacity retention rate were excellent even when the D50 of SiO applied to the negative electrode was increased or the content was reduced.

[0198] In the above Examples 7 to 9, the D50 of the bipolar single particles and / or pseudo-single particles and SiO is within the range of the present application, and the difference is less than 1 ㎛ or more than 12 ㎛. It was confirmed that the energy density and capacity retention rate are excellent, but lower than in the above Examples 1 or 2.

[0199] That is, in Examples 7 and 8, the D50 particle size of the positive electrode single particles and / or pseudo-single particles increases compared to Examples 1 and 2, respectively, and thus the battery performance may be deteriorated due to occurrence of lithium precipitation, etc., as a result of an increase in relative diffusion resistance, and in Example 9, the life performance may be deteriorated due to occurrence of side reactions as the difference in the D50 particle size of the positive electrode single particles and / or pseudo-single particles and SiO increases.

[0200] In the case of Comparative Example 1, single particles and / or pseudo-single particles were not applied to the anode, Comparative Examples 2 and 3 were cases where the D50 of the single particles and / or pseudo-single particles of the anode was less than or exceeded the range of the present application, Comparative Example 4 was cases where the D50 range of SiO was less than the range of the present application, and Comparative Example 5 was cases where SiO was not applied to the cathode.

[0201] In this case, it was confirmed that the energy density and capacity retention rate were lower compared to the above example.

[0202] Specifically, when the D50 of the positive single particle and / or pseudo-single particle is formed to be smaller than the range of the present application, as in Comparative Example 2, even if the D50 of the silicon oxide included in the negative electrode is larger, it was confirmed that the reactivity with the electrolyte increases due to the increase in the specific surface area of ​​the single particle and / or pseudo-single particle, which increases side reactions and results in a decrease in life performance. In addition, when the particle size of the single particle and / or pseudo-single particle becomes smaller, the particle strength decreases, making it difficult to manufacture the electrode with the desired thickness during the rolling process during electrode manufacture, which also results in a decrease in energy density.

[0203] In Comparative Example 3, the D50 of the single particles and / or pseudo-single particles of the positive electrode exceeds the scope of the present invention. In this case, the particle size increases, making layering / discharging difficult. Accordingly, it was confirmed that the lifespan is reduced and the energy density is reduced due to a decrease in capacity.

[0204] In the case of Comparative Example 4, the D50 of SiO included in the negative active material was formed to be smaller than the range of the present invention. In this case as well, it was confirmed that the reactivity with the electrolyte increased due to the increase in the specific surface area of ​​SiO, resulting in a decrease in life performance due to an increase in side reactions.

[0205] In the case of Comparative Examples 1 and 5, the anode did not contain single particles and / or pseudo-single particles, and the cathode did not contain SiO, respectively, and it was confirmed that in this case, the desired energy density could not be achieved compared to the examples.

Claims

1. A lithium secondary battery comprising: a positive electrode including a positive active material; a negative electrode including a negative active material; a separator provided between the positive electrode and the negative electrode; and an electrolyte. The above positive electrode active material comprises a lithium composite transition metal compound containing nickel (Ni), cobalt (Co) and manganese (Mn), The lithium composite transition metal compound comprises at least one of single particles and pseudo-single particles, and the average particle diameter (D50) of at least one of the single particles and pseudo-single particles is 1 ㎛ or more and 10 ㎛ or less, The above single particle is composed of one nodule, and the above pseudo-single particle is a complex composed of 30 or fewer nodules, The above negative active material is SiOx(0 <x<2)로 표시되는 산화실리콘을 포함하고, 상기 SiOx(0<x<2)로 표시되는 산화실리콘의 평균 입경(D50)은 1 ㎛ 이상이며, The average particle diameter (D50) of at least one of the above single particles and pseudo-single particles is SiOx(0 <x<2)로 표시되는 산화실리콘의 평균 입경(D50) 보다 작은 것인 리튬이차전지.

2. In claim 1, the average particle diameter (D50) of at least one of the single particles and pseudo-single particles is 10 μm or less, The above SiOx(0 <x<2)로 표시되는 산화실리콘의 평균 입경(D50)은 15 ㎛ 미만인 것인 리튬이차전지.

3. In claim 1, the average particle diameter (D50) of at least one of the single particles and pseudo-single particles is SiOx(0 <x<2)로 표시되는 산화실리콘의 평균 입경(D50) 보다 1 ㎛ 내지 12 ㎛ 작은 것인 리튬이차전지.

4. In claim 1, The above SiOx(0 <x<2)로 표시되는 산화실리콘은 마그네슘 금속 또는 리튬 금속으로 도핑된 것인 리튬이차전지.

5. In claim 1, the lithium composite transition metal compound further comprises secondary particles, A lithium secondary battery, wherein the average particle diameter (D50) of at least one of the single particles and quasi-single particles is smaller than the average particle diameter (D50) of the secondary particles.

6. A lithium secondary battery according to claim 5, wherein the average particle diameter (D50) of at least one of the single particles and the pseudo-single particles is 1 ㎛ to 18 ㎛ smaller than the average particle diameter (D50) of the secondary particles.

7. In claim 1, the negative active material further includes graphite, The above SiOx(0 <x<2)로 표시되는 산화실리콘의 평균 입경(D50)은 상기 흑연의 평균 입경(D50) 보다 작은 것인 리튬이차전지.

8. In claim 7, the SiOx(0 <x<2)로 표시되는 산화실리콘의 평균 입경(D50)은 상기 흑연의 평균 입경(D50) 보다 1 ㎛ 내지 25 ㎛ 작은 것인 리튬이차전지.

9. In claim 1, the lithium composite transition metal compound further comprises secondary particles, The above negative active material further contains graphite, At least one of the secondary particles, the single particles and the pseudo-single particles, the graphite and the SiOx(0 <x<2)로 표시되는 산화실리콘의 평균 입경(D50)이 각각 A, B, C 및 D로 표시되며, B < D ≤ A < C 인 것인 리튬이차전지.

10. In claim 1, the negative active material further includes graphite, At least one of the above single particles and pseudo-single particles, the graphite and the SiOx(0 <x<2)로 표시되는 산화실리콘의 평균 입경(D50)이 각각 B, C 및 D로 표시되며, B < D < C 인 것인 리튬이차전지.

11. A lithium secondary battery according to claim 1, wherein the positive electrode active material further contains aluminum.

12. In claim 1, at least one of the single particles and quasi-single particles is included in an amount of 15 to 100 parts by weight based on 100 parts by weight of the positive electrode active material, The above SiOx(0 <x<2)로 표시되는 산화실리콘은 상기 음극 활물질 100 중량부 대비 3 중량부 내지 30 중량부로 포함되는 것인 리튬이차전지.

13. A lithium secondary battery according to claim 1, wherein the lithium composite transition metal compound contains nickel at 80 mol% or more among metals other than lithium.

14. A lithium secondary battery according to claim 1, wherein the positive electrode further includes a positive electrode binder and a conductive material.

15. A lithium secondary battery according to claim 1, wherein the lithium secondary battery is a cylindrical battery.

16. In claim 1, the average particle diameter (D50) of at least one of the single particles and the pseudo-single particles and the SiOx(0 <x<2)로 표시되는 산화실리콘의 평균 입경(D50)의 비가 1.5:2 내지 1.5:20인 것인 리튬이차전지.

17. In claim 1, the positive electrode further includes a positive electrode active material layer including the positive electrode active material, and the negative electrode further includes a negative electrode active material layer including the negative electrode active material. A lithium secondary battery, wherein the thickness of the positive and negative electrode active material layers is 10 ㎛ or more and 500 ㎛ or less, respectively.

18. In claim 1, the positive electrode further includes a positive electrode active material layer including the positive electrode active material, and the loading per unit volume of the positive electrode active material layer is 250 mg / 25 cm 2 900 mg / 25cm 2 And, The above negative electrode further includes a negative electrode active material layer including the negative electrode active material, and the loading amount per unit volume of the negative electrode active material layer is 100 mg / 25 cm 2 600 mg / 25cm 2 Lithium secondary battery.

19. A lithium secondary battery according to claim 1, wherein the energy density of the lithium secondary battery is 400 Wh / L to 900 Wh / L.

20. A battery module comprising a lithium secondary battery according to any one of claims 1 to 19.

21. A battery pack comprising the battery module of claim 20.

22. A battery pack comprising a lithium secondary battery according to any one of claims 1 to 19.